ML20202H199
| ML20202H199 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 02/13/1998 |
| From: | Terry C TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TXX-98039, NUDOCS 9802200321 | |
| Download: ML20202H199 (14) | |
Text
-
lllllllll:' T:b F9 Log # TXX 98039
)
F.le # 10010.1 C
C 905.2 (clo) 1UELECTRIC February 13, 1998 C. F ance Ttrry Senwr Mce President
& PrincipalNuclear Offleer U. S. Nuclear Regul6 tory Commission Attn: Document Control Desk Washington, DC 20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATIUN (CPSES)
DOCKET N05, 50 445 AND 50 446 TRANSHITTAL OF RISK INFORHED INSERVICE TESTING INFORMATION REQUESTED BY NRC REF:
- 1) TV Electric letter logged TXX 96371, from C. L. Terry to the NRC, dated June 3, 1996,
- 2) TV Electric Letter logged TXX 97272, from C. L. Terry to the NRC, dated December 18, 1997, i
Gentlemen:
At a public meeting on December 8, 1997, and during followup phone conversations with the NPC, the f. r equested that TV Electr4 : submit a draft revision of Enclosure 2 of Reference 1.
TV Electric submitted a draft revision on December 18, 1997, via Reference 2.
As a result of phone convetsations with the NRC staff on January 14, 1998 TU Electric agreed to submit a second draft revision of Enclosure 2 of Reference 1.
TV Electric has developed the second draft "P,isk Informed Inservice Testing Program Dascription," dated February 13, 1998 (Enclosure).
1U Electric will re submit this document.if ter final resolution of comments.
This communication contains commitments regarding CPSES Units 1 and 2 as identified in the Attachment.
If you have any auestions, please call Carl Corbin at (254) 897 0121.
Sincerely
?$
u C. L. Ter ry By:
e%4 N.
-4
..;vVU2 RogeVD. Walker CBC/cc Regulatory Affairs Manager Attachment i
Enclosure i
c-E. W. Herschoff, Region IV J. I. Tapia, Region IV I
T. J, Polir.h. NRR d{ql Resident InspectgCgEb smm u u1Ric sTAlloN f
jg' g i,} j g a Ill,
., i g P.O. Ihn no: Glen Rme, Tnas 4 043 1002
,I, 0802200321 960213 JJH ADOCK 05000445 P
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l Attachment to TXX 98039 Page 1 of 1 Attachment 2
This communication contains the following commitment which will be completed as noted:
ACL Number Commitment 97 147 TU Electric will re submit the Risk Informed Inservice Testing Program Description after inial resolution of comments.
The ACL (Action Correspondence Lo0) number is used by TU Electric for the internal tracking of CPSES commitments which are one time action requirements.
l This communication contains the following potential commitment which is ongoing in nature and will be incorporated into the CPSES licensing basis in the next appropriate update to Inservice Testing Plan (IST):
j CDF Number Commitment
)
26998 If a risk informed Inservice Testing (IST) program is implemented. it will be maintained in accordance with an NRC approved " Risk Informed Inservice Testing Program Description".
This program will be described in a relief request to the IST Plan.
The CDF (Cormitment Data Form) number is used by TV Electric for internal tracking of CPSES commitments.
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Enclosure to TXX 98039
, ', Page 1 of 12 I
RISK INFORMED INSERVICE TESTING PROGRAM DESCRIPTION (RI IST) 2 The proposed alternative is a risk informed process to determine the safety 3
significance and testing strategy of components in the ASHE Section XI 4
Inservice Testing (IST) Program, and identify non ASME IST components (pumps &
5 valves) modeled in the Indivddual Plant Examination (IPE) that are determined 6
to be High Safety Significant Components (HSSCs). The process cur.sists of the 7
following elements.
l 8
1)
Utilization of the Probabilistic Risk Analysis (PRA) techniques to
)
9 identify component importance measure values.
(PRA Techniques) 10 2)
Categorize components based on importance measures determined by the PRA 11 techniques.
(Component Risk Category) i 12 3)
Blended deterministic and probabilistic data to perform a fina.
13 importance ranking of components and categorization as either Low Safety 14 Significant Component (LSSC) or High Safety Significant Component 15 (HSSC).
(Integrated Decision Process) (IDP) 16 4)
Develop / Determine Test Frequencies and Test Methodologies for the IST 17 components.
(Testing Philosophy) 18 5)
Evaluate the cumulative impact of the test frequency changes on total 19 plant risk (i.e., CDF and LERF) to ensure that the change in plant 20 safety is within the acceptable range.
(Cumulative impact) 21 6)
Develop an implementation plen.
(Implementation) 22 7)
Develop a Corrective Action plan.
(Corrective Action) 23 8)
Perforr Mriodic reassessments.
(Periodic Reassessments) 24 9)
Develi
!. methodology for making changes to the RI IST.
(Changes to RI-25 IST) 26 1)
PRA Techniaues 27 PRA methods will be used to determine the risk significance of 28 components based on end states of interest, such as core damage 29-frequency (CDF) and release of radioactivity (e.g. large early release 30 frequency (LERF)).
31 The PRA techniques are used in conjunction with the Integrated Decision 32 Process (IDP) to ensure that all the available information is accounted 33 for in developing the importance nieasures. As such, a review of plait 34 equipment and operating procedures will be performed to identify 35 potential plant s>ecific initiating events as well 2s those initiating 36 events that have 3een identified in the Nuclear industry.
Evaluation of 37 initiating events will also include loss of support systems and other 38 special initiators.
39 Any changes to the PRA models used for the development of importance 40 measures for the R! IST will be independently reviewed.
The independent-41 reviews will be by either the in house personnel or outside consultants.
RISK INFORMED INSERVICE TESTING 1
DRAFT PROGRAM DESCRIPTION February 13. 1998
Enclosure to TXX 98039 l', Page 2 of 12 I
The PRA will be periodically evaluated (See Section 8) to reflect the i
2 current plant design, procedures, and programs.
Also the PRA will be 3
evaluated prior to moving components to the LSSC category.
l
~
4 A full scope PRA is not required. However, any limitations (e.g.
missing initiating events) will be addressed by the IDP using the 6
methodology described in Section 2 below.
7 The potential degradation of components will be considered in the 8
overall assessment of risk associated with the implementation of the RI-9 IST.
As a result, any effect on common cause failure estimations will 10 d o be evaluated.
To the extent possible, plant specific data will be 11 utilized to assess component de"adation.
12 Compensatory measures which are used as part of the IDP process to 13 cualitatively justify the extension of test interval will be re verified 14 curing the IDP process update (See Section 8).
15 2)
Comoonent Risk Category 16 Two figures of merit will be used to initially determine the risk 17 categories of IST components.
These two methods are Fussell Vesely (FV) 18 and Risk Achievement Worth (RAW).
For the RI IST Program, the following 19 criteria will be used to initially rank components for review by the 20 Integrated Decision Process (IDP).
21 Cateaorv Criterion 22 High FV > 0.001 23 Potentially High FV < 0.001 and RAW > 2 24 Low FV < 0.001 and RAW < 2 25 The aCDF and 6LERF for the change are within the acceptance 26 guidelines of Regulatory Guide 1.174.
27 Methodoloav/ Decision Criteria for Limited ScoDe PRA 28 The following describe = a methodology that may be used to 29 categorize components in the RI IST when the program is
- 3 0 --
reassese.ed.
However, only those elements that are significantly 31
.affected by the model changes (e.g., design modifications or 32 procedural changes) need to be reviewed in detail using this 33 process.
The scope of the review and the justification for it 34 will be documented as part of the IDP.
35 ADolv Imoortance Criteria to PRA and Review 36 Review FV and RAW importance measures for pumps and valves 37 considered in the PRA against the criterii and determine if tne 38 grouping of components is logical.
39 Review component importance measures to make sure that their bases 40 are well understood.
RISK INFORMED INSERVICE TESTING 2
DRAFT PROGRAM DESCRIPTION February 13. 1998
Enclosure to TXX 98039
,', Page 3 of 12 1
Robustness / Validation of Results Address the sensitivity of the results to common cause 2
3 failures (CCF), assuming all/none of the CCF importance is 4
6ssigned to the associated component.
Evaluate the sensitivity due to human action modeline.
5 6
Identify / evaluate operator actions omitted by the IPE that 7
can change the ranking of a com)onent.
The omitted recovery 8
actions are those not credited )ecause they are not 9
important to the CDF.
Consider industry history for particular IST components, 10~
11 Review such sources as NRC Generic Letters. SOERs. 10ERs and 12 Technical Bulletins and rank accordingly.
For components with low FV/high RAW ensure that other 13 14 compensatory measures are available to maintain the 15 reliability of the component.
Identify and evaluate components whose performanen shows a 16 17 history of caus' 1 entry into LCO conditions. To ensure 18 that safety margins are maintained, consider retaining the 19 ASME test frequency for these components.
Ensure that truncated components have been eliminated due to 20 21 redundancy of function rather than solely due to 22 reliability.
If they are truncated due to their high 23 reliability, then those components should be qualitatively 24 re evaluated and re categorized appropriately.
25 Validate or change the PRA based component ranking.
If the 26 validated PRA ranking is high, rank the component high: if t1e PRA 27 ranking is low and the other factors such as the operating 28 performance of the component validate the ranking, rank as low.
29 Fire. Tornado and Seismic Considerations 30 Consider the following for risk ranking cocponents for extr;rnal
-31 events-.
Calculate risk importance measures for components in the 32 33 fire and tornado cutsets.
Compare these calculated values 34 and'the PRA values to identify those components that are 35 less risk significerit for the IPE but more risk significant 36 for fire and tornado.
37 Review component importance measures and the PRA limitations 38 for fire and tornado in a r.anner similar to that described 39 for internal events discussed above and adjust the rankings 40 of the components accordingly.
RISK INFORMED INSERVICE TESTING 3
DRAFT PROGRAM DESCRIPTION February 13, 1998
i Enclosure to TXX 980.19
, ', Page 4 of 12 1
For those components on the Safe Shutdown Equipment List i
2 (SSEL) and the containment systems list, review their risk 3
categories to ensure that those components important to 4
seismic and containment integrity are appropriately 5
categorized.
6 7
Qutaae Criteria l
8 Consider the following for risk ranking of :omponents for outage 9
modes:
10 If a component performs the same function and is in the same 11 initial state as at power, the at power ranking usually 1
12 bounds the outage ranking.
If not, the risk category of the 13 component for the outage mode will be evaluated using a 14 qualitative set of rules.
If a component performs a different function or is in a 15 16 different initial state than at power, then the outage 17 ranking must be evaluated.
This is done using a qualitative i
18 approach where components are ranked into three categories I
19 based on a qualitative set of rules.
The risk categories 20 are defined as follows:
21 1.
Category 1: High safety significant components (High 22 FV) 1 23 2.
Category 2: Potentially high safety significant 24 component (low FV, moderate to high RAW) i 25 3.
Category 3: Low safety significant components (low FV, 26 low RAW) 27 Back.end imoortance 28 Consider components / systems that are potential contributors to 29 large, early release. There are essentially four groups of 30 potential contributors to large, early releases:
31 containment cooling systems 32 containment isolation valves e
33 e'
high to low pressure interfacing valves (i.e., interfacing 34 systems LOCA) 35 ECCS systems uniquely important to preventing high pressure 36 core damage scenarios 37 Determine FV LERF for components and/or determine which would have 38 the ecu1 valent of a high FV with respect to LERF and rank 39 accorc ingly.
40 IST Components Not in PRA 41 Review components not explicitly modeled in the PRA to ensure an 42 IST component is, in fact, low risk.
RISK INFORMED INSERVICE TESTING 4
DRAFT PROGRAM DESCRIPTION February 13, 1998
~.
Enclosure to TXX 98039
[, Page 5 of 12 i
Hiah Risk PRA Comoonents Not in the IST Proaram 2
Identify other high risk pumps and valves that are not in the IST 3
program but should be tested commensurate with their risk 4
importance.
i 5
Evaluate the PRA modeling assumptions, component failure 6
modes, operator actions, recoveries and any other effects 7
that could substantiate the components risk category as 8
"high risk" even if they are not in the IST Program, 9
Determine whether current plant testing is commensurate with 10 the importance of these valves.
If not, determine what 11 test e.g., the IST test, would be the most appropriate.
12 Other Considerations 13 Perform sensitivity studies, as needed, to evaluate the cumulative 14 impact of changes in the IST Program test strategies on the total 15 CDF.
16 l
17 3)
Intearated Decision Process 18 The purpose of utilizing the Integrated Decision Process (IDP) is to 19 confirm or adjust the initial risk ranking developed from the PRA 20
,asults, and to provide qualltative assessment based on engineering 21 judgement and ex urience. This qualitative assessment compensates for 22 limitations of tie PRA, including cases where adequate quantitative data 23 is not available.
24 The IDP utilizes deterministic insights, engineering judgement, 25 experience and regulatory requirements as described above in Section 2, 26 The IDP will review the initial PRA risk ranking, evaluate applicable 27 deterministic information, and determine the final safety significance 28 categories. The IDP considerations will be documented for each 29 individual component to allow for future repeatability and scrutiny of 30 the categorization process.
31 The scope of the IDP includes both categorization and application.
The 32 IDP is to provide deterministic insights that might influence 33 categorization.
The IDF will identify components whose performance 34 justifies a higher categorization.
35 The IDP will determine appropriate changes to testing strategies.
The 36 IDP will identify compensatory measures for potentially high components 37 or justify the final categorization.
The IDP will also concur on the 38 test interval for components categorized as low.
39 The end product of the IDP will be components categorized as Low Safety 40 Significant Component-(LSSC) or High Safety Significant Component 41 (HSSC).
42 In making these determinations, the IDP will ensure that key safety 43 principles, namely defense in depth and safety margins, are maintained 44 and that the chane i in risk for both CDF and LERF are acceptable per 45 the guidelines
n, sed in Section 2 at
,e.
The key safety principles RISK INFORMED INSERVICE TESTING 5
DRAFT i
PROGRAM DESCRIPTION February 13, 1998
_ _._ ~ _ _ _ -
Enclosure to TXX 98039
,\\Page6of12 1
are described below.
2 Defense in Deoth 3
To ensure that defense in depth is maintained by the CPSES RI IST 4
program, adherence to four basic principles will be reviewed and 5
documented as part of the IDP for any future changes to the program.
6 The following describes these four basic principles:
7 1.
No changes to the plant design or operation's procedures will be 8
made as part of the RI IST program which either significantly 9
reduce d?fense in depth or place strong reliance on any particular 10 plant feature, human action, or programmatic-activity.
11 12 2.
The results and dominant contributors to core damage risk will be 13 reviewed to ensure that the categorization of components using PRA 14 is done on an evenhanded basis covering the full scope of safety 15 functions. A review will be done to ensure that components which 16 mitigate the spectrum of accidents are not ranked low solely 17 because of initiating event frequency.
Further, sensitivity 18 studies will be performed fu human actions to ensure that 19 components which mitigate the s)ectrum of accidents are not ranked 20 low solely because of the re11a)111ty of a human action.
21 22 3.
The methodology for component categorization, namely the selection 23 of importance measures and how they are applied and understanding 24 the basic reasons why components are categorized HSSC or LSSC, 25 will be reviewed to ensure that redundancy and diversity are 26 preserved as the more important princiales.
If a component is 27 categorized as LSSC solely due to its ligh reliability, then it 28 must be confirmed that:
- 1) plant performance has been good and 2) 29 a compensatory measure or feedback mechanism is available to 30 ensure adverse trends in equipment performance can be detected in 31 a timely manner. A review will be done to ensure that relaxation 32 in the RI IST )rogram occurs only when the level of redundancy or 33 diversity in t1e plant design or operation supports it.
In this 34 regard, all components that have significant contributions to 35 common cause failure will be reviewed to avoid relaxation of 36 requirements on those components with the lowest level of 37 diversity within the system, 38 39 4.
The use of mult d e risk metrics, including core damage frequency 40 (CDF) and large early release frequency (LERF), with additional 41 checks for large but late releases and consequence mitigation, 42 will be done to ensure a reasonable balance between risk reduction 43 methods.-
r 44 Other Considerations Related To Defense In Deoth.
45 When the PRA does not explicitly model a component, function or mode of 46 operation, a qualitative method may be used to classify the component 47 HSSC or LSSC and to determine whether a compensatory measure is 48 required.
RISK INFORMED INSERVICE TESTING 6
DRAFT PROGRAM DESCRIPTION February U, 1998
~
- - _~
Enclosure to TXX 98039 Page 7 of 12 j
j i
Sufficient Safetv Harain is Maintained 2
The IDP will perform reviews to ensure that sufficient safety margir. is 3
maintained when compared to the existing IST program.
In performing 4
this review, the IDP will consider such things as proposed changes to j
5 test intervals and, where appropriate, test methods.
The IDP will 6
ensure that the )roposed compensatory measures are effective fault 7
finding tasks, w1ere this is required in the progrcm, to assure safety 8
margin is maintained.
To enhance the safety margin, the IDP will also 9
review PRA important com>onents not in the current IST program for 10 potential inclusion in t1e RI IST program.
]
11 Cateaorization Guidelines 12 Modeled Comoonents/ Functions I
13 For modeled compone,1ts/ functions with a FV 20.001 the IDP either 14 confirms the component categorization is HSSC or justification of 15 conservatism in the PRA model will be developed.
16 For modeled components / functions with a FV <0.001, but a RAW E2.0, i
17 the component will be categorized LSSC provided a compensatory 18 measure exists that ensures operational readiness and the 19 components' performance has been acceptable.
If a compensatory 20 measure is not available or the component has a history of 21 performance problems, the component will be ranked HSSC.
j 22 For modeled components / functions with a FV <0.001 and a RAW <2.0, 23 the component will be categorized as LSSC provided the com)onents' 4
24 performance has been acceptable.
For those components witi 25 performance problems, a compensatory measure will be identified to 26 ensure operational readiness or the component will be categorized t
27 as HSSC.
28 Non Hodeled ComDonents/ Functions 29 For components not modeled or the safety function not modeled in 30 the PRA, the categorization is as follows:
d' 31 If the sister train is modeled then the component takes that 32 final categorization.
33 If the component is implicitly modeled, the FV and RAW are 34 estimated and the deliberation is as discussed for modeled 35 components / functions.
36 If the component is not implicitly modeled. the system 37 ranking associated with the Maintenance Rule will be 38.
confirmed.
For confirmed system ranking, the component 39 performance history will be reviewed.
For acceptable 40 performance history the component will be categorized as 41 LSSC.
For poor performance history, a compensatory measure 4
42 will be identified to ensure operational readiness and the 43 comoonent categorized as LSSC, or if no compensatory 44 measures are available, categorize the component as HSSC.
RISK INFORMED INSERVICE TESTING 7
DRAFT PROGRAM DESCRIPTION February 13, 1998
Enclosure to TXX 98039
,', Page 8 of 12 1
Documentation 2
Documentation of the IDP will be available for review at the plant site, 3
4)
ItJLtf na Philosoohy 4
Motor Ooerated Valves (HOVs) 5 HSSC Testing will be performed in accordance with Code Case 6
OMN 1 (except the maximum test interval will be 6 7
years), and NRC Generic Letter 89 10 and 96 05 8
commitments.
9 LSSC Testing will be performed in accordance with Code Case 10 OMN 1 (except the maximum test interval will be 6 11 years), and NRC Generic Letter 89 10 and 96 05 12 commitments.
13 Performance Monitoring (applicable to HSSC and LSSC):
14 termination inspection 15 stem threads relubed 16 actuator gear box grease inspection 17 motor current trending 18 T drain ins)ection 19 limit switc1 gear box grease inspection 20 visual inspection of housings 21 stem nut staked and secure 22 23 Relief Valves 24 HSSC &
Testing will be performed in accordance with the Code 25 LSSC of Record as defined in 10CFR50.55a.
26 Performance Monitoring (applicable to HSSC and LSSC):
27 test results trended 28 new valves tested prior to installation 29-valves bench set at i 1% (where practical) prior to 30 installation 31 Check Valve Testina Strateav 32 HSSC Testing will be performed in accordance with the ASME 33 Code of Record as defined by 10CFR50.55a.
34 Certain HSSC check valves will also be tested in 35 accordance with the Check Valve Reliability Program 36 (CVRP). This program was developed in response to 37 IhP0 SOER 86 03.
Testing for the CVRP includes 38 nonintrusive testing (e.g. accoustic monitoring) and
-39 where conditions direct, valve disassembly.
The 40 enhanced nonintrusive testing provides fer condition RISK INFORMED INSERVICE TESTING 8
DRAFT PROGRAM DESCRIPTION February 13, 1998--
Enclosure to TXX.98039 Page 9 of 12 1
monitoring by comparing data from current testing to a
~
2 known baseline where the valve was operating in a j
3 satisfactory manner.
4 LSSC Testing will be performed in accordance with the ASME 1
5 Code of Record as defined by 10CFR50.55a except at a 1
6 test frequency not to exceed 6 years (with 25%
7 margin).
I 8
Certain LSSC check valves will be tested in accordance 9
with the CVRP as necessary.
l 10 Performance Monitoring (applicable to HSSC and LSSC):
I 11 acoustic monitoring data is trended 12 Air Ooerated Valves (A0Vs) 13 HSSC Testing will be performed in accordance with the Code 14 of Record as defined by 10CFR50.55a.
15 LSSC Testing will be performed in accordance with the Code 16 of Record as defined by 10CFR50.55a except with a test 17 frequency not to exceed 6 years (with 25% margin).
18 Additionally LSSC A0Vs will be stroked at least once 19 during the operating cycle.
20 Performance Monitoring (applicable to HSSC and LSSC):
21 diagnostic testing 22 elastomer replacement program i
23 response time testing 24 Note: Currently certain A0V's are tested using diagnostic 25 equipment. TV Electric is participating in a tailored.
26 collaboration project with EPRI to develop an A0V program
.27 similar to the MOV Program mandated by GL 39 10 and 96 05.
+
28 This program will evaluate the valve / operator-29 characteristics / capabilities and the design conditions under 30 which the valve is expected to operate.
Once this 31 information is= developed the valves will be tested and 32 modified as necessary to meet their safety function.
33 Pumps i
-34 HSSC Testing will be performed in accordance with the Code 35 of Record as defined by 10CFR50.55a.
36 LSSC Testing will be performed-in accordance vith the Code 37 of Record as defined by 10CFR50.55a except with a test 38 frequent.y not to exceed 6 years (with 25% margin).
39 Performance Monitoring (applicable to HSSC and LSSC):
40 thermography of the drivers RISK INFORMED INSERVICE TESTING 9
DRAFT PROGRAM DESCRIPTION February 13. 1998
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Enclosure to TXX 98039
[, Page 10 of 12 1
lube oil analysis e
2 alignment checks e
3 motor current testing 4
vibration monitoring 5
6 5)
Cumulative Imoact 7
Evaluate the cumulative impact of the test frequency changes on total 8
plant risk (i.e., CDF and I.ERF) to ensure that the change in plant 9
safety is within the acceptable range. This is done by the following 10 methods:
11 The PRA models will be updated to reflect the changes to the test 12 frequency of modeled compenents, and the PRA study will be re-13 evaluated to quentify the aggregate impact of the changes.
14 e
The cumulative impact of the test frequency changes will be 15 reviewed through the IDP.
16 6)
Imolementation 17 Implementation of the RI IST to LSSC will consist of grouping components 18 and then staggering the testing of the group over the test frequency.
19 Grouping:
20 Components will be grouped based on:
21 manufacturer 22 model 23 service condition 24 size 25 The population of the group will be dependent on:
26 total population available 27 maintaining current testing schedule 28 Grouping components in this manner and testing on a staggered basis over 29 the test frequency will reduce the importance of common cause failure 30 modes as com>onents in the same staaaerina failure mode group are 31 continually )eing tested.
This ensures that the component capability 32 will be maintained over the test interval (i.e., 6 years).
33 Testing of components within the defined group will be staggered over 34 the test interval. typically 6 years. Testing will be scheduled on 35 regular intervals over the 6 year period to ensure all components in the 36 group are tested at least once during the 6 year test interval and not 37 all components are tested at one time. The staggering allows the 38 trending of components in the group to ensure tno test frequency
-39 selected _is appropriate.
-40 Testing will be scheduled / planned such that there "s no more than one 41 cycle between tests of components in a group.
RISK INFORMED INSERVICE TESTING 10 DRAFT PROGRAM DESCRIPTION February 13, 1998 l-.
Enclosure to TXX 98039 Page 11 of 9 1
7)
Corrective Action 2
When a componer.t on the extended test interval fails to meet established 3
test criteria, corrective actions will be taken in accordance with the 4
CPSES corrective action program as described below for the RI IST.
5 For components not meeting the acceptance criteria, an Operation 6
Notification and Evaluation (ONE) Form will be generated.
This document 7
initiates the corrective action
)rocess.
Also, the initiating event for 8
a ONE Form may be from causes otler than an unacceptable IST test.
9 Programt axist that provide timely information to the IST coordinator 89 that the performance of a reliable component has degraded.
For example, tI a common compensatory action for pump discharge. check valves would be 12 the IST >um) test.
Since this test can not be considered satisfactory 13 if the c1ect valve fails to perform its risk significant function, a 14 test failure would be recorded and a ONE Form initiated. The recorded 15 information could then be used to assess whether a significant change in 16 component reliability has occurred such that the component would merit a 17 change in test interval.
18 The initiating event could be any other indication that the component is 19 in a non conforming condition.
The unsatisfactory condition will be 20 evaluated to:
21 a)
Determine the impact on system operability and take appropriate 22 action.
23 b)
Review the previots test data for the component and all components 24 in the group.
25 c)
Perform a root cause analysis.
26 d)
Determine if this is a generic failure.
If it is a generic 27 failure whose implicaticns affect a group of components, initiate 28 corrective action for all components in the affected group.
29 e)
Initiate corrective action for failed IST components.
30 f)
Evaluate the adequacy of the test strategy.
If a change is 31 required, review the IST test schedule and change as appropriate.
32 The results of component testing will be provided to the PRA group for 33 input to PRA model evaluation.
(See Section 8) 34 For an emergent plant modification, any new IST component added will 35 initially be included at the current Code of Record test frequency.
36 Only after evaluation of the component through the RI IST Program (i.e.,
37 PRA model evaluation if applicable and IDP review) will this be 38 considered LSSC.
39 8)
Periodic Reassessment 40 As a living process, components will be reassessed at a frequency not to 41 exceed every other refueling outage (based on Unit I refueling outages) 42 to reflect changes in plant configuration, component performance test 43 results, industry experience, and other inputs to the process.
The RISK INFORMED INSERVICE TESTING 11 DRAFT PROGRAM DESCRIPTION February 13. 1998
Enclosure to TXX 98039
,, Page 12 of 12 I
1 RI IST reassessment will be completed within 9 months of completion of 2
the outage.
1 3
Part of this periodic reassessment will be a feedback loop of 4
information to the PRA.
This will include information such as 5
components tested since last reassessment, number and type of tests, 6
num)er of failures, corrective actions taken including generic 7
implication and changed test frequencies.
Once the PRA has been 8
reassessed, the information will be brought back to the IDP for 9
deliberation and confir;.ation of the existing lists of HSSCs and LCCSs 10 or modification of these lists based on the new data. As part of the 11 IDP, confirmatory measures previously utilized to categorize components 12 as LSSC will be validated. Additionally, the maximum test interval will 13 be verified or modified as dictated by the IDP, i
14 9)
Chanaes to RI IST 15 Changes to the process described above and to the evcluation of risk 16 impact will require prior NRC approval.
Changes to the categorization 17 of components and associated testing strategies using the above process 18 will not require prior NRC approval. As changes to component 19 categorization are made TU Electric will periodically submit them to 20 the NRC for their information.
i I.
RISK INFORMED INSERVICE TESTING 12 DRAFT PROGRAM DESCRIPTION February 13, 1998
_