ML15134A204
| ML15134A204 | |
| Person / Time | |
|---|---|
| Issue date: | 05/14/2015 |
| From: | Giitter J NRC/NRR/DRA |
| To: | Tschiltz M Nuclear Energy Institute |
| Moulton C | |
| References | |
| Download: ML15134A204 (3) | |
Text
May 14, 2015 Mr. Michael D. Tschiltz Director, Risk Assessment Nuclear Energy Institute 1201 F St., NW, Suite 1100 Washington, DC 20004-1218
SUBJECT:
REVISION OF INTERIM TECHNICAL GUIDANCE ON FIRE IGNITION FREQUENCIES AND NON-SUPPRESSION PROBABILITIES
Dear Mr. Tschiltz:
The U.S. Nuclear Regulatory Commissions Office of Nuclear Regulatory Research (NRC-RES) and the Electrical Power Research Institute (EPRI) completed technical guidance on Fire Ignition Frequencies and Non-Suppression Probabilities using the updated fire events database in January 2015 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML15016A069). This new interim guidance supersedes the earlier issuance of interim guidance from September 2009 (ADAMS Accession No. ML092190457). Enclosed is a copy of the revised interim guidance (ADAMS Accession No. ML15134A046).
At the time the previous interim guidance was issued, NRC-RES and EPRI had initiated a program to update the EPRI 1011989 / NUREG/CR-6850 fire events database, to be inclusive through year 2008, as well as to establish a process for subsequent periodic updating. However, the NRCs Office of Nuclear Reactor Regulation staff had not yet completed a confirmatory analysis of the proposed revised ignition frequencies. The previous interim guidance indicates that upon successful completion of the update of the fire events database, NRC-RES and EPRI should jointly revise EPRI 1011989 / NUREG/CR-6850, to establish new frequencies for the fire bin ignition categories... The revised interim technical guidance serves as an NRC staff position on fire ignition frequencies and non-suppression frequencies until EPRI 1011989 / NUREG/CR-6850 is revised to include this guidance.
We welcome further dialogue to enhance analytical methods for use in fire PRA regulatory applications.
If you have any questions, please feel free to contact Stacey Rosenberg at (301) 415-2357.
Sincerely,
/RA/
Joseph G. Giitter, Director Division of Risk Assessment Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission
Enclosure:
Revised Interim Technical Guidance
ML092190457). Enclosed is a copy of the revised interim guidance (ADAMS Accession No. ML15134A046).
At the time the previous interim guidance was issued, NRC-RES and EPRI had initiated a program to update the EPRI 1011989 / NUREG/CR-6850 fire events database, to be inclusive through year 2008, as well as to establish a process for subsequent periodic updating.
However, the NRCs Office of Nuclear Reactor Regulation staff had not yet completed a confirmatory analysis of the proposed revised ignition frequencies. The previous interim guidance indicates that upon successful completion of the update of the fire events database, NRC-RES and EPRI should jointly revise EPRI 1011989 / NUREG/CR-6850, to establish new frequencies for the fire bin ignition categories... The revised interim technical guidance serves as an NRC staff position on fire ignition frequencies and non-suppression frequencies until EPRI 1011989 / NUREG/CR-6850 is revised to include this guidance.
We welcome further dialogue to enhance analytical methods for use in fire PRA regulatory applications. If you have any questions, please feel free to contact Stacey Rosenberg at (301) 415-2357.
Sincerely, Joseph G. Giitter, Director Division of Risk Assessment Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission
Enclosure:
Revised Interim Technical Guidance DISTRIBUTION:
JSHyslop HBarrett CMoulton MSalley RidsNrrDra RidsNrrDraApla ADAMS Accession Nos: Pkg: ML15134A243 Ltr: ML15134A204 Encl: ML15134A046 OFFICE NRR/DRA NRR/DRA NRR/DRA NRR/DRA DD: NRR/DRA NAME JSHyslop CMoulton SRosenberg AKlein JGiitter DATE 05/14/2015 05/14/2015 05/14/2015 05/14/2015 05/14/2015