[Between the Lines]

If this is true, does anyone know if there’s a solution other than managing the sites’ isolation for all the years?

One way is to ship it elsewhere. Radioactive reactor to be shipped to S.C.

[chimera]

This is just routine disposal of activated materials. The Trojan reactor vessel went to Hanford, as I recall.

Mild steel will have the usual suite of activation products, short-lived forms like 59Fe, and longer-lived trace elements like 60Co. But even at 5.25 years half-life, it's literally the blink of an eye in terms of geologic disposal (even shallow, low-level waste disposal).