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SECY-99-256
October 29, 1999
| FOR: | The Commissioners |
| FROM: | William D. Travers /s/ Executive Director for Operations |
| SUBJECT: | RULEMAKING PLAN FOR RISK-INFORMING SPECIAL TREATMENT REQUIREMENTS |
PURPOSE:
To obtain the Commission's approval of a rulemaking plan and issuance of an Advance Notice of Proposed Rulemaking for risk-informing special treatment requirements.
SUMMARY:
The staff has prepared a rulemaking plan (Attachment 1) that describes an alternative risk-informed approach to special treatment requirements.(1) These alternative requirements would vary the treatment applied to structures, systems, and components (SSCs) on the basis of their safety significance using a risk-informed categorization method. SSCs that are safety significant would be subject to greater regulatory control than SSCs of low safety significance. This approach differs from the current special treatment requirements, which are based on those SSCs that are determined to be safety-related or important to safety based on deterministic considerations. This alternative approach would maintain safety while reducing unnecessary regulatory burden to licensee's and improving the staff's regulatory effectiveness and efficiency. The rulemaking plan implements the approach described under Option 2 in SECY-98-300, "Options for Risk-Informed Revisions to 10 CFR Part 50 - 'Domestic Licensing of Production and Utilization Facilities,'" dated December 23, 1998.
Four issues that represent significant challenges to completing this rulemaking have been identified: (1) selective implementation (discussed in SECY-98-300), (2) potential impact of these rule changes on other rules (e.g., 10 CFR Part 19, 10 CFR 50.120, 10 CFR Part 54, 10 CFR Part 55), (3) the type and amount of staff review required before licensees can implement the alternative requirements, and (4) the level of regulatory treatment required for SSCs based on their safety-significance.
The rulemaking plan includes six major efforts: (1) review of the South Texas Project (STP) exemption request;(2) (2) issuance of an advanced notice of proposed rulemaking (ANPR, Attachment 2); (3) a categorization pilot program; (4) review of a Nuclear Energy Institute (NEI ) guideline on SSC categorization; (5) issuance of a proposed rulemaking; and (6) issuance of a final rulemaking. Some of these efforts are ongoing.
If Commission approval of the rulemaking plan is granted within 6 weeks of the date of this Commission paper, the staff estimates that the final rule can be submitted to the Commission for approval in October 2001. Licensee implementation could then begin in March 2002. Execution of the rulemaking plan is estimated to require 47 full-time equivalent (FTE) staff, and $3.0 million of technical assistance over FY 2000, 2001, and 2002.
BACKGROUND:
In SECY-98-300, the staff presented three options for risk-informed modifications of 10 CFR Part 50: (1) continue ongoing rulemaking activities and risk-informed approaches making no changes to the current Part 50; (2) change the special treatment rules in Part 50 to modify their scopes to be risk informed; and (3) make changes to specific requirements in the body of regulations, including general design criteria (GDC).
Under Option 2 of SECY-98-300, it was recommended that risk-informed approaches to the application of special treatment requirements be developed. This option of SECY-98-300 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. SECY-98-300 indicated that safety related SSCs that are of 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 proceeding with Option 2.
The staff also addressed three policy issues related to Option 2 in SECY-98-300: (1) voluntary versus mandatory conformance with the modified Part 50, (2) use of industry pilot studies with selected exemptions to facilitate implementation of Options 2 and 3, and (3) modification of the scope of the maintenance rule.
With respect to Option 2, in the staff requirements memorandum (SRM) for SECY-98-300 dated June 8, 1999, the Commission approved (1) implementing Option 2, including incorporation of the maintenance rule into Option 2; (2) voluntary implementation of the risk-informed alternative requirements, but deferred judgment on the issue of selective implementation; and (3) use of industry pilot studies.
The staff's rulemaking plan for implementing Option 2 is summarized below. The staff's effort regarding Option 3 of SECY-98-300 will be provided in another Commission paper. The two regulatory efforts are being coordinated and it is expected that the Option 3 effort will be able to build upon the framework discussed below.
DISCUSSION:
In response to the June 8, 1999 SRM, this paper provides a rulemaking plan as one of the following three attachments:
Attachment 1 is the rulemaking plan.
Attachment 2 is the ANPR.
Attachment 3 is the methodology and criteria for selecting candidate rules.
In the course of preparing the rulemaking plan, the staff (1) developed guiding principles in the form of a mission statement; (2) developed a general scheme to categorize SSCs and vary their treatment by overlaying a risk-informed approach onto the current deterministic framework; (3) identified the preferred rulemaking approach; (4) identified the rules to be considered for inclusion in the rulemaking; (5) developed an ANPR; (6) established the framework for an acceptable categorization pilot program; and (7) identified policy and implementation issues that present significant challenges to completing the rulemaking. The results of these efforts are summarized below and discussed in more detail in the attachments.
The mission statement is described in Section 1.2 of the rulemaking plan (Attachment 1). The mission statement provides the strategies and objectives for the effort. Its purpose is to provide overall guidance in determining what issues and approaches are appropriate and it contains measures for determining whether the rulemaking effort is successful.
The purpose of this rulemaking is to develop an alternative regulatory framework that enables licensees, using a risk-informed process for categorizing SSCs according to their safety significance (i.e., a decision that considers both traditional deterministic insights and risk insights), to reduce unnecessary regulatory burden for SSCs of low safety significance by removing these SSCs from the scope of special treatment requirements. In the process, both the NRC staff and industry should be able to better focus their resources on regulatory issues of greater safety significance. This framework should improve regulatory effectiveness and efficiency, and contribute to enhanced plant safety. To accomplish this goal, it is necessary to amend the governing regulations. The current regulations use terms such as "safety-related," "important to safety," and "basic component" to identify the groups of SSCs and associated activities that require "special treatment." This rulemaking will build into the regulations an alternative that offers licensees the flexibility of utilizing a risk-informed process to evaluate the need for special treatment. This risk-informed process will ensure that risk insights will be used in a manner that complements the NRC's traditional deterministic approach. The risk-informed approach will be consistent with the defense-in-depth philosophy, will maintain sufficient safety margins, will ensure that any increase in core damage frequency or risk is small and consistent with the safety goal policy statement, and will include a performance measurement strategy. The risk-informed framework will also be aligned to the NRC Reactor Inspection Oversight process by incorporating the cornerstones from the reactor safety and radiation protection safety areas into the SSC categorization process.
A graphical depiction of the changes that are expected to result from a risk-informed re-categorization of SSCs is illustrated in Figure 1. The figure is only intended to provide a conceptual understanding of the new SSC categorization process. The staff's thinking is continuing to evolve on this matter and as suggested in the Advisory Committee on Reactor Safeguards (ACRS) letter of October 12, 1999, the staff will explore whether more than two levels of safety significance is a better approach. The staff is requesting stakeholder feedback regarding safety significance categories in question C.3 of the ANPR. The figure depicts the current safety-related versus nonsafety-related SSC categorization scheme with an overlay of the new risk-informed categorization. The risk-informed categorization would group SSCs into one of the four boxes in Figure 1.
Box 1 of Figure 1 contains safety-related SSCs that a risk-informed categorization process concludes are significant contributors to plant safety. These SSCs are termed risk-informed safety class 1 (RISC-1) SSCs. SSCs in this box would continue to be subject to the current special treatment requirements. In addition, it is possible that some of these SSCs may have additional requirements concerning reliability and availability, if attributes which cause an SSC to be safety significant are not sufficiently controlled by current special treatment requirements. However, the staff is not currently aware of any examples of this situation.
Box 2 depicts the SSCs that are nonsafety-related, and that the risk-informed categorization concludes make a significant contribution to plant safety. These SSCs are termed RISC-2 SSCs. Examples of RISC-2 SSCs could include the station blackout emergency diesel, startup feedwater pumps, or SSCs that function for pressurized water reactor (PWR) "feed and bleed" capability. For RISC-2 SSCs, there will probably need to be requirements to maintain the reliability and availability of the SSCs consistent with the probabilistic risk assessment (PRA). As discussed below, it is currently envisioned that 10 CFR 50.69 (i.e., the new rule) would contain the regulatory treatment requirement for RISC-1 and RISC-2 SSCs regarding the reliability and availability of these SSCs.
Figure 1: Diagram of Categorization and Treatment
Box 3 depicts the currently safety-related SSCs that a risk-informed categorization process determines are not significant contributors to plant safety. These SSCs are termed RISC-3 SSCs. The rulemaking would revise Part 50 to contain alternative requirements (per �.69) such that RISC-3 SSCs would no longer be subject to the current special treatment requirements. For RISC-3 SSCs, it is not the intent of this rulemaking to allow such SSCs to be removed from the facility, or to have their functional capability lost. Instead, the RISC-3 SSCs will need to receive sufficient regulatory treatment such that these SSCs are still expected to meet functional requirements, albeit at a reduced level of assurance. The staff may determine that this level of assurance can be provided by licensee's commercial grade programs. As discussed below, it is currently envisioned that �.69 would contain the regulatory treatment requirements for RISC-3 SSCs.
Box 4 depicts SSCs that are nonsafety-related and continue to be categorized as not being significant contributors to plant safety. These SSCs are out of scope of both current special treatment and any future regulatory controls of �.69. The functional performance of these SSCs is controlled under the licensee's commercial grade program (no change from the current requirements).
As described in Section 4.1 "Selection of the Rulemaking Approach" of the rulemaking plan, the staff is recommending a rulemaking approach that would include development of a new Part 50 rule. This rule would be supported with an appendix that utilizes new terminology as presented in Figure 1. The staff is recommending this approach in lieu of modifying the definition of "safety-related" and defining "important to safety" as was suggested in SECY-98-300 because if the current terminology is redefined to include a risk-informed part and voluntary and selective implementation is allowed, the meaning of "safety-related" and "important to safety" would be licensee and rule-specific. The staff believes that this outcome would result in confusion among both the staff and industry. With the use of new terminology, it would be immediately apparent whether a licensee was using the risk-informed alternative or the current requirement. The staff's proposed terminology, as previously described, is risk-informed safety class (RISC)1, 2, and 3.
The rulemaking approach includes two parts. The first part is a new rule, 10 CFR 50.69, that will allow the use of the new risk-informed categorization for the regulations identified within that rule.(3) Section 50.69 will require that licensees use a method that complies with criteria in a new Appendix T "Categorization of SSCs Into Risk-Informed Safety Classes," or is otherwise found acceptable by the staff, to identify the appropriate SSCs for each risk-informed safety class. Section 50.69 will also provide requirements for regulatory treatment depending on the risk-informed safety class. Licensees would be allowed to use the risk-informed approach for any of the rules, or sets of rules as appropriate, that are identified in �.69. The second part is a new 10 CFR Part 50 Appendix T that provides the criteria and categorization processes to properly identify safety significant SSCs that require special treatment. An objective of this rulemaking is to attempt to establish criteria in Appendix T such that licensee's who satisfy those requirements will be able to implement the risk-informed alternative with little or no prior staff review of the categorization process. The staff will not be able to determine the feasibility of this approach until after both the South Texas Project (STP) exemption effort and the categorization pilot program are complete.
The staff's methodology for determining the set of rules that should be considered for modification includes (1) a review of the regulations to identify those that use a scope based on terminology such as "safety-related," "important to safety," or a similar construct; (2) development of criteria for establishing which rules belong in this effort; and (3) evaluation of the rules identified in the first step against the criteria. A fourth step, which would be accomplished as part of the proposed rulemaking, would be to review other regulations that do not have a safety-related or important-to-safety type scope to identify any requirement that may be affected by the modifications to the special treatment requirements. This method is described in detail in Attachment 3.
The staff's preliminary assessment using this method identified the following rules for consideration in this rulemaking (bold means the rule was discussed as an example of a special treatment rule in SECY-98-300):
| 50.34, Contents of applications; technical information (FSAR) 50.36, Technical specifications 50.44, Combustible gas control 50.48, Fire protection 50.49, Environmental qualification 50.54(a)(3), Conditions of licenses (in reference to Quality Assurance Programs only) 50.55, Conditions of construction permits 50.55a, Codes and standards 50.59, Changes, tests and experiments(4) 50.65, Monitoring effectiveness of maintenance 50.71(e), Maintenance of records, making of reports 50.72/50.73, Reporting Appendix A, General Design Criteria | ||
| GDC 1, Quality standards and records GDC 2, Design bases for protection against natural phenomena GDC 3, Fire protection GDC 4, Environmental and dynamic effects design bases GDC 37, Testing of emergency core cooling system GDC 40, Testing of containment heat removal system GDC 42, Inspection of containment atmosphere cleanup systems GDC 43, Testing of containment atmosphere cleanup systems GDC 45, Inspection of cooling water system GDC 46, Testing of cooling water system | ||
| Appendix B, Quality Assurance Appendix J, Containment leakage Appendix R, Fire Protection Appendix S, Seismic Part 21, Reporting of defects and noncompliance Part 52, Advanced Reactors Part 54, License Renewal Part 100, Appendix A, Seismic | ||
The ANPR (Attachment 2) provides a description of, and requests that the public comment on: (1) the alternative new terminology and proposed criteria (the proposed Appendix T); (2) the staff's proposed approach for modifying the special treatment requirements; (3) the staff's expectations with respect to conduct of the pilot program; (4) the staff's proposed activities and schedules for completion; and (5) certain policy and implementation issues. The staff believes that the ANPR provides the following benefits:
The proposed approach includes two distinct pilot activities as part of the pilot program. They are (1) review of the STP exemptions as a proof-of-concept prototype pilot and (2) a categorization pilot program to demonstrate the acceptability of the contemplated new Appendix T and the NEI guideline.
The staff's review of the STP exemption request will address many of the same issues as this rulemaking. It may establish the type of staff review necessary to allow implementation of risk-informed alternatives and will address the regulatory treatment associated with maintaining the functionality of RISC-3 SSCs. It is not expected, however, that the STP exemption will demonstrate whether the contemplated Appendix T or the NEI guideline is adequate.
The categorization pilot program will be conducted to demonstrate the adequacy of the contemplated new terminology and categorization acceptance criteria in the proposed Appendix T. The staff further recommends that final rulemaking be deferred until the staff has confirmed the acceptability of the proposed rule language and the NEI guideline. Under the proposed schedule, the staff would complete this evaluation in July 2001. The staff could then issue exemptions to the pilot program participants at that time.
The staff is evaluating a number of issues to determine their effect on the scope and character of this rulemaking. These issues are summarized below, and additional details are provided in the ANPR.
| 1. | Selective Implementation |
| Selective implementation is defined as either implementing a subset of alternative regulatory treatment requirements or implementing those
requirements for a subset of SSCs at a facility, or both. In SECY-98-300, the staff stated that if selective implementation is allowed, some licensees
could focus their efforts in areas where unnecessary regulatory burden could be reduced, and may not focus in areas where it would be appropriate to
place additional regulatory controls on SSCs given their safety significance. Therefore, selective implementation was judged incompatible with the
intent of risk-informed regulation. However, the Commission determined that a decision on this topic was premature. The staff now believes that
selective implementation for a subset of alternative special treatment requirements should be accommodated. The staff has not reached a conclusion
regarding selective implementation for a subset of SSCs, but acknowledges that implementation of this framework would likely be through a phased
approach by licensees. Selective implementation of alternative regulatory treatment requirements would introduce additional complexity into the
regulatory process and the staff will need to assess the practicality of the approach. In addressing this issue, the staff will need to establish an
implementation approach which recognizes all of the NRC's outcome oriented goals, not just reducing unnecessary regulatory burden. The staff is
continuing to evaluate this issue and thus is seeking stakeholder feedback through the ANPR. | |
| 2. | Effect on Other Regulations |
| The staff has determined that implementation of risk-informed alternatives in Part 50 may affect implementation of other regulations (e.g., Part 21, Part
55, and Part 54). In some cases, such as operator licensing (Part 55), rule changes may not be necessary; however, licensees may need to make changes
to programs implementing these regulations in order to ensure compliance. In other cases such as Part 21 and Part 54, it appears that changes may be
needed (Refer to Section 4.3 of the rulemaking plan). | |
| 3. | Staff Review Requirement |
| As described in SECY-98-300 and in the mission statement objectives, the preferred approach is to avoid the need for prior staff review and approval of
either the licensee's PRA and SSC categorization process (other than confirmation that it meets the criteria in the proposed Appendix T) or the results of
that process (i.e., the list of SSCs of safety significance). This approach may not be feasible. In that event, the staff will need to determine what level of
review would be necessary. | |
| By providing detailed categorization requirements in the proposed Appendix T, it is the staff's intent to provide a regulatory framework supporting
implementation of risk-informed alternative requirements without prior NRC review and approval. Appendix T will be developed, in part, from existing
guidance such as RG 1.174, and from experience gained by review of the South Texas Project (STP) Graded Quality Assurance methodology. Several
significant aspects of the proposed categorization technique rely upon subjective and qualitative judgement. For example, it is expected that an expert
panel will consider defense-in-depth as part of the assessment of SSC risk significance. Terms such as defense-in-depth and margin of safety are often
defined only in qualitative, not quantitative, terms. Such terms are difficult to translate into inspectable and enforceable regulations yielding consistent,
objective results. Therefore, application of these concepts within Appendix T creates a significant challenge for the staff. It should be noted that work to
risk-inform the technical requirements of 10 CFR 50 (Option 3) must also address the defense-in-depth and safety margin issue and the work in this area
will be closely coordinated between Options 2 and 3. To support a "no prior approval" approach, Appendix T will need to be constructed such that
expert panels will reach sound and consistent judgements. It is important to note that SSCs categorized as RISC-3 are not being removed from
regulatory treatment (i.e., there will be some requirements in 50.69 to address functionality). If the staff cannot develop criteria that result in consistent,
objective results, then some level of prior NRC review and approval will be necessary. | |
| The "no prior staff approval" approach puts increased emphasis on the quality of the underlying PRA. It is currently the staff's intention that the issue of
PRA quality will be addressed through the staff's endorsement of national consensus standards on PRA quality. | |
| 4. | Identification and Control of Attributes Requiring Special Treatment |
| The staff anticipates development of regulatory controls for RISC-1 and RISC-2 SSCs to ensure the attributes of these SSCs that make them safety
significant are adequately preserved. For RISC-1 SSCs, it is possible that existing special treatment requirements do not adequately address these
attributes. For RISC-2 SSCs, the safety significant attributes are probably not subject to regulatory control in the existing deterministic framework.
Therefore, for these components, the staff is considering what are the appropriate regulatory controls that should be applied. | |
| For RISC-3 SSCs, appropriate controls must be established to preserve functional performance. For example, safety-related hydrogen recombiners
installed in large dry containments may be determined to be of low safety significance. Nonetheless, the hydrogen recombiner's function must be
preserved until such time that 10 CFR 50.44 criteria are revised under Option 3. It is expected that criteria for preservation of functional capability (at a
reduced level of assurance ) will be developed and incorporated into 10 CFR 50.69. Defining the controls that are appropriate for maintaining
functionality of RISC-3 SSCs will be a significant challenge. | |
| Regarding the appropriate level of regulatory controls to be placed on RISC-1, RISC-2, and RISC-3 SSCs, the staff expects that it will receive significant stakeholder feedback through the ANPR. Refer to questions E.1 through E.4 of the ANPR. |
LEGAL ANALYSIS AND BACKFIT ANALYSIS:
The Office of the General Counsel (OGC) has not identified any bases for legal objection to the contemplated rulemaking approach. The rulemaking provides an alternative method for ensuring that the requirements of the Atomic Energy Act (AEA) of 1954 as amended are complied with, that there can be reasonable assurance of adequate protection to public health and safety, that the operation of a nuclear power plant will not impose an undue risk to public health and safety, and that appropriate levels of protection are provided to minimize danger to life and property. Accordingly, OGC believes that the AEA provides the Commission with sufficient authority to promulgate the contemplated rule. OGC has concluded that the contemplated rulemaking appears to comply with rulemaking requirements.
OGC has also determined that the contemplated rulemaking would not constitute a backfit as defined in Section 50.109(a)(1). This determination is made on the basis that each of the rules being modified in this rulemaking would provide a voluntary alternative to licensees that wish to utilize risk-informed methods for selecting the SSCs that are subject to special treatment requirements. Licensees that choose not to use such an approach can continue to rely upon their existing designations of safety-related and important to safety.
SCHEDULE:
The proposed schedule, described in Section 17 of the rulemaking plan, includes six major efforts: (1) the STP exemption; (2) the ANPR; (3) the categorization pilot program; (4) the NEI guideline review; (5) the proposed rulemaking; and (6) the final rulemaking. Assuming that the staff requirements memorandum (SRM) for this rulemaking plan paper is issued within 6 weeks of the date of this Commission paper, the staff's proposed schedule would result in the following projected milestone dates:
The proposed schedule, while achievable, does assume that all issues can be resolved promptly. As described in the rulemaking plan, even short delays in many of the tasks could delay the project as a whole. In addition, since this rulemaking represents a developmental activity, it is possible that extensive public comments or unforeseen issues could arise that may be difficult to resolve and thus delay the schedule.
RESOURCES:
As described in Section 17 of the rulemaking plan, the total resources estimated for this effort are 47 FTE and $3.0 million in technical assistance, as illustrated in the following table. The resource estimates are consistent with each office's budget, except for the FY 2000 technical assistance estimate for NRR.
|
FY 2000 |
FY 2001 |
FY 2002 | ||||
| FTE | $ (000s) | FTE | $ (000s) | FTE | $ (000s) | |
| NRR | 22* | 1,350 | 12 | 150 | 3 | 0 |
| RES | 2 | 500 | 3 | 500 | 3 | 500 |
* This includes 3 FTE to review the STP exemption.
During the staff's interactions with industry, the public, ACRS and other stakeholders in September and October 1999, the difficulty of the task of identifying the appropriate level of assurance for each safety class became apparent. Thus, additional effort may be necessary to establish the impact of removing equipment from the scope of the current special treatment requirements, and to assess the appropriate level of assurance in the proposed �.69. For NRR, the preliminary technical assistance estimate for this effort is that it could be as much as $1.1 million more than budgeted for FY 2000. At this time the staff plans to move ahead using internal resources. At mid-year the staff will reassess using the PBPM process to identify whether additional resources are needed. The staff will then provide the results of the PBPM assessment for the agency mid-year review to identify whether resources should be reallocated.
These estimates are tentative and may change as better information is developed as a result of public comments on the ANPR, and as the staff addresses the technical and policy issues associated with the rulemaking. In the event schedule delays occur, substantial revisions to the estimated resources would be necessary, in particular for FY 2002. In the event reprogramming is necessary as a result of issues that are raised or schedule delays, the staff will use the PBPM process to reallocate resources as necessary at that time.
These estimates only encompass the effort associated with the rulemaking, including development of appropriate regulatory and inspection guidance. It does not include resources necessary to implement the final rules, such as staff training or review and inspection of licensee programs (except for the effort to review the STP exemption and pilot plant program and exemptions). The implementation resources can be better estimated once a final decision on the regulatory approach has been made (e.g., whether prior staff review and approval is required).
COORDINATION:
The staff conducted three information briefings with the ACRS, and provided an information briefing for the Committee to Review Generic Requirements (CRGR). By letter dated October 12, 1999, the ACRS indicated its general agreement with staff's proposal to develop a new rule and supporting appendix to risk-inform special treatment requirements. 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. The Office of the Chief Information Officer has reviewed the rulemaking plan for information technology and information management implications and concurs in it. However, the plan suggests changes in information collection requirements that must be submitted to the Office of Management and Budget at the same time the rule is forwarded to the Federal Register for publication.
The staff is also developing an internal and external communications plan regarding the rulemaking. The objective will be to engage internal (e.g., NRC staff, ACRS, CRGR) and external (e.g., NEI, licensees, members of the public) during the rulemaking process.
RECOMMENDATIONS:
The staff recommends that:
| Original signed by
William D. Travers |
| CONTACT: | Thomas A. Bergman, NRR 301-415-1021 |
| Attachments: | 1. Rulemaking plan for Risk-Informing Special Treatment Requirements 2. Proposed ANPR 3. Rule selection methodology |
1. Special treatment requirements are current requirements imposed on structures, systems, and components that go beyond industry-established requirements for equipment classified as commercial grade that provide additional confidence that the equipment is capable of meeting its functional requirements under design basis conditions. These additional special treatment requirements include additional design considerations, qualification, change control, documentation, reporting, maintenance, testing, surveillance, and quality assurance requirements.
2. STP has requested an exemption to a subset of the special treatment requirements included in the rulemaking plan to allow use of a risk-informed approach similar to that proposed in this rulemaking plan. This exemption request was submitted to the NRC on July 13, 1999.
3. This approach assumes that identifying in �.69 the set of regulations to which the risk-informed categorization can be applied will be a sufficient regulatory modification. It is possible that some rule-specific issues may also need to be addressed in this new rule. If these rule-specific issues become excessive, the staff may alternatively modify some individual rules.
4. Although �.59 is considered a special treatment requirement, the change to �.59 is proposed to be limited to obviating the need for an evaluation of the change in special treatment for a safety-related SSC that is of low safety significance (see rulemaking plan Section 4.3).
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