Nuclear Energy - Domestic Nuclear Energy Production

The percentage of U.S. electricity supplied by nuclear power grew considerably during the 1970s and 1980s before leveling off in the 1990s. In 1973 nuclear power supplied only 4.5% of the total electricity generated in the United States. By 2003 nuclear power's 19.8% share of electricity production was down only slightly from the 2001 all-time high of 20.6%. In 2002 nuclear power plant operations provided an all-time high of nuclear electricity net generation of 780.1 billion kilowatt-hours.

The increase in production of electricity in nuclear power plants was achieved largely through an increase in average capacity factor. The capacity factor is the proportion of electricity produced to what could have been produced at full-power operation. In 2002 the capacity factor was at an all-time high of 90.3%. In 2003 the capacity factor was 88.2%. Better training for operators, longer operating cycles between refueling, and control-system improvements contributed to increased plant performance.

In 2003 and 2004, 104 nuclear reactors were in operation (see Figure 5.6 and Figure 5.7) in thirty-one states. In 2003 these 104 reactors had a total net generation of 763.7 billion kilowatt-hours of energy. Most of these reactors

FIGURE 5.5

are located east of the Mississippi River, where the demand for electricity is high. The number of plants operating is lower than the 135 reactors that were either planned, in construction, or in operation in 1974.

Since 1978 no new nuclear power plants have been ordered, and many have closed. (See Table 5.1.) Several factors have contributed to the slowdown in U.S. nuclear reactor construction. Overall costs have increased as a result of more expensive financing, partly influenced by longer delays for licensing. Expenses have also increased because of regulations that were instituted as a result of the Three Mile Island incident. Operating costs have been higher than expected as well. Originally, it was projected that plants could run almost 90% of the time, with brief pauses for refueling, but for many years this was not the case.