RADIOISOTOPE PRODUCTION

Genuine production of significant quantities of isotopes for commercial utilization typically requires a higher reactor power and a major investment in hot cell equipment for processing. Prospective isotope producers are advised to analyse international market prices, assess the market situation in their region and contact potential users to assess the potential customer base before making this a major part of their strategic plan for the facility. 

However, many research reactor facilities are capable of irradiating materials to produce certain isotopes in small quantities for research applications. In this way, they can supply the needs of their more local users, perhaps at a university. 

References to additional information on isotope production are listed in the Bibliography. 

Some isotope production is possible in a low ( 10 n cm s ) flux reactor. However, more is possible in an intermediate (lO -lO n cm s ) or high ( 10 n cm s ) flux reactor. It should be recognized that in order to be able to realistically produce radioisotopes, the operating cycle of the reactor for all but short lived isotopes needs to be as long as possible. 

Flux traps are useful for reactors of all power levels and a variety of irradiation facilities is desirable (e.g., pneumatic transfer, hydraulic transfer, irradiating baskets in core, or in beam tubes). Similarly, capabilities for thermal interactions and fast neutron irradiations should be available. 

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From observed variations of 14C/C in tree-ring samples we have indications of a 200 y cycle in the radioisotope production and P /P0 is suggested to be of the order of 25 percent [13]. 

Molecular [ F]fluorine (P F]F2) is produced in the cyclotron target usually during the irradiation for radioisotope production (see Section 2.4). 

The remaining classes of nuclear reactors range from zero-power, subcritical neutron sources for university training to large-scale reactor systems for plutonium-239 production. Portable reactors have provided heat, power, and water to U.S. bases in Alaska, Antarctica, and Panama. Private industry has operated various test reactors for reactor studies and radioisotope production. 

Eister, W, et al., Radioisotope Production in the U.S., Radioisotope Production Study, Sao Paulo, Brazil, IAEA-124, International Atomic Energy Agency, Vienna, 1970. 

W. J. Whitehouse, J. L. Putman, Radioactive Isotopes - An Introduction to their Preparation, Measurement and Use, Clarendon Press, Oxford, 1953 H. A. C. McKay, Principles of Radiochemistry, Butterworths, London, 1971 International Atomic Energy Agency, Radioisotope Production and Quality Control, IAEA Technical Reports Series No. 128, Vienna, 1971... 

M. S. Livingstone, J. P. Blewett, Particle Accelerators, McGraw-Hill, New York, 1962 M. H. Blewett, The Electrostatic (Van de Graafi) Generator, in Methods of Experimental Physics (Eds. L. C. L. Yuan, C. S. Wu), Vol. 5B, Academic Press, New York, 1963 P. M. Lapostolle, L. Septier, Linear Accelerators, North-Holland, Amsterdam, 1970 A. P. Wolf, W. B. Jones, Cyclotrons for Biomedical Radioisotope Production, Radiochim. Acta 34, 1 (1983)... 

Many reactors and accelerators around the globe are involved in the business of radioisotope production. Most of them satisfy only local needs many would be glad to find customers outside their region. As a matter of interest, we mention ... 

Low-level radioactive wastes from laboratories and radioisotope production... 

During its lifetime, a fusion reactor presents little radiation hazard. The internal structure, particularly the vacuum containment vessel and the heat exchanger, will be subject to intense neutron bombardment. The neutrons will convert some of the elements of the structure into long-lived radioactive isotopes. Selecting construction materials that do not easily become activated can minimize radioisotope production. No material is entirely resistant to neutron activation, thus the decommissioning of a fusion reactor will require the handling and disposal of potentially hazardous radioactive isotopes. Because of the lack of uranium, plutonium, and fission products, the total radiation exposure hazard from the decommissioned fusion reactor is 10,000 to 1,000,000 less than from a decommissioned fission reactor. 

Medicinal products presented for an entirely new indication, products based on radioisotopes, products derived from human blood or human plasma and products... 

IAEA (1966). Manual of Radioisotope Production, Tech. Report 63, IAEA, Vienna. 

The section Radioactive Methods in volume 9 of the Treatise on Analytical Chemistry (Kolthoff and Elving 1971) discusses radioactive decay, radiation detection, tracer techniques, and activation analysis. It has a brief but informative chapter on radiochemical separations. A more recent text. Nuclear and Radiochemistry Fundamentals and Applications (Lieser 2001), discusses radioelements, decay, counting instruments, nuclear reactions, radioisotope production, and activation analysis in detail. It includes a brief chapter on the chemistry of radionuclides and a few pages on the properties of the actinides and transactinides. 

To get into this medical imaging field, you need to have an in-depth knowledge of one aspect of the research. This could be in the medical applications, physics of radioisotope production, radiochemical synthesis, pharmacology, or any one of ten other areas. All that is required is that you be able to contribute something to the overall research effort. The same is true of all other research in bioengineering, biotechnology, or any other field in the life sciences. 

Manzini, A.C., Progress on hssion radioisotopes production in Argentina, in Proceedings of the International Meeting on Reduced Enrichment for Research and Testing Reactors, RERTR, Vienne, Austria, November, 7-12, 2004. 

Major functions Radioisotope production, material irradiation, physics research... 

Before nuclear reactors became available for radioisotope production, the Szilard-Chalmers process mentioned in Sect. 24.1 was very important for its availability to prepare radioisotopes with high specific activity. This unique technique survived for many years after the first nuclear reactor started to operate in 1942. The activity A of a radionuclide produced by activation can be expressed as... 

A French radioisotope production group provided radionuclides such as Cr, Fe, Cu, Zn, and As by the Szilard-Chalmers processes (Henry 1957). At the Japan Atomic Energy Research Institute, this process was applied to obtain pure from neutron-irradiated potassium phosphate. Ordinary products using (n,p) reaction in a nuclear reactor contain an impurity isotope P in P, but P produced by (n,y) reaction in neutron-irradiated phosphate does not contain P. Hot atom chemically obtained P by (n,y) reaction was therefore appropriate for some special experiments in which contamination of P with different half-life and P-particle energy had to be excluded (Shibata et al. 1963). 

The nuclear reaction cross section data are needed in radioisotope production programs mainly for optimisation of production routes, i.e., to maximize the yield of the desired product and to minimize the yields of the radioactive impurities. From a given excitation function, the expected yield of a product for a certain energy range, i.e., target thickness, can be calculated using the expression ... 

Most of the irradiations for medical radioisotope production at cyclotrons are done using extracted beams. There is more versatility in working with the extracted beam than with the internal beam. Through controlled defocusing and wobbling, it is possible to decrease the... 

Ha an HE, Qaim SM, Shubin Yu, Azzam A, Morsy M, Coenen HH (2004) Appl Radiat Isot 60 899 Hermanne A, Gul K, Mustafa MG, Nortier FM, Oblozinsky P, Qaim SM, Scholten B, Tal cs S, Tarkanyi F (2001) Photon emitters, in charged particle cross section datebase for medical radioisotope production. IAEA-TECDOC-1211, IAEA, Viemra, pp 153-233... 

IAEA (2001) Charged particle cross section database for medical radioisotope production diagnostic radioisotopes and monitor reactions, lAEA-TECDOC-1211, International Atomic Energy Agency, Vienna, http //www-nds.iaea.or.at/medical/Gap68Ge0.html... 

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