ML20136B775

Forwards SER Re Licensee Development of Troubleshooting Plans to Investigate 850609 Incident Concerning Inoperable Redundant source-range Nuclear Instrumentation Channels. Return to Power Operation Acceptable

ML20136B775
Person / Time
Site:	Davis Besse
Issue date:	12/24/1985
From:	Holahan G Office of Nuclear Reactor Regulation
To:	Stolz J Office of Nuclear Reactor Regulation
Shared Package
ML20136B780	List: ML20136B775 ML20136B784
References
NUDOCS 8601020914
Download: ML20136B775 (3)

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[! aut ~g i UNITED STATES 8 o NUCLEAR REGULATORY COMMISSION

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% ....+ DEC 2 41985 MEMORANDUM FOR: John F. Stolz, Director PWR Project Directorate No. 6 FROM: Gary M. Holahan, Director Operating Reactors Assessment Staff, NRR

SUBJECT:

DAVIS-BESSE -- SOURCE RANGE NUCLEAR INSTRUMENTATION During the June 9, 1985 incident at the Davis-Besse plant, both redundant source range nuclear instrumentation channels were inoperable. Because of the attention given to this event, the licensee developed systematic and thorough troubleshooting plans to investigate these problems, most of which had existed for a long time.

We agreed to review the licensee's findings reports related to these trouble-shooting plans. In the enclosed SER, we conclude that the significant contributors to these problems have now been identified and that the corrective actions have been effective in improving the performance of these instrumentation channels. From the standpoint of the source range nuclear instrumentation, return to power operation is now acceptable.

8 Y Gary M. Ho ahan, Director Operating Reactors Assessment Staff, NRR Enclosure Safety Evaluation Report cc: A. DeAgazio D. Crutchfield

0. Parr i

CONTACT:

J. T. Beard, ORAS x27465 8601020914 851224 PDR ADOCK 05000346 S pon 1

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QJ MEMORANDUM FOR: John F. Stolz, Director PWR Project Directorate No. 6 FROM: Gary M. Holahan, Director Operating Reactors Assessment Staff, NRR

SUBJECT:

DAVIS-BESSEr-- SOURCE RANGE NUCLE"R

" INSTRUMENTATION During tb June 9, 1985 incident at the Davis-Besse plant, both redundant source _ nge i.- lear instrumentation channels were inoperable. Because of the etent'c'. 'v(n to this event, the licensee developed systematic and thorough troubie200 ting plans to investigate these problems, most of which had existM for a long time.

We agreed to review the licensee's findings reports related to these trouble-shocting plans. In the enclosed SER, we conclude +.nat the significant contributors to these problems have now been identified and that the corrective actions have been effective in improving the performance of these instrumentation channels. From the standpoint of the source range nuclear instrumentation, return to power operation is now acceptable.

Gary M. Holahan, Director Operating Reactors Assessment Staff, NRR Enclosure Safety Evaluation Report cc: A. DeAgazio D. Crutchfield O. Parr DISTRIBUTION Central File NRC PDR CONTACT: ORAS Rdg J. T. Beard, ORAS GHolahan x27465 JTBeard RWessman RKendall ERossi WRogers ORAS ( AS 0 JTBeard:dm " irgi W GHolahan 12//2-/85 12/f>/85 12/)/85 7

~P MEMORANDUM FOR: John F. Stolz, Director PWR Project Directorate No. 6 FROM: Gary M. Holahan, Director Operating Reactors Assessment Staf f, NRR

SUBJECT:

DAVIS-BESSE -- SOURCE RANGE NUCLEAR INSTRUMENTATION During the June 9, 1985 incident at the Davis-Besse plant, both redundant source range nuclear instrumentation channels were inoperable. Because of the attention given to this event, the licensee developed systematic and thorough troubleshooting plans to investigate these problems, most of which had existed for a long time.

We agreed to review the licensee's findings reports related to these trouble-shooting plans. In the enclosed SER, we conclude that the significant contributors to these problems have now been identified and that the corrective actions have been effective in improving the performance of these instrumentation channels. From the standpoint of the source range nuclear instrumentation, return to power operation is now acceptable.

Gary M. Holahan, Director Operating Reactors Assessment Staff, NRR Enclosure Safety Evaluation Report cc: A. DeAgazio D. Crutchfield O. Parr DISTRIBUTION Central File NRC PDR CONTACT: ORAS Rdg J. T. Beard, ORAS GHolahan x27465 JTBeard RWessman RKendall

! ERossi WRogers ORAS C AS D JTBeard:dm ^"" rg " M GHolahan

'2//S/85 12//>/85 12/)/85 7

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