ML20005E473

Responds to Generic Ltr 89-10, Safety-Related Motor-Operated Valve Testing & Surveillance. Complete Program Description,Including NRC Bulletin 85-003 & Subj Generic Ltr Valves,Will Be Formulated by 900628

ML20005E473
Person / Time
Site:	Arkansas Nuclear
Issue date:	12/28/1989
From:	James Fisicaro ARKANSAS POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
0CAN128913, CAN128913, GL-89-10, IEB-85-003, IEB-85-3, NUDOCS 9001050302
Download: ML20005E473 (7)

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L-December 28, 1989-r BCAN128913' i:

. U. S. Nuclear- Regulatory Commission

Document Control Desk D Mail Station P1-137 L ,

Washington, DC 20555

Subject:

Arkansas Nuclear One - Units 1 & 2 1

Docket Nos. 50-313 and 50-368 E License Nos. DPR-51 and'NPF-6 i Response to Generic Letter 89-10 'l Safety-Related Motor-Operated w Valve Testing and Surveillance Gentlemen:,

c Generic Letter.89-10, " Safety-Related Motor-0perated Valve Testing and

Surveillance," recommends that the licensee develop a program to coordinate t the~ design basis review, baseline testing and' periodic testing of all Motor

Operated Valves l(MOVs) within all safety-related systems. -This was transmitted to us in your letter of June 28,1989 (fKl4A068926). In

. addition,-the-NRC recommends that'in-situ design basis testing be performed on'as many MOVs as practicable. Compliance with the' recommendations of the  :

e Generic. Letter involves establishing a program which encompasses several i majorareas.

Arkansas Power & Light's (AP&L) response to IE Bulletin 85-03 for Arkansas  !

Nuclear One (ANO), Units 1 and 2, established a program, as required by the  !

Bulletin, for safety-related MOVs. In addition, AP&L on its own initiative,  ;

expanded its MOV program soon after the Bulletin was issued to include  !

.. 't safety-related and some non-safety-related MOVs in other systems. As a i result,. over 220 AN0 MOVs have currently been tested by the MOV Program, far 3.- exceeding the 75 MOVs required to be tested by IE Bulletin 85-03.

The major elements of AN0's MOV Testing Program currently encompasses many

'of those recommended by Generic Letter 89-10 and AP&L will comply with the ',

recommendations of the Generic Letter except as noted and justified below.

3: The following compares Generic Letter recommendations and AN0's existing program.

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' Generic Letter Scope The scope of the M0V testing program has been expanded to include all MOVs in safety-related piping systems. The ANO MOV Testing Program will bring i all such MOVs within its purview to allow AP&L to comply with this Generic  !

Letter recommendation. AP&L interprets the Generic Letter to not include motor-operated devices outside piping systems such as dampers and weir gates. Some of these devices, as well as selected non-Q valves, will be i tested and set by AP&L's MOV program; however, but design basis testing may  !

not be mandated.

ITEMS A & B - Design Basis Review and Determining Correct Switch Settings "a. Review and document the design basis for the operation of each M0V.

This documentation-should include the maximum differential pressure expected during both the opening and closing of the MOV for both normal operations and abnormal events, to the extent that these M0V operations and events are included in the existing approved design basis.

b. Using the results from item a., establish the correct switch settings.

This should include establishing a program to review and revise, as necessary, the methods for selecting and setting all switches (i.e. , torque, torque bypass, position limit, overload) for each valve operation-(opening and closing). One purpose of this letter is to ensure that a program exists for selecting and setting valve operator switches to ensure high reliability of safety-related MOVs."

The recommendations of the Generic Letter are already largely being met by the AN0 M0V Testing Program for the MOVs currently included. These recommendations include determining the design basis conditions for MOV operation during licensed design basis events, ensuring the compatibility of the valve with the actuator and verifying the correct control circuit logic and overload heater sizing. A few enhancements to the current AP&L program, which includes seismic and thrust loud combination as well as cable sizing and breaker settings, will be required to be in compliance with these >

recommendations. With the implementation of these enhancements, we believe our program will be in compliance in this area.

Certain factors presently used in our calculations that determine proper switch settings are the subject of NRC and other industry testing. These factors are valve factor and stem lubrication allowances. Other factors are presently not included in our calculations due to lack of industry consensus on their applicability. These include but may not be limited to hydraulic effects caused by piping configurations and rate of loadings of spring packs. AP&L is continuing to monitor the further development of these factors and will include the results into our MOV Program as they become fully defined. However, any of these items could potentially require a

. major revision to the methodology currently employed. It should be noted that such major methodology revisions could significantly impact the schedule.

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- December 28, 1989 ITEMS C & F - M0V Differential Pressure Testing

!' c . Individual MOV switch settings should be changed, as appropriate, to those established in response to item b. Whether the switch settings are changed or not, the MOV should be demonstrated to be operable by testing it at the design-basis differential pressure and/or flow determined in response to item a. Testing MOVs at design-basis conditions'is not recommended where such testing is precluded by the existing plant configuration. An explanation should be documented for any cases where testing with the design-basis differential pressure or flow cannot practicably be performed. This explanation should include a description of the alternatives to design-basis differential pressure testing or flow testing that will be used to verify the correct settings.

Each M0V should be stroke tested, to verify that the MOV is operable at no pressure or no-flow conditions even if testing with differential pressure or flow cannot be performed.

f. Documentation of explar.ations and the description of actual test methods used for accomplishing item c. should be retained as part of-the required records for the M0V."

The: Generic Letter also recommends that full flow differential pressure testing be performed for all MOVs in the program. Where full flow in-situ testing cannot be performed due to plant constraints, the Generic Letter recommends full flow differential pressure testing be performed on prototype MOVs with documentation sufficient to validate repeatability with the

-in-situ MOVs. As interim measures, the Generic Letter allows analytical methods employing conservative extrapolation from lower than full flow differential pressure testing to be considered until prototype testing is completed. AP&L believes that full compliance with these recommendations is questionable, within the schedule requirements of the Generic Letter, for the following reasons:

• In-situ testing of all the MOVs covered by the Generic Letter under full flow differential pressure conditions may not be possible without violating Technical Specifications or placing the plant systems, components or personnel in unsafe conditions. This is recognized by the NRC in the Generic Letter. AP&L is aware, however, that plant conditions will allow an as yet undetermined number of valves to be tested in this manner.

• The alternative method of full flow differential pressure testing allowed by the Generic Letter (prototype testing) will require the formulation of common testing criteria and testing databases since none broad enough to be useful are currently available. This view was 1

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, December - 28, 1989 presented by the industry at the workshops. Our agreement with this l position-is based on information gained by AP&L's participation and i leadership in various owner's groups following the issuance _of IE Bulletin 85-03. It is our belief that while testing results for tests j completed to date are available, they are not suitable for the purpose j of proving valve similarity due to differences in measurement criteria '

applied in the many separate tests. In addition, it is doubtful that

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l enough variables were measured or even identified to offer valid  !

similarity' arguments. The alternative method of prototype testing, j therefore, while. technically feasible is not now available from an j industry information sharing perspective and will require an unknown i period of time to become useable. The schedule recommendations of the  ;

Generic Letter may not allow time for the formulation of such programs t making compliance with the full flow differential pressure testing l recommendations, as stated, impractical. We acknowledge that the ~

primary concern voiced here is schedular, but with few results from ,

that testing underway, technical issues are also involved in our 1 position.

For the reasons stated above, AP&L cannot commit to full flow differential ]

pressure testing on all MOVs at this time. Those M0Vs which cannot be full l flow tested will be tested in-situ at lower pressures and flows with  ;

acceptable conservative extrapolation methods used to correlate to the design basis conditions as such methods are developed by the nuclear industry. A remaining small num%r of MOVs may offer no opportunity of flow

. testing without placing the plant in unsafe or unlicensed situations. These  !

will be set as-conservatively as possible by static testing. This approach' is the only reasonable one to pursue until the industry can formulate i accurate, repeatable and uniformly accepted testing methods or individual valves or classes of valves. In keeping with this position, AP&L will be  !

actively involved with various industry groups to work in a cooperative  ;

effort to ensure continued safe performance of our MOVs. 1 ITEM D - Verification of Switch Settings "d. Prepare or revise procedures to ensure that correct switch settings are determined and maintained throughout the life of the plant. These procedures should include provisions to monitor MOV performance to ensure the switch settings are correct. This is particularly important if the torque or torque bypass switch setting has been s!gnificantly raised above that required."

The Generic Letter recommends methods to initially verify by testing and to periodically reverify that the switches of each M0V are properly set to ensure that the MOV can meet its design basis functions. The existing AN0 MOV Testing Program employes the HENZE-MOVATS, Inc., testing apparatus to

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verify and re-verify proper switch settings during static MOV testing. AP&L plans to continue to use this method to' implement with this recommendation.

Other systems available to perform this testing will be periodically evaluated as they become available to ensure that the system which, in our judgement, best performs this task is employed.

ITEM H - Documentation "Each MOV failure and corrective action taken, including repair, alteration, analysis, test,andsurveillance,shouldbeanalyzedorjustifiedand documented. The documentation should include the results and history of each as-found deteriorated conditions, malfunction, test, inspection, analysis, repair, or alteration. All documentation should be retained and reported in accordance with plant requirements."

The Generic Letter recommends that MOV failure history, maintenance history and switch setting data be maintained as a means of verifying the results of the overall program and for extending the testing and reverification intervals. AP&L currently has systems in place (Station Information Management System and Condition Reporting System) which document failures and abnormal conditions as well as normal maintenance and testing activities. -This.information will be factored into databases either existing or newly created which will allow compliance with the Generic Letter recommendations.

ITEM I - Schedule "i. Each licensee with an operating license (0L) should complete all design-basis reviews, analyses, verifications, tests, and inspections that have been instituted in order to comply with items a. through h.

within 5 years or three refueling outages of the date of this letter, whichever is later. Each licensee with a construction permit (CP) should complete these actions within 5 years of the date of this letter or before the OL is issued, whichever is later.

For plants with an OL, the documentation described in items 1. and 2.

below should be available within 1 year or one refueling outage of the date of this letter, whichever is later. For plants with a CP, the documentation outlined in items 1. and 2. should be available within one year of the date of this letter or before the OL'is issued, whichever is later. The documents should include:

1. The description and schedule for the design-basis review recommended in item a. (including guidance from item e.) for all safety-related MOVE and position-changeable MOVs as described, and

2. The program description and schedule for items b. through h. for all safety related MOVs and position-changeable MOVs."

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t U. S. NRC-Page 6 December 28, 1989 The Generic Letter requires scheduling and program information by one year of its issuance and that all baseline testing be complete within five years l or three refueling outages of the issuance of the letter on June 28, 1989.

Refueling outages begun within six (6) months of the Letter issue date do not have to be counted in those allowed. It is AP&L's understanding that the schedule requirements stated in the Generic Letter were formulated based - 1 on NUREG/CR-5140, "Value-Impact Analysis for Extension of NRC Bulletin 85-03 i to Cover All Safety-Related M0V." This document assumed a "best estimate" MOV population in excess of those covered by IE Bulletin 85-03 of 100 per unit and a "high estimate" of 130 MOVs per unit.. Using the high estimate as a basis, it is AP&L's interpretation, 50 tests or less for each of. the three  !

outages were assumed by the Generic Letter with no retesting of IE Bulletin <

85-03 valves. AP&L believes that it is not possible to commit to the Generic Letter schedule requirements at this time for the following reasons:

1. It is not practical to-exclude the previously tested IE Bulletin 85-03 valves from retesting in the coming refueling outages since periodic retesting is required due to plant modifications, maintenance and to i configure the 85-03 valves more conservatively as new industry i calculation methods become accepted.

2. The MOV populations at Arkansas Nuclear One, Unit 1 and 2, which will be under the perview of the Generic Letter, while as yet not finalized, will certainly be greater than the high estimates used in i NUREG/CR-5140. At this point in our evaluation there are approximately 226 Unit 1 valves and 252 Unit 2 valves included in our program.  ;

In summary, AP&L will formulate by June 28, 1990, a complete program description (and best available schedule information). The entire program j will include 85-03 valves as well as those newly identified by the Generic Letter. Final scheduling will be based on an assessment of the completion of the unresolved factors and industry efforts to perform prototype testing as discussed earlier with regard to differential pressure testing.

The program description will include a breakdown of those MOVs to be full flow differential pressure tested in-situ, those which can be tested at lower flows and pressures, and those for which no test is possible. >

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E Should you or your_ staff have questions regarding .this response, do not  :

~ hesitate-to call:. t L-p 'Very truly yours,

. .).a.L -

r J. J. isicato Manager,-Licensing  !

JJF/1w

-Attachments ,

cc: Mr. Robert Martin ~

U. -. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 7_6011 ,

NRC Senior Resident Inspector Arkansas Nuclear One - ANO-1-& 2 Number-1, Nuclear Plant-Road-Russellville, AR 72801 Mr.-C. Craig Harbuck NRR Project Manager, Region IV/ANO-1 U. S. Nuclear Regulatory Commission t NRR Mail Stop 13-D-18 One White Flint North- '

11555 Rockville Pike Rockville, Maryland 20852 Mr. Chester Poslusny NRR Project Manager, Region IV/AN0-2 U. S. Nuclear Regulatory Commission NRR Mail Stop 13-D-18 One White Flint North 11555 Rockville Pike Rockville, Maryland 20852 Mr. Thierry Ross (NRC Lead Project Manager)

U. S. Nuclear Regulatory Commission Document Control Desk Mail Station P1-137 Washington, DC 20555