ML19257A641
| ML19257A641 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 12/21/1979 |
| From: | Vollmer R Office of Nuclear Reactor Regulation |
| To: | Chmielewski C, Dareid D, Power J AFFILIATION NOT ASSIGNED |
| Shared Package | |
| ML19257A642 | List: |
| References | |
| NUDOCS 8001070101 | |
| Download: ML19257A641 (4) | |
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December 21, 1979 Docket No. 50-10 SEE ATTACHED LIST This is in response to your recent letter to Dr. Hendrie, which expressed your cor. ceca relcted Lv the chemical decontamination of Dresden Nuclear Power Station, Unit No. 1.
We have been reviewing this project since Commonwealth Edison's initial decontamination proposal on December 12, 1974.
On December 9,1975, we issued a conditional authorization which allowed Commonwealth Edison to initiate the chemical decontamination subject to the completion of three items which would be resolved as follows:
1.
The testing program will be completed and the results submitted for the review and approval of the NRC staff prior to perfoming the proposed chemical cleaning.
2.
A pre-service inspection program for the primary coolant boundary will be fomulated and submitted for NRC review and approval prior to returning the reactor to service.
3.
A post-cleaning surveillance program which includes additional surveillance specimens and a specimen withdrawal and examination schedule will be submitted for NRC review and approval prior to returning the reactor to service.
A copy of our Safety Evaluation in support of these actions is enclosed for your infomation.
Since our 1975 authorization Commonwealth Edison has completed its materials test program and construction of the necessary support facilities to carry out the project in a safe and environmentally acceptable manner. Our review of the testing program and the facility construction is continuing and will be completed prior to the chemical cleaning that is currently scheduled for early 1980.
The cecontamination process involves the circulation of a Dow Chemical Company cleaning solvent through the reactor primary cooling system.
The solvent, identified as NS-1, has been developed to remove the thin, tightly adherent, layer of highly radioactive oxide that has formed on the inside surfaces of the Dresden 1 primary cooling system.
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- The solvent will preferentially dissolve the oxide without s'Jnifici,atly ittacking the underlying base metal of the primary. cooling system piping.
After removal of the uranium fuel, the solvent will be circulated through the primary coolant system for approximately 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> at about 25&F.
After circulation the solvent and the dissolved oxides will be drained from the reactor to a waste treatment facility located adjacent to the reactor. Any remaining solvent will be cleaned from the reactor by rinsing with demineralized water. The rinse water and solvent will be stored in the waste treatment facility storage tanks until processed to concentration and solidify the solvent and dissolved radioactive corrosion products.
The decontamination will be carried out entirely within a closed system and all waste processing will be accomplished within a speciclly designed, earthquake proof, leak tight, building. All transportation of radioactive wastes will be done in accordance with all applicable NRC and Department of Transportation regulations.
Because of these precautions, there will be no increased hazard to the health and safety of the citizens of Illinois or any degradation of the environment in Illinois.
After processing the concentrated waste soiution will be solidified in 55 gallon drums using a process developed by the Dow Chemical Company for the solidification of low level radioactive wastes. This plidification process has been tested on the NS-1 solvent and produced a solid waste fonn that contained no free liquids. The waste solidification procedures include a quality control process test on each barrel of waste to provide additional assurance that the liquid waste has been properly solidified.
After solidification the waste drums will be transported by a commercial radioactive waste carrier to a licensed solid waste burial ground such as Beatty, Nevada or Hanforti, Washington. These arid, desert sites have been specifically selected for the disposal of the Dresden waste to further assure that there is no interaction of the waste with ground water.
Because the waste is in a solid form, the ground water level is approximately 300 feet below the surface, and the burial sites are located in remote, uninhabited locations, there is adequate assurance that the waste will remain isolated from potential pathways for exposure of the population.
The cost of the Dresden 1 decontamination has been estimated at 36 inillion doll ars. Much of this cost represents one time development costs which would not be incurred in subsequent reactor decontamination at Dresden 1 or other nuclear facilities. At this time there are no plans to decon-taminate the primary cooling system of other U. S. nuclear facilities, 1692 141
.. however, preliminary estimates of the cost for decontaminating currently operating U. S. reactors range from 1 million to 5 million dollars per reactor an'd would vary depending on the extent of modification required at a specific facility to perfom the decontamination.
The decontamination of reactor primary cooling systems will reduce the radiation exposure levels in the areas of these systems, thereby pemit-ting greater access to the system for inspections, modifications, and repairs.
These activities provide greater assurance of the continued safe operation of the reactor and are therefore in the best interest of the health and safety of the public.
Furthemore, the decontamination will reduce the occupational exposure of the individuals employed at Dresden.
With respect to requests for the preparation of an Environmental Impact Statement for the Dresden Unit 1 decontamination, Title 10 Part 51.5 of the United States Code of Federal Regulations identifies the following actions as requiring the preparation of such a Statement:
"(1) Issuance of a pemit to construct a nuclear power reactor, testing facility, or fuel reprocessing plant pursuant to P et 50 of this chapter; (2) Issuance of a full power or design capacity license to operate a nuclear power reactor, testing facility, or fuel reprocessing plant pursuant to Part 50 of this chapter; (3) Issuance of a pemit to construct or a design capacity license to operate an isotopic enrichment plant pursuant to s50.33 of this chapter; (4) Issuance of a license to possess and use special nuclear material for processing and fuel fabrication, scrap recovery, or conversion of uranium hexafluoride pursuant to Part 70 of this chapter; (5) Issuance of a license to possess and use source material for uranium milling or production of uranium hexafluoride pursuant to Part 40 of this chapter; (6) Issuance of a license authorizing commerical radioactive waste disposal by land burial pursuant to Parts 30, 40, and/or 70 of this chapter; (7) Conversion of a provisional operating license for a nuclear power reactor, testing facility or fuel reprocessing plant to a full power or design capacity license pursuant to Part 50 of this chapter where no final environmental impact statement has been previously prepared; g
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. (8) Issuance of a license to manufacture pursuant to Appendix M of Part 50 of this chapter; (9) Amendments of Parts 30 and 40 of this chapter concerning the exemption from licerising and regulatory requirements of any equip-ment, devise, cocnodity or other product containing byproduct material or source material; and 1
(10) Any other action which the Commission determines is a major Commission action significantly affecting the quality of human environment."
Our review to date has concluded that the decontamination of the Dresden 1 primary coolant system is not one of the identified actions requiring that an Environmental Impact Statement be prepared.
The Commission has not determined that this action is a major Commission action significantly affecting the quality of the human environment.
In summary, the Dresden decontamination has been carefully planned to improve the safety of the reactor and red Jce the exposure of plant personnel to radiation. The waste produced by the process is similar in type and quantity to the waste routinely produced at Dresden and its processing, transportation, and disposal will not cause any new hazards not previously evaluated and deemed acceptable.
Sincerely,
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/
Richard H. Vollmer, Acting Assistant Director for Systematic Evaluation Program Division of Operating Reactors
Enclosure:
Safety Evaluation 1692 143