80 FR 24293 - Net Positive Suction Head for Emergency Core Cooling and Containment Heat Removal System Pumps

NUCLEAR REGULATORY COMMISSION

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

The U.S. Nuclear Regulatory Commission (NRC) is withdrawing regulatory guide (RG), RG 1.1 ``Net Positive Suction Head for Emergency Core Cooling and Containment Heat Removal System Pumps.'' The guide is being withdrawn because the same guidance is provided with more detail by RG 1.82, ``Water Sources for Long-Term Recirculation Cooling Following a Loss-of-Coolant Accident.''

[Federal Register Volume 80, Number 83 (Thursday, April 30, 2015)]
[Notices]
[Pages 24293-24294]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2015-10076]


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NUCLEAR REGULATORY COMMISSION

[NRC-2015-0107]


Net Positive Suction Head for Emergency Core Cooling and 
Containment Heat Removal System Pumps

AGENCY: Nuclear Regulatory Commission.

ACTION: Regulatory guide; withdrawal.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is withdrawing 
regulatory guide (RG), RG 1.1 ``Net Positive Suction Head for Emergency 
Core Cooling and Containment Heat Removal System Pumps.'' The guide is 
being withdrawn because the same guidance is provided with more detail 
by RG 1.82, ``Water Sources for Long-Term Recirculation Cooling 
Following a Loss-of-Coolant Accident.''

DATES: Effective April 30, 2015, the NRC withdraws RG 1.1.

ADDRESSES: Please refer to Docket ID NRC-2015-0107 when contacting the 
NRC about the availability of information regarding this document. You 
may obtain publicly-available information related to this document 
using any of the following methods:

[[Page 24294]]

     Federal Rulemaking Web site: Go to http://www.regulations.gov and search for Docket ID NRC-2015-0107. Address 
questions about NRC dockets to Carol Gallagher; telephone: 301-415-
3463; email: [email protected]. For technical questions, contact 
the individual(s) listed in the FOR FURTHER INFORMATION CONTACT section 
of this document.
     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 available in 
ADAMS) is provided the first time that a document is referenced.
     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.

FOR FURTHER INFORMATION CONTACT: Ahsan Sallman, Office of Nuclear 
Reactor Regulation, telephone: 310-415-2380 email: 
[email protected], and Richard Jervey, Office of Nuclear Regulatory 
Research, telephone: 301-251-7404, email: [email protected]. Both 
are staff of the U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001.

SUPPLEMENTARY INFORMATION: 

I. Introduction

    The NRC is withdrawing RG 1.1 because its guidance has been 
incorporated into RG 1.82, ``Water Sources for Long-Term Recirculation 
Cooling Following a Loss-of-Coolant Accident.''

II. Further Information

    The withdrawal of RG 1.1 does not alter any prior or existing 
licensing commitments based on its use. Although a regulatory guide is 
withdrawn, its use in existing licenses is still valid, and changes to 
the licenses can be accomplished using other regulatory products. 
Withdrawal of an RG means that the guide no longer provides useful 
information or has been superseded by other guidance, technological 
innovations, congressional actions, or other events. A withdrawn guide 
should not be used for future NRC licensing activities.
    This RG 1.1 provides guidance on meeting the requirements in part 
50, appendix A of Title 10 of the Code of Federal Regulations (10 CFR), 
General Design Criteria (GDC), GDC 35, ``Emergency Core Cooling,'' and 
GDC 38, ``Containment Heat Removal.'' The GDC 35 and 38 require that 
the emergency cooling and containment heat removal systems be capable 
of accomplishing their required safety functions assuming loss of 
offsite power and single failure. The ability to accomplish these 
safety functions reliably depends in part on the proper performance of 
system pumps which, in turn, depends on the conditions under which the 
pumps must operate. One of these conditions is suction pressure and the 
closely related characteristic net positive suction head. The 
information in RG 1.82 has been updated from extensive reviews of the 
emergency core cooling system recirculation systems which have reduced 
the uncertainties contained in modeling studies of these systems. The 
NRC staff has determined that the RG 1.82 guidance is more thorough and 
provides the needed detail to allow consideration of nuances in design 
which were not contemplated when RG 1.1 was written in 1970.
    The guidance from RG 1.1 pertaining to suction pressure and net 
positive suction head has been incorporated into RG 1.82, ``Water 
Sources for Long-Term Recirculation Cooling Following a Loss-of-Coolant 
Accident,'' which includes detailed guidance related to emergency 
cooling systems. The RG 1.1 is superseded by RG 1.82.

    Dated at Rockville, Maryland, this 23rd day of April, 2015.

    For the Nuclear Regulatory Commission.
Thomas H. Boyce,
Chief, Regulatory Guidance and Generic Issues Branch, Division of 
Engineering, Office of Nuclear Regulatory Research.
[FR Doc. 2015-10076 Filed 4-29-15; 8:45 am]
 BILLING CODE 7590-01-P