ML20148L055
| ML20148L055 | |
| Person / Time | |
|---|---|
| Issue date: | 06/13/1997 |
| From: | Matthews D NRC (Affiliation Not Assigned) |
| To: | Drake A WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| References | |
| PROJECT-694 GL-96-05, GL-96-5, TAC-M98172, TAC-M98173, NUDOCS 9706190032 | |
| Download: ML20148L055 (9) | |
Text
_.-. -.. _. - _ _. _. _ _. _
i June 13, 1997 l:
Mr. Andrew Drake, Project Manager j
Westinghouse Owners Group Westinghouse Electric Corporation Mail Stop ECE 5-16 P.O. Box 355 Pittsburgh, PA 15230-0355 i
SUBJECT:
JOINT OWNERS GROUP PROGRAM ON MOTOR-0PERATED VALVE PERIODIC VERIFICATION (TAC N0s. M98172 and M98173)
Dear Mr. Drake:
In response to Generic Letter (GL) 96-05, " Periodic Verification of Design-Basis Capability of Safety-Related Motor-0perated Valves," the Boiling Water Reactor (BWR) Owners Group, the Westinghouse Owners Group, and Combustion i
Engineering (CE) Owners Group are jointly sponsoring an industry-wide program i
for the periodic verification of the design-basis capability of safety-related motor-operated valves (MOVs). This program is referred to as the Joint Owners Group (J0G) Program on M0V Periodic Verification.
On March 3, 1997, the Westinghouse Owners Group submitted to the NRC for review and comment its Topical Report MPR-1807 (Revision 0, February 1997),
" Joint BWR and Westinghouse Owners Group Program on Motor-0perated Valve (MOV)
Periodic Verification." - On March 7, 1997, the BWR Owners Group submitted its Licensing Topical Report NEDC-32719 (March 1997), "BWR Owners' Group Program on Motor-Operated Valve (MOV) Periodic Verification." The technical content of these topical reports is identical. Also, we have been informed that the CE Owners Group is a full participant in the J0G program.
Enclosed for your consideration are our comments on your topical report on the J0G Program on MOV Periodic Verification. A similar letter is also being sent to the BWR Owners' Group. You aight want to coordinate your responses with the other participating owners groups.
If you have any questions regarding our comments, you may contact Thomas G. Scarbrough, at 301-415-2794.
Sincerely,
/S/
David B. Matthews, Chief j't /
Generic Issues and Environmental Projects Branch Division of Reactor Program Management Office of Nuclear Reactor Regulation Project No. 694
- l. l p
Enclosure:
NRC St3ff Comments on r /0} " p/ g, l
J0G Program on MOV Periodic Verification cc w/ enclosure:
See next page.
J
^/
Distribution:
Central Files NRC PDR EMEB RF/CHRON GWeidenhamer AHansen JRosenthal EBrown JHWilson CGraig DOCUMENT NAME:
G:\\SCARBROU\\RHWJ0G.WOG and J0GCOMM i
Ts recilve a copy of this document, Indicate In the box C= Copy w/o attachment / enclosure E= Copy with attadhMnt/ enclosure N = No copy 0FFICE E QE' d~
EMEB:DE v 6 EMEB:DE N
O PQiBh NAME TSca N gh DTeraob RWessman) h DM N hews M DATE
$/[.297
[o/t1/97 b/Y97
[o/h/97
/
0FFICIAi RECORD COPY 9706t90032 970615 7NY P
= "*l*J NRC RLE CENTER COPY
June 13, 1997 Mr. Andrew Drake, Project Manager i
{
Westinghouse Owners Group i
Westinghouse Electric Corporation Mail Stop ECE 5-16 P.O. Box 355 Pittsburgh, PA 15230-0355 i
SUBJECT:
JOINT OWNERS GROUP PROGRAM ON MOTOR-0PERATED VALVE PERIODIC VERIFICATION (TAC N0s. M98172 and M98173)
Dear Mr. Drake:
~
In response to Generic Letter (GL) 96-05, " Periodic Verification of Design-l Basis Capability of Safety-Related Motor-Operated Valves," the Boiling Water Reactor (BWR) Owners Group, the Westinghouse Owners Group, and Combustion j
Engineering (CE) Owners Group are jointly sponsoring an industry-wide program i
for the periodic ver)fication of the design-basis capability of safety-related l
motor-operated valves.(MOVs). This program is referred to as the Joint Owners j
Group (J0G) Program on MOV Periodic Verification.
)
On March 3, 1997, the Westinghouse Owners Group submitted to the NRC for review and comment its Topical Report MPR-1807 (Revision 0, February 1997),
i
" Joint BWR and Westinghouse Owners Group Program on Motor-Operated Valve (MOV) l Periodic Verification." On March 7, 1997, the BWR Owners Group submitted its Licensing Topical Report NEDC-32719 (March 1997), "BWR Owners' Group Program i
on Motor-Operated Valve (MOV) Periodic Verification." The technical content
]
of these topical reports is identical. Also, we have been informed that the l
CE Owners Group is a full participant in the J0G program.
1 i
Enclosed for your consideration are our comments on your topical report on the l
J0G Program on M0V Periodic Verification. A similar letter is also being sent i
to the BWR Owners' Group.
You might want to coordinate your responses with l
the other participating owners groups.
If you have any questions regarding our comments, you may contact Thomas G. Scarbrough, at 301-415-2794.
Sincerely,
/s/
i David B. Matthews, Chief Generic Issues and Environmental j
Projects Branch Division of Reactor Program Management Office of Nuclear Reactor Regulation i
Project No. 694 l
Enclosure:
NRC Staff Comments on i
J0G Program on MOV Periodic Verification j
cc w/ enclosure: See next page.
j Distribution: Central Files NRC PDR EMEB RF/CHRON GWeidenhamer AHansen JRosenthal EBrown JHWilson CGraig DOCUMENT NAME: G:\\SCARBROU\\RHWJ0G.WOG and J0GCOMM j
Ta recalve a copy of thle document. Indicate in the box Cecopy w/o attachment / enclosure Escopy with e WedhMnt/ enclosure N e ho copy l OFFICE E E QE' d'
EMEB:DE. v 6 EMEB:DE N
O PMB, hPM i
NAME TSca N gh DTeraob RWessmani DM N hews M DATE
[/M97
[o/lt/97 b/Y97
[n/h/97
/
OFFICIAL RECORD COPY y
\\
1
6 Westinghouse cc:
Nicholas Liparulo, Manager.
Regulatory and Engineering Networks Westinghouse Electric Corporation Mail Stop ECE 4-15 P.O. Box 355 Pittsburgh, PA 15230-0355 t
Mark Beaumont Westinghouse Electric Corporation One Montrose Metro 11921 Rockville Pike, Suite 450
. Rockville, MD 20852 f
i
s J
NRC STAFF COMMENTS ON J0G PROGRAM ON MOV PERIODIC VERIFICATION J0G Proar==atic Issues 1.
The final MOV periodic verification test criteria of the J0G Program on MOV Periodic Verification will not be established until completion of the J0G dynamic test program and the evaluation of the test data by J0G.
At this stage, the NRC staff is not able to approve the final criteria until reviewing the J0G program evaluation of the test data and justification for establishing the final criteria.
Following the J0G dynamic test program, the NRC staff requests that J0G submit for NRC review and approval a revision to the topical report describing the final test criteria and the justification for those criteria. The J0G should discuss more specifically its plans for using static and dynamic test data to determine the final test criteria.
4 2.
Licensees implementing the J0G program as part of their response to Generic Letter (GL) 96-05, " Periodic Verification of the Design-Basis Capability of Safety-Related Motor-0perated Valves," will be expected to address any conditions or limitations in the NRC evaluation and conclusions on the J0G program provided in the NRC Safety Evaluation, 4
and its supplement to be prepared following submission of the revised topical report that will include the results of the J0G dynamic test i
program.
3.
The topical report does not address thr. procedures for identification of valve performance issues that might reveal operability concerns with MOVs in nuclear power plants.
The topical report should discuss the l
process for satisfying the requiremerts of 10 CFR Part 21.
Further, the topical report should also emphasize that licensees implementing the J0G program are responsible for addressir'g the information provided as a result of the J0G program during and following the J0G dynamic test program.
4.
The J0G program does not include consideration of ASME Code Case OMN-1, -
" Alternative Rules for Preservice and Inservice Testing of Certain Electric Motor Operated Valve Assemblies in LWR Power Plants, OM Code 1995 Edition; Subsection ISTC." Licensees choosing to implement the OMN-1 code case are required to submit a request for relief from IST requirements for application of the code case, pursuant to 10 CFR 50.55a(a)(3).
5.
The Westinghouse Owners Group and BWR Owners' Group each submitted a topical report describing the J0G Program on MOV Periodic Verification.
These topical reports are currently identical in content.
The Owners' Groups will be expected to ensure that the description of the J0G program remains the same for each participant.
ENCLOSURE
t a
J0G Proaram Scone 6.
Licensees are responsible 'for identifying any valves which are outside the scope of applicability of the J0G overall program or the J0G dynamic test program such as valve manufacturer, size, type, or service conditions.
-7.
The discussion of gate valves in-Section 3 of the topical report needs to be clarified.
For example, the topical report does not discuss disk-to-guide friction or potential anomalies that can affect gate valve performance. The first and second bullets following the first full paragraph on Page 3-2 imply that the listed valves will perform in a similar. manner although some of these valves have not undergone testing programs. On Page 3-3, in the second bullet from the top of the page, l
the topical. report does not discuss the secondary flow in the WKM valve that can affect performance. On Page 3-3 in the fourth bullet, the topical report states that the J0G program applies to Deloro 50, Monel, and 400 stainless steel, although these materials have not been subject to programs to study age-related effects on valve performance.
Review and revision of the gate valve discussion in Section 3 is needed to address these issues.
8.
The discussion of globe valves in Section 3 of the topical report needs to be clarified with respect to unbalanced disk globe valves.
For i
example, in the last full sentence on Page 3-3, the topical report states that unbalanced disk globe valves are insensitive to friction, although disk flow load pressing the _ disk against the surface of the cylindrical guide can affect the magnitude of the required thrust. At the top of Page 3-4, the topical report states that unbalanced globe valves can be addressed using only static tests, although the globe valve model developed by the Electric Power Research Institute has not been validated above 150 *F and globe valve performance above this temperature is not well known.
i l
9.
The topical report allows licensees to apply adjustments to either the actuator output thrust or required thrust. These differing approaches I
in applying uncertainties in thrust and torque setup calculations can result in different amounts of margin if applied to the same M0V. Where justified, licensees may retain their approach for MOV setup provided MOVs are properly evaluated for operability. However, because of the small margins allowed by the J0G interim periodic test program, the l
staff will expect licensees to account for uncertainties, as appropriate, regarding the output or required thrust (or torque) when establishing test frequencies under the J0G program.
J0G Interim Proaram l
l 10.
Licensees must ensure that each MOV in the J0G program will have adequate margin to remain operable until the next scheduled test, l
regardless of its risk categorization or safety significance.
2 l
o In addition to the general test frequency established in the J0G 11.
program, licensees must consider the operating history of the specific valve, and its application and environment, in determining whether the test frequency is appropriate.
12.
The NRC staff reviewed and approved, with certain conditions, the use of BWR Owners' Group Topical Report NEDC-32264, " Application of Probabilistic Safety Assessment to Generic Letter 89-10," for the prioritization of safety-related MOVs for testing in response to GL 89-10, " Safety-Related Motor-Operated Valve Testing and Surveillance." The staff references NEDC-32264 in GL 96-05.
Licensees that did not participate in the development of NEDC-32264 will be expected to justify.their risk categorization methodology as part of their implementation of the J0G program. The topical report provides limited guidance in this regard on Page 4-2, but does not discuss the potential for common mode failure of MOVs.
13.
As an editorial comment, the topical report should reference the Supplement (dated February 20,1997) to the NRC Safety Evaluation on the EPRI MOV Performance Prediction Program.
14.
On Page 4-6, the topical report discusses the use of the EPRI MOV Performance Prediction Methodology (PPM) in evaluating the amount of available margin in categorizing the MOVs.
The topical report should be revised to indicate that licensees should evaluate the results of the EPRI PPM before determining whether an MOV has high, medium or low margin.
For example, the statement might not apply to those valves having test-determined vtive factors or to valve designs that require compensating factors in f.he models such as the Aloyco, WKM, Westinghouse, Anchor / Darling double-disc, and other designs not tested i
in the EPRI program. The statement might also not apply to limit-switch
'i controlled valves.or to valves with Class 2 Warnings (galling), as defined by the EPRI PPM.
15.
As an editorial comment, the last bullet on Page 4-6 should include the l
provision that the MOV is maintained in good working order.
J0G Dynamic Testina Proaraql 16.
The topical report describes the J0G receipt evaluation of test data from participating licensees as part of the J0G dynamic testing program.
The J0G receipt evaluation involves comparing the test results with previous tests and assessing any observed trends with similar valves and the J0G program criteria. The interim periodic test program allows i
margins less than 5% to account for age-related degradation. The J0G receipt evaluation appears to allow a 10% increase in thrust requirements. For the NRC staff to review the J0G test criteria, the topical report should be revised to clarify the 10% review criterion, including the relationship to required thrust and actuator output i
adjustments.
3 l
l
17.
The interim test frequency allows some MOVs to be tested at intervals longer than 5 years. The M0Vs with tentative test schedules beyond 5 years should be grouped with similar MOVs that will be tested on a more frequent basis.
Test data should be evaluated before exceeding 5 years, such that applicable MOVs will be tested within 5 years if the test results do not support longer test intervals.
The topical report should be revised to include this guidance.
18.
On Page 5-1, the topical report discusses the information that can be obtained from dynamic testing. The topical report should indicate that the information is most applicable for the particular differential pressure and fluid conditions and becomes less reliable with extrapolation.
Therefore, the J0G program should ensure that sufficient test data are collected to encompass a broad range of valves and service conditions such that licensees will not need to extrapolate the J0G program results.
Also, on Page 5-1, the topical report should caution licensees that the transfer of information on unwedging thrust from one valve to another might be unreliable because of specific valve characteristics.
Also, on Page 5-1, the first bullet should include a reference to disc-to-seat and disc-to-guide friction (or valve factor).
19.
In the first full paragraph on Pa the dynamic test program matrix. ge 5-2, the topical report discusses The J0G program should attempt to have the interval between tests to be as long as possible within the parameters of the program to provide a better opportunity to observe age-related degradation.
20.
On Page 5-2, the topical report discusses the use of the results from The topical report should discuss the collection of informa cycles and service conditions for these M0Vs to be able to evaluate the effect of service wear over that time interval.
Actuator Outout Thrust and Toroue 21.
On Page 3-7, the topical report states that the actuator is outside the scope of the J0G program.
The J0G Program focuses on the potential age-related increase in the thrust and torque required to operate the valves.
The topical report in Section 4 discusses the information that can be obtained from static testing.
Industry testing has revealed that information from static testing provides an indication of actuator output at that specific time for that specific MOV, but that extrapolation of that information to other MOVs and times is less reliable.
To assist licensees in addressing potential degradation in actuator output thrust and torque as part of their long-term MOV programs, the J0G should include an evaluation of potential degradation in actuator output thrust and torque as part of its dynamic test program. This evaluation should address the effects of aging on rate-of-loading and stem friction coefficient under dynamic conditions.
4
3 i
DP Test Groun (Annendix C) l 22.-
In Table C-3, the topical report should indicate the testing of the unbalanced globe valves.
i 23.
Table C-3 indicates that globe valve testing will only be conducted t
under cold conditions. With the uncertainties surrounding globe valve performance under hot conditions, the J0G program should include dynamic testing of balanced and unbalanced disk globe valves under both cold and v
hot conditions.
24.
The tables in Appendix C should be finalized.
j 25.
As an editorial comment, the word " unbalanced" on Line 4 of Page C-1 should be " balanced."
l In-Plant Test Specification (Aonendix D) i I
26.
On Page 2 of Appendix D, Section 3.2 should require that the valve internals not be exposed to air because this could reduce the thrust requirements.
27.
On Page 3 of Appendix D, the word " maximum" in the third line of i
Section 4.3 should be deleted.
28.
On Page 3 of Appendix D, the phrase "the packing load" in Line 9 of Section 4.3 should be changed to "the sum of the absolute values of the packing load and the stem rejection load," in order to provide more assurance of a reliable thrust measurement.
l 29.
On Page 5 of Appendix D, Section 4.6 should include identification of f
the disk wedge angle, where applicable.
I
-30.
- On Page 6 of Appendix D, the first bullet should note the importance of clearly identifying a point of flow isolation.
Pressure instrumentation l
alone might not. reliably predict the point of flow isolation.
- Further, the friction coefficient determined when the disk is sliding on the seating surface is the most reliable for extrapolation and trending with respect to other valves.
31.
On Pages 6 and 7 of Appendix D, tLe closing and opening valve factor equations are provided. Discuss the basis for use of these equations rather than more up-to-date equatir.ns.
l l
32.
On Pages 7 and 8 of Appendix D, the topical report should indicate l
l whether the seat diameter "d" is based on seat or guide measurements for l
I 33.
On Page 10 of Appendix D, Section 4.7 should include provisions for l
documenting the number of IST and operational strokes that the MOV has i
l-experienced between J0G-specified tests.
5 I
l i
i
. - - _. ~. -.
a 34.
On Page 10 of Appendix D, Section 4.7 should require that actual a
diagnostic electronic data be provided to J0G in addition to paper data traces for more detailed evaluation.
l T
6
-