March 7, 2013 Tepco document regarding testing of the fuel assemblies removed from the Unit 4 fuel pool with summary translation by Fukushima Diary:
They measured 1,400,000,000 Bq/Kg of Co-60 [...]
It was taken when they washed the new fuel assembly [...]
Tepco states it felt like grit. Some parts were broken into sand, which couldn’t be collected. [...]
See also: Gundersen on Gamma Rays: "Implies rubble was activated by neutrons, or that activation products like Cobalt-60 are in rubble -- Interesting"
Published: March 26th, 2013 at 9:30 pm ET