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[en] The UK Nuclear Science Forum (UKNSF) is deemed to be the appropriate body within the UK for technical discussions on the measurement and evaluation of nuclear data (e.g., neutron cross sections, decay data and fission yields). The Forum also has the support of the UK Department of Trade and Industry and the nuclear-based Industry Management Committee (IMC) to act as the communications network for all matters relating to the NEA Data Bank/Nuclear Science Committee and the IAEA-Nuclear Data Section. Two meetings of the UKNSF were held in 1996 on 16 May and 5 December. Membership covers approximately 20 different organisations, including nuclear plant operators, vendors, regulators, non-energy applications, academia, and various data measurers and evaluators. A comprehensive request list has been prepared for nuclear data needs within the UK, covering both measurement and evaluation requirements. This document represents the up-to-date situation within the UK nuclear industry, following a major review and the deletion of a significant number of requests for fast-reactor data. (author)
[en] Vascular radiology includes procedures in which the radiologist or other medical specialist uses the radiological image to diagnose or treat a specific vascular structure. In the published MIRA-2004 report (Milieu- en natuurrapport Vlaanderen) is mentioned that in 2001 the diagnostic vascular procedures comprised only 0.9% and the interventional (cardiology) procedures only 0.4% from the total number of performed radiological medical examinations in Flanders. Notwithstanding the frequency is low, their contribution to radiation exposure in medicine is considerably higher in respect to all X-ray examinations. Due to the complexity of these procedures, the application of the ALARA-principle, keeping doses as low as reasonably achievable without jeopardizing image quality, is a great challenge. It is obvious that optimization of patient doses necessitates a reliable insight in dose levels associated with the different examinations. However, in Belgium there is a great lack of quantitative data in vascular radiology and no explicit instructions are available on how the work could be done practically. Therefore, the first purpose of the study was to define, to measure and to calculate doses to patients in 7 different hospitals. In the thesis, patient doses are measured and calculated for 3 specific vascular procedures: angiography of the lower limbs, angiography of the carotid arteries and cerebral embolisation. The doses are evaluated against different technical parameters of the equipment and of the working procedure. In view of optimization purposes, a protocol for performing dose audits in vascular radiology is suggested. From the results and conclusions in this study, some practical guidelines could be given for the radiological protection of the patient. For 158 patients, relevant parameters as tube voltage (kVp), tube load (mAs), field size, number of frames, fluoroscopy times etc. were recorded. With a flat ionization chamber, positioned in the radiation beam, the product dosexfield area (DAP) was measured for every beam projection separately. Skin doses were measured with thermoluminiscent dosimeters (TLDs) attached to the skin of the patient. These measurements confirmed that radiation doses are high and that for every procedure a large dose variability exists between the different hospitals and between the patients within one hospital. The quantification and analysis of patient doses for procedures of this kind was not easy, as the procedures are complex and not performed frequently. The study also learned us that 'effective dose' is a useful quantity to estimate in view of dose optimization. The effective dose is the weighted sum of organ doses and therefore can not be measured directly. By means of the Monte Carlo computer code, new and appropriate conversion coefficients were determined for the calculation of effective dose for vascular radiology procedures. If every beam projection in the procedure is considered separately, the calculation of effective dose is very complex and only suitable for studies with a small amount of patients involved. For that reason, also a practical method to calculate the effective dose was worked out, for which only one conversion coefficient is used in combination with the total DAP-value of the procedure. Different national and international organizations have recommended the use of patient dose audits in diagnostic radiology as a means of inter institutional comparison and the establishment of reference dose levels. Several studies 2,3,4 indicated that the performance of dose audits could reduce the difference between the highest and lowest measured dose with a factor of 2. Because of the high doses associated with vascular radiology, dose surveys could here also be of obvious benefit, but will not be straightforward due to the complexity of the procedures. The thorough analysis of the patient doses against all possible technical parameters of the equipment and the work procedure, made it possible to set up a protocol for the performance of dose audits in vascular radiology. We propose to register, in addition to the total DAP-values, also parameters as total number of frames, average kVp en possible copper filtration. These data can be used to set diagnostic reference levels (DRLs) or to compare them with existing DRLs per procedure. The information about the energy spectrum of the radiation (kVp and filtration) also makes it possible to estimate the effective dose. Finally, the extensive dose analysis leads to the proposition of some practical guidelines, in order to restrict patient dose, while maintaining an appropriate image quality. Although the current digital systems for vascular radiology need a lower radiation intensity compared to the conventional film-screen systems, it was found that in practice much more images were taken with the digital systems. If the number of frames is sufficiently reduced and if an appropriate dose level is set at the entrance of the image intensifier, depending on the type and the purpose of the procedure, the dose could already be substantially reduced. Although such guidelines can be raised by medical physicists, it will remain the choice of the radiologist if and how they will be implemented in practice. Keeping the medical staff informed and alert about radiation protection is therefore an important issue in the process of optimization
[en] The article describes the key activities of the Institute for Communication, General Services and Administration (CSA) of the Belgian Nuclear Research Centre SCK-CEN. CSA deals with communication and knowledge management and co-ordinates courses on the fundamentals and applications of nuclear research. CSA also comprises the administrative, financial, logistic and central technical services, as well as human resources and ICT
[en] Prolonged exposure to space radiation and extended microgravity has revealed profound physiological and clinical changes in astronauts. The health problems thought to be related to the effects of microgravity include a decrease in the heart and the respiratory rates, a loss of body weight, changes in bone calcium, a redistribution of body fluids with a greater amount in the upper body, a decrease in muscle tissue, a weakening of the veins and arteries in the legs, as well as an underproduction of red blood cells leading to anaemia. At the cellular and molecular levels, microgravity is known to induce both a loss of T-cell activation and changes in gene expression patterns, as well as a three-dimensional growth of normal cells and tumour cells, an alteration of the mitochondrial organization, a modification of the production of extracellular matrix proteins and apoptosis in some types of cells. The Earth's magnetic field protects us from harmful radiation. On Earth, we are still exposed to small amounts of radiation when we go for medical x-rays, when we travel on transcontinental flights or just from radon in the air. However, astronauts are exposed to 50 to 100 times as much radiation - and that is just in a low Earth orbit. In deep space, astronauts can be exposed to even higher doses. It is well known that large amounts of radiation can cause severe health effects by altering DNA in our cells. The health effects from space radiation are therefore a critical safety concern for long-term space travel. Possible health risks include cancer, cataracts, acute radiation sickness, hereditary effects, and damage to the central nervous system. The aims of this research are 1) to ensure the immunological monitoring of a cohort of astronauts (having spent around 6 months aboard the International Space Station ISS) and 2) to investigate the effects of an in vitro exposure of endothelial cells and other types of cells to radiation and/or microgravity conditions
[en] Implementation of remedial actions after a radiological contamination of the environment has to take into account, alongside with radiological and feasibility criteria, also the acceptability of the countermeasures, ethical and environmental considerations, as well as the spatial variation and the needs of people in urban, rural and industrial environments. This highlights multi-criteria analysis as a suitable tool, since it is able to structure discussions and to facilitate a common understanding of the decision problem, with the values and priorities of the actors involved. The related theoretical framework, multi-criteria decision aid (MCDA), has emerged from the operational research field as an answer given to a couple of important questions encountered in complex decision problems. Firstly, the aim is not to replace the decision maker with a mathematical model, but to support him to construct his solution by describing and evaluating his options. Secondly, instead of using a unique criterion capturing all aspects of the problem, in MCDA one seeks to build multiple criteria, representing several points of view. The methods belonging to MCDA can be classified as multi-attribute utility/value methods, outranking methods and interactive methods. Past attempts to apply multi-criteria analysis in the context of nuclear emergency management have highlighted however the need to better integrate the operational and socio-political context of the decision-making process into the tools and models developed for decision-support. This PhD project had two main objectives: 1) to develop a multi-criteria decision aid model for the decision problem on countermeasures for contaminated milk, that better accommodates the nuclear crisis management context in Belgium and 2) to build prototype tools implementing and demonstrating the methodology developed
[en] The article refers to an abstract of a doctoral thesis. From a legal perspective there exists a clear need for a general framework describing conditions and consequences of risk management in the field of high technology. Despite the existence of many kinds of Safety Procedures and Soft Law, specific guidelines are lacking for regulators and courts, especially in case of scientific controversy and uncertainty about the health effects of an activity or a product such as low doses of ionising radiation, electro-magnetic fields, genetically modified organisms, PCB's in salmon etc. The research of the PISA Project on Legal Aspects and Liability has been focussed on the medical applications of ionising radiation. The safety approach depends on the risk characterisation and differs for stochastic and deterministic effects. The most important objective was to find liability or funding systems which can cope with these differences, in particular between dose limits (as for the nuclear industry), reference dose levels foreseen in the EC medical Directive (as for nuclear medicine), and Optimisation referring to the ALARA principle. Risk assessment and risk management that are based on traditional narrow risk-assessment models have to be revised in the light of the Precautionary Principle. This principle urges policy-makers to adopt a broader, more pluralistic approach, considering the societal equilibrium, i.e. the general interest of the activity at stake, the general impact of individual protective measures and the existence of reasonable alternatives from a sociological, economical, scientific and technological point of view. One of the characteristics of the Precautionary Principle relates to our opinion to the collective damage to human health, i.e. a detriment that relates to a group of people. Nevertheless, as a result of the application of the Precautionary Principle, we believe that in case of individual damage the standard of care shall be more and more defined, following the risk characterisation and assessment which has to be introduced once a scientific or societal problem occurs with regard to medical practices, already subject to the legal duty of Justification and of Informed Consent. For some specific cases, as paediatric CT doses, the 2003 report of the Belgian Health Council gives a clear warning and refers to collective doses that are significantly higher than in the neighbouring countries. It cannot be denied that such a repeated warning urges decision makers and hospitals to take corrective actions, in particular when poor optimisation is put in place. Causality in the nuclear field is another complex problem, where worldwide alternatives are under consideration, such as probability of causation. However, such a concept, based on statistical proof, can hardly be implemented in Belgian law since our tort- and insurance-system is based on the individual relationship between liable actor and victim
[en] The The mission of the Learning Centre at the Belgian Nuclear researcxh Center SCK-CEN is to develop the competences of its own members of staff, doctoral students, temporary workers and external employees. For this purpose, the Learning Centre organises a range of training courses specifically aimed at the expectations and needs of various target groups.
[en] Safety culture generally focusses on human and organisational contributions to safety performance within organisations that are characterised by a high level of risk. The term safety culture is used in different sectors. The literature distinguishes between two visions on culture and safety culture. According to the first view, culture culture is considered as an organisational tool. This view is the predominant view in the nuclear sector and postulates that the organisation can develop, assess, enhance and rectify culture by organisational actions. The second view considers safety culture as a metaphor of the organisation. It is a kind of culture of facts. Within this anthropological approach, each organisation transports values and beliefs that are partly adopted by workers. The culture is seen as a source of description and understanding. As part of a PhD study, safety culture in the nuclear sector was investigated based on an exploratory approach that is used in social sciences. In particular, the Focus Group technique was used and fieldwork was applied to two sites: a nuclear power plant in France and the Belgian Nuclear Research Centre SCK-CEN. The different groups of players that were taken into account include workers, safety officers and managers. Current results indicate that different safety cultures group similar components, in particular regulatory, organisational, mental, relational and informal components. The specificity of a safety culture is the result of the predominance of one or two components and their ranking
[en] The water tower located at the Belgian Nuclear Research Center SCK•CEN was constructed in the mid-1950s. It ensures that there is sufficient pressure in the drinking water mains on the site and also serves as a physical separation between the public water supply and the SCK•CEN supply. The article describes work undertaken with respect to the renovation of the water tower.