ML20151W232

Ro:On 980826,facility Bldg Air Monitor (Fam Channel 4) Failed Daily Fam Alarm Checks Prior to Reactor Operation. Caused by Failed Alarm Relay.Staff Is Preparing Formal Written Procedures for Testing Configurations for Fam Sys

ML20151W232
Person / Time
Site:	05000128
Issue date:	09/08/1998
From:	Reece W TEXAS A&M UNIV., COLLEGE STATION, TX
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
98-0249, 98-249, NUDOCS 9809150228
Download: ML20151W232 (4)

Text

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TEXAS ENGINEERING EXPERIMENT STATION TEXAS A&M UNIVERSITY COLLEGE STATION TEXAS 77843-3575

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NUCLEAR SCIENCE CENTER 409/845-7551 September 8,1998 98-0249 U.S. Nuclear Regulatory Commission ATTN: Document Control Washington, D.C. 20555-0001

Subject:

Reportable Occurrence at Texas A&M University Nuclear Science Center on August 26,1998

Reference:

Facility Operating License R-83, Docket 50-128

Dear Sirs:

The following is a description of the events leading to a Reportable Occurrence at the Texas A&M University Nuclear Science Center Reactor (NSCR) and the corrective i actions. This event was reported to the NRC on August 27,1998.

Description of Reportable Occurrence On August 26,1998, the Facility Building Air Monitor (FAM Channel 4) failed the daily ]

FAM alarm checks prior to reactor operation. This system is required to be in operation i as a Limiting Condition of Operation (NSCR Technical Specification 3.5.1). The system  ;

was removed from service for troubleshooting and a failed alarm relay was discovered in l the NIM module. Spare parts were no longer available from the manufacturer and an i equivalent relay was ordered from another source. NSC Management considered FAM \p Channel 4 to be inoperable and the Reactor Manager was directed to monitor the building using an equivalent but not required channel (FAM Channel 2). The NSC Air Monitor sample transport piping is configured to allow individual detectors to sample from alternate points (Figure 1).

The Duty Health Physicist (DHP) intended to line up the system such that FAM Channel ,

2 would monitor the reactor building particulates. Although the DHP had performed  ;

several Argon-41 calibrations involving the FAM piping, the valve lineup was positioned l incon ectly (Figure 2). A cap for a quick connection was missing and the DHP moved a l cap from Detector 6 to that location. The combination ofincorrect valve arrangement and the missing cap caused a leakage path that bypassed or significantly reduced flow through all particulate detectors. The air leakage flowed through the building and  ;

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98-0249 Page 3 L . .

effluent gas detectors and out through the flow meters. The indications to the DHP appeared normal because the air flow meters (rotometers) indicated normal 350 cfh flow.

l The reactor was operated in this condition for another eight hours. The next day, the L DHP questioned the abnormally low readings on all FAM meters (<5 cps). The Senior l Reactor Operator investigated with the DHP and found the incorrect valve line-up. The

[ ~ NSC Director, Reactor Safety Board Chairman and the NRC (Marvin Mendonca) were all informed of the Reportable Occurrence. j l t Root Cause Analysis J l

l Several weaknesses were found during a root cause meeting of the NSCR staff on August

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1. There was no written valve lineup procedure for abnormal conditions of the Facility j

Air Monitoring System.  !

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2. - A certified Duty Health Physicist (DHP) performed valve manipulations without a -l L system check by the on-duty Senior Reactor Operator or Reactor Operator. Although j not formally required, usually the SRO confirms valve alignments.

l l 3. Readings were logged in the contral room during the eight hour occurrence. These readings clearly indicated a decrease in radioactive counts. The evening shift operators, unfortunately, did not recognize the trend to be a system failure.

l Corrective Actions I 1. The Reactor Operations and Health Physics Staff are preparing formal written l procedures for normal, abnormal and testing configurations of the FAM system.

l- These procedures should be reviewed and approved by the Reactor Safety Board.

l-

2. The NSCR Tag-out and Lock-out procedure is being rewritten to require a second check of any tag by a licensed Reactor Operator.  ;

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' 3. The NSCR staff will be trained on the new procedures, the necessity for system tag-  !

outs for facility and personnel protection and normal expected indications on all i facility equipment.

l

!' . This Reportable Occurrence and the conective actions will be rcviewed at the next p meeting of the Reactor Safety Board. The Board may make additional requirements l . necessary. l

. i

1 98-0249 Page 4 Conclusion This Reportable Occurrence will be documented in the Reactor Safety Board meeting minutes and the facility Annual Report. Please contact Dr. Dan Reece or Mr. Sean O' Kelly at 409-845-7551 if more information is required.

Respectfully, bs . LA.

W. D. Reece Director WDR/tll xc: 12110/ Central File 17124/NRC Reportable Occurrence Dr. Ted Michaels, USNRC Mr. Marvin Mendonca, USNRC Dr. Don B. Russell, Reactor Safety Board Chairman