ML19305A018
| ML19305A018 | |
| Person / Time | |
|---|---|
| Issue date: | 12/18/1978 |
| From: | Minogue R NRC OFFICE OF STANDARDS DEVELOPMENT |
| To: | Hart G SENATE, ENVIRONMENT & PUBLIC WORKS |
| Shared Package | |
| ML19305A019 | List: |
| References | |
| RULE-PRM-50 NUDOCS 7901020004 | |
| Download: ML19305A018 (3) | |
Text
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DEC 1 g 1978 The Honorable Gary Hart, Chairman Subcommittee on Nuclear Regulation Committee on Environment and Public Works United States Senate Washington, D.C.
20510
Dear Mr. Chairman:
Enclosed for your information are copies of an advance notice of proposed rulemaking to amend 10 CFR Part 50.
The parts of 10 CFR Part 50 that we are considering amending are those affecting the analysis and evaluation of the emergency core cooling requirements for light water nuclear power reactors.
Certain specific changes are being considered for S 50.34, " Contents of Applications; Technical Information," S 50.46, " Acceptance Criteria for Emergency Core Cooling Systems for Light Water Nuclear Power Reactors,"
and Appendix K, to Part 50, "FCCS Evaluation Models." The rulemaking process would be conducted in two phases--one involving changes to be made in the near future, and the other, changes to be made over a longer period of time.
The changes being considered are both procedural and technical in nature.
In each case, they will take into account (1) experience gained in the licensing process, (2) new research information, and (3) operating experience.
The thrust of the proposed changes under Phase 1 concerns first, proce-dural changes which would allow minor changes to the NRC-approved ECCS analysis codes without requiring, as is now the case, a complete ECCS reanalysis by the license applicant and its associated review by the NRC staff; and second, certain specific technical changes that would improve the realism of the evaluation models.
The thrust of the proposed changes under Phase 2 is to incorporate new technical data and operating experience, obtained since the current performance criteria became effective in 1974, into the ECCS analysis and review procedures.
Conservative assumptions will continue to be used in areas where realistic data still are lacking.
An c.verall level of con-servatism will be preserved consistent with present day knowledge.
The Commission staff is presently assessing the impact on the overall conservatism of the rule of the proposed Phase 1 char ges.
Concurrently, the staff is developing the methodology for assessing the technically complex Phase 2 changes.
It is expected that the Phaue 1 assessment will be completed within six months.
A completion time fo the Phase 2 assess-ment has not been established, but this assessment is expected to take l
7901020o04
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The Honorable Gary Hart 2
several years to complete.
In each case, the drafting of the proposed rule could begin with the end of the assessment.
The purpose of the notice is to inform the public of the proposed rule-making and to invite advice and recommendations on several questions concerning the acceptance criteria for emergency core cooling systems in light-water-cooled nuclear power plants.
There will be later oppcrtunity for public comment in connection with any proposed rules that may be developed by the Commission.
The notice is being transmitted to the Office of the Federal Register and comments are requested to be submitted within 60 days following publication.
Copies of a public announcement we plan to issue on this matter are also enclosed.
Sincerely, f
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Robert'B. Minogue, Di, rector Office of Standards Development
Enclosures:
1.
Advance notice of proposed rulemaking to amend 10 CFR Part 50 2.
Public announcement cc:. Senator James McClure l
e MAILING LIST The Honorable Gary Hart, Chairman Subcommittee on Nuclear Regulation Committee on Environment and Public Works
. United States Senate
. Washington, D.C.
20510 cc:
Senator James McClure The Honorable Morris K. Udall, Chairman Subcommittee on Energy and the Environment Committee on Interior and Insular Affairs Un.ted States House of Representatives Washington, D.C.
20515 cc:
Representative RcLert Bauman The Honorable John D. Dingell, Chairman Subcommittee on Energy and Power Committee on Interstate and Foreign Commerce United States House of Representatives Washington, D.C.
20515 cc:
Representative Clarence J. Brown
.