WASHINGTON — Both Sen. Orrin Hatch and the Bush administration are warning anew that, unless Congress acts quickly, the government again will run out of money to compensate downwind cancer victims of atomic testing.

Possibly making the money squeeze tighter, Hatch also called Wednesday for expanding compensation to cover new people with additional types of cancer and to give downwinders more money to match the higher amounts now given to cancer victims who were Energy Department employees or Nevada Test Site participants.

That came during a hearing of the Senate Judiciary Committee, chaired by Hatch, on the Radiation Exposure Compensation Act program, which Hatch and the late Rep. Wayne Owens, D-Utah, pushed through Congress in 1990. Hatch later expanded it in 2000.

Deputy Assistant Attorney General Jeffrey S. Bucholtz testified that without action by Congress, "The trust fund would be exhausted, based on our projections, during fiscal 2005."

The trust fund ran out of money before — and the government merely sent claimants IOUs until money was available months later — after the program was expanded to include more people with more types of cancer in 2000.

To help ensure that would not happen again, Congress in 2002 passed legislation to automatically appropriate each year what it thought would be adequate amounts of money for the program through 2011.

However, it assumed a sharp decrease in claimants would occur through the years. Bucholtz said those steep drops have not occurred, leaving a projected $72 million shortfall for successful claims through 2005.

President Bush's 2005 budget already requested that extra amount to fill the gap, and the House included it in its version of the Commerce-State-Justice Appropriations bill. However, the Senate has yet to act, and the money could always drop out in House-Senate negotiations on a final bill.

Even if that amount is added for shortfalls through 2005, Hatch said he is worried the program will continue to face future shortfalls. He noted the General Accounting Office recently predicted additional shortfalls of another $35 million between 2006 and 2011.

Bucholtz, who oversees administration of the program, had even worse news. "The GAO estimate will be on the low side" — with the shortfall possibly being up to $80 million, he said, although firm figures are not yet available.

Hatch asked that firmer figures be prepared soon to give Congress time to fill the gap before any IOUs are ever issued again.