ML13326A826
| ML13326A826 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/01/1991 |
| From: | Ray H SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML13326A827 | List: |
| References | |
| NUDOCS 9111120213 | |
| Download: ML13326A826 (2) | |
Text
Southern California Edison Company 23 PARKER STREET IRVINE, CALIFORNIA 92718 HAROLD B. RAY TELEPHONE SENIOR VICE PRESIDENT 714-458-4400 November 1, 1991 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No..50-206 Supplement 2 to Amendment Application No. 170 Airlock Test Pressure San Onofre Nuclear Generating Station, Unit 1 This letter provides Supplement 2 to Amendment Application No. 170 to revise the test pressure for the containment airlocks from 10.0 psig to 8.0 psig.
The supplement also provides the additional justification for lowering the containment airlock test pressure which was requested by the NRC staff during a telephone conversation on October 12, 1990. The supplement is provided as.
Background
The request to lower the airlock testing pressure was included with Amendment Application No. 170 developed in response to the broader containment venting issue. The containment venting issue is being resolved on an industry wide basis as multi-plant action B-24, "Containment Venting and Purging."
Resolution of this item is on the list of Cycle 11 Full Term Operating License projects for San Onofre Unit 1. The venting issue was originally scheduled for resolution prior to Cycle 11 operation but was rescheduled for resolution during Cycle 11 operation by NRC Amendment 141 on December 28, 1990.
In response to multi-plant action B-24, we provided Amendment Application No.
170 on June 7, 1989. The amendment application incorporates a limitation on the opening angle of the containment vent valves and adds leak testing acceptance criteria for the containment ventilation isolation valves and the containment airlocks and lowers the test pressure for the containment airlock from 10 psig to 3 psig. The amendment application also proposes Limiting Conditions for Operation and Action statements for the personnel air locks and containment ventilation isolation valves consistent with the Westinghouse Standard Technical Specifications.
On May 3, 1990, in response to an NRC letter dated February 22, 1990, a supplement to Amendment Application No. 170 was submitted. The supplement proposes Limiting Conditions for Operation for the containment ventilation 9111120213 911101 D)R ADOCK 05000206
Document Control Desk
-2 proposes Limiting Conditions for Operation for the containment ventilation isolation valves to keep them closed as much as practicable during power operation.
As a result of NRC staff review, questions arose during a telephone call on October 12, 1990 with the NRC staff.
The NRC requested additional justification regarding our request to lower the test pressure for the containment airlocks from 10 psig to 3 psig. During the process of developing the additional justification, we determined that a test pressure of 8.0 psig would provide acceptable results. The enclosed supplement to Amendment Application No. 170 therefore revises the proposed test pressure to 8.0 psig.
Leakage Error Calculation During the October 12, 1990 telephone conversation, the NRC staff reviewers also questioned the error calculation in the test data included with the June 7, 1989 submittal of Amendment Application No. 170. The leakage rates were calculated by measuring the pressure and temperature at the beginning and end of the test period. The formulas described in Attachment 5 to Enclosure 1 are from ANSI/ANS 56.8-1981 and were used to calculate the leakage rates and the errors associated with the leakage rates. We have reviewed the results of these calculations and determined they are correct.
Supplement 2 to Amendment Application No. 170 The enclosed supplemental amendment application contains all the applicable information from the previous supplement submitted on May 3, 1990 and the original amendment application submitted on June 7, 1989. The amendment application provided as Enclosure 1 therefore supersedes the earlier submittals.
If you have any questions, please do not hesitate to call.
Very truly yours, Enclosures cc:
J. B. Martin, Regional Administrator, NRC Region V George Kalman, NRC Senior Project Manager, San Onofre Unit 1 J. 0. Bradfute, NRC Project Manager, San Onofre Unit 1 C. W. Caldwell, NRC Senior Resident Inspector, San Onofre Units 1, 2&3 C. D. Townsend, NRC Resident Inspector, San Onofre Unit 1 J. H. Hickman, California Department of Health Services