ML20080D643
| ML20080D643 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 08/26/1983 |
| From: | Dixon O SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.2, TASK-TM NUDOCS 8308300529 | |
| Download: ML20080D643 (3) | |
Text
.
SOUTH CAROLINA ELECTRIC & GAS COMPANY post orrics ve4 COLUMalA. south CAnoWNA 29218 August 26, 1983 O. W. Ol1CN. JR.
Vice PatsiDENT NUCLEAR OPERATIONS Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.
S. Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
Virgil C.
Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 Inadequate Core Cooling TMI Item II.F.2 Ref:
O.
W.
Dixon letter to H.
R.
Denton, dated March 8, 1983.
Dear Mr. Denton:
In the referenced letter, South Carolina Electric and Gas Company (SCE&G) committed to providing the staff with information concerning any changes to the inadequate core cooling system described in previous submittals.
The final design of the core exit thermocouple extension cable to meet NUREG 0737 II.F.2 requirements is different than previously stated and is described as follows.
l SCE&G is upgrading all fifty-one channels of its incore thermocouple extension cable system.
The thermocouple signals will be routed in two trains with twenty-five signals in one train and twenty-six in the other.
The individual thermocouple cables exiting the reactor vessel instrument ports will connect j
to a mineral insulated transition cable assembly.
This assembly l
takes four or five individual thermocouple pairs and combines i
them into a single multiconductor mineral insulated cable.
Each transition cable connects to a multiconductor mineral insulated head area lif t rig cable using a qualified quick-disco' 'ect connector.
This cable will connect to a multiconductc. organic insulated thermocouple extension cable also using qualified quick-disconnect connectors.
This cable will then connect to a qualified thermocouple penetration.
Outside of-containment j
multiconductor thermocouple extension cable will carry the signals to qualified thermocouple signal isolators.
These isolators will be located in easily accessible areas.
The signals from the output of the isolators will be routed to the
~
plant computers and the subcooling monitors.
A minimum of eight (two per core quadrant) thermocouple signals will_be sent to_each i
subcooling monitor.
The use of qualified thermocouple penetrations eliminates the need for qualified reference junction boxes inside containment.
(b0*g
\\\\
8308300529 830826 PDR ADOCK 05000395 P
Mr. Harold R.
Denton August 26, 1983 Page 2 NUREG 0737 II.F.2, Appendix B, criterion 1, and Regulatory Guide 1.97, Revision 2, Paragraph 1.3.2, state that "where the instrumentation channel signal is to be used in a computer based display, qualification applies to and includes the channel isolation device."
SCE&G will use the installed Westinghouse core subcooling monitors as the required back-up thermocouple display.
These are computer based monitors which calculate and display degrees subcooling or superheat and display thermocouple temperatures.
Since qualified isolators are being used to isolate the thermocouple signals prior to reaching the subcooling monitors, the subcooling monitors will not be qualified.
Additional display is available on the Technical Support Center computer and the plant process computer.
Any one of these devices will ensure that Technical Specification requirements are met with respect to display of incore thermocouple temperatures.
The attached updated table shows the equipment to be used along with installation, calibration, qualification and testing dates.
Qualification testing has been completed on the equipment being parcha+ed by SCE&G, and no additional testing is required.
We will :.itify you if there are any additional changes to the system.
If there are any questions, please let us know.
Very truly yours,
/
/
O.
W.
Dixon, Jr.
JG:lkh Attachment cc:
V.
C. Summer C. A.
Price T.
C. Nichols, Jr./O. W.
Dixon, Jr.
A.
R.
Koon E.
H.
Crews, Jr.
C.
L. Ligon (NSRC) l E. C. Roberts G.
J. Braddick l
H.
N.
Cyrus J.
C. Miller i
H.
R.
Denton J.
L.
Skolds J.
P. O'Reilly J.
B. Knotts, Jr.
Group / General Managers NPCF O.
S.
Bradham File j
R.
B.
Clary
4 Attachment H.
R.
Denton Page 3 Table Equipment Installation Calibration Qualification Testing 1.
RVLIS Complete Complete Complete Complete
'2.
Core Subcooling Complete Complete Not Required Complete Monitors 3.
Incore Thermocouples Complete Complete Not Required Complete (See R.G.
1.97 Rev.
3.,
Draft 1) 4.
_ Thermocouple End of 1st N/A Complete N/A Extension Cable Refueling (Fifty-one T/C's) 5.
Qualified T/C End of 1st N/A Complete N/A Penetrations (Two)
Refueling 6.
Qualified T/C End of 1st N/A Complete End of 1st Isolators
-Refueling Refueling