ML20031F090
| ML20031F090 | |
| Person / Time | |
|---|---|
| Site: | 05000394 |
| Issue date: | 10/06/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20031F088 | List: |
| References | |
| NUDOCS 8110190161 | |
| Download: ML20031F090 (2) | |
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING ORDER AUTHORIZING DISMANTLING OF FACILITY AND DISPOSITION OF COMPONENT PARTS CALIFORNIA POLYTECHNIC STATE UNIVERSITY DOCKET NO. 50-394 Introduction By application dated April-30,1981, as revised September 8,1981, the California Polytechnic State University (CPSU) requested authorization to dismantic the AGN-201 Training Reactor and dispose of its component parts in accordance with a pro-posed dismantling plan.
Discussion The AGN-201 Training Reactor is a small research reactor which operated at a power level of 0.1 watt at CPSU. Tne reactor core consists of polyethylene disks im-pregnated with uranium dioxide. The disks are about 10 inches in diameter and twenty percent enriched with U-235. Reactor operation requires the insertion of the two fueled safety rods and the fueled course control rod into the core. A fine control rod, also fueled, is used for adjusting reactor power level.
The AGN-201 core is contained within an aluminum core tank (the core can) which is surrounded by a graphite reflector and then a lead shield. The lead shielding is surrounded by a water filled shield tank. The entire AGN-201 structure is about 61/2 feet in diameter by 7 feet high.
The AGN-201 Training Reactor was operated first by the U. S. Naval Postgraduate School in Monterey, California, from April 30,1957 until 1971.
It operated inter-mittently at a 0.1 watt thermal power level until the NRC authorized a power level of 10 we.tts thermal in 1963 following facility modifications. A total of 631 watt-days accumulated during operation of this reactor at the USN Postgraduate School.
The reactor was shut down in 1971, dismantled in 1973, and relicensed at a power level of 0.1 watts thermal at CPSU on October 7,1975. The facility operated peri-odically until final shutdown on May 30, 1978. The reactor accumulated only 0.043 watt-days of operation at CPSU.
Evaluation Nuclear criticality safety of the AGN-201 is assured because all four of the fueled safety and control rods have been removed and are in secured storage. The dismantling plan requires that these fueled rods remain in locked storage during dismantling operations. The AGN-201 is designed so that it cannot become critical without the insertion of at least three of the four fueled rods. As an additional precaution, a cadmium (neutron absorber) rod is inserted into the " Glory Hole" which passes horizontally through the core. This cadmium rod will remain in place except for its temporary removal to allow the " core can" to be lifted out of the AGN-201 structure.
The cadmium rM will be repiaced into the " Glory Hole" immediately after the " core
'8110190161 81100 J DR ADOCK 0500039
SE can" is removed. The fuel disks will be removed from the " core can" and stored in two separate locked vaults, one-half in each. A gamma monitoring meter and neutron survey meter will be in continuous operation during the
" core can" removal operation.
In addition, two.of the three thermal neutron channels will be in operation during all disassembly operations. All disassembly operations will be supervised by an AGN-201 Senior Licensed Operator. Radiation safety during dismantling of the reactor is not a rajor problem because of low rediation levels involved. The RaBe startup source has been removed and stored in a shielded container. Also, calculations by CPSU show the reactor. core (fuel) will have radioactive levels of less than 2 mrem /hr on contact.
The CPSU Radia-tion Safety Officer will assure that monitoring is accomplished during disassrJbiy and that procedures will maintain exposures as low as reasonably achievable.
Packaging of fuel and RaBe startup source into Department of Transportation approved con' tainers and shipping will be supervised by-a Senior Licensed Operator. The fuel and startup source will be shipped to a Department of Energy (DOE) facility.
The fuel will be reprocessed by DOE for use in other reactor programs. Reactor com-ponents will be decontaminated and stored at CPSU for future use at other research reactor facilities, use at the University or disposal as scrap.
If some reactor components remain radioactively contaminated or activated, they will be packaged in approved containers and shipped to an authorized waste burial site.
Conclusion We have concluded, based on the considerations discussed above, that dismantling the CPSU AGN-201 Training Reactor and disposing of component parts as described in the dismantling plan will not be inimical to the common defense and security or to the health and safe +.y of the public.
Dated: October 6,1981
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