Экология сегодня. Макеева М.Н - 32 стр.

UptoLike

ВУЗ: 

ТГТУ | Тамбов

Составители: 

Рубрика: 

1. Сложноподчиненные предложения (The Complex Sentences).
2. Функции Причастия I и Причастия II (Participle I, Participle II).
3. Герундий (Gerund).
Text:
THE NUCLEAR ENERGY CHALLENGE
The atom, the smallest component of any element, contains enormous energy. When it is split – a process
called fission, this energy is released in the forms of tremendous heat and light. This energy was released on
Hiroshima and Nagasaki, Japan, by two separate atom bombs in 1945 that led to the conclusion of World War
II. The horrors created by those two bombs led the international community to condemn further use of atomic
weapons.
Still, engineers, governments and scientists realized that if the atom’s energy could be controlled and har-
nessed, it would revolutionize the world’s energy markets and provide significant electricity reserves to help
meet the world’s energy demands. It was even envisioned that it could one day replace the need for fossil fuels.
As a result, the first usable electricity from nuclear fission was produced at the Idaho National Engineering
Laboratory in 1951.
In 1954, The Atomic Energy Act was passed to promote the peaceful use of nuclear energy. Subsequently,
in 1957, the International Atomic Energy Agency (IAEA) was formed to promote peaceful use of nuclear en-
ergy and to provide international safeguards and an inspection system to ensure nuclear materials are not di-
verted from peaceful to military uses. It was later replaced by the Nuclear Regulatory Commission and the En-
ergy Research and Development Administration, the latter of which became the US Department of Energy in
1977.
Commercial nuclear power plants became a commercial reality in the late 1960s when large numbers of
orders were placed for nuclear power reactors in the United States. Yet, in 1979, America’s fears about nuclear
power were realized when a partial meltdown occurred in a reactor at the Three Mile Island facility in Harris-
burg, Pennsylvania. Though minimal radioactive material – which can cause serious damage to or kill living
tissue – was released, the potential for greater disaster lurked.
This greater potential was realized in April 1986 when a full reactor meltdown and fire occurred at the
Chernobyl Nuclear Power Plant in the former Soviet Union. This resulted in the massive release of radioactive
materials, resulting in major environmental catastrophe. As a result of these disasters, global support for nuclear
energy – which already had significant negative public support – plummeted to lower levels.
Over the last 15 years, vast improvements to nuclear reactors have been made to make them safer and last
longer. There is still strong support for nuclear energy from many sectors that are convinced it is the future of
the world’s energy sources. While nuclear energy has several advantages over fossil fuels, particularly consid-
ering that it does not release the harmful greenhouse gas carbon dioxide into the atmosphere, public resistance
remains high.
Nuclear energy requires sources of radioactive elements found naturally in our environment and manmade
with which to create the nuclear fission process that splits the atoms. The most common and most used of these
elements is Uranium, which is found in two different types or species (called isotopes): U-238 and U-235. U-
235 is the type used for nuclear fission because it can be readily split, releasing massive energy. The other type
of Uranium is called U-238, which is barely radioactive. Of all the known Uranium reserves in the world, al-
most all of it is U-238, with just over a half a percent of those reserves being U-235.
Plutonium and Thorium are the only other available sources that are used for nuclear energy. Plutonium is
not naturally occurring. Thus, the Plutonium used in nuclear reactors is man-made, coming from a nuclear reac-
tor. It is not as stable as U-235 and is harder to use. Thorium, though not yet a mainstream nuclear energy sup-
ply source, is being heavily studied and applied as a safer, cleaner alternative to Uranium. Still, Uranium is king
as the premiere provider of nuclear energy.
Perhaps the greatest challenge facing nuclear energy production – after any potential for nuclear disasters
similar to the 1986 Chernobyl event – is disposal of the highly radioactive wastes. It could take at least 10,000
years for these materials to fully break down into harmless elements so the challenge is to store them safely for
at least that length of time. It is possible, but where and how are still troubling issues.
Exploitable Uranium supplies also pose some more short-term challenges. According to the Organization
for Economic Cooperation and Development, the world’s economically exploitable Uranium reserves are likely
to last between 35 and 63 years, depending on whether demand is such as to justify the higher cost of mining
less easily exploitable reserves.

Страницы