ML20040E265

Forwards Safety Evaluation Re SEP Topics V-II.A & V-II.B Supplementing Previously Submitted Contractor Evaluation. Mods to Residual Heat Removal Isolation Valve Control Circuitry Will Be Proposed

ML20040E265
Person / Time
Site:	Yankee Rowe
Issue date:	02/01/1982
From:	Caruso R Office of Nuclear Reactor Regulation
To:	Kay J YANKEE ATOMIC ELECTRIC CO.
References
TASK-05-11.A, TASK-05-11.B, TASK-5-11.A, TASK-5-11.B, TASK-RR LSO5-82-02-015, LSO5-82-2-15, NUDOCS 8202040093
Download: ML20040E265 (4)

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February 1, 1982

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Docket No.50-029 s

LS05-82-02-015 Pen.

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Mr. James A. Kay 6'K vf Senior Engineer - Licensing Yankee Atomic Electric Company Q

1671 Worcester Road

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Framingham, Massachusetts 01701

SUBJECT:

SEP TOPIC V-11.A. REQUIREMENTS FOR ISOLATION OF HIGH AND LOW PRESSURE SYSTEMS AND V-ll.B. RHR INTERLOCK REQUIREMENTS SAFETY EVALUATION REPORT FOR YANKEE ROWE The enclosed staff safety evaluation supplements our contractor's evaluation that has been made available to you previously. This evaluation is consis-tent with the findings in our contractor's evaluation of Topics V-11.A and V-11. B.

As a result of our safety evaluation of Topics V-11.A and V-11.B.

we propose modifications to the RHR is51ation valve control circuitry.

The need to actually implement these changes will be determined during the integrated plant safety assessment. This topic assessment may be revised in the future if your facility design is changed or if NRC criteria relating to this topic are modified befgre the integrated assessment is completed.

l Sincerely,

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Operating Reactors Branch No. 5 p e Ralph Caruso, Project Manager Division of Licensing s

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Enclosure:

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j Mr. James A. Kay cc Mr. Jaines'E. Tribble, Pres'ident

-Yankee Atomic Electric Company 25 Research Drive Westborough,. Massachusetts' 01581 Greenfield ' Community College 1 College Drive Greenfield, Massachusetts 01301

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Chairman Board of Selectmen Town of Rowe

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Rowe, Massachusetts 01367

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Energf Facikities Siting Council 14th Floor One Ashburton Place

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Boston, Massachusetts 02108 U. S. Environmental Protection Agency l

Region 1 Office ATTN: Regional Radiation Represen'tative JFK Federal Building Boston,. Massachusetts 02203 Resident Inspector Yankee Rowe Nuclear Power Station c/o U.S. NRC Post Office Box 28 Monroe Bridge,liassachusetts 01350 1

Ronald C. Haynes, Regional Administrator Nuclear Regulatory Commission, Region I Office of Inspection and Enforcement 631 Park Avenue King of Pr'ussia, Pennsylvania 19406 1

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t SYSTEMATIC EVALUATION PROGRAM _

YANKEE R0WE_

V-11.A, REQUIREMENTS FOR ISOLATION OF HIGH AND. LOW PRESS TOPICS:

V-11.B, RHR INTERLOCK REQUIREMENTS I.

INTRODUCTION Several systems that have a relatively low design pressure are connect-The valves that form the ed to the reactor coolant pressure boundary. interface betwe redundancy and interlocks to assure that the low pressure systems are The not subjected to coolant pressures that exceed design limits.

problem is complicated since under certain operating modes (e.g.,

shutdown cooling and ECCS injection) these valves must open to assure adequate reactor safety.

II.

REVIEW CRITERIA _

The review cri',eria are presented in Section 2 of EG&G Report 1350F,

" Electrical Instrumentation and Control Features for Isolation High and Low Pressure Systems."

3 ELATED SAFETY TOPICS AND INTERFACES _

III.

The scope of review for this topic,was lim'it$ed to avoid duplication of effort since some aspects of the review were performed related topics. Each of the related topic reports contain the criteria tified below.

and review guidance for its subject matter.

Overpressurization Protection V-3 V-10. B RHR Reliability VI-4 Containment Isolation IV-19 :

Loss of Coolant Accidents IV.

REVIEW GUIDELINES The review guidelines are presented in Section 7.3 of the Standard Review Plan.

V.

EVALUATION As.noted in'I'G&G Report 1350F, Yankee Rowe

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These are the Raactor Heat Removal (RHR) and the to the RCS.

Chemical Volute Control (CVCS) Systems.

The RHR system and CVCS are not in compl below.

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(1 ) ' -The HR' system isolatio'n v'alves do not have any interlocks to prevent opening when P.CS pressure exceeds RHR system design l

pressure.as' required by BTP RSB 5-1; (2) No interlocks are provided to automatically close any RHR

_ system isolation valves if RCS pressure increased above RHR systera design pressure during RHR system operation as required bylBTP RSB 5-1; and I

(3) The isolation valves for the CVCS do not have interlocks.to i

prevent CVCS overpressurization as required by BTP EICSB-3.

The CVCS letdown 1 1s isolated by two remote, motor operated, manually I

controlled valves'in series inside of containment and an air operated automatic valve outside of containment. The air operated valve auto-matica11y closes on low pressurizer pressure.

The positive displacement charging pumps and the charging pump dis-charge line are designed for reactor system pressure. The discharge

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line is isolated by two remote, motor operated, manually controlled valves, one valve is inside of containment.

The other is outside of containment.

'The tiesign of the CVCS letdown and charging system is similar to Palisades and Gi.nna.

The radiological consequences of a break in the CVCS system was evaluated under Topic XV-19 for these plants and found to be acceptable, i

The valving arrangements in these plants was also found to be acceptable.

VI.

CONCLUSIONS

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The RHR system isolation valve control circuitry should be modified to prevent opening when RCS pressure ex'ceeds RHR system design pressure as

, required by BTP RSB 5-1.

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Interlocks to close these valves if RCS pressure increases above RHR systen; design pressure during RHR system operation are not necessary l

because of the overpressure protection system.

Pending a detailed. review under SEP Topics VI-4 and XV-19, the isola-

' tion of the CVCS system is acceptable based on previous reviews of similar systems. -

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