Harper International has been awarded a contract to supply an advanced thermal processing system for the sintering of nuclear fuel pellets. Sintering is the crucial final step in the refinement of nuclear fuels before they can be used in nuclear power plants.
Typically, nuclear fuel is initially produced in a powder form, but needs to be converted into pellets before being assembled into rods or special bundles of rods. The powder is mixed with a binder and the pressed into a pellet shape. The sintering stage fires the pellets at high temperature, often in special atmospheres to induce reduction or other chemical reactions to and remove the binder. Sintered pellets are a hard, dense solid with few pores.
Nuclear fuel sintering systems must meet several critical requirements such as hydrogen gas atmosphere with controlled dew point in the 1700–1800°C temperature range, as well as temperature uniformity, and safety control systems. The company says it has advanced furnace of this type in operation on four continents.
Harper International hasn’t put all of its eggs in the nuclear basket. It has a diversified energy strategy that has it working on silicon production, solar cells, wind energy and thermal processing of advanced materials for energy storage systems. Many of these advanced materials have been commercialized with process development and process optimization assistance labs at the Harper Technology Center in Buffalo, N.Y.
Here is a generic video illustrating a sintered pellet.