[Federal Register Volume 59, Number 37 (Thursday, February 24, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-4132]


[[Page Unknown]]

[Federal Register: February 24, 1994]


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NUCLEAR REGULATORY COMMISSION

 

Public Workshop: Reliability of Reactor Designs Proposing To Use 
Passive Safety Systems

AGENCY: Nuclear Regulatory Commission.

ACTION: Notice of public workshop.

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SUMMARY: The Nuclear Regulatory Commission (NRC) is announcing a public 
workshop on reliability assessments of safety system designs having 
passive features. The purpose of the workshop is to review the present 
status of available methodology for assessing safety systems having 
passive features, to discuss possible improvements in these methods and 
to develop guidelines for performing meaningful assessments of such 
systems. This action is being taken to initiate a dialogue on this 
important topic and to provide the opportunity for early public 
participation in the development of review methods and criteria for 
passive safety systems. In addition to open public participation in 
this workshop, the NRC is inviting all known interested parties to 
attend.

DATES: The workshop will be held on Tuesday, March 1 and on Wednesday, 
March 2, 1994, from 8:30 am to 5 pm.

ADDRESSES: The workshop will be held at the Cliffside Inn, P.O. Box 
786, Harpers Ferry, West Virginia 25425. Phone: (304) 535-6302. 
Reservations may be made by calling: 1-800-782-9437.

FOR FURTHER INFORMATION CONTACT:
Brad Hardin, Office of Nuclear Regulatory Research, U.S. Nuclear 
Regulatory Commission, Washington, DC 20555. Telephone (301) 492-3733.

SUPPLEMENTARY INFORMATION: The purpose of this workshop is to initiate 
a dialogue on practical approaches for assessing the reliability of 
engineering systems comprised partially or completely of passive 
components and/or subsystems such as for example gravity fed emergency 
water supplies. Even though the workshop focus will be on the generic 
issues associated with nuclear reactor safety systems having passive 
features, it is also intended to draw on relevant experience in 
engineering fields other than nuclear such as the chemical industry or 
NASA's space programs. Another objective of this workshop is to discuss 
ways for improving our understanding of the sensitivity of functional 
success of passive systems to changes in controlling system parameters. 
Examples of such changes include variations in heat transfer 
coefficient and driving pressure (P) across check valves under 
conditions of natural circulation and low driving head. Due to the 
preliminary nature of the NRC's reviews of the advanced reactor designs 
planning to utilize passive safety features, the workshop will not 
include discussions of specific proprietary design information. The 
results of the workshop will provide an input to assessing the need for 
additional research into understanding passive system reliability in 
integral designs.
    Specific Topics: The proceedings of this meeting will address 
issues pertinent to the assessment of reactor safety systems having 
passive features including such topics as:

1. Regulatory needs for assessments of passive safety system 
reliability. What ingredients must logically be included in the 
quantification of functional reliability of passive systems? What 
results (e.g., uncertainty analysis) should be presented and 
documented?
2. What is meant by the reliability of a passive safety system and by 
the uncertainty in its reliability? What is the best way of determining 
this uncertainty and of incorporating experimental information to 
reduce the uncertainty?
3. Discussion of past efforts to assess the reliability of reactor 
systems that utilize passive features. What methods have proven 
successful in past efforts in light of stated needs (Item I) and what 
were their shortcomings?
4. Which assessment methods are good candidates for improvement and 
what might those improvements be?

    Other questions on the proposed approach to the assessment of 
passive safety systems will be entertained if time permits.

    Dated at Rockville, Maryland, this 17th day of February 1994.

    For the Nuclear Regulatory Commission.
Joseph Murphy,
Acting Director, Division of Safety Issue Resolution, Office of Nuclear 
Regulatory Research.
[FR Doc. 94-4132 Filed 2-23-94; 8:45 am]
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