On-Site Storage of Low-Level Waste (Generic Letter 80-51)
GL80051
UNITED STATES
NUCLEAR REGULATORY COMMISSION
WASHINGTON, D. C. 20555
JUNE 9 1990
MEMORANDUM FOR: T. Novak, Assistant Director for Operating Reactors, DL
R. Tedesco, Assistant Director for Licensing, DL
G. Lainas, Assistant Director for Safety Assessment, DL
FROM: D. G. Eisenhut, Director, Division of Licensing
SUBJECT: LETTER TO LICENSEES CONCERNING ON-SITE STORAGE OF
LOW-LEVEL WASTE
The attached letters which has concurrence from the appropriate
organizational entities in the new NRR organization, should be sent to all
power reactors by each Operating Reactors Branch and the Licensing Branches
for Sequoyah, Salem 2, and North Anna 2 within the five working days.
D. G. Eisenhut, Director
Division of Licensing
Enclosure:
As stated
cc w/enclosure:
B. Snyder
H. Denton
V. Stello
E. Case
R. Minogue
D. Ross
T. Murphy
B. Grimes
V. Malafeew
R. Bangart
DOL BCs
R. Weller
S. Bland
G. Bidinger
J. Martin
P. Psmas
R. Browning
P. Wagner
D. Smith
B. Singer
R. Ryan
Contact: P. Grant, X28066
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UNITED STATES
NUCLEAR REGULATORY COMMISSION
WASHINGTON, D. C. 20555
LETTER TO: ALL POWER REACTOR LICENSEES
SUBJECT: TEMPORARY ON-SITE STORAGE OF LOW LEVEL RADIOACTIVE WASTE
Recent restrictions and reduced allocations at commercial burial sites have
caused numerous Licensees to actively consider increased on-site storage.
Several Licensees are currently storing waste on a temporary basis and
proposing to establish new facilities for longer term storage. If on-site
storage is necessary, the Licensee must assure that the design and operation
of the proposed facilities are adequate to maintain public health and
safety, minimal risk to operating personnel, and present a minimal
environmental impact.
Any decision to incorporate on-site storage requires a 10 CFR 50.59 safety
review of the areas of (1) Radioactive Material and Effluent Control, (2)
Radiation Dose Control for both on-site and off-site individuals, and (3)
Accident Prevention and Control. Enclosed is a draft NRC Licensing Position
for "Safety Considerations for Temporary On-Site Storage." This draft is
forwarded for your information and use in evaluating low-level waste (LLW)
storage criteria.
The NRC is presently evaluating both temporary and long term on-site storage
and its implications. Currently, 10 CFR 50.59 requires that you furnish a
report containing a brief description and summary of the safety evaluation
for each 10 CFR 50.59 change to your facility. The proposed model Appendix I
generic technical specifications (NUREG 0472 and 0473) contained guidance on
the desired detail necessary in that report for radwaste system. In the
interim, until Appendix I technical specifications are incorporated in your
operating license, you are requested to include reviews for on-site storage
additions in the monthly operating report following the period in which the
evaluation was completed. This report should detail the major
additions/changes and contain a summary of the safety evaluation. This
summary should include as a minimum your evaluation of each of the safety
review areas described herein, including consideration of the guidance
provided in the enclosed draft Licensing Position, man-rem impacts
anticipated radiological release assessments, final disposition of waste,
and final conclusion of the 50.59 evaluation.
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No formal response is required concerning this letter unless waste storage
facilities are modified. Comments however, are invited concerning the
enclosed draft Licensing position.
Branch Chief
Operating Reactors Branch #
Division of Licensing
Enclosure:
As stated
.
UNITED STATES
NUCLEAR REGULATORY COMMISSION
WASHINGTON, D. C. 20555
SAFETY CONSIDERATION FOR TEMPORARY ON-SITE STORAGE OF LOW LEVEL RADIOACTIVE
WASTE
I. Introduction
The objective of this technical position is to provide guidance to the
Licensees considering additional on-site low level radioactive waste
storage capabilities. The duration of the intended storage, the type
and form of waste, and the magnitude of radionuclides present will
dictate the safeguards and the level of complexity required to assure
public health and safety, and minimal risk to operating personnel. The
longer the intended storage period, the greater the degree of controls
that will be required for radiation protection and accident prevention.
For purposes of this document, the duration of temporary material
storage is to be up to four (4) years. The magnitude of the on-site
storage safety hazard is predicated on the type of waste being stored,
the amount of radionuclides present, and how readily they might be
transported into the environment. In general, it is preferable to start
radioactive material in solid form. Under some circumstances, however,
temporary storage in a liquid form may be desirable or required. The
specific design and operation of any storage facility will be
significantly influenced by the various waste forms, consequently, this
document addresses wet waste, solidified wet waste and dry low level
radioactive waste.
II. General Information
Prior to any implementation of additional on-site storage, substantial
safety reviews and environmental analysis need to be conducted to
assure adequate public health and safety, and minimal environmental
impact. The acceptance criteria and performance objectives of any
proposed storage facility, or area, will need to meet minimal
requirements in areas of design considerations operational
considerations, safety considerations and policy considerations. For
purposes of this branch position the major emphasis will be on safety
considerations in the storing, handling and eventual disposition of the
radioactive waste. Design and operational acceptability will be based
on minimal requirements which are defined in existing SRP's, Regulatory
Guides, and industry standards for proper management of radioactive
waste. Policy considerations for waste minimization and volume
reduction will also have to be integrated into the waste management
plan and the on-site storage alternative. Additional considerations for
ALARA, decontamination, and decommissioning of the temporary storage
facility also need to be integrated into the design and operation of
the proposed waste storage facility. Integration of waste
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volume reduction and eventual disposal should be performed as early as
possible because future requirements for waste forms may make stored
wastes unacceptable for final disposition.
III. Wet Radioactive Waste Storage
(a) Wet radioactive waste will be defined as nay liquid or
liquid/solid slurry. for storage considerations, we waste is
further defined as any waste which does not meet January 1, 1981
burial requirements for solidified waste (i.e, < 0.5% free water
by volume of container or < 1.0 gallon per container whichever is
less).
(b) The facility, supporting structure and tanks should be designed to
prevent uncontrolled releases of radioactive materials due to
spillage or accident conditions.
(c) The following design objectives and criteria are applicable for
wet radioactive waste facilities.
(1) Structures that house liquid radwaste storage tanks should be
designed to seismic criteria as defined in Standard Review
Plan (NUREG 75087) - Section 11.2). Foundations and walls
shall also be designed and fabricated to contain the liquid
inventory which might be released during a container/tank
failure.
(2) All tanks or containers should be designed to withstand the
corrosive nature of the wet waste stored. The duration of
storage under which the corrosive conditions exist shall also
be considered in the design.
(3) All storage structures should have curbs or elevated
thresholds with floor drains and sumps to safely collect wet
waste assuming the failure of all tanks or containers.
Provisions should be incorporated to route spilled wet waste
to the radwaste treatment systems.
(4) All tanks and containers shall have provisions to monitor
liquid levels and to alarm potential overflow conditions.
(5) The quantity of radioactive material allowed and the
shielding configurations will be dictated by the dose rate
criteria for both the site boundary and unrestricted areas
on-site. The 40 CFR 190 limits will restrict the annual dose
from direct radiation and effluent release to the Public
(individual) to less than 25 mrem per year to the whole body
from all sources of the Uranium fuel clycle; therefore,
off-site doses from on-site
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storage must be sufficiently low to account for other sources
(e.g., < 1 mrem/year). On-site dose limits associated with
temporary storage will controlled per 10 CFR Part 20
including the ALARA principle of 10 CFR 20.1.
(6) All potential release pathways of radionuclides (e.g.,
evolved gases breach of container, etc.) shall be controlled
and, monitored as per 10 CFR 50 Appendix A (General Design
Criteria 60 and 64). Surveillance programs should incorporate
adequate methods for monitoring breach of container integrity
or accidental releases.
(7) All temporarily stored wet waste will require additional
reprocessing prior to shipment off-site; therefore, provision
should be established to integrate the required treatment
with the waste processing and solidification systems. The
interface and associated systems should be designed and
tested in accordance with the codes and standards described
in NUREG-75/087 Section 11
IV. Solidified Radioactive Waste Storage
(a) Solidified radwaste for storage purposes shall be defined as that
waste which meets January 1, 1981 burial site solidified waste
criteria. Therefore, solidified radwaste will be identified as wet
waste (e.g., evaporation bottoms, resins, and sludge) which is
solidified and contains < 0.5% free water (by container volume) or
1.0 gallon of liquid (in the container), whichever is less. For
purposes of this document resins or filter sludges dewatered to
the above criteria will be defined under this waste
classification/criteria.
(b) Dewatered resins and filter media with radioactivity levels above
1 uCi/cc (>5 yr, half-life) which are disposed of a after July 19
1981, will be required to be solidified or stored in high
integrity, containers (e.g. reinforced concrete) Any storage
plans, should address container protection as well as reprocessing
requirements for eventual shipment & burial.
(c) Cask, tanks, and liners containing solidified radioactive waste
should be designed with good engineering judgment to preclude or
reduce the occurrence of uncontrolled releases of radioactive
materials due to handling, transporting or storage. Accident
mitigation and control for design basis events (e.g., fire,
flooding, tornadoes, etc.) must be evaluated and protected against
unless otherwise justified.
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(d) The following objectives and criteria are applicable for
solidified waste storage containers and facilities:
(1) All solidified radwaste should be located in restricted areas
where effective material control accountability can be
maintained. While structures are not required to meet seismic
criteria, protection should be afforded to insure the
radioactivity is contained safely by use good engineering
judgment, such as the use of curbs and drains to contain
spills of dewatered resins or sludges.
(2) Container material selection should conform to requirements
established in NUREG-75/087 (Section 11). If liquids exist
which are corrosive, proven provisions should be made to
protect the container (i.e., special liners or coatings) and,
or neutralize the excess liquids. If deemed appropriate and
necessary, highly non-corrosive materials (e.g., stainless
steel) should be use. Potential corrosion between the solid
waste forms and the container should also be considered. In
the case of dewatered resins, highly corrosive acids and
bases can be generated which will significantly reduce the
longevity of the container. The Process Control Program
(PCP), should implement steps to assure the above does not
occur, and provisions on container material selection and
precoating should implement steps to assure the above does
not occur, and provisions on container material selection and
precoating should be made to insure that container breach
does not occur during temporary storage periods.
(3) Potential release pathways of all radionuclides present in
the solidified waste form shall be monitored as per 10 CFR 50
Appendix A. Surveillance programs shall incorporate adequate
methods for detecting failure or container integrity and
measuring releases to the environment. For outside storage,
periodic direct radiation and surface contamination
monitoring shall be conducted to insure that levels are below
limits specified in 10 CFR 20.202, 20.205, and 49 CFR
173.397. All containers should be decontaminated to these
levels or below before storage.
(4) Provision should be made for additional reprocessing or
repackaging due to container failure and/or, as required for
final transportation and burial as per DOT and burial site
criteria. Contamination isolation and decontamination
capabilities should be developed. Whereby significant
handling personnel exposure can be anticipated, ALARA method
should be incorporated as per Regulatory Guides 3.8 and 8.10.
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(5) Procedures should be developed and implemented for early
detection, prevention and mitigation of accidents (e.g.,
fires). Storage areas and facility designs should incorporate
good engineering features and contingencies so as to handle
accidents and provide safeguard systems such as fire
detectors and suppression systems, (e.g., smoke detector and
sprinklers), personnel training and administrative procedures
to insure both control of radioactive materials and minimum
personnel exposures. Fire suppression devices may not be
necessary if combustible materials are minimal in the area.
(6) Provisions should be incorporated for collecting liquid
drainage including provisions for sampling all collected
liquids. Routine of the collected liquids should be to
radwaste systems of contamination is detected or to normal
discharge pathways if the water ingress was from external
sources and remained uncontaminated
(7) Low level solidified waste stored in outside areas should be
held securely by installed hold down systems. The hold down
system should secure all containers during severe
environmental conditions up to and including the design basis
event for this waste storage facility.
(8) Container integrity should be assured against corrosion from
the external environment; external weather protection should
be included where necessary and practical storage containers
should be raised off storage pads where water accumulation
can be expected to cause external corrosion and possible
degradation of container integrity.
(9) The quantity of radioactive material allowed and the
shielding configurations will be dictated by the dose rate
criteria for both the site boundary and unrestricted arts
on-site. The 40 CFR 190 limits will restrict the annual dose
from direct radiation and effluent releases to the Public
(individual) to less than 25 mrem per year to the whole body
from all sources of the Uranium fuel cycle; therefore,
off-site doses from on-site storage must be sufficiently low
to account for other sources (e.g., < 1 mrem/year). On-site
dose limits associated to temporary storage will be
controlled per 10 CFR Part 20 including the ALARA principle
of 10 CFR 20.1.
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(10) Total curie limits should be established based on the design
of the storage area and the safety features provided
(11) Inventory records of waste types, contents, dates of storage,
shipment, etc., should be maintained
V. Low Level Dry Waste Storage
(a) Low level dry waste is classified as contaminated material (e.g.,
paper, trash, air filters) which contains sources of radioactive
material that is dispersed in small concentrations throughout
large volumes of inert material which contain no free water.
Generally, this consists of dry material such as rags, clothing,
contaminated materials and small equipment (i.e., tools and
instruments) which cannot be easily decontaminated
(b) Licensees should implement controls to segregate and minimize the
generation of Low Level Dry Waste to lessen the impact on waste
storage. Integration of Volume Reduction (VR) hardware should be
considered to minimize the need for additional waste storage
facilities.
(c) The following design objectives are criteria are applicable for
low level dry waste storage containers and facilities.
(1) All dry or compacted radwaste should be located in restricted
areas where effective material control and accountability can
be maintained. While structures are not required to meet
seismic criteria, protection should be afforded to insure the
radioactivity is contained safely by use of good engineering
judgment
(2) The waste container should be designed to insure radioactive
material containment during normal and abnormal occurrences.
The waste container materials should not support combustion.
The packaged material should not cause fires through,
spontaneous chemical reactions, retained heat, etc.
(3) Potential release pathways of all radionuclides present in
the solidified waste form shall be monitored as per 10 CFR 50
Appendix A. Surveillance programs shall incorporate adequate
methods for detecting failure of container integrity and
measuring releases to the environment. For outside storage
periodic direct radiation and surface contamination
monitoring shall be conducted to insure that levels are below
limits specific in 10 CFR 20.2029 20.2051 and 49 CFR 173.397.
All containers should be decontaminated to these levels ar
below before storage
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(4) containers should generally comply with the criteria of 10
CFR 71 and 4 CFR 170 to minimize the need for repackaging for
shipment.
(5) Increased container handling and personnel exposure can be
anticipated, consequently, all ALARA methodology should be
incorporated per Regulatory Guide 8.8 and 8.10.
(6) The quantity of radioactive material allowed and the
shielding configurations will be dictated by the dose rate
criteria for both the site boundary and unrestricted areas
on-site. The 40.CFR 190 limits will restrict the annual dose
from direct radiation and effluent release to the Public
(individual) to less than 25 mrem per year to the whole body
from all sources of the Uranium fuel cycle; therefore,
off-site doses from on=site storage must be sufficiently low
to account for other sources (e.g., <1 mrem/year). On-site
dose limits associated to temporary storage will be
controlled per 10 CFR Part 20 including the ALARA principle
of 10 CFR 20.1.
(7) Total curie limits should be established based on the design
of the storage area and the safety features provided.
(8) Provisions should be incorporated for collecting liquid
drainage including provisions for sampling all collected
liquids. Routing of the collected liquids should be to
radwaste systems if contamination is detected or to normal
discharge pathways if the water ingress was from external
sources (e.g, rain water or moisture) and remained
uncontaminated.
(9) Low-level waste stored in outside areas should be held
securely by installed hold down systems. The hold down system
should secure all containers during severe environmental
conditions up to and including the design basis event for
this waste storage facility.
(10) Container corrosion should be assured against from both the
internal and external environment. Special internal liners
and external weather protection should be included where
necessary and practical. Storage containers should be raised
off storage pads where water accumulation can cause external
corrosion and resultant loss of container integrity.
(11) Inventory records of waste types, contents, dates of storage,
shipment, etc., should be maintained.
Page Last Reviewed/Updated Tuesday, March 09, 2021