Chemobyl-4 reactor accident

Anspaugh LR, Catlin RJ, and Goldman M (1988) The global impacts of the chemobyl reactor accident. Science 242 1513-1519. 

As discussed above, in a world with 4000 well-designed reactors, one would expect less than a 4% chance of a Chemobyl-scale reactor accident per century. If one estimates that such an accident might cause 20,000 eventual cancer deaths, the calculated risk over a century from reactor accidents would be of the order of 800 deaths. Reactors might do better or worse than this, but the anticipated scale of harm is in the ballpark of a thousand deaths per century - with large uncertainties in either direction,... 

Chernobyl. The most weU-known graphite-moderated reactor is the infamous Chemobyl-4, in Ukraine. It suffered a devastating accident in 1986 that spread radioactivity over a wide area of Europe. 

The accident at the Three Mile Island (TMI) plant in Pennsylvania in 1979 led to many safety and environmental improvements (4—6). No harm from radiation resulted to TMI workers, to the pubHc, or to the environment (7,8), although the accident caused the loss of a 2 x 10 investment. The accident at the Chernobyl plant in the Ukraine in 1986, on the other hand, caused the deaths of 31 workers from high doses of radiation, increased the chance of cancer later in life for thousands of people, and led to radioactive contamination of large areas. This latter accident was unique to Soviet-sponsored nuclear power. The Soviet-designed Chemobyl-type reactors did not have the intrinsic protection against a mnaway power excursion that is requited in the test of the world, not was there a containment building (9—11). 

The worst nuclear power plant accident occurred at the Chemobyl-4 plant in the Soviet Union. A remarkable series of events began on April 25, 1986 and continued over several days, resulting in more than 30 deaths and 237 injuries from radiation exposure, as well as massive contamination of wide geographical areas. The radiation released was measurable over much of the globe. A combination of human errors, design errors, and complacency contributed to the accident. In many ways, the attitude toward nuclear safety in the Soviet Union was similar to the pre-TMI attitude in the United States. This section provides a brief overview of the Chernobyl reactor design, a description of the sequence of events leading to the accident, and a discussion of the relevance of the accident to U.S. plants. 

The Chernobyl-type reactors have undergone many design and operation changes since the accident at Chemobyl-4. The discussion below portrays the design as it existed at the time of the accident and does not reflect the many changes that have since occurred. 

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