ML20215E596
| ML20215E596 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 10/03/1986 |
| From: | Nauman D SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| IEB-85-003, IEB-85-3, NUDOCS 8610150393 | |
| Download: ML20215E596 (5) | |
Text
, - -
bNh
~
gthggna Electric & Gas Company n
n gumgag,29218 Nuclear Op3 rations SCE&G Ocgber3,1986
,,,.m.,.
d'E 6
g 61 Dr. J. Nelson Grace Regional Administrator U. S. Nuclear Regulatory Commission Suite 2900 101 Marietta Street, NW Atlanta, GA 30323
Subject:
V. C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 IE Bulletin 85-03 Supplemental Response l
Dear Dr. Grace:
Attached is a supplemental response to IE Bulletin 85-03, " Motor Operated Valve Common Mode Failures During Plant Transientt Due to Improper Switch Settings," dated November 15, 1985. This response is provided in accordance with a telephone request on September 4, 1986 from Mr. Leo Modenos of your staff.
Should you have additional questions after your review of the attached response, please contact us at your earliest convenience. The undersigned affirms that the statements and matters set forth in this letter are true and correct to the best of my knowledge, information and belief.
r ul
- ours, i
0.
r MRH:rh Attachments i
pc:
Page 2
/
8610150393 861003 PDR ADOCK 05000395 G
y Dr. J. Nels:n Grace October 3, 1986 Page 2 pc:
- 0. W. Dixon, Jr./T. C. Nichols, Jr.
E. H. Crews, Jr.
E. C. Roberts J. G. Connelly, Jr.
W. A. Williams, Jr.
O. S. Bradham D. R. Moore Group Managers W. R. Baehr C. A. Price W. T. Frady C. L. Ligon (NSRC)
R. M. Campbell K. E. Nodland R. A. Stough G. O. Percival R. L. Prevatte J. B. Knotts, Jr.
M. D. Blue M. R. Hazel I&E Washington Document Management Branch NPCF File
. Attachment to Dr. J. N21s:n Grac2 l
October 3, 1986 Page 1 of 3 I.
Definitions:-
A/E Architect / Engineer DBA Design Basis Accident AP Differential Pressure Final Safety Analysis Report FSAR LOCA Loss of Coolant Accident NSSS Nuclear Steam System Supplier Pounds per square inch - differential psid psig -
Pounds per square inch - gage RWST Refueling Water Storage Tank SCE&G -
South Carolina Electric & Gas Company VCT Volume Control Tank II.
The following questions as we understand them were asked via telecon on September 4, 1986:
1)
How will torque switch settings be determined and who would perform the determination (valve or operator vendor, A/E, NSSS)?
2)
How was the the maximum differential pressure calculated for each of the SCE&G identified valves?
3)
How does SCEF.G intend to perform maximum differential pressure testing required by IEB 85-03? If that is not
- feasible, 4)
What methodology does SCE&G intend to use to verify proper torque switch settings?
III.
Responses:
1)
Torque switch settings will be determined by the appropriate valve vendor as related to current design differential pressure requirements.
2)
A.
Valves XVG-8107, 8108-CS The DBA for which these valves must close is the LOCA.
For this case, the reactor coolant system will be depressurizing and the charging pumps will be proceeding to maximum operating conditions. Based on analysis, the lowest core pressure of 500 psig (concurrent with the maximum runout charging pump pressure of 2680 psig) results in a maximum conservative figure of 2200 psid AP against which these valves should close.
B.
Valves XVG 8801-A,B-CS The same discussion as presented under 2A applies for these valves except the function of the valves is to open.
j
Attachment to Dr. J. Nels:n Grice l
0ctober 3, 1986 Page 2 cf 3 C.
Valves LCV 115,C,E-CS The DBA for which these valves must close is the LOCA.
This differential is from the VCT to the suction header of the charging pumps. The VCT is located at elevation 463' with a maximum overgas pressure of 75 psig. The suction header of the charging pumps at elevation 388' and the valves located at elevation 425' (concurrent with an 8-foot water level in the VCT) results in a conservative figure of 96 psig on the upstream side of the valves. Assuming zero psig pressure in the suction header of the charging pumps yields a AP of 96 psid.
D.
Valves LCV 115 B,D-CS The AP for which these valves must open is the LOCA.
This differential is from the RWST highest level to the valves' location at elevation 401'. Assuming the highest.
level (471') of water available in the RWST (concurrent with zero psig pressure in the charging pump suction header) yields a conservative figure of 33 psid AP.
E.
Valves XVG 1001-A and B; 1002, 1008, 1037-A, B-EF The AP for which these valves must perform their design basis function has been verified to be 60 psid. This value was obtained from current flow diagrams and applicable system descriptions.
3&4) SCE&G intends to perform differential pressure testing, where feasible, during the third refueling outage. Sp aific procedures will be developed to support each valve's individual testing configuration for the required ulve operation. Details of the testing program will be provided when completed.
The capability of testing the valves identified in response to IEB 85-03 has been evaluated and is specified below.
Valve Maximum AP (psid)
Test Cateaory XVG-8107-CS 2200 maximum XVG-8108-CS 2200 maximum XVG-8801A,B-CS 2200 maximum LCV-115B,0-CS 33 partial 1/
LCV-115C,E-CS 96 partial 1/
XVG-1001A,8-EF 60 none 2/
XVG-1002-EF 60 none 2/
XVG-1008-EF 60 none 2/
XVG-1037A,B-EF 60 none 2/
i 1/ See Page 3 g/ See Page 3
Attachment to Dr. J. N21stn Grace
/
October 3, 1986 Page 3 of 3 For all identified valves, whether they fall in the category of maximum, partial, or no differential pressure testing, SCE&G intends to incorporate M0 VATS signature analysis techniques to obtain valve stem thrusts, motor current, and time sequence activation of all operator control switches.
The data obtainable through the use of this analysis will enable the monitoring of valve performance for the required i
design basis action both presently and in future years.
SCE&G is using these techniques for various valves and will expand its testing to include IEB 85-03 identified valves during the third refueling outage.
In addition, SCE&G is now enhancing the present M0 VATS 2000 series equipment to the series 2150 in conjunction with obtaining the MOVATS remote motor control center dynamic testing equipment. The M0 VATS equipment upgrades are expected to be available by year end 1986 to support the third refueling testing requirements.
1/ Due to plant configuration in Mode 4, we anticipate being unable to reach maximum AP.
2/ These valves will not be subjected to differential pressure testing to preclude possible contamination of the steam generators from the Service Water System supply paths.
I I
i i
t i
I l
)