ML18153C692
| ML18153C692 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 08/09/1991 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 91-467, NUDOCS 9108140174 | |
| Download: ML18153C692 (3) | |
Text
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e VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 2 3 2 61 August 9, l99l United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 OPERABILITY OF EQUIPMENT DURING TECHNICAL SPECIFICATION REQUIRED TESTING Serial No.
NO/DAS Docket Nos.
License Nos.91-467 R7 50-280 50-281 DPR-32 DPR-37 In recent discussions with the NRC staff concerning operability determinations, several instances in the Surry Technical Specifications were identified where the required actions to perform a surveillance could, in conjunction with opposite train testing requirements, render the entire safety system inoperable while the surveillance test is performed. For these examples, if a train of safety equipment becomes inoperable due to the performance of a surveillance test, the opposite train must be tested to establish its operability prior to "repairing" the inoperable train. Based on the NRC position on the use of administrative controls, when the opposite train is tested in accordance with the Technical Specifications, the plant would have to voluntarily enter the six-hour action statement of T.S. 3.0.1 with both trains inoperable. This opposite train testing requirement is specified in the Technical Specifications for the Low Head Safety Injection System (T.S. 3.3), the Containment and Recirculation Spray Systems (T.S.
3.4), Emergency Diesel Generators (T.S. 3.16), and the Auxiliary Ventilation Exhaust Filter Trains (T.S. 3.22).
From the initial issuance of the operating license, the interpretation of Technical Specifications has been that these affected subsystems were maintained operable for the required surveillance by administrative controls. To declare them inoperable and require subsequent opposite train operability by testing could have resulted in voluntarily exceeding the Technical Specifications. Conduct of surveillances, which would result in the voluntary rendering of the entire safety system inoperable, is inconsistent with the intent of Technical Specifications, which is to ensure the ability of safety systems to perform their function. To address this issue, we will be submitting a Technical Specification change request consistent with the intent of Standard Technical Specifications by September 20, 1991. The proposed change will eliminate (or modify in the case of Emergency Diesel Generators) the additional testing requirement for the opposite train based on no common mode failure considerations and previous surveillance testing within the period having established operability of the opposite train.
In the interim, we have implemented an operations standard which was approved by the Station Nuclear Safety and Operating Committee and provides guidance on the operability of safety systems during performance of surveillance testing required by Technical Specifications. Specifically, prior to performance of a surveillance test, operations will determine whether the test will place the train in an alignment in which its intended function cannot be accomplished. If testing would render the subject train inoperable, the redundant train will be reviewed to verify that it is operable prior to testing the subject train. The period of time during the surveillance test in which the affected train is in an inoperable status will be minimized. Personnel involved in the periodic test will be briefed on the actions required to promptly return the train in test to operable status in the event the system is required to mitigate an event. This guidance will be applied to routine surveillance testing and corrective maintenance activities as follows.
For routine surveillance testing, the affected train will be declared "inoperable" and the applicable action statement entered. However, opposite train operability testing will not be invoked.
The "inoperable" train is not inoperable due to an equipment deficiency or malfunction requiring repair and can be readily restored to an operable status by manual action. Furthermore, operability of the opposite train has been previously established and verified by separate surveillance test.
The current Technical Specifications typically require a demonstration of operability "prior to initiating repair of the inoperable subsystem." This assumes that the inoperable equipment has malfunctioned and is in need of repair. For that case, additional testing is specified to assure the redundant train has not likewise been affected. In the case of routine surveillance testing, however, repairs are not required to restore operability and the concern of a common mode failure is not present. Therefore, the necessity to establish operability of the redundant train should not be a requirement. This is consistent with Standard Technical Specifications and MERITS.
If corrective maintenance is required, the affected train will be declared inoperable and the applicable action statement entered. Per recent discussions with the NRC, a one-time waiver of compliance from the requirements of Technical Specifications may be requested on a individual case basis to address interim situations which require opposite train testing. With the exception of Emergency Diesel Generators, a waiver would be requested to avoid requiring safety system inoperability by opposite train testing and unnecessarily entering T.S. 3.0.1. For the Emergency Diesel Generators, the waiver would request a provision in the opposite train testing requirement to permit a limited time for which both trains may be inoperable to perform testing without entering T.S. 3.0.1.
If you have any questions regarding our interim actions, please contact us.
Very truly
- urs, Jlffi/,~~
W. L. Stewart Senior Vice President - Nuclear
J cc:
U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N. W.
Suite 2900 Atlanta, Georgia 30323 Mr. M. W. Branch NRC Senior Resident Inspector Surry Power Station