[en] The High Flux Reactor (HFR) in Petten, The Netherlands, is a light water cooled and moderated multipurpose research reactor of the closed-tank in pool type. It is operated with highly enriched Uranium fuel at a power of 45 MW. Since its first criticality in 1961 the reactor has been continuously upgraded by implementing developments in fuel element technology and increasing the power from 20 MW to the present 45 MW. In 1984 the reactor vessel was replaced by a new one with an improved accessibility for experiments. In the following years also other aging equipment has been replaced (primary heat exchangers, pool heat exchange, beryllium reflector elements, nuclear and process instrumentation, uninterruptable power supply). Control room upgrading is under preparation. A new safety analysis is near to completion and will form the basis for a renewed license. The reactor is used for nuclear energy related research. The beam tubes are used for nuclear physics as well as solid state and materials sciences. Radioisotope production at large scale, processing of gemstones and silicon with neutrons, neutron radiography and activation analysis are actively pursued. A clinical facility for boron neutron capture therapy is being designed at one of the large cross section beam tubes. It is foreseen to operate the reactor at least for a further decade

[en] A brief overview is given of the current status of the High Flux Beam Reactor, including the ongoing safety review, and of plans for the upgrade of the instruments on the experimental level

[en] The paper gives a brief information on the physical improvements and the technical data of the Berlin Research Reactor BER II, which was upgraded from 1985 until 1990. The licensing procedure is described and the regulations applied. (author)

[en] The FRG-research reactors The GKSS-research centre is operating two research reactors of the pool type fueled with MTR-type type fuel elements. The research reactors FRG-1 and FRG-2 having power levels of 5 MW and 15 MW are in operation for 31 year and 27 years respectively. They are comparably old like other research reactors. The reactors are operating at present at approximately 180 days (FRG-1) and between 210 and 250 days (FRG-2) per year. Both reactors are located in the same reactor hall in a connecting pool system. Backfitting measures are needed for our and other research reactors to ensure a high level of safety and availability. The main backfitting activities during last ten years were concerned with: comparison of the existing design with today demands (criteria, guidelines, standards etc.); and probability approach for events from outside like aeroplane crashes and earthquakes; the main accidents were rediscussed like startup from low and full power, loss of coolant flow, loss of heat sink, loss of coolant and fuel plate melting; a new reactor protection system had to be installed, following today's demands; a new crane has been installed in the reactor hall. A cold neutron source has been installed to increase the flux of cold neutrons by a factor of 14. The FRG-l is being converted from 93% enriched U with Alx fuel to 20% enriched U with U₃Si₂ fuel. Both cooling towers were repaired. Replacement of instrumentation is planned

[en] This paper provides a brief overview of the 1988 National Research Council study of the role and value of university research reactors in the US. (author)

[en] Modifications have been made to the High Flux Isotope Reactor (HFIR) which permit the operation of instrumented irradiation capsules in the target region, and more and larger capsules in the removable beryllium region. As many as two instrumented target capsules can now be accommodated and positions for up to eight 46-mm-diam instrumented capsules are now available in the removable beryllium region. One instrumented target capsule has already been irradiated and new capsules have been prepared for irradiation in the removable beryllium region

[en] The construction of the upgraded Japan Research Reactor No.3 (JRR-3) has almost completed. The old reactor was removed from the reactor room, and the new reactor is reconstructed at the place where the old core was. The upgraded reactor is a pool type, 20MW(th), light water moderated and cooled, beryllium ad heavy water reflected. Fuels are 20% low enriched UAl_x-Al(LEU) plate type as part of the international Reduced Enrichment for Research and Test Reactors (RERTR) program. Maximum thermal and fast flux are expected to be more than 2 x 10¹⁴ n/cm² s. The upgraded JRR-3 has several beam experimental holes and irradiation facilities for multipurpose utilization, including a cold neutron source facility. (author)

[en] Modifications have been made to the High Flux Isotope Reactor (HFIR) which permit the operation of instrumented irradiation capsules in the target region, and more and larger capsules in the removable beryllium region. As many as two instrumented target capsules can now be accommodated and positions for up to eight 46-mm-diam instrumented capsules are now available in the removable beryllium region. One instrumented target capsule has already been irradiated and new capsules have been prepared for irradiation in the removable beryllium region. (author)

[en] The High Flux Reactor (HFR) in Petten, The Netherlands, is a light water cooled and moderated multipurpose research reactor of the closed-tank in pool type. It is operated with highly enriched Uranium fuel at a power of 45 MW. The reactor is owned by the European Communities and operated under contract by the Dutch ECN. The HFR programme is funded by The Netherlands and Germany, a smaller share comes from the specific programmes of the Joint Research Centre (JRC) and from third party contract work. Since its first criticality in 1961 the reactor has been continuously upgraded by implementing developments in fuel element technology and increasing the power from 20 MW to the present 45 MV. In 1984 the reactor vessel was replaced by a new one with an improved accessibility for experiments. In the following years also other ageing equipment has been replaced (primary heat exchangers, pool heat exchanger, beryllium reflector elements, nuclear and process instrumentation, uninterruptable power supply). Control room upgrading is under preparation. A new safety analysis is near to completion and will form the basis for a renewed license. The reactor is used for nuclear energy related research (structural materials and fuel irradiations for LWR's, HTR's and FBR's, fusion materials irradiations). The beam tubes are used for nuclear physics as well as solid state and materials sciences. Radioisotope production at large scale, processing of gemstones and silicon with neutrons, neutron radiography and activation analysis are actively pursued. A clinical facility for boron neutron capture therapy is being designed at one of the large cross section beam tubes. It is foreseen to operate the reactor at least for a further decade. The exploitation pattern may undergo some changes depending on the requirements of the supporting countries and the JRC programmes. (author)

[en] On the first day of this meeting a variety of reports has been given on projects covering the range from major upgrades of existing research reactors or experimental installations up to totally new research reactor facilities. From these project descriptions it was clear that a strong need of all these groups for R and D research and development) work had to be anticipated. So the purpose of the present workshop was - on the one hand - to identify those fields in which the results of R and D work would be required by IGORR member groups. On the other hand - there is an appreciable amount of R and D work either being planned for the near future or being performed right now (or having just been completed) by IGORR member groups. So the purpose of this workshop was to identity those fields in which R and D work actually is or will be (or has been) performed by IGORR members. Topics of interest were: Thermal-hydraulic tests and correlations, Corrosion tests and analytical models , Multidimensional kinetic analysis for small cores, Fuel plates fabrication, Fuel plates stability, Fuel irradiation, Burnable poison irradiation, Structural materials irradiation, Neutron guides irradiation, Cold Source materials irradiation, Cold Source LN₂ test, Source LH2-H₂O reaction (H or D), Instrumentation upgrading and digital control system, Man-machine interface