Radionuclides technical applications

Radionuclides of major importance in the geosphere and the biosphere are listed in Table 21.1. Not taken into account are radionuclides with half-lives h/2 < 1 d (in the case of activation products of materials used in nuclear reactors, i/2 < 1 y) and with half-lives ti/2 > lO y, radionuclides with fission yields <0.01%, radioisotopes of elements that are not members of the natural decay series,and radionuclides produced solely for medical or technical applications. The radionuclides are arranged according to their position in the Periodic Table of the elements, in order to facilitate the discussion of their chemical behaviour. Radionuclides with half-lives >10y are underlined, because their behaviour over long periods of time is of special importance. 

Other radiations Technical applications of radionuclides and ionizing radiation <0.02mSv/y... 

Nuclear radiation absorption methods have many technical applications. These methods are not to be confused with radioisotope tracer methods, although radioisotopes may be used as radiation sources. In the tracer method the chemical properties of the radionuclide are important while in the applications discussed in this section only the type and energy of radiation emitted are irqx>rtant. 

International Atomic Energy Agency (IAEA) (1985) Sediment Kd s and concentration factors for radionuclides in the marine enviroment. Technical Reports Series 247. IAEA, Vienna, Austria Ivanovich M, Murray A (1992) Spectroscopic methods. In Uranium-series disequilibrium applications to earth, marine, and environmental sciences. Ivanovich M, Harmon RS (eds) Oxford University Press, New York, p 127-173... 

E. H. Evans, J. B. Truscott, L. Bromley, P. Jones, J. Turner, B. E. Fairman, in R. W. Morrow, J. S. Crain (Eds), Applications of Inductively Coupled Plasma-Mass Spectrometry to Radionuclide Determinations, ASTM Special Technical Publication, 1344 (1998), 79-88. 

Technical and Industrial Applications of Radionuclides and Nuclear Radiation... 

Radiophotovoltaic (photoelectric) radionuclide batteries operate in two stages. First the radiation energy is converted to light by means of luminescent substances and then to electric energy by means of photoelements. Because of radiative decomposition of luminescent substances, the number of radionuclides applicable is limited. Alpha emitters are unsuitable, and the most suitable f emitter is " Pm. The construction of this kind of radionuclide batteries is relatively simple radionuclide and luminophore are mixed in a ratio of about 1 1 and brought between two photoelements (e.g. Cu-Se or Ag-Si) in form of a thin layer. Efficiencies of the order of 0.1 to 0.5% and powers of the order of lOpW per cm are obtained. Because of the low efficiency, this type of radionuclide battery has no technical significance. 

Applications include the use of radionuclides in geo- and cosmochemistry, dating by nuclear methods, radioanalysis, the use of radiotracers in chemical research, Mossbauer spectrometry and related methods, the use of radionuclides in the life sciences, in particular in medicine, technical and industrial applications and investigations of the behaviour of natural and man-made radionuclides, in particular actinides and fission products, in the environment (geosphere and biosphere). Dosimetry and radiation protection are considered in the last chapter of the book. 

In addition, radionuclide generators intended for applications in life science, in particular in the context of routine clinical use, must meet strict regulatory and quality control requirements. The production of the radionuclide generator parent, its separation from the target material, the chemical and technical construction of the separation of the radionuclide generator daughter are factors, which in totality shall finally result in an efficient and easy handling. They are discussed below. 

The process of determining a permanent disposal solution involves social, political, economic, and technical issues that compete and coalesce to determine the specific end state. Characteristics that make permanent disposal of TRU and HLW complex include contamination with long-lived radionuclides (e.g., plutonium-239 has a half-life of approximately 24,000 years) and high concentrations of radioachvity. While less contentious, LLRW disposal also presents challenges, as discussed in Section 16.6. The discussion in this section is primarily applicable to TRU and HLW disposal. 

Other measures, such as chromium plating of the surfaces of the materials, which in experiments showed a beneficial effect in retarding the incorporation of radionuclides into the oxide layers have also been considered. As yet, however, no technical-scale application has been reported presumably, there are still technical questions to be solved. 

---