ML100431305

LER from Us Dept. of Defense, Armed Forces Radiobiology Research Institute Occurred on 03/16/09

ML100431305
Person / Time
Site:	Armed Forces Radiobiology Research Institute
Issue date:	03/16/2009
From:	Lillis-Hearne P US Dept of Defense, Armed Forces Radiobiology Research Institute
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
44909
Download: ML100431305 (3)

Text

ARMED FORCES RADIOBIOLOGY RESEARCH INSTITUTE 8901 WISCONSIN AVENUE BETHESDA, MARYLAND 20889-5603 DIR 16 MARCH 2009 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:

Attached is the Licensee Event Report (LER) for the reportable event that occurred on 16 March 2009, and was reported to the USNRC Operations Center (Mr. Bill Huffman) and Mr. Patrick Isaac telephonically (NRC Notification Number 44909).

The point of contact for further information is Stephen Miller, Reactor Facility Director at (301) 295-9245, millers cdafrri. usuhs.mil Sincerely, Patricia K. Lillis-Hearne COL; MC, USA Director Copy to:

USNRC Attn: Mr. Patrick Isaac Mail Stop 12D3 USNRC Attn: Mi F-x-Al h &derAdams' Mail Stop 12G13 Washington, DC 20555 USNRC Attn: Mr. Johnny Eads Mail Stop 12G15 Washington, DC 20555

Licensee Event Report For the AFRRI TRIGA Reactor Facility Docket 50-170 I declare under penalty of perjury that this event po is Prue and correct EPH N PILLER DATE eacor Fac lity Director

I Abstract While operating at 75% power, the operator observed that fuel temperature channel number 1 was fluctuating between approximately 375 and 160 degrees C. After several minutes the temperature reading stabilized at approximately 170 degrees C. At 75%

power, the expected reading is approximately 300-400 degrees C. This reading was indicative of a failure in the measuring channel. Technical Specifications 2.2, 3.2.1 and 3.2.2 require two functional fuel temperature measuring and scram channels. With fuel temperature channel 1 inoperable, the reactor was operating outside of the limiting conditions of operations, Technical Specifications chapter 3..x.x. The reactor was manually shut down, and the problem repaired before returning to normal operations.

Root Cause The safety system was tested prior to operations at the beginning of the work day. There are two fuel measuring and scram channels, both of which are required. The root cause of this event was a failure of a thermocouple and could not have been prevented.

Assessment of Safety Consequences There are no safety consequences of this event. There are two redundant safety channels such that the automatic system would still execute a system scram in the event that the fuel temperature would exceed the limiting safety system setting.

Description of Corrective Actions Facility management investigated the circumstances of the event, and concluded that an unavoidable equipment malfunction occurred. The following actions were completed before the system was placed back into operations:

1. An instrumented fuel element from storage was moved to B5 to replace the damaged thermocouple.

2. The system was tested and returned to service.

Reference to Any Previous Similar Events A review of records for the past 10 years did not find any similar events.

Point of Contact for any Ouestions Point of contact for additional information is Stephen Miller, Reactor Facility Director, (301) 295-9245