The detonation of a radiological dispersal device (RDD) may result in casualties receiving exposure of radioactive materials. Assessments of potentially contaminated personnel are necessary to determine the level of contamination received in order to prioritize and treat individuals. The use of improvised explosive devices (IEDs) and the number of orphan sources in deployed and combat areas such as Iraq, present an opportunity for terrorists to use an RDD against deployed ground forces. There is limited capability in Iraq to assess radiological casualties, as the process of obtaining and analyzing bioassays is time consuming and not readily available in country. Military units are equipped with AN/VDR-2 and AN/PDR-77 radiac detectors which are capable of detecting gamma radiation. Therefore, a study of the use of these radiac sets in assessing internal contamination was conducted. A model of the detector probe was created using the Los Alamos National Laboratory Monte Carlo N-Particle transport code, MCNP Version 5. This model was experimentally validated and used in conjunction with both reference male and reference female computational Medical Internal Radiation Dose (MIRD) phantoms to compute internal dose. The instrument model was evaluated at the following locations, the posterior upper right torso, the anterior upper right torso, the lateral upper left thigh and the anterior of the neck. Nuclides were distributed throughout the phantoms using the Oak Ridge National Laboratory Dose and Risk Calculation (DCAL) software for inhalation pathways. Based on the likelihood for use in RDDs and the capabilities of the instrument, Co-60, Cs-137 and Ir-192 were evaluated.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-11-01T21:51:37Z No. of bitstreams: 1 AlexandreBarbosaBruno_DISSERT.pdf: 10742068 bytes, checksum: 8856afbc18039f28f1ae0f2c51179126 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-11-08T21:56:39Z (GMT) No. of bitstreams: 1 AlexandreBarbosaBruno_DISSERT.pdf: 10742068 bytes, checksum: 8856afbc18039f28f1ae0f2c51179126 (MD5) / Made available in DSpace on 2017-11-08T21:56:39Z (GMT). No. of bitstreams: 1 AlexandreBarbosaBruno_DISSERT.pdf: 10742068 bytes, checksum: 8856afbc18039f28f1ae0f2c51179126 (MD5) Previous issue date: 2017-08-07 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A radia??o t?rmica ? um mecanismo de transfer?ncia de calor muito importante em processos que envolvem gases participantes, como CO2 e H2O, em temperaturas elevadas. Contudo, a solu??o exata linha-por-linha da transfer?ncia de calor por radia??o em gases participantes ? computacionalmente dispendiosa. Uma das formas de abordagem para esse tipo de problema consiste na utiliza??o dos m?todos de distribui??o-k, como o FSK e SLW, os quais s?o exatos quando aplicados a meios uniformes, mas possuem limita??es no tratamento de meios n?o-uniformes. A aplica??o do m?todo FSK a meios n?o-uniformes requer a ado??o da hip?tese de k-correlacionado (resultando no m?todo FSCK, Full spectrum correlated-k). Isso resulta em um erro devido ao fato dos coeficientes de absor??o de meios reais n?o serem verdadeiramente correlacionados. Diante disto, este trabalho prop?e e investiga uma nova abordagem para considerar meios n?o-uniformes utilizando o m?todo FSK e que n?o requer a hip?tese de k-correlacionado. O m?todo FSK aplicado em conjunto com a abordagem proposta foi denominado FSAK, (Full spectrum averagedk). Com o objetivo de demonstrar a aplica??o do novo m?todo e analisa-lo, o mesmo foi utilizado na solu??o de uma s?rie de casos teste envolvendo gases compostos por CO2 e esp?cies n?o participantes. Os resultados obtidos com o m?todo FSAK foram mais precisos na presen?a de gradientes de temperatura e concentra??o das esp?cies qu?micas mais elevados, condi??es em que o FSCK torna-se menos preciso. Tamb?m verificou-se que o uso de diferentes procedimentos para o c?lculo do coeficiente de absor??o do m?todo FSAK resultam em significativas diferen?as entre os resultados, demonstrando que diferentes procedimentos para o c?lculo desses coeficientes podem levar a diferentes n?veis de precis?o, indicando que procedimentos para o c?lculo da m?dia que tornem o m?todo mais preciso poder?o ser encontrados em futuros trabalhos de pesquisa. / Thermal radiation is a very important mechanism of heat trasnfer in processes that contains participating gases, as CO2 and H2O, at high temperature. However, exact lineby- line solution of radiation heat transfer in participating media is highly computer time consuming due to the dependence of the radiative properties with the wavenumber. A manner to approach such a problem is employing k-distribution methods, as FSK and SLW, which are exact when applied to uniform media, but have limitations in the treatment of non-uniform media. The application of the FSK method to non-uniform media requires the k-correlated assumption (resulting in the FSCK method). This leads to error due the fact that the absorption coefficients of real media are not truly correlated. Therefore, this work proposes and investigates a new approach to solve non-uniform media using the FSK method and which does not require the k-correlated assumption. The FSK method applied with this new approach was labeled FSAK (Full spectrum averaged-k distribution). The method was used to solve a series of problems involving gases composed of CO2 and non-participating species. The results obtained with the FSAK method were more accurate when temperature and species mole fraction gradients where high. It has also been verified that different procedures can be used to average the absorption coefficient, and that the procedure highly influences the accuracy of the results, indicating that averaging procedures to increase the method accuracy could be found in further research works.