@USNAC

UNITED STATES NUCLEAR REGULATORY COMMISSION

Protecting People and the Environment

Electric Power Research Institute
(EPRI)

Sandia National Laboratories (SNL)

Scientech

Information Sheet: Fire Human Reliability Analysis Methods Development, Susan Cooper, Kendra Hill

(NRC/RES/DRA)
The Risk

The Individual Plant Examination of External Events
(IPEEE) program and the experience from actual fire
events identified that fire, depending on design and
operational conditions, can be a significant or dominant
contributor to nuclear power plant risk. Human actions,
and subsequently, human error, have also been shown
to be a significant contributor to overall plant risk,
including the risk from fires, due to the significant role
that operators play in the fire protection defense-in-depth
strategy on safety. Human reliability analysis (HRA) is
the tool used to assess the implications of various
aspects of human performance on risk. Currently
existing HRA methods are being expanded to provide an
approach to evaluate the impact of human failures in the
fire protection defense-in-depth safety strategy.

The Needs

In 2004, the NRC amended its fire protection
requirements to allow existing reactor licensees to
voluntarily adopt the risk-informed, performance-based
rule, 10CFR50.48c, which endorses NFPA 805
“Performance Based Standard for Fire Protection for
Light Water Reactor Electric Generating Plants”, as an
alternative to the existing prescriptive fire protection
requirements. In order to realize the full benefits of
transitioning to the Risk Informed/Performance Based
standard, plants will need to perform a fire PRA which
should include quantitative human reliability analysis for
post-fire mitigative human actions modeled in a fire PRA.

In 2001, Electric Power Research Institute (EPRI) and
US NRC Office of Nuclear Regulatory Research (RES)
embarked on a cooperative project to improve the state-
of-the-art in fire risk assessment to support this new risk-
informed environment in fire protection. This project
produced a consensus document, NUREG/CR-6850
(EPRI 1011989), entitled “Fire PRA Methodology for
Nuclear Power Facilities” which addresses fire risk for at-
power operations.

This report provides high level qualitative guidance and
quantitative screening guidance for conducting a fire
HRA. However, this document does not provide a
detailed quantitative methodology to develop best-
estimate Human Error Probabilities (HEPs). To fulfill this
need, NRC-RES is working collaboratively with EPRI to
develop a methodology and associated guidance for
performing quantitative human reliability analysis for

post-fire mitigative human actions modeled in a fire PRA.
This guidance will build upon NUREG/CR-6850
(EPRI1011989) and is expected to be published in 2009.

The Applications

The Fire HRA guidance is intended to support plants
transitioning to 10CFR50.48c, as well as NRC reviewers
evaluating the adequacy of submittals from licensees in
the process of transitioning to this rule.

Program Management
Principal John Forester (SNL)
Investigators: Bill Hanneman (EPRI)
Stacey Hendrickson (SNL)
Jeff Julius (Scientech)
Jan Grobbelaar (Scientech)
Susan Cooper (NRC)
Project Manager(s): Kendra Hill (NRC)
Susan Cooper (NRC)
Bijan Najafi (EPRI)

For More Information
Contact Kendra Hill at 301-415-5456 or visit the NRC
website at http://www.nrc.gov.