核能廠是什麼樣退休的nuclear power plant decommissioning

對於某網上傳媒在節目中講述有關核電廠運作的問題,  他們說當核電廠的牌照完結後, 必須用100-150年來清理核廠內一切輻射物.  這使我非常懷疑!   我立即去他微博詢問, 而他在第二日節目中, 仍堅持了這個答案!

我問他哪一個政府如此愚昧, 要用100-150年去清理核廠?  因為我心信這是很不cost effective(可知道你仍要付100-150年的牌照費的), 也不是一件friendly to envirioment 的事.  再講, 沒有一個民主政府可以獨裁如此的; 如果這個是事實,  104 nuclear power plants are operating in America ( number 1 in the world),  59 nuclear power plants are operating in France ( world number 2), 54 nuclear power plants are operating now in Japan ( number 3 in the world in the number of nuclear power plants, and one of the most earthquake prone places in the world!  這些數據會不會叫你心寒??

在wikipedia

Generally speaking, nuclear plants were designed for a life of about 30 years. Newer plants are designed for a 40 to 60-year operating life.  即核電廠的壽命有限, 舊式設計的去到30年, 新式設計的就去到40至60年!  就要退休並且清拆 (當然, 所有power plant 包括coal & gas都一樣是有限年期的). 

http://en.wikipedia.org/wiki/Nuclear_decommissioning

而退休計畫有3個Options選擇的:

  • Immediate Dismantling (or Early Site Release/’Decon’ in the US): This option allows for the facility to be removed from regulatory control relatively soon after shutdown or termination of regulated activities. Usually, the final dismantling or decontamination activities begin within a few months or years, depending on the facility. Following removal from regulatory control, the site is then available for re-use.
  • Safe Enclosure (or ‘Safestor’): This option postpones the final removal of controls for a longer period, usually in the order of 40 to 60 years. The facility is placed into a safe storage configuration until the eventual dismantling and decontamination activities occur.
  • Entombment (or ‘Entomb’): This option entails placing the facility into a condition that will allow the remaining on-site radioactive material to remain on-site without the requirement of ever removing it totally. This option usually involves reducing the size of the area where the radioactive material is located and then encasing the facility in a long-lived structure such as concrete, that will last for a period of time to ensure the remaining radioactivity is no longer of concern.

簡單的說:

1.  “Decon”  立即清拆:  當核電廠關閉後, 一切設備必須跟據政府控制的規定下於最快幾個月甚至幾年後移除, 使得該地域可重新再用.

2. “Safestor”  安全屏蔽/覆蓋: 此選項為, 可以延期在一段較長時間才清拆, 通常可長達40至60年,   而核電廠內的設備(包括一切有輻射的事物)必須放置在安全儲存的結構之內直至最終的拆除和清污的行動發生(當然, 牌照費要照收, 收到此地清理好為止).

3.  “Entomb” 埋葬:  此選項, 是你可以將所有輻射性材料和設備留在原地(可能是有特別原因是不能移除甚至永不能時).  此選項你可以將全部的反應爐(通常核能廠會有3或6個反應爐)的輻射材料和設備齊集一區(即將所有這些輻射材料設備的佔用地區縮小).   然後用混凝土結構來長封, 並且肯定這些輻射性長期下都不會毒害環境和人類的.  (此選項也可用於當你有多個 reactors 時, 其中一個要退休了, 此時便可將它埋葬, 比喻建成停車場, 那樣其他的 reactors 便可繼續使用了.

http://www.world-nuclear.org/info/default.aspx?id=472&terms=nuclear%20power%20plant%20decommissioning

所以依以上3項來說, 如果我要將全個地區(即可能有兩至4個reactors 反應爐) 的核電廠清除!  最省又最快的方法, 是沒有理由不選 Decon 的.  除非你錢多, 又或核電廠有新的發展, 比喻你有更新的技術可改建核電廠為其他更高科技的發電廠, 那你便可以選 safestor 了,  延長牌照了.  當然這項選擇也要看監管的批准與否了.   最後的entomb 在上面已經說了, 除了建停車場的例子, 最好的例子就是切爾諾貝爾chernobyl 核電廠那副石棺了.

 

好了,  究竟核電廠退休後要用多少年清拆那些富輻射性的建築物?

我找到鐵般事實的兩個好例子:

1.  Maine Yankee Atomic Power Company

此核電廠由1972-1996, 共24年的運作.  關閉後, 只用了8年(由1997-2005時間)便全部清理, 且清理地而面3呎以下並合付嚴格清理的標準.

The nuclear power plant underwent a successful decommissioning from 1997-2005 with all plant structures removed to three feet below grade and the site restored to stringent clean-up standards.

用的是爆破技術,  在每 200,000工作小時下,   0人受傷 .

完成退休, 不到一半的政府規定的遺留輻射劑量限值

放射的清理顯著低於 10 millirem的目標

  • Zero lost time injuries from May 2002 through the end of decommissioning in October 2005. For every 200,000 hours worked, the decommissioning project had a Lost Time Incident Rate of .26 compared with a demolition industry rate of 3.6.
  • Completed decommissioning for less than half the NRC radiological dose limit;
  • Radiological cleanup of the site was significantly lower than the 10 millirem target;

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2.  Connecticut Yankee (CY) nuclear power plant

此核電廠由1968-1996運作了28年, 關閉後, 只用了9年(由1998-2007時間)便全部清理, 且清理地而面3呎以下並合付嚴格清理的標準.

From 1968 until permanent shutdown in 1996, Connecticut Yankee operated a 619 megawatt pressurized water reactor at the Haddam Neck site. The nuclear power plant underwent a successful decommissioning from 1998-2007 with all plant structures removed to three feet below grade and the site restored to stringent clean-up standards.

CY chose immediate dismantlement (the DECON method) because it was the most practical and environmentally responsible option for the plant. Other considerations included the use of current plant employees who were trained and knowledgeable about the facility, prevention of long-term maintenance costs, and the availability of low-level waste disposal facilities. Significant decommissioning activities began at CY in May 1998, and were completed in November 2007 with NRC approval of the termination of the operating license on the plant area.

More than 40 U.S. research reactors have been safely and securely decommissioned as well as 10 U.S. commercial nuclear plants that have been or are being decommissioned.

http://www.connyankee.com/html/decommissioning.html

43_vccs02CY_Home_Page2CY_Home_Page21Recent_aerial2_largeRecent_aerial3_large

http://www.connyankee.com/html/methods.html

再講:

We should not be scared of something just because we don’t understand it!  當你愈疑惑, 就更加要找出真相. 

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