119th Advisory Committee on Nuclear Waste (ACNW) Meeting, June 14, 2000
UNITED STATES OF AMERICA
NUCLEAR REGULATORY COMMISSION
ADVISORY COMMITTEE ON NUCLEAR WASTE
***
119TH ADVISORY COMMITTEE ON NUCLEAR WASTE (ACNW)
***
Nuclear Regulatory Commission
Two White Flint North
Room 2B3
11545 Rockville Pike
Rockville, MD 20852-2738
Thursday, June 14, 2000
The committee met, pursuant to notice, at 8:34
a.m.
MEMBERS PRESENT:
B. JOHN GARRICK, Chairman, ACNW
GEORGE M. HORNBERGER, Vice Chairman, ACNW
RAYMOND G. WYMER
MILTON LEVENSON. C O N T E N T S
ATTACHMENT PAGE
Update on Repository Design and Flexibility
in Operations 102
DOE's Respository Safety Strategy 173
Proposed Yucca Mountain Site Suitability
Guidelines, 10 CFR 963 220
Status of the NRC Low-Level Radioactive Waste
Program 239
. P R O C E E D I N G S
[8:34 a.m.]
CHAIRMAN GARRICK: Good morning. The meeting will
now come to order. This is the second day of the 119th
meeting of the Advisory Committee on Nuclear Waste. My name
is John Garrick, Chairman of the ACNW. Other members of the
committee include George Hornberger, Ray Wymer and Milton
Levenson. This entire meeting will be open to the public.
Today the committee will first hear from
representatives of the Department of Energy on the status of
the design for the proposed high level waste repository at
Yucca Mountain. We will discuss the evolving Revision 4 of
the Yucca Mountain repository safety strategy, hear a
briefing on Yucca Mountain's specific siting guidelines, 10
CFR Part 963, review the status of the NRC's low level
radioactive waste program with representatives of the
staff's Uranium Recovery and Low Level Waste Branch and
prepare reports and letters on such topics as:
(1) risk-informed approaches to nuclear materials
regulatory application;
(2) comments on the NRC's plan to provide
sufficiency comments on the Yucca Mountain Site
Recommendation Consideration Report;
(3) comments on DG 1067 and 1071, Decommissioning
Regulatory Guides;
(4) comments on the Low Level Waste Branch
Technical Position on Performance Assessment;
(5) highlights of the visit to the U.K. and France
by the ACNW and staff; and (6) hear discussions with
Divisions of Waste Management staff regarding the NRC's
policy to decommissioning the West Valley Demonstration
Project.
Richard Major is the designated federal official
for the initial portion of today's meeting.
This meeting is being conducted in accordance with
the provisions of the Federal Advisory Committee Act.
As far as I know, we have received no written
statements from members of the public regarding today's
session, and, as usual, should anyone wish to make comment,
please contact one of the committee's staff. And we suggest
that each speaker use a microphone, identify themselves and
speak with clarity and volume so that they can be readily
heard.
Okay. The member of the committee that will lead
the discussion on the first part of the Yucca Mountain
material, and we will be talking Yucca Mountain essentially
all morning, the committee member will be Milton Levenson.
So, Milt, I am just going to let you take over.
MR. LEVENSON: Thank you, John.
We realize that the design of Yucca Mountain is
still in a significant state of flux and that some of the
things in the way of design may be firm, some may not be.
We want an update at this time. I think it would be helpful
to the committee if you could differentiate for us what
aspects of the design are concepts that you think you will
be staying with and what parts of it are details which may
be getting revised between here and the license application
time.
There is still a fair amount of time and I would
hope that we might benefit from some of the experience of,
say, the WIPP project, where they locked in very early
details on, in this case, a shipping container, and once
they had their license, they found that they had an almost
impossible design to build, and I think they are now on
their twentieth amendment to the license, and that is not a
helpful thing for either the licensee or the regulator. So,
I, for one, would encourage you to make a best effort to get
a design, but one that is practical and one you can live
with.
With that, I think we would like to hear what you
have to say.
MR. HARRINGTON: I am Paul Harrington of the
Department of Energy, I am the engineering lead for Yucca
Mountain.
The intent today was to do several things, talk to
you about the design changes, but not really to go through
an elicitation of hardware, but to also talk about what it
means to us and why we have the flexibility that we think we
ought to have. This is, in part, driven by some of the
concepts we went through when we did the enhanced design
alternative study and came up with enhanced design
alternative 2 as a recommendation. One of the reasons for
that was the flexibility that that particular design
offered.
We are making use of that flexibility in several
different modes now, operational modes, ability to react to
higher thermal content in waste packages, so, I think that
is valuable.
Also, I will talk about the uncertainties from the
thermal concerns that we and others have, now that is
driving the design process. If you have questions that go
to the process itself, I may defer those to Dr. Brocoum or
Jack Bailey, they own the process. My interest is in
primarily how that affects the engineering.
And, lastly, talk about the operating flexibility
concepts. We have realized that many of the discussions
that we have had regarding above-boiling or below-boiling
repositories are not mutually exclusive. The concept that
we have now, we think has sufficient flexibility that, by
turning some knobs, we can accomplish either goal,
accommodate either concern.
In the subsurface area, I have to apologize, I
didn't put graphics in many of these first several pages.
If you do want to flip to page 25, there is a layout of the
current subsurface. I will talk to that more, obviously,
when I get there, but just to give you a visual of what it
looks like now.
The drifts have been reoriented. They had been 18
degrees above the east-west plain, as you go to the west,
now they are 18 degrees below the east-west. We have also
changed the ventilation shaft arrangement. It used to be,
especially in the VA concept, that the supply was through
the emplacement tunnel and exhausts were out through shafts
through the top of the mountain. This current concept,
because we have gone to the higher flow velocities, we have
more modularized, so, now there are several sets of panels,
five or six panels within the layout and each of those -- in
fact, I will just go ahead and put that one up, each of
those has its own supply and exhaust arrangement.
Within the upper block, this is the access ramp,
the ESF, north and south portals, okay, this has been the
basic development. You will see now that there is a supply
and an exhaust system about every fifth of the repository.
There is one set here, one set there, one set there, again
and again. You will also see that this is extended to the
south further than it had been before.
It used to be that there was a low point at the
northeast corner and the repository continually rose as we
went to the south. We put an inflection point in the
middle, though, and now this slopes back down as you go
further to the south. That is because the overburden slopes
down as you go to the south. So, doing this, we were able
to pick up additional area.
Also, you will see on the emplacement, or the
supply ventilation shafts, there are cross-drifts that will
then distribute the supply to either side of the emplacement
drifts, the same collection through the emplacement drifts,
the same drop from the emplacement drift down to the
ventilation shaft underneath, and the same collection and
exhaust that there had been. We have just done it a number
of different panels now.
Question?
DR. HORNBERGER: Yeah. If we looked at this in
cross-section, are these basically at the same level as the
emplacement drifts? Above it, below it?
MR. HARRINGTON: These cross-supply drifts are.
They will distribute air from the surface down and then to
each of the sides of the mains. The ventilation drift here
is about 10 meters below the emplacement drifts and they are
connected by vertical risers from each of the emplacement
drifts. That concept is the same as we have had before, but
because of the increased flow rate, we needed a more
distributed supply system.
Let's see, other changes, we are looking at the
lower block now to accommodate larger inventories. I will
get to that in that part of the discussion, but there is the
general layout. So, the main changes are the expansion to
the south, the panelization, if you will, with attendant
supply and exhausts, there. The way we do that, doing that
reorientation reduced some of costs of construction. It
also had an affect on the size of the design basis rock.
Now, one of the IRSRs, one the KTIs with the NRC,
it was the subsurface design, and in there we talk about
rock size. We had a technical exchange about a month ago
where we went through why we did this. Now, it is important
to note that the resultant largest rock, by the time you go
out to the end of the tails, is still larger than we are
using as the design basis rock, but the reason for that is
the orientation of that rock, to get that large, has to have
length down the drift greater than the length of an
individual drip shield segment or waste package. So, all of
that load from a rock that gets that long would not be taken
on an individual drip shield or waste package segment.
Remove the backfill. Okay. That came about in
January of this year, that was driven by our realization
that the input waste stream had changed. Earlier in '99,
the M&O redid the waste throughput study. In there, there
were two major factors. One was the removal of a
hypothetical interim storage facility, which resulted in the
average age of the fuel being a couple of years younger than
it had been presumed to be earlier, and, also, the fact that
the utilities will go to higher burnups that the earlier
study had assumed.
So, due to the higher burnup and slightly lesser
fuel life, there was a higher thermal content in the fuel
assemblies, primarily for 21 PWR packages. Consequently,
the average thermal content of the 21 PWRs went from 9.8
kilowatts to 11.3 kilowatts per package. The maximum that
we wanted to have for a waste package was 11.8.
So, moving the average up that much caused some
thermal problems. We had problems meeting the thermal goals
of 350C on the cladding, of 200C on the rock, and, also,
having a reasonable preclosure period, especially when we
are looking at what do we do to keep the ability to remain
sub-boiling.
So, we went through several iterations of that,
and in January decided that the most appropriate response
would be to remove the backfill. That was effectively a
thermal blanket. Backfill would have been applied at
closure. It isn't something that is applied earlier in the
preclosure life. But having that backfill prevented the
packages from radiating heat and caused us a problem with
that higher thermal load.
There were a couple of other options that we had
looked up, but that decided that was the most appropriate.
Yes?
DR. WYMER: What do you mean by a reasonable
preclosure period?
MR. HARRINGTON: We are looking for something that
could be closed as early as about 100 years. Now, you have
heard us talk about 300 years. The intent there was not to
have a design that required 300 years of preclosure
ventilation to be acceptable, because of the concerns over
institutional control, others, but, rather, have a design
that was flexible enough to be able to be closed reasonably
early, and we chose about 100 years as that lower limit, or
be kept open should people choose to do so.
Yes?
CHAIRMAN GARRICK: Excuse me. Now, what about the
advantages of the backfill? What does that mean to you in
terms of the loss of those advantages? They didn't put the
backfill just because they wanted to put backfill, it was --
there were good reasons.
MR. HARRINGTON: We thought that the benefits of
the backfill were outweighed by the problems that it created
with respect to thermal management.
Now, part of the benefits, if I remember right,
were that it would keep the temperature higher so that you
would delay the onset of moisture on the packages. But the
problem with the higher thermal content within the package
was that the temperatures became too high.
So, because of that, it became more of a problem
than the solution and we pulled it out.
CHAIRMAN GARRICK: As I recall, one of the other
benefits was that it provided some protection against
falling rocks, et cetera.
MR. HARRINGTON: Right. The drip fields
themselves, initially the first concept out of the gate was
that they would be 20 millimeters thick and corrugated.
As we've done more rock analysis, rock fall, we've
determined that we can accommodate a rock fall without
backfill with a drip shield that's only 15 millimeters
thick, with internal stiffener ribs inside that drip shield.
CHAIRMAN GARRICK: You've made the point several
times that with the flexible design, you have the
opportunity to vary the ventilation. You have some control
over the aging of the fuel, and you still have some control
from a design standpoint over the spacing of the fuel.
Now, I suppose you did tradeoffs between
backfill/no-backfill, and the aging control. Certainly you
can control the thermal lode by what you put in the
mountain. I suppose you did those kind of tradeoffs?
MR. HARRINGTON: Yes, and, in fact, some of the
first cuts at resolution of this issue were to have further
spacing between waste packages. There were one or two
others, but ultimately because of the problems that those
created in terms of additional space, number of waste
packages, extent of drip shield, the cost of the titanium
for the drip shield, we came to this conclusion of removing
the backfill as the preferred alternative.
As we get to the back, there is some discussion on
what it means to have additional space between packages. We
can do that for thermal control, but there's a cost,
obviously, associated with that.
A question?
DR. HORNBERGER: Yes, just a followup. Was
backfill considered in your analysis in terms of the
intrusion of magma into the drift in terms of a volcanic
analysis?
MR. HARRINGTON: I can't answer that. Can someone
else here, somebody from the Science side? Dr. Brocoum?
MR. BROCOUM: This is Steve Brocoum. Yes,
backfill did add a benefit in terms of the volcanic
scenario, which is a benefit we lose when we remove
backfill.
One point I want to make on backfill: We're not
precluding it. In other words, the design will not preclude
it, and we will consider that again in the future if it's
appropriate.
But the design we're going into the SRCR and ESER
with will not have backfill.
CHAIRMAN GARRICK: One final question on backfill:
Of course, in the WIPP facility, the backfill plays a very
important geochemical role, because it provides some
assurance of maintaining the pH within a certain
well-defined range.
And that's important in the mobilization of the
waste. Dos the backfill -- did it have any role with
respect to geochemical role, for example, with respect to
the establishment of the source term?
MR. HARRINGTON: We had a geochemical concern
about backfill, and that's one of the considerations that
was leading us to a selection of a particular backfill
material.
I think that for that reason we were leaning
toward the silica sand rather than crushed tuff, for
example.
But as far as a significant beneficial feature in
terms of geochemical performance of backfill, I don't know
that we had assigned any particular performance to that.
CHAIRMAN GARRICK: Okay, thank you.
MR. HARRINGTON: We were just trying to make sure
it wasn't a deleterious feature.
MR. LEVENSON: I have one question: You mentioned
that one of the problems with the backfill was that it
reduced radiation heat loss from the containers.
I'm having a little trouble identifying that
radiation heat transfer would really be significant if the
clad temperature is 350 and you've got a double-walled
container. What's your surface temperature of your
container?
MR. HARRINGTON: It was on the order of 250 C,
somewhere in that range.
MR. LEVENSON: And so radiation cannot be the
primary mechanism by which it's transferring heat. And the
titanium drip shield you're going to add is, in fact, a
reflector, and probably interferes with cooling of the
container.
Has all of that been taken into account in your
assumption that you're better off, heat transfer-wise?
MR. HARRINGTON: Yes, actually, as I understand
it, the radiant transfer is the predominant mechanism.
MR. LEVENSON: Even at that low a temperature?
MR. HARRINGTON: Yes. There is very little
conduction because of the minimal contact with the --
MR. LEVENSON: That's without backfill. With
backfill, conduction would probably be the major transfer.
MR. HARRINGTON: Well, except the backfill would
not be contacting the waste package directly.
It would be contacting the drip shield, so you'd
still have to radiate from the drip shield -- or from the
waste package up to the drip shield.
MR. LEVENSON: Did you ever have a concept of
backfill without the drip shield? The question is, why do
you need the drip shield if you have backfill?
MR. HARRINGTON: The drip shield was there to make
sure that water didn't condense onto the waste package. It
was an attempt to keep moisture off of the waste package,
and provide a dry environment around it.
One of the concerns with having backfill on the
waste package directly was the ability to hold moisture on
the waste package surface.
MR. LEVENSON: But also the ability to channel
moisture around the waste package.
MR. HARRINGTON: Yes, yes. Others?
[No response.]
MR. HARRINGTON: Okay, we pulled the backfill.
That gave us back the cladding credit. One of the concerns
that we also had on backfill was the physical act of
emplacing it at closure.
Obviously, both the drip shield and backfill were
to have been emplaced. You'd be working in an environment
that you couldn't really send personnel into. You were
relying on performance.
That was another more near-term personnel exposure
benefit to pulling it out, obviously, removing dose in
handling.
We've also defined the drip shield emplacement
gantry concept. It really looks quite similar to the waste
package emplacement gantry.
There is a set of rails on either side of the
waste package, running down the sides of the drift, and
either of -- we have actually about three gantries, one for
emplacement of the waste package, one for emplacement of the
drip shield at the end of the preclosure period, and another
one for performance confirmation.
That one hasn't really changed much since the VA
design approach. It's basically another gantry-mounted
device that would straddle waste packages and be able to go
down.
With respect to the waste package, the biggest
issue is our success at causing stress corrosion cracking at
Lawrence Livermore test facility, and then what that meant
to us in terms of the design for closure lids.
The approach that has been taken for SR is to
identify a third lid of C-22, as second of C-22, a third lid
overall on the outside of the waste package. I'm sorry I
didn't bring a graphic today.
It is this. I know some of you got a chance to
see it beforehand. Basically, this brown outer section is
the Alloy 22 shell.
There is a device now that's mounted to the
outside of it with a groove in it, one on each end. That
will be for lifting. I'll talk about that in a moment.
Inside of that is the yellow stainless steel
structural material. There is a blue inner Alloy 22 lid,
and a red outer Alloy 22 lid.
Now, because of the stress corrosion cracking
concern, we decided we need to do a stress relief activity
on the closure welds, not of the 316 stainless, but of the
two Alloy 22s.
The mechanism for that, because we can't post --
heat-treat stress relief the closure welds, we can the rest
of the vessel, so it's really only the closure welds that
are in question.
We came up with the concept of laser painting the
weld on the inner lid, and believe that will give us on the
order of two to three millimeters worth of penetration of
stress relief.
And doing a thermal stress relief by induction
coils on the outer weld, there's a little device that's to
fit over that weld and rotate around the lid. They could
have done the entire lid at once, but the power requirements
for that are pretty extreme.
The intent is to take this up to about 1100 C for
about 15 seconds, and then cool it quickly. That much power
was too much to try and do the entire vessel at once, so the
concept is now rotated.
Admittedly, this is a complex solution, three
separate welds to close a waste package with no shielding on
the inside of the package means that trying to rework
rejectable indications on any of the welds would be
problematic.
So, one of the advances that we're looking at
between SR and the LA, is how to simplify this. With
respect to a site recommendation, we think this is
technically understandable.
We think that we can make a case to show the
corrosion resistance of multiple barriers. But from an
operational perspective, for a license application, we would
expect to have something simpler.
Okay, use of a trunion ring: This outer groove is
designed to accept a section trunion ring to fit around each
end of the waste package.
Now, the reason we did that was in the earlier VA
design, there were skirts. The outer skirt of the waste
package extended out past the inner lid of the waste
package, and the lifting apparatus came in from each end and
engaged the skirt.
Okay, we have decided in this line-loading concept
to move the packages much closer together. Now they're
about a tenth of a meter apart, end-to-end, and because of
the change of the joint geometry on the end for the welding,
there's no skirt and you can't lift it that way.
So, we need some other way to grapple the package,
so the concept is to put a ring, a recessed ring on each end
and to have a section -- and it may be bolted, it may be
screwed in some fashion -- the two sections lifting trunion
apparatus that would be assembled to the disposal containers
in the surface facility prior to loading the waste package.
The waste package would be loaded and handled
within the surface facility with those rings, and they would
be used to lay it down onto a pallet prior to taking the
waste package underground.
At that point, the lifting trunion rings would be
removed, and the package would simply sit on the pallet. We
would then lift and handle the pallet. We would not be
handling the waste package directly.
That's the reason for that. Now, that poses some
problems for retrievability. Obviously, we have to be able
to retrieve.
The older design had three holes and the screwed
extension, and the intent was to grapple into those holes,
if we were unable simply to reverse the emplacement process
for retrieval.
With this, the hole are gone, there is no
extension. We're working to come up with some mechanism
that would be able to in situ engage that ring recess there.
Let's see, a smooth surface drip shield, earlier
concepts were looking for simplicity and drip shield concept
by having it corrugated so that you wouldn't need stiffeners
on the inside to the extent you would with a flat piece.
But trying to roll the corrugations and then form
that into a U, caused its own set of problems, so we've
gotten away from that.
The current concept for a drip shield is that it
is a flat plate, weld into not quite a 180-degree V.
There's a little bit of a slope to it, and it has a series
of almost labyrinth seals, if you will, on the end of each
section.
Yes?
DR. WYMER: To what extent have you experimentally
tested these concepts?
MR. HARRINGTON: In the ATWS facility over on
Lossee Road in Las Vegas, we're doing some drip shield
segment or testing now. And they do have some conceptual
drip shield models there with simulated waste packages heat
inside of them, and some backfill on it in some cases,
looking at moisture movement and drip shield performance.
DR. WYMER: So you've got some fabrication
information?
MR. HARRINGTON: I think that the fabrication of
those was so conceptual it's not particularly relevant to
the real concept that we're looking at here.
DR. HORNBERGER: Are the stiffeners welded?
MR. HARRINGTON: Yes, yes. There are stiffeners
welded to the inside of the U-shape above it and they are
welded to the outside of the supporting skirts underneath
it. Obviously you have a sketch there.
The emplacement pallet we talked about a little
bit. The supporting pieces of that and dimensionally the
pallet consists of two V-grooves, V-blocks with each block
under each end of the waste package. Each block is about
half a meter wide and each block is made out of Alloy 22, so
there is no dissimilar metal issue.
The two blocks are tied together by stainless
steel tubing. That really only serves a role during the
emplacement and potential retrieval period. For post-closure
those tubes don't serve any real function. The function
will be taken by the Alloy 22 support pads.
Are there questions on the waste package before I
go to the waste handling building?
[No response.]
MR. HARRINGTON: Okay. On the waste handling
building itself, and notice this one is specifically flagged
as potential changes between SR and LA, the reason for that
is for the SRCR and for the SR itself the designed for
surface facility will be very much the same as what we had
in the viability assessment, a few changes.
The VA had three wet assembly transfer lines and
two dry canister transfer lines. For the SRCR and SR there
will be two wet assembly lines and one dry canister line, so
we will have made a few changes to the access to the
building but effectively it's very much the same as it had
been in the VA.
When we talked last, you folks expressed some
concerns about what does that mean to us in terms of worker
risk, especially with the blending, the blending hotter and
cooler packages to achieve these lower thermal goals, so for
a license application we are getting ready to take a much
closer look at that.
For a site recommendation obviously the focus is
really on the subsurface facility, on waste package, on
waste form, how that might interact with the site. Not as
much focus was given to the surface facilities. For license
applications certainly we need to put much more effort into
that than we have in the past, so we tasked the M&O several
months ago with doing a study to identify what an
appropriate set of requirements would be for the license
application design evolution for a surface facilityy.
This is a series of recommendations, of
considerations that are in the analysis right now. This is
certainly not final. The M&O hasn't even presented it to
their own management yet. It has not been therefore
presented to the DOE as a set of recommendations but I
thought it appropriate to share it with you because it is
insight as to where we may be going or are certainly
considering going in a license application to simplify
surface facility to give us a little more flexibility,
reduce personnel exposures, those sorts of things.
CHAIRMAN GARRICK: Do you have any -- it's the
wrong word but I'll use it anyhow -- interim storage
capacity in the waste handling building?
MR. HARRINGTON: Inventory -- and yes, we do.
The earlier concept, about a year ago, was that
when we first looked at blending we might need on the order
of 5,000 MTU worth of storage to accomplish that. That is
driven by the very narrow delta between the average 21 PWR
of 11.3 kilowatts and the maximum of 11.8 kilowatts.
With only about 4 percent margin you need quite a
bit of inventory then to be able to hit that average, so
that looked at the time like it might mean something like
5,000 MTU worth of available inventory.
One of the concepts here is that we may not need
to hold the maximum waste package thermal content at 11.8,
so they have looked at moving it up to 13.5 kilowatts. What
that did, because you then have about 20 percent margin
between that and the average, it cut the amount of inventory
needed for this thermal blending down to a few hundred, on
the order of 500 MTU but, yes, there is some operational
inventory to accommodate thermal blending and also for
upsets of either incoming waste stream, if the
transportation system stops for some reason, or if the
emplacement system stops or the canister or assembly
handling systems stop, yes, we do have some inventory to
accommodate that.
CHAIRMAN GARRICK: Just one more question on that.
You talk about the aging as one of the
parameters --
MR. HARRINGTON: Correct.
CHAIRMAN GARRICK: -- for which you have some
flexibility. Is most of that going to come from the
arrangement between the repository operation and the reactor
sites, for example, and is the whole shipment process going
to be coordinated with respect to providing some control
over the thermal load?
MR. HARRINGTON: We would like to get to that
point. At this point we haven't defined what an optimum
receipt scenario would look like. Now it may be that we
would want to try and load the hotter packages earlier so
that we would have time then for them to cool during a
ventilation period and save some of the older, cooler fuel
from utilities until late in the emplacement period to
offset some of the hotter fuel that would be being generated
at that point, but we haven't yet really determined what an
optimum scenario would be.
Right now in the standard contract with the
utilities really is not a vehicle for us to define to them
what would be sort of a DOE preferred waste stream.
Effectively obligated to take whatever it is that they
choose to send us. Now I think both we and they believe
that some accommodation would be appropriate and can be made
by both parties. I think we have the ball now to try and
identify what a good receipt scenario would look like to us
and then once we have that and agree that this is something
we want to take forward we would probably then get with the
utilities and see what arrangements we could make to have
them accommodate that.
CHAIRMAN GARRICK: Yes. The thrust of my question
is just how are you going to achieve age management and it
seems as though the alternatives are to basically use the
reactor sites as the interim storage site.
MR. HARRINGTON: That's if we have the ability to
do that --
CHAIRMAN GARRICK: Yes.
MR. HARRINGTON: -- certainly that would be
helpful. If, for whatever reason, we are not able to ever
get there, and we did decide to do the aging of the fuel
prior to emplacement, then that could be done at the
repository facility.
MR. LEVENSON: One follow-on question -- what
conceptually is the nature or form of this inventory
storage? Do you just kind of store it in shipping
containers? Unload shipping containers?
MR. HARRINGTON: No. The transportation casks we
need to recycle -- to return them. For SRCR and SR that
will be wet pool storage for the commercial fuel both BWR
and PWR.
One of the notes here --
MR. LEVENSON: You are going to be putting back
into wet storage fuel that has been dry stored for a number
of years?
MR. HARRINGTON: Well, that is the reason we have
the bullet here. Obviously there were a number of problems
associated with that -- why would we do that, would we want
to get the transportation cask wet, would we want to wet the
fuel and then have to redry it, what happens to a pool in a
seismic event -- a lot of concerns are causing us, given the
potentially smaller inventory needed, to consider dry
storage instead.
Now for SRCR and SR we simply don't have time to
put that in there. We will have the ability to show a waste
storage facility but the expectation for license application
is that dry storage may make a lot more sense for the
reasons we just talked about.
See the numbers here in reduction of cranes and
drop heights. I certainly at this point wouldn't want to
commit that four is the final number of cranes but the whole
concept in this facility reassessment was to try and develop
a simpler approach to fuel handling and we are using as
models a lot of what the Navy is doing up in Idaho. They
don't lift their canisters very often. Generally they left
by using lifts, hydraulic lifts, underneath them, up-end the
devices, close shutters underneath them, transport on
skidpads, rollers. There's not a lot of lifts by crane
involved. Consequently they have removed a lot of the drop
accident scenarios so we are taking that sort of approach to
try and define a set of requirements that says if you can
get around having to do a crane lift, do so. If you can
minimize the lift height, do so.
There are some conceptuals of a different approach
to the surface facility that are trying to simplify it a
lot. Another -- let's see, we obviously reduce the number
of lifts there. We talked about the pools.
Shielding -- okay, when transportation casks come
in, we have to remove the end-fittings, open the lids, that
sort of stuff. Also for the packaging within the waste
package itself, we'll have to be putting lids on there,
doing backfills of inert gases, doing welding, doing NDEA on
them.
Part of the concepts we are looking at is how can
we do that with more protection to workers than previous
designs, reduce exposures, facilitate potential reworks, so
one of the concepts they are looking at is putting a set of
shielding jackets around the waste package, around the
disposal container. I mentioned earlier the trunnion thing.
Part of that, one of the concepts there is that part of that
trunnion arrangement is a shield and that that would be on
the disposal container during its handling process through
the facility.
Also, another is that on the closure weld
arrangement you could do that in an area where shielded
floor sections come down over the package and a shielded
work station, if you will, comes down over the end of the
waste package.
That leaves you a little annual gap for access to
the individual welds but does in some manner facilitate
being able to work closer to that device.
Another concept that the Navy at least has
included in their large canister concept is inclusion of
shield material within the canister itself. I wouldn't rule
that out either.
Before I leave the design change part and go to
the thermal uncertainties, any other questions on that?
MR. LEVENSON: One quick question.
MR. HARRINGTON: Yes?
MR. LEVENSON: What is the shielding internal to
the Navy casks?
MR. HARRINGTON: I don't know. I don't know that
I have asked them that. Certainly we have -- we can get
that from them.
Because of the thermal uncertainties, we're having
a lot of difficulty, both inside and outside the program,
producing uncertainties.
And one of the big considerations is what can we
do to reduce uncertainties. We're trying to address what
are those things that contribute to it, and what is an
appropriate set of actions to be taken to resolve those.
Obviously, there are physical and chemical
changes, a function of time and temperature. We can reduce
the temperatures. Some of those effects will be reduced.
The magnitude and duration of the coupled effects
go up with increasing temperatures.
We've gotten a lot of input, and it's really
obvious to us that the period of time of performance of a
repository engineered solution is far longer than the
history available to us for the engineered materials.
Certainly, some metals have hundreds of years or
thousands of years worth of history, but because we're
wanting the increased corrosion performance that we can get,
we believe, from the latest corrosion-resistant,
nickel-based materials, consequently there is really not a
significant history to them.
So, as you know, we're doing a lot of
age-accelerated testing in very aggressive environments up
at Lawrence Livermore, but this is always an issue; that
there's just not a lot of history associated with many of
these materials that we're crediting.
Also, now, the extent of testing of the natural
system that was induced by, say, the large block test, the
single heater test, and even the drift scale test, is not
the same extent that an overall repository would be subject
to.
So all of these are thermally-driven
uncertainties. We're having to then decide how we represent
those in PA space, and what that means to us in terms of
design to be able to come up with solutions that can
adequately address those uncertainties.
This next graphic really is just a set of the
various design features associated with the near-field
processes. I won't go through all of the processes.
You can see them on your handout and I think
they're things that you've heard about many times. But with
respect to what that means to design, the current era has a
preclosure period of 50 years. Okay, a moment ago I said
100 years.
The delta is trying to define what an adequate
period would be that could allow us to remain sub-boiling,
and still be something that we think is reasonably short?
Now, Part 60 and Part 63 say that we have to have the
ability to retrieve for at least 50 years from start of
emplacement.
That sort of defines a 50-year period as the
minimum preclosure. It also says that the Department has
the ability to come back and ask for a different period, if
we so choose. I don't expect we would ever do that.
So if we were looking to close in the minimum
amount of period necessary, that would be 50 years, but
given the design solution we have, that would be also be an
above-boiling solution.
If we wanted to keep the host rock below boiling,
that would be something longer than 50 years, and a little
later in the presentation, there is a series of curves that
are tradeoffs between ventilation durations, waste package
spacing and aging of the fuel.
Thermal loading is 60 metric tons per acre.
That's with these waste packages spaced a tenth of a meter
apart, and it's really staggering. It's a repetitive
pattern of 21 PWRs, Defense high-level waste packages, with
DOE S&F canisters inside of them; 44 BWR packages.
There are a few 12-element PWR packages for the
very hottest PWR fuels, but it's effectively a repeating
pattern of a number of different packages, but the intent on
having them close together is what we call the line-loading,
and that's to have the cooler packages adjacent to the
hotter packages, trying to act as heat sinks to allow
removal of heat from the hotter packages and then reject it
a little further down the drift.
DR. HORNBERGER: I think that I heard last week,
62 metric tons heavy metal. Did I mishear last week?
MR. HARRINGTON: Sixty-two per acre, you mean? I
don't know where that came from. We've generally been using
60. Out of curiosity, where was that?
DR. HORNBERGER: That was the technical exchange
last week.
MR. HARRINGTON: Okay, I'll find out where that
came from.
DR. HORNBERGER: It may just be that I misheard.
MR. HARRINGTON: Okay. What this means to us is
that if we did do the closure in 50 years, the boiling of
water within the rock would peak at a few hundred years,
200-500 years. That front would extend about 12 meters into
the rock.
It's really quite circular. We had asked the M&O
to take a look at it, vertically, above and below, and
horizontally, both sides, with the expectation that there
may be some delta between vertical and horizontal, and it
was really quite circular.
It would take 1-2,000 years for the drift wall to
come back down below boiling, and at 10,000 years, drift
wall would be back down at about 50 degrees C.
Yes?
MR. LEVENSON: I have a question. Everybody keeps
using the word, boiling. Here I see that you've put it in
quotation marks.
What is the significance of boiling? There's no
discontinuity of the vapor pressure curve at boiling.
What's the significance of boiling?
MR. HARRINGTON: A sensitivity to mixed-phased
flow. There is a concern that if we have the rock above the
boiling temperature of water, then it will be very difficult
to model what happens to moisture coming in, and then the
vapor phase of that water as it goes somewhere, either out
or back in.
MR. LEVENSON: So this isn't a safety issue at
all; it's your inability to model it. If you adjust your
design, would it be easier to model?
MR. HARRINGTON: Obviously, there is a perception
that if we can't model, then we don't know what would happen
to the waste package, and that it would translate to a
safety issue.
MR. LEVENSON: That's true of a lot of things in
this world we know about, that we can't model. But I don't
understand the significance.
This is not going to heat up instantly.
MR. HARRINGTON: That's right.
MR. LEVENSON: It heats up relatively slowly.
And, in fact, a significant amount of the water, since there
is no discontinuity in the vapor pressure curve, a fair part
of the water in rock will be evaporated long before you ever
reach the boiling point.
How do you take that into account? You're not
going to have two-phase flow in a rock surface for a very
long time, if ever.
DR. HORNBERGER: Sure you will; you'll just have
it below boiling as well as above -- below 100 degrees as
well as above.
MR. LEVENSON: Yes.
DR. HORNBERGER: If your problem is two-phase
flow, then whether you're five degrees below or five degrees
above boiling makes no difference.
MR. HARRINGTON: There is very strongly a
perception that having it above boiling is a step function,
in both performance and uncertainty, and I'm trying to
relate concern --
MR. LEVENSON: But where does that come from? It
doesn't come from vapor pressure.
MR. HARRINGTON: I really can't answer that.
Possibly Dr. Brocoum or Mr. Bailey or someone might want to
take a cut at that.
MR. BROCOUM: This is Steve Brocoum, DOE. As Paul
said, there is a lot of concern, particularly by the Nuclear
Waste Technical Review Board, that the uncertainties
increase above boiling. We don't observe -- you know, we're
now in the -- all the data collection we do is at ambient
temperatures, so -- and we just have a few thermal tests.
So, their concern was that the uncertainties are
lower and easier to understand and easier to model below
boiling. I don't think there is a real concern, because a
lot of people on the project believe that above boiling, in
fact, improves performance, because it tends to drive the
water more away.
So the real concern has been the degree of
uncertainty in how we represent that and how we understand
it as we develop our design.
MR. LEVENSON: Uncertainty in connection with
what? It isn't uncertainty in connection with vapor
pressure or rate of evaporation or any of those things.
MR. BROCOUM: I think that it's more connected to
the information we collect, which is mostly at ambient, and
being able to model and understand it, and then being able
to extrapolate it to above-boiling design.
You would have to ask the people that raised these
concerns. These are generally concerns, as I told you, that
come from the Nuclear Waste Review Board.
CHAIRMAN GARRICK: Yes, but you're designing this
thing, and it seems that what we're trying to do is figure
out the design basis. And I think that's -- you know, if
you're saying that you're doing it because people are asking
questions, and you can't rationalize it from a first
principles basis, you know, that's something maybe to be
concerned about.
MR. LEVENSON: I would hope that you didn't modify
the design on the basis of some of the questions we ask,
some of which are based in ignorance.
MR. BROCOUM: One of the things we're doing is, we
don't have to make that decision today. And I think that
what Paul is trying to tell you is, we're trying to keep a
flexible design so that as we get our arguments together and
develop our models, and better understand the uncertainty
and how it's related to all the parameters we're having, we
can then make the best decision on how to operate the
repository.
So that's the whole point of this presentation
today, is to point out that we don't have to know that
today, because this design that we have can both accommodate
a below boiling by a few degrees, and an above boiling by a
few degrees.
And if it ends up not being important, which way
we go, then we can make that decision on cost, for example.
MR. HARRINGTON: We have a design basis for the
design. We believe that we have adequate modeling to show
what will happen during above- and below-boiling scenarios.
The part I was struggling with was explaining the
rationale of other organizations. So, I'm comfortable with
ours.
MR. HARRINGTON: Contributions to corrosion of the
waste package. Obviously we need to know near field host
rock issues, temperatures above boiling temperature of water
at that elevation, low relative humidities, what that does
in terms of precipitants and salts. Obviously accumulation
of that can affect the ingress of water into the drift,
therefore onto the package potentially.
The drip shield and the waste package surfaces
themselves be above boiling, lower relative humidity, what
has been deposited on them by water coming in from the host
rock and how does that then drive corrosion of the waste
package, and the invert itself.
One of the things we're looking at in the invert
and the host rock below invert proper is fracture flow out
of the drift -- will the flow paths remain to remove water
similar as to what brought water in, or may there be
something going on that would cause them to plug and
increase water concentration in the drift.
Question?
CHAIRMAN GARRICK: Yes. Do you have any specific
information about what sort of salts you expect to be more
concentrated than 10 molal?
MR. HARRINGTON: I don't. I'm sorry.
Okay. Several different types of corrosion
mechanisms on the right-hand side of the page, general and
localized corrosion, we will have that. There's nothing we
can do to get away from that. It's relatively low
dependent, not very dependent upon temperatures. Given the
aqueous conditions, we expect that.
Pitting and crevice corrosion, though, we don't
expect to see that based on the lab testing that we've been
doing. We are continuing that. Stress corrosion cracking,
though, based upon what we've done at Livermore, we have
seen some of that. Consequently, then, the redesign of the
closure lids on the end of the waste package.
Somewhat temperature dependent, near boiling.
Less so otherwise. And phase segregation fairly low for
temperatures below about 260 degrees C, which, as I said,
the waste package skin will be generally lower than that.
CHAIRMAN GARRICK: What does phase segregation
mean?
MR. HARRINGTON: The question is, what does phase
segregation mean, and I'm not a metallurgist, I have only a
vague understanding of the mechanics of the metal phases
within the heat affected zone and they change. I think
there is some migration.
CHAIRMAN GARRICK: That's what I understand it to
mean.
MR. HARRINGTON: Okay.
Degradation of the waste form itself, okay, the
degree of cladding degradation is formerly dependent. We
recognize and understand that, but that's primarily an
effect above about 350 C.
To date, we have held simply a straight 350-C
temperature requirement on cladding. We've gotten input and
recognize ourselves that it would be more accurate to have a
time-temperature dependence, but that's additional work,
that if we don't exceed 350 at this point may not offer us
commensurate benefits with the resources. So, yes, we'll
understand the issue there, but as long as we're keeping the
cladding below 350 C, we think that's conservative.
Solubility of the waste form, somewhat temperature
dependent. Degradation rates of uranium oxide vary by about
one order of magnitude between 25 and 96 C. We don't have
test data above those temperatures yet but think that we're
being conservative in our modeling of that at this point.
Okay. These are -- the next page --
MR. LEVENSON: Excuse me. Is that in salt water
like what's in the bottom here, or is that in pure water?
MR. HARRINGTON: I understood that to be in
concentrated J-13 water. That's generally what we're using
as the testing medium for these in situ tests.
MR. LEVENSON: What's J-13 water?
MR. HARRINGTON: Oh, I'm sorry. J-13 is one of
the water wells at the site. We took water from that,
analyzed it for much of the testing that's going on at
Lawrence Livermore, we have concentrated that. We duplicate
the water in a concentrated fashion.
MR. LEVENSON: Okay. The context of my question
is, from the previous slide, one of the things that could
cause pooling is if you get salt accumulation which plugs
things up and --
MR. HARRINGTON: Right.
MR. LEVENSON: -- fill things back up. So I guess
the question is, what's the rationale? If you're going to
have water there, isn't it going to be whatever came from
the previous slide?
MR. HARRINGTON: Yes. Yes, that's the J-13 water.
MR. LEVENSON: But that's not -- no, no, no, no.
MR. HARRINGTON: Wait. Okay. Let me go back.
MR. LEVENSON: No. The previous slide, the invert
accumulation and fractures, precipitants and salts could
result in pooling of water.
MR. HARRINGTON: Yes.
MR. LEVENSON: That's the water that's going to be
in contact with the fuel, right? So why --
MR. HARRINGTON: Yes.
MR. LEVENSON: -- do you use a different water for
the test?
MR. HARRINGTON: Well, the J-13 water is
representative of the water at the site and the
concentration --
MR. LEVENSON: Not what's representative of what
would accumulate in the repository.
DR. HORNBERGER: Right, but I don't think that we
would expect that the local pooling in the invert would
flood the waste element. The waste elements would still be
exposed to water dripping in through the rock, and it might
be concentrated due to the thermal effects, evapo
concentrated, but it certainly wouldn't be the same as water
that you would anticipate pooling in the invert.
MR. LEVENSON: I disagree because what drips in
from the top is not going to see the fuel. Fuel is only
going to see what pools up from the bottom and reaches it.
DR. HORNBERGER: If that's the case, I think we
all doubt that the fuel would see any water.
MR. LEVENSON: Well, I agree.
MR. HARRINGTON: Yes. The actual expectations are
for water on the fuel is that dripping would eventually
degrade the top of the package, fill the package up rather
than filling the entire drift.
These are a series of tests and analyses to
address thermaling induced uncertainties. They are
categories, hydrologic, mechanical, chemical, et cetera.
Within the hydrologic, for example, the volume and
the fate, what happens to the mobilized water, is one
uncertainty, so we have a series of tests going on or that
have gone on or are planned to address that, including the
drift scale test and the single heater element test, which
are complete. Our large block test and the single heater
test are complete. Drift scale test is ongoing now. A
cross-drift thermal test is something that we're planning
for the future.
We drove the somewhat smaller cross-drift across
the repository horizon, somewhat above the plain of the
emplacement drifts in the repository horizon down at about a
45-degree angle simply to get a more representative
understanding of the rock across the plain. And because in
part the existing drift scale test is in a rock that's
representative of a relatively small portion of the
repository horizon itself, we expect to do another drift
scale -- or heater test over at the end of the cross-drift
just to be in the actual lower lift where about 85 percent
of the repository resin is located.
Mechanical fracturing of the rock above, there is
a concern, especially with elevated temperatures, that you
may get degradation of the rock itself if you subject it to
significantly elevated temperatures and what then would be
the effect on drift stability post-closure.
Chemical processes going on there. We've talked
about that a little bit. Corrosion, we've talked about that
a little bit. And waste form degradation. Again talked
about that a little bit on the previous slide.
DR. HORNBERGER: Paul, just a quick question. I
notice under corrosion, you have iron meteorite analogs.
Are there natural minerals that -- nickel alloys that are
close to Alloy-22?
MR. HARRINGTON: I think that what I've heard is
the use of those meteorites, since they contain some nickel,
as being maybe the closest analogs to that. I have not
heard of anything more representative. It doesn't mean that
somebody hasn't determined that there is.
Let me jump to page 12 -- 11 was very similar to
10 -- and I see I'm getting a little close on time. We're
creating a strategy for addressing the uncertainties. The
next several pages capture that.
That has been presented by Abe Van Luik to the
Board. We're treating the uncertainties in the SRCR and
then developing guidance for how to do that in the LA.
This is being led in part by Bill Boyle and a team
and participating on that are Abe Van Luik and the PA folks.
You folks may or may not have had some interaction with that
yet. But it's basically got four key parts to it:
analyzing the known uncertainties, assessing all of the
uncertainties, managing the uncertainties, and communicating
them.
So in a little more detail, the analysis is to
identify what the uncertainties with respect to the
mathematical models are, variability and parameters, what
are the potentially disruptive events, sensitivity and
importance analyses, determine which features are truly
sensitive to performance and which are not. That sort of
activity is really kind of fundamental to repository safety
strategy which Jack Bailey will talk to a little later.
It's identifying what are the significant contributors to
uncertainty and where should we put our resources.
Okay. Assessing all the uncertainties, how do we
treat that in TSPA, the limits that we're assigning to the
distributions of those uncertainties, confidence in the
models and importance of those with respect to conclusions
that we're drawing, and what uncertainties do we know about
but have not incorporated, and how might we treat unknown
unknowns.
We think we're identifying design basis events.
What happens if there's something that comes up that we have
not yet identified? Stress corrosion cracking is a good
example. Until relatively recently, we had not thought that
was going to be an issue. It turned out to be, so we came
up with a design.
So what sort of defense-in-depth features do we
need to have to allow us to have a design that can
accommodate uncertainties in the future?
We need to manage those uncertainties, identify
which are the important ones, and how might we reduce or
mitigate them.
There are a number of different contributors
there: What measures do we need to have to increase
confidence?
What flexibilities, we talked about that a moment
ago, potentially changing the design to address those, and
then communicate those.
I want to go the operational flexibility
discussion.
CHAIRMAN GARRICK: Just in passing, the whole
issue of uncertainty deserves a special session all of its
own, and I don't want to get into it too much.
But the Committee is, of course, very interested
in this, given the emphasis that exists with respect to a
risk-informed approach. And I think eventually we're very
interested in knowing just exactly how you're handling
unknowns of unknowns, for example, and whether or not you
are building into your distribution functions, allowance for
what some people might call unquantifiable uncertainties.
MR. HARRINGTON: Okay.
CHAIRMAN GARRICK: I don't particularly like that
term myself, but that's a term that's being used in the
reactor arena.
So, I think that the state of the art is in pretty
good shape as far as information uncertainty is concerned,
but once you get into modeling uncertainty, it's an entirely
new ball game.
I think there are those who believe that this is
the major contributor to uncertainty, and given that, it has
to be something that we put quite a bit of attention on. So
I think that sooner or later, we're going to really want to
home in on those contributors to uncertainty about which
there's not really a good mathematical trail.
Sooner or later we'll want to come back to that.
MR. HARRINGTON: We'd be happy to do that and make
sure we get the right people here to do that for you.
CHAIRMAN GARRICK: Right.
MR. HARRINGTON: Okay. A lot of discussion had
taken place a year or two years ago, even relatively
recently about an above-boiling versus below-boiling design.
And they were almost considered to be either/or; either you
had one or you had the other.
One of the considerations criteria for selection
and the LA design selection activity a year ago was
flexibility for change, as I mentioned earlier. We chose
EDA-2, Enhanced Design Alternative 2, in part because it has
quite a bit of flexibility.
Given the interest and potentially keeping the
host rock below the boiling temperature of water and the
post-closure arena, we've come to realize that EDA-2, by
turning a few knobs, can also be made to do that.
So this next discussion really is on which knobs
are the right knobs to turn? Why did we come to that
conclusion, the conclusion of which knobs are appropriate,
and what does that mean to us in terms of tradeoffs between
ventilation duration, waste package spacing, and aging of
fuel?
And there are obviously a few other things that
could be considered also. So, what will be in the SRCR
design and considerations in establishing that, controlling
thermal responses, this is the intro to the rest of it.
There may be a number of reasons to have a
flexible design. Obviously, policy, should we develop
alternative technical objectives, get new information like a
somewhat hotter waste stream, for example or other
considerations.
There were a few design requirements and features
that we have, really not a lot. The cladding, we want to
protect that, so we'll keep below 350 C. Now, certainly if
that were sort of the defining feature, we'd probably want
to invest more time in developing the time/temperature
curves above that.
But especially in consideration of host rock
temperatures, cladding at 350 is reasonable as an item to
keep. We also wanted to allow water to drain between
drifts.
That was one of the fundamental precepts of EDA-2,
where we move from the VA spacing of 28 meters to the last
spacing of 81 meters between drifts. That really was to
dissociate the thermal effects from one drift to another to
provide a cool regime between drifts so that you wouldn't
develop a potentially pond of water above drifts if you were
above boiling.
Even if you had localized boiling, there is still
a reasonable flow path between drifts. The DOE simply said
provide a flow path; the M&O has assigned a number of 50
percent of the pillar ligament width to be the number.
Design features, 81 meters; the 7.6 kilowatt
average waste package power, I mentioned earlier, 11.3. The
11.3 is for the 21 PWRs, taking all waste packages together,
the Defense high-level waste co-disposal, the BWR, the Navy
fuel, et cetera, average is 7.6.
At a tenth of a meter spacing between them, that
then comes out to just under 1.5 kilowatts per meter,
average power density.
We've got a ventilation flow rate of 15 cubic
meters per second. That's up appreciably from the VA. We
think that's effectively about as fast as you can pump air
through there and still remove additional heat.
We've looked at going above that, but the amount
of heat actually removed above that flow rate was minimal.
It wasn't worth the tradeoff in additional capital
expenditures for that.
In terms of what that means relative to miles per
hour of wind down the tunnel, that's about a mile an hour,
given a 5.5 meter cross section.
MR. WYMER: That's the flow rate per drift?
MR. HARRINGTON: That's per drift. Now, remember
that a drift has inlets on each end, and an exhaust down
through the middle.
So when you look at the number of drifts, you have
to consider each end of each drift when you add up to get
the total flow rate.
Also, drip shield on the packages, the fuel is an
average of 26 years old at point of receipt at a repository.
Now, operational features, as distinct from design
features are the spacing between waste packages.
The preclosure period, how long might you keep the
repository open, and the amount of staging or aging of fuel
prior to emplacement, and the last drift loaded, takes about
25 years to do emplacement.
There are about 70,000 MTU at about 3,000 MTU per
year, so it's about 25 years, so that means that the last
drift emplaced would only have about a 25-year cooling
period prior to closure, if you did a 50-year closure of the
entire -- 50-year entire preclosure period.
So that means that, again, the host rock would get
up to about 200 degrees C, and that the front would
eventually advance in about 12 meters.
A number of considerations, starting in the top
left with the fuel itself, okay, the enrichment of the fuel
as a contributor, the exposure -- that's the time in core,
leading to burnup as a contributor, the age from point of
discharge from the reactor is a contributor. The longer the
point of discharge, aging, the cooler it is.
Those factors then determine the thermal output of
the individual fuel assemblies, and that along with the
number of assemblies in a waste package, the mix of
assemblies in a waste package, sets the hotter and colder
assemblies -- potentially, we might even mix boiling water
reactor fuel elements along with PWR elements in a single
package.
That introduces some additional design and
operational complexities, though, so we wouldn't do that it
unless it really provided a benefit.
MR. WYMER: How much analysis have you done on
what you might call the tradeoff between the controlling the
temperature in the drift by providing a lot more surface
storage capacity for long decay times before you put it into
the drift?
It seems to me that that's a tradeoff that you
could consider if you're talking about years.
MR. HARRINGTON: Right. And that shows up in a
couple of slides on a set of curves. There is a set of
curves for staging that is the aging of the fuel, either on
the surface at a repository or if we're successful with
utilities, there.
MR. WYMER: So that's coming up later?
MR. HARRINGTON: Yes.
MR. WYMER: Okay.
CHAIRMAN GARRICK: In this issue of operational
flexibility, one of our former members reminded us that
there is not only the opportunity here to engineer the
near-field, and, most particularly, the waste package, but
there is also a great opportunity to engineer the natural
setting.
Now, except for the spacing of the tunnels, you
haven't said much about things that are under consideration
or that you might do to the natural setting to enhance the
flexibility of the repository, or, more particularly, to
reduce the likelihood of water having access to the
near-field.
Is this something you're also doing? I'm thinking
here of everything from a drainage system, to diversion
systems, to Richard's barriers, to what have you.
MR. HARRINGTON: Well, we've talked a lot in the
past about what modifications we might do to the natural
system around the drifts. I know one concept had several,
two or three emplacement drifts stacked vertically with a
cap over it to try and shed water.
What that did for us, though, was concentrate the
heat, and, effectively, you were reducing the overall
emplacement area, you were having drifts closer together
than they would otherwise have been.
So we were not then able to take advantage of
being able to reject heat into the further-field. That was
causing some problems.
Another consideration with that was what happens
to the water once it passes the lips of those shields?
There is a fair amount of fracturing, and there is some
lateral movement of water also as it goes down.
So, yes, we've looked at number of different
natural system modifications. To date, we have not
determined that we would proceed with many of those, simply
because of the concern over how well they can work, how well
we can demonstrate them to work in a regulatory arena, and
the cost/benefit tradeoff of them versus some of the other
things we're doing.
CHAIRMAN GARRICK: I guess what I'm thinking of is
that the regulations are pretty explicit with respect to the
performance being dependent on both engineered systems and
the natural setting.
MR. HARRINGTON: Right.
CHAIRMAN GARRICK: And it seems that we're moving,
we're getting a much better handle on what the contribution
to performance might be from the engineered systems than we
are from the natural setting. I realize that the whole site
characterization program was designed to provide the
baseline information on the containment capability of the
natural setting, but somewhere along the line, that question
is probably going to have to be addressed in a quantitative
form or some sort of a quantitative form as to how much of
the performance really comes from the natural setting.
I'm just curious as to -- without taking a lot of
time here to discuss that, if there is some sort of an
effort comparable to what you're doing here, to quantify the
impact of the natural setting on bottom-line performance.
MR. HARRINGTON: We are spending a great of time
trying to understand what the natural system is and what its
effect on engineered features would be, and, therefore, the
contribution of the natural system to the total system
performance. Modifications that we might do to the natural
system, I guess I would really have considered those to be
engineered features, something like a shield of clay or
whatever it might be, above emplacement drifts, is really an
engineered feature. Trying to make this --
CHAIRMAN GARRICK: But you try to engineer it in
such a way that you take advantage of the natural
properties.
MR. HARRINGTON: This is true.
CHAIRMAN GARRICK: And that connection has got to
be very important. We all know, too, that the state is
extremely interested in having insight on the capability of
the site to do this job as much as it possibly can on its
own, without undue assistance from the near-field engineered
systems.
And, of course, in Europe it seems that the
emphasis is much more on the natural setting than it is on
the near-field and the elaborate designs of the waste
package.
MR. HARRINGTON: Yeah. I had the opportunity to
go to Sweden last fall and went to the hard rock lab, to the
canister development lab, and to their interim storage
facility, and that was very enlightening.
CHAIRMAN GARRICK: Right. Okay.
MR. HARRINGTON: They have a little different set
of issues to deal with. Because of the interim storage
facility, they inherit, at a repository, appreciably cooler
material than we are having to accommodate in a design, and
they also have only about a tenth of it. So, both of those
would be beneficial tradeoffs.
DR. WYMER: But you don't really have to
accommodate higher temperatures if you have substantial
surface storage for an extended period of time.
MR. HARRINGTON: That's true.
DR. WYMER: It seems to me that is a tradeoff that
a fair amount of attention ought to be paid to. You are
actually talking about going down in your amount of
inventory you need. It seems to me, you might be thinking
about going up.
MR. HARRINGTON: Well, if we go to staging, some
appreciable staging, yes, that number would go up by --
DR. WYMER: And the total problems go down.
MR. HARRINGTON: Yeah. Yeah. Well, the thermal
content, the temperatures would go down. Whether or not is
a problem, you know, if we can make a case that says an
above-boiling repository is adequately understandable,
defensible, uncertainties are acceptably low, then that may
be a reasonable path to take if we show commensurate cost
benefits.
Now, as we get a little further back to that chart
I mentioned earlier, there are a number of five different
cost points on it. Every one of them is $6-$8 billion more
expensive than the closure at 50 years with letting the
post-rock go somewhat above boiling. So, again, it is a
tradeoff. So, if we can make an adequate technical case
that says it is reasonable to close and go above boiling,
then that is a substantial amount of money that doesn't need
to be spent.
MR. LEVENSON: I want to ask a question. In your
present concept, at the time you get ready to close the
repository, when would the last fuel that is scheduled for
the repository have come out of a reactor? What is the
minimum cooling time?
MR. HARRINGTON: Five years. The minimum cooling
time is five years. In the standard contract, there is a
requirement that all fuel be at least five years out of
reactor. With respect to defining a waste stream other than
that, at this point we don't have that. That is something
that we would like to get to.
We talked about that a little bit earlier, our
need to develop what the best emplacement scenario would be.
I am not convinced that I want to take all the cold stuff
first and delay the very hottest till the end. It may make
sense to retain some of the colder stuff toward the end to
offset some of the hotter stuff that will be generated then,
but we haven't finished that work yet.
MR. LEVENSON: Okay. That was the exactly the
context of my question, is that, if, in fact, putting hot
fuel in the repository causes problems, you ought to put the
hot stuff in while you have the longest period of forced
ventilation and cooling, put the coolest stuff in just
before you are ready to close it up.
MR. HARRINGTON: Yeah, that is an approach, and,
obviously, that is one of the things we are considering.
Let's see, that is thermal output of assemblies
along with -- another question? Okay. Along with those
things contribute to the thermal loading, distance between
drifts, ventilation duration and rate give the overall
thermal response.
Why did we choose the things that we did to use as
operational variables? Enrichment, we can't control that.
Exposure, time spent by assembly in core, we can't control
that. Age from discharge, we can address that through the
use of staging, either at point of receipt or prior to
emplacement. Number of assemblies in the waste package,
obviously, that is something we can change, but changing the
spacing between waste packages has the same effect, so we
settled on the latter, it is a little more manageable. It
also would not necessarily increase the number of waste
packages.
Let's see, blending of dissimilar assemblies, we
talked about that a little bit in terms of the BWR and PWR.
For perspective of this exercise, though, we have already
got blending covered as an operational mode with the hotter
and cooling waste packages, and, so, we think that is
manageable. Distance between waste packages, obviously, we
can control that.
Distance between drifts, now that we decided to
move them out as far as they are to 81 meter spacing, that
is center line spacing, there is relatively little effect on
thermal interaction from one drift to the next by trying to
keep this large sub-boiling region between them to
facilitate the drainage. So, that is not a significant
contributor.
Ventilation duration, we can control. Ventilation
flow rate, right now we are expecting that the 15 cubic
meters per second would remove about 70 percent of the heat
generated by the waste after placed underground prior to
closure. There may be some ways we can change the layout of
that, but, operationally, it might not get greater than
maybe 80 or 85 percent efficient. But we think that we have
got that effect bounded by the consideration of staging,
that is 100 percent heat removal. So, from an operational
perspective, we think staging covers it.
Yes?
DR. WYMER: At closure, do you intend to plug up
all these ventilation ports?
MR. HARRINGTON: Yes. Yes.
DR. WYMER: In general, close the whole darn
thing?
MR. HARRINGTON: Yeah. We talk about the backfill
in the emplacement drifts and we said that we have made a
decision that that would not be part of the case, as Steve
correctly pointed out. We didn't rule it from future
consideration, but that is just the emplacement drift for
the thermal issue. The parameter drift, the ventilation
drifts, the access ramps, those, we would expect to backfill
and put seals in.
DR. WYMER: It would be sealed?
MR. HARRINGTON: Yeah. We have looked at what is
the feasibility of operating this design to keep the rock
below boiling. Those three things that we have talked
about, the staging, it is aging of waste packages,
increasing the spacing between the waste packages and
increasing the duration of the ventilation, there is a link
to preclosure duration there certainly, are things that we
can, from an operational perspective adjust to keep the host
rock below boiling if we determine that that, in fact, is a
necessary or valuable feature.
There are some hot spots, some areas in the host
rock that would be above boiling even if we did that.
Typically, that is in the invert blow the waste package
where the support component for the waste package is
touching the waste package and then able to conduct to the
invert, and in some areas of the host rock immediately
adjacent to the hottest packages, but that is a very limited
effect.
We have, we think, general consensus that that
very limited amount of rock above boiling is not
problematic. The concern by many is really a more extensive
degree of above-boiling.
That brings us to the curves. This has been
referred to as the Rosetta Stone, a number of other things.
Let me walk through it in a set of issues. Okay. First, we
will talk about the years of staging. This is the amount of
life of aging that would be given to fuel assemblies prior
to emplacement beyond the average age of fuel at receipt
now, which is 26 years. So, basically, if we received it in
the front door and emplaced it relatively soon, that is
considered to be no staging, if we had the ability to let a
fuel assembly cool for an additional 10 years, either at
repository or utility, it doesn't matter, then we could be
out on these curves.
What this is is the set of distances between waste
packages, this is the gap, not a center line spacing, versus
ventilation duration after loading of a waste package, that
you would then either be below boiling in the host rock
after closure, or above boiling in the host rock after
closure. Preclosure period, it stays below boiling all the
time because of the higher ventilation flow rates that we
have now. The issue is postclosure. So, above and to the
right of each of these curves, host rock stays below. Below
and to the left of each of these curves, host rock would go
above boiling to some extent.
Now, we have got SR base operations here. That is
because SR has a tenth of a meter spacing between packages,
and for a 50 year closure, with about a 25 year emplacement
period, then that leaves about a 25 year ventilation period.
So, that is where that falls, but that is also relative to
years of staging zero, so, it is substantially on the
above-boiling side.
One point to consider is if we had no staging and
we wanted to keep the minimum distance, we could, between
waste packages, minimize the extent of tunneling and drip
shields, but yet close at 100 years. What is the point?
Okay, this is the point, there is no staging and it
intersects this 100 year preclosure line. What this line
represents, each point on this line is a sum of three
things. It is the sum of the staging, plus a 25 year
emplacement campaign, plus a ventilation duration after
completion of emplacement.
So, for example, here, no staging, 25 years about
of emplacement, plus an additional 75 years of ventilation
after that means closure in 100 years. In January, when we
agreed with the M&O that the removal of backfill was the
most appropriate solution to the increased thermal content
issue, we sent the letter -- a letter to the M&O and
directed them to develop a change request to remove the
backfill from the current design, not to preclude it, but to
also answer a number of other questions. And one of the
caveats we put in that was to come up with a design solution
that could allow closure in about 100 years. That seemed to
be a reasonable approach for trying to keep a sub-boiling
repository.
MR. HARRINGTON: Each of these points on the
curve, then, represent what a 100-year preclosure duration
would look like. So if we ended up with, say, ten years of
staging and had a spacing between the packages of about 1.4
meters and had about a 65-year preclosure duration of
ventilation after completion of emplacement, we could close
in 100 years and remain -- keep the host rock below boiling.
So that is then these sets of curves and what this one
represents.
Now, we put some limits on this thing. One of
them, you see nothing goes beyond 75 years. We could have,
but the reason for that was we said we wanted to see
100-year preclosure, so this represents 75 years in
ventilation plus 25 years of emplacement.
There is also an upper bound to it, and we'll get
to that in a slide or two where I had shown you the layout
of the repository subsurface with the lower and upper
blocks.
To accommodate 97.4 MTU -- it's really MTHM --
what that represents is 84,000 MTU of commercial fuel and
all of the DOE high-level waste and SNF. That's considered
to be equivalent to about 13,000 MTHM. That's what we're
using for our total system life cycle work, so that's
something that we wanted to be able to address.
Given the finite amount of space in the upper and
lower blocks, we wanted to see how much we could use and
still fit within that. Now, you may remember that in the
EIS, we show for the low thermal load, the 25 MTU, 105 -- 25
MTU per acre low thermal load -- the 105,000 MTU commercial
fuel case.
Obviously that is more than in the upper and lower
block, so we have some satellite regions out below Jet Ridge
across the canyon for that. But with respect to really the
primary area of focus, the upper block and the lower block
on the east side of Ghost Dance, there's a fixed amount of
space. So to fit the TSLCC quantity, the total system
quantity into that space, we can't have more than about four
meters between packages. So that's the upper limit.
Now, we wanted to do some trade-offs, okay? We
have the costs associated with that point on the curve, but
we wanted to see what it would take for several other
scenarios, so we looked at this cost and doesn't involve any
more staging, but it's about 2.3 meters between package, so
there's more tunnelling involved.
The drip shield segments are not individual drip
shields over individual waste packages; they are continual
segments. Therefore, if we increase the space between waste
packages, that then increases the amount of drip shields
required even though it doesn't increase the number of waste
packages.
So because of the increase in spacing, tunneling,
drip shields, and also because it would require 75 years of
ventilation after emplacement rather than shutting it off at
50 years, there's about $6 billion additional total system
life cycle costs and net present value that's discounted to
about six-tenths of a billion.
One of the reasons for that is the procurement of
the additional drip shield material doesn't happen until the
end, until closure, so you would be setting that out 75
years.
Okay. Also on that zero year of staging, we went
out to the maximum spacing that would still fit within a
characterized area -- four meters -- that's about seven
billion, about nine-tenths of a billion net present value.
It's a little more expensive than this, driven by the
tunnelling and drip shield costs more than offsetting the
reduced operations and maintenance cost of having the
extended ventilation.
Okay. It went down to the ten-year staging line
and took several spots on it. One again is the 75-year
ventilation period, and that's about six-tenths of a
billion. We came back to the same 2.3 meter spacing as we
looked at here. It's about seven-tenths of a billion. And
came back to the same 4 meter spacing as we looked at here,
and that's about 8 billion.
The progression here is the same -- six to seven
to eight. We see that it's costing us more money to go with
the greater spacing, the additional amount of tunnelling,
the additional amount of drip shields than we're saving due
to reducing the O&M costs on the ventilation period.
CHAIRMAN GARRICK: Paul, I hate to do this to you,
but can you wrap it up in about five minutes?
MR. HARRINGTON: Yes.
CHAIRMAN GARRICK: We have a comment from the
public that we want to accommodate.
MR. HARRINGTON: Okay. There's just a couple more
slides after this.
CHAIRMAN GARRICK: Okay.
MR. HARRINGTON: The next one is the layout we
looked at earlier. The reason I put this in here was to
point out where these items fell with the 70,000 inventory
at a tenth of a meter. It goes here.
The whole TSLCC at a tenth of a meter goes to
here. 70,000 at 2.3 meters goes here. The EIS inventory,
the 119,000, that's the extended case for EIS at a tenth
takes this much. We can even accommodate the EIS at 2.3
within this, but trying to go beyond goes out further.
This is a graphic representation of the tradeoffs
between space and amount of the upper and lower blocks
that's required, and really the last are summary slides. We
think it's flexible, we think it's the right thing to do,
and that's the main discussion. The rest of it really is
summary of what I've already said, so I won't do that in the
interest of time.
Questions.
CHAIRMAN GARRICK: I'm just curious. This whole
project and its immensity would lend itself well to very
interesting simulation, particularly with respect to the
operations and the exercising of these parametric curves and
what have you. Are you doing some of that? Are you doing
computer simulation of the operations?
MR. HARRINGTON: Yes. There's something called a
witness model that the M&O is using. I'm not sure how
widespread it is. I understand it's fairly widely used.
And they are using mean time to repair values, mean time
between failure values that they're pulling in from industry
from previous experience, and plugging into the witness
model is primarily an exercise that the surface facility
folks are going through to identify where the hold-ups might
be.
We have, obviously, more work to do there. Some
of the initial values that they were using were very
optimistic with respect to, say, times to repair major crane
failures, things like that.
So yes, we're doing a lot of computer modelling of
handling activities, those sorts of things.
CHAIRMAN GARRICK: Using the VA as a baseline for
a moment, and you've presented some of that information and
you have the curves that probably answer the question, but
what price are you paying or savings are you attaining as a
result of going from, say, the VA design to the so-called
flexible design?
Obviously you've saved about a billion dollars,
have you not, by eliminating the backfill.
MR. HARRINGTON: Going overall from VA to LADs was
more expensive by about $4 billion. Giving up the backfill,
the number associated directly with that, last I remember,
was about $600 million, so say on the order of a billion
dollars.
CHAIRMAN GARRICK: So the $4 billion is what the
-- the delta increase?
MR. HARRINGTON: Was, yes.
CHAIRMAN GARRICK: Yes. Was.
MR. HARRINGTON: Yes.
CHAIRMAN GARRICK: Okay.
Go ahead.
MR. BAILEY: I would only restate what I said
earlier. It seems to me that there is some advantages in
putting in more surface storage space not only with respect
to the thermal problem, but with respect to giving you a
chance to evaluate some of your design as you go along and
make changes over time in the package design or whatever.
MR. HARRINGTON: Yes.
MR. BAILEY: So I suppose you've done these
trade-offs, but it seems to me that that is very much
worthwhile.
CHAIRMAN GARRICK: Yes. I would extend that
question to include the total system, because with the
direction that plants are going with dry storage and
extensive risk assessment of the dry storage facilities, it
seems as though something that would be very interesting,
and I don't see that you have that, would be a comprehensive
plan for the management of the -- of a variable is critical
as fuel aging.
MR. HARRINGTON: Okay. The surface study that I
was referring to earlier that you won't see in the SR but
what we'll be using as a basis for the LA work is
identifying how the surface facility would accommodate that,
and right now, what they're looking at is to have the
flexibility for three major sets of target approaches to
developing inventory.
One is to -- if you had some particularly hot fuel
that you really did not want to take underground but you
were ready to load into a waste package, load it into a
waste package and set that on the surface and some structure
and allow it to age there rather than inputting all of that
heat underground.
Another is that you may want to have some sort of
canistered storage facility rather than the waste package
either if we're receiving non-disposable canisters, store
them that way, or develop our own non-disposable canisters
if that was the right design solution. So we're looking at
those two.
CHAIRMAN GARRICK: Isn't that kind of going back
to the original concept of multiple-purpose containers or
canisters?
MR. HARRINGTON: Well, the multi-purpose canisters
were intended to be disposable also in addition to storable
and transportable. We've never really given that up. Yes,
the department quit developing it, but from a disposal
perspective, obviously that would simplify our surface
facility immensely if we didn't have to handle individual
fuel assemblies.
The Navy canisters are in effect MPCs.
CHAIRMAN GARRICK: Yes.
MR. HARRINGTON: They are large disposable
canisters that we would never have to open. But the other
side of that is, then, that any understanding of fuel
necessary for disposal would have to be accomplished at
point of canisterization.
Right now, the standard contract doesn't require
utilities to identify a great deal of information. If we
need to do some more characterization or do some observation
prior to canistering, that will have to be done at point of
loading.
The third thing between either loaded waste
packages or canisters is also DOE waste. Because of the
need to sort of intermingle the hotter and cooler packages,
it makes sense to us to have some DOE both S&F and high
level waste canisters available for that, so this study is
looking at adjacent pads to be able to store that sort of
material.
CHAIRMAN GARRICK: Okay. Well, thank you very
much.
We do have Amy Shollenberger who wants to make a
comment, then maybe we should do that right now, and then
the committee has a picture appointment at 10:30, which we
have just passed, but as soon as we break up, would you stay
together so we can accommodate that.
I guess, Paul, we're finished with your
presentation. We appreciate it. It helps us a great deal.
MR. HARRINGTON: All right. Thank you.
CHAIRMAN GARRICK: Amy.
MS. SCHOLLENBERGER: I'm here representing Public
Citizen's Critical Mass Energy and Environment Program.
Thanks to Chairman Garrick for making a few minutes for
allowing me to comment.
I have a few questions that I don't really expect
answers to right now, but I just wanted to get them on the
record:
The first is, this discussion about interim
storage happening onsite at the reactors to allow for aging,
I'm curious to know how, if there's an agreement worked out
with the reactors for that onsite storage, how will that
affect especially the transportation schedule and the queue,
and also eventually the placement schedule?
Will that push it out past the 25 years, because
it may take longer to get everything to the repository if
stuff is aging onsite. If anybody has an idea where I might
get that answer, I'd appreciate it.
Secondly, I'm wondering, with this idea about
flexible design, it seems to me like what DOE is really
saying here is that this design is never actually going to
be finalized until the repository is closed, if that ever,
indeed happens.
And I'm wondering how in the world they're going
to complete an FEIS and show what the effects on the local
environment and the local public health is going to be if
they have no idea until they're actually emplacing the
waste, how it's going to be emplaced.
And as a follow on to that, I'm wondering,
shouldn't there be another DEIS to allow the public to
comment on all of these changes that are happening between
the draft and the final EIS, because, you know, obviously
what we commented on last year has nothing to do with what's
actually going to happen at this point.
And, finally, this is not explicitly related to
this presentation, but I think it is indirectly related.
There has been a move throughout the NRC and also now it's
in Congress with Senator Murkowski's new Energy Security
Act, S. 2257, to take away the public's right to formal
hearings.
And that move would specifically impact the Yucca
Mountain licensing. And I'm really worried for the public
that there's nowhere. If that happen, a move to informal
hearings, there is nowhere where the public has recourse to
any of these design changes, to even get the information
until it's actually happening, and to comment on that
information.
So, I would really once again -- Public Citizen
has been saying this repeatedly for the past several months,
but once again I would really like to say that it's really a
mistake to take away the public's right to formal hearings.
It would be fine and maybe even desirable to do
informal hearings along with the formal hearing, but it's
absolutely not acceptable to not have formal hearings on
this license.
And it's been pointed out by my colleague, Jim
Riccio, several times that there was a promise made in the
SECY paper that said that Yucca Mountain would have formal
hearings, no matter what the NRC decided on the hearing
process in general, and we would just really like to
encourage you all to keep that promise.
Thanks.
CHAIRMAN GARRICK: Than you. Those questions vary
from the very specific having to do with design, to the very
global, having to do with Congress. And they are a part of
the record, and I think they are deserving of a response.
I think we'll have to find a way to do that, other
than through the session today, but we are pleased with your
bringing them up, and somehow we will get to them.
Now, unless there are members of the Committee
that would like to comment on anything that's been said, I'd
like to maintain our schedule as close as we can, and,
therefore, call for a break right now.
[Recess.]
CHAIRMAN GARRICK: We're going to now turn our
attention to repository safety strategy, and George
Hornberger will lead our discussion in this area.
DR. HORNBERGER: The repository safety strategy,
as we understand it, is continuing to evolve. Jack Bailey
is here to give us an update so that we can try to keep
abreast of the progress that DOE and the contractors are
making.
Jack, it's good to see you again.
MR. BAILEY: Thank you, sir. It's a pleasure to
be here.
Yes, we're going to talk about the repository
safety strategy. We're going to talk about the ongoing
development of the repository safety strategy. As you
pointed out, it is, in fact, continuing to evolve; it is not
complete.
I will preface the entire discussions by, these
are preliminary results. There are some results and some
findings in here, and they are, in fact, preliminary, and
we'll be back as we continue to move forward and work it.
We've had some confusion as to what is the
repository safety strategy? It's a strategy, but it also is
a plan.
I've got several slides here to try and get around
what we're trying to accomplish with the RSS and how we're
going about it.
It's central to the DOE's evaluation of the
current technical knowledge and how to move forward. That's
what the repository safety strategy is about. And we do
that in a couple of ways:
First, there's a safety case, and you've heard the
safety case before, and it will show up a couple or three
times in here. It's the five elements, the TSPA, margin,
defense-in-depth, natural analogs, disruptive events, and
performance confirmation.
And we think about how to hang the flesh on those
bones, of here's how we want to make the argument. It's a
layered argument. It's a mean by which we gain confidence
that the system will work through all of these methods.
And the RSS takes a look at what we know about the
current safety case, what we know about the current
knowledge and how to move forward. So the plan is
determined by management after you get technical input.
Now, management also gets to make some choices in
this. It is not purely technical. You can decide where to
put your resources. You have timing issues, you have money
issues, you decide where it is that you want to go work.
Now, we chose the current, and we went to the
license application. You can put VA, you can put EDA-2, you
can put EDA-2 and SR, you can put SR and SRCR and SR, and
you can think about it. We tried to do it in an iterative
fashion as we get some new set of information.
I'm not sure everybody's slides in the audience
came out as well as we had hoped. I think there was some
double printing. If there was, let us know and we'll try to
help you.
The iterative nature, you can jump in anywhere you
want. Let's start up here with the repository system
characteristics. That's the entire system, not just one
piece of the system, but the entire system, because you have
to look at the whole system here in terms of satisfying the
standards, which happens down here.
And in there, you address your hazards for
pre-closure, or your performance in the post-closure. You
identify your credible features, events, and processes,
define your scenarios, your event trees, get your
probability, assess your consequences.
And evaluate results of your hazards analysis with
the results of your performance analysis. Compare it with
your standards, and then assess the uncertainties.
Decide what you know. Decide how well you know
it, decide what confidence you have in order to move
forward.
You assess then what do we need to do next? In
one direction, you go and you say here's the safety case, we
write it out, here are the requirements we're going to place
on the system, and in some cases, the Q-list. We go all the
way back to the basics of we have systems, structures, and
components, and we're going to place requirements on them.
And so from there, you can do that. You also feed
that back into the safety strategy. How do we hang the meat
on the bones from what we know now? And then you decide
what new information do I need to acquire?
How do I need to modify designs? What models do I
really need? And so you're constantly going through these
processes in an iterative fashion to come up with a design
that is the design that you want to move forward with.
And I use design in the system sense here, not
just in the engineering sense, but in the system sense.
What do you choose to rely upon? What is providing you with
the performance that you need?
What can you demonstrate about that performance
through a rigorous licensing process? That always has to be
in the back of your mind or in the front of your mind
sometimes, because it becomes very important as to whether
or not you can really prove what you're saying.
What are we trying to do in the RSS? Get an
adequate understanding, the identification of the principal
factors determining safety. We really try and look at the
system and say what is it about this system that really
drives the performance? What really makes a difference?
In a probabilistic sense, if we think we
understand the system and we take a parameter and we push it
all the way to the bad -- I'll call it -- edge of the
distribution, and it doesn't change the result to the
receptor at the biosphere, then we probably don't have to
know a whole lot about that, other than have confidence that
we have captured correctly, the basic behavior of that
particular parameter.
If, on the other hand, we find something that
really affects the far end, then we really need to have a
good understanding of that.
We need to have an understanding of how it behaves
and how either a good look at what the probability density
function looks like, or something that we can clearly defend
as a bound or a simplified area. I'll talk about that a
little bit more.
We need to do the performance assessment. That is
our tool for putting all of these pieces together for
looking at the interaction, and it is not just the tool that
-- I want to speak highly of the PA, because it isn't just a
tool that gives us a squiggly line or a bunch of squiggly
lines at the end. It is the tool by which you assemble
this, and then you start using your intellectual processes
from your principal investigators, your PA analysts, and
start deciding, does this system come together correctly?
Do these things make sense? Are they borne out by
what we're seeing? Is the modeling really representative
here?
And have we done simplified or bounding type
approaches that, in fact, are skewing the answer or hiding
something from us?
Those are the types of analysis we have to do. We
learn from the PA. We not only get squiggly lines; we learn
from the PA.
And then finally you have to have measures to
increase your confidence in safety. Why are we sure? Why
do we think we're right?
And there are measures to address residual
uncertainty and any other potential vulnerabilities. And
the word, vulnerabilities, is going to come up again later,
and I'm not sure that's the right word. That's why this is
preliminary, but we'll talk about some vulnerabilities.
I think you've seen this slide, but I really like
it. There's an evolving technical basis, and it keeps
going, and it runs off the edge of the page. It should be
out here because it doesn't stop.
Performance confirmation doesn't stop. Study in
the rest of the world doesn't stop. Inquisitiveness doesn't
stop. It may not be quite the same height, but it's still
there.
The viability assessment we put together,
basically a viability assessment safety case that was found
in Volume IV of the VA.
And it said here's what we know about the system,
here is how important we think it may be, here's how much we
know, and here's how much more we can know in a couple of
years. That was the first look at where do we need to apply
resources, because we can learn something in another few
years, as opposed to 20 or 30 or 40.
For the enhanced design alternative, which if you
recall was the corrosion resistant on the outside package,
the drip shield, backfill, we did some preliminary analysis
and came up with -- and we actually made some decisions as
to where the performance seemed to be clustered, if I can
use that word.
We did in this -- it's important to note that we
did. In this, it's important to note we did a traceability.
We did a transparency type approach where we followed a drop
of water through the mountain. That's not how you did the
TSPA. We tried to find a way to get what are all the
processes that it faces as it moves through the mountain?
And we gave all of them equal weight, and you'll
see that in a minute. Here we went through there and we did
exactly what I said, we started skewing those probability
distributions to find out which ones really made a
difference.
And the ones that didn't push the answer at the
back end, we chose not to try and study as hard or in as
much detail as we did the others, because the others make a
bigger difference to the overall safety.
And what we're doing in Rev 3 -- Rev 3 was done
off of VA models that were modified for a nominal run only,
no probabilistic runs to speak of, off of the Enhanced
Design Alternative 2. In Rev 4,, we will have run the TSPA
for the SRCR, which I'll talk about in a minute.
We have a big improvement in the models that we
can use to do our sensitivities, do our barrier analysis and
do our study of the system.
Elements of the safety case. I ran through this
one for you, you have seen it many times in the postclosure
safety case. The repository safety strategy for Rev. 4 is
going to include considerations of the preclosure. We have
looked at the 10,000 year dose in accordance with the
regulation. We are now going to start looking at the
preclosure safety case. What happens in the local area
because we are handling fuel, we are packaging fuel, we are
moving fuel? And I talk about that, I will come back to it
at the end.
And we go back and we do what is called an
integrated safety analysis. That is a probabilistic
approach to identify the operation of the system, what is
important. We look at safety margin and defense-in-depth as
a part of that. We do an analysis of design basis events.
It still comes back to what are the events that typically
bound the others, as opposed to a pure probabilistic. We
look at industry precedent and experience. What has worked?
What hasn't worked? How can we use it? And technical
specifications and surveillance, this is a facility we can
touch every day, and, so, we can place some operational
conditions to ensure safety.
Safety margin and defense-in-depth can be handled
a couple of ways, by the way. One is choosing codes and
standards, commonly used. We would like to help ourselves
in the licensing process by using existing codes and
standards that the NRC is familiar with. And the
defense-in-depth, we will probably do some barrier tech
analysis again.
So, what do we do for the postclosure? Site
characteristics and engineered barrier design, we do the
analysis, we do the performance assessment. Identify
credible features, events and processes. Get our scenarios,
probability, assess consequences, evaluate the expected
performance. Same chart, only this for the postclosure. We
compare with the standards and assess uncertainties. We go
over and look, what can we do to improve the PA? Gain
confidence, make it better.
How do we enhance our safety margin, our
defense-in-depth? How do we evaluate them? Increase the
information about potentially disruptive events. Increase
natural analogue information and update the performance
confirmation plans, what should be done next.
Now, Rev. 2, the principal factors, as I said, and
I will go through this quickly, because I have covered some
it, nominal case factors, all that might play a role. The
drop of water moving through. There was no consideration of
disruptive events. The performance assessment was the VA
design and the VA models. And what did we do? Well, we
decided we had better look at safety margin, and we had
better look at defense-in-depth and some of the other
elements of the safety case, because at this point we are
working almost purely with the PA, the performance
assessment.
It is noteworthy at this point to identify the
attributes of the system, because the attributes of the
system haven't changed in years. And the attributes are to
limit the water contacting the waste package. They are to
have a long-lived waste package. To keep the waste inside
the engineered barrier system, inside the drift area,
near-field. And to identify and understand the reduction of
radionuclides as it is transported through the unsaturated
zone and the saturated zone out to the receptors.
Those four things, those four pieces of the
strategy have no changed over the last many years. The
approach is still the same. Which factors, which models and
how they have evolved has changed a bit. But the basic
approach has not changed.
In Rev. 3, it is important to see Rev. 3, the
principal factors, we made some subjective judgments about
the factors expected to be the most important to
performance, and they were supported by the barrier
neutralization analysis. What we did was is we sat down the
PA analysts, we sat down the principal investigators, we sat
down this preliminary PA that we had done, we did these
barrier neutralization analysis, non-mechanistic cases.
What if there is no rock above, and it rains right on the
package? What if there is no package? Those types of
things. Classical "what if." And we went back and asked
questions of these people. Do you think we got this right?
Did we not get it right? How does this do this? And this
was important and we spent the time with those people
because it, in fact, did point the way at where we spent our
resources in the last two years getting ourselves ready for
the SRCR.
Our performance assessment was this design, we
used the VA models for the natural system. And what did we
do? We did the preliminary consideration of safety margins
and defense-in-depth, that was the barrier analysis, in
particular. And we put out Rev. 0 of the performance
confirmation plan, which basically said, what might we need
to measure and how can we measure it? Very broad scope, not
a plan as much as a capability document to be able to look
at things in the future.
Rev. 4, the principal factors are being developed
following the risk-informed, performance-based approach,
which I will describe. We did our first full evaluation of
features, events and processes. We went through every
portion of the system, international database, and worked
through what features, events and processes should be
considered and marked them in or marked them out, documented
that. That has been -- some of those have been reviewed.
We are supplying some of our technical material to the NRC
staff, and they have looked at those and had comments on
them, and our documentation probably needs a little
tightening up, but we have done that -- or we are doing
that.
And this is, however, the first full evaluation of
features, events and processes. Up until this point in
time, the PA analysts generally tried to make a good guess
at what it was going to be. They documented what and why.
This time we did it a different way, and that different way
was our updated models are fully documented in the process
model reports and the analysis and model reports. We have
done a lot of science on this over the years.
What we imposed in this past year, or past two
years, has been an architecture of these AMRs and PMRs,
where we have broken it down into the models that go into
the PA, and we have assigned a lead to every one of those
models in the scientific community. And he has on his team,
himself, that is the scientific lead, he has a PA analyst
for that area and he has a regulatory engineer to assist him
to make sure we answer the NRC's questions, and to make sure
we have the integration between the science and the PA.
We wrote RSS 3 and said, here is the basis that we
want you to follow. These can be simplified. These should
be more realistic. And they followed that basis in terms of
putting together some 122 AMRs which together, including
FEPs, AMRs, process AMRs and abstraction AMRs, put together
all of those pieces in a unified approach to get the models
pulled together for the TSPA and to create a PMR that shows
how you derive from what you learned in the field to how you
model in the TSPA.
So, we have, as it says, fully documented, it is
fully traceable, we can explain why we did what we did. We
will probably have lots of arguments about that, but we can
explain what we did, why we did what we did. The FEPs are
fully involved in that piece. And, in fact, it followed
RSS 3 with pieces of bounding or pieces of full
probabilistic.
Now, you will notice it says the analyses address
a range of uncertainties. This may or may not be the full
range. The unsaturated zone leader will tell you that he
has simplified how he has gone about doing seepage. It is
not -- you know, it is skewed so as to be defendable. I
think that the waste package people would tell you the same
thing, that they have skewed it a certain extent to be
defendable.
CHAIRMAN GARRICK: What are they saying? Are they
saying they have made a distribution curve conservative to
be defensible?
MR. BAILEY: Yes.
CHAIRMAN GARRICK: That is bad. The whole idea of
risk modeling is to tell it the way you believe it is and
what the evidence can support, not some fudging to the right
or to the left on the basis of trying to win a case. This
is just a sore point that those people who are practicing
risk assessment and start monkeying around with
distributions on the basis of hunches or what-have-you, and
changing them, and that that change is not supported by
tangible evidence, are violating the most fundamental rule
that exists with respect to risk assessment.
MR. BAILEY: I understand the sore point, and let
me see if I can clarify. What they have is, in fact, fully
supportable and it is not a hunch. It is, however, perhaps
not the full extent, it is supportable. There are no
hunches, there are no -- well, we are going to put it over
here because we don't know anything. It is we know that we
can defend it being here, and here is the data that can
support it being here. Could we defend it to be more?
Perhaps. I do understand the sore point.
TSPA includes both the nominal and igneous
activity scenarios this time. We did pick up one of the
disruptive events.
What measures do we have? Full evaluation of the
safety margins and defense-in-depth will be done when RSS 4
is done. And Revision 1 of the performance confirmation
plan goes back to the repository safety strategy Rev. 3,
since one of most important things to measure are the things
that we want to be confident of, and starts to focus the
performance confirmation plan on the most things to review.
MR. LEVENSON: I have a question about that.
MR. BAILEY: Yes, sir.
MR. LEVENSON: You use the term "full evaluation
of the safety margins." That implies that you are keeping
track as you go about the conservatism and every component,
and that you are going to add them up at the end. Is that
really what you are doing?
MR. BAILEY: No, sir. You saw a slide in Paul
Harrington's discussion that said we need to do a better job
of that than we are doing. This is a full evaluation based
on what is in there and then the back end look at it.
What did we do? That is what we did, the same
thing that I said. It comes over to principal factors and
then we try and find some specific vulnerabilities. Where
do we think we are weak? Here is an example of features,
events and processes evaluation. We have a waste package.
We numbered all the FEPs so that we can track them and find
why we did them like we did. We have a title. We went back
over to which process model factor we fit them into, and you
can see we have some that fit and we have some that we have
excluded.
This is an example, these are, in fact,
documented. One that is kind of interesting here,
mechanical impact on the waste container, effects of
rockfall on the drip shield or on the waste package. Even
if the drip shield is not present, excluded by design, -- it
caught my eye. I expect it caught yours. It will show up
again in a couple of minutes, if I can beg your indulgence.
Again, the documentation that we have been
providing to the NRC Staff, which I presume you have access
to, contains the AMRs and the FEP analysis that would
support these in particular. We will be having a lot of
discussions over that.
So what were the process model factors that we
came up with for the nominal scenario? We had flow, which
included -- and you go back to the lists -- climate
infiltration unsaturated zone flow seepage, thermal effects,
the environments, the drip shield and waste package
performance, the wasteform performance, the concentrations
dissolved and colloid associated, the EBS radionuclide
transport, the transport in the UZ and the SZ, and finally
the biosphere dose conversion factors.
CHAIRMAN GARRICK: Jack, when you use the words
"credible factors" you are suggesting that the issue of
likelihood entered into the decision as to what you consider
and what you don't consider, and when the issue of
likelihood enters into it, the issue of probability is an
inherent part of it.
Is that a formal process?
MR. BAILEY: Yes, it is. It is a formal process
in accordance with the regulation, which tells us to
conclude one of three things.
First, does it meet a probabilistic rate of
occurrence,
Second, you look at it from a systemwide basis.
Third, you look at the consequences.
You go through those three screens and that is why
you see some of these FEPs, Features, Events and Processes,
that we probably did screen number three without having run
the TSPA -- judgment as opposed to numbers.
CHAIRMAN GARRICK: Thank you.
MR. BAILEY: For the igneous case, and all this is
preliminary I remind you, we looked at the igneous activity
factor. It was kind of interesting. You have a probability
of the igneous activity. Does it even occur?
The magma intrusion characteristics -- how does it
intrude into a drift? Does it erupt down a drift, does it
flow down a drift, what exactly is the energy content? That
makes a difference in terms of how the waste package and the
waste respond; the response of the repository to the magma
intrusion, as I just said; the UZ flow contacting the
waste -- if you damage the packages, now you are back
into -- your engineered barriers are gone and you are
carrying it straight through with UZ. The concentrations,
how does it get into the system? Radionuclide transport in
UZ and SZ.
Then of course you have two biosphere conditions.
One is an inhalation pathway and one is an ingestion
pathway. You have to consider and combine them, which is
different than the water-borne pathway that we have been
concerned with in the nominal case so we pick up a few more
things that we have to work on in order to answer those
questions.
TSPA, as I said before, is our basis. We look at
sensitivity studies, barrier importance analysis and try and
bring all that together.
We have been holding a series of workshops to work
through the features, events and processes to work through
our understanding of the system. We have another workshop
in a couple of weeks which is going to be the workshop where
we actually get TSPA results in sensitivity analyses and it
will be a well-attended workshop but a large number of PA
analysts and principal investigators in order to understand
the results and have the discussion of what does it really
mean.
Now the approach changes focus from the subjective
judgments to the specifics identified. What does the math
tell us? What does it mean?Do we have the data to support
it?
The approach also helps ensure consistency and
completeness. It also makes you look at the whole system.
You have to find a way to look at the whole system.
In simple form, the VA, we looked at everything --
what can we learn about it, how much more can we learn, and
how do we represent it?
In Revision 3 we went back and found seven
principal factors, which we discussed several times.
RSS-4 pretty much ratifies that. You will notice
the colloid-associated radionuclide concentration has come
back on the screen based on investigations in the last year.
DR. HORNBERGER: Could you tell us, the ones that
popped back up, could you say just a few words as to why
they popped back up? Colloids in igneous activity is what I
am interested in.
MR. BAILEY: I'll go back to the igneous activity.
It is the first time we have analyzed it, to be honest with
you. It just hasn't been analyzed because we have always
done a nominal case up to this point in time.
Part 63 says that we have to include the
disruptive events along with the nominal case and so we had
always done the disruptive case separately and now we are
putting them together. That is why that one shows up.
The colloids was in fact an issue back in this
timeframe and we didn't have enough data to kick it up or
not kick it up. We kind of left it in the dissolved
radionuclide concentration and now that we understand the
issue better, we believe it deserves its own name so that we
can keep track of the ongoing development.
What this says is that we have chosen a path and
the math still seems to support that. The naysayers may
say, well, you chose a path and you are making it work. We
don't believe we are doing that. We believe that we have
adequate understanding in these areas. We believe we
understand them. We believe we have confidence in why that
is and that in fact what we knew a couple years ago, after
many years of study, and now some concerted effort to put it
into place, stayed about the same.
DR. HORNBERGER: Jack, before you leave, there was
one other than fell into that category and that's the
biosphere dose conversion factors that fell off in Rev. 3
and came back in Rev. 4.
MR. BAILEY: You're correct. I'm sorry. The
biosphere dose conversion factors was in Rev. 2 because
there were ways to put the biosphere together at the back
end of the system. There were different ways to do it and
how you put it together was important.
In Rev. 3 it came off because the regulation
specifies how it is to be done.
In Rev. 4 the igneous activity is not specified
per se because it basically specifies an aqueous ingestion
approach and if we in fact have to deal with an eruptive
event then you have got to look at the inhalation as well,
so it came back because of that.
Then we said let's look at barriers. Wet makes
the difference. Wet gives us a 1000 year holdup time, 1000
year delay or a 10 to the minus 4th reduction in
radionuclide transport, and these are the things, the
overlying rock, the drip shield, the waste package outer
barrier, the UZ, the SZ transport.
There are some other barriers and this come back
to Dr. Garrick's hot spot of why aren't they in there? That
is the waste canister and the waste package inner barrier.
Both of them are metals. They are not particularly robust
metals in this environment, and so we don't model them.
Does that carbon steel inner lining fall off the moment the
outer lining gets a pinhole in it? No, but conservatively
we don't try and make that modeling. We do look to see if
there is deleterious effects because of it but we don't try
to model it, but in actual fact the inner barrier is there
and the defense high level waste in particular is inside a
canister, which takes some period of time to fail.
We look at cladding. How much credit do you get
for cladding? That is probably a good example of part of
the problem in the probabilistic approach -- at the risk of
going to the hot button --
[Laughter.]
MR. BAILEY: -- and that is clad's there. Clad's
there. I have the same problem. Clad is there. You know,
we have a fairly good understanding of clad because it was
manufactured with certain requirements. It was handled by
the utilities and they know what happened to their clad, at
least during operation. It's now been in a pool. It's been
transferred perhaps to a canister. It's been transported.
The question that is unanswerable is what is the condition
of the clad when you receive it, because you have got to go
through a corrosion calculation here, and what has happened
to it over that timeframe.
When you have got 17 by 17 roughly, 289 pins per
element and you are handling hundreds of thousands of
elements, how do you sample that. How many of those do you
have to rip apart? How much sampling do you have to
do?Different utilities, different handling, different
scenarios, different burnups, different smelts of the zirc.
It becomes very difficult to come up with a realistic or an
exact initial condition and so you select one that bounds
it. Is it as good as the real one? Probably not.
The drift invert may have some capability if we
engineer it correctly in conjunction with the drip shield we
may be able to get diffusive transport and really get a much
slower movement through the EBS which is both retardation,
decay, and delay. We haven't tried to do that at this point
in time. In fact, we basically let it out of the drift very
quickly right now, so there are some other barriers that may
be important that we haven't gone full up on yet.
Coming back to that vulnerability word, and that
is now that we have some analysis, and this is what has come
out of the workshops, what do we think are the problems with
what we have done to date?
Well, oddly enough, inadequacy of the treatment of
model uncertainty -- Paul talked about that. We are taking
some action. We need to increase the consistency of the
treatment of uncertainty. We need to mitigate uncertainties
to defense-in-depth. That is a way to deal with it if we
have high uncertainties that we can't learn any more
about -- we may understand them but we may not be able to
make them go away -- and lo and behold, maybe we better
ensure the effects of rock fall are analyzed, if you go back
to what happens with designing a way rocks falling on the
package. The question in the workshop was maybe we haven't
covered that one quite right yet, so we are going back to
look at that.
DR. HORNBERGER: Jack, when you go back to look at
that, I know Paul talked about a really huge rock. Now our
friend Charles Fairhurst tells us both that that is an
impossibly large rock, that the rocks that really come out
of the roof are not going to be anywhere near that huge.
Are you going to actually again try to do this a little more
realistically when you go back and look at it?
MR. BAILEY: Yes. That is part of the issue. The
rocks that will come out of the roof we believe will be much
smaller than the one that -- I didn't hear Paul's particular
talk. I didn't see the size but I think we are going to go
back to try to look. Hopefully Paul will nod that he
agrees. That is our intent. We took a very conservative
approach.
We have some overconservatism in some models.
There is no question of that. I think wasteform is one of
your absolute stellar examples of that. The waste is in
fact inside of zirc. It is a metal oxide. When that first
drop of water penetrates the package we consider that the
entire exposed fuel, whatever we choose because of the clad
assumption, is immediately saturated.
That first drop of water goes a long way. Not
only is it immediately saturated, it is immediately
equilibrium and it is available for transport back out
through the same hole that it came in as soon as the next
drop comes in. Very conservative.
Can we do better than that? Probably -- but we
haven't yet.
MR. LEVENSON: I have to object. You punched my
button.
[Laughter.]
MR. BAILEY: Okay. Good.
MR. LEVENSON: Overestimating the consequences so
severely is almost never conservative because it causes you
to make other decisions and do other things which have their
own risk.
MR. BAILEY: Yes.
MR. LEVENSON: And when you severely overestimate
by many orders of magnitude a consequence -- sometimes you
have to because of uncertainties, but when you do things
that are ridiculous you seriously challenge your credibility
in other things you are doing.
MR. BAILEY: I understand that, sir, but we do a
number of overconservatives and that is in fact the word we
chose. There is some overconservatism that we would like to
take out.
We believe our answer is in fact overstating it
but --
CHAIRMAN GARRICK: Of course, it is important here
to know what the intervening events are. Sometimes in the
case of cladding on fuel and a reactor loss of coolant
accident, who cares? It doesn't make any difference what
the quality of the cladding is, and that is because once you
lose the coolant you lose all hope of integrity of the fuel
anyhow.
MR. BAILEY: Right.
CHAIRMAN GARRICK: So it really depends upon what
the intervening events are and this is something that has to
be picked up in the FEPs, I guess, since you don't seem to
employ the more traditional approach of risk assessment,
namely a scenario-based approach where you can clearly see
the sequence of events that are taking place and have a
basis for judging what these intervening conditions might
be.
Now you must have them in your FEPs analysis and
in your process models, but it is something that has to be
taken into account because if you start isolating these and
say you are conservative on these out of context, it is a
lot like in the old days in the reactor PRAs where people
would say, well, we have analyzed System A, System B, we
have done the fault trees on them. All we have got to do is
connect them together and we have a PRA. The answer is you
absolutely do not --
MR. BAILEY: Right.
CHAIRMAN GARRICK: -- because the boundary
conditions of those systems are very dependent upon where
they appear and what they are asked to do in the sequence
you happen to be in. That is very boundary condition
dependent, so this is something we were talking about during
the break that we really have to take a very hard look at is
this whole issue of the uncertainty analysis and how the
uncertainties are aggregated.
MR. BAILEY: Yes.
CHAIRMAN GARRICK: And whether or not there is
indeed a structure or a mechanism with which this
aggregation makes sense.
MR. BAILEY: Yes, sir. I don't disagree with you.
MR. LEVENSON: A slightly different question.
Listening to your discussion about the complexities of the
state of the cladding, and I appreciate and understand that
exactly, but if I now go back into the model, has that been
carried along or will I find that in the model the
assumption is made that all the cladding fails coherently at
the same time rather than over an extended period of time?
MR. BAILEY: I have to think. I believe that the
way we have clad modeled now is that there is a certain
amount of clad that is available and then it fails through
two or three different mechanisms. Some of it is
corrosion --
MR. LEVENSON: But all at the same time?
MR. BAILEY: No. Some of it corrosion, some of it
a splitting, if you will, and I think it is in fact time
spaced. I believe it is. I will have to check on that for
you, sir.
You have two vulnerabilities the team has
identified -- we'll have to work on it -- the thermal
loading issues which Paul talked about at some length.
Those of course make a difference in how you do your
modeling, perhaps not to the overall result but certainly in
how you do your modeling so we have to be alert to it.
The potential for igneous activity at the site --
we have to go through. You saw the new chart of all the
pieces that are there. We really have to solid that up.
The reliability of the complex metal barriers --
the waste package provides a lot of performance right now.
I think Paul described a number of the modeling pieces that
are in there. We are looking at general corrosion. We are
looking at stress corrosion cracking. We looked at
microbiologically induced corrosion. We looked at small weld
failures inside the package that help, if you will,
accelerate the failure of the throughwall of the package.
We have got a fairly comprehensive model in there
but metals are tough, and so we need to look.
Consideration of peak dose -- peak dose is pretty
far out. As you might expect -- go to Dr. Garrick --
running this model for a million years isn't how the system
works. This has FEPs that are in the 10,000 year timeframe,
not in a million year timeframe.
The conservatisms we placed there for a regulatory
basis, if you will, for 10,000 years is probably
inappropriate out hundreds of thousands of years. That is a
long way out. We are looking at how do you make a licensing
argument in some of these in taking some conservative
stances that probably aren't appropriate, so we have to
think through how to deal with the peak dose because it is
in fact a different analysis.
Now, if you work this back the other direction,
which is the five pieces of the safety case, the quality of
the performance assessment, we need to address the issue of
uncertainty. There is a confidence issue there.
Dr. Levenson has suggested that conservatism may,
in fact, not build confidence, it may, in fact, hurt
confidence. We need to finish our FEPs.
MR. LEVENSON: Not conservatism. Severe,
over-estimating consequences, which is different. You need
conservatism.
MR. BAILEY: Yes.
MR. LEVENSON: But you need to know what it is, it
needs to be a defined safety margin, you have to understand
it.
MR. BAILEY: Okay.
MR. LEVENSON: Just throwing in over-estimates
wherever you go is not conservatism.
MR. BAILEY: That's fair. That is also a good
clarification. Thank you.
I think he is working on his tapes. I'm sorry he
missed that.
And we need to ensure a consistency in the overall
uncertainty. The safety margin and defense-in-depth, we
don't want the single failure point. It is a system, the
system needs to be used in total. We need to evaluate the
designs to look and see what we can do with the
defense-in-depth aspects. And we need to look at the
confidence in the process models that we are putting in
there for defense-in-depth, not just throw them in, but
really believe that they work.
The explicit consideration of potentially
disruptive processes and events. We have got to finish our
evaluation of the features, events and processes, document
our basis for excluding others, the criticality, seismic
activity and water table rise, which we have excluded from
this particular runs of the TSPA, although we do consider
them as additional runs to show what would happen. But we
don't believe that they occur and we need to document that.
And we have got to finish the igneous activity
and, of course the human intrusion scenario, now that it is
being defined by regulation.
Insights from natural analogues. Obviously, it
would be nice to get some metal passive layer knowledge,
better knowledge on the transport models and the effects of
heat on host rock.
There was a question earlier about, are there any
natural analogues for the Alloy-22? And I can't pronounce
them, I am not a geologist, Josephenite, I will just take a
stab at it, is apparently a nickel/iron, naturally occurring
mineral that may or may not have some capability in that
arena, and we believe we ought to go take a look at it and
see if, in fact, it does work as an analogue and if we, in
fact, can learn something. There will probably be a
recommendation from the repository safety strategy.
Pena Blanca, looking at what we are doing in
Busted Butte, the analogue volcanoes, so we get better
knowledge of what is really out there.
And, finally, we called it safety assurance here,
it should be the performance confirmation, but they are
trying to making a point that, in fact, you are going to do
performance confirmation testing. You always have
retrievability available to you during this because of the
regulation. You have to make a closure decision at some
point. Why? What is the basis for it? And there is a
requirement there for some postclosure monitoring. So, you
really have four thing that you are working with
institutionally before you can make your decisions to close.
And, of course, we want to go back and work the performance
confirmation plan.
Now, there was another piece on the agenda that
talked about the relationship between the RSS and the KTIs,
and I have a couple of pages to just go through that
quickly. Obviously, working the repository safety strategy,
which is the whole system, touches or runs across the KTIs,
which are the NRC's key technical issues. So, we cross-cut
them as we walk through all of this.
Several of the KTI subissues are closely linked to
the principal factors, the things that we find important,
the things that we find really control performance. Some of
them, where detailed questions are asked, we don't find make
a lot of difference to performance, and that, in fact, we
may have enough knowledge now to move on from there.
And we have been discussing this, I think the next
slide does that. No, actually, the next slide tries to give
you a relationship between the KTI and what our principal
factors are. And what we are telling you here is that in
the radionuclide transport arena, the thing that we consider
important out of that KTI, and before the staff gets too
worried, on a gross scale, it is the retardation pieces that
are most interesting.
The rest of the radionuclide transport is not as
significant as those. And, so, that is the simple purpose
of this table, is to point out the KTI. And what is shown
over here are those portions of that KTI or our principal
factor, which could be related back, is what we think is
really important to that, and other items are of lesser
importance.
Plans for addressing the individual KTI acceptance
issues obviously come from the RSS because that is our basis
of what we think is important and where we are going to put
our resources. We need to focus work on the LA on reducing
uncertainties in the areas closely linked to performance.
As I said, we will tend to bound or to simplify in other
areas. And the information that we intend to provide for
each subissue will reflect the importance of that subissue
to the safety case. That is our strategy.
We had a technical exchange with the staff on
April 25th and 26th. It was kind of one of these. We told
them what our -- what we thought we were and what we thought
were the principal factors, and they told us theirs. And we
go some alignment and some misalignment, and we have a whole
series of meetings throughout the summer and fall to come
back, basically, to the process model report, is how we
chose to focus it, because that is our summary document, and
work backwards, if you will, to make sure we get some
alignment on what the KTIs and the principal factors and the
factors are. And those meetings will, hopefully, make that
happen so that we can have the meaningful discussions to try
and close on it.
Preclosure safety, I will talk to very quickly.
The same chart, you do almost the same things. You evaluate
your hazard, you select your category 1 or 2 in accordance
with the regulation, and you find your design basis events,
and you find out what you need. Your strategy, you do
prevention. Keep it from happening. Paul talked about it
today. Don't do a lot of lifts, you know, kind of shimmy it
up and shimmy it down if that is all you have to do. Open
something and push it up and close it. Try and get into
prevention. Don't let the event happen. If it has to
happen, find the best way to mitigate it.
And, of course, you can go back and modify design
or you can modify operations in order to control those
items. Feed it back, get it into the system, and, again, it
feeds the safety case, the requirements, and the Q-list.
Make sure that you put these pieces together. And, of
course, out here, now that you know this information on
frequencies and importance and what it contributes, you can
start getting into grading. So, you can get the
classification and then you can get the grading.
How do you do it basically? I don't think there
is any revelations here. You have to look at your external
events, your fires, your tornadoes, your tsunamis. Tsunamis
probably won't make it. Determine your project
applicability of the events. Does it exist? Is it
operative during the preclosure? No. You screen it out,
define why. Yes. How do you handle it?
External events, obviously, are problematic, you
can't prevent them, but you have to mitigate them.
Come back to the internal. The internal,
obviously, has to do with what your design looks like, what
your operational modes are, how you put the system together.
It is design-dependent. And you go back, you determine your
design and operational features.
We chose to put a big emphasis here on the energy
source. What is it that makes the radionuclides become
active? This is really a fairly benign facility, this is
not like a reactor with high pressure, high temperature.
This is move some stuff, it is not -- you know, it is
material that has to be respected, but it is not a high
energy material at this point in its life. And, so, we
obviously want to put a lot of energy into not having a lot
of energy. That is part of the prevention strategy. So,
you look for it. If there isn't an interaction, then you
are okay. If there is, then you start looking at -- how do
you put these together? How do you come up with your design
basis events? Where can you do prevention and mitigation?
And pull that together.
So, what are the decisions? Well, what the RSS
will give us, postclosure, preclosure assessments,
mitigation, additional information. Consider the
feasibility, any other factors that we need to go work at.
Work on the safety case for the LA. How do we put it
together, get our confidence? Develop the requirements
based on the safety case, so that we can go back. As Paul
said, they want to do some different work in the fuel
handling building. We need to work on how to go about that.
And, finally, get the Q-list, so you can get into the
system, structure component portion of this if the site
recommendation is advanced and told to continue.
We are in process. I expect that late summer or
early fall, we will be able to get a pretty good view of
what the results are. I can't commit to that, that is a
rough schedule, in that timeframe. But I expect that is the
next time when there is a meaningful update on actual
progress of this document.
DR. HORNBERGER: Thanks very much, Jack.
MR. BAILEY: You're welcome.
DR. HORNBERGER: I am sure that there are some
questions, I think. Let me start. I want to -- I accept
your point, -- go back to the fact that igneous activity
popped up in your RSS Rev. 4 preliminary. And I accept what
you said, that this is the first time that you have included
this in the analysis. However, it strikes me that it is, in
part, based on preliminary results that you have seen.
MR. BAILEY: Yes.
DR. HORNBERGER: Which might lead one to think
that the way that you have modified the analysis post-VA,
mainly in response to NRC's staff urging to use the ash
plume model and you had the size of the material too large,
possibly, your preliminary analysis suggests that you do
have to look at this and that it isn't a no-never-mind. Can
I take that as the status? Am I reading this correctly?
MR. BAILEY: We have modified the analysis.
Analysis was, in fact, performed to the viability
assessment, which I think is what you are referring to.
DR. HORNBERGER: Well, it was performed separate.
MR. BAILEY: Yes.
DR. HORNBERGER: But the NRC staff had some major
issues.
MR. BAILEY: Yes, they did, and they made some
comments in many of the areas that you have suggested, and
we have gone back and put some of those changes in the
model, and see what the model results are. We have not yet
agreed that those are, in fact, the right changes to make to
the model. But now with the NRC's approaches and their
beliefs in how this looks, yeah, we have to look at it.
CHAIRMAN GARRICK: I am curious a little bit about
how you are going to use the RSS as -- are you going to use
it as kind of a management tool, or is it principally
documentation of the strategy? What function is this
document doing?
MR. BAILEY: It does both. It does both. It has
to -- let me see if I can explain this correctly. It does
the evaluation of the technical work of the TSPA. It is
intended to put the meat on the bones of the safety case,
so, this is how we would make these arguments. It then sets
up a strategy of what are the next things that we need to
work on based on the way we want the safety case to come
out. And it is endorsed by the DOE management through the
process. And when that happens, it becomes the planning
guidance.
And, so, it does both. It lays out the strategy
of what we intend to rely upon, the basis for that reliance
as it comes through the analytical basis. It lays out how
we are going to accomplish that, and then it lays out where
we need to go do more work, which becomes a planning basis.
CHAIRMAN GARRICK: I guess for those people who
lack confidence in the performance assessment process, and I
am not one of those, --
MR. BAILEY: Yes, sir.
CHAIRMAN GARRICK: -- it answers the question --
what else is being considered for the safety case beyond the
performance assessment?
MR. BAILEY: That's correct. That's correct. It
says there is four more things, take a look at it. Now, you
could roll -- I will go back. I will show the right slide,
it is the next one. If we stick to whichever side this is.
The PA is your mathematical representation and all
the sensitivity studies that go with it to gain that
understanding. It is not just a squiggly line, it is, in
fact, the understanding.
We chose to segregate safety margin and
defense-in-depth. This treatment of uncertainty,
conservatism, how much do we have, and doing an analysis.
Perhaps in a manner here for the defense-in-depth, it is not
purely probabilistic. It probably will be a stressing of
the system to see how it responds. You could call that a
sensitivity analysis, but we believe it, in fact, is a means
of stressing the system to make sure that you don't have any
single dependencies.
The insights from natural analogues, that could be
rolled into the total system performance assessment and,
obviously, will be, as part of the basis for how we chose
the probabilities that we used inside of there. But we felt
that it was appropriate to separate it and give it a higher
level of visibility so that you can see that some of the
results, in part from this, can be related back to nature.
CHAIRMAN GARRICK: Yes, I would hope, though, that
those who are raising the question about what else are you
considering would appreciate the fact that what you mean by
total systems performance assessment is the consideration of
any evidence that would in any way impact the performance of
the repository and would have something to do with the
quantification of that performance, and that is all those
things. So, I don't see those as separate and independent
issues.
I would think that, to the extent that natural
analogues tell you something about the long-term performance
of the repository, that has to be a part of the TSPA.
MR. BAILEY: It does.
CHAIRMAN GARRICK: I would think the extent to
which measurements are going to be made or monitoring is to
be done, that has to be a part of the evidence base that you
have for the TSPA. So, to me, this is all sort of an
artifact of displaying information for people who are asking
questions who don't have confidence in TSPA or don't
understand TSPA, which should include every one of those
things.
So, anyway, but that is --
MR. BAILEY: It is, in fact, communications.
CHAIRMAN GARRICK: Right.
MR. BAILEY: I don't argue that at all.
CHAIRMAN GARRICK: Right.
MR. BAILEY: In fact, I think I made the same
discussion, that each of these could be and should be, in
fact, found inside of there.
CHAIRMAN GARRICK: Right.
MR. BAILEY: But you break them out in order to
show the layering.
CHAIRMAN GARRICK: Sure. Sure.
MR. BAILEY: That it is in there, it is ragout,
right, it is in there, but let's bring it out and show you
that we have tomatoes and peppers.
Well, I am reassured to know that you understand
that, because there is no bounds on what you put in a
performance assessment. It should be everything that has
anything to do with, in any significant way, in a visible
way, with the performance of the repository. And all those
things are in that category. Okay.
DR. HORNBERGER: Just one quick follow-up on that,
if I may. Is it your understanding, Jack, that this list,
in fact, then would satisfy the TRB, in particular, who has
said that you need something more than performance
assessment? Is it your understanding that this is what they
mean? It is hard to put Jack on the spot, he is very
nimble.
CHAIRMAN GARRICK: I didn't want to name names.
George has named names.
MR. BAILEY: I want to give you a responsive
answer here. To Jack, this communicates very well to me. I
am a deterministic guy, I will admit it. I think I
understand probabilities on odd-days, odd-days of the week.
But, to me, this communicates. It provides that layering.
It brings it out in a communications manner. I mean we can
find all of these things.
Now, for example, the barrier analysis,
neutralization analysis, is kind of an example here. The
neutralization analysis is probably not really part of this
because there is no case where the overlying rock isn't
there. You know, it might be a .00001 that it isn't there,
but there is not a zero that it isn't there. And, so, in
that one area of neutralizations, it probably isn't
necessarily part of the TSPA.
But, to me, this communicates. It says, I have
got the math and I have put the system together and I have
learned from it. It says, I know I have got a separation, I
know I have some margin. I know it is going to work better
than -- I know it is going to beat the regulation. I have,
like I said, I am a deterministic kind of guy, I like to go
"what if." You know, what if I step on the brakes and it
doesn't work, what do I do next? Do I downshift? Do I pull
on the brake that has a wire? At least I hope it still has
a wire. I know what I am going to do next.
The analysis of potentially disruptive events, it
is a classical, of course, which is the low probability,
high consequence, and people, I find people think like that.
I do. What is the worst thing that can happen to me?
In here, it is just part of the curve. Now, is it
in there? You bet it is in there. The analysis is there,
you can pull it apart. This displays it. And I think this
answers the questions that deterministic type people tend to
answer, and create that layered argument that says, yeah, we
have a probabilistic view of it and we also have some other
views of it that lend some confidence.
CHAIRMAN GARRICK: We keep making it difficult to
communicate what we mean. There's another one out there,
too, that clouds the issue, and that's the Integrated Safety
Analysis. I, for the life of me, don't know what gave that
a berth, because the ultimate integrated safety analysis is
a PRA.
MR. BAILEY: Yes.
CHAIRMAN GARRICK: And so integrated safety
analysis has to be a subset of that. But, nevertheless, if
it enhances understanding and communication, you know, it
has its value.
But at the same time, we shouldn't misrepresent
it. We shouldn't lead the Technical Review Board or anybody
else to think that PSA, TSPA, is bounded or PRA is bounded.
It all depends upon what we have identified as our
performance measure or our risk measure. With respect to
that risk measure, it should be totally unbounded.
Now, we may not have identified enough risk
measures or the proper risk measure, and that's another
issue, but to the extent that you identify one, then the
analysis has to include everything that affects that
measure.
MR. BAILEY: Oh, yes. I would not even suggest
that the TSPA doesn't include this.
CHAIRMAN GARRICK: Right.
MR. BAILEY: This is a representation of that
external for communications.
DR. HORNBERGER: Okay, good.
DR. WYMER: John sort of stole my thunder, but I'm
going to go ahead anyway.
MR. BAILEY: Can I give the same answer or
non-answer?
DR. WYMER: I'll get to a question eventually.
[Laughter.]
DR. WYMER: It's clear that the RSS is central to
the license application, and it's really needed to get on
with this whole business.
But unless there is feedback from this activity
into the design or the analysis or request for additional
data, it's a passive exercise with respect to what you're
doing in building the repository.
So the question then is what formal mechanism is
there for feeding back the results of the safety analysis,
and what's the documentation of that formal process?
MR. BAILEY: It goes into the planning guidance
for the upcoming year. The RSS is published, signed out by
the Department of Energy's management. It says here's our
path forward.
And it provides guidance, on, factor-by-factor,
what we need to know, what we think we need to work on, what
the minimums are to do in those areas, and where we want
those results, if you will -- not predetermining the
results, but what basic answers we want those results to
provide us.
We'll let the chips fall where they may, but this
is the part of the puzzle that you have to fit into, and it
goes into the planning guidance.
And that's what gets funded, and that gets
reviewed by all levels of management, including DOE, to say
this is the right work to do.
I can guarantee you that when the RSS is issued,
people know it and it has an effect.
DR. HORNBERGER: Thank you. Staff, anyone with
any questions?
MR. LARSON: I have a question.
MR. BAILEY: Yes, sir?
MR. LARSON: You know, reactor safety strategy, I
assume that it's based on the Part 63 is going to be your
basis, but does it include a contingency, should EPA's 197
standard require changes to Part 63, or is it so broad now
that it covers everything including groundwater travel and
groundwater release?
MR. BAILEY: The repository safety strategy is, in
fact, tied to Part 63. Part 63 will be conformed with 40
CFR 197 when the time comes. There are a few differences
between the receptor. The biosphere data is slightly
different in the EPA approach.
Obviously, the groundwater analysis is different
or is additional, and there are some slight nuances, I
believe, in the human intrusion scenario.
And we will true all that up. We chose at this
point to follow 63 for the site recommendation, and we
consider 197, but it's mostly focused on 63, and we'll have
to true it up when the time comes and the analysis to do the
groundwater can be done.
DR. HORNBERGER: Thank you very much, Jack.
MR. BAILEY: You're welcome.
DR. HORNBERGER: We'll look forward to keeping
posted as you make more progress.
CHAIRMAN GARRICK: As it evolves.
MR. BAILEY: As it evolves. Thank you.
DR. HORNBERGER: So, typically, the ACNW looks
forward with relish to having the chance to grill Carol
Hanlon, but Carol has decided not to make the next
presentation, despite the schedule, and Chris Kouts is going
to deal with our very difficult questions.
MR. KOUTS: Can you hear me everyone? Am I
electrified? That's good.
My name is Chris Kouts. I'm not related to Herb
Kouts who some of you may know, but he did call me up once
and ask me if we were related.
[Laughter.]
MR. KOUTS: Kouts is a shortened Greek name, so I
think his is more germanic in origin, I think.
Here we go. Okay. Today I'm going to give you a
presentation on the status of the Department's effort to
revise the repository siting guidelines, the Yucca Mountain
suitability guidelines. Before I get into the presentation
of what our proposal was, I think I ought to go back and do
a little history.
I should mention also that I know the item on the
agenda following mine is of most importance to everyone
here, and I will endeavor to keep my remarks short.
For those of you who followed this program for
awhile, you might remember in 1984 that the Department
issued repository/ -- what we called siting guidelines at
that time. It was based on a requirement in the Nuclear
Waste Policy Act, Section 112, which indicated that the
Department needed to develop these guidelines in order to
select among sites for suitability -- not for suitability,
but for site characterization.
Comments that we got back during that time
indicated that the public wanted us also to use these
guidelines for the suitability decision the Department would
make, and the Secretary's decision to recommend the site to
the President. So we also are going to use those guidelines
for that same purpose.
Flash forward: Let me flash back for a moment.
Those guidelines were originally written to select among
sites, in other words, compare among sites.
We don't have -- we only have one site at this
time, as required by Congress under the amendments to the
act in 1987. As a result, we toyed with the idea of
changing the guidelines, removing the comparative aspects of
it.
We went through a series of public meetings back
in the early 90s to address whether or not we ought to
change the guidelines based on the amendments to the act in
1987.
We essentially came to a decision that we wouldn't
change them, but we did reserve the right that we would
change the -- we could change them, if, indeed, regulations,
our parenting regulations, either the NRC or the EPA, did
change.
In 1996, although there were no changes in
regulations, we felt that we had a basis for modifying the
guidelines. We went through a rulemaking, a propose
rulemaking at that time which we never finalized. And last
November, we issued a revised Notice of Proposed Rulemaking
in which we proposed that the Secretary of Energy would use
site-specific guidelines for Yucca Mountain to determine
suitability.
And those site-specific guidelines essentially
said that if the required evaluation showed that the
proposed repository is likely to meet applicable radiation
protection standards for the preclosure and post-closure
periods, then the site could be deemed suitable by the
Secretary of Energy.
Now, suitability, in and of itself, is a
necessary, but not -- is sufficient, but not a necessary
requirement for the site recommendation.
There are other requirements under Section 114
that the Secretary needs to evaluate before he makes his
recommendation to the President.
So, a) if, indeed, the Secretary does decide the
site is suitable, that's not necessarily -- that doesn't
necessarily mean that he'll recommend the site. There are
other issues that he has to take into account.
And those issues are again outlined in Section 114
of the Act. Okay, I think that covers most of that slide.
I'm going to focus more on the post-closure
aspects, but our rationale for revising the guidelines
essentially is to align them with the latest science and
scientific analytical techniques for assessing repository
performance. One of the real sore points associated with
the changing of the guidelines is the removal of the
subsystem requirements that were in the original guidelines.
When NRC issued Part 63 and essentially indicated
that those subsystem requirements were no longer needed and
that essentially we were going to a TSPA approach, the
Department is basically following Part 63, proposed Part 63.
We're also following what's proposed in 40 CFR 197
which are the EPA proposed standards.
We also issued them in -- we also addressed the
public comments in the 1996 proposal in our revised Notice.
Now, we are leaving 10 CFR 960 in place. We are
not taking that out of play, if you will If at some future
date we are selecting among sites for site characterization
purposes, we will use 960 or revise 960, as appropriate, at
that time.
We are recommending or we are proposing a new Part
963 to establish the suitability guidelines for Yucca
Mountain.
963 presents the criteria and methodologies for
assessing the performance of a potential repository, Yucca
Mountain, in meeting both preclosure and post-closure
applicable radiation protection standards.
The preclosure approach, I won't spend a lot of
time talking about it, but it essentially utilizes a
preclosure safety evaluation that is generally consistent
with proposed Part 63.
Post-closure aspects essentially use TSPA, which
we have been talking about this morning, and is generally
consistent with the regulatory structure in the EPA proposed
rule, and the NRC proposed rule, and is consistent with what
the NAS suggested in their 1995 report on technical bases
for Yucca Mountain standards.
The post-closure suitability criteria which we
call out in the rule, are essentially represent those
characteristic traits, what we believe pertinent to
assessing the performance of the repository, Yucca Mountain.
This addresses essentially the physical processes
of water falling on the mountain, moving down through the
mountain to the unsaturated zone, interacting with the
engineered barrier system, down through the rest of the
unsaturated zone to the saturated zone and then out to the
biosphere.
The criteria that we use are essentially the --
mirror the process model reports that we are producing for
our TSPA for the SRCR, and if we go forward, to the SR.
Disruptive events, we also address, and there are
four of those, which is somewhat inconsistent with 63, but
we added another one.
The disruptive events that we're proposing are
vulcanism, seismic events, nuclear criticality, and
inadvertent human intrusion.
And these would all be part of the TSPA for
evaluation of the suitability of the site.
The post-closure suitability criteria, if you're
familiar with our PMRs, which I'm sure you are, you'll see
how they track essentially one-for-one. For each PMR we
have, we have a suitability criteria.
We opened a 90-day public comment period which was
extended and closed on February 28th of this year. We
received nearly 100 responses from the public, held two
public hearings, one in Pahrump, Nevada, and one in Las
Vegas.
We considered the comments we received, and
developed a draft final notice of proposed rulemaking. That
notice was transmitted from the Director of the program to
the Chairman of the Commission on May 4th, in which we
requested concurrence, NRC concurrence on the rule. We're
following the procedural requirements of Section 112 of the
Act.
In that request, we asked for timely consideration
of the draft final rule, and its concurrence to allow the
Department to utilize the final rule in the upcoming site
recommendation process that is right now planned for this
Fall.
And that's all I have, and I'll be willing to
answer any questions you might have.
DR. HORNBERGER: Thanks very much, Chris. Milt,
questions?
MR. LEVENSON: No.
DR. WYMER: I have just a naive question. 963 is
so close to 63, why did you need it?
MR. KOUTS: Well, you could say, why did we need
960 then. Simplistically, the suitability evaluation on the
part of the Secretary is an evaluation as to whether or not
the site is likely to be licensed. It's a DOE evaluation as
to whether or not we feel we have enough information to have
a credible license application.
So it's a DOE internal decision, and it's a
logical one. If the Department felt that after doing all
this site characterization work, we didn't think we could
meet NRC licensing requirements and the EPA standard, then
why go forward?
So this is essentially an evaluation on the part
of the Department to see whether or not the site is likely
to be licensed in our own estimation.
DR. WYMER: But you could have made that
evaluation based on Part 63.
MR. KOUTS: We could, but it created a process,
and it creates a regimented process the Department would go
through in order to do that evaluation.
DR. WYMER: That's the answer.
MR. KOUTS: Okay.
DR. HORNBERGER: John?
CHAIRMAN GARRICK: I don't think I have a comment,
but I'll just say to Chris that the rule for speaking to
this Committee is to use 50 percent of the time, not 15.
MR. KOUTS: Oh, I'm sorry.
[Laughter.]
CHAIRMAN GARRICK: But we appreciate it; it's
refreshing.
MR. KOUTS: Well, as I mentioned at the beginning,
I was concerned about the next agenda item.
CHAIRMAN GARRICK: I understand.
MR. KOUTS: I was sensitive to that.
DR. HORNBERGER: I just had one quick one that is
really, I think, basically the same question that Ray asked.
But in answer to Ray you said that this somehow creates a
process?
So part of 963 is a process for the DOE internal
review?
MR. KOUTS: What it does is direct the Department,
under its own regulations, for the Secretary to go through
this evaluation for the suitability of the site.
Now, it's arguable that we never had to go through
a regulatory framework in order to do this. The original
guidelines in Section 112 of the Act, never indicated that
the Department should issue federal regulations on this.
But we started that process back in 1984. We're going
through a regulatory process on these, and for our own
evaluations in order to get public input on it.
There will be, for instance, at the end of this
year, assuming we go forward with an SRCR, part of that
document or those -- that several-volume document will be an
evaluation against the guidelines, our own preliminary
evaluation against the guidelines, and we'll be issuing that
for public comment.
So, we're going through what we feel is a
reasonable process in order to do this evaluation, and it
also allows the public to give some input, as we went
through a process to allow the public to comment on the
proposed rule.
DR. HORNBERGER: It's almost to keep you on a
parallel track because 960 came into being?
MR. KOUTS: Yes, and we actually did get comments
from certain organizations that felt that we should
withdrawn the guidelines and not go through this, but we
felt it was important still to do it.
DR. HORNBERGER: Okay, thanks very much.
Questions from the Staff?
[No response.]
DR. HORNBERGER: Thanks very much, Chris. I
appreciate it. We have another request from Amy
Schollenberger to make a comment, so now would be an
appropriate time.
MS. SHOLLENBERGER: Thank you.
Amy Shollenberger, Public Citizen. I just wanted
to add our two cents in here. I think that it's very nice
of Mr. Kouts to consider that lunch is the next agenda item
and do a very cursory review of 963 as a result.
I think this whole thing is really just a farce
because it is not a system that is set up to allow public
comment. It is not a system that is addressing public
concerns. What it is is it is moving the individual
disqualifiers from Yucca Mountain so that there's no way to
say that it is not a suitable site.
I think that, you know, I have heard your argument
several times that you are saying the amendments to the NWPA
say that we shouldn't consider more than one site, we are
going to focus on Yucca Mountain but that language does not
specifically say we should remove the individual
disqualifiers, which are specifically required in the
original Act. I think the Department of Energy's
justification of doing 963 is really just that. It is a
just a justification and it doesn't really address what the
public wants or what is required by the Act.
Also, I think that to say that you are doing it
just to bring it in line with Part 63 again is just a
justification because if it is truly for the Department of
Energy to look at the site and say is this a suitable site,
should we recommend it, then it shouldn't have anything
really to do with whether the NRC thinks it is a suitable
site because, as you said, it is all before the
recommendation. It doesn't have anything to do with
applying for a license and I think that it is really a joke
to even say that you are doing this to consider what the
public wants unless you are considering the public as NEI
and the nuclear industry because that is who really wants
this to happen. Thank you.
DR. HORNBERGER: Thank you, Amy. Back to you,
John.
CHAIRMAN GARRICK: Thank you. I guess there's
been -- the question that we always have to ask here is do
we want to write a report or a letter on this topic, and is
there a need for one. I really thinking of not only the 963
topic but maybe the topic before as well, but let's talk
about 963.
DR. HORNBERGER: No.
CHAIRMAN GARRICK: Okay. What about the other
topics?
DR. HORNBERGER: I think that the other topics
really --
CHAIRMAN GARRICK: The design --
DR. HORNBERGER: -- fall into some of what Lynne
presented yesterday and probably will come into play in
terms of the Yucca Mountain Review Plan and what the Staff
is doing, so I think probably not individually but I think
that they very much fit into what we seem to be planning.
CHAIRMAN GARRICK: So it is part of the
aggregation of those things that you described yesterday and
the preparation of some specific reports downstream?
MS. DEERING: As long as we do capture through our
other means, there is not an explicit letter on repository
safety strategy, I think there are some issues on for
example the alignment of key -- the subissues and the
principal factors. To the extent that NRC and DOE are -- I
guess what I am trying to say is that as Jack Bailey pointed
out, they had found some of the subissues that were not
necessarily relevant to the strategy DOE is taking and at
some point I guess what we would do is want to look at the
Yucca Mountain Review Plan and make sure Staff has a
mechanism to in fact when it reviews and is concerned about
these subissues that they have a flexible approach to back
off if there is a bounding analysis, for example.
We are doing that. I understand that with the
Yucca Mountain Review Plan, and that is one way to capture
it. That is kind of my thinking on it.
CHAIRMAN GARRICK: Well, another way to split this
is to think of the repository safety strategy as an
individual product and maybe if the committee had some
comments or suggestions to make that would be of benefit to
the Commission to address them, but as far as the design
update is concerned on Yucca Mountain I don't think at this
time it would be appropriate for us to comment given the
heavy agenda we have over the next three months of Yucca
Mountain activities in relation to the review plan and the
suitability issues.
I think that if we have a comment on the strategic
plan, that could be a possible source for a letter, but
again I think that here we are not talking about a letter to
DOE. We are talking about a letter to the Commissioners on
what we heard in this repository strategic safety strategy
and I don't know if there was the kind of information there
that is a basis for such a letter, and I would like to hear
from the rest of the committee on that.
MR. LEVENSON: On the design issue, John, we heard
from DOE about work in progress. DOE has not yet made their
final selections as to what is going to be.
I think it would be inappropriate for us to
comment that we think things are acceptable or not
acceptable when they haven't even been submitted to NRC. We
don't write letters to DOE. We write them to the
Commissioners, so I think this is just a status report at
least on the design aspects and I don't think it warrants a
letter.
CHAIRMAN GARRICK: Yes.
DR. HORNBERGER: I think the update on the design
was very important for us because this is the design that we
are going to see as part of the SR and therefore I think it
was critical that we have that update and have a chance to
ask Paul and some others questions, but I agree with what
everyone's assessment is.
On the RSS the ACNW said for a long time, years,
that the RSS was something that we really did want to keep
tabs on.
Again, as Jack presented it, it is evolving and it
is on purpose it is evolving and so I think that I agree
with you that in mulling this over we have some comments
sort of on the nature of a high level strategic approach
that we need to make to the Commission there may be a
letter.
CHAIRMAN GARRICK: Yes.
DR. HORNBERGER: I believe that we may find that
this will better wait until we see some of these details.
CHAIRMAN GARRICK: Okay, so I think it sounds like
the question is still slightly open on the repository safety
strategy but we have other places in the net here to address
the issues of design and we will do that later.
One of the things that struck me as Amy was
talking earlier was the possible confusion between the
notion of a flexible design and the issue of fixing the
design. A flexible design can be fixed, of course, and I
think that is kind of what they are talking about, but it
did suggest that there might be some confusion there that
somewhere along the line needs to be resolved.
I would be uncomfortable too if we were getting
ourselves in a situation that this design continued its
instability deep into the licensing processess.
We have said and we have had working group
sessions on this that there is real merit in not fixing the
design too early because of things that we learn and the
fact that the site characterization program is an ongoing
activity and the fact that this is the first time such a
license has been attempted and where everybody is learning a
great deal as we go along, and I think even the National
Academy of Sciences' somewhat famous document on rethinking
radioactive waste management made the same point, that we
should not too far in advance try to put a fix on what that
design should be.
I do think it is very important that we be very
clear on what is meant by that and that we not get ourselves
in a position of confusing the current strategy of adopting
a design that is reasonably flexible as meaning that we are
going to keep the design open, so to speak, deep into the
licensing process, so we may want to at some, sooner or
later, clarify that issue.
DR. HORNBERGER: You have just muddied it for me.
[Laughter.]
DR. HORNBERGER: I am pretty much of the opinion,
and I think that Ray asked a question I think of Paul that
would reflect that, and that is that even deep into the
operational period if you have surface storage and somehow
you discover a better way to do something, you certainly --
and I know that you preclude this --
CHAIRMAN GARRICK: right.
DR. HORNBERGER: -- and I don't think on the
record we would want anyone to interpret something that we
would say that you would fix the design and freeze it and
the never improve it, ever. If you can make improvements
you want to have the flexibility to make improvements.
CHAIRMAN GARRICK: Well, absolutely, and even all
of the things that the NRC licenses, you will find a large
number of amendments and design changes associated with
them.
On the other hand, there is a fundamental aspect
about the performance here that we have to have high
confidence in, and so there are certain parts of the design
that clearly have to be understood in advance, but no, we
would not want to close the door on any breakthroughs that
might come about as a result of the long-term operating
period.
In fact, the opportunity is kind of unique that we
have a long operating period during which to do continued
study and research to increase our confidence in the
longterm performance and we should take advantage of that,
but I think what I am talking about here, and I didn't mean
to muddy it, is communication again, making it clear what is
meant by what is said.
The words "flexible" and "fixing the design" could
be confused.
Okay -- any other comments from either the
members, the Staff, the NRC Staff, or any from the audience?
[No response.]
CHAIRMAN GARRICK: Having none, I think we will
adjourn for lunch. Thank you.
[Whereupon, at 12:25 p.m., the meeting was
recessed, to reconvene at 1:30 p.m., this same day.]. A F T E R N O O N S E S S I O N
[1:30 p.m.]
CHAIRMAN GARRICK: Good afternoon. The meeting
will come to order.
This afternoon we are going to talk about the
status of the NRC Low Level Waste Program. The committee
member that will lead the discussion will be Dr. Wymer.
Ray?
DR. WYMER: This is an activity which NRC has
apparently given a fairly low priority to in recent years,
largely because the low level waste had to a large extent
been relegated to the states and undertaken and the disposal
undertaken by private concerns. An ever decreasing number
of private concerns are accepting low level waste.
There is sort of a sleeper in this. If it should
happen that the Department of Energy facilities come under
DOE regulation there could be a substantial increase in the
amount of effort required in this and, as many of you know,
there was a pilot program where several sites sort of had
the NRC looking over their shoulder with respect to what
they were doing with handling the waste materials, but that
is still in abeyance and we don't know where that will
ultimately turn out, so we are looking forward to getting an
update in this field.
Tom Essig, Chief of this branch, will make this
presentation this afternoon. Please.
MR. ESSIG: Thank you very much. I realize that
my name may be new to this committee. I came to NMSS from
NRR about six months ago and at that time I came in as the
chief of the Uranium Recovery and Low Level Waste Branch, so
I have had low level waste responsibility since that time.
You will notice on the title slide that it is now
the Environmental and Performance Assessment Branch and I
will go into that reorganization, just touch on it so you
understand where some of the pieces fit together and then
John Greeves, when he is here tomorrow, will go into the
subject a little bit further.
What I would like to talk to you about today are
basically these five areas and Jim Kennedy, who is my
technical assistant, will be sharing the presentation with
me, so I am going to cover probably the first two-thirds and
then Jim will cover the last two-thirds and then any of the
really tough questions I get I am going --
DR. WYMER: That's four-thirds of a presentation.
MR. ESSIG: I'm sorry. I thought the last
one-third.
[Laughter.]
DR. WYMER: I am not sure we have got enough time.
MR. ESSIG: That was a test question.
Today I am going to talk to you about the status
of the National Low Level Waste Program, and by the national
program we really are referring to that which is outside of
the NRC that is conducted by licensees and so forth and
which we regulate, either directly or through an Agreement
State, and we will talk about the future of the program,
some initiatives that are on the horizon and then we will
talk about the NRC's program, and that is the internal
resources that we have devoted to it, and then we will get
into related activities and activities that involve low
level waste in some way or other, like decommissioning,
TENORM and so forth, and then lastly we will summarize.
In terms of the current status, this map is
reasonably up to date except for one addition. It doesn't
reflect the fact that South Carolina --
CHAIRMAN GARRICK: Why don't you give him the
lapel mike and then he can be as flexible as he wants.
[Pause.]
MR. ESSIG: Okay. The only thing that we could
have possibly updated on this would be to reflect that South
Carolina is now part of the Atlantic Compact, including
Connecticut and New Jersey and that just has happened very
recently. In fact, June 7th the Governor of South Carolina,
as I think many of you know, signed the legislation that
established South Carolina as a member of the Northeast
Compact and yesterday the Northeast Compact approved an
order authorizing South Carolina to join the compact.
There will be some exchanges of money -- $70,000
here and $12 million there and then it will be effective and
as I mentioned be the Atlantic Compact.
Now some events that have happened over the last
several years -- I am just trying to summarize here on this
slide -- that have happened in the course of developing or
attempting to develop new sites pursuant to the Low Level
Waste Policy Amendments Act or Low Level Waste Program
Radioactive Policy Act, 1985, Texas, as you well know,
started to develop the Sierra Blanca facility and the
regulator denied the application on October of '98.
Nebraska in December of '98, the regulator denied that
license application. It was to be in Boyd County. Then
more recently in California, the Governor announced the
formation of an Advisory Group on Low Level Waste to study
alternatives to the Ward Valley. Of course, Ward Valley is
no longer being considered.
The last point there is a conclusion that was
reached by the GAO in a report that they prepared at the
request of Congress to determine the status of the state and
compact efforts to develop new facilities and alternative
approaches, and they have just basically concluded that
efforts by the states in compact to develop new facilities
have essentially stopped, which I think that would be a
pretty accurate statement of what we see currently.
With the possible exception of U.S. Ecology -- I
think it was mentioned yesterday in the Chairman's opening
remarks -- is -- I'm sorry, I am getting a little ahead of
myself. I want to talk about U.S. Ecology first. It
operates a facility at Richland on the Hanford site that
provides support for the 11 Western states, the ones that I
have listed there that are members of the two compacts,
Northwest and Rocky Mountain.
Then of course we still have the Chem-Nuclear
facility at Barnwell, which as I mentioned will be part of
that Atlantic compact.
The provisions of the compact, as you may be
aware, are that it will gradually step down the amount of,
the volume of waste that can be received at that facility
until after 2008. There will be no waste received at that
facility from outside of the three-state compact.
Recently the operator of the site, Chem-Nuclear,
has been sold to GTS Duratek, and as best we know, that will
not have any effect on the operations of the Barnwell
facility. We fully expect it to continue as it currently
is.
Next, talking about Envirocare of Utah, it
currently accepts Class A waste along with, under their
state license, and then 11(e)(2) byproduct material under
license from NRC and NORM.
I believe as the Chairman mentioned yesterday,
Envirocare has applied to the Utah DEQ, Department of
Environmental Quality, for a Class B and C license, and I
will be saying a little more on that a little bit later.
Waste Control Specialists, the other private
facility in this business, is currently accepting NORM and
other low activity waste for storage. It was recently
discussed with the -- and then disposal in a RCRA cell --
but it was recently discussed with the Texas compact. That
is still being discussed with the legislature so we are not
sure exactly where that is proceeding but I think as was
mentioned yesterday also we are aware that Waste Control
Specialists is also considering a site right across the
border from the Andrews County, Texas, site, and New Mexico
has expressed an interest in reviewing the application
should it be tendered, but that is about all we know at this
point.
I believe our recent discussions with Waste
Control Specialists indicate that that isn't moving anywhere
real quickly but it still is on the horizon.
MR. LARSON: That is not an Agreement State so
that would be a facility that if they proceeded ahead that
the NRC would license.
MR. ESSIG: That would be a New Mexico licensee,
as I understand it, if that went forward.
MR. KENNEDY: New Mexico I believe is an Agreement
State.
MR. ESSIG: Yes.
DR. WYMER: Tom, let me make a comment.
MR. ESSIG: Yes.
DR. WYMER: I had a request from the audience that
any time we use an acronym that we go ahead and say what the
acronym stands for, because people get lost in the alphabet
soup.
MR. ESSIG: Certainly -- such as NORM on the
slide? Naturally Occurring Radioactive Material. Yes.
The Waste Control Specialists, whether or not that
materializes, remains to be seen, but at least it is in the
discussion stages..
In terms of the future of the national program,
the California Low Level Waste Advisory Group has issued a
draft report. They are considering four options -- shipping
to other states, decaying the short-lived radionuclides in
California -- in other words, the status quo, dividing the
waste stream by hazard, building a short isolation facility
or building and operating a new disposal facility, but the
group, the blue ribbon panel that advised the Governor, made
no specific recommendation on that.
DR. HORNBERGER: How does that second one provide
an option? How does dividing the waste stream solve the
disposal problem?
MR. ESSIG: I don't know that it particularly
solves the disposal problem. It is another way of handling
it. That is, they would either dispose or store certain
materials in the state and then would have to -- what they
didn't dispose or store there they would have to go
elsewhere. Is that --
MR. KENNEDY: Yes. The principal dividing line
would be the nuclear power plants on the one hand and
everybody else on the other. I think in general it is fair
to say that the group and the report focuses on an option
whereby everyone like universities and hospitals and so
forth, they would all fall into one category and potentially
be managed at a facility with 100 years of institutional
controls and closed up after that, and then the nuclear
power reactors would be left to store it on site or put it
in their containment building or something.
That basically is where the division is. It's
between nuclear power plant waste and everything else.
"Hazard" by the way is defined by half-life
principally.
CHAIRMAN GARRICK: It is hard to separate alpha
and beta and gammas.
MR. KENNEDY: Yes. There has been a lot of debate
about the recommendation.
MR. ESSIG: And then the last point there, Texas
we expect will take up the low level waste issue again next
January during the legislative session and they will be
considering short isolation.
Back to the Envirocare situation, the Class B and
C application. The state required that they do this in two
steps. One was the first they had to get approval of the
site even though it was, the site was already in use, but
the state insisted that a siting application be tendered.
That application has since been approved and then the next
step will be the actual review of the license application by
the Utah DEQ and then it will ultimately have to go to the
legislature and the Governor.
There is a window of opportunity for doing that.
The legislative session is 45 days each year, starting in
late January, so if the Utah DEQ has approved and is ready
to pass it on to the legislature and the Governor by late
2000 or even very early 2001 then the legislature could
possibly consider it and act on it, but if they miss that
window of opportunity it won't be until 2002 when that could
be a reality.
The second point there is that there has been a
study that was completed in September '99 by the GAO and it
examined the status of compacts, the current disposal
situation, and looked at alternatives for waste management
including repealing the Low Level Waste Radioactive Waste
Policy Amendments Act and letting private industry step in,
using DOE low level waste sites. The study found that the
underlying and recurring reason that no disposal facilities
have been developed is public and political opposition, the
number one reason, and the report didn't make a particular
recommendation.
The last point on this slide is really a
work-in-progress which we have been approached by the
National Academy to fund a low level waste study. We are in
the process of replying to the Academy. The letter hasn't
been signed out yet but it is very high in the concurrence
chain and it is about ready to be issued, and we will in
that letter if it is issued as we understand it, the latest
version of it will offer to work with the National Academy
and fund at some level to be determined.
Our internal program or in-house program is,
basically, the current direction that we have, that we are
pursuing was established by the Commission in '97, based on
a strategic assessment effort. At that point, a larger
program was rejected and the staff efforts to actively
promote new site development were rejected as well.
The current level of effort is about three FTE,
down from what we had was five. And we were told that the
staff should maintain every effort -- or should make every
effort to maintain the core technical disciplines needed to
assess the low level waste disposal issues and that the
technical experts should be utilized in other NRC programs
as appropriate. And, as you will see in a minute, we try to
do just that.
I will say a word about our organization and then
after I am done, then I am going to Jim Kennedy, but this is
-- of course, these organizational elements are familiar to
you, Bill Kane, our office director, Marty Virgilio, John
Greeves, who I mentioned you will be hearing from tomorrow,
and Joe Holonich, our deputy division director.
What is new is, as I mentioned at the outset, we
have this environmental performance assessment branch which
was formed after the uranium recovery function was moved to
fuel cycle safety and safeguards, and the performance
assessment function was moved from the high level waste
branch to here. So, my branch then currently has the low
level waste function, environmental impact statement, which
is an office-wide function and performance assessment, which
is a division-wide function.
And the resources that we have drawn upon
currently, and in the past, of course, are Jim Kennedy, who
is sitting at the table with me today, Tim Harris, who is
sitting over to my left, and Mark Thaggard, whom you heard
from yesterday, and Boby Eid, who has been involved with a
lot of dose assessment activities, and Nick Orlando from our
decommissioning branch, who frequently we view as our mixed
waste cognizant person, and Mike Lee, who has also worked on
some PA guidance recently.
So, that is pretty much our new organization, so,
we have an environmental and low level waste section, and
that is where the EIS function is discharged, as well as the
low level waste responsibility. Well, it is actually split
because Jim Kennedy reports directly to me and he has some
and then Tim Harris has some at the section level. And
Charlotte Abrams is the newly announced section chief for
that. And Sandy Wassler is the section chief for
performance assessment. Those were just announced within
the past week.
So, with that, I will turn it over to Jim Kennedy.
MR. KENNEDY: I want to talk about some of the
details of our low level waste program, both the narrow low
level waste program that we define, basically, by our budget
and, also, sort of more expansively, the low level waste
program in general, that is, the word low level waste as
applied generically into all kinds of radioactive wastes
that happen to be low in radioactivity or specific activity.
First, this is the low level waste program as it
is defined in our budget. Some very specific activities,
most of which are performed in the division of waste
management. One thing to point out at the very outset is
that it does not involve any licensing of Part 61
facilities. There is a little bit of import-export
licensing, but, unlike other NRC programs where the bread
and butter of their work is licensing and inspection and so
forth, we have none of that in the NRC low level waste
program. There are no states about to submit a license
application to us. We have no licenses that we have issued
to states, and the only licenses for Part 61 facilities that
are out there in the country are Envirocare, Barnwell and
U.S. Ecology out in Washington State. So, this sort of
basic NRC activity, or Agreement State activity even, is
just not a part of what we do.
But we do do a number of different things. First,
you are aware of the performance assessment guidance, which
we talked to you about yesterday. I won't go into that, but
that has been a long effort beginning around 1993 or so, and
it has been a lot of work, and we are on the verge of
completing it.
Another item that we have in our budget for low
level waste activities is providing assistance to states
that request assistance on low level waste. In the past,
this used to be at times a fairly large activity. Nebraska,
for example, asked for help on their performance assessment
of that site. We have assisted California, actually, with
respect to the Ward Valley site in a number of different
ways over the years. We had involvement with Texas and all
kinds of other states.
At the moment, as you might imagine, that effort
is not large. We do, for example, go to low level waste
forum meetings, as long as they will continue. They will
have another this fall. I was out at a conference of
Michigan generators at the request of the State of Michigan
a couple of weeks ago, talking to their generators about all
the low level waste and clearance initiatives, and so forth,
that we have underway here at NRC.
But our goal is to continue to be responsive to
state requests for low level waste disposal and management,
given their important responsibility in that respect.
Another activity that we have is to review on-site
disposal requests under 10 CFR 20.2002. That is a section
of the regulations that allows licensees to dispose of their
waste, not in a Part 61 facility, but by other unspecified
means that we review, basically, on a case-by-case basis.
Now, it may be disposal, for example, most often of
carbon-14 on a licensee's site. It could also be disposals
of relatively low levels of radioactivity at a regular
landfill. And under the regulations in 20.2002, a licensee
can submit a request to us to authorize that disposal. Tim
Harris of our staff generally does those, using, basically,
the license termination rule and Part 20 as the criteria, 25
millirem per year, and evaluating it with DandD and RESRAD
and so forth.
Generally, those are -- or I would say always
those are not large disposals, they are fairly small
quantities.
Another activity we have is to review
import-export applications. We do about a half a dozen of
those a year. Technically, there is not any challenge to
that. The criteria in the regulations are not technically
stringent because the technical criteria kick in when the
waste comes into the country and falls under the control of
the licensee and the disposal site. But they are important
to us because they get a lot of -- potentially, get a lot of
visibility, waste crossing international borders.
We want to make sure that there is a place for its
disposal in the U.S. And the problem we most encounter with
these applications to us is that the states that have
disposal facilities, namely, Utah, Washington and South
Carolina, often are reluctant to accept this out-of-country
waste. And I would say probably about half of our
applications don't address adequately where it is going to
be disposed of, and, ultimately, they are dropped.
Another activity that we have underway is to
coordinate with the Environmental Protection Agency on mixed
waste rulemakings. Now, EPA, over the past couple of years
has had two rulemakings underway to better address mixed
waste, and let me see if I can get this right. One of the
rulemakings is to allow for the disposal of low hazard mixed
waste in 10 CFR Part 61 radioactive waste disposal
facilities. And what they mean by that, and what we mean by
that, is that radioactive waste that has small
concentrations of hazardous constituents that normally would
go to a hazardous waste landfill can, instead, go to a Part
61 facility and utilize the waste isolation features in a
Part 61 facility to not only isolate the radioactive waste,
but also the hazardous waste constituents that are in it.
The converse to that rule, or the flip side of
that rule is to allow low activity mixed waste, or low
activity high hazard mixed waste to go to a Resource
Conservation and Recovery Act, Subtitle C, hazard waste
facility. And the same idea applies there, that when the
radioactivity is low, the specific activity is low, that the
risk management features and waste isolation features of a
hazardous waste landfill can be adequate to not isolate the
hazardous waste from the environment, but also the
radioactive waste.
It turns out, I understand, that the biggest
hazard in the hazardous waste facility, excepting
radioactive waste, is to the worker. That is, once it goes
into the cell itself, there is not much of a hazard to the
environment or to the public, but there are doses associated
with exposures of workers to radioactive materials coming
into the facility.
MR. LARSON: How old are those, Jim? The reason I
ask is that the EDO, under Dr. Paperiello's signature, asked
the committee to comment on that if they had any
observations. And, you know, it has never been -- neither
one of those has been presented to the committee, so I don't
know how old they are or what the status is, and we have
been asked to say something.
MR. KENNEDY: Yes. Well, both are a couple of
years old. I mean they started out as an idea, one
rulemaking, the one that allows hazardous waste to go --
slightly hazardous waste to go to a Part 61 facility, that
was issued for public comment as a proposed rule on November
19th and that is expected to be issued, actually, as a final
rule around the end of this year. Our involvement has been
relatively minor in that, as you might imagine.
Now, the other rule is one where, once EPA passed
its rule, this is the one that would allow low activity
mixed waste to be disposed of in a RCRA facility, once EPA
promulgated its rule, or just before that, NRC would also
need to promulgate a rule to issue a general license to RCRA
hazardous waste facilities that would enable them to accept
radioactive waste. And that would be the one where there
would be both more NRC staff involvement, because we would
have to write a rule allowing for a general license for RCRA
hazardous waste landfills, and there would be ACNW
involvement, too.
Now, that rule at the moment actually is on hold.
NRC and EPA, first off, have some issues on it, including 15
versus 25 millirem per year. There is also some concerns
about whether EPA has authority to set standards based on
worker protection, because it turns out that the limiting
factor is exposure of the workers, and, under law, EPA does
not have authority over worker protection. And, so, that
needs to be ironed out. We know what the issues are.
EPA, at the moment, actually, is devoting more
attention to the high level waste standard that they are
developing for 40 CFR 197, and, so, this rule is on the
back-burner at the moment, but it is a rule that folks have
an interest in, particularly, the industry. It is a better,
more efficient way of managing waste and more sensible,
risk-informed way of managing low level waste and mixed
waste, so that we hope that will come in the future.
Another effort, specific effort that we have
underway on the staff is to develop a rule for greater than
Class C low level waste storage at nuclear power plant dry
storage facilities. Many nuclear power plants at the moment
store their small quantity of GTCC waste, it isn't very
much, many of them store that waste in their spent fuel
pools now. And under our existing regulations, if they get
an independent spent fuel storage installation, a dry
storage facility, and license it under Part 72, there are no
provisions that allow them to store greater than Class C
waste.
It turns out that, under Part 72, all they can do
is store spent fuel and nothing else. So, when they get rid
of their spent fuel pool and try to transfer everything, not
just the spent fuel, but the small amount of GTCC, there is
no place to put it. Unless they were to get -- they could
get a separate NRC license under Part 30 to store byproduct
material, which is what the GTCC is. But that doesn't make
a whole lot of sense, and what we are doing is streamlining
things and allowing for, with this proposed rule, the
storage of GTCC, under Part 72, in spent fuel storage
installations.
That proposed rule has just -- it is about to go
up to the Commission in a Commission paper. Maybe it has
gone up as of today, but it is imminent, and it will be
going out, after the Commission decides on it as a proposed
rule in the near future, we hope. That might be something
you would want to look at. I don't know, but I think,
normally, don't you often get involved in proposed rules
reviews? I leave that to you.
Another activity that we have is to participate in
IMPEP reviews. IMPEP is Integrated Materials Performance
Evaluation Program. It is our reviews of both NRC regions
and Agreement States to ensure that they are carrying out
their programs adequately. It is managed out of the Office
of State Programs. It is something that largely has to do
with Agreement States, because there are many more Agreement
States than they are NRC regions.
But they take teams of, typically, four to six
people out to either the region or an Agreement State, with
NRC staffers from different offices, typically, the Office
of State Programs, of course, but, also, our materials
licensing folks, division of waste management people, and
they always include a member of an Agreement State, too, to
go along as a member of the team. And they routinely do
those reviews, of course, for materials licensing, and we
also do them occasionally for Part 61 disposal facility
licensing in the states of Washington, Utah and South
Carolina.
We were down in South Carolina, I believe it was
last summer. Boby Eid actually participated in that review.
I think we were out in Washington last year also, and, Utah,
I am not sure when we will be going to Utah, but we will be
a part of that review and go out and examine their low level
waste disposal program and see how well they are doing.
And, finally, there is just a whole host of
miscellaneous things that come up in low level waste
disposal. Nuclear power reactor inspections, for example,
where they have to classify and package waste under Part 61.
We get involved in that. We get involved in guidance
interpretation for members of the public and licensees
around the country. We work with Congressional Affairs on
miscellaneous issues that come up on the Hill and public
affairs issues that come up mainly with members of the
public, periodically, we get a few of those a week.
Any questions on that part? Do we want to save
those for later?
[No response.]
DR. WYMER: Fine. Proceed.
MR. KENNEDY: I don't say a lot, but I think I
could talk about this chart for a hour, but I'll try not to.
[Laughter.]
MR. KENNEDY: To me, there is so much here. This
is a chart. Now, let me just explain what it is first.
It's a chart of relative specific radioactivity
for the different kinds of radioactive waste. Specific
radioactivity means curies per cubic meter, or picocuries
per gram.
Originally, we had these units down here in terms
of curies per cubic meter, which are the units that are in
Part 61 for waste classification, and we prepared this slide
actually for some Congressional testimony that hasn't
happened yet.
But we wanted to simplify it, and rather than put
in curies per cubic meter, what we did was, we took the low
end of soil and just called that one and put everything else
in terms of the low end of soil. In other words, TENORM,
for example, the high end of TENORM is technologically
enhanced naturally occurring radioactive material; that is
naturally occurring radioactive materials that have been in
some way altered by man, either moving them or concentrating
the radionuclides, or both.
It would, for example, be uranium ore that's
removed from the earth and left in the pile.
You can see that's about five times ten to the
fourth or about 50,000 times higher than the low end of soil
in terms of its specific radioactivity.
CHAIRMAN GARRICK: What soil is that? When you
say soil, that's your standard?
MR. KENNEDY: That's standard, run-of-the-mill
U.S. soil. We got it from NCRP-50, typically like, oh, one
to four picocuries per gram of uranium, plus Thorium 232 and
radium and so forth, and their daughters, in that
neighborhood.
The absolute numbers are not so important here.
They are approximate, first off, because many of these don't
have a rigid, firm, top end. TENORM doesn't, low-level
waste doesn't. Exempt source material does, and I'll talk
more about that.
Uranium mill tailings doesn't have a single number
that's at the top or even at the bottom for that matter, but
you get the idea.
And what we've done is just calculated from -- a
lot of this data came from DOE's integrated database report,
last published, I believe, in 1996, which is an excellent
overview of radioactive wastes in the U.S., all the sources
of it, and radionuclides and concentrations and volumes and
so forth.
And what we've done is take that information and
just put a range of the relative radioactivity for 11(e)(2)
byproduct material, or uranium mill tailings, for low-level
waste, for NORM and TENORM. NORM is naturally-occurring,
and accelerator-produced radioactive material. TENORM is
naturally-occurring material that's been technologically
enhanced in some way by man, by humans.
Exempt source material is a provision in the
regulation under 40.13 whereby source material less than .05
weight/percent is exempt from regulation by NRC, so that
turns out to be .05 percent uranium and/or thorium, and this
is spent reactor fuel way up here.
CHAIRMAN GARRICK: I'm wondering if that sends the
right message? Because your low-level waste, as you just
said, goes up to your -- almost to the bottom of your spent
fuel category.
MR. KENNEDY: We've had that pointed out to us.
And actually there is a corresponding chart that we've made
that can go along with this. We haven't always used it.
But what it shows is that this waste up here --
and, in fact, you can take radionuclides out of Part 61, and
what you will find is that the shorter-lived radionuclides
are the ones father up like Cobalt-60 and Strontium-90.
And if you look at this chart after 1,000 years or
10,000 years, what you'll find out is that the spent fuel
has decayed a couple of orders of magnitude, the high end of
low-level waste has virtually disappeared and it's all down
in this end now; and down for these other materials,
11(e)(2) byproduct material, NARM and TENORM, and exempt
source material, they're principally made up of uranium,
thorium, and radium, and so they stay virtually the same.
So, another way to look at this chart is take it
after 1,000 or 10,000 years and what you'll see is that this
is way down here.
CHAIRMAN GARRICK: Yes, yes. It's just that it
seems that there needs to be some sort of benchmark or
markers that would give people some measure of the specific
activity or something that would indicate whether it's
dangerous or not dangerous.
MR. KENNEDY: Yes. Well, I hear what you're
saying, and like all of these things, this chart, there is a
lot of information here that's pertinent that's not shown
because it's two-dimensional.
CHAIRMAN GARRICK: Right. I'm always a little
suspect of dimensionalist, non-physical meaning methods of
measure.
DR. HORNBERGER: We just plot them on an
arithmetic scale and you only see the high level.
CHAIRMAN GARRICK: Right, yes, okay. Well, I
appreciate what you're trying to do. It's just that it's a
question of whether or not it's a good way -- a good form of
risk communication.
MR. KENNEDY: Yes, I understand what you're
saying. We've had a number of folks, environmental groups,
in particular, come back to us and say, ah, what do you
mean, low-level waste? Low-level waste is almost like
high-level waste, you know?
CHAIRMAN GARRICK: Yes.
MR. KENNEDY: And so more needs to be said about
that.
MR. LEVENSON: Can you show distributions with
activity level? That would help.
MR. KENNEDY: Yes. Like I said, I could go on all
day with this, but another thing that's not shown on this is
volumes. I think that's really instructive.
You know about spent fuel volumes. All of that
will go to Yucca Mountain, and there's not much greater than
Class C waste, which is right up here, and maybe comprises
just the tip of that bar there.
There's 2,000 cubic meters that will be generated
in the next -- both in storage now and that will be
generated by nuclear power reactors over the next 30 years
-- 2,000 cubic meters. That's not very much.
NARM, TENORM, there's, I understand from a recent
EPA report, some 1.6 billion tons of TENORM in the U.S. --
1.6 billion tons. I don't know about the quantities for
that. Low-level waste, I don't know the precise quantities
of that down here, but we do know it's millions and millions
of cubic feet, just in the commercial programs when you take
the SDMP sites and decommissioning of nuclear power
reactors, for example, and contaminated soil and so forth.
So, you know, compare 2,000 cubic meters, which is
90,000 cubic feet or so, and millions of cubic feet down
here, so another dimension of this, if we had a third
dimension, would show volumes very, very large down here on
the orders of magnitude difference between what's down at
this end and what's up here.
Another thing that's important is that these
materials have in some cases, anyway -- are required by
regulation and law to be disposed of in different ways, even
when the hazard is similar or the same.
For example, 11(e)(2) byproduct material or
uranium mill tailings, must go to a licensed 11(e)(2) mill
tailings impoundment under 10 CFR Part 40, Appendix A.
Low-level waste, on the other hand -- I'll talk
more about this end of low-level waste, but in general, it's
required to go to a Part 61 disposal facility, and we'll
talk about some exceptions to that.
TENORM, well, TENORM is regulated not by -- it's
regulated by states. They regulate it in different ways.
There are some states that don't regulate it at all.
Some of it or much of it is allowed to go to RCRA
Subtitle C facilities. In the state of Michigan, anyway, if
not a few other states, it's also allowed in some cases to
go to conventional landfills.
And some of the TENORM, at the high end in
particular -- this is really hot here, by the way. This is
like 400,000 picocuries per gram at the high end.
It's not required to go any particular place, but
it's often sent to a low-level waste disposal site because
it's so hot and so hazardous.
Exempt source material is simply exempt under our
regulations right now, and that typically either goes to a
Part 61 facility, or more and more these days it's going to
RCRA hazardous waste facilities. Of course, you know about
spent fuel.
Any questions on that, because I'm going to flip
to the next page?
[No response.]
MR. KENNEDY: And what we find being the focus of
low-level waste these days is not Part 61 facility
developed. We talked about how the state and compact
efforts are stalled. There are some private initiatives out
there, which are ongoing and which we support.
But what we also find in a much larger respect is
folks encouraging us generators and even the Commission
taking some initiative in this, too, of looking at
alternatives for better managing -- let's see if I can do
this right -- better managing the low end of low-level
waste.
I was trying to get that back up there, but --
yes. It doesn't seem to be working.
Let me start up with rubbelization. It's such a
large file it takes a long time to do it. But we find a lot
of focus, because of the large volume and high cost of
generators coming to us and we're taking some initiatives on
our own, of addressing this end, this waste down here.
Part 61 facilities, in general, are designed to
handle the higher activity, B/C waste, and higher end of
Class A, and are really not needed in all cases for this low
end.
And yet this is where there's a lot of waste. The
cost is high to get rid of it, the hazard is not very high,
and so what we see is an increased emphasis on the low end.
And one thing that just jumps out to me from this
chart is that why can't some low-level waste go to a mill
tailings impoundment when everything else is the same, and
why can't some go to where TENORM goes, when everything else
is the same? So, we'll talk about how we're answering that
question.
Let me continue with that point before I come back
to entombment. But one of the ways that that is manifesting
itself is this concept of rubbelization whereby nuclear
power reactors would clean up buildings and leave some
residual radioactivity on buildings, but dispose of the
rubbelized concrete and building debris and so forth in a
building onsite in the foundation of a building, and cover
it over with soil.
And it's low specific activity material. It's
material that could be called low-level waste and might, in
the old days, be sent to a low-level waste site. But with
that approach, it becomes simply residual radioactivity from
decommissioning, and can be left onsite because even with
that material there, they would be required to meet the 25
millirem per year dose limit for reactor decommissioning.
Another takeoff on that earlier chart and
expanding the disposal options is the use of uranium mill
tailings impoundments for disposal of similar low-level
waste, that is, waste that has the same radionuclides,
uranium, thorium, and their daughters, and disposing of
those in uranium mill tailings impoundments.
Now, the Staff prepared a Commission paper last
year, SECY 99-012. It was prepared in response to some
National Mining Association initiatives, a white paper that
they prepared that proposed and argued for expanded use of
mill tailings impoundment for low-level waste disposal.
And so the Commission has addressed that in the
Commission paper. That's been before the Commission about a
little bit more than a year now. And the Commission, we
think, is going to be issuing a decision on that shortly.
The decision will be, first, whether to
incorporate into a new Part 41, provisions that would allow
for that, and to specify which low-level waste and under
what conditions it could be allowed to go to a uranium mill
tailings impoundment.
Let me come back up to entombment. That is a
little bit different in the sense that it doesn't involve
particularly the low end material but involves the high end
material and the idea is to take lower level waste from a
nuclear power reactor, entomb it into the containment
building -- that is, seal it into the containment building,
to monitor the containment building for 100 to 300 years and
then to allow for unrestricted release after that period of
time.
What it does is it allows for onsite disposal, of
course, but it allows for leaving a lot of the relatively
short-lived low level waste in the building itself and
letting it decay away after 100 to 300 years and then
releasing the site, rather than send it to a Part 61
disposal facility. That is something that is being explored
right now. We have had a couple of workshops on that. There
is a Commission paper also about to go up to the Commission
describing the results of a workshop that we had last
December, and we expect to be moving ahead with that.
The step that we need to take to make that more
real is to promulgate a rulemaking allowing for that to
happen. The rulemaking is probably somewhat far off, but we
are moving step by step on that effort. That would also, by
the way, have a huge impact on the amount of low level waste
that is generated from decommissioning of a nuclear power
reactor because most of it would be left onsite.
Another alternative in a somewhat different sense
are short isolation facilities. A short isolation facility,
I think most of you are familiar with that, right, Howard?
-- is a new concept that is not disposal but it is an option
for managing low level waste whereby the waste would be
placed into a facility that looks like a modern, highly
engineered facility but it would be placed there without any
commitment to leave it there forever.
In other words, it might be left there or it might
not be. The options for how it gets handled into the near
future or just in future even are left open.
One of the ideas behind that is that the local
community would have a chance to gain confidence in the
performance of the facility if it were going there without a
final decision and would be there forever and --
CHAIRMAN GARRICK: What of the licensing, what are
the alternatives for the duration of the license?
MR. KENNEDY: Well, that is the $64,000 Question,
and that is the one that we haven't given an answer to. The
proponents of a short isolation have come up with a
licensing strategy whereby a license would be issued for
storage in renewable terms of, say, 10 to 30 years, and that
after each term one would simply decide at that point --
first off, the operators would decide whether they were
going to keep the waste there and the licensing organization
would decide whether it could be renewed for another 10 to
30 year term.
CHAIRMAN GARRICK: So it is not unlike the way EPA
has certified WIPP --
MR. KENNEDY: Yes.
CHAIRMAN GARRICK: -- where they have five year
recertifications.
MR. KENNEDY: Exactly.
CHAIRMAN GARRICK: Yes.
MR. KENNEDY: In fact, conceptually in some ways,
in important ways I would argue, it resembles a RCRA
permitting scheme and even risk management approach in that
the primary means of managing risk with a short isolation is
through institutional controls and the commitment to monitor
it and survey it and make sure it is working right.
One of the advantages that the proponents argue is
that you don't need a good site. You can put it anywhere,
and you don't need to do a performance assessment and
modeling for 10,000 years, which they argue is difficult and
creates difficulties in licensing, but that one can simply
issue a storage license for 10 years or 30 years and that is
no big deal.
It has some advantages. The Commission has not
been very much involved in that. We are certainly aware of
it. Chairman Jackson has written a few letters on it. We
have identified some concerns like the main one being under
what provisions of our regulations or in Agreement State
regulations should such a facility be licensed -- that is,
the storage regulations or Part 61 and, you know, just what
is it? Is it storage or is it disposal? The Commission has
not spoken on that.
We are simply waiting to have a proposal put
before us, which we haven't had yet.
The state of Texas has an application from
Envirocare of Texas for one of these facilities. They had
rejected the application or put it on hold. I understand
that as of last month they have taken it off hold and I
think they got some eight pages of review comments on it
right now.
We have been talking to Texas. We have asked
Texas to keep us informed of what they are doing so that the
Commission is informed and agrees with whatever licensing
concepts that they come up with.
Clearance of solid materials -- that is the
clearance rulemaking, an extension of what we were talking
about earlier, and that is allowing some of the low end, low
level waste go to other types of facilities. If you carry
that thinking a step further, it is logical to include the
release of solid materials at some very low levels for
unrestricted use and of course that is what the clearance
effort is all about. I am sure you are all aware of that.
What that is basically is that at some level near
background radiation, near the level of radioactivity that
is in soil it is okay and it is safe to release licensed
radioactive material for unrestricted use.
Another item that we are working on right now is
low and source material rulemaking and one of the bars on
that earlier chart was exempt quantities of source material,
which is .05 percent uranium or thorium in our regulations
that is exempt from regulation.
In SECY 99-259 the Staff proposed that we add a
provision to that rulemaking to better define the conditions
under which it could be released for unrestricted use and
for disposal. It turns out that in some cases some fairly
conservative cases of unimportant quantities of source
material like a worker handling zircon flour for 2000 hours
a year of flour material that he inhales a fair amount of,
you can get doses up over a rem per year potentially and so
we are doing a rulemaking that addresses some of those cases
and it looks like the proposed rule will have in it a 100
millirem per year maximum dose to anyone including a worker
at a facility handling these quantities of source material.
That rulemaking is just beginning. I think we are
supposed to have a proposed rule in place or out on the
street -- we are up to the Commission rather in September of
this year.
Finally, I will mention something different here,
the FUSRAP program or Formerly Utilized Site Remedial Action
Program. This is a program that is currently being
implemented by the Army Corps of Engineers. It involves
Manhattan Engineer District sites around the country from
the 1940s and 1950s that have radioactive contamination.
Much of it is 11(e)(2) byproduct material that is the
residuals from the extraction of uranium.
That program was transferred to the Army Corps
from the Department of Energy in 1997 and the Army Corps has
been quite vigorous in looking at alternatives to disposal
from conventional disposal facilities like 11(e)(2) disposal
cells in low level waste sites and they have promoted I
would say and looked at carefully and are using RCRA
Subtitle C facilities around the country for disposing of
this kind of waste and kind of the basic principle is that
if it is good enough for TENORM or it's good enough for
other low end radioactivity materials, it is okay for the
FUSRAP material, which also is down at the low end.
Mostly it is 11(e)(2) byproduct material mixed
with soil so it is not even as big a range as what we are
showing up on that chart.
We don't regulate FUSRAP. The Army Corps is
self-regulating under CERCLA for their onsite cleanups but
there has been a lot of interest in it. It was on the front
page of the Washington Post about two months ago I think.
We get a fair number of requests from people on
the outside concerning the FUSRAP program, from states
sometimes. We have a couple of 2.206 petitions, one from
the Snake River Alliance out in Idaho concerning a RCRA
Subtitle C facility out there that is accepting some of this
waste and the other from Envirocare of Utah, both asking us
to regulate the disposal of that material. They believe it
needs to be done and those were submitted about three months
ago I think and we are processing those petitions right now.
One thing I didn't mention today is research.
There is no discrete Low Level Waste Program or research
program for low level waste but we do do research upstairs
under a program that is called Radionuclide Transport in the
Environment that pertains not just to decommissioning and
high level waste but also potentially to low level waste
disposal facilities, and we are doing work for example on
degradation of concrete which applies to most modern
disposal facilities and potentially to our short isolation
facilities.
We are doing work on absorption of radionuclides
and monitoring and transport of waste in the ground and the
Vadose zone for example, so there is some research being
done by the Office of Research, although it doesn't fall
under the name of low level waste per se.
Here is a summary of what -- wrong way -- whoops.
That is the first time I have used Corel Presentation, so
bear with me. Here's the summary of Tom and I, both Tom and
I talked about today.
First, I think it is fairly clear. It states some
compacts haven't been able to develop new facilities. We do
have disposal capacity available today but the future isn't
certain. Barnwell is going to be closing down over the next
eight years. It is not clear when or whether Envirocare
will get their BC application approved.
We continue to implement our Low Level Waste
Program as directed by the Commission in general in 1997. We
continue to support other in-house initiatives and I would
say spend even more time on this. That involves
alternatives to conventional management and disposal of low
level wastes, such as entombment, rubbelization, low end
source material, use of mill tailings, empoundments and so
forth, and we are also supporting outside efforts to examine
alternatives such as the NAS study for low level radioactive
waste disposal in the country.
DR. WYMER: Thank you very much for a very
thorough and informative presentation. We appreciate it.
Are there any questions?
CHAIRMAN GARRICK: I just have one. Approximately
four years ago this committee, which was made up of mostly
different people than now exist, sent a letter to the
Chairman describing what ACNW thought would constitute a
basic or an adequate Low Level Waste Program for the NRC.
The overarching message of that letter was that
the NRC should maintain a national cognizance of the low
level waste business.
Do you in your branch have information or do the
type of analysis that would really respond to a question
that might come from Congress or somewhere that says
something about the urgency or lack of urgency of low level
waste disposal? Do we really have a good handle on where we
are, given that we have had so many failures, if you wish,
at the state compact level?
Two or three of the items that we had in our
letter was to maintain an evaluation capability, to maintain
some of the elements of a research perspective, and to be in
a position to fill gaps as we learn about them, as the
states get experience.
So my real question is should we be worrying about
this? Should this committee be pushing the Commission to be
more active or to look for alternatives or what have you? I
am basically an analyst so what I would say is needed is an
analysis of the inventory and what capacity exists and some
sort of a time-wise assessment of when we are getting in
trouble.
Obviously you can probably always have the
capacity if you are willing to pay the price, but I am
thinking in terms of a cost benefit being a part of that
equation as well.
MR. KENNEDY: I would think we would all agree
that that kind of study would be useful, that most people
agree if not everyone that even though we have disposal
capacity today the future is uncertain, that anything could
happen, and particularly with decommissioning of nuclear
power plants coming on in the next, who knows? -- I mean
some of it is ongoing now and certainly there will be more
as time goes on.
My sense is when the Commission considered this
back in 1996 and 1997 with respect to the strategic
assessment effort, they decided to not get into some of
these bigger issues about what might we do to better ensure
future disposal capacity. You know, we put that option
before them and they intentionally did not choose it, and my
personal sense is, and I think this is an Agency sense too,
is that that is something that would be difficult to do, to
study the future and do all the analysis and so forth.
I think where we are on it is this letter
supporting the National Academy proposed study that should
be going out any day now where we make a commitment to
provide some funds and that is the exact thing that they are
going to do. They are going to look at the waste stream
today, what it might be in the future, what the disposal
needs might be in the future, what the likelihood is of
having new disposal capacity to handle that waste, and we
feel and I feel that they are far better equipped to look at
that and study it and make recommendations than we are.
CHAIRMAN GARRICK: Do you have a schedule for
that?
MR. KENNEDY: No, we don't. There are -- they
haven't begun it yet. They are looking for funding. They
need to get a certain level of funding before they can begin
it.
CHAIRMAN GARRICK: The problem with the Academy,
and I am involved with several of those types of studies, is
that it is usually a three-year effort.
MR. KENNEDY: Yes.
CHAIRMAN GARRICK: Before you get results.
MR. KENNEDY: Right.
CHAIRMAN GARRICK: Okay --
DR. HORNBERGER: Sometimes they are more timely
than that.
CHAIRMAN GARRICK: Yes.
DR. HORNBERGER: I have a question, sort of a
two-part question.
You have mentioned research. I am glad you did
mention that.
The two parts of the question are, first, can you
tell me how you use the results that are produced by
research, how they feed into low level in the more general
sense, the more expansive sense that you have used it today.
Second of all, how do you have input that might
shape the priorities for the Office of Research?
MR. KENNEDY: I'm not the best person to answer
that. I think one of the -- the Office of Research and the
fellows up there who are working on projects that
potentially involve low-level waste in the future -- Tom
Nicholson, Ed O'Donnell, Jake Phillip and so forth, Linda
Kovach -- they tend to have much more interaction with folks
in the performance assessment section, Mark Thaggard, Bobby
Eid and so forth, than they do with me. I'm more a project
manager type.
I'll be honest, I think we could do more with the
information that they are generating in terms of being aware
of what it is and making sure that it's being utilized as
best as possible by the technical staff.
I think another place where we could do better at
that is making sure that that information gets out to the
states and other people who potentially have an interest in
it, because as you know, the states are the ones who are
doing the licensing of these facilities right now -- that
is, Barnwell, Washington and Utah -- and they need to be and
I think can be better plugged into what we're doing in
research. We right here could do a better job in making
that connection happen than we have in the past.
MR. ESSIG: I would offer that we'll try to speak
to that a little bit more tomorrow when John Graves is here,
see if we can --
MR. RANDALL: May I add something? Years ago when
there was a program dedicated to low-level waste research,
we had an outreach meeting with several state parties and
some that aren't even involved anymore, like North Carolina,
and I think we dropped the ball because we didn't follow up
on it. We had a staff member designated to keep the states
involved through a newsletter and she changed jobs and we
didn't get anybody else to pick up on it.
I think that Jim's idea is good, that we should --
that the Research Office should be doing something to
support the state programs, state low-level waste programs.
We're really not doing it.
MR. KENNEDY: Tim, did you have something you
wanted to add?
MR. HARRIS: Yes. One thing that we were doing
was attending -- DOE had a technical TCC, technical
coordinating committee, which was basically a technical
meeting of states developing things, and that was really an
interchange. Ed O'Donnell and I used to attend those, and
that would be an information transfer.
They are no longer conduct that, I don't believe,
so --
MR. KENNEDY: That has been eliminated.
MR. HARRIS: That activity has ceased. But that
was one way that we did transfer that information to the
states.
DR. HORNBERGER: Is there any comment on the
second part of my question as to the input you have, or did
you want to put that off until we talk to John Greeves?
MR. ESSIG: I think I would just as soon put it
off until we talk with John and we'll give you a better
answer than we're able to give you today.
DR. CAMPBELL: I think part of your question, I
think can answer since I've been a team leader up in
Research for the last six months for the Rad Transport and
Decommissioning Group.
First of all, about 75 percent of the work up
there is in response to user needs from NMSS. Virtually all
of that is decommissioning type of work, work on DND, work
on RESRAD. Some of the work that Tom has been doing is user
need work. There are a few other projects. But most of the
work done up there is in response to a need from Division of
Waste Management, and certainly Research, with or without me
up there, is going to be responsive to any user need
requests that come from the division from the performance
assessment and low level waste branch.
In terms of how that's used, you know, that's
usually in response to very specific needs that they have
for modeling decommissioning sites, dose modeling the
decommissioning sites and materials. Linda's work on the
slags was in response to -- we had no information on what
those slags were, what the mineralogy was, what their
potential for leeching was. That's where Linda's work fit
in.
The input to Research, there's a lot of
interaction at the branch chief level. Cherly Trottier
attends branch chief meetings John Greeves holds on a
regular basis. I've been to those meetings.
So there is an ongoing dialogue, if you will, and
interactions. In addition, the Ops plans, which have very
specific products and targets, are coordinated between the
two offices, if you will, and the Division of Waste
Management has on its Ops plan RES projects and specific
products out of those projects, and our Ops plan requires
that the people in the group make sure their products get
done in a reasonable timeframe, and if there's a missing of
a target date or something like that, then that's done.
So there is a lot of interaction going on and
coordination.
DR. HORNBERGER: Just one other comment.
We've heard pretty much what you've said, Andy, so
it's not as if we're operating in full ignorance of those
things. I'm just curious to ask the question of people
let's say in the trenches doing the work to see whether or
not, in fact, the transfer is as efficient as those in
Research and elsewhere would like it to be. That's just a
curiosity question. I was curious as to your views.
DR. WYMER: I want to follow up just a little bit
on one comment. It had to do with cost and cost benefit.
As you are more aware than I am, the amount of money at
stake for the industry is enormous, and the decision such as
rubblization and the clearance rule and in general the high
volumes of low-level waste going to expensive storage
facilities.
So my question to you is, can you go beyond the
statement of saying people have got to meet the 25 millirem
per year standard, can you go beyond that and say how cost
figures into what you do and the kind of recommendations and
decisions you make?
MR. KENNEDY: Well --
MR. ESSIG: I could attempt to answer that. Of
course, the licensee has to meet the 25, but then there's an
ALARA provision and that's where cost considerations come.
DR. WYMER: That's where you've got your
flexibility.
MR. ESSIG: That's where the tradeoffs are made.
DR. WYMER: So how do you handle that?
MR. ESSIG: That's unfortunately an area that we
aren't involved in. It's our Decommissioning Branch. We
could again offer to provide an answer tomorrow when John is
here.
DR. WYMER: It does become low-level waste.
MR. ESSIG: Yes.
DR. WYMER: Okay. Let's wait.
MR. ESSIG: It's really a cost consideration
that's being made by the licensee that's undergoing the
decommissioning, and that aspect of it is reviewed by our
Decommissioning Branch.
DR. WYMER: We'll hold that one until tomorrow,
too, then.
MR. ESSIG: Okay.
MR. KENNEDY: Can I add one thing on that? Or
actually, two things. I can't resist.
One of them is, on the 25 millirem for year in the
decommissioning rule, cost was looked at in the generic
environmental impact statement for that rulemaking. That
was one of the considerations.
The other is, of course you have a point. I mean,
to illustrate that, we just look at TENORM, for example.
Much TENORM isn't being managed or it's going to other kinds
of facilities, in large part because there's so much of it
and the cost is so enormous to dispose of it that folks are
allowing it to basically be disposed of with potentially
higher dose levels than 25 millirem per year.
DR. WYMER: That's in the nature of the kind of
thing I was getting at, yes.
MR. KENNEDY: Yes.
DR. WYMER: Okay.
MR. KENNEDY: And you probably know that under
CERCLA, cost is a consideration that's allowed to be
considered, and the risk range for CERCLA cleanups,
according to the recent NAS report, goes all the way down to
ten to the minus two lifetime cancer risk, which equates to
about 300 millirem per year, and that's because cost is a
factor that's allowed to be considered in CERCLA cleanups.
DR. WYMER: You and I should sometime have a more
thorough discussion of just that aspect.
MR. KENNEDY: Yes. Exactly.
MR. LEVENSON: Can you retrieve slide 12? That's
your bar graph. You can expect to be challenged when you
come here.
MR. KENNEDY: I don't think it will load up.
[Laughter.]
MR. LEVENSON: Well, okay --
MR. KENNEDY: No, I'm trying, actually. It's
about two megabytes. That's why --
MR. LEVENSON: Oh. Yes. Okay.
MR. KENNEDY: Here it is.
MR. LEVENSON: Let me ask you a question.
Congress chose to define a whole category or radioactive
materials as non-radioactive if they came from sources like
coal plants. Are they listed in your bar graph under like
exempt, or are they just not there at all?
MR. KENNEDY: They would be TENORM, actually.
MR. LEVENSON: So all of the coal-plant fly ash
and everything is in the TENORM category?
MR. KENNEDY: Yes. Yes. And actually, your
probably aware, it sounds like, that EPA just exempted
everything in coal ash from being regulated, not just the
radioactive materials, but also the hazardous constituents.
MR. LEVENSON: Yes. The mercury and everything.
MR. KENNEDY: Right. But that's part of the
TENORM. Usually, the coal ash is pretty low in
radioactivity, like ten picocuries per gram, I think, but in
some cases, it's as high as 3,000 picocuries per gram.
MR. LEVENSON: Yes. Fly ash can be quite high.
MR. KENNEDY: Yes.
MR. LEVENSON: The second thing which your chart
doesn't show is volume.
MR. KENNEDY: Yes.
MR. LEVENSON: Of the TENORM, is the coal residue
a major -- I don't want any numbers -- is it a major
percentage of the total TENORM?
MR. KENNEDY: You know, I just don't know. I
could find out and get back to you, because I do have
figures on it.
MR. LEVENSON: I'm curious. Okay. Thank you.
MR. KENNEDY: There's a lot of TENORM out there --
phosphate fertilizer residue, --
MR. LEVENSON: Tin mill smelting.
MR. KENNEDY: Tin mill smelting, yes. Radium pipe
scale, uranium mining overburden.
DR. WYMER: There's a lot of don't ask, don't tell
stuff.
MR. KENNEDY: Yes.
MR. LEVENSON: One that usually gets overlooked --
people are aware of thorium and uranium. People don't
necessarily know that tin is normally accompanied by uranium
and thorium, and so the slag --
MR. KENNEDY: Yes. Yes. We have a couple of NRC
licensees that were simply metal processors who got above
.05 percent source material and had to get an NRC license
because of the concentration of uranium and thorium.
MR. LEVENSON: Thank you.
DR. WYMER: Anybody else. The staff?
DR. CAMPBELL: I have a couple of questions.
In California, this advisory committee said they
were talking about dividing the waste stream by hazard, and
use half-life. Is that the only criteria they use? Because
a lot of the low-level waste with a long half-life doesn't
necessarily come out of power reactors. A lot of it comes
from industrial producers, label product compound products
and the biotech industry and so on. Carbon 14, uranium,
thorium and things like that show up in low-level waste as
Class A waste. Did they make some further distinctions or
was it just power plants versus everybody else?
MR. KENNEDY: I believe -- I haven't read the
report that carefully, but I believe it's mainly based on
half-life or what they call hazardous life. There are a few
exceptions, but in general, it seems to be geared toward
separating out the nuclear power plant waste from everything
else and doing that as effectively and as best they can.
DR. CAMPBELL: Okay. On the -- and I don't know
what page it was, there was a -- said the Commission
rejected a larger program of staff efforts to actively
promote new site development. We always steered away from
that concept. We were promoting regulatory oversight, but I
didn't think there was ever any effort to promote site
development on the NRC's --
MR. KENNEDY: That was one of the options we put
before the Commission as part of strategic assessment, was
to take that role of promoting new site development, and the
Commission explicitly rejected that, said don't do it.
DR. CAMPBELL: The only other question is, do the
assured isolation facilities provide for a decommissioning
fund? I mean, obviously the radionuclides are there whether
you call it storage, whether you call it assured isolation
or you call it low-level waste disposal, at the end of some
period of time, you've still got the same stuff there. Do
they then provide a fund for decommissioning at the end of
their storage lifetime?
MR. KENNEDY: Yes, they do, and the idea is --
assured isolation by definition has as one of its future
options the off-site disposal of low-level waste, and so
they would have to decommission the facility, they would
also have to provide funds to dispose of whatever residual
radioactive waste there might be just from the low-level
waste that was put in there.
Now, that's a big, important question because if
you do the numbers, if you assume that after ten years,
whatever low-level waste is left needs to be disposed of at
Barnwell at $500 a cubic foot, that facility is not going to
be economical just by inspection.
On the other hand, the assumptions I've seen them
make are that there's about $50,000 set aside at the
beginning and that waste would not be removed for at least
100 years, and you get so much growth in the $50,000 fund
that there is enough money at the end of 100 years to get
rid of the remaining waste and to decommission the facility
because it appreciates in value so much.
DR. CAMPBELL: Does it require a change in NRC
policy that preferred disposal over storage?
MR. KENNEDY: In effect, it does. That's one of
the big questions, right. Right.
DR. WYMER: Are there any other questions from
anybody?
[No response.]
DR. WYMER: If not, well, thank you very much.
Again, it was very a very informative presentation. We
appreciate it.
MR. KENNEDY: Thank you.
CHAIRMAN GARRICK: All right. Our plan is now to
-- we'll take our break, and then we're going to come back
and discuss reports. Most of that time is going to be taken
in the members working at their word processors and actually
writing reports and letters. We will reconvene for a few
minutes to consider some guidance on that, and also the
sufficiency letter that we were contemplating sending to the
EDO, but most of the time is going to be taken in our
respective offices developing drafts.
So unless there's comments, questions, we'll
adjourn.
[Whereupon, at 2:54 p.m., the recorded portion of
the meeting was concluded.]
Page Last Reviewed/Updated Monday, October 02, 2017