POLICY ISSUE 

INFORMATION 

April 7, 2009 SECY-09-0056

FOR: The Commissioners 

FROM: R. W. Borchardt 

 Executive Director for Operations 

SUBJECT: 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 

PURPOSE: 

To inform the Commission of the staff’s planned approach regarding the following: 

1. rulemaking for a risk-informed and performance-based revision to Part 50 of Title 10 of the 

Code of Federal Regulations (10 CFR Part 50), “Domestic Licensing of Production and 

Utilization Facilities,” for future reactors, and 

2. development of a policy statement on defense-in-depth (DID) for future reactors. 

SUMMARY: 

In its staff requirements memorandum (SRM) on SECY-07-0101,1

 the Commission approved 

the staff’s recommendation to defer rulemaking for risk-informed and performance-based 

10 CFR Part 50 reactor requirements for advanced reactors until after the development of the 

licensing strategy for the Next Generation Nuclear Plant (NGNP) or receipt of an application for 

a Pebble Bed Modular Reactor (PBMR) design certification (DC) or combined license (COL). 

CONTACT: Thomas J. Kenyon, NRO/ARP 

 (301) 415-1120 

 

1

 SRM on SECY-07-0101, “SECY-07-0101 - Staff Recommendations Regarding a Risk-Informed and 

Performance-Based Revision to 10 CFR Part 50 (RIN 3150-AH81),” dated September 10, 2007 (Agencywide 

Documents Access and Management System (ADAMS) Accession No. ML072530501). All documents referenced in 

this paper are available in ADAMS on the NRC’s web page (www.nrc.gov) under the accession number provided. 
The Commissioners - 2 - 

The Commission further directed the staff to develop a draft policy statement on DID for future 

plants for Commission consideration, stating that this draft policy could be evaluated using the 

insights gained through the development of the NGNP licensing strategy and completion of the 

PBMR pre-application review. In the same SRM, the Commission also directed the staff to 

publish the technology-neutral framework discussed in SECY-07-0101 and to test the concept 

of the technology-neutral framework on an actual design. 

Although different approaches for a risk-informed, performance-based regulatory structure have 

been discussed and documented by the U.S. Nuclear Regulatory Commission (NRC) staff, 

reactor designers, and potential COL applicants since 2001, differences exist in important 

aspects of these proposals that have not been fully evaluated or resolved by the staff. 

Considerable further evaluation is needed to resolve the range of outstanding issues with these 

approaches. Therefore, the staff plans to continue to defer rulemaking for risk-informed and 

performance-based reactor requirements for future reactors until the review of a license 

application for the NGNP prototype design or other non-light-water reactor (LWR) design has 

progressed far enough to provide useful insights into the application of such an approach to an 

actual design. To respond to Commission direction, the staff plans to test the concepts and 

methods from a technology-neutral framework during the licensing review of a high-temperature 

gas-cooled reactor (HTGR). In addition, the staff plans to integrate its position on DID with its 

positions on other policy and key technical issues for future reactor designs. The staff plans to 

continue development of a position on DID along with development of other related Commission 

policy and technical positions, but will defer activities to finalize a DID policy statement until 

additional experience and related insights are gained from the NGNP or other non-LWR 

reviews. 

BACKGROUND: 

Development of Risk-Informed, Performance-Based Regulations for Future Reactor Licensing 

In SECY-03-0059,2

 the staff discussed its plan to develop a technology-neutral, risk-informed 

structure for new plant licensing. In subsequent Commission papers, the staff provided status 

reports on these efforts, including identification and discussions of specific policy issues 

identified during this activity. 

In its SRM on SECY-06-0007,3

 the Commission directed the staff to provide its recommendation 

on whether and, if so, how to proceed with rulemaking for risk-informed, performance-based 

technical requirements for future reactors. In SECY-07-0101,4

 the staff recommended that the 

Commission approve the deferral of such rulemaking until after the development of the licensing 

strategy for the NGNP or receipt of an application for DC or a license for the PBMR. The staff 

committed to provide the Commission with a recommendation on initiating rulemaking six 

months after the licensing strategy for the NGNP was finalized. In its SRM on SECY-07-0101, 

 

2

 SECY-03-0059, “NRC Advanced Reactor Research Program,” dated April 18, 2003 (ADAMS Accession 

No. ML023310534) 

3

 SRM on SECY-06-0007, “Staff Requirements – SECY-06-0007 – Staff Plan to Make a Risk-Informed and 

Performance-Based Revision to 10 CFR Part 50,” dated March 22, 2006 (ADAMS Accession No. ML060810277) 

4

 SECY-07-0101, “Staff Recommendations Regarding a Risk-Informed and Performance-Based Revision to 10 CFR 

Part 50 (RIN 3150-AH81),” dated June 14, 2007 (ADAMS Accession No. ML070790236) 
The Commissioners - 3 - 

the Commission approved the staff’s recommendation to defer this rulemaking until after the 

development of the licensing strategy for the NGNP, or receipt of an application for a PBMR DC 

or COL. It directed the staff to publish the technology-neutral framework discussed in 

SECY-07-0101 and test the concept of this framework on an actual design. Further, in its SRM 

on COMSECY-08-0018,5

 consistent with the direction provided in the SRM to SECY-07-0101, 

the Commission directed the staff to plan how best to capture risk-informed, performance-based 

insights and lessons for use in a technology-neutral framework during the NGNP licensing 

process and test the concepts and methods prescribed in the staff’s draft technology-neutral 

framework. 

Defense-in-Depth Policy Statement 

In SECY-03-0047,6

 the staff recommended that the Commission approve the development of a 

policy statement or description on DID for nuclear power plants. In its SRM on SECY-03-0047,7

the Commission approved the staff’s recommendation and stated that the staff should consider 

whether it can accomplish the same goals by updating the Commission Policy Statement on 

Use of Probabilistic Risk Assessment (PRA) Methods in Nuclear Regulatory Activities. In 

SECY-07-0101, the staff stated that stakeholders supported development of a separate policy 

statement on DID because they believed that DID is broader than, and not limited to, PRA. In 

its SRM on SECY-07-0101, the Commission directed the staff to develop a draft policy 

statement on DID for future plants for Commission consideration and stated that this draft policy 

could be evaluated using the insights gained through the development of the NGNP licensing 

strategy or completion of the PBMR pre-application review. 

DISCUSSION: 

In accordance with Commission direction, the staff issued the technology-neutral framework as 

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

Structure for Future Plant Licensing,” Volumes 1 and 2, in December 2007.8

 This NUREG 

documents a framework that provides an approach and criteria that (1) could be used to 

develop an alternative set of technical requirements to 10 CFR Part 50 applicable for future 

non-LWR nuclear power plants (the framework includes a proposed draft set of technical 

requirements), and (2) could be used to establish risk-informed licensing basis events and the 

safety classification of structures, systems, and components. 

In its letter dated August 31, 2001,9

 Exelon submitted a white paper describing and 

documenting its proposed risk-informed and performance-based licensing approach to be used 

in a PBMR COL application. At the time that Exelon terminated its pre-application interactions 

with the staff, there remained a number of technical issues that had been identified and 

 

5

 SRM on COMSECY-08-0018, “Staff Requirements – COMSECY-08-0018 – Report to Congress on Next 

Generation Nuclear Plant (NGNP) Licensing Strategy,” dated June 16, 2008 (ADAMS Accession No. ML081680501) 6

 SECY-03-0047, “Policy Issues Related to Licensing Non-Light-Water Reactor Designs,” dated March 28, 2003 

(ADAMS Accession No. ML030160002) 

7

 SRM on SECY-03-0047, “Staff Requirements - SECY-03-0047 - Policy Issues Related to Licensing Non-LightWater Reactor Designs,” dated June 26, 2003 (ADAMS Accession No. ML031770124) 

8

 ADAMS Accession Nos. ML073400763 and ML073400800 

9

 ADAMS Accession No. ML012490160 
The Commissioners - 4 - 

remained unresolved. Subsequently, in 2006, to address these unresolved issues and to 

provide additional details on its proposed risk-informed licensing approach for the PBMR, 

PBMR (Pty) Ltd. submitted four follow-on, more detailed white papers to the NRC for 

consideration.10 In its March 21, 2008, letter,11 PBMR (Pty) Ltd. responded to staff requests for 

additional information12 on these topics. Since then, however, the staff has not had the 

resources needed to review and document its evaluation of these aspects of the proposed 

PBMR licensing approach. The NRC needs to conduct additional technical evaluations on the 

different risk-informed, performance-based licensing approaches presented in NUREG-1860 

and by PBMR (Pty), Ltd. The staff continues to evaluate how to develop a risk-informed and 

performance-based set of requirements that could be used to license the PBMR, or support 

rulemaking for risk-informed and performance-based reactor requirements for future reactors. 

In the licensing strategy for the NGNP that was issued to Congress in August 2008, “Next 

Generation Nuclear Plant Licensing Strategy - A Report to Congress,”13 the Secretary of Energy 

and the Commission jointly determined that the best option for licensing the NGNP prototype 

would be to use a risk-informed and performance-based technical approach that employs the 

use of deterministic judgment and analysis, complemented by NGNP-specific PRA information. 

This licensing approach would adapt the existing LWR technical requirements to address the 

acceptability of the NGNP design and to establish the NGNP-unique requirements that are not 

addressed by existing LWR requirements and guidance. However, the NGNP licensing strategy 

does not propose to apply PRA insights and information to the degree proposed by either 

PBMR (Pty) Ltd. for DC of the PBMR or to the degree described in NUREG-1860. In the NGNP 

licensing strategy, the Commission concluded that once NGNP technology is successfully 

demonstrated through operation and testing of the NGNP prototype, and a quality PRA that 

includes data from operation of the prototype becomes available, greater emphasis on a designspecific PRA to establish the licensing basis and requirements will be a more viable option for 

licensing a commercial version of the NGNP reactor. 

Based on the above, the staff plans to continue to defer rulemaking for risk-informed and 

performance-based reactor requirements for future reactors until the review of a license 

application for the NGNP prototype design or other non-LWR design has progressed far enough 

to provide useful insights into the application of such an approach to an actual design. To 

respond to Commission direction, the staff plans to test the concepts and methods from the 

technology-neutral framework during the pre-application and license review of the NGNP 

prototype or other non-LWR design. The experiences gained during these future reviews will 

inform a staff recommendation to the Commission on the possible use of risk-informed and 

performance-based approaches within rulemakings to support the licensing of Generation IV 

reactors. 

In addition, the staff has concluded that the PBMR pre-application review will need to progress 

significantly further once additional PBMR design information is provided by the designer, to 

provide an acceptable technical basis for a policy decision on adequate DID for the PBMR and 

 

10 ADAMS Accession Nos. ML060950275, ML061930123, ML062400070, and ML063470549 11 ADAMS Accession No. ML080810340 12 “Requests for Additional Information Regarding Pebble Bed Modular Reactor (PBMR) Pre-Application White 

Papers,” September 24, 2007, ADAMS Accession No. ML072190293. 

13 ADAMS Accession No. ML082290020 
The Commissioners - 5 - 

the development of a DID policy statement for future reactors. Moreover, the staff concludes 

that its position on DID should not be developed in isolation, but should be integrated with other 

related policy and key technical positions, such as its positions on containment functional 

performance requirements and emergency planning requirements. Therefore, the staff plans to 

continue development of a position on DID along with development of resolutions of other 

related issues, but will defer activities to finalize a DID policy statement until additional 

knowledge of these reactor designs and related insights are gained from the NGNP or other 

non-LWR reviews. When sufficient information and additional evaluation is available to support 

this effort, the staff will (1) consider positions previously developed on DID, including those 

developed by international bodies, such as the International Atomic Energy Agency’s INSAG-12 

for LWRs, “Basic Safety Principles for Nuclear Power Plants,” International Nuclear Safety 

Advisory Group (October 1999), and the approach recommended by the Advisory Committee on 

Reactor Safeguards in its May 19, 1999 letter, “The Role of Defense-in-Depth in a 

Risk-Informed Regulatory System”;14 (2) determine the potential implications of DID policy 

issues on other policy and key technical issues for new advanced reactor designs; and (3) apply 

the concepts and methods discussed in NUREG-1860 and develop an integral approach to 

address these policy issues during a staff review of an actual design. Consistent with the 

approach used during the design reviews of larger evolutionary and passive LWRs, the staff will 

provide recommendations to the Commission on proposed resolutions to policy and key 

technical issues identified during the pre-application and license review of the NGNP or other 

HTGR, including proposed resolutions of issues such as DID, containment functional 

performance requirements, and emergency planning requirements. 

FRAMEWORK TEST APPROACH:

The test will be performed in parts in a phased manner such that the results of each phase will 

be used to determine if continuation of the test is warranted. If the staff determines that the 

results of the test supports rulemaking, and if the Commission decides to proceed with 

rulemaking, the staff would proceed with the actual development of the regulations, advanced 

notice of proposed rulemaking, statements of consideration, regulatory analysis, and the 

associated regulatory guides and standard review plan. 

In order for the staff to comply with the Commission’s direction to test the concepts and 

methods from a technology-neutral framework on an actual design, an applicant would need to 

agree to participate in the test, as the NRC staff may need additional information and analysis 

from the applicant to support the test. To date, only PBMR (Pty) Ltd. has proposed a 

risk-informed, performance-based licensing approach for its PBMR design. In its March 22, 

2007, letter,15 PBMR (Pty) Ltd. has indicated that it may submit a DC application in the latter half 

of 2009, but that schedule could change if the U.S. Department of Energy (DOE) selects the 

PBMR design for the NGNP facility. If that occurs, PBMR (Pty) Ltd. would likely place the 

highest priority on the license application schedule documented in the NGNP licensing strategy, 

and place a lower priority on submitting an application for DC of the PBMR design. 

 

14 ADAMS Accession No. 9905260038 15 ADAMS Accession No. ML070890084 
The Commissioners - 6 - 

The staff could also conduct the framework test on the NGNP, regardless of the HTGR design 

chosen by DOE, provided that the applicant and DOE agree to participate in the test. 

Section 644(c) of the Energy Policy Act of 2005 directs that 

The Secretary shall seek the active participation of the Nuclear Regulatory Commission 

throughout the duration of the Project to... (3) develop risk-based criteria for any future 

commercial development of a similar reactor architectures. 

A test of the framework using the NGNP prototype design would provide input during the 

development of these criteria. Because no other designer has proposed that the staff use a 

risk-informed, performance-based licensing approach for its design, the staff has determined 

that other advanced reactors would not be good candidates for this test at this time. 

Provided that the applicant agrees to participate in the test, the staff plans to use the following 

approach for conducting the test. 

(1) The staff will perform an initial test during the pre-application review of an HTGR. It is 

not likely that at this time there will be sufficient information to thoroughly test the 

framework. This test will examine the concepts and approach in light of an actual design 

to determine their feasibility. This test will identify, for example, whether additional work 

on the concepts are needed and identify what design information is needed to implement 

such an approach. 

(2) If the results of the initial test indicate that continuation of the test is warranted, the staff 

will perform a complete test of the framework once the NRC receives a licensing 

application for an HTGR. This test will be performed in parallel with the licensing review 

and, to the extent practicable, will take advantage of the license review of the design. 

However, although a license applicant is required to only provide a summary description 

and the results of the PRA, this test will require that the applicant submit the PRA. This 

test will determine if the technical requirements resulting from applying the framework 

would result in a more effective and efficient regulatory structure for future non-LWR 

nuclear power plants. 

In addition, the staff will need to ensure that the review and resolution of any issues that the test 

review raises do not unnecessarily delay the expedited review schedule identified in the NGNP 

licensing strategy. The licensing strategy calls for a very aggressive 4-year review period 

ending in fiscal year (FY) 2017. Key safety issues raised by the test will have to be addressed. 

However, resolution of certain technical issues related to uncertainty questions may be delayed 

because test results required to address these issues may not be available. The staff expects 

that such issues will be addressed through the application of compensatory measures to the 

NGNP prototype. These compensatory measures may not be required for the commercial 

NGNP design if additional experimental data or confirmatory prototype plant testing justifies the 

change in design or operation of the commercial plant. The license review of an HTGR other 

than the NGNP may be delayed while such issues are resolved, unless compensatory 

measures are adopted by the vendor. 
The Commissioners - 7 - 

This approach to testing the framework will provide insights applicable to the NGNP prototype or 

other HTGR under review, future commercial reactor designs, and risk-informed, performancebased rulemaking activities, while ensuring that sufficient information, including a detailed PRA, 

is available to support that review. It will provide continuity and consistency in conducting the 

test due to the real-time interactions between test review and licensing review activities. The 

test approach will also allow for timely establishment of the risk-informed and performancebased requirements, if the Commission decided to proceed with rulemaking. If the test were 

conducted on the NGNP prototype, the first part of the test could start during the pre-application 

review of the NGNP prototype, and the second part in 2013 with the licensing review of the 

NGNP. 

RESOURCES: 

In its June 11, 2008, SRM on SECY-08-0019,16 the Commission directed that the staff 

specifically address the resources needed in FY 2009 and FY 2010 to ensure that the NRC 

remains a leader in developing the regulatory framework for advanced reactor designs and to 

minimize the need for dramatic spikes in resources. The following is a discussion of the 

resources needed to support the preparation and execution of the test discussed in this paper 

predicated on the assumption that the test will be conducted on the NGNP. If another reactor 

designer agrees to participate in the test review, the staff will reevaluate the time and resource 

efforts necessary to conduct the test. 

Part 1 of the test will require approximately 4 years to complete beginning in FY 2009. The staff 

estimates that the total resources necessary to conduct these efforts will be 0.4 full-time 

equivalent (FTE) in FY 2009 that includes 0.1 FTE for the Office of New Reactors (NRO), 

0.2 FTE for the Office of Nuclear Regulatory Research (RES), and 0.1 FTE for the Office of the 

General Counsel (OGC). The staff estimates the total resources necessary in FY 2010 would 

be 1.1 FTE that includes 0.5 FTE for NRO, 0.5 FTE for RES, and 0.1 FTE for OGC. The 

required resources are included in the FY 2009 budget and the FY 2010 budget request. 

Resources for FY 2011 and FY 2012 will be requested by the Planning, Budgeting, and 

Performance Management Process. At the end of Part 1 of the test, the staff will determine 

whether continuation of this effort is warranted and what changes, if any, should be made to the 

test approach. If the staff concludes that it should continue the test, the staff will assess its 

resource needs and determine the resources necessary to conduct Part 2 of the test. These 

resources would be addressed in the staff’s development of future budget requests, including 

the appropriate prioritization of the test in comparison to other activities before the agency. 

CONCLUSIONS: 

The staff plans to defer rulemaking activities for risk-informed and performance-based reactor 

requirements for future reactors until it conducts a test review of a license application for the 

NGNP prototype design or other non-LWR design in accordance with the proposed approach 

discussed in this paper. In addition, the staff plans to defer activities to finalize a DID policy 

statement until additional experience and related insights are gained from the NGNP or other 

 

16 “Staff Requirements – SECY-08-0019 – Licensing and Regulatory Research Related to Advanced Nuclear 

Reactors,” (ADAMS Accession No. ML081630507) 
The Commissioners - 8 - 

non-LWR reviews. However, the staff plans to continue to develop a position on DID that is 

integrated with other related policy and key technical positions, and test these proposed 

positions during the review of an actual design. 

COORDINATION: 

This paper has been coordinated with the OGC, which has no legal objection, and with the 

Office of the Chief Financial Officer. 

 /RA/ 

R. W. Borchardt 

Executive Director 

 for Operations 
The Commissioners - 8 - 

non-LWR reviews. However, the staff plans to continue to develop a position on DID that is 

integrated with other related policy and key technical positions, and test these proposed 

positions during the review of an actual design. 

COORDINATION: 

This paper has been coordinated with the OGC, which has no legal objection, and with the 

Office of the Chief Financial Officer. 

 /RA/ 

R. W. Borchardt 

Executive Director 

 for Operations 

WITS 200700304/EDATS: SECY-2007-0348 

WITS 200700305/EDATS: SECY-2007-0349 

WITS 200800265/EDATS: SECY-2009-0031 

ADAMS Accession Number: ML090360197 * via email SECY-012 

OFFICE PM:NRGA/NRO LA:NRGA/NRO TECH ED:ADM BC:PTRB/NRO D:ARP/NRO 

NAME TKenyon RRobinson KAzariah-Kribbs * WReckley MMayfield 

DATE 02/19/09 02/11/09 02/09/09 02/20/09 02/27/09 

OFFICE OCFO D:RES OGC - NLO D:NRO EDO 

NAME TPulliam * BSheron 

(J.Lyons for*)

H. Benowitz * MJohnson RWBorchardt 

DATE 03/31/09 03/27/09 03/31/09 03/31/09 04/07/09 

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