NOC-AE-000518, Requests Exemption from Various Special Treatment Requirements of 10CFR50,as Described in Encls to Ltr.Stp Believes That Pilot Application Will Assist NRC in Development & Implementation of risk-informed 10CFR50

Requests Exemption from Various Special Treatment Requirements of 10CFR50,as Described in Encls to Ltr.Stp Believes That Pilot Application Will Assist NRC in Development & Implementation of risk-informed 10CFR50

ML20209G724
Person / Time
Site:	South Texas
Issue date:	07/13/1999
From:	Sheppard J HOUSTON LIGHTING & POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NOC-AE-000518, NOC-AE-518, NUDOCS 9907190234
Download: ML20209G724 (51)

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July 13,1999 NOC-AE-000518 STI: 30861238 File No.: G.04.01, G.09.19 10CFR50.12 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 Request For Exemption to Exclude Certain Components From The Scope Of Special Treatment Reauirements Reauired by Reculations

Reference:

Letter from M. A. McBurnett to the Document Control Desk dated April 8,1999 (NOC-AE-000506)

In accordance with the provisions of 10CFR50.12, the STP Nuclear Operating Company r qnests exemption from various special treatment requirements of 10CFR50, as described in the attachments to this letter. The exemption is based on risk-informed insights from the South Texas Project (STP) Probabilistic Risk Assessment (PRA) and is an extension of risk-informed STP programs (e.g. Graded Quality Assurance) that have already been reviewed and appmved by the Nuclear Regulatory Commission (NRC). The proposed exemption is consistent with the NRC's proposed options for risk-informed revisions to 10CFR50 as described in SECY-98-300.

STP believes that this pilot application will assist the NRC in development and implementation of a risk-informed 10CFR50.

As discussed in SECY-98-300, Options for Risk-Informed Revisions to 10 CFR Part 50, NRC's regulations in Pans 21,50, and 100 contain special treatment requirements that impose controls to ensure the quality of components that are safety-related, imponant to safety, or otherwise come within the scope of the regulations. These special tmatment requirements go beyond normal commercial and industrial practices, and include quality assurance (QA) requirements, environmental qualification requirements, and Maintenance Rule requirements.

The scope of these regulations applies to some components that have little or no safety or risk significance.

The NRC has approved a risk-informed process for determining the safety / risk significance of structures, systems, and components (SSCs) as part of the graded quality assurance (GQA) program for STP. In accordance with this approved risk-informed process, 7

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PDR ADOCK 05000498 j

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NOC-AE-000518 Page 2 STP has determined that a large percent of the safety related components in the plant are low safety / risk significant (LSS) or non-risk 'significant (NRS). In the referenced letter, STP has mquested the NRC concur with STP's position that NRS components are not "important to safety" and, upon verification _that these components do not satisfy the definition of safety-related in 10CFR50.2, ' an be reclassified to non-safety related without prior NRC approval. That letter c

' addressed the NRC's comments made at the March 15,1999, meeting to discuss a draft version of the proposed exemption request. Those NRC comments suggested that STP should be able to reclassify components without NRC approval if the components to be reclassified did not meet

. the regulatory definition of safety-related.- As a complement to that letter, STP now requests an exemption to exclude safety-related LSS and 'the remaining safety related NRS components from -

the scope of NRC's regulations that impose special treatment requirements. In addition, STP requests an exemption from non-safety related LSS and NRS components affected by the Maintenance Rule. STP also requests an exemption from the associated process-related regulations that requim prior NRC approval of cenain changes in the special treatment provisions in the licensing basis (or alternatively requests that the NRC take certain actions that would

. obviate the need for prior NRC approval of such changes). The specific regulations in question are identified in Attachment 2.

In the March 15, 1999,- meeting,-the NRC also observed that the draft included exemptions from the requirements of 10CFR50.55a for Inservice Inspection (ISI) and Inservice Tes'ing (IST) and commented that other licensees had used relief requests for implementing risk-t informed ISI and IST. STP has compared the scope of its intended risk-informed approach to industry experience and concluded that the STP program can also use relief requests.

Consequently, STP is not requesting an exemption to 10CFR50.55a in this proposal.

The detailed development of the proposed exemption and the demonstration that it meets the 10CFR50.12 criteria are provided in Attachment 1. provides responses to questions identified as a result of the March 15, 1999, meeting between the NRC and STPNOC which were included as an enclosure to the memo with' subject " Summary of Meeting Discuss STPNOC'S Proposed Risk-informed Exemptions L

Needed for Low Safety Significant Components,'.' dated April 30,1999.

This exemption request is being developed primarily to enhance nuclear safety at the site.

In addition, STP anticipates savings that will exceed $2 million per year for component and pan replacement and for streamlining and enhancements of processes fer safety-related LSS and NRS components.

STP requests that the exemption be' approved not later than March 31,2000 to facilitate STP's implementation and to facilitate industry planning for implementation of a risk-informed 10CFR50.

i NOC-AE-000518 Page 3 If you have any questions, please call Mr. A. W. Harrison at 361-972-7298 or me at 361-972-8787.

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W J. J. Sheppard Vice President Nuclear Engineering and Technical Services 1

AWH/ : Request for Exemption to Exclude Certain Components fmm the Scope of Special Treatment Requirements Required by Regulations : List of Regulations for Which an Exemption is Requested : Responses to Preliminary NRC Questions i

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NOC-AE-000518 File No.: G04.01, G09.19 Page 4

- cc:

Ellis W.Merschoff Jon C. Wood Regional Administrator, Region IV Matthews & Branscomb U. S. Nuclear Regulatory Commission One Alamo Center 611 Ryan Plaza Drive, Suite 400 106 S. St. Mary's Street, Suite 700

- Arlington, TX 76011-8064 San Antonio,TX 78205-3692 Thomas W. Alexion Institute of Nuclear Power Project Manager, Mail Code 0-13H3 Operations - Records Center U. S. Nuclear Regulatory Commissic-.

~ 700 Galleria Parkway Washington, DC 20555-0001 Atlanta, GA 30339-5957 Comelius F. O'Keefe Richard A. Ratliff Sr. Resident Inspector Bureau of Radiation Control c/o U. S. Nuclear Regulatory Commission Texas Department of Health P. O. Box 910 1100 West 49th Street Bay City, TX 77404-0910 Austin, TX 78756-3189 J. R. Newman, Esquire D. G. Tees /R. L. Balcom Morgan,Iewis & Bockius' Houston Lighting & Power Co.

1800 M. Street, N.W.

P. O. Box 1700 Washington, DC 20036-5869 Houston,TX 77251 M. T. Hardt/W. C. Gunst Central Power and Light Company City Public Service ATTN: G.E. Vaughn/C. A. Johnson P. O. Box 1771 P. O. Box 289, Mail Code: N5012 San Antonio,TX 782%

Wadsworth,TX 77483 A. Ramirez/C. M. Canady U. S. Nuclear Regulatory Commission City of Austin Attention: Document Control Desk Electric Utility Department Washington, D.C. 20555-0001

- 721 Barton Springs Road Austin,TX 78704 Joseph F. Williams Pmject Manager, Mail Code 0-82C U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 i

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NOC-AE-000518 Page 1 Request For Exemption to Exclude Certain Components From The Scope of Special Treatment Requirements Required by Regulations

'1.0 Purpose i

As discussed in SECY-98-300, Options for Risk-Informed Revisions to 10 CFR Part 50, 1

Nuclear Regulatory Commission's (NRC) regulations in Pans 21,50, and 100 contain special i

treatment requirements that impose controls to ensure the quality of components that are safety-related,important to safety, or otherwise come within the scope of the regulations. These special treatment requirements go beyond normal commercial and industrial practices, and include quality assurance (QA) mquirements, environmental qualification requirements, and Maintenance Rule requirements. The scope of these regulations applies to some components that have little or no safety or risk significance.

The NRC has approved a risk-informed process for determining the safety / risk significance of stmetures, systems, and components (SSCs) as pan of the Graded Quality Assurance (GQA) program for the South Texas Project (STP). In accordance with this approved risk-informed process, STP has determined that a large percent of the safety related components

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in the plant are low safety / risk significant (LSS) or non-risk significant (NRS). In a separate letter dated April 8,1999, STP has requested the NRC to concur with STP's position that NRS components are not "important to safety" and, upon verification that these components do not satisfy the definition of safety-related in 10CFR50.2,' can be reclassified to non-safety related without prior NRC approval. As a complement to that letter, STP now requests an exemption to exclude safety-related LSS and those NRS components that satisfy the definition of safety-related in 10CFR50.2 fmm the scope of NRC's regulations that impose special treatment requirements.

STP also requests an exemption from the associated process-related regulations that require prior NRC approval of cenain changes in the special treatment provisions in the licensing basis (or alternatively requests that the NRC take certain actions that would obviate the need for prior NRC approval of such changes).

The specific regulations in question are identified in. While STP understands that cenain industry efforts have begun to risk-inform 10CFR50, STP desires to fully implement a GQA process that was approved for STP in 1997, and not to be delayed by rulemaking to make 10CFR50 risk-informed.

This exemption request provides the information required by 10 CFR 50.12 and 21.7 and is organized as follows:

Section 2.0 provides background regarding the NRC-approved process for determining the safety / risk significance of SSCs at STP.

Section 3.0 identifies the objectives of the exemption request.

Section 4.0 identifies the regulations to which the exemption would apply.

L NOC-AE-000518 Page 2 Section 5.0 provides the technical justificatior for the exemption, including a L

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discussion of the relevant provisions in Regulatory Guide 1.174 applicable to risk-L informed requests for NRC approval of changes to the licensing basis.

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Section 6.0 demonstrates that special circumstances exist under 10 CFR 50.12 for the l.

granting of this exemption request.

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' Section 7.0 describes STP's planned-approach for a phased implementation of the e-exemption and identifies STP's provisions to facilitate the NRC's review and inspection of implementation of the exemption.

Section 8.0 concludes that the exemption request isjustified and should be granted.

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2.0 Background

On March 28,1996, STP submitted a request under 10 CFR 50.54(a) for approval of the GQA program. The purpose of that request was to enable STP to implement its QA program in a graded manner, commensurate with the SSC's significance to safety. The NRC conducted an extensive review of the proposed GQA program, including holding many meetings with STP, evaluations. at the site, telephone discussions, and requests for additional information. In response, STP submitted supplementary information, followed by a final submittal on August 4, 1997. By letter dated November 6,1997, the NRC determined that the GQA program was acceptable and transmitted a Safety Evaluation that documented its detailed review. The final l

approved version of the GQA program was made effective for implementation on February 1, 1998, as part of Revision 13 of the Operations Quality Assurance Program.

The GQA program, as approved by the NRC, applies to adjustments in STP quality assurance controls based on the risk significance evaluation process. South Texas Project's risk significance evaluation process establishes a complete statement of a component's role and function (s), and as such can be applied to station programs and processes, as applicable, in j

addition to quality assurance.

The GQA program utilizes a risk-informed process for determining the safety / risk significance of SSCs, including e-The use of an Expert Panel and associated Working Groups to implement a risk-informed comprehensive risk management program.

A methodology, which combines probabilistic risk assessment (PRA) data with e.

deterministic insights and performance-based information, to determine the safety / risk significance of SSCs.

- A configuration control program which documents the risk significance evaluation process in the form'of system specific risk significance basis documents.

'A feedback loop to reassess SSC safety / risk significance when new information becomes available, such as PRA changes and SSC performance changes.

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NOC-AE-000518 Page 3 i

Deterministic insights used in arriving at the safety / risk significance of SSCs include factors such as whether failure of the SSC could directly cause an initiating event or result in

' failure of another risk-significant SSC; whether the system is used to mitigate an accident or transient, or is used in the emergency operating procedures (EOPs); and whether the SSC is significant to the safety of mode changes and shutdown conditions.

The process for determining the safety / risk significance of SSCs places a component into one of four categories: 1) high safety / risk significant (HSS),2) medium safety / risk significant (MSS),3) low safety / risk significant (LSS), and 4) non-risk significant (NRS). STP expects that the majority of the safety-related components will be categorized as LSS and NRS because they support ancillary functions (e.g., vents, drains, and local indications) for safety-related systems and do not provide, suppon, or affect the primary safety functions of the systems.

In the first 20 systems evaluated under the GQA program, approximately 90% of all components (out of more than 23,000 components in total) are either LSS or NRS. This component population includes approximately 14,000 safety-related components. Of these safety

related components, approximately 20% are safety / risk significant (i.e., HSS or MSS), and approximately 80% are not safety / risk significant (i.e., LSS or NRS).

The GQA program only allows STP to apply a reduced level of quality assurance to MSS, LSS, and NRS components, commensurate with their safety / risk significance. It is imponant to note that STP's safety / risk significance evaluation process establishes the importance of an SSC for all evaluated plant equipment not only for quality assurance applications, but also for applications in maintenance, engineering, and operations processes. The importance of an SSC is used to establish appropriate strategies for all plant programs commensurate with an SSC's imponance to safety (i.e.,its risk significance). In practice, a fully risk-informed set of controls defined by'a risk informed program cannot be implemented due to the special treatment iequirements imposed by 10 CFR Pans 21,50, and 100 for SSCs classified as safety-related, important to safety, or otherwise within the scope of the regulations. Regardless of their risk significance, SSCs that have been classified as safety-related are subject to requirements for quality assurance (QA) in Appendix B to Part 50, environmental qualification (EQ) under 10 CFR 50.49 and for monitoring the effectiveness of maintenance under 10 CFR 50.65. Given the

' lack of safety / risk importance of LSS and NRS components to protect the health and safety of the public as determined'by the approved risk-informed categorization process, an exemption is appropriate to exclude safety-related LSS and NRS components from the scope of the special treatment requirements in these regulations.

Furthermone, the regulations in 10 CFR 50.59 require a safety evaluation for changes in the special treatment provisions in the Updated Final Safety Analysis Report (UFSAR), and most of these UFSAR changes would normally require prior NRC approval. Preparing a safety valuation and seeking prior NRC approval for each of these changes would be extremely e

inefficient and overly burdensome for both STP and the NRC. Therefore, an exemption from Section 50.59 is essential to permit STP to implement these changes without the need for a

NOC-AE-000518 Page 4 separate evaluation and approval of each change. For similar reasons, exemptions are needed fmm 10 CFR 50.54(a), which restricts changes in the QA program description. In the alternative, STP requests that the NRC take certain actions, as described in more detail in Section 4.2, that would obviate the need for prior NRC approval of such changes.

3.0 Objectives of the Exemption Reauest i

The exemption will enable STP to remove safety-related LSS and NRS components from the scope of special treatment requirements. As a result, this exemption will reduce occupational radiation.exposmes and costs that would otherwise be incuned in providing unnecessary qualifications, quality assurance contmls, maintenance requirements, testing, and inspection for the safety-related LSS and NRS components.

Both LSS and NRS. components have no significant effect on public health and safety and do not warrant such comprehensive levels of control.

STP is not requesting an exemption from the provisions in 10 CFR Parts 50 and 100 that specify functional requirements for SSCs; i.e., the requirements that specify the safety functions to be performed by a system or component (including features to prevent _ adverse impacts upon the safety function of one SSC due to the failure of another SSC). Furthermore, STP is not pmposing to use this exemption to. change any functional requirements in the UFSAR or the Technical Specifications. However, because STP will not be applying the special treatment requirements in Parts 21,50, and 100 to such components, replacement safety-related LSS and

NRS components could be procured from non Appendix B suppliers or as commercial grade without meeting the rigorous quality assurance and qualification requirements otherwise imposed on components that are safety-related or important to safety.

In summary, STP is requesting a limited exemption from the regulations that impose special treatment requirements. The exemption would enable STP to exclude only safety-related LSS and NRS components from the scope of the special treatment requirements. HSS and MSS

safety related components would still be subject to these regulations. Furthermore, safety-related LSS and NRS components would still be subject to these regulations to the extent that they also

' impose functional requirements.

4.0 Renulations to s Sich the Exemption Would Anolv STP is seeking to exclude safety-related LSS and NRS components from the scope of NRC's special tientment requirements, without the need to seek prior NRC approval for each specific' change. To accomplish this objective, STP is requesting an exemption 1) to exclude safety-related LSS and NRS components from the scope of the special treatment requirements in Parts 21,50, and 100; and 2) from several process-related regulations that govern changes in the special treatment provisions in the licensing basis (in the alternative, STP requests that the NRC i

take certain actions, as described in more detail in Section 4.2, that would obviate the need for prior NRC approval of such changes). A list of the specific regulations in question is provided in. Each of the exemptions is discussed in Sections 4.1 and 4.2 below.

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NOC-AE-000518 l

l Page 5 4.1 Exemption to Exclude Safety-Related LSS and NRS Components from the i

Scope of Special Treatment Requirements There are a number of NRC regulations that impose special treatment j

requirements on SSCs that are safety-related, important to safety, or otherwise within the scope of the regulations. These regulations apply to the designated components, even if i

those components are LSS or NRS. As discussed in Section 5.0 below, it is not necessary i

for the_ protection of the public health and safety to apply comprehensive special treatment requirements to LSS and NRS components, and an exemption to exclude these components from the scope of these requirements would reduce unnecessary burdens on both STP and the NRC, and allow more attention to be focused on safety / risk significant SSCs. Therefore, STP seeks an exemption to exclude safety-related LSS and NRS components from the scope of the specia treatment requirements in Parts 21,50, and 100.

i LSS components have " minimal" risk significance. As their name implies, NRS components have no risk significance. However, as discussed previously in Section 3.0, STP is not requesting that safety-related LSS and NRS components be exempted from every regulation in Parts 21,50, and 100. For example, there are numerous regulations that govem the functions of SSCs (e.g.,10 CFR 50.46, which applies to the Emergency Core Cooling System, and most of the General Design Criteria (GDC) in Appendix A to l

Part 50). STP is not requesting an exemption from the regulations goveming the l

functional requirements for SSCs. This request only seeks to exclude safety-related LSS and NRS components from the scope of the special treatment requirements in Pans 21, 50, and 100. Funhermore, although safety-related LSS and NRS components would be excluded from the scope of cenain special treatment requirements, STP will ensure that l

safety-related LSS critical attributes will be documented and incorporated into corrective action and design control processes.

4.1.1 Special Treatment Regulations Sublect to this Request identifies the specific special treatment regulations in Parts 21,50, and 100 to which this exemption request applies. These regulations are as l

follows:

l Oualification Reauirements in 10 CFR 50.49, GDC 2, GDC 4, and Part 100, l

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Appendix A.VI (which. is incorporated in Part 50 through 10 CFR 50.34(b)(11)) - - These regulations impose environmental, dynamic, and seismic qualification requirements on certain classes of SSCs. In particular, these regulations require testing, inspection, and documentation to demonstrate that components can perform their safety functions under the conditions in question, and require that the components be maintained in their qualified condition. These requirements apply to components that are safety-l

NOC-AE-000518 j

Page 6 related or important to safety, without regard to their actual safety / risk significance. Given the lack of safety / risk significance of MS and NRS components, the requimments for their testing, inspection, and documentation 1

are unduly burdensome and divert resources from items with safety / risk significance. Therefore, in order to be able to procure and maintain components in a manner commensurate with.their safety / risk significance, STP is requesting an exemption to exclude safety-related LSS and NRS components from the scope of these qualification requimments.

Maintenance Rule Reauirements in 10 CFR 50.65 - - This regulation imposes requirements for monitoring the effectiveness of maintenance for a broad category of SSCs, including safety-mlated SSCs. These requirements apply to components'that come within the scope of the Maintenance Rule, without regard to their actual safety / risk significance. Given the lack of safety / risk significance of MS and NRS components, requirements for monitoring of j

maintenance effectiveness and performing unnecessary preventive maintenance are undcly burdensome.

Instead, normal commercial and industrial maintenance practices and application of the STP corrective action program are an appropriate and acceptable means for assuring the adequacy of LSS and NRS components. Therefore, in order to be able to implement the maintenance program in a manner commensurate with their safety / risk significance, STP is requesting an exemption to exclude safety-related LSS and NRS components from the scope of the Maintenance Rule.

Ouality Assurance Requirements in GDC 1,10 CFR Part 21, and 10 CFR Part 50, Appendix B (which is incorporated in 10 CFR 50.34(b)(5)(ii)) - - These regulations impose QA, procurement / dedication, and reporting requir'ments on SSCs that are important to safety or safety-related. These requirements apply to components within the scope of the regulations, without regard to their actual safety / risk significance. As discussed in Section 3.5.1 of the NRC's Safety Evaluation for the GQA Program, the GQA Program was designed to comply with the requirements in Appendix B. Therefore, under the GQA Program, STP is still required to apply a certain level of quality assurance to safety-related LSS. and NRS components. However, LSS and NRS components have no significant effects on public health and safety and do not warrant such comprehensive levels of control. Given the lack of safety / risk significance of LSS and NRS components, these formal QA

- mquirements are unduly burdensome.

Instead, normal commercial and industrial practices and application of the STP corrective action program are an appropriate and acceptable means for assuring the adequacy of LSS and

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NRS components. Therefore, in order to be able to implement a QA program in a manner commensurate with their safety / risk significance, STP is requesting an exemption to exclude safety-related LSS and NRS components from the scope of these regulations. However, as discussed more fully later,

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NOC-AE-000518 L

Anachment I l

Page 7 STP will continue to apply its design control and corrective action programs to f

safety-related LSS and NRS components.

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• Insocction and Testine Reauirements in GDC 18, and 10 CFR Part 50, Appendix J - - These regulations impose inspection and testing requirements t for certain types of components. These requirtments apply to components within the scope of the regulations, without regard to their actual safety / risk significance. ISS and NRS components have no significant effects on public health and safety and do not warrant such comprehensive levels of control.

Given the lack of safety / risk significance of LSS and NRS components, requirements for formal inspection and testing programs for these components are unduly burdensome. Instead, normal commercial and industrial practices and application of the STP cormctive action program are an appropriate and acceptable means for assuring the adequacy of LSS and NRS components.

Therefore, in order to be able to implement' inspection and testing programs commensurate with their safety / risk significance, STP is requesting an exemption to exclude safety-related LSS and NRS components from the scope -

of these regulations.

In summary, STP is requesting an exemption to exclude safety-related LSS and NRS components from the scope of special treatment requirements that are intended to provide a high level of assurance of the quality of safety significant components. In lieu of these requirements, STP would apply normal commercial and industrial practices for these components, similar to the type of practices applied to the power production side of the plant. These practices will result in an appropriate and acceptable level of assurance that these components will be capable of performing their functions, commensurate with their safety / risk significance. These practices are effective in maintaining the reliability and availability of power production components, and are similar to practices used effectively thmughout the world in commercial and industrial applications.

4.1.2 Preservation of Safety Functions This exemption will not alter the functional requirements applicable to safety-related LSS and NRS components. In particular, these components will still be available to function under applicable design conditions even though they are not important from a risk perspective to mitigate or prevent accidents.

The exemption will, however, eliminate the need to qualify safety-related

-LSS and NRS components for such conditions. Thus, for example, STP will j

tilize purchase requirements or other evaluations to ensure the availability of u

. replacement components to function und'.;r design conditions, without performing i

qualification tests, j

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NOC-AE-000518 Attcchment 1 Page 8 Although such components would not need to be qualified, STP will take j

the following actions to ensure that the components will be available to function

'under the conditions in question:

STP will provide maintenance for safety-related LSS and NRS components, as

" appropriate, using similar commercial and indhstrial practices currently in place oc the power production equipment.

• STP will ensure that LSS critical attributes will be documented and incorporated into cortective action and design control processes.

If this exemption is granted, LSS and NRS Class IE electrical equipment could be replaced with non-Class IE equipment. In such an event, STP will take actions as necessary to ensure that HSS and MSS Class 1E components are appropriately protected per the requirements in the UFS AR.

Since STP's compliance with the ASME Code was originally established on a system level basis, most safety related LSS and NRS components are currently subjected to ASME Code requirements. For LSS and NRS components, STP seeks to re-establish ASME Code class boundaries on a subsystem level basis

- rather than on a system level basis without prior NRC approval. If this exemption is granted, LSS and NRS ASME components may be replaced with non-ASME components without prior NRC appmval.

Fmally, safety related LSS and NRS components would still be available to function in a safe shutdown earthquake (SSE), but are not important from a risk perspective to mitigate the transient. LSS and NRS components will continue to be designed so as to not impact HSS and MSS safety-related SSCs during a SSE.

4.2~

Exemptions from Process-Related Reauirements in Part 50 The changes in special treatment discussed above would normally be governed by

'several of NRC's process-related regulations. These regulations are 10 CFR 50.59 (which govems changes in the facility and procedures as described in the UFSAR) and 10 CFR 50.54(a) (which govems changes in the QA program description referenced in the

, UFSAR), As described more fully below, STP requests an exemption from each of these process-related requirements for safety-related LSS and NRS components to facilitate its

' implementation of the exemption from the special treatment requirements.

As described in more detail below, the exemptions from Sections 50.59 and

. 50.54(a) may not be necessary,if certain pending rule changes become effective and if the NRC interprets the revised rules as obviating the need for NRC review and approval of the individual changes to the special treatment provisions in STP's licensing basis as applicable to safety-related LSS and NRS components.

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l NOC-AE-000518 Attachment i Page 9 4.2.1 ExemDtIOR from 10 CFR 50.59 Section 50.59 requires a separate evaluation for each change in the facility or procedures as described in the UFSAR and requires NRC approval for any changes that involve an unreviewed safety question. In order to remove safety-related LSS and NRS components from the tcope of special treatment requirements, STP will need to change the UFSAR.

- Performing a 50.59 evaluation (and, as necessary, obtaining NRC approval) for each change in a special treatment requirement would be extremely burdensome and prohibitively costly for both STP and the NRC. Therefore, STP desires an exemption from Section 50.59 to eliminate the need for individual 50.59 evaluations (and prior NRC approval) for each change in special treatment described in the UFSAR for safety-related LSS and NRS components. Following approval of this exemption, STP will be able to screen changes in UFSAR special treatment provisions for safety-related LSS and NRS components from further evaluation under Section 50.59 The requested exemption from Section 50.59 applies not only to UFSAR special tmatment provisions required by the regulations, but also to other UFSAR special treatment provisions that are not directly required by a regulation. For example, under 10 CFR 50.55a, the installation mquirements in Section III of the ASME Code are only applicable technically to holders of construction permits and not to holders of operating licenses.

However, in general, the UFSAR commitments to Section III of the ASME Code are not limited to construction, but also apply to mplacement components installed during operation. For safety-related LSS and NRS components, the requested exemption would enable STP to replace an ASME component with a non-ASME component without the need to perform a detailed 50.59 evaluation or seek prior NRC approval. Similarly, STP would not need to perform a detailed 50.59 evaluation or seek prior NRC approval for UFSAR changes involving other inspection, maintenance, testing, qualification, and QA provisions applicable to safety-related LSS and NRS components that am not specifically covered by regulations (for example, such changes could involve the testing provisions for motor operated valves or air operated valves, and inspection of snubbers).

STP notes that the NRC has issued a proposed rule (63 Fed. Reg. 56098),

and the NRC staff has issued a draft final mie (SECY-99-130), that would raise the thmshold of changes requiring prior NRC approval under Section 50.59. If the Commission issues a final mie in substantially the same form as provided in SECY-99-130, it might be possible to interpmt the revised rule as not requiring prior NRC approval for revision of the special treatment described in the UFSAR.

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NOC-AE-000518

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Attcchment !

Page 10 For example:

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SECY-99-130 defines " change" in terms of impacts on " functions." Since i

STP's proposal on special treatment requirements is not intended to affect the functions of safety-related LSS and NRS components, it could be considered that STP would not be making a " change" as defined in SECY-99-130. Similarly, it might be possible io consider the definition of

" procedures" and " facility" in SECY-99-130 ~ as excluding changes in UFSAR special treatment requirements.

SECY-99-130 provides eight criteria for determining when a change requires prior NRC approval. The most relevant criterion requires prior NRC approval for changes that " result in more than a minimal increase in the likelihood of occurrence of a malfunction" of an SSC previously evaluated in the UFSAR. It might be possible to interpret this criterion (and the other criterion in SECY-99-130) as not requiring prior NRC approval for the change in special treatment requirements given the lack of safety / risk significance of safety-related LSS and NRS components.

. However, the NRC has not issued sufficient guidance on the proposed rule to permit a conclusive determination on these issues. Therefore, there is substantial uncertainty whether STP could make these changes in the UFSAR without seeking prior NRC approval.

Once the final revision to Section 50.59 is issued, STP's request for an exemption from Section 50.59 may be unnecessary if the NRC were to interpret the revised rule as described above. Consequently, STP will withdraw its request for an exemption from Section 50.59 if the NRC staffissues a written position or guidance clearly stating that the types of changes in special treatment sequirements being proposed by STP do not require prior NRC approval under Section 50.59.

4.2.2 Exemption from 10 CFR 50.54(a)

Section 50.54(a) requires a separate evaluation for each change in the QA program description referenced in the UFSAR, and requires NRC approval for any changes that involve a reduction in commitments. Removal of safety-related LSS and NRS components fmm the scope of the QA program will entail a change (and a seduction in commitment) in the QA program description. Performing a 50.54(a) evaluation and obtaining NRC approval for each change would be extremely burdensont and prohibitively costly for both STP and the NRC.

Therefore, STP desires an exemption from Section 50.54(a) to eliminate the need for a separate 50.54(a) evaluation and prior NRC approval for removal of safety-

-i I

related LSS and NRS components from the scope of the QA program.

l 4-u

NOC-AE-000318 Attachment i Page 11 STP notes that the NRC has issued a direct final rule (64 Fed. Reg. 9030)

I that would raise the threshold of changes requiring prior NRC approval. This mle became effective on April 26, 1999. It would be reasonable to interpret the revised mle as.not requiring prior NRC approval for the exclusion of safety-related LSS and NRS components from the scope of the QA program. In particular, Section 50.54(a)(3)(ii) cf the Direct Findi Rule states that prior NRC appmval is not required for changes in the QA program that make use of a quality

assurance alternative or exception approved by an NRC safety evaluation. This section could be interpreted as not requiring NRC approval for changes in the STP QA program description made in accordance with NRC's safety evaluation for this exemption request.

However, the NRC has not issued sufficient guidance on the rule to permit a conclusive determination on these issues. Therefore, there is uncertainty whether STP could make these changes in the QA program description without seeking prior NRC approval.

STP's request for an exemption from Section 50.54(a) may be unnecessary if the NRC were to develop their interpretation of the rule as described above.

Consequently, STP will viithdraw its request for an exemption from Section 50.54(a) if the NRC staff issues a written position or guidance clearly stating that the NRC's safety evaluation for STP's exemption request obviates the need for prior NRC approval under Section 50.54(a) of the types of changes in the QA program description being proposed by STP.

5.0 Technical Justification for the Exemption 5.1 Section 50.12 and Section 21.7

-10 CFR 50.12(a)(1) allows exemptions that are." Authorized by law, will not present an undue risk to the public health and safety, and are consistent with the common defense and security." Similar pmvisions are in 10 CFR 21.7. Although 10 CFR Part 100 does not include a provision for exemptions, Part 100 is incorporated by reference in Part 50 through Section 50.34(b)(11); therefore, the exemption pmvisions in Section 50.12 are applicable to requests for exemptions from Part 100.

The requested exemption satisfies the requirements in Sections 50.12 and 21.7 described above:

The reauested exemption is not inconsistent with any law - There is nothing in the Atomic Energy Act or other statute applicable to the NRC that requires j

that the special treatment provisions in question be applied to safety related IJSS or NRS components, or that the NRC establish or implement the process-related regulations in question, j

NOC-AE-000518 Attochment 1 Page 12

• The reauested exemption is consistent with the common defense and security -

The requested exemption relates solely to special treatment requirements and the process-related regulations, and does not pertain to the security or i

safeguards plans. Therefore, it does not have any effect on the common

defense and security.

e j The reauested exemption would not present an undue risk to the public health and safety 'Ihe exemption would apply.only to safety-related I.SS and NRS components, but would include non-safety related LSS and NRS components as it applies to the Maintenance Rule. From a risk perspective, components that are categorized as LSS and NRS do not involve or affect the performance of any significant safety function. Furthermore, the exemption would exclude such components only from special treatment requirements and the process-related regulations, but not from the functional requirements for these components. As explained in the next section, the exemption from the special treatment requirements and the process-related regulations will not impact defense-in-depth or safety margins, and will result in no net increase in risk.

In addition, the approval and implementation of this exemption request will focus more attention on safety / risk significant SSCs. This will result in a risk positive outcome. Therefore, the exemption will not impact the public health and safety.

5.2 Regulatory Guide 1.174 -

Regulatory Guide 1.174 provides technical guidance for licensees who irquest NRC approval for changes in the licensing basis using a ris'k-informed approach. This guidance establishes five principles governing risk-informed changes to the licensing basis. As demonstmted in the following sections, the requested exemption satisfies these principles.

5.2.1 Compliance with Current Reeulations Regulatory Guide 1.174 states that the proposed change in the licensing basis should meet current regulations, unless it is explicitly related to a requested i

exemption or rule change. This exemption request implements this prmciple.

i i

5.2.2 Defense-in-Depth f ~ Regulatory Guide 1.174 states the proposed change in the licensing basis should be consistent with the defense-in-depth philosophy.

The impact of this exemption on defense-in-depth is similar to the GQA program impact, which was previously approved by the NRC in Section 3.5.2 of the Safety Evaluation for the GQA program.

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NOC-AE-000518 Attachment !

Page 13 For example:

I Functional requirements and the design configuration of systems are retained.

No existing plant barriers will be removed or altered.

Design provisions for redundancy, diversity, and independence will be e-g maintained.

A

_ The plant's response to transients or other initiators will not be affected.

Preventive or mitigative capability of components will be preserved.

Normal commercial and industrial practices will provide an appropriate and acceptable level of assurance that safety-related LSS and NRS components will be able to perform their intended functions.

As discussed in the following section, even if it is unrealistically assumed that the use of commemial and industrial practices would result in substantial increases in failure rates, STP has performed bounding sensitivity analyses a

which demonstrate that there would be little, if any, impact on the safety / risk categorization of the components. It is important to note that STP's corrective action program will continue to be used to identify adverse trends for plant systems and/or _ equipment (including safety related LSS and NRS components), and as such, is a significant barrier against allowing unacceptable levels of performance degradation to occur.

Therefore, for the reasons discussed in the NRC's Safety Evaluation for the approved GQA program, the exemption will be consistent with the defense-in-depth philosophy.

5.2.3 Safety Mareins Regulatory Guide 1.174 states that the proposed change in the licensing basis should maintain sufficient safety margins.

Similar to the GQA program approved by the NRC, the requested exemption does not involve a change in any functional requirements or the configuration of SSCs. Because of the low risk significance of the components in the scope of the exemption and the lack of any change in the functional requirements for SSCs, STP does not expect the need to change any of the safety analyses in the UFSAR. Therefore, sufficient safety margins associated with the design will be maintained by the exemption.

The requested exemption will enable STP to remove safety > elated LSS and NRS components from the scope of special treatment requirements in Pans 21,50, and 100 related to qualifications, quality assurance controls, maintenance requirements, and inspection and testing. This change will result in an appropriate and acceptable level of assurance of the quality of these components for the following reasons:

I

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NOC-AE-000518 Page 14 E

STP 'does not intend to replace the existing safety-related LSS and NRS components, absent good cause (e.g., obsolescence or failure). Since the existing safety-related LSS and NRS components were designed, procured, manufactured, and installed in accordance with the existing special treatment requirements, these components have inherent ddsign margins to perform their intended functions that will not be adversely affected by this exemption.

The exemption will allow safety-related LSS and NRS components to be e

inspected, tested, and maintained under normal commercial and industrial practices for non-safety-related components.

In addition, replacement components may be designed, manufactured, procured, and installed under STP's normal commercial and industrial practices. These practices provide an appropriate and acceptable level of assurance that the components will satisfy 3

their functional requirements. Given the minimal safety / risk significance of the components in question, these practices are sufficient to ensure that the components will satisfy their functional requirements and have sufficient safety margin. Furthermore, performance of the systems / trains containing s -

safety-related LSS and NRS components will be monitored under the both

. Maintenance Rule program, as applicable, and the Corrective Action Program to ensure that these systems / trains maintain satisfactory levels of performance.

As discussed later, STP will continue to apply its corrective action program to safety-related LSS and NRS components. This program provides reasonable assurance that deficiencies involving safety-related LSS and NRS components

. will be identified, corrected, and necessary action taken to ensure acceptable performance levels are maintained.

Although STP has a high' level of confidence that the LSS and NRS components will continue to function, in the unlikely event that they fail, there would be no significant consequences as discussed below:

• Components categorized as NRS are not sufficiently significant to warrant modeling in the PRA. The safety-related NRS components generally include local indicators, vents, drains, and root valves sized 1" and under. Even if it is assumed that a safety-related NRS component were to fail, the results of the PRA would be unaffected.

• In the systems reviewed to date using the approved risk-informed categorization process, approximately 30% of the safety-related components have been categorized as LSS. These LSS components generally include piping, locked open valves, handswitches, and outside containment isolation valves sized 3" and under. STP has performed sensitivity studies to bound the impact on overall risk of changes in the reliability of selected LSS components i

m

NOC-AE-000518 Attcchment i Pr.ge 15 (including tne aggregate impact of a simultaneous change in reliability of I

modeled MSS and LSS components of a similar type within the scope of the PRA). In performing these analyses, STP very conservatively assumed that the failure rate for these components could be a factor of ten greater than indicated by operating experience.

Despite this overly conservative assumption, STP determined that the risk-informed categwization of the components was not adversely affected. Therefore, even if it is assumed that the controls for inspection, testing, and maintenance activities for IES components may not be as effective as those for safety-related components, there would be little,if any, impact on risk.

In determining the categorization of a component, STP considers whether failure of the component could directly cause an initiating event or result in failure of another risk-significant SSC; whether the system is needed to mitigate an accident or transient, or is used in the Emergency Operating Procedures (EOPs); and whether the SSC is significant to the safety of mode changes and shutdown conditions. If any of these conditions could exist, a consistent, proceduralized methodology is applied to determine the i

significance of the condition. If failure of the component is determined to have a significant impact and/or if the event in question is considered probable, the component is classified as HSS or MSS. As a result, failure of i

an LSS or NRS component would not cause the failure of a significant safety j

function.

~

STP's normal commercial and industrial practices provide an appropriate and acceptable level of assurance that safety-related LSS and NRS components will continue to have sufficient margin to satisfy their functional requirements.

Nevertheless, even if it were assumed that these components would not perform as expected, there would be no significant impact on safety.

5.2.4 Channes in Risk 5.2.4.1 Increases in Risk Regulatory Guide 1.174 states that, when proposed changes in the licensing basis result in an increase in core damage frequency or risk, the increase should be small and consistent with the intent of the J

Commission's Safety Goal Policy Statement.

For purposes of the GQA program, STP uses a site-specific PRA in the risk-informed process for categorizing SSCs. The NRC has previously i

I approved the quality of the PRA, quality assurance for the PRA, the scope of the PRA, and the application of the PRA results and insights to the risk-informed process for categorizing components, as described in Section 3.2

{

NOC-AE-000518 l

l Page 16 of the NRC's Safety Evaluation for the GQA program. These same tools 1

will be used for this exemption.

1' As discussed previously, NRS components are not sufficiently significant to warrant modeling in the PRA. Therefore, the exemption to exclude safety-related NRS components.from the scope of special treatment requirements will not affect the results of the PRA for STP.

With respect to the LSS components, the changes in the special treatment requirements do not lend themselves to a quantitative risk assessment, because the relationship between the special treatment requirements and equipment performance has not been firmly established.

However, the change in the special treatment requirements for LSS components is not expected to impact system performance levels, because STP will continue to monitor system performance under the Maintenance Rule program and take appropriate corrective actions as necessary to maintain system performance.

Funhermore, the vast majority (approximately 90%) of the safety-related LSS components were so categorized solely for deterministic reasons; i.e., they were not sufficiently significant to warrant modeling in the PRA. Therefore, the exemption to exclude these components from the scope of the special treatment requirements will not affect risk levels as determined by STP's PRA.

With regard to the remaining LSS components, Section 3.2.5 of the NRC's Safety Evaluation for the GQA program states that a component is 1 categorized as LSS under the PRA only if it meets cenain criteria related to the Fussell-Vessely (FV) imponance, which is the fraction of the core damage frequency (CDF) to which failure of the component contributes, and the risk achievement wonh (RAW), which is the factor by which the CDP would increase given that the component is guaranteed to fail.

Specifically, a component must have a FV value of less than 0.005, and a RAW of less than 2, to be categorized as LSS. Given these values and 5

STP's estimated CDF of approximately 10 /yr and estimated large early 4

release frequency (LERF) of approximately 5 x 10 /yr (excluding shutdown risk), it is apparent that LSS components contribute very little to the overall CDF and IERP or changes in CDF and LERF. Therefore, j

there will be' little or no increase in CDF and LERF, even assuming j

unrealistically high failure rates for thesc compor 'nts.

Furthermore, as described and approved in Section 3.2.5 of the NRC's Safety Evaluation for the GQA program, STP performed sensitivity studies in which unreliability was simultaneously increased for j

NOC-AE-000518 Page 17

' MSS and LSS components of a similar type within the scope of the PRA.

U These studies evaluated the impact of increasing the unreliability of the group of components by as much as an order of magnitude. Based upon these studies, STP determined that increases in the failure rate by as much

. as an order of magnitude had little, or no, impact on the final component risk categorization.

i Finally, the change in special treatment requirements should have no adverse impact upon the availability of safety-related LSS and NRS components. Failures of such components will still be subject to the STP

. corrective action program. Fuithermore, since STP may be taking these components out-of-service less frequently for unnecessary maintenance, inspection, and testing, the availability of such components may actually increase as a result of the exemption.

Based upon the above, STP concludes that, even if it is unrealistically' assumed that the change in the special treatment requirements were to result in significant degradation of a group of LSS components of a similar type within a system, there would be little or no

. increase in risk.

5.2.4.2 Decreases in Risk Regulatory Guide 1.174 states that licensees asking for relief using risk-informed approaches should also identify areas in which requirements should be increased based upon the results of risk analyses. For STP, this j

provision would apply to those components that are currently classified as non-safety-related but have been categorized as HSS or MSS. To date, STP has identified approximately 100 such componenti,.

STP will evaluate processes for non-safety-related components categorized as HSS or MSS to ensure that the existing controls are sufficient to maintain the reliability and availability of these components in a manner that is consistent with their categorization. In areas where the current controls are deemed inadequate, this condition will be documented in the STP corrective action program, and actions will be taken to enhance the controls in a timely manner. Additionally, as provided in the approved GQA program, these HSS and MSS components will be subject to the TARGETED QA program. Examples of these process enhancements may include:

Performing routine preventive maintenance (PM) tasks more e.

frequently to ensure component reliability

NOC-AE-000518 Attachment i Page 18 Ensuring that the component's critical attributes are functionally validated following maintenance activities (e.g., the Planner's Guide will specifically ensure that affected component critical attributes are satisfactorily tested following maintenance).

Ensuring - that replacement part controls are enhanced for the components (e.g., TARGETED components will require engineering evaluation for item equivalency replacements).

Increasing the quality oversight of work activities and work documentation (e.g., the Quality Review Matrix has been updated to include audit, surveillance, and monitoring activities for TARGETED components).

At this time, STP has not quantified the effect of these changes on the dsk profile of the plant. However, STP expects that these changes will result in some improvements in the reliability of the HSS and MSS coinponents, which in turn will result in a decmase in risk.

5.2.4.3 Conclusions Recardine Chances in Risk As discussed above, the exclusion of safety-related LSS and NRS components from the scope of the special treatment requirements could result in a small decrease in reliability of these components, but the improvements in the controls for HSS and MSS non-safety-related components are expected to result in some increase in reliability of these components. Based upon its experience with the dsk-informed categorization process, STP estimates that the increased controls for MSS and HSS non-safety-related components and removal of safety-related LSS and NRS components from the scope of special tmatment requirements will result in a net decmase in risk (or will be risk neutral). The reason for this determination is that MSS and HSS non-safety-related components will receive augmented controls, and safety-related LSS and NRS components will still be maintained sufficient to meet their associated system performance levels, such that resulting risk levels are maintained at current levels (i.e., risk neutral) or improved (i.e., dsk positive). The NRC reached similar conclusions in Section 3.5.4 of its Safety Evaluation for the GQA program.

5.2.5 Monitorine of the ImDact of the Proposed Channe Regulatory Guide 1.174 states that the impact of the proposed change in the ~ licensing basis should be monitored using performance measurement strategies.

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NOC-AE-000518 l(

l-Page t9 I

.In order to monitor the impact of the changes in the special treatment requirements, STP will use the monitoring and feedback programs established as part of its GQA program.- The NRC approved these programs in Sections 3.3 and

. 3.5.5 of the Safety Evaluation for the GQA program. Since these programs cover the SSCs that are the subject of this exemption request, the existing programs can be used for monitoring of both the GQA program and the changes in the special treatment requirements.

Some of the requested exemptions from the special treatment requirements relate to elements of the monitoring programs. STP will take the following steps to ensure that'these exemptions do not adversely impact the effectiveness of the monitoring programs:

Maintenance Rule Monitorina As indicated in Regulatory Guide 1.160, e

although there may be a need to perform monitoring under the Maintenance Rule at the component level, most monitoring is performed at.the train / system / plant level. To the extent that any safety-related LSS and NRS i

components are currently monitored under.the Maintenance Rule at the component level, the requested exemption from the Maintenance Rule will relieve STP of the need to monitor the effectiveness of maintenance for individual safety-related LSS and NRS components. However, STP will still be required to monitor the effectiveness of maintenance for the trains / systems containing these components. Therefore, the Maintenance Rule monitoring program will continue 1o ensure the reliability and availability of the functions of the systems containing the safety-related LSS and NRS components.

Furthermore, based upon experience to-date with the risk-informed categorization process for components, the Maintenance Rule monitoring program for STP currently does not require component-level monitoring for most of the components categorized as safety-related LSS and NRS.

Therefore, STP expects that there will be relatively little change in the input from the Maintenance Rule program to the monitoring program, and the changes that'will occur will consist of use of system / train level moriitoring data rather than component level monitoring data. This data will be sufficient to ensure the reliability and availability of system functions.

1 Corrective ~ Action Program - STP's request includes an exemption to exclude

[

safety related LSS and NRS components from the scope of the QA requirements in Parts 21 and 50. However, STP will continue to apply its 4

corrective action program to components that are categorized as safety-related LSS and NRS, as approved by the NRC in Section 3.4.1.9 of the Safety Evaluation for the GQA program. This will ensure that input from the corrective action program regarding degradation or failures of safety-related l

LSS and NRS components (including information from trending and causes l

NOC-AE-000518 Page 20 analyses) will continue to be provided to the monitoring and feedback program to assess the impact of the changes in the special treatment requirements and the need for future adjustments to ensum the continued reliability and availability of the components.

The approved monitoring and feedback programs include provisions for evaluating performance at a component level. These provisions include the following:

The Operating Experience Group (OEG) collects and evaluates problems reported in the STP corrective action program database, which will include problems with individual safety-related LSS and NRS components. The OEG also supports identification of adverse equipment trends, possible common cause or common mode failures, and similarities to station and industry operating experience.

The Risk and Reliability Analysis Department updates the PRA at least once every eighteen months (unit I refueling outage), including equipment failure rate updates to reflect observed equipment performance. The results of the revised PRA are furnished to the Working Group, which, as part of the feedback and corrective action process, can recategorize the safety / risk signifkance of components as needed.

Under the Maintenance Rule, STP will continue to monitor performance on a plant, system, or train level, as appropriate. When performance goals are not satisfied, STP will perform evaluations to determine the cause and corrective action, including, as r:cessary, corrective action for safety-mlated LSS and NRS components.

Therefore, the existing monitoring program approved by the NRC for the GQA program will be sufficient to monitor the effects of the changes in the special treatment requirements for safety-related LSS and NRS components and to ensure that SSCs will continue to satisfy their functional requirements.

6.0 Special Circumstances Section 50.12(a)(2) provides that "special circumstances" must be present before the NRC will grant an exemption. Similarly, Section 21.7 requires that exemptions be in the public interest. As discussed below, this exemption request satisfies several of the criteria for special circumstances identified in Section 50.12(a)(2), which also demonstrates that the exemption is in the public intenst under Section 21.7.

NOC-AE-000518 Attachment i Page 21 6.1 Satisfaction of the Second Criterion for Special Circumstances The second criterion states: " Application of the regulation in the particular circumstances would not serve the underlying purpose of the rule or is not necessary to

- achieve the underlying purpose of the rule."

The purpose of Part 50 is to provide reasonable assurance that the facility will be operated safely. The exemption is consistent with this purpose. The requested exemption will not1 change the functional requirements of plant systems or components.

Furthermore, components that are HSS or MSS will continue to be subject to the special treatment regulations, thereby providing assurance that components with safety / risk significance will demonstrate proof to perform their functions.

As discussed in Section 5.0 above, application of the special treatment requirements in Parts 21,50, and 100 to safety-related L.SS and NRS components is not necessary to provide adequate protection of the public health and safety. The scope of the cunent regulations is based upon a deterministic approach. The scope of the existing regulations was developed without benefit of the insights currently available from probabilistic risk assessments and is more extensive than necessary to provide adequate protection v safety. Specifically, these regulations apply to safety-related LSS and NRS components that are not risk significant as determined by the PRA, and are not significant to safety based'upon other deterministic considerations (e.g., their ability to mitigate accidents or transients and the consequences of their failure). Thus, it is not necessary to apply the special treatment regulations to safety-related LSS and NRS components to achieve the underlying purpose of the regulations. Therefore, the exemption satisfies the second criterion of Section 50.12.

Similarly, it is not necessary to apply the process-related regulations that are the subject of this exemption request in order to achieve their underlying purpose. The process-related regulations are intended to ensure that the NRC reviews and approves significant changes in the licensing basis for a plant. This. purpose will be served by NRC's approval of this exemption request. It is not necessary for the NRC to review and approve the numerous individual changes in special treatment requirements, because those changes will be implemented in accordance with NRC-approved criteria for this exemption.

6.2 Satisfaction of the Fourth Criterion for Special Circumstances The fourth criterion is: "The exemption would result in benefit to the public health and safety that compensates for any decrease in safety that may result from the grant of the exemption."

As discussed in Section 5.2.4.2, there are some components at STP that are not safety-related but have been categorized as MSS or HSS.~ As part of STP's risk-informed

NOC AE-000518 Page 22 approach to safety, STP will apply additional controls to these components. These i

controls will provide. additional assurance that these components will satisfy their functional requirements and as such represents a benefit to public heath and safety.

STP has not performed a quantitative analysis to determine the decrease in rit' from application of special controls to such non-safety-retated components. However, based upon its experience with the risk-informed categorization process, STP estimates

. that the increased controls for MSS and HSS non-safety-related components and removal of safety-related LSS and NRS components from the scope of special treatment 4

requirements will result in a net decrease in risk. The reason for this is that MSS and HSS non-safety-related components will receive augmented controls, and safety-related

)

LSS and NRS components will still be maintained sufficient to meet their associated system performance levels, such that resulting risk levels am maintained at current levels or improved.

Additionally, the exemption will lead to irduced occupational radiation exposures that would otherwise be incuned in providing unnecessary maintenance, testing, and inspection for the safety-related LSS and NRS components.

STP concludes that the exemption will either result in a net benefit to the pubhc I

health and safety or will be risk neutral. Therefore, the exemption satisfies the fourth j

criterion of Section 50.12.

i 6.3 Satisfaction of the Sixth Criterion for Special Circumstances This exemption request also satisfies the sixth criterion for special circumstances; namely, that "There is present any other material circumstance not considered when the i

I regulation was adopted for which it would be in the public interest to grant an exemption."

At the time the special treatment regulations were issued, STP and other plants a

did not have an approved PR.A or risk-informed process for categorizing the safety / risk significance of components.. After the special treatment regulations were issued, STP established a risk-informed process for assessing the relative safety / risk significance of SSCs, and the NRC has reviewed and accepted this pmcess for implementation.

Application of this process provides a sound basis for identifying components that do and do not warrant special treatment commensurate with each component's safety / risk

~

significance. Such information on the relative safety / risk significance of SSCs was not

' considered when the special treatment regulations were issued.

Furthermore, when the regulations were issued, no consideration was given to the costs and benefits of applying special treatment requirements. As discussed above, the special treatment regulations, as applied to safety-related LSS and NRS components, do not provide'any significant benefit to safety. Furthermore, these regulations impose

I i

NOC-AE-000518 Attcchment 1 Page 23 unnecessary burdens with respect to safety-related LSS and NRS components. STP estimates that, upon full implementation of the GQA program and implementation of this exemption, component and part replacement savings will exceed $1 million per year.

Additionally, STP conservatively' estimates that the streamlining and enhancements of processes for safety-related LSS and NRS components could result in a total savings of more than $1 million per year from the Station's present operating and maintenance budget.

In addition, requiring special treatment for safety-related LSS and NRS components increases occupational radiation exposure and diverts management and station personnel attention from activities that are more significant to safety and plant

-reliability. Themfore, an exemption would be beneficial from both a safety and cost perspective.

This new information demonstrates that safety-related LSS and NRS components provide little or no safety benefits, and that the costs of the special treatment regulations for safety-related LSS and NRS components outweigh the minimal safety benefits of such tmatment.

This information constitutes a changed circumstance, which justifies exempting safety-related LSS and NRS components from these special treatment regulations.

Similarly, when the process-related regulations addressed by this exemption mquest were issued, it was n'ot considered that a licensee would want to make changes in the special tmatment requirements'for thousands of components. Consequently, the unnecessary burden posed by the need to evaluate each of these changes under these process-related regulations was also not foreseen.

This constitutes a changed circumstance, which justifies the exemption from these process-related requirements.

6.4 Conclusions Related to Special Circumstances l

The requested exemptions for both the special treatmcnt requirements and the process-related regulations satisfy several of the criteria for special circumstances and is j

in the public interest. Therefore, this exemption request meets the requirements of Sections 50.12 and 21.7, and should be granted.

7.0 Phased Anoroach to Impiementation of the Exemption Upon approval of the exemption, STP will begin the implementation process. Due to the unique nature of this exemption, a deliberate, phased approach will be pursued. This phased approach will enable the NRC to gain additional confidence that STP is implementing the exemption in an appmpriate manner. In addition, with more than 23,000 components already classified thmugh the appmved risk-informed process for caqorizing components, STP cannot reasonably implement all aspects of the exemption at one time.

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Page 24 7.1 Phased Implementation of the Risk-Informed Process for j

Catenorizine Components q

As part of its approval of the GQA program, the NRC approved a risk-informed process for' categorizing the safety / risk significance of components. The component evaluations (and the associated bases for the resulting safety / risk significance), system

)

function categorization, component critical attributes, and assessments performed by Licensing, Operating Experience, Quality, Operations, PRA, and Engineering personnel are documented in Risk Significance Basis Documents which are generated for each system evaluated. The development of the Risk Significance Basis Documents is govemed by approved Station procedures, and the Risk Significance Basis Documents, once approved, are controlled through the STP Document Control process. The approved safety / risk significance evaluation information is electronically loaded into the Station's Master Equipment Database for reference and use by Station personnel. Use of the available safety / risk significance information cannot occur until the associated controlling processes or programmatic procedures have been revised.

Using this process, STP has already completed the categorization of components in the following systems:

CV-Chemical and Volume Control

. RA-Radiation Monitoring EW-Essential Cooling Water DG - Emergency Diesel Generator (and eight auxiliary systems)

RC - Reactor Coolant HE - Electrical Auxiliary Building Heating Ventilation and Air Conditioning (IIVAC)

CC-Component Cooling Water CH-Essential Chilled Water.

HF-Fuel Handling Building HVAC SI -SafetyInjection AF-Auxiliary Feedwater.

HM-Mechanical Auxiliary Building HVAC RH-Residual Heat Removal SB -Steam Generator Blowdown MS -Main Steam FW-Main Feedwater In-addition to the above systems, STP is targeted to complete component categorization for the following systems by the end of 1999:

i IA-Instmment Air

' HC - Reactor Containment Building HVAC WL-Liquid Waste Processing FC-Spent Fuel Pool Cooling l

PS -Primary Sampling

NOC-AE-000518 Page 25 STP will implement the exemption on the above systems first. STP may complete component categorization for subsequent systems and anticipates that it will then implement the exemption for these systems on a routine basis.

As part of its review of the GQA program, the NRC staff reviewed the GQA Risk Significance Basis Documents used to categorize components in the RA, EW, and DG systems. The staff concluded in Section 3.3.4 of its Safety Evaluation for the GQA program that the documents are " comprehensive, well organized, and capable of providing a scrutable record of the functional relationships linking system functions to individual component attributes for proper categorization" of components.

The documentation of the safety / risk significance evaluation process and the evaluation results for the other completed systems will also be available for NRC review at the STP site.

7.2 Planned Implementation Approach Initially, implementation of the exemption will focus on the systems for which the risk-informed categorization process has been completed at the time the exemption is granted. Upon approval of the exemption, STP will begin a phased implementation of the exemption for those systems as described in the following sections.

7.2.1 Procedure Channes STP will evaluate and revise its procedures applicable to each of the areas addressed by the exemption. For example:

Procurement - STP will revise procedures that govern the equipment procurement for routine part and component replacement to reflect the exemption from the need to procure safety-related LSS and NRS components pursuant to a QA program under Appendix B.

Maintenance - STP will operate and maintain safety-related LSS and NRS components in a manner that reflects commercial and industrial practices to ensure component availability and reliability.

The maintenance procedures / processes will be streamlined for safety-related LSS and NRS components to provide greater reliance upon use of the skill of the craft to correct deficiencies and perform preventive maintenance. Additionally, as discussed previously, STP will modify its Maintenance Rule program as appropriate to monitor safety-related LSS and NRS components as part of system / train level monitoring rather than component level monitoring.

Ouality Assurance - STP will evaluate its quality assurance and other e

administrative procedures applicable to safety-related LSS and NRS

1

1. -

l, NOC-AE-000518 j

Page 26 components.

This evaluation will look for opportunities to streamune C

burdensome processes applicable to safety-related LSS and NRS components, while ensuring that beneficial and prudent controls are applied to maintain the functional requirements of these components. QA and other administrative procedures for safety-related LSS and NRS components will then be modified accordingly.

Until these procedures are revised, STP will continue to ensure that safety-related LSS and NRS components are subject to applicable safety-related and quality-related procedures. In addition, as appropriate, STP will modify various programs (e.g., provisions for motor operated valve (MOV) program, air operated valve (AOV) program, snubber testing program, molded case circuit breaker program) to remove safety-related LSS and NRS components from the scope of these programs. Although an exemption is not required to modify these programs, the modifications will be processed in accordance with STP's Cortective Action Program.

7.2.2 Channes in Licensine Basis Documents In conjunction with the evaluations and changes in procedures discussed above, STP will evaluate the need for corresponding changes in the UFSAR and the Operations Quality Assurance Program (OQAP). STP will provide the NRC with reports of these changes as required by 10 CFR 50.71(c) and 50.54(a). Since STP is requesting an exemption from Sections 50.59 and 50.54(a) for changes to special treatment requirements for safety-related LSS and NRS components, STP will not need to perform the evaluations normally required by these regulations, and will not need to seek prior NRC approval of such changes.

Currently, STP does not anticipate that such changes will impact the Technical Specifications.- However, to the extent that an individual change in the UFSAR will also entail a change in the Technical Specifications, STP will not implement the modification without first applying _for and receiving NRC approval of a separate application for an amendment of the Technical Specifications.-

j i

The Technical Specifications apply to some systems that include safety-related LSS and NRS components. These Technical Specifications provisions will. continue to apply' after the exemption is granted. Therefore, STP will continue to evaluate nonconforming and degraded conditions involving safety-

' related LSS and NRS components to determine whether such conditions affect the operability of systems controlled by the Technical Specifications.

l l

j 1

l i

NOC-AE-000518 Page 27 7.2.3 Channes in Activities and Comp <ments in the Field Following revisions of the procedums applicable to the safety-related LSS and NRS components, STP will begin to implement the revised procedures.

For example, following the revisions of the governing procurement procedums, STP will begin procuring commercially available parts on an as-needed basis for currently installed safety-related LSS and NRS components. The procurement of these commercial parts will occur as needs develop and as j

required to support regularly scheduled maintenance activities.

j

\\

The NRC will have the opportunity to inspect the implementation of the exemption for these initial systems.

STP will factor the results of these inspections into its feedback and monitoring process described below.

7.2.4 Feedback and Monitorine ofImplementation Activities i

As discussed previously, STP will maintain a feedback mechanism in place to periodically evaluate the system and equipment performance results, and to assess the impact of the changes that have been made. This assessment will include HSS and MSS nonsafety-related components to determine what additional j

controls are necessary to ensure equipment performance, availability, and reliability. Plant / system / train performance levels will be monitored, as applicable, in accordance with Maintenance Rule requirements to ensure that changes to the controls for safety-related LSS and NRS components will not have an adverse effect on system performance. Also, the assessment will evaluate if reductions in quality controls or other requirements have resulted in a decrease in component reliability, and if it would be prudent to enhance the oversight controls or simply procure another component.

The feedback mechanism will include an evaluation of the following inputs:

• Performance Data e Maintenance Rule Status Industry Events / Operating Experience

• PRA Model Revisions Plant Design Changes Plant Procedure Changes Condition Report Process

• External and Internal Audits and Surveillance The Working Group will continue to meet at least once per six months to evaluate the feedback and to recommend any revisions to the previously approved component risk significance evaluations. Any recommended changes will be forwarded to the Expert Panel for approval prior to implementation. Additionally,

p NOC-AE-000518 Attechment 1 Page 28 l

based upon the results of this monitoring and feedback process for the initial

' systems that go through this process, STP will develop lessons leamed and apply them to subsequent systems, as appropriate. If STP determines that a safety I

related LSS or NRS component should be reclassified as MSS or HSS, STP will document this condition on a Condition Report, and will disposition the condition under the STP corrective action program.

7.2.5 Sununary In summary, STP will i,mplement this exemption in a phased ' approach.

This will enable STP to account for lessons leamed from initial implementation, and will enable the NRC to perform inspections and reviews to gain additional confidence in STP's proposed implementation process before the process is applied across additional systems at the plant.-

8.0 Conclusions

' The request $d exemption satisfies the requirements in Sections 50.12 and 21.7 and the intent of Regulatory Guide 1.174, will reduce unnecessary burdens, and will enable STP to focus attention and resources on matters that are truly significant to safety. Therefore, STP requests that NRC grant STP an exemption from the regulations identified in Attachment 2. These exemptions will enable STP to exclude safety-related LSS and NRS components from the scope of the special treatment' requirements, and to make associated changes in its licensing basis

. without seeking prior NRC approval for each change.

In addition, STP believes that this pilot application will assist the NRC in developing the risk-informed approach to 10CFR50.

Clarifications on some of the NRC questions that have been expressed to date are provided in Attachment 3.

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NOC-AE-000518 Page1 RESPONSES TO PRELIMINARY LIST OF NRC QUESTIONS L

Probabilistic Risk Assessment l

1.

Explain why STPNOC is proposing that both low safety significant (LSS) and non-risk significant (NRS) structures, systems and components (SSCs) be removed from l

scope and not, for example, only NRS. If not all LSS and NRS SCCs are to be removed from scope, explain how some will be selected and others not.

Response

' As explained in Section 5.2.4 of Attachment 1, minimal risk increases would result from changes in LSS components and no risk increases would result from changes in NRS components. It is our opinion that in a risk informed mgulatory environment these impacts am acceptable, and regulatory oversight and purview can be reduced and/or eliminated for LSS and NRS components without impact to public health and safety. It should be noted that LSS and NRS components will be programmatically controlled by station programs and procedures in a similar manner that balance-of-plant equipment is currently controlled.

2._

Explain why the SSC categorization process approved by the staff solely to determine which SSCs could not be subjected to a reduction in some Quality Assurance (QA) controls, is also applicable to support the much more encompassing change arising from placing SSCs outside the scope of regulations.

< Response:

The approved risk significance evaluation process is applicable to support placing SSCs outside the scope of regulations and is an essential step in risk informing 10CFR50. The SSC categorization process is independent of any particular pmgram (such as the QA pmgram) and instead is based upon system and component functions. The reason the SSC i

categorization process is appropriate and acceptable is as follows:

l

1) The SSC categorization pmcess blends probabilistic and deterministic information, L

~and in so doing addresses a full spectrum of initiating events including both design

- basis events and events beyond design basis; l

2) The SSC categorization pmcess determines system functions (both accident l

prevention / mitigation functions and other lesser functions such as venting, draining, i

local indication) and component functions (i.e., what the components must do to

. perfonn their functions be it a risk significant function or non risk significant such as merely to provide local indication) over all modes of plant operation to determine component failure modes and critical attributes;

NOC-AE-000518 Page 2

3) The SSC categorization process evaluates the impact of failure of SSCs to other risk significant SSCs.

'Under the deterministic process, station programs addressing special treatment requirements are applicable to components defined as " safety-related" (or important to safety)._ The risk significance evaluation is a more appropriate tool than the cunent deterministic process for defining safety-related components. Based on the items above. and by assessing likelihood of occurrence and. associated performance

. information, the risk significance evaluation process is a more robust and rigorous method for establishing the scope to which special treatment requirements are appropriate and for which they will provide measurable benefits relative to nuclear safety. SSCs that are not risk significant do not warrant any special treatment (QA or otherwise).

3..

During the Graded QA (GQA) application review, the staff determined that the LSS SSCs would be subject to QA controls appropriate to their low safety significance.

Given that for GQA, LSS and NRS are treated identically, the staff did not review the differentiation between LSS and NRS beyond confirming that NRS was at least LSS. Explain how SSCs placed in the NRS are so much less significant than SSCs placed in LSS.

Response

The first distinction to be noted is that LSS components may be included in the scope of the PRA whereas NRS components are not.

Some LSS components could have quantifiable impacts based on assumptions. of their reliability or availability even though those impacts could be exceedingly small. Depending upon the magnitude of the assumed change in reliability or availability, the aggregate effects for quantifiable LSS items would range from no impact to linear impact effects proportional to the magnitude of the l

assumed change. NRS components do not readily lend themselves to quantification since they'are not' within the scope of the PRA. Therefore, increased failure rates in NRS components do not translate to risk significance or public health effects in and of themselves.

- Another distinction between LSS, and NRS components is the response to the key deterministic questions ' contained in the risk significance evaluation process. The NRS components have responses to the key deterministic questions ranging from zero (i.e.,

negative.or no impact) to minor impacts (i.e., very little impact, if any, or little impact under restrictive or specific assumed initial conditions). Components are classified as NRS based on having composite scores from the key deterministic questions less than 20 (i.e., out of a possible maximum score of 100). It should be noted that the deterministic I

questions associated with risk determination are weighted such that a clear distinction exists between components classified as LSS and NRS. Thus, the risk significance j

q

NOC-AE-000518 Page 3 evaluation process provides not only objective distinctions between IJSS and NRS 1

components but is biased to classify components to higher risk significance for key areas of concern. Components not reaching a composite score of 20 are not risk significant and merit no regulatory oversight.

Even though NRS components have less risk significance than LSS components, it is appropriate to treat LSS and NRS components similarly with respect to special treatment requirements. As discussed in Section 5.2.4 of Attachment 1, changes in special ticatment requirements for LSS components are expected to have little or no impact on risk.

Therefore, the effects of changes in special treatment requirements for LSS components are similar to the effects of changes in special treatment requirements for NRS components, and from a risk-informed perspective there is no reason to have a different special treatment requirements for each of these types of components.

4.

A claim that there will be no decrease in equipment availability following a reduction in QA controls, environmental qualificatE seismic qualification and various other special treatment requirements, will t %ost certainly not be demonstrable. Assuming that some impact on margms or availability is possible, explain how the potential aggregate risk impact of removing NRS (and possibly LSS) SSCs from the scope of regulations will be determined.

Response

As stated in Section 5.2.4.1, STP performed sensitivity studies in which unreliability was simultaneously increased for LSS components of a similar type within the scope of the PRA. These studies evaluated the impact of increasing the unreliability of the group of components by as much as an order of magnitude. Based upon these studies, STP determined that increases in the failure rate by as much as an order of magnitude had little, or no, impact on the final component risk categorization.

The effect on equipment availability of reduced or eliminated special treatment requirements will be seen based on future PRA performance data updates and the periodic GQA performance evaluation and feedback process. The aggregate risk impact for LSS and NRS components will be assessed quantitatively using the following:

1)

Station performance indicators, 2)

Periodic updates of the PRA with respect to performance data, and 3)

Periodic Maintenance Rule assessments.

Additionally, qualitative assessments will be performed using the Corrective Action Program. Equipment deficiencies and nonconformances will be identified on all components regardless of their risk significance. LSS and NRS components will be reviewed, and if necessary, adjustments made, by the GQA process as part of the periodic i

feedback and reassessment.

p J

NOC-AE-000518 Attcchment 3 Page 4 5.'

Explain why, if current Inservice Testing (IST) policy is only to allow increased inspection intervals for LSS, your proposal to remove them from regulatory scope (e.g., allowing no testing) is acceptabic.

Response

ISI/IST have been removed from the request and separate relief requests will be submitted on a case by case basis as the need arises.

6.

'As a pilot, does STPNOC plan to identify regulatory changes that would allow the changes you propose without requiring exemption requests?

Response

The regulations that STPNOC believes to be affected are tabulated in the submittal.

Recommending specific changes to these regulations is beyond the scope of this exemption request. STPNOC would expect to provide that input through industry efforts such as the NEI efforts to risk inform 10CFR Pan 50. In addition, STPNOC would be pleased to discuss specific regulatory changes and provide input identifying changes as a parallel effon.

Quality Assurance 1.

Explain why STPNOC does not propose using the existing Regulatory Guides for developing a risk-informed QA program.

Response

STP has already applied the provisions of Regulatory Guide 1.176 in development of its original GQA submittal. However, the approved GQA program only allows STP to apply a reduced level of quality assurance to MSS, I.SS and NRS components, commensurate with their safety / risk significance. In practice, a fully risk-informed set of controls defined by a risk informed program cannot be implemented due to the special treatment requirements imposed by 10 Chi Parts 21,50, and 100 for SSCs classified as safety-related, important to safety, or otherwise within the scope of the regulations. Given the lack of safety / risk importance of LSS and NRS components to protect the health and safety of the public as determined by the approved risk-informed categorization process, an exemption is appropriate to exclude safety-related LSS and NRS components from the scope of the special treatment requirements in these regulations. Such a chang'is beyond the scope of the existing Regulatory Guides.

r 1

\\

l WOC-AE-000518 Page 5 2.

STPNOC should maintain the GQA progrma commitment for the feedback loop to

/

make adjustments, when necessary,in the application of the QA controls for l

LSS/NRS equipment based on plant / industry performance, and plant modifications.

I

Response

1 As described in Section 5.2.5 of Attachment 1, STP will maintain a feedback mechanism in place to periodically evaluate the system and equipment performance results, and to assess the impact of the changes that have been made. This assessment will include HSS and MSS nonsafety-related components to determine what additional controls are necessary to ensure equipment performance, availability, and reliability.

Plant / system / train performance levels will be monitored, as applicable, in accordance with Maintenance Rule requirements to ensure that changes to the controls for safety-related LSS and NRS components will not have an adverse effect on system performance.

Also, the assessment will evaluate if reductions in quality controls or other requirements have resulted in a decrease in component reliability, and if it would be prudent to enhance the controls applicable to LSS and NRS components.

3.

Page 6 of the March 1,1999, letter describes other programs (such as motor operated valves (MOVs), air operated valves (AOVs), molded case circuit breakers that are not listed in Attachment 1, where LSS and NR$ equipment will be treated differently. STPNOC should explicitly identify all technical areas where LSS and NRS equipment will no longer be within scope of the current program controls.

j

Response

The technical areas where LSS and NRS equipment will no longer be within the scope of the current program controls addressed in NRC regulations are covered in Section 4.1 of. STPNOC does not believe approval of the proposed exemption is required for scope changes to other programs (such as MOV and AOV programs) that are not subject to separate NRC regulations.

4.

STPNOC should provide amplifying information on how commercial vendors, not necessarily the original equipment manufacturer (OEM), will provide a suitable engineering analysis to demonstrate the LSS/NRS equipment conforms to the STPNOC procurement specifications which include typical nuclear requirements (i.e., seismic loading, harsh environment profiles).

Response

l LSS and NRS components will be available to function in the environments that I ne been identified for them since the procurement specifications will still specify the

i NOC-AE-000518 Page 6 environmental parameters that the components must be able to withstand. If the LSS component has critical attributes, STPNOC procurement processes will assure these attributes are satisfied.-

STPNOC believes that engineering analyses, qualification testing, or other specialized efforts to provide empirical evidence or otherjustifications of an SSCs ability to function in adverse environments is overly burdensome and not necessary for LSS and NRS components (i.e., not commensurate with their safety significance). STPNOC j

procurement processes will be used to identify to suppliers' specific attributes and parameters to which SSCs must conform. In this regard, LSS and NRS components will be capable and available to function under the range of environmental conditions as identified through procurement specifications (similar to other components that are purchased using commercial and industrial practices).

5.

STPNOC should re-consider waiving the entire scope of the QA program for LSS/NRS equipment. For example, why are the nonconformance/ corrective action, monitoring programs, and design controls eliminated in their entirety? Why is the basic QA program no longer acceptable for LSS/NRS equipment?

Response

STP is not waiving the entire scope of the QA program for LSS and NRS equipment, and has retained the nonconformance/ corrective action, monitoring progrems, and design controls, as discussed in Sections 4.1.1 and 5.2.5 of Attachment 1.

6.

STPNOC should provide amplifying justification on the usefulness of normal plant operational feedback mechanisms to demonstrate the functionality of LSS/NRS equipment with respect to special treatment provisions like equipment qualification and seismic qualification provisions.

Response

In order to monitor the impact of the changes in the special treatment requirements, STP will use the monitoring and feedback programs established as part of its GQA program.

The NRC approved these programs in Sections 3.3 and 3.5.5 of the Safety Evaluation for the GQA program. Since these programs cover the SSCs that are the subject of this exemption request, the existing programs can be used for monitoring of both the GQA program and the changes in the special treatment requirements. This is covered in Section 5.2.5 of Attachment 1.

i 7.

Page 20 and 21 of the March 1,1999, letter discuss a commitment for enhanced treatment of non-safety related high safety significant (HSS) and medium safety

NOC-AE-000518 i

l Page 7 l

significant (MSS) equipment with respect to technical areas. How will this commitment be integrated into a licensing basis document, and what specific l

technical enhancements will be considered? STPNOC should confirm that the GQA provisions for treatment of non-safety related HSS and MSS equipment remains intact.

Response

This exemption request does not affect the GQA provisions for non-safety-related HSS and MSS components, and such provisions will remain in effect. Section 5.2.4.2 of Attachment I discusses STP's provision for enhanced treatment of non-safety MSS and HSS components. The commitment for enhanced treatment of non-safety related high safety significant (HSS) and medium safety significant (MSS) equipment will be integrated into appropriate stati documents.

8.

Page 24 and 25 of the March 1,1999, letter provide a high level discussion as to why the composite set of changes will ensure adequate protection of public health and safety. The basis for this conclusion should be augmented to justify how the whole set of LSS and NRS could be found so unimportant.

Response

By definition IJSS and NRS components generally support ancillary functions (e.g., vents, drains, and local indications) for safety-related systems and do not provide, support, or affect the primary safety functions of the systems. Given the lack of safety / risk importance of LSS and NRS components to protect the health and safety of the public as determined by the approved risk-informed categorizatiorgprocess, an exemption is appropriate to exclude safety-related LSS and NRS components from the scope of the special treatment requirements in these regulations. This is discussed in Sections 2.0, 5.2.2 to 5.2.4 of Attachment 1.

Since the existing safety-selated LSS and NRS components were designed, procured, manufactured, and installed in accordance with the existing special tmatment requirements, these components have inhemnt design margins to perform their intended functions that will not be adversely affected by this exemption. STPNOC's normal commercial and industrial practices provide an appropriate and acceptable level of assurance that replacements for safety-related LSS and NRS components will continue to have sufficient margin to satisfy their functional requirements. Although STP has a high level of confidence that the LSS and NRS components will continue to function, in the unlikely event that they fail, there are no significant consequences as discussed in Section 5.2.3 of Attachment 1.

NOC-AE-000318 Page 8 J

Similar to the GQA program approved by the NRC, the requested exemption does not involve a change in any functional requirements or the configuration of SSCs. Because of the low risk significance of the components in the scope of the exemption, STP does not expect the need to change any of the safety analyses in the UFSAR.

9.

STPNOC should first take advantage of current mechanisms to resolve the problems on burdensome special treatment controls, such as using the design i entrol program to re-classify equipment as non-safety related.

Response

STP plans to take advantage of current mechanisms to resolve the problems on burdensome special treatment controls as stated in the letter to the NRC from M. A.

McBumett dated April 8, 1999, " Request for Concurrence with Process for Reclassification of Non-Risk Significant Components."

Maintenance Rule 1.

With respect to the Maintenance Rule, monitoring LSS and NRS SSCs at the system / train level is acceptable (STPNOC is requesting an exemption from monitoring at the component level). There are no requirements to monitor at the component level even for HSS SSCs. Also, the Regulatory Guide /NUMARC guidance calls for plant level monitoring (scrams, transients) for most LSS/NRS SSCs.

Response

Although monitoring at the component level is not a requirement for all components, Regulatory Guide 1.160 stater that some component-level monitoring may be necessary.

Therefore, STPNOC believes an -xemption to 10CFR50.65 is necessary to clarify that the Maintenance Rule is not applicable to individual NRS and LSS components.

General Desien Criterion 17 1.

With the utilization of commercial grade electrical components (i.e., components determined to be LSS or NRS that previously met all Class 1E requirements),

explain how independence is preserved between redundant safety system (i.e., how will the availability of the minimum required equipment be assured during any i

design basis event?).

NOC-AE-000513 Page 9 i

Response

STPNOC does not plan to revise the design basis separation criteria. As discussed in Section 4.1.2 of Attachment 1, separation will be maintained between IE and non-1E equipment as described in the STP UFSAR.

a)

Present the' criteria 'and their basis (i.e., current UFSAR commitments and/or new commitments) that establish the minimum requirements for preserving the independence between redundant safety systems).

Response:(SEE RESPONSE ABOVE) b)

If an isolation device is utilized to isolate (Class 1E HSS or MSS from LSS or NRS),

will this isolation device be required to be HSS or MSS? If not, provide justification.

Response

STP would expect the device to be classified consistent with the equipment it protects.

STP will take actions as necessa,j to ensure that HSS and MSS Class IE components are apprep-iately protected per the mquirements in the UFSAR as discussed in Section 4.1.2 of Attachment 1.

c)

Provide a description of the extent te which the recommendations of Regulatory Guide 1.75 are followed.

Response

STP expects no change in its commitment to Regulatory Guide 1.75 from the proposed exemption.

Environmental Oualification 1.

Since 50.49 only requires components to be qualified to 50.49 requirements if they are exposed to the design basis accident (DBA) environment and must function in order to mitigate the consequences of the DBA, it is not clear which components need exemption. Provide clarification.

Response

LSS and NRS components will still be procured and maintained in accordance with design and environmental requirements; however, this exemption would enable STPNOC to procure and install the e components without formal equipment qualification testing as

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l NOC-AE-000513 f

Page 10 required by 10CFR50.49. Since those components will be suitable and capable of l

performing their intended function (s), there would be no risk increase due to this change.

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Inservice Testing 1.

Explain why STPNOC did not use the existing Regulatory Guide 1.175 for risk-informed IST?

Response

1 IST in not included in the scope of the Exemption Request. STP will use the existing Regulatory Guide 1.175 to risk-informed IST.

1 2.

Discuss why, without monitoring at the component level, common cause failures of LSS components are not important to safety.

l

Response

i As discussed in Section 5.2.5 of Attachment 1, the Operating Experience Group (OEG)

- collects and evaluates problems reported in the STP corrective action program database, which will include problems with individual safety-related LSS and NRS components.

l The OEG also supports identification of adverse equipment trends, possible common l

l cause or common mode failures, and similarities to station and industry operating experience.

Under the Maintenance Rule, STP will continue to monitor performance on a plant, system, or train level, as appropriate. When performance goals are not satisfied, STP will perform evaluations to determine the cause and corrective action. 'ncluding, as necessary, corrective action for safety-related LSS and NRS components.

Therefore, the existing monitoring program approved by the NRC for the GQA program will be sufficient to monitor the effects of the changes in the special treatment l

requirements for safety-related LSS and NRS components and to ensure that SSCs will continue to satisfy their functional requirements.

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3.

Discuss how you can assure that LSS and NRS components in safety-related systems purchased without QA documentation (e.g., material certifications) will meet design and procurement specification requirements (e.g., strength, ductility, and corrosion-resistance).

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NOC-AE-000518 Page11 4

Response

Normal commercial and industrial practices will provide an appropriate and acceptable j

level of assurance that safety-related LSS and NRS compottents will be able to perform

)

their intended functions. As discussed in Sections 5.2.2 and 5.2.3 Attachment 1, even ifit is unrealistically assumed that the use of commercial and industrial practices would result in substantial increases in failure rates, STP has performed bounding sensitivity analyses which demonstrate that there would be little, if any, impact on the safetyhisk categorization of the components.

4.

Explain why it is acceptable for failures of LSS and NRS components in a safety-related system to occur when those components are not modeled in your probabilistic risk assessment (PRA). Could failures of LSS and NRS components impact the ability of a safety-related system to perform its intended functions?

i

Response

As discussed in Section 554 of Attachment 1, NRS components are not sufficiently significant to warrant modeling in the PRA. Therefore, the exemption to exclude safety-related NRS components from the scope of special treatment requirements will not affect the results of the PRA for STP. For purposes of the GQA program, STP uses a site-specific PRA in the risk-informed process for categorizing SSCs. The NRC has previously approved the quality of the PRA, quality assurance for the PRA, the scope of the FRA, and the application of the PRA results and insights to the risk-informed process for cate'gorizing components, as described in Section 3.2 of the NRC's Safety Evaluation for the GQA program. These same tools will be used for this exemption. As provided by these tools, failure of an LSS or NRS component will not have an impact on a significant safety function.

S.

Describe any feedback that will occur when LSS and NRS components are found in a degraded or nonconforming condition. Will the feedback explicitly address each special treatment area being affected by the exemption request (e.g., to re-establish QA or IST requirements as may be appropriate)?

Response

As discussed in Section 5.2.2 of Attachment 1, STP's corrective action program will continue to be used to identify adverse trends for plant systems and/or equipment

- (including safety related LSS and NRS components), and as such, is a sigrificant barrier against allowing unacceptable levels of performance degradation to occur.

e

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NOC-AE-000510 l_

Page 12 6.

Quantitt 'ively assess, to the extent practical, the aggregate effect on core damage frequenc, (CDF) and large early release frequency (LERF) of deleting the various special treatment requirements. What would be the effect on CDF and LERF if all LSS and NRS components were assumed to be unavailable?

Response

NRS components are not sufficiently significant to warrant modeling in the PRA.

Therefore, the exemption to exclude safety-related NRS components from the scope of special treatment requirements will not affect the results of the PRA for STP. See Section 5.2.4 of Attachment 1. It is not realistic (and contrary to accepted procedures for perfoiming a PRA) to assume that all modeled LSS components fail simultaneously during an accident, merely because such components are subject to normal commercial and industrial practices rather than special treatment requirements.

However, as described in Section 5.2.4.1 of Attachment 1, even if it is unrealistically assumed that the unreliability of all LSS and MSS components of a similar type within the scope of the PRA were increased by an order of magnitude, there would be no impact on STP's risk

]

categorization.

. 7.

Discuss the basis for deleting IST requirements for LSS components (components with a Fussell Vessely (FV) less than 0.005 and a risk achievement worth (RAW)

{

less than 2.0) in light of the fact that the ASME component specific and risk-informed Code cases, currently under development, derme IST requirements for i

t hese c.~aponents.

Response

IST has been removed from the scope of the Exemption Request.

8.

Describe the deterministic factors considered by the expert panel in categorizing components. How does the licensee's overall categorization process ensure that appropriate level of QA, testing, maintenance, etc., is conducted on components categorized as LSS and NRS?

Response

The deterministic factors considered by the expert panel in categorizing components were discussed in STP's application for the GQA program and were approved by NRC in its Safety Evaluation for the GQA program. This categorization process is based upon the l

1

NOC-AE-000518 Page 13 importance of a component to the performance of safety functions, and is not based upon 4

(and does not specify) the level of special treatment requirements for the component.

As discussed in Section 5.2.4 of Attachment 1, the exemption will allow safety-related LSS and NRS components to be inspected, tested, and maintained under normal commercial and industrial practices for non-safety-related cdmponents. In addition, replacement components may be designed, manufactured, procured, and installed under STP's normal commercial and industrial practices. These practices provide an appropriate and acceptable level of assurance that the components will satisfy their functional requirements. Given the minimal safety / risk significance of the components in question, these practices are sufficient to ensure that the components will satisfy their functional requirements'and have sufficient safety margin. Furthermore, perfonnance of the systems / trains containing safety-related LSS and NRS components will be monitored under the both Maintenance Rule program, as applicable, and the Corrective Action Program to ensure that these systems / trains maintain satisfactory levels of performance.

Inservice Inspection 1.

Explain why STPNOC does not propose using the existing Regulatory Guides for developing a risk-informed Inservice Inspection (ISI) Program (for piping).

Response

ISI has been removed from the scope of the Exemption Request.

2.

How does the change in risk category impact ASME classification for the purpose of ISI?

Response

ISI has been removed from the scope of the Exemption Request.

Seismic Oualification 1.

A seismic event is a common cause failure initiator. Real earthquake experience data had indicated that some equipment is vulnerable to earthquake motions.

Reliance on design and purchase specifications may not be sufficient to demonstrate the functions of some mechanical and electrical equipment. Discuss what criteria and procedures you plan to use to assure that LSS and NRS components will function during and after an earthquake without performing equipment seismic qualification in accordance with the current provisions in the UFSAR.

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NOC-AE-000518 Page 14 1

1.

Response

~

As explained in Section 4.1.2 of Attachment 1, procurement specifications will require j

the LSS and NRS components be able to function following a seismic event, to the extent i

required by their critical attributes. Normal commercial and industrial practices will be utilized to ensure that such components satisfy these requirements. Experience with

. commercial and industrial components indicates that there is reasonable assurance that l

the components will survive those seismic events for which they are designed.

l l Nevertheless, even if some LSS and NRS components were te fail during a design basis

' earthquake, there would be no significant impact on a safety function, as discussed below.

As stated in Section 5.2.3'of Attachment 1, STP has a high level of confidence that the l.

IES and N'IS components will continue to function in the event of an e?.rthquake. In the l

unlikely event that they fail, there are no significant consequences smce componen's t

categorized as NRS are not sufficiently significant to warrant modeling in the PRA. The safety-related NRS components generally include local indicators, vents, drains, and root valves sized 1" and under. Even if it is assumed that s safety-related NRS component were to fail, the results of the PRA would be unaffected.

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