ML20062A091
| ML20062A091 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 10/05/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20062A090 | List: |
| References | |
| NUDOCS 9010190074 | |
| Download: ML20062A091 (2) | |
Text
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SAFETY EVALUATION BY TFE OFFICE OF NUCLEAR REACTOR REGULATION P, ELATED TO AMENDMENT NO.144 TO FACILITY OPERATING LICENSE NO. DPR-32 AND AMENDMENT NO.141 TO FACILITY OPERATING LICENSE NO. OPR-37 VIRGINIA ELECTRIC AhD POWER COMPANY SURRY POWER STATION, UNIT NOS. 1 AND 2 DOCKET NOS. 50-280 AND 50-281
1.0 INTRODUCTION
By letter dated June 25, 1990, the Virginia Electric and Power Company, the licensee for operation of Surry Power Station, Units 1 and 2, requested amendments to the Technical Specifications of Surry Units 1 and 2 to extend operation to Cycle 11 with the pressurizer safety valve (PSV) setpoint of 2485 psig and a tolerance of +5/-1 percent, which is currently allowed for Cycle 10 operation. Specifically, the request would modify the footnote of TS 3.1-4 to read:
"For the remainder of Cycle 10 and Cycle 11 operation for both units, the valve lift settings shall be maintained at 2485 psig (+5,-1 percent.)"
2.0 EVALUATION The Surry Units 1 and 2 PSVs are installed downstream of loop seals which are filled with 300'F water. The lift setpoints of the PSVs were set with steam conditions.
In October 1989 the licensee was informed by Westinghouse of a findingthattheactualPSVIiftsetpointcouldshiftby4to8percentunder a condition different from that used to establish the setpoint. The licensee's test results of the Unit 2 PSVs in October 1989 also showed an increase of lift setpoint of 3.5 to 5 percent from the as-found setpoint established with steam due to the loop seals.
By a letter of November 10, 1989, the licensee requested amendments to the Surry Units 1 and 2 TS 3.1.A 3.c to allow Cycle 10 operation of Units 1 and 2 with the PSV lift setting of 2485 psig and a tolerance increased from +1/-1 percent to +5/-1 percent. This TS change was supported by a safety
' analysis assuming a 5.4 percent increase in the PSV lift pressure. The results indicated that the reactor coolant system pressure in the limiting overpressuri-zation events would remain below the acceptance criterion of 2750 psia (110 per-cent of design pressure),
in addition, the licensee proposed compensatory measures to maintain operability of at least one power-operated relief valve (PORV) and the anticipatory reactor trip on turbine trip circuit.
Based on the licensee's analysis and proposed compensatory actions, NRC approved the TS change which allowed operation with an increased PSV setpoint tolerance of
+5/-1 percent for the remainder of Cycle 10 (Amendment Nos.135 and 135 dated November 16,1989). The staff also indicated that it was evaluating the PSV setpoint problem on a generic basis, and that the outcome of the staff generic l
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L evaluation for a long-term solution would also apply to Surry Units 1 and 2.
L Since a generic resolution to this issue has not yet been completed by industry
.and the NRC, and since the licensee has decided to continue to take the same compensatory measures to provide added assurance that the primary pressure will remain below 2750 psia, we conclude that the continued operation with increased PSV setpoint tolerance of +5/-1 percent for the remainder of Cycle 10 and Cycle 11 operation is acceptable.
3.0
SUMMARY
The staff has reviewed the licensee's request for the Surry Units 1 end 2 TS change to extend the allowable operation from Cycle 10 to Cycle 11 wi*h the current PSV setpoint of 2485 psig +5/-1 percent, and finds it acceptab e.
4.0 ENVIRONMENTAL CONSIDERATION
These amendments involve a change in the installation or use of facility components located within the restricted areas as defined in 10 CFR Part 20.
The staff has determined that these amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite and that there is no significant increase in individual or cumulative occupational radiation exposure.
The Commission has previously issued a proposed finding that these amendments involve no significant hazards consideration and there has been no public coment on such finding. Accordingly, these amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b)noenvironmentalimpactstatementorenvironmentalassessmentneedbe prepared in connection with the issuance of these amendments.
ll
5.0 CONCLUSION
l We have concluded, based on the considerations discussed above, that:
(1) there 1.s reasonable assurance that the health and safety of the will not be endangered by operation in the proposed manner, and (2) public such L
activities will be conducted in compliance with the Comission's regulations i
and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
l Dated: October 5, 1990 Principal Contributor:
Y. Hsil 1
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