ML20199B570
| ML20199B570 | |
| Person / Time | |
|---|---|
| Issue date: | 10/15/1997 |
| From: | Rathbun D NRC OFFICE OF CONGRESSIONAL AFFAIRS (OCA) |
| To: | Inhofe J, Schaefer D HOUSE OF REP., SENATE, ENVIRONMENT & PUBLIC WORKS |
| References | |
| CCS, NUDOCS 9711190030 | |
| Download: ML20199B570 (2) | |
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UNITED STATES s
NUCLEAR REGULATORY COMMISblON WASHINGTON. O.C. BeteH001 October 15, 1997 i
The Honorable Dan Schaefer. Chair:,an Subcomittee on Energy and Power Committee on Ccemerce i
United States House of Representatives Washington, DC 20515
Dear Mr. Chairman:
On September 28, 1992, the Nuclear Regulatory Comission (NRC) published in the Federal Reaister an Advance Notice of Proposed Rulemaking (ANPRM). The notice discussed alternative approaches to generic regulation addressing the challenges from severe accidents for future light water reactors.
Since the need for this proposed rule no longer exists and will not exist for the foreseeable future, the Comission has decided to withdraw the ANPRM.
A purpose of the proposed rule was to provide guidance for future designs and to facilitate design certification rulemaking. The design certification is complete for the ABWR and System 80+ and is nearing completion for the AP600.
There are no new potential plant or design applicants in the foreseeable future. Therefore, expenditure of resources to develop and promulgate the regulation is not justified at this time. Should there be a new plant or design applicant, the process used in design certification of the ABWR System 80+ and AP600 would be adequate to address potential challenges from severe accidents Sincerely.
Dennis K. Rathbun. Director Office of Congressional Affairs
Enclosure:
Federal Register Notice cc: Representative Ralph Hall
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,5 NUCLEAR REGULATORY COMMIS810N WASHINGTON D.C. N October 15, 1997 The Honorable James M. Inhofe. Chairman Subcommittee on Clean Air. Wetlands. Private Property and Nuclear Safety Comittee on Environment and Public Works United States Senate Washington, DC 20510 rW r Mr. Chairman:
On September 28. 1992, the Nuclear Regulatory Commission (NRC) published in the Federal Recister an Advance Notice of Proposed Rulemaking (ANPRM).
The notice discussed alternative approaches to generic regulation addressing the challenges from severe accidents for future light water reactors.
Since the need for this proposed rule no longer exists and will not exist for the foreseeable future. the Commissior. has decided to withdraw the ANPRM. A purpose of the proposed rule was to provide guida x 'or future designs and to facilitate design certification rulemaking. The design certification is complete for the ABWR and System 80+ and is nearing completion for the AP600.
There are no new potential plant or design applicants in the foreseeable future. Therefore, expenditure of resources to develop and promulgate the regulation is not justified at this time. Should there be a new plant or design app 11 cent, the process used in design certification of the ABWR System 80+. and AP600 would be adequate to address potential challenges from severe accidents.
Sincerely.
Dennis K. Rathbun. Director Office of Congressional Affairs
Enclosure:
Federal Register Notice
-cc: Senator Bob Graham
_ _. _ _ _ _._ ~..
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NUCLFAR REGULATORY COMMISSION 10 CFR Part 50 RIN 3150-AE38
-Acceptability of Plant Performance for Severe Accidents:-
Scope of Consideration in Safety Regulations
' AGENCY: Nuclear Regulatory Commission, ACTION: Advance notice of proposed rulemaking: Withdrawal.
SUMMARY
- The Nuclear Regulatory Commission (NRC or Commission) is withdrawing an advance notice of proposed rulemaking that outlined alternat ue approaches
'to generic regulation addressing the challenges from severe accidents for future light water reactors. The Commist, ion has decided that a rule change to provide generic requirements for performance during postulated severe accidents is not warranted at'this time.
The basis for this decision-is that a-purpose for the rule was to provide guidance for future designs and to facilitate then ongoing design certification rulemaking.
With all current design certification rulemaking either complete or nearing completion and future. applicants not foreseen, expenditure of the resources to promulgate the rule is'not warranted.
FOR FURTHER INFORMATICN CONTACT: Charles E. Ader, Office of Nuclear Regulatory Research U.S Nuclear Regulatory Commission. Washingcon DC 20555-
- 0001, telephone (301) 415-5622,
. SUPPLEMENTARY INFORMATION: On September 28, 1992. (57 FR 44513), the Commission published an advance notice of proposed rulemaking (ANPRM) to
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, consider amending its regulations to provide generic requirements to address d
the challenges from severe accidents for future ',ight water reactors. The advance notice of proposed rulemaking outlined three alternative approaches to the specification of requirements addressin; severe accident performance. The first alternative, described as a hardware oriented rule, would specify reasonable design features or design characteristics directed towards prevention or mitigation of explicitly identified risk significant phenomena, The risk significant phenomena identified were:
hydrogen generation, transport and combustion, high pressure melt ejection, core concrete interactions and basemat ablation, long term containment overpressurization, steam explosions from fuel coolant interactions, and containment bypass.
These phenomena represent the potential contributors to containment failure or bypass and thus the mechanisms for large offsite radioactive release.
Alternative 2 described as a phenomena oriented rule, was a modification of the first alternative wherein an overall containment performance goal would be specified along with the phenomena to be considered, as identified above.
The designer would then be required to perform analyses of the impact of those phenomena and develop and propose the design features to meet the goal.
4 Regulatory guides would address analytical methods, acceptance criteria and design criteria for hardware. This approach, similar to Alternative 1, would be an overlay on the existing design basis specified in 10 CFR Part 50 and justified on an enhanced safety basis. The third alternative, described as a general design criteria (GDC) oriented rule, involved development of a set of new design requirements to address specific challenges and issued as changes to Appendix A. " General Design-Criteria" to 10 CFR Part 50.
Each new design criterion would describe the nature of the challenges as well as the success 2
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criterion and involve the development of Regulatory Guides to provide additional guidance on analysis methods and assumption.
This approach was similar to the other alternatives, especially Alternative 2, but differs in that the existing 10 CFR Part 50 design basis would be modified to include
-severe accidents.
A primary purpose for the generic severe accident rulemaking was to add consistency and standardization to the resolution of severe accident issues
.for future designs based on current technical information. While, in general.
consistency among many design reviews is best achieved through generic rules, as a practical matter, since the number of new applicants is likely to remain quite limited, it is more efficient to proceed with design-specific reviews.
In fact, the Commission is not aware of any new applicants in the foreseeable future.
Another purpose of'the generic severe accident rulemaking, i.e..
facilitation of design certification rulemaking, has been rendered moot by the experience gained in design certification rulemakings. The design certification rulemakings are completed for the General Electric Advanced Boiling Water Reactor and ABB-CE System 80+ and the only design currently under review is the Westinghouse AP600. The resolution of severe accident design specific requirements would be set forth in the AP600 design control document and approved in tha AP600 ' design certification rulemaking.
While certain arguments in favor of generic rulemaking (i.e., promoting consistency. and standardization in the resolution of severe accident issues 3
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and providing guidance to future LWR designers and applicants) continue to a
apply'in varying degrees, practical aspects limit the need for such an
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activity. At this point. given the lack of any new potential plant or design applicants, the Comission believes that the benefits of generic rulemaking do t
not justify the allocation of resources to proceed with the development of new l
regulations addressing severe accidents.
i Upon consideration of the potential value of a generic rule. the status of the review and design certification of future reactors, and the potential resource requirements, the Comission believes that the value in pursuing generic se'.ere accident rulemaking does not warrant the resource expenditure.
While the Comission does not perceive the need-for generic rulemaking in the foreseeable future, should conditions change regarding potential applicants.
the Commission would reassess the merits of rulemaking at that time.
For the reasons discussed the Comission is withdrawing the ANPRM.
d Dated at Rockville. Maryland this.7 -
day of October, 1997.
For the Nuclear Regulatory Comission 1
fb Y
y JohnA. Hoyle.
Secretary of the Comission.
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