80 FR 24290 - Refining and Characterizing Heat Release Rates From Electrical Enclosures During Fire (RACHELLE-FIRE)

NUCLEAR REGULATORY COMMISSION

Federal Register Volume 80, Issue 83 (April 30, 2015)

The U.S. Nuclear Regulatory Commission (NRC) is issuing for public comment a draft NUREG, NUREG-2178 (EPRI 3002005578), ``Refining and Characterizing Heat Release Rates from Electrical Enclosures During Fire (RACHELLE-FIRE), Volume 1: Peak Heat Release Rates and Effect of Obstructed Plume.''

[Federal Register Volume 80, Number 83 (Thursday, April 30, 2015)]
[Notices]
[Page 24290]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2015-10130]



[[Page 24290]]

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NUCLEAR REGULATORY COMMISSION

[NRC-2015-0059]


Refining and Characterizing Heat Release Rates From Electrical 
Enclosures During Fire (RACHELLE-FIRE)

AGENCY: Nuclear Regulatory Commission.

ACTION: Draft NUREG; request for comment.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is issuing for 
public comment a draft NUREG, NUREG-2178 (EPRI 3002005578), ``Refining 
and Characterizing Heat Release Rates from Electrical Enclosures During 
Fire (RACHELLE-FIRE), Volume 1: Peak Heat Release Rates and Effect of 
Obstructed Plume.''

DATES: Submit comments by June 15, 2015. Comments received after this 
date will be considered if it is practical to do so, but the Commission 
is able to ensure consideration only for comments received before this 
date.

ADDRESSES: You may submit comments by any of the following methods 
(unless this document describes a different method for submitting 
comments on a specific subject):
     Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2015-0059. Address 
questions about NRC dockets to Carol Gallagher; telephone: 301-415-
3463; email: [email protected]. For technical questions, contact 
the individual listed in the FOR FURTHER INFORMATION CONTACT section of 
this document.
     Mail comments to: Cindy Bladey, Office of Administration, 
Mail Stop: OWFN-12-H08, U.S. Nuclear Regulatory Commission, Washington, 
DC 20555-0001.
    For additional direction on obtaining information and submitting 
comments, see ``Obtaining Information and Submitting Comments'' in the 
SUPPLEMENTARY INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT: David Stroup, Office of Nuclear 
Regulatory Research; telephone: 301-251-7609; email: 
[email protected]; U.S. Nuclear Regulatory Commission, Washington, 
DC 20555-0001.

SUPPLEMENTARY INFORMATION: 

I. Obtaining Information and Submitting Comments

A. Obtaining Information

    Please refer to Docket ID NRC-2015-0059 when contacting the NRC 
about the availability of information for this action. You may obtain 
publicly-available information related to this action by any of the 
following methods:
     Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2015-0059.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly-available documents online in the 
ADAMS Public Documents collection at http://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``ADAMS Public Documents'' and 
then select ``Begin Web-based ADAMS Search.'' For problems with ADAMS, 
please contact the NRC's Public Document Room (PDR) reference staff at 
1-800-397-4209, 301-415-4737, or by email to [email protected]. The 
ADAMS accession number for each document referenced (if it is available 
in ADAMS) is provided the first time that it is mentioned in the 
SUPPLEMENTARY INFORMATION section. Draft NUREG--2178, ``Refining and 
Characterizing Heat Release Rates from Electrical Enclosures During 
Fire (RACHELLE-FIRE), is available in ADAMS under Accession No. 
ML15056A144.
     NRC's PDR: You may examine and purchase copies of public 
documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555 
Rockville Pike, Rockville, Maryland 20852.

B. Submitting Comments

    Please include Docket ID NRC-2015-0059 in the subject line of your 
comment submission.
    The NRC cautions you not to include identifying or contact 
information that you do not want to be publically disclosed in your 
comment submission. The NRC will post all comment submissions at http://www.regulations.gov as well as enter the comment submissions into 
ADAMS. The NRC does not routinely edit comment submissions to remove 
identifying or contact information.
    If you are requesting or aggregating comments from other persons 
for submission to the NRC, then you should inform those persons not to 
include identifying or contact information that they do not want to be 
publicly disclosed in their comment submission. Your request should 
state that the NRC does not routinely edit comment submissions to 
remove such information before making the comment submissions available 
to the public or entering the comment into ADAMS.

II. Discussion

    The Refining and Characterizing Heat Release Rates From Electrical 
Enclosures During Fire (RACHELLE-FIRE) program involves a working group 
of experienced fire protection and fire probabilistic risk assessment 
researchers and practitioners focused on enhancing the methodology used 
to model electrical enclosure fires in nuclear power plants. This 
report documents the results from the working group's efforts to 
develop technical information in three areas: (1) Classification of 
electrical enclosures in terms of function, size, contents, and 
ventilation; (2) determination of peak heat release rate (HRR) 
probability distributions considering specific electrical enclosure 
characteristics;, and (3) development of a method to account for the 
impact of the enclosure on the vertical thermal zone of influence above 
the enclosure during fire. Electrical enclosures have been classified 
in groups based on their electrical function, contents, and size. Peak 
HRR distributions for the different classification groups have been 
developed. These distributions are based on the results of different 
experimental programs intended to measure the HRR associated with fires 
in electrical enclosures. In order to provide a comprehensive 
characterization of electrical enclosure fires, the working group 
evaluated the temperature characteristics of fire plumes associated 
with these events using the Fire Dynamics Simulator program. Computer 
simulations of various enclosure configurations were developed for 
evaluating the fire burning inside electrical enclosures and the fire 
plume temperature characteristics that would be generated. Based on 
this research, new fire plume temperature profiles reflecting the 
obstructed nature of fire plumes generated from fires inside electrical 
enclosures are provided. Finally, examples, consolidating the 
information described in this report, are provided to illustrate how to 
incorporate the information documented in this report into existing 
approaches for modeling fires in electrical enclosures.

    Dated at Rockville, Maryland, this 21st day of April, 2015.

    For the Nuclear Regulatory Commission.
Mark Henry Salley,
Chief, Fire Research Branch, Division of Risk Analysis, Office of 
Nuclear Regulatory Research.
[FR Doc. 2015-10130 Filed 4-29-15; 8:45 am]
 BILLING CODE 7590-01-P