ML19323A514
| ML19323A514 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 03/15/1980 |
| From: | Vollmer R Office of Nuclear Reactor Regulation |
| To: | Rogers L AFFILIATION NOT ASSIGNED |
| Shared Package | |
| ML19323A515 | List: |
| References | |
| NUDOCS 8004210295 | |
| Download: ML19323A514 (6) | |
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UNITED STATES
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March 15,1980 Docket No. 50-10 Mr. L. Wayne Rogers 2006 W. William Champaign, Illinois 61820
Dear Mr. Rogers:
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 Commonwealth 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 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 ba subaitted 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 information.
Since our 1975 authorization Connonwealth 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 t
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 formad on the inside surfaces of the Dresden 1 primary cooling systam.
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Mr. L. Wayne Rogers March 15,1980 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 factif ty 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 accor::plished 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.
After processing the concentrated waste solution will be solidified in 55 gallon drums using a process developed by the Dow Chemical Cortpany 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 i
assurance that the liquid waste has been properly solidified.
After 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 l
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 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,
l Mr. L. Wayne Rogers 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 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 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 will reduce the occupational exposure of the individuals enployed at Oresden.
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With respect to requests for the preparation of an Environmental Impact Statement for the Oresden Unit 1 decontamination, the Nuclear Regulatory Comission is fully comitted to satisfying all requirements of the National Environmental Policy Act (NEPA). Our regulations which inplement 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 issued 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 nust prepare an environmental inpact statement:
"(1) Issuance of a permit to constmct 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 constmet or a design capacity license to operate an isotopic enrichment plant pursuant to 50.22 of this j
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 comerical radioactive waste disposal by land burial pursuant to Parts 30, 40, and/or 70 of this chapter; l
I Mr. L. Wayne Rogers tiarch 15, 1980 (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 l
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-t ment, device, comodity or other product containing byproduct material or source material; and (10) Any other action which the Cocrnission determines is a major I
Comission action significantly affecting the quality of the human envi ronment. "
The Comission is presently in the process of modifying our 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 igact 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 igact statement need not be prepared, a negative declaration and environmental igact appraisal will be prapared in accordance with Sections 51.7 and Sl.50(d) of our pro-cedures for environmental protection. We will coglete 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 pumps, valves, heat exchangers, and pipes. This experience has demonstrated j
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, i
inspection or modification. Such components have been cleaned, inspected, l
and returned to service without any evidence of damage caused by decon-tamination.
In addition to the decontamination of reactor cogonents, at least eighteen reactor primary cooling systems or parts of those systems have been deconhminated 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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Mr. L. Wayne Rogers March 15,1980 TABLE 1 Plutonium Recycle Test Reactor 1962 Shippingport PWR 1964 Plutonium Recycle Test Reactor 1965 Hanford, N Reactor 15 major decontac.
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 Canada 1975 Dresden Unit 1 Test Loop using 1976 Dow NS-1 Solvent Peach Bottom Regenerative Heat 1977 Exchanger using DOW 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, kr Richard H. Vollmer, Acting Assistant Director for Systematic Evaluation Program Division of Operating Reactors
Enclosure:
Safety Evaluation i
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UNITED STATES
'i NUCLEAR REGULATORY COMMISSION W ASHINoToN. D. c. 2055s SAFEIY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AUTHORIZATION TO CHEMICALLY DECONTAMLETE THE PRIMARY COOLING SYSTEM AT DRESDEN UNIT 1 CO)BiONIGALTH EDISON COMPA.W DRESDEN NUCLEAR POWER STATION UNIT 1 DOCKET NO. 50-10 IhTRODUCTION By letters dated December 16,1974, April 1,1975 and April 14, 1973, the Co =enwealth Edison Cc=pany (Ceco) re uested authorization to carry out a che:ical deconta=ina:icn wf the interior surfaces of the Dresden Unit I primary coolant syste=,
ne purpose of the decontanination is to remove a deposition of activated corrosion products which is tightly bonded to the pri=ary coolant system
. piping and cc=ponents. ne presence of the corrosion products in the system results in high' levels of radiation in adjacent areas and li=its access to these areas for the pu:aose of in-service '.nspection, rou.ine maintenance and plan: =odifications.
CECO has tentatively scheduled the che=ical cleaning project to beg ~.n in Jaruary 1977 with an anticipated return to service scheduled for July 1977.
EVALUATION ne staff's review of CECO's proposed
- che=ical decontanination of-the interior surfaces of the Dresden Unit i pri=ary ' coolant system has been completed.' The results of this' review are as follows:
1.
Environmental I= pact ne. che..ical decontacination of the Dresden 1 pri=a::y coolant syst~em will be perfor:ed entirely within a closed deco. a=ination system, ne syste has been designed so that no chemical or radiological vas:ss will be released to the environ =ent fr:m the deconta=ination All wastes generated in' the process will be either ~solidf!ied,
process.
for offsite burial at a licensed burial ground er reprocessed for reuse onsite.
The solid westes produced are similar in type and cuantity,to these hendled routinely a-the site. Theref:re, no adverse environmental <
i= pacts are anticipc ed due to the deconta=ination.
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Materials Co=patibility The staff has reviewed the results of the =aterial testing progra=
that has been carried out in st:pper: of the proposed Dresden 1 The test progra= was organi:ed to look decontamination program.
at corrosive effects during the deconta=ina ion process and possible residual effects during subsequent reactor operation.
Based upon our review of the resu'lts of the testing progra= ce=pleted to date, we have concluded that the tes: progrs= adequately evaluated those aspects of the =aterials ce=patibility that we consider to be As a result cf our discussions with CECO's consultan:,
i=portant.
the Dr. Craig Cheng of Argonne Sa:ional Laboratory, we find tha:
re=aining progra= will be conducted in a manner that will answer our results will be adequately, presently unresolved concerns and the tes
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interpreted and reported.
We conclude that upen the successful ce=pletion of the testing progra=
described in the subnit:als and wi'th an adequa:e surveillance and inspection progra=, the Dresden Suelear Power Station Unit 1 can be subjected to the described che=ical cleaning process without undue corrosion or other deleterious =aterials ce=patibility effects -Jsa:
would adversely effect the integrity of the pri=ary coolant syste=
and connec:ed syste=s.
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 tha:
authori:2: ion to cz ry out the' che=ical deconta=ination should be -
g anted in anticipation of the successful resolutien of these open in the near future. The following open ite=s are identified ite=5this time as requiring resolution to the staff's satisfaction:
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a:
The i::aterials test prog:'am will be co=pleted and the test (a) results will be analy:ed and reviewed prior to the beginning of the cleaning process.
Su veillance :peci=eris in ad'dition to those now planned will be (b) determined by mutual agreement with the applicant and a schedule for s ecimen withdrawal will be stated.
A pre-service inspection progrs= for the pri=ary coolant boundars-(c) and scie:y related systers will be for=ulated and perforced prio'r to re:U"3 *o power..
3.
Effluen: Trea =ent Systems i
We have determined that the effluent treatment systen, if construe:ed as described in the CECO submittals, is capable of handling the types and quantities of effluents expected to be generated by the decon-ta=ination progra=. Ou'r review was li=ited to the use of the syste:
for chemical deconta=in'a: ion only, and use of the syste= for any c:..er purpose subsequent 'to that progra= =ust be reviewed prior to such u.s e.
i 4.
Radiological Safety We ha've furth'er concluded that the radiological safe:y progra=
l described in the sub=it als is adequate to assure that the health and safety of the public and the onsite personnel will not be endangered by the Dresden I decontaninstion proj ect.
CONCWSION We have concluded, be. sed on the considerations discussed above, that:
(1) because the chenical cleaning does not involve a significant increas e in the probability or consequences of accidents previously considered and does not involve a significan decrease in a safety =argin, the cleaning
'1 projec: does not involve a significan hacards consideration, (2) there is reasonable assurance tha: the health and safety of the public will n::
be endangered by operation in the proposed =anner, and (3) such acti.ities will be conducted in compliance with the Co=ission's regulations and -J.e issuance of this anend=en will not be inimical to the ce=en defense ' nd.
a security or to the health and' safety of the public.
Date:
December 9,1975 l
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