ML20023A894
| ML20023A894 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley, Point Beach, Pilgrim, Brunswick, Surry, Farley, Robinson, Zion, McGuire, 05000000 |
| Issue date: | 06/18/1982 |
| From: | Chiramal M NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Michelson C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| References | |
| TASK-AE, TASK-E226 AEOD-E226, AOED-E226, IEB-79-24, NUDOCS 8211010031 | |
| Download: ML20023A894 (4) | |
Text
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ro UNITED STATES y
- *t, NUCLEAR REGULATORY COMMISSION g
j WASHINGTON, D. C. 20666 AE00/E226 1
This is an internal, pre-RN181M deciSica1 document not necessarily representing a position of AE00 or NRC.
MEMORANDUM FOR: Carlyle Michelson, Director Office for Analysis and Evaluation of Operational Data FROM:
Matthew Chiramal Reactor Operations Analysis Branch, AE00
SUBJECT:
IN0PERABILITY OF INSTRUMENTATION DUE TO EXTREME COLD WEATHER
REFERENCE:
(1)
IE Bulletin 79-24, Frozen Lines (2) Memora.:Jum dated June 15, 1981 for H. Denton, NRR, and V. Stello, IE, from C. Michelson on "Inoperability of Instrumentation Due to Extreme Cold Weather" (3) Memorandum dated August 5, 1981 for T. E. Murley, NRR, from R. Mattson, NRR, on "Inoperability of Instrumentation Due to Extreme Cold Weather" (4) Memorandum dated October 13, 1981 for S. Bryan, IE, from R. Baer, IE, on " Proposed Inspection Procedure Preparation for Extreme Cold Weather" (5) Memorandum dated August 14, 1981 for C. Michelson, AE00, from H. Denton, NRR, on "AE00 Memorandum on the Inoperability of Instrumentation Due to Extreme Cold Weather" (6) Memorandum dated November 30, 1981 for C. Michelson, AE00, from R. DeYoung, IE, on "Inoperability of Instrumentation Due to Extreme Cold Weather (AITS H07003276)"
In June 1981 we had issued a memorandum (Reference 2) regarding events involving frozen instrumentation lines and provided recommendations with the objective of lowering the rate of these occurrences.
By memorandum (Reference 3), NRR had initiated actions to address the concerns identified in subsequent operating license reviews. A Branch Technical Position (BTP) on freeze protection requirements for instrumentation sensing and sampling lines for systems important to safety was proposed to be included in the Standard Review Plan.
IE by a memorandum (Reference 4) had proposed issuing inspection procedures to address the concerns involved. The NRR memorandum (Reference 5) stated that NRR concurs with IE that the issuing of an inspection procedure will be more effective than issuing a supplement to IE Bulletin 79-24 as we had recommended.
By a memorandum (Reference 6) IE stated that the Reactor Engineering Branch has prepared Inspection Procedure 71714, " Cold Weather Protection" which was to be included in the January 1, 1982 revision to the IE Manual.
8211010031 820618 PDR ADOCK 05000261 P
s L
I Carlyle Michelson jg j $ jg Based on our review of Licensee Event Reports (LERs) of events that occurred in the winter of 1981-1982, we find that the incidence of inoperability of certain instrumentation lines due to extreme cold weather has not significantly reduced. The attached enclosure provides a listing of the plants and events involved. Of particular note is the events involving freezing of main steam line pressure sensing instrumentation lines at certain PWR units. This category of failure is a recurring one that was highlighted in our previous memorandum (Reference 2). Failures involving fire protection equipment, feedwater instrumentation channels and refueling water storage tank level sensors are also repetitive.
Since IE Inspection Procedure 7174 was to be included in the IE Manual in January 1982, it was ineffective during the winter of 1981-1982. The effect of the procedure should be evident during future winter seasons, and our tracking of events during next winter should show a decrease in similar cold weather-related failures.
The approach of amending the Inspection Manual may have its advantages, but it does not directly provide licensees with the finding and concerns raised in our evaluation of failures due to extreme cold weather. To inform licensees of operating reactors of the types of failures that have occurred due to extreme cold weather andthe concerns raised, we could include the highlights from our memorandum of June 1981 and the failure data of the winter of 1981-1982 in the next Power Reactor Events.
/4 w Matthew Chiramal Reactor Operations An."ysis Branch Office for Analysis al.d Evaluation of Operational Data
Enclosure:
As stated cc w/ enclosure:
RMajors, ACRS 00krent, ACRS SRosen, INP0 CHeltemes, AE00
" cv
- s Enclosure Plant Name LER No.
Date of Occurrence Brief Description of Event Point Beach 1 81-20/03L 12/19/81 "A" steam generator pressure
~
82-01/03L 01/07/82 sensing lines had frozen on four 01/10/82 different occasions. The events were caused by inadequate freeze protection and extremely cold weather.
Zion 2 82-01/03L 01/09/82 A SG 2C pressure channel failed high due to frigid outside air entering the transmitter location and causing a frozen sensing line.
H.R. Robinson 2 81-34/03L 12/11/81 A steam line pressure channel was indicating higher reading than others. This was caused by freezing of the pressure trans-mitter sensing lines.
It was found that the freeze protection circuit for this transmitter was not in service.
McGuire 1 82-07/03L 01/11/82 Exposure to cold conditions began to cause errors in l
instrumentation that affected automatic feedwater control.
Efforts to prevent instrument line from freezing were made all day on January 10 and January 11; but two channels of SG A pressure tripped due to freezing of the sensing lines.
ESF was automati-cally actuated as a result of 2/3 low pressure coincidence trip of SG-A.
Inadvertent actuation of ESF caused safety injection, I
steam line isolation and reactor and turbine trips.
Farley 2 82-04/03L 01/11/82 A main steam line pressure channel was declared inoperable due to frozen sensing lines.
Sections of the line were found to have inadequate insulation.
Farley 2 82-02/03L 01/11/82 An instrumentation loop i
associated with main feed flow transmitter was declared inoperable due to frozen transmitter sensing lines.
r
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Plant Name LER No.
Date of Occurrence Brief Description of Event Farley 2 82-03/03L 01/12/82 An~ instrumentation loop associated with a RWST level transmitter was declared inoperable when its indicator failed low. The exposed diaphragm on the associated level switch ruptured due to freezing, causing leakage of the sensing line.
j Pilgrim 82-02/03L 01/18/82 Pressure switch associated with 01/19/82 the diesel fire pump was 01/23/82 inoperable on three occasions.
The sensing line freezing l
during cold weather was the cause l
of switch failures.
Surry 1 82-04/03L 01/12/82 Unusually low temperatures caused stagnant water in the l
body of several fire hydrants to freeze and prevented hydrant valve operation.
Beaver Valley 1 82-02/03L 01/19/82 SG drain tank recirculation line cracked due to freezing within the line as a result of an extended cold spell.
The heat tracing of the line found to be inadequately sized.
Brunswick 2 82-04/03L 01/11/82 Frozen condensate in CAC system vaporizer condensate return line prevented the vaporizer adding nitrogen to the drywell - heat
' acing and insulation lagging I
of lines found missing.
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