The goal of internal dosimetry is to assess the dose to an individual from an intake of a radionuclide. This usually encompasses assessing the intake amount based on some form of bioassay measurement used with a biokinetic model. There are many published biokinetic models that describe the transfer of radionuclides throughout the body. It would be beneficial at times if one could interchange certain biokinetic models with another to assess an intake based on bioassay data to save time and make calculations simpler. This research compared the daily excretion rates by interchanging widely used biokinetic models in different combinations. These model combinations were then used to assess an unknown intake of a case study. It was shown that the ICRP-30 and ICRP-66 respiratory tract models can only be interchanged at specific times post intake to give similar excretion results from an inhalation intake. It is feasible to interchange the ICRP-67 plutonium systemic model or the newer Luciani and Polig plutonium systemic model to assess an intake based on fecal bioassay data, but not urine bioassay data for ingestion intakes. It is not feasible to interchange the systemic models when assessing intakes from a wound or injection. Using different combinations of biokinetic models predicted intakes within 30% for a case study which included a relatively long inhalation chronic intake followed by a much shorter chronic inhalation intake. It was shown that the predicted initial chronic intake for each combination of models gave fecal excretion values which deviated the most from the worker's fecal bioassay data. This could mean that the biokinetic models yield inaccurate excretion rates for long chronic intakes.

The goal of internal dosimetry is to assess the dose to an individual from an intake of a radionuclide. This usually encompasses assessing the intake amount based on some form of bioassay measurement used with a biokinetic model. There are many published biokinetic models that describe the transfer of radionuclides throughout the body. It would be beneficial at times if one could interchange certain biokinetic models with another to assess an intake based on bioassay data to save time and make calculations simpler. This research compared the daily excretion rates by interchanging widely used biokinetic models in different combinations. These model combinations were then used to assess an unknown intake of a case study. It was shown that the ICRP-30 and ICRP-66 respiratory tract models can only be interchanged at specific times post intake to give similar excretion results from an inhalation intake. It is feasible to interchange the ICRP-67 plutonium systemic model or the newer Luciani and Polig plutonium systemic model to assess an intake based on fecal bioassay data, but not urine bioassay data for ingestion intakes. It is not feasible to interchange the systemic models when assessing intakes from a wound or injection. Using different combinations of biokinetic models predicted intakes within 30% for a case study which included a relatively long inhalation chronic intake followed by a much shorter chronic inhalation intake. It was shown that the predicted initial chronic intake for each combination of models gave fecal excretion values which deviated the most from the worker's fecal bioassay data. This could mean that the biokinetic models yield inaccurate excretion rates for long chronic intakes.

Em 1958 a Comissão Internacional de Proteção Radiológica (CIPR) propôs a primeira filosofia do sistema de limitação de dose, introduzindo os Limites Anuais Máximos Permissíveis (LAMP). O grande avanço da era nuclear nas últimas décadas impôs novos paradigmas e a necessidade de atualização da filosofia em questão. O presente trabalho tem por objetivo apresentar uma análise da evolução da filosofia do sistema de limitação de dose, desde a década de 50 até os dias atuais. A primeira mudança de paradigma se deu com a criação dos Limites Anuais Máximos Admissíveis (LAMA), ainda vigentes. Por meio de um cuidadoso estudo das publicações do Organismo Internacional de Energia Atômica (OIEA) e das recomendações da CIPR, foi possível evidenciar e detalhar o processo de evolução dos LAMA ao longo das últimas décadas. A pesquisa aborda momentos-chaves que impulsionaram mudanças na filosofia do sistema de limitações de dose como, por exemplo, a crise internacional do petróleo e suas implicações no desenvolvimento da área nuclear. A comparação entre as diversas publicações das duas entidades (OIEA e CIPR) permitiu um estudo aprofundado desde o surgimento dessas filosofias até suas últimas publicações. Os resultados deste estudo apontam importantes informações que constam em publicações da CIPR, hoje consideradas \"superseded\", que não são encontradas nas publicações atuais. O OIEA, que elabora suas recomendações baseado na filosofia da CIPR, também não aborda as referidas informações. Por meio da presente pesquisa, foi possível evidenciar e detalhar valiosas informações que se perderam durante o processo de atualização das publicações e edição de recomendações de ambas as entidades. Este trabalho se propõe a apresentar essas informações, que foram estudadas em profundidade, discutindo seu real valor, propondo à comunidade internacional novas reflexões sobre a importância e a possibilidade de reintroduzir as informações perdidas em futuras publicações. / In 1958 the International Commission on Radiological Protection (ICRP) first proposed the philosophy of the dose limitation system by introducing the Permissible Maximum Annual Limits (PMAL). The breakthrough of the nuclear age in recent decades has imposed new paradigms and the need to update the philosophy in question. This work aims to present an analysis about the philosophy evolution of the dose limitation system, from the 50\'s to the present day. The first paradigm shift occurred with the creation of Allowable Maximum Annual Limits (AMAL), still in force. Through a careful study of the International Atomic Energy Agency (IAEA) publications and the ICRP recommendations, it was possible to highlight and detail the process of evolution of AMAL over the past decades. The research addresses key moments that have driven change in the philosophy of the dose limitation system, for example, the international oil crisis and its implications in the development of nuclear area. The comparison of the various publications of the two entities (IAEA and ICRP) allowed a thorough study since the emergence of these philosophies to their latest publications. The results of this study indicate important information contained in ICRP publications, now considered \"superseded\", which are not found in current publications. The IAEA, which prepares its recommendations based on the philosophy of the ICRP, also does not address such information. Through this research, it was possible clear and detail valuable information that was lost during the process of updating publications and editing recommendations of both entities. This study aims to present this information, which were studied in depth, discussing their real value, proposing to the new international community reflections on the importance and the possibility of reintroducing the lost information in future publications.

Em 1958 a Comissão Internacional de Proteção Radiológica (CIPR) propôs a primeira filosofia do sistema de limitação de dose, introduzindo os Limites Anuais Máximos Permissíveis (LAMP). O grande avanço da era nuclear nas últimas décadas impôs novos paradigmas e a necessidade de atualização da filosofia em questão. O presente trabalho tem por objetivo apresentar uma análise da evolução da filosofia do sistema de limitação de dose, desde a década de 50 até os dias atuais. A primeira mudança de paradigma se deu com a criação dos Limites Anuais Máximos Admissíveis (LAMA), ainda vigentes. Por meio de um cuidadoso estudo das publicações do Organismo Internacional de Energia Atômica (OIEA) e das recomendações da CIPR, foi possível evidenciar e detalhar o processo de evolução dos LAMA ao longo das últimas décadas. A pesquisa aborda momentos-chaves que impulsionaram mudanças na filosofia do sistema de limitações de dose como, por exemplo, a crise internacional do petróleo e suas implicações no desenvolvimento da área nuclear. A comparação entre as diversas publicações das duas entidades (OIEA e CIPR) permitiu um estudo aprofundado desde o surgimento dessas filosofias até suas últimas publicações. Os resultados deste estudo apontam importantes informações que constam em publicações da CIPR, hoje consideradas \"superseded\", que não são encontradas nas publicações atuais. O OIEA, que elabora suas recomendações baseado na filosofia da CIPR, também não aborda as referidas informações. Por meio da presente pesquisa, foi possível evidenciar e detalhar valiosas informações que se perderam durante o processo de atualização das publicações e edição de recomendações de ambas as entidades. Este trabalho se propõe a apresentar essas informações, que foram estudadas em profundidade, discutindo seu real valor, propondo à comunidade internacional novas reflexões sobre a importância e a possibilidade de reintroduzir as informações perdidas em futuras publicações. / In 1958 the International Commission on Radiological Protection (ICRP) first proposed the philosophy of the dose limitation system by introducing the Permissible Maximum Annual Limits (PMAL). The breakthrough of the nuclear age in recent decades has imposed new paradigms and the need to update the philosophy in question. This work aims to present an analysis about the philosophy evolution of the dose limitation system, from the 50\'s to the present day. The first paradigm shift occurred with the creation of Allowable Maximum Annual Limits (AMAL), still in force. Through a careful study of the International Atomic Energy Agency (IAEA) publications and the ICRP recommendations, it was possible to highlight and detail the process of evolution of AMAL over the past decades. The research addresses key moments that have driven change in the philosophy of the dose limitation system, for example, the international oil crisis and its implications in the development of nuclear area. The comparison of the various publications of the two entities (IAEA and ICRP) allowed a thorough study since the emergence of these philosophies to their latest publications. The results of this study indicate important information contained in ICRP publications, now considered \"superseded\", which are not found in current publications. The IAEA, which prepares its recommendations based on the philosophy of the ICRP, also does not address such information. Through this research, it was possible clear and detail valuable information that was lost during the process of updating publications and editing recommendations of both entities. This study aims to present this information, which were studied in depth, discussing their real value, proposing to the new international community reflections on the importance and the possibility of reintroducing the lost information in future publications.

The commission on radiological protection through publication 118 decided to recommend a change to the eye dose limit in 2011. ICRP recommendations made in publications, especially ‘publication 60’ and its subsequent update ‘publication 103’ has served as standards for regulatory authorities worldwide in limiting ionizing radiation exposure both to workers and members of the public. For example in Canada, the Canadian Nuclear Safety Commission (CNSC) generally directly adopts recommendations from ICRP. The previous dose limit for the lens of the eye was 150 mSv year-1, based on Publication 60 and 103. Regulatory agencies worldwide have been using this value and subsequently nuclear facilities, hospitals and universities have designed their radiation protection program based on this dose limit for several decades. The new revised eye dose limit now being equivalent to the whole body dose limit will pose significant challenges for sectors where the eye exposure was not characterized as the limit was previously five times over the whole body exposure. A two-step approach was used in conducting this study, firstly a through literature search was conducted on the effects of ionizing radiation to the eye, its radiobiology, fundamentals in established both dose limits was analyzed. Secondly, the authors spent time researching institutions that use ionizing radiation and interviewed engineers, medical physicists, radiation safety officers and regulators from a wide array of fields and industries. Based on the ICRP publications, the review of the literature and the interviews conducted with the nuclear industry, there is consensus in Canada and among IAEA member states that the dose limit for the lens of the eye should be reduced from the original proposed limit of 150 mSv per year. However not to the recommendations suggested by ICRP 118, but, to a standard reasonable and an achievable limit that is 50 mSv per year. / Thesis / Master of Science (MSc) / The International Commission on Radiological Protection (“ICRP”), the independent governing body responsible for radiation protection, since the early 1950s has been issuing recommendations that are widely used as radiological protection standards by regulatory agencies worldwide, primarily UN member states. Since its inception in 1928, the ICRP has served as the basis for radiation protection and value based judgements in protecting both human and non-human biota. In 2011, the commission published (ICRP Pub. 118) its review of epidemiological studies and decided to recommend a change to the previously established eye dose limit. Based on the review of the literature and the research conducted within the academic, veterinary, nuclear and medical industry, there is general consensus in Canada and among IAEA members states that the dose limit for the lens of the eye should be reduced from the original proposed limit, but not to the recommendations suggested by ICRP 118.

Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2014-11-10T12:03:00Z No. of bitstreams: 0 / Made available in DSpace on 2014-11-10T12:03:00Z (GMT). No. of bitstreams: 0 / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2014-11-10T12:03:00Z No. of bitstreams: 0 / Made available in DSpace on 2014-11-10T12:03:00Z (GMT). No. of bitstreams: 0 / De acordo com a Comissão Nacional de Energia Nuclear (CNEN), a avaliação de impacto radiológico ambiental resultante da liberação de radionuclídeos para o meio ambiente, devido à operação normal de instalações nucleares, para propósito de proteção do público, é feita considerando o conceito de grupo crítico. Contudo, em 2006, a International Commission on Radiological Protection (ICRP), para o mesmo propósito, propôs a adoção do conceito de indivíduo representativo. Uma vez que, em algum momento, o Brasil possa adotar esse novo conceito, no presente trabalho são avaliadas as alterações, em termos de procedimentos de cálculo e dos consequentes resultados, decorrentes da aplicação da metodologia de indivíduo representativo em comparação com a metodologia de grupo crítico atualmente utilizada para o controle regulatório das instalações nucleares brasileiras. Como referência, utilizou-se as potenciais liberações de radionuclídeos previstas para a operação normal da Unidade de Produção de Hexafluoreto de Urânio (USEXA), localizada no Centro Experimental Aramar (CEA). De forma específica, os objetivos são: efetuar a avaliação de impacto radiológico ambiental para o CEA, utilizando as duas metodologias recomendadas (determinística e probabilística) para o indivíduo representativo, conforme descritas pela ICRP (2006); efetuar a comparação dos resultados obtidos com essas metodologias com os obtidos com a metodologia utilizada para o grupo crítico; e efetuar uma análise crítica da necessidade e da disponibilidade de dados para a aplicação dessas metodologias, bem como das suas consequências para o controle operacional do CEA. Com base nos resultados obtidos, destaca-se que a utilização da metodologia de cálculo de grupo crítico continua sendo uma maneira simples e eficiente para a avaliação de impacto radiológico ambiental, quando comparada à utilização da metodologia de indivíduo representativo, o que torna o estabelecimento de programas de monitoramento e, consequentemente, o controle radiológico ambiental, mais simples e objetivos. / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

No presente trabalho foram determinadas as concentrações de radônio em seis cavernas do Parque Estadual Turístico do Alto Ribeira (PETAR) e foi estimada a dose efetiva anual recebida pelos guias turísticos da região. O PETAR apresenta quatro núcleos de visitação: Santana, Ouro Grosso, Caboclos e Casa de Pedra e recebe anualmente cerca de 40 mil visitantes. As cavernas escolhidas foram Couto, Água Suja, Laje Branca, Morro Preto e Santana, do núcleo Santana e a caverna Alambari de Baixo do núcleo Ouro Grosso, por receberem o maior número de turistas. Os níveis de radônio foram determinados utilizando detectores de traços nucleares do estado sólido Makrofol E expostos trimestralmente por um período de 26 meses, entre Outubro de 2003 e Novembro de 2005. As concentrações de 222Rn variaram na faixa de 153 Bq.m-3 a 6607 Bq.m-3, sendo observado que, de uma maneira geral, os níveis de radônio diminuem nos períodos frios. A dose efetiva anual, considerando os cenários mais realistas, com média geométrica das concentrações, fator de equilíbrio 0,5 e tempo de exposição anual para cada caverna, variou entre 0,2 mSv.a-1 para a caverna Couto, bastante ventilada e 4,0 mSv.a-1 para a caverna Santana, a mais visitada, com galerias sem comunicação externa. Para o pior cenário, com média aritmética das concentrações, fator de equilíbrio 1 e tempo de exposição anual para todas as cavernas, a dose efetiva anual total foi 16,1 mSv.a-1. Todas as estimativas da dose efetiva anual estão abaixo de 20 mSv.a-1, sugerido como o valor limite para dose efetiva anual para exposição ocupacional pela Comissão Internacional de Proteção Radiológica (ICRP 60, 1990). / In the present work, radon concentrations in six caves of PETAR - Parque Estadual Turístico do Alto Ribeira (High Ribeira River Turistic State Park) were carried out with Makrofol E solid state nuclear track detectors (SSNTD) and used to assess the annual effective dose received by regional tour guides. The park has four visitation centers: Santana, Ouro Grosso, Caboclos e Casa de Pedra and receives nearly 40,000 people annually. The caves evaluated were Couto, Água Suja, Laje Branca, Morro Preto and Santana, from Santana center and Alambari de Baixo from Ouro Grosso center, for being the most frequently visited caves. The exposure period of the SSNTD was, at least, three months, over a period of 26 months, from October 2003 to November 2005. The 222Rn concentrations lay in a range from 153 Bq.m-3 to 6607 Bq.m-3 and we observed that, in general, for chilly weather, the radon levels decrease. The annual effective dose, considering the most realistic scenario, with geometric mean concentrations, an equilibrium factor of 0.5 and annual exposure time for each cave, varied from 0.2 mSv.a-1 for the Couto cave, strongly ventilated, to 4.0 mSv.a-1 for the Santana cave, the most frequently visited and no external communication. For the worst scenario, with arithmetic mean concentrations, equilibrium factor 1 and annual exposure time for all caves, the annual effective dose was 16.1 mSv.a-1. All assessed effective doses received by the tour guides are bellow 20 mSv.a-1, suggested as an annual effective dose limit for occupational exposure by the International Commission of Radiological Protection (ICRP 60, 1990).

No presente trabalho foram determinadas as concentrações de radônio em seis cavernas do Parque Estadual Turístico do Alto Ribeira (PETAR) e foi estimada a dose efetiva anual recebida pelos guias turísticos da região. O PETAR apresenta quatro núcleos de visitação: Santana, Ouro Grosso, Caboclos e Casa de Pedra e recebe anualmente cerca de 40 mil visitantes. As cavernas escolhidas foram Couto, Água Suja, Laje Branca, Morro Preto e Santana, do núcleo Santana e a caverna Alambari de Baixo do núcleo Ouro Grosso, por receberem o maior número de turistas. Os níveis de radônio foram determinados utilizando detectores de traços nucleares do estado sólido Makrofol E expostos trimestralmente por um período de 26 meses, entre Outubro de 2003 e Novembro de 2005. As concentrações de 222Rn variaram na faixa de 153 Bq.m-3 a 6607 Bq.m-3, sendo observado que, de uma maneira geral, os níveis de radônio diminuem nos períodos frios. A dose efetiva anual, considerando os cenários mais realistas, com média geométrica das concentrações, fator de equilíbrio 0,5 e tempo de exposição anual para cada caverna, variou entre 0,2 mSv.a-1 para a caverna Couto, bastante ventilada e 4,0 mSv.a-1 para a caverna Santana, a mais visitada, com galerias sem comunicação externa. Para o pior cenário, com média aritmética das concentrações, fator de equilíbrio 1 e tempo de exposição anual para todas as cavernas, a dose efetiva anual total foi 16,1 mSv.a-1. Todas as estimativas da dose efetiva anual estão abaixo de 20 mSv.a-1, sugerido como o valor limite para dose efetiva anual para exposição ocupacional pela Comissão Internacional de Proteção Radiológica (ICRP 60, 1990). / In the present work, radon concentrations in six caves of PETAR - Parque Estadual Turístico do Alto Ribeira (High Ribeira River Turistic State Park) were carried out with Makrofol E solid state nuclear track detectors (SSNTD) and used to assess the annual effective dose received by regional tour guides. The park has four visitation centers: Santana, Ouro Grosso, Caboclos e Casa de Pedra and receives nearly 40,000 people annually. The caves evaluated were Couto, Água Suja, Laje Branca, Morro Preto and Santana, from Santana center and Alambari de Baixo from Ouro Grosso center, for being the most frequently visited caves. The exposure period of the SSNTD was, at least, three months, over a period of 26 months, from October 2003 to November 2005. The 222Rn concentrations lay in a range from 153 Bq.m-3 to 6607 Bq.m-3 and we observed that, in general, for chilly weather, the radon levels decrease. The annual effective dose, considering the most realistic scenario, with geometric mean concentrations, an equilibrium factor of 0.5 and annual exposure time for each cave, varied from 0.2 mSv.a-1 for the Couto cave, strongly ventilated, to 4.0 mSv.a-1 for the Santana cave, the most frequently visited and no external communication. For the worst scenario, with arithmetic mean concentrations, equilibrium factor 1 and annual exposure time for all caves, the annual effective dose was 16.1 mSv.a-1. All assessed effective doses received by the tour guides are bellow 20 mSv.a-1, suggested as an annual effective dose limit for occupational exposure by the International Commission of Radiological Protection (ICRP 60, 1990).

The ICRP recommends a radiation weighting factor of one for all low-LET radiation. However, many experimental studies find inconsistencies between low-LET RBE and the ICRP's current radiation weighting factor. Generally, there is evidence that dependence exists between radiation energy and radiation RBE where lower energy radiations tend to have a greater biological effect than higher energy radiation. Specifically, the radiations of tritium and carbon K-shell x-rays have been studied in numerous experiments and the biological effects of both of these radiations are consistently greater than that of Co-60. In this work, the relationship between radiation energy and radiation effect has been investigated with the use of a newly developed double strand break (DSB) yield estimation algorithm. This algorithm makes use of a detailed solenoidal 30 nm DNA chromatin model to describe the radiation-sensitive biological target. In addition to the DNA model, NOREC, an event by event Monte Carlo code, was used in this algorithm to characterize the electron track. As an alternative to the conventional approach of computationally simulating DNA damage by spatial overlay of an electron track on DNA, this algorithm instead focuses on quantifying the distance between ionizations in an electron track and next determining the likelihood that any given ionization pair forms a DSB. The first step of the algorithm involves electron characterization while the second step relies on DNA molecule characterization. By assuming a DSB biological endpoint and determining the DSB yield as a function of electron energy, energy dependent RBE values were estimated for monoenergetic electrons from 10 eV to 1 MeV. Photon RBE values, x-ray RBE values and radionuclide RBE values were also calculated and reported in this work in addition to electron RBE values. Photon RBE values were estimated based upon the electron RBE calculation. Photon RBE values were reported from 1 eV to 10 MeV. In turn, x-ray RBE values were calculated based upon photon values for several tube voltage and filter combinations. Finally, RBE values for over 1000 radionuclides were estimated and reported.