ML20197J584
| ML20197J584 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 05/13/1986 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 86-276, IEB-85-003, IEB-85-3, NUDOCS 8605200079 | |
| Download: ML20197J584 (7) | |
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VIHOINIA 13LECTRIC AND POWEH COMI%NY Hicnxonn,Vmoixa 2:tunt v.L.sTHWANT May 13, 1986 Vwn Pamosommv Ne'ca. man Oramarions Dr. J. Nelson Grace Serial No.86-276 Regional Administrator N0/ ALM / ace j
Region II Docket Nos. 50-280
(
U.S. Nuclear Regulatory Commission 50-281 l
Suite 2900 License Nos. DPR-32 101 Marietta St., N.W.
DPR-37 Atlanta, Georgia 30323 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNIT NOS. 1 AND 2 RESPONSE TO IE BULLETIN 85-03 MOV COMMON MODE FAILURES DURING PLANT TRANSIENTS DUE TO IMPROPER SWITCH SETTINGS As requested by IE Bulletin 85-03, the Virginia Electric and Power Company is developing and plans to implement a program to ensure that valve operator switches are selected, set and maintained properly.
We are reviewing those motor operated valves (MOV) in the high pressure safety injectica and auxiliary feedwater systems which are required by 10 CFR 50.55a (g) to be tested for operational readiness.
The results of the review will be submitted in two parts.
The first part is presented here and consists of two attachments.
Attachment I discusses the basis for selection of the MOVs and the method I
of determining the maximum differential pressure during opening and closing.
The resulting maximum differential pressures are presented in table form with identifying valve numbers and a short description of the valve function.
Attachment II identifies our schedule for establishing l
the correct switch settings, demonstrating the operability of the valves, j
and preparing and revising procedures to ensure correct switch settings are determined and maintained.
The second submittel will provide 1) verification of completion of the requested program, 2) a summary of the findings of valve operability prior to any adjustments, and 3) a summary of data in accordance with the bulletin's suggested data summary format.
This submittal will occur within 60 days of completing the items identified in Attachment II.
f Item e.l. specifies that the required actions be completed as soon as practical and within two years from the date of the bulletin (dated November 15, 1985.)
Our schedule for resolving this issue is provided in Attachment II.
Resolution of action item c will begin during the present Surry Unit 1 outage scheduled for May 9 through June 26, 1986.
I
VanonutA ELacraic Ann Powra COMPAwY TO Over half of. the Unit 1 MOVs 5:111 be functionally tested during this outage to obtain signature analysis data and 'to verify our methodology; at least 3 of the MOVs will be stroke tested at the maximum diffsrential pressure.
Unit 2 action items will be addressed by the end of the refueling outage which is scheduled for October 10 through December 7, 1986. For Unit 1, additional action (i.e. resetting switches and stroke testing) may be necessary after completing the calculation of the correct switch settings, which is scheduled to be completed by September 30, 1986.
We plan to complete the remaining action items for Unit I during the refueling outage scheduled for January 1 through February 18, 1988. Since this is approximately three months after the bulletin's target date for resolution, we request an extension of sixty days after the completion of the Unit 1 outage in early 1988 to provide you with our final report.
The information provided in this response is trua and accurate to the best of my knowledge.
If additional information is required, p1tase let me know.
Very truly yours, W. L. Stewart Attachments cc:
Mr. Roger D. Walker, Director Division of Reactor Projects NRC Region II NRC Senior Resident Inspector Surry Power Station Mr. Chandu P. Patel NRC Surry Project Manecer PWR Project Directorate No. 2 Division of PWR Licensing-A U.Si Nuclear. Regulatory Commission,(Original)
Document. Control Desk-
' Washington, D.C. 205553-
A'ITACHMENT I MAXIMUM DIFFERENTIAL PRESSURE SURRY POWER STATION This attachment provides a discussion of the basis for selection of the MOVs, the method of determining maximum differential pressure expected during opening and closing, and the design basis differential pressure for each MOV.
1.
High Pressure Safety Injection The subject high pressure safety injection MOVs are listed in Table 1 of this report. The MOV selection is based on MOVs in the initial line up of high pressure safety injection.
The initial line up of high pressure safety injection at the Surry Power Station Units 1 and 2 consist of the charging pumps taking suction from the refueling water storage tank (RWST) and discharging to the Reactor Coolant System cold legs. The MOVs included in Table 1 are the MOVs required to realign the charging pumps from normal charging to high pressure safety injection and MOVs which if inadvertently opened or closed would isolate safety injection (SI).
Based on a review of the system realignment, the maximum differential pressure across the charging pump discharge MOVs is based on the maximum charging pump discharge pressure on the upstream side of the valve and a zero psig pressure on the downstream side. This condition could exist for a LOCA where the RCS pressure drops to zero and the charging pumps are started on a SIS signal or for a line break downstream of the valves. Since this is the worst case differential pressure per review of the UFSAR accident analysis, emergency procedures, and system configuration, this differential pressure bounds all opening ind closing design basis events for the high pressure safety injection discharge valves. The maximum differential pressure across the MOVs in the suction lines to the charging pumps is based on the maximum pressure from the RWST or volume control tank (VCT) for level control valves, and from the discharge pressure of the low head safety injection pumps when discharging to the charging pump suction for the low-head SI pump to high-head SI pump isolation valves.
2.
Auxiliary Feedwater The subject auxiliary feedwater MOVs are listed in Table 1 of this report.
The MOV selection is based on MOVs in the line up of the auxiliary feedwater to the steam generators. The auxiliary feedwater system at the Surry Power Station Units 1 and 2 consist of one steam driven and two motor driven auxiliary feedwater pumps per unit which
take suction from the two 110,000 gallons emergency condensate storage tanks and discharge to the steam generator feedwater lines.
The MOVs listed in Table 1 are the MOVs in the discharge lines which, if inadvertently closed, could isolate auxiliary feedwater.
These MOVs are normally open and remain open.
However, if they were inadvertently closed, they would require reopening. Also, these MOVs would be closed to isolate a break downstream (feedwater line break) of the MOVs to prevent loss of auxiliary feedwater through the break.
The auxiliary feedwater pump discharge lines between Units 1 and 2 at Surry are cross-connected in the event tha-the headers of one Unit's pumps are lost.
Two MOVs are provideri. per Unit and they are normally closed and are remote manually opened if required.
Based on a review of the system configuration, the maximum differential pressure across the MOV is the discharge pressure of the auxiliary feedwater pumps on the upstream side of the valve and zero psig downstream due to a line break downstream of the M0V. The review of the UFSAR accident analysis, emergency procedures, and system operation confirms that this differential pressure bounds all opening and closing design basis events for the auxiliary feedwater MOVs.
The maximum differential pressure for each MOV is listed in Table 1.
Table 1 also provides the valve mark number and valve function.
TABLE 1 MOV DATA
SUMMARY
SURRY UNITS 1 AND 2 Design Valve Valve Function Basis pP*_
LCV-1115B, D RWST to high-head SI pump isolation 27 psi LCV-2115B, D 27 psi LCV-1115C, E VCT to charging pump isolation 84 psi LCV 2115C, E 84 psi 1267A, B Low-head SI to high-head SI isolation 145 psi 2267A, B 145 pri 1269A, B 145 psi 2269A, B 145 psi 1270A, B 145 psi 2270A, B 145 psi 1286A, B, C Charging Pump to normal charging isolation 2630 psi 2286A, B, C 2630 psi 1289A, B 2630 psi 2289A, B 2630 psi 1867C, D High-head SI to cold leg isolation 2630 psi 2867C, D 2630 psi FW-151A-F Auxiliary feed pump to steam generator 1180 psi FW-251A-7 isolation 1180 psi FW-160A, B Aux feed cross-connect isolation 1180 psi FW-260A, B 1180 psi
- These values are based on best available information and are presently being verified to ensure accuracy. We will inform you of corresponding changes that may occur as a result of this verification process.
y
ATTACHMENT II IMPLEMENTATION SCHEDULE FOR MOV PRCGRAM SURRY POWER STATION This attachment outlines our schedule for completing action items b through d of IEB 85-03.
Action Item b.
We will establish the correct switch set:ings and the required thrust to assure proper operation of the MOV at the maximum differential pressure by September 30, 1986 for the MOVs ideatified in Attachment I.
Action Item c.
Individual valve settings changes will be made as required.
The valves identified in Attachment I will be verified to assure that the MOV switches are set properly by performing signature analysis, as required.
We will validate this method by performing a maximum differential pressure test on selected valves.
Due to cystem configurations required, these tests will be accomplished during refueling outages for each unit.
We plan to perform these tests during the refueling outages from May 9 through June 26, 1986 and Jtmuary 1 through February 18, 1988* for Unit 1 and October 10 to through December 7, 1986 for Unit 2.
Action Item d.
The preparation of new procedures or the revision of existing procedures to ensure that correct switch settings are determined and maintained will be completed and approved by September 30, 1986.
- Note: This refueling outage occurs after the NRC target date for completing the requirements of the bulletin. Completion of item c during the 1988 refueling is necessary because items b and d could not be completed prior to the 1986 refueling for Unit 1.
1
..-.e
I COMMONWEALTH OF VIRGINIA )
)
CITY OF RICHMOND
)
The foregoing document was acknowledged befoje me, in and for the City and Commonwealth aforesaid, today by W.
L.
Stewart who is Vice President -
Nuclear Operations, of Virginia Electric and Power Company.
He is duly authorized to execute and file the foregoing document in behalf of that Company. and the statements in the document are true to the best of his l
knowledge and belief.
Acknowledged before me this
\\S, day of h._
19 9 \\ c 9
My Commission expires:
Y eh t t w
\\n 19 9 %
k %\\cb%o Notary Public l
L l
(SEAL)
S/001
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