ML19319C766
| ML19319C766 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 02/11/1980 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | Parshall G E.I. DU PONT DE NEMOURS & CO., INC. |
| Shared Package | |
| ML19319C767 | List: |
| References | |
| NUDOCS 8003040701 | |
| Download: ML19319C766 (2) | |
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4 UNITED STATES
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WASHINGTON. D. C. 20555
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2a Docket No. 50-320 George W. Parshall E. I. Du Pont De Nemours & Co.
Central Research and Development Department Experimental Station Wilmington, Delaware 19898
Dear Mr. Parshall:
Your letter of April 16, 1979, to Chairman Hendrie has been referred to this office for response.
Your interest in the efforts of the Nuclear Regulatory Commission (NRC) to resolve problems associated with the Three Mile Island accident is appreciated.
I apologize for not answering your letter sooner, but as you are aware, the Commission and staff are occupied with continued support of the efforts at Three Mile Island and the realignment of our own resources and priorities to give immediate attention to the problems resulting from the accident.
Your lettar suggested that operators of nuclear power plants be required to maintain records of the composition of coolant water (i.e., pH, dissolved solids, additives and particulate matter). We recognize the importance of such a requirement. The staff reviews applicant Safety Analysis Report (SAR) submittals containing the details of the water chemistry programs. Under these programs PWR reactor coolant analyses typically are done for:
total solids, baron, lithium, pH, dissolved oxygen, chlorides, hydrogen, florides and total dissolved gas. The information submitted in the SAR constitutes a commitment to perform these analyses and maintain records on the results.
In addition, plant technical specifications are issued as an appendix to the facility operating license. They define plant limits and requirements, including those for primary coolant water, and cannot be changed without NRC approval.
The technical specifications require water quality analysis for oxygen, chlorides, and florides and set limitations on the amount of each of these items.
These items are selected since they have been shown to be the major causes of degradation of primary coolant boundary materials. The technical specifications further require that records of the water quality analysis be kept by the licensee.
With respect to your coments on requiring utilities to measure trace elements, some nuclear power plants do include in their reactor coolant water chemistry program the analysis of items such as lead, sulfates, nitrates, and other contaminants. However, this is not a mandatory requirement by the NRC.
The primary coolant water of a number of pressurized water reactors has been extensively analyzed and characterized.
This characterization included the evaluation of a number of trace elements. There is an extensive body of literature available on this subject with details of the elements analyzed and THIS DOCUMENT CONTAINS P00R QUAUTY PAGES 600304o %
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George W. Parshall the analytical procedures employed.
For example, an excellent recent review paper is the Electric Power Research Institute Report, EPRI-NP-522 dated March 1979, entitled, " Survey of Corrosion Product Generation, Transport, and Deposition in Light Water Nuclear Reactors."
It is true that we need to know more about the role that trace elements play in stress corrosion cracking, especially at high temperatures.
Research programs sponsored by both NRC and the Electric Power Research Institute are currently investigating mechanisms of corrosion and transport of corrosion products within the light water reactor systems. These programs which are looking at the entire aspect of stress corrosion ~ cracking in nuclear components include work on the effect of trace elements, and it is expected that their role in stress cerrosion cracking will be clarified on completion of the research effort.
I accreciate your concern in this matter and trust that this information will be helpful.
Sincerely yours,
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M Harold R. Denton, Director Office of Nuclear Reactor Regulation i
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