ML20080G303
| ML20080G303 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 02/07/1984 |
| From: | Tucker H DUKE POWER CO. |
| To: | Adensam E, Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8402130337 | |
| Download: ML20080G303 (6) | |
Text
w Dunn POWER GOMPANY P.O. ISOX 33180 CHAHLOTTE, N.C. 28242 HALB. TUCKER TELEPHONE
. d "- ~/ 1 1.
February 7,1984 Mr. Harold R. Denton, Director -
Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Ms. E. G. Adensam, Chief Licensing Branch No. 4 Re: Catawba Nuclear Station Docket Nos. 50-413 and 50-414
Dear Mr. Denton:
Section 8.4.7 of the Catawba Safety Evaluation Report discusses Confirmatory Item 36, Flooding of Electrical Equipment as a Result of a LOCA.
In response to this item, attached is a revised response to Question 440.48.
Very truly yours,
[
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Hal B. Tucker ROS/php Attachment cc: Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303 NRC Resident Inspector Catawba Nuclear Station Mr. Robert Guild, Esq, Attorney-at-Law P. O. Box 12097 Charleston, South Carolina 29412 Palmetto Alliance r
21351.Devine Street Columbia, South Carolina 29205 f
l Mr. Jesse L. Riley I
Carolina Environmental Study Group f
L 854 Henley Place
, I Charlotte, North Carolina 28207 S402130337 840207
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PDR ADOCK 05000413 i
E PDR
d 4;
i CNS
. Response:
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The maximum post-accident flood level inside containment has been determined.to be elevation 571' 0".
The safety related control instrumentation below this elevation are the reactor coolant loop elbow flow rate instruments and the reactor coolant system wide range temperature RTD's.
The flow rate instrumentation provides both con-trol room indication and a reactor trip (on low flow in any one loop) neither of which is required after an accident (no operator actions taken on indication, and reactor trips due to safety injection signal).
The RTD's are sealed units which are terminated above the flood level tand therefore are not affected by submergence.
s A list of-safety related solenoid valves in containment that are be-
' low maximum flood elevaticn is presented in Table Q440.48-1.
These solenoids perform one of two functions; namely, controlling air to air diaphragm operated valves and providing air to the lower personnel air lock inflatable seals.
All of the air diaphragm operated valves are designed to assume their safety position on loss of air.
All of the solenoids controlling the air supply are designed to vent the air diaphragm on loss-of power. Therefore, even if control of these solenoid valves is lest the air operated valve will assume its correct position.
The solenoids which supply air to the lower personnel air lock seals are designed to fail in the position which supplies air to i
.the seals.
None of these valves are required to be repositioned to
. perform short or long term ECCS functions.
~
L
- A list ~of active valves in containment that are below maximum flood L
' elevation is presented in Table Q440.48-2.
In this evaluation it was discovered that two valves were required to be raised above flood elevation-(the two' valves -- INW46A and 1NW1108 provided sealing water for several containment isolation valves).
The valves which will
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potentially be flooded are, except as noted, electric motor operated.
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-These are assumed to fail in the position they-are in when flooded.
L
.There is' sufficient time for the ones which' receive a safety signal
-to stroke to their safety positions before being flooded.
None of these valves are required to be repositioned.to perform short or long term ECCS functions.
b In addition,'18 valve operators were not previously qualified for submergence (1KC429B, INC54A, 1NI95A, 1NI266A, 1NI267A, 1NM6A,
-1NM72B,71NM758, 1NM78B, INM818, 1NM187A,~INM190A, 1NM1978, 1NM200B,
, ~,
L "1NM207A, 1NM210A, 1NM2178, and 1NM220B).
i These valves close on Containment Isolation Phase A (ST) signals.
There is sufficient time for them to close before being flooded.
To prevent possible repositioning after flooding, the valves motor con-trols circuits are being modified (see Fig. Q440.48-1). One relay per train will be energized by a ST signal and mechanically latched in.
Normally closed contacts from this relay will be wired between the
-limit-switches and the open motor starter coils of valves of the 440-45a Rev. 9 i
L.
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_-.~~.-._,_.,_,,-_._...-,,.....--,;.-
i.
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corresponding train.- These contacts will open on ST and prevent any spurious limit switch operation from repositioning the valves.
These relays will have manual reset capability in the control room.
Breakers and fuses are coordinated such that, in the case of faults caused by submergence, the faulted valve circuits will be isolated without adversely affecting the upstream class 1E power sources.
These modifict.tions will be completed prior to fuel loading.
An additional valve, 1NI438A, has been identified as being approxi-mately three feet below the final flood elevation.
This valve is a normally closed, EMO.which, supplies nitrogen from a cold leg accumulator.to a pressurizer PORV as a part of the low temperature overpressure protection system (LTOP).
Since is is near the top of the flood elevation, it is not flooded during the time that cold leg accumulator injection is required and spurious operation if it were to occur after the valve is flooded presents no safety question.
440-45b Rev. 9 Carryover
Table Q440.48-1 l
SAFETY RELATED SOLEN 0ID VALVES INSIDE CONTAINMENT BELOW ELEVATION 571'0" Solenoid Valve Functional Description CN1NVSV0010 Controls air to valve 1NVIA Letdown Isolation CN1NVSV0020-Controls air to valve 1NV2A Letdown Isolation CNINVS'/0320 Centrols air to valve INV328 Charging Isolation CNINVSV0390 Controls air to valve 1NV39A Charging Isolation I
CN1NVSV0520 Controls air to valve 1NV52A RCP #1 Seal Leakoff Isolation CM1MVSV0630 Controls air to valve 1NV63B RCP #1 Seal Leakoff Isolation CNINVSV0740 Controls air to valve 1NV74A RCP #1 Seal Leakoff Isolation CNINVSV0850 Controls air to valve 1NV858 RCP #1 Seal Leakoff Isolation
.CN1NVSV1010 Controls air to valve 1NV101A RCP #1 Seal Bypass CN1NVSV1020 Controls air to valve 1NV102A RCP #1 Seal Standpipe Makeup CNINVSV1070 Controls air to valve 1NV1078 RCP #1 Seal Standpipe Makeup CNINVSV1120 Controls air to valve INV112A RCP #1 Seal Standpipe Makeup CNINVSV1170 Controls air to valve 1NV1178 RCP #1 Seal Standpipe Makeup CN1NVSV1220 Controls air to valve 1NV1228 Excess Letdown Isolation CNINVSV1230
-Controls air to valve 1NV1238 Excess Letdown Isolation CN1NVSV1240 Controls air to valve 1NV124B Excess Letdown Control Valve CNINVSV1241 Controls air to valve 1NV124B Excess Letdown Control Valve
-CNINVSV1250 Controls air to valve 1NV125B Excess Letdown Flowpath l CNINCSV0580 Controls air to valve INC58A Prt Spray Valve 440-45c Rev. 9
Table 440.48-2 l
ACTIVE VALVES INSIDE. CONTAINMENT BELOW ELEVATION 571'0" Valve Number Valve Function.
18B149B BB Tempering Line Containment Isolation 18B150B BB Tempering Line Containment Isolation 1NC196A NCP Motor Oil Fill Line Containment Isolation INDlB NC to ND Suction Isolation Valve IND2A NC to ND Suction Isolation Valve INC36B NC to ND Suction Isolation Valve IND37A NC to ND Suction Isolation Valve 1NV1A Letdown Isolation (air operated)
INV2A Letdown Isolation (air operated)
INV10A Letdown Orifice Selection & Containment Isolation (air operated)
INV11A Letdown Orifice Selection & Containment Isolation (air operated)
INV13A Letdown Orifice Selection & Containment Isolation (air operated) l 1NV37A NV Auxiliary Pressurizer Spray 1NV1228 Excess Letdown / Isolation (air operated)
INV1238 Excess Letdown / Isolation (air operated)
INV89A Seal Water Return Containment Isolation (air operated) j 1RN429A RN Return Header Containment Isolation 1RN484A RN Return Header Containment Isolation 1WL605A'
- NCDT Discharge Containment Isolation lWL825A Containment Floor & Equip Sunip & II Sump Containment Isolation 1WL876A
' Vent, Unit Condensate Drain Containment Isolation IVQ16A Containment Air Addition & Release Containment Isolation n
IKC429B KC Equipment Drain Header Containment Isolation 1NC54A Prt Sample & Vent Containment Isolation o
440-45d Rev. 9 y
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i.-,
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Table 440.48-2 (continued) l ACTIVE VALVES INSIDE CONTAINMENT BELOW ELEVATION 571'0"
-Valve Number Valve Function
~1NI95A NI Test Header Containment Isolation i~
-INI266A UHI Test Header Containment Isolation 1NI267A UHI Test Header Containment Isolation INM6A Pzr Sample Containment Isolation
'1NM728 Cold Leg Accumulator Sample Containment Isolation INM75B Cold Leg Accumulator Sample Containment Isolation INM78B Cold Leg Accumulator Sample Containment Isolation INM81B Cold Leg Accumulator Sample Containment Isolation j
INM187A Steam Generator Sample Containment Isolation 1NM190A Steam Generator Sample Containment Isolation
~ 1NM1978
' Steam Generator Sample Containment Isolation 1NM2008 Steam Generator Sample Containment Isolation INM207A.
Steam Generator Sample Containment Isolation INM210A Steam Generator Sample Containment Isolation 1NM2178 Steam Generator Sample Containment Isolation INM2208 Steam Generator Sample Containment Isolation
'N154A Cold Leg Accumulator Isolation Valses i
l 1N165B Cold Leg Accumulator Isolation Valves l-1N17EA Cold Leg Accumulator Isolation Valves.
LIN188B.
Cold' Leg Accumulator Isolation Valves
[.
1N1438A Cold' Leg Accumulator Nitrogen Supply to PORV Activator l IKC3328 KC Return from NCDT Containment Isolation 440-45e Rev. 9
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