One of the primary reasons the spent fuel problem is not mentioned in the article is because it became an issue fairly recently with the fire in the #4 building. Note that the date on the article is 3/12, whereas the fire and concerns in #4 are fairly recent, occurring on 3/15 and 3/16.
++Also, the spent fuel and the reactors themselves are separate problems, so I fail to see why an article about the reactors in under obligation to mention them.++
UPDATE: I concede that the article should be updated to include the #4 fire, as that is very pertinent (see below).