Radioisotope-production reactor

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. 

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 ... 

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. 

IAEA, Production and Use of Short-lived Radioisotopes from Reactors, Vienna, 1963. 

Y. Matsumura, Production of Short-lived Radioisotopes from Reactors (Proceedings of a Seminar, Vienna, November 5-9, 1962) Vol. II, pp. 137-144 (1963). 

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. 

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 major anthropogenic sources that have lead, or could potentially contribute, to the radionuclide contamination of the environment are the following (1) the testing and production of nuclear weapons (2) the normal activities of the nuclear power fuel cycle (3) the radioisotope production and research reactors and (4) the nuclear accidents. 

These options were presented, in view of the economic realities, in the national, regional and extra-regional contexts for those countries that participated in TC Regional Project RLA/4/018 and which currently operate nuclear research reactors for radioisotope production, fundamental research in physics and biology, materials irradiation, education and training. 

Increased power and load factor of the research reactor The operational flexibility of research reactors coupled with new needs, such as radioisotope production and fuel qualification programmes, have led in some cases to an increase the reactor power and its... 

Currently, the reactor operates at 4 MW and is used mainly for radioisotope production, neutron activation analysis, neutron radiography, and research studies, including nuclear physics experiments and boron neutron capture therapy. A further power increase to 5 MW is... 

The assemblies are arranged together with wedge shaped graphite elements to form a sector of an annular cylinder. The core is surrounded with graphite blocks to work as a reflector. A cylindrical block of graphite is also inserted into the inner part of the annular cylinder, with the same objective. Demineralized water is used as moderator and to remove the heat produced in the core, by natural circulation. The reactor is used for training, research and some minor radioisotope production. 

Six stainless steel clad cadmium blades, inserted between the fuel assemblies, are used for control and safety purposes. Beryllium blocks are used as reflector, and demineralized light water is used as moderator and coolant. The reactor is used for radioisotope production, neutron activation analysis, geological samples irradiation, training, and research involving material irradiation, neutron radiography and neutron physics. 

RP-10 is a 10 MW research reactor designed and constructed by Argentinian engineers, with the main objectives to produce neutrons for research and for radioisotope production. Located at the RACSO Nuclear Centre, about 30 km from Lima, it reached criticality for the first time in November 1988. 

The main Argentine research reactor, which is dedicated to radioisotope production, is RA-3 (10 MW). It is located at Centro Atomico Ezeiza in Buenos Aires, and its spent fuel is stored in a separate decay pool, physically independent of the reactor pool, located inside the reactor building. Figure 1 shows the decay pool used for operational storage of the spent fuel assemblies of the RA-3 research reactor. 

A high flux reactor usually operates continuously (e.g., 100 hours) to meet the requirements of its experimental users and radioisotope production fits easily into this schedule. 

With corresponding improvements, the ABV reactor may also be used to develop nuclear technologies including reactor tests of fuel and structural materials and radioisotope production for commercial and medical applications. 

The reactor was under-utilized. Radioisotope production (small amounts of lo and Ir), activation analysis and training of University students (nuclear engineering, physics, chemistry and biology) constituted the main uses. 

The reactor was intended for a variety of applied studies and investigations of materials properties, radioisotope production and for other purposes. 

From the inception of the IAEA in 1957, there has been broad interest at the IAEA in the benefits to be derived from the safe operation of research reactors by IAEA Member States. These benefits can be gained not only in the traditional areas of nuclear power technology, radioisotope production, nuclear medicine and personnel training but also in the vital areas of materials development and environmental pollution control. To achieve these benefits, the safety of research reactors must be ensured. The IAEA has a long tradition in the area of research reactor safety. 

International Atomic Energy Agency, Vienna). Reactor-Produced Isotopes. Pp. 63-542 of Radioisotope Production and Quality Control (1971). 26 11832... 

Unstable niobium isotopes that are produced in nuclear reactors or similar fission reactions have typical radiation hazards (see Radioisotopes). The metastable Nb, = 14 yr, decays by 0.03 MeV gamma emission to stable Nb Nb, = 35 d, a fission product of decays to stable Mo by... 

The neutrons in a research reactor can be used for many types of scientific studies, including basic physics, radiological effects, fundamental biology, analysis of trace elements, material damage, and treatment of disease. Neutrons can also be dedicated to the production of nuclear weapons materials such as plutonium-239 from uranium-238 and tritium, H, from lithium-6. Alternatively, neutrons can be used to produce radioisotopes for medical diagnosis and treatment, for gamma irradiation sources, or for heat energy sources in space. 

Eighteen isotopes of sulfur, 17 of selenium, 21 of tellurium, and 27 of polonium have been registered of these, 4 sulfur, 6 selenium, and 8 tellurium isotopes are stable, while there is no stable isotope of polonium. None of the naturally occurring isotopes of Se is radioactive its radioisotopes are by-products of the nuclear reactor and neutron activation technology. The naturally occurring, stable isotopes of S, Se, and Te are included in Table 1.2. 

UIC. 1997. Most smoke detectors contain an artificially produced radioisotope americium-241. Americium-241 is made in nuclear reactors, and is a decay product of plutonium-241. Uranium Information Center. Nuclear Issues Briefing Paper 35. http //www.uic.com.au/nip35.htm. January 27, 2000. 

A glass tube fixed-bed reactor was used as a closed static reactor. The cyclotron produced nC-radioisotope (Ti/2=20.4 min) was used for nC-labeled methanol production by radiochemical process. The nC-labeled methanol (shortly nC-methanol, - 3pmol, -600 MBq) was then introduced into 250 mg of zeolite at ambient temperature by He gas flow. Afterwards, equivalent volume of liquid methyl iodide was injected into nC-methanol to have mixture of methanol and methyl iodide and introduced into catalyst for investigation of methyl iodide influence. After adsorption (2 min), the catalyst was heated up to the required temperature. 

Uranium production, 17 525-526 by country, 25 400t Uranium radioisotopes, 21 319 Uranium reactor fuel manufacture, hydrogen fluoride in, 14 19 Uranium recovery, ion-exchange resins in, 14 421-422... 

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