The European Fusion Development Agreement (EFDA) recently launched a programme on Power Plant Physics and Technology (PPPT) with the aim to develop a conceptual design of a fusion demonstration reactor (DEMO) addressing key technology and physics issues. A dedicated part of the PPPT programme is devoted to the neutronics which, among others, has to define and verify requirements and boundary conditions for the DEMO systems. The quality of the provided data depends on the capabilities and the reliability of the computational tools. Accordingly, the PPPT activities in the area of neutronics include both DEMO nuclear analyses and development efforts on neutronic tools including their verification and validation. This paper reports on first neutronics studies performed for DEMO, and on the evaluation and further development of neutronic tools.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 28446247The activity was a joint work of the associations ENEA, KIT, CCFE and MESCS-SFA. The shutdown dose rate in the JET torus was determined experimentally, in parallel calculations have been done. The activity was a follow-up of past activities, performed over several years. Basically two different methodological approaches have been developed in the frame of the Fusion Technology Program for the three-dimensional calculation of the shutdown dose rate: the so-called Rigorous two-step method (R2S) developed by KIT and the Direct one-step method (D1S) developed by the ITER team and ENEA. Both methods, even if with different approaches, use the MCNP Monte Carlo Code for transport calculation and the FISPACT inventory code. The aim of the present task is the measurement and corresponding calculation of the shutdown dose rate at short cooling times, more accurate with respect to the previous ones. Additional information on the main contributors to the doses is also obtained through gamma spectrometry.
F.01 Acquisition of new practical knowledge, information and skills
COBISS.SI-ID: 28556583Head to the JSI team for the start-up zero power physics tests in the Nuclear Power Plant Krško; cycle 28 After each outage in the Krško NPP it is necessary, in accordance with the requirements of the SNSA, to perform the testing of the reactor on zero power before the increase of its power. In doing so, the responses to the insertion of the reactor control assemblies, temperature changes and the concentration of boric acid in the coolant are compared with the previously calculated values. Since 2004, with one exception for postdoctoral training abroad, I have led a group of experts from the Jožef Stefan Institute, to perform the said tests. Each time the tests were performed successfully and thus the permission for the operation for the next cycle could be obtained.
F.12 Improvements to an existing service
COBISS.SI-ID: 29359911As the DT fusion reaction produces neutrons with energies significantly higher than in fission reactors special fusion relevant benchmark experiments are often performed using DT neutron generators. However, commonly used Monte Carlo particle transport codes such as MCNP or TRIPOLI cannot be directly used to analyze these experiments since they do not feature capabilities to model production of DT neutrons. Three available approaches to model the DT neutron generator source are the MCUNED code, the ENEA-JSI DT source subroutine and the DDT code. The MCUNED code is an extension of the well-established and validated MCNPX Monte Carlo code. The ENEA-JSI source subroutine was originally prepared for the modelling of the FNG benchmark experiments using different versions of the MCNP code (-4, -5, -X) and was later extended to allow the modelling of both DT and DD neutron sources. The DDT code is a code that prepares the DT source definition file (SDEF card in MCNP) which can then be used in different versions of the MCNP code. In the paper the methods for the simulation of the DT neutron production, with implication on the use for JET calibration is described. The codes are briefly described and compared for the case of a simple accelerator based DT neutron source.
F.04 Increase of the technological level
COBISS.SI-ID: 29366055Seminar at ORNL, Reactor and Nuclear Systems Division / Radiation Transport Group An overview of the work performed at the Reactor Physics Division of the Jožef Stefan Institute, Slovenia, was presented. The research is focused around the TRIGA reactor and the fusion reactors JET and ITER. The research in reactor physics is oriented mostly into new methods for power and research reactor calculations, where special attention is given to the calibration and benchmarking of nuclear data and computational methods. A power reactor core design package has been developed by Department's researchers and is being used to calculate fuel cycles for Krsko Nuclear Power Plant since its initial startup. We are intensively involved in transport calculations for JET – the Joint European Torus with neutron calibration support and transport calculations and for the future reactor ITER.
B.04 Guest lecture
COBISS.SI-ID: 29092391