ML20045H795
| ML20045H795 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 07/01/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20045H790 | List: |
| References | |
| NUDOCS 9307210279 | |
| Download: ML20045H795 (3) | |
Text
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w AssiscTON, D. C. 20555 sy f SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 179 TO FACILITY OPERATING LICENSE NO. DPR-32 AND AMENDMENT NO. 179TO FACILITY OPERATING LICENSE NO. DPR-37 VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION. UNIT NOS. 1 AND 2 DOCKET NOS. 50-280 AND 50-281
1.0 INTRODUCTION
By letter dated No'; ember 14, 1990, Virginia Electric and Power Company (licensee) requested amendments, in the form of changes to the Technical Specifications, to Operating License Nos. DPR-32 and DPR-37 for the Surry Power Station, Un'ts 1 and 2, respectively. The proposed changes would:
1.
change the required leak rate test pressure from 39.2 psig to 45.0 psig, 2.
reduce the leik test pressure for the emergency escape airlock seal from 45 psig to 10 psig, and 3.
correct h typographical error for maximum service water temperature.
2.0 EVALUATION 2.1 Proposed Chanu_1 The request to change the leak rate testing pressure was made as a result of a reanalysis of the containnent peak pressure, as indicated in the licensee's submittal.
The new calculated peak pressure is 44.98 psig, as opposed to the previously calculated value of 35.2 psig.
The design pressure is 45 psig.
The significant change of the calculated peak pressure is a result of the changes in the analytical methodology as well as changes to the containment systems. A brief history of the changes is as follows:
09/70:
Calculated P,
39.2 psig Hot Leg LOCA 12/78: Calculated P.
42.2 psig Change to Cold Leg LOCA 06/80: Calculated P,
44.71 psig Result of an additional sensitivity study 06/89:
Calculated P,
44.98 psig Result of the use of the measured containment spray pump flow rate instead of design flow 9307210279 930701 PDR ADOCK 05000200 p
f To perform the test at 45 psig, the containment is initially pressurized to 47 psig to allow for containment expansion and pressure equalization. The licensee estimates that the performance of the Type A test at 47 psig will have no detrimental effect on the containment structure since the calculated stresses were found to be well within the allowable yield strengths of the structural reinforcing bars.
2.2 Prooosed Chanae 2 The request to approve the reduced leak test pressure for the airlock seal.is not justified because the licensee has not adequately demonstrated that the 10 psig pressure test provides the required assurance that the emergency escape airlock seal will function as required to minimize outleakage during and following a LOCA.
The NRC staff will review this issue further if the licensee elects to provide necessary additional supportive information.
2.3 Pronosed Chance 3 The request would correct a typographical error for the maximum service water temperature.
This request was previously granted in Amendment Nos. 153 and 150 for Units 1 and 2, respectively, dated April 11, 1991, and therefore is not addressed here.
3.0 SUMMRY The staff has reviewed the licensee's request and concluded that:
1.
The licensee has performed a number of the containment peak pressure calculations which changed the maximum calculated peak pressure from 39.2 psig to 44.98 psig.
In all of the analyses, the analytical tool used was the same as the one used as the basis for the issuance of the original plant license (i.e. Stone & Webster proprietary computer code LOCTIC).
The resultant calculated peak pressure is bounded by containment design pressure (45 psig).
Therefore, the staff finds the proposed change acc ept abl e.
2.
The staff is rejecting the Proposed Change 2 for the reasons discussed in Section 2.2 above.
3.
The request to correct a typographical error was granted in Amendment Nos. 153 and 150 for Units 1 and 2, respectively, dated April 11, 1991.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Virginia State official was notified of the proposed issuance of the amendments.
The State official had no comment.
5.0 ENVIRONMENTAL CONSIDERATION
Pursuant to 10 CFR 51.21, 51.32 and 51.35, an environmental assessment and finding of no significant impact was prepared and published in the Federal Reaister (58 FR 6424). Accordingly, based upon the environmental assessment, the NRC staff has determined that the issuance of these amendments will not have a significant effect on the quality of the human environment.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors:
A. Drozd B. Buckley Date: July 1, 1993 1
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