Thesis (doctoral)--Georg-August-Universität zu Göttingen.

Thesis (Ph. D.)--Tufts University, 1987. / Includes bibliographical references (leaves 540-604).

Typescript. / Bibliography: leaves [127]-130. / viii, 130 l illus., tables

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in fulfilment of the requirements for the degree of Masters of Science. Johannesburg, 2017 / The monitoring of personnel for exposure to radioactive elements is a regulatory requirement for any nuclear installation and due to the nature of the research, the need for a non-invasive procedure for the monitoring for exposure to plutonium has been identified at the South African Nuclear Energy Corporation (NECSA). Historically, analyses of short-lived radioactive elements were performed by α-spectrometry. But due to the well documented drawbacks of the older generation of α-spectrometer analysis, Quadrupole Inductively Coupled Mass Spectrometry (Q-ICP-MS) was suggested as an alternative technique. A feasibility study was undertaken to determine whether sub-trace concentrations of plutonium in urine can be determined using a modern, standard Q-ICP-MS. A simplified One Variable at a Time (OVAT) approach was used to establish optimal analytical conditions starting from instrument setup and ending in sample preparation. The optimum sample preparation determined required 50 mL urine which underwent co-precipitation, wet-ashing and solid phase extraction using Tetra Valent Actinide (TEVA)-resin. Calibration standards ranged from 5 to 100 pg L-1 and the optimised method produced LOD’s of 0.2 pg L-1 and LOQ’s of 0.5 pg L-1. Sample intra-assay precision at 0.5- and 15 pg L-1 were 11.3% and 4.43% respectively, in the urine matrix. The bias was 8% and 0% at the same concentrations. The method was evaluated using samples from an international proficiency study and two out of the three tests that could be quantified passed specification. According to ISO 13528 a method is acceptable if two out of three tests pass. The method has been verified and a modern, standard Q-ICP-MS has been proven to be a suitable alternative to α-spectrometry with respect to sub-trace plutonium analysis. / MT 2017

Thesis (M.Env.St.) -- University of Adelaide, Dept. of Geographical and Environmental Studies. / Bibliography: leaves 101-110.

Thesis (Ph. D.)--University of Oregon, 2002. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 665-706). Also available for download via the World Wide Web; free to University of Oregon users.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in fulfilment of the requirements for the degree of Master of Science, Johannesburg 2018 / The calculation of reactor-specific fission Q-values is important for the safety analyses of nuclear reactors. The recoverable energy from the fission Q-value is used to normalise reactor quantities to the total power of the reactor. In this work, a detailed recoverable energy from fission Q-value and spatial heat deposition calculations are presented for the SAFARI-1 nuclear reactor. The fission Q-value is composed of the energy released in a fission event by fission products, neutrons, prompt and delayed gamma rays, beta particles and neutrinos. The energy released by neutrinos is not recoverable; however, part of it is recovered by the gamma and beta radiation from the decay of activated materials. We present two methods to calculate the recoverable energy released per fission. The first one uses the Monte Carlo N-Particle (MCNP5) code. MCNP is a probabilistic transport code that has the capability of calculating most of the heating contributions due to particle interactions with matter. The second method uses the Evaluated Nuclear Data File, ENDF/B-VII and ENDF/B-VII.1 data libraries. The ENDF data libraries contains the information required to calculate all the fission Q-value components, excepttheenergyreleasedfromradiativecapture, sincethisquantity depends on the reactor materials. To calculate this, we use the radiative capture reaction rate in MCNP5 and the binding energy of the product of the activation. We obtained a final Q-value of 200.8±0.6 MeV/fission for SAFARI-1. Using the fission Q-value result, we obtained the spatial heat distribution for SAFARI-1 by ii calculating the heating rates of the Q-value components. It was established that 97% of the heat produced is deposited in the fuel and 3% is deposited in the surrounding region of the reactor. / XL2019

No description available.

No description available.

Thesis (Ph. D.)--Middle East Technical University, 2004. / Keywords: B-meson decays, Branching Ratio, Lepton Polarization Asymmetry.