ML19309G679
| ML19309G679 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 04/08/1980 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | Drom J AMERICAN MEDICAL STUDENT ASSOCIATION, ILLINOIS, UNIV. |
| Shared Package | |
| ML19309G674 | List: |
| References | |
| NUDOCS 8005070358 | |
| Download: ML19309G679 (6) | |
Text
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UNITED STATES
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WASHINGTON D. C. 20555
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APR 8 1980 Docket No. 50-l0 American Medical Student ALsociation University of Illinois - Urbana-Champaign ATTN: Ms. Jennifer Drom 501 W. California Urbana, Illinois 61801
Dear Ms. Drom:
This is in response to vour letter dated February 9,1980, to Chairman John Ahearne in which you have identified several concerns related to the proposed chemical decontamination of Dresden Nuclear Power Station Unit No. 1.
We have been reviewing this project since Comonwealth Edison's initial decontamination proposal on December 12, 1974. On December 9,1975, we issued a conditional authorization which allowed Conmonwealth 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 conpleted and the results submitted for the review and approval of the NRC staff prior to performing the proposed chemical cleaning.
2.
A pre-service inspection program for the primary coolant boundary will be formulated and submitted for NRC review and abproval prior to returning the reactor to service.
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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 December 9,1975 Safety Evaluation in support of these actions is enclosed for your information. This Safety Evaluation summarized our environmental impact evaluation that concluded that no adverse environmental impacts were anticipated due to the decontamination.
Since our 1975 authorization Comonwealth Edison has completed its materials test program and construction of the necessary support f acilities to carry out the project in a safe and environmentally acceptable manner. Our review of the testing program and the facility constrJCtion is Continuing and will be Completed prior to the chemical cleaning that is currently scheduled for the first half of 1980.
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American Medical Student Association 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.
The solvent will preferentially dissolve the oxide without significantly attacking 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 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 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 specially 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 solution will be solidified in 55 gallon drums using a process developed by the Dow Chemical Corpany 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 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 olid 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 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.
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American Medical Student Association With regard to your contention that this action is an experimental, first time attegt to decontaminate an operating reactor, the chemical decontamination of nuclear reactors is not an experimental process.
Over the past twenty years, extensive experience has been obtained in the decontamination of reactor cogonents such as pumps, valves, heat exchangers, and pipes. This experience has demonstrated that radioactive contamination can be removed from reactor cogonents and significantly reduce the occupational radiation exposure to personnel who require access to these cogonents for purposes of repair, inspection or modi-fication.
Such cogonents have been cleaned, inspected, and returned to service without any evidence of damage caused by decontamination.
In addition to the decontamination of reactor components, at least eighteen reactor primary cooling systems or parts of those systems have been decontaminated in the United States since the early 1960's. Table 1 identifies these and other major decontaminations that have taken place to date throughout the world:
TABLE 1 Plutonium Recycle Test Reactor 1962 Shippingport PWR 1964 Plutonium Recycle Test Reactor 1965 Hanford, N Reactor 15 major decontam.
1964 to present SENA Power Plant Chooz, France 1967 Rheinsberg PWR Rheinsberg, Germany 1968 Douglas Point Canada 1970 NPD Canada 1973 Gentilly Canada 1973 Douglas Point Calada 1975 Dresden Unit 1 Test Loop using 1976 Dow NS-1 Solvent Peach Bottom Regenerative Heat 1977 Exchanger using DOW NS-1 We have evaluated the study that identifies migration of liquid waste from the waste disposal burial site at Oak Ridge National Laboratory. The migration of radioactive waste which you have referred to was reported by Means, Crerar and Duguid (Science, Vol. 200, 30 June 1978).
The referenced paper discusses the disposal-of 35 million gallons of liquid waste in burial pits at Oak Ridge National Laboratory between 1951 and 1965.
Conraonwealth Edison, the licensee for Dresden Unit No.1, has agreed to dispose of the Dresden 1 waste at either Beatty, Nevada or Hanford, Washington connercial low level waste burial sites. These sites differ significantly in their geologic and hydrologic characteristics from the Oak Ridge site where chelant-aided migration of radionuclides was observed by Means, Crerar and Duguid.
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A. eri:an Medical Student Association S;ecifically, the Oak Ridge site, where migration occurred, experiences very..igh precipitation and has a water table so shallow that it probably intersects the disposal pits and trenches during periods of heavy rain fall.
In addition, the Oak Ridge topography is hilly with steep slopes underlain by fractured shale material which allows underground water and radioactive waste to flow down hill through the fractures until it seeps to the surface within 250 feet of a perennial stream.
Conversely, the commercial waste burial sites at Beatty and Hanford, where no mi; ration of radionuclides has been observed, are flat desert areas with very low precipitation, a water table approximately 300 feet below ground level and a distance of 8 to 10 miles to the nearest perennial stream.
In addition to these site characteristics, which prevent the migration of radioactive material from the desert waste burial sites, another significant difference between the proposed waste disposal technique and the now discon-tinued Oak Ridge methods is that the Dresden waste will be disposed of as a s oli c.
At Oak Ridge over 35 million gallons of liquid radioactive waste was pumped into the disposal trenches. We estimate that approximately 7 million gallons of liquid waste was disposed of in Trench No. 7, which was identified as a source of chelated radionuclides.
Because of the differences we have concluded that the Dresden wastes should be disposed of in a dry burial site.
The decontamination of the Dresden Unit 1 primary cooling system will reduce the radiation exposure levels in the areas of this systens, thereby permitting 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 will significantly reduce the occupational exposure of the individuals employed at Dresden.
With respect to requests for the preparation of an Environmental Impact Stater,ent for the Dresden Unit 1 decontamination, the Nuclear Regulatory Commission is fully committed to satisfying all requirements of the National Environmental Policy Act (NEPA). Our regulations which implement the NEPA requirements are contained in Title 10, Part 51.5, of the United S ates Code of Federal Regulations. These regulations are in conformance with gJidelines issued by the President's Council on Environmental Quality which were in effect prict to July 30, 1979. They identify the following types of actions for which NRC must prepare an environmental impact statement:
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American Medical Student Association "(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 0 permit to construct or a design capacity license to operate an isotocic 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 f abrication, scrap recovery, or conversion of uranium hexafluoride pursuant to Part 70 of this chapter; (5) Issuance of a licensa 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 comerical 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 f acility 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; (9) Amendments of Parts 30 and 40 of this chapter concerning the exemption from licensing and regulatory requirements of any equip-ment, device, comodity or other product containing byproduct material or source material; and (10) Any other action which the Comission determines is a major Comission action significantly affecting the quality of the human envi ronment. "
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American Medical Student Association The Comission is presently in the process of modifying our Environmental protection regulations to take into account, voluntarily, the regulations promulgated by CEQ which became effective July 30, 1979. We have concluded that this action is not one of these actions requiring an environmental impact statement under current Comission regulations.
While our regulations do not require the preparation of an environmental impact statement, we are evaluating the environmental impact of the proposed action to determine whether an environmental impact statement should be prepared because of specific circumstances related to this particular action.
If it is determined that an environmental impact statement need not be prepared, a negative declaration and environmental impact appraisal will be prepared in accordance with Sections 51.7 and 51.50(d) of our pro-cedures for environmental protection. We will complete our review and issue the appropriate statement or appraisal prior to the Dresden decontamination.
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 nee hazards not previously evaluated and deemed acceptable.
I hope that this letter is responsive to your request.
Sincerely, i
c:'lM ~mi by
,;!.2.c:at:a Harold R. Denton, Director Office of Nuclear Reactor Regulation
Enclosure:
Safety Evaluation
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NUCLEAR REGULATO,RY COMM!&SION 1D AsMINcToN. D. C. 20sss i
SAFETY D'ALUATION BY Thi 0FFICE OF NUCLE.G PJXTOR REGULATION SUPPORTING AUTHORIZATION TO CHEMICALLY DECONTAMINATE THE PRIMA.R COOLING SYSTEM AT DRESDEN UNIT 1 CORiONWEALTH EDISON COMPAW
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DRESDEN NUCLEAR POWER STATION L' NIT 1 DOCKET NO. 50-10 IhTRODUCTION By letters dated Dece:ber 16,1974, April 1,1975 and April 14, 1975, the CommonweaJth Edison Co pany (CECO) requested authori:ation to carry a chemical decontamination of the interior surfaces of the Dresden out Unit 1 primary coolant system.
Tne purpose of the decentamination is to re: eve a deposition of activated corrosion products which is tightly bonded to the primary coolant syste=
The presence of the corresien products in the piping and cc:ponents.
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results in high levels of radiation in adj acent areas and limits syste:
access to these areas for the purpose of in-service inspection, routine maintenance and plant modifications.
CECO has tentatively scheduled the che=ical cletning project to begin in Jaruary 1977 with an anticipated return to service scheduled for July 1977.
EVALUATION The staff's review of CECO's proposed
- chemical decontanination of-the interior surfaces of the Dresden Unit i pri=ary ' coolant syste= has been co=pleted.' The results of this' review are as follows:
1.
Environmental Impact The. che.-ical decontamination of the Dresden 1 pri=ary coolant syst'em will be perfor:ed entirely within a closed deconta=ination system.
The system has been designed so that no che=ical or radiological from the dcccr.timir.ation wastes wi31 be released to the environ =ent All wastes generated in' the process will be either' solidi?ied,
proces s.
for offsite burial at a licensed burial ground er reprocessed for reuse onsite. The solid wastes produced are si:ilar in type and quantity to these hsndled routinely at the site. Theref tre, no adverse environmental i pacts are anticipcted due to the decontamination.
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Materials Co patibility The staff has reviewed the results of the material testing progrs=
that has been carried out in support of the proposed Dresden 1 ne test progrs= was organized to look at corrosive effects during the deconta=ination process and possible~
decontamination program.
residual effects during subsequent reactor operation.
Based upon our review of the resu' ts of the testing program co=pleted I
to date, we have concluded that the test progrr.= adequately evaluated thos e asrects of the caterials co:pa:ibility that we consider to be imper:ani.
As a result of our discussions with Ceco's consultant, Dr. Craig Cheng cf Argonne National 1.aboratory, we find that the will be conducted in a manner that will answer our remaining progra results will be adequately, presently unresolved concerns and the tes interpreted and reported.
We conclude that upon the successful cocpletion of the testing program des cribed in the subnittals and with an adequate sun eillance and I can be inspecti:n progra, the Dresden Nuclear Power Station Unit subjected to the described chemical cleaning process without undue corresien or other deleterious materials ce=patibility effects that would adversely effec: the integrity of the primary coolant system and connected systems.
A sna11 nu.ber cf items of concern have not been resolved to the However, we conclude that staff's full satisfaction at this time.
authorizatien to cr.rry out the' chemical deconta=ination should be granted in anticipation of the successful resolutior) of these open ne following ope:) ite.s are identified items in the near future.
at this time as requiring resolution to the staff's satisfaction:
The materials test progra:s will be ce=pleted and the test (a) results will be analyzed and reviewed prior to the beginning of the cleaning process.
Su veillance specimen's in a[dition to those now planned will be (b) determined by mutual agreement with the applicant and a schedule fer specimen withdrawal will be stated.
A pre-service inspection program for the primary coolant boundary (c) and safety related systens will be fo =ulated and performed prior to return to power.
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Effluen: Trea: en: Systems
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We have deter =ined that the effluent trea:=en: 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-Our review was li=ited to the use of the syste _
tarination progrs=.
for chemical decontamination only, and use of the system for any other pu pose subse:;uent to that program must br reviewed prior to such us e.
4 Radiological Safety We have further cencluded that the radiological safe:y progra:.
described in the sub=ittals is adeo,uate to assure that the health and safety of the public and the onsite personnel. will not be endangered -
by the Dresden I decontanination project.
CONC 1.USION h'e have concluded, based on the considerations discussed above, that:
(1) because the chemical cleaning does not involve a sigt.ificant increas e in the probability er censeo,uences of accidents previously censidered a.d does not involve a significan: decrease in a safety targin, the cleaning ha:ards consideration, (2) there proj ect.does not involve a significan is reasonable assurance that the health and safety of the public will nt-be endangered by operatien in the preposed manner, and (3) such activities will be conducted in ec::liance with the Co=issien's regulatiens and the issuance of this amendment will not be initical to the co=en defense and.. '
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security or to the health and safety of the public.
Date:
Dece ber 9, 1975 e
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