ML20235V787

Forwards Memo Describing Incident Which Occurred at Reactor Critical Facility.Understands That Incident Does Not Require Immediate Notification to NRC

ML20235V787
Person / Time
Site:	Rensselaer Polytechnic Institute
Issue date:	02/17/1989
From:	Harris D RENSSELAER POLYTECHNIC INSTITUTE, TROY, NY
To:	Kane W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
NUDOCS 8903100333
Download: ML20235V787 (3)

Text

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d Department of Nuclear Engineenng & Engineering Physics February 17, 1989 William F. Kane, Director Division of Reactor Projects United States Nuclear Regulatory Commission Region 1 _ _

476 Allendale Road King of Prussia, PA 19406

Dear. Sir:

Enclosed is a copy of a memo describing for your information an incident which occurred recently at the RPI Reactor Critical Facility.

It is our understanding that this incident does not require immediate notification to the NRC.

Sincerely, ll. .

Dr. Donald R. Harris, Director RPI Reactor Critical Facility DRH:jjd Enc. I cc: P. DeRusso, Acting Dean G. Judd, Vice Provost for Academic Affairs R.C. Block R.T. Lahey, Jr.

M.Z. Podowski B.K. Malaviya R. Hockenbury R. Ryan P. Angelo F. Rodriguez-Vera R. Rohr T. Michaels, NRC H. Eichenholy, NRC 8903100333 890217

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h(kh Rensselaer W T?zyfDih Q g;,w p aika 1 i Departraent of Nudear Enaneering & Enancering Physics INTERDEPARTMENTAL MEMORANDUM

. DATE: February 10, 1989

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TO: Dr. Robert C. Block, Head Department of Nuclear Engineering & Engineering Physics FROM: Dr. Donald R. Harris, Director h

Reactor Critical Facility 7 >

The RPI Reactor Critical Facility (RCF) includes two coil heaters rated at 18 kilowatts each near the bottom of the reactor tank. These heaters are used to heat the reactor water in order to measure the effect of temperature on reactivity. We have thought that these coll heaters would be damaged if they were turned on when no water was in the reactor. No interlock prevents this, although the RCF operating procedures Indicate that this should not occur.

On Saturday February 4,1989 the RCF was operated during a Reactor Sharing Tour for a high school group arranged by Denise Jeffers and Mark Smith of RPl. The coil heaters were used to heat the water. When the reactor was secured the water was dumped (as is required) into the dump tank. Unfortunately the Reactor Supervisor, Mr. Peter Angelo, forgot to turn of f the coil heaters. I had conducted the tour but had lef t when the tour group lef t and before the reactor was secured.

On Tuesday February 7,1989 Mr. Angelo arrived at the RCF and found the reactor room was uncomfortably hot. Upon inspection he found that the coil heaters were on and no water was in the reactor tank. Mr. Angelo stated that the colls were glowing. He turned off the coil heaters and tested the systern components including introducing water to the reactor tank. The system components tested satisfactorily except that the neutron source could not be fully Inserted. The reactor water surf ace showed thin raf ts of paraf fin.

The core temperature Indicators, which had been turned on when the system components were tested, showed that the reactor core region reached about 180 degrees Farenheit. The reactor neutron source, located above and to one side of the core, is contained in a paraffin-cadmium shleid tank. This tank was found to have lost about three Inches of paraffin; this was established both visually and by observing an enhanced neutron dose above the shield tank.

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e , a m .b Dr. Robert C. Block February 10, 1089 Page 2 It was found that the neutron source could not be fully inserted because there were several inches of paraffin at the lower end of the source Insertion tube. When this paraffin was removed the source inserted normally. A swimming pool skimmer was obtained and the paraffin raf ts were removed from the water surface. The RCF pool filter was brought to the reactor deck and the water was filtered for l about two hours. The reactor water was then dumped into the dump tank and the reactor was secured. On Thursday February 9,1989 a considerable amount of paraffin was removed from the reactor tank wall and taase and from the core. Additional paraffin was added to the neutron shield tank. The reactor system now appears to be fully functional although the water is not completely clean. The coil heaters, contrary to expectations, appear to be undamaged. An Interlock to prevent future occurrences is being examined.

The Tuesday and Thursday Critical Laboratory classes were cancelled. No RCF sharing activities were scheduled so none needed to be cancelled.

DRH:JJd cc: P. DeRusso, Acting Dean Gary Judd, Vice Provost for Academic Affairs D.R. Harris R.C. Block R.T. Lahey, Jr.

M.Z. Podowski B. Malavlya R. Hockenbury R.Ryan P. Angelo F. Rodriguez-Vera R. Rohr

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