[chimera]

That is mostly a fission product spectrum. 58Co is produced by an n-p reaction in nickel, which is used in quite a few reactor internals, as well as being a component of zircalloy. 95Zr is a neutron capture product from 94Zr, again from the zircalloy. There is normally an inventory of these products in the reactor coolant from leaching of atoms from the fuel cladding.

None of this is surprising in the least. We know there is fuel damage. The hydrogen detonations were evidence of the zirconium-steam reactions. We know they lost backup cooling capability and probably exposed some or all of the length of the fuel elements. This is exactly the kind of release you would expect from a LWR that had some measure of fuel damage.

[RummyChick]

So in essence, the cladding has been compromised, hydrogen was generated and fission byproducts were released.

why were there neutron beams measuring 1.5 kilometers seen at least 13 times