ML20136F654
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NUCLEAR. REGULATORY COMMISSION C
E W ASHINGTON, D. C. 20555 -
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.JAN 17 -1985
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}o Wf pA 9&.5 NEMORANDUMFOR:
Vince S. Noonan, Project Director for Comanche Peak, Division of Licensing FROM:
Olan D. Parr, Chief, Auxiliary Systems Branch, Division of Systems Integration
SUBJECT:
STAFF POSITION ON SPENT FUEL POOL LINER In response to your memorand'um dated December 7,1984, the Auxiliary Systems Branch (ASB) has prepared responses to the six questions contained in the enclosure. These answers address the staff position on the need to classify 8
the liner plate Category I and to have the plate included in the quality assurance program.
It is the ASB position that the liner need not be
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Category I if it is designed such that its failure following an SSE will not
-jeopardize the stored fuel. The detailed answers are contained in-the i
enclosure.
This effort was coordinated with the Structural and Geotechnical Engineering Branch and the Quality Assurance Branch, I&E. The ASB reviewer and coordinator was Joseph Holonich who can be reached on extension 28299.
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a O an D. Parr, Chief Auxiliary Systems Branch Division of Systems Integration
Enclosure:
As Stated cc w/ enclosure:
R. Bernero L. Rubenstein T. Novak S. Burwell A. Vietti F. Rinaldi J. Spraul G. Lear T. Ankrum
Contact:
J. Hononich, X28299 k'
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ENCLOSURE
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1.
What are the NRC's acceptance criteria for the desfgn, cons,truction and N
inspection of the spent fuel pool liner?
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Comment: We are aware of the SRP (NUREG-0800) acceptance of a nonseismic
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Category I pool liner with qualifications. However, we do not find this
.i in the earlier SRP. What is the background and basis for the change in j
acceptance-criteria in NUREG-75/087 'and NUREG-0800; i.e., the acceptance of a' non-seismic Category I pool liner. Was the change in the acceptance criteria reviewed and approved by the Reactor Regulation Review Committee l
(RRRC)?: What request or event triggered the change?
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Pesponse j
.i The acceptance criteria used to review the design of the spent fuel pool lineraregiveninStandardReviewPlan(SRP)Section9.1.2. As stated on SRP. page 9.1.2-5, the applicant must classify the liner as seismic Category.I or demonstrate that the failure of the plate as a result of l
a safe shutdown earthquake (SSE) will not cause:
- 1) 'he loss of ability f
to cool'the spent fuel stored in the pool; 2) ~the release of radioactivity; and 3) damage to safety-related' equipment.
l Originally the SRP (NUREG-75/087) did not contain acceptance criteria for j
the seismic design of the fuel pool liner. At that time, the staff assumed that when an applicant stated that the fuel pool would be designed to seismic Category I, the liner plate was included. However,
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in 1978 Region III raised.a concern over the fact that Midland did not l
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consider the liner plate safety related. After a review of the stresses induced during an SSE and the stresses which the liner could tolerate, I
the' staff concluded that the liner need not be Category I.
i Because of, the above, the staff-revised SRP 9.1.2 in early 1979. This revision incorporated the acceptanfe criteria presently found in the SRP.
The revision did not undergo a Reactor Regulation Review Committee l
evaluation since the changes were a clarification of Regulatory Guides (RG) 1.13 and 1.29. Approval of the new version was received from the Director, e
Office of Nuclear Reactor Regulation on February 2, 1979.
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2.' Describe the relationship between the guidelines in Regulatory Guides 1.13 -
and 1.29 and the staff's acceptance criteria as given in SRP NUREG-0800.
Response
RGs 1.13 and 1.29 are in'orporated into the Acceptance Criteria of SRP c
Section-9.1.2. All of the documents are in agreement with respect to the classification of the liner plate.
I Position C.6 of RG 1.13 requires that those components needed to maintain water quality and quantity be designed such that any maloperation or failure will not cause fuel uncovery.
However, these components need not meet i
Category I requirements.
l Regulatory Guide 1.29 requires that systems or portion of system required for cooling the spent fuel pool remain functional following an SSE and be classified Category I.
The responses to Questions 4 and 5 contain the basis for the acceptance of the Comanche Peak design. As discussed in these responses, the spent fuel pool liner plate is not an essential element in maintaining coolant inventory following an SSE. Therefore, it need not meet the recommendation of Position C.1.d of the Guide.
The criteria given in the SRP are discussed in Question 1.
These criteria allow for either a Category I plate or a design to ensure that failure of the liner will not jeopardize the spent fuel.
Since none of the above documents require the liner to be Category I, all of the documents are consistent in their treatment of the plate.
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- Since the fuel pool liner may fail following an SSE, it cannot be assured -
that it will remain functional, e.g., leak tight.
In addition, the plate
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is surrounded by a Category I concrete pool which is "necessary to assure ry uired safety functions" for the SSE.
In actuality it is the pool itself thich is safety-related and not the liner. Thus, the liner need not be placed on a Q-list or be part of those items subject to the QA requirements of 10 CFR 50, Appendix B.
4.
Describe the manrier in which the Comanche Peak spent fuel pool liner meets the requirements of GDC 2 relative to protection against natural phenomena (earthquakes), and GDC 16 relative to preventing a significant reduction in fuel storage coolant inventory under accident conditions.
Response
GDC 2 requires that structures, systems, and components important to safety t
be designed to withstand the effects of natural phenumena, including earth-quakes, without the loss of their safety functicn.
As noted in Question 3, the purpose of the liner is to maintain a leak tight barrier which ensures that water remains in the pool.
Because the plate is not a Category I component, it may fail following an SSE.
However, the liner is designed such that its failure will not result in any significant loss of water from the pool or damage to the stored fuel which could cause the release of radioactivity.
Hence, the pool will not. lose its safety function since the water will' remain in the pool following a liner failure. Therefore, the liner meets GDC 2.
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s N - The Comanche Peak' design also meets the requirements of GDC 61, Item (5).
which states that the fuel storage systems (note the word " systems" not individual components) should be designed to prevent a significant reduc-tion in coolant inventory. The manner in which the design meets the requirement is:
1.
'the. pool itself 1.s a Category I structures that will retains its integrity following an SSE and a significant loss of water will not occur; 2.
the system includes a leak detection and chase system for the liner along with low level alarms; and 3.
the applicant states in FSAR Section 9.1.2.2 that the system is designed in accordance with RG 1.13.
Therefore, it has a seismic Category I makeup system which can' provide water from several sources.
The makeup system is the reactor makeup water system but sater from the refueling water storage tank can also be provided.
5.
Describe the Comanche Peak FSAR comitments relative to seismic and quality standards for the spent fuel pool liner.
In so far as possible, describe the criteria or basis upon which the spent fuel pool was found acceptable in the SER, particularly as it relater to the quality of the spent fuel pool liner.
Response
There is no commitment in the Comanche Peak FSAR which pertains to just the liner. The applicant has,comitted or stated that the spent fuel pool system was designed in accordance with RG 1.13.
Position C.6 of the guide states that if a system is n,eeded to maintain water quantity it should be designed such that any maloperation or failure will not cause fuel uncovery.
It further states that these systems need not be Category I.
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.' Staff acceptance of the Comanche Peak spent fuel pool design was based on several factors. These were:
1.
those. components needed to maintain fuel integrity are Category I; 2.
a leak chesc system to detect and locate leaks in the liner plate is included in the design; 3.
there are redundant systens of makeup water; 4
the design of supply and return lines are such that the water level will not drop one foot below normal;' and 5.
the installation of alarms to inform operators of a high or low level in the pool.
I As noted earlier, the liner is not a safety-related piece of equipment and need not be qualified. As can be seen from the above discussion, the acceptance of the fuel pool system is based on the entire system being able to perform its function. The quality of the liner will not alter i; hat finding.
6.
Please identify all documentation used in the review of Comanche Peak spent fuel pool liner; e.g., old FSAR pages, SER references, memorandums and reviewer notes.
In our review we used the FSAR (current pages), SRP and applicable RGs.
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