ML071100121
| ML071100121 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 05/10/2007 |
| From: | Donohew J NRC/NRR/ADRO/DORL/LPLIV |
| To: | Sheppard J South Texas |
| Thadani M, NRR/DLPM, 415-1476 | |
| References | |
| GL-07-001, TAC MD4382, TAC MD4383 | |
| Download: ML071100121 (6) | |
Text
May 10, 2007 Mr. James J. Sheppard President and Chief Executive Officer STP Nuclear Operating Company South Texas Project Electric Generating Station P.O. Box 289 Wadsworth, TX 77483
SUBJECT:
SOUTH TEXAS PROJECT, UNITS 1 AND 2 - RE: GENERIC LETTER 2007-01, INACCESSIBLE OR UNDERGROUND POWER CABLE FAILURES THAT DISABLE ACCIDENT MITIGATION SYSTEMS OR CAUSE PLANT TRANSIENTS, PROPOSED ALTERNATIVE COURSE OF ACTION (TAC NOS. MD4382 AND MD4383)
Dear Mr. Sheppard:
On February 7, 2007 the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2007-01, Inaccessible or Underground Power Cable Failures that Disable Accident Mitigation Systems or Cause Plant Transients (Agencywide Documents and Access Management System (ADAMS) Accession No. ML070360665). The purpose of GL 2007-01 is to (1) inform licensees that the failure of certain power cables can affect the functionality of multiple accident mitigation systems or cause plant transients, (2) inform licensees that, in the absence of adequate monitoring of cable insulation, equipment could fail abruptly during service, causing plant transients or disabling accident mitigation systems, and (3) request licensees to provide (a) information on the monitoring of inaccessible or underground electrical cables within 90 days of the date of the GL, or (b) an alternative course of action within 30 days of the date of the GL.
By letter dated March 8, 2007 (NOC-AE-07002126) (ADAMS Accession No. ML070740056),
South Texas Project (STP) Nuclear Operating Company (the licensee) submitted a 30-day response to the GL for the South Texas Project Electric Generating Station, Units 1 and 2. In its letter, the licensee provided an alternative course of action for providing the requested information in accordance with Item (2) of the Required Response, which states Addressees who choose not to provide information requested or cannot meet the requested completion dates are required to submit written responses within 30 days of the date of this generic letter.
The responses must address any alternative course of action proposed, including the basis for the acceptability of the proposed alternative course of action.
In its letter, the licensee stated that Unit 2 has a refueling outage that is scheduled during the requested 90-day period to respond to the GL and the engineering organizations that would be providing support to prepare and submit the requested information in the GL are now focused on outage support activities for the safe plant operation in the outage. As discussed with the NRC staff on February 27, 2007, due to the extensive resources required to support these modifications, the licensee stated that it would provide the requested information in the GL by July 26, 2007.
J. J. Sheppard In the letter, the licensee also provided the following additional justification for the proposed extended response date:
1.
Initial search of the Corrective Action Program database did not find any cable failures within the scope of the Generic Letter.
2.
The 480vac [volts alternating current], 120vac, 125vdc [volts direct current] and 250vdc systems are all ungrounded and monitored with continuous ground fault detectors.
3.
Medium voltage cables are all Ethylene Propylene Rubber (EPR) insulated which is the most resistant [insulation] to water related failure mechanisms.
4.
Cables were tested at installation.
5.
STP cable installation was done later than many plants and incorporated improvements in pulling procedures and compounds resulting in lower pull stresses.
6.
STP has been proactive in replacing cables in particular the ECW 480vac motor control center power feeders were replaced where insulation resistance readings were trending low. The cables are being replaced prior to the low insulation resistance readings being an operability concern.
7.
STP has a program that inspects for and removes water from the underground cable vaults and manholes. The preventions in place include sump pumps, inspection ports at sealed manhole covers, repairing manhole seals, and procedural controls over work in manholes.
8.
STP periodically tests a representative sample of 480vac, 4,160vac and 13,800vac cables as part of the Preventive Maintenance program.
The NRC staff reviewed the licensees proposed alternative course of action and the above justification, and concluded that the alternative would be acceptable if the licensee would change its proposed GL response date from July 26, 2007, to June 22, 2007. This was discussed with members of the licensees staff in a conference call on March 20, 2007, and the licensee agreed to change its response date to June 22, 2007. Based on this, the NRC staff concludes that the licensees alternative course of action for responding to the GL is acceptable for Units 1 and 2.
J. J. Sheppard If you have any questions concerning this letter, please contact Mohan C. Thadani at (301) 415-1476.
Sincerely,
/RA/
Jack N. Donohew, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-498 and 50-499 cc: See next page
March 2007 South Texas Project, Units 1 & 2 cc:
Senior Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 289 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 J. J. Nesrsta/R. K. Temple E. Alercon/Kevin Pollo City Public Service Board P.O. Box 1771 San Antonio, TX 78296 INPO Records Center 700 Galleria Parkway Atlanta, GA 30339-3064 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 Steve Winn/Christie Jacobs Eddy Daniels/Marty Ryan NRC Energy, Inc.
211 Carnegie Center Princeton, NJ 08540 Judge, Matagorda County Matagorda County Courthouse 1700 Seventh Street Bay City, TX 77414 A. H. Gutterman, Esq.
Morgan, Lewis & Bockius 1111 Pennsylvania Avenue, NW Washington, DC 20004 E. D. Halpin Site Vice President STP Nuclear Operating Company South Texas Project Electric Generating Station P.O. Box 289 Wadsworth, TX 77483 S. M. Head, Manager, Licensing STP Nuclear Operating Company P.O. Box 289, Mail Code: N5014 Wadsworth, TX 77483 C. T. Bowman General Manager, Oversight STP Nuclear Operating Company P.O Box 389 Wadsworth, TX 77483 Marilyn Kistler Sr. Staff Specialist, Licensing STP Nuclear Operating Company P.O. Box 289, Mail Code 5014 Wadsworth, TX 77483 Environmental and Natural Resources Policy Director P.O. Box 12428 Austin, TX 78711-3189 Jon C. Wood Cox, Smith, & Matthews 112 East Pecan, Suite 1800 San Antonio, TX 78205 Director Division of Compliance & Inspection Bureau of Radiation Control Texas Department of State Health Services 1100 West 49th Street Austin, TX 78756
March 2007 South Texas Project, Units 1 & 2 cc:
Mr. Ted Enos 4200 South Hulen Suite 422 Ft. Worth, TX 76109 Brian Almon Public Utility Commission William B. Travis Building P.O. Box 13326 1701 North Congress Avenue Austin, TX 78701-3326 Susan M. Jablonski Office of Permitting, Remediation and Registration Texas Commission on Environmental Quality MC-122 P.O. Box 13087 Austin, TX 78711-3087 Ken Coates Plant General Manager STP Nuclear Operating Company South Texas Project Electric Generating Station P.O. Box 289 Wadsworth, TX 77483 Mr. Terry Parks, Chief Inspector Texas Department of Licensing and Regulation Boiler Division P.O. Box 12157 Austin, TX 78711
J. J. Sheppard If you have any questions concerning this letter, please contact Mohan C. Thadani at (301) 415-1476.
Sincerely,
/RA/
Jack N. Donohew, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-498 and 50-499 cc: See next page DISTRIBUTION:
PUBLIC LPLIV Reading RidsNrrDorlLpl4 RidsNrrDprPgcb RidsNrrPMMThadani RidsNrrLALFeizollahi RidsAcrsAcnwMailCenter RidsRgn4MailCenter RidsOgcRp RidsNrrDeEeeb Accession No.: ML071100121 OFFICE NRR/LPL4/PM NRR/LPL4/LA PGCB/BC EEEB/BC NRR/LPL4/BC NAME JDonohew LFeizollahi CJackson GWilson THiltz DATE 4/24/07 4/25/07 5/8/07 5/9/07 5/10/07 OFFICIAL RECORD COPY