How is plutonium extracted

Moreover, the steep financial costs of reprocessing argued against development of a plutonium economy. During the mid- to late s, orders for new nuclear plants stagnated, further reducing the demand for uranium-based fuels and plutonium reprocessing. However, in addition to impediments to siting repositories for radioactive waste, the global problems of proliferation and the threat of nuclear terrorism act as countervailing forces to development of a plutonium economy to support increases in nuclear power.

Growing stockpiles of separated civilian plutonium increase the risk that states or terrorists might acquire this material to build nuclear weapons. Public health and reactor safety could also worsen if the use of plutonium-fuel in commercial power plants expands beyond the current small level of usage.

Research and development of advanced proliferation-resistant fuel cycles and safer reactor designs may eventually lead to greater use of plutonium in power plants. The continuing high economic costs associated with these programs, however, will likely slow adoption. On June 27, , the world celebrated the 50th anniversary of commercial nuclear power.

Fifty years ago, the Obninsk nuclear power station in Russia was commissioned, helping to spark the growth of civilian nuclear energy. This expansion lasted into the mid- to late s when orders for new nuclear plants stagnated in the United States and have yet to recover although the nuclear industry touts signs of a nuclear renaissance.

The United States still has operating commercial reactors, the largest number of any other nation. During the golden age of nuclear power from the s to the late s, nuclear industry leaders envisioned building even more reactors than currently exist.

At that time, dreams of nuclear electricity "too cheap to meter" notwithstanding, nuclear fuel projections pointed toward potential shortages of uranium in the near term. Only 0. The most abundant isotope, uranium, which comprises Plutonium production appeared to offer a solution to projected shortfalls of uranium fuel.

As indicated, both uranium and plutonium can fuel reactors to release large amounts of nuclear energy, which can be transformed into electricity. Because plutonium isotopes decay much more rapidly than uranium isotopes, uranium is far more naturally abundant than plutonium, which exists in only trace quantities in nature.

Nuclear reactors, however, make plutonium when uranium absorbs neutrons and then undergoes a relatively rapid series of radioactive decays to become plutonium Thus, the relatively huge amounts of uranium available in mines located in many nations could, in principle, serve as fertile material to produce vast amounts of nuclear fuel.

Three-fourths about of the world's commercial reactors are light-water reactors in which ordinary water cools the reactor's core by transporting nuclear energy from the core to the part of the plant that produces electricity. Water also moderates, or slows down, neutrons in order to increase the likelihood of causing uranium and plutonium to fission and emit energy. Nuclear fuel in a light-water reactor lasts typically one to three years before the buildup of radioactive fission products makes it increasingly harder to extract energy from a fuel assembly.

At this point, the plant operators remove the spent fuel and then add fresh fuel to the reactor core. The spent fuel, however, still contains uranium and various isotopes of plutonium. This material could potentially be used to create more energy.

A technique known as reprocessing can chemically separate the uranium and plutonium from the other radioactive materials in spent fuel. By weight percentage, spent fuel typically consists of The uranium and plutonium can be recycled into new fuel. Doing this is called closing the nuclear fuel cycle. In contrast, an open fuel cycle, also known as a once-through cycle, would use the initial batch of uranium fuel once and then dispose of the spent fuel, rather than extracting the unused uranium and plutonium.

Because of the aforementioned uranium shortage projections, many nations invested in reprocessing methods to provide a source of recycled fuel.

As a result, reprocessing knowledge and technology spread widely across the world. The plutonium extracted by reprocessing could be formed into fuel for reactors employing slow, or thermal, energy neutrons, such as light-water reactors, or could be used to power a different type of reactor: the fast neutron breeder reactor. The uranium shortfall forecasts spurred intense interest in developing fast breeder reactors to create, or breed, new fuel and concurrently burn plutonium.

Making use of the principle mentioned above, that uranium can absorb neutrons to produce plutonium, these reactors, which are called "fast" because they employ fast, or high energy, neutrons to fission fuel, can "breed" more fuel than they consume. Thus, the projected limited supply of uranium could allow a bootstrapping to a plutonium economy through large-scale use of fast breeder reactors.

The nuclear ploughshare offered by reprocessing to close the fuel cycle, however, leads a double-life as a nuclear sword. The same technology can allow a nation to extract plutonium for use in nuclear bombs. In , the "peaceful" nuclear explosion in India served as a wake-up call to the dangers of the proliferation of reprocessing methods.

India had produced plutonium in the Cirus heavy-water research reactor which used heavy water, rather than light water, as coolant and moderator for the reactor core.

Canada had provided the reactor, and the United States had supplied the initial batch of heavy water. Through the dispersion of reprocessing knowledge stemming from U. President Dwight Eisenhower's Atoms for Peace program, which began in December , India was able to acquire all that it needed to create and extract plutonium from a modestly sized reactor.

India's nuclear test provoked a reversal of U. Until , the United States had supported closing the nuclear fuel cycle. In April of that year, then-President Jimmy Carter decided to defer indefinitely commercial reprocessing of plutonium. He also sought to persuade other nations to reconsider their commitments to reprocessing on the grounds of preventing nuclear proliferation and saving money. In , the Clinton administration reiterated this U. Just prior to the U.

While the Bush administration still adheres to this policy, it has expressed strong interest in proliferation-resistant methods of reprocessing, as discussed later. As suggested above, economics played a role in contributing to Carter's decision. In particular, by the mid- to late s, the nuclear industry experienced a major downturn in the demand for new nuclear power plants in the United States, and there was a realization that uranium supplies were not going to run out in the coming decades.

Thus, reprocessing was and remains a more expensive endeavor than using uranium-based fuels in a once-through cycle. Nonetheless, the "energy crisis" during the Organization of Petroleum Exporting Countries OPEC oil embargo sounded an alarm about the urgent need to invest in alternative energy resources instead of relying heavily on fossil fuels, such as petroleum and natural gas. Japan, for instance, around that time began investing significant resources into a pilot-scale reprocessing plant at Tokai-mura.

Development of a commercial-scale plant at Rokkasho-mura proceeded gradually as Japan tapped into the reprocessing capabilities available in Europe. France and the United Kingdom built large reprocessing facilities at La Hague and Sellafield, respectively. Despite the U. The mock-ups minimized the time workers spent above the tunnel, reducing their exposure risk and avoiding additional weight on the tunnel.

A number of safety controls also ensured employee and environmental safety during grout placement, including continuous monitoring and detection systems to alert workers to potential chemical or radiological exposure conditions, lights and cameras installed in the tunnel to allow crews to remotely monitor grout placement and progress, and onsite batching of the grout to ensure reliable delivery of grout while decreasing effects on traffic.

Tunnel 1 was successfully grouted in fall and Tunnel 2 was successfully grouted in May With grouting complete, the PUREX tunnels returned to surveillance mode, during which crews will inspect the exteriors of the tunnels at least once a year. On Oct. Department of Energy Hanford Site. Hanford Site Fire Danger About Hanford Cleanup. Hanford History. Hanford Site-Wide Programs. Hanford Workers Compensation. Contact Us. Received : 15 February Accepted : 01 March Issue Date : August Anyone you share the following link with will be able to read this content:.

Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative. Skip to main content. Search SpringerLink Search. Abstract The extraction behavior of uranium VI , plutonium IV and some fission products like zirconium, ruthenium and europium from 3. References 1.

Google Scholar 2. Google Scholar 3. Google Scholar 4. Google Scholar 5. Google Scholar 6. Google Scholar 7. Google Scholar 8. Google Scholar 9. Generation IV reactor designs are under development through an international project. Four of the six designs are fast neutron reactors and will thus utilize plutonium in some way.

Despite being toxic both chemically and because of its ionising radiation, plutonium is far from being "the most toxic substance on Earth" or so hazardous that "a speck can kill". On both counts there are substances in daily use that, per unit of mass, have equal or greater chemical toxicity arsenic, cyanide, caffeine and radiotoxicity smoke detectors.

There are three principal routes by which plutonium can get into human beings who might be exposed to it:. Ingestion is not a significant hazard, because plutonium passing through the gastro-intestinal tract is poorly absorbed and is expelled from the body before it can do harm.

Contamination of wounds has rarely occurred although thousands of people have worked with plutonium. Their health has been protected by the use of remote handling, protective clothing and extensive health monitoring procedures. The main threat to humans comes from inhalation. While it is very difficult to create airborne dispersion of a heavy metal like plutonium, certain forms, including the insoluble plutonium oxide, at a particle size less than 10 microns 0.

If inhaled, much of the material is immediately exhaled or is expelled by mucous flow from the bronchial system into the gastro-intestinal tract, as with any particulate matter. Some however will be trapped and readily transferred, first to the blood or lymph system and later to other parts of the body, notably the liver and bones.

It is here that the deposited plutonium's alpha radiation may eventually cause cancer. However, the hazard from Pu is similar to that from any other alpha-emitting radionuclides which might be inhaled. It is less hazardous than those which are short-lived and hence more radioactive, such as radon daughters, the decay products of radon gas, which albeit in low concentrations are naturally common and widespread in the environment.

In the s some 26 workers at US nuclear weapons facilities became contaminated with plutonium. Intensive health checks of these people have revealed no serious consequence and no fatalities that could be attributed to the exposure. In the s plutonium was injected into and inhaled by some volunteers, without adverse effects. In the s Queen Elizabeth II was visiting Harwell and was handed a lump of plutonium presumably Pu in a plastic bag and invited to feel how warm it was.

Plutonium is one among many toxic materials that have to be handled with great care to minimize the associated but well understood risks.

Half-life is the time it takes for a radionuclide to lose half of its own radioactivity. The fissile isotopes can be used as fuel in a nuclear reactor, others are capable of absorbing neutrons and becoming fissile i. Alpha decays are generally accompanied by gamma radiation. The term 'fissionable' applies to isotopes that can be made to undergo fission. If a fissionable isotope only requires neutrons with low kinetic energy to undergo fission, then it is said to 'fissile'.

Thus, all fissile isotopes are fissionable. Pu is fissionable, as it undergoes fission in a fast neutron reactor — but it is not a fissile isotope. It is theoretically possible, but very unlikely, that some UK civil plutonium may have been transferred to the US and used in the US nuclear weapons programme before See also I. Gurban and M. HV Henderickz, Plutonium: blessing or curse?

Plutonium Updated April Over one-third of the energy produced in most nuclear power plants comes from plutonium. It is created in the reactor as a by-product. Plutonium recovered from reprocessing normal reactor fuel is recycled as mixed-oxide fuel MOX.

Plutonium has occurred naturally, but except for trace quantities it is not now found in the Earth's crust.