ML102080500
| ML102080500 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 07/21/2010 |
| From: | Harrison A South Texas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NOC-AE-10002573, TAC ME2259, TAC ME2260 | |
| Download: ML102080500 (4) | |
Text
Nuclear Operating Company South Texas Proect Electric Generating Station P. Box 289 Wadsworth, Texas 77483 July 21, 2010 NOC-AE-10002573 File No.: G25 10 CFR 26.9 10 CFR 26.205 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 Licensee Clarification Letter Regarding an Approved Exemption from Specific Requirements of Title 10 of the Code of Federal Requlations Part 26 (TAC Nos. ME2259/ME2260)
Reference:
Letter from Mohan Thadani, Nuclear Regulatory Commission, to Edward D. Halpin, STP Nuclear Operating Company, dated July 2, 2010, "South Texas Project, Units 1 and 2 - RE: Exemption from Specific Requirements of Title 10 of the Code of Federal Regulations Part 26 (ML101690114) (AE-NOC-1 0001992)
The referenced correspondence approved an exemption from specific requirements under Title 10 of the Code of Federal Regulations, Part 26, "Fitness for Duty Programs," for South Texas Project, Units 1 and 2. The purpose of this letter is to provide clarification to some of the statements in the exemption. These clarifications do not materially affect the conditions or the basis for the exemption. This letter is not requesting any action from the Nuclear Regulatory Commission staff.
Clarification of the statements of concern is provided as an attachment to this letter.
There are no commitments in this letter.
If there are any questions, please contact Ken Taplett at 361-972-8416 or me at 361-972-7298.
- ayne Hario Manager, Licensing
Attachment:
Clarification of Statements of Concern STI: 32703216 9-
NOC-AE-1 0002573 Page 2 of 2 cc:
(paper copy)
(electronic copy)
Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 612 East Lamar Blvd, Suite 400 Arlington, Texas 76011-4125 Mohan C. Thadani Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (MS 8B1A) 11555 Rockville Pike Rockville, MD 20852 Senior Resident Inspector U. S. Nuclear Regulatory Commission P. 0. Box 289, Mail Code: MN1 16 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 A. H. Gutterman, Esquire Morgan, Lewis & Bockius LLP Mohan C. Thadani U. S. Nuclear Regulatory Commission John Ragan Catherine Callaway Jim von Suskil NRG South Texas LP Ed Alarcon Kevin Polio Richard Pena City Public Service Jon C. Wood Cox Smith Matthews C. Mele City of Austin Richard A. Ratliff Texas Department of State Health Services Alice Rogers Texas Department of State Health Services
Attachment NOC-AE-1 0002573 Page 1 of 2 SOUTH TEXAS PROJECT (STP)
UNITS 1 AND 2 Clarification of Statements of Concern
Reference:
Letter from Mohan Thadani, Nuclear Regulatory Commission, to Edward D. Halpin, STP Nuclear Operating Company, dated July 2, 2010, "South Texas Project, Units 1 and 2 - RE: Exemption from Specific Requirements of Title 10 of the Code of Federal Regulations Part 26" (ML101690114)
Statements from Exemption, Page 3:
"According to the National Weather Service's Tropical Cyclone Classification, a sustained wind speed of 40 miles per hour (mph) makes travel unsafe for the common traveler (National Weather Service Glossary). If conditions worsen such that sustained winds of 73 mph are present on-site, then an unusual event will be declared. When an unusual event is declared, the licensee will shutdown the plant, and the exception under current regulations at 10 CFR 26.207(d), "Plant Emergencies," will allow the licensee not to meet the requirements of 10 CFR 26.205(c) and (d), from the time that the storm or hurricane sequestering conditions are met until severe weather exit conditions are sustained. The exemption will only apply to individuals in the storm crew who perform duties identified in 10 CFR 26.4(1) through (5)."
STP Clarification:
This clarification applies to the statement the "When an unusual event is declared, the licensee will shutdown the plant." The clarification also applies to a similar statement found on Page 7 (provided below) of the exemption. The following clarification is provided for completeness regarding when the units will be shutdown.
Section 8.3.4.6 of the STP Updated Final Safety Analysis Report provides guidelines for the response to a Station Blackout event that are incorporated into STP emergency and off-normal operating procedures. Regarding the response to a severe weather event, Section 8.3.4.6 states the following regarding unit shutdown.
"The guidelines for preparation for and response to a severe weather event (e.g.,
hurricane or tornado) are presented in two STPEGS procedures, one of which documents the overall site Severe Weather Plan, and the other providing specific guidance to the plant operators during severe weather events. As discussed in Section 8.3.4.3, STP is classified as P3* according to the NUMARC 87-00 criteria. This is based in part on procedures requiring the plant to be in Hot Standby at least two hours before the onset of sustained 73 mph winds onsite. Since hurricane season coincides with the summer peak electrical demand, it is likely that the electrical grid will be heavily loaded at the time a hurricane is threatening in the Gulf of Mexico. In such a situation, close coordination with the system dispatcher and Independent System Operator (ISO) will be required to assure grid stability as STP, which is one of the largest power sources on the grid, is taken off-line in an orderly fashion. The STP procedures allow STP management to authorize deviation from the NUMARC 87-00 criteria for grid conditions where an untimely shutdown may
Attachment NOC-AE-1 0002573 Page 2 of 2 increase the likelihood of a LOOP. The NUMARC 87-00 criteria remain the target and the procedures require that STP be in Hot Standby before the expected arrival onsite of sustained winds exceeding 96 mph."
Statements from Exemption, Page 7:
"Unit Shutdown The STP exemption request states that following the declaration of an unusual event resulting from predicted natural phenomenon, the units are required to be shut down to hot standby at least 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> prior to hurricane force winds arriving on-site. Lessons learned from Hurricane Andrew, NUREG-1474, include having both units shut down and on residual heat removal when the storm strikes so that a loss-of-offsite power will not jeopardize core cooling.
The NRC staff concludes that the STP plan is consistent with the lessons learned."
STP Clarification:
The first sentence is correct in that STP procedures require the units to be shutdown to hot standby (Mode 3) at least two hours prior to hurricane force winds arriving on-site except as noted above. The second and third sentences can be interpreted to mean that the units are shutdown to a condition that places the units on residual heat removal when hurricane force winds arrive on-site. Placing the units on residual heat removal is a hot shutdown (Mode 4) condition. STP hurricane procedures do not require the units to be shutdown to hot shutdown.
Any further Mode changes to the units would be an operational decision necessary for placing the units in a safe condition based on the effects of the storm.