RRFM 2009 Transactions - European Nuclear Society

Fig 1. Design of the core and reflector
Fuel elements
2. The JHR fuel element
2.1 Design and characteristics
The three main parts of the element are (Fig 2):
- the lower and upper aluminium end pieces; they keep the element in position in its
location in the core,
- the fuel assembly.
Stiffeners
Fuel plates assembly
Boron Aluminium
plates
Fig 2. The fuel element
The fuel assembly consists of 8 concentric rings (Fig 3), each of them resulting from the
coupling of three bended U 3 Si 2 /Al fuel plates crimped inside 3 aluminium stiffeners. For
neutron consideration, small boron (10% mass) aluminium plates are set in the upper side of
the plates (Fig 2). The cooling water channels defined by 2 rings are 1.95mm wide, and the
velocity of the water through the channels is 15m/s. The fuel active length is 600mm. The
inner and outer diameters of the element are 41mm and 96mm respectively; the inner hole
has been designed to host an experimental device or a control rod.
Fig 3. Cross section of the plates
assembly
Coolant channels
The fuel meat is co-laminated with an aluminium cladding in order to obtain fuel plates (Fig
4.b); the fuel plate meat thickness is 0.61mm. The fuel plate cladding average thickness is
0.38mm; the cladding material is AlFeNi. The fuel meat is U 3 Si 2 particles with MEUfuel
uranium density of 4.8g/cm 3 . These particles are dispersed in an aluminium matrix (Fig 4.b).
Fig 4: .a Fuel plate, .b Fuel meat
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