Wastes, radioactive gaseous

The plasma energy recycle and conversion (PERC) process is an indirectly heated ex situ thermal recycling and conversion technology. According to the vendor, it treats hazardous waste, mixed radioactive waste, medical waste, municipal solid waste, radioactive waste, environmental restoration wastes, and incinerator ash in gaseous, hquid, slurry, or solid form. The technology uses an induction-coupled plasma (ICP) torch as its heat source coupled to a reaction chamber system to destroy hazardous materials. 

Fig. 9.5. Main paths of exposure of the human body through radioactive gaseous waste and items to be...

The radioactive waste treatment systems provides all equipment necessary to coUect, process, monitor, and dispose of radioactive gaseous, liquid, and solid wastes that are produced during reactor operation. 

Radioactive waste. Radioactive material in gaseous, liquid or solid form for which no further use is foreseen and which is controlled as radioactive waste by the regulatory authority under the legislative and regulatory framework. 

Gaseous Radioactive Wastes - the Environment Report, section 3.2 of the Environment Report (reference 15.6) summarises the sources of gaseous radioactive waste, the gaseous radwaste system (WGS), and a BAT assessment for the chosen design options. 

Systems for the containment of highly radioactive waste in gaseous, vapour, liquid and/or solid form. 

The generation of radioactive gaseous waste should be kept to the minimum practicable by adopting suitable measures, including the following ... 

Uranium oxide [1344-57-6] from mills is converted into uranium hexafluoride [7783-81-5] FJF, for use in gaseous diffusion isotope separation plants (see Diffusion separation methods). The wastes from these operations are only slightly radioactive. Both uranium-235 and uranium-238 have long half-Hves, 7.08 x 10 and 4.46 x 10 yr, respectively. Uranium enriched to around 3 wt % is shipped to a reactor fuel fabrication plant (see Nuclear REACTORS, NUCLEAR FUEL reserves). There conversion to uranium dioxide is foUowed by peUet formation, sintering, and placement in tubes to form fuel rods. The rods are put in bundles to form fuel assembHes. Despite active recycling (qv), some low activity wastes are produced. 

High-level waste (HLW), intermediate-level waste (ILW), and low-level waste (LLW) are produced at all stages of the nuclear fuel cycle as well as in the non-nuclear industry, research institutions, and hospitals. The nuclear fuel cycle produces liquid, solid, and gaseous wastes. Moreover, spent nuclear fuel (SNF) is considered either as a source of U and Pu for re-use or as radioactive waste (Johnson Shoesmith 1988), depending on whether the closed ( reprocessing ) or the open ( once-through ) nuclear fuel cycle is realized, respectively (Ewing, 2004). 

The simplest way to classify radioactive waste is by its physical state, that is, whether it is a gas, liquid, or solid. Gaseous waste arises from gas evolution,... 

The waste resulting from the above activities comes in various forms (i.e., gaseous, liquid, or solid). These wastes have different characteristics. For safety and technical reasons, the various forms of wastes are usually categorized by their levels of radioactivity, heat content, and potential hazard. 

Although gaseous and liquid wastes originating from the operation of nuclear facilities and radioactivity treatment facilities etc. are allowed to be released in... 

Categorization of Radioactive Wastes Solid Liquid Gaseous... 

Gaseous Radioactive Wastes—Noble Gases Separation.875... 

The solid, liquid and gaseous radioactive waste (see marginal notes) produced during the reprocessing of spent fuel elements has to be safely stored, to prevent entry into the biosphere. 

The second step is to dissolve the metal oxide fuel using strong nitric acid. The object is to bring all the fission products, uranium, and transuranics, into solution to feed the extraction process. Some of the fission products exceed solubility limits and the fine solids formed must be removed before extraction. Provisions to recover nitrogen oxides and collect gaseous fission products released during this step must be in place. The stainless steel and zircaloy fuel jackets from the fuel assemblies do not dissolve and are separated from the solution, washed, checked for radioactivity, and packaged for disposal as low-level radioactive waste. 

The primary gaseous carrier for transport of C from the low-level radioactive-waste disposal site (lat. 41 20 N, long. 89 47 W), near Sheffield, Bureau County, Illinois is C02 (1). Production of the gas is caused by aerobic microbial decomposition of organic waste buried in waste-disposal trenches. This results in steep gradients in P C02 in undisturbed glacial and eolian sediments adjacent to the site. To collect samples of unsaturated zone gases, nests of gas piezometers were installed along a cross section in boreholes located at distances of 12,29, and 46 m from the end wall... 

As for the material, the primary distinction is between solid, liquid, and gaseous waste. Solid waste includes any kind of contaminated or activated plant components, tools, filters, and protective clothing. Most of the liquid wastes are aqueous solutions or sludges. The term gaseous waste will be used for radioactive gases recovered from off-gas streams and contained in an appropriate form. 

Hazardous waste could be solid, semi-solid (sludge), liquid and gaseous and possesses variable characteristic properties such as toxicity, reactivity, flammability, explosivity, corrosivity and radioactivity. 

Nuclear power engineering is the main source of gaseous radioactive wastes. They are released from fuel assemblies, which have become non-gas-tight during the operation, and further from a residual contamination of the surface of fuel elements resulting from the production and from the activation of the primary coolant and its admixtures. The contributions from these sources are remarkably variable, depending on the type of the... 

The main chemical engineering principles and processes used in the United Kingdom over the past 25 years to achieve these objectives are discussed below under the headings of gaseous, liquid, and solid radioactive wastes. 

Treatment of Caseous Waste. Gaseous wastes arise from the ventilation of process vessels and the concrete cells that house the plant and equipment used for reprocessing spent nuclear fuel. This gaseous waste is largely air contaminated with small entrained liquid or solid particles containing radioactive components. Some ventilation streams also are contaminated with oxides of nitrogen. 

In principle, dispersion is only applicable for the gaseous and liquid wastes, which would need negligible pretreatment. The limitations are practical (how efficient is the dispersion into air and sea ), radiological (what radioactive concentrations are acceptable in air and sea ) and political/legal (can it be permitted ). 

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