VENUS - zero-power critical facility
What was VENUS used for?
The VENUS reactor is an experimental low-powered reactor of the “zero-power critical facility” type. It was critical for the first time in 1964 with a water-moderated core.
VENUS was converted in 1968 to carry out neutron studies of new reactor configurations. Large power reactor cores were reproduced on a small scale (about 50 x 50 x 50 cm).
The VENUS reactor was modernised in 1991 and in 2000-2001, the internal parts of the reactor vessel were modified in order to enable to load fuel of 1 m instead of 50 cm for new application areas.
Calculations for a more efficient fuel use
VENUS has been used for the validation of reactor codes. These codes are applied to make more efficient use of the core loading during the exploitation of nuclear installations. They have proven their usefulness for the determination of the optimal nuclear fuel configuration with regard to parameters like power distribution, neutron economy and neutron irradiation of the reactor vessel. If, however, one wants to deviate from the standard configuration and enter new domains, the codes must be revalidated. The critical VENUS facility was particularly fit for this purpose: the flexibility of the installation enables the development of realistic simulations.
In June 2003, SCK•CEN carried out a unique experiment in VENUS. For the first time a fuel assembly, irradiated in a power reactor like Doel or Tihange, was loaded. Because of burning in the nuclear reactor, irradiated fuel contains less uranium than non-irradiated fuel. The difference is called the “burn-up credit”. The risk of attaining a critical mass and causing a spontaneous nuclear reaction diminishes and the irradiated fuel can be placed closer together than non-irradiated fuel. This affects the storage in nuclear power plants. Moreover, less irradiated fuel transports are needed and these rods can be stored more compactly in case of geological disposal. The codes have been validated in VENUS for the calculation of the “burn-up credit”.
The GUINEVERE project at the VENUS installation
During 2008 and 2009, the VENUS facility was modified in the framework of the GUINEVERE project in order to allow the experimental programme to start in 2010. These experiments aim to provide an answer to the questions of on-line reactivity monitoring, subcriticality determination and operational procedures in ADS.
GUINEVERE: Generator of Uninterrupted Intense NEutrons at the lead VEnus REactor
More information about the project can be found in the section 'Our Research - Research projects - GUINEVERE'.