[en] The MICROX-2 code prepares broad group neutron cross sections for use in diffusion- and/or transport-theory codes from an input library of fine group and pointwise cross sections. The neutron weighting spectrum is obtained by solving the B₁ neutron balance equations at about 10000 energies in a one-dimensional (planar, spherical or cylindrical), two-region unit cell. The regions are coupled by collision probabilities based upon spatially flat neutron emission. Energy dependent Dancoff factors and bucklings correct the one-dimensional calculations for multi-dimensional lattice effects. A critical buckling search option is also included. The inner region may include two different types of fuel particles (grains). This report describes the present PSI FORTRAN 90 version of the MICROX-2 code which operates on CRAY computers and IBM PC's. The equations which are solved in the various energy ranges are given along with descriptions of various changes that have been made in the present PSI version of the code. A completely re-written description of the user input is also included. (author) 7 figs., 4 tabs., 59 refs

[en] The shutdown system of the Smolensk nuclear power plant unit-3 was evaluated in cooperation with the RRC Kurchatov Institute (RRC-KI) and the Research and Development Institute of Power Engineering (RDIPE) in Moscow. The objectives of the cooperation were to investigate the adequacy of RBMK shutdown systems with regard to shutdown effectiveness and shutdown rate and to compare the results of the respective calculations performed by the individual partners using their own computational techniques. It was not the intention to perform a comprehensive, representative safety analysis for the plant. The project was structured in three phases. Phase I: code, implementation and testing; phase II: steady state analysis of Smolensk-3; phase III: transient analysis of Smolensk-3. As a consequence of this project the reactor designer will eliminate the short-comings of the control and protection system and implement an additional diverse shutdown system in all RBMK. This system will utilize the present 24 fast acting shutdown rods in combination with a liquid poison system as an additional mean to shut the reactor down from any operational or accidental condition and to provide long term subcriticality. The reactor scram system (first shutdown system) will utilize the remaining rods to shut the reactor down quickly enough to cope with any accident and to maintain long term subcriticality. The new systems have been reported to be installed in Sosnoby Bor in 1997. (author) figs., tabs., 6 refs

[en] These lecture notes are intended as a pedagogical introduction to several popular extensions of the standard model of strong and electroweak interactions. The topics include the Higgs sector, the left-right symmetric model, grand unification and supersymmetry. Phenomenological consequences and search procedures are emphasized. (author) figs., tabs., 18 refs

[en] The concentrations of the cosmogenic radionuclide ³²Si were measured in four fresh snow samples from the Jungfraujoch in the Swiss Alps (3450 m asl.) to study the feasibility of measuring this potential dating nuclide with Accelerator Mass Spectrometry. This technique could reduce drastically the amount of material needed for measurements of ³²Si concentrations in environmental samples in contrast to conventional radiometric detection. The measured ³²Si concentrations in the snow samples were between 1.84 and 6.28 μBql^-1. These values agree with other measurements of precipitation samples. The measured ³²Si/Si_tot ratios ranged from 2.5.10^-17 to 2.3.10^-15 and were thus below the present detection limit of about 10^-14, showing that at present it is not possible to carry out AMS measurements of ³²Si in precipitation samples. For the first time, experimental cross sections of the reaction ⁴⁰Ar(p,X)³⁶Cl have been determined for the proton energy range 16-590 MeV. These cross sections were measured using a gas target, a novel method which was tested successfully by irradiating nitrogen targets to confirm literature values of the N(p,X)⁷Be and N(p,X)¹⁰Be cross sections. In fact, good agreement was found between the obtained cross sections with those using solid targets. Production of several radionuclides in the reaction of proton with nickel were also measured. Comparison of these cross sections with literature data proved that the proton flux measurements carried out with ionization chambers were very accurate. The excitation function of the reaction ⁴⁰Ar(p,X)³⁶Cl exhibits two maxima at proton energies of 20 MeV for the (p,αn)reaction and 95 MeV for the (p,2p3n) reaction, with maximum cross sections of 105 mb and 53 mb, respectively. (author) figs., tabs., refs

[en] This study aims at a comparison of future reactor concepts, paying particular attention to aspects of safety, of the fuel cycle, the economics, the experience-base and the state of development. Representative examples of typical development lines, that could possibly be 'of interest' within a time horizon of 50 years were selected for comparison. This can be divided into three phases: - Phase I includes the next 10 years and will be characterised mainly by evolutionary developments of light water reactors (LWR) of large size; representative: EPR, - Phase II: i.e. the time between 2005 and 2020 approximately, encompasses the forecasted doubling of today's world-wide installed nuclear capacity; along with evolutionary reactors, innovative systems like AP600, PIUS, MHTGR, EFR will emerge, - Phase III covers the time between 2020 and 2050 and is characterised by the issue of sufficient fissile material resources; novel fast reactor systems including hybrid systems can, thus, become available; representatives: IFR, EA, ITER (the latter being). The evaluated concepts foresee partly different fuel cycles. Fission reactors can be operated in principle on the basis of either a Uranium-Plutonium-cycle or a Thorium-Uranium-cycle, while combinations of these cycles among them or with other reactor concepts than proposed are possible. With today's nuclear park (comprising mainly LWRs), the world-wide plutonium excess increases annually by about 100 t. Besides strategies based on reprocessing like: - recycling in thermal and fast reactors with mixed oxide fuels, - plutonium 'burning' in reactors with novel fuels without uranium or in 'hybrid' systems, allowing a reduction of this excess, direct disposal of spent fuel elements including their plutonium content ('one-through') is being considered. (author) figs., tabs., 32 refs

[en] For ultratrace analysis as well as for studies of the physical properties of actinide elements by means of resonance ionization mass spectroscopy (RIMS) suitable beam sources are required delivering a stable atomic beam of the element of interest with a high yield. This can be accomplished using sandwich filaments with tantalum as the backing material and titanium as a covering layer. The evaporation kinetics, the desorption and the diffusion as well as the surface ionization and the associative desorption are considered. Furthermore the requirements for an atomic actinide beam source are described with respect to the evaporation behaviour of the actinide elements and their oxides. Results are presented on the desorption and adsorption of actinides on Ti- and Ta surfaces and the influence of various parameters. Data on the reproducibility of the evaporation of Ti-actinide-Ta-filaments obtained with RIMS are given together with some applications. (author) 24 figs., 11 tabs., 67 refs

[en] The element Pu (Z = 94) is a member of the actinide series of the elements (Z = 89 -103). The actinides have similar chemical properties and are also similar to the lanthanides (Z = 57 -71). Sixteen isotopes of Pu have been synthesized, all of which are radioactive. The Pu present in the environment originates from the atmospheric nuclear tests from 1950 to 1963, which produced the so-called 'global fallout'. As a result, 6.5 · 10¹⁵ Bq ²³⁹Pu (2.8 tons), 4.4 · 10¹⁵ Bq ²⁴⁰Pu (0.52 tons), and 3.7 · 10⁴ Bq ²⁴¹Pu (0.04 tons) were dispersed over the world. A contribution also to the global fallout was the ignition of the satellite SWAP 9A in the atmosphere in 1964, equipped with a battery powered by 6.3 · 10¹⁴ Bq (1 kg) of ²³⁸Pu. In addition to these sources, nuclear reactors, reprocessing plants and radioactive waste facilities may contribute with their emissions to increase locally the Pu concentration in their environment. In the PSI laboratory, we are confronted with the determination of traces of ²³⁸Pu, ²³⁹Pu and ²⁴⁰Pu in environmental and biological materials. Because of the low quantity of Pu in the analyzed samples, which is usually below 100 mBq, it is mandatory to separate the Pu from all other accompanying elements. The separated Pu is then measured by alpha spectrometry. In this work, the anion exchanger BIO-RAD AG 1 is extensively used for the separation of Pu from different matrices. This exchanger is superior when only Pu is determined in the sample. In addition, it is also very suitable when other actinides, such as Am and Cm, are also determined. No preconcentration step is necessary for the Pu separation. The resins introduced by the company Eichrom Industries in the 90's, which allow the separation of the actinides from the major environmental elements and from each other, requires relatively small volumes of sample solution. This report describes the extensive utilization of the classical anion exchanger BIO-RAD 1-X2 in 8 molar nitric acid for the separation of plutonium from matrices such as air filters, concrete, cooling reactor water, faeces, smear reactor samples, and soils, and for the purification of plutonium tracers. Detailed procedures are given for all these matrices, from the dissolution of the sample to the final electro deposition preceding alpha spectrometry. Also included is the behaviour in the anion exchanger of potentially interfering nuclides of elements such as Am, Np, Po, Th, and U. Special attention has been given to the isotopic exchange between plutonium in the sample and the plutonium tracer added for the recovery determination, as well as some usual operations performed during the analysis

[en] This comprehensive report by the Paul Scherrer Institute PSI in Switzerland documents the development of the Swiss TIMES Electricity Model (STEM-E). This is a flexible model which explicitly depicts plausible pathways for the development of the Swiss electricity sector, while dealing with inter-temporal variations in demand and supply. TIMES is quoted as having the capability to portray the entire energy system from resource supply, through fuel processing, representation of infrastructures, conversion to secondary energy carriers, end-use technologies and energy service demands at end-use sectors. The background of the model's development and a reference energy system are described. Also, electricity end-use sectors and generating systems are examined, including hydropower, nuclear power, thermal generation and renewables. Environmental factors and the calibration of the model are discussed, as is the application of the model. The document is completed with an outlook, references and six appendices

[en] The measurement flights of the exercise ARMO9 were performed between 22^nd and 26^th of June 2009 under the direction of G. Scharding of the National Emergency Operations Centre (NAZ) and coordination by the Expert Group for Aeroradiometrics (FAR). According to the alternating schedule of the annual ARM exercises, the environs of the nuclear power plants Muehleberg (KKM) and Goesgen (KKG) were surveyed. The measurements showed similar results to those obtained in former years. The participation of the Swiss team in the tri-national exercise in Germany was main focus of this year's program. Teams from Germany, France and Switzerland participated in the exercise, which was organised by the German Office for Radiation Protection and the German Federal Police. The exercise areas were located in the vicinity of Munich and in the Upper Palatinate. As during the tri-national exercise in 2007, the Swiss team could profit also this year from the experience of the German and French colleagues. In spite of inclement weather, important aspects of aero gammaspectrometric measurements were investigated, especially due to the proficient choice of exercise tasks by the German organizers. One exercise demonstrated practically the difficulties in tracking moving car-borne radioactive sources with the help of aero gammaspectrometric measurements. Measurements in different altitudes above Lake Chiemsee presented for the Swiss measurement system open questions concerning the background and radon correction, The Swiss search strategy for hidden radioactive sources, revised according to the results of the 2007 tri-national exercise, performed well. (author)

[en] In the framework of the project 'Windbank unteres Aaretal' local winds over complex terrain were measured over a 4 month period with a dense network of 43 meteorological stations. Based on these data, a cluster analysis is used to identify 13 different typical wind fields persisting up to a maximum of 19 hours over the region. The question was arisen: what is a minimum subset of representative stations to identify the classes of almost all hours correctly? With a subset of 21 stations a 'hitting rate' of 90% and with a subset of 6 stations a hitting rate of 75% of all hours was achieved. For every class, the mean wind vectors at all stations were interpolated to form a windfield over a regular grid. These windfields were used to calculate typical dispersion scenarios for a hypothetical source. (author) 17 figs., tabs., refs