ML20059D169

Grants NRR Temporary Waiver of Compliance Re Steam turbine- Driven Auxiliary Feedwater Pumps Based on 900824 & 29 Requests

ML20059D169
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	08/30/1990
From:	Wessman R Office of Nuclear Reactor Regulation
To:	Mroczka E CONNECTICUT YANKEE ATOMIC POWER CO.
References
NUDOCS 9009060120
Download: ML20059D169 (6)

Text

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WASHINGTON, D. c. 20555 August 30, 1990 No. 50-213 Mr. Edward J. Mroczka Senior Vice President Nuclear Engineering and Operations Connecticut Yankee Atomic Power Company Northeast Nuclear Energy Company a

P.O. Box 270 Hartford,' Connecticut 06141-0270

SUBJECT:

HADDAM NECK PLANT - NRR TEMPORARY WAIVER OF COMPLIANCE i

RELATED TO THE STEAM TURBINE-DRIVEN AUXILIARY FEEDWATER PUMPS By letter dated August 24, 1990, and supplemented by a letter dated August 29, 1990, Connecticut Yankee Atomic Power Company (CYAPCO), on behalf of the Haddam Neck Plant, requested a Temporary Waiver of Compliance and an emergency amendment to Operating License No. DPR-61.

The waiver would allow the plant to progress in' power ascension with auxiliary feedwater (AFW) automatic initiation t

system not meeting Technical Specification operability requirements.

The-Haddam Neck Plant AFW system consists of two 100% steam driven Terry turbine pumps. The proposed amendment would redefine the operability of the automatic initiation of auxiliary feedwater to include credit for operator action.to adjust AFW to full flow following automatic initiation and reliance on the nonsafety grade control air system to ensure successful' automatic AFW initiation.

The waiver'and amendment are necessary because Technical Specification Tabie 3.3-2 Item 3, " Auxiliary Feedwater" restricts power operation to less than 10%

power with the AFW automatic initiation system inoperable.

The Haddsm Neck Plant is in the process of returning to operation following the Cyr',e 15 refueling outage.

As part of the AFW system testing performed during the preparations for and during start-up, CYAPC0 has identified two issues for which CYAPCO' concludes that the plant is aot'in conformance with the requirements regarding automatic initiation of AFW.

dAPCO has determined that the calculated flow rate achieved oy automatic initiation of AFW alone (if one of the two AFW pumps fails to start) is not sufficient to assure that the criteria of,the design basis loss of feedwater analysis are met and that-the. safety grade automatic initiation: system relies en~a nonsafety grade control air system'for proper operation.

The waiver and amendment will allow the Haddam Neck' Plant to proceed with power ascension above 10% by' redefining ope Tiility of the automatic initiation of the AFW to include credit for operato= act1 m to adjust-AFW to full required flow following automatic initiation and reliance on the nonsafety grade control air system to ensure successful automatic AFW initiation.

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a Mr. Edward J. Mroczka '

Recent calculations by the licensee have concluded that with the automatic initiation of the auxiliary feedwater system one pump will not provide adequate l

flow to the steam generaters to assure that the criteria of the design basis i

loss of feedwater analysis are met.

To compensate for the inadequate flow, the I

design basis analysis must credit operator actions to increase AFW flow to its design value.

Since the loss of feedwater event will cause a reactor trip very quickly, the operator would enter the emergency operating procedures (EOP)

E-0, Reactor Trip, and on the fourth step enter ES-0.1, Reactor Trip Response, for which one of the first steps is to verify adequate AFW flow and to take steps to manually achieve the required flow.

Therefore, taking manual control of the AFW system is covered in training and practiced routinely on the simulator.

CYAPC0 states that the importance of the AFW system is always stressed to the operators and during current simulator training an emphasis will be made on the above concern.

l In addition, recent testing of the AFW system revealed that if the steam admission valve went fully open rapidly, as caused by a rapid loss of control air, the Terry turbines would trip on overspeed. As a result of the testing, the licensee has concluded that the safety grade automatic AFW initiation scheme relies on a nonsafety grade system (i.e., control air) for proper operation.

While control air is a non-Category I system, CYAPC0 has demonstrated that it is highly reliable.

Only one of three control air compressors is necessary to provide the minimum air pressure recuired in the system, the compressors are powered from the emergency diesel generators, cooling water is l

maintained to the compressors and the system is equipped with accumulators.

The I

primary event that could lead to a catastrophic loss of control air is a seismic event.

The air line tubing is not seismically designed, however, it is comprised primarily of copper tubing and in some areas stainless steel tubing, l

both which are relatively ductile materials.

CYAPC0 concluded based on engineering l

judgement that a catastrophic failure of the tubing is not lilrely to occur j

during a seismic event.

CYAPC0 will take manual action to ensure adequate AFW flow.

The importance of the AFW system is emphasized to the operators and taking control o" the AFW system is covered in training and practiced routinely on the simulator.

CYAPCOnasestimated.ghatthesmallbreakLOCAprobabilitywillbeincreased aporoximately 3.4x10 for the next refueling cycle.

The staff agrees that l

this represents approximately a ninc percent increase in the calculated small break LOCA probability at the Haddam Neck Plant and is acceptable for one cycle.

In addition, as a compensator / measure the licensee has agreed to dispatch an operator to the Terry turbine building whenever AFW is automatically initiated to ensure that local control of the AFW system is available if required.

CYAPC0 has committed to provide an AFW initiation event analysis-with best estimate assumptions using ANS 58.8, " Time Response Design Criteria for Nuclear Safety Related Operatcr Actions" as a guidance.

CYAPC0 will also perform a walk-through of the new AFW initiation process to verify that operator actions can be performed within the required response times.

The results of 1

the analysis and walk-through will be provided to the staff.

Based on our review of CYAPC0's request and justification provided by letters dated August 25 and 29, 1990 and your commitment to resolve both concerns prior to restarting for Cycle 17, we conclude that the operation of the Haddam Neck Plant in conformance with TS Table 3.3-2 Item 3 as amended by this' request provides an acceptable level of safety and does not present any undue risk to the health and safety of the public.

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Nr. Edward J. Mroczka 3'-

This. letter grants a temporary waiver of compliance with the cited TS requirements and will be in effect until we cumplete the processing of an emergency license amendment.

Sincerely, l

Richard Wessman, Acting Assistant Director for Region I Reactors Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation cc: See next page t

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Mr. Edward J. Mroczka -

.,, Connecticut Yankee Comic Power Company Haddam Neck Plant CC:

l Gerald Garfield, Esquire-

.R. M. Kacich, Manager-L Day, Berry and Howard Generation Facilities Licensing L

Counselors at Law Northeast Utilities Service Company City Place Post Office Box 270 Hartford, Connecticut 06103-3499 Hartford,-Connecticut 06141-0270 l

W.-D. Romberg, Vice President-D. O.'Nordquist Nuclear Operations-Director of-Quality Services Northeast Utilities Service Ccmpany Northeast Utilities Service Company-L Post Office Box 270 Post Office Box 270 Hartford, Connecticut- 06141-0270 Hartford, Connecticut 06141-0270 Kevin McCarthy, Director Regional Administrator Radiation ~ Control Unit Region I Department-of Environmental Protection U. S. Nuclear Regulatory Commission-State Office Building.

475 Allendale Road Hartford, Connecticut 06106 King of Prussia, Pennsylvania 19406 i

Bradford S. Chase, Under Secretary Board of Selectmen Energy Division Town Hall Office of Policy and Management Haddam, Connecticut 06103 80 Washington Street Hartford, Connecticut- 06106 J. T. Shedlosky, Resident Inspector, Haddam Neck Plant E. A. DeBarba, Nuclear Station Directoc c/o U. S. Nuclear Regulatory Commission 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 flampton, Connecticut 06424 G. H. Bouchard, Nuclear Unit Director-Haddam Neck Plant Connecticut Yankee Atomic Power Company RFD 1, Post Office Box 127E East Hampton, Connecticut 06424

Mr. Edward J. Mroczka August 30,:1990_

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This letter grants a temporary waiver of compliance with the cited TS requirenients and will be in effect until we complete the processing of an emergency-license amendment.

Sincerely,

/s/

3 Richard Wessman, Acting Assistant Director for Region I Reactors i

Division of Reactor Projects - I/II Office of Nuclear. Reactor Regulation cc: See next page

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