WATERFORD, Conn. (AP) — Nuclear power plants across the United States are building or expanding storage facilities to hold their spent fuel — radioactive waste that by now was supposed to be on its way to a national dump.

The steel and concrete containers used to store the waste on-site were envisioned as only a short-term solution when introduced in the 1980s. Now they are the subject of reviews by industry and government to determine how they might hold up — if needed — for decades or longer.