TSTF-18-11, TSTF Comments on Draft Safety Evaluation for Traveler TSTF-563, Revision 0, Revise Instrument Testing Definitions to Incorporate the Surveillance Frequency Control Program
| ML18285A088 | |
| Person / Time | |
|---|---|
| Site: | Technical Specifications Task Force |
| Issue date: | 10/12/2018 |
| From: | Gullott D, Joyce R, Miksa J, Sparkman W, Vaughan J BWR Owners Group, PWR Owners Group, Technical Specifications Task Force |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TSTF-18-11 | |
| Download: ML18285A088 (28) | |
Text
11921 Rockville Pike, Suite 100, Rockville, MD 20852 Phone: 301-984-4400, Fax: 301-984-7600 Administration by EXCEL Services Corporation TECHNICAL SPECIFICATIONS TASK FORCE A JOINT OWNERS GROUP ACTIVITY TSTF October 12, 2018 TSTF-18-11 PROJ0753 Attn: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
TSTF Comments on Draft Safety Evaluation for Traveler TSTF-563, Revision 0, "Revise Instrument Testing Definitions to Incorporate the Surveillance Frequency Control Program"
REFERENCE:
Letter Victor Cusumano (NRC) to the TSTF, "Draft Safety Evaluation of Technical Specifications Task Force Traveler TSTF-563, Revision 0, 'Revise Instrument Testing Definitions to Incorporate the Surveillance Frequency Control Program'," dated September 20, 2018 (ADAMS Accession No. ML18226A327).
On May 10, 2017, the TSTF submitted traveler TSTF-563, Revision 0, "'Revise Instrument Testing Definitions to Incorporate the Surveillance Frequency Control Program," to the Nuclear Regulatory Commission (NRC) for review (Agencywide Documents Access and Management System (ADAMS) Accession No. ML17130A819). In the referenced letter, the NRC provided the draft Safety Evaluations for TSTF-563 for comment. contains a summary table providing the TSTF's comments on the draft Safety Evaluations. Attachment 2 contains a mark-up reflecting the TSTF's comments.
Should you have any questions, please do not hesitate to contact us.
James P. Miksa (PWROG/CE)
Ryan M. Joyce (BWROG)
David M. Gullott (PWROG/W)
Jordan L. Vaughan (PWROG/B&W)
Wesley Sparkman (APOG)
TSTF Comments on the TSTF-563 Draft Safety Evaluations TSTF Markup of Draft Safety Evaluations cc:
Michelle Honcharik, Technical Specifications Branch, NRC Victor Cusumano, Technical Specifications Branch, NRC
Page 3 TSTF Comments on the TSTF-563 Draft Safety Evaluations General Comments
- 1. The traveler SE states that the change is not applicable to AP1000 plants. NUREG-2194 was included in the traveler and the Request for Additional Information did not question its inclusion. There is no technical difference between the application of TSTF-563 to AP1000 plants and other plant designs. AP1000 plants should not be excluded from the traveler.
The footnote is revised to state that incorporation of TSTF-563 into a future revision of NUREG-2194 is dependent on incorporation of a Surveillance Frequency Control Program (SFCP).
AP1000 plants should not be excluded from the model Safety Evaluation because the traveler can only be adopted by plants that have an SFCP. If an AP1000 plant has previously adopted an SFCP, then TSTF-563 is applicable.
- 2. Changes "TSs" to "TS." The term Technical Specifications is already plural.
Page 4 Comments on the TSTF-563 Traveler Draft Safety Evaluation Page(s)
Line(s)1 Comment 1
20-21, 22-23 and footnote General Comment 1.
2 17 Editorial change. The word "are" appears to be missing.
2 19,28 General Comment 2.
3 5-6 General Comment 1.
3 25 General Comment 1.
3 34 General Comment 1.
4 4
General Comment 2.
5 18, 24, 42 General Comment 2.
8 45 General Comment 2.
9 34 Editorial change. Revise "evaluated" to "evaluate."
10 48 General Comment 1.
10 49, 50 General Comment 2.
11 11 General Comment 2.
1 Line numbers correspond to the attached proposed revision, not to the documents provided by the NRC.
Page 5 Comments on the TSTF-563 Draft Model Safety Evaluation Page(s)
Line(s)2 Comment 1
39 Defined SFCP.
2 12, 15, 25, 49 General Comment 2.
2 14-15 It is more accurate to refer to the plant-specific amendment that revised the plant's TS to incorporate an SFCP than to refer to TSTF-425, which only revised the STS.
4 23 General Comment 2.
5 4, 19, 30, 36 General Comment 2.
5 10-11 The model SE example variation refers to differences in the plant design.
TSTF-563 is not dependent on the design. The model application refers to plant TS different from the STS, as wording differences in the affected definitions could be relevant to the change. Revisions to the model SE are provided.
5 40 It is more accurate to refer to the plant-specific amendment that revised the plant's TS to incorporate an SFCP than to refer to TSTF-425, which only revised the STS.
6 4
General Comment 2.
7 32-36 General Comment 1.
10 30, 33, 41 General Comment 2.
11 1
General Comment 2.
2 Line numbers correspond to the attached proposed revision, not to the documents provided by the NRC.
TSTF Markup of Draft Safety Evaluations DRAFT SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION 1
TECHNICAL SPECIFICATIONS TASK FORCE Traveler 2
TSTF-563, REVISION 0 3
REVISE INSTRUMENT TESTING DEFINITIONS TO INCORPORATE THE SURVEILLANCE 4
FREQUENCY CONTROL PROGRAM 5
USING THE CONSOLIDATED LINE ITEM IMPROVEMENT PROCESS 6
(CAC NO. MF9955, EPID L-2017-PMP-0006) 7 8
9
1.0 INTRODUCTION
10 11 By letter dated May 10, 2017 (Agencywide Documents Access and Management System 12 (ADAMS) Accession No. ML17130A819), the Technical Specifications Task Force (TSTF) 13 submitted Traveler TSTF-563, Revision 0, Revise Instrument Testing Definitions to Incorporate 14 the Surveillance Frequency Control Program. By letter dated April 27, 2018, the TSTF 15 responded to the U.S. Nuclear Regulatory Commission (NRC) staff requests for additional 16 information (RAIs) (ADAMS Accession No. ML18117A326). Traveler TSTF-563 proposes 17 changes to the Standard Technical Specifications (STS) for all plant designs, including 18 Babcock & Wilcox (B&W), Combustion Engineering (CE), Westinghouse, General Electric (GE),
19 and Westinghouse AP1000 plants. However, the NRC staff did not review and has not 20 approved this change for Westinghouse AP1000 plants. These changes will be incorporated 21 into future revisions of NUREG-1430, NUREG-1431, NUREG-1432, NUREG-1433, and 22 NUREG-1434, and NUREG-2194.1 This traveler will be made available to licensees for 23 adoption through the consolidated line item improvement process (CLIIP).
24 25 1 U.S. Nuclear Regulatory Commission, Standard Technical Specifications, Babcock and Wilcox Plants, NUREG-1430, Volume 1, Specifications, and Volume 2, Bases, Revision 4.0, April 2012 (ADAMS Accession Nos ML12100A177 and ML12100A178, respectively).
U.S. Nuclear Regulatory Commission, Standard Technical Specifications, Westinghouse Plants, NUREG-1431, Volume 1, Specifications, and Volume 2, Bases, Revision 4.0, April 2012 (ADAMS Accession Nos. ML12100A222 and ML12100A228, respectively).
U.S. Nuclear Regulatory Commission, Standard Technical Specifications, Combustion Engineering Plants, NUREG-1432, Volume 1, Specifications, and Volume 2, Bases, Revision 4.0, April 2012 (ADAMS Accession Nos. ML12102A165 and ML12102A169, respectively).
U.S. Nuclear Regulatory Commission, Standard Technical Specifications, General Electric, BWR/4 Plants, NUREG-1433, Volume 1, Specifications, and Volume 2, Bases, Revision 4.0, April 2012 (ADAMS Accession Nos. ML12104A192 and ML12104A193, respectively).
U.S. Nuclear Regulatory Commission, Standard Technical Specifications, General Electric BWR/6 Plants, NUREG-1434, Volume 1, Specifications, and Volume 2, Bases, Revision 4.0, April 2012 (ADAMS Accession Nos. ML12104A195 and ML12104A196, respectively).
U.S. Nuclear Regulatory Commission, Standard Technical Specifications, Westinghouse Advanced Passive (AP1000) Plants, NUREG-2194, Volume 1, Specifications, and Volume 2, Bases, Revision 4.0, April 2016 (ADAMS Accession Nos. ML16110A277 and ML16110A369, respectively). (Incorporation of TSTF-563 into a future revision of NUREG-2194 is dependent on incorporation of a Surveillance Frequency Control Program.)
The proposed changes would revise the current instrumentation testing definitions of Channel 1
Calibration, Channel Functional Test, Channel Operational Test (COT), and Trip Actuation 2
Device Operational Test (TADOT) to permit determination of the appropriate frequency to 3
perform the Surveillance Requirement (SR) based on the devices being tested in each step, for 4
those plants that have an approved Surveillance Frequency Control Program (SFCP) that uses 5
Nuclear Energy Institute (NEI) 04-10, Revision 1, Risk-Informed Method for Control of 6
Surveillance Frequencies, (ADAMS Accession No. ML071360456). NEI 04-10, Revision 1, 7
was approved by the NRC on September 19, 2007 (ADAMS Accession No. ML072570267).
8 Traveler TSTF-425, Revision 3, Relocate Surveillance Frequencies to Licensee Control -
9 RITSTF [Risk-Informed TSTF] Initiative 5b, provided a model for incorporating an SFCP into 10 the STS. Traveler TSTF-425, Revision 3, was approved by the NRC staff on June 23, 2009 11 (ADAMS Accession No. ML090900716).
12 13
2.0 REGULATORY EVALUATION
14 15
2.1 DESCRIPTION
OF SURVEILLANCE FREQUENCY CONTROL PROGRAM AND 16 INSTRUMENT TESTING 17 18 The STS state the surveillances for instrumentation channels are to be performed within the 19 specified frequency, using any series of sequential, overlapping, or total channel steps.
20 Traveler TSTF-425 revised the TSs to relocate all periodic surveillance frequencies to licensee 21 control. Changes to the relocated surveillance frequencies are made in accordance with the TS 22 program referred to as the SFCP. The SFCP allows a new surveillance frequency to be 23 determined for the channel, but that frequency must consider all components in the channel and 24 applies to the entire channel.
25 26 A typical instrument channel consists of many different components, such as sensors, rack 27 modules, and indicators. These components have different short-term and long-term 28 performance (drift) characteristics, resulting in the potential for different calibration frequency 29 requirements. Under the current TSs, the most limiting component calibration frequency for the 30 channel must be chosen when a revised frequency is considered under the SFCP. As a result, 31 all components that make up a channel must be calibrated at a frequency equal to the channel 32 component with the shortest (i.e., most frequent) surveillance frequency.
33 34 Some channel components, such as pressure transmitters, are very stable with respect to drift 35 and could support a substantially longer calibration frequency than the other components in the 36 channel. Currently, the SRs in many plants are performed in steps (e.g., a pressure sensor or 37 transmitter is calibrated during a refueling outage and the rack signal conditioning modules are 38 calibrated while operating at power). The proposed change extends this concept to permit the 39 surveillance frequency of each step to be determined under the SFCP based on the 40 component(s) surveilled in the step instead of all components in the channel. This will allow 41 each component to be tested at the appropriate frequency based on the components long-term 42 performance characteristics.
43 44 Allowing an appropriate surveillance frequency for performing a channel calibration on each 45 component or group of components could reduce radiation dose associated with inplace 46 calibration of sensors, reduce wear on equipment, reduce unnecessary burden on plant staff, 47 and reduce opportunities for calibration errors.
48 49
2.2 PROPOSED CHANGE
S TO THE STANDARD TECHNICAL SPECIFICATIONS 50 51 The proposed changes to the STS would revise the definitions of Channel Calibration, Channel 1
Functional Test, COT, and TADOT by adding the words, and each step must be performed 2
within the Frequency in the Surveillance Frequency Control Program for the devices included in 3
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 for all plant 6
designs (B&W, CE, GE, and Westinghouse plants, NUREG-1430 through NUREG-1434 and 7
NUREG-2194). The Westinghouse plant definition (NUREG-1431 and NUREG-2194) does not 8
include the phrase shown in brackets and the CHANNEL FUNCTIONAL TEST. Changes are 9
shown in italics:
10 11 A CHANNEL CALIBRATION shall be the adjustment, as necessary, of the 12 channel output such that it responds within the necessary range and accuracy to 13 known values of the parameter that the channel monitors. The CHANNEL 14 CALIBRATION shall encompass all devices in the channel required for channel 15 OPERABILITY[ and the CHANNEL FUNCTIONAL TEST]. Calibration of 16 instrument channels with resistance temperature detector (RTD) or thermocouple 17 sensors may consist of an inplace qualitative assessment of sensor behavior and 18 normal calibration of the remaining adjustable devices in the channel. The 19 CHANNEL CALIBRATION may be performed by means of any series of 20 sequential, overlapping, or total channel steps [, and each step must be 21 performed within the Frequency in the Surveillance Frequency Control Program 22 for the devices included in the step].
23 24 The following paragraph denotes the changes to the Channel Functional Test definition for 25 B&W, CE, and GE plant designs (NUREG-1430 and NUREG-1432 through NUREG-1434). In 26 the Westinghouse plant definition (NUREG-1431 and NUREG-2194), the Channel Functional 27 Test is replaced with two tests: the COT and the TADOT. Changes are shown in italics:
28 29
...The CHANNEL FUNCTIONAL TEST may be performed by means of any 30 series of sequential, overlapping, or total [channel] steps [, and each step must 31 be performed within the Frequency in the Surveillance Frequency Control 32 Program for the devices included in the step].
33 34 The following paragraphs denote the changes of the COT and TADOT definitions for 35 Westinghouse plants (NUREG-1431 and NUREG-2194). Changes are shown in italics:
36 37 A COT shall be the injection of a simulated or actual signal into the channel as 38 close to the sensor as practicable to verify OPERABILITY of all devices in the 39 channel required for channel OPERABILITY. The COT shall include 40 adjustments, as necessary, of the required alarm, interlock, and trip setpoints 41 required for channel OPERABILITY such that the setpoints are within the 42 necessary range and accuracy. The COT may be performed by means of any 43 series of sequential, overlapping, or total channel steps [, and each step must be 44 performed within the Frequency in the Surveillance Frequency Control Program 45 for the devices included in the step].
46 47 A TADOT shall consist of operating the trip actuating device and verifying the 48 OPERABILITY of all devices in the channel required for trip actuating device 49 OPERABILITY. The TADOT shall include adjustment, as necessary, of the trip 50 actuating device so that it actuates at the required setpoint within the necessary 51 accuracy. The TADOT may be performed by means of any series of sequential, 1
overlapping, or total channel steps [, and each step must be performed within the 2
Frequency in the Surveillance Frequency Control Program for the devices 3
included in the step].
4 5
The various instrumentation functions in the TSs require surveillances to verify the correct 6
functioning of the instrument channel. The proposed change extends the definition of 7
instrumentation channel components to permit the surveillance frequency of each step to be 8
determined under the SFCP based on the component(s) surveilled in the step instead of all 9
components in the channel. This will allow each component to be tested at the appropriate 10 frequency based on the components long-term performance characteristics.
11 12 The proposed changes in the definition for instrument testing would allow the licensee to control 13 the frequency of associated components being tested in each step. The SR for the overall 14 instrumentation channel remains unchanged. The proposed change has no effect on the 15 design, fabrication, use, or methods of testing the instrumentation channels and will not affect 16 the ability of the instrumentation to perform the functions assumed in the safety analysis.
17 18 Traveler TSTF-563 distinguished between instrumentation SRs (Channel Calibration, Channel 19 Functional Test, COT, and TADOT) and other SRs. These instrumentation testing definitions 20 state that, [t]he [test type] may be performed by means of any series of sequential, overlapping, 21 or total channel steps. Traveler TSTF-563 proposed the surveillance frequency of these 22 subsets to be established based on the characteristics of the components in the step rather than 23 the most limiting component characteristics in the entire channel. Each of these steps are 24 evaluated in accordance with the SFCP.
25 26 2.3 APPLICABLE REGULATORY REQUIREMENTS AND GUIDANCE 27 28 Section IV, The Commission Policy, of the Final Policy Statement on Technical Specifications 29 Improvements for Nuclear Power Reactors, published in the Federal Register on July 22, 1993 30 (58 FR 39132), states, in part:
31 32 The purpose of Technical Specifications is to impose those conditions or 33 limitations upon reactor operation necessary to obviate the possibility of an 34 abnormal situation or event giving rise to an immediate threat to the public health 35 and safety by identifying those features that are of controlling importance to 36 safety and establishing on them certain conditions of operation which cannot be 37 changed without prior Commission approval.
38 39
[T]he Commission will also entertain requests to adopt portions of the 40 improved STS [(e.g., TSTF-563)], even if the licensee does not adopt all STS 41 improvements. The Commission encourages all licensees who submit 42 Technical Specification related submittals based on this Policy Statement to 43 emphasize human factors principles.
44 45 In accordance with this Policy Statement, improved STS have been developed 46 and will be maintained for each NSSS [nuclear steam supply system] owners 47 group. The Commission encourages licensees to use the improved STS as the 48 basis for plant-specific Technical Specifications. [I]t is the Commission intent 49 that the wording and Bases of the improved STS be used to the extent 50 practicable.
51 1
As described in the Commissions Final Policy Statement on Technical Specifications 2
Improvements for Nuclear Power Reactors, the NRC and industry task groups for new STS 3
recommend that improvements include greater emphasis on human factors principles in order to 4
add clarity and understanding to the text of the STS, and provide improvements to the Bases of 5
STS, which provides the purpose for each requirement in the specification. The improved 6
vendor-specific STS were developed and issued by the NRC in September 1992.
7 8
The regulation at Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36(b) 9 requires:
10 11 Each license authorizing operation of a utilization facility will include 12 technical specifications. The technical specifications will be derived from the 13 analyses and evaluation included in the safety analysis report, and amendments 14 thereto, submitted pursuant to [10 CFR] 50.34 [Contents of applications; 15 technical information]. The Commission may include such additional technical 16 specifications as the Commission finds appropriate.
17 18 The categories of items required to be in the TSs are provided in 10 CFR 50.36(c). One such 19 category is SRs, which are defined in 10 CFR 50.36(c)(3) as requirements relating to test, 20 calibration, or inspection to assure that the necessary quality of systems and components is 21 maintained, that facility operation will be within safety limits, and that the limiting conditions for 22 operation will be met.
23 24 The regulation at 10 CFR 50.36(c)(5) requires TSs to include administrative controls, which are 25 the provisions relating to organization and management, procedures, recordkeeping, review and 26 audit, and reporting necessary to assure operation of the facility in a safe manner.
27 28 Traveler TSTF-425 revised and relocated most periodic surveillance frequencies to licensee 29 control. Changes to the relocated surveillance frequencies are made in accordance with the 30 SFCP. The SFCP requires that changes to the relocated frequencies be made in accordance 31 with the NRC staff approved topical report NEI 04-10.
32 33 Topical report NEI 04-10 describes an evaluation process and a multi-disciplinary plant 34 decisionmaking panel that considers the detailed evaluation of proposed surveillance frequency 35 revisions. The evaluations are based on operating experience, test history, manufacturers 36 recommendations, codes and standards, and other deterministic factors, in conjunction with risk 37 insights. The evaluation considers all components being tested by the SR. Process elements 38 are included for determining the cumulative risk impact of the changes, updating the licensees 39 probabilistic risk assessment (PRA) models, and for imposing corrective actions, if necessary, 40 following implementation of a revised frequency.
41 42 The NRC staffs guidance for the review of TSs is in Chapter 16.0, Technical Specifications, of 43 NUREG-0800, Revision 3, Standard Review Plan for the Review of Safety Analysis Reports for 44 Nuclear Power Plants: LWR [Light-Water Reactor] Edition (SRP), March 2010 (ADAMS 45 Accession No. ML100351425). As described therein, as part of the regulatory standardization 46 effort, the NRC staff has prepared STS for each of the LWR nuclear designs. Accordingly, the 47 NRC staffs review includes consideration of whether the proposed changes are consistent with 48 the applicable reference STS (i.e., the current STS), as modified by NRC-approved Travelers.
49 In addition, the guidance states that comparing the change to previous STS can help clarify the 50 TS intent.
51 1
Regulatory Guide (RG) 1.174, Revision 2, An Approach for Using Probabilistic Risk 2
Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis 3
(ADAMS Accession No. ML100910006), describes an acceptable risk-informed approach for 4
assessing the nature and impact of proposed permanent licensing basis changes by 5
considering engineering issues and applying risk insights. This regulatory guide also provides 6
risk acceptance guidelines for evaluating the results of such evaluations.
7 8
RG 1.177, Revision 1, An Approach for Plant-Specific, Risk-Informed Decisionmaking:
9 Technical Specifications (ADAMS Accession No. ML100910008), describes an acceptable 10 risk-informed approach specifically for assessing proposed TS changes.
11 12 RG 1.200, An Approach for Determining the Technical Adequacy of Probabilistic Risk 13 Assessment Results for Risk-Informed Activities (ADAMS Accession No. ML090410014),
14 describes an acceptable approach for determining the technical adequacy of PRAs.
15 16 The NRC staffs guidance for evaluating the technical basis for proposed risk-informed 17 changes is provided in SRP, Chapter 19, Section 19.2, Review of Risk Information Used to 18 Support Permanent Plant-Specific Changes to the Licensing Basis: General Guidance 19 (ADAMS Accession No. ML071700658). The NRC staffs guidance on evaluating PRA 20 technical adequacy is provided in SRP, Chapter 19, Section 19.1, Revision 3, Determining the 21 Technical Adequacy of Probabilistic Risk Assessment for Risk-Informed License Amendment 22 Requests After Initial Fuel Load (ADAMS Accession No. ML12193A107). More specific 23 guidance related to risk-informed TS changes is provided in SRP, Chapter 16, Section 16.1, 24 Revision 1, Risk-Informed Decision Making: Technical Specifications (ADAMS Accession 25 No. ML070380228), which includes changes to surveillance test intervals (STIs) (i.e.,
26 surveillance frequencies) as part of risk-informed decisionmaking. Section 19.2 of the SRP 27 references the same criteria as RG 1.177, Revision 1, and RG 1.174, Revision 2, and states 28 that a risk-informed application should be evaluated to ensure that the proposed changes meet 29 the following key principles:
30 31 The proposed change meets the current regulations, unless it explicitly relates to a 32 requested exemption or rule change.
33 34 The proposed change is consistent with the defense-in-depth philosophy.
35 36 The proposed change maintains sufficient safety margins.
37 38 When proposed changes result in an increase in risk associated with core damage 39 frequency or large early release frequency, the increase(s) should be small and 40 consistent with the intent of the Commissions Safety Goal Policy Statement.
41 42 The impact of the proposed change should be monitored using performance 43 measurement strategies.
44 45
3.0 TECHNICAL EVALUATION
46 47 Revising the frequency of a Channel Calibration, Channel Functional Test, COT, and TADOT 48 instrument channel under the SFCP requires assurance that component performance 49 characteristics, such as drift between each test, will not result in undetected instrument errors 50 that exceed the assumptions of the safety analysis and supporting instrument loop uncertainty 1
calculations. These requirements are consistent with the methodology described in NEI 04-10, 2
which the SFCP requires to be followed. The SFCP does not permit changes to the TS 3
Allowable Values or Nominal Trip Setpoints; but allows only the surveillance frequency to be 4
changed when determined permissible by NEI 04-10. Therefore, prior to extending the test 5
intervals for an instrument channel component or components associated with a given 6
calibration step, the component performance characteristics must be evaluated to verify the 7
Allowable Value or Nominal Trip Setpoint will still be valid and to establish a firm technical basis 8
supporting the extension. In addition, each change must be reviewed by the licensee to ensure 9
the applicable uncertainty allowances are conservative (bounding) (e.g., sensor drift, rack drift, 10 indicator drift). Documentation to support the changes shall be retained per the guidance in 11 NEI 04-10.
12 13 In response to the NRC staff RAI, the TSTF identified that Section 4.0 of NEI 04-10, Steps 4, 7, 14 10a, 10b, 10c, 12, 14, 15, and 16, document the requirements pertaining to changing the SRs.
15 As an example, Step 4 requires documenting when STIs cannot be changed. These guidelines 16 include qualitative and quantitative measures to assess the acceptability of the change. Since 17 Traveler TSTF-425 and NEI 04-10 have been previously approved by the NRC, the explanation 18 provided is satisfactory and acceptable to NRC staff.
19 20 Five key safety principles that must be evaluated before changing any surveillance frequency 21 are identified in Section 3.0 of NEI 04-10. Principle 3 requires confirmation of the maintenance 22 of safety margins, which, in this case, includes performance of deterministic evaluations to 23 verify preservation of instrumentation trip setpoint and indication safety margins.
24 25 The evaluation methodology specified in NEI 04-10 also requires consideration of common 26 cause failure effects and monitoring of the instrument channel component performance 27 following the frequency change to ensure channel performance is consistent with the analysis to 28 support an extended frequency.
29 30 The method of evaluating a proposed surveillance frequency change is not dependent on the 31 number of components in the channel. Each step needs to be evaluated to determine the 32 acceptable surveillance frequency for that step. The proposed change to permit changing the 33 surveillance frequency of channel component(s) does not affect the test method or evaluation 34 method. The requirement to perform a Channel Calibration, Channel Functional Test, COT, or 35 TADOT on the entire channel is not changed.
36 37 For example, an evaluation in accordance with NEI 04-10 may determine that a field sensor 38 (e.g., a transmitter) should be calibrated every 48 months, the rack modules should be 39 calibrated every 30 months, and the indicators should be calibrated every 24 months. Under 40 the current TS requirements, all devices in the channel must be calibrated every 24 months.
41 However, under the proposed change, sensors, rack modules, and indicators would be 42 calibrated at the appropriate frequency for the tested devices. As required by the Channel 43 Calibration definition, the test would still encompass all devices in the channel required for 44 channel operability.
45 46 To address the issue of a potential extension of up to 48 months for field transmitters, the NRC 47 staff requested clarification regarding adequate data to support such long SR extensions. The 48 TSTF stated in the RAI response that NEI 04-10 methodology is used to evaluate surveillance 49 frequency changes to determine if such SR extensions could be applied. Process elements are 50 used to determine the cumulative risk impact of changes, updating the PRA, and imposition of 51 corrective actions, if needed, following implementation. Further, the applicant pointed to several 1
steps required by NEI 04-10, Step 7, to be evaluated prior to determining the acceptability of 2
changes. These steps include history of surveillance tests, industry and plant specific history, 3
impact on defense-in-depth, vendor recommendations, required test frequencies for the 4
applicable codes and standards, ensuring that the plant licensing basis would not be 5
invalidated, and other factors. The NRC staff finds these measures acceptable in determining 6
the SR extensions.
7 8
The NRC staff requested further information regarding the cumulative effect of various changes 9
on potential setpoint changes. The TSTF responded with the following:
10 11 The SFCP and NEI 04-10, Rev. 1, have no provisions to change 12 licensee-controlled setpoints, or TS values such as Allowable Values or Nominal 13 Trip Setpoints. If the surveillance frequency evaluation determines that the 14 proposed frequency would require a change to a TS limit, the change cannot be 15 made. If the proposed surveillance frequency change affects a 16 licensee-controlled setpoint (i.e., not a TS limit), the licensee would perform the 17 setpoint change following their procedures. TSTF-563 would not alter that 18 process.
19 20 TSTF-563 allows the NEI 04-10, Rev. 1, methodology to be applied to a subset 21 of instrument channel components instead of the entire channel when 22 considering a frequency change. It does not alter the technical approach 23 required by the SFCP that was approved by the NRC in NEI 04-10, Rev. 1, and 24 TSTF-425. TSTF-563 makes no changes to the method of evaluating a 25 surveillance frequency extension other than the scope of components considered 26 in an evaluation.
27 28 In addition, Step 16 of Section 4.0 of NEI 04-10 requires an Independent Decisionmaking Panel 29 (IDP) to review the cumulative impact of all STI changes over a period of time. This is also 30 required by RGs 1.174 and 1.177. The IDP is comprised of the site Maintenance Rule Expert 31 Panel, Surveillance Test Coordinator, and Subject Matter Expert who is a cognizant system 32 manager or component engineer. Based on the above information, the NRC staff finds that the 33 setpoint changes will be tracked in an acceptable manner.
34 35 The NRC staff reviewed the justification for the proposed revision to the instrumentation channel 36 definitions to ensure the request did not propose a change beyond the scope of NEI 04-10. In 37 response to the RAIs, the TSTF stated:
38 39 As stated in TSTF-563, Section 2.4, Description of the Proposed Change, only 40 plants that have adopted an SFCP (i.e., TSTF-425) may adopt the proposed 41 definition changes.
42 43 The NRC staff notes that limiting the proposed changes to licensees who have an approved 44 SFCP, allows for appropriate implementation of the program by incorporating NEI 04-10, 45 Revision 1, by reference into the Administrative Controls section of TSs.
46 47 Licensees with an SFCP may currently revise the surveillance frequency of instrumentation 48 channels. The testing of these channels may be performed by means of any series, sequential, 49 overlapping, or total channel steps. However, all required components in the instrumentation 50 channel must be tested in order for the entire channel to be considered Operable.
51 1
The NRC staff notes that industry practice is to perform instrument channel surveillances, such 2
as Channel Calibrations and Channel Functional Tests, using separate procedures based on 3
the location of the components. Each of these procedures may be considered a step. The 4
results of all these procedures are used to satisfy the SR using the existing allowance to 5
perform the SR by means of any series of sequential, overlapping, or total channel steps.
6 Traveler TSTF-563 allows for determining an acceptable surveillance frequency for each step.
7 As stated by the TSTF in the RAI response:
8 9
In response to Question b.I, the proposed approach can be reflected in the 10 current approaches for modelling actuation signals in the PRA. If the current 11 PRA model does not allow explicit consideration of subsets of the channel, a 12 bounding analysis may be performed, or the model may be revised to allow an 13 explicit evaluation.
14 15 In response to Question b.II, if the PRA currently cannot model subsets of an 16 instrument channel and cannot be modified to model the subsets of the channel, 17 a bounding evaluation may be used, the proposed frequency may be revised and 18 reevaluated, or the frequency change may be abandoned. These steps are 19 consistent with the guidance in NEI 04-10, Rev. 1, and risk informed decision 20 making which will ensure that only acceptable changes to the frequency will be 21 implemented.
22 23 The NRC staff notes that the NEI 04-10 methodology includes the determination of whether the 24 structure, system, and components (SSCs) affected by a proposed change to a surveillance 25 frequency are modeled in the PRA. Where the SSC is directly or implicitly modeled, a 26 quantitative evaluation of the risk impact may be carried out. The methodology adjusts the 27 failure probability of the impacted SSCs based on the proposed change to the surveillance 28 frequency. Where the SSC is not modeled in the PRA, bounding analyses are performed to 29 characterize the impact of the proposed change to the surveillance frequency. Potential 30 impacts on the risk analyses due to screening criteria and truncation levels are addressed by 31 the requirements for PRA technical adequacy, consistent with the guidance contained in 32 RG 1.200, and by sensitivity studies identified in NEI 04-10. Traveler TSTF-563 is not 33 proposing to change the methodology or the acceptance criteria for extending STIs, and 34 licensees will need to evaluated changes in the frequency for performing each of the steps in 35 the instrumentation surveillance test per the methodology in NEI 04-10.
36 37 Therefore, the NRC staff concludes that the proposed change to determine an acceptable 38 test frequency for individual steps within instrumentation channel surveillance tests is 39 acceptable, because any extended STIs from applying Traveler TSTF-563 will be developed 40 within the established constraints of the SFCP and NEI 04-10.
41 42 The regulatory requirements in 10 CFR 50.36 are not specific regarding the frequency of 43 performing surveillance tests. The proposed change only affects the frequency of performance 44 and does not affect the surveillance testing method or acceptance criteria. Therefore, the 45 proposed change is consistent with the surveillance testing requirements of 10 CFR 50.36.
46 47 PRA Acceptability 48 49 The guidance in RG 1.200 states that the quality of a licensees PRA should be commensurate 50 with the safety significance of the proposed TS change and the role the PRA plays in justifying 51 the change. That is, the greater the change in risk or the greater the uncertainty in that risk as a 1
result of the requested TS change, or both, the more rigor that should go into ensuring the 2
quality of the PRA.
3 4
Use of Traveler TSTF-563 by a licensee requires NRCs prior approval of the licensees request 5
to an SFCP that uses NEI 04-10. As part of its evaluation of that request, the NRC staff will 6
have performed an assessment of the PRA models used to support the approved SFCP that 7
uses NEI 04-10, using the guidance of RG 1.200 to assure that the PRA models are capable of 8
determining the change in risk due to changes to surveillance frequencies of SSCs, using 9
plant-specific data and models. Capability Category II of the NRC-endorsed PRA standard is 10 the target capability level for supporting requirements for the internal events PRA for this 11 application. Any identified deficiencies to those requirements are assessed further to determine 12 any impacts to proposed decreases to surveillance frequencies, including the use of sensitivity 13 studies where appropriate, in accordance with NEI 04-10.
14 15 Traveler TSTF-425 permits revising of the surveillance frequency for instrumentation channels.
16 The NRC staff asked the TSTF how NEI 04-10 can be applied to subsets in an instrument 17 channel when the SFCP currently specifies a surveillance interval that is applied to the entire 18 channel. The TSTF stated in its RAI response that the current channel surveillance may be 19 performed by means of any series of sequential, overlapping, or total channel steps. In 20 practice, this means that a channel is divided into subsets and each subset is tested 21 separately. Therefore, the current instrument channel testing is already composed of a 22 sequence of individual tests.
23 24 The NRC staff also requested the TSTF to clarify how the NEI 04-10 methodology can be 25 applied to the variety of current approaches for modeling actuation instrument channels in 26 PRAs. In the response to the RAI the TSTF stated that [a]n instrument function may be 27 modeled in the PRA differently depending on the site and the function (e.g., channel may be 28 modeled individually, subsets may be modeled, or the channel function may be modeled as a 29 single entity). The TSTF identified different steps through the evaluation methodology in 30 NEI 04-10 that could be used based on the different PRA modeling approaches. The 31 appropriate modeling of these different approaches is included in the NRC staffs review of the 32 PRA modeling during the review of the application to implement an SFCP.
33 34 Licensees who adopt Traveler TSTF-563 will use a PRA that was used to support the adoption 35 of Traveler TSTF-425 or an approved SFCP that uses NEI 04-10. Traveler TSTF-563 will give 36 licensees the capability to change the surveillance frequency of individual steps in the Channel 37 Calibration, Channel Functional Test, COT, and TADOT for instrumentation. The NRC staff 38 finds that changes to the surveillance frequency for individual steps can be appropriately 39 evaluated with the current SFCP and the current PRAs. The NRC staff finds that the 40 risk-informed methodology review and the PRA acceptability review that NRC staff performs 41 during approval of an SFCP that uses NEI 04-10 will be adequate to allow the adoption of 42 Traveler TSTF-563, and therefore, the NRC staff finds the proposed traveler acceptable for 43 use by plants that have an approved SFCP.
44 45
4.0 CONCLUSION
46 47 The NRC staff reviewed Traveler TSTF-563, which proposed changes to NUREG-1430, 48 NUREG-1431, NUREG-1432, NUREG-1433, and NUREG 1434, and NUREG-2194. The NRC 49 staff determined that the proposed changes to the STS meet the standards for TSs in 50 10 CFR 50.36(b). The regulations at 10 CFR 50.36 require that TSs include items in specified 51 categories, including SRs. The proposed changes modify the definitions applicable to 1
instrumentation channel components but do not alter the technical approach that was approved 2
by the NRC staff in NEI 04-10 and Traveler TSTF-425, and the TS, as revised, continue to 3
specify the appropriate SRs for tests and inspections to ensure the necessary quality of affected 4
SSCs is maintained.
5 6
Additionally, the changes to the STS were reviewed and found to be technically clear and 7
consistent with customary terminology and format in accordance with SRP Chapter 16.0. The 8
NRC staff reviewed the proposed changes against the regulations and concludes that the 9
changes continue to meet the requirements of Sections 50.36(b), 50.36(c)(3), and 50.36(c)(5) 10 of 10 CFR, for the reasons discussed above, and thus provide reasonable assurance that 11 adoption of these TSs will have the requisite requirements and controls to operate safely.
12 Therefore, the NRC staff concludes that the proposed TS changes are acceptable.
13 14 Principal Contributors: M. Chernoff, NRR/DSS 15 G. Singh, NRR/DE 16 J. Evans, NRR/DRA 17 18 Date:
19 General Directions: This Model SE provides the format and content to be used when preparing 1
the plant specific SE of an LAR to adopt TSTF 563, Revision 0. The bolded bracketed 2
information shows text that should be filled in for the specific amendment; individual licensees 3
would furnish site-specific nomenclature or values for these bracketed items. The italicized 4
wording provides guidance on what should be included in each section and should not be 5
included in the SE.
6 7
DRAFT MODEL SAFETY EVALUATION 8
BY THE OFFICE OF NUCLEAR REACTOR REGULATION 9
TECHNICAL SPECIFICATIONS TASK FORCE TRAVELER 10 TSTF-563, REVISION 0 11 REVISE INSTRUMENT TESTING DEFINITIONS TO INCORPORATE THE SURVEILLANCE 12 FREQUENCY CONTROL PROGRAM 13 USING THE CONSOLIDATED LINE ITEM IMPROVEMENT PROCESS 14 (CAC NO. MF9955, EPID L-2017-PMP-0006) 15 16 17
1.0 INTRODUCTION
18 19 By application dated [enter date] (Agencywide Documents Access and Management System 20 (ADAMS) Accession No. [MLXXXXXXXXX]), [as supplemented by letter(s) dated [enter 21 date(s))), [name of licensee] (the licensee) submitted a license amendment request (LAR) for 22
[name of facility (abbreviated name), applicable units].
23 24 The amendment would revise the current instrumentation testing definitions of Channel 25 Calibration(( and Channel Functional Test] OR [, Channel Operational Test (COT), and Trip 26 Actuation Device Operational Test (TADOT))) to permit determination of the appropriate 27 frequency to perform the Surveillance Requirement (SR) based on the devices being tested in 28 each step. The proposed changes are based on Technical Specifications Task Force (TSTF) 29 Traveler TSTF-563, Revision 0, Revise Instrument Testing Definitions to Incorporate the 30 Surveillance Frequency Control Program, dated May 10, 2017 (ADAMS Accession 31 No. ML17130A819). The U.S. Nuclear Regulatory Commission (NRC or the Commission) 32 issued a final safety evaluation (SE) approving TSTF-563, Revision 0, on [enter date] (ADAMS 33 Accession No. [MLXXXXXXXXX]).
34 35
{NOTE: TSTF-563 is only applicable to plants that have already adopted TSTF-425 or have an 36 approved SFCP that uses NEI 04-10.}
37 38 A Surveillance Frequency Control Program (n SFCP) was incorporated into the [PLANT] TS in 39 a license amendment dated [enter date] (ADAMS Accession No. [MLXXXXXXXXX]).
40 41
((The licensee has proposed variations from the TS changes described in TSTF-563. The 42 variations are described in Section 2.2.1 of this SE and evaluated in Section 3.1.] OR [The 43 licensee is not proposing any variations from the TS changes described in TSTF-563 or 44 the applicable parts of the NRC staffs SE of TSTF-563.))
45 46
[The supplemental letters dated [enter date(s)], provided additional information that 1
clarified the application, did not expand the scope of the application as originally 2
noticed, and did not change the NRC staffs original proposed no significant hazards 3
consideration determination as published in the Federal Register on [enter date] (cite FR 4
reference).]
5 6
2.0 REGULATORY EVALUATION
7 8
2.1 DESCRIPTION
OF SURVEILLANCE FREQUENCY CONTROL PROGRAM AND 9
INSTRUMENT TESTING 10 11 The technical specifications (TSs) require the surveillances for instrumentation channels to be 12 performed within the specified frequency, using any series of sequential, overlapping, or total 13 channel steps. A previous amendment TSTF-425, Revision 3, Relocate Surveillance 14 Frequencies to Licensee Control - RITSTF [Risk-Informed TSTF] Initiative 5b, revised the TSs 15 to relocate all periodic surveillance frequencies to licensee control. Changes to the relocated 16 surveillance frequencies are made in accordance with the TS program referred to as the 17 Surveillance Frequency Control Program (SFCP). The SFCP allows a new surveillance 18 frequency to be determined for the channel, but that frequency must consider all components in 19 the channel and applies to the entire channel.
20 21 A typical instrument channel consists of many different components, such as sensors, rack 22 modules, and indicators. These components have different short-term and long-term 23 performance (drift) characteristics, resulting in the potential for different calibration frequency 24 requirements. Under the current TSs, the most limiting component calibration frequency for the 25 channel must be chosen when a revised frequency is considered under the SFCP. As a result, 26 all components that makeup a channel must be calibrated at a frequency equal to the channel 27 component with the shortest (i.e., most frequent) surveillance frequency.
28 29 Some channel components, such as pressure transmitters, are very stable with respect to drift 30 and could support a substantially longer calibration frequency than the other components in the 31 channel. Currently, the SRs in many plants are performed in steps (e.g., a pressure sensor or 32 transmitter is calibrated during a refueling outage and the rack signal conditioning modules are 33 calibrated while operating at power). The proposed change extends this concept to permit the 34 surveillance frequency of each step to be determined under the SFCP based on the 35 component(s) surveilled in the step instead of all components in the channel. This will allow 36 each component to be tested at the appropriate frequency based on the components long-term 37 performance characteristics.
38 39 Allowing an appropriate surveillance frequency for performing a channel calibration on each 40 component or group of components could reduce radiation dose associated with inplace 41 calibration of sensors, reduce wear on equipment, reduce unnecessary burden on plant staff, 42 and reduce opportunities for calibration errors.
43 44
2.2 PROPOSED CHANGE
S TO THE TECHNICAL SPECIFICATIONS 45 46 Currently, the Channel Calibration(( and Channel Functional Test] OR [, COT, and TADOT))
47 may be performed by any series of sequential, overlapping or total channel steps. The 48 proposed changes to the TSs would revise the definitions of Channel Calibration(( and Channel 49 Functional Test] OR [, COT, and TADOT)) to indicate that the step must be performed within 50 the most limiting frequency for the components included in that step by adding the words, and 1
each step must be performed within the Frequency in the Surveillance Frequency Control 2
Program for the devices included in the step at the end of the last sentence of each definition.
3 4
The following paragraph denotes the changes to the Channel Calibration definition. Changes 5
are shown in italics:
6 7
{NOTE: For B&W, CE, and GE plant designs use this paragraph.}
8 9
[A CHANNEL CALIBRATION shall be the adjustment, as necessary, of the 10 channel output such that it responds within the necessary range and 11 accuracy to known values of the parameter that the channel monitors. The 12 CHANNEL CALIBRATION shall encompass all devices in the channel 13 required for channel OPERABILITY and the CHANNEL FUNCTIONAL TEST.
14 Calibration of instrument channels with resistance temperature detector 15 (RTD) or thermocouple sensors may consist of an inplace qualitative 16 assessment of sensor behavior and normal calibration of the remaining 17 adjustable devices in the channel. The CHANNEL CALIBRATION may be 18 performed by means of any series of sequential, overlapping, or total 19 channel steps, and each step must be performed within the Frequency in 20 the Surveillance Frequency Control Program for the devices included in the 21 step.]
22 23
{NOTE: For Westinghouse plant designs use this paragraph.}
24 25
[A CHANNEL CALIBRATION shall be the adjustment, as necessary, of the 26 channel output such that it responds within the necessary range and 27 accuracy to known values of the parameter that the channel monitors. The 28 CHANNEL CALIBRATION shall encompass all devices in the channel 29 required for channel OPERABILITY. Calibration of instrument channels 30 with resistance temperature detector (RTD) or thermocouple sensors may 31 consist of an inplace qualitative assessment of sensor behavior and 32 normal calibration of the remaining adjustable devices in the channel. The 33 CHANNEL CALIBRATION may be performed by means of any series of 34 sequential, overlapping, or total channel steps, and each step must be 35 performed within the Frequency in the Surveillance Frequency Control 36 Program for the devices included in the step.]
37 38
{NOTE: For B&W, CE, and GE plant designs use this paragraph.}
39 40
[The following paragraph denotes the changes to the Channel Functional Test definition.
41 Changes are shown in italics:
42 43
...The CHANNEL FUNCTIONAL TEST may be performed by means of any 44 series of sequential, overlapping, or total [channel] steps, and each step 45 must be performed within the Frequency in the Surveillance Frequency 46 Control Program for the devices included in the step.]
47 48
{NOTE: For Westinghouse plant designs use this paragraph.}
49 50
[The following paragraphs denote the changes to the COT and TADOT definitions.
1 Changes are shown in italics:
2 3
A COT shall be the injection of a simulated or actual signal into the channel 4
as close to the sensor as practicable to verify OPERABILITY of all devices 5
in the channel required for channel OPERABILITY. The COT shall include 6
adjustments, as necessary, of the required alarm, interlock, and trip 7
setpoints required for channel OPERABILITY such that the setpoints are 8
within the necessary range and accuracy. The COT may be performed by 9
means of any series of sequential, overlapping, or total channel steps, and 10 each step must be performed within the Frequency in the Surveillance 11 Frequency Control Program for the devices included in the step.
12 13 A TADOT shall consist of operating the trip actuating device and verifying 14 the OPERABILITY of all devices in the channel required for trip actuating 15 device OPERABILITY. The TADOT shall include adjustment, as necessary, 16 of the trip actuating device so that it actuates at the required setpoint 17 within the necessary accuracy. The TADOT may be performed by means of 18 any series of sequential, overlapping, or total channel steps, and each step 19 must be performed within the Frequency in the Surveillance Frequency 20 Control Program for the devices included in the step.]
21 22 The various instrumentation functions in the TSs require surveillances to verify the correct 23 functioning of the instrument channel. The proposed change extends the definition of 24 instrumentation channel components to permit the surveillance frequency of each step to be 25 determined under the SFCP based on the component(s) surveilled in the step instead of all 26 components in the channel. This will allow each component to be tested at the appropriate 27 frequency based on the components long-term performance characteristics.
28 29 The proposed changes in the definition for instrument testing would allow the licensee to control 30 the frequency of associated components being tested in each step. The SR for the overall 31 instrumentation channel remains unchanged. The proposed change has no effect on the 32 design, fabrication, use, or methods of testing the instrumentation channels and will not affect 33 the ability of the instrumentation to perform the functions assumed in the safety analysis.
34 35 These instrumentation testing definitions state that, [t]he [test type] may be performed by 36 means of any series of sequential, overlapping, or total channel steps. The surveillance 37 frequency of these subsets would be established based on the characteristics of the 38 components in the step rather than the most limiting component characteristics in the entire 39 channel. Each of these steps are evaluated in accordance with the SFCP.
40 41 2.2.1 Variations from TSTF-563 42 43
{NOTE: Technical reviewers and/or project manager are to assess the adequacy of any 44 variations from the approved traveler and document their acceptability. Choose the applicable 45 paragraphs based on information provided in the LAR.}
46 47
[The licensee is proposing the following variations from the TS changes described in 48 TSTF-563 or the applicable parts of the NRC staffs SE of TSTF-563. [Describe the 49 variations and why TSTF-563 is still applicable.] These variations do not affect the 1
applicability of TSTF-563 or the NRC staff's SE to the proposed LAR.]
2 3
[The [PLANT] TSs utilize different [numbering][and][titles] than the Standard Technical 4
Specifications on which TSTF-563 was based. Specifically, [describe differences 5
between the plant-specific TS numbering and/or titles and the TSTF-563 numbering 6
and/or titles.] These differences are editorial and do not affect the applicability of 7
TSTF-563 to the proposed LAR.]
8 9
[The [PLANT] TS contain requirements that differ from the design is different than the 10 model plant assumed in the Standard Technical Specifications, but the TSTF-563 11 justification and the NRC staff's SE are still applicable. [Describe differences and why 12 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 A previous amendment Traveler TSTF-425 revised and relocated most periodic surveillance 40 frequencies to licensee control. Changes to the relocated surveillance frequencies are made in 41 accordance with the SFCP. The SFCP requires that changes to the relocated frequencies be 42 made in accordance 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 50 probabilistic risk assessment (PRA) models, and for imposing corrective actions, if necessary, 1
following implementation of a revised frequency.
2 3
The NRC staffs guidance for the review of TSs is in Chapter 16.0, Technical Specifications, of 4
NUREG-0800, Revision 3, Standard Review Plan for the Review of Safety Analysis Reports for 5
Nuclear Power Plants: LWR [Light-Water Reactor] Edition (SRP), March 2010 (ADAMS 6
Accession No. ML100351425). As described therein, as part of the regulatory standardization 7
effort, the NRC staff has prepared STS for each of the LWR nuclear designs. Accordingly, the 8
NRC staffs review includes consideration of whether the proposed changes are consistent with 9
the applicable reference STS (i.e., the current STS), as modified by NRC-approved Travelers.
10 In addition, the guidance states that comparing the change to previous STS can help clarify the 11 TS intent.
12 13 Regulatory Guide (RG) 1.174, Revision 2, An Approach for Using Probabilistic Risk 14 Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis 15 (ADAMS Accession No. ML100910006), describes an acceptable risk-informed approach for 16 assessing the nature and impact of proposed permanent licensing basis changes by 17 considering engineering issues and applying risk insights. This regulatory guide also provides 18 risk acceptance guidelines for evaluating the results of such evaluations.
19 20 RG 1.177, Revision 1, An Approach for Plant-Specific, Risk-Informed Decisionmaking:
21 Technical Specifications (ADAMS Accession No. ML100910008), describes an acceptable 22 risk-informed approach specifically for assessing proposed TS changes.
23 24 RG 1.200, An Approach for Determining the Technical Adequacy of Probabilistic Risk 25 Assessment Results for Risk-Informed Activities (ADAMS Accession No. ML090410014),
26 describes an acceptable approach for determining the technical adequacy of PRAs.
27 28 The NRC staffs guidance for evaluating the technical basis for proposed risk-informed 29 changes is provided in SRP, Chapter 19, Section 19.2, Review of Risk Information Used to 30 Support Permanent Plant-Specific Changes to the Licensing Basis: General Guidance 31 (ADAMS Accession No. ML071700658). The NRC staffs guidance on evaluating PRA 32 technical adequacy is provided in SRP, Chapter 19, Section 19.1, Revision 3, Determining the 33 Technical Adequacy of Probabilistic Risk Assessment for Risk-Informed License Amendment 34 Requests After Initial Fuel Load (ADAMS Accession No. ML12193A107). More specific 35 guidance related to risk-informed TS changes is provided in SRP, Chapter 16, Section 16.1, 36 Revision 1, Risk-Informed Decision Making: Technical Specifications (ADAMS Accession 37 No. ML070380228), which includes changes to surveillance test intervals (STIs) (i.e.,
38 surveillance frequencies) as part of risk-informed decisionmaking. Section 19.2 of the SRP 39 references the same criteria as RG 1.177, Revision 1, and RG 1.174, Revision 2, and states 40 that a risk-informed application should be evaluated to ensure that the proposed changes meet 41 the following key principles:
42 43 The proposed change meets the current regulations, unless it explicitly relates to a 44 requested exemption or rule change.
45 46 The proposed change is consistent with the defense-in-depth philosophy.
47 48 The proposed change maintains sufficient safety margins.
49 50 When proposed changes result in an increase in risk associated with core damage 1
frequency or large early release frequency, the increase(s) should be small and 2
consistent with the intent of the Commissions Safety Goal Policy Statement.
3 4
The impact of the proposed change should be monitored using performance 5
measurement strategies.
6 7
{NOTE: Choose applicable STS}
8
[U.S. Nuclear Regulatory Commission, Standard Technical Specifications, Babcock and 9
Wilcox Plants, NUREG-1430, Volume 1, Specifications, and Volume 2, Bases, 10 Revision 4.0, dated April 2012 (ADAMS Accession Nos. ML12100A177 and ML12100A178, 11 respectively).
12 13 U.S. Nuclear Regulatory Commission, Standard Technical Specifications, Westinghouse 14 Plants, NUREG-1431, Volume 1, Specifications, and Volume 2, Bases, Revision 4.0, 15 dated April 2012 (ADAMS Accession Nos. ML12100A222 and ML12100A228, respectively).
16 17 U.S. Nuclear Regulatory Commission, Standard Technical Specifications, Combustion 18 Engineering Plants, NUREG-1432, Volume 1, Specifications, and Volume 2, Bases, 19 Revision 4.0, dated April 2012 (ADAMS Accession Nos. ML12102A165 and ML12102A169, 20 respectively).
21 22 U.S. Nuclear Regulatory Commission, Standard Technical Specifications, General 23 Electric BWR/4 Plants NUREG-1433, Volume 1, Specifications, and Volume 2, Bases, 24 Revision 4.0, dated April 2012 (ADAMS Accession Nos. ML12104A192 and ML12104A193, 25 respectively).
26 27 U.S. Nuclear Regulatory Commission, Standard Technical Specifications, General 28 Electric BWR/6 Plants NUREG-1434, Volume 1, Specifications, and Volume 2, Bases, 29 Revision 4.0, dated April 2012 (ADAMS Accession Nos. ML12104A195 and ML12104A196, 30 respectively).]
31 32 U.S. Nuclear Regulatory Commission, Standard Technical Specifications, Westinghouse 33 Advanced Passive (AP1000) Plants, NUREG 2194, Volume 1, Specifications, and 34 Volume 2, Bases, Revision 4.0, April 2016 (ADAMS Accession Nos. ML16110A277 and 35 ML16110A369, respectively).]
36 37
3.0 TECHNICAL EVALUATION
38 39 Revising the frequency of a Channel Calibration(( and Channel Functional Test] OR [, COT, 40 and TADOT)) instrument channel under the SFCP requires assurance that component 41 performance characteristics, such as drift between each test, will not result in undetected 42 instrument errors that exceed the assumptions of the safety analysis and supporting instrument 43 loop uncertainty calculations. These requirements are consistent with the methodology 44 described in NEI 04-10, which the SFCP requires to be followed. The SFCP does not permit 45 changes to the TS Allowable Values or Nominal Trip Setpoints; but allows only the surveillance 46 frequency to be changed when determined permissible by NEI 04-10. Therefore, prior to 47 extending the test intervals for an instrument channel component or components associated 48 with a given calibration step, the component performance characteristics must be evaluated to 49 verify the Allowable Value or Nominal Trip Setpoint will still be valid and to establish a firm 50 technical basis supporting the extension. In addition, each change must be reviewed by the 1
licensee to ensure the applicable uncertainty allowances are conservative (bounding) (e.g.,
2 sensor drift, rack drift, indicator drift). Documentation to support the changes shall be retained 3
per the guidance in NEI 04-10.
4 5
Five key safety principles that must be evaluated before changing any surveillance frequency 6
are identified in Section 3.0 of NEI 04-10. Principle 3 requires confirmation of the maintenance 7
of safety margins, which, in this case, includes performance of deterministic evaluations to 8
verify preservation of instrumentation trip setpoint and indication safety margins.
9 10 The evaluation methodology specified in NEI 04-10 also requires consideration of common 11 cause failure effects and monitoring of the instrument channel component performance 12 following the frequency change to ensure channel performance is consistent with the analysis to 13 support an extended frequency.
14 15 The method of evaluating a proposed surveillance frequency change is not dependent on the 16 number of components in the channel. Each step needs to be evaluated to determine the 17 acceptable surveillance frequency for that step. The proposed change to permit changing the 18 surveillance frequency of channel component(s) does not affect the test method or evaluation 19 method. The requirement to perform a Channel Calibration, Channel Functional Test, COT, or 20 TADOT on the entire channel is not changed.
21 22 For example, an evaluation in accordance with NEI 04-10 may determine that a field sensor 23 (e.g., a transmitter) should be calibrated every 48 months, the rack modules should be 24 calibrated every 30 months, and the indicators should be calibrated every 24 months. Under 25 the current TS requirements, all devices in the channel must be calibrated every 24 months.
26 However, under the proposed change, sensors, rack modules, and indicators would be 27 calibrated at the appropriate frequency for the tested devices. As required by the Channel 28 Calibration definition, the test would still encompass all devices in the channel required for 29 channel operability.
30 31 The NEI 04-10 methodology is used to evaluate surveillance frequency changes to determine if 32 such SR extensions could be applied. Process elements are used to determine the cumulative 33 risk impact of changes, updating the PRA, and imposition of corrective actions, if needed, 34 following implementation. Several steps are required by NEI 04-10, Step 7, to be evaluated 35 prior to determining the acceptability of changes. These steps include history of surveillance 36 tests, industry and plant specific history, impact on defense-in-depth, vendor recommendations, 37 required test frequencies for the applicable codes and standards, ensuring that plant licensing 38 basis would not be invalidated and other factors. The NRC staff finds these measures 39 acceptable in determining the SR extensions.
40 41 In addition, Step 16 of Section 4.0 of NEI 04-10 requires an Independent Decisionmaking Panel 42 (IDP) to review the cumulative impact of all STI changes over a period of time. This is also 43 required by RGs 1.174 and 1.177. The IDP is comprised of the site Maintenance Rule Expert 44 Panel, Surveillance Test Coordinator, and Subject Matter Expert who is a cognizant system 45 manager or component engineer. Based on the above information, the NRC staff finds that the 46 setpoint changes will be tracked in an acceptable manner.
47 48 Licensees with an SFCP may currently revise the surveillance frequency of instrumentation 49 channels. The testing of these channels may be performed by means of any series, sequential, 50 overlapping, or total channel steps. However, all required components in the instrumentation 1
channel must be tested in order for the entire channel to be considered Operable.
2 3
The NRC staff notes that industry practice is to perform instrument channel surveillances, such 4
as Channel Calibrations and Channel Functional Tests, using separate procedures based on 5
the location of the components. Each of these procedures may be considered a step. The 6
results of all these procedures are used to satisfy the SR using the existing allowance to 7
perform it by means of any series of sequential, overlapping, or total channel steps. The 8
proposed changes would allow for determining an acceptable surveillance frequency for each 9
step.
10 11 The NRC staff notes that the NEI 04-10 methodology includes the determination of whether the 12 structure, system, and components (SSCs) affected by a proposed change to a surveillance 13 frequency are modeled in the PRA. Where the SSC is directly or implicitly modeled, a 14 quantitative evaluation of the risk impact may be carried out. The methodology adjusts the 15 failure probability of the impacted SSCs based on the proposed change to the surveillance 16 frequency. Where the SSC is not modeled in the PRA, bounding analyses are performed to 17 characterize the impact of the proposed change to the surveillance frequency. Potential 18 impacts on the risk analyses due to screening criteria and truncation levels are addressed by 19 the requirements for PRA technical adequacy, consistent with the guidance contained in 20 RG 1.200, and by sensitivity studies identified in NEI 04-10. The licensee is not proposing to 21 change the methodology, or the acceptance criteria for extending STIs, and licensees will need 22 to changes in the frequency for performing each of the steps in the instrumentation surveillance 23 test per the methodology in NEI 04-10.
24 25 Therefore, the NRC staff concludes that the proposed change determine an acceptable test 26 frequency for individual steps within instrumentation channel surveillance tests is acceptable 27 because any extended STIs will be developed within the established constraints of the 28 SFCP and NEI 04-10.
29 30 The regulatory requirements in 10 CFR 50.36 are not specific regarding the frequency of 31 performing surveillance tests. The proposed change only affects the frequency of performance 32 and does not affect the surveillance testing method or acceptance criteria. Therefore, the 33 proposed change is consistent with the surveillance testing requirements of 10 CFR 50.36.
34 35 PRA Acceptability 36 37 The guidance in RG 1.200 states that the quality of a licensees PRA should be commensurate 38 with the safety significance of the proposed TS change and the role the PRA plays in justifying 39 the change. That is, the greater the change in risk or the greater the uncertainty in that risk as a 40 result of the requested TS change, or both, the more rigor that should go into ensuring the 41 quality of the PRA.
42 43 The NRC staff will have performed an assessment of the PRA models used to support the 44 approved SFCP that uses NEI 04-10, using the guidance of RG 1.200 to assure that the PRA 45 models are capable of determining the change in risk due to changes to surveillance 46 frequencies of SSCs, using plant-specific data and models. Capability Category II of the NRC-47 endorsed PRA standard is the target capability level for supporting requirements for the internal 48 events PRA for this application. Any identified deficiencies to those requirements are assessed 49 further to determine any impacts to proposed decreases to surveillance frequencies, including 1
the use of sensitivity studies where appropriate, in accordance with NEI 04-10.
2 3
The SFCP permits revising of the surveillance frequency for instrumentation channels. The 4
NRC staff evaluated whether NEI 04-10 can be applied to subsets in an instrument channel 5
when the SFCP currently specifies a surveillance interval that is applied to the entire channel.
6 The NRC staff notes that the current channel surveillance may be performed by means of any 7
series of sequential, overlapping, or total channel steps. In practice, this means that a channel 8
is divided into subsets and each subset is tested separately. Therefore, the current instrument 9
channel testing is already composed of a sequence of individual tests.
10 11 The instrument function may be modeled in the PRA differently depending on the site and the 12 function (e.g., channel may be modeled individually, subsets may be modeled, or the channel 13 function may be modeled as a single entity). There are different steps through the evaluation 14 methodology in NEI 04-10 that could be used based on the different PRA modeling approaches.
15 The appropriate modeling of these different approaches is included in the NRC staffs review of 16 the PRA modeling during the review of the application to implement an SFCP that uses 17 NEI 04-10.
18 19 The licensee is using a PRA that was used to support their application that implemented an 20 SFCP that uses NEI 04-10. The amendment will change the capability of the licensee to 21 change the surveillance frequency of an entire channel to now change the frequency of each 22 subset of the channel. The NRC staff finds that changes to the surveillance frequency caused 23 by defining and using individual, testable component subsets can be appropriately evaluated 24 with the current SFCP and the current PRAs. The NRC staff finds that the risk-informed 25 methodology review and the PRA acceptability review that was performed during the review of 26 the licensees application to implement an SFCP that uses NEI 04-10 is adequate.
27 28 The NRC staff determined that the proposed changes to the TS meet the standards for TS in 29 10 CFR 50.36(b). The regulations at 10 CFR 50.36 require that TSs include items in specified 30 categories, including SRs. The proposed changes modify the definitions applicable to 31 instrumentation channel components but do not alter the technical approach that was approved 32 by the NRC in NEI 04-10, and the TSs, as revised, continue to specify the appropriate SRs for 33 tests and inspections to ensure the necessary quality of affected SSCs is maintained.
34 35 Additionally, the changes to the TS were reviewed and found to be technically clear and 36 consistent with customary terminology and format in accordance with SRP Chapter 16.0. The 37 NRC staff reviewed the proposed changes against the regulations and concludes that the 38 changes continue to meet the requirements of Sections 50.36(b), 50.36(c)(3), and 50.36(c)(5),
39 of 10 CFR, for the reasons discussed above, and thus provide reasonable assurance that 40 adoption of these TSs will have the requisite requirements and controls to operate safely.
41 Therefore, the NRC staff concludes that the proposed TS changes are acceptable.
42 43
[3.1 VARIATIONS FROM TSTF-563 44 45 The licensee described variations from TSTF-563 in Section 2.2 of the LAR. The licensee 46 provided justification for the proposed variations and exceptions. The staff reviewed the 47 justifications and concluded the variations are [not] acceptable because.
48 49 The [PLANT] TSs utilize different [numbering][and][titles] than the Standard Technical 1
Specifications on which TSTF-563 was based. The NRC staff agrees these differences 2
are editorial and do not affect the applicability of TSTF-563 to the proposed LAR.]
3 4
4.0 STATE CONSULTATION
5 6
{This section is to be prepared by the plant project manager.}
7 8
In accordance with the Commissions regulations, the [Name of State] State official was notified 9
of the proposed issuance of the amendment(s) on [date]. The State official had [no]
10 comments. [If comments were provided, they should be addressed here.]
11 12
5.0 ENVIRONMENTAL CONSIDERATION
13 14
{This section is to be prepared by the plant project manager in accordance with current 15 procedures.}
16 17
6.0 CONCLUSION
18 19
{This section is to be prepared by the plant project manager.}
20 21 The Commission has concluded, based on the considerations discussed above, that: (1) there 22 is reasonable assurance that the health and safety of the public will not be endangered by 23 operation in the proposed manner, (2) there is reasonable assurance that such activities will be 24 conducted in compliance with the Commissions regulations, and (3) the issuance of the 25 amendment(s) will not be inimical to the common defense and security or to the health and 26 safety of the public.
27 28
7.0 REFERENCES
29 30
{Optional section to be prepared by the PM and primary reviewers. If document is publicly 31 available, the ADAMS Accession No. should be listed.}
32 33
{NOTE: These are the principal contributors for the model SE of the traveler. Replace these 34 names with those who prepared the plant-specific SE.}
35 36 Principal Contributors: M. Chernoff, NRR/DSS 37 G. Singh, NRR/DE 38 J. Evans, NRR/DRA 39 40 Date:
41