ML15261A713
| ML15261A713 | |
| Person / Time | |
|---|---|
| Issue date: | 10/01/2015 |
| From: | Giitter J NRC/NRR/DRA |
| To: | Tschiltz M Nuclear Energy Institute |
| Metzger B | |
| References | |
| NUREG-2178, NUREG/CR-7197 | |
| Download: ML15261A713 (3) | |
Text
October 1, 2015 Mr. Michael D. Tschiltz Director, Risk Assessment Nuclear Energy Institute 1201 F St., NW, Suite 1100 Washington, DC 20004-1218
SUBJECT:
AVAILABILITY OF NUREG-2178, REFINING AND CHARACTERIZING HEAT RELEASE RATES FROM ELECTRICAL ENCLOSURES DURING FIRE (RACHELLE-FIRE), VOLUME 1: PEAK HEAT RELEASE RATES AND EFFECT OF OBSTRUCTED PLUME
Dear Mr. Tschiltz:
The U.S. Nuclear Regulatory Commissions (NRC) Office of Nuclear Regulatory Research has developed NUREG-2178, Refining and Characterizing Heat Release Rates from Electrical Enclosures During Fire (RACHELLE-FIRE), Volume 1: Peak Heat Release Rates and Effect of Obstructed Plume, available in the NRCs Agencywide Documents Access and Management System (ADAMS) at Accession No. ML15266A516. The U.S. NRCs Office of Nuclear Reactor Regulation (NRR) has reviewed the document and determined that it contains information that may be used by licensees to approximate heat release rate (HRR) and zone of influence values for various types of electrical enclosures commonly found in nuclear power plants (NPPs).
Although NUREG-2178 is still in the final publication process, it is expected that any revisions to the document will be non-technical.
Since only a limited spectrum of electrical enclosure configurations found in NPPs have been physically tested, an ad-hoc working group was tasked with expanding and interpreting available data in order to capture as many categories of enclosures as possible. As a result, the working group produced the information contained in NUREG-2178, which may not represent or bound all cases in NPPs and, therefore, should be used with caution. It remains NRRs expectation that licensees provide an acceptable level of detail and justification in their submittals to allow the staff to make an independent determination of acceptability based on the technical merits and completeness of a submittal. For instance, National Fire Protection Association (NFPA) Standard 805, "Performance-Based Standard for Fire Protection for Light-Water Reactor Electric Generating Plants" (NFPA 805), Section 2.4.3.3 states, in part, that the fire risk evaluation approach, methods, and data shall be based on the as-built and as-operated and maintained plant. In addition, licensees choosing to apply the information contained in NUREG-2178 without physically assessing the internal contents and configuration of an electrical enclosure but who later determine that the internal contents or configuration were non-conservative (e.g., amount of combustible wire insulation or physical arrangement of wiring) or otherwise inconsistent with the assumptions made in NUREG-2178, shall maintain their design basis documents in accordance with NFPA 805, Section 2.7.2 to reflect the condition, enter the
M. Tschiltz 2
condition in their corrective action program, and take actions to address the condition in accordance with their fire protection quality assurance program.
Sincerely,
/RA/
Joseph G. Giitter, Director Division of Risk Assessment Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission
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condition in their corrective action program, and take actions to address the condition in accordance with their fire protection quality assurance program.
Sincerely,
/RA/
Joseph G. Giitter, Director Division of Risk Assessment Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission DISTRIBUTION:
DRA r/f AKlein HBarrett RGallucci SRosenberg MSalley DStroup RCorreia SLewis/EPRI ADAMS Letter Accession No.: ML15261A713 *via email OFFICE NRR/DRA/AFPB NRR/DRA/APLA NRR/DRA/AFPB NRR/DRA NAME BMetzger SRosenberg
- AKlein JGiitter DATE 9 / 30 / 2015 9 / 30 / 2015 9 / 30 / 2015 10 / 01 / 2015 OFFICIAL RECORD COPY