ML18052A368

From kanterella
Jump to navigation Jump to search
Withdraws Exemption Request Re Fire Protection for Charging Pump Room & Verifies That Exemption for Instrumentation Separation Inside Containment Required,Per Compliance w/10CFR50.48 & App R
ML18052A368
Person / Time
Site: Palisades Entergy icon.png
Issue date: 10/04/1985
From:
CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
Office of Nuclear Reactor Regulation
References
NUDOCS 8604030128
Download: ML18052A368 (24)
v • d • e


Text

consumers Power company_ ---

General Offlc*: 1945 Wen P*rnell Aoecl. JKkeon. Ml 49201 * (!1171 788-0!150 October 4. 1985 Director.

Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington. DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT -

FIRE PROTECTION - EXEMPTION REQUEST - COMPLIANCE WITH 10CFR50.48 AND APPENDIX R NRC and Consumers Power Company staff representatives participated in a meeting and plant tour at our Palisades Plant on.June 3 and June 4. 19.85 to resolve a number of requested exemptions to 10CFR50,Appendix R.

That meeting and an additional conference call oil June 6,- 1985 resulted in the June 19.

1985 Consumers Power submittal which addressed.all the outstanding exemption requests and either withdrew or re~submitted them with the exception of those for the Charging Pump Room (Attachment 7)*and for instrument separation within the Containment Air Room (Attachment 14).

The.June 19, '1985 submittal* committed. CPC*toadditional review of the

. r~q~irement for these two exemption*-re.quectsl referred to as Attachment 7 (for

-* the Charging Pump Room) and as Attachment 14.-Cf or the Instrument Separation Inside Containment).

This letter withdraws the Exemption Request (Attachment 7) for the Charging Pump Room, verifies that exemption for Instrumentation Separation Inside Containment (Attacmient 14) is required. and provides new information regarding the eventual. location of redundant instruments in the Containment Air Room.

  • A. - Charging Pump Room Consumers Power Company has analysed and evaluated the High Pressure Safety Injection (HPSI) Pumps P-66 A or Bas being.redundant to Charging_
  • Pumps P-55 A. B or C to maintain Hot Shutdown and has concluded.that HPSI pump P-66B is redundant to the Charging Pumps for that application~ P-66A is not considered redundant because the separation of its power supply from the power supply to the Charging Pumps does not meet the criteria 'of 10CFR50 Appendix R.

A thermal-hydraulic analys~s was performed by Energy Incorporated (EI) using the RETRAN 03 computer program.

A description of the model used is included with this submi\\:ta.l as Attachment A.

OC0885-0011A-NL02 r

\\,

860403AOD0128cu 80~688~55 l PDR n '

' \\

F

Director, NRR Palisades Plant Exemption Request October 4, 1985 2

The Attachment 7 exemption request concerned the separation criteria of Sections III.G.2 and III.G.3 of Appendix R for the power supplies for P-55 B & C.

This exemption is not required because the separation between the power supplies and controls for HPSI Pump P-668 and the power supplies and controls for Charging Pumps P-55 A, B and C meets the criteria of Appendix R.

Therefore, we have concluded that HPSI pump P-66B is redundant to Charging Pumps P-55A, B, and C during post fire conditions.

Use of P-668 to maintain PCS inventory and 25°F subcooling immediately after a fire in the 590' corridor of the Auxiliary Building may require the operator, during the first 2.25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> after reactor ~rip, to go to the Engineered Safeguards Room to remove the air from CV-3059, located in the discharge line from P-668, open the power supply breakers located in the cable spreading room for M0-3007, M0-3009, M0-3011 and M0-3013, each of which is located in a branch of the P-668 discharge line, open the power supply breakers for SV-3031A and SV-3031B which control the borated flow between the Safety Injection Refueling Water Tank (SIRWT) and the P-66B intake, and then enter containment to manually open at least one of the above listed motor operated valves.

Consumers Power Company withdraws - Exemption Request - Charging Pumps P-55B and P-55C, revision 1, dated July 16, 1984.

B. 4 - Instrument Separation Inside Containment Revision 3 of Attachment 14 describes the Containment Air Room and its contents after the Electrical Equipment Qualification (EEQ) modification that will be completed during the upcoming 1985 refueling outage.

EEQ requirements necessitate relocating some of the instrumentation within containment.

These new locations will not increase the separation of redundant instruments enough to meet the criteria of 10CFR50, Appendix R, Section III~G.2. Therefore, we have concluded that an exemption from Section III.G.2 of 10CFR50, Appendix R for the Containment Air Room is indeed necessary.

To eliminate future confusion as to which instruments are exempted from the III.G.2 criteria, steam generator level transmitters for both SG-A and SG-B have been added to the list of equipment included in this exemption_

request even though 20 ft separation does exist between level indicators for SG-B.

Additionally, Pressurizer (PZR) Pressure Transmitter PT0103 has been deleted and PZR Pressure Transmitters PT0104A, 0104B, 0105A and 0105B have been added.

The attached sketches, Fr~CAR_-LT _and FP-CAR-PT, and Table #1, below, indicate the relative position, after the EEQ modffieation, of the* level and pressure transmitters affected by this exemption request.

With reference to sketches FP-CAR-LT and FP-CAR-PT, areas A, B and D are on the

  • 590' level and walls A, B and D extend upward from that level. Area C is on a platform at the 597'-l~" level and contains a vertical structure OC0885-0011A-NL02

Director, NRR Palisades Plant Exemption Request October __ 4, J. 9as _

3 which extends upward 7 ft. Area E is on a platform at the 598'-10" level.

Wall E is the inside containment perimeter wall.

Instruments *are mounted on the vertical walls and structure within 7 ft of the floor or platform elevation.

Table 81 indicates the relative position of redundant instruments and the maximum separation distance.

Pressurizer SG-A SG-B TABLE Ill INSTRUMENT LOCATION AREAS (SEPARATION)

Pressure Level Transmitters Transmitters B & D (8')

C & E (15')

A (8'-10')

D & E (8')

C & D & E (15')

A & D (20')

For example, referring to Table. #1, the redundant Pressure Transmitters for the Pressurizer are located in areas B and D and are approximately eight (8) feet apart.

The separation indicated in Table 1 verifies that Consumers Power Company must reconfirm our requested exemption from Appendix R separation requirements regarding the pressure and level transmitters located in the Containment Air Room for the Pressurizer and Steam Generators.

The description of the Air Room, the instruments contained therein, and other information stated in the Justification section of the Exemption Request

.remain accurate and justify granting an exemption.

James L Kuemin (Signed) __

  • James L Kuemin Staff Licensing Engineer CC-Administrator,_ Region III, USNRC NRC Resident Inspector - Palisades Attachments A - Description of the model used with computer program RETRAN 03.

17 - Exemption Request - Charging Pumps P-55B and P-55C

  1. 14 - Exemption Request - Instrument Separation Inside Containment OC0885-0011A-NL02

"' -d

~ PTo\\o5A, a~&..\\ b...,_ *.,.. ~\\a-A'-LA.. ~.

f~-CAR-~T 1i/:z...,J1~ R11v o

~wS

>T o ~o L\\ ~, B T.01°'5A ~.,,.

I

~

I P\\cnoz !

t9T O"l"'+

I

PT 01s2..4,13,c :D i

<~

.--~*

1 l

i I

t...1'" 0751 A-IC t:rd7S7,4<>>S

.
r 075S A~]/'/ -<"------

s 'l(;f'itH r:?-CAI<'- )...\\

s/z.-,('i~f.'.. vO (Cw.

).lc?5'1}3~..D

.J..TO/OIAB

~..

J.. T Ot OZ. ~ ji1 C_., ):)

I I

I I J..1 0?.52. J'9AC. :D I

i I

'~..... "!

/\\::r"

~:

AT-T-ACHMENT A-Consumers Power Company Palisades Plant Docket 50-255 A description of the Palisades single loop model used with computer program RETRAN 03 to calculate the Palisades Plant response to a postulated "worst case" fire in the Cable Spreading Room coincident with the loss of all AC power and to determine the adequacy of one BPSI pump to maintain PCS inventory and 25°F subcooling for a period of 2.25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br /> after reactor trip September 12. 1985 5 Pages IC0985-0002A-NA02-NL02

1

SUMMARY

Based on the CPCo Palisades single loop model, EI consolidated t~e previous RETRAN-02 input model from 53 volumes and 84 junctions down to 16 volumes and 30 junctions with the objective of conserving computer execution time while preserving enough nodalization detail to insure a valid transient solution.

All unnecessary valves, fills, trips, and control systems were deleted from the original single loop model.

The new condensed Palisades single loop input model used the RETRAN steady state initialization option to obtain the initial conditions which were benchmarked against CPCo's latest best estimate Palisades two loop input model.

The Palisades single loop model was then used with a pre-released version of RETRAN-03 to calculate the plant response to a postulated fire in the cable

  • spreading room.

This assumed accident scenario includes the folloWing; reactor trip, turbine trip, reactor coolant pump trip, main feedwater trip, pressurizer beater trip, loss of chemical and volume control system (including all three charging pumps), and assumed loss of backup diesel generator power.

The RETRAN-03 calculated transient was arbitrarily terminated at 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> and 20 minutes.

The plant has gone through the initial transient and is now in natural circulation cooldown mode with steam being vented through the auxiliary feedwater turbine, hogging air ejector, and hogging air ejector safety valve.

NODALIZATION The reactor vessel nodalization for the long-term cooldown transient is shown in Figure 1. This nodalization is adequate to model the decay heat transfer and natural circulation flow for tbe*long~term cooldown transient.

In the long-term cooldown transient, the reactor coolant pumps are tripped at the beginning of the transient due to the loss of ac power.

Pressurizer spray capability is lost due to the loss.of forced recirculation. Therefore, the

  • -pressurizer spray is unavailable for the dura~ion of this transient and is not

-**modeled.

Also, the pressurizer safety valves and PORVs were not included in this model, because the.long-term cooldown transient pressurizer pressure

- response will not challenge the pressurizer safety valve or PORV setpoints. -

The primary system piping volumes were combined wherever possible in order to reduce the total number of volumes and to save computer run time.

However, the piping volumes still retain sufficient detailed nodalization to preserve

.- th*e elevation be~d that is important for properly. calculating the prim.a:ry system natural circulation flow rates*.

The steam generator inlet plenum fluid volume was combined with the-bot leg piping fluid volume.

This was based on the assumption that the hot leg fluid and steam generator inlet plenum fluid were at the same thermal condition.

Under natural circulation flow conditions this assumption is valid. Based on the same assumption, the steam generator outlet plenum and pump suction piping volumes were combined into a single volume.

The cold leg piping volume was retained from the original single loop model.

IC0985-0002A-NA02-NL02

2 To conserve computer ruriii!iig 1:1Jne. die-steam generator-secondary-side volumes __ _

were condensed into the minimum number of volumes necessary to.model the secondary side heat transfer. recirculation flow, steam and feedliater interaction. and safety valve action. The new simplified single loop nodalization is shown in Figure 2.

This model introduces the assumption that the entire secondary side tube bundle fluid region and riser region is at an average fluid temperature and quality. This is a fairly good approximation for the long-term cooldown transient when only reactor decay heat is being removed by the steam generator heat transfer.

The steam generator upper and lower downcomer fluid volumes were combined into a sin_gle downcomer volume.

This nodalization will introduce* a slight error in the junction enthalpy at the bottom elevation of the downcomer whenever the water level drains out of the steam dome volume and the downcomer average enthalpy becomes two phase *.. This condition will allow the downcomer outlet junction enthalpy to be slightly higher than.it would be in reality. However.

this condition will only occur for a short time at the beginning of the transient before auxiliary feedwater refills the steam generator. Therefore.

the impact of this simplified nodalization will be minimal.

The single volume steam dome region with the separated volume option was retained from the original single loop model.

The steam separator process is modeled with the RETRAN bubble:rise model.

The long-term cooldown transient is initiated by an assumed loss of *all ac power which causes an immediate turbine trip.

Based on expected transient performance. the safety valve input model was changed from 3 groups of 8 combined valves each to only 3 groups of 2, 2 and 4 valves, as the relieving capacity of 8 valves was more than sufficient for this transient. The grouping of valves was based on actual plant valve setpoint from surveillance tests. The safety valve junctions were modeled so that the junction geometry input accounted for the length of steam line from the steam dome to the safety valve location. The safety valve junctions discharged to a time dependent

-volume with atmospheric pressure.

The safety valve junction areas were

.. adjusted to give the correct valve flow capacity under choked flow conditions.

The atmospheric dump valves were deleted from the model as it was assumed th~

dump valves would not function due to the loss of ac power.

The MSIV's were deleted from the model as unnecessary for this transient.

To allow for a

  • steady state initial condition, a main steam flow junction was maintained that

.. connected the steam generator dome volume with the time dependent turbine sink

. volume.

This.main steam junction contained a valve model that closed* *upon*

receiving a turbine trip signal.

In the long-~erm cooldown transient, the postulated controlled cooldown will be initiated by manually opening a steam path to the hogging air ejector and ~

its associated safety relief valve. Therefore, two new junctions with valves were added between the steam dome and the time dependent sink volume to model the hogging air ejector and safety relief valve steam flows.

The junction flow areas were adjusted to give the correct design flow capacities under choked flow conditions.

IC0985-0002A-NA02-NL02.

  • 1

=

3 Another new junction was connected to the steam generator dome volume to model the steam flow to the turbine drive of the auxiliary feedwater.pump.

This small steam flow was modeled as a pressure dependent negative fill junction with constant flow over the range of the *turbine inlet pressure controller.

During the later stages of the transient as steam generator pressure decreases below the pressure controller setpoint for the auxiliary feedwater turbine driver, _the steam flow will be increased as appropriate to maintain constant turbine speed and auxiliary feedwater pump speed.

The number of control data was reduced from 112 control blocks and 55 control inputs in the original single loop model to 36 control blocks and 22 control inputs in the new simplified single loop model.

FEEDWATER CONTROL SYSTEM A new controller was. incorporated into the model to control the initial main f eedwater flow as a time dependent flow that trips off on a steam generator low level trip and linearly ramps down to zero flow after the tr~p. The auxiliary f eedwater flow controller was modeled as a dual purpose control syst.em.

After main feedwater is tripped off, the auxiliary feedwater controller is switched on manually by an elapsed time trip. The auxiliary feedwater flow remains on until the steam generator water inventory returns to the normal.level.

The auxiliary feedwater flow is then manually turned off by an elapsed time trip. The second part ~f the auxiliary feedwater flow controller is then activated automatically. This part of the flow controller sums all the steam flows leaving the steam dome volume and integrates over time to obtain the total steam mass leaving the steam generator.

The controller then adds the appropriate amount of ~\\ll[iliary feedwater to maintain.

a water mass balance in the steam generators. This control action will simulate the long-term operator action of throttling auxiliary feedwater flow to maintain steam generator level and inventory.

The. plant indicated steam generator level calculation control blocks were

  • retained from the original single loop IDOdel with a slight modification in the
    • liquid level summation because of the new steam generator downcomer nodalization.

HPSI CONTROL SYSTEM The long-term cooldown transient was initially postulated to regain charging system capacity later in the transient. For the pupose of determing whether

.the-HPSI pump can be.considered redund.ant to *the charging pump, th*e charging flow controller was deleted and replaced with a HPSI flow controller. * 'l'he HPSI flow controller is activated by an elapsed time trip and is designed to siliiulate the long-term operator control of HPSI flow.

A function generator control block provides the pressure dependent flow.

A set of trip monitors control turning HPSI off and on to maintain normal pressurizer level. Only one of two HPSI pumps is assumed to be available for operation. This will still provide sufficient flow capacity to maintain control of primary side conditions.

IC0985-0002A-NA02-NL02

PAJ,rnMlES COOi.DOWN MODEL -

PRIMARY STDF.:

110

~*

~

\\.

390 Steam Leakage Path 123

  • -..1~~-

301

Charginr, Line Fir.URE 1 Letdown Line &

Liquid Leakage Path

~ '

  • I

I l'Al.1LlAIJlili t.;UUJ.JJUWH MUUJ!:L -

Ul!:t.;UhJJAIU

~HlJ.l~

Relief, Valves -

Driver Hog Ho Aux FW Pump Steam 1551 Turbine

~

,~~~~-t~+--1-.+--i--1---.

~e

',, ~-*---............-..----...----______....... _........._,_

\\.

-e

~

521 550

-1 FIGURE 2 555 Feedwater & Aux Feedwater Line VI

=

ATTACHMENT 7 Consumers Power Company Palisades Plant - Docket 50-255 EXEMPTION REQUEST SECTION III.G.2 AND III.G.3 OF APPENDIX R TO 10 CFR 50 CHARGING PUMPS P-55B AND P-55C FP0685-0001-NL04 Original Submittal - April 23, 1984 Revision 1 - July 16, 1984 Withdrawn - October 4, 1985 8 Pages

I

=

ATTACHMENT 7 EXEMPTION REQUEST

_C~G!NG PUMPS P-55B AND P-55C Approval Status NRC review in progress.

Equipment Under Consideration Charging Pumps P-55B, P-55C.

Safety Function(s) Of Equipment The charging pumps are used for reactivity control and inventory control.

Exemption Request a)

Section III.G.2 of Appendix R to 10 CFR 50 to the extent that the charging pumps and cables are required to be separated by twenty feet with no intervening combustibles.

b)

Section III.G.3 of Appendix R to 10 CFR 50 to the extent that the alternate power is required to be in fire area independent of the power supplies to charging pumps P-55A and P-55B.

c)

Section III.G.2 and III.G.3 of Appendix R to 10 CFR 50 to the extent that suppression and detection is required "in the area." *(Generic Letter 83-33, October 19, 1983 defines "in the area" to be "through-out the area".)

Necessary Plant Modifications Reroute power feeds to charging pumps P-55C and P-55B.

Seal penetrations into pipeway et al 602'0".

Add Suppression to rooms 104, 104A and 104B.

  • -Implementation Schedule For Modifications Power feed and seal penetration - Title 10 CFR 50.48 Section C.3 (before startup from the current refueling outage which began August 1983).

Suppression - Title 10 CFR 50.48 Section D.3 (before startup from the current refueling outage which began August 1983).

Justification For Exemption Request I. -

Room Under Consideration; Charging Pump Room (Charging Pump Room consists of rooms 104, 104A and 104B.)

a)

The room is approximately SO' x 12' x 18' of reinforced concrete and concrete block. The room is essentially cutoff from the rest of the plant by these walls.

FP0685-0100S-NL02

=

Exemption Request CHARGING PUMPS P-55B AND-P-55C-2 The reinforced concrete walls, floor and roof provide a barrier having a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire resistance.

Entrance into the room is through openings in the north and south walls.

Two 11 foot long corridors, running east and west along the rooms' north and south walls, open into the entrances.

The corridors contain negligible amounts-of combustibles. The corridor construction is also of reinforced

concrete, A fire from the 590' elevation of the auxiliary building is not postulated to spread into the charging pump room due to the lack of combustibles in the corridors and the fire travel distance.

The room is uncongested as it contains only the charging pumps.

The pumps are separated by 15 feet with no intervening combustibles or fire hazards.

In addition a poured concrete radiation wall is situated between each pump.

This wall effectively acts as a fire shield wall.

A curb has been installed in the opening between the P-55A and P-55B pumps to contain any oil that might leak from one of the pumps.

The curb will_ prevent an oil fire from spreading to the other pumps.

An oil fire is considered highly unlikely due to the small amounts of oil (23~ gallons in P-55A, 5~ gallons each in P-55B and C) and no sources of ignition, and the oil is totally enclosed in the pumps, from spreading to the other p1,UDps. The access around the shield walls does not provide a direct line of sight path between the pumps.

b)

Combustible loading is negligible consisting of only the pumps, motors, associated cabling in conduit and minor amounts of high flash point lube oils. Transient combustibles are negligible.

Personnel traffic into and through the room is light and infrequent.

The area is easily and readily available for fire fighting.

c)

A fire detection system is installed in the room.

An automatic sprinkler system is being installed in the room.

Portable fire e~tinguishers are available immediately outside of the room and in the surrounding areas. A fire hose station is available in the hallway outside of the room.

The detection and sprinkler systems -

provide independent alarms which are annunciated in the control room.

A fire brigade will respond immediately upon receiving the alarm.

d)

The power feeds for pumps P-55B and C are being rerouted so that

  • -they Will be separated -from each othe_r _by a wall within the charging pump room.

The power feed for P-55B pump Will enter the P-55B cubicle directly from the hallway.

The power feed for P-55C,pump Will enter the C cubicle directly from the hallway.

Within the pump room the power feeds will be separated by the shield wall.

FP0685-0100S-NL02

3 Exemption Request

- CHARGING-PUMPS -P-55B AND P~ssc e)

An alternate power feed for pumps P-55B and P-55C is routed in the 602' elevation pipeway until it enters the charging pump room.

The alternate is run entirely in conduit.

The alternate fe~d enters the P-55B cubicle and immediately crosses to the P-55C cubicle.

A manual switch box is located in the P-55C cubicle.

The switch transfers the alternate power feed to either Pump P-55B or Pump P-55C.

The 602' elevation pipeway is entirely devoid of combustibles.

f)

Consumers Powe.r Company believes that with the present cable routing and the modifications that are being made, one charging pump will always be available in the event of a fire anywhere on the 590' elevation.

g)

Please refer to the attached drawing, chart, and explanations.

There are several unprotected openings from the 590' elevation to the 602' elevation pipeway.

However, it is not considered credible for a fire to spread from 590' corridor to 602' pipeway.

Th~ paths from the 590' corri4or to the 602' pipeway are winding ones.

The fire must start in the corridor, travel through a door or doors, round corners and then travel up to the 602' elevation.

Once the fire leaves the corridor it will run out of combustibles.

When it reaches the opening to the pipeway there will be no combustibles.

The pipeway is entirely devoid of.combustibles so the fire cannot spread into it. Some heat and smoke may enter the pipeway but the volume and massive heat sink of the pipeway will not allow damage to the alternate power feed.

The charging pump room was evaluated and found acceptable by the NRC for access, egress and fire protection for the room and adjacent hallway.

Reference Palisades SER dated September 8, 1978, Section 4.12 and 5.8.

h)

The HVAC ducts in the charging pump room/corridor are constructed of heavy gauge steel. The ducts are used for return air only.

The ducts pull air from the charging pump room and exhaust it out of the auxiliary building.

Fire dampers will not be placed in these ducts where they pass through the walls because of minimal fire loading,_ and the automatic sprinklers will prevent any fire from damaging the duct work and because the ducts are exhaust only fire dampers will hinder the removal of smoke.

II.

Rooms Under Consideration:

Refer to table and figure which follow.

Justification: Refer to table and appropriate explanations.

FP0685-0100S-NL02

Fire PALISADES Charging Pumps Fire and Alternate Methods of Power Feed Refer to attached drawing and explanations Location

1.
2.
3.
4.
s.
6.
7.
8.
9.

Possible Fire Damage Available Charging Pump(s)

Power feeds for P-SSA, B and C charging Alternate power feed to P-55B and C pumps pumps Power feed for P-SSA and B charging pumps P-55C power feed Alternate power feed Power feeds for P-55A, B and C charging Alternate power feed to P-55B and C pumps pumps Power feed for P-55C charging pump P-55A and B power feed Alternate power feed for B P-55A pump and power feed P-55B and C pumps and power feeds Alternate power feed P-SSA power feed, P-55B pump, Alternate

  • P-55C pump and power feed p,ower feed P-55A power feed, P-55C pump, Alternate P-55B pump and power feed power feed P-55A, B and C power feeds Alternate power feed P-558 and C pumps P-55A power feed, P-55C motor, P-558 pump and power feed Alternate Power Feed FP0685-0100S-NL02
  • ~
  • I E~planatio41*
1.
2.
3.
4.
5.
6.
7.
9.

5 Exemption Request

_ ~HARGING PUMPS P-SSB AND P-SSC

- Explanatfons

1.

A fire in the 590' corridor outside the lC switchgear room may damage the power feeds to charging pumps P-SSA and P-SSB.

After a period of time the fire may breach the unrated, but substantial, doors into the spent fuel pool equipment room.

This is considered unlikely because the combustibles in the corridor are above the level of the door.

Other penetrations from the room to the corridor have been sealed. If the fire does extend into the room, the C pump power feed is assumed to be damaged.

2.

This leaves the alternate power feed to pumps P-55B and P-55C.

The alternate feed is run in the 602' pipeway in conduit. It exits the pipeway and enters the 590' radwaste exhaust fan room.

From there it enters the component cooling water pump room (CCW).

The doors from the CCW pump room to the corridor consist of two sets of back-to-back, double doors.

One set is watertight and always closed.

The. other set is of substantial steel construction.

A fire is not postulated to breach these doors.

The entrance to the radwaste exhaust fan room is an open walkway from the corridor.

The walkway is free of combustibles and of concrete construction.

A fire is not postulated to spread from the hallway into the walkway due to the lack of combustibles and distance.

A fire in front of the lC switchgear room would have to travel approximately 35' to the walkway and then another 30' without combustibles to the alternate power feed conduit.

Smoke will enter the walkway as will heat.

The alternate feed is in conduit and it is not considered credible to be damaged by such a fire.

The corridor is equipped with smoke detectors that alarm in the control room.

A five-man fire brigade will respond.

Fire extinguishers and hose stations are available to the area.

A fire in the 590' corridor outside the decontamination room and the

-walkway to the radwaste exhaust fan room may damage the power feeds to -

charging pumps P-55A and P-558.

The power feed to the C charging pump and the alternate power feed would not be damaged.

The alternate power feed would not be damaged for reasons found in Explanation 1.

The C pump power feed would not be damaged either.

The fire would have to -travel-approximately 35' and enter the spent fuel pool eq~ipment room.

This is considered unlikely because the combustibles are above the level of the door.

The door is a substantial steel door.

Another path from the fire to the P-55C power feed is through the decon-tamination room.

This is not considered credible. The doors are substantial steel doors and always closed.

The amount of cambustibles in the room are not great enough to spread a fire across the room and through the second set of doors.

The fire would go out in the decontam-ination room.

FP0685-0100S-NL02

~ ----- ---~ -

6

  • GHARGING.PUMPSP-55B AND P-55C
3.

A fire in the 590' corridor outside the south entrance to the charging pump room may damage the power feeds to the P-55A, P-55B and P-55C charging pumps.

The fire cannot spread into the charging pump room because there are no combustibles in the entrance corridor. "The fire cannot spread north along the corridor because there are no combustibles.

The fire can spread east down the corridor which may cause damage explained in 1 and 2 above.

The alternate power feed is separated from the corridor and a fire cannot extend into the pipeway.

An operator can enter the charging pump room using the north entrance.

Once inside, he can switch control to the alternate power feed.

The operator would wear self-contained breathing apparatus.

4.

A fire anywhere in this corridor would only damage the P-55C pump power feed.

In situ combustibles are negligible.

This means that the fire must be fed by transient combustibles.

Thus, the fire would be confined to the area of the combustibles.

The fire is not postulated to spread beyond the area of involvement.

5.

A fire in the P-55A charging pump cubicle would damage only the P-55A pump.

The detection system will alarm in the control room.

The auto-matic sprinkler will contain or extinguish the fire.

The shield wall will prevent damage to the P-55B pump.

The fire will not spread into the corridor. due to the lack of combustibles along the path.

6.

A fire in the P-55B charging pump cubicle would damage the P-55B pump, the P-55A pump power feed and the alternate power feed.

The detection system will alarm in the control room.. The automatic sprinkler system will contain or extinguish the fire.

The shield wall will prevent damage to the P-SSC pump.

The low amount of combustibles will limit the size of the fire.

-7.

A fire in the P-55C charging pump cubicle would damage the P-55C pump, the P-SSA pump power feed and the alternate power feed.

The detection system will alarm in the control room.

The automatic sprinkler system will contain or extinguish the fire.

The shield wall will prevent damage to the P-SSB pump.

The low amount of combustibles will limit the size of the fire.

8.
  • A fire in the cable spreading room will damage the power feeds to the P-55A, B and C charging pumps.

However, the alternate feed is totally separate and cutoff from the cable spreading room by minimum three-hour

  • -construction.
9.

A fire in the walkway between the P-SSB and P-55C charging pumps may damage the power feed to pump P-55A, the alternate feed to P-55B'and possibly the motor on P-55C.

The normal power feed to P-55B and the motor and pump itself would not be damaged.

FP0685-0100S-NL02

~Exemption Request CHARGING -PUMPS -p.;..SSB-AND P-55C -

7 A fire at this location would be a transient combustible fire.

There are no in-situ combustibles at this location.

A fire would be highly unlikely because this location is in the walkway.

Transient *combustibles would not accumulate because they would block the walkway; causing them to be removed immediately.

There are no sources of ignition in the area.

Personnel traffic is very light during operation due to radiation levels in the room.

The detection system will detect the fire quickly and alarm in the control room.

The automatic sprinkler system will contain or extinguish the fire.

The low amount of combustibles will limit the size of the fire.

The P-SSB pump is approximately 4 feet from the fire location. The motor is farther away.

The pump itself is of massive steel and iron construction.

Steel and iron begin to weaken at 1100°F. However, the pump is filled with water which is flowing and taking heat away.

The motor is also made of a large mass of steel and iron.

The sprinkler system will provide cooling to the motor and pump.

The fire would have to be unrealistically large to create enough heat to damage the pump or motor.

In addition, the room itself* is a massive.heat sink.

The power feed to the P-SSB_pump is in conduit.

The power feed is routed in an area away from the fire location~ The conduit will provide protection to the cable.

In addition, the sprinkler system will provide cooling to the conduit.

A fire brigade will respond immediately upon receiving the detection or sprinkler alarm in the control room.

Fire hoses and extinguishers are readily available outside the room.

Therefore, the P-SSB pump remains undamaged should a fire occur in the walkway between the P-SSB and P-SSC pumps *.

FP0685-0100S-NL02

c I

"~'L.

  • __;-.!'F!i=AJJllwllwllwUwUu.iOu.illu.Uu.UuU'tf &..1 _.;.1.'M.....,!l._.l..,l...,ll.,.l-,1,*

I ti tl.

~

i li.

(-;;(,

It

~~!

.. ~::.~.................,.

Q)::f!t::~,:.'.J~-,. -----....

Q>:-:::=r:~~.=.~ :=.:!'"'/

I I

................ ~

c.........,....,.~....,

IQDl'"l*I tOUfoOll

"~"" 1trc PLAN o*

~L,'JO-. If

.~*11 _,,

.. :*,.,:_ **:tfl:.:;,~ !&i

,.~~,,.,

i:;_:'-!-J-.~..L..~_,..--:~-:-1 L-------+---------------*------,----~---:--'----r-----::;:;i

"* i'

=

ATTACHMENT 14 Consumers Powe.r Company Palisades Plant - Docket 50-255 EXEMPTION REQUEST - SECTION III.G.2 OF APPENDIX R TO 10 CFR 50 INSTRUMENT SEPARATION INSIDE CONTAINMENT FP0685-0001-NL04 Original Submittal - July 16, 1984 Revision 1 - December 28, 1984 Revision 2 - October 4, 1985 3 Pages

ATTACHMENT 14 EXEMPTION REQUEST - SECTION III G.2 OF APPENDIX R TO 10 CFR 50 INSTRUMENT SEPARATION INSIDE CONTAINMENT Approval Status NRC review in progress.

Equipment Under Consideration Steam Generator "A" Pressure (PT-0751 A, B, C and D); Steam Generator "B" Pressure (PT-0752 A, B, C and D);

Steam Generator "A" Level (LT-0751 A, B, C, and D; LT-0757 A and B; LT-701; LT-702) Steam Generator "B"-*Level (LT-0752 A, B, C, and D; LT-0758 A and B;

  • LT-703; LT-704) Pressurizer Level (LT-0101 A, B; LT-0102 A, B, C and D; LT-0103; LT-0105);

Pressurizer Pressure (PT-0101 A, B; PT-0102 A,B,C & D, PT-104 A and B; PT-105 A and B)

(Reference Drawings:

E-350, E-382 detail C).

Safety Funct~on(s) Of Equipmen~

Process monitoring for steam generator and pressurizer.

Exemption Request III.G.2.d of Appendix R to 10 CFR 50 to the extent that redundant instrumen-tation is required to be separated by a minimum of 20 feet.

Necessary Plant Modification None

The room is oddly shaped with a 13~ foot high ceiling extending up to 34-feet *in the area of the staircase. Total volume is approximately 14,420 cubic feet. The walls, floor and ceiling are constructed of poured, reinforced concrete. The room is on the 590' elevation of containment.

The northeast corner contains a metal staircase which goes up only.

There

  • are two unrated*, bq.t substantial, steel doors in the room that lead to other areas of containment. The *room is well ventilated by natural circulation supplemented by forced circulation (i.e. HVAC).

Th~ room's ~on~tri:iction provides. a massive beat sink that would absorb the heat from a fire. The ventilation would dissipate the beat quickly.

The instruments of concern are located on the east* wall opposite the 480V pressurizer heater load centers. The instruments*are listed above.

Equipment locations are shown in the attached drawing (E-382 detail C).

FP0685-0100P-NL02

Attachment l4 Exemption Request

  • B.

The instruments have steel or aluminum cases and all wiring to them is run in conduit.from cable trays.

The casings and conduit effectively act as a radiant energy shield. The case is a hollow steel or aluminum shell which covers, but does not directly touch, the sensing device.

A radiant energy shield is a noncombustible material which blocks.the path of radiant energy from the fire to the instrument of concern.

The cases are made of steel or aluminum and conduit are made of steel and thus noncombustible.

the cases and conduit surround the instruments and cable thus blocking radiant energy from reaching them.

The instruments are LOCA qualified. This qualfication provides added assurance that the instruments can operate under harsh environmental conditions (e.g. high temperature, high humidity).

C.

This room is in containment. Access is severely limited. During operation, personnel entering containment they wear full Anti-C's and Self Contained Breathing Apparatus.

They dress and undress outside of containment.

There* are no "step-off" pads and no discarded Anti-C's inside of containment during operation.

Everything is stored or discarded outside of containment when the plant is operating.

Smoking is strictly prohibited in containment during plant operation by Administrative Procedures 7.03. *in fact, it is impossible because of the self contained breathing apparat~s worn by personnel.

Flammable liquids are. not brought into cont~inment during operation because they a*re not needed for anything.

D.

Combustible loading in this room is light, consisting of small amounts of cable in trays.

The trays and cables are located above the instruments.

There are no combustibles at the* floor level. Heat.and smoke from an in-situ fire would be above the instruments. There are no transient sources of ignition.

-E. Strict administrative controls dictate that all loose material be removed from containment prior to startup to prevent containment sump plugging and transient fires. Administrative Procedure Number 4.04, Revision 0, "Plant Housekeeping" states "Prior to.startup following any significant mainten~

ance work, the containment building shall be given a thorough inspection for any unnecessary debris which could wash into the containment sump and plug the recirculation path during post-LOCA conditions. Particular attention should be given to the 590' level. In.addition, material which could pose ~ fire threat s.hall be Temoved."

  • Two.other procedures also assure*tbat* there are no.transient_~om~u~ti~~~~

in containment.

They are:

l. Operations Checklist 1.3 Revision 4, "250 Pound Heat-Up Checklist, Containment Building" states "Complete a walk through of the contain-ment building to ensure that transient combustibles and/or flammable materials have been removed."

FP0685-0100P-NL02 2

l r -* 4 Exemption Request

2.

Fire Protection Implementing Procedure Number 7 Revision 3 "Fire Prevention Activities" states "Combustible materials shall be removed as soon as possible after use to keep the amount of combustibles as low as possible." It also states "The person responsible for the work activity in a safety related area shall assure the removal of all waste, debris, scrap, rags, oil spills or other combustibles resulting from the work activi~y, or at the end of each work shift, whichever is sooner." Since the containment building is a safety related area, the procedure applies to work activities in the containment building.

Thus, three procedures assure that there are no transient combustibles in

~he air room during operation.

There are no sources of ignition in the air room.

Therefore, a transient combustible fire is virtually impossible in the air room.

F.

Smoke detectors are installed in the room and alarm automatically in the control room.

A fire hose is readily available to the room.

Portable fire extinguishers are also readily available. The fire brigade will respond immediately upon receipt of the alarm.

G.

Consumers Power Company concludes, based on the reasons above, that a transient fire in the air room will not occur and both the present arrangement and the planned after EEQ modification arrangement of the instruments in the containment air.room is adequate and that an exemption from the requirements of Appendix R, section III.G.,should be granted.

FP0685-0100P-NL02 3

Retrieved from "https://kanterella.com/w/index.php?title=ML18052A368&oldid=5022959"