It has been nine years now and federal regulators said a Columbia, SC, plant that makes nuclear reactor fuel has not followed through on safety recommendations.
The recommendations would have further reduced the chances the Westinghouse Electric Co. plant southeast of downtown Columbia could suffer a radiation leak in an earthquake.
Westinghouse officials said they are still working on some of the recommendations. They would not specify the suggestions, but said some involved removing potentially hazardous chemicals.
The U.S. Nuclear Regulatory Commission said walls could collapse and equipment topple in a severe earthquake.
The chances of that kind of quake are rare, and workers would probably be the only people exposed to radiation, but regulators are more cautious after last year’s disaster in Japan, where three nuclear plants melted down in Fukushima after an earthquake and tsunami hit the region.