ML20195D431

Informs Commissioners of Staff Actions to Reduce Testing During Power Operation

ML20195D431
Person / Time
Issue date:	10/26/1988
From:	Stello V NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO)
To:
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ML20195D423	List: ML20195D419 ML20195D431 ML20195D444
References
TASK-PII, TASK-SE SECY-88-304, NUDOCS 8811070008
Download: ML20195D431 (10)

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POLICY ISSUE October 26, 1988 (in Ormation) SEcY-88-304 For: The Comissioners i Fro;n: Victor Stello, Jr.

Executive Director for Operations Subject,: STAFF ACTIONS TO REDUCE TESTING AT POWER

Purpose:

To inform the Comissioners of staf f at.tions to reduce testing during power operation.

Background:

By a staff requirements memorandum dated February 25, 1988, the Comission requested that the staff investigate the pros and cons of continuing to require surveillance and testing of equipment while the plant is at power and inform the Comission of any proposed modifiestions of the present requirements. In a subsequent June 20, 1988 Comission briefing on the status of the Technical Specifications Improvement Program the staff described some of

-- its ongoing work in this area. Following that briefing the staff received another staff requirements memorandum dated July 6, 19'38 requesting that a Comission paper on the results of continuing stJ f actions to reduce testing during power operation be provided by October 17, 1988.

Discussion: Identifying and eliminating unnecessary testing in general, and at power in particular, has long been an important objective of the staff. Beg'nning in 1983 with the publishing of NUREG-1024 "Technical Specifications -- Enhancirig the Safety impact," the staf f initiated a program to develop analytical methods to support the implementation of changes in required surveillance intervals for testing safety-related equipment. This program '

was consucted by the Office of Nuclear Regulatory Research and was titled Procedures for Evaluating Technical Specifications (P;TS). The effort to actually implement changes to surveillance requirements has been integrated into the current

Contact:

Edward J. Butcher, NRR 49-21183

, 2-Technical Specifications Improvement Program associated with the Interim Commission Policy Statement on Technical Specifications improvement issued in February 1987.

The early focus of this work has been on extending surveillance intervals for safety-related instrumentation. So far the staff has approved three topical reports which propose reduced surveil-lance testing of reactor protection system instrumentation, one for Westinghouse-designed pressurized water reactors and two for General Electric-designed boiling water reactors. The staff reviews of six more reports from all four reactor vendors proposing to reduce surveillance testing on reactor protection systems (RPS).

. engineered safety feature ectuation systems (ESFAS). Emergency Core Cooling Systems (ECCS) and BWR isolation instrumentation common to RPS and ECCS are scheduled for completion this fall.

! This will complete staff review of all industry proposals currently submitted to the staff for review which cover virtually all on-line testing of safety-related actuation instrumentation for major systems. Overall, when fully implemented, these changes will result in a factor of three reduction in the number of tests of these systems. The work of the PETS program was an important

, factor in enabling the staff to approve these changes at this time.

Other More Recent Staff Initiatives In addition to the instrumentation work discussed above, the staff has recently broadened its efforts in this area to include major rechanical equipment and systems and to explore methods to

! give greater consideration to the effectiveness of maintenance programs in establishing test frequency requirements. This work was started in June of this year when NRR initiated a short-term study (approximately 120 days) of Technical Specifications testing requirements. The focus is on changes that can be implemented in a relatively short period of time and justified primarily on the basis of engineering judgment and existing or new short-term studies

! of actual failure rate data, as opposed to the more rigorous and time consuming PRA based analysis used to evaluate the changes in testing requirements approved for safety-related instrumentation.

1 The study began with a comprehensive line-by-line review of all of the testing requirements in the Technical Specifications to

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identify potential candidates for change. Specifications which ,

met one or more of the following four criteria were selected  ;

for further study: i (1) The surveillance is a burden on-plant-personnel because the time required is not justified by the safety significance of the requirement.

(2) The surveillanca could lead to a-plant transient.

(3) The surveillance results in unnecessary wear to equipment.

(4) The surveillance results in exposing plant personnel to radiation levels that are not justified by the safety significance of the requirement.

An important part of the study was staff vitits to five nuclear power plants to obtain information from reactor operations, maintenance, engineering, chemistry, planning, and testing personnel on which Technical Specifications surveillance

requirements meet one or more of the four criteria used for the study. The sites visited were Crystal River Nuclear Plant.

Unit 3; San Onofre Nuclear Generating Station, Units 1, 2, ano 3; Catawba Nuclear Station, Units 1 and 2; North Anna Power Station, Units 1 and 2; and La Salle County Station, Units 1 and 2.

The study also made use of the work done as part of the NRC Nuclear Plant Aging Research (NPAR) program (NUREG-1144, Revision 1).

The reports on various systems and components prepared under this I program gave insight into the rate of failure of specific systems and components and also into the causes of the failures. This

, information was used to assess whether more testing is being rione than could be justified based on the f ailure rates of equipment.

Findings l

The technical work of the study is essentf ally complete and the results are being documented in a comprehensive report to be issued this month for peer review. Some of the more important general findings are summarized below. Examples of the specific recommendations that are under peer review are listed in the enclosed table. This list is not complete and it is likely that the peer review process will result in refinament to the specific recommendations.

., o A large number of surveillance tests are required by the r Technical Specifications. For example, the licensee for Limerick provided the following information on the total number of surveillances done on an annual basis. For 1986, with no refueling outage 14.888 surveillances were performed. For 1987, with a refueling outage. 17.540 surveillances were performed. ApproxioMely 98% of these were required by the Technical Specfteatt?ns, the other 2% were required by other agreements bc ,w fa th( licensee and the NRC.  ;

A simple vem m 'pe 4 over 40 tests per day for the year with no a lfag outags.  ;

o The surs ,'d ..:e se equired by Technical Specifications whi:h ar6 e rest t i-, ient causes of reactor trips are:  ;

RPS Testing cNR. Bv.,

Turbine Valve n.: ting (PWR, BWR)

Control Rod Movement Testing (PWR) e Main Steam Isolation Valve Surveillance Testing (FWR. BWR)

Reactor Trip Breaker Testing (PWR; Fuclear Excore Instrumentation Testing (PWR) i o The surveillance tests required by Technical Specifications which cause the most significant equipment wear are: '

. r Auxiliary Feedwater Pump Testing and othar safety 4related I pump testing in which a recirculation line is inadequately ,

sized (PWR)

Emergency Diesel Generator Testing o Two programs directed by the Of fice of Nuclear Regulatory .

Research (RES) are studying ways tc improve the testing of  ;

emergency diesel generators. These programs are Generic

, Issue B-56, "Diesel Reliability" and the Nuclear Plant Aging Research (NPAR) program. Generic issue B-56 is scheduled t for completion in June 1989. It will provide the staff with l the capability to review licensee reliability programs to assure that diesel generator reliability meets the goals of  !

the Station Blackout rule, 10 CFR 50.63, with the least adverse effect on the diesel generators. l i

The surveillance tests which result in the most significant o

radiation dose to plant personnel are:

Containment Purge and Exhaust Isolation Valve Leak Testing (PWRs)

Waste Gas Storage Tank Surveillance Walkdowns to Verify Valve Position Snubber Inspections

. o Surveillance and inservice testing account for approximately 20% of the annual cumulative radiation dose at a reactor.

Maintenance is the largest cortributor to cumulative dose. '

o improving preventive maintenance programs is an important element in reducing testing at power. A review of licensee event reports and other data shows that many of the failures found from testing are due to dirt or impurities in fluid systems, bent or broken parts, loose parts, etc., which should have been corrected before they resulted in failure. Sur-veillance testing can only identify that a piece of equipment is in an inoperable condition so that the time it is inoperable can be limiteit preventive maintenance, however, can limit the number of failures that occur. In this way, improved preventive maintenance can make a greater contribution to reactor safety than is being made by surveillance testing.

ImplementationSchedup As noted above, some of the propcsed redactions in surveillance testing for RPS and ESL AS instrumentation Mye already been approved with the remainder scheduled for approval before the end of the year. Individual licensees are expected to begin to submit the license amendment applications necessary to implement these changes early next year. It is possible that they could

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be fully implemented by the end of 1989. The implementation of

! these changes will result in a reduction in the frequency of tests which have been identified as being major causes of testing-induced reactor trips and thereby improve safety.

With respect to changes in testing requirements for major mechanical equipment ant, systems, the staff expects to complete its peer review of specific recommendations by the end of 1988. The actual implementatian of the approved changes will be integrated with the implementation of the overall Technical Specifications Improvement Program through individual plant conversions to the new Standard Technical Specifications or individual license amendments. The implementation process and schedule for these types of changes at any specific plant will be based on the most cost effective use of available staff resources recognizing that, while important, they do nut have the same safety significance as the changes nroposed for RPS and ESFAS instrumentation.

. Longer Term Activities Based on the work that has been done to date the staff is studying the feasibility of a longer term effort with the objective of developing an entirely new approach to establishing test frequencies based on actual failure rate experience and preventive maintenance activities. Conceptually the approach would be to set minimum test intervals and reliability goals for '.

systems and equipment and allow licensees.the, flexibility to increase these intervals as part of an-integrated maintenance and testing program using actual failure rate history to verify tnat the reliability goals are being met. We understand that a similar concept is being used in Canada today. The ultimate '

objective would be to eliminate all testing at power for any equipment where acceptable reliability can be achieved without l such testing.

A detailed schedule and milestones for this effort have not been worked out. The staff has, however, met with various industry groups and individual utilities that are pursuing programs in this area. In July of this year the staff visited the San Onofre site and met with corporate engineers and site operation and maintenance staff who are developing a program which shares many of the objectives we have established for a

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reliability-based integrated maintenance and surveillance program. One option for continuing this work, which is under i active consideration, would be for the staff to work with an individual licensee or group of licensees to develop a pilot i program to serve as a model for all plants.

P The staff believes that additional work in this area could be an '

important first step in developing a fully integrated risk and reliability based approach to Technical Specifications. l Summ1ry Of In summary, a review of operating events caused by surveillance [

Conclusions:

testing shows that the large majority are caused by problems l crising from surveillance on RPS and ESFAS instrumentation. '

However, the actual number of reactor trips related to such testing ,

is not high. It is currently less 'chan one per plant per year. I The staff approval of the industry's proposals to increase the .

surveillance. testing intervals for this instrumentation should, i by reducing the test frequency, reduce these types of reactor I trips, engineered safety features actuations, and other transients.

The staff is prepared to begin to receive license amendment requests to implement these changes immediately with a goal of  ;

full implementation by the end of 1989. However, the actual rate at which changes are implemented will depend upon the ,

extent to which individual licensees elect to participate in '

this voluntary program, i i

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The implementation of the work on Technical Specifications surveillance testing of major mechanical equipment and systems will not have a large effect on reducing transients since trips due to surveillance testing make up only a small fraction of the total number of trips. Implementation of the recommendations of this work, along with the implementation of the reduction in RPS and ESFAS testing proposed in the owners groups topical reports is, however, expected to substantially reduce the. number of transients caused by testing. This will result in an increase in reactor saf ety. The reduction in testing will also increase the performance and availability of safety-related equipment.

resulting in greater reactor safety. A reduction in the Technical Specifications-related 'forkload will result in utility technicians and engineers having more time available for other work more important to safety such as preventive maintenance.

And finally. the staf f intends to continue to pursue work in developing a fully integrated risk and reliability L'ased approach j to technical specificalions with the ultimate objective of eliminating all testing at power fcr any equipment where acceptatie reliability can be achieved without such testing.

The staff plans to place a copy of this Information Parer in the Public Document Room. We will continue to keep the Comission informed of the results of this offort as they develop.

l ../ .

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j Victor Ste o. [P Executive Director

for Operations

Enclosure:

i As stated DISTRIBUTION:

Commissioners OGC j OI

OIA

GPA I

REGIONAL OFFICES

EDO ACRn i ACNW l ASLBP

! ASLAP i SECY l

Table Examples of recommended changes to surveillance requirements undergoing peer review TS surveillance requirement Recommended change REACTIVITY CONTROL SYSTEMSc -

Control rod movement testing Change to quarterly from every 31 (PWR)

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days Standby liquid control system Change surveillance test interval pump test monthly (BWR) (STI) to quarterly Reactor trip test to verify Delete requirement operability of scram discharge volute vent and drain valves.

Required once every 18 months.

(BWR)

INSTRUMENTATION in core detector surveillance Change CE surveillance done weekly on CE plants and requirement to B&W surveillance 7 days prior to use for B&W requirement.

• __ plants (PWR)

Turbine overspeed protection: Change all turbine valve testing Turbino valves cycled once per to quarterly if turbine vendor 7 days. Dire.ct observation of agrees.

turbine valve cycling required i

every 31 days (PWR, BWR) l l REACTOR COOLANT SYSTEM 1

Leak test RCS isolation valves Change 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days, if in cold shutdown for more than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> if not leak tested in last 9 months (PWR)

Check capacity of pressurizer Change f requency to refueling heaters (PWR) intervals f rom every 92 days.

Demonstrate emergency power Retain for those plants where supply to pressurizer heaters power is not from vital bus, is operable (done every 18 Otherwise delete.

months) (PVR) i

Table-(Continued)

TS surveillance requirement Recomended change EMERGENCY CORE COOLING SYSTEM Verify boron concentration in Change to delete boron concentra-accumulator after makeup and tration check if makeup from every 31 days (PWR) normal source (RWST).

At least every 31 days, check Change to af ter integrated leak for air in ECCS (PWR) rate test (ILRT) or maintenance on system af ter initial check each cycle.

Do analog channel operational Change to quarterly from 31 days, test on accumulator level ano pressure instrumentation (PWR)

CONTAINMENT Check areas entered in contain- Change to only once ou idst entry

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ment for loose debris after when successive entries are made.

each entry (PWR) liydrogen recombiner (PWR, BWR) Change surveillance test to refueling intervals. Presently every 6 months.

Test containment spray nozzles Extend to 10 years but require for obstructions every 5 years test at first refueling.

(PWR)

Verify operability of ice Change to 18-month refueling out-condenser doors (PWR) age for all doors rather than 25%

each quarter (approved for McGuire, Catawba).

Chemical analysis of concen- Change analysis to refuelieg tration of sodium outage (presently every 9 months) tetraborate and pH of ice (PWR)

s Table (Continued)

TS surveillance requiremetit Reconnended change PLANT SYSTEh5 AFW pump surveillance test (PWR) Change from monthly to quarterly.

Verify that control room tem- Delete or revise requirement.

perature is less than specified value (typically) 100'F) (PWR, BWR greater than ELECTRICAL SYSTEMS, Diesel generator testing The testing for the diesel. generators (PWR,BWR) should be based on reliability concepts. A reliability goal should be selected, and a program established (such as that in NUREG/CR-5078 des icped for Generic Issue B-5,) which will

__ establish a testing plan to assure that the reltability gr al s is met.

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