NG-97-0417, Forwards 180-day Response to GL-96-05, Periodic Verification of Design-Basis Capability of Safety-Related Motor-Operated Valves

Forwards 180-day Response to GL-96-05, Periodic Verification of Design-Basis Capability of Safety-Related Motor-Operated Valves

ML20137C736
Person / Time
Site:	Duane Arnold
Issue date:	03/17/1997
From:	Franz J IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:	Collins S NRC (Affiliation Not Assigned), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-89-10, GL-96-05, GL-96-5, NG-97-0417, NG-97-417, NUDOCS 9703250102
Download: ML20137C736 (8)

Text

__

,. o .

i IES Utilities Inc. l 200 Fwst Street SE.

Po. Box 351 Cedar Rapds, IA 52406-0351 1 Telephone 319 398 8162 '

Fax 319 398 8192 UTILITIES , , , , _ , , , ,

l Mce President, Nuclear March 17,1997 NG-97-0417 Mr. Samuel J. Collins, Director Office of Nuclear Reactor Regulation

U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station Pl-37 j Washington, DC 20555-0001 ,

Subject:

Duane Arnold Energy Center Docket No: 50-331 l Op. License No: DPR-49 l 180 Day Response to Generic Letter 96-05," Periodic Verification of l Design-Basis Capability of Safety-Related Motor-Operated Valves" File: A-101b

Dear Mr. Collins:

l The purpose of this letter is to provide IES Utilities' 180 day response to Generic Letter (GL) 96-05, " Periodic Verification of Design-Basis Capability of Safety-Related Motor-Operated Valves."

As requested by the GL, the attachment to this letter contains a summary description of our MOV periodic verification program established to verify on a periodic basis that safety-related Motor-Operated Valves continue to be capable of performing their safety functions in accordance with our current design and licensing bases.  !

Requested actions of GL 96-05 have been completed.  ;

I 9703250102 970317 i PDR ADOCK 05000331 P PDR

1. [

k 3

l . .

1 An IES Industnes Company

I Mr. Samuel J. Collins J NG-97-0417 March 17,1997 Page 2 -

Please contact this office if you have further questions regarding this matter. i This letter is true and accurate to the best of my kr.owledge and i:elief.

IES Utilities Inc.

i By -

M '

/ John F. Franz l

Vice President, Nuclear l

State oflowa  !

County of Linn '

l Signed and swom to before me on this /7 day of /VA ,1997, f I by John F. Franz.

l p DONNA M.BIRKICEf l Wary Public in and for the State ofIowa  !

/Y) % M /197

! # ' Commission Expires '

Attachment cc: R. Murrell

! L. Root G. Kelly (NRC-NRR)

A. B. Beach (Region III)

NRC Resident Office l DOCU l

l l

l l

Attachment to NG-97-0417

, , Page 1 of 6 DUANE ARNOLD ENERGY CENTER MOTOR OPERATED VALVE PERIODIC VERIFICATIONPROGRAM PURPOSE The purpose of this document is to summarize the Duane Arnold Energy Center (DAEC)

Motor Operated Valve (MOV) Periodic Verification Program established as part of our MOV Program.

BACKGROUND Generic Letter (GL) 89-10 recommended that each nuclear power plant establish a program to demonstrate that safety-related MOVs are capable of performing their design basis function. DAEC developed and implemented such a program and NRC acceptance was obtained in November,1995.

Although GL 89-10 included recommendations for long-term periodic verification of MOV performance, these elements were separately summarized by the NRC in the recently issued GL 96-05. GL 96-05 supersedes GL 89-10 and its supplements with regard to periodic verification. The NRC followed this approach so that the major analysis and testing efforts associated with GL 89-10 could be " closed out," and the remaining focus placed on the long-term confirmation of MOV adequacy under GL 96-05.

GL 96-05 requests that each plant establish a program, or ensure the effectiveness of its current program, to verify on a periodic basis that safety related MOVs continue to be capable of performing their safety functions within the current design basis of the facility.

The program should also ensure that changes in required performance resulting from degradation (such as those caused by age) can be properly identified and accounted for.

DAEC EXISTING PROGRAM The re-verification program developed at DAEC under GL 89-10 is based on the static testing of each safety related MOV within a three refuel outage interval and differential pressure testing of 10% of the differential pressure tested valves each outage for three refuel outages. The existing re-verification program will be superseded by the GL 96-05 l Periodic Verification Program as it relates to test frequencies. The GL 96-05 program will be phased in before completion of Refuel Outage (RFO) 15 (currently scheduled for Spring,1998).

i

l Attachment to  ;

NG-97-0417

, Page 2 of 6 DISCUSSION Because each plant invested significant resources to demonstrate MOV adequacy in their GL 89-10 programs, there is a benefit if several plants can take advantage of this information, including follow-up testing that may be done at individual plants. To achieve this benefit, the Boiling Water Reactor Owners' Group (BWROG) and i Westinghouse Owners' Group (WOG) joined together to sponsor the Joint Owners' Group (JOG) Periodic Verification (PV) Fregram. It is the intent of the DAEC to commit j

to accepting and participating in this program for the development, implementation and maintenance ofit's Motor Operated Vnive Periodic Verification Program. The objectives of this program are:

1. Provide an approach for member plants to use immediately in their GL 96-05 programs. The approach covers prioritization of MOVs based on risk significance  ;

and margin, and specifies intervals for static MOV testing. '

2. Develop a basis for addressing potential degradations (increases) in required  !

thrust or torque under differential pressure (DP) conditions. The basis is i supported by a set of planned tests to be performed in-plant, which cover the change in DP thrust or torque over a period of several years.

l

3. To use the basis from Item 2 to confirm, or if necessary to modify, the approach l defined in Item 1.

GL 96-05 PROGRAM ELEMENTS The GL 96-05 program will consist of three basic elements. l

1. The first element is an interim static test program, which is intended to be used immediately by member plants to address GL 96-05. The static testing is meant j to provide confirmation that each MOV is set up in a manner which ensures positive margin for operability. The static testing is carried out at a frequency which depends on the importance (risk contribution) and margin (defined below) of the valve. The risk and margin criteria are preliminary and are based on judgment and experience developed during the GL 89-10 program.

It is important to note that the operability of each MOV is assured by proper evaluation and setup, as controlled by the DAEC GL 89-10 program. As long as these criteria are satisfied, the valve is fully expected to operate properly, and the static testing provides confirmation that the setup is consistent with operability.

2. The second element is a dynamic test program, which is carried out in a coordinated manner by performing DP tests of selected MOVs at member plants over a period of five years. These tests provide the technical basis to verify, or if necessary modify, the criteria in the interim program. The tests are performed in

l  ?

Attachment to {

NG-97-0417 1

. . Page 3 of 6 accordance with a specification to ensure that consistency is obtained in data from multiple sites. The MOVs to be tested cover the range of valve design factors  !

(e.g. materials) and application factors (e.g. stroking history or water quality)

{

which may potentially affect degradation. During the dynamic test program, there  ;

is periodic assessment and evaluation of test results to ensure that findings are j quickly fed back to the participating plants.

3. The third element is the final program, which is achieved by analyzing, evaluating and resolving all of the data from the dynamic test program. The objective of the final program is to provide final, justified criteria for periodic testing, which form a credible basis to ensure that GL 96-05 is satisfied at each participating plant.

J GL 96-05 PROGRAM SCOPE Safety-related MOVs currently within the scope of the DAEC GL 89-10 MOV Program ,

will be included within the scope of the GL 96-05 Periodic Verification Program.  !

i 1

STATIC TEST CRITERI A (INTERIM PROGRAM) ,

i i The proposed criteria for the GL 96-05 program is as follows

i 1

1. Continued MOV exercising per the inservice testing (IST) program will be  ;

addressed separately from this program. However, this program may be used to  ;

provide justification for future revisions to the IST program (i.e. Stroke Time Testing). ,

2. MOVs are to be statically tested using diagnostic equipment, on a frequency which depends on the safety significance (risk) of the valve and on the functional  !

capability (margin) of the valve. Thejustification of the specific margin  !

categories is to be confirmed by the JOG PV dynamic test program. Accordingly,  ;

, the program approach is considered " interim" until confir nation (with dynamic l l testing) is achieved.  !

l The following table illustrates the risk and margin categories for testing frequency.  !

The risk criteria are identified as simply High, Medium and Low. The criteria for determining which valves are in which category are based on the BWR Owners' Group Topical Report NEDC 32264," Application of Probabilistic Safety Assessment to Generic l Letter 89-10 Implementation."

The margm criteria are identified as simply High, Medium and Low. The available l margin is identified as the difference between available thrust capable of being delivered by the actuator and required thrust demanded by the valve under design basis conditions.

Margin should be adequate to cover potential degradations. Margin for factors other than l

l l

l

l Attachment to l NG-97-0417 i

, , Page 4 of 6 diagnostic equipment error and torque switch repeatability have been addressed in accordance with the existing DAEC GL 89-10 MOV Program requirements.

Margin is defined as follows:

(Thrust at control switch trip minus error)- Minimum Required Thrust {

Margin (%) = X 100 l Minimum Required Thrust j 1

MOV STATIC TEST FREQUENCY TABLE RISK MARGIN HIGH (>10%) MEDIUM (5-10%) LOW (<5%) I HIGH 3 CYCLES 2 CYCLES 1 CYCLE  !

l MEDIUM 6 CYCLES

• 4 CYCLES 2 CYCLES LOW 6 CYCLES

• 6 CYCLES

• 3 CYCLES

• NOT TO EXCEED 10 YEARS EPRI PPM MARGIN DETERMINATION The intent of EPRI PPM is to define a bounding thrust requirement which is an adequate design value throughout the life of the valve. It is considered that a thrust prediction from the EPRI PPM has " built-in" margin for degradation in required thrust. Therefore, for the purpose of this program the valve is considered to have "high" margin, with regard to l determining required static test frequency. The MOVs set up using the EPRI PPM are l identified in the DAEC GL 89-10 program.

I DYNAMIC TEST PROGRAM DP testing will be performed in accordance with the JOG PV Program. This program consists of a series of in-plant MOV tests performed under differential pressure

~ -

Attachment to NG-97-0417

, , Page 5 of 6 conditions. Each valve is to be tested a minimum of three times under nominally identical DP conditions. Consecutive tests are to be separated by at least one year, and all three tests are to be completed within five (5) years after the start of the program (i.e. by February,2002). It is intended that, for many of the valves, a DP test performed as part of the GL 89-10 program will serve as the initial test in the three-test series. Evaluation of the applicable JOG test data will be evaluated in accordance with existing DAEC MOV Program requirements.

FINAL PV PROGRAM As a result of evaluating test results as part of the interim program, either the interim criteria will be shown to be satisfactory, or modifications to the criteria will be identified.

At the conclusion of the dynamic test program phase (5 years), a set of final program criteria will be documented, and the justification for these criteria (based on data obtained and evaluated throughout the 5-year program) will be sununarized. The issuance of these criteria and theirjustification will be the last step of the interim program.

SUMMARY

1. DAEC will participate in the Joint Owners' Group Periodic Verification program.

2. Differential Pressure testing will be conducted within the requirements of the JOG program.

3. DAEC will review the test results provided by the JOG in accordance with established procedures.

4. Static testing will be scheduled in accordance with the static test matrix provided.

Testing may include a mix of MOV and Motor Control Center testing.

5. MOV program scope will include those safety related MOVs currently listed within the GL 89-10 program.

6. Transition from the existing GL 89-10 program to the Periodic Verification program will be phased in and completed by the end of RF015 which is currently scheduled for Spring,1998.

7. Existing GL 89-10 program procedures will be applicable to the Periodic l Verification program.

8. DP testing or engineering evaluation and applicable static testing will be performed when valve internal maintenance is performed that may affect the required thrust. l I l I

1

-. - - - . _ m - . _ . _ .

,a *

~  :

a Attachment to NG-97-0417 Page 6 of 6

9. Periodic verification criteria for the 17 MOVs removed from the GL- 89-10 program (reference letter NG-96-0522, " Generic Letter 89-10 Program Scope,"  !

dated March I8,1996) will be provided as follows:

1. The valves listed below shall have their torque switch settings maintained

not less than the previously tested values.

l

2. Industry operating experience and data feedback from valves tested in the Periodic Verification program will be evaluated to determine if any adjustments to control switch settings are required.

3. If future torque switch setting adjustments are required, Section 5 of MOV l program manual procedure 3.1,"Limitorque Motor Operators Design and Acceptance Criteria" shall be used to calculate settings. Any switch setting adjustments will be performed during the next appropriate scheduled maintenance activity. Periodic verification DP and static diagnostic testing will not be performed on these valves.

17 VALVES REMOVED FROM GL 89-10 PROGRAM SCOPE:

MOl912 - RHR Pump IP-229B Shutdown Cooling and Fuel Pool Cooling Suction Isolation MOl920 - RHR Pump IP-229D Shutdown Cooling and Fuel Pool Cooling Suction Isolation l MOl936 - RHR Drain to Waste Surge Tank Outboard Isolation MOl937 - RHR Drain to Waste Surge Tank Inboard Isolation MOl941 - RHR Heat Exchanger IE-201B Outlet Isolation MO2010 - RHR Loops "A" and "B" Cross-tie header Isolation i MO2011 - RHR Pump IP-229A Shutdown Cooling and Fuel Pool Cooling Suction Isolation MO2016 - RHR Pump IP-229C Shutdown Cooling and Fuel Pool Cooling Suction Isolation MO2031 - RHR Heat Exchanger 1E-201 A Outlet Isolation MO2112 - Core Spray Loop "A" Test Bypass Valve MO2115 - Core Spray Loop "A" Injection Outboard Isolation MO2132 - Core Spray Loop "B" Test Bypass Valve

~

MO2135 - Core Spray Loop "B" Injection Outboard Isolation MO2311 - HPCI Pump Discharge Isolation MO2316 - HPCI and RCIC Test Return Redundant Shutoff Valve MO2511 - RCIC Pump Discharge Isolation MO2515 - RCIC Pump Discharge Test Line Isolation

_