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Experimental rigs for MTR's (BR2, JHR, MYRRHA)

Project engineering and design

Developing new irradiation devices is a multidisciplinary field of activities, integrating a broad range of design and engineering tasks, such as:

Project management, including budget and time planning
Technical and financial bids to customers
Study and design activities, covering:
- mechanical design (structural analysis, thermal analysis, physical, chemical and radiation behaviour of materials, construction codes, …),
- specifications for reactor physics calculations,
- thermohydraulic design,
- process control, automation, instrumentation, supplies (electric, hydraulic, pneumatic), safety systems;
Safety and risk analysis
Study of dismantling and waste disposal
Follow-up of drawing work, fabrication, assembly, testing and qualification, which implies detailed specifications and instructions to the other expert groups involved
In frequent cases also the operation of the irradiation devices in BR2 and the data analysis and reporting

When facing complicated geometries and operational conditions, advanced engineering tools are used, such as MSC.MARC, RELAP, Fine/HEXA, ORIGEN. Because of the specificity of the devices, in-house calculation codes are also frequently used and developed if necessary.

Design, construction and testing are performed following the rules of national and international standards and codes (ARAB, ASME, DIN, AFNOR, etc) and the facilities are commissioned by the official safety authorities and authorised inspectors.

Operational and reusable devices

CALLISTO (Material and fuel irradiation in PWR conditions)

The CALLISTO loop is a facility operating in a representative PWR environment (pressure, water flow, temperature and water chemistry). Connected to a common pressurised circuit, three in-pile double-walled pressure vessels are installed in 3 BR2 channels allowing to perform simultaneously different dedicated irradiation studies. During the recent years, following programmes have been run: testing of instrumented advanced fuel rods (OMICO), testing of ADS steel in a PbBi environment (TWIN-ASTIR), irradiation of various vessel steel and fusion materials (MICADO, IRFUMA), qualification of in-pile instrumentation (IRINA, FICTIONS).

MISTRAL (Material irradiation between 200 and 350 °C)

The MISTRAL irradiation device is a double wall capsule with a He gas between the walls and an electrical heater to control the temperature; it is loaded in the central hole of a V fuel-plates BR2 element. Designed for high fast flux irradiation of material specimens at temperatures between 200 and 300 °C, it has been used to irradiate material for ADS and for fusion.

PWC/CCD (LWR fuel transients)

The PWC/CCD device is dedicated to perform power ramping of BWR and PWR fuel rods. It consists of a pressurised de-mineralised water capsule (PWC) surrounded by a calorimeter (CCD) that accurately measures the generated heat. Power ramping (100 W/cm/min from 250 W/cm up to 450 W/cm) is presently done by increasing the BR2 power.

INSIDE (In-Situ tensile testing)

Specific irradiation devices have been developed for in-pile mechanical testing in a thimble tube of the BR2 reactor. They were devoted to in-pile tensile testing and in-pile fatigue testing of fusion reactor materials (copper alloys and other material specimens) with continuous measurement of load and deformation. This has never been done before.

ROBIN (Low dose material irradiation)

The aim of the ROBIN facility is to irradiate needles loaded with material specimens (typically tensile or mini-charpy) in a GDG (large thimble) loaded in the BR2. Because the GDG is open to the reactor pool, ROBIN can be loaded and unloaded during reactor operation which allows to achieve the requested fluence. To compensate for the fast flux radial gradient through the selected irradiation position, this basket is designed to rotate during irradiation. The irradiation temperature, typically 200 °C, can be measured inside dummy specimens. ROBIN was firstly used for fusion reactor materials.

RIED

RIED is a general-purpose irradiation test facility to study under vacuum or inert gas the electrical degradation in ceramic materials in the BR2. A turbo-molecular pump can control vacuum conditions up to 10 ^-2 mbar; the rig gas environment can also be set with helium up to 15 bar. The temperature is actively controlled by means of heating elements and the voltage applied on the samples can vary from 1V to 300V. RIED was developed initially to test diagnostic ceramic materials for the fusion programme.

SMIRNOF

SMIRNOF is a facility for radiation assessment of optical fibres in a fission reactor environment.

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Innovative devices under design and construction

POSEIDON (Pool side facility for silicon doping)

The innovative POSEIDON facility is designed for NTD of large volumes of silicon (capacity of 30 tons/year). Because the market demands 6 and 8 inch Si ingots, it is not possible to irradiate these inside the BR2 reactor core. Therefore, POSEIDON is a 'pool side facility', consisting mainly of a large aluminum box, containing graphite and being positioned very close to the reactor vessel wall. Six cylindrical holes inside the box allow the loading of six target positions, both for 6 or 8 inch ingots. The graphite filling will further thermalise the neutrons in the device and, therefore, produce an NTD doped Si of high quality.

EVITA (S

EVITA piping in the BR2 pool

emi-open loop for LEU MTR fuel testing)

EVITA is an innovative water loop, designed for testing full size fuel elements of the reactor JHR. Although of similar geometry as the BR2 fuel elements (i.e. with concentric fuel plates), the JHR elements are larger in diameter (8 plates instead of 6 for BR2) and therefore require to be irradiated in a large 200 mm channel of BR2. In fact, the central 200 mm channel is reserved for this project because of the targeted high fission power in the JHR fuel. Inside the loop the fuel element is directly cooled by BR2 primary reactor water.

SPEED-ASTIR (Material irradiation in heavy liquid metals)

SPEED-ASTIR is a more or less classical capsule, designed to test ADS material samples inside a stagnant bad of liquid PbBi. It will be loaded inside a BR2 fuel element (for maximum fast neutron dose) and will be automatically temperature regulated (target 450 °C). However, its innovation is linked to the irradiation of PbBi in an MTR and to the safety and technological issues of Po management. The post-irradiation activities (rig dismantling and PIE) are also in connection with these issues.

PRF5+6 (Xe-Mo Isotopes production)

The existing series of four PRF devices in BR2 is permanently used for the production of radioisotopes Xe-Mo by the irradiation of highly enriched fissile targets. These very flexible devices are loaded and unloaded from the reactor during operation in order to achieve the programmed production schemes with the target activities of the isotopes. Because of increased demands, two additional PRF rigs (numbers 5 and 6) are urgently needed, requesting construction in 2007-2008. Also, a new control panel is needed to simultaneously serve the six PRF rigs.

IrrDemo (Gas Fast Reactor Fuel Testing)

IrrDemo is an experimental irradiation of GFR (Gas cooled fast reactor) fuel prototypes elements, which intends to validate the conception and to point towards optimisation and improvement of the GFR fuel.