[en] After the TMI accident 1979, and later the Tjernobyl accident, the future of nuclear power was vividly debated in Sweden. The negative public opinion governed a number of political decisions that marked an ambition to out-phase nuclear power prior to 2010. Due to this, the student's interest in nuclear technology ceased and together with the fact that public funding to nuclear technology was withdrawn, academic research and education within the field were effectively dismounted. In the beginning of 1990 it became clear to the society that nuclear power could not easily be closed down and the issue of the future competence supply to the nuclear industry was initiated. In the mid-nineties the situation became acute due to the fact that personnel in the nuclear industry started to retire in an increasing pace necessitating measures to be taken in order to secure the future operation of the nuclear power plants. In the year 2000, the Swedish nuclear power plants, Westinghouse Electric Sweden and the Swedish Radiation Safety Authority embarked a project together with the three major universities in the field, Uppsala University, The Royal Institute of Technology and Chalmers University of Technology. The aim of this project was to define a financial platform for reconstructing the Swedish research and education in nuclear technology. The project, named the Swedish Centre for Nuclear Technology (SKC), has during a decade been the major financier to nuclear technology research and education. Using funding from SKC, Uppsala University formulated a strategy along two tracks: 1) Instead of creating ambitious master programs in nuclear technology, the already existing engineering programs in a wide range of fields were utilized to expose as many students as possible to nuclear technology. 2) A program was initiated together with the nuclear industry aiming at educating newly employed personnel. The result is encouraging; starting from essentially zero, typically 100 undergraduate students follows at least one nuclear technology course each year and about 25 students conduct their Diploma work within nuclear technology annually. Meanwhile about 150 persons from the nuclear industry follow the 'industrial' courses and an increasing amount of undergraduate students chose to follow also these courses. The volume goal has now been reached and the next step is to launch a Bachelor program in nuclear technology during second part of 2010. (author)

[en] After the TMI accident 1979, and later the Tjernobyl accident, the future of nuclear power was vividly debated in Sweden. The negative public opinion governed a number of political decisions that marked an ambition to out-phase nuclear power prior to 2010. Due to this, the student's interest in nuclear technology ceased and together with the fact that public funding to nuclear technology was withdrawn, academic research and education within the field were effectively dismounted. In the beginning of 1990 it became clear to the society that nuclear power could not easily be closed down and the issue of the future competence supply to the nuclear industry was initiated. In the mid-nineties the situation became acute due to the fact that personnel in the nuclear industry started to retire in an increasing pace necessitating measures to be taken in order to secure the future operation of the nuclear power plants. In the year 2000, the Swedish nuclear power plants, Westinghouse Electric Sweden and the Swedish Radiation Safety Authority embarked a project together with the three major universities in the field, Uppsala University, The Royal Institute of Technology and Chalmers University of Technology. The aim of this project was to define a financial platform for reconstructing the Swedish research and education in nuclear technology. The project, named the Swedish Centre for Nuclear Technology (SKC), has during a decade been the major financier to nuclear technology research and education. Using funding from SKC, Uppsala University formulated a strategy along two tracks: 1) Instead of creating ambitious master programs in nuclear technology, the already existing engineering programs in a wide range of fields were utilized to expose as many students as possible to nuclear technology. 2) A program was initiated together with the nuclear industry aiming at educating newly employed personnel. The result is encouraging; starting from essentially zero, typically 100 undergraduate students follows at least one nuclear technology course each year and about 25 students conduct their Diploma work within nuclear technology annually. Meanwhile about 150 persons from the nuclear industry follow the 'industrial' courses and an increasing amount of undergraduate students chose to follow also these courses. The volume goal has now been reached and the next step is to launch a Bachelor program in nuclear technology during second part of 2010. (author)

[en] Channel bow in boiling water reactors (BWR) can be detected by simultaneous measurement of the thermal and fast neutron fluxes. There is a robust linear correlation between the ratio of the thermal and fast neutron fluxes and the void fraction close to the detector through the core. The moderation will be modified by channel bow and this change in moderation will affect the thermal neutron flux strongly and the fast flux weakly, i.e., the thermal flux will act as an indicator that the moderation or power has changed but the fast flux will reveal if the change is due to difference in moderation or power. The thermal and fast fluxes are furthermore affected in opposite directions, thus enhancing the deviation from linearity of the ratio between the fluxes, caused by channel bow. By comparing the void fraction calculated by a core simulator with the void fraction predicted by the ratio of the thermal and fast neutron fluxes, channel bow can be detected as a deviation from the linear void correlation of 4% per mm bow. This implies that it is reasonable to detect channel bow 2 mm or larger, assuming that the uncertainty of the detectors does not exceed 5%. (authors)

[en] A collaborative research project has been launched on neutron-induced light-ion production measurements using the new Uppsala neutron beam facility. The available energy range of quasi mono-energetic neutron beams is extended up to 175 MeV. Double-differential cross sections (DDXs) of light-ion production (p, d, t, ³He, and α) are measured using a conventional spectrometer system which consists of eight counter telescopes. Each telescope is composed of two silicon surface barrier detectors as the ΔE detectors and a CsI(Tl) scintillator as the E detector. Response of the scintillators to 160 MeV protons is measured to test the performance. The measured response is reproduced well by a PHITS transport calculation. The DDXs of light-ion production are measured for Ca at 94 MeV and C at 175 MeV at angles between 20 to 160 degrees in steps of 20 degrees. The preliminary experimental (n,xp) data are shown in comparison with a model calculation using the TALYS code and the evaluated cross sections in the JENDL high-energy file. (authors)

[en] In the framework of the HINDAS project, we have studied the feasibility of (n,Xn) measurements at intermediate energy (20-200 MeV). To achieve this goal, we have developed a new set-up and performed several experiments using the monoenergetic neutron beam facility at the Svedberg laboratory (Sweden). The performance of this set-up is illustrated by first results obtained in 100 MeV neutron-induced reactions on a lead target. (orig.)

[en] This paper presents the ongoing analysis of two fission experiments. Both projects are part of the collaboration between the nuclear reactions group at Uppsala and the JRC-IRMM. The first experiment deals with the prompt fission neutron multiplicity in the thermal neutron induced fission of ²³⁵U(n,f). The second, on the fission fragment properties in the thermal fission of ²³⁴U(n,f). The prompt fission neutron multiplicity has been measured at the JRC-IRMM using two liquid scintillators in coincidence with an ionization chamber. The first experimental campaign focused on ²³⁵U(n_th,f) whereas a second experimental campaign is foreseen later for the same reaction at 5.5 MeV. The goal is to investigate how the so-called sawtooth shape changes as a function of fragment mass and excitation energy. Some harsh experimental conditions were experienced due to the large radiation background. The solution to this will be discussed along with preliminary results. In addition, the analysis of thermal neutron induced fission of ²³⁴U(n,f) will be discussed. Currently analysis of data is ongoing, originally taken at the ILL reactor. The experiment is of particular interest since no measurement exist of the mass and energy distributions for this system at thermal energies. One main problem encountered during analysis was the huge background of ²³⁵U(n_th,f). Despite the negligible isotopic traces in the sample, the cross section difference is enormous. Solution to this parasitic background will be highlighted. (authors)

[en] A new facility producing intense mono-energetic neutron beams has been developed at The Svedberg Laboratory (TSL), Uppsala, Sweden. The facility utilizes the existing cyclotron and a flexible lithium target in a rebuilt beam line. The new facility can operate at unsurpassed mono-energetic neutron intensities and provides flexibility of the neutron beam properties, like energy and geometrical shape

[en] The process of particle emission in the pre-equilibrium stage has a very important contribution in this energy region and several approaches have been proposed to explain it. Their prediction power must be tested using comparison with the data for a variety of configurations. Calculations have been done using the exciton model and two main approaches proposed to improve its predictive power for complex particle emission. Data reported in this work allow the extension to higher energies of databases that are now limited to energies around 60 MeV. Together with other experimental results available in the literature they allow a more global view on the capabilities of each approach

[en] Spin isospin excitations are studied at Laboratoire National Saturne using charge exchange reactions. New data, completing the (³He,t) one, have been recently obtained. We present measurements done on the (d,2p) reaction with a special emphasis on the quasi free and Δ regions. Spin observables are also discussed. We also present the results of a systematic study of the characteristics of the Δ excitation by ¹²C, ¹⁴N, ¹⁶O and ²⁰Ne scattering. The cross section dependence with respect to projectile and ejectile is qualitatively understood. As observed in all other charge exchange reactions, the Δ peak on nuclei is shifted by ∼ 70 MeV with respect to the free Δ

[en] Double-differential cross sections for neutron-induced light-ion production at 96 MeV have been measured for a variety of nuclei at The Svedberg Laboratory. Using the measured cross-section data, we deduce the Kerma coefficient from carbon and oxygen for p, d, t, ³He and α particles. In order to get the total Kerma for C and O, we add GNASH calculation values where experimental data are not available and obtain a Kerma coefficient of 7.85 ± 0.63 fGy m² for carbon and 7.09 ± 0.57 fGy m² for oxygen. The C/O Kerma coefficient ratio then becomes 1.11 ± 0.11. In addition we determine the Kerma ratio between ICRU muscle and A-150, again adding calculations with the GNASH code where no experimental data are available, and obtain a value of 0.98 ± 0.05. While the Kerma coefficients for carbon and oxygen do not agree with the prediction in ICRU Report 63, the ratio values are in good agreement with existing predictions.