ML20133C533

Safety Evaluation Supporting Amend 16 to License DPR-61

ML20133C533
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	07/14/1977
From:	Office of Nuclear Reactor Regulation
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Shared Package
ML20133C497	List: ML20133C495 ML20133C525 ML20133C527 ML20133C533
References
NUDOCS 8510070416
Download: ML20133C533 (4)

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR SUPPORTING AMENDMENT NO.16 TO FACILITY OPERATING CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK PLANT 4

DOCKET NO. 50-213 Introduction By letter dated December 18, 1974, Connecticut Yankee Atomic Power C (the licensee) proposed to completely revise and resubmit the Connecticut Yankee report on high energy pipe breaks (HEPB) outside of containment.

Previously, on March 29, 1974, the AEC staff had concluded, that upon completion of proposed inservice inspection (ISIplant modifications and implementation of the

3 'to withstand the consequen)ces of HEPB. program, the Haddam Neck Plant I Difficulties in completing these necessary plant modifications were attributed to material availability

problems and were cited by the licensee as the basis for completely revising and resubmitting the HEPB a'nalysis.

7 By letter dated February 5,1975 and supplemented by letters dated March 13,1975. April 4,1975, May 1,1975, ,1une 20,1975. May 10,1976 and November 9,1976, the licensee proposed an alternative method for mitigating the consequences of HEPB and requested an amendment.

The changes to the Technical Specifications incorporate aucmented inservice inspection for piping cot:conents outside containment.

This report discusses our review of the proposed syste: of barriers, restraints, and encapsulation sleeves which are oesigned to provide the necessary protection against HEPB and discusses our review of the

! proposed license amendment to incorocrate augmented inservice inspection for piping components outsioe containment.

Minor editorial changes were made to the proposed Technical Specification, consisting of n-numbering of paragraphs and word substitutions. The licensee concurred with these minor editorial enanges on December 7,1976, 1

Discussion The licensee had originally planned to install an independent emergency shutdcwn panel and a motor driven auxiliary steam generator feeowater pumo energyas pipea part of the breaks actions outside to be taken to control the effects of high containment. On March 29, 1974, we issued

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f Change No. 26 to Provisional Operating License No. DDR-14. (Facility

} Operating License No. DPR-61 was issued'Deceder 27,1974) which approved the hardware modifications proposed by the licensee to provide an alternate means of safe plant shutdown in the event of a HEPB. Subsequently, the concept of pmventing pipe whip and jet impingement through the use of barriers, restraints and encapsulation sleeves and the use of augmented inservice inspection to assure continued integrity of high energy piping systems outside containment was approved on Millstone Units 1 and 2 and other operating reactors. In December 1974, as a nsult of material availability problems, schedule delays and increased costs, the licensee proposed a system of barriers, restraints and encapsulation sleeves and augmented inservice inspection as a revised approach to HEPB protection.

' By letter dated January 17, 1975 we infomed the licensee that the system of barriers, restraints and encapsulation sleeves could be substituted for the previously approved modifications pending our review and .

acceptance of the detaile'd design. This revised approach to HEPB protection was approved for operating reactors holding an operating license prior

' to Deceser 1972 by Mechanical Engineering Branch Technical Position No. 4 which was issued March 17, 1975 Evaluation

1. Auomented Inservice Inspection The licensee's submittals of May 10, 1976 and November 9,1976 requested an amendment to the Facility Operating License No. DPR-61,

,! to revise the Technical Specifications to incorporate augmented inservice inspection for piping components outside containment. The licensee's proposed ISI program is consistent with MEB criteria for

" Augmented Inservice Program for Piping Components Outside Containment"

issued March 17, 1975, with one exception.

' The exception is to tne sethod of exacination of welded attachmena on the fee &ater lines. The ISI criteria n;uires volumetric examination in accordance with ASME Code Section II for pipe break welds that uoan rurture may nsult in i

unacceptable consequences. The licensee initially proccsed a visual l examination of these welded attachments because the geometry of the welded attachment prevents the use of volumetric examinations.

These fee &ater line welded attachments were inspected and photocrached ,

by NRC Region I Inspectors during the week of October 26, 1976. During  !

a meeting at the plant on Noveser 19, 1976, the licensee proposed a visual examination for the fee $<ater line welded attachment in

' accordance with ASME Code Section XI in place of a volumetric examination. The staff, after reviewing the geopetry of the welds at feedwater break location X3, reouimd a surface examination in order to assure weld integrity. The licensee agreed on May 25, 1977 to a footnote to Table 4.12-1 of the Noveder 9,197c submittal stating "A Surface Examination in accordance with ASME Code Section XI will be

performed in place of Volumetric Examination for* Break Location X3".

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A surface examination in accordance with ASMI Code Section XI for the i

• feedwater line welded attachment, break location X3, is acceptable because (1) the weld is on the outside surface of the 12" feedwater

' line, (2) volumetric examination would not determine weld integrity, and (3) surface and visual examination will provide sufficient information to determine weld integrity.

2. Barriers, Restraints and Encaosulation Sleeves With proper adjustment in the hot condition and maintenance of critical clearances, the restraints and encapsulation sleeves will have negligible effect on the normal operating stress of the lines to which they are affixed. The proposed system of barriers, restraints and encapsulation sleeves provides an acceptable basis for satisfying the applicable requirements of NRC General Design Criteria No. 4 and is consistent with MEB Position No. 4 dated March 18, .1975, titled, " Pipe Break Considerations in Plants Holding

!. an Operating License Issued Prior to December 1972 - Augmented

. Inservice Inspection and Secondary Protective Measures".

The proposed system of barriers, restraints and encapsulation sleeves is an acceptable alternative to the installation of an independent

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~ emergency shutdown panel and motor driven auxiliary steam generator feed water pump to control the effects of HEPB.

' We therefore, find that the Augmented Inservice Inspection of potential high energy pipe break locations, proposed by the licensee, provides reasonable assurance of the continued integrity of high energy pioing systems located outside containment. We also find that the system of barriers, restraints and encapsulation sleeves installed by the licensee to mitigate the consecuences of a high' energy pipe break are acceptable.

We have determined that the amendment does not authorize a change in effluent types or total amounts nor an increase in p:wer level and will nct result in any significant environmental imsact. Having made this determination, we have further concluded that the amendment involves an action which is insionificant fro: the standocint of environmental imoact and, pursuant to"10 CFR 151.5(d)(4), that an environmental imoact statement or negative declaration and environmental icoact appraisal need not be prepared in connection with the issuance of this acendment.

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I Conclusion We have concluded, based upon the considerations discussed above, that:

(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the amendment does not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Comission's regulations and the issuance of this amendment will not be inimical to the comon defense and security or to the health and safety of the public.

Dated: July 14, 1977

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Mr. W. G. Counsil, Vice President Nuclear Engineering and Operations NOV $ 51982 Connecticut Yankee Atomic Power Company Post Office Box 270 Ne:1 er n in r ng pers ---

Hartford, Connecticut 06101

SUBJECT:

AUXILIARY FEEDWATER SYSTEM EVALUATION - NUREG-0737 ITEM II.E HADDAM NECK The Safety Evaluation forwarded to you by letter dated November 20, 1981, documented our review of your responses to the NRC staff's short-tem and long-term recommendations that resulted from our reliability evaluation of the Haddam Neck Plant auxiliary feedwater system. We found your response to our recommendations acceptable with the exception of Long Tem Recom-mendation 3 for which the staff had not completed its review.

Your letter dated August 27, 1981, addressed Long Term Recommendation 3, which deals with the power diversity position in Branch Technical Position ASB 10-1.

We have reviewed your submittal and find that it satisfactorily resolves this concern. Our Supplemental Safety Evaluation Report is enclosed.

We considered Plant our review of TMI Action Item II.E.1.1 for the Haddam Neck to be complete.

Sincerely,

,k Dennis M. Crutenfield/ Chief Operating Reactors Branch !S Division of Licensing

Enclosure:

Supplemental Safety Evaluation Report

', cc w/ enclosure:

See next page

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. Mr. W. G. Counsil . November 9, 1982 cc William H. Cu'ddy, Esquire State of Connecticut Day, Berry & Howard Office of Policy Management Counselors at Law ATN: Under Secretary Energy One Constitution Plaza Division Hartford, Connecticut 06103 80 Washington Street Hartford, Connecticut 06115

• Board of Selectmen Town Hall Resident Inspector Haddam, Connecticut 06103 .

Haddam Neck Nuclear Power Station c/o U. S. NRC Northeast Nuclear Energy Company ATTN: Superintendent East Haddam Post Of.fice East Haddam, Connecticut 06423 Millstone Plant L P. 0. Box 128 .

U. S. Environmental Protection Waterford, Connecticut 06385 Agency

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Region I Office ATTH: Regional Radiation Representative JFK Federal Building Boston, Massachusetts 02203 .

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Resident Inspector c/o U. S. NRC Superintendent

'P. D. Box Drawer KK Haddam Neck Plant Niantic, Connecticut 06357 RFD !1 Post Office Box 127E Ronald C. Haynes, Regional Administrator East Hampton, Connecticut 06424 Nuclear Regula~ tory Com:ission, Region I 631 Park Avenue -

r.ing of Prussia, Pennsylvania 19406 First Selectman of the Town of Waterford Hall of Records 200 Boston Post Road

• '4tterford, Connecticut DE3E5 John F. Opeka Systems Supe-intendent Northeast Utilities Service C c::any P. O. Box 270 Hartford, Connecticut 06101 Mr. Richard T. Laudena' Manager, Generation Facilities Licensing Northeast Utilities Service Company P. O. Box 270 Hartford, Connecticut 05101

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ENCLOSURE SUPPLEMENT TO SAFETY EVALUATION. REPORT FOR HADDAM NECK NUCLEAR PLANT NUREG-0737, ITEM II.E.1.1 AUXILIARY FEEDWATER SYSTEM Lono Term Recommendation 3 Introduction

. In the Safety Evaluation Report (SER) dated November 20, 1981 concerning power source diversity for the auxiliary feedwater (AFW) pumps, th'e staff indicated that it would provide resolution of this matter in a supplement '

to the SER. The licensee's response of August 27, 1981 indicated that the lack of power source diversity for their plant is not of sufficient signifi-cance to warrant corrective action. However, the licensee has modified the AFW system piping to allow for the use of a motor driven pump to provide

~'heedwater to the steam generator in the event the turbine driven AFW pumps are not operable. The licensee does not propose to provide the capability to start and control the motor driven pump from the control room.

Evaluation The Haddam Neck auxiliary feedwater system consists of two turbine-driven pumps and one motor-driven pu .p; the motor-driven pumo cannot be powered fror; a safety bus. Tne turbine-driven AFW pumps will start automatically and in addition are capable of being started and controlled from the control room.

These pumps are independent of AC power for initiation, valve alignment and

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cooling of the turbine lubricating oil. Therefore, in case of loss of offsite power (LOOP) and the loss of all AC power (LOAC) events; the two turbine-driven AFW pumps are available to provide flow to the steam gener-ators. The motor-driven pumo has only local start and control capability.

Since Haddam Neck is a Westinghouse plant which has about 30 minutes steam generator dryout time, the operator is provided with time to manually start the motor operated AFW pump at the local station.

The AFW system has three water sources. A bypass flowpath has been added to the single suction valve to prevent a single failure from negating the water sources to the pumps. The licensee has installed permanent, seismic supported spool pieces on the suction and discharge sides of the motor-

~ driven pump trains in the event of a design basis earthquake.

In order to provide additional perspective regarding system availability under certain transient events, the staff upgraded the reliability evalua-tion cf the AFW system considering the system changes since TMI-2. The staff's evaluation of the system indicated that the Haddan Neck AFW System with two turbine driven pumps has an unavailability of 1.5 X 10-#/ demand for both the LOOP and LOAC events utilizing the methodology and data base of NUPlG-0511. Comparing the Haddam Neck AFWS unavailability with those of other plants analyzed in NUREG-0611, its reliability can be placed in the medium range of tne reliability scale for the LOOP events and high range for the LOAC events. -

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Conclusion We conclude that with the addition of the motor driven AFW pump to the Haddam Neck AFW System, the system provides an acceptable level of power source diversity. In addition, the staff evaluation of the system under LOOP and LOAC events indicates that for these limiting events, the system availability is acceptable with only the availability of the turbine driven AFW pumps. For other transients where offsite power is available the addition of the motor driven AFW pump will further enhance system availability.

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