ML20246A942
| ML20246A942 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 06/30/1989 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 89-206D, NUDOCS 8907070142 | |
| Download: ML20246A942 (6) | |
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VIRGINIA ELECTAIC AND POWER COMPANY i
l RICHMOND, VIRGINIA 23261 l
W. L. STEWART June 30, 1989 SExtoR Vice PRESII)ENT 4
PonER U. S. Nuclear Regulatory Commission Serial No.
89-206D Attention: Document Control Desk N0/SEC-LIC:RCC: hts:6124 1
Washington, DC 20555 Docket Nos.
50-338
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50-339 License Nos. NPF-4 NPF-7 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 SAFETY SYSTEM OUTAGE MODIFICATION INSPECTIONS SIGNIFICANT ITEM STATUS Our letter Serial No. 89-2068 dated April 28, 1989, provided the Virginia Electric and Power Company response to significant items identified as a result of the Safety System Outage Modification Inspection (SSOMI). The April 28, 1989 response addressed the issues as they pertain to both Unit I and Unit 2,
however, it specifically addressed Unit 2 startup issues.
The purpose of this letter is to address North Anna Unit 1 SSOMI issues and provide a status of the remaining open SS0MI items.
If you have further questions or require additional information, please contact us immediately.
Very trulg y~urs,
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J. L, Stewart Attachment cc:
U. S. NJclear Regulatory Commission 101 Marietta Street, N.W.
Suite 2900 Atlanta, GA 30323 Mr. J. L. Caldwell NRC Senior Resident Inspector North Anna Power Station 8907070142 890630 PDR ADOCK 05000338 O
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. ITEM 1-3 1
The. Linspectim team. identified that the service water system spray and bypass
> valve motor actuators were sized for an incorrect differential pressure rating
~f 50' psi.
In addition, the. corresponding torque switch settings for the-o actuators were also based on the 50 psi differential pressure ra ting.
This calls into question the. ability of this safety system to operate:if called on to function. VEPCO was requested to verify the correct differential pressure rating for these valves vand make any' changes necessary.to ensure the actuators would deliver the required torque under all postulated design basis conditions.
STATUS OF SSOMI ITEM #1
'To assure-Spray Array MOV operation; the torque switches have been reset to a-i value of 5.0 (to open and= to close).
The appropriate documents have been
' revised to reflect these new settings. The Service Water Bypass Valves are currently under administrative control to prevent operation from a throttled position. Work is in progress to procure the heavier spring packs for the bypass MOVs which will enable the MOVs to develop sufficient torque to operate Junder throttled position. An installation procedure to install these heavier spring packs is currently being prepared. These spring packs will be installed as soon as possible after completion of the work procedure and delivery of the 4
spring packs.
The installation of the spring packs will complete the actions j
u-required to resolve-SSOMI Item O.
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RESPONSE TO ADDITIONAL. QUESTIONS, SSONI ITEM #1 During a teleconference with members of your staff on April 13, 1989, additional questions were received regarding the measures that VEPC0 has taken to identify and resolve deficiencies involving the specified pressure differential and the resulting concerns involving M0V's on other safety-related systems at North Anna Power. Station. The questions were specifically directed at those design changes which had required a change in M0V's. The response to this questions follows:
A review of MOV's replaced or modified by design change or EWR was initiated for North Anna Units 1 and 2.
The results of the North Anna Unit 2 review were reported by our letter dated April 28, 1989. Our review of M0V's replaced or modified by the design change or EWR processes is complete for North Anna Unit I and has confirmed the adequacy of these valves to meet design pressure differential and torque requirements.
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ITEM 2 As a result of the inspection team's identification of various unjustified assumptions and omissions in setpoint calculations, the team became concerned that a controlled methodology for performing setpoint' calculations did not exist.
To provide assurance that no safety system setting limits had been inadvertently compromised as a result of design changes implemented since the plant was licensed, the inspection team requested that a specific sample of 10 setpoint calculations be verified, including proper consideration of instrument span, drift value, cable accuracy and measuring / test equipment accuracy. Also, I
VEPC0 was requested to report any reduction in safety margin identified as a result of this verification.
STATUS OF SSOMI ITEM 2 In our letter dated May 15,1989 (Serial No. 89-206C), VEPC0 submitted finalized setpoint calculations and safety margin conclusions for SS0MI item 2.
With that submittal, S50MI item 2 is considered closed.
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4 ITEM 3 The inspection team identified that non-Class IE pressure transmitters'for the service water system were powered from a Class IE vital power source, without proper-isolation., Virginia Electric and Power Company was requested'to justify or correct the specific service water instrumentation as well as evaluate.other possible instances of improper isolation elsewhere in the facility.
STATUS OF SSOMI ITEM 3.
In our letter dated April 13,1989 (Serial No. 89-026A), VEPC0 made four'(4) commitments associated with Item 3.
A~ status of the four commitments is as follows:
1.
Qualified Class IE isolator cards have been installed and tested for the specific Service Water modification (DCP 84-43).
2.
.To ensure no other new circuits have a similar deficiency applicable design change packages (DCP's) and engineering work requests (EWR's) implemented since NAS-3012 was issued (April 1987) were reviewed.
The review did not-find any additional discrepancies.
The review of backlogged EWRs not being implemented this outage is contf ruing.
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NAS-3012' will be revised to distinguish between the isolation requirsents of the original plant design and the isolation requirek1ents of new designs.
This revision will be issued by August 15, 1989.
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Individuals responsible for implementation of the requirements of NAS-3012 will be trained on the new revision discussed in Item 3 above, per the.
training. requirements of Section 7.4.3 of Standard EE-011, Revision 3,
" Electrical Engineering Personnel Indoctrination and Training".
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. training will be completed by September 15, 1989.
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.e ITEM 4 The... inspection team noted that design change packages (DCPs) did not explicitly-prescribe the necessary testing required to ' demonstrate functionality of' the system -and' affected components -following the change. -VEPC0 has: committed to update the associated procedures to ensure that the required testing would be accomplished.for future modifications.
To insure that the modifications being installed __during the current optage are functionally. tested subsequent.to the installation and. to ensure that the capability of the affected systems to
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mitigate the design basis accidents has not been compromised, VEPCO was requested' to incorporate the specific post-modification testing requirements into the design change packages or engineering work request scheduled to be installed for this outage.
STATUS OF SSOMI ITEM #4 As discussed with members of your staff during a SS0MI follow-up inspection conducted.the week of April 3 through 7,1989, and as stated-in our letter' Serial No.89-206 dated March 31, 1989, Design Change Packages (DCPs) and Engineering Work Requests-(EWRs) being implemented during the 1989 refueling.
outages that affect system performance are being reviewed to insure that the testing criteria as stated in the letter have' been met.
Also, procedures governing 'DCP and EWR preparation have been revised to assure adequate functional testing for the modification and affected systems is. addressed.
Unit 2 DCP's and EWR's have been reviewed and appropriate changes made where necessary.
The review of any EWR's implemented during the Unit 1 outage will be completed prior to entering Mode 4.
Backlogged EkR's and DCP's that are I
approved and awaiting implementation, but riot yet senoculed have been reviewed and changes made as required.