Leaching of Accelerator-Produced Radionuclides (original) (raw)
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Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2007
We use a description of the work carried out to determine the radioactive inventory for a redundant beam-dump from the PSI accelerator complex, as an illustration of techniques for the classification and characterisation of accelerator waste and how some difficulties can be circumvented. The work has been carried out using a combination of calculation and sample analysis: The inventory calculation effectively involves a large scale Monte-Carlo transport calculation of a medium-sized spallation facility and for the sample analysis, standard radiochemical analysis techniques have had to be extended to include AMS measurements so as to allow measurement of some of the long half-life, waste disposal relevant, nuclides.
Radiochemical analysis of a copper beam dump irradiated with high-energetic protons
Radiochimica Acta, 2009
The radionuclide inventory of a copper beam dump from the 590 MeV proton accelerator of the Paul Scherrer Institute in Switzerland was determined, focusing on radioisotopes with half-lives of more than 60 d, and in particular, of long-lived isotopes with T 1/2 = 10 4-10 7 years, which are important regarding radioactive waste management. The measurements were carried out using high resolution γ-measurement without sample destruction, as well as liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS) after chemical separation. For the first time, a beam dump from a high power accelerator facility was completely characterized concerning the depth and radial distribution profile of the most hazardous and/or long-lived radionuclides. Moreover, it turned out that some of the investigated radionuclides, like for instance 26 Al, 44 Ti or 60 Fe represent valuable material for application in several scientific fields like nuclear astrophysics, basic nuclear physics research, radiopharmacy and many others. Therefore, based on the analytical results, a special research and development program has been started at PSI objecting on specific preparative extraction of longlived radioisotopes (ERAWAST-exotic radionuclides from accelerator waste for science and technology).
Radionuclide Decay and In-growth Technical Basis Document
… Tests Area Project …, 2004
Chapter 3 Radionuclide Decay and In-growth Technical Basis Document Annie B. Kersting, David L. Finnegan, Brad K. Esser, Andrew FB Tompson, David K. Smith, Mavrik Zavarin, Carol J. Bruton, and Gayle A. Pawloski Exe tive The purpos radionuclid conducted at the ...
Residual radioactivity at the CERN 600MeV synchro-cyclotron
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2012
The 600 MeV synchro-cyclotron (SC) was the first accelerator that came into operation at CERN in 1957. It provided beams for CERN's first particle and nuclear physics experiments and operated for 33 years until it was shut down in 1990. In view of a planned partial decommissioning of the facility, a range of measurements were carried out to evaluate the levels of residual radioactivity in the accelerator and its surrounding after about 20 years of cooling time. Gamma spectrometry measurements were performed on 113 samples collected inside the three floors of the accelerator vault, on the cyclotron itself and on concrete samples taken from various parts of the building walls, up to a depth of 50 cm in the shield. About 40% of all samples contain traces of neutron-induced radionuclides, mainly 60 Co (in metals), 133 Ba, 137 Cs, 152 Eu and 154 Eu (in concrete). Values of specific activities range from 5 mBq/g to 781 Bq/g. The maximum activity induced in concrete was observed at the depth of 40 cm in the wall near the cyclotron extraction channel. The laboratory measurements were supplemented by in-situ gamma spectrometry performed with the ISOCS system. A complete dose rate survey was also performed yielding isodose maps of the three levels of the building. The isotope production and the residual radioactivity in the barite walls of the SC bunker were simulated with the FLUKA and JEREMY codes in use at CERN for predicting residual radioactivity in activated accelerator components, and the results compared with the gamma spectrometry data. A detailed comparison of calculated and measured specific activities shows generally good agreement, to within a factor 2 in most cases. These results serve as indirect validation of the capabilities of these codes to correctly predict residual radioactivity with only a very approximate knowledge of the irradiation profile and after a very long (20 years) cooling time. Overall the results provided in this paper may be of use for estimating residual radioactivity in proton accelerators of comparable energy and for benchmarking computer codes.
Journal of Medical Radiation Sciences, 2011
Th is article continues from the earlier article "An Introduction to Nuclear Medicine" where the general principles of nuclear medicine were discussed. Radionuclides are required in both diagnostic and therapeutic nuclear medicine procedures. Naturally occurring radionuclides are generally not suitable for diagnostic and therapeutic procedures due to their typically long half-lives or less than ideal physical or chemical characteristics; therefore appropriate radionuclides need to be produced. Th e common methods of radionuclide production for nuclear medicine include: fi ssion, neutron activation, cyclotron and generator.
Predicting Induced Radioactivity at High Energy Accelerators
1999
Radioactive nuclides are produced at high-energy electron accelerators by different kinds of particle interactions with accelerator components and shielding structures. Radioactivity can also be induced in air, cooling fluids, soil and groundwater. The physical reactions involved include spallations due to the hadronic component of electromagnetic showers, photonuclear reactions by intermediate energy photons and low-energy neutron capture. Although the amount of induced radioactivity is less important than that of proton accelerators by about two orders of magnitude, reliable methods to predict induced radioactivity distributions are essential in order to assess the environmental impact of a facility and to plan its decommissioning. Conventional techniques used so far are reviewed, and a new integrated approach is presented, based on an extension of methods used at proton accelerators and on the unique capability of the FLUKA Monte Carlo code to handle the whole joint electromagnetic and hadronic cascade, scoring residual nuclei produced by all relevant particles. The radiation aspects related to the operation of superconducting RF cavities are also addressed.
Behavior and Removal of Radionuclides Generated in the Cooling Water of a Proton Accelerator
Nuclear Science and Engineering, 1995
Radionuclides such as 7 Be, 60 Co, 65 Zn, and 54 Mn are present in the magnet cooling water of a proton accelerator. These nuclides may be dissolved or bound to colloids and pass through micrometric filters below 100 nm. A cooling water purification strategy is discussed. The most efficient procedure uses a cation exchanger in H + form.
WASTE CONTAINING ENHANCED CONCENTRATION OF NATURALLY OCCURRING RADIONUCLIDES
2000
SUMMARY: Since radiation risk is usually considered to be related to nuclear energy or atomic bomb, majority of researches on radiation protection have focused on artificial radionuclides and radioactive waste. Far less attention has been paid to radiation risk caused by exposure to ionizing radiation originating from naturally occurring radioactive materials (NORM) despite the fact that their presence touches many
Separation of long-lived radionuclides from high active nuclear waste
Comptes Rendus Physique, 2002
The management of vitrified high activity waste issued from the reprocessing of spent nuclear fuel is often made questionable by the presence within this waste of long-lived radionuclides (LLRNs). New management scenarios of this waste are under study at the CEA since the beginning of the 1990s, involving the development of separation processes for some LLRNs. Six LLRNs are the targets of these studies; they are: (i) the minor actinides: neptunium, americium and curium; (ii) the fission products: technetium, iodine and caesium. The present paper highlights the main achievements of the research performed at the CEA in this field. To cite this article: C. Madic et al., C. R. Physique 3 (2002) 797-811. 2002 Académie des sciences/Éditions scientifiques et médicales Elsevier SAS nuclear waste / reprocessing / partitioning / long-lived radionuclides / liquid-liquid extraction Séparation de radionucléides à vie longue des déchets nucléaires de haute activité
RADIONUCLIDE AND RADIATION PROTECTION DATA HANDBOOK 2002
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