ML20198T201
| ML20198T201 | |
| Person / Time | |
|---|---|
| Site: | 05000294 |
| Issue date: | 06/03/1986 |
| From: | Malchman W, Wilkinson B MICHIGAN STATE UNIV., EAST LANSING, MI |
| To: | Dosa J Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8606110367 | |
| Download: ML20198T201 (2) | |
Text
9 MICHIGAN STATE UNIVERSITY COLLEGE OF ENGINEERING
- DIVISION OF ENGINFE RING RESEARCII EAST LANSING
- bitCHIGAN
- 48824 June 3, 1986 Mr. John Dosa, Project Manager Standardization and Special Projects Directorate Division of PWR Licensing-B United States Nuclear Regulatory Commission Washington, D.C.
20555 Ref: Docket 50-294
Dear Mr. Dosa:
Thank you for sending the material related to reactor decommissioning requirements. We have examined the documents along with the ANSI 15.10 standard you recommended. The possible decommissioning of our reactor is still being considered and there are several questions for which we would like to obtain answers before making a final decision.
The items of particu-lar concern are listed below.
It is possible that a meeting to discuss the ramifications of these questions would be appropriate and we will plan to call you in several weeks to see if such a meeting would be useful and, if so, to set up an appointment.
The present plans tentatively call for putting the MSU reactor in a " Safe-store" mode by removal of all fuel and shipment to the Dept. of Energy (under the present license) and (perhaps) shipping the remaining radioactive core non-fuel components to a suitable site (either for disposal or to some other Triga site where they might be useful).
In this case the only remaining radioactivity would be contained in the reactor tank walls and the concrete shielding surrounding the wall. This radioactivity would be below ground.
(We have monitored the soil outside the concrete shield and are unable to detect the presence of contamination in this area).
By converting to Safestore, the University would obviously commit to ultimate removal of the contaminated tank and concrete at some future date.
Delaying this process would allow the radioactivity in the material to decay and thus reduce the exposure to personnel during the removal and the cost of the disposal process.
During the interim period of Safestore, the University would like to simply seal off the top of the reactor tank and release the remainder of the reactor room to non-nuclear research activities. Obviously, monitoring of the radioactivity on a periodic basis would be required.
Isolation of the public from the radioactivity would be assured by the location of the contamination (sealed in the tank wall and concrete) and the cover over the reactor tank.
Do you think such an arrangement could be authorized?
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June 3, 1986 Page 2 During the final decommissioning phase (several years hence), the question will need to be resolved is to what levels of contained induced radioactivity can be allowed to remain in the concrete left in place. At the present time we do not have an indication as'to the radioactive concentrations in this concrete and it is impossible to measure this until the reactor has been converted to Safestore. At.some time, it may be possible to perform test borings through the aluminum reactor tank and into the concrete. These horings would allow us to measure'the concentrations and identifications of tho'various isotopes that have been induced in the concrete and thus make a projection of the activity-va-depth profile of the contamination. We would like to have some indication as to the allowable non-removable radioactivity that could be authorized at the present time and, further, whether you feel that this concentration limit might be reduced in the future. Such numbers would tus useful to the University in planning the scheduling and budgetary operations for the ultimate conversion of the facility to an unrestricted use.
Your assistance in replying to these questions in a formal or informal manner would be of great assistance to us in our deliberations. Thank you for your assistance. We will call you in the near future to discuss whether a visit would be appropriate.
Sincerely, (du Y=:
s W.H. Malchman, Director B.W. Wilkinson Office of Radiological, Reactor Supervisor Chemical & Biological Safety