[en] a large percentage of patients with cancer are receiving radiotherapy as part of their treatment. At present it is possible to plan with precision these treatments, reducing the risk of side effects and increasing therapeutic efficiency. Proton therapy (also known as particle therapy) is a form external radiotherapy that uses beams of energized protons to treat cancer. The main advantage of proton therapy is its ability to accurately manage an optimal dose of radiation to the tumor, without damaging surrounding healthy tissues and significantly reducing the likelihood and/or severity of side effects. (Author)

[en] Solid state track detectors (SSTDs) are increasingly used for the registration of radiation in different fields of nuclear physics. Because of their small sizes and masses and the absence of any electronics during exposure SSTDs do not cause distortions in the system to be investigated and are useful for measurements at such places being difficult of access. The elaboration of a method is described for fission rate measurements in fast neutron fields applying SSTDs and different fissionable isotopes which were electrodeposited on stainless steel backings. Experiences of the electrodeposition and results of quality checks are presented. The evaluation of the etched tracks is performed with spark counter technique. The dependence of the counting result on essential influence parameters is discussed. (author)

[en] This handbook describes the instruments and methods which may be used in workplace environments in the nuclear industry, at accelerator facilities, and in aircraft, to measure: neutron spectra, photon spectra in mixed neutron gamma fields, and the direction distribution for both types of radiation. This information is needed in radiation protection research both to characterise those fields where it is important to know the dose equivalent accurately, and to investigate the performance of area survey meters and personal dosemeters in order to select the most suitable devices or to determine correction factors, or to do both. For neutron fields neither types of dosemeter, can, in general, be relied upon to give the correct answer. The spectrometry instrumentation is covered here in sufficient detail to enable an end user to select the optimum system for a particular application, and also to construct and commission the chosen system

[en] A new plant damage assessment technique was developed by plant ecologists from Bechtel Nevada at the U.S. Department of Energy's National Security Administration Nevada Operations Office and funded by the Strategic Environmental Research and Development Program Project CS-1131 in cooperation with the U.S. Army's National Training Center (NTC) at Fort Irwin, California. The technique establishes linear transects the width of vehicle tracts from evidence of vehicle tracks in the soil (usually during a prior training rotation period of 30 days or since the last rain or wind storm), and measures vegetation within the tracks to determine the area of plant parts being run over, the percent of the impacted parts damaged, and the percent of impacted parts expected to recover. It documents prior-damage classes based on estimated of damage that plants have apparently experienced previously (as assessed from field indicators of damage such as plant shape and height). The technique was used to evaluate different vehicle types (rubber-tire wheels vs. tracks) in six area at the NTC with different soils and training intensity levels. The technique provides tabular data that can be sorted and queried to show a variety of trends related to military vehicular impacts. The technique also appears suitable for assessing other non-military off-road traffic impacts. Findings report: (1) differences in plant sensitivity of different vehicular impacts, (2) plant cover and density by species and training area, (3) the degree to which wheels have less impact than tracks, and (4) the mean percent survival is inversely proportional to the degree of prior damage received by the vegetation (i.e., plants previously impacted have lower survival than plants not previously impacted)

[en] Risk assessment of transuranic wastes at Los Alamos is reviewed. In this assessment, vertical erosion appeared to be a critical scenario. However, burying the waste at least 72 ft from the cliff or the edge of the mesa would provide an adequate margin. A generic or allowable limit could not be derived from this assessment

[en] Twenty-five years ago, in the night of July 27 to 28, 1978, the AKR-1 nuclear training reactor of the Dresden Technical University went critical for the first time and was commissioned. On the occasion of this anniversary, a colloquy was arranged with representatives from science, politics and industry, at which the reactor's history, the excellent achievements in research and training with the reactor, and the status and perspectives of this research facility were described. The AKR-1 had been built within the framework of the Nuclear Development Program of the then German Democratic Republic (GDR). The Nuclear Power Scientific Division of the Dresden Technical University had been entrusted with the responsibility, among other things, to train university personnel for the GDR Nuclear Power Program. The review by an expert group in 1996 of this plant had resulted in a recommendation in favor of long-term plant operation. A nuclear licensing procedure to this effect was initiated, and the necessary technical backfitting measures were implemented. The AKR-1 plant now equally serves for the specialized training of students and for research. (orig.)

[en] A 4-wheel drive van has been outfitted for rapid and varied monitoring response to radiological emergencies. The vehicle's capabilities include 4-wheel drive plus auxiliary winch for access to rugged off-road terrain. On-board equipment is powered by a 6.5 kilowatt ac generator or by external ac power where available. Monitoring systems include two multichannel analyzers; one, a 2 K portable analyzer with intrinsic germanium detector, the second, a microprocessor based 4 K analyzer with a swivel head intrinsic germanium detector. Rapid gamma searches are performed with a delta rate meter system using a chart recorder and two 4'' x 4'' x 16'' NaI detectors. Other equipment includes portable high volume air samplers and a portable phoswich, as well as the usual portable radiation survey instruments. The construction is modular so that equipment racks, detectors, AC generator and other major structures can be removed or replaced in a matter of minutes

[en] Training reactors contribute to the maintenance and enhance nuclear know-how and competence. Even today with the current political circumstances in Germany, characterized by phasing out nuclear power, there is considerable demand for young engineers and scientists in the nuclear sector. The demand is driven by retirement of staff members at existing NPP and nuclear industrial suppliers, decommissioning of nuclear facilities, continued work in the field of basic nuclear physics research, nuclear engineering, radiation protection, waste disposal, nuclear medicine, and the regulatory bodies, technical inspection organizations or international organizations. For students, the training reactors in Stuttgart, Furtwangen, Ulm and Dresden provide a unique opportunity to get a hands-on experience of neutronics in addition to their theoretical education. (orig.)

[en] Measuring procedures used in reactor and neutron physics appear suitable which verify the fuel by only a single integral measurement. The complexity of the problem to verify the nuclear material by all its characteristic parameters with high accuracy is opposed to the request to simplicity and minimum working effort and loss of time. How far such a sophisticated verification procedure can be optimized is determined by the acceptable uncertainties in safeguards and depends on the type of reactor. (orig./HP)

[en] The Department of Energy (DOE) convened a panel of independent scientists to assess the performance impact of shallow burial of low-level radioactive waste from the Fernald Environmental Management Project, in light of a transportation incident in December 1997 involving this waste stream. The Fernald waste has been transported to the Nevada Test Site and disposed in the Area 5 Radioactive Waste Management Site (RWMS) since 1993. A separate DOE investigation of the incident established that the waste has been buried in stress-fractured metal boxes, and some of the waste contained excess moisture (high-volumetric water contents). The Independent Panel was charged with determining whether disposition of this waste in the Area 5 RWMS has impacted the conclusions of a previously completed performance assessment in which the site was judged to meet required performance objectives. To assess the performance impact on Area 5, the panel members developed a series of questions. The three areas addressed in these questions were (1) reduced container integrity, (2) the impact of reduced container integrity on subsidence of waste in the disposal pits and (3) excess moisture in the waste. The panel has concluded that there is no performance impact from reduced container integrity--no performance is allocated to the container in the conservative assumptions used in performance assessment. Similarly, the process controlling post-closure subsidence results primarily from void space within and between containers, and the container is assumed to degrade and collapse within 100 years