ML19275A662
| ML19275A662 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 09/28/1979 |
| From: | Pappas H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 7910180078 | |
| Download: ML19275A662 (2) | |
Text
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- pn nsang'o, UNITED STATES
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NUCLEAR REGULATORY COMMISSION
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799 ROOSEVELT ROAD o,,
GLEN ELLYN. ILLINOls 60137 o j SEP 2 : 1979 MEMORANDUM FOR: Those on Attached List FROM:
Helen Pappas, Chief, Administrative Branch
SUBJECT:
IE Bulletin No. 79-24 The attached IE Bulletin No. 79-24, titled, " Frozen Lines" was sent to the following licensees on September 27, 1979, for action and information:
ACTION American Electric Power Service Corporation Indiana and Michigan Power Company D. C. Cook 1, 2 (50-315, 50-316)
Commonwealth Edison Company Dresden 1, 2, 3 (50-10, 50-237, 50-249)
Quad-Cities 1, 2 (50-254, 50-265)
Zion 1, 2 (50-295, 50-304)
Consumers Power Company Big Rock Point (50-155)
Palisades (50-255)
Dairyland Power Cooperative LACBWR (50-409)
Iowa Ele.ctric Light & Power Company Duane Arnold (50-331)
Northern States Power Company Monticello (50-263:
Prairie Island 1, 2 (50-282, 50-306)
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 Zimmer (50-358)
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Cincinnati Gas & Electric Company i
29lo'3007%
Those on Attached List SE.' ~
1373 Cleveland Electric Illuminating Company Perry 1, 2 (50-440, 50-441)
Commonwealth Edison Company Braidwood 1, 2 (50-456, 50-457)
Byron 1, 2 (50-454, 50-455)
La Salle 1, 2 (50-373, 50-374)
Consumers Power Company Midland 1, 2 (50-329, 50-330)
Detroit Edison Company Fermi 2 (50-341)
Illinois Power Company Clinton 1, 2 (50-461, 50-462)
Northern Indiana Public Service Company Bailly (50-367)
Public Service of Indiana Marble Hill 1, 2 (50-546, 50-457)
Union Electric Company Callaway 1, 2 (50-483, 50-486)
The Ohio Edison Company Erie 1, 2 (50-580, 50-581)
Sincerely, Helen Pappas, Chief Administrative Branch
Enclosures:
1.
List of IE Bulletins Issued in Last Six Months cc w/encls:
Central Files Reproduction Unit NRC 20b Local PDR NSIC TIC D. W. Kane, Sargent and Lundy
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VOJ P
/ge 9/28/79
N
&wer Addressees Memorandum dated a-
=- M 1979 IE Files AD/FFMSI/IE NMSS/FCSL (AD)
NMSS/FCWM (AD)
NMSS/FCMS (AD)
MPA/DTS Central Files Repro Unit PDR NSIC 1185 089 A
sus b O V/ v
Accession No. 7908220114 SSINS No:
6820 s
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 September 27, 1979 IE Bulletin No. 79-24 FROZEN LINES Summary:
On January 3, 1979, an unusual event occurred at Davis-Besse, Unit 1.
The event involved the freezing of the water in a portion of the high pressure coolant injection (HPCI) system recirculation line that is common to both high pressure coolant injection pumps. The line was not thawed until January 5, 1979, and the event was not reported to NRC until March 12, 1979.
In addition, over the past five years, there have been several events involving frozen instrument and sampling lines.
Description of Circumstances:
The condition was discovered on January 3,1979, while the reactor was operating at approximately 96 percent power.
During a monthly surveillance test of the HPCI pumps, there was no flow through the recirculation line from the pump discharge to the Borated Water Storage Tank (BWST).
Investigation revealed that water in a portion of the line exposed to the outside weather was frozen.
This portion of the line to the BWST is common to both HPCI pumps. The line has redundant heat tracing (a heated wire to prevent freezing); it is insulated; and it has a low-temperature alarm system to warn of freezing conditions.
Water in the line froze apparently because of prolonged sub-freezing temperatures and a defect in the insulation. There was no apparent malfunction of the heat tracing or temperature alarm circuits, although the temperature sensing elements are located in an area not exposed to the coldest temperature conditions.
This recirculation line serves two purposes: One is to provide a flow path for surveillance testing, and the other is to provide a minimum flow path to prevent possible damage to the pump in the event it is operated against a closed discharge valve or a reactor coolant system pressure greater than the maximum discharge pressure of the pump (approximately 1600 psig).
In the initial review of the event on January 3,1979, the licensee concluded that the pumps were still operable with the recirculation line frozen. Therefore, no immediate action was taken to thaw the frozen section of the line. On January 5, 1979, the line was thawei
' '" -"~aillance test of the pumps was successfully completed.
DUPLICATE DOCUMENT L
Entire document previously entered into system under:
1?NSIW qq85 090
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No. of pages:
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