ML20092E443
| ML20092E443 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 02/08/1992 |
| From: | Horn G NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NSD920115, NUDOCS 9202180121 | |
| Download: ML20092E443 (2) | |
Text
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a-P O DOX 4W COLUMEJIS. id DRASKA (.86dNW9 i, Nebraska Public Power District
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liSD920115 February 8, 1992 U.S. !Juelcar Regulatory Conunisalon Attention: Document Control Desk Washington, D.C.
205$5 Gentlernen:
Subject:
110tification of 250 Volt Battery System Inoperability Cooper 11uclear Station
!?RC Docket lio. 50 + 290, l.icense !!o. DPR 46 In accordance with Specification 3.9.B.1.c of the Cooper !!ucicar Station (C!lS)
Technical Specifications and 10 CFR 50.4(b)(1), I!ebraska Public Power District (District) is notifying the 1;RC of an inoperabic 250 volt battery system. This specification requires, when one of the two 250 volt battery systems becomes inoperable, that the NRC be notified within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the situation, the precautions be taken during the period of inoperability and t.h e plans to return the battery systern to an operable state.
Co.md1Llan_itqui rinr the I;ot i f i cn t t on At 1320 on February 7, 1992, following discussions with !!RC Headquarters and Region IV personnel, 250 Volt Battery System A was declared inoperable. One of the 120 individual battery cells of this battery system failed to meet the acceptance criteria of Surveillance Requirement 4,9,A,4.b,2, which states:
- For each connected cell, the voltage is 2.15V minimum and specific gravity is 1.190 minimum, corrected for 77 F and electrolyte level.
The average specific gravity of all connected cells will be a minimum of 1.200."
Cell number 110 of battery systen A indicated an individual cell voltage less than 2.15 volts.
All other cells of both battery systems meet or exceed the above acceptance criteria of the Technical Specification surveillance requirement.
freenutions Taken While Batterv System A Is Ineptrable The following preenutions have been implemented:
1.
An engineering analysis has been performed which verifies that, with the low individual cell voltage condition on ec11 110, 250 Volt Battery System A is still capable of supplying all safety related loads normally energized on its bus.
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- 11. S. Nuclear Regulatory Comraission page 2 of 2 r
-Febryary 8, 1992 2.
The surveillance requirements of Technical Specification 4.9.A.4.a for the 250 Volt Battery System B-will be monitored daily to verify its operability.-
3.
The nuclear safety systems and engineered safety features supplied by the 250 Volt Battery System B will remain operable.
Plans to Return the Bntrerv System A to an Oncrobic State i
The District plans to return the 250 Volt Battery Systern A to an operable condition at the earliest opportunity within the time contraints allowed by the LCO. The District intends to either jumper or replace cell 110 with a now cell i
which meets all Technical Specification requirements. A repincement battery cell is currently being. charged and tested in preparation for. service. Maintenance instructions are being prepared to safely perform the required corrective actions.
The District is aware that procedures have been developed to allow replacement of cells during normal plant operation.
If the. District can adapt these procedures such that nuclear and electrical safety considerations are maintained, i
the cell will be replaced during normal-operation.
If not, the plant will be brought to a cold shutdown condition to perform this maintenance activity..
Per our di.cussione'on February 7, 1992, the District will review the 250 Volt Battery System requirements contained in the CNS Technical Specifications for revision as appropriate.
By copy of 'this letter and attachment the NRC Region IV Office and the CNS Resident Inspector are also being notified in accordance with 10 CFR 50.4 (b)(1).
Should you have any questions or require any additional information regarding this submittal, please contact me.
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Sinyerely.
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G.h!!orn Nuclear power Group Manager GRil/ MAD
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NRC Regional Administrator i
Region-IV Arlington, TX
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NRC Resident Inspector Cooper Nuclear Station i
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