- CROCUS
CROCUS is a
research reactor atÉcole Polytechnique Fédérale de Lausanne inSwitzerland , sometimes described as "zero power" but in fact limited to 100 W.This low power means that within a few hours of shutdown, it is safe for personnel to enter the biological shield, as the residual
radioactivity of the core has decayed to safe levels. The biological shield consists of aconcrete wall, with a 14-ton door for personnel access. There is also a removable 50-ton concrete trapdoor in the top of the shield, to allow for fuel and equipment changes.CROCUS uses low-enriched uranium (LEU) metal fuel, immersed in a tank of demineralised
light water which acts as moderator and reflector. There is no special provision for cooling required.CROCUS is controlled by two control rods and by adjusting the water level in the moderator tank. A neutron source is placed under the core to aid startup. In addition, there are two safety control rods and four surge tanks, making six independent safety systems. Any one of these six is capable of producing a complete emergency shutdown (
scram ) in less than one second, and is triggered automatically should power exceed the authorised level.CROCUS is used for teaching reactor physics.
External links
*fr [http://lrs.epfl.ch/page10669.html CROCUS] page at the
École Polytechnique Fédérale de Lausanne website.
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