ML20209G161

Employee Concern IN-86-064-001, Mechanical Equipment Reliability/Design

ML20209G161
Person / Time
Site:	Sequoyah
Issue date:	08/04/1986
From:	Gardner G, Lagergren W, Mcvay J TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20209G085	List: ML20209G082 ML20209G101 ML20209G115 ML20209G140 ML20209G161 ML20209G176
References
1439T, 301.12-SQN, NUDOCS 8609120382
Download: ML20209G161 (5)

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TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT EMPLOYEE CONCERNS TASK GROUP OPERATIONS CEG Subcategory: Mechanical Equipment Reliability / Design Employee Concern: IN-86-064-001 Report Number: 301.12 SQN Evaluator: Ova S-9-OL G. D. Gardner Date Reviewed by: S. 2 hil ,, f!0 OPS'dEGyember / Chte Approved by: .( * - " Y!hb "W.R.Lagefgpen i D&te 1439T 8609120382 860909 PDR ADOCK 05000327 P PDR

I. System 31 Not Operated Properly This report evaluates the generic applicability for Sequoyah Nuclear Plant (SQN) of an employee concern regarding air flow switches on 480-volt board room air handling units. This issue was determined potentially safety significant by the Employee Concerns Task Group (ECTG) Technical Assistance Staff.

II. ISpecific Evaluation Methodology The employee concern identified to Quality Technology Company (QTC) for Watts Bar Nuclear Plant (WBN) is as follows:

IN-86-064-001 Four (4) air follow switches on the 480 volt board room air handlers do not function, Aux Bldg., Units 1

& 2 Elevs. 772' & 786'. These switches have been removed and re-calibrated and results have always been within acceptable tolerance; however, they remain inoperable. (Names / details known to QTC and release of this information would jeopardize CI's confidentiality) CI has no further information.

Nuclear Power Concern.

The ECTG files were reviewed and a Nuclear Safety Review Staff (NSRS) report was found to address the issue at WBN. This report along with informal interviews with cognizant engineers in SQN instrument maintenance formed the basis of the evaluation.

III. Findings The NSRS report for WBN (reference 1) was reviewed and it was determined that the area of concern was with Fluid Components Incorporated (FCI) flow switches. The report stated that the FCI probes were slow acting measuring up to 20 seconds to clear. Unless the operator held the start button for more than 20 seconds, the airhandling units (AHUs) would trip on low flow. The report noted that WBN instrument maintenance had initiated corrective action to relocate some of the probes in the ductwork and replace others with fast response probes to resolve the problems at WBN.

The cognizant engineers at SQN instrument maintenance for systems 30 and 31 (ventilation and air conditioning) were contacted. They stated that Dwyer diaphram type flow switches are used on the 480-volt board room AHUs and in most applications at SQN although FCIs are used on some equipment. Most of the FCIs were added as a result of modifications and were successfully tested. Both slow and fast probes are used at SQN and both engineers stated no problems had occurred similiar to WBN. Should any problems occur, they would be addressed at that time.

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Conclusion The issue presented by employee' concern IN-86-064-001 was not validated for SQN. The responsible engineers contacted stated problems which occurred at WBN have not occurred at SQN.

IV. Root Cause N/A V. Generic Applicability Evaluations conducted at both SQN and WBN resulted in no corrective actions. The concern was specific to WBN and was being addressed according to NSRS evaluations. This issue is therefore not considered generic.

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, VI. Reference 1

l 1. NSRS Investigation Report I-85-416-WBN, " Airflow Switches j Inoperable," Employee concern IN-86-064-001, December 18, 1985 l

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VII. Immediate or Long-Term Corrective Action a

N/A l

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