U-602068, Ro:On 921107,ORIX-PR008 Was Declared Inoperable Due to Lo Fail Signal Received for Channel 3 Which Was Unable to Be Reset.Preplanned Alternate Method of Monitoring HVAC Stack Initiated

Ro:On 921107,ORIX-PR008 Was Declared Inoperable Due to Lo Fail Signal Received for Channel 3 Which Was Unable to Be Reset.Preplanned Alternate Method of Monitoring HVAC Stack Initiated

ML20127N341
Person / Time
Site:	Clinton
Issue date:	11/24/1992
From:	Spangenberg F ILLINOIS POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
U-602068, NUDOCS 9212010191
Download: ML20127N341 (2)

Text

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Hlinom Power Compo J!

Chnton Power Sta .' i

,-- P.O Box 678

.,. Chnton, IL 61727 Tot 217 935-8881

~

U-602068 L30-92 (11-24)-LP

" ILLIN9IS 1E.100c POWER 10CFR50.35 November 24, 1992

%cket Nc. 50-461 Document Control Desk Nucicar Regulatory Commission k'ashington, D.C. 20555 Subj ect: Special Reporu Extended Inoperability of the HVAC Stack High Range Radioactivity Monitor (ORIX-PR008) at Clinton Power-Station (CPS)

Dear Sir:

Clinton Power Station (CPS) Technical Specification 3.3.7.5, " Accident Monitoring Instrumentation," requires the Heating, Ventilation, and Air Conditioning (HVAC) Stack High Range Radioactivity Monitor to be OPERABLE,when the plant is in OPERATIONAL CONDITION 1,- 2,_or 3. In the event the monitor becomes-inoperable, the= Technical Specification requires-(per-Action Statement

81) either the monitor be restored to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or a preplanned alternate method of monitoring the parameter be initiated and a Special Report be submitted to the Commission pursuant to Technical Specification 6.9.2 within 14 days. The Special Report must cutline the action taken,'the cause of the inoperability, and plans and schedule for restoring the monitor to OPERABLE status.

At 1420 hours0.0164 days <br />0.394 hours <br />0.00235 weeks <br />5.4031e-4 months <br /> on. November 10, 1992, the HVAC Stack High Range Radioactivity Monitor (ORIX-PR008) had been inopercole to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. As a result, thia Special Report la.being submitted in accordance with CP3 Technical Specification Table 3.3.7.5-1 Action Statement 81 and CPS Technical Specification 6.9.2.

Event Summary (Description and Cause)

At.1420 hours0.0164 days <br />0.394 hours <br />0.00235 weeks <br />5.4031e-4 months <br /> on November 7, 1992,.ORIX-PR008 was declared inoperable l 'due to a "Lo Fall" signal received for Channel 3 which was unable to.be reset.

l -A failed radiation datector wms determined to be the cause for the signal','and l a new detector was 4nstalled. During replacement of the detector,

, . conununication with the' rest of the system also failed. Troubleshooting of the-l failed monitor was initiated, and it was determined that a circuit card had'

failed. A new safety-related circuit card was ordered, and crernight delivery

) was anticipated.

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9212010191 921124 -

I PDR ADOCK 05000461 -- 1 gl 5 """

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_y A't 1420 hours0.0164 days <br />0.394 hours <br />0.00235 weeks <br />5.4031e-4 months <br /> on November 10, 1992, the 72-hour Technical Specification time limit. expired prior.to receipt of the replacement circuit card. CPS initiated the preplanned alternate method of_ monitoring the HVAC stack radiation level as required by Action Statement 81 of CPS Technical Specification Table 3.3.7.5-1. These alternate methods are described in Section 8.7 of CPS Procedure 7410.77, " Operation of Eberline Accident Range Monitors (AKMs)." Also, additional control and instrumentation technician inanpower was scheduled to replace the circuit card upon its arrival. -As previously noted, the replacerant circuit card was expected on November 11, 1992. However, due to a delay in shipping, the card arrived at the end.uf the work day on November 12, 1992.

Following installation of the new circuit card on November 13, 1992, a post-maintenance surveillance _ test was performed on the monitor. However, the monitor failed one part of the radiation source response check, _Another new, radiation detector was subsequently installed, and the monitor successfully passed the cource response check. Following review of the results of CPS Procedure No. 9437.64, the monitor was restored to OPERABLE status at 1700' hours on November 14, 1992.

4 l

Sincerely yours, m

F. A, Spangenbe , III l Manager, Licensing and Safety l CIJ/msh cc: NRC Clinton Licensing Project Manager NRC Resident Office. V 690 Regional Administrator, Region. III, USNRC Illinois Department of Nuclear Safety 1

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