"Nuclear fuel rods at one of the reactors may have become became fully exposed raising the risk they could melt down and cause a radioactive leak, Japanese news agency Jiji said."
The properties of the fuel rods didn't change due to the tsunami+earthquake. If the article it wrong, it's wrong. But it's not wrong because things are 'different this time.'
"Nuclear fuel rods at one of the reactors may have become became fully exposed raising the risk they could melt down and cause a radioactive leak, Japanese news agency Jiji said."