But, at the end of the day, it is still not known what happens, chemically speaking, when seawater mixes with damaged nuclear fuel, notes Notre Dame professor Peter Burns and his co-authors in an article in this week's journal Science.
It's difficult to model nuclear reactor core-melt accidents, and adding massive amounts of seawater only muddies such predictions. There has been study of the short-term effects of the damaged fuel -- there's gaseous and other short-lived chemicals released -- but there's still a lot to explore.
Over time, damaged nuclear fuel interacting with water and air may pose significant environmental risk, since radioactive chemicals may be released that have very long half-lives (meaning they will be around a long time before they decay).
"Fukushima Daiichi itself would provide a very instructive experiment if and when it becomes possible to retrieve and study the fuel," Burns and colleagues write.