Environmental Engineering Reference
In-Depth Information
Reserves, resources, and occurrences of uranium are based on a once-through
fuel cycle operation. Closed fuel cycles and breeding technology would increase
the uranium resource dimension 50-60 fold. Thorium-based fuel cycles would en-
large the fissile resource base further.
If the other problems related to the use of nuclear energy, such as nuclear waste
disposal and nuclear proliferation, are resolved, nuclear energy could contribute
more to the energy supply in the 21st century.
Several countries, particularly the United States, have attempted to stimulate
a “nuclear renaissance” in the last few years. Until the end of 2010 there were
signs of such a “renaissance,” with the start of construction of a few new reactors,
mainly in China, Russia, and Eastern Europe. In addition to that, some 50 develop-
ing countries indicated their interest in installing nuclear reactors, although many
of them do not have electricity grids large enough to accommodate large nuclear
units, which are very expensive.
These plans have been put in question by the nuclear accident in Fukushima,
Japan, where six reactors were severely hit by an earthquake followed by a
tsunami. The consequences were very serious due to the partial melting of some
of the fuel rods at the core of the reactor and a release of radioactive Cesium 137
greater than 15% of the emissions in the Chernobyl disaster and more than 100
times the amount released by the Hiroshima atomic bomb. This release of radio-
activity forced the evacuation of hundreds of thousands of people living in a radius
of 20 kilometers of the Fukushima plant. The accident was classified as a level 7
on the scale of gravity of nuclear accidents, which is at the same levels as the one
in Chernobyl.
Worldwide the Fukushima accident led to a tightening of security measures to
avoid the repetition of such disasters and a general reappraisal of the future role of
nuclear energy in the world energy matrix.
Several OECD countries (Germany, Belgium, Italy, and Switzerland) decided to
phase out existing reactors at the end of their useful life and cancelled plans for new
ones. Japan cancelled plans for new reactors. The International Energy Agency re-
duced by 50% its projection for the number of new reactors (approximately 200)
planned to be installed by 2035. China has halted expansion plans pending a re-
view of safety procedures.
