ML20094K072

RO 50-020/1992-2:on 911030,three Fission Chambers Missing During Annual Inventory of SNM Matl.Search for Missing Chambers Completed on 920311 W/O Locating Chambers.Snm Inventory for 1991 Has Been Amended

ML20094K072
Person / Time
Site:	MIT Nuclear Research Reactor
Issue date:	03/12/1992
From:	Bernard J, Kwok K, Masse F MASSACHUSETTS INSTITUTE OF TECHNOLOGY, CAMBRIDGE
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
50-020-1992-2, 50-20-1992-2, NUDOCS 9203180188
Download: ML20094K072 (3)

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l NUCLEAR REACTOR LABORATORY  ;

/@64- AN INTERDEPARTMENTAL CENTER OF W i MASSACHUSET1S INSTITUTE OF TECHNOLOGY  ;

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' O. CL HARLING 138 Atany Stfewt.Camtwxige. Mass 02139 4290 J A, BERNARD, JH [

Director Te@ fax No- $17)P53 F300 Dwctor of Heactor Operatons i Teles No 92 Mit AM Tel No. pt7) 42tt 4202/8 5642

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March 12,1992 U.S. Nuclear Regulatory Conunission l ATIN; Document Control Desk .,

Washington, D.C. 20555  !

Subject:

Reportable Occurwnec 50-20/1992 2, incorrect Inventory of Three Fission i Chambers ,

Gentlemen: [

Massachusetts Institute of Technology hereby submits this repon of an occurrence at the MIT Research Reactor in accordance with 10 CFR 70.52. A formal report of this occurrence wu made to NRC Region 1 (Mr. Arthur Della Ratta) on Match 12, 1992. .

Informal repons on the possibility of this occunence had been nwie on several previous occasions to either NRC Region I (Mr. Thomas F. Dragoun) or NRC lleadquarters (Mr.

Alexander Adams, Jr.).

The format and content of this report are based on Regulatory Guide 1.16, ,

Revision 1. i

~1, . Renort No.: 50 20/1992-2 2a. Repon D. ale: 12 March 1992  :

. 2 b. . Date of occurn nee: 30 October 1991 with search completed on l' 11 March 1992

3. . Eacjlily: MIT Nuclear Reactor laboratory 138 Albany Street Cambridge,MA 02139

4. Identification of Occurrencs:'

Three fission chambers could not be located during the annual inventory of SNM'  :

material required under license No, SNM 986. He tlure chambers are:  ;

' WI-7657 SN100 WL 7657 SN101  :

WL-6376 SN313 .

f' 9203180198 920312 I h PDR ADOCK 05000020 [v/

0 PDR /

r- nwe~s.m r ym .- w - + .e w -o ,-e e ,w m ,,,, w .m.,,,, m. ,w- -r * - ~ ~ + - ~ - - - - - - - - - -

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l Reportable Q;cunence 50-2(W2-2 l l' age 2 i Two contain 1.68 grams of enriched U 235 and one contains 1.72 grams of enriched U 235.

5. Conditions 14ior to Occumna:

The three fission chambers were used for operation of the original hilt Research Reactor, hilTR 1. They had leen placed in a shielded storage area (wall storage) pending their disposal as low level waste.

6. Descritition of Occuntng:

All special nuelcar material held under license No. SNht 986 is inventoried annually in OeLober. For most of this material, the inventory consists of a visual sighting.

110 wever, this is not possible for certain items such as installed instruments or used chambers that are in shleided storage where opening of the storage facility might generate significant personnel exposure and/or contamination. For SNht in this situation, the inventory consists of venrying records of the item's use and, where appropriate, seats on ic storage area.

In 1991,it was decided to sight all SNht visually except that which was pan of an installed instrument. Upon opening the shielded wall storage area where chambers WL-7657 SN100, WL7657 SNIOL, and WL-6376 SN313 were recorded as being located, the three chambers could not be found. A systematic search was then made of all mssible storage areas, This was quite time consuming because of the potential radiation inzards involved. The search was completed on Atarch 11,1992 without locating the three chambers in question.

7. Description of Aormrent.Cause of Occum nce:

In addition to instituting a scarch of all possible storage areas, a review was conducted of waste shipment reconis to detemiine if the three missing chambers might have been legally disposed of as waste. To the best of our knowledge this is in fact what occurred. The cause of this occurrence is therefore believed to be a fa i lure to update inventory records. Specifically, from 1979 to 1981, three shipments of waste items from the original hilt Research Reactor we e made. The last of these occuntd in February 1981 and it was authorized to contain 11 grams (0.0001 Ci) of enriched uranium in metallic, alloy, or oxide fomi. Unfortunately, the shipment records gave no breakdown of the matenal. The individuals in charge of the 1981 shipment have been interviewul and, to the best of their reco!'ection, the SNht in that shipment consisted of used fission chambers and a small quantity of unmium that had been used for student thesis research. Inventory records document the disposal of the latter, but not the chambers.

8. Analysis of OcettEnc:

l It is believed that the three missing chambers were properly disposed of and that this occunence is simply the result of a failuir to update the inventory records.

6 e .

Reportable Occurrence 50 2@2 2 Page 3

9. Corrective Action:

The 1991 SNM inventory has been amended to show the probable disposition of <

the ateve-identined three fission charnbers as identined in this report. ,

10. Failure Data:

None.

Sincerely,

(:;LcL.- f L.J(L Kwan S. Kwok, Ph.D.

Superintendent

- MIT Research Reactor

.% CL h John A. Bernard, Ph.D.

Directorof Reactor Operations Mir Researth Reactor sf( l0 W

- # Francis k. Masse, CllP Mrr Radiation Protection Officer JAD/gw cc: MrrRSC USNRC - Project Manager, NRR/PDNP USNRC - Region 1 - Chief, Effluents Radiation Protection Section (ERPS)

FRSSB/DRSS

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