ML19344A726

Informs That Encl IE Bulletin 80-18, Maint of Adequate Min Flow Through Centrifugal Charging Pumps Following Secondary Side High Energy Line Rupture, Was Sent to Listed Licensees on 800724

ML19344A726
Person / Time
Issue date:	07/25/1980
From:	Pappas H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	Wright G ILLINOIS, STATE OF
References
NUDOCS 8008220071
Download: ML19344A726 (2)

Text

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798 ROOSEVELT ROAD GLEN ELLYN. ILLINOIS 60137

'JtII.* 2 51980 State of Illinois Department of Public liealth ATTN:

Mr. Gary N. Wright, Chief Division of Nuclear Safety 535 West Jefferson Street Springfield, IL 62761 Gentlemen:

The attached IE Bulletin No. 80-18 titled " Maintenance of Adequate Minimum Flow Thru Centrifugal Charging Pumps Following Secondary Side High Energy Line Rupture" was sent to the licensees listed below on July 24, 1980:

ACTION American Electric Power Service Corporation Indiana and Michigan Power Company D. C. Cook 1, 2 (50-315, 50-316)

Commonwealth Edison Company Zion 1, 2 (50-295, 50-304)

Consumers Power Company Palisades (50-255)

Northern States Power Company Prairie Island 1, 2 (50-282, 50-306) j l

Toledo Edison Company Davis-Besse 1 (50-346)

Wisconsin Electric Power Company Point Beach 1, 2 (50-266, 50-301)

Wisconsin Public Service Corporation Kewaunee (50-305)

INFORMATION Commonwealth Edison Company Braidwood 1, 2 (50-456, 50-457) i Byron 1, 2 (50-454, 50-455) 8008220 o 7/

State of Illinois Consumers Power Company Midland 1, 2 (50-329, 50-330)

Public Service of Indiana Marble Hill 1, 2 (50-546, 50-547)

Union Electric Company Callaway 1, 2 (50-483, 50-486)

Sincerely, i

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Iaten Pappas Thief Administrat ve Branch

Enclosure:

IE Bulletin No. 80-18 l

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Mr. D. W. Kane, Sargent & Lundy Central Files Reproduction Unit NRC 20b Local PDR NSIC TIC Y

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SSINS No.: 6820 Accession No.:

UNITED STATES 8005050062 NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 IE Bulletin No. 80-18 Date:

July 24,1980 MAINTENANCE OF ADEQUATE MINIMUM FLOW THRU CENTRIFUGAL CHARGING PUMPS FOLLOWING SECONDARY SIDE HIGH ENERGY LINE RUPTURE Description of Circumstances:

Letters similar to the May 8, 1980 notification made pursuant to Title 10 CFR Part 21 (enclosure) were sent from Westinghouse to a number of operating plants and plants under construction (list, within enclosure) in early Msy, 1980.

The letters and the enclosed "Part 21" letter contain a complete description of the potential problem summarized below. The letters indicated that under certain conditions the centrifugal charging pumps (CCPs) could be damaged due to lack of minimum flow before presently applicable safety injection (SI) termination criteria are met. The particular circumstances that could result in damage vary somewhat from plant to plant, but involve unavail-ability of the pressurizer power operated relief valves (PORVs), with operation of one or m'are CCPs repressurizing the reactor during SI following a secondary system high energy line break. Since the SI signal automatically isolates the CCP mini-flow return line, the flow through the CCPs is determined by the individual pump characteristic head vs. flow curve, the pressurizer safety valve setpoint, and the flow resistances and pressure losses in the piping and in the reactor core. That minimum flow may not be adequate to insure pump cooling, and resulting pump damage could violate design criteria before current SI termination criteria are met.

Westinghouse recommends that plant specific calculations outlined in the letter (enclosure) be performed to determine if adequate minimum flow is assured under all conditions. If adequate minimum flow is not assured, Westinghouse recommends specific equipment and procedure modifications which will result in adequate minimum flow. The recommended modifications assure availability of the necessary minimum flow by assuring that the mini-flow bypass line will be open when needed, but will be closed at lower pressures when the extra flow resulting from bypass line closure might be necessary for core cooling.

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