ML20212A792
| ML20212A792 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 09/13/1999 |
| From: | Pastis H NRC (Affiliation Not Assigned) |
| To: | Roche M GENERAL PUBLIC UTILITIES CORP. |
| References | |
| GL-95-07, TAC-M93495, NUDOCS 9909170130 | |
| Download: ML20212A792 (4) | |
Text
Mr. Micha:1 B. Roch3 September 13, 1999 f
Vice Pr:sident cnd Dir:ctor l
GPU Nucirr, Inc.
Oyster Creek Nuclear Generating Station i
P.O. Box 388 r
Forked River, NJ 08731 i
SUBJECT:
SECOND REQUEST FOR ADDITIONAL INFORMATION - GENERIC LETTER 95-07, " PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES," OYSTER CREEK NUCLEAR I
GENERATING STATION (TAC NO. M93495)
Dear Mr. Roche; 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.
In a letter dated May 9,1996, GPU Nuclear, Inc. (GPU) submitted its 180-day response to GL 95-07 for Oyster Creek Nuclear Generating Station. The NRC staff reviewed the licensee's submittal and requested additional information in a letter dated July 10,1996. In a letter dated September 5,1996, you provided the requested information.
i The staff has reviewed GPU's GL 95-07 submittals for Oyster Creek and has determined that additional information is necessary to complete its safety evaluation. The enclosed request for additional information (RAI) was discussed with David Distell of your staff on June 14, 1999, 1
and it was agreed that your response would be submitted within 45 days of the date of this letter. GL 95-07 includes a description of the regulatory basis for this request. If you have any questions regarding this matter, or if circumstances result in the need to revise the target date, please call me at the earliest opportunity. I may be reached at (301) 415-1261.
Sincerely, Original signed by:
Helen N. Pastis, Sr. Project Manager, Section 1 Project Directorate i Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-219
Enclosure:
RAI NRCIU CENTER C9P1 cc w/ encl: See next page DISTRIB&W SeeketPth " i EAdensam (e-mail)
PDI-1 Rdg.
HPastis MOprencek, RI l
SBlack SLittle FILENAME: G:\\PDI-1\\ Oyster Creek \\RAl93495.wpd OFFICE P(VI:Pph1 LA:Pk SC:PDI-7
[ Ok Ntik:lec NAME P
SL SBajw DATE l ' / h/99 9 / h/99
/ h/99 OFFICIAL RECORD COPY 9909170130 990913 PDR ADOCK 05000219 P
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Mr. Micha:l B. Roche September 13, 1999 Vic3 Presid:nt and Director
.GPU Nucl:ar, Inc.
9 Oyster Creek Nuclear Generating Station P.O. Box 388 Forked River, NJ 08731
SUBJECT:
SECOND REQUEST FOR ADDITIONAL INFORMATION - GENERIC LETTER 95-07," PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES," OYSTER CREEK NUCLEAR GENERATING STATION (TAC NO. M93495)
Dear Mr. Roche; 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.
In a letter dated May 9,1996, GPU Nuclear, Inc. (GPU) submitted its 180-day response to GL 95-07 for Oyster Creek Nuclear Generating Station. The NRC staff reviewed the licensee's submittal and requested additional information in a letter dated July 10,1996. In a letter dated September 5,1996, you provided the requested information.
The staff has reviewed GPU's GL 95-07 submittals for Oyster Creek and has determined that additional information is necessary to complete its safety evaluation. The enclosed request for additionalinformation (RAl) was discussed with David Distell of your staff on June 14,1999, and it was agreed that your response would be submitted within 45 days of the date of this letter. GL 95-07 includes a description of the regulatory basis for this request. If you have any questions regarding this matter, or if circumstances result in the need to revise the target date, 1
please call me at the earliest opportunity. I may be reached at (301) 415-1261.
Sincerely, Original signed by:
Helen N. Pastis, Sr. Project Manager, Section 1 Project Directorate i Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-219
Enclosure:
RAI cc w/ encl: See next page DISTRIBUTION:
Docket File EAdensam (e-mail)
OGC PUBLIC SBajwa ACRS PDI-1 Rdg.
HPastis MOprencek, RI SBlack SLittle FILENAME: G:\\PDI-1\\ Oyster Creek \\RAl93495.wpd OFFICE PM PDW1 LA:PQh SC:PDl-7 Phti :Icc SLlt SBajw NAME DATE l'/
/99 O / h/99
/[h/99 OFFICIAL RECORD COPY
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t UNITED STATh l
NUCLEAR REGULATORY COMMISSION f
WASHINGTON, D.C. 2055M001
]
September 13, 1999 Mr. Michael B. Roche Vice President and Director GPU Nuclear, Inc.
Oyster Creek Nuclear Generating Station P.O. Box 388 Forked River, NJ 08731
SUBJECT:
SECOND REQUEST FOR ADDITIONAL INFORMATION - GENERIC LETTER 95-07," PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES," OYSTER CREEK NUCLEAR I
GENERATING STATION (TAC NO. M93495)
Dear Mr. Roche; On August 17,199S, 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.
]
In a letter dated May 9,1996, GPU Nuclear, Inc. (GPU) submitted its 180-day response to GL 95-07 for Oyster Creek Nuclear Generating Station. The NRC staff reviewed the licensee's submittal and requested additional information in a letter dated Juif 10,1996. In a letter dated September 5,1996, you provided the requested information.
The staff has reviewed GPU's GL 95-07 submittals for Oyster Creek and has determined that aoditionalinformation is necessary to complete its safety evaluation. The enclosed request for additionalinformation (RAI) was discussed with David Distell of your staff on June 14,1999, and it was agreed that your response would be submitted within 45 days of the date of this letter. GL 95 07 includes a description of the regulatory basis for this request. If you have any questions regarding this matter, or if circumstances result in the need to revise the target date, please call me at the earliest opportunity. I may be reached at (301) 415-1261.
Sincerely,
?
Llj y
s, Helen N. Pastis, Sr. Project Manager, Section 1 Project Directorate I
, Division of Licensing Project Management si Office of Nuclear Reactor Regulation Docket No. 50-219
Enclosure:
RAI cc w/ encl: See next page
[A.
i L.
M. Roche j
GPU Nuclear, Inc.
cc:
1 Mr. David Lewis Deborah Staudinger Shaw, Pittman, Potts & Trowbridge Hogan & Hartson
' 2300 N Street, NW Columbia Square i
Washington, DC 20037 55513* St., NW Washington, DC 20004 Manager Licensing & Vendor Audits GPU Nuclear, Inc.
j 1 Upper Pond Road -
Parsippany, NJ 07054 Manager Nuclear Safety & Licensing Oyster Creek Nuclear Generating Station Mail Stop OCAB2 P. O. Box 388 Forked River, NJ 08731 Regional Administrator, Region l U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406-1415 Mayor Lacey Township 818 West Lacey Road Forked River, NJ 08731 Resident inspector c/o U.S. Nuclear Regulatory Commission P.O. Box 445 Forked River, NJ 08731 Kent Tosch, Chief New Jersey Department of Environmental Protection Bureau of Nuclear Engineering CN 415 Trenton, NJ 08625
SECOND REQUEST FOR ADDITIONAL INFORMATION OYSTER CREEK NUCLEAR GENERATING STATION t
RESPONSE TO GENERIC LETTER 95-07.
" PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES" 1.
The September 5,1996, submittal states that a calculation was used to demonstrate that the isolation condenser return valves, V-14-34 and V-14-35, would operate during pressure-locking conditions when reactor pressure is greater than 500 psig. The valves are cycled during plant cooldown at approximately 500 psig reactor pressure. A g
modified industry gate valve thrust equation was used to calculate the thrust required to open these double disk gate valves during pressure-locking conditions.
The NRC staff approved the use of a modified industry gate valve thrust equation (double disk area) to calculate the thrust required to open double disk gate valves during pressure-locking conditions. The double disk gate valve pressure locking thrust prediction methodology and the testing used to validate the methodology are described in NUREG/CR-6611,"Resu!!s of Pressure Locking and Thermal Binding Tests of Gate Valves." Test data demonstrated that the results of the double disk gate valve pressure locking thrust prediction methodology trended with the pressure locking test results but generally underestimated the thrust required to open a pressure locked valve. The NRC staff considers sizing and setting the valve actuator to deliver the thrust determined from the double disk gate valve pressure locking thrust prediction methodology to be acceptable long-term corrective action for GL 95-07 provided that the margin between calculated pressure locking thrust and actuator capability exceeds 40 percent. This large margin is needed to account for valve degradation, diagnostic equipment accuracy and the additional thrust that was required to open the test valve.
Discuss the margin between actuator capability and the thrust required to overcome pressure locking for V-14-34 and V-14-35 using GL 89-10 program valve and stem factors.
2.
In Attachment 1 to GL 95-07, the NRC staff requested that licensees include consideration of the potential for gate valves to undergo pressure locking or.! haw,al binding during surveillance testing. During workshops on GL 95-07 in each Region, the NRC staff stated that,if closing a safety-related power-operated gate valve for test or surveillance defeats the capability of the safety system or train, the licensee should perform one of the following with!o the scope of GL 95.
i 1.
Verify that the valve is not susceptible to pressure locking or thermal binding while
- closed, 2.
Follow plant technical specifications for the train / system while the valve is closed, 3.
Demonstrate that the actuator has sufficient capacity to overcome these phenomena, or Enclosure
. 4.
Make appropriate hardware and/or procedural modifications to prevent pressure locking and thermal binding.
The staff stated that normally open, safety-related power-operated gate valves, which are closed for surveillance but must return to the open position, would be evaluated within the scope of GL 95-07.
Section 3.1.4 of your May 9,1996, submittal states that potential accident conditions occurring during testing are not considered pressure locking and thermal binding concerns since the probability of an accident during a short time of testing is very low.
This conflicts with Section 3.2.3 of the submittal which states that normally open valves that are closed for testing, that have a safety function to re-open, were evaluated for pressure locking and thermal binding. During a telephone conversation conducted on
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June 14,1999, you stated that Section 3.2.3 of the submittal was applicable. Verify that this is correct.
3.
During a telephone conversation conducted on June 14,1999, you stated that the containment spray recirculation valves, V-21-13 and 17, are susceptible to thermal induced pressure locking and that you are using a hub analysis pressure locking thrust prediction methodology to demonstrate that the valves will operate during pressure-locking conditions.
On April 9,1997, a public meeting was conducted to discuss the Commonwealth Edison (Comed) and Entergy Operations, Inc. (EOI) pressure locking thrust prediction methodologies presented in GL 95-07 submittals. The minutes of the public meeting were issued on April 25,1997, and placed in the Public Document Room (PDR)
(Accession No. 9707300022). The Comed and EOl methodologies that predict the thrust required to open pressure locked flexible-wedge gate valves, validation testing of the analytical method, enhancernents to the Comed pressure locking methodology, and pressure locking tests sponsored by the NRC conducted by Idaho National Engineering and Environmental Laboratory were discussed during the meeting. The minutes of this public meeting indicate the type of information requested by the NRC in order to review and approve pressure locking thrust prediction methodologies.
The NRC staff has reviewed the Comed pressure locking thrust prediction methodology and concluded that its acceptable long-term corrective action provided the recommended margins, diagnostic equipment accuracy requirements and methodology limitations are incorporated into the pressure-locking calculations. In a letter to the NRC dated May 4,1999 EOl stated that they have recently revised their pressure locking thrust prediction methodology. The NRC is reviewing the EOl pressure locking thrust prediction methodology. Comed and EOl validated their pressure locking thrust prediction methodologies with test programs.
The NRC has also accepted the modified industry gate valve thrust equation (double disk area) described in NUREG/CR-6611 as acceptable long-term corrective action to demonstrate that flexible wedge gate valves will operate during pressure-locking conditions. Test data presented in NUREG/CR-6611 demonstraten that the results of
]
.- this methodology conservatively predicts the thrust required for flexible we@e gate valves to operate during pressure-locking conditions.
in order for the NRC to review your hub analysis pressure locking thrust prediction methodology, please provide the following information:
j Provide the test procedure /results that validated the methodology. Include any a.
information that will help evaluate if your valves are similar to test valves as applicable.
b.
Results from pressure locking testing sponsored by the NRC performed by Idaho National Engineering and Environmental Laboratory on a double disk and a flexible wedge gate valve have been placed in the PDR (NUREG/CR-6611). Please discuss if your pressure locking thrust prediction methodology accurately predicted the results of these pressure locking tests, j
i c.
Discuss the recommended margin between actuator capability and the calculated thrust value when using your pressure locking prediction methodology, any limitations associated with the use of your methodology and any diagnostic test equipment accuracy requirements. Commonwealth Edison Company provided this j
type of information to the NRC in a letter dated May 29,1.998. This letter is in the PDR (Accession No. 9806040184).
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