ML20070N647

Ro:On 830110,fuel Temp Indication Failed to Respond During Reactor Startup.Caused by Shorted Thermocouple Wires in Terminal Box.Reactor Shut Down & Fuel Temp Instrument Connected to More Conservative Indication

ML20070N647
Person / Time
Site:	05000128
Issue date:	01/11/1983
From:	Rogers D TEXAS A&M UNIV., COLLEGE STATION, TX
To:	Madsen G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
NUDOCS 8301250568
Download: ML20070N647 (2)

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TEXAS ENGINEERING EXPERIMENT STATION THE TEXAS A&M UNIVERSITY SYSTEM COLLEGE STATION. TEXAS 77843 f'

W i NUCLEAR SCIENCE CENTER 11 January 1983 713/845-7551 Mr. G. L. Madsen bbh  ! .

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Office of Inspection and Enforcement Region IV M l 7 l9 @

U.S. Nuclear Regulatory Commission 611 Ryan Plaza, Suite 1000 J

' --g Arlington, Texas 76012 ,

Subject:

Failure of Fuel Temperature Indication to Respond During Reactor Startup

Dear Mr. Madsen:

Enclosed is a final report of a reportable occurrence observed during reactor operations of the NSCR. This report is submitted in compliance with Section 6.4 and 1.8 of Change No. 11 of the Technical Specifications, Facility License No. R-83 for the Nuclear Science Center, Texas A&M University.

Sinc ely,

d. rw DaleRogers,Mbger Reactor Operations DR/ym Enclosure b

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8301250568 830111

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{DRADOCK 05000128 PDR RESEARCH AND DEVELOPMENT FOR MANKIND

Final Report of Failure of Fuel Thermocouple During Reactor Startup Repor ta ble___0ccurrence On January 10, 1983 during a reactor startup to 400 kiiowatts it was noticed by the reactor operator that the fuel temperature indication was not tracking.

This startup was the initial startup following a core loading during which the instrumented fuel element was handled. The thermocouple was verified operational prior to startup and indicated approximately ambient pool temperature. It was not until the reactor was above the point of adding heat that the operator noted no increase in fuel temperature. At that point the startup was discontinued, and the reactor was shutdown for investigation.

Corrective Action _

Shorted thermocouple wires were discovered in a terminal box causing the indication to read approximately ambient temperature at all times. The problem was corrected, but during subsequent operation at 400 kilowatts it was noted that the fuel temperature indication was somewhat lower than that indicated on a second thermocouple (TC #2) in the same element. Therefore, the reactor was shutdown again, and the fuel temperature instrument was connected to the more conservative (highest) indication (TC #2 in IF #8795). The reactor has operated since that time with no further problems.

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