ML18153C147
| ML18153C147 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 03/14/1990 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 90-124, NUDOCS 9003210336 | |
| Download: ML18153C147 (2) | |
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VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 March 14, 1990 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 FUNCTIONAL TEST OF HIGH SETPOINT
- FOR POWER OPERATED RELIEF VALVES Serial No.
NO/ETSR-3 Docket Nos.
License Nos.90-124 50-280 50-281 DPR-32 DPR-37 In support of the interim Technical Specification change on pressurizer safety valve setpoint tolerance, we committed to provide compensatory measures.
These compensatory measures include the operability of one of two Power Operated Relief Valves (PORVs) and the turbine trip-reactor trip anticipatory circuit.
Either compensatory measure in conjunction with the higher pressurizer safety valve lift setpoint is sufficient to limit any expected pressure transient to below Code requirements.
The Safety Evaluation Report (SER) for the Emergency Technical Specification change for Pressurizer Safety Valves, issued on November 16, 1989, was discussed during a telephone conversation on March 9, 1990 with the NRC staff. The SER requires both compensatory measures to be in place, but does not specifically identify operability testing requirements other than those implied by normal Technical Specification required testing.
It was brought to our attention that the SER was granted under the assumption that the operability of the PORVs is being established by performing a monthly functional test of the PORV circuitry that includes the "high" setpoint.
Surry Technical Specifications require a channel calibration on a refueling basis and a channel functional test every 31 days.
The Technical Specification channel functional testing requirement was interpreted to test the protection function of the valves. The protection functions of the PORV are: 1) to prevent overpressurization of the Reactor Coolant System at low temperatures, and 2) to ensure PORV closure following a pressure transient at operating pressure and temperature for inventory control. Accordingly, the low temperature PORV setpoints, as well as the pressurizer
- 9003210336 900314 PDR ADOCK 05000280 Q
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presture channel inputs to the 2000 psi PORV interlock, have been routinely tested.
Until the generic issue on pressurizer safety valves was identified, credit was not taken '
in the safety analysis for the automatic operation of a PORV for any analyzed accident initiating at normal plant operating temperature and pressure. Therefore, the open setpoint (high setpoint), which is considered a control function, was not included in the monthly channel functional test.
We agree that the compensatory measure requiring operability of at least one PORV should include a channel functional test of the "high" setpoint. Therefore, in a second March 9 telephone conversation with the NRC staff, we committed to prepare and perform a channel functional test of the PORV "high" setpoint. This functional test was satisfactorily performed on March 9, 1990 for each PORV. In addition, we committed to continue to perform the "high" setpoint test on a thirty-one day basis, as long as PORV operability was necessary to support the Pressurizer Safety Valve Interim Technical Specification.
Very truly yours, JL_~
W. L. Stewart Senior Vice President - Nuclear cc:
U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, N. W.
Suite 2900 Atlanta, Georgia 30323 Mr. W. E. Holland NRC Senior Resident Inspector Surry Power Station Commissioner Department of Health Room 400 109 Governor Street Richmond, Virginia 23219