ML19254D052
| ML19254D052 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 12/09/1975 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19254D048 | List: |
| References | |
| FOIA-80-548, FOIA-80-550 NUDOCS 7910220101 | |
| Download: ML19254D052 (3) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION W ASHIN G TON. D.
C, 20555 SAFETY EVALUATION BY THE OFFICT OF NUCLEAR REACTOR REGULATION SUPPORTING AUTHORIZATION TO CHEMICALLY DECON'TAMINATE THE PRIhRRY COOLING SYSTEM AT DRESDEN UNIT 1 COSD10 WEALTH EDISON COS:PANY DRESDEN NUCLEAR POWER STATICN UNIT I DOCFET NO. S0-10 0
0 D
INTRODUCTION By letters dated December 16, 1974, April 1, 197S and April 14, 197S, the Commenwealth Edison Co:pany (CECO) requested authorization to carry out a chemical decontamination of the interior surfaces of the Dresden Unit 1 priman coolant systen.
Tne purpose of the decontanination is to remove a deposition of activated corrosion products which is tightly bonded to the primary coolant system piping and components. The presence of the corrosion products in the system results in high levels of radiation in adj acent areas and limits access to these areas for the purpose of in-service inspection, routine caintenance and plant nodifications.
CECO has tentatively scheduled the chemical cleaning proj ect to begin in Jaruary 1977 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 1 primary coolant system has been completed.
The results of this review are as follows:
1.
Environmental Impact The cher.ical decontarination of the Dresden 1 primary coolant system will be rerf:rned ertirely within a closed deconta.ination syster.
Tne svstcr '.as been designed so that no chemical or radiological wastes will be releasea to the environment from the decontamination process.
All wastes generated in the process will be either solidified for offsite burial at a licensed burial ground or reprocessed for reuse ersite. The solid wastes produced are similar in type and quantity to these handled routinely at the site.
Therefore, no adverse environmental irpa:ts are anticipated due to the deconta.ination.
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2.
Materials Compatibility The. aff has reviewed the results of the material testing progra.
that has been carried out in support of the preposed Dresden 1 decentanination program The test progra was organized to look at corrosive effects during the deconta-ination process and possible residual effects during subsequent reactor operation.
Bases upon our review of the results of the testing program completed to date, we have cencluded that the test pregr.: adequately evaluated those aspects cf the materials corpatibility that we consider to be important. As a result of our discussions with CECO's consultant, Dr. Craig Cheng of Argonne National Laboratory, we find that the remaining prograr will be conducted in a nanner that will answer our presen:1y unresolved concerns and the test results will be adequately interpreted and reported.
We conclude that upon the successful completien of the testing program described in the subnitials and with an adequate surveillance and inspection progrr., the Dresden Nuclear Power Station Unit I can be subjected to the described chemical cleaning process without undue corresien or other deleterious caterials cc patibility effects that would arcersely effect the integrity of the primary coolant system and connected systems.
A small number of itens of concern have not been resolved to the staff's full satisfaction at this tite.
however, we conclude that authori:ation to carry out the chemical decontamination shculd be granted in anticipation of the successful resciution of these open iters in the near future.
The following cpen items are identified at this time as requiring resolution to the staff's satisfaction:
(a) The materials test program will be completed and the test results will be analyzed and reviewed prior to the beginning of the cleaning process.
(b)
Surveillance specimens in addition to those now planned will be determined by mutual agreement with the applicant and a schedule for specirer withdrawal will be stated.
(c)
A pre-service inspection progrr for the primary coolan: boundary and safe:v rc:acd sysicrs will be formulated and perferred prior
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. 3.
Effluent Treatment Systems he have determined 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 decen-tar.ination pro; ram Our review was limited to the use of the syster for che:;.ical decontamination only, and use of the system for any other purpose subsequent to that program must be reviewed prior to such use.
4.
Radiological Safety he have further concluded that the radiological safety progra described in the submittals is adequate to assure that the health and safety of the public and the onsite personnel will not be endangered by the Dresden 1 decontamination proj ect.
CONCLUSION We have concluded, based on the considerations discussed above, that :
(1) because the chemical cleaning does not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the cleaning proj ect does not involve a significant ha:ards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Date:
December 9, 1975
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