車諾比核能電廠事故

車諾比事件後的週遭輻射污染劑量分佈圖。

車諾比核能電廠事故烏克蘭語:Чорнобильська катастрофа)是一起發生在蘇聯烏克蘭車諾比核電站核子反應爐事故。該事故被認為是歷史上最嚴重的核子電廠事故,也是國際核事件分級表(International Nuclear Event Scale)中唯一的第七級事件。因為功率的劇增導致反應爐被破壞,令嚴重的放射性物質被釋放到環境中。在最初發生的蒸氣爆炸導致了兩人死亡,而事故中絕大部分受害者的死因都歸咎於放射線

1986年4月26日的凌晨1點23分(UTC+3),烏克蘭普里皮亞季鄰近的車諾比電廠,第四號反應爐發生了爆炸。後續的爆炸引發了大火併散發出大量高輻射物質到大氣層中,涵蓋了大面積區域。這次災難所釋放出的輻射線劑量是投在廣島原子彈的400倍以上。[1]

核輻射塵污染過的雲層飄往眾多地區,包括原蘇聯西部的部分地區、西歐東歐斯堪地那維亞半島不列顛群島北美東部部分地區。此外,烏克蘭白俄羅斯俄羅斯境內均遭受到嚴重的核污染,超過336,000名的居民被迫撤離。依據前蘇聯的官方報告[2],約60%受到輻射塵污染的地區皆位於白俄羅斯境內。

這次意外引起了眾人對於前蘇聯核能發電工業上的安全顧慮,也減緩了一系列的核能工程進度。同時此次事件也促使了前蘇聯政府的資訊趨向較為透明化。蘇聯瓦解後的各個獨立國家,包括俄羅斯、烏克蘭、白俄羅斯,至今仍為清理車諾比事件所造成的污染問題及其引起的健康問題上付出著極大的代價。因事件所造成的死亡人數難以精確計算,前蘇聯時期的刻意隱瞞,使得追查犧牲者方面的工作變得更為困難,事實上,前蘇聯政府當局在事件發生之後不久,已禁止醫生在死亡證明上提及因「輻射線」而死亡[3]

這個災難總共損失大概兩千億美元,包含將通貨膨脹也列入計算。這使得車諾比災難在近代歷史中成為最「昂貴」的災難事件之一。[4]

國際原子能總署世界衛生組織所主導的車諾比論壇在2005年所提出的車諾比事件報告中,56人的死亡被歸咎於此事件(47名救災人員,9名罹患甲狀腺癌的兒童),並估算在高度輻射線物質下暴露的大約60萬人中,會有將近額外有4,000人將死於癌症。[5]此數據包括已診斷出的4,000名兒童甲狀腺癌會造成的死亡(依據白俄羅斯的經驗,存活率接近99%)。綠色和平組織所估計的總傷亡人數是9萬3千人,但引用在最新出爐的一份報告中的數據指出發生在白俄羅斯、俄羅斯及烏克蘭單獨事件在1990年到2004年間可能已經造成20萬起額外的死亡。儘管疏散區域和某些限制地區還有些管制,但是大多數的受影響區域已經被認為可以安全地居住和經濟活動。[6]

Source: http://zh.wikipedia.org/wiki/%E5%88%87%E5%B0%94%E8%AF%BA%E8%B4%9D%E5%88%A9%E6%A0%B8%E4%BA%8B%E6%95%85

Chernobyl disaster

Chernobyl Disaster.jpg

The nuclear reactor after the disaster. Reactor 4 (center). Turbine building (lower left). Reactor 3 (center right).
Date 26 April 1986
Time 01:23:45 a.m (Moscow Time UTC+3)
Location PripyatUkrainian SSRSoviet Union

The abandoned city of Pripyat with Chernobyl plant in the distance

Radio-operated bulldozers being tested prior to use

Abandoned housing blocks in Pripyat

The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in the Ukrainian SSR (now Ukraine). 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.

The disaster began during a systems test on 26 April 1986 at reactor number four at the Chernobyl plant, which is near the town of Pripyat. There was a sudden power output surge, and when an emergency shutdown was attempted, a more extreme spike in power output occurred, which led to a reactor vessel rupture and a series of explosions. This event exposed the graphite moderator components of the reactor to air, causing them to ignite. The resulting fire sent a plume of radioactive fallout into the atmosphere and over an extensive geographical area, including Pripyat. The plume drifted over large parts of the western Soviet UnionEastern EuropeWestern Europe, and Northern Europe. Large areas in UkraineBelarus, and Russia had to be evacuated, and over 336,000 people were resettled. According to official post-Soviet data,[1][2] about 60% of the fallout landed inBelarus.

Despite the accident, Ukraine continued to operate the remaining reactors at Chernobyl for many years. The last reactor at the site was closed down in 2000, 14 years after the accident.[3]

The accident raised concerns about the safety of the Soviet nuclear power industry as well as nuclear power in general, slowing its expansion for a number of years and forcing the Soviet government to become less secretive about its procedures.[4][notes 1]

Russia, Ukraine, and Belarus have been burdened with the continuing and substantial decontamination and health care costs of the Chernobyl accident. Fifty deaths, all among the reactor staff and emergency workers, are directly attributed to the accident. Estimates of the total number of deaths attributable to the accident vary enormously.

Source: http://en.wikipedia.org/wiki/Chernobyl_disaster

Chernobyl disaster incident PART 1

http://www.youtube.com/watch?v=bSRC1_OZPIg&feature=related

Chernobyl disaster incident PART 2

http://www.youtube.com/watch?v=zByDY-nPNJc&feature=watch_response

三哩島核泄漏事故

三哩島核泄漏事故,通常簡稱「三哩島事件」,是1979年3月28日發生在美國賓夕法尼亞州薩斯奎哈納河三哩島核能發電廠(Three-Miles Island Nuclear Generating Station)的一次部分爐心融毀(partial core meltdown)事故。這是美國核電歷史上最嚴重的一次事故。

事故簡述

TMI-2機組的結構簡圖

TMI-2機組爐心融毀的示意圖

當天凌晨4時半,三哩島核能發電廠95萬千瓦壓水堆電站二號反應爐主給水泵停轉,輔助給水泵按照預設的程序啟動,但是由於輔助迴路中一道閥門在此前的例行檢修中沒有按規定打開,導致輔助迴路沒有正常啟動,二迴路冷卻水沒有按照程序進入蒸汽發生器,熱量在堆心聚集,堆心壓力上升。堆心壓力的上升導致減壓閥開啟,冷卻水流出,由於發生機械故障,在堆心壓力回復正常值後堆心冷卻水繼續注入減壓水槽,造成減壓水槽水滿外溢。一迴路冷卻水大量排出造成堆心溫度上升,待運行人員發現問題所在的時候,堆心燃料的47%已經融毀並發生泄漏,系統發出了放射性物質泄漏的警報,但由於當時警報蜂起,核泄漏的警報並未引起運行人員的注意,甚至現時無人能夠回憶起這個警報。直到當天晚上8點,二號堆一二迴路均恢復正常運轉,但運行人員始終沒有察覺堆心的損壞和放射性物質的泄漏。

此後,第76任賓州州長迪克·松伯(Dick Thornburgh)[1]出於安全考慮於3月30日疏散了核能發電廠5英里範圍內的學齡前兒童和孕婦,並下令對事故堆芯進行檢查。檢查中才發現堆芯嚴重損壞,約20噸二氧化鈾堆積在反應爐壓力槽底部,大量放射性物質堆積在核反應爐安全殼內,少部分放射性物質泄漏到周圍環境中。

Source: http://zh.wikipedia.org/wiki/%E4%B8%89%E5%93%A9%E5%B3%B6

Three Mile Island accident

President Jimmy Carter leaving Three Mile Island for Middletown, Pennsylvania, April 1, 1979

The Three Mile Island accident was a partial core meltdown in Unit 2 (a pressurized water reactor manufactured by Babcock & Wilcox) of the Three Mile Island Nuclear Generating Station in Dauphin County, Pennsylvania near HarrisburgUnited States in 1979. The plant was owned and operated by General Public Utilities and the Metropolitan Edison Co. It was the most significant accident in the history of the American commercial nuclear power generating industry, resulting in the release of up to 481 P Bq (13 million curies) of radioactive gases, but less than 740 GBq (20 curies) of the particularly dangerous iodine-131.[1]

The accident began at 4 a.m. on Wednesday, March 28, 1979, with failures in the non-nuclear secondary system, followed by a stuck-open pilot-operated relief valve (PORV) in the primary system, which allowed large amounts of nuclear reactor coolant to escape. The mechanical failures were compounded by the initial failure of plant operators to recognize the situation as a loss of coolant accident due to inadequate training and human factors, such as industrial design errors relating to ambiguous control room indicators in the power plant’s user interface. The scope and complexity of the accident became clear over the course of five days, as employees of Metropolitan Edison (Met Ed, the utility operating the plant), Pennsylvania state officials, and members of the U.S. Nuclear Regulatory Commission (NRC) tried to understand the problem, communicate the situation to the press and local community, decide whether the accident required an emergency evacuation, and ultimately end the crisis.

In the end, the reactor was brought under control, although full details of the accident were not discovered until much later, following extensive investigations by both a presidential commission and the NRC. The Kemeny Commission Report concluded that “there will either be no case of cancer or the number of cases will be so small that it will never be possible to detect them. The same conclusion applies to the other possible health effects.”[2] Several epidemiological studies in the years since the accident have supported the conclusion that radiation releases from the accident had no perceptible effect on cancer incidence in residents near the plant, though these findings have been contested by one team of researchers.[3]

Public reaction to the event was probably influenced by The China Syndrome, a movie which had recently been released and which depicts an accident at a nuclear reactor.[4] Communications from officials during the initial phases of the accident were felt to be confusing.[5] The accident crystallized anti-nuclear safety concerns among activists and the general public, resulted in new regulations for the nuclear industry, and has been cited as a contributor to the decline of new reactor construction that was already underway in the 1970s.

Source: http://en.wikipedia.org/wiki/Three_Mile_Island_accident

大亞灣核電站

维基百科,自由的百科全书

大亞灣核電站位於中國廣東省深圳市龍崗區大鵬半島,是中國大陸建成的第二座核電站,也是大陸首座使用國外技術和資金建設的核電站[1]。此後,在大亞灣核電站之側又建設了嶺澳核電站,兩者共同組成一個大型核電基地。

概述

最初,建設大亞灣核電站的目的是為了向香港供電。1980年代初,香港的電力供應曾一度緊張,中華人民共和國水利電力部廣東省政府計劃在靠近香港、廣州深圳等電力負荷中心的深圳市大鵬鎮境內建設一座核電站,因選址在大亞灣畔的嶺澳村,故命名為大亞灣核電站。該電站引入香港的供電商參股,並將所發電力的大部分售予香港。但在籌備期間,因早前國外先後發生三哩島切爾諾貝爾事故,發生了大量香港民眾到港島中區集會反對建設核電站,共有百萬港人簽名反對興建[2],以及中國政府和英國政府商討香港主權移交等事件,而延遲了核電站的建設。為消除各方顧慮,電站引進了法國的核島技術裝備和英國的常規島技術裝備進行建造和管理,並由一家美國公司提供質量保證。歷經種種坎坷之後,大亞灣核電站終於在1987年開工,使用壓水型反應爐技術,安裝兩台90萬千瓦發電機組(實際功率2*98.4萬千瓦),分別於1994年2月和1994年5月併網發電。

在大亞灣核電站建成後,中國政府決定在大亞灣核電站東北方向一千米處繼續建造一座新的核電站,定名為嶺澳核電站。嶺澳核電站規劃安裝4台100萬千瓦發電機組,分兩期建設。一期工程於1997年開工,於2002年7月和2003年3月投入商業運行。一期工程安裝兩台壓水型反應爐發電機組,技術上採用了大亞灣核電站的翻版改進,內部布局亦十分相似,並增加了設備國產化率。

二期工程位於一期工程的東北側,同樣為兩台壓水型反應爐發電機組。於2005年開工,兩台機組於2010年2011年建成投入商業運行。

大亞灣—嶺澳核電站所在的廣東省目前有一座可為核電站安全穩定經濟運行提供配套的抽水蓄能電站,即廣州抽水蓄能電站,位於廣東省從化市,安裝8台30萬千瓦發電機組,總裝機容量240萬千瓦。

組織結構

大亞灣—嶺澳核電站目前共有4台發電機組,總裝機容量380萬千瓦。在組織結構上,分為二個實體。

大亞灣核電站的業主為廣東核電合營有限公司,該公司主要股東中國廣東核電集團有限公司(75%)、中電控股有限公司(25%)

  • 大亞灣1號機組裝機容量90萬千瓦,1993年8月併網發電。
  • 大亞灣2號機組裝機容量90萬千瓦,1994年2月併網發電。

嶺澳核電站的業主為嶺澳核電有限公司,該公司的主要股東有中國廣東核電集團有限公司(100%)

  • 嶺澳一期1號機組裝機容量100萬千瓦,2002年2月併網發電。
  • 嶺澳一期2號機組裝機容量100萬千瓦,2002年9月併網發電。

核洩漏事故

自由亞洲電臺引《廣東大亞灣核電站,嶺澳核電站第八屆核安全咨詢委員會第五次會議》報告指核電廠曾在2010年5月23日發生核洩漏輻射事故,輻射洩漏出核電站。[3]中華電力回應指事輕微不影響公眾安全。大亞灣核電廠核安全諮詢委員會成員之一的溫石麟批評中電誤導公眾,但其後委員會又再否認輻射洩漏核電站。[4]

核電廠在2010年10月23日為一個反應爐進行例行大修時,工作人員發現冷卻反應爐的喉管出現了三條裂紋,並發現滲漏出帶有輻射的硼結晶,工作人員吸收不多於2毫希輻射量,相當於照20次X光的劑量,是八年來最嚴重的事件,也是這一年內第三次出現事故。這次洩漏事故屬於第一級的異常事件,較今年5月燃料棒事故嚴重,但核電廠分別在事後4日及10日才知會中電管理層及港府。[5]

參考文獻

  1. ^大亞灣核電站核泄漏事故報導失實 事件被誇大中國廣播網
  2. ^核泄漏恐懼源自不透明 管理安全還要公衆安心
  3. ^深圳大亞灣核電站發生核洩漏事故
  4. ^核輻射疑續洩漏變羅生門核安委會統一口徑漏夜發聲明否認輻射洩出廠外
  5. ^深圳大亞灣核電廠 發生8年來最嚴重核輻射外洩

Source: http://zh.wikipedia.org/wiki/%E5%A4%A7%E4%BA%9A%E6%B9%BE%E6%A0%B8%E7%94%B5%E7%AB%99

Daya Bay Nuclear Power Plant

From Wikipedia, the free encyclopedia
Daya Bay Nuclear Power Plant

Daya Bay nuclear power plant
Daya Bay Nuclear Power Plant is located in China

Location of Daya Bay Nuclear Power Plant

Country People’s Republic of China
Locale Longgang DistrictShenzhen,Guangdong
Coordinates 22°36′N 114°33′ECoordinates22°36′N 114°33′E
Status Operational
Commission date Unit 1: August 31, 1993
Unit 2: February 2, 1994
Operator(s) Guangdong Nuclear Power Joint Venture Company (GNPJVC)[1]
Reactor information
Reactors operational 2 x 944 MWe (net)
2 x 984 MWe (gross)
Reactor type(s) PWR

Daya Bay Nuclear Power Plant is located on Daya Bay in Longgang DistrictShenzhenGuangdongPeople’s Republic of China, north of Hong Kong. Daya Bay has two 944 MWe PWR nuclear reactors based on the French 900 MWe three cooling loop design,[2] which started commercial operation in 1993 and 1994.[3]

History

Although located within Guangdong Province, in 1985 the building of Daya Bay nuclear power plant incited controversies and raised objections from prominent politicians in the neighboring Hong Kong, such as Martin Lee and Szeto Wahlegislative councilors, district board members. Over a hundred community groups dealt with the construction topics with the opposition focusing on environmental issues and the rights of Hong Kong residents.[4]

Unit 1 began power operations on August 31, 1993, and Unit 2 began power operations on February 2, 1994. The reactors were designed and built by the French National Company, Framatome, with Chinese participation. Daya Bay is 25% owned by Hong Kong-listed CLP Holdings, which buys about 70% of the plant’s output to supply Hong Kong’s power needs.[5]

On June 16, 2010 Radio Free Asia[6] informed that there was a leak in one of the fuel tubes. Officials denied this information stating that “Daya Bay’s two reactor units are functioning safely and stably. There has been no radioactive leak”. Radio Free Asia quotes a unidentified expert, that radioactive Iodine has been released. It also informs, that the incident was not initially reported to the government, but was kept secret for some time. The New York Times reported differently, quoting one of the shareholders of the plant, China Light & Power (CLP), a Hong Kong-based utility, that the government nuclear safety watchdog in both mainland China and Hong Kong were notified and briefed. CLP said in a statement that the leak was small and fell below international standards requiring reporting as a safety issue. No radioactive monitoring stations in Hong Kong detected any rise in radioactivity.[7] Mainland news outlets also quoted officials explaining the situation, which was under normal operation conditions and fell below international standards for reporting.

The plants are named Guangdong-1 and Guangdong-2 in the IAEA PRIS database.[3]

References

  1. ^“Nuclear Power Reactor Details – GUANGDONG 1”Power Reactor Information System (PRIS). International Atomic Energy Agency. Retrieved 2010-07-18.
  2. ^“Fuel loading starts at new Chinese reactor”. World Nuclear News. 22 April 2010. Retrieved 18 July 2010.
  3. ab“China, People’s Republic of: Nuclear Power Reactors”PRIS database. International Atomic Energy Agency. Retrieved 18 July 2010.
  4. ^Asiasociety.org
  5. ^[1]
  6. ^China nuclear firm denies leak, admits tube cracks
  7. ^ Bradsher, Keith (June 15, 2010). “Chinese Nuclear Plant Experienced a Small Leak Last Month, a Stakeholder Says”The New York Times. Retrieved 2010-07-18.

Source: http://en.wikipedia.org/wiki/Daya_Bay_Nuclear_Power_Plant

Accidents and safety

Nine nuclear power plant accidents with more than US$300 million in property damage, to 2011[98][99][100]
Date↓ Location↓ Description↓ Cost
(in millions
2006 $)↓
December 7, 1975 Greifswald, East Germany Electrician’s error causes fire in the main trough that destroys control lines and five main coolant pumps US$443
February 22, 1977 Jaslovské Bohunice, Czechoslovakia Severe corrosion of reactor and release of radioactivity into the plant area, necessitating total decommission US$1,700
March 28, 1979 Middletown, Pennsylvania, US Loss of coolant and partial core meltdown, see Three Mile Island accident and Three Mile Island accident health effects US$2,400
March 9, 1985 Athens, Alabama, US Instrumentation systems malfunction during startup, which led to suspension of operations at all three Browns Ferry Units – operations restarted in 1991 for unit 2, in 1995 for unit 3, and (after a $1.8 billion recommissioning operation) in 2007 for unit 3 US$1,830
April 11, 1986 Plymouth, Massachusetts, US Recurring equipment problems force emergency shutdown of Boston Edison’s Pilgrim Nuclear Power Plant US$1,001
April 26, 1986 Chernobyl, near the town of Pripyat, Ukraine Steam explosion and meltdown with 4,057 deaths (see Chernobyl disaster) necessitating the evacuation of 300,000 people from the most severely contaminated areas of Belarus, Russia, and Ukraine, and dispersing radioactive material across Europe (see Chernobyl disaster effects) US$6,700
March 31, 1987 Delta, Pennsylvania, US Peach Bottom units 2 and 3 shutdown due to cooling malfunctions and unexplained equipment problems US$400
September 2, 1996 Crystal River, Florida, US Balance-of-plant equipment malfunction forces shutdown and extensive repairs at Crystal River Unit 3 US$384
March 10, 2011 Fukishima, Japan Earthquake followed by tsunami cause Fukushima I Nuclear Power Plant to lose ability to cool nuclear reactors. Explosion of secondary containment wall occurs during live TV. 300,000 people from the vicinity were evacuated.[101] Rising

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

How to protect yourself against nuclear radiation
Just in case……

 

In 1945, at the time of the atomic bombing of Japan, Tatsuichiro Akizuki, M.D. was Director of the Department of Internal Medicine at St. Francis’s Hospital in Nagasaki. Most patients in the hospital, located one mile from the center of the blast, survived the initial effects of the bomb, but soon after came down with symptoms of radiation sickness from the fallout that has been released.

Dr. Akizuki fed his staff and patients a strict diet of brown rice, miso and tamari soy soup, wakame, kombu and other seaweed, Hokkaido pumpkin, and sea salt and prohibited the consumption of sugar and sweets.

As a result, he saved everyone in his hospital, while many other survivors perished from radiation sickness.
Source: Tatsuichiro Akuziki, M.D. Nagasaki 1945, London Quarter books, 1981. (Brown rice, miso, Sea vegetables, Salt)

In 1968 Canadian researchers reported that sea vegetables contained a polysaccharide substance that selectively bound radioactive strontium and helped eliminate it from the body. In laboratory experiments, sodium alginate prepared from kelp, kombu, and other brown seaweeds off the Atlantic and pacific coasts was introduced along with strontium and calcium into rats. The reduction of radioactive particles in bone uptake, measured in the femur, reached as high as 80%, with little interference with calcium absorption.

The evaluation of biological activity of different marine algae is important because of their practical significance in preventing absorption of radioactive products of atomic fission as well as in their use as possible natural decontaminators.
Source: Y. Tanaka et. Al. ” Studies on Inhibition of Intestinal Absorption of Radioactive Strontium”, Canadian Medical Association Journal 99: 169-75. (Sea Vegetables)

WHOLE GRAINS PROTECT IN FIVE WAYS

Whole grains help to protect us from the deleterious health effects of radiation exposure in five ways:

1) Grains are low on the food chain. Although they may have been exposed to pollution and radiation, they do not have the concentration of contaminants that is found in meat and large fish, which are at the top of the food chain.

2) Important with respect to radiation protection is the high fiber and phosphorous contents in grains. The binding ability of these substances helps the body to remove poisons.

3) The bulking factor of grains lessens the intestinal transit time and so hasten the elimination of all toxins.

4) Being neither very acid nor very alkaline, grains help us to maintain the middle-range pH that has been found to increase our resistance to radiation.

5) Whole grains provide vitamin B6, which is indispensable for the thymus. In addition, their calcium content guards against uptake of radioactive strontium, and their vitamin E and selenium prevent cellular damage caused by free radicals.
THE FOODS BETTER TO AVOID

1) Refined, genetic modified and processed foods

2) Fatty foods (meat, dairy products)

3) Simple sugars (white sugar), soft drinks

Source: Diet for the Atomic Age by Sara Shannon-Avery Publishing Group Inc., Wayne, New Jersey.

The products mentioned in this message are available in most of the health stores.

Source: http://home.iae.nl/users/lightnet/health/radiation.htm