Hallmark said the Labor Department has designated Area 51, the 60-square mile guarded installation on the northeast border of the Nevada Test Site, as part of the test site for purposes of the Energy Employees Occupational Illness Compensation program.

Initial estimates varied widely of how many people might be eligible to gain payments, from less than a hundred to several thousand.

Darwin Morgan, a test site spokesman, said only about 25 to 100 people may be covered. While the Energy Department controlled Area 51 for much of its history, the secret development of military aircraft and weaponry at the site was performed by Defense Department contractors who are not covered by the compensation law, Morgan said.

But John Funk, a Las Vegas advocate and former test site carpenter, said it was clear to workers employed by Bechtel Nevada, Reynolds Electrical and Engineering Company, EG&G Energy Measurements Inc., and Wackenhut Services Inc., among other firms, that they were there at the behest of DOE and its predecessor agencies.

Funk said test site employees routinely were sent "over the hill" to the secret base. He said as many as 2,000 former workers may be covered.

"You can call them what you want, but they were all DOE workers," said Funk, chairman of the nonprofit Atomic Veterans and Victims of America.

Labor Department officials could not estimate the number of potentially covered workers. Sen. Harry Reid, D-Nev., is attempting to clarify the eligibility question, aides said.

As for designating Area 51 part of the health program, Reid said, "This is very good news."

"I have been working for this for a long time now because these workers deserve a fair shake," Reid said. "Clearly, there are still some questions that need to be answered and I will continue to work to have those concerns addressed."

Hallmark said in an interview that examiners will identify all claims that have been filed to determine if they may be affected by the program expansion. Claims that have been denied may be reopened.

He suggested former workers and their families who believe they may be affected should contact the Las Vegas Resource Center that processes claims under the energy workers compensation act. The toll free number is 866-697-0841.

"We also will conduct other outreach efforts to get this information to all affected claimants and to all former NTS employees and their families who have yet to file a claim but may be affected by this change," Hallmark said.

Hallmark cautioned that the Department of Health and Human Services, which works with Labor to administer the program, may need to take further actions as well.

The health department may need to update its Nevada Test Site profile that provides the basis for weighing claims. It also may need to determine whether certain workers fall into "special exposure cohort" categories that would make them eligible for streamlined claims processing.

The compensation law covers the Nevada Test Site and dozens of other Energy Department and contractor facilities where workers took part in nuclear weapons programs and could have been exposed to radiation and toxics.

Former workers who contracted cancers or other diseases linked to exposures to radiation, silica or beryllium are eligible for $150,000 lump sum payments and medical expenses. Another part of the program provides worker compensation-style payments for job-related illnesses.

The Labor Department declared eligibility for DOE workers who were at Area 51 for the period between January 1, 1958 through December 31, 1999. Those were the years DOE controlled the site that is roughly 90 miles northwest of Las Vegas.

A land swap at the end of 1999 gave control to the Air Force.