ML20125D092

Advises of Unacceptability of Util Response to IE Bulletin 79-05C Until Response to Encl Request for Addl Info Is Received & Appproved.Reactor Coolant Pumps Must Be Manually Tripped When Primary Pressure Reaches Actuation Point

ML20125D092
Person / Time
Site:	Rancho Seco
Issue date:	12/14/1979
From:	Ross D NRC - TMI-2 BULLETINS & ORDERS TASK FORCE
To:	Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT
References
IEB-79-05C, IEB-79-5C, NUDOCS 8001140027
Download: ML20125D092 (7)

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20cket No.: 50-312 DEC 141979 e W Mr. J. J. Mattimoe S Assistant General Manager and d p Chief Engineer Sacramento Municipal Utility District ll- #gf [ y A T._

6201 S. Street 2" -

P. O. Box 15830' ghgD , gg 'S Sacramento, California 95813 g.y

Dear Mr. Mattimoe:

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SUBJECT:

RANCHO SECO EMERGENCY PROCEDURES FOR SMALL-BREAK LOCAs

Reference:

Letter, R. S. Davis to S&W 177 Owners' Group - Technical Subcommittee on TMI-2 Incident Related Tasks dated November 27, 1979 During a meeting with the NRC staff on November 8,1979, Mr. Rodriguez of your staff discussed the way he interpreted IE Sulletin 79-05C with regard to reactor coolant pump (RCP) trip for both LOCA and non-LCCA transients.

Mr. Rodriguez stated that upon seeing the symptoms of a LOCA, the operator would take certain immediate actions to regain control of reactor coolant system (RCS) pressure and pressurizer level. These actions may include the manual initiation of high pressure injection (HPI). By aanually initiating HPI, prior to aute:natic initiation at 1600 psig, the operator would not be required to trio the RCPs even if RCS pressure dropped below the autcmatic actuation setpoint. Mr. Rodriguez correctly stated that IE Bulletin 79-05C reads, "Upon reactor trip and initiation of HPI caused by low reactor coolant system pressure, iricediately trip all operating RCPs." He interpreted the words " ... initiation of HPI caused by low reactor coolant system pressure" as meaning automatic initiation. He based his accaptability of this approach on an analysis performed by Scbcock & Wilcox (3&W) :hich shows that for the range of breaks requiring RC? trip, the reactor coolant system prassure decreases at such a rate that the ocerator would not have time to take manual action prior to reaching the automatic setpoint.

Following manual initiation of HPI, the cperator would -onitor primary system parameters including the 1.? cunt of subcooling in the hot leg. If 200F of subcooling could not be maintained, the operators were instructed to trip the RCPs. Thus, it was believed that this overall approach would preclude tripping of the PCPs for non-LOCA transients even if the low pressure HPI actuation setpcint clas reached. However, RCP trip for LOCA transients would be assured by the predicted pressure decay rate and the hot leg subcooling cri aria.

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Mr. J. J. Mattimoe DEC 1

• 1979 At the m.ceting, the staff stated that although we agreed in principle with this approach, it did not moet the intant of the bulletin. We requested that 57.90 submit to the staff, for evaluation, additional information regarding this matter.

'Sile we hava not received a formal submittal from you, we ha.ve received the reference letter ,vhich was transmitted to us by B&W at your request. Fecm our review of this letter, we cannot at this time conclude the acceptability of the Rancho !cco interpretation of Sulletin 79-05C for RCP trip critaria.

This was di:.cussad with ifr. Rodriguez on Caccmber 6,1979. In additien, the reference letter identifies a concern with regard to manually initiating -

"P bec ,use frequent actuation will add appreciability to approaching Je dasign thanaal cycles on the HPI nozzles.

In order to fully evaluate the acceptability of your approach, we would need the additional information described in the enclosure. Therefore, until we have received this information and have provided our approval, we require that your procedures comply fully with the staff requirements for B&W plants; namely that when primary pressure reaches the HPI actuation setpoint, the operators are to manually trip the reactor coolant pumps.

Sincerely, Q 67 D. FI oss, Jr. , Director Bulletins and Orders Task Force Office of Nuclear Reactor Regulation

Enclosure:

.is stated -

cc: R. Rodriguez ',3 MUD)

R. Gill, (B&W Owners' Group)

J. Taylor (B&W) e t

90023275

RELATED CORRESPONDENCE 3 ' i s t!'i : .

Christopher Eilisen, Esq.

g i l% / 'b Dian Grueuf ch, Esc.

David S Xapian, Secretary California Energy' Commission General Counsel r. y A 1111 Howe Avenue 52::1 S Street O. cx 15S30

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1. Sacramento, California 95825 Sa:ramen o, California g5 551 3 g S cra. ento County

~ 9@@*h4@g/ 6 Ms. Eleanor Schwart:

California State Office 600 Fennsyl vania Aver.ae , S. E. , Rm. 201 3:ard of'Su;ervisors Washington, D.C. 20003 s

527 7th Street, Room 424  %

Scramer.to, California 9581 68I Docketing and Service Section

~

Mrbert H. Grown, Esq. Office of the Secret?.ry U vence Coe :4anpher, Esq.

U. S. Nuclear Reculatory Commission .

'!ashincten, D.C. 20555 Mill, C*iristcpher and Phillips, P.C. .

1900 M St.eet, N W .

Thoma5 A'. Baxter, Esq.

hshington D C 20036 - Shaw, Pittman, Potts *, Troworidge

.irector, T. ec hnical Assessrent 1800 M Street N W Washinoton, D. C. 20036 Division Dr. Richard F. Cole Cf f1[,D')ce y Radiation Programs Atomic Safety and Licensing Board S. -nvirencental Protection Agency

.e . Panel

-U. S. Nuclear Regulatory Comission yrystal I.all e2 Washington, D.C. 20555

. cling:cn, v,irginia ,0460 4

Ul S. Envi r:nmental Protection Agency Mr. Frederick J. Shen Atomic Safet"v and Licensing Board yagion y 0,iice 4TTfh  :.IS COORDINATOR ?anel

-- U. S. Nuclear Reculatory Co=ission

• jan. a;.-rem:ntStreet r anci sco , Ca ii r.ornia 94111 Washington, D.C. ~ 20555 Mr. Richard D. Castro D'. ROLart 3. 3ersum 2231 K Street

?ac::ck & Wilcox Sacramento, California 0551a Lclear ~?cwer Generation ivision Suita 420, 7735 Old Georce:o-n Read -

! l Cathesda, Maryland 20054 James S. Reed, Esq.

Atomic Safety & Lic'ensing' Board Panel Michael H. Remy, Esq.

U. S. % clear Regulatory Ccanission Reed, Samuel & Remy Washington D C 20555 717 K Street, Suite a05 Sacramento, California 95314 At:mic Safety & Licensing Appaal Board Panel U. S. ':uclear 0.egulatory Ccmission Mr. Gary Hursh, E'sq.

,ashin; ton, D. C. 205cc 520 Capitol Mail - Suite 700 5acramento, California 95314 5:iza:stn S. Iowers, Esq. , Chairman California Depart: ent cf Health

.:mic Safe:y L Licensing Scarc Fanel ATTil: Chief, Envir nnantal Radiaticn V, 5. '.; clear Reculat:ry C:=ission Control Unit

.:shir n:n, D. C! 20555

" Eadiciocical Health Secti:n 714 ? Sireet, Room a98

'r. 'i :h ael R. Eat:n Sacramento, California 95514 5 ar;y Issues Coor:inator Sierra Cl.b '_egislative Cffice l'07 i:h 5:rcct Eccm 1C20

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HPI upon reactor trip is necessary, then a recre complete explanatien of <hy it is necessary should be provided. 'oreover, you should submit your plan for ongoing stress analysis of the HPI nozzles to assure they have been designed to withstand the plant transients to which they have been exposed.

5. .The staff believes that pump trip based on loss of hot leg subccoling should rely on direct measurement of hot leg subcocling, and not by ,

indirect means, such as comparison by the operators of measured to saturation temperatures at the' system pressure frorr steam tables.

Ofscuss the instruments to be used by the operator to determine subcooling.

Discuss how their uncertainty, the uncertainty of the coolant temperature measurement, and the measurement time constant both are accounted for in the procedures as well as how they affect availaole operator L n.n I time.  !

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l 90023277

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istri:-

Christopher Ellisen, Esq.

Dav id S. Y.aplan, Secretary and Dian Grueuich, Esq.

California Energy Cor..a.ssion Sensral Counsel lill Howe Avenue c2 I,01o,5ge (jrati'5830 Sacramento, California 9582:.

Sacramen o, California 95813 Ms. Eleanor 5:,nwartz 1 S cramento County California State Office r- ' 3) 600 Pennsyl vania .. venue, S- ,. , .m 3:a:d of'5upervisors Washington, D.C. eu003 S27 7th Street, Room 424 .

Sacramento, California 95814 -

Docketing anc. Service Section Herbert H. Brown, Esq. Office of the Secretary , ,

Lawrence Coe Manpher, Esq. U. 5. Nuclear Regulatory Commission '

Washingt:n, D.C. 20555 Hill, Christopher and Phillips, P.C.

1900 M Street, N W Thomas. .A.. . Baxter, Esq.

'lashington 0 C 20036 Shaw, Pittman, Potts & Trowbridge

f re'ctor, Technical Assessment 1800 N Street N W Washington, D. C. 20036 .

Divisien Office of Radiation Programs Dr. Richard F. Cole

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(AW-459) Atomic Safety and Licensing 5 card U. S. Environmental Protection Agency Panel -

Crystal Mall #2 U. S. Nuclear Regulatory Corm.ission Arling :n, Virginia 20460 Washington, D.C. 20555 Ul S. Environmental Protection Agency Mr. Frederick J. Shen Atomic Safety and Licensing Board gigion p Office iiN: -IS COORDINATOR Panel U. S. Nuclear Reculatory Commissien

.jl:r.

remon:. Street ~

.an reancisco, Callrornia..

94111 Washing:en, D.C. 2C555 Mr. Ecbert 3. 5crsum Mr. Richard D. Castro 5ab::ck & Wilcox 2231 K Street Sacramento, California 95314

%cisar' Power Generation Division Ivi ta a20, 7735 Cid Georgetown Road -

Eethesda, Maryland 20014 James S. Reed, Esq.

Atomic Safety & Lic'ensincj Board Panel Michael H. Remy, Esq.

V. S. *:uclear Regulatory Commission Reed, Samuei & Remy Washington 0 C 20555 717 K Street, Suite 105  :

Sacramento, California 95814 At:mic Safety & Licensing Appeal Scard Panel U. S. I;uclear Regulatory C0mmission Mr. Gary Mursh, Esq.

'ashington, D. C. 20555 520 Capitol Mall - Suite 700 Sacramento, California 95314 Eli:a:eth S. 5cuers, Esq., Chairman California Department of Mealth A :mic Safety & Licensine Board Panel ATTH: Chief, Environmental Radia-icn U. S. *.uclear Recula:Ory"Crmission C:ntrol Unit

ashin .:n, D. C! 20553

- Radiolecical Heal .h Secti n 71a P Street, Room 293

'r. .'i:nael R. 5aton Sacramen c, California 95514 Ener;y Issues C::rcinator -

Sierra 12 Legislative Office 1107 9 n Street Re:m 1C20 -

5acra.an0, California 95514 90023(l0

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istri:-

Christopher Eilisen, Esq.

David S. Kaplan, Secretary and Ofan Grueufch, Esc. .

California Energy Cor..ission General Counsel lill Howe Avenue 95825 5201 S S:reet Sacramento, Califcrnia

. O. Sex 15330 Sacramen o, California 95813 Ms. Eleanor 5:hwartz 5 cramento County California State Office 600 Pennsyl vania Avenue , S.E. , Em. D1 B:ard of'Eupervisors Washington, D.C. 20003 827 7th Street, Room 424 ,

Sacramento, California 95814 Docketing and ' Service Section Harbert H. Brown, Esq. Office of the Secretary Lawrence Coe Manpher, Esq.

U. S. Nuclear Regulatory Commission -

Washington, D.C. 20555 Hill, Christopher and Phillips, P.C. '

1900 M Street, N W Thomas'A. Saxter, Esq.

Washington 0 C 20036 Shaw, Pittman, Potts & Trewbridge *

.i re'cto'r, T'echnical Assessment 1800 M Street N W Washington, O. C. 20036 ,

Civisien Office of Radiation Programs Dr. Richard F. Cole Atomic Safety and Licensing Board

,J.S.i9}

(AW cnvironmental Protection Agency Panel U. S. Nuclear Reculatory Commissior.

grystalMalle2 Washington , D. C.' 20555

,.rlingten, Virginia 20460 Ul S. Environmental Protection Agency Mr. Frederick J. Shon Region IX Office Atomic Safety and Licensing Board ATTN: EIS COORDINATOR Panel .

. 215 Frem:nt Street- U. S. Nuclear Regulatory Commissica San Francisco, California 94111 Washington, D.C. 20555 Mr. Robert S. Borsum Mr. Richard O. Castro 2231 K Street

?abc:ck & Wilcox Sacramento, California 95514

%claar ' Power Generation Division Icit2 420, 7735 Old Georgetown Road -

Othesda, Maryland 20014 James S. Reed, Esq.

Atomic Safety & Lic'ensingi Board Panel Michael H. Remy, Esq.

V. S. Muclear Regulatory Commission Reed, Samuel & Remy Washington 0 C 20555 717 K Street, Suite 405 Sacramento, California 95814 Atemic Safety & Licensing Appeal Board Panel i U. S. Nuclear Regulatory Commission Mr. Gary Mursh, Esq.

, asnin;:en, D. C. 20555 520 Capitol Mall - Suite 700 Sacramento, California 95814 E'iza':e:h S. Ecwers, Em ., Chairman California Department of Health A::mic Safety & Licv. sing Board Panel ATTN: Chief, Environrental Radia:i:n

'J. 5. '.; clear Regu n:Ory Commission C:n:rol Unit

.:ashin;;:n, D. C. 20555 Radi:1ccical Health Section 714 p street, Room a93

'jr. icjael R. Eaton Sacramen:c, California 95514

.nargy .ssues Coordina:or Sierra :1.b Legislative Cffice 1107 i:n Street Room 1020 '

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C.. closure

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Mditicnal Infomation Needs on Rancho, Seco Pumo Trip Procedures 1

1. Submit a copy of your proposed procedures which would allow pump operation beyond ESFAS actQating on low pressure and only require manual trip on loss of subcooling margin.

2. You have stated that for small breaks in which analyses indicate pump trip is necessary, the pressure decay to the HPI lcw pressure actuation setpoint will occur before opeator action could be taken to manuaily initiate HPI.

Provide more detailed information on why th.e operators do not have ancugh time to take this action.

Present analyse's indicate a maximum of 2 minutes to be available to the operator to trip the pumps if excessive cladding temperature are to be avoided for all small breaks. If the operators manually initiate HPI and therefore base pump trip on hot leg subcooling, hcw much time is available to trip the pu.wr Pee the subcooled condition no longer exists?

3. The approved B&W gu " ines stata that when HPI is actuated because of low pressure conditions, spen .fic criteria must be met (e.g., 50*F subccoling) before HPI can be terminated. If the HPI is manually initiated for a small break, per your procedures, are the termination critaria still to be folicwed?

If not, explain why?

4. In the reference to the transmittal letter, B&W ex;ressed c:ncern regarding the capability of the HPI nozzles to accormodate a high nurter cf cycles of HPI injection associated with HPI being manually 60tuated upon react:r trip.

D,e staff is not of the opinion that manual actuation of hPI up;n react:r trio is a prudent course of action to take since the system was not specifically designed to cparate in this rede. If you ccnclude that mar.ual ir.itiatien of 90023280