In 1954, the country built its first small research heavy water reactor.

A similar or possibly larger heavy water reactor has been under construction at Khushab since about 2002.

During the 1970s, the Republic of China had an active program to produce plutonium using heavy water reactors.

The fact that thorium can theoretically be utilized in heavy water reactors has tied the development of the two.

Iran also plans to produce plutonium, another fuel for nuclear weapons, by building a 40-megawatt heavy water reactor at Arak.

Nonproliferation experts see heavy water reactors as a danger because they are a relatively simple way to produce bomb fuel.

Because they do not require uranium enrichment, heavy water reactors are of concern in regards to nuclear proliferation.

The department said last year that it would take about 10 years to build a new heavy water reactor at the Savannah River Plant.

Nor does it prevent the building of the heavy water reactor or, indeed, the resumption of enrichment in the future.

Pressurised heavy water reactors do have some drawbacks.

Use of heavy water reactors has been particularly attractive for the nation because it allows Uranium to be burnt with little to no enrichment capabilities.

Both were heavy water reactors, motivated by the option to use Swedish uranium without isotope enrichment.

"A heavy water reactor of 40 megawatts is likely to have one significant purpose - the production of plutonium for nuclear weapons."

James Chadwick recruited him to a Cambridge University team working on a possible heavy water reactor.

As part of that effort, the Lab built a 5-megawatt heavy water reactor for neutron diffraction studies and additional isotope separation research.

Their main concern is a site at Arak, where Iranian construction crews are starting work on a 40-megawatt heavy water reactor that will make plutonium.

The Steam Generating Heavy Water Reactor was also developed at the site.

The Arak heavy water reactor was at an early stage of development and was not progressing very rapidly though many people were working on the site.

IR-40 is an Iranian 40 megawatt (thermal) heavy water reactor under construction in Arak.

Graphite and heavy water reactors tend to be more thoroughly thermalised than light water reactors.

This differentiates it from a heavy water reactor, which uses heavy water as a neutron moderator.

Lithium containing salts will cause significant tritium production (comparable with heavy water reactors), even if pure Li is used.

In light water reactors and heavy water reactors it doubles as the nuclear reactor coolant.

Iran has also offered to renounce plutonium extraction technology, thus ensuring that its heavy water reactor at Arak cannot be used to make bombs either.

The Czechoslovak government completed its first nuclear power plant - a gas-cooled heavy water reactor - in 1972 in Bohunice.