POLICY ISSUE 

INFORMATION 

November 2, 2011 SECY-11-0156

FOR: The Commissioners 

FROM: Michael R. Johnson, Director 

 Office of New Reactors 

SUBJECT: FEASIBILITY OF INCLUDING RISK INFORMATION IN CATEGORIZING 

STRUCTURES, SYSTEMS, AND COMPONENTS AS 

SAFETY-RELATED OR NONSAFETY-RELATED 

PURPOSE: 

The purpose of this paper is to inform the Commission of the staff’s assessment of the feasibility 

of including risk information in categorizing structures, systems, and components (SSCs) as 

safety-related or nonsafety-related for the design-specific small modular reactor (SMR) reviews 

either in the short term or the longer term. This paper does not address any new commitments. 

SUMMARY: 

The staff requirements memorandum (SRM) on SECY-11-0024, “Use of Risk Insights to 

Enhance the Safety Focus of Small Modular Reactor Reviews,” dated May 11, 2011 

(Agencywide Documents Access and Management System (ADAMS) Accession No. 

ML111320551), directed the U.S. Nuclear Regulatory Commission (NRC) staff to complete a 

feasibility study for using risk information in categorizing SSCs. The staff reviewed previous 

Commission policies that addressed “safety-related” or “nonsafety-related” SSC classification. 

This review went beyond issues related to new and advanced reactors, considering the 

spectrum of Commission policies, regulations, and guidance addressing this topic. 

CONTACT: Gregory Cranston, NRO/ARP 

 (301) 415-0546 
The Commissioners - 2 -

Based on this review and engagement with the Office of the General Counsel (OGC) and 

external stakeholders, the staff concludes that in the short term the most appropriate use of risk 

information is to continue with the current plans to apply it in the SMR reviews. It is not feasible 

to make more substantive changes regarding the use of risk information in categorizing SSCs 

without significant modifications to the current regulations and associated guidance. 

In the longer term the staff will develop recommendations to the Commission that address a 

new risk-informed and performance-based regulatory structure. The staff has devised an 

approach for the development of this regulatory structure that includes a pilot study, as 

described in SECY-11-0024, dated February 18, 2011. The pilot would test the concepts of a 

new, risk-informed regulatory framework, such as that described in NUREG-1860, “Feasibility 

Study for a Risk-Informed and Performance-Based Regulatory Structure for Future Plant 

Licensing,” Volumes 1 and 2, issued December 2007. 

With respect to resources, the staff is budgeted to conduct the short-term efforts. The staff has 

some resources to begin the longer-term efforts but would need additional resources to 

complete them. 

BACKGROUND: 

SRM-SECY-11-0024, “Use of Risk Insights to Enhance the Safety Focus of Small Modular 

Reactor Reviews,” directed the staff to complete a feasibility study for using risk information in 

categorizing SSCs. 

 

Specifically, SRM-SECY-11-0024 directed that: 

• The staff should provide the Commission with a paper that explores the feasibility 

(e.g., regulatory infrastructure changes, resource requirements, and timing for 

implementation) of including risk information in categorizing SSCs as safety-related 

and nonsafety-related for the design-specific SMR review plans in both the short and 

longer term. Stakeholder input should be considered, as appropriate. 

• The staff should consult with OGC on the Commission paper to determine if there 

are legal obstacles to this approach, namely to determine if this can be done without 

a rule change. 

• The Commission paper should address its potential application to the overall 

regulatory framework and not be limited to SMRs. 

• The Commission paper should include a review of previous Commission policies on 

the spectrum of new/advanced reactor policy issues that may have used 

“safety-related” or “non safety-related” SSC classification as part of the policy 

resolution. 

DISCUSSION: 

The staff reviewed key documents, including applicable Commission policy statements, 

regulations, and guidance related to a risk-informed approach to categorize SSCs. Enclosure 1 

is a chronological list of those NRC documents. For most of these documents, the staff 

provides comments summarizing the salient points, especially as they relate to the use of risk 

information in SSC classification. 
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These documents describe an extensive history of NRC efforts to risk-inform SSC 

categorization and to develop a new risk-informed regulatory framework. In reviewing the past 

experience, the staff also explored options and tested current assumptions regarding what is 

needed to successfully implement risk-informed approaches to categorizing SSCs. The staff 

reaffirmed the current plans for developing a more risk-informed regulatory framework. These 

plans are described later in this paper. The staff then evaluated what changes are feasible in 

both the short term (prior to the receipt of an SMR design certification or license application) and 

in the longer term as they relate to the application of risk insights in the licensing of SMRs. 

As a general matter, regulatory and policy changes, other than for minor interpretations and 

guidance, require notice and comment rulemaking. Also, substantive changes in guidance or 

interpretations are considered equivalent to a rule change requiring notice and comment under 

certain circumstances. Past experience suggests that the NRC would need to expend 

substantial resources, and substantially engage in stakeholder interactions, to complete 

rulemaking. It is not feasible to complete notice and comment rulemaking to make substantive 

changes to regulations and guidance to include risk information in the categorization of SSCs 

prior to receipt of a SMR application, based on current anticipated SMR design certification (DC) 

or construction permit application dates. The staff notes that once an application is received, 

the Commission can, on a case-by-case basis, allow the use of risk information in the 

categorization of SSCs by issuing exemptions and imposing application-specific requirements 

by order. 

NRC’s current regulations and policies, as well as associated guidance and interpretations, 

have a long historical practice of using deterministic concepts. A shift to a risk-informed 

interpretation, with its associated substantive changes to guidance and interpretations would 

effectively constitute a change in the NRC interpretation of the regulation and would likely 

require notice and comment. The staff notes that one of the reasons the NRC chose to 

implement Title 10 of the Code of Federal Regulations (10 CFR) 50.69, “Risk-Informed 

Categorization and Treatment of Structures, Systems and Components for Nuclear Power 

Reactors,” as a rulemaking, rather than as a change in interpretation of existing regulations, was 

because implementation of the risk-informed SSC classification concept represented a change 

in regulatory practice and would have a broad impact on other regulations. Based on historical 

practice, any other approach to using risk information in categorizing SSCs would likely require 

either some form of notice and comment rulemaking or the issuance of exemptions to existing 

regulations. 

With this information in hand, the staff reached out to external stakeholders. Stakeholder input 

was obtained from public meetings that included a public meeting with the Nuclear Energy 

Institute and potential SMR vendors and applicants on June 15, 2011; the 10 CFR 50.69 

Tabletop Exercise for New Plants public meeting on August 9, 2011; and a publicly-noticed 

teleconference on SRM-SECY-11-0024. Applicants for new, large light water reactors (LWRs) 

indicated they are focusing their resources on receiving a combined license (COL), however, 

some new reactor applicants have indicated a desire to pursue the flexibility in categorizing 

SSCs afforded by 10 CFR 50.69 after COL issuance. Similarly, SMR vendors and applicants 

are focusing their resources on preparing their design certification or license applications. No 

applicant indicated they plan to pursue the possible benefits that might be achieved through the 
The Commissioners - 4 - 

use of 10 CFR 50.69 prior to receiving a COL. In addition, no applicant indicated they plan to 

submit an exemption to the regulations related to the use of risk information in classifying their 

SSCs. 

Next Steps

In the short term, the staff plans to continue its efforts to risk-inform the SMR reviews. These 

include the activities discussed in SECY-11-0024, which consist of the preparation and 

application of Design-Specific Review Plans (DSRPs) in the review of SMR design applications 

The DSRPs use risk insights to enhance the safety focus and efficiency of the SMR reviews. 

 

In addition, the staff is prepared to review any application referencing existing regulations, such 

as 10 CFR 50.69, to apply risk insights and 10 CFR 50.12, “Specific Exemptions” to request 

exemptions as stated above. The staff believes that the current provisions of 10 CFR 50.12 

would permit the Commission to approve regulatory exemptions that allow for implementation of 

risk-informed changes to operational and qualification requirements. 

In the longer term the staff has devised an approach as described in SECY-11-0024, for the 

development of a new risk-informed and performance-based regulatory structure. This would 

involve development of a risk-informed framework for both LWRs and non-LWRs and would not 

be limited to SMRs. The staff’s approach is a multistep process that will extend over several 

years and is expected to include several pilot studies in which the principles of a 

technology-neutral regulatory framework are considered for an integral pressurized water 

reactor (iPWR) design application and preapplication activities for non-LWRs to the extend 

those activities are practical and are supported by Commission budget decisions. In pursuing 

this approach, the staff will remain cognizant of efforts and Commission direction pursuant to 

SRM SECY-11-0093, “Near-Term Report and Recommendations for Agency Actions Following 

the Events in Japan,” dated August 19, 2011. The staff also will use, as appropriate, the results 

from the Task Force for Assessment of Options for More Holistic Risk-Informed, 

Performance-Based Regulatory Approach chartered by the Chairman’s tasking memorandum to 

the Executive Director for Operations and the General Counsel, dated February 11, 2011. 

The first step in the staff’s longer-term approach would include a pilot study in which the 

principles of a technology-neutral regulatory framework are considered for an iPWR design 

application. The staff would conduct a pilot study of an iPWR design application by applying the 

principles of a technology-neutral regulatory framework (e.g., NUREG-1860) for review of the 

application. This pilot study is distinct from the licensing review, although the staff would seek 

to conduct the pilot study in parallel with review of the iPWR design application. The staff would 

determine the scope and depth of the pilot study during the iPWR preapplication activities (using 

preliminary results from probabilistic risk assessments) and would begin the pilot study following 

the submittal of the application. The staff intends to conduct this study in cooperation with the 

applicant and in a manner to minimize burden on the applicant. The staff may need to make 

assumptions or otherwise compensate for limitations on interactions with designers and the 

possible lack of information beyond that needed for the actual licensing review. The staff would 

develop and document insights that it acquires from the pilot study. 

The resource estimates for the pilot study are provided in the Resource section below but will 

need to be refined during detailed project planning wherein the scope, methodology and 

schedule are determined. 
The Commissioners - 5 - 

In pursuing the longer term approach, the staff may indentify possible changes to the 

regulations that would result in a risk-informed framework that would address, among other 

things, the categorization of SSCs. While it is possible that a change to the regulations 

stemming solely from the longer term approach could be proposed, the staff thinks it more likely 

that an integration of concepts from pursuing SRM SECY-11-0093 and the activities being 

conducted in response to the Chairman’s tasking memorandum would provide the basis for 

substantive risk-informed changes to the regulations (i.e., 10 CFR Part 5X). 

In response to SRM SECY-11-0024, the staff has provided resource estimates for a rulemaking 

that might follow from the longer-term activities. However, these estimates do not reflect any 

integrated activity that might be proposed. 

RESOURCES: 

As described above there are essentially no short term additional funding requirements. 

Cost estimates for longer-term activities are provided below. 

The resource estimate for the pilot study is approximately 1 Office of New Reactors (NRO) 

full-time equivalent (FTE) staff member and 1 Office of Nuclear Regulatory Research (RES) 

FTE and $1 million over 1 year. 

The resource estimate for developing a new 10 CFR Part 5X based on results from the 

longer-term activities described in this paper is 25 to 50 NRO FTE over 4 to 8 years and 2 to 3 

RES FTE for 2 to 3 years and $750K. 

NRO has budgeted 4 FTE in the FY 2012 Budget Request and the FY 2013 Performance 

Budget under Business Line: New Reactors, Product Line: Licensing; Product: Licensing 

Support. However, the majority of the longer-term activities would require additional funding. 

RES has no budgeted resources in FY 2012 or FY 2013 to conduct pilot studies. Longer-term 

activities will require additional funding. The additional funding will be requested as part of the 

NRC’s FY 2014 budget process. 

It should be noted that staff with the appropriate skill sets to support the pilot study will also be 

supporting the review of upcoming SMR DC and license applications expected to begin in 2013. 

This may create limitations on resource skill set availability for both the staff and industry that 

could affect the schedules discussed above as priority will be given to the certification and 

licensing reviews. 
The Commissioners - 6 -

COORDINATION: 

OGC has reviewed this paper and has no legal objection. The Office of the Chief Financial 

Officer has reviewed this paper for resource implications and has no objections. 

/RA/ 

Michael R. Johnson, Director 

Office of New Reactors 

Enclosure: 

1. Key References and Documents Reviewed 

 Including Applicable Previous Commission Policies 
The Commissioners - 6 -

COORDINATION: 

OGC has reviewed this paper and has no legal objection. The Office of the Chief Financial 

Officer has reviewed this paper for resource implications and has no objections. 

Michael R. Johnson, Director 

Office of New Reactors 

Enclosure: 

1. Key References and Documents Reviewed 

 Including Applicable Previous Commission Policies 

WITS 201100153/EDATS: SECY-2011-0310 

ADAMS Accession No.: ML112690353 *via-email SECY-012 

OFFICE PM:NRO/ARP/ARB2 Tech Editor* BC:NRO/ARP/ARB2 D:NRO/ARP DD:NRO/DCIP 

NAME GCranston JDougherty SMagruder MMayfield LDudes(JTappert for)

DATE 10/5/2011 10/3/2011 10/5/2011 10/26/2011 10/6/2011 

OFFICE D:NRR/DRA* D:NRO/DSER D:NRO/DSRA D:NRO/DE D:RES/DRA* 

NAME MCheok SFlanders CAder TBergman DCoe 

DATE 10/6/2011 10/7/2011 10/6/2011 10/6/2011 10/13/2011 

OFFICE OGC/GCHEA* OCFO D:NRO 

NAME MZobler (SVrahoretis for) JDyer (GPeterson) MJohnson 

DATE 10/28/2011 10/7/2011 11/2/2011 

OFFICIAL RECORD COPY 
Enclosure 

Key References and Documents Reviewed, Including Applicable Previous 

Commission Policies

Below is a chronological listing of references and documents reviewed, including previous 

Commission policies, related to a risk-informed approach to categorizing structures, systems and 

components (SSCs). Dates for references in Title 10 of the Code of Federal Regulations (10 CFR) 

references are based on the latest revision. 

Date Document and Comments

1956 10 CFR 50.2, “Definitions” (specifically for SSCs) 

1984 Generic Letter 84-01, “NRC Use of the Terms, "Important to Safety" and "Safety-Related," 

dated January 5, 1984. 

• The staff clarified the staff’s use of the terms “safety-related” and “important to safety.”

1991 10 CFR 50.65, “Requirements for Monitoring the Effectiveness of Maintenance at Nuclear 

Power Plants,” latest revision 2007. 

• The term “risk significance” first appeared in Regulatory Guide (RG) 1.160, January, 

1995, “Monitoring the Effectiveness of Maintenance at Nuclear Power Plants,” which 

endorsed NUMARC 93-01, Industry Guideline for Monitoring the Effectiveness of 

Maintenance at Nuclear Power Plants,” as one acceptable method to satisfy 10 CFR 

50.65 requirements. 

1985 10 CFR 50.12, “Specific Exemptions.”

• Current NRC regulations allow applicants and licensees to request the application of 

risk insights in the design, construction, and operation of nuclear power plants 

through the exemption provisions in 10 CFR 50.12.

1995 SECY-95-132, "Policy and Technical Issues Associated with regulatory treatment of 

nonsafety systems (RTNSS) in Passive Plant Designs,” dated May 22, 1995.” 

• The paper discussed the new NRC process for the RTNSS in passive plants. 

• It established the Reliability Assurance Program. 

1997 Direction-Setting Issue-12 (Draft), “Risk-Informed, Performance-Based Regulation” 

(Agencywide Documents Access and Management System (ADAMS) Accession 

No. ML051610706), dated April 15, 1997. 

• The Commission stressed the use of probabilistic risk assessment (PRA) concepts 

that allow a risk-graded approach for determining high- and low-risk activities. Risk 

insights could be used to reduce unnecessary regulatory burdens, as well as to 

identify areas where requirements should be increased. 
2 

1998 SECY-98-300, “Options for Risk-Informed Revisions to 10 CFR Part 50—‘Domestic 

Licensing of Production and Utilization Facilities,’” (ML992870048), dated December 23, 

1998. 

• This SECY presented three options for risk-informed modifications to 10 CFR Part 50: 

(1) continue ongoing rulemaking activities and risk-informed approaches, making no 

changes to the current 10 CFR Part 50, (2) modify the scope of special treatment rules 

in 10 CFR Part 50 to be risk informed, and (3) make changes to specific requirements 

in the body of regulations, including Appendix A, “General Design Criteria [GDC] for 

Nuclear Power Plants,” to 10 CFR Part 50. 

• Proposed that safety related SSCs that are low safety significance would move from 

special treatment to normal industrial (sometimes called commercial grade) treatment. 

They would, however, remain in the plant and be expected to perform their design 

function, although without the additional margin, assurance, or documentation 

required for current safety-related SSCs. Conversely, SSCs that are currently not 

safety-related but that are determined to be safety significant would move from normal 

industrial to regulatory treatment. 

• The staff recommended developing risk-informed approaches to the application of 

special treatment requirements. This option only addressed implementing changes to 

the regulatory scope for SSCs needing special treatment in terms of providing 

assurance that the SSCs will perform their functions. It did not address changing the 

design of the plant or the design-basis accidents, which establish the physical 

complement of plant systems included in the design. 

• This paper recognizes that current provisions of 10 CFR 50.12 would permit the 

Commission to approve regulatory exemptions that allow for early implementation of 

risk-informed reductions to operational and qualification requirements. The NRC could 

grant an exemption to operational requirements that involve, in total, no change or a 

decrease in risk, pursuant to 10 CFR 50.12(a)(2)(iv). The NRC could grant an 

exemption under 10 CFR 50.12(a)(2)(vi) that involves an increase in risk, if the 

Commission were able to find that quantitative risk information had not been 

considered in establishing the regulatory requirement that is the subject of the 

exemption. The rationale for granting an exemption under 10 CFR 50.12(a)(2)(vi) 

would be that quantitative risk information constitutes a “material circumstance” not 

considered when the regulation was adopted. 

Granting limited exemptions to a limited number of plants for purposes of pilot testing 

does not pose any special problems, but the repeated issuance of a large number of 

exemptions that, considered together, represent a fundamental alteration of the 

conceptual nature of the licensing basis, to more than a limited number of plants, 

essentially constitutes a generic change to the regulatory requirements in 

10 CFR Part 50. Such generic changes should be adopted through rulemaking, rather 

than case by case, which is inherent in the regulatory approach embodied in the 

issuance of exemptions. Similarly, the granting of a large number of exemptions to a 

single plant should not be so extensive that the validity of the original license is called 

into question (e.g., granting wholesale exemptions to all GDC and regulations for an 

extensive subset of SSCs).
3 

1999 Staff Requirements Memorandum (SRM) for SECY-98-300, dated June 8, 1999. 

• The Commission approved the following: 

• Implement Option 2 and incorporate the Maintenance Rule. 

• Allow voluntary implementation of the risk-informed alternative requirements. 

The Commission deferred judgment on the issue of selective implementation. 

• Use industry pilot studies. 

1999 SECY-99-256, “Rulemaking Plan for Risk-Informing Special Treatment Requirements,” 

dated October 29, 1999. 

• This resulted in the staff issuing 10 CFR 50.69 in 2004. 

• The staff proposed creating an Appendix T, “Categorization of SSCs Into 

Risk-Informed Safety Classes,” to 10 CFR Part 50. 

• The staff decided not to define or redefine the existing terms (i.e., “safety related” or 

“important to safety”), primarily because it judged this approach to be relatively 

inefficient and ineffective from a regulatory standpoint. The staff concluded that the 

use of the same terms having two different meanings would unnecessarily complicate 

and confuse the existing regulations governing power reactors. The potential level of 

confusion could be significant, considering the potential for licensees to elect to 

implement the risk-informed alternative for only a subset of revised rules, resulting in 

the use of similar language with different meanings in the licensee’s licensing-basis 

documents and in the associated plant-implementation documents. In fact, this type 

of confusion would be unavoidable when licensees are phasing in the new approach 

at their facilities as they recategorize the SSCs in various plant systems. Both the 

terms “safety related” and “important to safety” have a long regulatory history that has 

established their meaning and interpretation in both a technical and regulatory sense. 

The staff concludes that it is better to avoid the potential for reopening previous 

debates concerning these terms (and the associated resource drain for both the staff 

and industry). 

• Introduced the explicit 4-box risk-informed safety class (RISC) category boxes for 

SSCs. 
4 

2002 NUREG-1755, “Some Observations on Risk-Informing Appendices A and B to 10 CFR Part 50,” 

prepared for the Advisory Committee on Reactor Safeguards, January 2002. 

• This discusses possible changes to the GDC of Appendix A to 10 CFR Part 50 to make 

them more consistent with a risk-informed regulatory structure. It considered (1) changing 

the scope of the GDC from “important to safety” to “important to risk,” (2) modifying 

individual criteria to address risk more directly, and (3) replacing the GDC with safety goals 

and risk acceptance criteria. As written, the GDC apply to SSCs important to safety, which 

are defined as those SSCs that are required to provide reasonable assurance that there will 

be no undue risk to public health and safety. If the scope is changed to “important to risk,” 

the GDC can be applied to those SSCs that will have the greatest impact on reducing risk, 

as measured by risk metrics such as core damage frequency or large early release 

frequency. 

• Such changes might involve replacing requirements for redundancy, diversity, and 

independence with an overall reliability goal for a system or function. The staff examines 

the applicability of the GDC to plants that are not light-water reactors (LWRs) and concludes 

that slightly more than half of the criteria could apply to non-LWRs, but the remainder 

should be modified or replaced to address phenomena important to the safety of other 

reactor types. Another brief discussion of the quality assurance requirements of 

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

Plants,” to 10 CFR Part 50 concludes that Appendix B has sufficient flexibility to permit less 

stringent requirements for SSCs that are less important to risk. 

2003 SECY-03-0059, “NRC’s Advanced Reactor Research Program,” April 18, 2003. 

• This paper included a discussion of the staff’s plan to develop a technology-neutral, riskinformed regulatory structure for new plant licensing. 

2004 10 CFR 50.69, “Risk-Informed Categorization and Treatment of Structures, Systems and 

Components for Nuclear Power Reactors,” November 22, 2004. 

• It established an alternative risk-informed approach for the treatment of nuclear power plant 

SSCs, based on their safety significance, as an alternative to the special treatment 

requirements for safety-related SSCs specified in the NRC regulations. 

• The determination of the safety significance of SSCs uses an integrated decisionmaking 

process incorporating both risk and traditional engineering insights. The safety functions of 

SSCs include both the design-basis functions (derived from the safety-related definition) 

and functions credited for preventing or mitigating severe accidents. Treatment 

requirements are then commensurately applied to the categorized SSCs to maintain their 

functionality. The 10 CFR 50.69 risk-informed SSC categorization scheme overlays the 

safety-related versus nonsafety-related SSC categories with the safety-significance 

categories. Risk insights can be used to identify SSCs as being either safety significant or 

low safety significant. (The NRC introduced the safety-significance categorization earlier as 

a part of the Reliability Assurance Program for new plants licensed under 10 CFR Part 52, 

“Licenses, Certifications, and Approvals for Nuclear Power Plants.” The NRC derived the 

criteria from those established under the Maintenance Rule.) 

• It incorporated the SECY-98-300 approach of combining the “safety-related” and 

“safety-significant” terminology and placing SSCs in one of four RISC category boxes. 
5 

2006 SECY-06-0007, “Staff Plan to Make a Risk-Informed and Performance-Based Revision to 

10 CFR Part 50,” January 9, 2006. 

• This SECY requested Commission approval to issue an Advance Notice of Proposed 

Rulemaking (ANPR) soliciting stakeholder feedback on rulemaking approaches related to 

making technical requirements for power reactors risk informed and performance based and 

to allow the staff to supplement the ANPR with additional information, as needed, to solicit 

stakeholder input. 

2006 SRM for SECY-06-0007, March 22, 2006. 

• The SRM directed the staff to recommend whether to issue a rulemaking for 

risk-informed, performance-based technical requirements for future reactors and, if so, how 

to proceed. 

• It approved issuance of an ANPR, addressed in SECY-07-0101 (see below). 

2006 RG 1.201, “Guidelines for Categorizing Structures, Systems, and Components in Nuclear 

Power Plants According to Their Safety Significance,” Revision 1, May 2006 

• The staff accepted Nuclear Energy Institute (NEI) 00-04, “10 CFR 50.69 SSC 

Categorization Guideline,” Revision 0, issued July 2005 as one means of categorizing 

nuclear power plant SSCs in support of the implementation of 10 CFR 50.69. 

2007 SECY-07-0101, “Staff Recommendations Regarding a Risk-Informed and Performance-Based 

Revision to 10 CFR Part 50,” June 14, 2007. 

• The staff requested Commission approval of recommendations for a risk-informed and 

performance-based revision to 10 CFR Part 50 for the next generation nuclear non-LWRs, 

specifically the pebble bed modular reactor. 

• The SECY also informed the Commission of the results of the staff’s review of stakeholders’ 

comments provided in response to an ANPR on the development of risk-informed and 

performance-based requirements applicable to nuclear power reactors. 

• The staff recommended deferring rulemaking. 

2007 SRM for SECY-07-0101, September 7, 2007 (ADAMS Accession No. ML072530501).

• The Commission indicated that the staff should publish its technology-neutral regulatory 

framework, discussed in SECY-07-0101. 

• The Commission approved deferring the rulemaking.

2007 NUREG-1860, “Feasibility Study for a Risk-Informed and Performance-Based Regulatory 

Structure for Future Plant Licensing,” December 2007. 

• This NUREG established the feasibility of developing a risk-informed and performancebased regulatory structure for licensing future (advanced non-LWR) nuclear power plants. 

• It documented a framework that provides an approach, scope, and criteria for developing a 

set of requirements that would serve as an alternative to 10 CFR Part 50 for licensing future 

non-LWRs. 

• It incorporated a safety classification scheme in which all plant SSCs fall into two 

categories, safety significant or nonsafety significant, distinguished by whether the SSCs 

need special treatment or not. This differs from the scheme for current reactors, where a 

distinction is made among safety-related, safety-significant, nonsafety-related, and 

important-to-safety equipment. 

• The concepts in NUREG-1860 can be used to develop a risk-informed and 

performance-based process for licensing future nuclear power plants. 
6 

2009 SECY-09-0056, “Staff Approach Regarding a Risk-Informed and Performance-Based Revision 

to Part 50 of Title 10 of the Code of Federal Regulations and Developing a Policy Statement on 

Defense-in-Depth for Future Reactors,” April 7, 2009. 

• This paper informed the Commission of the staff’s planned approach about rulemaking for a 

risk-informed and performance-based revision to 10 CFR Part 50 for future reactors and the 

development of a defense-in-depth policy statement for future reactors. 

• The staff recommended deferring rulemaking. 

• The paper described current NRC activities related to developing a risk-informed regulatory 

structure and testing it in parallel with the review of the NGNP application. 

2009 Memorandum, “Alternative Risk Metrics for New Light-Water Reactor Risk-Informed 

Applications,” dated February 12, 2009, from R. W. Borchardt, NRC Executive Director for 

Operations, to the Commission, enclosing a “White Paper on Options for Risk Metrics for New 

Reactors.” (ADAMS Accession No. ML090150636). 

2009 NEI letter to Girija S. Shukla, NRC, “Transmission of Industry White Paper, ‘Risk Metrics for 

Operating New Reactors,’ for ACRS Review,” March 27, 2009 (ADAMS Accession 

No. ML090900674). 

2010 SECY-10-0034, “Potential Policy, Licensing, and Key Technical Issues for Small Modular 

Nuclear Reactor Designs,” March 28, 2010. 

• The staff identified potential policy, licensing, and technical issues that might require 

Commission consideration to support future design and license review applications for small 

modular reactors (SMRs). 

2010 Commission COMGBJ-10-0004/COMGEA-10-0001, “Use of Risk Insights to Enhance Safety 

Focus of Small Modular Reactor Reviews,” July 9, 2010. 

The Commission requested the following (which led to the development of SECY-11-0024): 

• Develop a framework, implementation strategy, plans, and schedules to more fully integrate 

the use of risk insights into preapplication activities and the review of SMR applications, 

consistent with Commission policy statements. This effort should focus on the use of risk 

insights to identify risk-significant SSCs and aspects of the design that contribute most to 

safety. 

• Align review resources, consistent with regulatory requirements, to risk-significant SSCs to 

enhance the efficiency of the review process. The plan should address the staff’s use of 

risk insights in determining which portions of existing review guidance (e.g., standard review 

plans) it should apply to SMRs. 

• Develop risk-informed licensing review plans for each of the SMR reviews, including the 

associated preapplication activities. 

• Develop a new risk-informed regulatory framework, with a longer-term objective to build on 

the SMR reviews, insights gained from future non-LWR review activities, and the earlier 

technology-neutral framework presented in NUREG-1860. 
7 

2010 SRM on COMBGJ-10-0004/COMGEA-10-0001, August 31, 2010 (ADAMS Accession 

No. ML102510405). 

The Commission requested the following (which led to the development of SECY-11-0024): 

• Describe how the staff intends to develop resolution strategies for—and engage the 

Commission on—the substantive policy considerations for SMR licensing laid forth in 

SECY-10-0034. Some of these policy issues include accident source terms that would be 

used to assess the effectiveness of the containment and plant mitigation features, site 

suitability, and emergency planning; requirements for operator staffing for small or 

multimodular facilities; and security and safeguards requirements for SMRs. 

• Include a discussion of how the staff would propose to align (or deconflict) NRC resources 

for licensing new reactors to support this development. 

• In the plans and schedules to be included in the staff’s paper, account for the existence of 

ongoing prelicensing activities with SMR vendors who have already discussed their 

licensing strategies with the staff. In developing this paper, the staff should seek input from 

SMR vendors and other relevant external stakeholders. 

2010 SECY-10-0121, “Modifying the Risk-Informed Regulatory Guidance for New Reactors,” 

September 14, 2010. 

• The paper requested Commission approval of the staff’s recommendation to modify the riskinformed regulatory guidance to recognize the lower risk profiles of new reactors and to 

prevent a significant decrease in the enhanced levels of safety provided by new reactors. 

2011 SRM for SECY-10-0121, March 2, 2011. 

• The Commission disapproved the staff’s recommendation to modify risk guidance for new 

reactors and approved a hybrid of options described in SECY-10-0121. 

2011 SECY-11-0024, “Use of Risk Insights to Enhance the Safety Focus of Small Modular Reactor 

Reviews,” February 18, 2011. 

• The staff reviewed the history of the application of risk insights to nuclear power plant 

regulation and discussed its plans to apply such insights in licensing SMRs. 

• The staff responded to the Commission request to develop a policy paper, with near-term 

efforts focused on integral pressurized-water reactor designs that address the following: 

o Develop a framework, implementation strategy, plans, and schedules to more fully 

integrate the use of risk insights into preapplication activities and the review of SMR 

applications consistent with Commission policy statements. 

o Align review focus and resources, consistent with regulatory requirements, to 

risk-significant SSCs and other aspects of the design that contribute most to safety to 

enhance the efficiency of the review process. 

o Develop risk-informed licensing review plans for each of the SMR reviews, including the 

associated preapplication activities. 

o Develop a new risk-informed regulatory framework and, as a longer-term objective, build 

on the SMR reviews, insights gained from the future NGNP review activities, and the 

earlier technology-neutral framework presented in NUREG-1860. 

o In the plans and schedules to be included in the staff’s paper, account for the existence 

of ongoing prelicensing activities with SMR vendors who have already discussed their 

licensing strategies with the staff. 

• As stated in SECY-11-0024, the staff has developed an approach for creating, over the 

longer term, a new risk-informed and performance-based regulatory structure for licensing 

advanced reactor designs (e.g., high-temperature gas reactors and liquid metal reactors) in 

response to paragraph d of SRM-COMGBJ-10-0004/COMGEA-10-0001. 
8 

2011 SRM on SECY-11-0024, May 11, 2011. 

• The Commission approved the staff’s proposed plan as outlined in SECY-11-0024. 

• It directed the staff to explore the feasibility (e.g., regulatory infrastructure changes, 

resource requirements, and timing for implementation) of including risk information in 

categorizing SSCs as safety related and nonsafety related for the design-specific SMR 

review plans in both the short and longer term. 

2011 RG 1.174, “An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions 

on Plant-Specific Changes to the Licensing Basis,” Revision 2, May 2011. 

• The RG describes an acceptable approach for assessing the nature and impact of changes 

to proposed plant licensing bases by considering engineering issues and applying risk 

insights. 

2011 IAEA Draft Safety Guide DS 367, “Safety Classification of Structures, Systems and 

Components in Nuclear Power Plants,” dated February 4, 2011. 

• The NRC has comments and has not yet endorsed this guide. 

2011 SECY-11-0089, “Options for Proceeding with Future Level 3 Probabilistic Risk Assessment 

Activities,” July 7, 2011. 

• This paper provides the basis for proceeding with a full-scope comprehensive site Level 3 

PRA. 

2011 SECY-11-0093, “Near-Term Report and Recommendations for Agency Actions Following the 

Events in Japan,” July 12, 2011. 

2011 SRM for SECY-11-0093, August 19, 2011.

2011 Task Force for Assessment of Options for More Holistic Risk-Informed, Performance-Based 

Regulatory Approach, chartered by the Chairman’s tasking memorandum to the Executive 

Director for Operations and the General Counsel, February 11, 2011.