[en] The routine health physics work at the IEAR-1 reactor and the modifications that are being made, are described. The Personal Dosimetry Laboratory, Waste Disposal and Decontamination Laboratory, Shielding Calculation Section, Dosimetry Laboratory, Radioactive Source and Instrumentation Calibration, are presented. Methods of calibration of radioactive sources and instrumentation are also presented

[en] The aim of this publication is to show the concepts and in vitro bioassay techniques as well as experimental procedures related with internal contamination evaluation. The main routes of intake, metabolic behavior, and the possible types of bioassay samples that can be collected for radionuclides analysis are described. Both biological processes and the chemical and physical behavior of the radioactive material of interest are considered and the capabilities of analytical techniques to detect and quantify the radionuclides are discussed. Next, the need of quality assurance throughout procedures are considered and finally a summary of the techniques applied to the internal routine monitoring of IPEN workers is given. (author)

[en] PHOEL provides a source term for a Monte Carlo code which calculates the electron transport and energy degradation in liquid water. This code is used to study the relative biological effectiveness (RBE) of low-LET radiation at low doses. The basic numerical data used and their mathematical treatment are described as well as the operation of the code

No abstract available

[en] A Monte Carlo computer code, PHOEL-2, is described for generating the energies of photoelectrons and Compton electrons in water irradiated uniformly by photons having an arbitrary energy spectrum. The code treats input photons individually on the basis of the energy-dependent cross sections for Compton scattering and for the photoelectric effect. Options exist for following each photon through successive Compton scattering events until it disappears by photoelectric absorption or allowing at most only a single Compton scattering event per input photon. The photoelectric effect can be turned on or off with either option. If energetically possible, the photoelectron is assumed to come from the oxygen K shell; otherwise, it originates in the L shell. An Auger electron of energy 0.508 keV is assumed to be emitted following the creation of a K vacancy. The basic numerical data used in PHOEL-2, their mathematical treatment, and the operation of the code are described. Detailed comparisons made with work for ⁶⁰Co, and monoenergetic x rays confirm the numerical validity of results obtained with the code. Some of the data of Cormack and Johns are extended by including successive Compton scatterings for the same photon and by including the photoelectric effect and Auger electrons. PHOEL-2 can be obtained from the Radiation Shielding Information Center at Oak Ridge National Laboratory. The new version differs from the old by employing a more realistic handling of the photoelectric cross section as a function of energy, compiling electron spectra instead of storing the energies of every electron produced, eliminating some former input restrictions, and using a different random number generator. PHOEL-2 does not treat pair production, which should be included for water at photon energies above about 2000 keV. 5 figures, 4 tables

[en] A Monte Carlo Code, PHOEL, is described for generating the initial energies of Compton and photoelectrons in water irradiated by photons with an arbitrary energy spectrum. An infinite, homogeneous water phantom is assumed in which the photon spectrum is uniform throughout. The neglect of pair production does not represent a significant omission for photons with energies below about 10,000 keV. The code PHOEL was written specifically to provide a source term for a Monte Carlo electron energy degradation and transport code for liquid water being used to study the relative biological effectiveness (RBE) of low-LET radiations at low doses. The basic numerical data used in PHOEL and their mathematical treatment are described as well as the operation of the code. Copies of the program are available from the Radiation Shielding Information Center at Oak Ridge National Laboratory. Some numerical computations which have been made for verification of the code are briefly described. The code processes 1000 photons at 200 keV in less than 2 s on the IBM 360/91. Because of multiple Compton scattering, the processing of higher-energy photons takes somewhat longer. The code has options for printing the electron energies and/or writing them on tape or disc. 1 figure, 2 tables

[en] The Brazilian legislation contemplates the work in potential danger places for practices involving originally inflammable materials, including explosive materials, and finally electricity. After the Goiania accident, ionizing radiation was also included in the Brazilian legislation, except for federal civil servants that were excluded because they work under special legislation. Immediately after the ICRP Publication-64: 'Protection from potential exposure: a conceptual framework' had become available, the potential exposure danger for federal civil servants was also acknowledged, and the federal government issued a new legislation based on three levels of danger, that favored them. Thus, we could include in the new legislation the main concepts of the framework suggested by the ICRP publication-64. This paper intends to discuss the manner in which the ICRP publication-64 was introduced in the Brazilian legislation. (author)

[en] This study is derived from the master's dissertation 'Evolution of the philosophy of the Imitation Dose System and the Question of Superseded Substitutions' written by this author. We aim to present the main differences collected from publications 60 and 103 of the International Commission on Radiation Protection - ICRP, in regard to the Limitation of Occupational Dose, with the addition of Justification of the Commission for these modifications over the years and the author's discussion with relationship to the advantages, disadvantages and justification of the Commission. Within the information observed in the study, we can cite as example the restrictive dose limits, are mentioned in the publication number 60 but they are not described in it, this description happens with the arrival of publication number 103 which, in addition to reinforcing the importance of restrictive limits, presents the different types of dose restrictions used in the protection system of the Commission (limits, restrictions, reference levels) that are shown in relation to the type of situation of exposure, exposure categories and factors that influence the choice of dose of restriction. In planned exposure situations, there are also restrictive risks for Consider potential exposures. Another peculiar issue addressed in this article, which is also a difference in the two publications is the issue of the annual dose limit for situations special exposition, increased from 50mSv to 100 mSv in publication 103. (author)

[en] A comparison between the old and now CNEN (Brazilian Nuclear Energy Commission) organizational structure was performed. The new structure lead to a new IPEN (Nuclear and Energetics Research Institute) organization and also to gave use to a Radioprotection Engineering Area, The principal modification raised a second block already in accomplishment. The main aim of the Radioprotection Engineering Area is to turn personnel team interested, concerned, dexterous, dynamic and competitive on their activities besides to provide it of a continuously improvement and updating about technical activities in radiation protection. From these results an evaluation of possible drawbacks and ways to overcome them will be performed. (author)

[en] External monitoring for air dose measurement using thermoluminescence CaSO(sub 4):Dy dosimeters put in fixed points was done inside the IPEN-CNEN/SP area. This measure was done with the objective to understand the influence of nuclear and radioactive facilities inside the IPEN-CNEN/SP workplaces into the environment. The adopted method involves the use of TLD's, which measure dose rather than dose rate. This study was carried out to evaluate the radiation level for electromagnetic radiation in different places at IPEN-CNEN/SP. The observed results at the previously established points was up to 15 times the background level. From the results of this evaluation we could get a gross estimation of plant influence and specific influence of some types of sources. This analysis opens a window to make more accurate studies to evaluate the contribution of each installation to background dose variation and what is its contribution to collective dose of IPEN-CNEN/SP population, inside the facilities, as well as in those people who suffer contributions from each facility