ML20028B211

Me Yankee Response to 10CFR50,App R

ML20028B211
Person / Time
Site:	Maine Yankee
Issue date:	11/10/1982
From:	Mccumber J, Rossman R, Urbanowski S Maine Yankee
To:
Shared Package
ML20028B206	List: ML20028B205 ML20028B211
References
YAEC-1330, NUDOCS 8211300171
Download: ML20028B211 (57)

Text

i E

C b

le l

iI Maine Yankee Response to 10CFR50 Appendix R i

l l

t I

l Prepared By:

cd ud4.w fl Et L

J. T. McCumber - Systems Engineering Group (Date)

Prepared By:

iffg

//((ef2-S. F. Urbanowski - Electrical Engineering Group (Date) l Prepared By:

MM Mo+w i) - E/,l[ h4[ [fC 6pq

//!

Md t

R. J. Rossman/- Instrument and Control

/ (D' te) a Engineering Group Reviewed By:

./

pt b /r ! 4 / h f

//f/h2

/ / /

' XDate)

Approved By:

6 d(d

////^ T2-(Date)

I Yankee Atomic Electric Company Nuclear Servicee rision 1671 Worceste.. ad Framingham, Massachusetts 01701 8211300171 821124 PDR ADOCK 05000309 y

PDR

e-I DISCLAIMER OF RESPONSIBILITY I

This document was prepared by Yankee Atomic Electric Company on behalf of Maine Yankee Atomic Power Station. This document is believed to be completely true and accurate to the best of our knowledge and information. It is authorized for use specifically by Yankee Atomic Electric Company, Maine I

Yankee Atomic Power Station and/or the appropriate subdivisions within the Nuclear Regulatory Cornission only.

With regard to any unauthorized use whatsoever, Yankee Atomic Electric Company, Maine Yankee Atomic Power Station and their officers, directors, agents and employees assume no liability nor make any warranty or representation with respect to the contents of this document or to its I

accuracy or completeness.

I I

I I

I I

I I -

I ABSTRACT An alternate shutdown methodology for the Maine Yankee Atomic Power Station to comply with the requirements of Appendix R (Fire Protection Rule) to 10CFR Part 50 has been developed and is described herein.

I I

I I

I I

I 1

I

-iii-

!I

TABLE OF CONTENTS Page DISCLAIMER OF RLSP0NSIBILITY....................................

11 ABSTRACT........................................................

iii L I S T O F F I GU RES.................................................

v LIST OF TABLES..................................................

vi 1.0 IN TRO D UCT IO N....................................................

I 1.1 Purpose...................................................

I 1.2 Scope.....................................................

1 2.0 SA FE S H U TDO WN REV I EW............................................

2 2.1 Fire Zone Identification.....

2 2.2 Normal Sa f e Shutdown Equipment and Ca ble Rout ing..........

3 2.3 C i rc u i t Se pa ra t i o n Ana lys i s........'.......................

4 3.0 A LTERN ATE S HU TDOWN HETHO D0 LOGY..................................

8 3.1 Ge n e r a l De s c r i p t i o n.......................................

8 3.2 Po s t-F i r e 0 bj e c t i ve s......................................

8 3.3 De s i g n Ba s e s a n d As s ump t i o n s..............................

9

' 3. 4 Al t e r na t e Powe r S u p p1y....................................

10 3.5 Alte rnate Shutdown Equipment and Cable Routing............ 11 3.6 Associated Circuits.......................................

12 3.7 In t e r f ac i ng Valve s a nd Equ i pme n t..........................

14 3.8 O pe ra t o r Ac t i o n s..........................................

16 4.0 RES PON SE TO NRC STA F F LETTERS................................... 38 4.1 NRC Gene ric Let ter (18-12), dated Februa ry 20, 1981.......

38 4.2 NRC Letter to Maine Yankee, dated April 24, 1981..........

47 5.0 RE FE RE NC E S......................................................

51

-tv-

LIST OF FIGURES Number Title Page 2.2-1 One-Line D1agram............................................

5 3.4-1 Alternate Power Supply One-Line Diagram.....................

17 3.4-2 Alternate Power Supply Equipment Layout.....................

18 3.5-1 Alte rnate Shutdown Equipment Locat ion Drawing...............

19 3.5-2 Example Primary System Makeup Flow Path.....................

20 3.5-3 Auxiliary Charging Pump Wiring..............................

21 3.5-4 Schematic for Auxiliary Steam Control Valve, PCV-1106....... 22 3.5-5 Schematic for Steam Generator Level, LT-1214, 1224 and 1234....................................................

23 3.5-6 Schematic for new Excess Flow Check Valve Solenoids.........

24 3.5-7 Schemati c for Decay Hea t Releas e Valve, HCV-1001............ 25 3.5-8 Schemat ic fo r Auxiliary Steam Stop Valve, TV-1102........... 26 3.5-9 Schematic for Auxiliary Feedwater Flow Control Valves, HCV-1201A, B and C..........................................

27 3.5-10 Schematic for Letdown Isolation Valve, TCV-20lK............. 28 3.5.11 Schematic for Seal Water Return Valves, HCV-251, 261, 271... 29 3.5-12 Typical Instrument Loop.....................................

30 3.6-1 Examples of Associated Circuits of Concern..................

31 3.7-1 Typical MOV Wiring Schematic................................

32 l

-v-

LIST 9' TABLES Number Title Page 2.2.1 No rma l Sa f e Sh u t down Eq u i pme n t..............................

6 3.5.1 Al t e rna t e S h u t d own Eq u ipme n t................................

33 3.6.1 Auxilia ry Feed ramp Area Associated Circuits................

34 3.7.1 I n t e r f a c i ng Va l ve s..........................................

35 3.8.1 Worst Ca s e Po s t-Fi re S ce na ri o...............................

37

-vt-

1.0 INTRODUCTION

1.1 Purpose This report reviews the Maine Yankee Atomic Power Plant's safe shutdown systems and its associated circuits for compliance with 10CFR50, Appendix R.

Areas of noncompliance are identified and protection to the health and safety of the public are demons

• rated through the use of alternate shutdown methods.

1.2 Scope Section 2 reviews the safe shutc7wn systems and associated circuits against the separation criteria provided in Appendix R,Section III.G.2.

Section 3 describes the alternate shutdown methods which will be utilized to demonstrcte protection to the public health and safety. Section 4 provides response to the NRC staff letters defining safe shutdown requirements.

l

2.0 SAFE SHUTDOWN REVIEW 2.1 Fire Zone Identification For review purposes, the Maine Yankee Atomic Power Plant was divided into the following distinct fire zones:

1.

Control Room and Cable Chase a.

Cable Chase b.

Control Room 2.

Protected Cable Vault 3.

Cable Tray Rooms (Protected and Unprotected) 4.

Turbine Building 5.

Circulating Water Pumphouse 6.

Primary Auxiliary Building Elevation 11'~0",

including pipe penetration area a.

f b.

Elevation 21 '-0" 1.

Charging Pump Cubicles 2.

General Areas I

l c.

Elevation 36'-0" 7.

Reactor Containment 8.

Containment Spray Pump Area _ _ _ _ _ _.

9.

Ventilation Equipment and Personnel Air Lock Area 10.

Steam and Feedwater Valve House 11.

Containment Penetration Area (Outside) a.

Cable Penetration Area A, Elevation 46 '-0" b.

Cable Penetration Arei B, Elevation 46 '-0" c.

MCC B reas, Elevation 33 '-4" and 21'-0" d.

New Cable Chase, Elevation 21'-0" 12.

Switchgear Rooms a.

Protected b.

Unprotected 13.

Auxiliary Feedwater Pump Room These fire zones are presently separated or will have separation provisions upgraded to meet the requirements of Section III G.2, as necessary to assure shutdown capability. The Fire Hazards Analysis, Reference a, has demonstrated the low fire loading in these zones and fire detection and suppression systems were upgraded to provide added assurance against a major fire. The reactor containment is subdivided, as necessary, based on distance and/or the use of fire shields.

2.2 Normal Safe Shutdown Equipment and Cable Routing l

The minimum equipment normally used to reach a safe shutdown is listed in Table 2.2.1.

No consideration is given to accident mitigation requirements. The cable routings, by fire zone, for normal shutdown equipment are also listed. L

Power supplies for safe shutdown equipment are discussed in Section 8.0 of the Maine Yankee FSAR. Figure 2.2-1 is a one-line diagram illustrating these power supplies.

2.3 Circuit Separation Analysis The areas of the plant housing shutdown equipment have generally been shown by the Fire Hazards Analysis to have low fire ratings, and upgraded fire protection measures have been taken where deemed necessary. However, a review of circuit separaration at Maine Yankee as defined by Appendix R, indicated the following:

1.

All 480 and 4160 volt power is fed from the Switchgear Room.

Separation between redundant switchgear and motor control centers does not meet Appendix R requirements.

2.

All critical instrumentation cables pass through the protected cable vault with separation provided between redundant trains not meeting Appendix R requirements.

3.

Several other fire zones include redundant trains of safe shutdown equipment with separation not meeting Appendix R requirements.

The possible alternatives of cable rerouting, equipment relocation, installation of barriers, or equivalent protection analysis associated with l

providing or demonstrating adequate protection to normal shutdown equipment would either diminish overall plant safety and/or would be economically restrictive.

As a result, it was decided to develop an alternate method of shutdown which would have a minimum impact on plant safety, normal shutdown 6r accident mitigating systems.

l l _ - _ _ _ _ _ _ _ _ _ _ _ _ _ - _

lll l

l 2

4 1

4 I

O C

a C

V N

N N

2 K

]

]

),I 1

S N

[

[

S I

U l

B C

4 N

V 0

S C

8 U

N 4

B Y

I l

C O

N V

N N

l A

0

]

l) l P

1 I

16

[

1 U

O S

M 4

3 6

B C

l a

C V

a O

N R

V N

)I 0

E Mm 8

W K

4 O

3 Mu P

1 1

C C

C N

N 4

I

)

1 M

MO 2

1 y

I S

U AT S

4 B

RA U

C B

41 V

1 AE 6

I E V

m 0

2 DK S

8 0

U N

4 2

EA 0

B 9

NY V

C C

E I

6 0

N N

R LE 8

U N

6

]

C 1

[

i

)I S

G EI N

4 BI 0

B I

NA U

F OM i

O G

0 N

D 6

V h

x 0

]

8

[

4 l

I O

O O

N N

N 7

h

]

]

7 l)I S

O l

i

[

[

0 U

N A

C l

5 B

x C

5 N

G N

V D

S

]

)I 0

I 8

U

[

B 4

I V

S O

0 U

N 3

6

)

1 B

1 3

I S

V 4

1 U

3 0

B a

0 C

C V

9 N

N 6

0 6

I

)I 8

2 4

a C

V N

C g

N 10 t

t 2

u I

f

)

2 f

I S

U 0

B C

1 3

N 4

V S

]

0 x

O

[

8 6

U N

4 B

4

]

[

C O

E V

N N

9 0

9 l)I S

6 4

1 0

U 2

4 3

B V

i C

C x

C V

V N

N N

t k^ g K

)

0

]

]

2 I

[

[

h I

8 f

4 C

2 N

I

)

l l

'Y l

Table 2.2.1 Normal Safe Shutdowa Equipment I

Cable Routing By F1re Zones Equipment Description Mark No.

Bus Power Control Control Rods Auntliary Feedwater Pump P-25A 6

12a, la, 2, 3, 11c, 13 12a, la, Ib, 2, 3, 11c, 13 Auxilia ry Feedwater Pump P-25C 5

12a, la, 2, 3, 11c, 13 12 a, la, I b, 2, 3, 11c, 13 Aun Feedwater Flow Control valves HCV-1201 A, B, C ~

See Figure 3.5-9 l

l Decay Heat Release Valve HCV-1001 See Figure 3.5-7 Decay Heat Release Stop Valve MS-M-161 8B 11c, 10 lb, 2, 11c, 10, 13 Cha rging Pump P-14A 5

4, 12a, 2, 3, 6a, 6bl 4, 12a, la, Ib, 2, 3, 6a, 6bt Charging Pump P-14B 6

4, 12a, 2, 3, 6a, 6b1 4, 12a, la, Ib, 2, 3, 6a, 6bt Charging Pump P-14S 5-6 4, 12a, 2, 3, 6a, 6hl 4, 12a, la, Ib, 2, 3, 6a, 6b1 Boric Acid Transfer Pump P-6A 7A 12a, la, 2, 3, 6b2 12a, la, Ib, 2, 3, 6b2 Boric Acid Transf er Pump P-6B 7A 12a, la, 2, 3, 6b2 12a, la, Ib, 2, 3, 6b2 Boric Acid Transfer Pump P-6C 8A 12a, la, 2, 3, 6b2 12a, la, Ib, 2, 3, 6b2 RHR Pump P-12A 5

4, 12a, 2, 3, 8 4, 12a, Ib, 2, 3, 8, 10 RHR Pump P-12B 6

4, 12a, 2,3,8 4, 12a, Ib, 2, 3, 8, 10 Service Water Pump P-29A 7

4, 12a, 3, 5 lb, 3, 12a Service Wa ter Pump P-29B 8

4, 12a, 3, 5 lb, 3, 12a Service Water Pump P-29C 7

4, 12a, 3, 5 lb, 3, 12a Se rvice Wa ter Pump P-29D 8

4, 12a, 3, 5 lb, 3, 12a Prima ry Component Cooling Pump P-9A 5

4, 12a, 3 lb, 3, 12a, 4 Secondary Component Cooling Pump P-10A 6

4, 12a, 3 lb, 3, 4, 12a Diesel Generator DG-1A 5

la, 2, 3, 12a Ib, 2, 3, 12a Diesel Gene rator DG-1B 6

la, 2, 3, 12a Ib, 2, 3, 12a Table 2.2.1 (continued)

Normal Equipment for Safe Shutdown l

Cable Routing By Fire Zones Eguipment Description Nbrk No.

Controls Pressurizer Level LT-101Y lb, 2, 7, lla f

lb, 2, 7,11b 1

Reactor Coolant Temperature TE-ll2CC, TE-112CD TE-ll2HC lt, 2, 7, llb (Hot and Cold Legs)

TE-ll2HD, TE-122CC, TE-122CD TE-122HC, TE-122HD, TE-132CC TE-132CD, TE-132HC, TE-132HD Pressurizer Pressure PT-102C, PT-102D, PT-10lY lb, 2, 7, llb PT-103-1 Steam Generator Level LT-1211Y, LT-1213C, LT-1213D lb, 2, 7, lib LT-1221Y, LT-1223C, LT-1223D LT-1233C, LT-1233D Main Steam Pressure PT-1013A, PT-1023A, PT-1033A lb, 2, 10, lla PT-1013B, PT-1023B, PT-1033B PT-1013C, PT-1023C, PT-1033C lb, 2, 10, lla, llb PT-1013D, PT-1023D, PT-1033D

3.0 ALTERNATE SHUTDOWN HETHODOLOGY 3.1 General Description Based on the previously discussed circuit separation analysis, there are postulated fires which could potentially cause a loss of normal shutdown capability. An alternate shutdown methodology was, therefore, developed for Maine Yankee with the following considerations:

1.

Minimize the effect on safety-related eat Ipment and its ability to perform accident mitigating functions.

2.

Locate alternate equipment remotely from normal shutdown equipment and cables.

Accordingly, Maine Yankee's alternate shutdown scheme utilizes the existing auxiliary charging pump and turbine-driven auxiliary feedwater pump.

Both have proven capability, yet have no safety-related functions. A new diesel generator will be used as the alternate power supply.

The alternate shutdown panels will be remotely located in the auxiliary feedwater pump room (Zone 13).

3.2 Post-Fire Objectives The following is an outline of the post-fire objectives used in the development of Maine Yankee 's alternate shutdown scheme:

1.

Insert negative reactivity into reactor core.

2.

Maintain plant in a stable hot shutdown condition while combating the fire:

a.

Maintain primary plant inventory.

I b.

Monitor critical plant parameters. -

c.

Remove decay heat.

d.

Preclude spurious operation of critical valves and equipment which could create a LOCA or compromise ability to stay in hot shutdown.

3.

Ascertain damage.

4.

Align flow path for Primary System makeup.

5.

Proceed with orderly plant cooldown, utilizing:

a.

Minor repairs.

b.

Manual valve line-ups.

c.

Alternate shutdown equipment, including fit e system.

3.3 Design Bases and Assumptions The following are the assumptions and design bases for the Maine Yynkee Atomic Power Plant safe shutdown review:

1.

The prime basis for design is to provide the ability to safely achieve and maintain safe shutdown conditions.

2.

For the purposes of analysis, it is assumed that:

a.

The reactor is operating at 100 percent power when a fire occurs; i

b.

It is also assumed that there is a manual or automatic reactor trip at the direction of the Shift Supervisor to bring the reactor to hot shutdown.

~ __

3.

In accordance with 10CFR50 Appendix R, Section III.G.1.(b), it is assumcd that there is a 72-hour period in which to attain the ability to achieve cold shutdown. During this three-day period, credit may be taken for manual system operation as well as for reasonable repairs, etc.

4.

No single or concurrent failures other than those directly attributable to the fire are considered.

5.

Repairs and manual valve line-ups will be utilized for plant cooldown.

6.

A short circuit involving three phase power cables which would result in energization of other equipment, as a result of the short, is not considered credible.

7.

Fire water and equipment is considere iable for plant cooldown after the fire has been extinguishes.

8.

The fire is assumed to be extinguished within two hours.

9.

Interfacing valves will not spuriously actuate prior to de energization of motor control certers.

3.4 Alternate Power Supply A new 480 V " Fire Bus" (MCC 9B1) will be installed as the alternate power supply for post-fire safe shutdown. A one-line diagram of the alternate power supply is provided in Figure 3.4-1.

MCC 9B1 will be located, as shown on Figure 3.4-2, outside the auxiliary feed pump area. Daring normal operation, the MCC will be powered from existing 480 V MCC 9B.

Following a fire, the MCC can be totally isolated from existing on-site and off-site power supplies and suFplied alternate power from a new dedicated diesel generator which will be located in the same general area. Mechanical and electrical interlocks will be provided between the normal and alternate supplies to MCC 9Bl.

The new diesel generator will provide post-fire power to the equipment shown in Figure 3.4-1.

..i

b A new 125 V de bettery and battery charger will be provided for olternate de control power. Also, a new 120 V ac inverter will be provided for instrument power.

3.5 Alternate Shutdown Equipment and Cable Routing The alternate equipment which may be used to shut down Maine Yankee following a fire is listed in Table 3.5.1.

The cable routing by fire zone, for alternate shutdown equipment is also given in Table 3.5.1.

Figure 3.5-1 provides an overall layout of the alternate shutdown equipment location and cable routings. Alternate shutdown panel (s) will be installed in the cuxiliary feedwater pump area. These panel (s) will include the necessary con,trols for alternate shutdown equipment and indication of critical plant parameters. Separate cabinets will be provided for safety class components.

The major components which comprise the alternate shutdown method are the auxiliary charging pump and turbine-driven auxiliary feedwater pump.

~

These pumps ~ provide for Primary System makeup and water for decay heat removal. Both pumps are located remotely from the pumps normally used for shutdown.

It should be nuted that for a fire in the auxiliary feedwater pump room (Zone 13), an alternate feed path is available via the first point heater whicP can be manually aligned in the steam and feed valve house. Local control of the turbine-drive auxiliary feedwater pump would be required.

The Primary System is isolated as explained in Section 3.7 to maintain i

existing water inventory.

Normal instrumentation monitoring critical plant parameters within the containment consists of two or more redundant channels with cables exiting the centainment through two separate Penetration Rooms. The rooms are separated by a 3-hour fire wall and a door which will be replaced to provide a 3-hour barrier. The cable associated with the alternate shutdown channels will all exit via Penetration Room A (Zone lla). The cables will leave the room through a new sleeve into the steam and feed valve house and then enter the dedicated 3-huur fire barrier encased cable chase through the lower level of the MCC areas to the auxiliary shutdown panels in the auxiliary feedwater pump crea.

________--_-Rh____---.-.-_.----_--------_-----

This routing provides complete separation from the normal shutdown channels truted through Penetration Room B (Zone llB) to the Control Room via the cable v ult. Cables for instruments within the steam and feed valve house will also tre the cable chase as explained above. Any cables associated with the citernate instrument channels which leave the auxiliary feed pump area will be protected by fuses.

Transmitters and cables for alternate shutdown instrumentation in the containment will be protected by shields or relocated as necessary to provide I

the required separation from normal shutdown channels.

There are air-operated valves in the steam supply line to the turbine-driven auxiliary feedwater pump, in addition to the decay heat release valve and auxiliary feedwater control valves, which require air and power to cperate.

One of the air compressors in the valve house will have the capability of being powered from the alternate power supply. This compressor will charge an accumulator which will serve the necessary valves. The valves can be controlled from the alternate shutdown panel.

i Adequate separation of cables for the auxiliary charging pump from the normal charging pump cables will be demonstrated. Several flow paths are I

available which can be manually aligned to allow Primary System makeup, an oxample is shown on Figure 3.5-2.

The Primary System can be cooled to approximately 300 F with the oteam-driven auxiliary feedwater pump and decay heat removal. Alternate water cupplies exist to replenish the existing condensate storage capability if required. The plant can then be brought to a cold shutdown condition by temporarily aligning the diesel-driven fire pump to feed a steam generator.

Schematic and wiring drawings of the alternate shutdown equipment are provided in Figures 3.5-3 through 3.5-12.

3.6 Associated Circuits to Reference (d) provided the definition of associated circuits for Appendix R consideration, the guidelines for protecting the safe -

chutdown capability from the fire-induced failures of associated circuits, and the information required by the staff to review associated circuits. Only circuits whose fire-induced failure could effect shutdown are of interest.

Associated circuits of concern are defined as those cables that:

1.

Have a physical separation less than that required by Section III.G.2 of Appendix R, and; 2.

Have one of the following:

A common power source with the shutdown equipment (redundant or a.

ai;2rnative), and the power source is not electrically protected from the circuit of concern by coordinated breakers, fuses, or similar devices (see Figure 3.6-la); or A connection to circuits of equipment whose spurious operation 3.

would adversely affect the shutdown capability (e.g., RHR/RCS isolation valves, ADS valves, PORVs, steam generator atmospheric dump valves, instrumentation, steam bypass, etc.)

(see Figure 3.6-lb); or A common enclosure (e.g., raceway, panel, junction) with the c.

shutdown cables (redundant and alternative) and; (1) are not electrically protected by circuit breakers, fuses or similar devices; or (2) will allow propagation of the fire into the common enclosure (see Figure 3.6-Ic).

A primary consideration in the design of Maine Yankee's Alternate Shutdown System was to locate equipment and cables remotely from normal chutdown equipment. This, in general, minimizes the potential impact of associated circuits. In addition, fire barriers will be utilized to separate citernste shutdown cables from possible associated circuits, if practicable.

All cables within the auxiliary feedwater pump area, which are not part cf the Alternate Shutdown System, were investigated as to the potential impact cf these cables on the safe shutdown capability. A listing of these cables is provided in Table 3.6.1.

It was determined that adequate protective devices existed to preclude damage of these cables from causing a loss of normal chutdown power supplies.

In addition, all penetrations from the room are or will be adequately sealed to preclude propagation of the fire outside the room.

The plant's power supplies are protected by protective devices. A fire-induced failure of cable will not tesult in loss of the power supply.

Other zones where alternate shutdown cables are in the proximity of' normal shutdown cables include the Reactor Containment, Penetration Room A, Primary Auxiliary Building, and the steam and feed valve house.

Cables in these zones have not been listed. In addition, shields and barriers will be utilized within the Reactor Containment, where possible, to provide separation of alternate shutdown cables from normal shutdown cables.

3.7 Interfacing Valves and Equipment 3.7.1 Interfacing Valves Interfacing valves are defined as valves that interface with the Primary Coolant System or Main Steam System, which if inadvertently opened by fire-induced causes could result in a LOCA or could unacceptably compromise the capability to reach and maintain a safe shutdown condition.

Table 3.7.1 provides a table of the interfacing valves, giving the cable routing of control and power cables and the MCC supplying power to each valve.

The interf acing valves are divided into two categories, as also indicated in Table 3.7.1.

1.

Valves normally closed which must be maintained in the closed i

position.

2.

Valves normally open which must be closed.

I Category 1 valves, in general, being normally closed, must be energized to open. Since a short of three phase power cable, which would in turn be capable of energizing a valve, is not considered credible, the only concern is a fire-induced failure of the control cables. The control cables are routed between the Control Room (Zone 1) and MCC areas (Zone lic), passing through the protected cable vault (Zone 2).

The cable vault and Control Room have inherent fire protection features es discussed in Reference (m).

The MCC area (Zone 11c) is protected by both fire detection and suppression equipment. The occurrence of a major fire in these areas, is therefore, highly unlikely. However, should such a fire cccur, inadvertent operation of these valves will be prevented by removing power to the applicable MCCs from the Switchgear Room. Upon confirmation of a fire in Zones 1, 2, or 11c, personnel will be immediately dispatched to the Switchgear Room. Specific guidelines for breaker positioning will be clearly delineated in the post-fire emergency procedures.

Removing power from the MCCs will provide adequate assurance against inadvertent valve operation and also reduce the electrical hazard to fire-fighting personnel.

Category 2 valves consist of the following:

1.

Letdown Valve 2.

Reactor Coolant Pump Seal Return Valves t

l 3.

Main Steam Excess Flow Check Valves The Letdown Valve, which will close on loss of air, will be isolated by a new solenoid valve, which can be controlled from the auxiliary shutdown psnel and will be provided alternate power from new MCC 9Bl. Energizing this l

colenoid will vent air and close the valve.

The reactor coolant pirmp seal return lines must be isolated if 1

component cooling to the seals has been lost. Separation between the power l

and control cables to the seal return valves and cables required to keep component cooling operable will be provided. Cables for the seal return l

valves will exit the containment in the same manner as the alternate instrumentation cables explained in Section 3.5, and will be controlled from the alternate shutdown panel and provided alternate power.

An alternative modification to assure the ability to isolate the seals is to add a redundant isolation valve to each seal return line. Tne valves would be powered from the new Fire Bus (MCC 9B1). The appropriate alternative will be chosen during the detailed design phase.

New solenoids will also be used to assure the main steam excess flow check valves can be closed. The solenoids will be controlled from the auxiliary shutdown panel and be provided with alternate power.

3.7.2 Interfacing Equipment Interfacing equipment is defined as pumps which feed the Primary System which if spuriously operated could compromise safe shutdown capability. The pumps of concern are the low pressure safety injection pumps and containment opray pumps.

In addition, the normal charging pumps and auxiliary feedwater pumps, if the alternate shutdown capability is being used.

For fires which can damage the control cables to these pumps, procedures will be developed to rack out breakern to disable the circuit.

As an additional precaution, post-fire procedures will include positioning switches in the Control Room to block safety injection, containment isolation, containment spray actuation and recirculation actuation signals.

i 3.8 Operator Actions An example of the operator actions based on a worst case fire scenario is listed in Table 3.8.1.

Post-fire shutdown procedures will be developed and l

operators trained accordingly. All temporary equipment required will be maintained on-site in identified accessible locations.

l l

l l _

3FE 480 V MCC-9B ID

[]aC 480 V MCC-931 (FIRE BUS) u Ik Yk h

ID NO{}IN OIK NC l

]

l

{}

UJ M

8 Ckt Distribution 75 5

gene 1 AY EP.

Alternate feed for 180 Ch rgi C-10A seal return valves

~

Diesel Generator (new)

Pun:p, P-7 typical for HCV-251, 261,271 (See Figure

_3.5-11)

FIGURE 3.4-1 ALTERNATE POWER SUPPLY ONE LINE DIAGRAM e

Aux. feed puaip area

/

/

/

Es 1851 lr8-l sl Underground l@

'O l- -l f

l z

1

~

?

Stack 3 Hr fire A

barrier

/

6' j

4 New material

./

~ ~ ~ ~ ~

Z l -; Conduit c.nclosure NTS i

(

\\ji'"'

180 kW Diesci

////// Protected cable routing Generator Scale 1/8" = 1 ft i

FIGURE 3.4-2 ALTERNATE POWER SUPPLY EQUIPMENT LAYOUT

i

+

G N

IWARD h

N 2

O b

I 6

T en A

3 8

o C

9 Z

I O

)

C C

'e L

E

• (N T

I 3

h I' NE

=

M C

. P' s'

P eA I" I

U Q

E

..E N

lM gI I

WO DT dr U

a H

Y S

E C.

T K

/

B.

A N

A 0

R 1

2 E

1 T

I V

I L

C A

N 1

E 5

ro t

t a 3

er 2

se wen E

NDC" eie e.

R

/

U Z

G I

F

.r b

4 e

e 1

1 1

t 1

1 1

2 r

a e

e e

e l

i.

n n

n n

o o

o o

n Z

Z Z

Z "a

C b

I

')

en

(

o Z

18 2

1 G

s 2

I t

~

,Y M $

t

/

e J J n

2 o

W Z

W

\\

K

l

• 0" G2 '

n n

e r

M V'a v

e CS i

t T~

1 t

r 5

Dd2 i 0 e-m 1

eeF s

nF n e T

a n

.s i

r o b

p t

ram uuu TAP O

s d

I ion r

e o

1 l

s 0

2 6

o 0

0 S

s 0

1&1 Ah hC eA 1

1 V

Vr0 1

C p1 V

V V

F F m-C E

E oC M

T T

C g1 l

l i

1 4

r ~-

Refueling water INSIDE OUTSIDE o

CON TAIN M ENT CONTAINMENT storage tanh l

TK-4 st l

'**SS-'

,,9...,3 J, -.

s

s...

.-/[

II ) r' <

b,,,

%. 3 L...

e t.C U C00t.= T i'

Cote tfG terw -

%e

%f C

' l t

v T.sr 3,

=a P-14B ll

-9 g, r J

L./L s,.

1 Y

oua E

h ll u

T 9

ts.+ h P-14S h

w

-Q

+'

N.e.cm crut,e

-/L/L--

coto Ltc too* 1 se -oo Ce ir v

O

}

%F

s. - -.

,,.g 1.s.-..:

l J j P-14A 3

si

'a q

s,.

3 y

3,

-.s ca c s.

3, se s,

L e

,c : :

e r~f kwyt y: <

Chem se g

s...c.c. Cont.,

a s-Addition, -

cn o us um i y

Tank

^

' t s 's Flow path n

$,)

~!

U

^

^

o s,

p.

M it':

<<'<W-++

g,sss s,

, ss,,,,,, s s, s ss ss-Auxiliary Charging FIGURE 3.5-2 EXAMPLE PRIMARY SYSTEM MAKEUP FLOW PATil

FIGURE 3.5-3 AUXILIARY CHARGING PUMP WIRING ALT. SHUTDOWN PANEL 480 V MCC-9B1 Isolation Start /stop (Fire bus) switch,,. 3 control FM

))

Pump Area Z 13 Aux.

) charging Pump 0

catrol T

~

s

(

Fuse Normal feed to MCC-9B1 I

PAB s'

CABLE EMER l

VAULT PC-227 PANEL I

Z2 (closes on i

Suct. Press.)

l 1

i PAB Elev. 11' 2 6a l

MCC-9B l

Aux.

)

1 gey Charging yog for P-7 Pump Cont.

P-7 PAB Aux. CH Elev. 21' Main Pump Z 6b Control Board MAIN CONTROL l

ROOM Z 1 l

C 1I

.B.

i 10A X '%

4

e i

Supply 1

Select

?

ASP ASP ASP SW IC 2C AT 43 ASP 1-

~

2

- P25B

-G

-R 7l 31 s

y l Loss of 3

ASP d

cont. pwr.

4

-B

-- CS 1

5 g3 (ESK-10AU) 2 -- P25 B' i P

/

4C g

d Q

ASP g

y 9

10 5

N 4 43 8l l2 T P25B s

d 9C l l 10C SP u

O h

5 ASP c

L h

74 P25B 74 SO U

L L

U Supply P25B 31 %

o

_f 33

_ _ 33 8

Select 6

HGA Y, - De-energ SW.

7-PCV

-PCV to open 1106 1106 j fY7%

PCV1106/ start Pump q

,7 m

at ASP STEAM CEN. AUX. FEED PP P25B CKT P25B 0

ASP 10A NOTES:

1.

Transfer switch (43) and supply select switch to be keylocked and annunciated.

l l

l I

FICURE 3.5 4 SCllEMATIC FOR AUXILIARY STEAM CONTROL VALVE, PCV-1106

~'

at ASP P

Level Transfer Ind.

switch

1. E at n

F1 ASP ASP Level l

0 ll Transmitter

{

b o

4TI l

i I l Fuse 3

{

I

'Til f

at ASP o

d d

Level Ind.

at Power supply at 120 Feedwater Reg.

VAC System g

i NOTES:

1.

Transfer switch is keylocked 6 annunciated.

FIGURE 3.5-5 SCllEMATIC FOR STEAM GENERATOR LEVEL, LT-1214, 1224, 1234

L L

Signal from excess flow valve s

control system.

Solenoid valves From control switch are energized to vent air from l

F

{d & power source at ASP.

Closed cylinders and close EFC valve.

i~ l l

l Energize solenoids to Either SOV will close EFC.

l~~]

vent air and close valve.

I I

I l

l 90-140VDC

% 90-140VDC I

T 1

I I

I l

p-----

-l-d l

Pressure gage l

l l

EFC test circuit I

l Locally Mtd.

l l

-)

l g

l I

g

g[g g(gVent' Test

//

70-100

//

p

'y 7

l l

Swi ch l

U l

PSIG

\\

I I.

l SOV-1001A,B, SOV-1001D,E,F

{ - _ _ _._ l _._ _

- r g

4 l

l lEFC-1001A,B,C SOV-1001G,II,J I

l l

l Open-Closed Limit Switches g

for test stroke N

/

Air to open 7

Spring to close NOES.

1.

SOV-100lG,11 & J, their associated controls and power source have been added 7

due to Appendix R.

2.

Control switch at ASP to be keylocked and annunciated.

FIGURE 3.5-6 SCllLMATIC FOR 14EW EXCESS FLOW CllECK VALVE SOLENOIDS

1 lll i

CDV 5

2 1

y J

l-R KB mg3x 9l lg A

1 00 k

1 c

o V

l C

y H

Sri e

I or k

C E

h V

t L

i A

w V

e d

E 5C en S

2 D d o A

1 V ii E

>p*

q vt L

n oa E

ri R

R pc 2J?

K n

T B

eu A

b n E

9I iA n

l l

C oa Dt Y

V m

A 5h o C

2 co E

1 t r D

i swl R

lh i so O

oc r

F P-rt d rt

,I S

ti i en C

C A

8 nw of o I

C A

os nsc T

A V

C en A

V 0

l ad M

0 2

orn E

2 1

ST a l

l 1

C S

S E

T 1 2 A

P O

7 B

C P

S N

C Ml C

l A

5 I

0 I

0 MT I

MI I

1,I'

,iI 'gg C

M 0

t

,I i

[H 0

/Na 7!

3 I

tE O

aS E

R UG I

~

F acl l

rCrI Tfl sT r

oWA^

i l

g l Ili'i'll l

I oS e

v a

P P

z M

M i

P A"

P 8

rs0

.k 8 ge1 S g4 "

S A.

eo0 A. )4

/

nl 1 1

1 ec -

J 3r V

n eoC g

e

'D t H

. f k Vi P

A O

V 0

5 SO P

[

Q s

{

1 l1

BKR P

C 7'

[ LKR i

P B

T I

Reset B

3C -- g_

Circuitry 3

CISB 3

U t

o ASP ASP 1

M Z:

Fuse l

Control g

6 H

Switch ASP N

i h

1 Transfer M

M i

P switch l

L a

j i

-- 3 3-L SOV Energize to TV E

2 1102 l

110 2 close TV i

~

o 0

_ f. A 1

N ii o

a,

~

ii w

I I

ASP y AN Fuse T

NOTES:

1.

Transfer switch to be provided with keylock ard control room annunciation.

2.

Rerouting of cable to solenoid is nec % sary.

3.

Requires internal panel separatian because of safety class equipment.

FIGURE 3.5 8 SCllEMATIC FOR AUXILIARY STEAM SUPPLY STOP VALVE, TV-1102

i Close on 2/3 low

,Sg. press

^

n 2

J O

E m

m Transfer

- T - --[

7#--

7-Transfer g

switch switch y

at SGEP l

g y

at SCEP g

(Note 3) y (Note 3) l y

g l

o<

l 1

1 l

c O

l 0

d

~

cp}

p

" ^

^ v IAir SUPPLY I--~~~~~~~7 i

l 2

0 c se Note 1 1

F

[T Transfer at ASP I

at at MCB De-energize to modulate,

Air E

} supply t ASP I

~

]

HCV-1201A NOTES:

(!!CV-1201B & C 1.

Ports 1 & 3 are open when SOV is de-energized.

similar)

Ports 1 & 2 are open when S0V is energized.

2.

Transfer switches to be provided with keylocks and control rocm annunciation.

3.

Requires internal panel separation because of safety class equipment.

FIGURE 3.5-9 SCllEMATIC FOR AUXILIARY FEEDWATER FLOW CONTROL VALVES, HCV-1201 A,B.C

((

1f.

I

\\'

1

,1 1

sU@G &gnk* E?E e

e s

P s

P utS i

'F aA utS F aA; l

oh rc t t ni P

owtS CsaA V

g O

[S o

y lp c,:. w r p i u sAS t

K s

l u

0 a

2 ST h

L y

x V

}/

~

E C

7 T

C.

v, E

N VL S

A l.O V

v.

v d

N G.

o' O

I C.

TA N

e L

t v

O A

s l

S K

u a

I 1

1 a

v 0

0 h

N 2

2 x

g W

B -

E

- n O

1 V

C i

D B0 C

I ch : :

T T

\\'

d s T

eo E

Ol,, sl L

=

G oc 2

,s rl R

I 0 2 A

B cg O

2 2 n

F S

li 6

A l r C

8 I

ap I

S K

FS T

f~

Yl g

0 A

K O0 M

1 2 C S2 E

0 1

2 l

lC 2

1 S

1 V

B_0 C 0

_M 1

5 2

3 E

RU N

IG 1

I 1

F lf

,li

'I xq,Sm y2e i gMm~

iY fjlll

Typical For HCV-251

-261 I

s

-271 l

MCC-9B1 I

N/

/\\

3 1

Alt Controll ASP o Control l

I

{

Transfer o

Switch w

l g --- -

' Pawer 8

i Transfe r l

l Switet Zone _13 MCC SB I

I 1

1

]-

I t

r To MCB iZone 11C (Normal Control)

FIGURE 3.5-11 SCilEMATIC FOR SEAL WATER RETURN VALVES, HCV-251, 261, 271

~ --

e MULTI-LOOP POWER SUPPLY at ASP 4

r1 r1 Process g

-)

Indicator

{-

at ASP Remote o

Process l

Transmitter l

l NOTES:

1.

Typical instrument loop for pressurizer level, pressurizer pressure, main steam pressure and reactor coolant temperature.

2.

Instrument loops for RCS-TE-115Y, 121Y & 135X (R.C. Temp.)

require resistance temperature detector (RTD) conversion devices.

3.

These instruments are dedicated to the auxiliary shutdown panel function.

FIGURE 3.5-12 TYPICAL INSTRUMENT LOOP

FIGURE 3.6;l EXAMPLES OF ASSOCIATED CIRCUITS OF CONCERN _

e I

FIRE. ARE A FIRE DBEh l

FIRE AREA

^

\\

\\

N, N

N

\\

li s

\\

11 x

x i-N

\\

.e N

l i

N N,

i N

c>1 s

N

sl l

Q l

\\

x g

\\

"I m

11 N

s

\\

I N

N

- t.

s 1

o l

.t N

e s

'f 1

N

.j l

N e x s

'f gl N

g g

h

'dl

\\

I-N l j

\\

\\

F

\\

E

\\

w N

\\

<l F

El N

1 12

\\

\\xxxx ixs NNN. NNNixxx' h\\'N\\\\ NN.Q ~D N

I I

cor,,,a a Euctos anE vs ag, run e l

E iupmed o, A,e sf,su The area barriers shown above meet the' appropriate sub-paragraphs (a-f) 6-Bus opu& co*M. 07fec/

of sdction Ill.G-2 of Appendix R.

t Skaldeant Diagram (O Diagram M Diagram (c)

(.* ( -

s.

il l'

l l

l l

l l

S 2O C

d l

4-rr 2C o

4 B

~

/

l

)

r o

G r

r l_

e o

i t

4 C

d, tn t

n

(_

e C

11l R

C n

l i

2C o

a 4

r tno C

ro t

i o

I e

M

. S7 T1 1

_. S1

_ L S7

_ L c-7

- S3 L MI S

r_

S8 L

C T

I

,h1-T o

A ta S5 M

r L

E e

I 2

l i

XVX C

p

!l O_

0 S

e 2

G 1

v 2C N

l I

4

.S a

R V

s I

u W

B V

V O

M I

I 0

8 L

4 AC I

q* l P

Y T

l I

1 1

7 L1 o

3 E

RUG l

I l

I i

F

'f4 ro

\\

to M

I iM*

I' l~l'

Table 3.5.1 Alternate Shutdown Equipment Cable Routing By Fire Zones

]

Equipment Description Ma rk No.

Bus Powe r Cont rol Auxitta ry Charging Pump P-7 981 6a, 6b2, 13 6a, 6b2, 13 Excess Flow Check Valve Compressor C-10A 981 10, 11d, 13 10, lid, 13 N2w Diesel Generator DG-3 13 13 Turbine-Driven Auxilia ry Feed Pump P-25B Auxiliary Feedwater Control Vaives HCV-1201A, B, C 981 13 13 Decay Heat Release Valve HCV-1001 981 10, lid, 13 10, lid, 13 Auxiliary Feedwater Pump Steam Supply Valve TV-1102 9B1 10, lid, 13 10, lid, 13 Auxiliary Feedwater Pump Steam Control Valve PCV-1106Y 981 10, lid, 13 10, lid, 13 Discol-Driven Fire Pump P-5 Instrumentation:

Pressurizer Level PT (new) 981 13 7, 10, lla, lid, 13 Pressurizer Pressure PT (new) 981 13 7, 10, lla, lid, 13 Steam Generator Level LT-1214, 1224, 1234 9B1 13 7, 10, lla, lid, 13 Main Steam Pressure PT (3 - new) 9B1 13 10, lid, 13 Reactor Coolant Temperature TE-115Y, 121Y,

135X 98L 13 7, 10, lla, lid, 13 I

Table 3.6.1 Alternate Feedwater Pump Area Associated Circuits Cable #

Use Protective Device

{

1M267 PUH 18 and 19 Circuit breaker 149PL135 FN-35 (Motor)

Circuit breaker 149PL136 FN-35 (Control)

Control circuit fuse 149PL138 FN-35 (Damper)

Circuit breaker 47PH1 P-25C (Motor)

Circuit breaker 47PH3 P-25C (Control)

Control circuit fuse 47PH4 P-25C (Control)

Control circuit fuse 47PH6 P-25C (Ammeter)

Not required (Note 1) 105PL72 Alt. Feed (SCEP)

Circuit breaker and fuses IVB125 Vital Bus 1 Circuit breaker IVB420 Vital Bus 4 Circuit breaker j

IVB324 Spare Not connected 1AN406 Annunciation Not required (Note 1) 148PH1 P-25A (Motor)

Circuit breaker 148PH3 P-25A (Control)

Control circuit fuse 148PH4 P-25A (Control)

Control circuit fuse 148PH7 P-25A (Ammeter)

Not required

• NOTES:

1.

Failure will not cause damage to other cables in the same raceway.

2.

Cables which comprise the alternate shutdown capability are not listed.

Figures 3.5.1 through 3.5.12 show these cables and protective devices.

l l

Table 3.7.1 Interfacing Valves Present Cable Routing By Fire Zone Closu re Valve Description Mark No.

Ca tegory MCC Power Cont rols RHR 1 solation Valve HCV-327 1

7B 7, 11a, 11c lb, 2, 11e RilR 1 solation Valve HCV-328 1

8B 7, lib 11c lb, 2, 11c Reactor Vent Valve MOV-3006 1

8B 7, 11 b, 11c lb, 2, 11e Reac t o r Ve n t Valve MOV-3007 1

7B 7, lla, 11c lb, 2, 11e Pre ssurizer Vent Valve MOV-3008 1

8B 7, 11b, 11c lb, 2, 11e Pressurizer Vent Valve MOV-3009 1

7B 7, lla, 11c lb, 2, 11e PORV SV-3004 1

7B 7, lla, 11c lb, 2, 11e PORV SV-3005 1

8B 7, 11 b, 11c lb, 2, 11e PORV Stop Valve MOV-3004 1

7B 7, lla, 11c lb, 2, 11e PORV Stop valve MOV-3005 1

8B 7, 11 b, 11 c lb, 2, 11e Loop Drain Valve HCV-113 1

7B 7, lla, 11c lb, 2,11c Loop Drain Valve HCV-114 1

7B 7, lla, 11c lb, 2, 11e Loop Drain Valve HCV-115 1

8B 7, 11b, 11c lb, 2, 11c Common Loop Drain Valve HCV-265K 1

7, lla,11c lb, 2,11c Le tdown Isolation Valve TGV-201K 2

See Figure 3.5-10 Sea l Wat e r Re tu rn Valve HCV-251 2

7B 7, lla, 11c lb, 2, 11e l

Seal Water Return Valve HCV-261 2

7B 7, lla, lic lb, 2, 11e l

1 Power f eeds to MCCs a re routed th rough Zones la, 2, 3 and 12a.

-3 5-

Table 3.7.1 (continued)

Interfacing Valves Present Cable Routing By F1re Zone Closu re Valve Description Mark No.

Cat ego ry MCC Powerl Cont rols Seal Water Return Valve HCV-271 2

7B 7, lla, 11c lb, 2, 11e Main Steam Excess Flow Check Valve EFC-1001A 2

See Figure 3.5-6 Main Steam Excess Flow Check Valve EFC-1001B 2

See Figure 3.5-6 Kat n Steam Excess Flow Check Valve EFC-1001C 2

See Figure 3. 5-6 1 Power feeds to MCCs a re routed th rough Zones la, 2, 3 and 12a.

1

_m.. _ _ _.

4 i

Table 3.8.1 Worst Case Post-Fire Scenario Time f

l T=0 o

Fire report received i

Dispatch personnel to determine locaticn and o

severity of fire

/

T = 5 - 15 min.

o Trip plant and institute emergency procedures Assemble fire brigade and move to fire o

{

Open SIS, CIS, CSAS and RAS breakers in o

Control Room Dispatch personnel to open required breakers o

in Switchgear Room T = 15 - 30 min.

o Establish, display and control at alternate shutdown panel in auxilliary feedpump area Start turbine-driven auxiliary feedpump and o

commence removing decay heat via decay heat release valve (controlled from alternate i

shutdown panel T = 30 - 120 min.

o Extinguish fire Continue to monitor critical plant parameters o

Continue to remove decay heat, as required o

T = 2 - 3 hrs.

o Ascertain extent of fire damage Establish a flow path to allow Primary System o

charging T = 3 - 72 hrs.

o Continue to monitor critical plant parameters o

Tie in supplemental water source for auxiliary feedwater pump Slowly cool down plant using Auxiliary o

Feedwater System Borate manually, as required o

Align fire water for steam generator feed o

T = 72 hrs.

c Bring plant to cold shutdown -

k 4.0 RESPON::E 10 NRC STAFF LETTERS 4.1 NRC Ceneric Letter (81-12), Dated February 20, 1981 Response to, Section 8 (Rewrite) 1.

Identify thoce areas of the plant that will not meet the requirements of Section III.G.2 of Appendix R and, thus alternative shutdown will be provided or an exemption from the requirements of Section III.G.2 of Appendix R will be 7tovided. Additionally, previde a statement that all other areas of the plant are or will be in compliance with Section III.C.2 of Appendix R.

Respon,ce:

Several fire zones within the plant do not comply with the specific requirements of Section III.G.2 of Appendix R.

Section 2.4 provides a discussion of the areas of non-con fo rmance.

For each of those fire areas of the plant requiring an Alternative Shutdown System (s), provide a complete set of responses to the following requests for each fire area:

Note: The alternate shutdown equipment proposed for use at Maine Yankee is generally located in fire zones which do not contain normal shutdown equipment. Circuits which pass through common areas are provided with isolation devices. Accordingly, the Alternate Shutdown System assures the capability of reaching safe shutdown for fires throughout the plant.

a.

List the system (s), or portions thereof, used te provide the shutdown capability with the loss of off-site power.

Response

h Portions of the following systems are used to provide shutdown capability with the loss of of f-site power:

l I

1) Control Rod Drive

2) Chemical and Volume Control

}

3) Auxiliary Feedwater i

4) Reactor Coolant (Instrumentation) i

5) Main Steam 1

k

6) On-Site Emergency Power b.

For those systems identified in 1.a. for which alternative or dedicated shutdown capability must be provided, list the equipment and components of the normal Shutdown System in the fire area, and identify the functions of the circuits of the normal Shutdown System in the fire area (power to what equipment, control of what components and instrumentation). Describe the system (s), or portions thereof, used to provide the alternative shutdown capability for the fire area, and provide a table that lists the equipment and components of the Alternative Shutdown System for the fire area.

For each Alternative System identify the function of the new circuits being provided.

Identify the location (fire zone) of the alternative shutdown equipment and/or circuits that bypass the fire area and verify that the alternative shutdown equipment and/or circuits are separated from the fire area in accordance with Section III.G.2.

Response

Normal safe shutdown equipment is described in Section 2.2 and listed in Table 2.2.1.

The cable routing for normal shutdown equipment, by fire zone, is also listed in Table 2.2.1.

Alternate safe shutdown equipment is described in....

Section 3.5 and listed in Table 3.5.1.

The cable routing for alternate shutdown equipment, by fire zone, is also listed in Table 3.5.1.

Provide drawings of the Alternative Shutdows System (s) c.

which highlight any connections to the normal Shutdown Systems (P& ids for piping and components, elementary wiring diagrams of electrical cabling). Show the electrical location of all breakers for power cables, and isolation devices for control and instrumentation circuits for the Alternative Shutdown Systems for that fire area.

Response

Figures 3.5-3 through 3.5-12 are schematic and one-line diagrams for the alternate shutdown equipment which show the location of all power cable breakers and isolation devices for control and instrumentation circuits, d.

Verify that changes to safety systems will not degrade safety systems (e.g., new isolation switches and control switches should meet design criteria and standards in the FSAR for electrical equipment in the system that the switch is to be installed; cabinets that the switches are to be mounted in should also meet the same criteria (FSAR) as other safety-related cabinets and panels; to avoid inadvertent isolation from the Control Room, the isolation switches should be keylocked or alarmed in the Control Room if in the " local" or " isolated" position; periodic checks should be made to verify that the switch is in the proper position for normal operation; and a single transfer switch or other new device should not be a source of a failure which causes loss of redundant safety systems).._

Response

Every effort has been made to avoid changes to safety systems. The Maine Yankee alternate shutdown scheme utilizes auxiliary pumps which have no present safety function, and non-safety instrument channels are utilized wherever possible. Where interface with safety systems is necessary, the electrical installation will meet the original Maine Yankee standards and design criteria.

Transfer switches, and/or fuses will be located at the alternate shutdown panel which will be provided with keylock and Control Room annunciation. Furthermore, in no instance will more than one traf n of a redundant safety system be tied to a single transfer switch.

e.

Verify that licensee procedures have been or will be developed which describe the tasks to be performed to effect the shutdown method. Provide a summary of these procedures outlining operator actions.

Response

Section 3.8 describes the actions which are required to effect the shutdown method. Table 3.8.1 is a summary of the overall post-fire scenario based on a worst case fire situation. Specific procedures, which will include instructions based on the fire zone involved, will be developed upon NRC approval of the methodology presented in this report.

f.

Verify that the manpower required to perform the shutdown functions using the procedures of e., as well as to provide fire brigade members to fight the fire, is available as required by the Fire Brigade Technical Specifications.

Response

Adequate manpower will be provided to perform the required shutdown functions and meet Fire Brigade Technical Specification requiremants.

g.

Provide a commitment to perform adequate acceptance tests of the alternative shutdown capability. These tests should verify that: equipment operates from the local control station when the transfer or isolation switch is placed in the " local" position and that the equipment cannot be operated from the Control Room; and that equipment operates from the Control Room, but cannot be operated at the local control station when the transfer isolation switch is in the " remote" position.

Response

A comprehensive pre-operational testing program will follow the installation of the alternate shutdown equipment. The concerns outlined above will be adequately demonstrated by this program.

h.

Provide Technical Specifications of the surveillance requirements and limiting conditions for operation for that equipment not already covered by existing Technical Specifications. For example, if new isolation and control switches are added to a Shutdown System, the existing Technical Specification surveillance requirements should be supplemented to verify system / equipment functions from the alternate shutdown station at testing intervals consistent with the guidelines of Regulatory Guide 1.22 and IEEE 338.

Credit may be taken for other existing tests using group overlap test coricepts.

Responce:

New isolation or control switches which interface with safety equipment governed by existing Technical Specifications will be included in the testing of that equipment.

i. For new equipment comprising the alternative shutdown capability, verify that the systems available are adequate to perform the necessary shutdown functions. The functions required should be based on previous analyses, if possible (e.g., in the FSAR), such as a loss of normal ac power or shutdown on Group 1 isolation (BWR). The equipment required for the alternative capability should be the same or equivalent to that relied on in the above analysis.

Response

The equipment which comprises the Alternate Shutdown System has been demonstrated by prior testing or by calculation to be adequate to perform the necessary safe shutdown functions.

J.

Verify that repair procedures for cold Shutdown Systems are developed and material for repairs is maintained on site.

Provide a summary of these procedures and a list of the material needed for repairs.

Response

The primary actions required to initiate a cold shutdown, based on a worst case fire scenario, are:

1) Run hose to provide makeup water to the demineralized water storage tank.

+

2) Run hose to allow for fire pump to be used for steam generator fill.

The proper hoses will be maintained on site for their specific uses. Other actions involve manual valve alignments which will be defined in the emergency procedures.

Response to Attachment 2, Safe Shutdown Capability Systems Approach 1.

For each area where an alternative or dedicated shutdown method, in accordance with Section III.G.3 of Appendix R is provided, the following information is required to demonstrate that associated circuits will not prevent operation or cause maloperation of the alternative or dedicated shutdown method:

Describe the methodology used to assess the potential of a.

associated circuits adversely affecting the alternative or dedicated shutdown. The description of the methodology should include the methods used to identify the circuits which share a common power supply or a common enclosure with the Alternative or Dedicated Shutdown System and the circuits whose spurious operation would affect shutdown. Additionally, the description should include the methods used to identify if these circuits l

are associated circuits of concern due to their location in the i

fire area.

l

Response

I l

l A discussion of associated circuits and its effect on Maine Yankee's safe shutdown capability is provided in Section 3.6.

l l

b.

Provide a table that lists all associated. circuits of concern l

located in the fire area.

f l

l (

Re sponse :

Refer to Section 3.6.

c.

Show that fire-induced failures (hot shorts, c,can circuits or shorts to ground) of each of the cables listed in b., will not prevent operation or cause maloperation of the alternative or dedicated shutdown method.

Response

Refer to Section 3.6.

d.

For each cable listed in b. where new electrical isolation has been provided, provide detailed electrical schematic drawings that show how each cable is isolated from the fire area.

Response

Refer to Section 3.6.

Provide a location at the site or other offices where all the e.

tables and drawings generated by this methodology approach for the associated circuits review may be audited to verify the information provided above.

l

Response

l Drawings and other information documenting Maine Yankee's l

review are on file at Yankee Atomic Electric Company, Nuclear i

Services Division in Framingham, Massachusetts.

2.

The Residual Heat Removal System is generally a low pressure system that interf aces with the high pressure Primary Coolant System. To preclude a LOCA through this interface, we require compliance with the recommendations of Branch Technical Position RSB 5-1.

Thus, this interface most likely consists of two redundant and

independent motor-operated valves. These two motor-operated valves and their associated cable may be subject to a single fire hazard.

It is our concern that this single fire could cause the two valves to open resulting in a fire-initiated LOCA through the subject high-low pressure system interface. To assure that this interface and other high-low pressure interfaces are adequately protected from the effects of a single fire, we require the following information:

Identify each high-low pressure interface that uses redundant a.

electrically controlled devices (such as two series motor-operated valves) to isolate or preclude rupture of any primary coolant boundary.

Response

Table 3.7.1 provides a listing of the interfacing valves.

b.

For each set of redundant valves identified in a.,

verify the redundant cabling (power and control) have adequate physical separation as required by Section III.G.2 of Appendix R.

Response

Table 3.7.1 provides a listing of control and power cable routing, by fire area, for each interfacing valve. A typical wiring schematic is provided in Figure 3.7-1.

It is typical that the valve control cables do not meet the separation requirements of Section III.G.2 of Appendix R in the Control Room (Zone 1), protected cable vault (Zone 2), and MCC areas (Zone 11c). Power cables do not meet the above requirements in the reactor containment (Zone 7) and MCC areas (Zone 11c).

For each case where adequate separation is not provided, show c.

that fire-induced failures (hot short, open circuits or short.

to ground) of the cables will not cause maloperation and result in a LOCA.

Response

Maine Yankee's position relative to interfacing valves is provided in Section 3.7.

4.2 NRC Letter to Maine Yankee, Dated April 24, 1981 Several recommendations were given in the above referenced letter which cre addressed below:

1.

The alternative shutdown capability should be modified to meet the requirements of Section III L of Appendix R to 10CFR Part 50, taking into consideration the above findings.

Response

The Alternate Shutdown System described in Section 3.0 addresses the areas of circuit isolation and loss of off-site power and in general complies with the requirements of Section III L of Appendix R to 10CFR50.

2.

All support functions including lube oil, cooling, and power should be shown to be available for the equipment used in the alternative shutdown capability.

Response

The support functions necessary for alternate equipment operation have been identified /will be provided.

3.

The process monitoring should be shown to be capable of providing direct readings of the process variables necessary to control reactivity, reactor coolant makeup, and reactor heat remova l.

Permanently installed instruments should be used to provide capability for reading pressurizer pressure, temperature and level, reactor coolant loop temperatures, steam generator level and pressure, auxiliary feedwater flow, condensate storage tank level and radiation levels, and reactor core flux density.

Response

The new emergency shutdown panel will include direct readings of the following process variables:

Steam generator wide range level, a.

b.

Main steam line pressures, c.

Reactor coolant loop temperatures, d.

Pressurizer pressure, and e.

Pressurizer level.

The instrumentation provided exceeds the display capability of the existing emergency panels and provides adequate information to allow a safe plant shutdown.

4.

All repair procedures for cold shutdcwn should be fully developed and it should be verified that the materials for the repairs are maintained on-site.

Response

Addressed in Section 4.1 (Item 8e).

5.

The procedures for alternative hot and cold shutdown should be fully developed. The manpower for these procedures and for the repair procedures should be shown to be available on-site and the work to be performed should be reasonable of the manpower available. l

Response

Addressed in Section 4.1 (Item 8f).

6.

The water requirements for core cooling and support functions associated with core cooling should be met without using the diesel fire pump and other systems designed for fighting fires.

Re sponse :

Fire water supplies and fire equipment are dedicated to the task of extinguishing the fire for a duration of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> (assumed maximum fire duration). Af ter this period fire water and equipment can be utilized for plant cooldown. Abundant water supplies are available at Maine Yankee via the diesel fire pump, to supply the proposed service requirements.

7.

Repairs to systems used to place the reactor in the hot shutdown operating mode should not be incorporated in the procedures established to bring the plant to hot shutdown.

Response

The actions required to reach and maintain hot shutdown are '.imited to breaker positioning and manual valve alignments.

8.

The licensee should demonstrate that alternative safe shutdown capability can be achieved with the loss of off-site power.

Response

Alternative safe shutdown is achieved by using a new diesel generated power source, which is independent of off-site power supplies.

9.

The licensee should demonstrate that the potential operating problem with the Containment Ventilation System referred to in the -_

Final Safety Analysis Report would not affect safe shutdown in the event of a fire.

Response

Should a fire render the Containment Ventilation System inoperable, it is expected that containment temperatures will rise at a very slow rate due to the large heat sink capacity available. The instruments in the containment which are used in the alternate shutdown scheme are qualified to post-LOCA temperatures and are not expected to be affected by any temperature increase due to loss of ventilation.

The balance of this letter is addressed in Section 4.1.

l l

l l

l l

l --..

5.0 REFERENCES

(c) License No. DPR-36 (Docket 50-309).

(b) USNRC Letter to Maine Yankee Atomic Power Company, dated February 20, 1981 (Generic Letter 81-12).

(c) USNRC Letter to Maine Yankee Atomic Power Company, dated April 24, 1981.

(d) USNRC Letter to Maine Yankee Atomic Power Company, dated May 19, 1982.

i (s) USNRC Letter to Maine Yankee Atomic Power Company, dated August 11, 1982.

(f) Maine Yankee Letter, WMY 78-52, dated May 31, 1978,

Subject:

Maine Yankee Fire Protection Program Information.

(g) Maine Yankee Letter, WMY 79-98, dated September 20, 1979,

Subject:

Submittal of Additional Information on Fire Protection Items.

(h) Maine Yankee Letter, FMY 81-17, dated February 9,1981,

Subject:

Request for Exemption.

(i) Maine Yankee Letter, FMY 81-23, dated March 6,1981,

Subject:

Request for Exemption.

(j) Maine Yankee Letter, FMY 81-35, dated March 12, 1981,

Subject:

Compliance with Revised Section 10CFR50.48 and New Appendix R to 10CFR50.

(k) Maine Yankee Letter, MN 82-19, dated February 2, 1982,

Subject:

Fire Protection Exemption Clarification Schedule.

(1) Maine Yankee Letter, MN 82-27, February 16, 1982,

Subject:

Fire Protection Request for Exemption.

(s) Maine Yankee Letter, MN 82-42, dated March 5, 1982,

Subject:

Request for Exemption.

(n) Maine Yankee Letter, MN 82-109, dated June 7, 1982,

Subject:

Fire Protection - Safe Shutdown Capability... _ - -. -. _

I I

YANKEE ATOMIC ELECTRIC COMPANY I

I I

I I

I Y

I I

I I

I I

I I

I

-