Follow-up Actions Resulting From The NRC Staff Reviews Regarding The TMI-2 Accident (Generic Letter 79-51)
GL79051
UNITED STATES
NUCLEAR REGULATORY COMMISSION
WASHINGTON. D. C. 20555
October 10,1979
(TO ALL LICENSEES OF PLANTS UNDER CONSTRUCTION)
Gentlemen:
SUBJECT: FOLLOWUP ACTIONS RESULTING FROM THE NRC STAFF REVIEWS REGARDING
THE THREE MILE ISLAND UNIT 2 ACCIDENT
Over the past several months following the Three Mile Island accident, the
NRC staff has been conducting an intensive review of the design and
operational aspects of nuclear power plants and the emergency procedures for
coping with potential accidents. The purpose of these efforts was to
identify measures that should be taken in the short-term to reduce the
likelihood of such accidents and to improve the emergency preparedness in
responding to such events. To carry out this review, efforts within NRR were
established in four areas: (a) licensee emergency preparedness, (b) operator
licensing, (c) bulletins and orders followup (primarily in the areas of
auxiliary feedwater systems reliability; loss of feedwater and small break
loss-of-coolant accident analysis; emergency operating guidelines and
procedures) and (d) Short-Term Lessons Learned.
The purpose of this letter is to provide for planning and guidance purposes
the NRR staff position on the status and applicability of the results of
these efforts to plants under construction. The Commission may add to or
modify these staff positions after reviewing them. Additional staff require-
ments may be developed as NRR's Lessons Learned Task Force completes its
long-term recommendations. Several other investigations, including the
Presidential Commission and NRC's Special Inquiry Group, can be expected to
lead to additional requirements.
Lessons Learned Task Force Report
The principal element of the staff activities listed above is contained
in the report titled, "TMI-2 Lessons Learned Task Force Status Report
and Short-Term Recommendations" (NUREG-0573), a copy of which was
previously sent to you. The Task Force report contains a set of
recommendations to be implemented in two stages over the next 16 months
on operating plants and pending operating license applications. The
Task Force recommended 20 licensing requirements and three rulemaking
matters in 12 broad areas.
The Advisory Committee on Reactor Safeguards has completed its review
of the Task Force report. The several public meetings of the ACRS
subcommittee on TMI-2 and the public meeting of the full committee on
August 9 provided
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October 10, 1979
an opportunity for the presentation and discussion of public comments
on the report. The ACRS letter of August 13, 1979 to Chairman Hendrie
states that the Committee agrees with the intent and substance of all
the Task Force recommendations, except four upon which the Committee
offered constructive comments to achieve the same objectives
articulated by the Task Force. A copy of the ACRS letter is provided as
Enclosure 1.
After evaluating all comments received, we have concluded that the
following actions are appropriate for plants under construction.
(a) The staff will be proposing a new rule on a Limiting Condition of
Operation to require plant shutdown for certain human or
procedural errors, particularly those which are repetitive in
nature. As such, no action is required on your part at this time.
(b) At the present time we are delaying efforts regarding proposed
rulemaking on both the inerting requirements for Mark I and II BWR
containments, and the requirement regarding hydrogen recombiner
capability; accordingly, no action is required on your part at
this time.
(c) The ACRS comments on the shift technical advisor have resulted in
our reassessment of the possible means of achieving the two
functions which the Task Force intended to provide by this
requirement. The two functions are accident assessment and
operating experience assessment by people onsite with engineering
competence and certain other characteristics. We have concluded
that the shift technical advisor concept is the preferable
short-term method of supplying these functions. We have also
concluded that some flexibility in implementation may yield the
desired results if there is management innovation by individual
licensees. We have prepared a statement of functional
characteristics for the shift technical advisor that will be used
by the staff in the review of any alternatives proposed by
applicants for operating licenses. A copy is provided as Enclosure
2. The Commission is considering whether or not additional
qualifications should be required for this individual.
(d) Three additional instrumentation requirements for short-term
action were developed during the ACRS review of NUREG-0578. These
items relate to containment pressure, containment water level and
containment hydrogen monitors designed to follow the course of an
accident. Descriptions of these items are provided in Enclosure
3.
(e) An additional requirement following issuance of NUREG-0578, which
concerned a remotely operable high point vent for gas from the
reactor coolant system, was developed. A description of this
requirement is provided in Enclosure 4.
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(f) The Lessons Learned- Task Force has compiled a set of errata and
clarifying comments for NUREG-0578. It is provided as Enclosure 5.
Following our review of the proposed Task Force recommendations, ACRS review
and comments received, we have concluded that all licensees of plants under
construction should implement the actions contained in NUREG-0578, as
modified and/or supplemented by items (a) through (f) above. Therefore, we
suggest that you also consider these requirements in developing your final
plant design and procedures, and include a description of your actions in
this regard in your application for an operating license. An implementation
schedule for operating plants and pending operating license applications is
provided in Enclosure 6 for information. The implementation dates for the
Commission rulemaking actions and those deferred actions, identified above,
will be established later.
Other Review Areas
Enclosure 7 outlines the requirements developed to date resulting from the
staff's Emergency Preparedness Studies. Enclosure 8, which applies to
operating plants and pending operating license applications, provides the
implementation schedules for the emergency preparedness recommendations
which, you will note, includes three of the Lessons Learned topics. The
staff position is that you should comply with each of the recommendations of
Enclosure 7. Therefore, we suggest that you also consider these requirements
in developing your final plant design and procedures, and include a
description of your actions in this regard in your application for an
operating license. Further, the Commission has initiated a rulemaking
procedure, now scheduled for completion in January 1980 in the area of
Emergency Planning and Preparedness. Additional requirements are to be
expected when rulemaking is completed and some modifications to the
emergency preparedness requirements contained in this letter may be
necessary.
Enclosure 9 outlines the staff recommendations concerning improvements in
the area of operator training which are provided for your information. These
recommendations are undergoing Commission review and are expected to be
adopted as requirements in the near future. Further Commission review in the
areas of operator training and qualification can be expected to result in
substantial additional requirements.
A number of other related actions on your facility may have been initiated
under the direction of the NRR Bulletins and Orders Task Group. Each
licensee will receive additional guidance from this group, particularly
related to auxiliary feedwater systems and small break LOCAs, in the near
future. Your activities should continue in these areas, as all the mentioned
activities are meant to complement one another.
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The measures discussed above represent a set of requirements that the staff
has concluded should be implemented at this time. As stated earlier, other
requirements may follow in the future. The procedures for Commission review
of TMI-related issues prior to the issuance of operating licenses have not
yet been established. The Commission is considering several alternatives,
and you will be notified when a decision is made in this matter.
If you have any questions regarding these actions, please contact the NRC
Project Manager for your facility.
Sincerely,
Domenic B. Vassallo, Acting Director
Division of Project Management
Enclosures:
1. ACRS Ltr: Carbon to Hendrie dtd 8/13/79
2. Alternatives to Shift Technical Advisor
3. Instrumentation to Monitor Containment Conditions
4. Installation of Remotely Operated High Point Vents
in the Reactor Coolant System
5. NUREG-0578 Errata
6. Implementation Schedule
7. Requirements for Improving Emergency Preparedness
8. Emergency Preparedness Improvements - Implementation Schedule
9. Improvements in Operator Training
Page Last Reviewed/Updated Tuesday, March 09, 2021