ML18046A918

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Forwards SEP Review of Station Svc & Cooling Water Sys, Topic IX-3, Final Evaluation
ML18046A918
Person / Time
Site: Palisades 
Issue date: 09/06/1981
From: Crutchfield D
Office of Nuclear Reactor Regulation
To: Hoffman D
CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
References
TASK-09-03, TASK-9-3, TASK-RR LSO5-81-09-019, LSO5-81-9-19, NUDOCS 8109140196
Download: ML18046A918 (26)
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September 6, 1981 A-'

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Docket No. 50-255 LS05 09-019 Mr. David P. Hoffman Nuclear Licensing Administrator Consumers Power Company 1945 W Parnall Road Jackson, Michigan 49201

Dear Mr. Hoffman:

SUBJECT:

SEP TOPIC IX-3, STATIOH SERVICE AND COOLING WATER SYSTEMS PALISADES

_E.n~lo~e9 is ti cppy of Ot.ff finii.1 ev~luil~ion of Sys1;em<itic Evaluati~n Program Topic IX-3, Station Service and Cooririg Water Systems.

This assessment compares your faci 1 ity as described in Docket No. 50-255 with the criteria currently used by the regulatory staff for licensing new fac11 ities. Your comments ()n our draft evaluation have been incorporated as we deemed appropriate. Our comments regarding your submittal are as follow*s:

1)

Table I, which was inadvertently left out of the draft evaluation, has ~en included in this report.

2,3) The containment heat load of_ 229E6 Btu/hr is based on the FS~R Section 14.11 ~sing vapor and liquid energy as an upper envelope.

Based on information in a more recent containment analysis (SEP Topic Evalua-tions VI~z.o and VI-3) this heat load figure is correct as an approximation.

With the assumed failure of Emergency Diesel Generator 1-~, the Palisades system has been found capable of removing this heat load provided that service water flow to the three inoperable conta1.nment a1r coolers is terminated.

Your.calculation of service water flow requirements assumed that flow to the inoperable air coolers had been cut off. As mentioned 1n our draft evaluation no plant operating proced~res exfst to ensure the. isolation of the inoperable air coolers, diesel generator, and engineered safeguards air coolers from the_.se.r_vJc.e_J~~t~r system. Addition of the proper operator actions to plant procedures_ wil ens~re sufficient heat removal capacity in a ~~~Jj-post-accident situation.

~/;

... *~

4)

The containment spray heat load is defined on page thirteen of our S *{I draft evaluation as the post-acc.ident heat load (229E6 Btu/hr) mi-nus.

tJ f.A) the design heat removal capacity of one containment air cooler (76.7E6 P..~pt/(,,.,

1

.. J}J:_l!/~r).

Th.e resultant containment spray heat load is:152E6 Btu/hr.

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NRC.FORM31B(1o~sorNRc~rn24d OFFICIAL "RECORD COPY USGPO: 1981-335-960

    • 5)

The 170 F value for SW temperature is based on staff analysis performed with information obtained from the FSAR. Unless you demonstrate by analysis that our conclusion is too conservative we have no basis to modify it.

i

6)

The loading of two service water pumps on emergency diesel generator 1-2 is confirmed.

7)

Upon failure of Emergency Diesel Generator 1-2,service water flow to the 3 inoperable air coolers must be diverted to the component cooling water heat exchangers to prevent exceeding CCW design temperatures.

Documentation of proper operator procedure to isolate the inoperable air coolers from the Service Water System (if not accomplished auto-mat1cally) 1s required.

This evaluation will be a basic input to the integrated safety assessment for your facility. This topic assessment may be changed 1n the future if your.

facility design is changed or if NRC criteria relating to this topic are modified before the integrated assessment is completed.

Enclosure:

As stated cc w/enclosure:

See next page Sincerely, Dennis*M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing

  • See previous yellow for additional concurrences.

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The 170°F ~vafve *for SW temperature is based on staff analysis performed with information obtained from the FSAR. Unless you demonstrate by analysis that our conclusion is to conservative we have no basis to modify it.

  • 6)

The loading of two service water pumps on emergency diesel generator 1-2 1s confirmed.

  • 7)

Upon failure of Emergency Diesel Generator 1-2 service water flow to the 3 inoperable air coolers must be diverted to the component cooling water heat exchangers to prevent exceeding CCW design temperatures.

Documentation of proper operator procedure to isolate the inoperable air coolers from the Service Water System (if not accomplished auto-matically) is required.

This evaluation will be a basic input to the integrated safety assessment for your facility. This topic assessment may be changed in the future if your facility design is changed or if NRC criteria relating to this topic are modified before the integrated assessment is completed.

Enclosure:

As stated.

cc w/enclosure:

See next page Sincerely, Dennis M. Crutchf1eld, Chief Operating Reactors Branch No. 5 Dfvfsion of Licensing OFFICE. *****~-~-~~*=**.... ***~~:*%*~-~ f-1!(-***** "rw~~~:~~~~-=.. ~D~~-~:~-~-~-~*l*~* *****~*~l*~~-~~-~*-*

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\\i~~.R9.~o,R~.~18 (1<>-80) NRCM0240 OFFICIAL RECORD.COPY USGPO: 1981--331>-960

\\

Mr. David P. Hoffman cc M. I. Miller, Esquire.

Isham, Lincoln & Beale

  • Suite 4200 One First National Plaza Chicago, Illinois *60670 Mr. Paul A. P~rry, Secretary Consumers Power Company
  • Judd L. Bacon, Esquire

. Consumers Power Company 212 West Michigan Avenue*

Jackson, Michigan 49201 Myron M. *Cherry, Esquire Suite 4501

,One I BM-Plaza* ~ * -

Chicago,.lllinois 60611 Ms. Mary P. Sinclair Great.Lakes Energy Alliance 5711 Summerset Drive Midland, Michigan 48640*

Kalamazo*o* Public Library 315 South Rose.Street Kalamazoo, Michigan 49006.

Townsh.ip Super~iSor Covert Township Route l, Box 10 Van Buren County, Michigan 49043

-Office of the Governor (2)

Room 1 - Capitol Building. *

. Lansing, Michigan 48913 William J. Scanlon, Esquire 2034 Pauline Boulevard

  • . Ahn Arbor, *Michigan 48103
  • Palisades Plant ATTN:

Mr. Robert Montross Plant Manager Covert, Michigan 49043 PALISADES Docket No. 50-25*5 U. S. Environm~ntal Protection

. Agency Federal Activities Branch Region V Office ATTN:

EIS COORDINATOR

  • 230 South Dearborn Street Chicago, Illinois* 60604 Charles Bechhoefe~, Esq., Chairma~

Atomic Safety and Licensing Board.*

Panel U. S. Nuclear *Regulatory Commission

20555 Dr. George C. Anderson Department of Oceanography University *of Washington

. Seattle, Washington*. 98195 4~

Dr~ M. Stanley *uvingston 1005 Calle Largo

.. Santa Fe, New Mexico 87501 Resident Inspector c/o u~ s. NRC Palisades Plant Route 2, P~ o. Box 155 Covert~ Michigan 49043

- ~. -~:*

STATION SERVICE AND COOL1N5

~!ATER SYSTEMS TOPIC 1x..:3 FOR THE PALISADES NUCLEAR PLANT y

I.

rnr::ooucno:~

The safety objective of Topic IX-3 is to 2ssure that the cooling *water*

systems have the c2pability, with adequate margin, to meet design objec-tiv~s and, in particular, to assure that:

a.

systems are provided with adequ~te physical separation such that thei*e are no 2dverse intc::ractions am::rng those syste:;is under any mode of operation;.

b.

sufficient cooling 1*1ater inventory h~s been provided or H.c.t adequate provisions for makeup are available;.

c.

tank overflow cannot be released to the enviro~ment without m::rnitcrir.g and"-~r:_1e~s the *1eve~ of radioac~iy_i~J:'. is within

.a~ceptable*limits;

d.

vital equipment necessary for achieving a controlled and safe sh"utdown is not flooded due to the failure of the main condenser circulating water syste~.

II.

REVIEW CRITERIA

,\\

The curr~nt criteria.and guidelines used to determine if the plant systems meet the topic safety objectives 2re those prov~.:'ed in Standard Revie1v Plcn (SRP) Sections 9.2. l, 11 Sta*~ion Service l*!ater System, and 9.2.2 "Reactor Auxiliary Cooling h'c.ter Systems".

III.

RELATED SAFETY TOPICS AND INTERFACES The scope of r~view for this topic was limited to avoid duplication

.of effort since some aspects of the review were performed under relite~

topics.

The related topics and the subject matter are identified below.

Each of the related topic reportsc6ntains the acceptance criteria and

- 2

  • 1 review g~idance for its subject matter.

11-2.A ~ Severe ~eather PhenoGena 11-3.B.1 - Flooding of Equipment 111-3.B -

Floodi~g of Equi~~Ent (Failure of Underdrain Syste~) _

Vl-7.D - Flocding of Equip~ent (Leng Ter~ Passive Failures)

I!I-3.C - Inservice Inspection of Water Control Structures III-4.C I n t e rn a l l y Ge n e r a t e d l*i i s s i l es * -

JJI Mass and Energy Releases (High Energy Line Break)

\\'I-2.D - t*:::ss and Energy Releases*.::.

III Se.~smic_.Qualification III _Envifonmental Qualification VI-7.C.l - Independence of Onsite Power VII Systess ke~~ired for Safe Shutdown VIII Dies::l Generators IX-1 Fuel Storage

."\\"*

IX-6 Fir~ Protecti6n The fo1101-:ing topics c;.re dependent on the present to;::i~c inforii1=.tion for*

comp let i*on:

VI Contain~ent Pressure and Cqabi 1 i ty IX Ventilation Systems XV-7 Reactor Coolant Pump Rotor Seizure' IV~

REVIEW GUIDELINES Jn addition to the guidelines of SRP Secti*ons 9.2.l and 9.2.2, in deter-mining \\*;hich systems to evaluate under this topic the stiff used the cefinition of 11syster::s ir:)ortant b. safety" pro\\1iced in Reference l.

The definition states syste~s i~~ortant to stfety are those necesstry to v

/

ensui*e (1) the integrity of the reactor coolant pressure boundary*, (2)

. t the capability to shutdown the reactor and maintain it in a safe cbndi-tion; 01* (3) the capability to prevent, or mitigate the consc:quences of,'

accidents that could result in potential offsite exposures comparable*

to the*guidelines of 10 CFR Part 100, "Reactor Site Criteria".

This definition was used to determine which systems or portions of systems

.\\*.'ere "essential".

Systems or portions of systerr:s 1*:hich perform functions important to safety were consider~d to be.essential.

It should be noted that this topic 1.,ii 11 be updated if future SEP re vi ev,rs identify additional cooling h'ater systems that are important to safety.

V.

EV.ll.LUATION The systems reviev,red under this topic are* the Rea:ctor Primary Sh.ield Coolirig System,.Charging P~mp Seal.Lub~ication System, Component Cooling Water System, and th~ Service Water System.. The Spent Fuel Pool Cooling System is discussed in the SEP revieh' of Topic IX-.l... "Fuel Storage.".

v. I.

REACTOR PRJ!.'ARY SHI ELD cooCrnG SYSTEM..

. ~. '

The Reactor Primary Shield Cooling System *(RPSCS) is a closed loop system with tl-:o full-capacity sets of shield cool.ir:ig co1ls, t1*:0 full-

  • capacity pumps~ a heat exchanger and *a surge tank (Reference 2, Section

. 9.2).

The system, 1*:hich is located.inside co_ntainiTi~nt, transfer_s heat from the shield wall to the Compbnent Cooling ~ater System.

  • Reactor Coola.nt Pressure Boundary is defined in 10 CFR Part 50 §S0.2(v).
  • ~*.
  • The design function of the RPSCS is to limit thermal stresses in the concrete shield wall surrounding the r~2ctor vessel.

Thermal stresses are the result of convective and radiative heat losses from the primary cool ant sys tern and heat senerated in the \\*:all i ts*e1 f from the absorption of g::mma and neutron i*adiation.

Pal is a des technical specif.ication 3.15 requires one RPSCS pump and cooling coil to be in O?eration whenever cooling is ~equired to keep the shield temperature_below appioximately l65°F.

The basis for this specificction states that the RPSCS function prevents \\*:eakening of the shield wall through less of moisture.

V.II.

CHARGING PUMP SEAL LUBRICATION SYSTEM

  • **
  • Pa 1 i sades' has t\\*fci constant speea*-*and *one vad ab 1 e speea -e:hargi ng*;pump.
  • The variable speed drive requires 26 gpm.
  • Each. pump package requires
  • 5 gpm.

(The total cooling requirement for the variable spe~d pump is 31 gpm.)

.. The constant speed charging pumps can be operated i l!~~rinittently without.

cooling flO\\.,r.

Normally cooling floh' is provided by the component cooling

  • _ water -sys tern..

V. II I.

COMPON EtH.. COO LI l~G \\*I AT ER SY ST EM The Component Cooling \\*later System (CCI./) 'is described. in Sectio.n 3.2 of the SEP-Review of Safe Shutdown Systems for the Pal~~ades.Plant (Referen~e 3r.. The system removes heat from various components* and transfers thi~

heat to the Service \\*.'ater System.

The components cooled by the CCW

  • system are:
1.

Reactor Primary.Shield Cooli_ng Heat Exchanger

2.

Chemical and Volume Control System (CVCS) Letdown He~~ Exchanger

3.

CVCS Charging Pumps

4.

Shut.:foi*m Cooling Sys tern Heat Exchangers

  • .-'- ** ~__

_J

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e. *
5.

Emergency Core O:~Hr-.g Syste:m High Pressure Safety Injection,

.. LOI*/ Pressure Safety Injection and Containment Spray Pumps (primary cooling system, Servite Water System is the bac~up cooling syst~m) 6.. Spent Fuel Pool Heat Exchangers

7.

Control Rod Drive Motors

8.

Primary Coolant Pumps

9.

Primary Sample Cooler

10. Vacuum Degas Seal Water Cool~r
11. Waste Gas Compressors
12. Radwaste Evaporators
  • During normal operation., one (of three) pum;:>s and one (of t\\'l'o) CCW heat exchangers can accor.odate heat removal reouirements.

Pum;:>s 'A and C are I

pm*/ered by 2.4kV bus *i'c;. pump B by 2.4kV bus 10.

When the Shutdown

  • Cooling System is placed in operation during a pl~nt cool down, two pumps

_and both f-*eat exchangers are nonr.ally used;_ hOl*:ever,,Jf one heat exchan~er were inoperable, the cooldown could continue but.at a slower rate.

The staff revie1-,1ed the heat rerroval require;-;-,2n~s of the CCI-! sys.tern during post-accident conditions.

The accidents considered were the Loss of Cool~nt*

Accident (LOCA) and the-~ain Ste~m Line Break (MSLS)**Inside Containment because these tl-:o events result in the greatest potential a*ci:ident heat' loads on the CC\\./ system.

The c'ontainmenf air toolers are also discussed..

here because they complement the CC\\.! system in the post-accident contain..:.

ment heat removal function.

. *~..

- 6 Section 14.18 of Reference 2 provides an analysi~ of the containment response to a LOCA.

Some part of the energy released to containment fo 11 o:-:i ng a LOCA must be rerroved to prevent exceeding the design pressure*

l ir.-1it of the containfi'lent.

Energy is rer:i::>ved by the containment spray (CS) system and the containment air coolers.

The containment spray system and*

  • the air coolers are fully redundant methods of containment heat removal.

The air coolers transfer heat from the containment atm0sphere to the service

~ater system (SWS).

The CS system removes heat from the containment atmosphere by spraying cool water*directly into the atmosphere.

T~is water, now heated, collects in the containment sump.

The heat is then

  • . *tran~fe~red ~o the CC~ syst~m throvgh the Shutdown Cooling Sy~tem (SCS) heat exchangers when the 5~ray system is aligned to remove water f~om

. the containment sump d~ring the recirculation mode*of ECCS operat{on.

The CS system ?low is piped to containment via the SCS heat exchangers (Se~

Chapter 6 of Reference 2).

The minimum combination.Af containment heat rem::>val systems occurs as a result of the assumed 16~'s of o"ffsite power

  • and the single failure of one of the two dies~l generators..

U~ing the design parameters of the CS, CCW, and SWS from Referenre 2, shown in Table l, and the containment analysis presented in Sett ion 14. 18 of Reference 2*,

the he2 t 1 oad v:hi ch must be rer.mved from containment ( 229E6 BTU/hr) can Je ac:co::1i1odated by the Cm and S\\*1$ given the assu1;1a'd failure of either diesel. generitor.. However, to accomodate the heat load when diesel generator 1-2 is assumed inoperable operator action i~ requi~ed to redfrect.Sl*!S... flow from the inoperable containment air coolers, diesel ~eneratot.,

  • The SEP will reevaluate the post~accident enerov balance in containment undc:r Toptc VI-2.D, "t*:ass and Energy Release for Postulated Pipe Breaks Inside Containment 11

.e and engineered safeguards air c.oolers heat exchangers.

If operator actfon is not taken, the design temperature of the CCW system (140°F) will be exceeded.

The required operator actions for this scenario are not presently contained in plant operating procedures.

Thus, although the SWS and CCW system have sufficient heat removal capacity for post-accident conditions and assumed single failures, operator action will be required to cope with the postulated single failure of die$el generator 1-2.

For the MSLB *inside containment event, the amount of energy added to the containment should be 3.4E6 BTU less than that added for the post-LOCA

  • case.. (Ongo1ng SEPrevie1vs~v:ill ye'l"ify that ttfe assunptfons used to

~.

  • determine the magnitude of energy addi.tion to the containment are acceptable.) Because s*afety injection flov.' v:ould not be avaiiable a~ a heat sink inside containm~nt following a ~SLB, the containment.

sump \\voul d be.filled by condensed fluid from the f!.SLS and CS water; and a higher sump'fluid tem~erature 0ould b~ achieved earlier in the accident than for the post-LOCA case.

This would not affect the heat load on the CCI-! system ho1*,1ever; be_cause if in the unl i-kely event that recirculation.

of the containment sump *fluid \\\\'ere necessar.Y, it i*:ould not be init1ated until much later into the !*~SLB accident sequence h'hen. containment sump level would be approxim~tely equivalent to the lev~l when recirculation would'be initiated following a LOC~. (Sump recirculatioh occurs al.itomit{ca]lj on a low level in the Safety Injection and Refueling Hater Storage Tank which supplies* water to the CS and s~fety irijection pumpsJ Given the similar heat release to containment following a MSLB and approximately

\\

v ti equal SL.'llij) levels at the start of recirculetion f?llo*.. dng both the

~SLB and LOCA, the heat load on the CCW system is expected to be no gre2ter than the heat load following a LOCA.

During normal and post accident operation, the CCW system is capable of being po1*:ered from both onsite and offsite electrical sources.

During no~mal CC~ system oper~tion, single failures could prevent flow to (1) the services inside containment (Letd01*:n heat exchanger, Primary Coo1ant Punip (RCP) c~.l coolers, Reactor Prir.,::ry Shield Cooling System and Control Rod Driv*e Motor Seals), (2) the spent *fuel pool cooling CCW

. header (spent.fuel pool, rafilh*aste ev~porators, pri.~~ry s_ampJ.e. cooler, c w~it~ ~as compr~sso;s a~~ ~acu~m-degas p~mp), ~nd (3) one CCW heat exchanger.

Loss of flow to containment.services and the spent fuel pool cooling header does n*ot present an immediate concern; hov,rever, the control room operator must take*,*,act ion to prevent equi p~1ent.q.~iilage from hi ~h tempera tu res.

  • The pl ant emergency procedure for 1 os~**of COJ i denti fies the conditions requiring timeiy plant shutdov:n.

The limiting.components are PCPs and CRDMs; loss of the spent fuel po61 cooJing header does not require operator action for a few hours.

The extended loss.of cooling to a running PCP may result. in pump shaft seizure bec.c.use of overheated

  • bearings~

(The consequences of a postulated PCP seizure are evaluated

~s an SEP Design Basi~ tveni.)

The licensee has provided information

~

(Reference 4) regarding.the loss of CCI~ to the PCPs.

Loss of CCH flo~i to and high CC*J temperature 'from a PCP are conditions alariiled in the control room.

Following the receipt of either of these alarms, the operator has 10 minutes to restore CCW flciw to the pumps before the.

9 *-

pum?S mJst 6e *stopped. * ~pproximately the same amount of time is available

. to restore fl Oh' to the CRD:*ls prior to taking action to deenergize them (and thus tripping the reactor).

By procedure, the operator is directed

-.to trip the reactor and turbine generator if PCP seal teraperature exceeds l70°F, PCP bearing tempErature exceeds 1750f, or if all (or most) CROM seal lec.kage ter:-;;:ieratures exceed 200°F.

Plant shutd01*m fo11mdng reactor trip is in accordance with established emergency procedures.*

The.ren:>tely operat~d valves in the CCW system are afr-operated: 'Upon a*

p6stula~ed failure of the air supply, the valves fail in the appropriate positions to supply CCW flow to. all loads except the spent tuel cooling.

  • .system and the.rad\\*:aste evaporators.. to v:hich flow is *se-cu.red.

During 'post-accident operation of th.e CW *system, floi-J to the containment services and spent fuel pool cooling supply is secure~, and f~6w is started.

to the ECCS pur.ps. *This is accomplished autcrratical,ly upon receipt of a.-

safety injection. signal.

S1ngle failures could result in no flow to the ECCS pumps or failure to secure flow td the spent fuel pooi cooling ~ysiem.

1 The first *of these fail:.:res is overcor.1e by shifting Eccs* pump coolin'g *

  • tci the backup s~pply - the SWS.

This can be performed from the control room by the operator v:ho is \\*,;arn~d of this condhi on. by low ECCS.pump cooling flow alarm.

Failure to secure CC\\"' flow to,'the spent fuel pool would n~t result in overloading the C~W syste~ because, with twd CCW :*

pumps operating, the CCW has enough heat removal capaci~y at the start

  • of CS recirculation to cope with the post~accident loads and the spent fuel pool.

' \\. ~-*

y

- 10

!so1.:.tic;1 of indivict:::l lee.king CCh' co::-:;::::inents is c:cco;;-,plished by r::rnual val~es.

Also, although the purn?S and h~at exchangers are redundant, they a1*e connected by 'single pipe hec.cers 1*:h~se fe:ilure could disable the system.* This ~as considered in the FOL r~vi~w of Palisades, and the staff concluded thc.t iri a post-Loe,; sc~r,=.rio, the Sc.fety Injection (SI) p~~~s could co~t~nue to recirculate spilled re~ctor coolant with d2cc.y heat befr1g re/i1oved* by the_cont9iri;;-2nt c.ir coolers (Reference 5).

lf th~ CCW failu~e occurred during a cocldo~n of the plant, with the reactor vessel head installed, the plant would return to hot shutdown and decay heat could b~ removed via th~ stea~ generator~ as des~ribed in Reference.3.

The plc:nt rnu.ld rerr:ain in h'ot shut"dO\\*.'!l \\':hile CC\\*! repairs

\\*:ere Tiled e.

For.decay heat re~oval ~hen the r~actor vessel he2d is removed, adequ~te cooling can be provided by keeping the core flooded using various sysie~s s:.i"ch as *scs c.rd eves and t1*2nsfefring the heat to the fuel pool \\*.'hile repairs are r.:ade to the cc: piping. *Therefore,.c.ithough the,.CO! systein 1*:ould be disabled by a ripe rupture, the Pc:lis~c2s p1=.nt has c:cceptc.ble *2lternate

J h

I h

1 h

I I

  • t t

rr:eans to re::-,ove core L:ecc.y.eat rnr s.ot r.0r;:,a s.. utco\\*tl c.na pos1..~c.cc10en*

long-term cooling.

Du.ring norm~l 2nd post accident cperation, therr.:al expansion and contraC,-

. tion of the CC\\.-! systefil 1 iquid is ac.co:n:idated by

~he CW. surge tc.nk*, and 1 eakage into or out of the system cc.n be detected by surge tank level changes.

High 2nd low surge tank levels are alarmed in the control room,

  • The p1p1ng is iS.

The leak rate cc.lculcte::l in acccrdcr;:e h'ith F:eference 6 for a 24" ~i;:ie at 110 psig is SSS 9~*0.

~.is 1*
:::JUid ri::St.:lt in the loss f

.LI.,

  • t
  • .L *

..L

  • L...

I

.J,.. 1

--I">

0 c'.-

0 we pcr::;J ne pos11..1'.'2 suci..ion 1.e::o appr:;>,11:,.: 1.E '::'.:.:J sec n -~.

. i

- 11 and a radiation monitor and alarra alerts the control room operator to the leakage ~f.rad{oactive fluid into the CCW_system from components which contain reactor coolant.

The surge tank also maintains a pdsitive suction head on the CCW pu~ps during norm31 and post accident operation.

Since en: system pressures and teP:;:>eratures for pos't accident operation are similaf to those for normal operation, no reduction of net positive suction head below that normally present is ~xpected for post accident conditions.

. **The safety "r*elated* furictio.ns of the CCW system identif_ied* in this review.

. are' to pro vi de cooling for: the scs heat exchan'gers (for post-:-accident and plant cooldown operatio~s), CVCS charging pumps, fCC~ pump *cooling (post-a~cident), the CROM seals, the PCPs, and the RPSCS.

Cooling of the letdown heat exchanger is not required because letdown is.not needed to achieve boration-for plant cooldown, arid sR~nt fuel pool

. cooling can be accomplished by other syste:;is (see SEP Topic. I~-1, "Fuel.*

Storage). Of these functions, only the cboling of the SCS heat exchangers (for plant C001ld01*1n) and eVCS charging P.Ur:i~ cooling (for. reactor:system

  • m2keup and boration) are considered essential.

The. other safety related functions can be performed by other sys terns; or operating procedures provide.adequat~ protection from the ~ffects of losing th~ function~:

It should be noted that, although the CCW functions for ~hutdown codling and eves charging pump cooling are.considered essential, loss of these functions can be tolerated for extended periods of time bec~use (1) as detailed above, upon loss of shutdoh'n cooling alternate means of removing :core

. \\

(,.

12 -

decay heat are availab~ and (2) the two constant.speed charging pumps can be operated intermittently with no CCW cooling flow.

So, these functions are more ~orrectly ccnsfdered to be essential only when they are required to be performed-to achieve plant cold shutdown conditions within a certain peri_od of time as requirc:d by Branch Technical Position RSB 3-1 1*.'hich is the basis for the SEP Safe Shutdo1*m Revie1-1 of Palisades (Reference 3).

  • V.IV.

SERVICE WATER SYSTEM The Service Water System (SWS).circulates cooling water from Lake _Michigan to various critical and noncritical heat loads.thr9ughout the plant. The ---

"1

  • ~

J s,ystem has three half--capacity pumps, two of h'hich are po*,*1er::d by 2.4 kV bus 10. - The rem3ining pump is powered from.2.4 kV bus. lC.

- - I

-The S\\~S piping is split into tl-.'O headers' (A and_ B) 1*thich supply redundant critical load trains (see Table 2):

Header A ~uppl~~s train A loads;

. header 8, train B loads.

Another header supp 1 i es various "noncrit i ca 1" loads (see Tab~e 3).

The noncritical supply header is automatically isolated on a safety injection signal by an air operated valve 1*:hich also fails closed on loss of air or loss of power to its air control solenoid valve. -

Du.ring normal plant operation, the Sl*:S suppl-ies flow to all loads except the di es el* genera tors and the engfoe~red safeguards_ roeim coo 1 ers.

During_

Shutdown Cooling System operation, the system supplies the critical loads (Tab 1 e 2 )(except di ese 1 genera tors) and the auxiliary bui 1 ding

  • See Section 3.2 of Reference 3.

(

.* air conditioning condenser, 2nd almost all noncritical loads (Table 3) are removed from the syste~. Following a LOCA or MSLB, the SWS supplies the critical loads only and, if necessary, supplies bc:ckup ccol.ing flow to the ECCS pu~p seals.

The flow requi~ement~ under all operating conditions 1*:ould normally be supplied by t:*m S\\*:S pumps.

As described in the p~evious CCW section, the failure of a diesel generator in a post-accident condition could lead to a de~raded ~WS operatin~ condition

\\*lith only one pump operable.*

This is the rr.ost 1 imiting configui-~tion for the SWS since one p0mp must supply s~fficient cooling flo~ to cool the containment and supoly cooling for.Sl*IS_ and CCI-! system po*st.;.acCident --- -

loads.

Although section*9.1.2.2 of Reference 2 states that t~o pumps*

are required in the eveht of an-accident, ohe SWS pump is capable of

.*supplying a11 post-:-accident requirements; howeve~. the operator must

~djust SWS flow as discussed in the CCI-! section to p,r.event exceeding CCW thermal limits.

The approximate required SWS flow. rates are 1625 gpm to the one containment air cooler, 3300 gpm to each of the CCW.heat**

exchangers, and 630 gpm to other required loads.

Assuming a CS heat load of 153E6 BTU/hr, which is the post-accident containment heat* load (Section

14. 18 of Reference 2) minus the design heat removal rat~. of one containment air cooler, the SWS temperature at the ~xit if the CC~ heat excha~ger approache~

170°F which is well below SWS design temperature (300°F) but which results'.. in CCW temperatures exceeding CCW design temperature.

To pre.vent this, the.

operator must divert additional SWS flow to the CCW heat exchangers as dis-cussed in the CCW section of this report.

-.*"°

System/Reference

  • Containment Spray (Ref. 2 Table 6-4)

Component Cooling (Ref. 2 Table 9-5)

Service Water (Ref. 2 Table 9-2 and Section 6.3.2)

TABLE I - SYSTEM DESIGN,PARAMETERS Parameters 3 pumps - 1800 gpm each l SCS heat exchangers - 83.5E6 BUT/hr each (with 4000 gpm~CW@ 114° and 1420 gpm CS

@ 283°)

3 pumps - 6000 gpm each 2 CCW heat exchangers - 85E6 BTU/hr each (post LOCA) 94.8E6 BUT/hr each

{at start of SCS operation) 3 pumps - 8000 gpm each 4 Containment Air Coolers - 76.6E6 BTU/hr each (with 1625 gpm SWS @ 75° and containment temperature @ 283°)

TP.BLE 2-CRITICAL Sl~S LOADS

1.

Diesel Generators (lube oil and jacket wat~r cooling)

2.

Control Room Air Conditioning Condensers

3.

Engineered Safeguards Room Coolers

4.

f:..ir Compressoi* Aftercoolers and jackets {sei*vice and ins trnme11t air)

5. _ECCS Pump Seals (backup to CCW system)
6.

Containment_Air Coolers

7.

Co~poi1ent Cooling 'Heat Exchangers

/

. (

(

(

NON-CRITICAL SWS LOADS

l.

Condensate pump seals

2.

Oily waste backwash

3.

Turbine exciter coolers

4.

Generator Hydrogen coolers

5.

Isolated Phase Bus cooler

6.

Seal oil coolers

7.

Feed pump lube oil and gland seal tool.ers

8.

Heater Drain Pump seals

9.

Electrohydraulit Oil coolers

10. Auxiliary Building air conditioning condenser 1 L Steam* generator bl midm*:*n-*'he2t exchanger.
12.

Turbine Plant Sample coolers-

13.

Room 128 air conditioning

14. Turbine Lube oil Coolers
15.

Radwast~ ai~ compressor

16.

Aux. building addition air conditioning

  • 17.

V~ntilation Equipment Room air conditioning ls..

  • Intake Chlorinator
19.

Cooling Tower pump cooling

20.

Cooling tower makeup

21.

Irrigation Discharge

22.

Makeup Water System feed

23.

Condenser Vacuum Pump cooling

- 14 To overcome single failures in the system, each train A load has a counterpart in train B, with the exception of the containment air

  • cool~rs (supplied by header B alone) and the CCW he~t exchangers (supplied by header A alone).

However, the ccntainment air coolers and CCW heat exch~ngers perform fully redundant contain~ent heat removal functions as previously described; and the SWS tritical headers can be cross-connected in the screenhoase and in the a_uxil iary building for additional operational flexibility.

The SWS is.susceptible to the single fail~re of the valv~ which isolates**

. th~* noncriiic~f he~d~r in ih~* event.of ~n accident which leads to a

  • safety injection signal.* If thi~*valve should fail to close~ the resultin~ SWS flows would be approximately 4000 gp~ each to the containment air coolers and CCW heat exchangers*; and 6000 gpm to the noncritical header.

These fl ov:ra tes to the cri ti ca*1**header* vmul d oot

  • .present a problem based on our previous discussion of the flowrates resulting f.roni the postulated failure o*f a diesel generator. However, isolation valve for the noncritical header can *be manu~lly closed lo~ally
  • to increase the flow to the critical headers.

The staff evaluated potential passive failure~ in fhe SWS.

Even though tiie he2.ders are joined in the auxiliary building by a double-valved

.i**

  • cross tie and header isolation valves h'hich permit the *isolation of either header upstrea~ of th~ crosstie, a rupture of a header downstream of the crosstie could eliminate SWS flow to either the CCW heat exch~ngers or the containment air coolers, depending upon which.header failed.

This sys~**.~i design is ::cceptc:ble because (l) *the containrilent air coolers are fully bai:ked up in the pest-accident scenario by the CS system,

and (2) the CCW heat exchangers can be lost during all plant operating conditions without significant consequences as described in th~ CCW section of this report.

Since the SWS is a moderate energy piping system, a pipe failure would probably result in a leak rather than a complete pipe rupture.

Using the method described in Reference 6, the staff estimates leakage from the 24 11 header (in. the screenhouse or

?uxiliary bu.ilding) to be 980 gpm using a SHS pressure of 90 psig.

Although a leak rat~ of 980 gpm may pos~. a flooding problem, the ~WS function \\*1ould not be signifi~antly impaired by this leak* rate.

(The.

capability of the Palisades Plant to \\*Jith'stand.the e_ff~cts of post1,.1iated..'._.~.,

~.

flooding from pipe leaks \\'/ill be assessed in SEP Topic III-5.B, "Pipe Breaks Outside Containment".

Leak detection fo~ the SWS is provid~d by h~ader pressure switches,

~*hich start the.standby Sl*:S pump on iow pressure, and by drain.sump level alarms in the buildings which house the SWS,.~jth th~ exception of the screenhouse.

Each heat load on the s1::s has either.an air..:operated or manual isolation valve to permit the load to be removed from the system without interruptin~ flow to other loaas.

The*pump discharge valves, header isolation and crcisstie valves, and other valves which isolate Sl*!S loads, as \\*;ell as the Sl*!S pumps, ~re operable from the

  • control room.

All of the re~otely operable valves in the SWS are air~

operated.

If a failure of the nonsafety grade air system is postulated,*

these valves f~il in the appropriat~ positions to *;sol ate the noncritical header, crosstie headers A. and B, and supply flow to all critical header

16 :-

except the ensi~ecr~d safe-s~ar~s pu~ps sc~l cooling supply which is the tac~~p supply to the CCW engineered safeguards pu~ps cooling fl oi.. *.

Power for the SWS pumps is provided by the 2~4 KV buses which can be

. supplied by the emergency diese1s or by offsite power.

At least one SWS pump is started on each diesel during post-accident diesel load sequencing.

Licensee Event Reports have noted that CCW heat exchanger tube leaks have occurred on two occasions (4/22/_71 and J/22/75)~ SWS_pump_dj~*c_harg~*

-~.

~

check valves have failed shut on three occasions (2/19/77, 9/20/77, and 4/28/78) and on one occasion the CCW heat exchanger heat transfer coefficients were found to be below the design valves because of SWS-side foul1ng (6/19/79).

With the exception of the discharge check valve failures., these events do not demonstrate any sisnific~nt failure trerids.

The licensee discovered these failures dl.ffing*atte,7,;:its to start S\\*IS pumps.. Licensee Event Report 78-15 reported ihat*~~w valve hinge pini

  • \\'.'Ould be installed to correct this pr::bleii1.

The nei'.' hinge pins and the rr.onthly testing of the Sl.. 15 pur..;:is required by the licensee's Inservice Pump and Valve Testing Program orovide adequate,2ssurance that (1) the Si*,'S pu::,;Js \\*:ill re;;.::in opera!:le, anG (2) the efficicy of the hinge p:in replacemeGt is de~onstrated.

The means of detecting radioactive contamination of the SWS (and CCW

~ystem) are evaluated in Reference 7.

Based on our review of the SWS, ~e co~sider the co~;:ionents supplied by the critical headers (Tcble* 2) to be the essential lo2ds on the system.

"(

- 17 Although our evalu2tion has shown that one SWS pump can supply all essential loads on the system, we were concerned that the successful functioning of both the SWS and the CCW system ~2y depend on the capacity of one SWS pump.if loss of offsite power and failure of 1iesel_generator 1-2 are assumed.

To provide additional SWS pumping capacity, the fire protection system pumps (two diesel driven, one electric D~tor driven, 1500 gpm each) are availc.ble and can be connected to the Sl-:S by a rr;anual 12 11 valv:e in the-screenhouse. *Even though the flow from these pumps would not approach that of cine S~S pump, the fire system pumps are cap~ble of c.u;~enting the flow of an SWS pump if required..

. VI.

CONCLUSION Based on our review of the service and coolihg.water 'systems for Palisades we have concluded that th.e essential systems and functions are:

RPSCS: Cooling for Reactor Primary Shield

~ "" I eves:

Pump Seal Lubrication: Cooling of Char~ing Pumps CCW: ( l ) SCS heat exchang~r cooling.for plant cboldOl*m (2) eves charging pump cooling for re actor system makeup and boration SWS: ( l ) All loc.ds supplied by the critical S\\*!S headers.

We have determined that the design of the above sy°stems is in conformance with *current regulatory guidelines and 1'i'ith General Design Criterion _,..,

(GDC) 44* re.garding capability and recundc.ncy of the ess.ential functions of the sys terns with the exception of the CC\\*! sys tern susceptibility to loss of function follovling certain assumed CC\\~ system pipe breaks.

I 18 However, the essential functions of the CCW system can be performed by other systeiils under all operating conditions.

The above systems also meet the require~ents of GDC 45 and 46 regarding system design to permit periodic inspections and testing.

To assure the capability of the SWS and CCW systems in a post-accident condition requiring containiiient cooling and 1*;ith the postulated single failure of diesel.generator 1-2, the licensee should provide, in the plant operating procedures, the requi~ed guidance to the operator to prevent exceeding CCW design temperature * (Note, no crdit should be taken for non-:

safety grade plant air systems.)

VI I.. REFERENCES

l. Regulato.ry GJide 1.105, "Instrur.;ent Setpoints.

11

2.

Consumers Po1*:er Coli1pany Palisades Plant Final Safety Analysis Report (FSAR}.

3.

SEP Review of Safe Shutdown Systems* for the Palisades Nuclear

. Plant (SEP Topics VII_-3, V-10.B, V-11.A, V-II.B-... X}

4.

Amendm~nt_No. 1~ to the Palisades Plant FSAR,.July 17, 1969~

Question 4.2.

5. Safety.Evaluation by the Directorate of.Licensing for the Palisades Plant, Docket No. 50-255, ~arch 6, 1970.
6.

Branch Technical Position MEB 3~1 appended to Standird Review Plan 3.6.2 *. -

7.

SEP Review of Topic V-10.A, "Residual Heat Remova:l System Heat**

  • Exchanger* Tube Failures."

~ *~ *.

./

~*

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