U.S. NUCLEAR REGULATORY COMMISSION May 2009

REGULATORY GUIDE

OFFICE OF NUCLEAR REGULATORY RESEARCH

The NRC issues regulatory guides to describe and make available to the public methods that the NRC staff considers acceptable 

for use in implementing specific parts of the agency’s regulations, techniques that the staff uses in evaluating specific problems 

or postulated accidents, and data that the staff needs in reviewing applications for permits and licenses. Regulatory guides are not 

substitutes for regulations, and compliance with them is not required. Methods and solutions that differ from those set forth in 

regulatory guides will be deemed acceptable if they provide a basis for the findings required for the issuance or continuance of a 

permit or license by the Commission. 

This guide was issued after consideration of comments received from the public. 

Regulatory guides are issued in 10 broad divisions—1, Power Reactors; 2, Research and Test Reactors; 3, Fuels and Materials 

Facilities; 4, Environmental and Siting; 5, Materials and Plant Protection; 6, Products; 7, Transportation; 8, Occupational Health; 

9, Antitrust and Financial Review; and 10, General. 

Electronic copies of this guide and other recently issued guides are available through the NRC’s public Web site under the 

Regulatory Guides document collection of the NRC’s Electronic Reading Room at 

http://www.nrc.gov/reading-rm/doc-collections/ and through the NRC’s Agencywide Documents Access and Management 

System (ADAMS) at http://www.nrc.gov/reading-rm/adams.html, under Accession No. ML083010447.

REGULATORY GUIDE 1.213 

(Draft was issued as DG-1149, dated June 2008) 

QUALIFICATION OF 

SAFETY-RELATED MOTOR CONTROL CENTERS 

FOR NUCLEAR POWER PLANTS 

A. INTRODUCTION 

This regulatory guide describes a method that the staff of the U.S. Nuclear Regulatory 

Commission (NRC) deems acceptable for complying with the Commission’s regulations for qualification 

of safety-related motor control centers for nuclear power plants. 

The Commission’s regulations in Title 10, Part 50, “Domestic Licensing of Production and 

Utilization Facilities,” of the Code of Federal Regulations (10 CFR Part 50) (Ref. 1), require that 

structures, systems, and components in a nuclear power plant that are important to safety be designed to 

accommodate the effects of environmental conditions (i.e., they must remain functional under postulated 

design-basis events (DBEs)). Toward that end, General Design Criteria 1, 2, 4, and 23 of Appendix A, 

“General Design Criteria for Nuclear Power Plants,” to 10 CFR Part 50 contain the general requirements. 

Augmenting those general requirements are the specific requirements pertaining to qualification of certain 

electrical equipment important to safety that appear in 10 CFR 50.49, “Environmental Qualification of 

Electric Equipment Important to Safety for Nuclear Power Plants.” In addition, Criterion III, “Design 

Control,” of Appendix B, “Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing 

Plants,” to 10 CFR Part 50, requires that test programs, when used to verify the adequacy of a specific 

design feature, should include suitable qualification testing of a prototype unit under the most severe 

DBE. 

This regulatory guide contains information collections that are covered by 10 CFR Part 50 that 

the Office of Management and Budget (OMB) approved under OMB control number 3150-0011. The 
RG 1.213, Page 2 

NRC may neither conduct nor sponsor, and a person is not required to respond to, an information 

collection request or requirement unless the requesting document displays a currently valid OMB control 

number. 

B. DISCUSSION 

The Working Group on Motor Control Centers (Subcommittee (SC 2.14)) of the Nuclear Power 

Engineering Committee of the Institute of Electrical and Electronics Engineers, Inc. (IEEE) developed 

Standard 649 2006, “IEEE Standard for Qualifying Class 1E Motor Control Centers for Nuclear Power 

Generating Stations.” The IEEE Standards Association approved this standard on September 15, 2006, 

and it was published December 29, 2006 (Ref. 2). This standard provides basic principles, requirements, 

and methods for qualifying safety-related motor control centers for applications in both harsh and mild 

environments in nuclear power plants. The demonstration that an installed motor control center will meet 

its design specification requires many steps (a program of quality assurance, design, qualification, 

production quality control, installation, maintenance, periodic testing, and surveillance). The scope of 

IEEE Standard 649-2006 is limited to qualification. 

The purpose of qualification is to provide assurance that the motor control center is capable of 

performing its required safety functions with no failure mechanisms that could lead to common mode 

failures under the postulated conditions stated in the equipment specification. 

Based on recent operating experience, the NRC staff has concluded that: (1) aluminum buses are 

more prone to oxidation than the copper buses in motor control centers; and (2) the ground fault 

protection for motor control centers is recommended to reduce the damage to the electrical equipment 

caused by fire initiated by a ground fault. Applicants and licensees should give appropriate 

considerations to these findings when designing motor control centers for new nuclear power plants. 

Clause 9.5 of IEEE Standard 649-2006 references IEEE Standard 344-2004, “Recommended 

Practice for Seismic Qualification of Class 1E Equipment for Nuclear Power Generating Stations,” 

published January 1, 2005 (Ref. 3), and provides additional guidance for seismic qualification of motor 

control centers. The vast majority of seismic qualification tests on motor control centers for operating 

plants were performed with input frequencies up to only 33 hertz (Hz). As a result of improved 

understanding gained in the high frequency seismic input motions, the NRC staff does not consider 

attempts to use past testing data for seismic qualification of motor control centers to be adequate for new 

nuclear power plants.1

 Recent studies related to early site permit applications at certain east coast hardrock-based plants indicate that the site-specific spectra may exceed the certified design spectra of new 

proposed plants in the very high frequency range (from 20 Hz up to 100 Hz). Plants located in the central 

and eastern United States on hard rock should evaluate whether high-frequency earthquake ground 

motion could affect motor control center components (such as digital components). 

Applicants and licensees should accomplish these objectives using qualification methods (type 

testing, operating experience, analysis as a supplement to type testing and operating experience, ongoing 

qualification, or any combination thereof) identified in IEEE Standard 649-2006. However, the preferred 

method of qualification is type testing because other methods may be based on older or dissimilar 

equipment that may not be comparable to the equipment being qualified. 

 

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 The safety of the operating plants is being addressed through the Generic Issues Program, document number GI-199, 

“Implementations of Updated Probabilistic Seismic Hazard Estimates in Central and Eastern United States on Existing 

Plants.” Additional information is available electronically through the Electronic Reading Room on the NRC’s public 

Web site, at: http://www.nrc.gov/reading-rm/doc-collections/generic-issues/open-gis/. 
RG 1.213, Page 3 

C. REGULATORY POSITION 

The NRC staff considers conformance with the requirements of IEEE Standard 649-2006 an 

acceptable method for use in satisfying the Commission’s regulations with respect to qualification of 

safety-related motor control centers, subject to the following: 

1. In addition to the typical functional tests specified in Table 2 of IEEE Standard 649-2006, 

the alternative criteria a, b, and c should be performed on all motor control center 

components that do not have a specific functional test during and after a harsh 

environment test. 

2. In addition to the typical functional tests specified in Table 2 of IEEE Standard 649-2006, 

the alternative criteria a, b, and c should be performed on all motor control center 

components that support or impact the intended safety function of the motor control 

center and that do not have a specific functional test during and after a harsh environment 

test. 

3. IEEE Standard 649-2006 references several industry codes and standards. If the NRC’s 

regulations separately incorporate a referenced standard, licensees and applicants must 

comply with the standard as set forth in the regulations. By contrast, if the NRC staff has 

endorsed a referenced standard in a regulatory guide, that standard constitutes an 

acceptable method of meeting a regulatory requirement as described in the regulatory 

guide. 

D. IMPLEMENTATION 

The purpose of this section is to provide information to applicants and licensees regarding the 

NRC’s plans for using this regulatory guide. The NRC does not intend or approve any imposition or 

backfit in connection with its issuance. 

In some cases, applicants or licensees may propose or use a previously established acceptable 

alternative method for complying with specified portions of the NRC’s regulations. Otherwise, the 

methods described in this guide will be used in evaluating compliance with the applicable regulations for 

license applications, license amendment applications, and amendment requests. 
RG 1.213, Page 4 

REFERENCES2

1. 10 CFR Part 50, “Domestic Licensing of Production and Utilization Facilities,” U.S. 

Nuclear Regulatory Commission, Washington, DC. 

2. IEEE Standard 649-2006, “Qualifying Class 1E Motor Control Centers for Nuclear 

Power Generating Stations,” The Institute of Electrical and Electronics Engineers, Inc., 

Piscataway, NJ. 3

 

3. IEEE Standard 344-2004, “Recommended Practice for Seismic Qualification of Class 1E 

Equipment for Nuclear Power Generating Stations,” The Institute of Electrical and 

Electronics Engineers, Inc., Piscataway, NJ. 

 

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 Publicly available NRC-published documents, such as Regulations, Regulatory Guides, NUREGs, and Generic Letters, 

listed herein are available electronically through the Electronic Reading Room on the NRC’s public web site at: 

http://www.nrc.gov/reading-rm/doc-collections/. Copies are also available for inspection or copying for a fee from the 

NRC’s Public Document Room (PDR) at 11555 Rockville Pike, MD; the mailing address is USNRC PDR, 

Washington, DC 20555; telephone 301-415-4737 or (800) 397-4209; fax (301) 415-3548; and e-mail 

PDR.Resources@NRC.GOV. 

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 Copies of the non-NRC documents included in these references may be obtained directly from the publishing 

organizations.