ML12005A210
| ML12005A210 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 12/21/2011 |
| From: | Harrison A South Texas |
| To: | Cindy Bladey Rulemaking, Directives, and Editing Branch |
| References | |
| 76FR63565 00012, NOC-AE-11002776, NUREG-1022 | |
| Download: ML12005A210 (4) | |
Text
"k Nuclear Operating Company South Texas Project Electric Generating Station PO. Box 289 Wadsworth, Texas 77483
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Ms. Cindy K. Bladey Chief, Rules, Announcements and Directives Branch Office of Administration Mail Stop TWB-05-BO1 M U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
' ~AA December 21, 2011 NOC-AE-1 1002776 STI: 33189121 File:_G25
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Wn STP Nuclear Operating Company Comments on Draft NUREG-1022 Revision 3, Event Reporting Guidelines
References:
- 1. NEI Letter from Chris Earls to Cindy K. Bladey dated December 6, 2011, Comments on Draft NUREG-1022, Revision 3 (ML11342A057)
- 2. Strategic Teaming and Resource Sharing (STARS) Letter from Scott A. Bauer to Cindy K. Bladey dated December 14, 2011, Comments Draft NUREG-1022, Revision 3, "Event Reporting Guidelines: 10 CFR 50.72 and 50.73" STP Nuclear Operating Company (STPNOC) is providing this letter in response to the NRC request for comments regarding Draft NUREG-1022, Revision 3, "Event Reporting Guidelines:
10 CFR 50.72 and 50.73" as published in the Federal Register (76 FR 63565) dated October 13, 2011.
STP Nuclear Operating Company has been an active participant in NRC meetings as well as the Nuclear Energy Institute (NEI) sponsored industry team reviewing proposed changes to NUREG-1022. STPNOC endorses the comments submitted by NEI in Reference 1 and those submitted by STARS in Reference 2.
STPNOC shares the concern that because of the expanded list of systems to be considered in scope and the inclusion of "inoperable" systems, the proposed changes would result in a significant increase in the reporting of Safety System Functional Failures (as discussed in the proposed changes to NUREG-1022, Section 3.2.7), when in many cases there would be no loss of the ability to provide the required safety function.
In addition to the comments provided in References 1 and 2, STP Nuclear Operating Company also provides the following comments.
- 1. STPNOC proposes that NUREG-1022, Section 3.2.2, "Operation or Condition Prohibited by Technical Specifications," be clarified such that missed conditional Surveillance Requirements listed in Action Statements that are subsequently performed successfully can be treated as another example of a non-reportable TS violation for a missed surveillance. The basis for applying the same logic to a late conditional SR imposed by an Action Statement same as for any other SR that is performed late, and is described in the NUREG:
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NOC-AE-1 1002776 Page 2 of 4 Generally, an operation or condition prohibited by the technical specifications existed and is reportable if surveillance testing indicates that equipment (e.g., one train of a multiple train system) was not capable of performing its specified safety functions (and thus was inoperable) for a period of time longer than allowed by technical specifications (i.e., LCO allowed outage time, or completion time for restoration of equipment in ISIS). Reporting is not required if an event consists solely of a case of a late surveillance test where the oversight is corrected, the test is performed, and the equipment is found to be capable of performing its specified safety functions.
The proposed clarification meets the regulation since it is an example of a TS violation and is only due to a missed SR. The fact that the SR was imposed by an Action Statement only changes the way in which the SR was required. Performing the conditional SR can only be initiated upon discovery that the action that requires it has been entered. If it is determined later that the plant had been in the action longer than the time specified to perform the conditional SR, then the conditional SR would be late (TS violation), even though the licensee could not have known it was required. Provided the SR is successfully performed, there is no value to reporting the TS violation from the late SR. Consequently, this example complies with the same logic as the existing example.
- 2. The term "significantly degrades I degraded plant safety" contained in the reportability criteria of 50.72(b)(3)(ii) and 50.73(a)(2)(ii)(B) is not defined. Providing a definition for this term in the NUREG-1022 guidance would aid licensees in providing consistent reporting of events or conditions with safety significance.
STPNOC recommends that NUREG-1022 Section 3.2.4, "Degraded or Unanalyzed Condition," should be expanded to include the following definition and examples:
Significantly degraded plant safety means a condition that degrades a fission product barrier or design limit to such an extent that when considering actual plant conditions, the safety analysis acceptance limits in the UFSAR would not be met. Single failure and loss of offsite power as required by the UFSAR should be considered in the evaluation.
Example 1: The moisture separator re-heater relief valve located down stream of the main stem isolation valve is discovered to fail open on a loss of off-site power. The steam line break dose analysis does not consider the single failure of the main steam line isolation valve on the faulted steam generator to be limiting because the down stream relief valves are assumed to fail closed on a los of off-site power. An analysis of the event with the single failure of the main steam isolation valve failing open and moisture separator re-heater relief valve failing open on a loss of off-site power using the bounding UFSAR assumption of 1 % failed fuel prior to the steam generator tube rupture shows that off-site dose would exceed the UFSAR acceptance limit stated in 10 CFR Part 100. However, records show that the plant has not experienced any fuel failure for the prior three years.
Revising the analysis to account for no fuel failure prior to the steam generator tube rupture shows the 10 CFR Part 100 limits would not be exceeded. Therefore, this condition would not be reportable under 50.73(a)(2)(ii)(B).
Example 2: An error in the analysis for the uncontrolled RCCA bank withdrawal at power event resulted in under predicting the RCS peak pressure. When the error was corrected and using the bounding assumptions in the UFSAR, the analysis showed that the RCS peak pressure would exceed the UFSAR acceptance limit of 110% design pressure for
NOC-AE-1 1002776 Page 3 of 4 this event. The analysis took credit for the high positive rate neutron flux rate reactor trip with a 3.0 second delay to limit the RCS peak pressure for the event. A review of the surveillance records for the previous three years found the actual delay time for this reactor trip was 0.5 seconds. The analysis was revised to account for a 0.5 second delay of the high positive rate neutron flux rate reactor trip and showed that the predicted RCS peak pressure would not exceed 110% design pressure. Therefore, this condition is not reportable under 50.73(a)(2)(ii)(B).
STP Nuclear Operating Company appreciates the opportunity to provide comments regarding Revision 3 to NUREG-1022. Should you have any questions regarding this letter, please contact either Jim Morris at 361-972-8652 or me at 361-972-7298.
ManagHarrison Manager, Licensing JRM
NOC-AE-1 1002776 Page 4 of 4 cc:
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Balwant K. Singal Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (MS 8 B1) 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 Balwant K. Singal U. S. Nuclear Regulatory Commission John Ragan Chris O'Hara Jim von Suskil NRG South Texas LP Kevin Polio Richard Pena City Public Service Peter Nemeth Crain Caton & James, P.C.
C. Mele City of Austin