ML19323A475
| ML19323A475 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 03/15/1980 |
| From: | Vollmer R Office of Nuclear Reactor Regulation |
| To: | Petrie L AFFILIATION NOT ASSIGNED |
| Shared Package | |
| ML19323A476 | List: |
| References | |
| NUDOCS 8004210260 | |
| Download: ML19323A475 (6) | |
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NUCLEAR REGULATORY COMMISSION E
WASHINGTON. D. C. 20S55 o.
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March 15,1980 Docket No. 50-10 Ms. Lee Petrie 608 N. Broadway Urbana, Illinois 61801
Dear Ms. Petrie:
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 Connionwealth 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 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 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 reacter to service.
3.
A post-cleaning surveillance program which includes additional surveillance specimens t.ad 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 information.
Since our 1975 authorization Comonwealth Edison has completed its materials test program and constmction 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 constniction 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.
800.4210260
Ms. Lee Petrie 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 l
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 transporation of radioactive
< wastes will.be done in accordance with all applicable NRC and Department of Transparation 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 Conpany 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 vaste has been properly solidified.
t 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 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 i
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,
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Ms. Lee Petrie 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 l
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 Dresden.
With respect to requests for the preparation of an Environmental linpact l
Statement for the Dresden Unit I 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 must prepare an environmental inpact statement:
"(l) 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; j
I (6) Issuance of a license authorizing comerical radioactive waste disposal by land burial pursuant to Parts 30, 40, and/or 70 of this chapter; 1
Ms. Lee Petrie March 15,1980' l
(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; l
(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 l
l (10) Any other action which the Comission determines is a ma3or
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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 i
promulgated by CEQ which became effective July 30, 1979. We have concluded I
that this action is not one of these actions requiring an environmental l
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 c
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 l
not be prepared, a negative declaration and environmental impact appraisal will be prepared 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.
f 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 k
and significantly reduce the occupational radiation exposure to f
personnel who require access to these cogonents for purposes of repair, inspection or modification. Such cog onents have been cleaned, inspected, and returned to service without any evidence of damage caused by decon-t tami nation.
In addition to the decontamination of reactor cogonents, at least eighteen reactor primary cooling systems or parts of those systems have I
been decontaminated in the United States since the early 1960's. Table 1 identifies these and other major decontamications that have taken place to date throughout the world:
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I Ms. Lee Petrie March 15,1980 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 l
Rheinsberg PWR Rheinsberg, Germany 1968 i
Douglas Point Canada 1970 NPD Canada 1973 l
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 DDW NS-1 In sunnary, 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 l
processing, transportation, and disposal will not cause any new hazards i
not previously evaluated and deemed acceptable.
Sincerely, j
Y ichard H. Vollmer, Acting Assistant Director for Systematic Evaluation Program Division of Operating Reactors
Enclosure:
Safety Evaluation l
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UNITO STATES
's NUCLEAR REGULATORY COM$ttSSION WASMINGToN. D. c. 2e555 SAFETY E1*ALUATION BY THE OFFICE OF NUC1. EAR REACTOR REGULATION SUPPORTING AUTHORIZATION TO CHEMICALLY DECO.TAMINATE 'IEE PRIMARY N
COOLING SYSTEM AT DRESDEN UNIT 1 COSBio. WEALTH EDISON COMPANY DRESDEN NUCLEAR POWER STATION UNIT 1 i
DOCET NO. 50-10 r
IhTRODUCTION i
By letters dated Dece=bcr 16,1974, April 1,1975 and April 14, 1975, the Co==enwealth Edison Co=pany (CECO) requested authori:ation to carry l
out a che=ical decontamination of the interior surfaces of the Dresden Uni: 1 pri=a:y coolan syste=.
The purpose of the decontamination is to re=ove a deposition of activated corrosion products which is tightly bonded to the pri=ary coolant system
. piping and ce=ponents. The presence of the cor esion products in the syste= results in high' levels of radiation in ad.iacent areas and limits access to these areas for the purpose of in-service inspection, routine
=aintenance and plan: =odifications.
CICo has tentatively scheduled the che=ical cleaning project to begin in Jaruary 1977 with an anticipated return to service scheduled for July 1977.
I EVALUATION
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The staff's review of CECO's proposed' che=ical decontanination of-the interior surfaces of the Dresden Unit i primary " coolant system has been ec=pleted.' The results of this' review are as fo11ews:
1.
Environ = ental I= pact The. che..ical deconta=ination of the Dresden 1 pri=ary coolant syst'em will be perfor=ed entirely within a closed decontarination system.
The syste: has been designed so that no che=ical or radiological wastes will be released to the environment fr:= the deconta=ination All wastes generated in':he process will be either solidiTied.
process.
for offsite burial at a licensed burial ground er reprocessed for reuse onsite. The solid wastes produced are sirilar in type and cuantity to these hsndled routinely a: the site. Tneref:re, no adverse environ = ental i= pacts are anticipated due to the decon:z=inati:n.
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Materials Co=patibility The staff has reviewed the results of the =aterial testing progra=
that has been carried out in supper: of the ' proposed Dresden i The test progrs= was organized to look decontamination program.
at corrosive effects during the deconta=ination process and possible~
residual effects during subsequent reactor operation.
Based upon our review of the results of the testing progra= completed to date, we have concluded that the test progra: adequately evaluated those aseects of the =sterials co=:atibility.that we consider to be i=portani. As a result cf our dis'cussions with CECO's consultan:,
Dr. Craig Cheng of Argonne National Laboratory, we find that the re=sining program will be conducted in a =anner that will answer our results will be adequately, presently unresolved concerns and the tes:
interpreted and reported.
We conclude that upon the successful co=pletics of the testing progra=
described in the sub=i::als and with an adequate surveillance and 1canbe inspe,c:icn progra=, the Dresden Nuclear Power Station Uni:
subj ected to the described the=ical cleaning process without undue corresion or other deleterious =aterials co=patibility effects that would adversely effect the integrity of the pri=ary coolant syste=
and connec:ed syste=s.
A s=all nu=ber of ite=s of concern have not been resolved to the staff's full satisfaction at this ti=e.
However, we conclude that authorization to carry out the' che=ical decents:ination should be -
granted in anticipation of the successful resolution of these open ite=s in the near future. The following open ite:s are identified at this time as requiring resolution to the staff's satisfaction:
The =aterials test program will be co=pleted and the test (a) results will be analyzed and reviewed prior to the beginning of the cleaning process.
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Surveillance speci=en's in addition to those now planned will be (b) determined by mutual agreement with the applicant and a schedule for speci=en withdrawal will be stated.
A pre-service inspection pr:gra= for the primary coolan boundary (c) and scie:y related syste=5 will be for=ulated and performed prior to re urn to power.
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3.
Effluent Treatment Syste=s he have deter =ined 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-tamination progrs=. Our review was li=ited to the use of the syste:
for chemical deconta=i:iation only, and use of the syste= for any c:;.e purpose subsequent to that progra: =ust be reviewed prior to such us e.
4 Radiological Safety We have further concluded tha: the radiological safety progrs=.
described in the sub=it:als is adec,uate to assure that the health and safety of the public and the onsite personnel will not 'be endangered by the Dresden 1 decentanination proj ect.
CONCLUSION We have concluded, based on the considerations discussed above, that:
(1) because the chemical cleaning does net involve a significant increas e in the probability or consecuences of accidents previously censidered and does not involve a significant decrease in a safety =argin, the cleaning proj ect does not involve a significan: hacards consideration, (2) there is reasonable assurance tha: the health and safety cf the public will n:-
be endangered by operatien in the preposed =anner, and (3) such activities will be conducted in compliance with the Cc==ission's regulations and :~.e issuance of this a=end=ent will not be inimical to the co =on defense i=d security or to the health and' safety of.he public.
Date:
December 9, 1975 e
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