They are completely ignoring the most serious part of the problem.
Quite true. More than two years later and still no one knows exactly where the melted cores are, but many experts speculate that at least one of them have melted completely through all containment and is in contact with the ground.
That scenario would be one explanation of observations about increases in groundwater contamination over time under the facility, although other hidden water leaks from within the reactor and turbine buildings, as well as the external storage tanks, could also be contributing to that, and there is little that TEPCO has been able to do to contain the groundwater.
There are multiple leaks and groundwater contamination problems at the site. Not just this one specific leak.