ML19323A524
| ML19323A524 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 03/15/1980 |
| From: | Vollmer R Office of Nuclear Reactor Regulation |
| To: | Bridges G AFFILIATION NOT ASSIGNED |
| Shared Package | |
| ML19323A525 | List: |
| References | |
| NUDOCS 8004210302 | |
| Download: ML19323A524 (6) | |
Text
{{#Wiki_filter:_- .. ggp / 4 UNITED STATES l' ) g #7, NUCLEAR REGULATORY COMMISSION i WASHINGTON, D. C. 20555 g { c,-{ f March 15,1980 DockeY lo. 50-10 Mr. George Bridges 811 S. Webber Urbana Illinois 61801
Dear Mr. Bridges:
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 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. t 2. A pre-service inspection program for the primary coolant boundary will be formulated and submitted for NRC review ead 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 fer your information. Since our 1975 authorization Comonwealth Edison has conpleted 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 Ccmpany cleaning solvent through the reactor primary cooling system. l The solvent, identified as NS-1, has been developed to remove the thin, I tightly adherent, layer of highly radioactive sxide that has formed on the inside sut1 aces of the Dresden 1 primary caoling system. i i l 8004210302 I
Mr. George Bridges 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 hours at about 250'F. After circulation the solvent and the dissolved oxides will be drained i 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 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 Cogar.y 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 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 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 Oresden 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 i ~ _.
Mr. George Bridges March 15,a1980 however, preliminary estimates of the cost for decontamination currently I operating U. S. raactors 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 egloyed at Dresden. l With respect to requests for the preparation of an Environmental Impact Statement for the Dresden Unit 1 decontamination, the Nuclear Regulatory Comission is fully comitted to satisfying all requirements of the National Environmental Policy Act (NEPA). Our regulations which implement j the NEPA requirements are contained in Title 10, Part 51.5, of the United i 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 igact statement: I "(1) Issuance of a permit to constmet a nuclear power reactor, i testing facility, or fuel reprocessing plant pursuant to Part 50 of this chapter; j (2) Issuance of a. full power or design capacity license to operate a nuclear power reactor, testing facility, or fuel reprocessing i plant pursuant to Part 50 of this chapter; (3) Issuance of a permit to construct or a design capacity license i to operate an isotopic enrichment plant pursuant to 50.22 of this chapter; (4) Issuance of a licensa 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 i disposal by land burial pursuant to Parts 30, 40, and/or 70 of this chapter; i f w M 909
Mr. George Bridges 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 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 i material or source material; and (10) Any other action which the Com.?ssion 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 re*gulations promulgated 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 1 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 inpact appraisal will be prepared in accordance with Sections 51.7 and 5b50(d) of our pro-cedures for environmental protection. We will coglete o1r 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 his 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 and significantly reduce the occupational radiation exposure to 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- ) tamination. j 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 decantaminations that have taken place to date throughout the world:
Mr. George Bridges March 15,1980 TABLE 1 Plutonium Recycle Test Reactor 1962 Shippingport PWR 1964 Plutonium Recycle Tc ' 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 i 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 Program Division of Operating Reactors
Enclosure:
Safety Evaluation i 1 l
VNITE3 STATES NUCLEAR REGULATORY COMNltSSION W ASHINGToN. D. c. 20s55 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AtJIHORIZATION TO CHEMICALLY DECONTAMINATE THE PRIMARY COOLING SYSTEM AT DRESDEN UNIT 1 CORiONWEAL'IH EDISON COMPA.W DRESDEN NUCLEAR POWER STATION UNIT 1 t DOCKET No. 50-10 [ i IhTRODUCTION By letters dated Dece=ber 16,1974, April 1,1975 and April 14, 1975, the Cc==enwealth Edison Co=pany' (CECO) requested authori:ation to carry out a che=ical deconta=ination of the interior surfaces of the Dresden Unit 1 pri=ary coolant system. The purpose of the decontamination is to re=ove a deposition of activated i corrosion products which is tightly bonded to the pri=ary coolant systa= . piping and ec=ponents. The presence of the corresion products in the i syste= results in high' levels of radiation in adj acent areas and li=its access to these areas for the purpose of in-service inspection, rou ine =aintenance and plant =odifications. l CECO has tentatively scheduled the chemical cleaning project to begin in Jaruary 1977 with an anticipated return to service scheduled for July 1977. 1 EVALUATION The 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 ce=pl et ed.' The res-21:s of this' review are as follows: 1. Environ = ental I= pac
- Tae. che..ical decon:s ination cf the Dresden 1 pri=a:y coolant system will be perfor=ed entirely within a closed deco.:1 ination system.
The syste: has been designed so that no che=ical or radiological wastes will be releas4d to the environment fro = the decontamination .9 l All wastes generated in' the process will be either' solidi!ied, process. for offsite burial a: a licensed burial ground er reprocessed for reuse onsite. The solid westes produced are sirilar in type and cuantity to thos e h:ndled routinely 2: the site. Theref:re, no adverse environ = ental i= pacts are anticipsted due to the decontarination. d1V l i l I 74toPOW\\ \\ e. ^'
1 l 2 2. Materials Co=patibility The staff has reviewed the results of the =aterial testing p: 7grs= in support of the ' roposed Dresden 1 p that has been carried ou decontarination progra=. The test progrs= was organi:ed to look at corrosive effects during the deconta=ination process and possible' residual effects during subsequent reactor operation. t Based upon our review of the resuits of the testing progra= ce=pleted to date, we have concluded that the test progra= adequately evaluated those aseects of the =aterials ce=oatibility.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 ~ re=aining progra= will be conducted in a =anner that will answer our presently unresolved concerns and the test results will be adequately, intezpreted and reported. upon the successful co:pletion of the testing program We conclude tha: described in the sub=1::als and with an adequate surveillance and inspe,c ion progra=, the Dresden Nuclear Power 5:atien Unit 1 can be subjected to the described the:ical cleaning process without undue corrosion or o:her deleterious =aterials co=patibility effects daa would adversely effect the integrity of the pri=ary coolan: systa= and connected systems. 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 decentzsination should be. granted in anticipation of the successful resolution of these epen The following open items are identified ite=s in the near future. this ti=e as requiring resolution to the staff's satisfaction: a: The haterials test progets will be completed and the test (a) results will be analy:ed and reviewed prior to the beginning of the cleaning process. Surveillance speci= ens in addition to those now planned will be (b) deter =ined by =utual agree =ent with the applicant and a schedule for specimen withdrawal will be stated. A pre-service inspection progrs= for the primary coolan boundary (c) and scie:y related syste:s will be for=ulated and perfor:ed prior to return to power, i t 1 1
3 f 3. Effluent Treatment Systems We have determined that the effluent treatment system, if construe:ed as described in the Ceco sub=ittals, is capable of handling the tyres and quantities of effluents expected to be generated by the decon.' Our review was limited to the use of the syste: tacination program. for chemical decontasitiation only, and use of the system for any c:her l purpose subsequent 'to that program =ust by reviewed prior to such us e. 4. Radiological Safety We ha've furth'er concluded tha: the radiolegical safety progra= 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. i CONC 1.USION i We have concluded, based on the considerations discussed above, that: (1) because the chenical cleaning does not involve a significant increase in the probability or consecuences of accidents previous 11 considered a.d does not involve a significant decrease in a safety =argin, the cleani::; 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 operatien in the proposed =anner, and (3) such acti.ities will be conducted in ec=pliance with the C-issien's regulations and the issuance of this a=endnent will not be inimical to the ec= mon defense and' security or to the health and safety of the public. Date: Dece=ber 9, 1975 i l f S m69 e o e .e e 9}}