ML19323A531
| ML19323A531 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 03/15/1980 |
| From: | Vollmer R Office of Nuclear Reactor Regulation |
| To: | Checker J AFFILIATION NOT ASSIGNED |
| Shared Package | |
| ML19323A532 | List: |
| References | |
| NUDOCS 8004210308 | |
| Download: ML19323A531 (6) | |
Text
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UNITED STATES y.
g NUCLEAR REGULATORY COMMISSION g,g WASHINGTON, D. C. 20555
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.....o March 15,1980 Docket No. 50-10 i
l Ms. Judith Checker 205 N. Gregory Urbana, Illinois 61801
Dear Ms. Cheuer:
This is in response.to your recent letter to Chairman John Ahearne, which expressed your concern related to 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 Comonwealth Edison to initiate the chemical decontamination subject to the conpletion 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 performing the proposed chemical cleaning.
2.
A pre-service inspection program for the primary coolant boundary will be fornulated 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.
i A copy of our Safety Evaluation in support of these actions is enclosed for your information.
l Since our 1975 authorization Conrnonwealth Edison has completed its l
materials test program and construction of the necessary support facilities to carry out the project in a safe and environmentally i
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, t
tightly adherent, layer of highly radioactive oxide that has formed on l
the inside surfaces of the Dresden 1 primary cooling system.
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Ms. Judith Checker March 15, 1980 i
The solvent will preferentially dissolve the oxide without significantly attacking the underlying base metal of the primary cooling system piping.
i 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.
l 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 l
to concentrate and solidify the solvent and dissolved radioactive corrosion products.
i 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.
l After processing the concentrated waste solution will be solidified in 55 l
gallon drums using a process developed by the Dow Chemical Company for the i
solidification of low level radioactive wastes. This soliddication process has been tested on the NS-1 solvent and produced a solid wasta #orm 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 comercial l
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 i
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.
i The cost of the Dresden 1 decontamination has been estimated at 36 million j
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, I
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' Ms. Judith Checker March 15,1980 however, preliminary estimates of the cost for decontamination currently operating U. S. reactors range from 1 million to 5 million dollars per l
reactor and would vary depending on the extent of modification required at a specific facility to perform the decontamination.
The decontamination of reactor primary cooling systens will reduce the radiation exposure levels in the areas of these systens, thereby permit-ting greater access to the system for inspection, modifications, and repai rs. 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 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 I 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 States Code of Federal Regulations. These regulations are in conformance with guidelines issudd by the President's Council on Environmental Quality which were in effect prior to July 30, 1979. They identify the following types of actions for which NRC must prepare an environmental impact 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; i
(2) Issuance of a full power or design capacity license to operate a nuclear power reactor, testing facility, or fuel repracessing 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 productior, of uranium hexafluoride pursuant to Part 40 of this chapter, (6) Issuance of a license authorizing commerical radioactive waste l
disposal by land burial pursuant to Parts 30, 40, and/or 70 of this chapter;
March 15,1980 l
Ms. Judith Checker (7) Conversion of a provisional operating license for a nuclear power reactor, testing facility or fuel reprocessing p1&nt 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 ifcense 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, co:rmodity 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. "
The Comission is presently in the process of modifying cur Environmental Protection regulations to take into account, voluntarily, the regulations pronulgated 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 igact of the proposed action to determine whether an environmental igact statement should be prepared because of specific circumstances related to this particular action.
If it is determined that an environmental iga;t statement need not be prepared, a negative declaration and environmental igact 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.
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 pugs, valves, heat exchangers, and pipes. This experience has demonstrated that radioactive contamination can be removed from reactor components and significantly reduce the occupational radiation exposure to personnel who require access to these cogonents for purposes of repair, inspection or modification.
Such cogonents have been cleaned, inspected, and returned to service without any evidence of damage caused by decon-tami nation.
In addition to the decontamination of reactor cog onents, 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:
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Ms. Judith Checker March 15,1980 TABLE 1 Plutonium Recycle Test Reactor 1962 Shippingport PWR 1964 Plutonium Recycle Te3t 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 i
Douglas Point
' Canada 1975 Dresden Unit 1 Test Loop using 1976-Dow NS-1 Solvent Peach Bottom Regenerative Heat 1977 Exchanger using DDW NS-1 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.
Sincerely, M
Richard H. Vollner, Acting Assistant Director for Systematic Evaluation Program Division of Operating Reactors
Enclosure:
Safety Evaluation v
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O Uw1Tto STATES
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NUCLEAR REGULATORY COMMISSION W ASHINCTCN. D. c. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REAMR REGULATION SUPPORTING AUIHORIZATION TO CHEMICALLY DECOSTAMINATE 'lHE PRIMARY COOLING SYSTEM AT DRESDEN UNIT 1 I
COSBiONWEALU! EDISON COMPANY DRESDEN NUCLEAR POWER STATION UNIT 1 i
DOCKET NO. 50-10 l
IhTRODUCTION I
By letters dated Dece=ber 16,1974, April 1,197S and April 14, 1975, the Co==enweal-Ji Edison Co=pany (CECO) requested authorization to carry out a che=ical deconta=ination of the interior surfaces of the Dresden Unit I pri=a:y coolant syste-Tne purpose of the decontamination is to re=ove a deposition of activated l
corrosion products which is tightly bonded to the pri=ary coolant system l
. piping and co=ponents. The presence of the corresien products in the l
system results in high' levels of radiation in adj acent areas and li=its l
access to these areas for the purpose of in-service inspection, routine l
l maintenance and plant modifications.
I CECO has tentatively scheduled the chemical cleaning project to begin in Jaruary 1977 with an anticipated return to service scheduled fo-i July 1977.
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EVALUATION i
The staff's review of CECO's proposed' chemical decontanination of-the
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interior surfaces of the Dresden Unit i primary ' coolant system has been i
completed.' The results of this' review are as follows 1
1.
Environ = ental Impact Tne. che.ical decontamination of the Dresden 1 primary coolant system will be perfor=ed entirely within a closed decontamination system.,,
The syste= has been designed so that no chemical or radiological wastes will be released to the environment from the decontamination All wastes generated in' the process will be either solidffied.
process.
for offsite burial at a licensed burial ground c reprocessed for reuse onsite. The solid wastes produced are similar in type and quantity to these hendled routinely a: the site.
Tnerefere, no adverse environmental i= pacts are anticipcted due to the decontarination.
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2.
Materials Compatibility l
The staff has reviewed the results of the material testing progra=
that has been carried cut in support of the ' proposed Dresden 1 The test program was organized to look decontamination program.
at corrosive effects during the decontamination process and possible residual effects during subsequent reactor operation.
Based upon our revice of the results of the testing program completed t
l to date, we have concluded that the test progrc' adequately evaluated we consider to be those aspects of the materials ce=patibility.ths :
As a result cf our discussions wit' CECO's consultant, important.
l Dr. Craig Cheng of Argonne Sa:ional Laboratory, we find that the l
remaining program will be conducted in a manner that will answer our i
presently unresolved concerns and the test results will be adequately, inteqpreted and reported.
We conclude that upon the successful co=pletien of the testing program described in the sub=ittals and with an adequa:e surveillance and
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i inspe,ction program, the Dresden Nuclear Power Station Unit I can be sub.iected to the described che=ical cleaning process without undue i
corresion or other deleterious materials co=patibility effects that would adversely effect the integrity of the primary coolant system and connected syste=s.
i A small nu=ber of ite=s of concern have not been resolved to the staff's full satisfaction at this time.
However, we conclude that l
authori:ation to carry out the' chemical decontamination should be.
granted in anticipation of the successful resolution of these open The following open items are identified items in the near future.
at this time as requiring resolution to the staff's satisfaction:
The haterials test progtym will be co=plet. d and the test e
(a) results will be analy:ed and reviewed prior to the beginning of the cleaning process.
Surveillance specimen's in addition to those now planned will be (b) determined by mutual agreement with the applicant and a sdhedule for speci=en withdrawal will be stated.
A pre-service inspection program for the primary coolant boundary (c) and sciety reisted syste=s will be for=ulated and performed prior to return to power.
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3.
Effluent Treatment Systems t
We have determined that the effluent treatment system, if constructed as described in the CECO submittals, is capable of handling the types 4
and quantities of effluents expected to be generated by the decon.
Our review was limited to the use of the syste tamination program.
for chemical decontamin'ation only, and use of the system for any c:her purpose subsequent 'to that program must be reviewed prior to such u.s e.
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4.
Radiological Safety We ha$ve furth'er concluded that the radiological safety progra=
l described in the sub=ittals is adec,uate to assure that the health and l
safety of the public and the onsite personnel will not be endangered by the Dresden 1 decontanination proj ect.
CONCLUSION We have concluded, based on the considerations discussed above, that:
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(1) because the che:ical cleaning does not involve a significant increas e in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety targin, the cleaning j
project does not involve a significant hacards consideration, (2) there is reasonable assurance that the health and safety of the public will nt:
be endangered by operation in the proposed manner, and (3) such acti.ities will be conducted in compliance with the Co==ission's regulations and the issuance of this amend:ent will not be inimical to the co mon defense 'and' security or to the health and safety of the public.
Date:
December 9,1975 l
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