ML14170A429
| ML14170A429 | |
| Person / Time | |
|---|---|
| Site: | Harris, Brunswick, Robinson  |
| Issue date: | 09/12/1979 |
| From: | O'Reilly J NRC/IE, NRC/RGN-II |
| To: | Jackie Jones Carolina Power & Light Co |
| References | |
| NUDOCS 7909270122 | |
| Download: ML14170A429 (10) | |
Text
0 0UNITED STATES 0
NUCLEAR REGULATORY COMMISSION aREGION II o
101 MARIETTA ST., N.W., SUITE 3100 ATLANTA, GEORGIA 30303 In Reply Refer To:
SEP 12 1979 RII:JPO 50-325, 50-324 50-400, 50-401 50-402, 50-403
< 26 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:
Enclosed is IE Bulletin 79-23 which requires action by you with regard to your power reactor facility(ies) with an operating license or a construction permit.
Should you have questions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely, James P. O'Reilly Regional Director
Enclosures:
- 1.
- 2.
List of IE Bulletins Issued in the Last Six Months
~9O92~7No\\
SEP 12 1979 Carolina Power and Light Company
-2 cc w/encl:
A. C. Tollison, Jr.
Plant Manager Box 458 Southport, North Carolina 28461 R. Parsons, Site Manager Post Office Box 101 New Hill, North Carolina 27562 R. B. Starkey, Jr., Plant Manager Post Office Box 790 Hartsville, South Carolina 29550
Accession No. 7908220104 SSINS No.:
6820 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 September 12, 1979 IE Bulletin No. 79-23 POTENTIAL FAILURE OF EMERGENCY DIESEL GENERATOR FIELD EXCITER TRANSFORMER Description of Circumstances:
Florida Power and Light Company recently reported a problem encountered during a 24-hour full load test of the emergency diesel generators (EDG) at their Turkey Point facility. Approximately 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> into the test, the A-EDG tripped due to a differential-relay lockout on B and C phases; the B-EDG was manually stopped, thus interrupting the test at that point in time.
Subsequent investigation and testing by the licensee revealed a design error on both the A and B EDGs which resulted in overheating of the Exciter Power Transformers (EPTs) at sustained high load operation.
The following nameplate data applies to the equipment installed at Turkey Point:
Emergency Diesel Generator General Motors (Electro-Motive Division)
Model EMD-999-20 Engine-turbocharged, 2 cycle, EMD design 20-645E4 Generator-EMD-design Model A-20 Exciter Power Transformer GE-single phase Model-9T24Y1004 Serial-MD Cycles-60 KVA 15 Insulation-4160 V The manufacturer's findings and recommendations regarding the above problem are described below:
"A potential problem can exist if the neutral of the generator and the neutral of the primary windings of the excitation power transformer (EPT) (sometimes referred to as the control power transformer (CPT)) are connected. A direct connection
SEP 12 1979 Mississippi Power and Light Company
-2 cc w/encl:
C. K. McCoy Plant Manager Post Office Box 756 Port Gibson, Mississippi 39150
IE Bulletin No. 79-23 September 12, 1979 Page 2 of 3 between the neutrals, or a connection through common grounding of both neutrals, are equally undesirable conditions.
Whenever either of these undesirable con ditions exist, high circulating currents can be induced by harmonics. These currents may exceed transformer ratings and result in transformer damage or failure.
The connection between the neutrals, either direct or through common grounding, may have been designated in the original wiring design, or may have been subsequently added by a contractor or by power plant personnel to balance excitation transformer voltages relative to the generator. No significant benefit is obtained by balancing the primary voltage of the excitation trans former by means of these connections."
According to the manufacturer, "to avoid this potential transformer damage or failure, the circuitry of each installation should be examined to determine if a circuit exists between the neutral of the primary windings of the EPT or CPT and the generator neutral.
If the condition exists, the neutral circuit should be disconnected, and the transformer primary neutral allowed to float."
Licensees may utilize Regulatory Guide 1.108, Revision 1, as a reference for the periodic testing of diesel generator units used as on-site electric power systems at nuclear power plants.
Action to be Taken by Licensees:
For all power reactor facilities with an operating license or a construction permit:
- 1.
Determine whether or not connections have been made between low KVA rated transformers and high KVA rated EDGs without adequate limitations on the flow of circulating currents. If applicable, provide a description of the corrective action being taken to address this problem.
- 2.
Provide a schedule for the completion of a sustained full-load operation test of the EDGs for a duration of not less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, or provide the results of the similar long duration, full-load test which has already been completed on the EDGs installed at your facility. The test should demonstrate full-load carrying capability for an interval of not less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, of which 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> should be at a load equivalent to the continuous rating of the diesel generator and 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> at a load equivalent to the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> rating of the diesel generator. The test should also verify that voltage and frequency requirements are maintained and that the cooling system functions within design limits.
- 3.
Provide a written report of the above actions within 45 days of the receipt of this Bulletin.
Reports should be submitted to the Director of the appropriate NRC Regional Office. A copy of your report should be sent to the U. S. Nuclear Regulatory Commission, Office of Inspection and Enforcement, Division of Reactor Opera tions Taspecyon, Washington, D.C 2Q555.
IE Bulletin No. 79-23 September 12, 1979 Page 3 of 3 Approved by GAO, B180225 (R0072); clearance expires 7/31/80. Approval was given under a blanket clearance specifically for identified generic problems.
00 IE Bulletin No. 79-23 Enclosure September 12, 1979 Page 1 of 4 LISTING OF IE BULLETINS ISSUED IN LAST SIX MONTHS Bulletin Subject Date Issued Issued To No.
79-23 Potential Failure of Emer-9/12/79 All Power Reactor gency Diesel Generator Facilities with an Field Exciter Transformer OL 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 79-21 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 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 79-17 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 79-15 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
S IE Bulletin No. 79-23 Enclosure September 12, 1979 Page 2 of 4 LISTING OF IE BULLETINS ISSUED IN LAST SIX MONTHS Bulletin Subject Date Issued Issued To No.
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 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 79-12 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
IE Bulletin No. 79-23 Enclosure September 12, 1979 Page 3 of 4 LISTING OF IE BULLETINS ISSUED IN LAST SIX MONTHS Bulletin Subject Date Issued Issued To No.79-06C Nuclear Incident at Three 7/26/79 To all PWR Power Mile Island - Supplement Reactor Facilities with an OL 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 79-05C 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-OSA 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. 79-23 Enclosure September 12, 1979 Page 4 of 4 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-OA 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)