ML20093K180
| ML20093K180 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 10/13/1995 |
| From: | Horn G NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-95-07, GL-95-7, NLS950200, NUDOCS 9510240120 | |
| Download: ML20093K180 (6) | |
Text
I GENERAL OFFICE P.O. BOX 499, COLUMBUS, NEBRASXA 68602-0499 Nebraska Public Power District
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NLS950200 October 13,1995 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001 Gentlemen:
Subject:
60 - Day Response to Generic Letter 95-07 Cooper Nuclear Station, NRC Docket 50-298, DPR-46
References:
1.
US NRC Generic Letter 95-07, dated August 17,1995: Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves 2.
Letter from Thomas E. Tipton, Nuclear Energy Institute to Chief, Rules Review and Directives Branch, US NRC, dated April 27,1995, " Industry Comments on Proposed NRC Generic Letter 95-XX" The discussim below provides the Nebraska Public District's (District's) initial response to NRC Generic i etter (GL) 95-07 (Reference 1), for Cooper Nuclear Station (CNS). GL 95-07 requests that licensees perfonn, or confirm that they previously performed (1) evaluations of operational configurations of safety-related, power-operated (including motor, air, and hydraulically operated) gate valves for susceptibility to pressure locking and thermal binding and (2) further analyses, and any needed corrective actions, to ensure that safety-related power-operated gate valves that are susceptible to pressure locking or thermal binding are capable of performing the safety functions within the current licensing bases of the facility. The District commits to perform these actions as discussed below, as qualified by the interpretations provided to the NRC in the Nuclear Energy Institute's (NEI's) April 27,1995 letter to the NRC (Reference 2).
Specifically, the District interprets valve safety function as those functions required to respond to events as described in the CNS USAR. Therefore, the District interprets the scope of this generic letter to exclude non-safety-related functions such as EOP functions, recovery from valve mispositioning, and operation dering surveillance testing, if those conditions differ from those expected during performance of the intended safety function of the valve. This position is consistent with that developed in the determination of the scope for BWR resolution of Generic Letter 89-10, and is equally applicable to the resolution of GL 95-07.
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U. S. Nuclear Regulatory Commission October 13,'1995 Page 2 of 5 e
i The District also endorses the position stated in Reference 2 concerning evaluation of valves for susceptibility to pressure locking and thermal binding (PIlrB) and evaluation of valve capability -
e for those valves determined to be potentially susceptible to these phenomena. Specifically, while lack of event occurrence alone may be an insufficient reason for exclusion, past performance supported by-testing and/or calculations can_ be sufficient to exclude certainL applications.
1' Additionally, the use of leakage rate may in certain applications be justifiable and technically-defensible. It is also the District's position that where 'necessary, it may be appropriate and justifiable to perform analysis to justify actuator capability, and performance of such capability
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analyses should not be limited to only small valves.
l
- The specific actions requested by Generic Letter 95-07 are listed below with the corresponding
-District response.
NRC RRQUEST-L Within 90 days of the date of this generic letter, each addressee of this generic letter is requested
- to perform and complete thefollowing actions:
1.
Perform a screening evaluation ofthe operational configurations ofallsafety-relatedpower-operated (i.e., motor-operated, air-operated, and hydraulically operated) gate valves to identsfy those valves that are potentially susceptible to pressure locking or thermal binding; and E
2.
' Document a basis for the operability of the potentially susceptible valves or, where operability cannot be supported, take action in accordance with individualplant Technical Spectfications.
DISTRICT RESPONSE The District will complete the above actions by November 15,1995 (90 days from August 17,1995).
The District has performed a preliminary screen of the susceptibility of valves to PI/fB. The District will enter a planned refueling and maintenance outage (RE16), on October 14,1995. The District will complete the requested screening and establish a basis for the operability of any valves determined to be potentially susceptible to PIlrB.
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NRC REQUEST
' Within 180 days of the date of this genediletter, each addressee of this generic letter is requested to, implement and complete the guidar.ce provided in Attachment 1 to perform thefollowing actions:
i 1.
- Evaluate the operational configurations of safety related power-operated (i.e., motor-
_ operated, air-operated, and hydraulically operated) gate valves in its plant to identify valves that are susceptible to pressure locking or thermal binding.
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U.S. Nuclear Regulatory Commission October 13,1995 Page 3 6f 5 -
2.
Perfonn further analyses as appropriate, and take needed corrective actions (orJustify longer schedules), to ensure that the susceptible valves identified in 1 are capable of perfonning their intended safetyfunction(s) under all modes ofplant operation, including test configuration.
DISTRICT RESPONSE The District will complete the above actions by Febmary 13,1996 (180 days from August 17,1995),
subject to the position established in Reference 2 and discussed above. Specifically, as discussed in Reference 2, the District does not plan to include PIlrB analysis for surveillance _ test configurations if such conditions differ from those expected during performance of the intended safety function (s) of the valve.
NRC REQUEST All addressees, including those who have already satisfactorily addressed pressure locking and thennal binding for MOVs by implementing the guidance in Supplement 6 to GL 89-10 (or equivalent industry methods), are requested to provide a summary description of thefollowing:
1.
The susceptibility evaluation of operational configurations perfonned in response to (or consistent with) 180-day Requested Action 1, and thefurther analyses perfonned in response to (or consistent with) 180-day Requested Action 2, including the bases or criteria for detennining that valves are or are not susceptible to pressure locking or thennal binding; 2.
The results of the susceptibility evaluation and thefurther analyses referred to in 1 above, including a listing of the susceptible valves identified; 3.
The corrective actions, or other dispositioning,for the valves identified as susceptible to pressure locking or thennal binding, including: (a) equipment or procedural modifications completed and planned (including the completion schedule for such actions); and (b) justificationfor any detennination that particular safety-relatedpower-operated gate valves susceptible to pressure locking or thennal binding are acceptable as is.
DISTRICT RESPONSE The District will submit the above requested information by February 13,1996 (180 days from August 17,1995).
. As required in GL 95-07, the District is submitting this response under oath.
0 -
'U S Nuclear Regulatory Conunission October 13,1995 Page 4 6f 5 Please contact me if you have any questions concerning this issue, or if you require any additional information.
- Sinc rely,.
.I r
' Vic sident - Nuclear
. cc:
' Regional Administrator USNRC-Region IV Resident Inspector Cooper Nuclear Station NRC NRR Project Manager USNRC - Rockville NPG Distribution A
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'U.S. Nuclear Regulatory Commission October 13,il995
'Page 5 6f 5 STATE OF NEBRASKA
)
)ss PLATTE COUNTY
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G. R. Horn, being first duly sworn, deposes and says that he is an authorized representative of the Nebraska Public Power District, a public corporation and political subdivision of the State of Nebraska; that he is duly authorized to submit this response on behalf of Nebraska Public Power
- District; d that the statements contained herein are true to the best of his knowledge and belief.
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R. Horn Subscribed in my presence and sworn to before me this
/5" dayof oc/o/W,1995.
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W NOTARY PUBLIC
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LIST OF NRC COMMITMENTS-l ATTACHMENT 3 Corres$ondence No: MrA950200 The following table identifies those actions committed to by the District in this
' document. Any other actions discussed in the submittal represent intended or
, planned actions by the District. They are described to the NRC for'the NRC's j
'information and are not regulatory comitments. Please: notify the Licensing Manager.
l>
at Cooper Nuclear. Station of any questions regarding this document or any associated i
4 COMMITTED DATE-COMMITMENT OR OUTAGE
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li L The District will perform a screening evaluation of the operational configurations of all safety-related power-operated (i.e., motor-operated, air-operated, and November 15* 1995 hydraulically operated) gate valves to identify those valves that are potentially 4
susceptible to pressure locking e. thermal binding.
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2.~
He District will document'a basis for the operabilit) of the potentially susceptible
. valves or, where operability cannot be supported, take action in accordance with November 15,1995 CNS Technical Specifications.
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- 3. He District will evaluate the operational configurations of safety related power-operated (i.e., motor-operated, air-operated, and hydraulically operated) gate Feb**'Y 13'1995 valves in its plant to identify valves that are susceptible to pressure locking or
[l thermal binding.
4.
He District will perform further analyses as appropriate, and take needed
. corrective actions (orjustify longer schedules), to ensure that the susceptible i
February 13,1995 valves identified in (3.) are capable of performing their intended safety l-function (s).
- 5. The District will provide a summary description of the susceptibility evaluation of
.. operational configurations performed in response to (or consistent with) (3.),' and the further analyses performed in response to (or consistent with) (4.), including February 13,1995 the bases or criteria for determining that valves are or are not susceptible to pressure locking or thermal binding.
6.
De District will provide a summary description of the results of the susceptibility evaluation and the further analyses referred to in (5.) above, including a listing of February 13,1995 the susceptible valves identified.
7, He District will provide a summary description of the corrective actions, or other dispositioning, for the valves identified as susceptible to pressure locking or thermal binding, including: (a) equipment or procedural modifications completed February 13,1995 l
l and planned (including the completion schedule for such actions); and (b) justification for any detennination that particular safety-related power-operated d
gate valves susceptible to pressure locking or thermal binding are acceptable as is.
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PROCEDURE NUMBER 0.42' REVISION NUMBER 0-
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