Nuclear fuel reprocessing origin

Nuclear fuel reprocessing was first undertaken with the sole purpose of recovering plutonium, for weapons use, from uranium irradiated in nuclear reactors. These reactors, called the production reactors, were dedicated to transmuting as much of the uranium as possible to plutonium. From its original scope of recovering exclusively plutonium, with no attempts to either recover or recycle uranium, nuclear fuel reprocessing has since grown into a much more sophisticated and complex operation with expanded scope. It is now called upon to separate uranium and plutonium from the fission products, and to purify these elements to levels at which these fissile materials can be conveniently recycled for reuse. The present scope also extends to fission products separation and concentration. 

Tc can reach the sea from both fallout from nuclear weapons testing and releases from the nuclear fuel cycle. The considerably high concentrations of I c of 4.5 and even 108 mBq/1 in the Irish Sea may originate from the Sellaficld nuclear fuel reprocessing plant at Scascalc, UK. with perhaps a contribution from the Capenhurst... 

On the other hand, sediments from the Ob and Yenisey Rivers show the presence of weapons-grade Pu originating from nuclear fuel reprocessing. The data are distinctly different from those of northern-hemisphere stratospheric fallout (see references in Haque and Nakanishi 1999). 

Chromox [Chromium oxidation] A process for destroying organic pollutants in aqueous wastes by oxidation with hydrogen peroxide, catalyzed by Cr6+. Developed by British Nuclear Fuels in 1995, originally for use in nuclear reprocessing. 

As is well known, ammunition containing depleted uranium (DU) was used by NATO, for example, in the former Yugoslavia. To evaluate the origin of DU (enrichment process of natural uranium or reprocessing of exhausted nuclear fuel) it is necessary to directly detect the presence... 

The fission products that accumulate as a reactor operates decrease the efficiency of the reactor by capturing neutrons. For this reason, commercial reactors must be stopped periodically to either replace or reprocess the nuclear fuel. When the fuel elements are removed from the reactor, they are initially very radioactive. It was originally intended that they be stored for several months in pools at the reactor site to allow decay of short-lived radioactive nuclei. They were then to be transported in shielded containers to reprocessing plants where the fuel would be separated from the fission products. Reprocessing plants have been plagued with operational difficulties, however, and there is intense opposition in the United States to the transport of nuclear wastes on the nation s roads. 

The low and intermediate level wastes that may be processed in an incineration facility are produced in different forms and are of different origins (e.g. from the operation, maintenance, modification and decommissioning of nuclear reactor facilities, from spent fuel reprocessing plants, from nuclear research laboratories, from hospital laboratories). Additional information on waste sources and characteristics is provided in Annex I. The radiological characteristics of the incinerator waste feed may vary considerably, and the wastes may be divided into three main categories ... 

In 1942, the Mallinckrodt Chemical Company adapted a diethylether extraction process to purify tons of uranium for the U.S. Manhattan Project [2] later, after an explosion, the process was switched to less volatile extractants. For simultaneous large-scale recovery of the plutonium in the spent fuel elements from the production reactors at Hanford, United States, methyl isobutyl ketone (MIBK) was originally chosen as extractant/solvent in the so-called Redox solvent extraction process. In the British Windscale plant, now Sellafield, another extractant/solvent, dibutylcarbitol (DBC or Butex), was preferred for reprocessing spent nuclear reactor fuels. These early extractants have now been replaced by tributylphosphate [TBP], diluted in an aliphatic hydrocarbon or mixture of such hydrocarbons, following the discovery of Warf [9] in 1945 that TBP separates tetravalent cerium from... 

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