ML20055A288
| ML20055A288 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 07/13/1982 |
| From: | Caruso R Office of Nuclear Reactor Regulation |
| To: | Kay J YANKEE ATOMIC ELECTRIC CO. |
| References | |
| TASK-06-07.B, TASK-6-7.B, TASK-RR LSO5-82-07-025, LSO5-82-7-25, NUDOCS 8207160081 | |
| Download: ML20055A288 (7) | |
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July 13, 1982 Docket No.50-029 LS05-82 025 Mr. James A. Kay Senior Engineer - Licensing Yankee Atomic Electric Company 1671 Worcester Road Framingham, Massachusetts 01701
Dear Mr. Kay:
SUBJECT:
YANKEE - SEP TOPIC VI-7.D, ESF SWITCi10VER FROM INJECTION TO RECIRCULATION (AUTOMATIC ECCS REALIGNMENT)
By letter dated June 4,1981, the staff issued a safety evaluation on SEP Topic VI-7.B focusing on the instrumentation and controls used for the switchover from injection to recirculation mode. The staff con-cluded that the instruments satisfy the single failure criterion.
Enclosed is the staff's draft safety evaluation of systems aspects of this topic including the time available for required operator actions.
Our conclusion is that the switchover method for your facility is acceptable.
You are requested to examine the facts upon which the staff has based its evaluation and respond either by confirming that the facts are correct or by identifying any errors.
Your response is requested within 30 days of receipt of this letter.
If no response is received in that time, we will assume you have no comments or corrections and will consider the topic to be complete.
Sincerely, udh) es Ralph Caruso, Project Manager g o n'.
Operating Reactors Branch No. 5 M bo7/g Division of Licensing
Enclosure:
As stated cc w/ enclosure: See next page 8207160081 820713 5
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. Mr. James A. Kay CC Mr. James E. Tribble, President Yankee Atomic Electric Company 25 Research Drive Westborough, Massachusetts 01581 Chairman Board of Selectmen Town of Rowe Rowe,Mhssachusetts 01367 Energy Facilities Siting Council 14th Floor One Ashburton Place Boston, Massachusetts 02108 U. S. Environmental Protection Agency Region I Office ATTN:
Regional Radiation Representative JFK Federal Building Boston, Massachusetts 02203 Resident Inspector Yankee Rowe Nuclear Power Station c/o U.S. NRC Post Office Box 28 Monroe Bridge,* Massachusetts 01350 Ronald C. Haynes, Regional Administrator Nuclear Regulatory Commission, Region I 631 Park Avenue King of Prussia, Pennsylvania 19406
YANKEE NUCLEAR POWER STATION SEP TOPIC VI-7.B SWITCH'VER FROM INJECTION TO RECIRCULATION 0
I.
Introduction Following a loss-of-coolant accident (LOCA), safety injection i is automatically initiated by a safety injection signal (SIS).
The signal starts three high pressure safety injection (HPSI) pumps and three low pressur,e s,afety injection (LPSI) pumps which take suction from'thE' safety inj'ection tank.
The
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combined flow contribution from the HPSI and kPSI pumps is at a rate of 3,261 gpm.
Injection of reactor coolant by alf pdmp's continues until the level in the injection tank reaches 18 feet.
At this levels the operator is instructed through emergency procedures to stop one HPSI and one LPSI pump.
Injection at the reduced rate (2,174 gpm) continues until the l ev et-i n the injection tank reaches 11 feet.
At this leveli the operator is instructed to transfer water supply for the pumps from the injection tank to the vapor container (VC) and, complete switchover from injection to recirculation.
II.
Review Criteria The current licensing criteria which govern the safety ~ issue are identified in Table 7-1 of the Standa'rd Review Plan.
The most significant of these criteria are:
t t
Branch T'chnical Po's'ition ICSB 20; 1.
e 2.
IEEE Std 279-1971; and 3.
Regu la t or y Guide 1.62.
III.I Related Safety Topics and Interfaces The scope of review for this topic was limited to avoid duplication of effort since some aspects of the review were pefformed unde 7 related top'i'cs.
The r e l a t e'd topics and
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the subject matter are identified below.
Each of the related topic report s c ont a in the acceptance criteria and review guidance for its subject matter.
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Seismic Design' Considerations III-6 III-10.A
- Thermal-Overload Protection for Motor Operated Valves III-11
- Component Integrity Envi r onme nt a l Qu a li f i c a t i on-III-12 Operation with Less Than All Reactor Coolant IV-1.A Loops in Service RHR Reliability V-10.B V-11
,High Pressure / Low Pressure. Interface ECCS Actuation System VI-7.A.3 Independence of Onsite Power VI-7.C.1 VI-10. A
- Testing of ESF Systems Shared Systems VI-10.8
. VIII-2 Onsite Emergency Power Systems i
" Emergency di Systems
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VIII-3 Containment Penetrations VIII-4 The following topics are dependent on the present topic information for c om p l e t i on:
I Containment Isolation System VI-4 VI-7C.2.
- ECCS Single Failure Criterion IV.
R eview Guidelines o
ICSB 20 states that automatic transfer to the recirculation d
mode is preferable to manual transfer and should be provided for standard plant designs submitted fgr, review on a generic basis under the Commission's standardization policy.
ICSB 20 also states that a design that provides manual initiation at the system level of the t ransf e r to the recirculation moder while not ideal, is sufficient and satisfies the intent of IEEE Std 279 provided that adequate instrumentation and information displays are available so tha't the operator can make the correct decision at th'e correct time.
Furthhrmore, it should be shown thate in case of operator error, there is sufficient time and information' available so that the operator can correct the errors and the consequences of such an error are acceptable.
V.
Evaluation
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The switchover from injection to recirculati,on is 1,ully manual.
Emergency procedures require operator action at about 11 minutes following a large LOCA to isolate one HPSI pump and one LPSI pump in order to reduce injection flow from 3,261 gpm to 2,174 gpm.
Alarms at the 18 ft. Level of the injection tank alert the operator to isolate the pumps.
The initial tank' L8 vel, as required by technical
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specifications, is assumed at 25.5 ft.
Injection at the rate of 2r174 gpm continues until the tank level reaches 11 ft.,
whereby the 6perator is instructed to complete switchover of water supply from the injection tank to the vapor container.
We have calculated the time avail =
able for switchover-before the injection tank empties to be on the order of 23 minutes, following t-he 41 ft. alarm level.
The operator actions are limited to realignment of the LPSI header isolation valves, HPSI pump recirculation valves, and VC and injection tank suction valves.
VI.
Conclusion As part of the SEP review for Yankeer we have evaluated the licensee's safety injection system design (Ref. 1), emergency procedures (Ref. 2) and the staff's instrumentation evalua-tion (Ref. 3) against the criteria of SRP Section 6.3,
Branch Techn~ical Pbsitiun RSB 6-1, and have concluded that the design is in conformance with those criteria.,, Addition-ally, we have determined that sufficient time is available.
for operator action for completion of switchover from injec=
gtion to recirculation.
References 1.
Yankee Atomic Electric Company, " Final S af e t y Apalys i s R epor t e" Docket No. 50-29.
2.
Yankee Atomic Electric Company, " Loss of Main Coolante" Procedure No. OP-3106, Revision 18, Revier dat e 2/82.
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3.
Letter from D.
Crutchfield (NRC) to J. A. Key (YAECO),
Subject:
SEP Topic VI-78, ESF SWITCHOVER, dated June 4, 1981.
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