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- Bernitt Cartemo, Petty, 1984
(författare)
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Radiation Detection Techniques for the Enhancement of Nuclear Safety
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The hazard originating from the use of nuclear materials in various areas of the society necessitates a number of experimental techniques for controlling and increasing the safety connected to radioactive substances.The following thesis is divided into two parts, representing different aspects to the detection of radiation effects.The first part aims at investigating radiation-induced material damage of steel alloys that may potentially be used in future Generation IV systems. Concepts like the LFR or SFR will operate under higher temperature and radiation levels than present LWR and detailed knowledge on the material integrity under high level conditions is important for the performance of the major safety barrier and thus the safety of a nuclear power plant. Ion-irradiation is used to simulate neutron-induced damage and the microstructure of the samples is investigated with the help of Positron Annihilation Lifetime Spectroscopy with the Chalmers Pulsed Positron Beam. A study regarding problems and challenges of ion-irradiation experiments is included. Additionally, depth profiling for the calibration of the measurement setup is performed.The second part aims at experimental and computational methods for purposes of Nuclear Safeguards and Emergency Preparedness, respectively. The chapter on safeguards measurements treats two of the major issues within the field, namely spent fuel and nuclear forensics. Firstly, an independent method for investigations of the boron content in a PWR fuel pool is presented, demonstrating how liquid scintillator detectors can be applied for estimations of the relative amount of neutrons absorbed in H and B. Secondly, HPGe measurements on strong Am-sources are performed for a qualitative analysis of inherent impurities to be used as signatures for the identification of unknown sources, helpful to forensic investigations.The chapter on Emergency Preparedness summarizes the computational work that was performed for simulations of source distributions in human phantoms. The IRINA voxel phantom is presented and Monte Carlo simulations for comparisons to the IGOR voxel phantom and the ICRP reference adult male voxel phantom are made for different distributions of Co and La in the human body.
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| 2. |
- Vesterlund, Anna, 1980, et al.
(författare)
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Characterization of strong 241Am sources
- 2015
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Ingår i: Applied Radiation and Isotopes. - : Elsevier BV. - 0969-8043 .- 1872-9800. ; 99, s. 162-167
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Tidskriftsartikel (refereegranskat)abstract
- Gamma ray spectra of strong 241Am sources may reveal information about the source composition as there may be other radioactive nuclides such as progeny and radioactive impurities present. In this work the possibility to use gamma spectrometry to identify inherent signatures in 241Am sources in order to differentiate sources from each other, is investigated. The studied signatures are age, i.e. time passed since last chemical separation, and presence of impurities. The spectra of some sources show a number of Doppler broadened peaks in the spectrum which indicate the presence of nuclear reactions on light elements within the sources. The results show that the investigated sources can be differentiated between by age and/or presence of impurities. These spectral features would be useful information in a national nuclear forensics library (NNFL) in cases when the visual information on the source, e.g. the source number, is unavailable.
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