ML20137Y629

RO-85-04:on 850912,transient Rod Followed Cylinder Out During Positioning of Transient Rod Cylinder.Air Solenoid for Transient Rod Sys Not Functioning as Designed.Air Solenoid Disassembled,Cleaned & Reassembled

ML20137Y629
Person / Time
Site:	05000128
Issue date:	09/24/1985
From:	Donna Anderson TEXAS A&M UNIV., COLLEGE STATION, TX
To:	Johnson E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
RO-85-04, RO-85-4, NUDOCS 8510080058
Download: ML20137Y629 (2)

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TEX AS E N GIN E E RIN G EX P ElllM E NT STATIO N THE TEXAS A&M UNIVERSITY SYSTEM COLLEGE STATION, TEXAS 77843-3575

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M J l 1 24 September 1985 NUCLEAR SCIENCE CENTER 409 ^845-7551 i DU ,r 03 I@, - . -

OY_ /.b h ji Mr. Eric Johnson

' lj Office of Inspection and Enforcement '

SEP 3 0 085 Region IV .

J7 U.S. Nuclear Regulatory Commission .

611 Ryan Plaza Drive, Suite 1000 U Arlington, Texas 76012 RE: Technical Specification 1.29.c, Reportable Occurrence 85-04

Dear Mr. Johnson:

I am forwarding the final report of the reportable occurrence of 12 September 1985. This report is being submitted in accordance with NSC Technical Specification Section 6.6.2 for License R-83, Texas A&M University.

Respe fully,

/J Donald G. Anderson, Manager Reactor Operations Enclosure cc: Feenan Jennings, Chairman, Reactor Safety Board Carl Erdman, Head, Department of Nuclear Engineering Les Constable, Nuclear Regulatory Commission Bruce Ernst, American Nuclear Insurers p

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d Reportable Occurrence #85-04 Transient Rod Solenoid Malfunction REPORTABLE OCCURRENCE On September 12, 1985, with the NSCR at a power level of 300 watts-in preparation for a pulse, the transient rod followed the cylinder out during positioning of the transient rod cylinder. This malfunction resulted in a positive reactivity insertion which was instantanously observed by the reactor operator, who then took immediate corrective action. Visual inspection of the control rod extension indicated that the transient rod was not remaining in the full down position and in fact was following the withdrawal of the cylinder.

The reactor was shutdown for evaluation and correction of the problem.

Technical Specification 1.29.C, Reportable Occurrence, requires that the USNRC be notified if the following occurs during reactor operation: "A reactor safety system component malfunction which renders or could render the reactor safety system incapable of performing its intended safety function unless the malfunction or condition is discovered during maintenance tests or periods of reactor shutdown".

CORRECTIVE ACTION The NSCR was immediately shutdown and the cause of the incident was discussed by the NSC Staff. It was determined that the air solenoid for the transient rod system was not functioning as designed. The air solenoid was disassembled, cleaned, and reassembled and rod drop time measurements were conducted. Rod drop times met the requirements of the technical specifications, so the NSCR was returned to service. A kit for the solenoid valve has been ordered and until the replacements are installed, drop times will be conducted prior to each days initial startup to demonstrate operability of the transient rod system.

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