Radioactive cleanup

As the result of many years of nuclear reactor research and development and weapons production in U.S. defense programs, a large number of sites were contarninated by radioactive materials. A thorough cleanup of this residue of the Cold War is expected to extend well into the twenty-first century and cost many billions of dollars. New technologies are needed to minimi2e the cost of the cleanup operation. 

Fig. 6. Impurity flow paths of BWR radioactive contamination (24). RWCU = reactor water cleanup system.

Water as coolant in a nuclear reactor is rendered radioactive by neutron irradiation of corrosion products of materials used in reactor constmction. Key nucHdes and the half-Hves in addition to cobalt-60 are nickel-63 [13981 -37-8] (100 yr), niobium-94 [14681-63-1] (2.4 x 10 yr), and nickel-59 [14336-70-0] (7.6 x lO" yr). Occasionally small leaks in fuel rods allow fission products to enter the cooling water. Cleanup of the water results in LLW. Another source of waste is the residue from appHcations of radionucHdes in medical diagnosis, treatment, research, and industry. Many of these radionucHdes are produced in nuclear reactors, especially in Canada. 

These include wastewater cleanup for electroplating (75—78), radioactive processing (79—82), landfill leachate (76,83), and municipal wastewater (84—87) ultrapure water production for electronics-grade (88,89), laboratory-grade (90), and pharmaceutical-grade (91) materials and food processing (qv) (9). 

The third example is compact cleanup units for waste treatment, mainly in consideration of the numerous radioactive sites, stemming from cold-war military developments [106]. The Hanford, Washington, USA, site with a multitude of seriously contaminated tank wastes is among them. Due to the unknown character of most polluting species, the installation of a central waste-treatment facility is said to be not the best and most inexpensive solution. Rather, small modular units, able to be individually adapted to various separation tasks, which are inserted into the tanks and perform cleanup on site, are seen as the proper solution. 

The existence of waste from past activities has created problems that will demand the attention of chemists and chemical engineers. Environmental cleanup —of toxic wastes, of contaminated groundwater, of radioactive waste—is a daunt-... 

In New York state a reprocessing plant near Buffalo began to reprocess nuclear wastes in 1966. After 6 years Nuclear Fuel Services (NFS), a subsidiary of W.R. Grace s Davison Chemical Company, abandoned the facility. There were 2 million cubic feet of radioactive material left behind along with 600,000 gallons of radioactive liquid waste that was seeping into a creek that flows into Lake Erie the source of drinking water for Buffalo. The cost of cleanup was estimated to be 1 billion. 

Bennett, P. D., Brumbach, B., Farmer, T. W., Funkhouser, P. L., and Hatheway, A. W., 1999, Remedy Selection for Cleanup of Uncontrolled Waste Sites Practical Periodical of Hazardous, Toxic, and Radioactive Waste Management, Vol. 3, No. 1, January, pp. 23-34. 

Minor spills must be cleaned first with absorbent blotter paper and then thoroughly rinsed with water. Always wear gloves during cleanup. Dispose of the blotter paper in the Solid Radioactive Waste container. The spill area should then be checked with a portable G-M counter. 

Knowledge of fission and its consequences is important for the nuclear power industry and the related fields of nuclear waste management and environmental cleanup. From the point of view of basic research, fission is interesting in its own right as a large-scale collective motion of the nucleus, as an important exit channel for many nuclear reactions, and as a source of neutron-rich nuclei for nuclear structure studies and use as radioactive beams. 

Spent Fuel The largest single radioactive waste disposal problem is the spent fuel from military and commercial reactors. As discussed earlier, the spent fuel from commercial reactors is stored in water ponds at the reactor sites. The spent fuel storage facility consists of a cooling and cleanup system for the water along with equipment to safely transfer the fuel rods from the reactor to the storage area. A typical pool will have a volume of 400,000 gal. The water will contain 2000 ppm boron that acts as a neutron absorber and will be maintained at a temperature of <70°C. 

In each step of nuclear fuel reprocessing, the solvent is exposed to various radioactive sources and consequently prone to more degradation than solvents in other industrial fields. The resulting damage can be either chemical or physical. Numerous experimental studies have been carried out most of them were applied research and therefore restricted to studying the impact of degradation on process performance in order to develop an adequate cleanup treatment. 

Follow the usual safety procedures when working in a radiological laboratory. This sample is more radioactive than most samples handled for other experiments. It also contains a wide variety of radionuclides, which makes cleanup more difficult if a spill occurs. 

Standards for Cleanup of Land and building Contaminated with Residual Radioactive Materials from Inactive Uranium Processing Sites... 

Establishment of Cleanup levels for CERCLA Site with Radioactive Contamination OSWER Directive 92004.18 ERA 1997b... 

EPA. 1995a. U.S. Environmental Protection Agency. Standards for cleanup of land and buildings contaminated with residual radioactive materials from inactive uranium processing sites. Code of Federal Regulations. 40 CFR 192, Subpart B. 

EPA. 1997b. U.S. Environmental Protection Agency. Establishment of cleanup levels for CERCLA sites with radioactive contamination (memorandum and attachments). OSWER No. 9200.4-18. Office of Solid Waste and Emergency Response. Office of Emergency and Remedial Response. http //www.epa.gov/superfund/... 

The above activity levels measured at Mururoa are comparable to the levels observed world-wide in the early 1980s (with the exception of a few specific sites). These concentrations result from earlier safety tests made on the motus in the northern zone of the atoll from 1966 to 1974, and from the cleanup work undertaken in the years 1981-1987. This work resulted in a great reduction of radioactivity on the ground, but produced a slight temporary increase of plutonium in the air. 

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