MIT’s Greg DeWitt, Thomas McKrell, Jacopo Buongiorno, Lin-wen Hu and Rae Joon Park won the Best Paper Award at the 9th International Topical Meeting on Nuclear Thermal-Hydraulics, Operation and Safety (NUTHOS-9) for their paper entitled "Experimental Study of Critical Heat Flux with Alumina-water Nanofluids in Downward-Facing Channels for In-Vessel Retention Applications”. The paper presented on September 12, 2012 in Kaohsiung, Taiwan, was based on Greg DeWitt’s dissertation entitled “Investigation of Downward Facing Critical Heat Flux with Water-Based Nanofluids for In-Vessel Retention Applications”.
The researchers found that adding just 0.001% by volume of alumina nanoparticles to water enhanced the Critical Heat Flux (CHF) — the upper limit of boiling heat transfer — by110%. This finding suggests that nanofluids could be used to enhance in-vessel retention of radioactivity during a hypothetical severe accident in which the nuclear fuel melts and relocates to the bottom of the vessel. Under normal operating conditions, the nanofluid would be stored in dedicated storage tanks, which, upon actuation, would discharge into the reactor cavity through injection lines. This could potentially provide benefits for safety (by creating larger safety margins) and for economics (through power uprates) at plants that are currently constrained in these dimensions by their expected behavior in severe accidents.
Figure shows CHF [q"chf] as a function of Mass Flux [G] for SS316L heaters at atmospheric pressure.