DISPOSING low-level radioactive waste from hospitals, pharmaceutical manufacturers and electric utilities will become more difficult and expensive in the US, with the collapse of a waste-disposal system functioning under a 12-year-old law. Now, the three states that have been operating radioactive waste dumps can refuse to accept waste generated outside their borders. While Nevada is expected to close its dump, Washington will accept waste from only six north-western states and Hawaii, leaving only South Carolina to cater to the rest of the country. Exploiting this monopoly, South Carolina has announced it will impose an "access" fee of $220 a cubic foot on waste from states outside the southwest region.