GO2-07-164, Response to Request for Additional Information Related to GL-07-001
| ML073381157 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 11/19/2007 |
| From: | Gambhir S Energy Northwest |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GL-07-001, GO2-07-164 | |
| Download: ML073381157 (2) | |
Text
Sudesh K. Gambhir ENERGY Vice President, Technical Services NORTHW EST P.O. Box 968, PE04 Richland, WA 99352-0968 Ph. 509.377.8313 I F. 509.377.2354 sgambhir@energy-northwest.com November 19, 2007 G02-07-164 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001
Subject:
COLUMBIA GENERATING STATION, DOCKET NO. 50-397 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION RELATED TO GENERIC LETTER 2007-01
Reference:
Letter dated May 1, 2007, WS Oxenford (Energy Northwest) to NRC, "Response to Generic Letter 2007-01, Inaccessible or Underground Cable Failures that Disable Accident Mitigation Systems or Cause Plant Transients"
Dear Sir or Madam:
Transmitted herewith in the attachment is Energy Northwest's (EN)- response to requests for additional information (RAI) communicated to EN by an email from the NRC on October 19, 2007. This RAI was in regard to EN's response to Generic Letter 2007-01, "Inaccessible or Underground Cable Failures that Disable Accident Mitigation Systems or Cause Plant Transients" referenced above. The response in this letter summarizes information presented in a phone conversation held between EN and members of the NRC staff on November 9, 2007.
There are no new commitments being made. If you have any questions, please contact GV Cullen, Regulatory Programs Manager at (509) 377-6105.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the date of this letter.
D-pectfully, iambhir Vice President, Technical Services cc: EE Collins, Jr. - NRC RIV RN Sherman - BPA/1 399 CF Lyon - NRC NRR WA Horin -Winston & Strawn NRC Senior Resident Inspector/988C )/h/7
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION RELATED TO GENERIC LETTER 2!607-01 Attachment Page 1 of 1 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION Request The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the cable failure history for Columbia in response to Generic Letter (GL) 2007-01, "Inaccessible or Underground Power Cable Failures that Disable Accident Mitigation Systems or Cause Plant Transients." During its review, the licensee identified failures of power cables within the scope of Title 10 of the Code of Federal Regulations (10 CFR), Section 50.65, "Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants" (Maintenance Rule). Upon review following the failure of circulating water pump 1C, the licensee found some overheating in power cables to circulating water pumps 1A and 1B. The licensee replaced these cables with higher ampacity-rated cable. If the replaced cables were within the scope of the GL, provide the data requested for each replaced cable, as requested in GL 2007-01.
Response
As part of the extent of condition review of the failure of the Circulating Water pump 1C cable, ampacity calculations for underground duct banks were identified as having deficiencies (reported in Columbia LER 86-033). The revision of the calculations resulted in the determination that the Circulating Water pump power supply circuits were undersized. Based on the revised calculations and indications of potential overheating, the power supply cables to Circulating Water pumps 1A and 1B were prudently replaced.
There were no in-service or test failures involved and therefore, there is no basis to include them in the number of failures at Columbia. The brief details related to Circulating Water pumps 1A and 1B cable replacement were provided in Columbia's Generic Letter 2007-01 response as information only to distinguish them from test or in-service failures.
Text
Sudesh K. Gambhir ENERGY Vice President, Technical Services NORTHW EST P.O. Box 968, PE04 Richland, WA 99352-0968 Ph. 509.377.8313 I F. 509.377.2354 sgambhir@energy-northwest.com November 19, 2007 G02-07-164 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001
Subject:
COLUMBIA GENERATING STATION, DOCKET NO. 50-397 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION RELATED TO GENERIC LETTER 2007-01
Reference:
Letter dated May 1, 2007, WS Oxenford (Energy Northwest) to NRC, "Response to Generic Letter 2007-01, Inaccessible or Underground Cable Failures that Disable Accident Mitigation Systems or Cause Plant Transients"
Dear Sir or Madam:
Transmitted herewith in the attachment is Energy Northwest's (EN)- response to requests for additional information (RAI) communicated to EN by an email from the NRC on October 19, 2007. This RAI was in regard to EN's response to Generic Letter 2007-01, "Inaccessible or Underground Cable Failures that Disable Accident Mitigation Systems or Cause Plant Transients" referenced above. The response in this letter summarizes information presented in a phone conversation held between EN and members of the NRC staff on November 9, 2007.
There are no new commitments being made. If you have any questions, please contact GV Cullen, Regulatory Programs Manager at (509) 377-6105.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the date of this letter.
D-pectfully, iambhir Vice President, Technical Services cc: EE Collins, Jr. - NRC RIV RN Sherman - BPA/1 399 CF Lyon - NRC NRR WA Horin -Winston & Strawn NRC Senior Resident Inspector/988C )/h/7
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION RELATED TO GENERIC LETTER 2!607-01 Attachment Page 1 of 1 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION Request The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the cable failure history for Columbia in response to Generic Letter (GL) 2007-01, "Inaccessible or Underground Power Cable Failures that Disable Accident Mitigation Systems or Cause Plant Transients." During its review, the licensee identified failures of power cables within the scope of Title 10 of the Code of Federal Regulations (10 CFR), Section 50.65, "Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants" (Maintenance Rule). Upon review following the failure of circulating water pump 1C, the licensee found some overheating in power cables to circulating water pumps 1A and 1B. The licensee replaced these cables with higher ampacity-rated cable. If the replaced cables were within the scope of the GL, provide the data requested for each replaced cable, as requested in GL 2007-01.
Response
As part of the extent of condition review of the failure of the Circulating Water pump 1C cable, ampacity calculations for underground duct banks were identified as having deficiencies (reported in Columbia LER 86-033). The revision of the calculations resulted in the determination that the Circulating Water pump power supply circuits were undersized. Based on the revised calculations and indications of potential overheating, the power supply cables to Circulating Water pumps 1A and 1B were prudently replaced.
There were no in-service or test failures involved and therefore, there is no basis to include them in the number of failures at Columbia. The brief details related to Circulating Water pumps 1A and 1B cable replacement were provided in Columbia's Generic Letter 2007-01 response as information only to distinguish them from test or in-service failures.