ML20056F871
| ML20056F871 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 08/24/1993 |
| From: | George Thomas DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-89-10, NUDOCS 9308310242 | |
| Download: ML20056F871 (7) | |
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- e-i Beaver Valley Power Station Shippmgport. PA 15077-0004 i
1412) 3934 206 (412) 643-8369 F AX j
f GEORGE S. THOMAS Dmpon Vice President nacicar services August 24, 1993 Nuclear Power Dmsron U.
S. Nuclear Regulatory Commission Attn:
Document Control Desk l
Washington, DC 20555 i
Subject:
Beaver Valley Power Station, Unit No. 1 and No. 2
}
BV-1 Docket No. 50-334, License No. DPR-66 BV-2 Docket No. 50-412, License No. NPF-73 Generic Letter 89-10, Request for Schedule Extension
Reference:
Duquesne Light Company letter to the
- NRC, f
Response
" Safety I
R91ated Motor-Operated Valve Testing and
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Sur'elllance," dated December 28, 1989 In accordance with Generic Letter (GL) 89-10, Duquesne Light Company (DLC) is notifying the NRC Staff of proposed changes to the schedule commitments provided in the referenced letter.
P The -NRC Phase 1
GL 89-10 Motor-Operated Valve (MOV) Inspection l
- Report, dated. June 10,
- 1992, for the Beaver Valley Power Station (BVPS) indicates that DLC has been aggressively pursuing the i
resolution of concerns with MOV performance at the BVPS.
During the inspection, it was noted that DLC would be performing a program assessment to determine the need for a schedule extension.
Since the inspection, we have reassessed the BVPS GL 89-10 Program and have l
Verified the need for schedule extensions to complete the dynamic testing of certain valves and the two stage switch setting approach of valves that cannot be tested in-situ.
This letter addresses these schedule extensions.
A summary description of the schedule extensions and associated i
milestones for valve testing and setting of switches is provided in the Attachment to this letter.
The extended schedules consist of one.
refueling outage for BVPS 1
and-two refueling outages for BVPS 2 beyond each plant's originally committed schedule.
DLC believes that
-the MOV program
- plan, as described in the Attachment, will provide the necessary assurance that MOVs will' perform their safety related functions when subjected to design basis conditions.
F o,
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9308310242 930824 L;
PDR ADOCK 05000334 N3 g
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PDR b,A t.
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i Benver Valley Power Station, Unit No. 1 and No. 2 BV-1 Docket No. 50-334, License No. DPR-66
- BV-2 Docket No. 50-412, License No. NPF-73 Generic Letter 89-10, Request for Schedule Extension Page 2 Should you have any questions regarding this submittal, please contact Ed Coholich at (412) 393-5224.
Sincerely, Abf nay 8
George S.
T omas Attachment cc:
Mr.
L.
W.
Rossbach, Sr. Resident Inspector Mr.
T.
T. Martin, NRC Region I Administrator Mr.
G.
E.
Edison, Project Manager l
Mr. M.
L. Bowling (VEPCO) i i
9 4
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Attachment BVPS GL 89-10 MOV Program Schedule Extension I
l Backaround h
During the NRC Phase 1
Inspection of the GL 89-10 Program i
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implementation, the inspection team found that the DLC
"...MOV program developed in response to the generic letter was proceeding in the right direction and most aspects of the program were consistent with the recommendations of the generic letter."
The report also noted that "In light of the results of recent industry diagnostic i
equipment accuracy testing and the concerns over measurement and detection of effects due to rate of loading, the licensee took a proactive step to incorporate transducers (i.e., torque thrust cells and stem strain rings) designed to provide direct measurement of available thrust."
The incorporation of these improvements required additional training for personnel and increased the t.ime to set up the diagnostic equipment and to perform the subsequent tmsting.
In
- addition, the diagnostic equipment problems (i.e.,
equipment accuracy and the open versus close issues), which required the reevaltation of
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- data, the recalculation of thrust values, and the resetting of motor
[
operator
- switches, have also slowed progress toward complet.ng some of the actions requested in the generic letter.
During the NRC
]
inspection, DLC indicated to the NRC Inspection Team that a schedule j
extension would most likely be required for the completion of the dynamic testing of the motor operated valves.
4 The following brief descriptions and the attached figure provide an overview of overlapping periods of MOV program development and BVPS 4
scheduled outages.
The corresponding dates provided for these i
periods of the program are approximate and only the first two periods are summarized on the figure.
t i
A major feature of the GL 89-10 Program involves the thrust values calculated by using the standard industry equations and valve i
factors.
Initially, the valve factors for specific valves were j
estimated as conservatively as possible while avoiding potentially unnecessary overstressing of the valve and/or overtorquing of the i
1 actuator.
Valve factors were more accurately determined as increasing amounts of test data became available.
The attached l
- ]
figure shows this phase of the program continuing on through 1991.
i The attached figure also illustrates a combined period of resolution
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l for two major sub-issues involving the overall accuracy of the diagnostic test equipment and the open versus close issue.
The i
period is shown to extend from 7/91, the date of issue of the MOV l
3 Users Group preliminary report on the validation testing of MOV l
diagnostic equipment, to 5/92, the date of issue of the Industry j
Guidance on the open versus close issue.
This phase of the program is seen to extend approximately from the middle of the eighth refueling outage, BR, for BVPS 1 to mid-3R for BVPS 2.
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Attachment
.BVPS GL 89-10 MOV Program Schedule Extension Page 2 l
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Schedule We are proposing the following changes to the schedules originally j
committed to by DLC:
I By the end of the originally committed schedule for each BVPS l
will be statically set using diagnostic equipment and consistent with the best available information.
l f
By the end of the originally committed schedule for each BVPS 1
- unit, the highly safety significant MOVs that are in-situ test able will be dynamically tested and evaluated according to the basis provided below.
By the end of the originally committed schedules, it is planned to dynamically test approximately 78% of the BVPS 1 and 50% of the BVPS 2 in-situ testable valves in the GL 89-10 programs.
The r
l information from these tests, in conjunction with the available
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industry information, will be used to validate the methodology
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for determining the proper performance of the MOVs.
By the end of 11R for BVPS 1 and by the end of 6R for BVPS 2, the dynamic testing will be completed for all the MOVs in the respective GL 89-10 Program to the extent practicable.
l By-the end of 11R for BVPS 1 and by the end of 6R for BVPS 2, the j
confirmation of switch settings using the two stage approach will l
be completed.
)
Basis After the NRC Phase 1
Inspection, the BVPS GL 89-10 Program was e
re-examined based on the MOV technical knowledge, field experience, t
i and testing skills learned up to that time.
The results of the reexamination, which are pertinent to the proposed schedule
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extensions, are included in the information below.
i The evaluation of motor operated valve design basis thrust values j
i has been completed and is being reevaluated based on recent NRC guidance.
We will proceed to complete the static setting of switches consistent with the results of the reevaluation and with I
the MOV data available from tests at BVPS.
We have determined j
that these actions can be completed by the originally committed j
schedules for each BVPS unit.
i 1
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Attachment
,BVPS GL 89-10 MOV Program Schedule Extension Page 3 Our participation in the EPRI MOV Performance Prediction Program and the MOV Users Group activities provides confidence that industry information is being channeled into the BVPS program, j
- Also, the MOV groupings, which were established earlier in the program and are based on design similarities in the valves, j
motor-operators, and their system conditions, will be maintained.
These groupings will aid in evaluating the operating 1
characteristics of MOVs for which the two-stage approach of setting switches is appropriate and for the testing of certain MOVs as presented below.
We have determined the scope of work and resources that will be needed for all MOV activities (i.e.,
dynamic testing, static setting of
- switches, corrective and preventative maintenance).
These activities are being integrated over three refueling outages on each unit; i.e.,
9R, 10R and 11R for BVPS 1 and 4R, SR and 6R for BVPS 2.
Sufficient dynamic testing of MOVs i
representing the GL 89-10 population at the BVPS is planned to be completed by the originally committed schedules such that data is available to validate the methodology being used at the site to 1
determine the proper performance of the BVPS safety related MOVs.
?
The MOV prioritization criteria developed at the beginning of the f
BVPS program have been integrated with the results of the recently completed IPE/PRAs for each unit.
The integration j
provides additional assurance that highly safety significant in-situ testable MOVs in the GL 89-10 program will be dynamically tested on a
priority basis.
The MOVs included in this category i
are the IE bu]letin 85-03 MOVs and the high risk MOVs as l
determined by their effect on the mean core damage frequency.
As l
a
- minimum, all the in-situ testable IE Bulletin 85-03 MOVs and all the high riskMOVshavingariskgmportancebasedonacore j
damage frequency cutoff of 1x10~
are scheduled to be dynamically tested by the end of the originally committed j
schedules.
As a
conservative measure, high risk MOVs having a t
risk importance based on a
core damage frequency cutoff of
-7 lx10 are also scheduled to be dynamically tested by the end 1
of the originally committed schedules.
However, these MOVs will be tested under the grouping approach.
At least one-half of each J
group of these valves will be tested during the original schedule with the remaining MOVs being dynamically tested during the first outage of the extended schedule of each BVPS unit.
Summary DLC has reexamined its GL 89-10 Program and has scheduled valve testing and switch setting activities to meet certain milestones within the original schedule.
Although some dynamic testing of valves will be on an extended schedule basis, sufficient dynamic testing of MOVs representing the GL 89-10 population at BVPS will be accomplished by the end of the original schedules to validate the methodology being used to determine proper MOV performance.
In
Finally, highly safety significant MOVs will be
l I
Attachment j
.BVPS GL 89-10 MOV Program Schedule Extension l
Page 4 i
tested at maximum achievable conditions by the original schedule for j
each BVPS unit.
Based on the above, DLC believes that the revised i
program plan and the extended schedules as described in this I
attachment will provide the necessary assurance that Movs will perform their safety related functions when subjected to design basis i
conditions.
l The documentation to support the above determinations is available onsite for NRC staff review.
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BVPS GENERIC LETTER 89-10 PROGRAM PROPOSED EXTENDED DYNAMIC TESTING SCHEDULES 4
AND SELECTED ISSUE AND OUTAGE OVERLAPS IN 1991 1992 1993 1994 1995 1996 l
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