Radionuclide release

Chapter 6 was concerned, with determining the probability of various failures leading to insufficient core cooling of a nuclear reactor. This chapter describes how the accident effects are calculated as the accident progresses from radionuclide release, radionuclide migration within the plant, escape from retaining structures, atmospheric radionuclide transport and the public health effects. 

The analysis of the consequences of nuclear accidents began with physical concepts of core melt, discussed the mathematical and code models of radionuclide release and transport within the plant to its release into the environment, models for atmospheric transport and the calculation of health effects in humans. After the probabilities and consequences of the accidents have been determined, they must be assembled and the results studied and presented to convey the meanings. 

Powers, D. A, et al., I985, VANESA, A Mechanistic Model of Radionuclide Release and Aerosol Generation during Core Debris Interaction with Concrete, NUREG/CR-4308. 

Pentreath RJ (1981) in Impacts of Radionuclide Releases into the Marine Environment. IEAE, Vienna, p 241 (STI/PUB/565)... 

Mistry, K. B., Bhujbal, B. M. and D Souza, T. J. (1974). Influence of agronomic practices on uptake of fission products by crops from soils of regions adjoining nuclear installations in India, page 303 in Environmental Behavior of Radionuclides Released in the Nuclear Industry, IAEA Publication No. STI/PUB/345 (International Atomic Energy Agency, Vienna). 

FukaiR, Murray CN (1973) Environmental behaviour of radiocobalt and radiosilver released from nuclear power stations into aquatic systems. In Environmental behaviour of radionuclides released in the nuclear industry. IAEA, Vienna pp 217-242... 

Luz A, Linzner U, Muller WA, et al. 1979. Osteosarcoma induction by simultaneous incorporation of Yh and inkc. Biological implications of radionuclides released from nuclear industries, Vol. 1. International Atomic Energy Agency, Vienna, 141-151. 

Pourcelot, L. Gauthier-Lafaye, F. 1999. Hydrothermal and supergen clays of the Oklo natural reactors conditions of radionuclide release, migration and retention. Chemical Geology, 157, 155-174. 

The reliable long-term safety assessment of a nuclear waste repository requires the quantification of all processes that may affect the isolation of the nuclear waste from the biosphere. The colloid-mediated radionuclide migration is discussed as a possible pathway for radionuclide release. As soon as groundwater has access to the nuclear waste, a complicated interactive network of physical and chemical reactions is initiated, and may lead to (1) radionuclide mobilization (2) radionuclide retardation by surface sorption and co-precipitation reactions and (3) radionuclide immobilization by mineralization reactions, that is, the inclusion of radionuclides into thermodynamically or kinetically stabilized solid host matrices. 

Mechanisms that may lead to the quasi irreversible binding of radionuclides to colloids belong to the key uncertainties of the assessment of the colloid problem. The kinetics of the dissociation of colloid-bound radionuclides are not yet understood. Radionuclide incorporation into stable colloids may enhance the colloid-mediated radionuclide release considerably. It is clear that only the investigation of the interaction mechanisms by spectroscopic methods is able to unravel the relevance of such processes. In order to allow the description of colloid-facilitated radionuclide migration, it is furthermore required to improve our understanding of the colloid interaction... 

Thus, a proper backfill material may act as a very effective chemical and mechanical barrier, preventing free migration of radionuclides released from the waste containers. 

Radioactive substances The principal sources of radionuclides released into the environment include nuclear weapon testing fallout from accidents such as the Chernobyl accident in 1986 or from foundering of nuclear submarines from the dumping of nuclear waste into the deep ocean and from discharges from nuclear power plants and nuclear reprocessing plants. 

Geochemical Controls on Radionuclide Releases from a Nuclear Waste Repository in Basalt Estimated Solubilities for Selected Elements... 

Radionuclide release rates from the waste package... 

Early, T. O. Jacobs, G. K. Drewes, D. R. "Geochemical Controls on Radionuclide Releases from a Nuclear Waste Repository in Basalt Estimated Solubilities for Selected Elements RHO-BW-ST-39, Rockwell Hanford Operations, Richland, Washington, 1982. 

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