BARNWELL, S.C. — Tubes, capsules and pellets of used radioactive material are piling up in the basements and locked closets of hospitals and research installations around the country, stoking fears they could get lost or, worse, stolen by terrorists and turned into dirty bombs.

.... For decades, the government urged states to build low-level nuclear waste landfills, either on their own or in cooperation with nearby states. But those efforts have run into strong not-in-my-backyard resistance of the sort that led South Carolina lawmakers to close the Barnwell County landfill to all but three states. Only one low-level landfill, in Utah, has opened in the past 30 years. One more could open in Texas by the end of next year, but it would accept trash from only Vermont and the Lone Star State.

The government never set up penalties for states that failed to build landfills.

'Congress should have gotten involved a long time ago,' said Richard Gallego, vice president of Thomas Gray and Associates Inc., a California company that prepares low-level waste for disposal.

Rich Janati, chief of nuclear safety for Pennsylvania's Department of Environmental Protection, said: 'It's a national issue, and we should look at it as a national problem and come up with a solution.'

The government this week did move to shore up security by requiring hospitals and labs to better secure machines used to irradiate blood. Also, dirty-bomb fears have prompted the National Research Council to urge replacing the roughly 1,300 such machines in the U.S. with less hazardous but more expensive equipment.