Nuclear Dump Would Not Threaten Water, Experts Say : Environment: Science panel backs advocates of Ward Valley site near the Colorado. But two members dissent.

A panel of the National Academy of Sciences has concluded that locating a proposed low-level radioactive waste dump in Ward Valley in the eastern Mojave Desert would not risk contamination of the Colorado River or other sources of drinking water.

The report, however, was neither unqualified nor unanimous. Two members of the 17-member committee of scientists dissented on a key safety issue. And the study, released Thursday after eight months of work, is laced with criticism of research done by the California Department of Health Services into the suitability of the site.

Nevertheless, the academy’s work could be most helpful in dispelling what has been the paramount concern about Ward Valley--that hazardous levels of nuclear power plant waste could leak into the Colorado, which is 20 miles away and a source of drinking water for millions of people in Southern California.

U.S. Interior Secretary Bruce Babbitt requested the academy study to help resolve a decade-old dispute over the safety of the proposed dump, which would receive low-level radioactive waste from nuclear power plants, hospitals, university laboratories and industries in California and three other states.

Although the panel conceded that tiny amounts of plutonium-239 could reach the river after hundreds or thousands of years, the report stated that “the potential impacts on the river water quality would be insignificant relative to present natural levels of radionuclides in the river and would meet accepted regulatory health standards.”

The panel’s conclusion, however, is bound to be controversial because it is based on an estimate--repeatedly challenged by dump opponents--that Ward Valley would receive a total of just 10 curies of plutonium-239 during its anticipated 30-year existence. (A curie is the amount of radioactivity given off by one gram of radium.)

At a news conference Thursday at the academy, the country’s oldest and most prestigious scientific organization, geophysicist George Thompson said that the panel derived the 10 curie figure from estimates by the Nuclear Regulatory Commission and the Congressional Research Service.

Thompson, the panel chairman, went on to say that even if 1,000 curies of plutonium leaked into the river, it would not pose a health hazard.

However, critics of the project point to another estimate, in the license application for the dump, that indicates that up to 3,500 curies of plutonium-239 could be disposed of at the facility.

As planned, the dump would consist of five sealed underground trenches designed to take about 5.5 million cubic feet of waste. It is up to Babbitt to approve the transfer of the site to the state of California, which wants to license the dump.

California is one of at least 30 states that have no place to legally dispose of radioactive waste. The Ward Valley facility would be the first of a new generation of state-operated nuclear facilities and the first to open in more than a quarter-century.

As opposed to a high-level nuclear waste dump, Ward Valley would not receive spent nuclear reactor fuel or other waste heavily contaminated with long lasting, highly toxic plutonium-239. However, Ward Valley would receive some nuclear power plant waste contaminated with the same radioactivity, only in much smaller quantities.

The growing shortage of approved waste sites has led to concerns that radioactive waste is being flushed into sewer systems or stockpiled in temporary storage facilities that are vulnerable to fire, earthquakes or other catastrophes.

The Clinton Administration has been at odds with Gov. Pete Wilson over Ward Valley, and Babbitt has indicated in the past that he would not transfer the land for the site until after courts in California ruled on safety issues raised by opponents of the dump. A lawsuit, now before a state appeals court, contends that Wilson authorized the dump on the basis of a faulty environmental impact analysis.

But now that the academy has addressed several of the issues that are before the courts, Wilson is urging Babbitt to approve the transfer.

“The study is complete, the facts are in, the site is safe,” Wilson said Thursday. “Enough is enough. Secretary Babbitt, move swiftly in turning over Ward Valley to the state.”

Babbitt issued a press release Thursday saying that “the thorough, independent review by the academy will measurably aid my decision-making on the proposed land transfer for the Ward Valley site.” But Babbitt was not available to take questions and did not indicate in his statement whether he still plans to postpone the land transfer decision until after the courts have ruled.

Babbitt sought the academy’s assistance after three U.S. government geologists challenged assertions by California officials that radioactive particles would not migrate from the site even after thousands of years.

One of the crucial issues confronting the academy panel was whether moisture from rainfall could become contaminated by the buried nuclear waste and trickle down 600 feet to the Ward Valley water table.

If the scientists determined that moisture does not penetrate deeply into the desert, a strong case could be made that nature created an impermeable crypt beneath the Ward Valley sands.

However, the academy panel had to contend with evidence that radioactive tritium is already present 100 feet below ground. Tritium occurs naturally in the Earth’s atmosphere and is also a byproduct of atmospheric nuclear testing. But much higher concentrations of tritium routinely show up in biomedical waste and could account for up to 90% of the radioactivity in the dump, if it is opened.

If small amounts of tritium can be detected deep into the ground at Ward Valley now, what would happen if more of the stuff were dumped at the site? And if one radioactive substance can move down through the sand toward the water table, why couldn’t another?

The majority of the panel blamed the detection of tritium on mistakes made by the state. “The committee concludes that inappropriate sampling procedures most probably introduced atmospheric tritium into the samples,” the report said.

Thompson added at the news conference Thursday that more research was needed on the tritium issue. But he said it need not hold up construction of the dump.

“We all agree that the tritium issue ought to be resolved,” Thompson said. “We should find out what went wrong, if it did with the measurements, and do other measurements either in the early construction phase or before.”

Two panel members dissented. Referring to tritium detected at Ward Valley and a now-closed dump in Beatty, Nev., hydrologist Martin Mifflin wrote that “the Beatty facility monitoring record and the significant tritium profile at the Ward Valley site combine to suggest that the . . . hydrology is not understood at either site.”

At the news conference, hydrologist June Ann Oberdorfer said that confirmation of tritium 100 feet below ground could put the future of the project in doubt.

“The issue needs to be resolved before you go forward,” said Oberdorfer, who also issued a written dissent on the tritium detection. “There is a reasonable chance you may find tritium at depth and, if you did, that would change the situation. It would mean you need to rethink a number of issues before going ahead.”

The entire panel found fault with the state’s plan for replacing habitat of the desert tortoise, which is on the federal endangered species list. A portion of the state’s population of tortoises lives in Ward Valley and would have to be relocated.

The panel concluded that the relocation plan would lead to increased mortality and recommended that it be re-evaluated in consultation with the U.S. Fish and Wildlife Service.

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Nuclear Dump

A panel of scientists reported Thursday that the proposed Ward Valley dump for low-level radioactive waste does not pose a significant threat to water supplies.