ML14170A501
| ML14170A501 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 09/27/1979 |
| From: | O'Reilly J NRC/IE, NRC/RGN-II |
| To: | Jackie Jones Carolina Power & Light Co |
| References | |
| NUDOCS 7910190239 | |
| Download: ML14170A501 (10) | |
Text
NPLEAR REGULATORY COMMISSION REGION II 101 MARIETTA ST., N.W., SUITE 3100 ATLANTA, GEORGIA 30303 SEP 2 7 1979 In Reply Refer To:
RII:JPO 50-325 50-324 Carolina Power and Light Company Attn:
J. A. Jones Senior Executive Vice President and Chief Operating Officer 411 Fayetteville Street Raleigh, North Carolina 27602 Gentlemen:
The enclosed Bulletin 79-24 is forwarded to you for action. Written responses are required. If you desire additional information regarding this matter, please contact this office.
Sincerely, James P. O'Reilly Director
Enclosure:
- 1.
- 2.
Designated Applicants for Operating Licenses 791019O02-3 7
0SEP 2 7 1979 Carolina Power and Light Company
-2 cc w/encl:
A. C. Tollison, Jr.
Plant Manager Box 458 Southport, North Carolina 28461 R. B. Starkey, Jr., Plant Manager Post Office Box 790 Hartsville, South Carolina 29550
Accession No. 7908220114 SSINS No:
6820 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 thawed and the surveillance test of the pumps was-successfully completed.
IE Bulletin No. 79-24 September 27, 1979 Page 2 of 2 Cause of Event:
This event is attributed to an inadequate design. The heat tracing provided on this recirculation line was unable to prevent freezing when the line was exposed to sub-freezing temperatures for a prolonged period of time. The temperature sensors which control the heat tracing and which trigger the low-temperature alarm were located in an area not exposed to the coldest temperatures to which the piping is subjected.
Corrective Action:
To prevent recurrence, the licensee increased the temperature setting of the thermostat for the heat tracing on the recirculation line. Further, a temporary enclosure was built around the line and additional heat tracing was installed.
After the line was thawed and blown down, surveillance testing to verify pump operability was performed. An engineering evaluation was initiated by the licensee to develop long-term corrective action.
Other Frozen Lines:
In addition to this event at Davis-Besse, there have been many events involving frozen instrument and sampling lines. During the last five years, facilities experiencing events of this kind include:
Arkansas Nuclear One Oconee Davis-Besse Pilgrim Duane Arnold Point Beach Hatch Salem Fitzpatrick Surry Haddam Neck Trojan Indian Point Zion Millstone Action To Be Taken:
All licensees and construction permit holders receiving this Bulletin for action are requested to review their plants to determine that adequate protective measures have been taken to assure that safety-related process, instrument, and sampling lines do not freeze during extremely cold weather.
The results of these reviews should be reported to the Regional Director by October 31, 1979.
Approved by GAO (R0072); clearance expires 7/31/80. Approval was given under a blanket clearance specifically for generic problems.
DESIGNATED APPLICANTS FOR OPERATING LICENSES Salem 2 North Anna 2 Diablo Canyon 1 & 2 Sequoyah 1 McGuire 1 San Onofre 2 Summer Watts Bar 1 & 2
00 IE Bulletin No. 79-24 Enclosure September 27, 1979 Page 1 of 5 LISTING OF IE BULLETINS ISSUED IN LAST SIX MONTHS Bulletin Subject Date Issued Issued To No.
79-24 Frozen Lines 9/27/79 All Power Reactor Facilities with an OL or a CP 79-23 Potential Failure of 9/12/79 All Power Reactor Emergency Diesel Facilities.with an Generator Field Operating License or Exciter Transformer a Construction Permit 79-14 Seismic Analyses For 9/7/79 All Power Reactor (Supplement As-Built Safety-Related Facilities with an OL
- 2)
Piping Systems or a CP 79-22 Possible Leakage of 9/5/79 Each Licensee who Tubes of Tritium Gas Receives Tubes of Used in Timepieces for Tritium Gas -in Luminosity Timepieces for Luminosity 79-13 Cracking in Feedwater 8/30/79 All Designated (Rev. 1)
System Piping Applicants for OLs 79-02 Pipe Support Base Plate 8/20/79 All Power Reactor (Rev. 1)
Designs Using Concrete Facilities with an OL (Supplement Expansion Anchor Bolts or a CP
- 1) 79-14 Seismic Analyses For 8/15/79 All Power Reactor (Supplement) As-Built Safety-Related Facilities with an OL Piping Systems or a CP 79-21 Temperature Effects 8/13/79 All PWRs with an on Level Measurements operating license 79-20 Packaging Low-Level 8/10/79 All Materials Licensees Radioactive Waste for who did not receive Transport and Burial-Bulletin No. 79-19 79-19 Packaging Low-Level 8/10/79 All Power and Research Radioactive Waste for Reactors with OLs, Transport and Burial fuel facilities except uranium mills, and certain materials licensees
IE Bulletin No. 79-24 Enclosure September 27, 1979 Page 2 of 5 LISTING OF IE BULLETINS ISSUED IN LAST SIX MONTHS Bulletin Subject Date Issued Issued To No.
79-18 Audibility Problems 8/7/79 All OL's for action Encountered on Evacua-All CP's for information tion of Personnel from High-Noise Areas 79-05C&06C Nuclear Incident at Three 7/26/79 To all PWR Power Mile Island - Supplement Reactor Facilities with an OL 79-17 Pipe Cracks in Stagnant 7/26/79 All PWR's with Borated Water Systems at operating license PWR Plants 79-16 Vital Area Access Controls 7/26/79 All Holders of and applicants for Power Reactor Operating Licenses who anticipate loading fuel prior to 1981 79-14 Seismis Analyses for As-7/18/79 All Power Reactor (Rev. 1)
Built Safety-Related Facilities with an Piping System OL or a CP 79-15 Deep Draft Pump 7/18/79 All Power Reactor (Supp. 1)
Deficiencies Licensees with a CP and/or OL 79-15 Deep Draft Pump 7/11/79 All Power Reactor Deficiencies Licensees with a CP and/or OL 79-14 Seismic Analyses for 7/27/79 All Power Reactor (Correc-As-Built Safety-Related Facilities with an tion)
Piping System OL or a CP 79-14 Seismic Analyses for, 9/7/79.-
All Power Reactor (Supp. 2)
As-Built Safety-Related facilities with an Piping System OL or a CP 79-14 Seismic Analyses for 7/18/79 All Power Reactor (Rev. 1)
As-Built Safety-Related Facilities with an Piping System OL or a CP
IE Bulletin No. 79-24 Enclosure September 27, 1979 Page 3 of 5 LISTING OF IE BULLETINS ISSUED IN LAST SIX MONTHS Bulletin Subject Date Issued Issued To No.
79-14 Seismic Analyses for 7/2/79 All Power Reactor As-Built Safety-Related facilities with an Piping System OL or a CP 79-13 Cracking in Feedwater 8/30/79 All PWR's with an (Rev. 1)
System Piping operating license 79-13 Cracking in Feedwater 6/25/79 All PWRs with an System Piping OL for action. All BWRs with a CP for information 79-02 Pipe Support Base Plate 6/21/79 All Power Reactor (Rev. 1)
Designs Using Concrete Facilities with an Expansion Anchor Bolts OL or a CP 79-01A Environmental Qualification 6/6/79 All Power Reactor of Class 1E Equipment (Defi-Facilities with an OL ciencies in the Environmental or CP Qualification of ASCO Sole noid Valves) 79-12 Short Period Scrams at 5/31/79 All GE BWR Facilities BWR Facilities with an OL 79-11 Faulty Overcurrent Trip 5/22/79 All Power Reactor Device in Circuit Breakers Facilities with an for Engineered Safety OL or a CP Systems 79-10 Requalification Training 5/11/79 All Power Reactor Program Statistics Facilities with an OL 79-09 Failures of GE Type AK-2 4/17/79 All Power Reactor Circuit Breaker in Safety Facilities with an Related Systems OL or CP 79-08 Events Relevant to BWR 4/14/79 All BWR Power Reactor Reactors Identified During Facilities with an OL Three Mile Island Incident 79-07 Seismic Stress Analysis 4/14/79 All Power Reactor of Safety-Related Piping Facilities with an OL or CP
IE Bulletin No. 79-24 Enclosure September 27, 1979 Page 4 of 5 LISTING OF IE BULLETINS ISSUED IN LAST SIX MONTHS Bulletin Subject Date Issued Issued To No.79-06B Review of Operational 4/14/79 All'Combustion Engineer Errors and System Mis-ing Designed Pressurized alignments Identified Water Power Reactor During the Three Mile Facilities with an Island Incident Operating License 79-06A Review of Operational 4/18/79 All Pressurized Water (Rev. 1)
Errors and System Mis-Power Reactor Facilities alignments Identified of Westinghouse Design During the Three Mile With an OL Island Incident 79-06A Review of Operational 4/14/79 All Pressurized Water Errors and System Mis-Power Reactor Facilities alignments Identified of Westinghouse Design During the Three Mile With an OL Island Incident 79-06 Review of Operational 4/11/79 All Pressurized Water Errors and System Mis-Power Reactors With an alignments Identified OL except B&W facilities During the Three Mile Island Incident 79-06C Nuclear Incident at Three 7/26/79 To all PWR Power Mile Island - Supplement Reactor Facilities with an OL 79-05C Nuclear Incident at Three 7/26/79 To all PWR Power Mile Island - Supplement Reactor Facilities with an OL 79-05B Nuclear Incident at 4/21/79 All B&W Power Reactor Three Mile Island Facilities with an OL 79-05A Nuclear Incident at 4/5/79' All B&W Power Reactor Three Mile Island Facilities with an OL 79-05 Nuclear Incident at 4/1/79 All Power Reactor Three Mile Island Facilities with an OL and CP
IE Bulletin No. 79-24 Enclosure September 27, 1979 Page 5 of 5 LISTING OF IE BULLETINS ISSUED IN LAST SIX MONTHS Bulletin Subject Date Issued Issued To No.
79-02 Pipe Support Base Plate 8/20/79 All Power Reactor (Rev. 1)
Designs Using Concrete Facilities with an (Supp. 1)
Expansion Anchor Bolts OL or a CP 79-02 Pipe Support Base Plate 6/21/79 All Power Reactor (Rev. 1)
Designs Using Concrete Facilities with an Expansion Anchor Bolts OL or a CP 79-01A Environmental Qualification 6/6/79 All Power Reactor of Class 1E Equipment Facilities with an (Deficiencies in the Envi-OL or CP ronmental Qualification of ASCO Solenoid Valves)