ML19323A489

Responds to Ltr Re Chemical Decontamination of Facility. Waste Disposal Will Not Cause Any New Hazards Not Previously Evaluated.Disposal Is Acceptable.Forwards Safety Evaluation

ML19323A489
Person / Time
Site:	Dresden
Issue date:	03/15/1980
From:	Vollmer R Office of Nuclear Reactor Regulation
To:	Fern B AFFILIATION NOT ASSIGNED
Shared Package
ML19323A490	List: ML19323A489 ML19323A498
References
NUDOCS 8004210272
Download: ML19323A489 (6)

Text

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1. o UNITED STATES

[] 3e NUCLEAR REGULATORY COMMISSION

C WASHINGTON, D. C. 205S5

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March 15, 1980

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Docket No. 50-10 Ms. Bobbie Fern 606 W. Nevada Urbana, Illinois 61801

Dear Ms. Fern:

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 Comonwealth 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 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 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.

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 Cocpany 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.

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Ms. Bobbie Fern 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.

i After circulation the solvent and the dissolved oxides will be drained from the reactor co a waste treatment facility located ad,jacent to the reactor. Any remaining solvent will be cleaned from the reactor by l

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.

l 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.

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After processing the concentrated waste solution will be solidified in 55 j

gallon drums using a process developed by the Dow Chemical Conpany for the solidification of low level radioactive wastes.

This solidification process l

has been tested on the NS-1 solvent and produced a solid waste form that l

contained no free liquids. The waste solidification procedures include a quality control process test on each barrel of waste to provide additional l

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 i

been specifically selected for the disposal of the Dresden waste to further assure that there is no interaction of the waste with ground l

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 f

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 I

dollars. Much of this cost represents one time development costs which would not be incurred in subsequent reactor decontamination at Dresden 1 l

or other nuclear facilities. At this time there are no plans to decon-i taminate the primary cooling system of other U. S. nuclear facilities, F

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Ms. Bobbie Fern March 15,1980 M

E3E Wi however, preliminary estimates of the cost for decontamination currently X2 operating U. S. reactors range from 1 million to 5 million dollars per

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• reactor and would vary depending on the extent of modification required

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The decontamination of reactor primary cooling systems will reduce the 55 radiation exposure levels in the areas of these systems, thereby permit-f55 ting greater access to the system for inspection, modifications, and 525 repai rs.

These activities provide greater assurance of the continued SE safe operation of the reactor and are therefore in the best interest of 55E the health and safety of the public. Furthermore, the decontamination

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will reduce the occupational exposure of the individuals employed at

'llg Dresden.

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.sm With respect to requests for the preparation of an Environmental Impact

!55 Statement for the Dresden Unit 1 decontamination, the Nuclear Regulatory 25 Comission is fully comitted to satisfying all requirements of the Z

National Environmental Policy Act (NEPA). Our regulations which iglement

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the NEPA requirements are contained in Title 10, Part 51.5, of the United M

States Code of Federal RegJiations. These regulations are in conformance 5fi with guidelines issued by the President's Council on Environmental Quality

55 which were in effect prior to July 30, 1979. They identify the following 16 types of actions for which NRC must prepare an environmental inact (M

statement:

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"(1) Issuance of a permit to constnact a nuclear power reactor,

!!E testing facility, or fuel reprocessing plant pursuant to Part 50 of this chapter; E=

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(2) Issuance of a full power or design capacity license to operate 55 a nuclear power reactor, testing facility, or fuel reprocessing E5 plant pursuant to Part 50 of this chapter;

f;5 mm (3) Issuance of a permit to construct or a design capacity license

1. 3 to operate an isotopic enrichment plant pursuant to 50.22 of this EEE chapter;

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E (4) Issuance of a license to possess and use special nuclear material

~~L for processing and fuel fabrication, scrap recovery, or conversion is of uranium hexafluoride pursuant to Part 70 of this chapter; g

(5) Issuance of a license to possess and use source material for r$

uranium milling or production of uranium hexafluoride pursuant to

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Part 40 of this chapter; E

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(6) Issuance of a license authorizing cormierical radioactive waste 5

disposal by land burial pursuant to Parts 30, 40, and/or 70 of this E5 chapter; EEi 5

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Ms. Bobbie Fern March 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 chapter where no final environmental impact statement has been i

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 proculgated 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 nege'ive 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 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 cogonents 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-tami nation.

In addition to the decontamination of reactor cogonents, 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:

Ms. Bobbio Fern March 15,1980 1

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 processing, transportation, and disposal will not cause any new hazards not previously evaluated and deemed acceptable.

Sincerely, Richard H. Vollmer, Acting Assistant Director for Systematic Evaluation l

Program t

Division of Operating Reactors

Enclosure:

Safety Evaluation i

i UNITED STATa3

't NUCLEAR REGULATORY COMNilSSION l

WASHINGTON, o. c. a8 Css l

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REA 3 R REGULATION SUPPORTING AUTHORIZATION TO CHEMICALLY DECONTAMINATE THE PRIMARY COOLING SYSTEM AT DRESDEN UNIT 1 i

ComiONWEALTE EDISON COMPANY DRESDEN NUC!. EAR POWER STATION UNIT 1 DOC)2T NO. 50-10 i

IhTRODUCT: i By letters dated Dece=ber 16,1974, April 1,1975 and April 14, 1975,

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the Cc==enwealth Edison Co=pany (CECO) recuested authorication to car y out a che:ical deconta=ination of the interior surfaces of the Dresden f

i Uni: 1 pri=a:y coolant syste.

I 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 cc=ponents. The presence of the corrosion products in the syste= results in high' levels of radiation in ad.iacent areas and limits j

access to these areas for the purpose of in-service inspection, routine i

=aintenance and plan: =odifications, j

CECO has tentatively scheduled the che=ical cleaning project to begin in Ja:ua:71977 with an anticipated return to service scheduled for July 1977.

l EVALUATION The staff's review of Ceco's proposed

• chemical decontanination of-the interior surfaces of the Dresden Unit i primary ' coolant system has been comoleted.

The results of this' review are as follows:

1.

Environ = ental I= pact The. chenical decon:: ination of -J.e Dresden 1 pri=ary coolant syste=

will be perfor=ed entirely within a closed deconta=ination syste=.

The syste: has been designed so that no che=ical or radiological i

wastes will be released to the environment fro = the deconta=ination All wastes generated in' he process will be either'solidEied,

proces s.

for offsite burial a: a licensed burial grou.d er reprocessed for reuse onsite.

The solid westes produced are si=ilar in type and cuantity to,.

these hendled routinely at the site. Tnerefere, no adverse environ = ental,

i= pacts are anticipcted due to the deconta=ination.

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2.

Materials Co=patibility The staff has reviewed the results of the =aterial testing progra=

in ' support of the proposed Dresden 1 that has been carried ou decontamination program. The test progrs= was organized to look

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at corrosive effects during the deconta=ination process and possible i

residual effects during subsequent reactor operation.

Based upon our review of the results of the testing program completed to date, we have concluded that the test program adequately evaluated those aseects of the =aterials co=ca:ibility that we consider to be i=portani. As a result cf our dis'cussions with CECO's consultant, Dr. Craig Cheng of Argonne Sational Laboratory, we find that the re=2ining program will be conducted in a =anner that will answer our presently unresolved concerns and the test results will be adequately,

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interpreted and reported.

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We conclude that upon the successful ec=pletion of the testing program t

described in the sub=it:als and with an adequa:e surveillance and inspection progra=, the Dresden Nuclear Power Station Unit 1 can be subjected to the described che=ical cleaning process without undue i

corr:sion or other deleterious =aterials co=patibility effects hat would adversely effect the integrity of the pri=ary coolan: system and connected syste=s.

i A s=all nu=ber of ite=s of concern have not been resolved to the this ti=e.

However, we conclude that staff's full satisfaction a:

authori:ation to ca ry out the' che=ical decon =ination should be granted in anticipation of the successful resolution of these open The following oper; items are identified ite=5 in the near future.

at this ti=e as requiring resolution ;o the staff's satisfaction:

The i::sterials tes progn:s will be ce=pleted and the test (a) results will be analy:ed and reviewed prior to the beginning of the cleaning process.

Su veillance specimens in addition to those now planned will be (b).

determined by =utual agree =ent with the applicant and a schedule for speci=en withdrawal will be stated.

I A pre-service inspection progra= for the primary coolant boundary and scie:y related syste=s will be for::n21ated and perfor=ed prior f

(c) to re:u n to power.

• 3.

Effluen: Treatment Syste=s We have determined that the effluent treatment system, 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-Our review was li=ited to the use of the syste:

ta=ination program.

for chemical deconomin'azion only, and use of the system for any c:her purpose subsequent 'to that program sust be reviewed prior to such us e.

4 Radiological Safety We have further concluded that the radiological safety progrs=.

described in the sub=it:als is adee,uate to assure that the health and safety of the public and the onsite personnel will not be endangered by the Dresden 1 decontanination proj ect.

CONCLUSION We have concluded, based en the censiderations discussed above, that:

(1) because the che:ical cleaning does not involve a significant increas e in the probability or censecuences of accidents previously considered and does not involve a significan: decrease in a safety cargin, the cleaning project 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 preposed =anner, and (3) such acti.ities will be conducted in ec=pliance with the Cc==ission's regulations and t'.e issuance of this amendment will not be inimical to the co==en defense and' security or to the health and safety of the public.

Date:

December 9,1975 e

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