The worsening crisis at the Fukushima Power Station in Japan has led to inevitable comparisons with the 1986 Chernobyl nuclear d

admin2013-02-16  24

问题     The worsening crisis at the Fukushima Power Station in Japan has led to inevitable comparisons with the 1986 Chernobyl nuclear disaster that killed workers at the plant instantly, caused cancers in the surrounding population and spread radioactive contamination so far that livestock restrictions are still in place at some farms around the Ukraine.
    The situation at Fukushima is certainly grave and immediately dangerous for those at the site who are fighting to make the crippled reactors and fuel storage ponds safe.
    But whatever warnings are now being issued by foreign governments to their citizens in Japan, there are significant differences that set this apart from the catastrophe in Ukraine.
    At Chernobyl the nuclear reactor exploded after a surge in power that blew the top off the power plant and sent how fuel high into the upper atmospheres, where it floated across national borders. A fire that broke out in the graphite core forced more radioactive material into the air, helping it spread further. The reactor had no containment facility to even slow the release of radiation from the plant.
    The Fukushima boiling water reactor is a 40-year-old power plant and it has some glaring design flaws, but the reactors have been switched off for five days, so there is less fresh radioactive material around, and each core is contained within a 20cm-thick steel container, which is then protected by a steel-lined reinforced concrete outer structure. Even in the case of a meltdown, these measures should at least limit the amount of radiation released.
    But what of the population beyond? The risk from radiation falls off substantially with distance. The authorities have already imposed an exclusion zone of 12 miles around the power station, introduced food bans and dispensed potassium iodide pills to those in the surrounding area.
    For the more distant population, the most serious radioactive substances that would be released are caesium-137 and iodine-131. These are extremely volatile., so can be carried a long way. But dangerous doses are not likely to travel far on the wind. The danger comes when radioactive iodine and caesium rain down on the ground, on the pastureland, for example, and livestock eat it. Cows concentrate radioactive iodine in their milk. Radioactive caesium accumulates in muscles, and in the past has built up in grazing sheep. The threat to humans then comes from drinking milk and eating contaminated meat. Both can raise the risk of cancer—iodine especially by being absorbed into children’s thyroid glands.
    What happened at Chernobyl, which was a much more serious accident than this, was that the local Soviet authorities were in denial, they didn’t get people out of the area, they didn’t evacuate quickly enough, and they allowed children to continue to drink heavily contaminated milk, and as a consequence, many children received high doses of radiation to the thyroid and we’ve seen thousands of thyroid cancers as a consequence.
Which of the following is NOT true?

选项 A、There are some obvious design defects in Fukushima’s power plant.
B、The radioactive substances may cause death to the distant population.
C、Potassium iodide tablets can guard against some effects of radiation exposure.
D、Unlike the Fukushima plant, Chernobyl’s reactor lacked a containment facility.

答案B

解析 本题为细节分析题。从倒数第二段可知,对远处居民能产生危害的放射性物质有两种,但这两种物质不太稳定,因此,不可能随风带到很远的地方。如果它们随雨水进入土壤或家禽体内,人类食用就会有致癌的风险,但文章并没有提到会致人死亡。因此,B选项不符合原意。由于选不正确的选项,因此,B选项为正确答案。
转载请注明原文地址:https://kaotiyun.com/show/pEmO777K
0

最新回复(0)