ML19290D986
| ML19290D986 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 01/31/1980 |
| From: | Vollmer R Office of Nuclear Reactor Regulation |
| To: | Thomas T AFFILIATION NOT ASSIGNED |
| Shared Package | |
| ML19290D987 | List: |
| References | |
| NUDOCS 8002290615 | |
| Download: ML19290D986 (4) | |
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January 31, 1980 Docket No. 50-10 Mr. Tim Thomas 196 Marian Parkway Crystal Lake, Illinois 60014
Dear Mr. Thomas:
This is in response to your recent letter to Dr. Hendrie, which expressed your concern related to the chemical decontamination of Dresden Nuclear Power Station, Unit No.1.
We have been reviewing this project since Conmonwealth Edison's initial decontamination proposal on December 12, 1974. On Deceraber 9,1975, we issued a conditional authorization which allowed Commonwealth Edison to it;itiate 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 perfonning the proposed chemical cleaning.
2.
A pre-service inspection program for the primary coolant boundary will be formulated 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 infonnation.
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 decontamination 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 significantly attacking the underlying base metal of the primary cooling system piping.
Af ter 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 250 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 concentrate and solidify the soivent 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 specially designed, earthquake proof, leak tight, building.
All transporation of radioactive wastes will be done in accordance with all applicable NRC and Department of Transporation 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.
Af ter processing the concentrated waste solution 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 solidification process has been tested on the NS-1 solvent and produced a solid waste form that contained no free liquids. The waste solidification procedures include a quality control process test on eac5 barrel of waste to provide additional assurance that the liquid waste has been properly solidified.
Af ter solidification the waste drums will be transported by a comercial radioactive waste carrier to a licensed solid waste burial ground such as Beatty, Nevada or Hanford, 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 fom, 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 million dollars. 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, however, preliminary estimates of the cort for decontamination currently operating U. S. reactors range from 1 million to 5 million dollars per reactor and would vary depending on the extent o' modification required at a specific facility to perform the decontami% tion.
The decontamination of reactor primary cooling systems will reduce the radiation exposure levels in the areas of these systems, thereby permit-ting greater access to the system for inspection, 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.
Furthermore, the decontamination g
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 permit to construct a nuclear power reactor, testing facility, or fuel reprocessing plant pursuant to Part 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 permit to construct or a design capacity license to operate an isotopic enrichment plant pursuant to $50.22 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 o' a license authorizing commerical radioactive waste disposal by lar 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;
. (8) Issuance of a license to manufacture pursuant to Appendix M of Part 50 of this Chapter; q
(9) Amendments of Pr.s 30 and 40 of this chapter concerning the exemption from licensing and regulatory requirements of any equip-ment, device, commodity or other product containing byproduct material or source material; and (10) Any other action which the Connission determines is a major Coamission action significantly affecting the quality of the human J
envi ronment. "
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 reduce 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.
- incerely, m_
[t,- Richard H. Vollo r, U
Acting Assistant Director Systematic Evaluation Program Division of Operating Reactors
Enclosure:
Safety Evaluation
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NUCLE A R REGULATORY COMMISSION W ASHIN GToN. D. C. 20s5s SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REA30R REGULATION SUPPORTING AUTHORIZATION TO CHEMICALLY DECOSTAMISATE *IEE PR3iARY COOLING SYSTEM AT DRESDEN UNIT 1 C0!f t' NEALTE EDISON COMPANY 2
DRESDEN NUCLEAR P0hTR !.TATION UNIT 1 DOCKET NO. 50-10 I!.7RODUCTION By letters dated Decerber 16,1974, April 1,1975 and April 14, 1975, the Co= meealth Edison Company (CECO) requested authori:ation to carry out a cherical decontamination of the interior surfaces of the Dresden Unit 1 p-~imary coolant syster.
The purpose of the decontanination is to remove a deposition of activated corrosion products which is tightly bonded to the primary coolant system piping and components. The presence of the corresion products in the system results in high levels of radiation in adjacent areas and limits access to these areas for the purpose of in-service inspection, routine maintenance and plant modifications.
CECO has tentatively scheduled the chemical cleaning project to begin in Jaruary 1977 with an anticipated return to service scheduled for July 1977.
EVALUATIUN
'Ihe staff's review of CECO's proposed
- chemical decontanination of-the interior surfaces of the Dresden Unit i primary coolant system has been completed.
The results of this' review are as follows:
1.
Environmental Impact
- me. che.ical de.ontamination of the Dresden 1 primary coolant system will be performed entirely within a closed decontanination system.
The system has been designed so that no chemical or radiological wastes will be released to the environnee f en the deconta.ination process.
All wastes generated in' the piecess will be either solidiTied for offsite burial at a licensed burial ;round er reprocessed for reuse onsite.
The solid wastes produced are similar in type and quantity to these handled routinely at the site.
Therefere, no adverse environmental impacts are anticipated due to the decontamination.
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Materials Compatibility The staff has reviewed the results of the material testing progra=
that has been carried out in support of the proposed Dresden 1 The test program was organi:ed to look decontamination progran.
at corrosive effects during the decontamination process and possible residual effects during subsequent reactor operation.
Based upon our review of the results of the testing program completed to date, we nave concluded that the test program adequately evaluated those aspects of the materials corpatibility that we consider to be As a result cf our discussions with CECO's consultant,
icportant.
Dr. Craig Cheng of Argenne National Laboratory, we find that the remaining program will be conducted in a canner that will answer our presently unresolved concerns and the test results will be adequately, interpreted and reported.
We conclude that upon the successful completion of the testing program described in the subnittals and with an adequate surveillance and I can be inspection program, the Dresden Nuclear Pcwer Station Unit subjected to the described chemical cleaning process without undue corresion or other deleterious caterials compatibility effects that would adversely effect the integrity of the primary coolant system and connected systems.
of concern have not been resolved to the A small number of ite:S staff's full satisfaction at this time. However, we conclude that authori:ation to carry out the chemical decontanination should be granted in anticipation of the successful resolution of these open items in the near future.
The following open items are identified at this time as requirin2 resolution to the staff's satisfaction:
The materia.3 test prog!sm will be completed and the test (a) results will be analyzed and reviewed prior to the beginning of the cleaning process.
Surveillance specimens in aci. tion to those now planned will be (b) determined by mutual agreement with the applicant and a schedule for specimen withdrawal will be stated.
A pre-service inspection program for the primary coolant boundary (c) and scfety related systens will be formulated and performed prior to return to power.
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Effluent Treatment Systems We have determined that the effluent treatment system, if constructed as described in the CECO submittals, is capable of handling the types and quantities of effluents expected to be generated by the decon-tarination program.
Our review was limited to the use of the syste-for chemical decontamination only, and use of the system for any cther purpose subsequent to that progran must be revie.<ed prior to such us e.
4.
Fadiologicc1 Safety We have further concluded that the radiological safety program described in the submittals is adequate to assure that the health and safety of the public and the onsite personnel will not be endangered by the Dresden 1 decontanination proj ect.
CONCLUS10S We have concluded, based on the considerations discussed above, that:
(1) because the chemical cleaning does not involve a significant increas e in the probability or consecuences of accidents previously considered and does not involve a significant decrease in a safety.argin, the cleanin-proj e ct does not involve a significant ha:ards consideration, (2) there is reasonable assurance that the health and safety of the public will nc-be endangered by operation in the proposed canner, and (3) such activities will be conducted in compliance with the Cc ission's regulations and the
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issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Date:
December 9, 1975 e
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