Officials in South Carolina and Washington state are considering digging up casks of radioactive waste as part of the search for two missing fuel rods from a Connecticut nuclear plant.

Officials with the Nuclear Regulatory Commission said this week they believe the rods from the Millstone One plant in Waterford were sent by mistake to low-level waste sites either in Barnwell, S.C., or Washington, or both. Highly radioactive spent fuel is not supposed to be buried at those low-level sites.

It is now up to the states involved to decide whether to dig up the casks.

Fuel rods have never before been reported missing in the history of commercial nuclear power in the United States, according to the NRC.

The NRC said earlier this week that the 13 1/2-foot-long rods were probably mistaken for other radioactive material and shipped off for long-term storage.

–Associated Press