ML20097D514
| ML20097D514 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 06/04/1992 |
| From: | Parker T NORTHERN STATES POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9206100217 | |
| Download: ML20097D514 (5) | |
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Northern Ltateti Power Company 414 Nict. Mah June 4, 1996 Minneapohs. Minnesota 55401 1927 Telephone (612) 330-5500 U S Nuclear Regulatory Commission Attn:
Document Control Desk Washington, DC 20555 PRAIRIE ISLAND NUCLEAR CENERATING PIANT Docket Nos. 50 282 License Nos. DPR-42 50-306 DPR 60 Request for Regional Temporary Waiver of Compliance to Auxiliary Feedwater Surveillance Reauirements The purpose of this letter is to confiru the results of a teleconference between Northern States Power Company and the NRC Staff on June 4, 1992, in which Northern States Power requested a Regional Valver of Compliance from the Auxiliary Feedwater System surveillance test requirements of Prairie Island Technical Specification Section 4.8.A.8.
As a result of not completing all of the individual surveillance test requirements specified in Section 4.8.A.8, all of the auxiliary feedwater pumps on both Prairie Island units were declared inoperable at 1055 on June 4, 1992.
A Unit 2 auxiliary feedwater pump was subsequently returned to operabic status at 1232 on June 4, 1992.
Northern States Power requests a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> delay in the completion of the test requirements as specified in Specification 4,8.A.8 and operability verification prior to the application of the shutdown requirements of Specification 3.0.C for Unit 1.
Reautrements for Vhich Relief is Reauested Section 4.8.A.8 of the Prairie Island Technical Specifications requires verification, at least once every 18 months during shutdown, that each aux'liary feedwater pump starts as designed automatically and each automatic valve in the flow path actuates to its correct position upon receipt of each auxiliary feedwater actuation test si nal.
These surveillance requirements F
were incorporated into the Prairie Is'and Technical Specifications by License Amendment Nos. 46 and 40, dated March 2, 1981.
Circumstances Leading to Reauest and Need for Promnt Action During a verification of compliance with the Auxiliary Feedwater System surveillance testing requirements, it was identified on June 4, 1992 that a portion of the surveillance testing required by Section 4.8.A.8 had not been adequately tested within the required time frame.
Based on incomplete surveillance testing, both auxiliary feedwuter pumps on each unit were l ~
pump was subsequently returned to operable status at 1232 on June 4, 1992.
declared inoperable at 1055 on June 4, 1992.
A Unit 2 auxiliary feedwater l
9206100217 920604 N88/
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USNRC June,4,1992 Nodhern States Power Company
, Page 2 There is no action statement specified in Section 3.4 of the Prairie Island Technical ~ Specifications for the condition where both auxiliary feedwater pumps on a unit are inoperable. Therefore, the requirements of Specification 3,0.C must be applied, which provides one hour to prepare to shutdown and an additional six hours to reach hot shutdown.
Currently, both units are at full power. The proposed Temporary Vaiver of Compliance is necessary to avoid the initiation of a shutdown of Unit 1 at 1555 on June 4, 1992.
Due to the nature of a missed surveillance event, it was not possible to foresee the occurrence of this event and take measures to avoid it.
Due to the short time duration allowed by Specification 3.0.C, it is not possible to complete the required surveillance testing and operability verification prior to the required shutdown of Unit 1.
For these reasons, it was not possible to avoid the submittal of this request'for a Temporary Waiver of Compliance.
Evaluation of Safety Significance and Potential Consecuences Ceneric Letter 87 09, " Sections 3.0 and 4.0 of the Standard Technical Specifications (STS) on the Applicability of Limiting Conditions for Operation and Surveillance Requirements", provided guidance on improvements to Section 4.0 of the Standard Technical Specifications which could be voluntarily
-adopted by licensies.
One of the improvements described in Generic Letter 87-09 revised Standard Technical Specification 4.0.3 to clarify when a missed surveillance constitutes a violation of the operability requirements of a Limiting Condition for Operation and to clarify the applicability of the action requirements and the time during which the limits apply.
The revised Specifica/_on reads as follows:
" Failure to perform a Surve11* ance Requiretsnt within the allowed surveillance interval, defined by Specification 4.0,2, sha11' constitute noncompliance with the OPERABILITY requirements for a Limiting Condition for Operation.
The time limits of.the ACTION requirements are applicable at the time it is identified that a Surveillance Requirement has not been performed.
The' ACTION requirements may be delayed for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to permit the completion of the surveillance when the allowable outage ti'.ne limits of the ACTION requirements are less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />."
The proposed Temporary Waiver of Compliance conforms with the guidance provided in this revision to Standard Technical Specification 4.0.3.
It is overly conservative to assume that systems or components are inoperable when a' surveillance requirement has not been performed, The apposite is in fact the case; the vast majority of surveillances demonstrate that systems or components in fact are operable.
When a surveillance has been missed, it is primarily a question of operability that has not been verified by the performance of the required surveillance.
The NRC Staff concluded in Generic Letter 87-09. after taking several factors into account, that 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> would be an acceptable time limit for enmpleting a missed surveillance when the allowed out of service times of the action requirements are less than this time limit or when shutdown action 1
a U
USFRC Ju*ne,4, 1992 Northern States Power Company Page 3 requirements apply. The NRC Staff concluded that the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> time limit would balance the risks associated with an allowance for completing the surveillance within this period against the riske associated with the potential for a plant upset and challenge to safety systems when the alternative is a shutdown to comply with action requirements before the surveillance can be completed.
Discussion of Compensatory 6ctions Even though the Unit 1 auxiliary feedwater pumps have been declared inoperable, the pumps and their actuation functions which have been
-successfully tested in accordance with Specification 4.8 A.8, remain available and-capable of responding to any plant transient requiring auxiliary feedwater.
There is a high probability that all pump actuation functions _are fully operable.
If_for cny reason a component is found to be inoperabic during the performance of the Auxiliary Teedwater System surveillance testing, actions will be taken immediately to return the component to operable status.
Even though there is a high probability that the Auxiliary Feedwater System will function as designed, an operator has been positioned in the control room for manual actuation of the Auxiliary Feedwater System if necessary.
Justification of Duration of the Reauest The proposed Temporary Vaiver of Compliance requests a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> delay in the shutdown requirements of Specification 3.0.C.
As discussed above, this delay conforms with the guidance provided in Generic Letter 87 09.
The proposed 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> delay also provides adequate time to perform the required testing in a controlled and safe manner and to review and verify that previous surveillance testing, in addition to the testing performed on June 4,1992, are adequate to
-assure that the requirements of Specification 4.8.A.8 have been met.
Significant Hazards Consideration Evaluation The proposed changes to the Operating License have been evaluated to determine whether they constitute a significant hazards consideration. This analysis is provided belcw:
.1. The proposed Temporary Waiver of Compliance will not involve a significant increase in the probability or consequences of an accident previously evaluated.
Even though the Unit 1 auxiliary feedwater pumps have been declared inoperable, the pumps and their actuation functions which have been successfully tested in accordance with Specification 4.8. A.8, remain available and capable of responding to any plant transient requiring auxiliary feedwater.
There is a high probability that all pump actuation functions are fully operabic.
j USNR6 Juhe 4, 1992 Northern States Power Company
-Page 4 The proposed short duration of continued plant operation with the Unit 1 Auxiliary Feedwater System potentially degraded will not significantly affect the probability of an accident.
Therefore, the proposed Ternporary Waiver of Compliance will not 1
significantly affect the probability or consequences of an accident 1
previously evaluated.
- 2. The proposed Temporary Waiver of Compliance will not create 'the possibility of a new or different kind of accident from any accident previously analyzed.
There are no new failure modes or mechanisms associated with the proposed Tercporary Waiver of Compliance.
The proposed Temporary Waiver of Compliance does not involve any modification of operational limits.
The proposed delay for completion of the inissed surveillance testing is consistent with the NRC Staff guidance provided by Generic Letter 87 09.
The NRC Staff concluded in Generic Letter 87 09, after taking several factors into account, that 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> would be an acceptable time limit for completing a missed surveillance when the allowed out of service times of the action requirements are less than this time limit or when shutdown action requirements apply.
Since the proposed changes conform with the guidance in Cenwric Letter 87 09, and because the Unit 1 auxiliary feedwater pumps and their actuation functions remain available and capable of responding to any plant transient requiring aaxiliary feedwater the proposed Temporary Waiver of Compliance does not create the possibility of a new or different kind of accident from any previously evaluated, and the accic'ent analyses presented in the Updated Safety Analysis Report will remain bounding.
- 3. The proposed Teroporary Waiver of Compliance will not involve a significant reduction in the marcin of safety.
The proposed delay for completion of the rnissed surveillance testing is consistent with the NRC Staff guidance provided by Generic Letter 87+09, 7
The NRC Staff concluded in Generic Letter 87 09,_after taking several l-factors-into account, that 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> would be an acceptable time limit for completing a snissed surveillance when the allowed out of service times of the action requirements are less than this time limit or when shutdown action requirements apply. The..AC Staff concluded that the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> time limit would balance the risks associated with an allowance for'cornpleting I
the surveillance within this period against the risks associated with the
(
potential for a plant upset and challenge to safety systems when the L
alternative is_a shutdown-to comply with action requirements before the surveillsnee can be completed.
Therefore, the proposed Temporary Waiver of Compliance will not result in any reduction in the plant's margin of safety.
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USNRC jJu'ne,4, 1992 Northern States Power Company n
Page 5 Based on the evaluation described above, Northern States Power Company has determined that operation of the Prairie Island Nuclear Generating Plant in accordance with the proposed Temporary Waiver of Compliance does not involve any significant hazards considerations as defined by NRC regulations.
Environmental A=,gpssment The proposed Temporary Waiver of Compliance does not change effluent types or total effluent amounts nor does it involve an increase in power level.
Therefore, this change will not result in any significant environmental impact.
Ooerations Committee Review and Annroval The Plant Operations Committee has reviewed and approved the proposed Temporary Waiver of Compliance.-
Please contact us if you have any questions related to the proposed Temporary Waiver of Compliance.
4 homas M Parker Manager Nuclear Support Services c: Regional Administrator - ReS on III, NRC i
Senior Resident Inspector, NRC NRR Project Manager, NRC J E Silberg
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