ML20211L035

Safety Evaluation Accepting Util 840625 & 850531 Proposed Conformance to Reg Guide 1.97,per Generic Ltr 82-33

ML20211L035
Person / Time
Site:	Arkansas Nuclear
Issue date:	12/03/1986
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20211L029	List: ML20211L025 ML20211L035 ML20211L047
References
RTR-REGGD-01.097, RTR-REGGD-1.097 GL-82-33, NUDOCS 8612150279
Download: ML20211L035 (2)

Text

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,4 UNITED STATES N[- i NUCLEAR REGULA10RY COMMISSION h j WASHINGTON, D. C. 20555 s 6

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR' REGULATION l ' CONCERNING 3

i THE CONFORMANCE TO REGULATORY GUIDE 1.97 FOR .

i ARKANSAS POWER AND LIGHT COMPANY ARKANSAS NUCLEAR ONE, UNIT 1 DOCKET NO. 50-313

1.0 INTRODUCTION

AND

SUMMARY

l Arkansas Power and Light Company was requested by Generic Letter 82-33 to . ~

, provide a report to the NRC describing how the post-accident monitoring instrumentation meets the guidelines of Regulatory Guide 1.97 as applied to emergency response facilities. The licensee's response to Regulatory Guide 1.97 was provided by letters , dated June 25, 1984, and May 31, 1985.

t A detailed review and technical evaluation.of the licensee's submittals e were performed by EG&G Idaho, Inc., under contract to the NRC, with general supervision by the NRC staff. This work was reported by EG&G in the Tech-nical Evaluation Report (TER), "Conformance to Regulatory Guide 1.97, Arkansas Nuclear One, Unit No. 1" dated August 1985 (enclosed). We have reviewed this report and concur with the conclusion that the licensee 4 either conforms to, or is justified in deviating from the guidance of Regulatory Guide 1.97 for each post-accident monitoring variable except for the containment sump water temperature.

f 2.0 EVALUATION CRITERIA -

Subsequent to the issuance of the generic letter, NRC held regional meetings in February and March 1983 to answer the licensee's questions and concerns

.; regarding NRC policy on Regulatory Guide 1.97. At these meetings, it was established that NRC review would only address exceptions taken to the t

guidance of Regulatory Guide 1.97. Further, where the licensee explicitly 4 stated that instrument systems confonn to the provisions of the regulatory ad guide, no staff review would be necessary. Therefore, the review performed and reported by EG&G only addresses exceptions to the guidance of the

Regulatory Guide. This safety evaluation addresses the licensee's submit-tais based on the review policy described in the NRC regional meetings and i the conclusions of the review as reported by EG&G.

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3.0_ EVALUATION _

We have reviewed the' evaluation performed by EG&G contained in the enclosed

. TER and concur with its bases and findings. The licensee either conforms

, to, or has acceptably justified deviations from, the guidance of Regula-i tory Guide 1.97 for each post-accident monitoring variable ex::ept for the containment sump water temperature.

Regulatory Guide 1.97 recomends a category 2 instrumentation to monitor the containment sump water temperature. The licensee has not provided i instrumentation for this variable. The licensee stated that the FSAR ac-cident analysis assumed a saturated condition for sump water during the recirculation phase, and thus, maintaining adequate Net Positive Suction Head (NPSH) for containment spray and safety injection pumps at all feas-ible temperatures of the sump water. The licensee also stated that the sump water temperature is not recorded or indicated because it is not required to mitigate the consequences of a design basis accident. Contrary to this, Regulatory Guide 1.97 lists " containment sump water temperature" as a type D variable and identifies containment sump as "the plant safety

- system that should be operative to help mitigate the consequences of an s accident." Also, the staff believes that an adequate NPSH is not the only reason for requiring the instrumentation. The temperature of the sump

. water is useful to the operator in determining the amount of, containment heat removed during recirculation, and thus, ascertaining the proper opera-tion of the containment cooling system. Therefore, we find the licensee's proposed exception to the guideline of the Regulatory Guide 1.97 unacceptable.

The licensee should provide a means of determining the containcent sump water temperature.

4.0 CONCLUSION

'l Based on the staff's review of the enclosed Technical Evaluation Report and the licensee's submittals, we find that the Arkansas Nuclear One, Unit No. I design is acceptable with respect to conformance to Regulatory 4 Guide 1.97, Revision 3, with the exception of the variable containment ,

sump water temperature.

It is the staff's position that containment sump temperature is useful to lj an operator in determining that the containment cooling system is func-tioning properly during the post-accident mode of operation. It is also

the staff's position that the licensee should install environmentally

., qualified containment sump temperature instrumentation, or identify i r.' suitable qualified alternate instrumentation to measure the heat removed j from the containment sump during the recirculation phase.

1 Y By letter dated November 21, 1986, the licensee indicated that during the f, current refueling outage, modifications planned for the completion of 1 Regulatory Guide 1.97 comitments would be completed. We will raquest

, the licensee to commit to a schedule for providing environmentally

] cualified containment sump temperature instrumentation.

Dated: December 3,1986 Principal contributors: I. Ahmed, G. S. Vissing n

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