Radiation find prompts new dump concerns

Friday, March 24, 2000 | 11:29 a.m.

Elected officials and scientists in Nevada said today the Department of Energy's finding of radioactive water a mile away from the Nevada Test Site boundary raises concerns about building a high-level nuclear waste repository at Yucca Mountain.

The type of radiation -- tritium, which could occur naturally -- was found in an exploratory well in July about a mile from Pahute Mesa in the northwest corner of the Test Site.

The DOE did not announce the discovery because government scientists believe it is from a natural source. Further tests to determine the age of the tritium are planned. Tritium younger than 40 years old generally indicates a nuclear weapon as the source.

Tritium is most commonly found in nuclear bombs and reactors. It is generally considered an early indicator of more serious radioactive contamination in ground water.

If the DOE's latest discovery is from nuclear weapons experiments, it would be the first evidence that radiation has migrated off the Test Site, 65 miles northwest of Las Vegas.

The find became public after a member of the agency's citizen advisory board on the Test Site read a report that detailed the finding.

The 126.8 picocuries of tritium per quart of water is a preliminary finding from a new well at a depth of 5,000 feet, Bob Bangerter, director of DOE's ground water monitoring, said. A picocurie is a common measurement of radiation in the environment.

Although the federal Environmental Protection Agency considers any radioactive contamination in drinking water to be unsafe, no standards have been established for tritium.

Senate minority leader Harry Reid, D-Nev., said he believes the DOE may have been afraid to announce the finding.

"I think it casts an ever-longer shadow over Yucca Mountain," Reid said.

Congress singled out Yucca in 1987 as the only site in the country for the DOE to study as a repository for 77,000 tons of highly radioactive commercial reactor and defense wastes.

Yucca Mountain is not contaminated from nuclear weapons testing.

Reid said he is concerned that the DOE did not report the finding to the public.

"They can't cover up any evidence of contamination whether it is natural or man-made," he said. "They can't operate in secrecy. The Cold War is over."

Reid said he would keep a close eye on the DOE's progress in its study of tritium and added that more studies are needed.

"The science has got to be done in the open," he said.

Sen. Richard Bryan, D-Nev., said Nevadans had been reassured by the DOE that the Test Site contamination would stay in place, but the evidence indicates how complex Nevada's geology is. He also called for further studies.

"The geology in Nevada that was supposed to contain this contamination for thousands of years is unpredictable," Bryan said. "I think the bottom line is we are learning just how unpredictable the movements of these contaminants are."

Reps. Shelley Berkley, D-Nev., and Jim Gibbons, R-Nev., couldn't be reached for comment today.

"Any time there is a report that there could be unexpected migration off the Test Site in a geological area similar to Yucca Mountain, it raises a concern," Berkley spokesman Richard Urey said.

Earle Dixon, who teaches hydrology in the UNLV Environmental Studies program and is technical adviser to the Test Site citizens group, said the DOE needs to establish a state-of-the-art monitoring program for ground water in Nye County to check existing and future radioactive contamination.

Radiation 25 times above federal safe drinking water limits was found 500 feet deep down a well in Nye County last month, but later samples by both state and federal agencies determined that the radiation came from natural sources, not the Test Site.

The appearance of the tritium at a depth of 5,000 feet in the DOE's well possibly indicates rapid recharge to the ground water within the last 40 years through the mesa's complex volcanic rocks, Dixon said.

The Test Site's complicated ground water flow system was scrutinized last year by a team of scientists headed by Lynn Gehlhar of the Massachusetts Institute of Technology. The panel concluded that the DOE's computer model to predict where the contamination would flow at Frenchman Flat was unacceptable.

Dennis Weber, a physicist and ground water expert at the Harry Reid Center at UNLV, served on the independent panel. He said the DOE does not have enough information to predict how much radiation has entered the ground water or how fast it is flowing at the site.

Pahute Mesa covers 200 square miles and the DOE does not have enough wells to intercept a contaminated plume, Weber said. The tritium could travel quickly in ground water flowing through fractures or earthquake faults, he said.

In 1993 the DOE discovered tritium at a depth of 3,000 feet in a well on Pahute Mesa. Further analysis by the U.S. Geological Survey and the U.S. Environmental Protection Agency confirmed that the tritium came from a 1968 underground nuclear blast called Schooner.