Radioactive contamination

Radioactive contamination or radiological contamination is the contamination of the environment with radioactive materials, where these materials are not present. Many radioactive substances have very long half lives; this means that if they are present in the envioroment, they can be dangerous for a very long time. Many nuclear power plants produce such substances; usually they are processed to radioactive waste. There is little danger that comes from radioactive waste,if it is stored safely.

The Hanford site represents two-thirds of the United States' high-level radioactive waste by volume. Nuclear reactors line the riverbank at the Hanford Site along the Columbia River in January 1960.

As of 2013, the Fukushima nuclear disaster site remains highly radioactive. About 160,000 people still live in temporary housing. Some land will be unfarmable for centuries. The difficult cleanup job will take 40 or more years, and cost tens of billions of dollars.^[1][2]

The 18,000 km² expanse of the Semipalatinsk Test Site (indicated in red), which covers an area the size of Wales. The Soviet Union conducted 456 nuclear tests at Semipalatinsk from 1949 until 1989 with little regard for their effect on the local people or environment. The full impact of radiation exposure was hidden for many years by Soviet authorities and has only come to light since the test site closed in 1991.^[3]

2007 ISO radioactivity danger symbol. The red background is intended to convey urgent danger, and the sign is intended to be used in long-term radioactive waste repositories, which might survive into a distant future where other danger symbols may be forgotten or misinterpreted.

Causes

• Incidents in nuclear power plants
• Nuclear medicine uses radiation for the treatment of illnesses. Sometimes, there are accidents.
• Explosions in nuclear facilities (and atomic bombs) cause nuclear fallouts: This means that nuclear particles are scattered using normal atmospheric phenomena, such as the weather
• Nuclear reprocessing can contaminate water

Accidents

Year	Type	Incident	ARS deaths	ARS survivors	Location
1945	criticality	Harry K. Daghlian	1	0	Los Alamos, New Mexico, United States
1946	criticality	Pajarito accident (Louis Slotin)	1	2	Los Alamos, New Mexico, United States
1957	alleged crime	Nikolay Khokhlov assassination attempt[4]	0	1	Frankfurt, West Germany
1958	criticality	Cecil Kelley criticality accident	1	0	Los Alamos, New Mexico, United States
1961	reactor	Soviet submarine K-19[5]	8	many	North Atlantic, near Southern Greenland
1961	criticality	SL-1 experimental reactor explosion	2	0	NRTS, near Idaho Falls, Idaho, United States
1962	orphan source	radiation accident in Mexico City	4	?	Mexico City, Mexico
1968	reactor	Soviet submarine K-27[6]	9	40	near Gremikha Bay, Russia
1985	reactor	Soviet submarine K-431[7]	10	49	Chazhma Bay naval facility near Vladivostok, USSR
1985	radiotherapy	Therac-25 radiation overdose accidents	3	3
1984	orphan source	radiation accident in Morocco[8]	8	3	Mohammedia, Morocco
1986	reactor	Chernobyl disaster	28	206 - 209	Chernobyl Nuclear Power Plant, Ukrainian SSR
1987	orphan source	Goiânia accident[9]	4	?	Goiânia, Brazil
1990	radiotherapy	radiotherapy accident in Zaragoza[10]	11	?	Zaragoza, Spain
1996	radiotherapy	radiotherapy accident in Costa Rica[11]	7 to 20	46	San José, Costa Rica
1999	criticality	Tokaimura nuclear accident	2	?	Tōkai, Ibaraki, Japan
2000	orphan source	Samut Prakan radiation accident[12]	3	7	Samut Prakan Province, Thailand
2000	radiotherapy	Instituto Oncologico Nacional accident[13][14]	3 to 7	?	Panama City, Panama
2006	crime	Poisoning of Alexander Litvinenko[4][15][16][17][18]	1	0	London, United Kingdom
2010	orphan source	Mayapuri radiological accident[12]	1	7	Mayapuri, India