Thomas Morrison never talked much about what he did during his months in the Bikini Atoll, in South Pacific waters that were azure in color but red hot in radioactivity. He was a smooth-cheeked, dark-haired ensign of 21, with a gentle, toothy grin, one of the legions of sailors who witnessed the world's fourth and fifth atomic blasts and then dove deep to see what damage had been wrought.

For the last several years, though, his wife has talked a lot about the past. Natalie Morrison has called government officials, written members of Congress and tenaciously pushed anyone possible for what is due her under the law. Her husband was only 44 when he was diagnosed with lymphoma. He was only 49 when he died. And his cancer, like so many other sailors' cancers, seemed the tragic epilogue of those radioactive blasts a quarter-century earlier.

At last the government agreed. But the letter that came recently for the Silver Spring widow hardly read like a victory.

"Unfortunately, the money available to pay claims has been exhausted," wrote Gerard W. Fischer, of the Radiation Exposure Compensation Act Program, through which Morrison is owed $75,000. "Thank you for your patience during this difficult situation."

"I just think it's an insult," Morrison retorted this week, surveying again the files of correspondence that document her claim -- which twice was rejected in error. "Why bother to have a law when they're not going to follow through? It's dishonest, it's not right, and I think the public should know."

The program's funding shortfall, nearly $84 million this fiscal year, is the latest blow to thousands of veterans, workers and families who became part of the nation's atomic testing program from 1945 to 1962. Out West, the program's legacy remains a bitter issue for the miners who helped dig the uranium that went into the bombs and the "downwinders" whose homes and farms were contaminated.

For decades, the government denied that anyone had been put in danger. Now it's out of money to compensate them. "These people who are sick and dying are getting IOUs," said Sarah Echols, a spokeswoman for Sen. Pete V. Domenici (R-N.M.).

Over the next 10 years, by some estimates, valid claims could total more than $700 million, and Domenici and others are pushing to make the fund a mandatory annual appropriation. For the moment, however, the only thing moving forward is an attempt to cover the $84 million due since May 2000. The Senate agreed Tuesday to insert that in an emergency supplemental spending bill. The House version includes nothing.

"Another 10 years, and it's not going to matter. We're all going to be dead," said Charles McKay, the Maryland commander for the National Association of Atomic Veterans and, like Tom Morrison, a Navy diver during Operation Crossroads. According to the association's survey of 1,572 men present for the 1946 Bikini Atoll detonations, 59 percent have died of cancer, at an average age of 57.

Operation Crossroads essentially ushered in the Cold War with two explosions code-named Able Day and Baker Day. Dozens of captured or surplus ships were assembled near ground zero so the Navy could gauge how well vessels and ammunition could withstand a nuclear attack.

Tens of thousands of men were involved. Ensign T.D. Morrison of the Naval Reserve was stationed on the USS Preserver. Years later, he would tell his wife about the massive column of water and stupefyingly huge mushroom cloud that followed the underwater blast on Baker Day, July 25. Dive teams spent hundreds of hours in the water afterward, checking instrumentation and retrieving equipment on the target ships. Others boarded to take photographs or to clean surfaces.

"We were constantly exposed," McKay said.

Following his time in the reserve, Morrison chose a career with the Navy as a civilian physicist. He and Natalie married and started a family. Two daughters were born, then a son. The boy was 1 when, in 1968, his father first discovered the lump.

Doctors told him the malignancy was unrelated to his military service. "It's been 20 years," his widow remembers a physician saying. "It couldn't be."

He died in 1973. The Radiation Exposure Compensation Act was not signed into law until 1990. But not until four years ago did Natalie Morrison learn of it -- from another atomic veteran's widow -- and realize her husband should be covered.

She filled out the requisite forms and prayed that 24-year-old hospital records hadn't been destroyed. And then she waited as her claim was twiced refused. She finally hired a lawyer but kept up her own drumbeat of phone calls and faxes. Her letters to federal officials would begin, "I was so in hopes that I would receive, before I die, the reparation for my husband's on-site exposure. . . ."

In a letter in May to Domenici, Assistant Attorney General Daniel J. Bryant noted that new cases had increased sharply since Congress broadened eligibility last year. As of Friday, 453 approved claims awaited funding, with more than 3,100 under consideration.

Since the program's inception, nearly 3,600 claims have been denied and 3,900 others approved, for $286.4 million. Veterans account for less than 7 percent of the latter.

"Their widows are dying," said Morrison's attorney Stevan Lieberman, who calls his effort on her behalf a "hollow victory." The lack of congressional action on the radiation fund makes lawmakers' speedy endorsement of a World War II memorial appear hypocritical in his eyes. "Congress has to appropriate the money for this. That's the only hope."

Principle continues to motivate Morrison. She is a trim, spirited woman, now 71, who still lives in the house she and her husband bought so long ago. Their son has few memories of his father and yet turned out so much like him.

"Seventy-five thousand dollars doesn't add up to much as far as a life," she said.