Population density is one critical lens through which other risks have to be assessed, says Laurent Stricker, a nuclear engineer who is chairman of the World Association of Nuclear Operators (WANO), created as an international forum on nuclear safety in the aftermath of the 1986 Chernobyl accident. "We need to look at the safety of reactors taking into account where they are," he says (see Nature 472, 274; 2011).
To carry out the population analysis, Nature teamed up with the NASA Socioeconomic Data and Applications Center based at Columbia University (see 'How population sizes were estimated' for an explanation of how the analysis was carried out). The KANUPP plant in Karachi, Pakistan, has the most people — 8.2 million — living within 30 kilometres, although it has just one relatively small reactor with an output of 125 megawatts (see 'Nuclear neighbours'). Next in the league, however, are much larger plants — Taiwan's 1,933-megawatt Kuosheng plant with 5.5 million people within a 30-kilometre radius and the 1,208-megawatt Chin Shan plant with 4.7 million; both zones include the capital city of Taipei. The findings of Nature 's population analysis are "scary", says Ed Lyman, a nuclear expert with the Union of Concerned Scientists in Washington DC.
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前面有提到 要對核電廠的危險程度排名是不可能的"
Nuclear experts say that an objective 'danger' ranking is almost impossible because each reactor has its own unique risk profile, and some risks are simply unknowable."
後面則陸續指出 External threats,Design and age ,Culture等等也都是評估時會考慮的風險因子
華爾街日報使用的資料來源
The Wall Street Journal looked at the location of more than 400 nuclear reactors across the world—as well as another 100 that are either planned or being built—using data provided by the World Nuclear Association, a London-based industry group. The Journal then used data from the Global Seismic Hazard Program, a 1999 study by the U.S. Geological Survey and the Swiss Seismological Service, to determine the earthquake risk at each plant.
比對後發現 台灣和日本的核電廠佔了多數
"Japan and Taiwan together account for 30 of the 34 high-activity reactors. But the U.S. has two reactors in such areas and Slovenia and Armenia have one each. Armenia has another planned."
External threats:
地震.海嘯.火災.洪水.颶風或恐怖攻擊,都是導致嚴重核災原因。核電廠規劃設計已超越工程師當初預期風險所能承擔範圍。
As Fukushima showed, external threats — such as earthquakes, tsunamis, fires, flooding, tornadoes or even terrorist attacks — are some of the greatest risk factors for a serious nuclear accident.
This means that nuclear plants situated outside known geological danger zones could pose greater accident threats in the event of an earthquake than those inside, as the former could have weaker protection built in.
The Fukushima Daiichi plant, for example, was located in an area designated, on Japan's seismic risk map, as having a relatively low chance of a large earthquake and tsunami; when the 2011 tsunami arrived, it was in excess of anything its engineers had planned for.
Deasign and Age
舊電廠不必然比新電廠危險,核電廠規模越大越危險。
Older reactors are not necessarily more dangerous than newer ones.
Some reactors and plants are inherently more dangerous than others. One factor is sheer size. A larger plant can generate more fallout, and when simultaneous crises develop at multiple reactors
Culture
提到過度自信.缺乏良善監督與貪污,都可能是淺在危險因子。
Operators must guard against complacency."One flaw that I worry about is that of overconfidence." Experts say that the largest single internal factor determining the safety of a plant is the culture of security among regulators, operators and the workforce — and creating such a culture is not easy.
Experts worry about lack of regulatory oversight and corruption in some regions.