The operation of large (1-GW, or 10 a watts, scale. nuclear power reactors began in about 1970 and there are approximately 350 nuclear power reactors operating worldwide today.

a. Roughly how many nuclear power reactor-years of operation have accumulated during this period?

b. During this period, there has been one accident that resulted in a major release of radioactivity (Chernobyl 1986) and one accident in which all but a small amount of release was prevented by the reactor containment building (Three-Mile Island 1979). On this basis, roughly what is the probability of a major release per reactor-year?

c. In 1975, the WASH-1400 Reactor Safety Study Report see box 1-2 and figures 1-6 and 1-7. estimated that the chances of a Chernobyl-type accident were around one in one million each year. Is this consistent with your estimate in (b)? What might account for the differences?

d. The Chernobyl accident may ultimately cause on the order of 10,000 extra cancer deaths (von Hippel and Cochrane 1991). How many would this come to per reactor-year?

e. Each year in the United States there are roughly fifty fatalities in coal mines, a few hundred in coal transport, and a few thousand due to respiratory diseases caused by the emission of SO2 by the equivalent of three hundred 1-GWe U.S. coal-fired power plants. On this (quite uncertain. basis, approximately how many coal-fired power plant fatalities are there per equivalent reactor-year?

f. Society does not respond in the same way to all risks, for example, the risks from nuclear and coal power plants--or to the fatalities from auto accidents, smoking, and skiing. Discuss why this appears to be the case.