ML18102A564
| ML18102A564 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 11/15/1996 |
| From: | Eric Simpson Public Service Enterprise Group |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| LR-N96377, NUDOCS 9611260083 | |
| Download: ML18102A564 (4) | |
Text
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- ..~ e Public Service Electric and Gas Company E. C. Simpson Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-1700 Senior Vice President - Nuclear Engineering U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 RESOLUTION OF SPENT FUEL STORAGE AND SAFETY ISSUES SALEM GENERATING STATION UNIT NOS. 1 AND 2 DOCKET NOS. 50-272 AND 50-311 Gentlemen; Public Service Electric and Gas (PSE&G) has reviewed the information provided in your letter dated September 27, 1996 on the above subject.
Comments on the information contained in the NRC report to the Chairman and Commissioners of the NRC are provided as Attachment 1 to this letter.
PSE&G has been proactive in keeping the NRC informed of its ongoing review of issues relating to the Salem SFPs and will continue to do so until all issues are satisfactorily resolved.
It should be noted that PSE&G has conducted extensive design reviews of the Spent Fuel Storage Pool and its Cooling System during the current refueling outages.
The results of these reviews to date support a conclusion that these structures and systems are in conformance with the applicable design and licensing criteria.
It is PSE&G's belief that any additional safety enhancements can be achieved through the use of improved administrative controls and operating procedures without the need for physical modifications to the present design.
If you have any questions regarding the information included in Attachment 1, please feel free to contact us.
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Document Control Desk LR-N96377 Attachment 2
C Mr. H. Miller, Administrator - Region I U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 NOV 151996 Mr. L. N. Olshan, Licensing Project Manager -
Salem U. S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 14E21 Rockville, MD 20852 Mr. C. Marschall (X24)
USNRC Senior Resident Inspector Mr. K. Tosch, Manager, IV Bureau 6f Nuclear Engineering 33 Arctic Parkway CN 415 Trenton, NJ 08625 95-4933
--ATTACHMENT 1 TO LR-N96377~
NRC REPORT ON SPENT FUEL POOL SAFETY ISSUES PSE&G COMMENTS Absence of Isolation Capability for Leakage Collection System NOV 1 5 1996 The NRC Report is correct in that no isolation valves are provided on the drain lines from the leakage collection system for the Salem Spent Fuel Pools (SFP).
This design has existed since original construction and was predicated on the fact that the Salem SFPs are Seismic Class l structures.
The NRC Report suggests that potential safety benefits could be derived by backfitting this capability into the Salem design, but does not identify any new failure modes which could challenge SFP liner integrity.
In PSE&G's opinion this backfit could be a costly process with little actual added safety benefit.
The question becomes one of whether a potential threat to the integrity of the Salem SFP liner exists within the current design or operating practices.
The following discussion addresses issues of design and operation which have previously been addressed within the Salem Licensing Basis.
The affects of load handling accidents have been previously evaluated and are summarized in Section 9.1.4 of the Salem Updated Final Safety Analysis Report (UFSAR).
Additionally, Technical Specification 3.9.7 requires positive controls be in place to limit the maximum load which can be handled over the storage pool by the installed load handling systems.
These controls assure that no new threats to liner integrity can be introduced without adequate safety evaluation.
The current licensing basis for the Salem Spent Fuel Storage Systems is based on analyses that were performed in support of the installation of maximum density spent fuel storage racks at Salem.
Those analyses evaluated rack-to-liner interactions during seismic events to determine if the potential existed for liner failure.
No liner failures were predicted as a result of those evaluations.
More recent evaluations of the SFP liners have confirmed that structural integrity of the liners will be maintained under conditions associated with boiling.
Given the above, PSE&G is unable to define a failure scenario which would support installation of isolation valves.
Limited SFP Decay Heat Removal Capability Salem Unit 1 and 2 SFP cooling systems were listed under this category in the NRC Report.
The Salem SFPs do not have a dedicated backup cooling system as noted in the NRC 1 of 2
--ATTACHMENT 1 TO LR-N96377~
NRC REPORT ON SPENT FUEL POOL SAFETY ISSUES PSE &G COMMENTS NOV 1 5 1996 report.
An analysis of the Salem SFP cooling system capability was submitted for NRC review in support of the installation of the maximum density storage racks at Salem Units 1 and 2.
That analysis concludes that an equilibrium temperature of 180°F would be achieved under the worst case assumed ultimate heat sink temperature with core offload occurring instantaneously at 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br /> after shutdown and at the end of the Units operating life.
This analysis contains substantial conservatism in that refueling operations are typically not scheduled during the summer months and core offload occurs over a period of several days.
Additionally, the current operating licenses for Salem Unit 1 and 2 do not expire until the years 2016 and 2020, respectively.
By letter dated August 2, 1996 (LR-N96218), PSE&G provided its commitments regarding the development of enhanced administrative controls for SFP Decay Heat Load Management.
These controls will address evaluation of expected heat load prior to core offload with the intent of verifying that equilibrium temperatures in the SFP's will be maintained at acceptable levels.
PSE&G recognizes that additional cooling capacity may be desirable at some point in the future.
The cost of this additional capacity would be balanced against other options such as longer delays in commencing core offload during refueling outages.
PSE&G is aware of no regulatory requirement or accident scenario which would dictate removal of the core from the reactor vessel on an expedited basis.
Under postulated accident scenarios, use of the Residual Heat Removal System for core decay heat removal represents the safest possible configuration.
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