震災危險性再評估 美東2核電廠超出安全停機值 | 台灣環境資訊協會-環境資訊中心

震災危險性再評估 美東2核電廠超出安全停機值

2014年04月24日
摘譯自2014年4月18日ENS美國,華盛頓特區報導;姜唯編譯;蔡麗伶審校

美國核能管制委員會(NRC)17日發表報告指出,2011年福島核災後,針對美國數十座反應爐重新評估地震耐受能力,卻發現地震風險大於原先的發照標準。

美國麻州參議員Edward Markey和Elizabeth Warren18日向NRC提出呼籲,要求麻省皮葛林核能電廠和新罕布夏州Seabrook核電廠立即針對新發現的地震風險實施解決方案。

Entergy公司的皮葛林核能電廠(照片由NRC提供)。

福島核災後 美本土核電廠安全性全面重評

2014年3月31日,美國本土和東部所有核電廠的執照持有人,都繳交地震災害危險性重新評估報告給NRC。這些送審資料指出,皮葛林和Seabrook兩個核電廠用後燃料池的地震災害危險性,都大於所謂的「安全停機值」,也就是「安全相關結構、系統和元件設計上所能承受的最大地震值」。

Markey和Warren行文NRC主席:「我們建議,NRC以強勢態度要求皮葛林核能電廠和Seabrook核電廠持照人,立即採取所有必要措施,確保反應爐、工作人員和附近居民的安全。」

由Entergy公司營運的皮葛林核能電廠位於波士頓東南方38英里處,發電量達2百萬瓦。最新地震資料顯示,皮葛林核能電廠能感受到400英里外的地震效果,是過去估計值的兩倍;Seabrook核電廠位於樸次茅斯市南邊13英里、波士頓北邊56英里,發電量達120萬瓦,能供應120萬戶家庭一年的用電量,持照人是NextEra Energy Seabrook能源公司。

業界專家先透露:24核電廠超出安全停機值

福島核災後,NRC發表短期工作報告建議持照人依最新研究和模型,重新評估各反應爐的地震災害危險性,以進一步了解潛在地震危險,並決定是否需要增加安全措施。

美中和美東數十座核電廠的持照人三月繳交地震災害危險性重新評估報告給NRC後,接下來必須分析各電廠結構和元件的地震風險,每份分析大約要價5百萬美元。

持照人必須在2017年前完成分析,但麻省參議員要求NRC下令Entergy公司「儘速實施必要的因應措施,確保反應爐能在地震發生時安全關機。」

兩位業界專家這個月向紐約時報透露,美國中部和東岸有24處核電廠的地震危險性大於安全停機值。NRC則尚未公布總數。

QUAKE RISK EXCEEDS LICENSED LIMITS AT U.S. NUCLEAR PLANTS
WASHINGTON, DC, April 18, 2014 (ENS)

Massachusetts Senators Edward Markey and Elizabeth Warren today called on the Nuclear Regulatory Commission to direct the licensees of Pilgrim Nuclear Power Station in Massachusetts and Seabrook Station in New Hampshire to immediately implement mitigation measures against seismic risks that were previously unknown.

Reports released Thursday by the NRC reveal that dozens of reactors that reassessed their vulnerability to earthquakes in the wake of the March 2011 meltdowns at Japan’s Fukushima Daiichi nuclear plant are at greater risk than they were originally licensed to withstand.

On March 31, 2014, licensees of all reactors in the continental and eastern U.S. submitted these seismic hazard re-evaluations to the NRC.

These submittals indicate that for both Pilgrim’s and Seabrook’s reactors and spent fuel pools, the new earthquake hazard is greater than the so-called “safe shutdown earthquake”, which is defined to be “the maximum earthquake potential for which certain structures, systems, and components, important to safety, are designed to sustain and remain functional.”

The two million watt Pilgrim nuclear power plant, operated by Entergy, is located 38 miles southeast of Boston, Massachusetts. The updated seismic data shows that Pilgrim could feel the effects of earthquakes as far away as 400 miles, double the previously estimated distance.

Seabrook is located 13 miles south of Portsmouth, New Hampshire, 56 miles north of Boston. It generates 1.2 million watts of electricity, enough to supply the annual needs of 1.2 million families. The licensee is NextEra Energy Seabrook, LLC.

“We urge you in the strongest possible terms to direct the licensees of the Pilgrim Nuclear Power Station and the Seabrook Station to immediately take all necessary measures to assure the safety of the reactors and those that live and work near them,” write Senators Markey and Warren to the NRC chair.

One of the recommendations of the NRC’s Near Term Task Force report following Fukushima was that licensees re-evaluate seismic hazards at each reactor using current research and models in order to develop a better understanding of possible earthquake hazards at the site and determine whether additional safety measures are needed.

Licensees of all reactors in the continental and eastern U.S. submitted these seismic hazard re-evaluations to the NRC in March. Now the licensees of several dozen reactors must analyze their structures and components for earthquake risk at an estimated cost of roughly $5 million for each analysis.

Two industry experts told the “New York Times” earlier this month that across the central and eastern United States, plants at 24 sites reported that the new earthquake threat was larger than what they were designed to face. The commission has not released a total yet.

Licensees are given until 2017 to complete their analyses, but the Massachusetts senators are asking the Nuclear Regulatory Commission to direct Entergy not to wait that long but to require the company to “more quickly implement mitigating measures for the reactor equipment that would be needed to safely shut down the reactors in the event of an earthquake.”

※ 全文及圖片詳見:ENS