[Jedidah]

Does the cesium release indicate that, although the containment structure is still intact, it may have been damaged by the quake and is leaking?

[dynachrome]

If I understand it correctly, it may mean that the fuel rods are damaged, which is not good.

[chimera]

137Cs is a fission product so it indicates somehow there are fission products in the release. It could be a partially damaged core. But it could also be a result of the earlier pressure releases where coolant had to be spurted out to relieve pressure when they lost their auxiliary cooling capability. There was a partial failure of containment isolation when emergency power was unavailable, and that allowed some containment effluent to be released to the outside. There is always a small inventory of fission products in the coolant of a LWR and we may be seeing those, not necessarily damaged fuel (although it could be that too).