No abstract available

[en] Using the MIRD method, the dose absorbed by the uterine wall of a non-patient was estimated. pregnant and in the case of a fetus /with three months of gestation. Kidney studies use the Tc-99m-DTPA, Tc-99m-DMSA and Tc-99m-MAG3 radiopharmaceuticals. In these studies the uterine wall and the fetus are exposed to radiation emitted by the Tc-99m from the organs of the biokinetics: bladder-content, kidneys and other organs. There is supposed to be no transfer placental radiopharmaceutical. In this work the anthropomorphic representation of the organs was used that were taken from Stabin (ORNL / TM-12907). The highest dose absorbed by the uterine wall and the fetus is due to the use of the Tc-99m-MAG3. The organ that contributes the highest dose to the wall uterine and fetus are due to the bladder, being 0.0174 mGy / MBq in the case of the uterine wall of the non-pregnant patient and 0.0134 mGy / MBq in the case of the fetus. On the other hand the lowest dose absorbed by the uterine wall and fetus were obtained when using Tc-99m-DMSA. The organ that contributes the highest dose to the uterine wall and the fetus is due to the other organs, being 0.0018 mGy / MBq for the case of the uterine wall and 0.0013 mGy / MBq for the case of the fetus. The results of dose absorbed by the uterine wall are consistent with those reported in the case of an embryo. 0.13 cm radius and 9.2 mg weight during organogenesis (JNM 17: 836-839 (1976)).

[en] The absorber NS-201 of the KNK II first core has been unloaded after a residence time of 273 equivalent full-power days, because gap closure between pellet and cladding had to be expected in 24 pins with B₄C-pellets. Selected pins of this element underwent post-irradiation examinations in the hot cells of the KfK Karlsruhe. The evaluated and interpreted results of the investigations, which are documented in this report, allow the conclusion that the absorber could have been irradiated for the full core residence time. The good irradiation behaviour of the pellets and the cladding without any visible interaction, lead to the plan for further irradiation of a complete pellet column of one pin in the third core of KNK II

[en] Objective: The aim of this study is to validate the clinical use of flattening filter-free (FFF) beam-based volumetric-modulated arc therapy (VMAT) in synchronous bilateral breast carcinoma (SBBC) patient treatments and to compare with flattening filtered (FF) beam-based VMAT. Materials and Methods: Computed tomography images of 15 SBBC patients were taken for this study. A dose of 50 Gy in 25 fractions was prescribed to planning target volume (PTV). VMAT plans were generated using both FFF and FF 6 MV X-ray beams in Eclipse treatment planning system. PTV and organs at risk (OARs) doses were analyzed quantitatively using dose–volume histograms (DVHs) to meet plan objectives. Pretreatment point and planar dosimetry were performed. Results: The findings were reported as mean ± 1 standard deviation. PTV volume receiving 95% of the prescribed dose was 95.71% ± 0.65% for FF-VMAT and 95.45% ± 1.33% for FFF-VMAT (P = 0.743). Conformity index was 1.12 ± 0.31 (FF-VMAT) and 1.12 ± 0.02 (FFF-VMAT). Right lung mean dose was 10.95 ± 1.33 Gy (FF-VMAT) and 10.60 ± 98.5 (FFF-VMAT). Left lung mean dose was 9.73 ± 1.56 (FF-VMAT) and 9.61 ± 1.53 Gy (FFF-VMAT). Tumor control probability (TCP) was 99.68% ± 0.02% (FF-VMAT) and 99.67% ± 0.01% (FFF-VMAT) (P = 0.390). Uncomplicated TCP was 98.72% ± 0.02% (FF-VMAT) and 98.72% ± 0.01% (FFF-VMAT) (P = 0.508). Conclusion: The planning objective parameters achieved using FFF-based VMAT showed that FFF can also be used clinically to treat bilateral breast carcinomas and the low-dose lung volumes were still lesser with FFF-VMAT plans than FF-VMAT. (author)

[en] The test of concentric and centric rings allows to estimate the absorbed dose in people exposed to ionizing radiation from venous blood samples. In accidents with multiple victims, There are methodologies that allow increasing the response speed. The concentric count with Triage criteria (reduction in the number of cells analyzed) allows a decrease in the time of analysis, allowing the classification of the victims in dose ranges of clinical importance. The Validation of this methodology was carried out through the participation of the Biological Dosimetry Laboratory (LDB) of the Nuclear Regulatory Authority in three intercomparison exercises: 2 organized by the Canadian Ministry of Health (international) whose objective was the determination of the absorbed dose at 10 dose points in the range of 0 to 5 Gy, with an X-ray source; and 1 exercise regional organized by the LDB in which 2 dose points were evaluated in a range of 0 to 0.5 Gy with a source of Ir-192. The results showed a better fit for doses less than 2.5 Gy, with a tendency to overestimate for larger doses. However, for doses close to the limit of detection, greater uncertainty was observed in the dosimetric estimation. These exercises show that the analysis of 50 metaphases provides enough information to perform a classification of victims in dose ranges for medical decision making, allowing the use of this methodology for the purpose of mutual assistance in the region. (author)

[en] Radiochromic film dosimeters have a disadvantage in comparison with an ionization chamber in that the dosimetry process is time-consuming for creating a density-absorbed dose calibration curve. The purpose of this study was the development of a simplified method of creating a density-absorbed dose calibration curve from radiochromic film within a short time. This simplified method was performed using Gafchromic EBT3 film with a low energy dependence and step-shaped Al filter. The simplified method was compared with the standard method. The density-absorbed dose calibration curves created using the simplified and standard methods exhibited approximately similar straight lines, and the gradients of the density-absorbed dose calibration curves were -32.336 and -33.746, respectively. The simplified method can obtain calibration curves within a much shorter time compared to the standard method. It is considered that the simplified method for EBT3 film offers a more time-efficient means of determining the density-absorbed dose calibration curve within a low absorbed dose range such as the diagnostic range. (author)

[en] An emergency core cooling system is described which discharges neutron absorber material, such as borated water, from a separate system of accumulators into the area beneath the reactor head and above the upper support plate structure for further distribution through coolant conducting devices to the top of the reactor core

[en] This invention concerns a hydraulic braking system for loads subjected to impacts and vibrations. These double acting telescopic type hydraulic braking systems possess significant drawbacks linked to possibly important hydraulic leaks due to (a) the use of many dynamic seals in such appliances and (b) the effects of the environment of the system on these seals, particularly when employed in nuclear power stations where the seals reach significant temperatures and are subjected to radiation. Under this invention a remedy is suggested to such drawbacks by integrating means to offset automatically the leaks and the accumulation of hydraulic fluid expansions, as well as facilities to show if such leaks have occurred

[en] A hydraulic apparatus is described that absorbs shocks that may be applied to fuel assemblies. Spring pads mounted on the upper end fittings of the fuel assemblies have plungers that move within hollow guide posts attached to the upper grids of the fuel assemblies. (L.L.)

[en] Object: To relieve a local output variation speed of fuel when a control rod is removed, thereby materially avoiding failure of fuel. Structure: The lower part of a control rod body is connected by a coupling to a control rod driving mechanism, when an attempt is made to draw out the control rod, it will immediately move downwardly. However, when an upper neutron absorber, which is provided with a buffer bucket, is moved, cooling water enters a buffer cooling water inlet to create turbulence within the bucket and as a consequence, resistance increases so that this portion is slowly moved along the guide. This enables output variation speed of the fuel assemblies adjacent the control rod to decrease. At the time of insertion, the buffer bucket, of which section is smooth in configuration, sufficiently maintain its function without possible engagement with fuel. (Kamimura, M.)