ML20125C210

Forwards Request for Addl Info Re Pump Trip Procedures,To Evaluate Response to IE Bulletin 79-05C

ML20125C210
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 8001080024
Download: ML20125C210 (7)

Text

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ocket tlo. : 50-312 DEC 141979 Mr. J. J. Mattimoe Assistant General Manager and Chief Engineer Sacramento Municipal Utility District 6201 S. Street P. O. Box 15830- -

Sacramento, California 95813

SUBJECT:

RANCHO SECO EMERGENCY PROCEDURES FOR SMALL-BREAK LOCAs

Reference:

Letter, R. B. Davis to B&W 177 Owners' Group - Technical Subcommittee on TMI-2 Incident Related Tasks dated flovember 27, 1979 During a meeting with the t!RC staff on flovember 8,1979, Mr. Rodriguez of your staff discussed the way he interpreted IE Bulletin 79-05C with regard to reactor coolant pump (RCP) trip for both LOCA and non-LOCA 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 manually initiating HPI, prior to auto.natic initiation at 1600 psig, the operator would not be required to trip the RCPs even if RCS pressure dropped below the automatic  !

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, iramediately trip all operating RCPs." He interpreted the words " ... initiation of HPI caused by low reactor coolant system pressure" 1 as meaning automatic initiation. He based his acceptability of this appecach on an analysis perforr:ed by 8:bcock & Wilcox (3&W) which shows that for the range of breaks requiring RCP trip, the reactor coolant system prassure decreases at such a rate that the operator would not have time to take manual action prior to reaching the automatic setpoint.

Following manual initiation of HPI, the operator would monitor primary system parameters including the amount of subcooling in the hot leg. If 200F of subccoling could not be maintained, the operators were instructed to trip the

'lCP s . Thus, it was believed that this overall approach would preclude tripping of the RCPs for non-LOCA transients even if the low pressure HPI actt.ation

'j setpoint was reached. However, RCP trip for LOCA transients wculd be assured by the predicted pressure decay rate and the hot leg subcooling critaria.

4 90010315 8001080 O N

9 Mr. J. J. Mattimoe DEC I ' 1]79 at the c.ceting, the staff stated that although we agreed in principle with this approach, it did not meet the intent _ of the bulletin. L.'e requested that SMUD submit to the staff, for evaluation,~ additional information regarding this matter.

hile we have not received a formal submittal from you, we have received the reference letter which was transmitted to us by B&W at your request. Fecm cur review of F.is letter, we cannot at this time conclude the acceptability of the L.cho '.eco interpretation of Sulletin 79-05C for RCP trip criteria.

This was di:. cussed with ifr. Rodriguez on December 6,1979. In addition,

he reference letter identifies a concern with regard to manually initiating -

SPI because frequent actuation will add appreciability to approaching 1 F.c design ther.aal 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 i 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, tha operators are to manually trip the reactor coolant pumps.

Sincerely,

'. n.

'kJ.Y(Nk D. . oss, Jr. , Director )

Bulletins and Orders Task Force '

Office of iluclear Reactor Regulation l

Enclosure:

As stated cc: R. Rodriguez (SMUD)

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

J. Taylor (B&W) 90010516

3 U srict .k 1 Christopher Ellison, Esq.

Dian Grueuich, Esq.

Dav id S.. Kaplan, Secretary and California Energy Corm.s sion Seneral Counsel lill Howe Avenue l

52 1 S Street Sacramento, California 95825 l

. O. 9ex 15830 l Sacramento, California 95313 California State Office Suramento County 600 Pennsyl vania Avenue , S. E. , Rm. 201 3::rd of' Supervisors Washingten, D.C. 2C003 32? 7th Street, Room 424 ,

Sscra.a nto, California 95814 -

Docketing and Service Section "irbert H. 3rown, Esq. Office of tha Secretary U. S. Nuclear Reculatory Commission I.wrenc2 Coe Manpher, Esq. 20555 Mill, Christcpher and Phillips, P.C. ashincton , D. C.

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1900 M St.aet, N W Thomas A. Saxter, Esq.

Lshingcon 0 C 20036 Shaw, Pittman, Potts & Trowbridge

irector, T'echnical Assesstent 1800 M Street N W Washington, D. C. 20036 Division Office of Radiation Programs Dr. Richard F. Cole Atcmic Safety and Licensing Soard

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U.S.j59} c.nvirennental Protection Agency Panel U. S. Nuclear Reculatory Cor. mission frystal Mall #2 Washington, D.C.' 20555 nelingtcn, '!1rginia 20460 S Mr. Frederick J. Shon

{yo. Environmental Protection n a Office Agency Ato ic Safety ard Licensing Soard

.,T IN : :IS CCORDINATOR r ane

--- U. S. Nuclear Regulatory Co.mmission ja)n:reancisco, ye gt Street ..

Cal 1Tornia 94111 Washington, D.C. 20555 Mr. Richard D. Castro

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R;Lart S. Sorsum 2231 K Street Fib::c'. & Wilcox Sacramento, California 95314 Qcl'ar ' Power Generation Civision Suita 420, 7735 Old Georcetcwn Road -

Cathesda, Maryland 20054 , _ _ . .

James S. Reed, Esq.

---

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

U. S. "uclear Regulatory Comnission Reed, Samuel & Remy Washington 0 C 20555 717 K Street, Suite 405 Sacramento, California 95314 At:mic Safaty & Licensing A;paal Board Panel U. S. *:uclear 3.egulatory Cor. mission Mr. Gary 'Hursh, Esq.

ashington, D. C. 20555 520 Capitol ' tall - Suite 700 Sacramento, California 95514 Elizabeth S. Iowers, Esq., Chairman California Department of Health ,

At;,ic Safety L Licensina Soard Fanel ATTN : Chief, Environmantal Radiat1cn U.S. .; clear Regulatorv'Ccr ission Control Unit

.:shir : ton, D. C. 20555'

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Padiological Health Section 714 ? Street, Room a93 "c. /.i:hael R. Eaton sacramento, Calif;rnia 953M I orgy issues Coordinator Sierra Club Legislative Office 1 07 i:n Strast :oca 1C20

~ wranto, California 952M 90010317

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liPI upon reactor trip is necessary, then a more complete explanatien of . hy it is necessary should be provirled. "creover, 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 pucnp trip based on loss of Sot leg tubc; cling 1 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 from steam tables.

Discuss the instruments to be used by the operator to determine subccoling.

1 Discuss how their uncertainty, the uncertainty of the coolant temperature measurement, and the measurement time constant both are accounted for in the procedures as .. ell as how they affect available operator action time. l l

I 90010318 I

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(,'istri:t Christopher Ellisen, Esq.

David S. Kaplan, Secretary and Dian Grueufch, Esq. .

California Energy Come.1ssion 1sneral Counsel lill Fowe Avenue 5201 S Street Sacramento, Califcrnia 95825 O. Eox 15830 Sacramen o, California 95813 Ms. Elcanor 5:hwartz Sacrar, ento County California State Office 600 Pennsylvania Avenue, S.E. , Rm. 231 B:ard of' Supervisors Washington, D.C. 20003 82? 7th Street, Room 424 ,

Sacramento, California 95814

• Docketing and Service Section Herbert H. Brown, Esq. Office of the Secretary Lawrence Coe Manpher, Esq.

U. S. Nuclear Reguia ory Commission Washington, D.C. 20555 Hill, Christopher and Phillips, P.C.

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

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Washington 0 C 20036 Shaw, Pittman, Potts & Trowbridge

f rector, T'echnical Assessment 1800 M Street N W Washington, D. C. 20036 ,

Divisicn Office of Radiation Programs . Dr. Richard F. Cole Atomic Safety and Licensing Board (AW-459}

S. ,,nvironnental Protection Agency

,J . e Panel U. S. Nuclear Regulatory Commissior.

grystalMall,#2 20555 nelingten, Virginia Washington , D. C.

20460 V S. Environmental Protecticn Agency Mr. Frederick J. Shen Regicn IX Office Atomic Safety and Licensing Scard ATTN: EIS COORDINATOR Panel

.215 Fremont Street U. S. Nuclear Regulatory Commissicn San Francisco, California 94111 Washington, D.C. 20555 Mr. Robert 8. Sorsum Mr. Richard D. Castro Fab::ck & Wilcox 2231 K Street Sacramento, California 95314 Nuclear ' Power Generation Division Suite d20, 7735 Old Georgetown Road -

l Cothesda, Maryland 20014 James S. Reed, Esq.

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

U. S. '!uclear Regulatory Commission Raco, Samuel & Remy Washington 0 C 20555 717 K Street, Suite 405 Sacramento, California 95814 Atomic Safety L Licencing Appeal Board Panel V. S. f'uclear Regulatory Commission Mr. Gary 'Hursh, Esq.

Washington, D. C. 20555 520 Capitol Mall - Suite 700 Sacramento, California 95814 Elizabeth S. 3owers, Esq., Chairman California Department of Health Atomic Safety L Licensing Board Panel ATTN: Chief, Environmental Radia:icn U. S. ',uclear Reculatory Cor.mir:. ion Control Unit

':ashington,D.C: 20555

. Radiological Health Section 714 P Street, Room 493 "r., .'icn ael R. Eaton Sacramen:c, California 95314 Energy issues Coordinator Sierra Club Legislative Office 1107 9:n Street Room 1020 Sacraranto, California 95314 90010319

.i . .

istri

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f Christopher Eilisen, Esq.

Dian Grueuich, Esc.

David S. Kaplan, Secretary and California Enargy 'Com.,ission General Counsel 1111 :-: owe Avenue 5201 S S.reet Sacramento, Califernia 95825 O. Box 15830 Sacramen:c, California 95813 Ms. Eleanor Schwartz S1crar. ento County California State Office 600 Fennsylvania Avenue , S.E. , Rm. 231 B:ard of' Supervisors Washington, D.C. 20003 827 7th Street, Room 424 ,

Sacrater.to, California 95814 -

Docketing and Service Section Herbert H. Brown, Esq. Office of the Secretary U. S. Nuclear Regulatory Commission Lawrence Coe Manpher, Esq. 20555 Hill, Christopher and Phillips, P.C. Washington, D.C.

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

Washington 0 C 20036 Shaw, Pittman, Potts & Troubridge l l

.irector, Technical Assessment 1800 M Street N W Washington, D. C. 20036 Civisicn Office of Radiation Programs Dr. Richard F. Cole W-Atomic Safe ~v and Licensing Board l v.

5.$59)tnvironmental Protection Agency Panel U. S. Nuclear Regulatory Commissior.

ggstalMall#2 ..

Washingten , D.C. 20555 eriingten, Virginia 20460 t 1 Protection Agency Mr. Frederick J. Shen

g on -b"e A91c SaTeg ad Ucensing ,ocaN ATTN: EIS COORDINATOR 215 Frem:nt Street U. S f uclear Regulatory Commissicn San rrancisco, Calir.ornia 94111 Washington, D.C. 20555 Mr. Richard O. Castro Mr. Robert S. Borsum 2231 K Street

?ah:ck & Wilcox Sacramento, California 95314 "uclaar ' Power Generation Division i Sui ta 420, 7735 Old Georcetown Road -

I Cathesda, Maryland 20054 -.

~ ~ -

James S. Reed, Esq.

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

U. S. Muclear Regulatory Commission Reed, Samuel & Remy Washington 0 C 20555 717 K Street, Suite a05 Sacramento, California 95314 Atomic Safety & Licensing Appeal Board Panel U. S. ';uclear Regulatory Commission Mr. Gary Hursh, Esq.

ashington, D. C. 205ao 520 Capitol Mall - Suite 700 Sacra..: ento, California 95814 Elizabeth S. Scwers, Esq. , Chairman California Department of Health A::mic Safety & Licensing Scard Panel ATIN: Chief, Environ ental Radia.ica U. S. '.; clear Reculatory Commission C:n:rol Unit

ashin.::n, D. C'. 20555 0.adiolocical Health Section 714 P Street, :com 493 Mr. Jicniel R. Eaton Sacramen c, California 95314 En3r;y Issues Coordinator Siarra Cl;b Legislative Of fice 1127 i:n Street Rcom 1020 Si:caranto, California 95314 C100103N

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C,. closure Additional Information Needs on Pancho_ Seco Pump Trip i Procedures

1. Submit a copy of your proposed procedures which would allow pump operation beyond ESFAS actuating 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 HP! Icw pressure actuation setpoint will occur befare ope 3 tor action could be taken to manually initiate HPI.

1 Provide more detailed information on why the operators do not have ancugh i take this action.

1 Present analyMes indicate a maximum of 2 minutes to be available to the l l

operator to trip the pumps if excessive cladding temperature are to be i 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 pumps once the subcooled condition no longer exists?

3. The approved B&W guidelines state that when HPI is actuated because of low pressure conditions, specific criteria must be met (e.g., 50 F subcooling) 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, 5&W expressed concern regarding the capability of the HPI nozzles to accomodate a high nurber of cycles of HPI injection associated with liPI being manually actuated up:n reactor trip.

The staff is not of the opinion that manual actuaticn of hPI upcn reactor trip is a pruoent course of action to take since the system was not specifically designed to operate in this mde. If you ccncluce that manual initiation of 90010321