Tiny Mussel Endangers A Giant Nuclear Complex

THE $7 billion Watts Bar nuclear-power plant - one of the largest construction projects in the United States - could be slowed or halted in the wake of studies that reveal several endangered species living near the site.

The unusual species, including one extremely rare freshwater mussel, were reported by a team of experts working for the Tennessee Valley Authority (TVA). Wildlife officials say the development could delay the March 1995, start-up of the plant, which is located 50 miles west of Knoxville.

Nuclear regulators also express concern. In a letter to TVA dated June 21, Steven Varga, an official with the Nuclear Regulatory Commission (NRC), cautioned that firing up Reactor No. 1 at Watts Bar ``could affect the endangered species.''

Lee Barclay, field supervisor for the United States Fish and Wildlife Service in the Tennessee-Kentucky region, said he was unaware that TVA had conducted an environmental analysis in August 1993.

Responding to a Monitor inquiry, Mr. Barclay, who enforces laws protecting endangered species, said further research may be necessary. He told this reporter: ``We haven't seen the review, and until you mentioned it, I did not know one existed.''

The endangered species found close to Watts Bar include the bald eagle, the gray bat, the snail-darter (a fish), and four varieties of mussels-- the fanshell, pink mucket, rough pigtoe, and dromedary pearly.

Of those on the TVA list, the dromedary pearly mussel could present the largest problem for the Watts Bar plant, Barclay says. ``The pearly mussel has only a couple of known reproducing populations, and part of one of those includes the [Watts Bar] area,'' he says.

The TVA environmental review was conducted by 14 specialists in biology, chemistry, physics, engineering, nuclear power, wildlife management, radioactivity, and zoology. Their major concerns involved the potential for chemical and radioactive contamination of the river by the Watts Bar reactor.

Fred Hebdon, a senior official in the NRC's Office of Nuclear Regulation, says of the problem: ``Hopefully, it is not serious. We have no reason to believe it is serious.... [But] we want to make sure. If there are significant new circumstances and information, we have to update the environmental-impact statement.''

But Ann Harris, a TVA employee and longtime safety advocate, calls the situation ``a fiasco.'' Mrs. Harris, who is associated with We the People Inc., a nuclear-whistleblower protection organization based in Rowley, Mass., says:

``This endangered species issue, coming at the 11th hour, is one more indication of TVA's absolute mismanagement of taxpayers' money. Why are our representatives in Congress not responsive to our concerns down here about TVA?''

Mr. Hebdon at NRC notes that the original environmental statement for Watts Bar in the 1970s concluded there might be a threat to three endangered species.

``I don't know why the number changed,'' he says. ``I am not exactly sure where the other four came from.... We are starting discussions with TVA so we can ... understand from a biological point of view what we are talking about here.''

JOHN JENKINSON, senior malacologist at TVA, says the endangered species found near Watts Bar should not delay the start date, however. The chemicals used at the plant will be so diluted by the time they reach the river that they will be ``virtually undetectable,'' he says.

Dr. Jenkinson, who specializes in mussels, says TVA has done extensive research on toxicity and that operation of Watts BAr will essentially pose no risk to organisms downstream.

The latest TVA report says: ``Operational impacts to the [endangered] fish and mussel species could occur through the release of radioactive and nonradioactive discharges to the river.... Such releases could also impact bald eagles and gray bats through effects on their prey base.''

Bald eagles eat fish from the river and roost on nearby hillsides. Gray bats, which occupy a cave four miles from Watts Bar, feed on aquatic insects downstream from the nuclear plant.

But wildlife officials say the greatest threat may involve endangered mussels. Although Watts Bar has a ``closed-loop'' system with its own cooling towers, it still must draw a limited amount of water from the Tennessee River and discharge used water and sediment back into the river.

Two nuisance species, Asiatic clams and zebra mussels, can potentially clog Watts Bar's water intake and release systems. To keep the system working, plant operators must use chemical biocides to kill both the clams and zebra mussels within the system, experts say. Unless these chemicals are made harmless by the time they are flushed into the environment, the dromedary pearly and other desirable mussels could be put at risk.

TVA, a federal agency, provides power to 3.3 million people in seven states, including most of Tennessee, and parts of Kentucky, Alabama, Mississippi, Georgia, North Carolina, and Virginia.

Known for its 36 power-producing dams, TVA today generates most of its power with coal. But it has a checkered history with its nuclear plants. In the 1970s, TVA began building 17 nuclear plants - the most ambitious program in the country. When energy demand slowed, however, TVA scrapped plans for eight units.