Nuclear Power Phase-out - Pros and Cons of The Phase-out - Arguments For The Phase-out - Nuclear Proliferation

Nuclear Proliferation

Another argument against nuclear energy is the potential for close connection of civil and military usage (which in most countries are kept strictly separate). In manufacturing nuclear fuel rods, the fraction of the fissile uranium isotope 235 has to be increased from the natural fraction from 0.7 to 5% in order to be able to create a chain reaction (exceptions include some designs that use heavy water or graphite as the moderator, such as CANDU reactors or Magnoxes). A station for the enrichment of uranium (e.g. the German station at Gronau) could—with extreme difficulty—increase the amount of U-235 to above 80% so it could be used in a weapon. Therefore, some of the techniques of uranium enrichment are kept secret (e.g. gaseous diffusion, gas centrifuge, AVLIS and nuclear reprocessing).

Opponents of nuclear power argue that it is not possible to discriminate between civil and military usage, and therefore that nuclear power contributes to the proliferation of nuclear weapons. While it is possible to operate a nuclear power plant with non-weaponized materials, having a reactor brings with it access to materials and facilities which can be used in special low burn military reactors and reprocessed into Plutonium which is the required ingredient for building a high yield nuclear weapon. Israel, India, North Korea, and South Africa (which later gave up its nuclear weapons) all started "peaceful" nuclear power programs with research reactors that were later used to make weapons-grade plutonium, and there is great concern that Iran's program has a similar goal, to enrich uranium to weapons-grade. Israel, Iran and North Korea do not have nuclear power plants at present, while South Africa started up its power plant long after acquiring nuclear weapons.

Design and construction of nuclear explosives based on normal reactor-grade plutonium may be difficult and unreliable, but was already done in 1962.

Much popular concern about possible weapons proliferation arises from considering the fissile materials themselves. For instance, in relation to the plutonium contained in spent fuel discharged each year from the world's commercial nuclear power reactors, it is correctly but misleadingly asserted that "only a few kilograms of plutonium are required to make a bomb". Furthermore, no nation is without enough indigenous uranium to construct a few weapons (however, that uranium would have to be enriched).

Plutonium is a substance of varying properties depending on its source. It consists of several different isotopes, including Pu-238, Pu-239, Pu-240, and Pu-241. All of these are plutonium but not all are fissile – only Pu-239 and Pu-241 can undergo fission in a normal reactor. Plutonium-239 by itself is an excellent nuclear fuel. It has also been used extensively for nuclear weapons because it has a relatively low spontaneous fission rate and a low critical mass. Consequently plutonium-239, with only a few percent of the other isotopes present, is often called "weapons-grade" plutonium. This was used in the Nagasaki bomb in 1945 and in many other nuclear weapons.

On the other hand, "reactor-grade" plutonium as routinely produced in all commercial nuclear power reactors, and which may be separated by reprocessing the spent fuel from them, is not the same thing at all. It contains a large proportion – up to 40% – of the heavier plutonium isotopes, especially Pu-240, due to it having remained in the reactor for a relatively long time. This is not a particular problem for re-use of the plutonium in mixed oxide (MOX) fuel for reactors, but it seriously affects the suitability of the material for nuclear weapons. Due to spontaneous fission of Pu-240, only a very low level of it is tolerable in material for making weapons. Design and construction of nuclear explosives based on normal (i.e. routinely discharged) reactor-grade plutonium would be difficult and unreliable, and has not so far been done. A nuclear device has been made however from low-burned plutonium from a Magnox nuclear reactor. It was tested in 1962. Its composition was never officially released but was evidently around 90% of fissile Pu-239. This method of production was very expensive, unreliable and easily detectable (fuel has to stay in the reactor for relatively short period (few weeks) as opposed to normal use (few years)), and with a relatively small yield. All these factors contributed to the fact that apart from the test device used in 1962 no new ones were created.

Amongst pro-Nuclear reactor advocates one factor in their support is due to the appeal that reactors have at reducing Nuclear weapons arsenals through the Megatons to Megawatts Program. A program which has thus far eliminated 425 metric tons of highly enriched uranium, the equivalent of 17,000 nuclear warheads, by converting it into fuel for commercial nuclear reactors, and is the single most successful non-proliferation program to date.

Some non-proliferation advocates want to see the Megatons to Megawatts Program not only continue but be expanded; the Bulletin of the Atomic Scientists has published extensive articles both for and against expansion. The program appeals to anti-Nuclear weapon advocates as it provides a financial incentive for countries with vast quantities of Nuclear weapons, like Russia, to dismantle their arsenal and sell the fissile fuel contained within to operators of Nuclear reactors.

The Megatons to Megawatts Program has been hailed as a major success by anti-nuclear weapon advocates as it has largely been the driving force behind the sharp reduction in the quantity of Nuclear Weapons worldwide since the cold war ended. However without an increase in reactors and greater demand for fissile fuel, the cost of dismantling and downblending their weapons grade fuel has dissuaded Russia from continuing their disarmament. Currently, according to Harvard professor Matthew Bunn: The Russians are not remotely interested in extending the program beyond 2013. The USA has managed to set it up in a way that costs them more and profits them less than them just making new low-enriched uranium for reactors from scratch. But there are other ways to set it up that would be very profitable for them and would also serve some of their strategic interests in boosting their nuclear exports.