ML19262B588
| ML19262B588 | |
| Person / Time | |
|---|---|
| Site: | 05000139 |
| Issue date: | 12/21/1979 |
| From: | Chalk W WASHINGTON, UNIV. OF, SEATTLE, WA |
| To: | |
| References | |
| NUDOCS 7912280608 | |
| Download: ML19262B588 (2) | |
Text
w o-UNIVERSITY OF WASHINGTON SEATTLE, WASHINGTON 98195 College of Engineering Department of.Vuclear Engineering December 21, 1979 Mr. Robert Ried Branch Chief Division Operating Reactors Nuclear Reactor Regulation Whshington, DC 20545
Dear Mr. Ried:
Re: Docket No. S0-139 As per our technical specifications which require a written report within ten working days of an abnormal occurrence this report is being sub-mitted.
On DL ember 11, 1979 a graduate student spilled about five gallons of water on the reactor top where his experiment is located. The reactor was shutdown at that time.
We believe that a portion of the water ran down the sides of the shield plugs for vertiem_ hole No. 2 and onto the graphite moderator. Some ran over the edge and onto the floor. About two gallons were found in the process pit where a drain from under VH No. 2 emerges.
The Region V Nuclear Regulatory Commission Office was notified by tele-phone on December 13, 1979 after a scheduled startup indicated that we had a loss of reactivity. They recommended that we meet with our safety advisory committee, discuss the problem, and file this report. The meeting was held on December 17.
Eollowing the meeting we removed the shield plugs of VH No. 2, inspected the hole and found no evidence of standing water nor did we find moisture with a cotton swab.
We believe roome water was absorbed by the graphite and has resulted in a negative reactivity of approximately 0.77. delta K/K which was calculated from a 1/M plot. We assume that the negative reactivity which apparently was caused by the spilled water constitutes an uncontrolled negative re-activity change which would make it an abnormal occurrance.
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Benson Hall, BF-10 / Telephone: (206) 543-2754 O
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Mr. Robert Ried Page 2 December 21, 1979 Currently we are in the process of resolving the problem while reporting our progress to our safety committee and the Region V representatives.
Sincerely yours,
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L William S. Chalk, Director Nuclear Engineering Laboratories WSC:lk 2:.n B
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