ML18153A461
| ML18153A461 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 06/06/1996 |
| From: | Edison G NRC (Affiliation Not Assigned) |
| To: | Ohanlon J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| GL-95-07, GL-95-7, TAC-M93526, TAC-M93527, NUDOCS 9606100133 | |
| Download: ML18153A461 (4) | |
Text
Mr. J.P. O'Hanlon
.a.
SeniQr Vice President~Nuclear v*i;~flnia Electric and Power Company 0-**50dO Domini on Blvd.
Glen Allen, Virginia 23060 June 6, 1996
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION - GENERIC LETTER 95-07, "PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES," SURRY POWER STATION, UNITS 1 AND 2 (TAC NOS. M93526 AND M93527)
Dear Mr. O'Hanlon:
On August 17, 1995, the NRC issued Generic Letter (GL) 95-07, "Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves," to request that licensees take actions to ensure that safety-related power-operated gate valves that are susceptible to pressure locking or thermal binding are capable of performing their safety functions.
The NRC staff is reviewing and evaluating your response to GL 95-07.
Additional information, as discussed in the enclosure, is requested in order for the staff to complete its review.
We request that you respond within 30 days.
The information requested by this letter is within the scope of the overall burden estimated in Generic letter 95-07, "Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves," which was a maximum of 75 hours8.680556e-4 days <br />0.0208 hours <br />1.240079e-4 weeks <br />2.85375e-5 months <br /> per response. This request is covered by Office of Management and Budget Clearance Number 3150-0011, which expires July 31, 1997.
Docket Nos. 50-280 and 50-281
Enclosure:
Request for Additional Information cc w/enclosure:
See next page Distribution See next page FILENAME - G: NOANNA M93526.RAI OFFICE LA:PDil-1 PM:PDII NAME
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Dunn,n ton DATE COPY
(~~~-!
9606100133 960606 PDR ADOC~ 05000280 P
PDR Sincerely, (Original Signed By)
Gordon E. Edison, Sr. Project Manager Project Directorate 11-1 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation
e ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION SURRY POWER STATION, UNITS 1 AND 2, RESPONSE TO GENERIC LETTER 95-07, "PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES"
- 1.
Regarding valves X-SI-MOV-X860A/B, LHSI Containment Sump Isolation, the licensee's submittal states that the containment sumps at Surry Power Station are maintained in a water-filled condition to provide a thermal barrier to prevent rapid heating of the fluid remaining in the bonnets of the normally closed valves. The NRC staff believes that reliance on water-filled containment sump piping to preclude thermally induced pressure locking under design basis accident conditions is uncertain. Therefore, the NRC staff believes it is important to review your calculations which demonstrate that water-filled piping will preclude thermally induced pressure locking of these valves.
Please provide this analysis for our review.
- 2.
Valves X-SI-MOV-X842, HHS! Pump Discharge to Alternate RCS Cold Legs, and valves X-SI-MOV-X869A/B, HHS! Pump Discharge to RCS Hot Legs, may be potentially susceptible to pressure locking during a design basis event.
The licensee's submittal states that these valves may be potentially susceptible, but does not provide any further analysis regarding their susceptibility.
Please discuss why no further analysis was provided for these valves.
- 3.
Valves X-SI-MOV-X867C/D, HHS! Pump Discharge to RCS Cold Legs, may be potentially susceptible to pressure locking during a design basis event.
Please discuss why these valves were not evaluated in the licensee's submittal.
- 4.
Valves X-RC-MOV-X535/X536, Pressurizer PORV Block Valves, may be potentially susceptible to pressure locking if needed to open to mitigate the consequences of a steam generator tube rupture event, as discussed for the PORV Block Valves at North Anna Power Station.
However, the licensee's submittal for Surry Power Station does not address this potential susceptibility. Please address this issue.
In addition, the licensee's submittal states that an analysis of the operator capability at degraded voltage condition demonstrated that the valves have adequate margin to open against the postulated thermally bound case.
Please provide this analysis for our review.
- 5.
Through review of operational experience feedback, the staff is aware of instances where licensees have completed design or procedural modifications to preclude pressure locking or thermal binding which may have had an adverse impact on plant $afety due to incomplete or incorrect evaluation of the potential effects of these modifications. Please describe evaluations and training for plant personnel that have been conducted for each design or procedural modification completed to address potential pressure locking or thermal binding concerns.
Mr. J. P. O'Hanlon Virginia Electric and Power Company cc:
Mr. Michael W. Maupin, Esq.
Hunton and Williams Riverfront Plaza, East Tower 951 E. Byrd Street
. Richmond, Virginia 23219 Mr. David Christian, Manager Surry Power Station Virginia Electric and Power Company 5570 Hog Island Road Surry, Virginia 23883 Senior Resident Inspector Surry Power Station U. S. Nuclear Regulatory Commission 5850 Hog Island Road Surry, Virginia 23883 Chairman Board of Supervisors of Surry County Surry County Courthouse Surry, Virginia 23683 Dr. W. T. Lough Virginia State Corporation Commission Division of Energy Regulation P. O. Box 1197 Richmond, Virginia 23209 Regional Administrator, Region II U. S. Nuclear Regulatory Commission 101 Marietta Street N.W., Suite 2900 Atlanta, Georgia 30323 Robert B. Strobe, M.D., M.P.H.
State Health Commissioner Office of the Commissioner Virginia Department of Health P.O. Box 2448 Richmond, Virginia 23218 Surry Power Station Office of the Attorney General Commonwealth of Virginia 900 East Main Street Richmond, Virginia 23219 Mr. M. L. Bowling, Manager Nuclear Licensing & Operations Support Innsbrook Technical Center Virginia Electric and Power Company 5000 Dominion Blvd.
Glen Allen, Virginia 23060 Mr. Al Belisle U.S. Nuclear Regulatory Commission 101 Marietta Street, N.W. Suite 2900 Atlanta, Georgia 30323-0199
e Memorandum Dated June 6, 1996 Distribution c:l)ocRet=f-.i=l=e=
PUBLIC PDII-1 RF S. Varga J. Zwolinski OGC ACRS R. Eaton H. Rathbun A. Belisle, RII