[en] After a general overview of the technological irradiation reactors existing in Europe, the paper details the safety approach adopted for a new research reactor to be constructed in France and the main recommendations resulting from IRSN assessment. (author)

[en] Four numerical programs are presented for experimental data processing of focusing configuration of a high-resolution crystal neutron diffractometer. The corresponding most relevant features of these programs (DAX, Rietveld, Monte Carlo, LSQ1) are given. (author)

[en] Due to the proximity of the Atominstitut der Osterreichischen Universitaeten to the IAEA, many research projects have been carried out and completed successfully during the past years, especially in the field of nuclear safeguards and security, some of them have just started recently. In the paper, a survey on selected cooperation projects is given to show how a small university institute can contribute significantly to international safeguards and security research. Small university laboratories have the advantage of low cost but highly qualified personnel who can concentrate on investigation and test series which would largely exceed the possibilities of international organizations and are, therefore, a typical example of successful outsourcing for the benefit of both partners. (author)

[en] The paper describes the general neutronic characteristics of the first core of the replacement research reactor (RRR) for the Australian Nuclear Science and Technology Organisation (ANSTO). A compact core with 16 FA has been designed to fulfil all the very demanding neutronic requirements of the RRR facility. The contractual performance parameters must be verified for the equilibrium core; a very important design effort was carried out in the initial fresh core to have a similar performance. The description covers different aspects of the neutronic design: a detailed nuclear design of U₃Si₂ first core, the design calculation tools, together with a comparison of the first core performance against the core design criteria and the equilibrium core performance. (author)

[en] After a general overview of the safety requirements applied to research reactors in France, the paper details the specific safety requirements adopted for the various barriers of the pool-type research reactors and related systems. Emphasis has been put particularly on the conditions in which a BORAX-type explosive reactivity accident has been considered for the design of these reactors. The safety of experimental devices as well as the process of periodic safety reassessments are also addressed. (author)

[en] The paper presents a general description of the development and application of basic safety criteria and the implementation of specific safety features in the design of the 20 MW pool-type research reactor currently being built by INVAP for the Australian Nuclear Science and Technology Organisation (ANSTO). A summary of the results of the preliminary deterministic safety analysis and the probabilistic safety assessment prepared by INVAP on ANSTO's behalf are presented as part of demonstrating the robustness of the design to the wide range of postulated initiating events considered. The paper also briefly describes the licensing process with respect to the way in which the licensing and regulatory regime within Australia influenced the design of the replacement research reactor (RRR). In particular, the reasoning for safety design features that have been incorporated as a result of the specific requirements of ANSTO and the Australian regulator is described. (author)

[en] The presence of a sample in the neutron field of a nuclear reactor createsa perturbation of the local neutron fluxes. In general, the interpretation of the sample activation due to thermal and epithermal neutrons requires the knowledge of two parameters: the thermal neutron self-shielding factor, G_th, and the resonance neutron self-shielding factor, Gres. In recent papers, the authors established a universal curve of G_res for isolated resonances and various geometries. The paper deals with the description of G_th in foils by means of a universal curve on the basis of a dimensionless variable which includes the physical, nuclear and geometrical properties of the sample. The universal curve is in very good agreement with experimental and calculated values obtained from the literature. The study of other geometries (spheres, wires and cylinders) is in progress. (author)

[en] The paper presents the experience gained by a regulatory body in a country operating only one nuclear research reactor. The majority of research reactors in the world have been designed and constructed by experienced companies and their operation is supervised by a local regulatory authority. Although the responsibility of such an authority should cover several topics, its main objective is, nevertheless, safe reactor operation. The regulations, instructions and experience of reactor operation gained in Poland over many years is described in detail, together with some general observations which may be of interest to other countries. (author)

[en] The Pakistan Research Reactor-1 (PARR-1) was operated at a power level of 5 MW for about 25 years using high enriched uranium (HEU). It was planned to convert the reactor core from HEU to low enriched uranium (LEU) fuel, installation of stainless steel lining on interior of the reactor pool and power upgradation from 5 MW to 10 MW. For this purpose, the reactor was partially decommissioned in 1990. After completing all the requirements, the reactor was re-commissioned with LEU fuel in October 1991. (author)

[en] Since the commencement of the High-flux Advanced Neutron Application Reactor (HANARO) operation in 1995, a significant number of experimental facilities have been developed and installed. Owing to the stable operation of reactor and rapid proliferation in utilization, more experimental facilities are continuously added up to satisfy the research needs arising. As a nationwide neutron research facility, HANARO is now successfully utilized in various fields such as neutron beam research, fuel and material tests, radioisotope production, and neutron activation analysis. The paper provides an overview of the present status and future plans of HANARO utilization. (author)