核輻射英語演講PPT

1、Even the spectacular nuclear disasters at Three-Mile Island and Chernobyl were far less serious as technical failures than they were in their ecological effects.即使三里島和切爾諾貝利的核災(zāi)難在技術(shù)上的失敗比起它們對于生態(tài)系統(tǒng)所造成的影響也小得多。The Chernobyl Nuclear AccidentThe Fukushima Daiichi nuclear disasterThe Three Mile Island Accide

2、ntThe Three Mile Island AccidentThe Chernobyl Nuclear AccidentThe Fukushima Daiichi nuclear disasterThe Three Mile Island AccidentThe Chernobyl Nuclear AccidentThe Fukushima Daiichi nuclear disasterThe Three Mile Island AccidentThe Chernobyl Nuclear AccidentThe Fukushima Daiichi nuclear disasterThe

3、Three Mile Island AccidentThe Three Mile Island accident was a partial nuclear meltdown which occurred in one of the two Three Mile Island nuclear reactors in Dauphin County, Pennsylvania, United States, on March 28, 1979. It was the worst accident in U.S. commercial nuclear power plant history. The

4、 incident was rated a five on the seven-point International Nuclear Event Scale: Accident With Wider Consequences.1.The Three Mile Island AccidentThe power plant was owned and operated by General Public Utilities and Metropolitan Edison (Met Ed). The reactor involved in the accident, Unit2, was a pr

5、essurized water reactor manufactured by Babcock & Wilcox.Main Causes當(dāng)天凌晨4時0分0秒，三哩島核電站95萬千瓦壓水堆電站二號反應(yīng)堆一回路的給水主泵停轉(zhuǎn)，汽輪機(jī)停機(jī)。備用泵按照預(yù)設(shè)的程序啟動，但是由于輔助給水系統(tǒng)中隔離閥在此前的例行檢修中沒有按規(guī)定打開，導(dǎo)致輔助給水系統(tǒng)沒有投入運(yùn)行。 Consequences of stuck valve(隔離閥隔離閥) The design of the PORV(減壓閥) indicator light was fundamentally flawed .And the opera

6、tors had not been trained to use it. The operators did not correctly diagnose the problemNuclear leak alarm did not attract the attention of operatorsHuman factors Emergency MeasuresSchools were closed and residents were urged to stay indoors.Pregnant women and pre-school age children were emergency

7、 evacuation.Farmers were told to keep their animals under cover and on stored feedCleanup started in August 1979 and officially ended in December 1993, with a total cleanup cost of about $1 billion Fifty miles around Three Mile Island nuclear power plant, none of the 2200000 residents had the acute

8、radiation reaction. 在以三哩島核電站為圓心的50英里范圍內(nèi)，220萬居民中無人發(fā)生急性輻射反應(yīng)。The average radiation dose to people living within ten miles of the plant was eight millirem. Eight millirem is about equal to a chest X-ray. 周圍居民所受到的輻射相當(dāng)于進(jìn)行了一次胸部X光照射的輻射劑量。 The accident has had no observable long term health effects 三哩島核泄漏事故對

9、于周圍居民的癌癥發(fā)生率沒有顯著性影響。Disease rates in areas further than 10 miles from the plant were never examined 三哩島附近未發(fā)現(xiàn)動植物異?，F(xiàn)象,當(dāng)?shù)剞r(nóng)作物產(chǎn)量未發(fā)生異常變化。But the leak accident of nuclear power plant reactor No. two was seriously damaged, the direct economic loss one billion. 但是泄漏事故造成核電站二號堆嚴(yán)重?fù)p毀，直接經(jīng)濟(jì)損失達(dá)10億美元之巨。 AftermathThe

10、Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in the Ukrainian SSR. It is considered the worst nuclear power plant accident in history, and it is the only one classified as a level 7 event on the International Nuclear Event Scale. 2. Th

11、e Chernobyl Nuclear AccidentMain CausesOperating instructions and design deficiencies Operator error initially faulted The reactor had a dangerously large positive void coefficient. A more significant flaw was in the design of the control rods that are inserted into the reactor to slow down the reac

12、tion.The developers of the reactor plant considered this combination of events to be impossible and therefore did not allow for the creation of emergency protection systems capable of preventing the combination of events that led to the crisis. The leakage radiation dust with air blowing into the we

13、stern region of Soviet Union, Eastern Europe and The Nordic Scandinavian Peninsula. Ukraine, Belarus and Russia are the Most polluted.Pollution scalesAftermath1)International spread of radioactive substances2)Radioactive release3)Health of plant workers and local people4)Residual radioactivity in th

14、e environmentMap of radiation levels in 1996 around Chernobyl.The Chernobyl accident killed more than 30 people immediately, and as a result of the high radiation levels in the surrounding 20-mile radius, 135,000 people had to be evacuated. In 2006, The Other Report On Chernobyl pointed out there ar

15、e about 4000 people will die from the excessive radiation. The resultant release of radioactivity threatens many thousands of people all over Europe with cancer. Up to now, the malformation fetus (畸形兒) still birth due to the long-term effects of radioactive material.The accident area is still contam

16、inated and uninhabitable. The once prosperous city has become a “ghost city”Actions April 26, 1986, over 8 tons leakage of strong radiation. Unit 4 was subsequently reinforced concrete seal, the name sarcophagus Sarcophagus has been in use for nearly 25 years, now it has been the appearance of crack

17、s. Ukraine hopes in the sarcophagus on the installation of a 100-meter high steel arch石棺“已使用了近25年，現(xiàn)在它已經(jīng)出現(xiàn)裂縫，烏克蘭希望在”石棺“上安裝高100米的鋼拱。3. Japans nuclear leakageThe Fukushima Daiichi nuclear disaster was a catastrophic failure at the Fukushima I Nuclear Power Plant on 11 March 2011, resulting in a meltdown of three of the plants six nuclear reactors.It is the largest nuclear incident since the 1986 Chernobyl disaster and the second (with Chernobyl) to measure Level 7 on the Internat