ML19323A505
| ML19323A505 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 03/15/1980 |
| From: | Vollmer R Office of Nuclear Reactor Regulation |
| To: | Little R AFFILIATION NOT ASSIGNED |
| Shared Package | |
| ML19323A506 | List: |
| References | |
| NUDOCS 8004210287 | |
| Download: ML19323A505 (6) | |
Text
'
,}&
, pma ll g h e( [g UNITED STATES 4
y g
NUCLEAR REGULATORY COMMISSION 3."T E
WASHINGTON, D. C. 20555 0
March 15,1980 Docket No. 50-10 Mr. Rob Little 904 S. Locust Street Champaign, Illinois 61820
Dear Mr. Little:
This is in response to your recent letter to Chairman John Ahearne, which expressed your concern related to the chemical decontaminatiori of Dresden Nuclear Power Station, Unit No.1.
We have been reviewing this project since Cocinonwealth 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 ch'emical 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 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 information.
Since our 1975 authorization Comonwealth 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.
800.4210267
Mr. Rob Little March 15,1980 l
l 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 i
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.
i 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 l
wastes will be done in accordance with all applicable NRC and Department of Traiisporation 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.
e After 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 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 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 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 co.t 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-l taminate the primary cooling system of other U. S. nuclear facilities, i
l
-c
i Mr. Rob Little March 15,1980 i
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 i
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 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 afety of the public.
Furthermore, the decontamination will reduce the occupational exposure of the individuals employed at D resden.
With respect to requests for the preparation of an Environmental Impact Statemenc 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 implement i
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 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; (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) Issnance 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; f
1
Mr. Rob Little March 15,1980 (7) Conversion of a provisional operating license for a nuclear power reactor, testing facility or fuel reprocessing plant to a fuil 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. "
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 environmenta!
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 1
will be prepared in accordance with Sections 51.7 and 51.50(d) of our pro-l 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 that radioactive contamination can be removed from reactor components and significantly reduce the occupational radiation exposure to personnel who require access to these components for purposes of repair, inspection or modification. Such components have been cleaned, inspected, and returned to service without any evidence of damage caused by decon-tamination.
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:
l
Mr. Rob Little 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 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 i
processing, transportation, and disposal will not cause any new hazards not previously evaluated and deemed acceptable.
Sincerely, i
) $1 Richard H. Vollmer, Acting Assistant 3
Director for Systematic Evaluaticn Program Division of Operating Reactors i
Enclosure:
Safety Evaluation i
l
IJNITE3 STATES NUCLEAR REGULATORY COMMISSION W ASHINGToN. D. C. 20s55 SAFE'IY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AUIMORI2ATION TO CHEMICALLY DECONTAMINATE THE PRIMARY COOLING SYSTEM AT DRESDEN UNIT 1 ComiO.WEALE EDISON COMPANY DRESDEN NUCLEAR POWER STATION UNIT 1 DOCKET NO. 50-10 l
l IhTRODUCTICX By letters dated December 16,1974, April 1,1975 and April 14, 1975, the Cors.:nwealth Edison Cc=pany (CECO) recuested authorication to carry out a chemical decenta=inatica of the interior surfaces of the Dresden Unit 1 prina y coolant system.
The purpose of the decenta=ination is to re=ove a deposition of activated cerrosion products which is tightly bonded to the primary coolant system piping and cc=ponents., The presence of the co resion products in the syste: results in high levels of radiation in adj acent areas and limits access to these areas fer the purpose of in-service inspection, routine maintenance and plan: =edifications.
CECO has tentatively scheduled the che ical cleaning project to begin in Jaruary 1977 with an anticipated return to service scheduled fo-l July 1977.
I EVALUATION 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 ce=pleted.
Se results of this' review are as follows:
\\
1.
Environ = ental Impac:
Tne, che:.ical deconta=ination of the Dresden 1 prira.y coolant syst'em will be performed entirely within a c1csed deco.:anination system.
i Tne syste: has been designed so that no che=ical or radiological wastes will be released to the environment from the deconta ination All wastes generated in' the process will be either ~solidiYied.
proces s.
for offsite burial 2: a licensed burial ground er reprocessed for reuse onsite.
The solid westes produced are similar in type and quantity to Tnerefere, no adverse environmental l those handled routinely a: the site.
i= pacts are anticipated due to the decents=inati:n.
J Pe D
2 2.
Materials Co=patibility The staff has reviewed the results of the material testing progra=
that has been carried out in support of the ' proposed Dresden 1 tae test progra= was organized to look decontamination progra=.
at corrosive effects during the deconta=ination process and possible residual effects during subsequent reactor operation.
Ba>cd uuon our review of the resu'lts of the testing program co=pleted
~
adequately evaluated to date, we have concluded that the test progra:
those aspects of the =aterials co=patibility.that we consider to be As a result cf our discussions with CECO's consultan:,
i=portant.
Dr. Craig Cheng of Argonne National Laboratory, we find that the remaining progra= will be conducted in a =anner that will answer our presently unresolved concerns and the test results will be adequately, interpreted and reported.
I
- We conclude that upon the successful co=pletica of the testing program described in the sub=ittals and with an adequa:e surveillance and 1 can be inspe,ction progra=, the Dresden Nuclear Power Station Unit subjected to the described chemical cleaning process without undue corresion er other deleterious =aterials co=patibility effects that would adversely effect the integrity of the pri=ary coolant system and connected syste=s.
l A small nu=ber of ite=s of concern have not been resolved to the I
staff's full satisfaction a: this time. However, we conclude tha-authori:ation to carry out the' che:ical decente ination shecid be granted in anticipation of the successful resolution of ".nese open i
The following open ite=s are identified ite=s in the near future.
at this ti=e as requiring resolution to the staff's satisfaction:
The =aterials test progtsm will be ce=pleted and the test (a) results will be analyzed and reviewed prior to the beginning of the cleaning process.
Serveillance speci=en's in addition to those now planned will be (b) dett r=ined by =utual agreement with the applicant and a schedule for speci=en withdrawal will be stated.
A pre-service inspection progra: for the pri=ary coolant boundary (c) and safety related syste=s will be for=ulated and perforned prior to re: urn to power.
I i
t e