RRFM 2009 Transactions - European Nuclear Society

4. Containment rig and sample-holder
The CALIPSO test device is composed of two main parts: the containment rig and the
sample-holder (Figure 3).
The containment rig is the outer shell of the test device that houses fluids. It is designed to
resist to the thermal-mechanical stresses and comply with the safety requirement. It fits to
the core mechanical structures and its outer shell is cooled by the reactor primary circuit.
The sample-holder is plugged into the containment rig through the circular opening situated
in the upper part. It holds the material samples to be irradiated and the specific experimental
instrumentation such as thermocouples, neutron dosimeters, pressure sensors, strain
gauges, displacement transducers. The sample–holder designed so far for CALIPSO
contains 15 tubular samples other the 60 cm of the active zone (5 levels of 3 samples placed
at 120°), with thermocouples and neutron dosimeters. Different sample holders will be
designed to reach specific experimental objectives such as dose accumulation, irradiation
growth, tensile and creep test.
Figure 3 : Overview of CALIPSO and its main components
5. Electro-magnetic pump for NaK circulation
The annular electromagnetic pump is located above the active zone. It has been designed in
order to fit in the available space of about 80 mm in diameter and for the following operating
conditions: NaK flow rate 2 m 3 /h, pressure drop 1.25 bar and NaK maximal temperature
450°C.
Induction coil and comb-shape ferromagnetic structures are mounted between the two tubes
of the containment rig. In order to close the field lines, an annular core is placed in the centre
of the pump. It is composed of ferromagnetic elements between two stainless steel tubes.
The pumping channel results from the annular gap between the inner tube of the induction
circuit and the outer tube of the magnetic core (Figure 4).
The three-phase inductor coil creates a magnetic field travelling along the annular duct gap,
inducing electric current in the conducting liquid metal. The interaction between the resultant
current and the magnetic field produces an electromagnetic body force pumping the NaK
flow through the channel.
In the case of CALIPSO, the circulation in the pumping channel is bottom-up, and after being
heated the return of the NaK is possible through the centre of the annular magnetic core.
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