ML20203J016

Forwards Addl Info Re 850529 & 1101 Requests for Deviation from IE Info Notice 84-09 & App R Requiring Reactor Coolant Hot & Cold Leg Temp Be Provided in Order to Monitor Natural Circulation Cooling,Per 860402 Meeting

ML20203J016
Person / Time
Site:	Summer
Issue date:	04/23/1986
From:	Nauman D SOUTH CAROLINA ELECTRIC & GAS CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
IEIN-84-09, IEIN-84-9, NUDOCS 8604300076
Download: ML20203J016 (21)

Text

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South Carolina Electric & Gas Company Den A.Naumen P.o. Box 764 Vica President Columbia. SC 29218 -

Nuclear Operatioro (803) 748-3513 SCE&G.

April 23,1986 -

Mr. Harold R. Denten Director, Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Otrnmission Washington, D.C.

20555

Subject:

Virgil C. Stznmer Naclear Station Docket No. 50/395 Operating License No. NPF-12 APPENDIX R REANALYSIS

Dear Mr. Denten:

4 On April 2,1986 a meeting was held in Bethesda between South Carolina Electric and Gas Ccrnpany (SCE&G) and the staff in order to clarify details related to three deviation requests submitted in our [[letter::05000395/LER-1985-013, :on 850429,reactor Trip Occurred Due to lo-lo Steam Generator Water Level in Steam Generator B. Caused by Transients in Deaerator Tank Level & Main Feedwater Pump Discharge Pressure|May 29, 1985 letter]] to your office and to further discuss our deviation request on natural circulation monitoring as originally detailed in our sutrnittal of November 1,1985. %is letter will-address our position on natural circulation and will sunrnarize the key points brought out in the April 2,1986 meeting along with providing additional information requested by the staff.:

Introducticn SCE&G has requested a deviation frcrn the guidance found in IN 84-09 which required that both Reactor Coolant hot leg temperature ('Ihot) and cold leg terporature (Teold) be provided in order to monitor natural circulation cooling.

Discussion r

As presented during the April 2,1986 meeting, there are four basic considerations in favor of our request:

3 1.

'Ihe deviation is required for only four of the gmater. than sixty fire areas in the plant:

FIRE AREA IB-3

'IRAIN A BATIERY WARGER AND MAIN DImititun0N PANEL B001 FIRE AREA IB-4

'IRAIN B BATTERY MARG 2R - AND MAIN DISTRIBiffIm PANEL ROM FIRE ZONE RB 1.1.1 WEST SIDE OF REACIOR WILDING KP.

412' ELEVATIm FIRE ZONE IB 25.4 WEST PENETRATIM ROOM ADJACENT 'ID 4

.REACIOR BUIIDING FIRE ZONE 1.1; O

8604300076 860423 1j PDR ADOCK 05000395 a

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-Fires in these four areas do not mquire control-room evacuation. Anple.

l supplemental information is therefore available in order to verify natural'-

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Lcirculation cooling. %ot and Teold'are available for the steem generator-

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loop of interest for all other fire amas'. In particular, : Attachment I is a' brief report that verifies that for all fires that mquire control man evacuation, %ot and Teold am available for:all three loops.'

2.. m ere exist alternatives to the use of % ot and Teold'for the four fim a

areas of interest. Our letter of. November 1,1985 presented the use of:

- steem generator pressure-to-detennine Tsat 'as an,altemative' to Teold -

3 i:

Considerable operational data exists to support this position.

Attachment II to this letter is a mport indicating-the availability off

- core-exit thermocouples (T/C) for fims.in the four amas for which Teold indicatim cannot be assured. his mport shows that at _least eight core-exit thermocouples,- two per. quadrant, are available for. direct read outi in the control roan.

In fact, either the A channel or B channel core subcooling monitor will be functional and will provide a direct readout of-T/C derived subcooling margin. In addition, the diff.erence between i

core-exit T/C and % ot will also be available for the steam. generator of choice. his provides an additional diagnostic tool to insum naturalo

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circulation flow is occuring.-

While it is desirable to have both h ot and Teold available for the four 7

i-fire areas of interest, sufficient equivalent and. supplemental infonnation -

is provided to insure the monitoring of natural; circulation cooling' i

L 3.

mere is a conflict between the channelization requirements for Tht i

and Teold for canpliance with Regulatory Guide 1.97 and IN 84-09. $n ' order to meet Westinghouse RG 1 97 design: criteria,~ % ot and Teoid nust.be powered.

so that.at least one is available for each loop. In order to meet-IN 84-09 i

guidance.%otandTeold must be powered so~that both are available-d l

for at least one loop.

Regulatory Guide Appendix R l

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Ouidancel(In 84-09) 7 LOOP.

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Mr. Harold R. Denton April 23, 1936 Page three Without additional. instrumentation, rerouting of cabling and conversion of

-power supplies, V.. C. Sumer Nuclear Station' cannot simultaneously meet both requirements. Preliminary engineering evaluations indicate that such a modification would cost approximately $400,000 including an estimated radiation exposure of 23 man-rem. In light'of the discussion in 1. and 2.

above, such a backfit seems to be highly cost ineffective.

4.

'Ihe methods of natural circulation determination' presented in our letter of ~

November 1,1985 and expanded upon in section 2. above, are fully consistent with the guidance found in the background information provided in the Executive Volume to the Westinghouse 0mers GroJp Emrgency Response Guidelines (ERG's) under the title Generic Issue, Natural Circulation. The ERG guidance places special emphasis on core exit thermoccuples, Thot-and steam generator pressure. 'It further indicates that given these three param ters, Teold is usefbl for confirmation, but not a requirement.

Conclusion It is SCE&G's position that sufficient information will be available to the operators to confirm natural circulation cooling for the four fire areas in-which Teold is potentially lost and that a deviation from _the guidance in IN 84-09 can be granted with out any risk to the health and safety of the public.

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.a an JHB/HID/ DAN /mn cc:

0. W. Dixon, Jr./T. C. Nichols, Jr.

R. M. Campbell E. H. Crews, Jr.

K. E. Nodland _.

E. C. Roberts G. O. Percival W. A. Williams, Jr.

R. L. Prevatte J. Nelson Grace J. B. Knotts,'Jr.

Group Managers H. G. Shealy O. S. Bradham NPCF D. R. Moore File 15.1360 C. A. Price J. H. Barker C. L. Ligon (NSRC) 1 1

l ATTACHMENT I SOUTH CAROLINA ELECTRIC AND GAS COMPANY VIRGIL C. SUMMER NUCLEAR STATION

-10CFR50 APPENDIX R COMPLIANCE REVIEW 4

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EVALUATION OF l

AVAILABILITY OF Th AND Tc INDICATION FOR CONTROL ROOM EVACUATION Enclosure to letter dated April 23,1986 from Mr. D. A. Nauman, Vice President,

' Nuclear Operations, SCE&G to Mr. Harold R. Denton, Director, Office of Nuclear Reactor Regulation f

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TABLE OF CONTENTS SECTION TITLE PAGE

1.0 INTRODUCTION

1 2.0 ANALYSIS 1

3.0 CONCLUSION

2 TABLE 1 CABLE LOCATIONS FOR TEMPERATURE SENSORS 3

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Appendix R Compliance Review Evaluation of Availability of Th and Tc

-indication for Control Room Evacuation 1.0. INTRODUCTION During the meeting between SCE&G and the NRC on April 2,1986, the NRC '

inquired about the availability of instruments indicating reactor coolant hot leg and cold leg temperature in'the event that a fire requires that the control room be evacuated. The V. C. Summer Nuclear Station Control Room Evacuation Panels arovide indicators for hot leg (Th) and cold leg (Tc) temperature for al three steam generator loops. This report provides an analysis that demonstrates that t lese six indicators will be operable in the z event of a fire in any one of the four fire areas which require control room evacuation.

2.0. ANALYSIS The fire areas of concern are the Control Room (CB-17), the Relay Room (CB-6),

the Upper Cable Spreading Room (CB-15), and the Lower Cable Spreading Room (CB-4). These four fire areas contain closely spaced train."A" and "B" systems such that a major fire in any one of them requires control room

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evacuation and the use of alternate shutdown procedures.

The alternate shutdown procedures make use of the Control. Room Evacuation Control Panels located in the Intermediate Building. These panels include indicators and signal processors for T and Tc RTD's on each of the three steam h

generator loops.- These RTD's are the secondary elements of dual element RTD's. The primary elements are connected (by independent cabling) to the.

Protection Set Process Control Cabinets in the Relay Room.

Table 1 lists the RTD element designations, the signal cable _ numbers, th~e fire, areas through which these cables are routed, and the' power source. A review -

of the table demonstrates that none of the signal cables are routed through -

the four fire areas of concern.

Power for the signal processors is supplied from dc power panels DPN1H A1 -

and DPN1HB1 via cables CEE1 A'and CEE3XB respectively. These cabies are routed through the following fire areas which are also not of concern: IB-3, I B-10, I B - 1 1, 18 - 14,18 -21.1,18-21. 2,18 -22.1, 18-25.1.2,18-25.6.2,18-25.10.

The basic shutdown analysis has demonstrated that power derived from the train "B" diesel generator and train "B" battery will be available at panel '

DPN1HB1 for the four fire areas of concern? The analysis has also shown that power derived from the train."B" diesel generator can also be supplied to the train " A" battery and panel DPN1HA1 by use of an installed spare battery charger (by defeating the normal interlocks designed to prevent interconnection of power trains).

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3.0 ' CONCLUSION Since none of the required components or cabling are located in the four fire areas of concern, a reliable indication of reactor coolant hot leg and cold leg temperature for each of the three steam generator loops will be available in the event of a control room evacuation. This will provide the operator with information that will enable him to monitor the performance of the reactor coolant system operating with natural circulation in one or more the steam generator loops.

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TABLE 1 CABLE LOCATIONS FOR TEMPERATURE SENSORS Power RTD Source For.

Signal Measured Temperature Signal Cable Fire Areas in Which Parameter Sensor Processor Number Signal Cable is Located Tc Loop A TE410A DPN1HB1 CEU21XE IB-11 RCU331XE RB-1.1.1, RB-1.2.1 RCU332XE 1B-15,1B-24,18-25.1.2, 18-25.4,18-25.6.2, IB-25.7 Th Loop A TE413A DPN1HA1 RCU271XA RB-1.2.1, RB-1.3.2,

. RB-1.3.3, RB-1.4.1 RCU272XA CB-18, CB-20,1B-14, 18-20,1B-21.1

,j Tc Loop B TE420A DPN1HB1 CEU22XE IB-11 RCU333XE

' RB-1.1.1, R B-1.1.2, RB-1.2.2 RCU334XE IB-15,18-24,18-25.1.2, 1B-25.4,18-25.6.2, IB-25.7 T Loop B TE423A DPN1HA1 RCU273XA RB-1.2, RB-l.3.2, RB-h 1.3.3, RB-l.4.1 RCU274XA-

. CB-18, CB-20,18-14, 18-20,18-21.1

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Tc Loop C TE430A DPN1HAl*

CEU23XE-18-11 RCU383XD*

RB-1.2.3, RB-1.3.2, RB-1.3.3, RB-1.4.1 RCU384XD*

AB-1.21.2, AB-1.27,-

CB-10, CB-18, CB-20, 18-14, IB-25.6.2, IB-25.9 3

4 Table 1 Cont'd

l J Th Loop C TE433A DPN1HB1 CEU24XE~

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RCU357XE RB-1.1.1, RB-1.1.2, RB-1.2.3 i

RCU338XE IB-15, IB-24,18-25.1.2, 18-25.4,18-25.6.2, IB-

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• This data shows the configuration after implementation of MRF 20801; similar -

routing applies to the existing cable.

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1 AT1'ACHMENT II' SOUTH CAROLINA ELECTRIC AND GAS COMPANY VIRGIL C. SUMMER NUCLEAR STATION 10CFR50 APPENDIX R COMPLlANCE REVIEW l

EVALUATION i

OF

' CORE SUBCOOLING MONITOR AVAILABILITY FOR FIRE ZONES l

1 IB-3,18-4,18-2S.4, AND RB-1.1.1

.i i

i Enclosure to letter dated i

April 23,1986 from Mr. D. A. Nauman, Vice President Nuclear Operations, SCE&G to Mr. Harold R. Denton, Director, Office of Nuclear Reactor Regulation

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TABLE OF CONTENTS i

SECTION TITLE

.PAGE l

f l

1.0 INTRODUCTION

1 l

1 2.0 DISCUSSION OF MONITOR OPERATION AND DISPLAYS 1

3.0 APPENDIX R ANALYSIS 2

i

4.0 CONCLUSION

S 3

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TABLE 1 ' CORE SUBCOOLING MONITOR INPUT AVAILABILITY i

TABLE 2 CORE SUBCOOLING MONITOR AVAILABILITY-ZONE ANALYSIS l

FIRE ZONE 18-3 l

4 TABLE 3 CORE SUBCOOLING MONITOR AVAILABILITY-ZONE ANALYSIS FIRE ZONE IB-4 l

TABLE 4 CORE SUBCOOLING MONITOR AVAILABILITY-ZONE ANALYSIS FIRE ZONE IB-25-4 TABLE 5 CORE SUBCOOLING MONITOR AVAILABILITY-ZONE ANALYSIS i

FIRE ZONE RB-1.1.1 l

3 TABLE 6

SUMMARY

OF VAllD CORE SUBCOOLING MONITOR DISPLAYS -

1 FIGURE 1 CORE SUBCOOLING MONITC3 INPUT & ASSOCIATED PROCESS CABINETS l

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i Appendix R Evaluation i

Core Subcooling Monitor Availability _

for Fires in Zones 18-3,18-4,18-25.4 & RB-1.1.1

1.0 INTRODUCTION

j There are two core-subcooling monitors, A&B, both of which are located in XPN 7218. The monitors are quality related as discussed in Technical Requirements Package TRP 11.

Each Core-Subcooling monitor has the following inputs:

. SUBCOOLING MONITOR CONFIGURATION l

.lNPUT SENSOR FOR SENSOR FOR l

NAME MONITOR A MONITOR B l

Incore T/C #1 TO2 (From A isol)

T10A (From B Isol) i incore T/C #2 TO9 (From A isol)

T11 A (From B Isol)

Incore T/C #3 TO21 A (From A isol)

T17A (From B Isol) incore T/C #4 TO22A (From Aisol)

T20A (From B isol) incore T/C #5 TO32A (From A isol)

T30A (From B Isol)

Incore T/C #6 TO35A.(From A isol)-

T38A (From B Isol)

Incore T/C #7 TO39A (From A lsol)

T40A (From B isol) i incore T/C #8 TO42A (From Aisol)

T43A (From'B isol)

Thot LOOP 1 TE413 (LOOP A)

TE423 (LOOP B).

Ihot LOOP 2 TE423 (LOOP B)

TE433 (LOOP C)

Tcold LOOP 1 TE410 (LOOP A)

TE420 (LOOP B)

Tcold LOOP 2 TE420 (LOOP B)

TE430 (LOOP C) j Pressure 1 PT402 (LOOP C).

PT402 (LOOP C)

Pressure 2 PT403 (LOOP A)

PT403 (LOOP A)

Pressure 3 PT455 (Pressurizer)

PT457 (Pressurizer)

Figure 1 provides a schematic representation of the various inputs to the monitors in conjunction with the signal processing cabinets through whicn

. they pass.

2.0 DISCUSSION OF MONITOR OPERATION & DISPLAYS

. Each of the subcooling monitors function to provide indication both at panel XPN7218 (located in the Control Room) and at the main control board of the margin to saturation in F subcooled. This indication is provided as follows:

o Each monitor receives three inputs for pressure. Two of these inputs are

. obtained from the RC loop pressure transmitters. The third pressure input is obtained from pressurizer pressure. The unit incorporates an autioneering circuit which selects the lowest of the three pressure inputs.

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i This pressure is then used by'a microprocessor to calculate the.-

corresponding saturation temperature.

From this, two basic displays are then available which provide indication ^

j of the margin to saturation in F subcooled. These displays are available o

from both the incore thermocouples and the Reactor Coolant Loop Hot &

Cold Leg RTD's. The saturation margin is calculated for both of these displays by the processor. Two separate displays are generated by the unit. One display is calculated based upon the autioneered highest Hot.

Leg or Cold Leg RTD Temperature; the other based upon the 1 autioneered highest incore thermocouple temperature. Both displays are available simultaneously at the monitoring panel or selectably at the main control board (a selector switch determmes which margin is displayed).

In general, out of range inputs are ignored by the processor and the calculation is performed on remaining items. For example,if a pressure signal is lost, the autioneered low pressure signal to the microprocessor used for.

calculation of the saturation temperature will only consider the two valid pressure inputs. Therefore, unless all pressure or all RTD or all T/C signals are j

lost, the core-subcooling monitor wTI provide anIiidication of saturation margin. ' Additionally, inputs can be manually bypassed at the monitor panel.

Another feature available at the local panel only is the ability to display AT information for each of the two loops for which hot and cold leg temperatures are provided. This display presents Average T/C Temp minus Thot'(T/C Av Thot) and Average T/C Temp minus Tcold (T/C Avg-Tcord) for each loop. If g-coolant circulation is taking place, the average temperature of the incore thermocouples and T ot should be very close. Also,the temperature display h

associated with Tcold gives an indication of temperature rise across the core, assuming that there is circulation.

A display of each in sut signal can be obtained at the core sub-cooling monitor panel by selectinc t le individual sensor to be displayed by means of a select button and thum awheel switches.

Two alarms are provided from the Core-Subcooling Monitors, one to indicate.

that the margin to saturation is between caution and alarm and the other to.

indicate that the margin is less than the alarm setpoint. These alarms are named " Caution" and " Alarm". In addition, the caution alarm indicates:

1.

Microprocessor stopped.

2.

All pressure or all RTD or all T/C inputs disabled or out of range.

3.0 APPENDIX R ANALYSIS-A previous analysis to determine the availability of Thot & Tcold temperature indications for confirmation of natural circulation as a result of an exposure fire has shown that Tcoid is unavailable for fire zones IB-3, IB-4,18-25.4 and RB.

1.1.1. Therefore, this analysis addresses the availability of displays for saturation margin, average T/C-Thot and average T/C-Tcold with respect to these four fire zones.

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i was to determine all inputs to the core

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The methodology used for the analysis,th their signal processing cabinets. (Se t

sub-cooling monitor,in conjunction wi Figure 1). Each senor input. in conlunction with its routing through the.

process cabinets was reviewed to d etermine if the cables passed through the 1

four identified fire zones. Additionally, power supplies to the various process -

l cabinets were similarly evaluated. This information is sumraarized in Table 1.

Each fire zone was then independently addressed to determine what displays would be available on the A and/or B Monitors. This analysis and insuing conclusions are presented in Tables 2 thru 5.

4.0 CONCLUSION

As indicated in Table 2 thru 5, displays of saturation margin are available, both at the core subcooling monitor panel and at the main control board for all four of the fire zones in question. Additionally, the difference between,.

average incore thermocouple temperature and Thot will be available at the monitor panel for all the fire zones.

Since different loops are used to establish natural circulation for the different l

fire zones, the Thot and Tcold sensor inputs may not be valid in all cases.

Therefore, the margin to saturation dis alay should always be used b'ased upon -

the incore thermocouples rather than tle Hot & Cold Leg RTD's. Also, Average incore T/.C tem aerature - Thot or Tcold displays will only be valid for those loops 3

which are circu ating. Table 6 provides a summary of t.he available displays i:

per fire zone based upon the fire analysis and the S/G loop used to establish natural circulation.

For fires in Zone IB-3 the "B" Sub-cooling monitor should be'used. For fires in Zones 18-4,18-25.4 and RB-1.1.1, the "A monitor should be used. Ambic uity.

i to the operator will be minimized since the non-functioning monitorwil be in

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TABLE 1 CORE SUBCOOLING MONITOR INPUT AVAILABILITY (0 Indicates item Not Available) i l

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FIRE ZONE

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TAG 18-3 18-4 18-2S-4 RB-1.1.1 SENSOR INPUTS:

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PT457 0

t TE433 0

0 TE410 0

0 TE420 0

0 TE430 0

0

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CABINET POWER SUPPLY:

IC T/C 'B' O

O O

l lC T/C 'A'.

0 l

XPN7001 0

XPN7002 0

XPN7003 0

XPN7004 0

XPN7218A 0

XPN7218B 0

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NOTE:

Inputs to the core-subcooling monitor not listed are not lost for any of the fire areas shown.

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- TABLE 2 CORE SUBCOOLING MONITOR AVAILABILITY-ZONE ANALYSIS FIRE ZONE 18-3 4

r (X Indicates item Available)

(O Indicates item Not Available)

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MONITOR MONITOR l

. INPUT NAME A

3 l

Incore T/C #1 0

X Incore T/C #2 0

X l

Incore T/C #3 0

-X Incore T/C #4 0

X Incore T/C #5 0~

X i

1-Incore T/C #6 0

X l

Incore T/C #7 ~

0 X-i 0

X i

Incore T/C #8 Thot oop 1 0

0' L

Thot oop 2 0

X L

e Tcord Loop 1 0(1)

O(1)

Tcoid Loop 2 y0(1) 0 i

C t

Pressure 1 t D' X

- Pressure 2 X

0 Pressure 3 0

.X Monitor Power 0

X l

. Analysis:

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' T/C Margin Display 0'

X T/C Avg - Thot 0-X-

T/C Avg - Tcold 0

O(1)-

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REMARKS:

-(1)

A fire in this zone will result in use of Loop C to establish natural circulation. Those items indicated above with (1) are available from a -

fire zone analysis; however, they may not have valid readings ~

associated with them since they may be in a non-circulatmg loop.

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TABLE 3 CORE SUBCOOLING MONITOR AVAILABILITY-ZONE ANALYSIS FIRE ZONE 18-4

-(X Indicates item Available)

(O Indicates item Not Available)

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MONITOR MONITOR INPUT NAME A

B

- incore T/C #1 X

0 incore T/C #2 X

0 incore T/C #3 X

0 incore T/C #4 X

0 Incore T/C #5 X-0 incore T/C #6 X

0 incore T/C #7 X

0 incore T/C #8 X

0

. ThotLoop 1 0(1) 0 ThotLoop 2 X

0(1)

Tcoid Loop i 0

0 Tcord Loop 2 0

X-Pressure 1 0

0 Pressure 2 X

X Pressure 3 X.

O Monitor Power X

0 Analysis:

T/C Margin Display X_ _

0 T/C Avg - Thot X(2) 0 T/C Avg -Tcold 0

0 REMARKS:

(1)

A fire in this zone will result in use of Loop B to establish natural circulation. Those items indicated above with (1) are available from a fire zone analysis; however, they may not have valid readings associated with them since they may be in a non-circulating loop.

(2)

The T/C Avg-Thot display is available at the monitor for both sets of Hot Leg temperature inputs. The loop 2 display, which provides data for Steam Generator Loop B, on the A monitor should be selected in this 1

. case since it will contain the valid data.

i 4

TABLE 4 4

CORE SU8 COOLING MONITOR AVAILABILITY-ZONE ANALYSIS FIRE ZONE 18-25 (X Indicates item Available)

(O Indicates item Not Available)

MONITOR MONITOR INPUT NAME A

B

-Incore T/C #1 X

0 Incore T/C #2

'X 0

incore T/C #3 X

0 i

incore T/C #4 X

0 Incore T/C #5 X

0 incore T/C #6 X

0 incore T/C #7 X

'O Incore T/C #8 X

0 ThotLoop 1 0(1)

X Thot loop 2 X-0 TcordLoop 1 0

0 Tcord Loop 2 0

0-Pressure 1 X

X Pressure 2 X

X Pressure 3 X

X Monitor Power X

X Analysis:

T/C Margin Display X

0(3)

T/C Avg -Thot X(2)-

0 T/C Avg -Tcord 0

0 q

REMARKS:

(1)

A fire in this zone will result in use of Loop B to establish natural circulation. Those items indicated above with (1) are available from a -

fire zone analysis; however, they may not have valid readings associated with them since they may be in a non-circulating loop.

(2)

The T/C Avg-Thot display is available at the monitor for both sets of Hot Leg temperature inputs. The loop 2 display, which provides data for y

Steam Generator Loop B, on the A monitor should be selected in this case since it will contain the valid' data.

(3)

Margin display would be available on the B monitor, however, the -

margin can only be determined from the one Thot nput, and not from i

the T/C's. The A" monitor should be used for this fire zone since it will ~

have a greater quantity of inputs and information available.

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4 CORE SUBCOOLING MONITOR AVAILABILITY-ZONE ANALYSIS FIRE ZONE RB-1.1.1 (XIndicates item Available)

(O Indicates item Not Available)

MONITOR MONITOR l

INPUT NAME A

B q

Incore T/C #1 X

0-Incore T/C #2 X

0 i

incore T/C #3 X

0 Incore T/C #4 X

0 l

Incore T/C #5 X

0 j

Incore T/C #6 X

0 j

incore T/C #7 X

0 Incore T/C #8 X

0 l

-Thot Loop 1 0(1)

- X Thot Loop 2 X

0

.l Tcola Loop 1 0

0 l

Tcold Loop 2 0

0 j

4

,3 Pressure 1 X

X Pressure 2 X

X Pressure 3 X

0 Monitor Power X-X Analysis:

l.i T/C Margin Display X

0(3)

T/C Avg -Thot X(2) 0~

T/C Avg -Tcoid 0

0 REMARKS:

1 (1)

A fire in this zone will result in use of Loop B to establish natural 1

l circulation.' Those items indicated above with (1) are available from a i

fire zone analysis; however, they may not have valid readings -

associated with them since they may be in a non-circulating loop.

-i t

(2).The T/C Avg-Thot disp ay is available at the monitor for both sets of Hot l

i Leg temperature inputs. The loop 2 display,hould be selected in thiswhich pro Ej Steam Generator Loop B, on the A monitor s i

case since it will contain the valid data.

q

- (3)

Margin display would be available on the B monitor, however, the

- margin can onl be determined from the one Thot nput, and not from y

i the T/C's. The A" monitor should be used for this fire zone since it will have a greater quantity of inputs and information available.

l 6

e

-w y,

.--_c.-.-.-e,.w--

m-

.-%.-,y

-+r

+ +

,ee,-w er m,, -,,,,,,

TABLE 6

SUMMARY

OF VALID CORE SUBCOOLING MONITOR DISPLAYS l

~

DISPLAYS-SATURATION FIRE ZONE MARGIN T/C Avg -THOTO)

T/C Avg-Tcoto 0) 1 B-3 Monitor B Monitor B N/A incore T/C Loop 2 1B-4 Monitor A-Monitor A N/A Incore T/C Loop 2 j

18-25-4 Monitor A MonitorA N/A incore T/C Loop 2 '

RB-1.1.1 Monitor A Monitor A N/A Incore T/C Loop 2 ~

Note:

(1)

The loop designation given refers'to the actual selector switch position l -

on the subcooled monitor panel. Monitor B, Loop 2 provides data 4

relative to Steam Generator Loop C. Monitor A, Loop 2 provides data relative to Steam Generator Loop B.

I

. i i

i 1

l l

~~r r

,s e

v.w,

,ere-vr ee---e s--,vv-,

,-eevr

. {

m., m

., 7

-;b

FIGURE.1 i

~

s

~

m.

4 c,,n.. - - c (w3:

Miin

,. +

- PROTECTION!

_MCB -

g,

{ SYSTEM.

"1 TERMINAL

- CABINETS -

7i,

.. CABINETS 4

XPN 7218 XPN 7.001

. XPN 7108 PT '

403'

" isOL.

.TE -

413 isOL.

~ SUB COOLING TE MONITOR -

423 ISOLn

A-PT.

455 ISOL il TE _

ISOL 430 s

4:.,.

. til

'if s

qp XPN 7003 ~

. TO MCB :

XPN 7 f 24 PT ISOL 457

' TO MCB 4L i

IV-XPN 7004 XPN 7122 5

P1 4

402 150L TE

, 1

-.SUB COOLING 433 isot

- MONITOR, 0

TE-

~

'r 410 isOL

. TE '

420

ISOL"

?

>-- :, i P

M V

- (8') -

. T/C ANAL

'TC5,,

.fSOLATOR.

(26)'

- (26),

,. g.

'I

.7 i IC ?

T/ CANAL

-(8)?'

[TOINCOREi ISOLATOR -

' <T

CABINET

, <

1 4,'

TCs

"(25) -

>1

- :, (25) _ -

4

.a

l e

n

1 4

^

f 7

4

,,re =.

j e

i ct+

t.

s

. - - -.