ML20086D520

Telecopy Ro:Heating Steam Coil Leak in Reactor Bldg Ventilation Supply Unit V-AH-4A Resulted in Freezing of Condensate at Inlet to Unit & Subsequent Inoperability of Associated Secondary Containment Isolation Dampers

ML20086D520
Person / Time
Site:	Monticello, 05000000
Issue date:	12/14/1977
From:	Eliason L NORTHERN STATES POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19289B550	List: 05000000/LER-1977-012, :on 770620,during Investigation of Cycle 5 Max Critical Power Ratio Limits,Ge Found That Pump Trip Delay Time Assumed in Original Cycle 5 Transient Analysis Not Appropriate.Amend Request Will Be Submitted 05000000/LER-1977-020-03, /03L:on 770404,RCS Leakage Determined to Be Greater than 10 Gpm.Caused by Packing Leakage Past Stems on RTD Bypass Throttle Valves 13RC20 & 14RC20.Valves Placed on Backseat & Stem Leakage Decreased 05000000/LER-1977-038-03, /03L:on 770519,RCS Leakage Determined to Be Greater than 10 Gpm from Stem Leakoff on Manual Isolation Valves 1PS24 & 1PS28 for Pressurizer Spray Valves.Caused by Packing Leakage.Valves Will Be Repacked at Next Outage ML20086D481 ML20086D514 ML20086D520 ML20086D537 ML20086D550 ML20086D554 ML20086D557 ML20086D561 ML20086D567 ML20086D606 ML20086D642 ML20086D691 ML20086D703 ML20086D760 ML20086D788 ML20086D818 ML20086D823
References
NUDOCS 8312020194
Download: ML20086D520 (2)

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NORTHERN STATES POWER COMPANY

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Bbnticello Nuclear Generating Plant blanticello, &N 55362 l

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Dects:ber 14, 1977 Mr. J. G. Keppler, Director Region III Office of Inspection and Enforcecent Lktited States Nuclear Regulatory Cosmission 799 Roosevelt Road Glen Ellyn, IL 60137

Dear Mr. Keppler:

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FDSTICELID NUCLEAR ENEIMTING PLebT Dockot No. 50-263 License No. LVR-22 A heating steam coil leak in one of the reactor building ventilation supply units (V-MI-4A) resulted in freezing of condensato at the inlet to the unit and subsequent inoperability of the associated secondary containment isola-i tion dampers. The ico was thawed using a steam lanco, the stmm coil was repaired and the isointion darpers were returned to service.

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f Further investigation of this occurrence JS in prugress.

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Yours very truly, j

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vh L. R. Eliason Plant 6hnager l

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Director, Office of Stanagement Infonnation and Program Contrul j

G. Charnoff i

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Minnesota Pollution Control Agency i

Attn:

J. W. Fernan d'

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NORTHERN STATES POWER COMPANY I

Bbnticello Nucicar Generating Plant Abiticello,>N 55362 i

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l Decccher 14, 1977 i

1 Mr. J. G. Keppler, Director i

Region III Office of Inspection and Faforcecent thited States Nuclear Regulatory Comission 799 Roosevelt Road Glen Ellyn, IL 60137 1

Dear Mr. Keppler:

>DNFICELLO NUCLEAR ENEIMTING PIANT Docket No. 50-263 License No. DPR-22 A heating stea:n coil leak in cite of the reactor building ventilation supply 4

mits (V-Alf-4A) resulted in freezing of condensato at the inlet to the toit and subsequent inoperability of the associated secondary containment isola-tion dapers. ' Die ice was thawed using a steam lanco, tho steam coil was repaired and the isolation danpers were retunted to service.

Further investigation of this occurrence is in pmgress.

Yours very truly,

.s w / u/ku L. R. Eliason Plant Mutager LRE/sdd cc: Director, Office of Management Infonnation and Program Control G. Charnoff Minnesota Pollution Control Agency j

Attn:

J. W. Fennan 4

File

-0 Copy sent by telecopier to Keppler.

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