ML18226A318
| ML18226A318 | |
| Person / Time | |
|---|---|
| Site: | Technical Specifications Task Force |
| Issue date: | 09/20/2018 |
| From: | Victor Cusumano NRC/NRR/DSS/STSB |
| To: | |
| Honcharik M, NRR/DSS, 301-415-1774 | |
| Shared Package | |
| ML18226A327 | List: |
| References | |
| CAC MF9955, EPID L-2017-PMP-0006 | |
| Download: ML18226A318 (11) | |
Text
1 General Directions: This Model SE provides the format and content to be used when preparing 2 the plant specific SE of an LAR to adopt TSTF 563, Revision 0. The bolded bracketed 3 information shows text that should be filled in for the specific amendment; individual licensees 4 would furnish site-specific nomenclature or values for these bracketed items. The italicized 5 wording provides guidance on what should be included in each section and should not be 6 included in the SE.
7 8 DRAFT MODEL SAFETY EVALUATION 9 BY THE OFFICE OF NUCLEAR REACTOR REGULATION 10 TECHNICAL SPECIFICATIONS TASK FORCE TRAVELER 11 TSTF-563, REVISION 0 12 REVISE INSTRUMENT TESTING DEFINITIONS TO INCORPORATE THE SURVEILLANCE 13 FREQUENCY CONTROL PROGRAM 14 USING THE CONSOLIDATED LINE ITEM IMPROVEMENT PROCESS 15 (CAC NO. MF9955, EPID L-2017-PMP-0006) 16 17 18
1.0 INTRODUCTION
19 20 By application dated [enter date] (Agencywide Documents Access and Management System 21 (ADAMS) Accession No. [MLXXXXXXXXX]), [as supplemented by letter(s) dated [enter 22 date(s))), [name of licensee] (the licensee) submitted a license amendment request (LAR) for 23 [name of facility (abbreviated name), applicable units].
24 25 The amendment would revise the current instrumentation testing definitions of Channel 26 Calibration(( and Channel Functional Test] OR [, Channel Operational Test (COT), and Trip 27 Actuation Device Operational Test (TADOT))) to permit determination of the appropriate 28 frequency to perform the Surveillance Requirement (SR) based on the devices being tested in 29 each step. The proposed changes are based on Technical Specifications Task Force (TSTF) 30 Traveler TSTF-563, Revision 0, Revise Instrument Testing Definitions to Incorporate the 31 Surveillance Frequency Control Program, dated May 10, 2017 (ADAMS Accession 32 No. ML17130A819). The U.S. Nuclear Regulatory Commission (NRC or the Commission) 33 issued a final safety evaluation (SE) approving TSTF-563, Revision 0, on [enter date] (ADAMS 34 Accession No. [MLXXXXXXXXX]).
35 36 {NOTE: TSTF-563 is only applicable to plants that have already adopted TSTF-425 or have an 37 approved SFCP that uses NEI 04-10.}
38 39 An SFCP was incorporated into the [PLANT] TS in a license amendment dated [enter date]
40 (ADAMS Accession No. [MLXXXXXXXXX]).
41 42 ((The licensee has proposed variations from the TS changes described in TSTF-563. The 43 variations are described in Section 2.2.1 of this SE and evaluated in Section 3.1.] OR [The 44 licensee is not proposing any variations from the TS changes described in TSTF-563 or 45 the applicable parts of the NRC staffs SE of TSTF-563.))
46 Enclosure 2
1 [The supplemental letters dated [enter date(s)], provided additional information that 2 clarified the application, did not expand the scope of the application as originally 3 noticed, and did not change the NRC staffs original proposed no significant hazards 4 consideration determination as published in the Federal Register on [enter date] (cite FR 5 reference).]
6 7
2.0 REGULATORY EVALUATION
8 9
2.1 DESCRIPTION
OF SURVEILLANCE FREQUENCY CONTROL PROGRAM AND 10 INSTRUMENT TESTING 11 12 The technical specifications (TSs) require the surveillances for instrumentation channels to be 13 performed within the specified frequency, using any series of sequential, overlapping, or total 14 channel steps. TSTF-425, Revision 3, Relocate Surveillance Frequencies to Licensee 15 Control - RITSTF [Risk-Informed TSTF] Initiative 5b, revised the TSs to relocate all periodic 16 surveillance frequencies to licensee control. Changes to the relocated surveillance frequencies 17 are made in accordance with the TS program referred to as the Surveillance Frequency Control 18 Program (SFCP). The SFCP allows a new surveillance frequency to be determined for the 19 channel, but that frequency must consider all components in the channel and applies to the 20 entire channel.
21 22 A typical instrument channel consists of many different components, such as sensors, rack 23 modules, and indicators. These components have different short-term and long-term 24 performance (drift) characteristics, resulting in the potential for different calibration frequency 25 requirements. Under the current TSs, the most limiting component calibration frequency for the 26 channel must be chosen when a revised frequency is considered under the SFCP. As a result, 27 all components that makeup a channel must be calibrated at a frequency equal to the channel 28 component with the shortest (i.e., most frequent) surveillance frequency.
29 30 Some channel components, such as pressure transmitters, are very stable with respect to drift 31 and could support a substantially longer calibration frequency than the other components in the 32 channel. Currently, the SRs in many plants are performed in steps (e.g., a pressure sensor or 33 transmitter is calibrated during a refueling outage and the rack signal conditioning modules are 34 calibrated while operating at power). The proposed change extends this concept to permit the 35 surveillance frequency of each step to be determined under the SFCP based on the 36 component(s) surveilled in the step instead of all components in the channel. This will allow 37 each component to be tested at the appropriate frequency based on the components long-term 38 performance characteristics.
39 40 Allowing an appropriate surveillance frequency for performing a channel calibration on each 41 component or group of components could reduce radiation dose associated with inplace 42 calibration of sensors, reduce wear on equipment, reduce unnecessary burden on plant staff, 43 and reduce opportunities for calibration errors.
44 45
2.2 PROPOSED CHANGE
S TO THE TECHNICAL SPECIFICATIONS 46 47 Currently, the Channel Calibration(( and Channel Functional Test] OR [, COT, and TADOT))
48 may be performed by any series of sequential, overlapping or total channel steps. The 49 proposed changes to the TSs would revise the definitions of Channel Calibration(( and Channel 50 Functional Test] OR [, COT, and TADOT)) to indicate that the step must be performed within
1 the most limiting frequency for the components included in that step by adding the words , and 2 each step must be performed within the Frequency in the Surveillance Frequency Control 3 Program for the devices included in the step at the end of the last sentence of each definition.
4 5 The following paragraph denotes the changes to the Channel Calibration definition. Changes 6 are shown in italics:
7 8 {NOTE: For B&W, CE, and GE plant designs use this paragraph.}
9 10 [A CHANNEL CALIBRATION shall be the adjustment, as necessary, of the 11 channel output such that it responds within the necessary range and 12 accuracy to known values of the parameter that the channel monitors. The 13 CHANNEL CALIBRATION shall encompass all devices in the channel 14 required for channel OPERABILITY and the CHANNEL FUNCTIONAL TEST.
15 Calibration of instrument channels with resistance temperature detector 16 (RTD) or thermocouple sensors may consist of an inplace qualitative 17 assessment of sensor behavior and normal calibration of the remaining 18 adjustable devices in the channel. The CHANNEL CALIBRATION may be 19 performed by means of any series of sequential, overlapping, or total 20 channel steps, and each step must be performed within the Frequency in 21 the Surveillance Frequency Control Program for the devices included in the 22 step.]
23 24 {NOTE: For Westinghouse plant designs use this paragraph.}
25 26 [A CHANNEL CALIBRATION shall be the adjustment, as necessary, of the 27 channel output such that it responds within the necessary range and 28 accuracy to known values of the parameter that the channel monitors. The 29 CHANNEL CALIBRATION shall encompass all devices in the channel 30 required for channel OPERABILITY. Calibration of instrument channels 31 with resistance temperature detector (RTD) or thermocouple sensors may 32 consist of an inplace qualitative assessment of sensor behavior and 33 normal calibration of the remaining adjustable devices in the channel. The 34 CHANNEL CALIBRATION may be performed by means of any series of 35 sequential, overlapping, or total channel steps, and each step must be 36 performed within the Frequency in the Surveillance Frequency Control 37 Program for the devices included in the step.]
38 39 {NOTE: For B&W, CE, and GE plant designs use this paragraph.}
40 41 [The following paragraph denotes the changes to the Channel Functional Test definition.
42 Changes are shown in italics:
43 44 ...The CHANNEL FUNCTIONAL TEST may be performed by means of any 45 series of sequential, overlapping, or total [channel] steps, and each step 46 must be performed within the Frequency in the Surveillance Frequency 47 Control Program for the devices included in the step.]
48 49 {NOTE: For Westinghouse plant designs use this paragraph.}
50
1 [The following paragraphs denote the changes to the COT and TADOT definitions.
2 Changes are shown in italics:
3 4 A COT shall be the injection of a simulated or actual signal into the channel 5 as close to the sensor as practicable to verify OPERABILITY of all devices 6 in the channel required for channel OPERABILITY. The COT shall include 7 adjustments, as necessary, of the required alarm, interlock, and trip 8 setpoints required for channel OPERABILITY such that the setpoints are 9 within the necessary range and accuracy. The COT may be performed by 10 means of any series of sequential, overlapping, or total channel steps, and 11 each step must be performed within the Frequency in the Surveillance 12 Frequency Control Program for the devices included in the step.
13 14 A TADOT shall consist of operating the trip actuating device and verifying 15 the OPERABILITY of all devices in the channel required for trip actuating 16 device OPERABILITY. The TADOT shall include adjustment, as necessary, 17 of the trip actuating device so that it actuates at the required setpoint 18 within the necessary accuracy. The TADOT may be performed by means of 19 any series of sequential, overlapping, or total channel steps, and each step 20 must be performed within the Frequency in the Surveillance Frequency 21 Control Program for the devices included in the step.]
22 23 The various instrumentation functions in the TSs require surveillances to verify the correct 24 functioning of the instrument channel. The proposed change extends the definition of 25 instrumentation channel components to permit the surveillance frequency of each step to be 26 determined under the SFCP based on the component(s) surveilled in the step instead of all 27 components in the channel. This will allow each component to be tested at the appropriate 28 frequency based on the components long-term performance characteristics.
29 30 The proposed changes in the definition for instrument testing would allow the licensee to control 31 the frequency of associated components being tested in each step. The SR for the overall 32 instrumentation channel remains unchanged. The proposed change has no effect on the 33 design, fabrication, use, or methods of testing the instrumentation channels and will not affect 34 the ability of the instrumentation to perform the functions assumed in the safety analysis.
35 36 These instrumentation testing definitions state that, [t]he [test type] may be performed by 37 means of any series of sequential, overlapping, or total channel steps. The surveillance 38 frequency of these subsets would be established based on the characteristics of the 39 components in the step rather than the most limiting component characteristics in the entire 40 channel. Each of these steps are evaluated in accordance with the SFCP.
41 42 2.2.1 Variations from TSTF-563 43 44 {NOTE: Technical reviewers and/or project manager are to assess the adequacy of any 45 variations from the approved traveler and document their acceptability. Choose the applicable 46 paragraphs based on information provided in the LAR.}
47 48 [The licensee is proposing the following variations from the TS changes described in 49 TSTF-563 or the applicable parts of the NRC staffs SE of TSTF-563. [Describe the
1 variations and why TSTF-563 is still applicable.] These variations do not affect the 2 applicability of TSTF-563 or the NRC staff's SE to the proposed LAR.]
3 4 [The [PLANT] TSs utilize different [numbering][and][titles] than the Standard Technical 5 Specifications on which TSTF-563 was based. Specifically, [describe differences 6 between the plant-specific TS numbering and/or titles and the TSTF-563 numbering 7 and/or titles.] These differences are editorial and do not affect the applicability of 8 TSTF-563 to the proposed LAR.]
9 10 [The [PLANT] design is different than the model plant assumed in the Standard Technical 11 Specifications, but the TSTF-563 justification and the NRC staff's SE are still applicable.
12 [Describe differences and why TSTF-563 is still applicable.))
13 14 2.3 APPLICABLE REGULATORY REQUIREMENTS AND GUIDANCE 15 16 Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36(a)(1) requires each 17 applicant for a license authorizing operation of a utilization facility to include in the application 18 proposed TSs.
19 20 The regulation at 10 CFR 50.36(b) requires:
21 22 Each license authorizing operation of a utilization facility will include 23 technical specifications. The technical specifications will be derived from the 24 analyses and evaluation included in the safety analysis report, and amendments 25 thereto, submitted pursuant to [10 CFR] 50.34 [Contents of applications; 26 technical information]. The Commission may include such additional technical 27 specifications as the Commission finds appropriate.
28 29 The categories of items required to be in the TSs are provided in 10 CFR 50.36(c). One such 30 category is SRs, which are defined in 10 CFR 50.36(c)(3) as requirements relating to test, 31 calibration, or inspection to assure that the necessary quality of systems and components is 32 maintained, that facility operation will be within safety limits, and that the limiting conditions for 33 operation will be met.
34 35 The regulation at 10 CFR 50.36(c)(5) requires TSs to include administrative controls, which are 36 the provisions relating to organization and management, procedures, recordkeeping, review and 37 audit, and reporting necessary to assure operation of the facility in a safe manner.
38 39 Traveler TSTF-425 revised and relocated most periodic surveillance frequencies to licensee 40 control. Changes to the relocated surveillance frequencies are made in accordance with the 41 SFCP. The SFCP requires that changes to the relocated frequencies be made in accordance 42 with NRC staff approved topical report NEI 04-10.
43 44 Topical report NEI 04-10 describes an evaluation process and a multi-disciplinary plant 45 decisionmaking panel that considers the detailed evaluation of proposed surveillance frequency 46 revisions. The evaluations are based on operating experience, test history, manufacturers 47 recommendations, codes and standards, and other deterministic factors, in conjunction with risk 48 insights. The evaluation considers all components being tested by the SR. Process elements 49 are included for determining the cumulative risk impact of the changes, updating the licensees
1 probabilistic risk assessment (PRA) models, and for imposing corrective actions, if necessary, 2 following implementation of a revised frequency.
3 4 The NRC staffs guidance for the review of TSs is in Chapter 16.0, Technical Specifications, of 5 NUREG-0800, Revision 3, Standard Review Plan for the Review of Safety Analysis Reports for 6 Nuclear Power Plants: LWR [Light-Water Reactor] Edition (SRP), March 2010 (ADAMS 7 Accession No. ML100351425). As described therein, as part of the regulatory standardization 8 effort, the NRC staff has prepared STS for each of the LWR nuclear designs. Accordingly, the 9 NRC staffs review includes consideration of whether the proposed changes are consistent with 10 the applicable reference STS (i.e., the current STS), as modified by NRC-approved Travelers.
11 In addition, the guidance states that comparing the change to previous STS can help clarify the 12 TS intent.
13 14 Regulatory Guide (RG) 1.174, Revision 2, An Approach for Using Probabilistic Risk 15 Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis 16 (ADAMS Accession No. ML100910006), describes an acceptable risk-informed approach for 17 assessing the nature and impact of proposed permanent licensing basis changes by 18 considering engineering issues and applying risk insights. This regulatory guide also provides 19 risk acceptance guidelines for evaluating the results of such evaluations.
20 21 RG 1.177, Revision 1, An Approach for Plant-Specific, Risk-Informed Decisionmaking:
22 Technical Specifications (ADAMS Accession No. ML100910008), describes an acceptable 23 risk-informed approach specifically for assessing proposed TS changes.
24 25 RG 1.200, An Approach for Determining the Technical Adequacy of Probabilistic Risk 26 Assessment Results for Risk-Informed Activities (ADAMS Accession No. ML090410014),
27 describes an acceptable approach for determining the technical adequacy of PRAs.
28 29 The NRC staffs guidance for evaluating the technical basis for proposed risk-informed 30 changes is provided in SRP, Chapter 19, Section 19.2, Review of Risk Information Used to 31 Support Permanent Plant-Specific Changes to the Licensing Basis: General Guidance 32 (ADAMS Accession No. ML071700658). The NRC staffs guidance on evaluating PRA 33 technical adequacy is provided in SRP, Chapter 19, Section 19.1, Revision 3, Determining the 34 Technical Adequacy of Probabilistic Risk Assessment for Risk-Informed License Amendment 35 Requests After Initial Fuel Load (ADAMS Accession No. ML12193A107). More specific 36 guidance related to risk-informed TS changes is provided in SRP, Chapter 16, Section 16.1, 37 Revision 1, Risk-Informed Decision Making: Technical Specifications (ADAMS Accession 38 No. ML070380228), which includes changes to surveillance test intervals (STIs) (i.e.,
39 surveillance frequencies) as part of risk-informed decisionmaking. Section 19.2 of the SRP 40 references the same criteria as RG 1.177, Revision 1, and RG 1.174, Revision 2, and states 41 that a risk-informed application should be evaluated to ensure that the proposed changes meet 42 the following key principles:
43 44
- The proposed change meets the current regulations, unless it explicitly relates to a 45 requested exemption or rule change.
46 47
- The proposed change is consistent with the defense-in-depth philosophy.
48 49
- The proposed change maintains sufficient safety margins.
50
1
- When proposed changes result in an increase in risk associated with core damage 2 frequency or large early release frequency, the increase(s) should be small and 3 consistent with the intent of the Commissions Safety Goal Policy Statement.
4 5
- The impact of the proposed change should be monitored using performance 6 measurement strategies.
7 8 {NOTE: Choose applicable STS}
9 [U.S. Nuclear Regulatory Commission, Standard Technical Specifications, Babcock and 10 Wilcox Plants, NUREG-1430, Volume 1, Specifications, and Volume 2, Bases, 11 Revision 4.0, dated April 2012 (ADAMS Accession Nos. ML12100A177 and ML12100A178, 12 respectively).
13 14 U.S. Nuclear Regulatory Commission, Standard Technical Specifications, Westinghouse 15 Plants, NUREG-1431, Volume 1, Specifications, and Volume 2, Bases, Revision 4.0, 16 dated April 2012 (ADAMS Accession Nos. ML12100A222 and ML12100A228, respectively).
17 18 U.S. Nuclear Regulatory Commission, Standard Technical Specifications, Combustion 19 Engineering Plants, NUREG-1432, Volume 1, Specifications, and Volume 2, Bases, 20 Revision 4.0, dated April 2012 (ADAMS Accession Nos. ML12102A165 and ML12102A169, 21 respectively).
22 23 U.S. Nuclear Regulatory Commission, Standard Technical Specifications, General 24 Electric BWR/4 Plants NUREG-1433, Volume 1, Specifications, and Volume 2, Bases, 25 Revision 4.0, dated April 2012 (ADAMS Accession Nos. ML12104A192 and ML12104A193, 26 respectively).
27 28 U.S. Nuclear Regulatory Commission, Standard Technical Specifications, General 29 Electric BWR/6 Plants NUREG-1434, Volume 1, Specifications, and Volume 2, Bases, 30 Revision 4.0, dated April 2012 (ADAMS Accession Nos. ML12104A195 and ML12104A196, 31 respectively).]
32 33
3.0 TECHNICAL EVALUATION
34 35 Revising the frequency of a Channel Calibration(( and Channel Functional Test] OR [, COT, 36 and TADOT)) instrument channel under the SFCP requires assurance that component 37 performance characteristics, such as drift between each test, will not result in undetected 38 instrument errors that exceed the assumptions of the safety analysis and supporting instrument 39 loop uncertainty calculations. These requirements are consistent with the methodology 40 described in NEI 04-10, which the SFCP requires to be followed. The SFCP does not permit 41 changes to the TS Allowable Values or Nominal Trip Setpoints; but allows only the surveillance 42 frequency to be changed when determined permissible by NEI 04-10. Therefore, prior to 43 extending the test intervals for an instrument channel component or components associated 44 with a given calibration step, the component performance characteristics must be evaluated to 45 verify the Allowable Value or Nominal Trip Setpoint will still be valid and to establish a firm 46 technical basis supporting the extension. In addition, each change must be reviewed by the 47 licensee to ensure the applicable uncertainty allowances are conservative (bounding) (e.g.,
48 sensor drift, rack drift, indicator drift). Documentation to support the changes shall be retained 49 per the guidance in NEI 04-10.
50
1 Five key safety principles that must be evaluated before changing any surveillance frequency 2 are identified in Section 3.0 of NEI 04-10. Principle 3 requires confirmation of the maintenance 3 of safety margins, which, in this case, includes performance of deterministic evaluations to 4 verify preservation of instrumentation trip setpoint and indication safety margins.
5 6 The evaluation methodology specified in NEI 04-10 also requires consideration of common 7 cause failure effects and monitoring of the instrument channel component performance 8 following the frequency change to ensure channel performance is consistent with the analysis to 9 support an extended frequency.
10 11 The method of evaluating a proposed surveillance frequency change is not dependent on the 12 number of components in the channel. Each step needs to be evaluated to determine the 13 acceptable surveillance frequency for that step. The proposed change to permit changing the 14 surveillance frequency of channel component(s) does not affect the test method or evaluation 15 method. The requirement to perform a Channel Calibration, Channel Functional Test, COT, or 16 TADOT on the entire channel is not changed.
17 18 For example, an evaluation in accordance with NEI 04-10 may determine that a field sensor 19 (e.g., a transmitter) should be calibrated every 48 months, the rack modules should be 20 calibrated every 30 months, and the indicators should be calibrated every 24 months. Under 21 the current TS requirements, all devices in the channel must be calibrated every 24 months.
22 However, under the proposed change, sensors, rack modules, and indicators would be 23 calibrated at the appropriate frequency for the tested devices. As required by the Channel 24 Calibration definition, the test would still encompass all devices in the channel required for 25 channel operability.
26 27 The NEI 04-10 methodology is used to evaluate surveillance frequency changes to determine if 28 such SR extensions could be applied. Process elements are used to determine the cumulative 29 risk impact of changes, updating the PRA, and imposition of corrective actions, if needed, 30 following implementation. Several steps are required by NEI 04-10, Step 7, to be evaluated 31 prior to determining the acceptability of changes. These steps include history of surveillance 32 tests, industry and plant specific history, impact on defense-in-depth, vendor recommendations, 33 required test frequencies for the applicable codes and standards, ensuring that plant licensing 34 basis would not be invalidated and other factors. The NRC staff finds these measures 35 acceptable in determining the SR extensions.
36 37 In addition, Step 16 of Section 4.0 of NEI 04-10 requires an Independent Decisionmaking Panel 38 (IDP) to review the cumulative impact of all STI changes over a period of time. This is also 39 required by RGs 1.174 and 1.177. The IDP is comprised of the site Maintenance Rule Expert 40 Panel, Surveillance Test Coordinator, and Subject Matter Expert who is a cognizant system 41 manager or component engineer. Based on the above information, the NRC staff finds that the 42 setpoint changes will be tracked in an acceptable manner.
43 44 Licensees with an SFCP may currently revise the surveillance frequency of instrumentation 45 channels. The testing of these channels may be performed by means of any series, sequential, 46 overlapping, or total channel steps. However, all required components in the instrumentation 47 channel must be tested in order for the entire channel to be considered Operable.
48 49 The NRC staff notes that industry practice is to perform instrument channel surveillances, such 50 as Channel Calibrations and Channel Functional Tests, using separate procedures based on
1 the location of the components. Each of these procedures may be considered a step. The 2 results of all these procedures are used to satisfy the SR using the existing allowance to 3 perform it by means of any series of sequential, overlapping, or total channel steps. The 4 proposed changes would allow for determining an acceptable surveillance frequency for each 5 step.
6 7 The NRC staff notes that the NEI 04-10 methodology includes the determination of whether the 8 structure, system, and components (SSCs) affected by a proposed change to a surveillance 9 frequency are modeled in the PRA. Where the SSC is directly or implicitly modeled, a 10 quantitative evaluation of the risk impact may be carried out. The methodology adjusts the 11 failure probability of the impacted SSCs based on the proposed change to the surveillance 12 frequency. Where the SSC is not modeled in the PRA, bounding analyses are performed to 13 characterize the impact of the proposed change to the surveillance frequency. Potential 14 impacts on the risk analyses due to screening criteria and truncation levels are addressed by 15 the requirements for PRA technical adequacy, consistent with the guidance contained in 16 RG 1.200, and by sensitivity studies identified in NEI 04-10. The licensee is not proposing to 17 change the methodology, or the acceptance criteria for extending STIs, and licensees will need 18 to changes in the frequency for performing each of the steps in the instrumentation surveillance 19 test per the methodology in NEI 04-10.
20 21 Therefore, the NRC staff concludes that the proposed change determine an acceptable test 22 frequency for individual steps within instrumentation channel surveillance tests is acceptable 23 because any extended STIs will be developed within the established constraints of the 24 SFCP and NEI 04-10.
25 26 The regulatory requirements in 10 CFR 50.36 are not specific regarding the frequency of 27 performing surveillance tests. The proposed change only affects the frequency of performance 28 and does not affect the surveillance testing method or acceptance criteria. Therefore, the 29 proposed change is consistent with the surveillance testing requirements of 10 CFR 50.36.
30 31 PRA Acceptability 32 33 The guidance in RG 1.200 states that the quality of a licensees PRA should be commensurate 34 with the safety significance of the proposed TS change and the role the PRA plays in justifying 35 the change. That is, the greater the change in risk or the greater the uncertainty in that risk as a 36 result of the requested TS change, or both, the more rigor that should go into ensuring the 37 quality of the PRA.
38 39 The NRC staff will have performed an assessment of the PRA models used to support the 40 approved SFCP that uses NEI 04-10, using the guidance of RG 1.200 to assure that the PRA 41 models are capable of determining the change in risk due to changes to surveillance 42 frequencies of SSCs, using plant-specific data and models. Capability Category II of the NRC-43 endorsed PRA standard is the target capability level for supporting requirements for the internal 44 events PRA for this application. Any identified deficiencies to those requirements are assessed 45 further to determine any impacts to proposed decreases to surveillance frequencies, including 46 the use of sensitivity studies where appropriate, in accordance with NEI 04-10.
47 48 The SFCP permits revising of the surveillance frequency for instrumentation channels. The 49 NRC staff evaluated whether NEI 04-10 can be applied to subsets in an instrument channel 50 when the SFCP currently specifies a surveillance interval that is applied to the entire channel.
1 The NRC staff notes that the current channel surveillance may be performed by means of any 2 series of sequential, overlapping, or total channel steps. In practice, this means that a channel 3 is divided into subsets and each subset is tested separately. Therefore, the current instrument 4 channel testing is already composed of a sequence of individual tests.
5 6 The instrument function may be modeled in the PRA differently depending on the site and the 7 function (e.g., channel may be modeled individually, subsets may be modeled, or the channel 8 function may be modeled as a single entity). There are different steps through the evaluation 9 methodology in NEI 04-10 that could be used based on the different PRA modeling approaches.
10 The appropriate modeling of these different approaches is included in the NRC staffs review of 11 the PRA modeling during the review of the application to implement an SFCP that uses 12 NEI 04-10.
13 14 The licensee is using a PRA that was used to support their application that implemented an 15 SFCP that uses NEI 04-10. The amendment will change the capability of the licensee to 16 change the surveillance frequency of an entire channel to now change the frequency of each 17 subset of the channel. The NRC staff finds that changes to the surveillance frequency caused 18 by defining and using individual, testable component subsets can be appropriately evaluated 19 with the current SFCP and the current PRAs. The NRC staff finds that the risk-informed 20 methodology review and the PRA acceptability review that was performed during the review of 21 the licensees application to implement an SFCP that uses NEI 04-10 is adequate.
22 23 The NRC staff determined that the proposed changes to the TS meet the standards for TS in 24 10 CFR 50.36(b). The regulations at 10 CFR 50.36 require that TSs include items in specified 25 categories, including SRs. The proposed changes modify the definitions applicable to 26 instrumentation channel components but do not alter the technical approach that was approved 27 by the NRC in NEI 04-10, and the TSs, as revised, continue to specify the appropriate SRs for 28 tests and inspections to ensure the necessary quality of affected SSCs is maintained.
29 30 Additionally, the changes to the TS were reviewed and found to be technically clear and 31 consistent with customary terminology and format in accordance with SRP Chapter 16.0. The 32 NRC staff reviewed the proposed changes against the regulations and concludes that the 33 changes continue to meet the requirements of Sections 50.36(b), 50.36(c)(3), and 50.36(c)(5),
34 of 10 CFR, for the reasons discussed above, and thus provide reasonable assurance that 35 adoption of these TSs will have the requisite requirements and controls to operate safely.
36 Therefore, the NRC staff concludes that the proposed TS changes are acceptable.
37 38 [3.1 VARIATIONS FROM TSTF-563 39 40 The licensee described variations from TSTF-563 in Section 2.2 of the LAR. The licensee 41 provided justification for the proposed variations and exceptions. The staff reviewed the 42 justifications and concluded the variations are [not] acceptable because.
43 44 The [PLANT] TSs utilize different [numbering][and][titles] than the Standard Technical 45 Specifications on which TSTF-563 was based. The NRC staff agrees these differences 46 are editorial and do not affect the applicability of TSTF-563 to the proposed LAR.]
47 48
4.0 STATE CONSULTATION
49 50 {This section is to be prepared by the plant project manager.}
1 2 In accordance with the Commissions regulations, the [Name of State] State official was notified 3 of the proposed issuance of the amendment(s) on [date]. The State official had [no]
4 comments. [If comments were provided, they should be addressed here.]
5 6
5.0 ENVIRONMENTAL CONSIDERATION
7 8 {This section is to be prepared by the plant project manager in accordance with current 9 procedures.}
10 11
6.0 CONCLUSION
12 13 {This section is to be prepared by the plant project manager.}
14 15 The Commission has concluded, based on the considerations discussed above, that: (1) there 16 is reasonable assurance that the health and safety of the public will not be endangered by 17 operation in the proposed manner, (2) there is reasonable assurance that such activities will be 18 conducted in compliance with the Commissions regulations, and (3) the issuance of the 19 amendment(s) will not be inimical to the common defense and security or to the health and 20 safety of the public.
21 22
7.0 REFERENCES
23 24 {Optional section to be prepared by the PM and primary reviewers. If document is publicly 25 available, the ADAMS Accession No. should be listed.}
26 27 {NOTE: These are the principal contributors for the model SE of the traveler. Replace these 28 names with those who prepared the plant-specific SE.}
29 30 Principal Contributors: M. Chernoff, NRR/DSS 31 G. Singh, NRR/DE 32 J. Evans, NRR/DRA 33 34 Date: September 20, 2018