Reactor Severe Accident Test Facility

Internationally recognized facility for conducting nuclear reactor severe accident materials experiments

Argonne’s Large Scale Severe Accident Test Facility, Cell 4 and Cell 5

Our reactor containment houses an experiment platform for studying large-scale spreading of prototypical reactor materials containing uranium and zirconium.  A thermite reaction generates ​“corium” (molten nuclear reactor core material) at temperatures up to ~2400°C, hot enough to melt through steel (Tmp ~1400°C).  Roughly 300 kg of corium comprised chiefly of UO2 and ZrO2 is poured into a water pool where spreading occurs. Instrumentation determines the rate and extent of spreading, which is completed in seconds. 

Corium spreading facility
Corium at >2300°C entering water pool as seen through end viewport. Melt is surrounded by steam and hydrogen and so not directly visible.

The containment once housed a zero-power research reactor.  Its rugged construction makes it possible to safely conduct these spreading tests, the largest of their kind, involving large thermal and chemical energies along with radiological hazards. 

Containment housing the severe accident test facility

  • 1 m-thick reinforced concrete walls & ceiling.
  • 45 kg TNT explosion rating.
  • 3.7 atm design over-pressure rating
  • 9.2 m x 12.2 m x 9.2 m high with 4500 kg crane.

Special containment features also allow us to test uranium thermites having zirconium metal that reacts with water to generate hydrogen.  Up to 10 kg batches of thermite are tested for reaction temperature and pouring characteristics.

10 kg of UO2/ZrO2/Zr mixture at >2300°C poured into water.

Selected Publications