United States. MIT's Nuclear Reactor Laboratory (Massachusetts Institute of Technology), Westinghouse Electric Company, and a group of professors have received funding to support research that could transform the performance of coating for fuel in light water reactors (LWRs).
Four known issues can affect the safe and reliable operation of LWR fuel coverage. Include:
- Wear of the grid and coupling bar by friction and foreign material; the accumulation of porous corrosion deposits
- Hydrogen absorption
- Boiling crisis
Wear can be covered through the fuel coating, while deposits and hydrogen absorption can lead to corrosion-based fuel failure, respectively. Finally, a "boiling crisis" is when the normally bubbling mode of boiling the coolant, called subcooled nucleated boiling, transitions to filtering the boil, isolating the fuel with a layer of steam and worsening heat transfer.
All four problems can and have caused fuel coating failures, which led to radioactive releases into the coolant and cost reactor operators more than $1 million per day of downtime to fix the problem.
The goal of the MIT project is to address all four problems while developing a viable solution, consisting of surface coatings and micro/nano geometric modifications to reduce or eliminate the four problems within three years.
The team will design a set of coatings and surface modifications for the Zircaloy-based fuel coating currently in use.
Source: MIT.
