ML13324A933
| ML13324A933 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/18/1986 |
| From: | Medford M Southern California Edison Co |
| To: | Lear G Office of Nuclear Reactor Regulation |
| References | |
| 7229F, NUDOCS 8608200165 | |
| Download: ML13324A933 (3) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 M. 0. MEDFORD TELEPHONE MANAGER. NUCLEAR LICENSING (818) 302-1749 August 18, 1986 Director, Office of Nuclear Reactor Regulation Attention: G. E. Lear, Director PWR Project Directorate No. 1 U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Gentlemen:
Subject:
Docket No. 50-206 In-Service Testing Program San Onofre Nuclear Generating Station Unit 1
References:
A. Letter, M. 0. Medford, SCE, to D. M. Crutchfield, NRC, dated January 24, 1984 B. Letter, M. 0. Medford, SCE to G. E. Lear, NRC, dated July 3, 1986 Details regarding SCE's In-Service Testing (IST) Program for pumps and valves were submitted via the Reference A letter.
Included in that submittal were pump and valve relief requests submitted for NRC approval in accordance with 10 CFR 50.55a(g)(5).
Revisions to some of the relief requests and additional information intended to clarify earlier requests were provided in the Reference B letter. During conversations with members of the NRC staff, it was determined that Valve Relief Request No. 9 was not actually required by the regulation and that the testing to be applied to two Feedwater System check valves would require a new relief request.
Valve Relief Request No. 9 concerned the testing frequency of certain valves not testable during plant operation. Article IWV-3412, "Exercising Procedure," requires valves to be "exercised to the position required to fulfill their function unless such operation is not practical during plant operation."
Further guidance specifically for check valves appears in Article IWV-3522, "Exercising Procedure," which repeats this requirement. Valve Relief Request No. 9 referred to San Onofre Engineering Procedure S01-V.2.15 which listed those valves not exercisable during operation. The same articles of the Code require that if those valves cannot be exercised during operation, they shall be part-stroke exercised as practical during plant operation and full-stroke exercised during cold shutdown. Valves in this category are required by the Code to be specifically identified by the owner.
The above procedure specifically identifies that these valves will be exercised at cold shutdown intervals as this is specified in the Code. Since the program for these valves meets the requirement of the Code, the valve relief request is not required and is hereby withdrawn.
8608200165 860618 DR ADOCVK 05000206 PD PDR
0 Mr. G.
August 18, 1986 For the two Feedwater System check valves, each with the number 12-600-222 (previously numbered FWS 438 and 439), discussed on page 10 of the enclosure to Reference B, a valve relief request is required but was not included in our previous submittal. These valves (located on the discharge of the Feedwater/Safety Injection Pumps) were replaced during the recent outage and are designed with a small pressure relieving hole drilled in the disc face. The hole relieves pressure during a safety injection event to facilitate opening of the HV 851 valves.
Testing for these valves includes a full stroke test (i.e., both opened and closed).
This test cannot be done during normal operation as stated in the Reference B letter, and also cannot be exercised during cold shutdown due to the potential for backflow through the hole in the check valve which may cause reverse rotation of the pumps and possibly damage. As an alternative, both these valves will be disassembled at each refueling with photographs of the as found internals taken and retained as records. A new Valve Relief Request No. 10 is enclosed which reflects this information.
If there are any questions or you require additional information, please let me know.
Very truly yours, Enclosure
Enclosure VALVE RELIEF REQUEST NO. 10 SYSTEM:
Feedwater/Safety Injection System COMPONENT:
12-600-222 (2 valves previously numbered FWS 438 and 439),
Feedwater/Safety Injection Pumps Discharge Valves CATEGORY:
C CLASS:
2 FUNCTION:
These valves prevent backflow through the Feedwater/Safety Injection Pumps, but relieve pressure between the pumps and Safety Injection System Valves HV-851A and HV-851B during a safety injection event.
TEST REQUIREMENT:
Full stroke exercising on a quarterly basis.
BASIS FOR RELIEF:
These valves cannot be exercised closed due to a hole which is drilled in the valves to relieve pressure between the pumps and the Safety Injection System valves. During the IST, backflow through these holes could cause reverse rotation of the feedwater pumps with potential for damage resulting.
ALTERNATE TESTING:
These valves will be disassembled, inspected and manually full stroke exercised at each refueling. Photographs of the valve "as found" internals will be taken and retained as records.
GEH:7229F