ML11220A326
| ML11220A326 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 08/08/2011 |
| From: | Lampert M Pilgrim Watch |
| To: | Atomic Safety and Licensing Board Panel |
| SECY RAS | |
| References | |
| RAS 20701, 50-293-LR, ASLBP 06-848-02-LR | |
| Download: ML11220A326 (5) | |
Text
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of Docket # 50-293-LR Entergy Corporation Pilgrim Nuclear Power Station License Renewal Application August 8, 2011 Pilgrim Watch Request for Leave to Supplement Pilgrim Watch Request for Hearing on the Inadequacy of Entergys Aging Management Program of Non-Environmentally Qualified (EQ) Inaccessible Cables (Splices) at Pilgrim Station, filed on December 10, 2010 and January 20, 2011.
Pilgrim Watch requests leave to file this supplement to the record. It includes new, significant and material information and is timely provided to inform the Board. 1 The attached Appendices are excerpts from NRCs Task Force Recommendations for Enhancing Reactor Safety in the 21st Century: The Near-Term Task Force Review of Insights from The Fukushima Dai-Ichi Accident, July 12, 2011 (Appendices A and B).
Conclusion We respectfully ask that this new, significant and material information relevant to Pilgrim Watchs Requests for Hearings filed on December 10, 2010 and January 20, 2011, provided by 1
Under NRC practice, parties have an obligation to keep the Licensing Board . . .informed of relevant and material new information. Sacramento Municipal Utility District (Ranco Seco Nuclear Generating Station), CLI-93-5, 37 NRC 168, 170 (1993).
NRC technical experts and submitted to inform the Board in a timely manner, be included in the record.
Respectfully submitted, Mary lampert (Signed Electronically)
Pilgrim Watch, pro se 148 Washington Street Duxbury, MA 02332 Tel. 781-934-0389 Email: mary.lampert@comcast.net August 8, 2011 2
APPENDIX A - FLOODING Excerpts from the Task Force Report Regarding Flooding
- 1. 4.1 Ensuring Protection from External Events [pg., 25]
The Task Force concluded that flooding hazards warranted further Task Force consideration due, in part, to significant advancements in the state of knowledge and the state of analysis in these areas in the time period since the operating plants were sited and licensed. [pg., 25]
- 2. With regard to flooding hazards, the assumptions and factors that were considered in flood protection at operating plants vary. In some cases, the design basis does not consider the probable maximum flood (PMF). [pg., 29]
- 3. The Task Force has concluded that flooding risks are of concern due to a cliff-edge effect, in that the safety consequences of a flooding event may increase sharply with a small increase in the flooding level. Therefore, it would be very beneficial to safety for all licensees to confirm that SSCs important to safety are adequately protected from floods. [pg., 29]
- 4. This reevaluation should consider all appropriate internal and external flooding sources, including the effects from local intense precipitation on the site, PMF on storm surges, seiches, tsunamis, and dam failures. Similar to seismic hazards, new flooding hazard data and models will be produced from time to time. Thus, there would be a continuing benefit to having operating reactors reevaluate the implications of updated flooding hazards at appropriate intervals. [pg., 30]
- 5. Recommendation 2 [pg., 30]
The Task Force recommends that the NRC require licensees to reevaluate and upgrade as necessary the design-basis seismic and flooding protection of SSCs for each operating reactor.
2.1 Order licensees to reevaluate the seismic and flooding hazards at their sites against current NRC requirements and guidance, and if necessary, update the design basis and SSCs important to safety to protect against the updated hazards.
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2.2 Initiate rulemaking to require licensees to confirm seismic hazards and flooding hazards every 10 years and address any new and significant information. If necessary, update the design basis for SSCs important to safety to protect against the updated hazards.
2.3 Order licensees to perform seismic and flood protection walk-downs to identify and address plant-specific vulnerabilities and verify the adequacy of monitoring and maintenance for protection features such as watertight barriers and seals in the interim period until longer term actions are completed to update the design basis for external events.
[pg., 30]
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APPENDIX B - MITIGATION TO PREVENT LOSS AC POWER Excerpts from the Task Force Report Regarding Mitigation:
4.2 Mitigation The following sections discuss the Task Force evaluation of insights from Fukushima and provide recommendations for enhancing the mitigation capability of U.S. reactors with regard to prolonged loss of ac power [pg., 32]
4.2.1 Prolonged Loss of Alternating Current Power
Background
Alternating current (ac) electrical power is critically important to the safety of nuclear power plants. Many of the SSCs intended to cool the nuclear fuel in the reactor and in the spent fuel pools, to maintain radioactive containment systems, and to provide ventilation systems to minimize release of radioactive materials rely on ac power. These systems depend on electrical power to drive pumps, fans, and compressors, operate instrumentation and control systems, and run motors to open and close valves and dampers. For these reasons, the loss of all ac power both onsite and offsite, as occurred at Fukushima, is highly significant. [pg., 32-33]
- 7. The NRC SBO rule (10 CFR 50.63) requires that each nuclear power plant must be able to cool the reactor core and maintain containment integrity for a specified duration of an SBO (defined in 10 CFR 50.2, Definitions, as a complete loss of required onsite and offsite ac electrical power). The specified duration is based on the following factors:
- the redundancy of the onsite emergency ac power sources
- the reliability of the onsite emergency ac power sources
- the expected frequency of loss of offsite power
- the probable time needed to restore offsite power RG 1.155, Station Blackout, describes an acceptable means to comply with 10 CFR 50.63. It primarily addresses three areas: (1) maintaining highly reliable onsite ac electric power systems
[pg., 33]
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- 8. The Task Force considers the issue of flood protection for SBO equipment to be significant and recognizes that flooding protection of such equipment would require it to be located at a suitable elevation (above the design-basis flood plus a significant margin) or require it to have an effective watertight enclosure. Establishing such protections may be difficult at some sites. Nevertheless, the Task Force concludes that such protection of SBO equipment is essential to implementation of the recommended framework for reactor safety. [pg., 37]
- 9. A beyond-design-basis flood could be established through extensive, probabilistic hazards analysis. As a practical matter, and to prevent undue delays in implementing additional SBO protections, the Task Force concludes that locating SBO mitigation equipment in the plant one level above flood level (about 5 to 6 meters (15 to 20 feet)) or in watertight enclosures would provide sufficient enhanced protection for this level of defense-in-depth. [pg., 37]
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