ML20136B039
| ML20136B039 | |
| Person / Time | |
|---|---|
| Issue date: | 06/12/1995 |
| From: | Spessard R NRC (Affiliation Not Assigned) |
| To: | Wiggins J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20136A631 | List: |
| References | |
| FOIA-97-045, FOIA-97-45 NUDOCS 9703100134 | |
| Download: ML20136B039 (2) | |
Text
- . .. . .. .. . .-
,y na f UNITED STATES
[ ?g S NUCLEAR REGULATORY COMMISSION U f WASHINGTON D.C. 20h0001 p l
- June 12, 1995 MEMORANDUM T0: James T. Wiggins, Director Division of Reactor Safety, Region I Albert F. Gibson, Director Division of Reactor Safety, Region II Geoffrey E. Grant, Director Division of Reactor Safety, Region III Thomas P. Gwynn, Director Division of Reactor Safety, Region IV FROM: R. Lee Spessard, Director ,,
- #eb Division of Technical Support Office of Nuclear Reactor Regulation
SUBJECT:
TEMPORARY INSTRUCTION 2515/126, "EVALUAI10N OF ON-LINE ,
MAINTENANCE" s
The purpose of this memorandum is to provide you with the results and conclusions from the evaluation of inspection findings using Temporary Instruction (TI) 2515/126, " Evaluation of On-line Maintenance." The TI was issued October 27, 1994, and the inspections were completed by the specified date of December 31, 1994.
A review committee, within the Office of Nuclear Reactor Regulation (NRR), was established to consolidate and review the TI inspection results and evaluate the industry's policies and controls concerning current on-1(ne maintenance practices. The results of the review committee's initial review were documented in a letter to the Nuclear Energy Institute (NEI) dated February 24, 1995 (see attachment 1). A more detailed summary of their findings and conclusions is provided as attachment 2 to this letter. Although this " snapshot" of licensees' on-line maintenance activities revealed several weaknesses (i.e., lack of comprehensive risk assessments, procedural controls, and training), the TI results did not identify any significant safety concerns. As discussed in the attached summary report, many of the reported TI inspection findings were incomplete and would require extensive followup to fill in the voids. Licensees' on-line maintenance practices and programs are changing and will continue to evolve as they implement the maintenance rule.
Therefore, a fill-in-the-blank approach at this point would not accurately reflect the licensees' activities when the TI was initially implemented and our initial baseline review was conducted.
In addition, both the Institute of Nuclear Power Operations (INPO) and NEI are aware of our concerns with on-line maintenance and are actively developing guidance and monitoring and assisting licensees in the INP0development and a recently issued implementation of suitable programs and ' controls.
I 9703100134 970305 PDR FOIA //f CURRAN 97-045 PDR
- E-letter te the EmJt%e 7tbavut b Operat90ts @T07 em a sample letter that was provided to each of IND03 member #i%r.ies proMmg detailed guidance for managing maintenact derits power <cpertt Imd
" Industry Guideline -for Moni.tcenug f be Effnr.isenma cf Wintenance at Nuclear Power Plants." Thes.e reviskra e omd m mr hdMts from the TI and the maintenance rule pilot site wi.nts, vid utll Svovide .gvidance to the industry on developing effective prograr, to contrc5 on-?.bre maintenance and associated activities in cccordance with the waintenante rule.
The Quality Assurance and Maintenance Branch (TQMB), with support from the regions and the Probabilistic Safety Assessment Branch (SPSB), has ccepleted nine pilot licensee visits to evaluate implementation activities in accordance In general, these assessments have indicated that with the maintenance rule.
licensees are in various stages of implementation, and that the implementation activities are progressing. During the pilot site visit in March 1995, for example, Crystal River was found to have made significant progress in on-line maintenance planning. At the time of the TI inspection in December 1994, Crystal River did not appear to formally incorporate risk insights into maintenance planning, while by March they were using a comprehensive on-line '
risk monitor to evaluate overall plant safety before and during on-line maintenance activities.
Regional offices may wish to utilize the information gained from the TI l results, provided in the attachments, as a meter to allocate inspection '
resources to assure all licensees are adequately evaluating the overall plant safety impact prior to the removal of equipment from service for on-line maintenance. We plan.to revise the core maintenance inspection procedure '
(IP) 62703, " Maintenance Observation," in early fall 1995 to include requirements and guidance for resident inspectors to continue to monitor l licensees' on-line maintenance practices and activities, particularly when to This revision potentially risk significant configurations are identified.IP 62703 w effect in July 1996. At that time, a new inspection procedure will be issued which details the inspection requirements for monitoring licensee compliance i with the rule including specific inspection guidance regarding on-line We are planning detailed training sessions for the maintenance activities.
regional inspectors beginning in the fall of 1995 on the maintenance rule inspection procedure, which will also include a discussion on the revised IP 62703.
In conclusion, it appears that the industry is aware of and reacting to NRC concerns with on-line maintenance practices, but continued inspection by the regional offices may be necessary to monitor and assess licensees' on-line We recommend that, aside from the revision to the maintenance activities. 2515/126 be inspection procedure, the NRR activities associated with TI considered complete.
Attachments: As stated i
A
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f ., , i UNITED STATES
~
i NUCLEAR REGULATORY CO"M'SSION
'g5 f [ wassiNcioN. D C 205SWO'
%, /
.....~ February 24 1995 Mr. Thomas Tipton
. Nuclear Energy Institute 1776 I Street NW, Suite 400
- Washington, DC 20006-3708
Dear Mr. Tipton:
As you are aware, the NRC has expressed a concern that licensees appear to be i performing maintenance activities more frequently during power operation without a complete understanding and evaluation of the potential impact on safety. These concerns were previously addressed in letters to the Institute of Nuclear Power Operations (from J. H. Sniezek to K. A. Strahm, dated December 27, 1990, and from J. M. Taylor to Z. T. Pate, dated October 6, 1994)
, and the Nuclear Energy Institute (from W. T. Russell to J. F. Colvin, dated October 6, 1994).
1 NRC Temporary Instruction (TI) 2515/126, " Evaluation of On-line Maintenance,"
was developed and implemented to take a narrow look at licensees' practices regarding the removal of equipment from service for scheduled on-line maintenance and its potential impact on safety. The NRR staff has completed its initial review of the TI preliminary inspection findings from each of the sixty-eight (68) plant sites. It is important to note that many of the TI l inspection findings reviewed by the NRR staff were inspection report inputs '
that had not been issued or reviewed by regional management. However, based on this initial review, we were able to gain several insights and draw general
, conclusions about the policies and programs established by licensees to control the risks associated with performing maintenance octivities during
- power operations.
We determined that nearly all of the U.S. nuclear power plants currently perform a significant amount of their scheduled preventive maintenance during ;
power operations, and this trend appears to be increasing. The majority of l the plants appear to coordinate on-line maintenance efforts to minimize out- 1 of-service time and maximize system availability. However, few plants consider the effects of non-safety related systems or use comprehensive plant safety (risk) assessments.
Many licensees appear to incorporate PRA insights when scheduling and planning on-1ene maintenance. However, the tools used by licensees appear to vary wfJely in approach, dependability, and sophistication. With respect to the training, knowledge, and awareness of risk insights of plant personnel, few plants appear to have formal training programs which include planning and control of on-line maintenance and insights from available PRAs. Training and awareness of risk insights often appeared to be limited to upper management.
schedulers, and operators and the level of awareness varied significantly among plants.
,,,1, Attachment 1
&,_a, , /v,, _3 w i; 6_,
~~~
T. Tipton ,
. l We will continue to evaluateand'*.ill the Il continue rew% arrJ mcmicm our n; e mmunicate ticamsees' activit!
in the area of on-line maintenanti :
concerns and observations in th.15 area pth Nf:1 and 'NRC liunsees.
Sinc'e re)f.
Cr '. ;us 11 gr er: sy 5wa: ean for:
Ashok Thadani, Associate Director for Techtical Assessment Office of Nuclear Reactor Regulation TQMB R/F DOTS R/F DISTRIBUTION: CENTRAL FILES /PDR
- SEE PREVIOUS CONCURRENCE DOCUMENT NAME: G:\ final \2515-126.kir w c cm ..mn, e. .. r.cm -e.w.w.. u .u.em ra - . .r e : - . m . DOTS /NRR l TQMS/ DOTS l TECM EDITOR l 0FFICE TQM5/ DOTS l 10MS/ DOTS l Calvo/Spessard RCorrefs SBlack CAME RFrohmJr 2/16/95 2/16/95 2/17/95*
2/16/95* 2/16/95*
DATE 2/16/95* tir l AC/A07 l D/ DISP l AD/ Arc 8
'0FFICE D/DSSA l Afhadani/GMotahan ,
RZttnmerman GMotahan(RJones) FGil,tespie l RAME 2/22/95* 2/22/95*
DATE 2/16/95* 2/21/95* i l D\NRR l OFFICE DD\hRR FMiragtia* WRussell*
KAME 2/24/95 2/24/95 ;
DATE Off!LIAL RECORD COPY r d
NRR TI 2515/126 REVIEW COMMITTEE ,
SUMMARY
OF RESULTS '
- I. Background
)
1
- During plant visits by several NRC senior managers, it was noted that licensees appeared to be increasing both the amount and frequency of maintenance performed during power operation. The licensees' expansion of the on-line maintenance concept without thoroughly considering the safety (risk) aspects raised significant concerns. As a result, Temporary Instruction
+
(TI) 2515/126, " Evaluation of On-line Maintenance" was developed and i
implemented to evaluate the impact on safety of licensees' practices regarding the removal of equipment from service for on-line scheduled maintenance. The inspections were completed by December 31, 1994, as required by the TI.
A review committee, within the Office of Nuclear Reactor Regulation (NRR), was established to consolidate and review the TI inspection results and evaluate
~
the industry's policies and controls concerning their on-line maintenance practices. The multi-disciplined review committee consisted of Ronald Frahm from the Quality Assurance and Maintenance Branch, James Luehman from the Technical Specifications Branch, Samuel Lee from the Probabilistic Safety Assessment Branch, George Thomas from the Reactor Systems Branch, and David l 1 Allsopp from the Inspection Program Branch. The review committee has !
completed its initial review of the TI preliminary inspection findings from l each of the sixty-nine (69) plant sites.
1
' It is important to note that many of the inspection findings reviewed by the review committee were preliminary copies of inspection report inputs which had not been issued nor reviewed by regional management. Due to the time )
constraints and the volatility of licensees' on-line maintenance programs, the i
review committee did not investigate and followup on issues that were unclear 1
in the inspection report inputs. This report summarizes the insights gained from the initial review of the TI inspection findings and provides preliminary conclusions about the licensees' policies and programs established to control the risks associated with performing maintenance activities during power
- operations.
II. Frequency of On-line Maintenance The review committee determined that nearly all of the U.S. nuclear power plants performed some of their scheduled preventive maintenance during power operations ("on-line"). The preliminary inspection findings revealed that only six (6) of the sixty-nine (69) plant sites do not presently perform any
- on-line maintenance. Of these six, all but two (2) indicated that they were l planning to develop and implement an on-line maintenance program in the near future. The majority of the plants, however, perform a significant amount of on-line maintenance, and this trend appears to be increasing. Some plants appear to be performing, or planning to perform, as much maintenance on-line 3 as possible while attempting to operate the plant safely and efficiently. As previously documented in NRC Inspection Manual, Part 9900
- Technical Guidance,
" Maintenance - Voluntary Entry into Limiting Conditions for Operation Action Statements to Perform Preventive Maintenance," and letters to the industry, Attachment 2
the practice of on-Time rainunance should be /mih5 tn these instances
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driven by a net .saf ety ihendit, sinng due conv&rtian tz overall plant safety at the actua? hme uf th mai,nfennatcrt, u k wermded iy operational -
necessity, not by convenienre_
III.
Established Policy and Prpredural Lottroh In general, the inspettions revnM that De medrews ud grocedures used to control activities being performed vMe the plant n. sperating have not performance of a changed significantly despite the mPphicabons added by tbt large amount of maintenance on-line. 7he mdority of the plants appeared to coordinate on-line maintenance Mostefforts plantstoincorporated minimize out-of-service time and a " window" concept to maximize system availability.
plan and control on-line maintenance outages, typically rolling twelve (12) or thirteen (13) week schedules, with a different system allocated to each week.
These controls appeared to help minimize the number of times that a system is removed from service by consolidating surveillances, maintenance, and testing activities to a single outage per cycle. Other licensees used a " train" concept to assure that maintenance activities were limited to a single train at any given time. In most cases, licensees appeared to attempt to minimize out-of-service time (and maximize equipment availability) when performing maintenance at power. Most plants had established policies which required limiting conditions for operation (LCO) maintenance to be completed within a Few licensees, certain percentage of the allowed outage time (typically 50%).
however, considered the risks associated with non-safety related equipment, limiting their analysis to the emergency core cooling systems and other equipment as described in the technical specifications.
Several of the licensees appeared to have policies in place that prohibited or discouraged multiple train outages. The majority analyzed plant conditions to assure the operability of diverse or redundant equipment before taking a system or component out-of-service. There were others, however, that permitted multiple train outages to the maximum extent allowed by their technical specification LCOs. The more conservative licensees limited on-line maintenance activities to one component or one LC0 entry at a time. A few plants reportedly added fully functional spare (back-up) components Based on while broad performing on-line maintenance to further minimize risk.
reviews of licensees' upcoming maintenance schedules, the inspectors did not identify any prominent instances where planned on-line maintenance could However, potentially result in a significant impact on plant safety (risk).
these brief inspections only looked at a small portion of each plant's schedule, and did not involve detailed risk evaluations.
The degree of commitment to the various practices used to minimize equipment unavailability varied widely. At one plant the practices might be enforced by strict procedural controls, while at another they might simply be goals The contained in a scheduling guidance document or unwritten good practices.
majority of the plants, in fact, did not appear to have formal in many procedures of the in plants that place to control on-line maintenance activities, had procedural controls, the detailed requirements for a risk analysis prior to the voluntary removal of equipment from service were not defined in the procedure. A few of the plants reportedly had performed self-assessments of their on-line maintenance programs in an effort to improve the related policies and procedures to more effectively control these activities. Some plants had either started or planned to incorporate risk assessments and other controls into their formal procedures to minimize the risk impact of performing maintenance at power.
IV. Incorporation of PRA Insights into Planning and Controls Many licensees appeared to incorporate PRA insights when scheduling and planning on-line maintenance. However, the tools used by the licensees to assess safety (risk) appeared to range widely in approach, dependability, and sophistication. These tools, or means to conduct safety (risk) assessments, typically consisted of one of the following: reliance on operations and l maintenance personnel knowledgeable of high risk plant configurations, )
consulting the plant PRA/PSA group, using a matrix depicting risk-significant '
combinations of equipment (limited to one-to-one system comparisons which did not consider the combinations of taking three or more systems out of service simultaneously), applying Individual Plant Evaluation (IPE)-based accident sequences to quantify risk, and using computer-based programs to monitor current risk configuration of the plant. Many of the licensees that relied on less sophisticated types of safety (risk) assessments reportedly expressed '
their intentions to upgrade their assessment capability. However, even these enhancement plans differed widely among the licensees, with some licensees settling for qualitative assessment tools and others developing computerized on-line risk monitors. Still, there were several licensees who appeared to be performing on-line maintenance without conducting any type of risk assessment using PRA insights.
The risk insights from the IPE did not appear to be utilized at most plants in their operational and maintenance decision process. For those licensees who evaluated risk, many did not appear to be considering all of the three risk factors cddressed in TI 2515/126, namely the probability of an initiating event, the probability of not being able to mitigate the event and prevent core damage, and the probability of not being able to mitigate the consequences of the event by preserving containment integrity. Most licensees appeared to concentrate solely on accident mitigation when evaluating risks.
A few licensees, however, were reported to consider the potential increased probability of an initiating event, and fewer were reported to consider the probability of being able to maintain containment integrity to prevent radioactive release to the environment.
To track equipment unavailability due to preventive on-line maintenance, a few licensees seemed to have developed programs to monitor equipment out-of-service (00S) times. Although most licensees appeared to place an administrative limit on outage times (i.e., 50% of the LC0 allowable outage time) and attempted to minimize 00S time for a given system or component, many of them did not appear to consider the cumulative 005 times. While the tracking of cumulative 005 times is not presently required for most equipment, some licensees are taking steps toward tracking equipment availability in preparation for the implementation of the maintenance rule (10 CFR 50.65). In addition to providing information for compliance with that regulation, tracking of ;umulative 00S times provides a means of validating IPE equipment
~
availability assumptions. The inspections did mote 1 Inupe of examplesIt of cquipment exceeding the cumulative 005 tin:e assumed in it e plant IPE. -
could not be determined,, ho. sever, if this was a prw31ent problem in the industry because of the inconsistencies in tracking unavailability times as discussed below.
The majority of *those plats Yeat reportedly had such equipment monitoring programs did not appear to track total equipment unavailability, which in addition to preventive maintenance, includes torrective maintenance, surveillances, and testing. This lack of consistency in measuring OOS time can significantly alter the result of a plant's overall safety (risk) assessment. Additionally, the programs were typically designed to monitor 005 time for safety-related equipment per technical specifications only; the non-safety equipment that may also be risk significant was rarely monitored.
In general, there seems to be a wide range of capability and variability in practice among the licensees to incorporate safety (risk) assessments for conducting preventive on-line maintenance. There seems to be a trend to incorporate more risk-based inputs and to upgrade risk assessment capabilities as the industry moves toward more on-line preventive maintenance.
V. Awareness and Training of Personnel Although the majority of the relevant personnel appeared to be knowledgeable of the scheduling and maintenance activities associated with on-line maintenance, very few of them understood or had training in PRA insights or their plant's IPE. Few of the plants appeared to have formal training programs that included planning and control of on-line maintenance and the insights to be gained by using PRA or other risk evaluations. Training and awareness were often limited to upper management, schedulers, and/or operators, and the level varied significantly between plants. Some of the plants relied heavily on the insights of experienced operations and maintenance personnel to assess the potential risks associated with planned on-line maintenance. A few of the plants indicated that they intend to formally train all pertinent plant personnel on the policies, procedures, and risks associated with on-line maintenance, but the timetables for such training were not clear.
VI. Conclusions The review committee determined that nearly all of the U.S. nuclear power plants currently perform a significant amount of their scheduled preventive maintenance during power operations, and this trend appears to be increasing.
Although most licensees appear to attempt to control on-line preventive maintenance and satisfy current regulatory requirements, comprehensive plant safety (risk) assessments are not typically completed prior to performing the maintenance activities. The majority of the plants appear to have only informal policies in place and have not developed detailed procedures to control on-line maintenance activities and conduct the associated safety In fact, a significant number of licensees appear to be (risk) assessments.
performing on-line maintenance without formal procedural controls, training, or consideration of risk insights. The committee did note that some of the
i l plants with these weaknesses are in the process of or have plans for enhancing
- their controls of on-line maintenance activities in preparation for
, implementation of the maintenance rule.
1
} In general, the industry appears to be adopting the practice of on-line 2 maintenance faster than it is developing and implementing effective controls
! to manage the safety (risk) implications of this practice. Although the 4 limited NRC inspection of on-line maintenance practices did not identify any q risk-significant implementation problems, it is imperative that licensees j carefully control on ....e maintenance activities to preclude significant i risks. The review committee recomends that the NRC continue to monitor licensees' activities in the area of on-line maintenance to assure that all i licensees have formal programs developed and implemented when the maintenance rule becomes effective on July 10, 1996.
i VII. Plant Review Summary
! The following table was developed by the review committee while evaluating the i Tl 2515/126 inspection findings. The information contained in the table i summarizes those findings and may be helpful to the regions when planning and 4 scheduling inspections. For each of the 69 plant sites, the table contains .
the review committea'c answers to ten questions, which are as follows: l 1
L 1. Does the licensee perform on-line preventive maintenance (PM)?
, (Consider frequency and trending information.)
i 2. Does the licensee plan and control on-line PM activities? (Consider t schedule adjustments to account for degraded or inoperable equipment.) ;
e
- 3. Does the licensee have in place formal procedures to schedule and !
j control on-line PM7 j j 4. Does the licensee incorporate PRA insights? 1
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- 5. Does the licensee use sophisticated quantitative or simple qualitative risk models?
- 6. Does the licensee consider the risk significance of maintenance J activities on both safety-related and non-safety-related equipment?
- 7. Does the licensee consider the operability and reliability of '
redundant / diverse systems?
3 8. Does the licensee monitor out-of-service (005) time?
- 9. Does the DOS include all potential unavailabilities (e.g.,
surveillances, PM, corrective maintenance, etc.)?
l 10. Are licensee personnel knowledgeable and trained? (Consider both a j basic knowledge of scheduling and maintenance activities as well as
- detailed PRA/IPE understanding.)
< l l Table 1. Site-Specific Summary Data ,
! PLANT REGION Q1QZ M M M M E M M Q1Q .
BEAVER VALLEY I Y Y Y N NA N Y- NR NR NR ,
. CALVERT CLIFFS I Y Y Y- Y S NR Y- NR NR Y FITZPATRICK I N+ NA NA NA NA NA NA NA NA NA 1 HADOAM NECK 'I Y+ Y NR N+ NA NR Y Y- Y- NR 1
- HOPE CREEK 1 Y+ Y NR Y S+ NR Y NR NR Y- l j 1
-- , ,, t-
-e ---g ----,,-,-a-, . , . ~ , ,mm
Table 1. Site--Specifit lumnrar.y ' Data (cnotinued)
PLANT REGION Q1 12 Q3 .Qf j) IL6 Q1 A8 Q9 QLQ INDIAN POINT 2 I Y Y N N NA NR Y NR NR Y-LIMERICK I Y Y' Y Y Q NR Y Y Y Y-MAINE YANKEE i Y Y Y Y S- NR Y- NR NR Y MILLSTONE I Y Y Y Y S+ N Y N N NR NINE MILE POINT I Y Y Y Y S- NR NR NR NR NR OYSTER CREEK I Y Y Y Y S- NR Y NR NR Y-PEACH BOTTOM I Y Y Y Y NR NR Y Y NR NR PILGRIM I Y Y Y Y S+ NR Y NR NR Y-R.E. GINNA I Y Y Y Y S NR Y NR NR NR SALEM I Y- Y Y Y Q- Y Y NR NR Y-SEABROOK I N+ NA NA NA NA NA NA NA NA NA SUSQUEHANNA I Y Y N+ Y S- NR Y- NR NR Y-THREE MILE ISLAND I Y Y N+ N+ NA Y Y NR NR NR VERMONT YANKEE I Y Y Y N+ NA NR Y Y- Y- NR BROWNS FERRY II Y Y Y- N+ NA Y- Y NR NR NR BRUNSWICK II Y Y Y- N NA NR NR NR NR NR CATAWBA II Y Y- Y- N N NR Y- NR NR N CRYSTAL RIVER II Y Y Y Y- NR NR Y Y Y NR FARLEY II Y+ Y N N NA NR Y NR NR NR GRAND GULF II Y Y Y Y S+ NR Y NR NR Y-HATCH 11 Y Y Y N NA NR Y NR NR NR H.B. ROBINSON II Y Y Y- N+ NA NR Y NR NR NR McGUIRE II Y Y N N NA NR Y Y Y- Y-NORTH ANNA II Y+ Y N Y S+ N Y Y Y Y-OCONEE II Y N N N N+ N N NR NR NR SEQUOYAH II Y Y Y N N+ NR Y NR NR Y-SHEARON HARRIS II Y Y Y- N+ NA NR Y NR NR N+
ST. LUCIE II Y Y Y Y- S NR NR NR NR N SUMMER II Y Y N N NA NR Y NR NR NR SURRY II Y Y N N N N Y NR NR NR TURKEY POINT II Y Y Y- Y NR Y Y NR NR Y '
V0GTLE II Y Y NR Y- S N+ Y N+ NR NR BIG ROCK POINT III N NA NA NA NA NA NA NA NA NA BRAIDWOOD III Y Y N N+ S- N- N NR NR Y-BYRON III Y+ Y N Y S+ N Y NR NR NR f CALLAWAY III Y Y Y Y S- N Y Y- Y- Y- l CLINTON III Y+ Y N Y S Y N Y- Y- Y-DAVIS-BESSE III Y Y Y Y S NR NR NR NR Y- ,
D.C. COOK III Y Y Y Y S Y Y NR NR NR l DRESDEN III Y+ Y- N N N N N N N NR DUANE ARNOLD III Y Y NR Y S+ Y Y- NR NR NR FERMI III Y+ Y N Y S N+ N+ NR NR N KEWAUNEE III N+ NA NA NA NA NA NA NA NA NA LASALLE- III Y Y Y N+ S Y- Y- NR NR NR MONTICELLO III Y Y Y Y- S- NR NR NR NR NR PALISADES III Y Y N+ Y Q- NR NR NR NR Y-PERRY III Y Y- N Y- S N Y- NR NR Y-t L_____m-- ____- + -r - - wp y-
Tabl'e I. Site-Specific Summary Data (continued)
PLANT REGION Q1 E M Q4 M M DZ g M QLO.
POINT BEACH III Y Y Y Y S- N Y Y Y N+
l PRAIRIE ISLAND III Y Y N N+ N+ NR NR NR NR NR
- QUAD CITIES III N NA NA NA NA NA NA NA NA NA l ZION III Y Y Y Y Q Y Y NR NR NR ANO IV Y Y Y- N NA NR Y NR NR NR COMANCHE PEAK IV Y Y Y Y S Y Y NR NR Y t COOPER IV N+ NA NA NA NA NA NA NA NA NA
! DIABLO CANYON IV Y Y Y Y Q Y Y Y Y NR FORT CALHOUN IV Y Y Y Y S NR Y NR NR NR PALO VERDE IV Y Y NR Y S+ NR Y NR NR NR RIVER BEND IV Y Y N+ N+ NA NR Y NR NR NR SAN ON0FRE IV Y Y Y Y Q Y Y NR NR Y SOUTH TEXAS IV Y Y N N+ NA NR NR NR NR Y-WATERFORD IV Y Y- N Y S+ Y Y Y- Y- Y-WNP-2 IV- Y Y Y Y- S Y Y Y- N NR WOLF CREEK IV Y Y Y Y- S NR Y NR NR NR Key: "Y" - yes, "N" - no, "NA" - not applicable, "NR" - not reported, "S" - simple qualitative, "Q" - quantitative risk methods,
"+" - increasing trend or planned improvements, and " " - with weaknesses.
1 1
l j 1
Institute el 700 Galleria Parkcay Nucleat Power Atlanta, GA 30339 5957 -
Operallons 404 644 8000 FAX 404 644 8549 Cy aylcr lhoan Ihompson 11aha March 1,1995 (x/.krJe Y d: Jord-Mr. James M. Taylor Executive Director for Operations jl8, def U.S. Nuclear Regulatory Commission 11555 Rockville Pike /Np M #-
Rockville, MD 20852 y,/J1/ &cc
)
Dear Mr. ylor; On Febn2ary 17,1995, we sent the attached letter to each ofINPO's member utilities.
It includes an attachment entitled ManagingMaintenance During Power Operatioru.
Information in the attachment was derived from collective industry experiences, with significant input from the Electric Power Research Institute and the Nuclear Energy Institute. l It will later be incorporated into appropriate INPO Guidelines.
We are providing you a copy of this letter and its attachment as part of our effort to keep NRC informed ofINPO activities in accordance with our Memorandum of Agreement, and because of the interest and concern expressed in your October 6,1994, letter regarding the conduct of maintenance during power operations.
Sincerely, Zack T. Pate President ZTP:Isb Attachments cc/w: Mr. J. Phillip Bayne, NEI Attachment 3 Q W r 4 W -f'7
Inslltulo of 700 Galleria Parkcay Nuclear P0 Der Atlanta. GA 30339 5957 3 Opers! Ions 40;.644.go00 FAX 404 644 8549 SAMPLE LETTER to executive points l of contact with carbon copies per roster.
Carbon copies with attachment tc, administrative points ofcontact. Internal February 17,1995 Distribution: president's office, executive vice president, division directors, team managers, and records center.
l l
Dear :
The purpose of this letter is to provide information on managing maintenance l during power operations. This infomiation is intended to complement existing INPO and other industry guidance on this subject and should be useful for preparing or resiewing plant-specific policies and procedures that address such activities. The content is based on practices common to plants that are effectively managing and conducting on-line maintenance.
Performance of maintenance or modifications on plant systems during power operations has been a subject of considerable discussion for several years. During this time, the availability of probabilistic safety assessments has improved and is now a useful )
supplement to other safety analyses, operating experience, and soundjudgment. Station ;
managers are thus better able to ensure a proper balance between the benefits of performing on-line maintenance and the potential impacts on safety and reliability. l The benefits of on-line maintenance include increased system and unit reliability, reduction of plant equipment and system materiel condition deficiencies that could adversely impact plant operations, more focused attention when fewer activities are I competing for specialized resources, and reduction of work scope during outages.
However, the margin of safety can be inadvertently impacted under certain conditions; for example, if maintenance is performed at power without proper controls, including careful consideration of risk.
emey c ,, o m _ _ _ _
Pay Two .
On-line maintenance must be carefully evaluated, planned, and executed to avoid undesirable conditions or tunsients, and to thereby ensure a conservative margin of core safety. The attached paper provides information that should be helpful in establishing responsibilities and management expectations to achieve this objective. Elective on-line maintenance should not be conducted on safety-significant systems without a thoughtful, controlled approach such as that described in the attachment.
INPO has coordinated the development of the attached information with the Nuclear Energy Institute and the Electric Power Research Institute. We will incorporate this information into INPO's Guidelinesfor the Conduct ofMaintenance at Nuclear Power Stattom and Guidelinesfor the Conduct ofOperations at Nuclear Power Stations.
INPO will also continue to review the management and conduct of on line maintenance or modiScations during plant evaluations.
Ifyou have any comments or questions regarding on-line maintenance or the attached information, please contact me at (404) 644-8202 or Don Gillispie, director, Plant Support Division, at (404) 644-8211; or lave your staff contact Gary Fader, manager, Maintenance Department, at (404) 644-8449. )
Sin rely, l
I Terence . :ullivan Executive Vice President TJS: bib
Attachment:
(As stated above)
MANAGING MAINTENANCE DURING POWER OPERATIONS 1
Purpose l
The purpose of this paper is to provide information gained from INPO's experience in reviewing maintenance or modifications performed on systems during power operations. This paper also considers beneficial practices of member utilities as well as inputs from the Electric Power l
Research Institute and Nuclear Energy Institute. This information should be useful in supporting the preparation or review ofplant-specific policies and procedures for managing on-line maintenance or modifications and is intended to complement existing INPO guidelines and other industry information on this subject.
On-line maintenance is a planned and scheduled activity to perform preventive or corrective maintenance, with the reactor at power, while properly controlling out-of servi.:e time of systems or equipment. The benefits ofwell managed maintenance conducted during pcwer operations i include increased system and unit reliability, reduction of equipment and system deficiencies that could impact operations, more focused attention during periods when fewer activities are competing for specialized resources, and reduction of work scope during outages. On-line
! maintenance must be carefully managed to achieve a balance between the benefits and potential l impacts on safety or reliability. For example, the margin of safety can be adversely impacted if l
maintenance is performed on multiple equipment or systems simultaneously without proper consideration of risk, or if operators are not fully cognizant of the limitations placed on the plant l due to out-of-service equipment.
It is not the specific purpose of this paper to address unscheduled, emergent maintenance that may be necessary to immediately restore equipment operability. However, many of the principles which follow are applicable to such situations.
Background
f In July 1991, INPO provided a paper to its member utilities entitled, " Managing Standby Safety I
System Performance." The purpose of that paper was to emphasize the need to understand and consider the impact that planned work activities have on both the rdability and availability of standby safety systems. In 1992, the Guidelinesfor the Conhet ofMaintenance at Nuclear Power Stations was revised to emphasize the need to carefully consider standby safety system
! reliability and availability when scheduling maintenance. Since 1992, utilities have gained more insight into the benefits and risks associated with performing on-line maintenance through use of plant-specific probabilistic safety assessment (PSA) models, plant safety analyses, and operating expe6ence.
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d To manage risk and avoid plant conditions that unnecessarily reduce plant safety or reliability, .
several utilities have developed or are in the process of establishing policies and procedures for performing maintenance on selected systems during power operations. The scope of these ,
systems is typically consistent with the selection criteria for systems, structures, and components being used by utilities in their efforts to monitor the effectiveness ofmaintenance. This scope would include standby safety systems, their support systems, and systems that can cause plant transients. l
't Utility policies and procedures for maintenance during power operations need to establish expectations for the following:
e the role and responsibilities of station managers e evaluation and management ofimpact on plant safety and reliability e on-line maintenance planning and scheduling ,
i e review and evaluation of the unavailability of risk significant systems Each of these areas is discussed in detail in the following sections. .
The role andresponsibilities ofstation managers Station managers are responsible for providing the direction needed to ensure on-line maintenance activities contribute to safe and reliable plant operations. Direction that reinforces a consistent, conservative approach to reactor safety when conducting on line maintenance activities should be incorporated into policies and procedures, as follows: l t
- The scope of systems for which on-line maintenance policies and procedures will apply are l identified based on selection criteria established by the station. ;
e The process for planning, scheduling, approving, and conducting on-line maintenance !
activities is clearly established. These activities may be incorporated into existing station l work management processes. i
- Roles and responsibilities for those involved in on-line maintenance activities are defined and communicated.
- The means for monitoring and assessing the overall effectiveness of on-line maintenance '
are established.
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. In addition, direction is established that ensures escalated senior station management approval is !
i e, obtained for on line maintenance situations that deviate from established practices addressed in policies and procedures. Examples of such situations that need to be considered are as follows:
l e simultaneous unavallebility of more than one train in a system )
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e simultaneous unavailability of more than one train in multiple systems that provide backup i
for the same function, such as auxiliary feedwater and high pressure safety injection for
- high pressure decay heat removal in pressurized water reactors e work on a system that may initiate a transient while a mitigating system that would be j used to respond to that transient is out-of-service, such as switchyard maintenance
! performed concurrently with emergency diesel generator maintenance i e unavailability of selected single-train systems such as high pressure coolant injection or
- reactor core isolation cooling systems in boiling water reactors L
e maintenance that cannot be completed within a specified percentage of the available time j for the applicable limiting condition for operation i
e removal of systems or equipment from service that could lead to a plant shutdown if not j restored in a relatively short time period, for example, less than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> e maintenance that could result in exceeding established unavailability thresholds or goals e activities that could significantly increase the probability of entry into the emergency plan Evaluarion and management ofimpact on plant safety and reliability Insights gained from available operating experience and analytical tools are incorporated into the on-line maintenance process. Such insights are used to identify the systems or equipment that can 1 be removed from service, considering assessments of when the systems would be least needed. ;
These insights are also used, where appropriate, to establish specific criteria for use in making decisions about planned equipment removal, frequency, and duration. In some cases, the overall i plant risk from taking systems out of service may be higher during an outage (or during particular !
phases of an outage) than when the maintenance is performed on-line. Actions to manage risk l l
generally are directed at properly controlling out-of-service time and maintaining configuration control to ensure defense-in-depth when certain systems or equipment are made unavailable.
The decision to take equipment out of service for maintenance during power operations takes into consideration the likelihood and possible consequences of an event occurring while the equipment is out of service. The following factors are addre'ssed in managics the risk of performing on-line '
maintenance:
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- The risk associated with the maintenance is evaluated using sound judgment and operating -
experience. Such evaluations are supported as appropriate using plant specific PSA models or plant safety analyses. Individuals or organizations are designated as resources to provide risk insights to station management and appropriate staff.
- Reviews and evaluations of the risks associated with on-line maintenance activities consider core damage as veall as other undesirable end states such as the need for emergency depressurization in a boiling water reactor or feed-and-bleed (once-through ,
cooling) in a pressurized water reactor.
e Because of their immediate importance in post-trip recovery and mitigating the consequences of a transient, particular attention is paid to performing maintenance on ,
systems providing electrical power and high pressure decay heat removal. These systems ,
include diesel generators; boiling water reactor high pressure coolant injection, reactor core isolation cooling, and high prassure core spray; and pressurized water reactor i auxiliary feedwater.
. Other maintenance or testing that significantly increases the likelihood ora plant transient or safety system actuation is generally not performed during the on-line maintenance period. +
w The cumulative effect of tak]ng equipment out of service with respect to other equipment I that is already or planned to be taken out of service is considered.
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- Consideration is given to the possibility of complications due to werther and other l external effects such as electrical distribution system stability during the period ofplanned !
equipment unavailability. :
- Compensatory measures are established, as necessary, considering the need for such i actions as providing alternate power sources, assigning supplemental fire watches, staging temporary equipment to be used in an emergency situation, and implementing temporary modifications. Responsible personnel are aware of the risk to plant operations and safety should redundant systems or equipment fail and are knowledgeable of what actions to .
take. Additional training or written guidance may be required to address the proper l response to emergency situations (e.g., review or development of actions that would be ,
necessary to recover equipment should it be needed during an event). [
On-line maintenanceplanning and scheduling !
i The station's work management process results in a well-coordinated station effort that effectively :
plans, schedules, and coordinates on-line maintenance activities to properly control out-of-service time. Key on line maintenance planning and scheduling practices are as follows:
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.. 1 i( o Representatives,from the various station organizathns that have responsibilities associated ,
- with on line maintenance (e.g., operations, maintenance, engineering, and radiological
- . protection personnel) review and approve the scope ofwork and conduct necessary '
preparation activities.
- e Contingency plans are developed, to the extent practicable, to restore equipment to i i service irredundant or backup equipment becomes unavailable, or ifemergent problems ,
occur during the performance of on-line maintenance. These plans may include i considerations such as obtaining additional personnel, locating special parts, or providing .,
j specific expertise. i
) e Risk insights are incorporated as part of the on-line maintenance planning and scheduling
) process. For example, risk insights are considered and used by some stations as part of 4
the normal work management process for developing 12 week rolling schedules. Many i l stations are now providing tools that present risk insights to appropriate personnel that are !
j useful in providing clear guidance to assist in scheduling on-line maintenance activities.
- For example, some stations have developed simple equipment matrices that show equipment or systems, or combinations thereof, that have been evaluated in determining if ,
j on line maintenance is allowed to be performed.
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- e Routine minor work that has no reliability benefits is deferred to lower risk periods. In i other words, minor work that can be appropriately deferred is not performed simply j because a system work window becomes available.
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- Consideration is given to the experience level, training, and qualification of personnel available to perform or support on-line maintenance. Shift manning is reviewed and j appropriately staffed based on these considerations. Also considered are needed services from outside the utility; such as vendor technical representatives. j e Supplemental training is provided to operations and maintenance personnel, as necessary, to prepare for the maintenance. Mock-ups or simulator training may be appropriate.
e Work packages for on line maintenance activities are thoroughly planned in advance of the
- scheduled work, and verified to be ready to support the maintenance through appropriate j reviews and walkdowns. All items needed to perform the maintenance such as parts, i tools, shielding, scaffolding, and procedures are readily available and, when possible, prestaged.
- The expectation for detailed prejob briefings and turnovers is clearly established for
- operations, maintenance, and other personnel supporting the work. Briefings heighten i personnel awareness of the plant configuration, compensatory and contingency actions,
) and the need for timely completion of work. Turnovers are conducted in a thoughtful,
! detailed manner and are as comprehensive as the original prejob briefing. Ineffective i turnovers can adversely impact the risk associated with the on-line maintenance. In i selected cases, it may be appropriate for managers to monitor or actively be involved in i prejob briefings as well as turnovers.
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e The time needed to complete the on-line maintenance activity and to restore the equipment to service is clearly established. It is important to consider not only the ;
personnel resources and qualifications required for the work as discussed previously, but l i
also shift schedules, crew starting and finishing times, and other factors that impact out-of-service time and, therefore, system or equipment unavailability.
- e Critiques of on-line maintenance activities are performed to refine the process and reduce [
planned equipment unavailability in time future. ]
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e Consideration is given to nonintrusive predictive techniques that might be used instead of maintenance activities that cause important systems to be inoperable. l l
Review and evaluation of the unavailability ofrisk significant systems I
At each plant, a number of systems are identified as being risk significant and have criteria established for allowable unavailability. For these systems, unavailability is periodically evaluated to ensure that maintenance activities are effective and result in high levels of system availability ,
and reliability. The total time that a risk significant system (or train)is out of service due to all causes (total unavailability) is monitored and controlled to avoid inadvertently increasing the risk l of a significant event. Responsibilities and actions for evaluating unavailability ofrisk significant l systems are as follows:
i e When system unavailability is monitored, contributors to unavailability, such as planned i maintenance (preventive maintenance, inspections, and tests) and unplanned maintenance to repair equipment, are evaluated. l e
e Realistic unavailability goals are established and monitored over appropriate time periods for those systems that are determined to be risk significant. The goals are in line with j plant-specific analyses or industry goals where available. In developing unavailability goals, consideration is given to the probability of both core damage and other undesirable end states. In some cases, it may be prudent to allocate a portion of the goal to planned 4
activities to prevent unplanned activities from exceeding the goal for total unavailability.
Situations in which on-line maintenance results in unavailability goals being exceeded l should be carefully reviewed during post maintenance critiques to determine if the goals I were realistic and unavailability was evaluated over appropriate time periods. j u
e Measurable thresholds are established for total unavailability on a cumulative, rolling time ,
interval. For example, some stations have established policies that senior station l management approvalis required for any maintenance that could potentially result in total unavailability exceeding an established percentage (system-specific) on a rolling 12-month basis.
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DRAFT FOR COMMENT
- Inspection Plan i 4
FACILITY NAME Program Applicability: 2515 Dates of Inspection: XXXXXXX Inspection Report Number: XXXXXXX Inspection Team: XXXXXXX XXXXXXX XXXXXXX Site Licensing
Contact:
XXXXXXX Regional Support: Paul J. Kellogg, Section Chief operational Programs Section Chief Reactor Projects Section !
l Approval:
Paul J. Kellogg, Chief, Operational Programs Section 1.0 Backaround Many licensees have elected to perform significant plant maintenance activities during periods of power operation rather than scheduling such maintenance during outages. The NRC's guidance allows such an activity, however, the agency's expectations are that licensee's will not routinely perform these maintenance items when technical specifications require the affected equipment to be operable.
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l DRAFT FOR COMMENT l ,
2.0 Obiective l
The objective of this inspection is to assess the licensee's programs, practices, and policies regarding the conduct of on-line maintenance activities. Special emphasis is placed upon those activities which have a significant safety impact and warrant the entry into technical specification limiting conditions for operation. Additionally, where possible, the risk significance of performing major maintenance activities during power operation should be assessed.
3.0 InsDection Recuirements The following areas represent recommended areas for the concentration of inspection efforts. It is not intended that these recommendations be prescriptive to the extent that individual inspection efforts are unduly restricted. Inspectors should use these recommendations as guidelines for general lines of inquiry and should pursue any relevant safety significant findings as appropriate.
222_. Evaluation of Licensee Programs Governina On-Line Maintenaugg A. Determine whether the licensee has established formalized programs for the conduct of on-line maintenance. Evaluate any such programs for adequacy.
B. Assess the frequency of significant on-line maintenance activities. The licensee should not abuse the allowance to perform a PM or other maintenance activity on-line by repeatedly entering and exiting Lc0 action statements.
C. Determine whether the on-line maintenance activities which are performed provide a net positive safety benefit to the facility. If a licensee has a reasonable expectation that an on-line PM program will improve safety by making equipment more reliable, the program may be implemented even though the unavailability of the equipment may increase. The 2
DRAFT FOR COMMENT licensee should be able to justify such an expectation .
of improved safety. The results of any quantitative '
risk analyses which may have been performed should be t evaluated. Where possible, a comparison of the rievs I associated with performing the maintenance on-line versus ..her operational modes or plant conditions i should be performed.
l D. Assess the licensee's policies and practices governing redundant and diverse equipment during on-line PM. The licensee should ave'.' removing this other equipment from service while performing the maintenance. ;
Additionally, the confidence in the operability of redundant / diverse equipment should be high during periods of on-line PM.
E. Evaluate the licensee's conduct of operations during on-line maintenance activities. The licensee should avoid performing other testing or maintenance that ,
would increase the likelihood of a transient. This j consideration should include degraded or out of service !
balance of plant equipment. l I
F. Evaluate any contingency plans or compensatory measures '
which may have been implemented by the licensee. Where possible, the licensee should have formal measures established to the extent practicable which would minimize the impact of any out of service equipment.
3.2 SDecific Guidelines for Assessina the' Risk of On-Line Maintenance Activities A. Determine whether the licensee has quantitatively assessed the risk of the maintenance activity.
Consideration should be given to use of any formalized probabilistic risk assessment (PRA). Other forms of quantitative assessments may include accident sequence precursor (ASP) type studies, or specific calculations performed for individual maintenance activities.
B. Evaluate the qualitative impact of any risk analyses.
The licensee should, in addition to any quantitative studies, explicitly define the source (s) of the risk associated with maintenance activities. Many activities may increase the plant risk, but the actual 3
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DRAFT FOR COMMENT reason for the increase may not be obvious. For l example, at a multi-unit site, removal of a shared EDG l
' from service may reduce the redundancy in the power supplies to both the SGTS and to an RHRSW pump. The resultant increase in CDF would be solely due to the effects associated with the RHRSW pump. Thus,
' scheduling considerations and contingency actions should be directed towards the functionality associated with the pump.
C. Evaluate the relative impact of on-line risk versus shutdown risk. Wherever possible, assess whether overall plant risk would be minimized by rescheduling the maintenance. If no quantitative results are available to conduct such an assessment, qualitative insights should be used.
D. For PMs and other maintenance activities which may not have been evaluated via a formal risk assessment, determine whether other methods are available (or have been employed) to ascertain the risk significance of proposed equipment outages. Examples of such methodologies are RCM approaches, failure modes and effects analyses, etc.
E. Evaluate the outage tima that equipment is actually taken out of service for on line maintenance. Compare the actual times equipment is out of service with the time assumed in the PRA/IPEs. Is there a mechanism for feeding back actual times into the PRA/IPE?
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- TI 2515/126 SUBMITTAL REVIEW ;
- TO DETERMINE ADHERENCE TO Tl REQUIREMENTS
- l These are the seven (7) primary questions / issues required to be addressed l
i per TI 2515/126-03 " Inspection Requirements" (paragraphs in parenthesis) with j discussions and results below based solely on the review by Ron Frahm Jr: :
i i- (A) Does the licensee have effective procedures for planning and scheduling
} on-line maintenance activities? (Ola) ,
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, Six of the plants reportedly do not perform on-line maintenance and do
- l. not require procedural controls. Of the remaining 62 plants, 36 ]
1 reportedly had effective procedures in place for planning and scheduling
- on-line maintenance, although many of these procedures did not require
- safety / risk assessments. 21 of the plants, however, did not appear to j have any formal procedural controls for planning and scheduling on-line i maintenance. Five of the submittals failed to address this question
{ / issue.
j (B) Does the maintenance planning and scheduling program incorporate risk insights derived from all three of the risk factors? (Ola) j Of the 62 plants which performed maintenance on-line, 22 reoortedly did
! not incorporate risk insights into their maintenance planning and scheduling program (12 of these were from Region II, none from Region
- IV). Of the 34 plants which appeared to incorporate risk insights, 20 l of these submittals failed to address the extent of these insights with
! respect to the three risk factors. Only 2 plants reportedly addressed 5
all three of the risk factors, while 6 reportedly considered 2 of the.
- factors (initiating events and accident mitig.ation),.and 6 reportedly only incorporated the risks associated with accident mitigation. Six of j the submittals failed to address whether the licensee incorporated risk
- insights at all.
! (C) Does the licensee evaluate the incurred risk by assessing the cumulative j effect of. multiple equipment maintenance activities and equipment
! outages? (Olb) i i
- 49 of the 62 plants which performed on-line maintenance reportedly assess the cumulative effect of multiple maintenance activities when i planning and scheduling on-line maintenance. Only 3 were reported to 2- have.not considered the cumulative effects and overall plant safety prior to performing maintenance on-line. 10 of the submittals (5 from j Region III) failed to clearly address whether multiple activities were l assessed for risk significance. !
1 l (D) Does the process integrate scheduled maintenance activities with
- existing degraded / inoperable equipment? (Olc) i
! Of the 62 plants which performed on-line maintenance, only 4 did not i appear to integrate maintenance activities with existing inoperable
- equipment. 45 plants reportedly did integrate on-line maintenance
! activities, while 13 of the submittals failed to clearly address this j question / issue.
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(E) What is the extent of personnel knowledge and awareness re planning and scheduling operations and maintenance activities? (Old) 31 of the 62 submittals from plants which performed on-line maintenance
, failed to address the level of knowledge and awareness of personnel. Of the 31 which addressed personnel knowledge and awareness, all but 4 (3 4
from Region II) indicated that personnel were generally knowledgeable of l the on-line maintenance activities, but the extent of knowledge varied !
between plants. ;
(F) Based on a review of the on-line scheduled maintenance for the upcoming l cycle, were any situations or configurations identified which could potentially have a significant impact on plant risk? (02)
Only 25 of the 62 submittals from plants which performed on-line maintenance indicated that the inspectors had reviewed the schedule of on-line maintenance activities for the upcoming cycle. None of these 25 reports identified any situations or configurations which could l potentially have a significant impact on plant risk. 37 of the '
submittals (14 from Region II alone) failed to address whether or not the sch-dule review was performed. l (G) Did tue inspector consult with and identify any concerns to regional ,
management for coordination with the NRR TI 2515/126 review committee? l (03)
Each of the 68 plants performed the inspection and reported the results in a section of the applicable monthly resident inspector's report.
Several of the submittals reviewed by the committee, however, were preliminary inputs which had not been reviewed by management or issued in an inspection report.
OTHER NOTES:
)
- 2515/126-05 states that the inspector should briefly document the results of the completion of this TI in a routine inspection report and transmit any concerns identified to NRR/TQMB through the regional office. This may have led inspectors to not fully document the completeness of their inspection efforts.
2515/126-10.02 states that approximately 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> of direct inspection effort will be necessary to complete this TI. It appears that many of the inspectors dedicated far less time to this TI than the estimated 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br />.
2515/126-10.04 states that no special training requirements are associated with this TI. It appears that some of the inspectors did not have adequate training in basic PRA concepts, l
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- NRC INSPECTION MANUAL TQMB
- TEMPORARY INSTRUCTION 2515/126 EVALUATION OF ON-LINE MAINTENANCE 1
2515/126-03 INSPECTION REQUIREMENTS
- 03.01 Maintenance Plannina and Scheoulina. Determine whether licensees have i
in place a program that focuses on all three of the risk factors discussed above and thoroughly evaluates the impact of scheduling on-line maintenance
' with regard to plant safety.
- a. Review the process and procedures that the licensee has in place to schedule on-line maintenance.
- b. Determine whether the licensee evaluates the risk incurred from 2
performing on-line maintenance activities by assessing the
, cumulative effect of multiple equipment maintenance activities and equipment outages, prior to performing the maintenance or taking i equipment out of service.
j c. Determine how the process integrates scheduled maintenance 2
activities with existing degraded / inoperable equipment.
- d. Determine the extent of knowledge and awareness of supervisory and working level personnel concerning the licensee's process for
- planning and scheduling operations and maintenance activities.
(The necessary level of knowledge of the comprehensive process should be dependent upon the extent to which the individuals are responsible for the dotails of specific and over all planning and scheduling).
03.02 Planned Maintenantg. Review the on-line scheduled maintenance for the
- upcoming cycle (should look at a time period between one month and one quarter of planned activity) to identify any specific instances (situations or configurations) where planned on-line maintenance could potentially have a significant impact on plant risk. As stated in the background section, multiple or single maintenance activities that simultaneously, or within a i -
short time frame, impact two or more risk factors tend to increase risk the j greatest.
4 03.03 Reoortina. Consult with and identify any concerns to regional
] management for coordination with the NRR TI 2515/126 review committee.
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266I09 REGION EG Wt'
%Gl00 fg 1 n a S NR 2 I I I 5 M2 EFFecHve proutdured NA 2 3 G MA r p @ I for planning N 4 G & 3 ZI N scheda/kg OLAi ?
II Il 7 7 3G y l
}
. NR 3 & 2- I G N2 3ccorporede- n?k NR+ 4 6 7 J 20 va. in,;7,p,8 ? h L
- MA e 3 - s a
}' N G 12 't 0 ,
2Z W o.l! % re.e rit h I 1 0 2 1 L G I foche ,
l 2 i e l 4 l 6 I l 3 I O G j l i 1 3 I NR I 2. 3 .
2 I IO NR Cumalahite eMeck 2- 3 of mri pie equ',p $l
- g NA @
1
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f6J NA l
N 5 / G j N V I6 l# lo c1 49 V R 4 3 3 3 13 pe &+egale wid NA 2- 0 3 I G MA aishhg degraded 9 g 2 4 N I I y inop equip ment ?
Y I2- 15 _- ..
l2' ... .G- _ 45 Y -
NR '1 to 9 3 3I ap Knowledge. oul g NA 2- @ 3 I G MA warere CC re N @ 3 1 0 4 H plannrhs < schedultr ,
Y lo ,5 8 4 27 y j NR 8 I4 9 G 37 NR Seuied Ofcom{na NA 2- Q 3 I G MA c,.gcle. for skC N 9 4 '7 ,5 25 N sijn,Picort combos.
j
- Y 0 6 A G y __
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- DRAFT REPORT -- FOR INTERNAL NRC USE ONLY
- i NRR TI 2515/126 REVIEW COMMITTEE
SUMMARY
OF RESULTS I. Background l During plant visits by several NRC senior managers, it was noted that licensees appeared to be increasing both the amount and frequency of maintenance performed during power operation. The licensees' expansion of the on-line maintenance concept without thoroughly considering the. safety (risk) l aspects raised significant concerns. As a result, Temporary Instruction !
(TI) 2515/126 was developed and implemented to evaluate the impact on safety i of licensees' practices regarding the removal of equipment from service for on-line scheduled maintenance. The inspections were completed by December 31, 1994, as required by the TI.
A review committee, within the Office of Nuclear Reactor Regulation (NRR), was established to consolidate and review the TI inspection results and avaluate the industry's policies and controls concerning their on-line maint ;ance practices. The multi-disciplined committee consisted of Ronald Frahm, Jr from the Quality Assurance and Maintenance Branch, James Luehman from the Technical Specifications Branch, Samuel Lee from the Probabilistic Safety Assessment Branch, George Thomas from the Reactor Systems Branch, and David Allsopp from the Inspection Program Branch. The committee has completed its initial review of the TI preliminary inspection findings from each of the sixty-eight (68) plant sites.
It is important to note that based on time constraints many of the inspection findings reviewed by the committee were preliminary copies of inspection report inputs which had not been issued nor reviewed by regional management. i Further, there was little consistency between the quality and quantity of the '
inspection report inputs, even within the same region. In numerous cases, the reports did not include some of the important issues required in the TI. The committee cannot be sure whether certain activities do or do not occur at a given plant, whether they were overlooked during the inspection, whether they ,
were simply not mentioned in the report, or whether the inspectors misunderstood the language in the reporting section of the TI. Due to the time constraints, the committee could not investigate and followup on issues that were unclear in the inspection report inputs. This report summarizes the insights gained from the initial review of the TI inspection findings and provides preliminary conclusions about the licensees' policies and programs established to control the risks associated with performing maintenance activities during power operations.
II. Frequency of On-line Maintenance The committee determined that nearly all of the U.S. nuclear power plants performed some of their scheduled preventive maintenance during power operations ("on-line"). The preliminary inspection findings revealed that '
only six (6) of the sixty-eight (68) plant sites do not presently perform any l l
$/M
DRAFT REPORT -- FOR INTERNAL NRC USE ONLY on-line maintenance. Of these six, all but two (2) indicated that they were planning to develop and implement an on-line maintenance program in the near future. Tr , majority of the plants, however, perform a significant amount of on-line maintenance and this trend appears to be increasing. Some plants appear to be performing, or planning to perform, as much maintenance on-line as possible while attempting to operate the plant safely and efficiently. As previously documented in NRC Inspection Manual, Part 9900, Technical Guidance
" Maintenance - Voluntary Entry into Limiting Conditions for Operation Action Statements to Perform Preventive Maintenance," and letters to the industry, the practice of on-line maintenance should be limited to those instances driven by a net safety benefit, giving due consideration to overall plant safety at the actual time of the maintenance, or be warranted by operational necessity, not by convenience.
III. Established Policy and Procedural Controls In general, the inspections revealed that the mechanisms end procedures used to control a tivities being performed while the plant is operating have not changed significantly despite the complications added by the performance of a large amount of maintenance on-line. The majority of the plants appeared to coordinate on-line maintenance efforts to minimize out-of-service time and maximize system availability. Most plants incorporated a " window" concept to plan and control on-line maintenance outages, typically rolling twelve (12) or thirteen (13) week schedules with a different system allocated to each week.
These controls appeared to help minimize the number of times that a system is removed from service by consolidating surveillances, maintenance, and testing i activities to a single outage per cycle. Other licensees used a " train" l concept to assure that maintenance activities were limited to a single train at any given time. In most cases, licensees appeared to attempt to minimize out of service time when performing maintenance at power (and maximize i equipment availability). Most plants had established policies which required l LC0 maintenance to be completed within a certain percentage of the allowed i outage time (typically 50%). Few licensees, however, considered the risks l associated with non-safety related equipment, limiting their analysis to the l emergency core cooling systems and other equipment as described in the technical specifications.
- Several of the licensees appeared to have policies in place that prohibited or
! discouraged multiple train outages. The majority analyzed plant conditions to assure the operability of diverse or redundant equipment before taking a system or component out-of-service. There were others, however, that permitted multiple train outages to the maximum extent allowed by their technical specification LCOs. The more conservative licensees limited on-line maintenance activities to one component or one LCO entry at a time. A few plants reportedly added fully functional spare (back-up) components while performing on-line maintenance to further minimize risk. Based on broad reviews of licensees' upcoming maintenance schedules, the inspectors did not identify any prominent instances where planned on-line maintenance could potentially result in a significant impact on plant safety (risk). However, DRAFT REPORT -- FOR INTERNAL NRC USE ONLY these brief inspections only looked at a small portion of each plant's schedule, and did not involve detailed risk evaluations. '
The degree of commitment to the varicus practices used to minimize equipment unavailability varied widely; at one plant they might be enforced by strict
. procedural controls while at another they might simply be goals contained in a scheduling guidance document or unwritten good practices. The majority of the plants, in fact, did not appear to have formal procedures in place to control on-line maintenance activities. In many of the plants that had procedural controls, the detailed requirements for a risk analysis prior to the voluntary removal of equipment from service were not defined in the procedure. A few of the plants reportedly had performed self-assessments of their on-line maintenance programs in'an effort to improve the related policies and procedures to more effectively control these activities. Some plants had either started or planned to incorporate risk assessments and other controls into their formal procedures to minimize the risk impact of performing maintenance at power.
IV. Incorporation of PRA Insights into Planning and Controls Many licensees appeared to incorporate PRA insights when scheduling and planning on-line maintenance. However, the " tools" used by the licensees to assess safety (risk) appeared to range widely in approach, dependability, and sophistication. These " tools" or means to conduct safety (risk) assessments typically consisted of one of the following: reliance on operations and maintenance personnel knowledgeable of high risk plant configurations, consulting the plant PRA/PSA group, using a matrix depicting risk-significant combinations of equipment (limited to one-to-one system comparisons which did ,
not consider the combination of taking three or more systems out ;
simultaneously), applying Individual Plant Evaluation (IPE)-based accident i sequences to quantify risk, and using computer-based programs to monitor current risk configuration of the plant. Many of the licensees which relied '
on less sophisticated types of safety (risk) assessments reportedly expressed their intentions to upgrade their assessment capability. However, even these 3 enhancement plans differed widely among the licensees with some licensees settling for qualitative assessment tools and others developing computerized on-line risk monitors. Still, there were several licensees who appeared to be ;
performing on-line maintenance without conducting any type of risk assessment using PRA insights. l i
The risk insights from the Individual Plant Evaluation (IPE) did not appear to be utilized at most plants in their operational and maintenance decision process. For those licensees who evaluated risk, many did not appear to be considering all of the three risk factors addressed in TI 2515/126, namely the probability of an initiating event, the probability of not being able to mitigate the event and prevent core damage, and the probability of not being able to mitigate the consequences of the event by preserving containment integrity. Most licensees appeared to concentrate solely on the risks associated with accident mitigation when evaluating risks. A few licensees,
- DRAFT REPORT -- FOR INTERNAL NRC USE ONLY however, were reported to consider the potential increased probability of an initiating event, and fewer were reported to consider the probability of being able to maintain containment integrity to prevent radioactive release to the environment.
To track equipment unavailability due to preventive on-line maintenance, a few licensees seemed to noe developed programs to monitor equipment out-of-service (00S) times. Although most licensees appeared to place an administrative limit on outage times (i.e. 50% of the LC0 allowable outage time) and attempted to minimize 00S time for a given system or component, many of them did not appear to consider the cumulative 00S times. While the tracking of cumulative 00S times i: ._t presently required for most equipment, some licensees are taking steps toward tracking equipment availability in preparation for the implementation of the maintenance rule (10 CFR 50.65). In addition to providing information for compliance with that regulation, tracking of cumulative 00S times provides a means of validating IPE equipment availability assumptions. The inspectiors did note a couple of examples of equipment exceeding the cumulative 00S time assumed in the plant IPE. It could not be deteradned, however, if this was a prevalent problem in the industry because of the inconsistencies in tracking unavailability times as discussed below.
The majority of those plants that reportedly had such equipment monitoring programs did not appear to track total equipment unavailability, which in addition to preventive maintenance, includes corrective maintenance, surveillances, and testing. This lack of consistency in measuring 00S time can significantly alter the result of plant's overall safety (risk) assessment. Additionally, the programs were typically designed to monitor 00S time for safety-related equipment per technical specifications only; the non-safety equipment that may also be risk significant was rarely monitored.
In general, there seems to be a wide range of capability and variability in practice among the licensees to incorporate safety (risk) assessments for conducting preventive on-line maintenance. Although there seems to be a trend to incorporate more risk-based inputs and to " upgrade" risk assessment capabilities as the industry is moving toward more preventive on-line maintenance, many of the licensees' int'.ntions appear to be unclear.
V. Awareness and Training of Personnel Although the majority of the relevant personnel appeared to be knowledgeable of the scheduling and maintenance activities associated with on-line maintenance, very few of them understood or had training in PRA insights or their plant's IPE. Few of the plants appea ed to have formal training programs which included planning and control of on-line maintenance and the insights to be gained by using Pf.A or other risk evaluations. Training and awareness was often limited to upoer management, schedulers, and/or operators and the level varied significantly batween plants. Some of the plants relied heavily on the insights of experienced operations and maintenance personnel to
- -- - -~ . - . = - - . .- - - - -- -- . - -~
4 1
J DRAFT REPORT -- FOR INTERNAL NRC USE ONLY !
- assess the potential risks associated with planned on-line maintenance. A few a
of the plants indicated that they intend to formally train all pertinent plant personnel on the policies, procedures, and risks associated with on-line {
l 4
maintenance, but the timetables for such training is not clear. j 4
VI. Conclusions '
1
' The committee determined that nearly all of the U.S. nuclear power plants l currently perform a significant amount of their scheduled preventive l maintenance during power operations, and this trend appears to be increasing. j i
Although most licensees appear to attempt to control on-line preventive 1 maintenance, and satisfy current regulatory requirements, comprehensive plant '
safety (risk) assessments are not typically completed prior to performing the maintenance activities. The majority of the plants appear to have only
- informal policies in place and have not developed detailed procedures to control on-line maintenance activities and conduct the associated safety (risk) assessmen+s. In fact, a significant number of licensees appear to be performing on-line maintenance regularly without formal procedural controls,
! training, or consideration of risk insights. We did note that some of the
, plants with these weaknesses have plans to enhance their controls of on-line maintenance activities in preparation for implementation of the maintenance rul e.
In general, the industry's increased use of and limited controls over on-line i maintenance activities appears to reduce overall safety at nuclear power plants. lhe industry appears to be adopting the practice faster than it is
' developing and implementing effective controls to manage the safety (risk) !
implications of this practice. Although the limited NRC inspection of on-line 1 maintenance practices did not identify any risk-significant implementation problems, it is imperative that licensees carefully control on-line j maintenance activities to preclude such situations. The committee recommends 2
that the NRC continue to monitor licensees' activities in the area of on-line i maintenance to assure that all licensees have formal programs developed and !
1 implemented when the maintenance rule becomes effective on July 10, 1996.
J 4
1 1
i
- c i, j j '.-
)
TI 2515/126 INITIAL REVIEW SUMMARIES ,
i FOR COMMONWEALTH EDISON PLANTS 1 4
e k Overall:
The Commonwealth Edison plants varied significantly regarding the d
approach to and sophistication of their on-line maintenance (OLM) i e programs. For example, Zion reportedly had a well developed program l which was procedura ized and considered risk insights. Braidwood and
)
. Dresden had significantly less developed programs which were not l formally proceduralized and did not incorporate PRA insights. Quad
, Cities did not have a program and did not currently perform any on-line i maintenance. The following is a summary of the strengths and weaknesses ;
l of each Commonwealth Edison plant as indicated by the inspection l submittals:
! Braidwood: )
i STRENGTHS High level of knowledge and awareness of supervisory and planning i personnel on scheduling and maintenance activities. j Risk model used to control OLM scheduling activities. '
, WEAKNESSES i Risk model based on deterministic Tech Sper LC0/A0Ts, not PRA. ;
- No formal procedure to'use risk model. <
l
- Scope of risk model was limited to Tech Spec equipment. ,
j
- Implementation weaknesses noted included the tagging out of S/R i j equipment longer than necessary prior to the start of work, and the 1 accidental removal from service of both an aux feed train and l centrifugal charging train simultaneously vice sequentially. .
4 Byron-STRENGTHS !
!'
- Informal operating policies: Multiple train outages and work on l 1
multiple equipment within the same train was not allowed.
3 Maintenance or testing activities which may increase the probability
- of an accident or render redundant equipment inoperable were not
- allowed.
i
- Operational Safety Predictor System (0SPRE) computer program expected to be operational by Summer 1995 to evaluate risk.
- WEAKNESSES
- No formalized procedures for risk assessment.
Dresden:
STRENGTHS l
- Informal policies: Intentionally entering more than one LC0 at a time is not allowed. Equipment unavailability is limited to one-third of the LCO allowed outage time.
WEAKNESSES l
- Risk management techniques were not defined or found to exist.
j-
- No formalized procedures for risk assessment.
Only senior managers had received basic PRA/IPE training.
}
4
a'
(
i LaSalle: '
STRENGTHS -
OLM activities controlled by procedure. '
OLM risk evaluations consider both safety-related and non-safety ;
related equipment.
- Scheduling guidelines established to limit 005 combinations. ;
WEAKNESSES i No'IPE which could be used effectively for risk insights. [
t Quad Cities: l STRENGTHS i Site VP decided not to perform any OLM until the station had ,
implemented a policy (currently in draft form).
Operational Safety Predictor System (0SPRE) computer program in i development (currently nu J.eduled implementation date). ;
WEAKNESSES .
Only senior managers had received basic PRA/IPE training. System i engineers' knowledge of PRA was weak, maintenance and operations personnel had no knowledge of PRA. !
Zion:
STRENGTHS .
OLM activities controlled by procedure. !
OLM risk evaluations consider both safety-related and non-safety related equipment.
Multiple train outages and work on multiple equipment within the ;
same train was not allowed.
Equipment unavailability is limited to 75% of the LCO allowed outage time.
Operational Safety Predictor System (0SPRE) computer program was used daily to perform risk evaluations.
WEAKNESSES No significant weaknesses identified, however, the risk of an initiating event resulting from testing or B0P maintenance could only be evaluated by the operator and was not controlled by procedura.