Nuclear waste volume

RICE, E>E., and PRIEST, C.C., An overview of nuclear waste disposal in space, fe The Technology of High-Level Nuclear Waste Disposal. Advances in the Science and Engineering of the Management of High-Level Nuclear Wastes, Volume 1 (P.L. Hofmann, editor). U.S. Department of Ener Report, Technical Information Centre, Oak Ridge, TN, DOE/TIC-4621 (1981) 370-386. 

HLW comprises most of the radioactivity associated with nuclear waste. Because that designation can cover radioactive waste from more than one source, the term spent nuclear fuel (SNF) will be used to discuss HLW originating from commercial nuclear reactors. LLW comprises nearly 90 percent of the volume of nuclear waste but little of the radioactivity. Nuclear power reactors produce SNF and most of the nation s LLW, although there are approximately 20,000 different sources of LLW. The name SNF is a bit of a misnomer because it implies that there is no useful material left in the fuel, when in fact some fissionable material is left in it. 

Despite the challenges, many see nuclear waste issues as being mostly political and social. There is a gi owmg awareness that technical answers alone will not solve the political and social concenis.. Some consider nuclear waste issues small in comparison to the volume and challenges associated with other kinds of wastes, whether generated by power plants or other human activities. 

A second major public concern is over nuclear wastes. Most experts believe that it is possible to dispose of these in a manner that poses little threat to the environment and human health, given the small volume of the spent fuel, the decay with time of the radionuclides, and the potential effectiveness of engineered and natural barriers. The success that is likely to be achieved is examined through Total System Performance Assessments (TSPA) (see, e.g, OCWRM, 1998). 

For nuclear waste disposal, in a site such as Yucca Mountain, if the maximally exposed individual receives the proposed annual limit of 0.15 mSv, present estimates (based on the linearity hypothesis) suggest a 0.00 1 % risk of an eventual fatal cancer. The maximum dose is reached only if the wastes are dissolved in a small volume of water, and therefore only a limited number of people would receive this dose. If this number were as high as 1000, the implied toll for Yucca Mountain neighbors would be one cancer fatality per century per repository site.19 This toll would not start for many centuries, when the waste canisters begin to fail, and it not unreasonable to expect that cancer prevention and treatment will be much improved by then. Ignoring this prospect, and assuming many repositories and some doses above the prescribed limit, it still appears that the expected toll would be well under a thousand deaths per century. 

Similarly, members ofthe public are concerned about nuclear wastes, which are very small in volume, have not harmed anyone, and have risks very small relative to the potential dangers of increasing fossil fuel use. 

Changes in density, unit cell dimensions, and macroscopic volume have serious effects. In an environment where point defects (or aggregates of point defects) are generated, such as in the components of nuclear reactors, or in vessels used for the storage of nuclear waste, where point defects are produced as a result of irradiation, dimensional changes can cause components to seize or rupture. 

The volume of nuclear wastes produced is relatively small compared with the volume of municipal solid wastes and industrial wastes and is very much less than that of agricultural and mining wastes. Each year, for example, the 104 nuclear power plants now operating in the United States generate a total of about 30,000 short tons (27,000 metric tons) of nuclear waste. That volume is about 0.001 percent the amount of hazardous wastes produced every year. In the five decades that nuclear power plants have been operating in the United States, a total of about 9,000 short tons (8,200 metric... 

Nuclear wastes are sometimes divided into two categories low-level wastes and high-level wastes. The difference in these two categories is the intensity of radiation produced. Low-level wastes tend to produce relatively small amounts of radioactivity and pose moderate health problems compared with high-level wastes. About 99 percent of all low-level waste originates in nuclear power plants. Such wastes consist of protective clothing, trash, contaminated water, and contaminated equipment, such as filters. X-ray equipment, and smoke alarms. Worldwide, low-level wastes make up about 90 percent by volume of all nuclear wastes, but they account for only about 1 percent of the total radioactivity emitted by those wastes. 

Radioactive wastes arise in many different forms and from a wide range of activities. The main streams come from plants and processes associated with nuclear power production and research, and unfortunately also from widespread military applications. There are other industrial applications also producing minor radioactive waste volumes. Categorization schemes are normally based on the following attributes ... 

FIGURE 9.19 Simplified schematic diagram illustrating sample preparation, separation, and detection for an on-line analyzer for the continuous monitoring of the total "Tc content of nuclear-waste process streams. A number of zero-dead volume syringe pumps and valves are not shown. 

Apps, J Doe, T Doty, B Doty, S Galbraith, R Kearns, A Kohrt, B Long, J Monroe, A Narasimhan, T. N. Nelson, P. Wilson, C. R. Witherspoon, P. A "Geohydrological Studies for Nuclear Waste Isolation at the Hanford Reservation, Volume II, Final Report" LBL-8764, Vol II, July 1979. 

Figure 2 Illustration of the solid phase extraction system involving the selective removal of Pb2+ from a matrix typically found in acidic high-level or low-level nuclear waste. Following selective removal of the Pb (Step 2), the column is washed to remove the solution remaining in the dead volume, and the Pb is eluted in highly purified form with a complexing agent such as citrate ion or ethylenediaminetetraacetic acid (EDTA)...

The wastewater to be disposed of should be low in volume, high in pollutant concentration, and must be difficult to treat with other methods. The wastewater should not react in the disposal zone and should also be biologically inactive. Nuclear wastes and petroleum wastes are often disposed of by this technique. 

The Dounreay site was established as the site of the UK Fast Breeder Nuclear programme in 1955 and became operational in 1958. It accommodated three reactors, the Materials Test Reactor, (DMTR, 1958-1969), the Dounreay Fast Reactor (DFR, 1959-1977) and the Prototype Fast Reactor (PFR, 1974-1994). With all reactor operations now finished and the reactors already de-fuelled the site is undergoing active decommissioning which is planned to be completed by 2032. The Dounreay site has been cited by UKAEA as being the second biggest nuclear decommissioning challenge in the UK with similar liabilities to those at Sellafield but with smaller waste volumes. 

Concern about nuclear power is usually focused on the highly toxic and radioactive spent fuel and nuclear waste. What is characteristic of these, however, in addition to their toxicity and radioactivity, is that they are limited in volume, which facilitates waste disposal. This contrasts sharply with the waste disposal problem for fossil-fuelled plants. 

Management and disposal of nuclear waste depends mainly on its type. For example, LLW and ILW are often treated (volume reduction) and/or conditioned (waste immobilization) prior to disposal. This area of LLW and ILW waste management, having been established and proven over past years, is considered to be quite... 

Some areas of application are the nuclear industry and the treatment of radioactive liquid wastes, with two main purposes reduction in the waste volume for further disposal, and reuse of decontaminated water. Pressure-driven membrane processes (microfiltration, ultrafiltration, nanofiltration, and reverse osmosis [RO]) are widely used for the treatment of radioactive waste. 

Radioactive wastes are generated in the following activities generation of electric power from nuclear fuel applications of radioisotopes in medicine, industry, and research and dismantling of nuclear and radioactive installations. With respect to waste volume and specific activity, the activities that generate the highest amounts of waste are those related to electric power generation. 

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