ML20195J793

Forwards NRC Revised Pages to Tech Spec Section 3.6 Re Operation of Charging Pumps After Safety Injection Signal, Proposed in Util .Agrees W/Util That Proposed Change Will Not Affect Safety of Plant

ML20195J793
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	06/20/1988
From:	Wang A Office of Nuclear Reactor Regulation
To:	Mroczka E CONNECTICUT YANKEE ATOMIC POWER CO.
References
TAC-68187, NUDOCS 8806290237
Download: ML20195J793 (4)

Text

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f June 20,1988 c

I-p Docket No. 50-213 DISTRIBUTION MDocket Fileja NRC & Local PDRs S.Vargh~

B.Boger S.Norris A. Wang Mr. Edward J. Proczka D.Hagan T.Barnhart(4)

Senior Vice President Wanda Jones E. Butcher Connecticut Yankee Atomic Power Company GPA/PA ARM /LFMB E. Jordan P.O. Box 270 OGC-WF J.Partlow ACRS(10)

Hartford, Connecticut 06141-0270 Grey File

SUBJECT:

Cr 1E TO BASES SECTION 3.6, CORE COOLING SYSTEMS OF THE HADDAM NECK PLANT TECHNICAL SPt:CIFICATIONS (Tac No. 68187)

By letter dated May 12, 1988, Connecticut Yankee Atomic Pcwer Company (CYAPCO) proposed to change Bases Section 3.6, "Core Cooling Systen s" of the Haddam Neck Plant Technical Specifications.

The proposed change describes the change in operation of the charging purrps after a safety injection signal.

The NRC staff has reviewed your proposed change in the Bases, to trip the charging pun:ps on a safety injection signal and trarually start a charging punp prior to resetting the safety injection signal, and we agree it will not affect the safety of the plant. This is based on the following:

1) The charging purrps are vulnerable to a single failure if they are not tripped on a safety injection signal,

2) The staff has confirmed that charging flow is not required in the injection phase for any accident, and 3)

For the worst case, charging flow in the recirculation phase would not be needed for 20 r.:inutes.

In the recirculation phase, the single failure vulnerability is not a problem as the charging ptnps take suction from the RHR pun.p discharge which will provide sufficient back pressure to prevent drawing dcwn of the volume control tank and cavitating the charging pun'p.

We have accordingly. revised Section 3.6 of the Haddam Neck Plant Technical Specifications. A copy of the revised page are enclosed.

Sincerely, original signed by Alan B. Wang, Project Manager Project Directorate I-4 8806290237 000620 Divisien of Reactor Projects I/II fDR ADOCK 05000213 Office of Nuclear Peactor Regulation PDn

Enclosure:

TS page 2-6 cc w/ enclosure:

See next page N

Nngh Nt 06//b/88 06/;o/cc 06/10/88

Kr. Edward J. Mroczka Connecticut Yankee Atomic Power Company Haddam Neck Plant ec:

Gerald Garfield, Esquire R. M. Kacich, Manager Day, Berry and Foward Generation Facilities Licensing Counselors at Law Northeast Utilities Service Company City Place Post Office Box 270 Hartford, Connecticut 06103-3499 Hartford, Connecticut 06141-0270 W. D. Rett +rg, Vice President D. O. Nordquist Nuclear Operations Fanager of Quality Assurance Northeast Utilities Service Company Northeast Nuclear Enecgy Company Post Office Eox 270 Post Office Box 270 Hartford, Connecticut 06141-0270' Hartford, Connecticut 06141-0270 Kevin McCarthy, Director Regional Administrator Radiation Control Unit Region I Cepartment of Environtrental Protection U. S. Nuclear Regulatory Comission State Office Building 475 Allendale Road Hartford, Connecticut 06106 King of Prussia, Penr.sylvante 19406 Bradford S. Chase, Under Secretary Board of Selectmen Energy Division Town Hall Office of Policy and Managerrent Haddam, Connecticut 06103 80 Vashington Street Hartford, Connecticut 061C6 J. T. Shediosky, Resident Inspectcr Haddam Neck Plant D. B. Miller, Station Superintendent c/o U. S. Nuclear Regulatory ComisH.:n Haddam Neck Plant Post Office Box 116 Connecticut Yankee Atomic Power Company East Haddam Post Office RFD 1, Post Office Box 127E East Haddam, Connecticut 06423 East Hampton, Connecticut 06424 G. H. Bouchard, Unit Superintendent Heddam Neck Plant i

RFD #1 Post Office Box 1275 East Hampton, Connecticut 06424 9

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With only one diesel generator operating and the pumps associated with that i

diesel operable as required in Item (2) of Specification 3.12, the high-pressure safety injection pump and the low-pressure safety injection pump would be started automatically.

With off-site power available, the high-pressure safety injection pump and the low-pressure safety injection pump would be started automatically.

The charging pumps will automatically trip upon receipt of a safety injection signal to prevent damage to the pumps in the event of failure of the VCT to charging pump suction valve to close or the RWST to charging pump suction valve to open. The operator may manually start a charging pump prior to resetting the safety injection signal.

In that case, the normal standby feature of the char discharge pressure,ging pump, which causes the idle pump to start on low is disabled.

The RHR and charging pumps would be available for manual start for long-term recirculation cooling.

As described in Reference 3, the RCS OPS, in conjunction with administrative controls, prevents exceeding the temperature and pressure limits in Specification 3.4 while RCS temperature is under 315'F or the nCS is not vented.

Part C establishing the limiting condition for operation regarding the disabling of the HPSI pumps to further assure that a pressure transient is not initiated.

Part D establishes requirements regarding the disabling of a charging pump to assure that a pressure transient is not initiated while retaining the flexibility to establish, under strict administrative controls, a redundant emergency boration path should such action be necessary.

FCV-796 is required to be throttled open within the range specified in and for the reasons cited within References (6) and (7).

That throttled position has been determined by separate analyses to insure acceptable core performance during post-LOCA recirculation.

In order to use the HPSI pumps to provide high-pressure recirculation following a small break loss of coolant accident (LOCA) coincident with a single active failure, the following modifications to the emergency core cooling system have been made. A piping crosstie between each HPSI pump suction and the RHR pump discharge has been installed. Two valves, SI-M0V-901 and SI-MOV-902, have been installed in this crosstie.

The two manual HPSI pump suction valves have been replaced with motor-operated valves, SI-MOV-854A and B, to prevent contaminated water from entering the RWST when using the HPSI pumps to provide flow to the core during recirculation. These valves will not be energized until 1989 and no credit will be taken for their use until this time and they will be locked in their safe position.

The manual core deluge isolation valve has been replaced with a de-energized motor-operated valve, SI-MOV-873. Thir valve will be locked open to ensure that adequate flow is available to the core deluge system.

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Reference:

(3)

D. C. Switzer (CYAPCO) letter to D. L. 2 emann (NRC),

dated May 22, 1978.

(4)

D. C. Switzer (CYAPCO) letter to D. L. Ziemann (NRC),

dated May 24, 1978.

(5)

D. C. Switzer (CYAPCO) letter to A. Schwencer (NRC),

dated September 7, 1977.

(6)

E. J. Mroczka (CYAPCO) letter to C. I. Grimes (NRC),

dated December 17, 1986.

(7)

E. J. Mroczka (CYAPCO) letter to C. I. Grimes (NRC),

dated December 19, 1986.

(8)

E. J. Mroczka (CYAPCO) letter to Document Cor. trol Desk (NRC),datedMay 12, 1988.

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