Ammonia, Chlorine Gases at Power Plants Hazardous if Released

WASHINGTON, DC, July 26, 2004 (ENS) - Terrorist or accidental releases of gaseous ammonia or chlorine by hundreds of power plants pose a potential danger to 3.5 million Americans that could be removed with existing technology, says a new report by an affiliation of public interest organizations known as the Working Group on Community Right-to-Know.

Anhydrous ammonia kept on-site by power plants to control nitrogen oxide (NOx) emissions and chlorine gas used to prevent fouling of cooling or steam generation water are the two chemicals of greatest concern, the Working Group says.

Their report, "Unnecessary Dangers: Emergency Chemical Release Hazards at Power Plants," presents for the first time an analysis of the power plants' own chemical risk management plans as submitted to the U.S. Environmental Protection Agency.

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American Electric Power’s General James M. Gavin power plant in Cheshire, Ohio (Photo courtesy University of Ohio)
Across the country, some 275 power plants report that they use large amounts of ammonia or chlorine gas. These power plants report the information under the Environmental Protection Agency’s Risk Management Planning (RMP) program.

Each facility’s Risk Management Plan shows how many nearby residents live in danger of exposure to a worst-case chemical release such as an accident or terrorist attack.

Power plant RMP reports indicate that 225 of these 275 plants could harm people off-site in an emergency chemical release. These 225 power plants use enough ammonia or chlorine gas to collectively endanger any of 3,568,658 people who live in nearby communities, according to their own statements.

"We urge power plants to replace these dangerous chemicals with safer alternatives that are readily available," said Paul Orum, director of the Working Group on Community Right-to-Know, and author of the report, issued Friday.

Many power plants use hazardous anhydrous ammonia to remove NOx in smokestack pollution control systems. Available alternatives to anhydrous ammonia do not pose the same dangers, Orum points out.

Dilute aqueous ammonia presents lower health and safety hazards, but does not eliminate the danger entirely, because aqueous ammonia retains limited ability to form a toxic cloud. Solid urea poses less danger because it allows utilities to generate ammonia for pollution control systems on-demand.

Some utilities have listened to public concerns about ammonia releases. In December 2000, American Electric Power’s General James M. Gavin power plant in Cheshire, Ohio selected a urea based pollution control technology after residents raised concerns about the dangers of an emergency ammonia release.

“Our neighbors in and around Cheshire told us they were very concerned about the impact of a serious accident involving a major release of anhydrous ammonia," said John Norris, senior vice president of operations and technical services, in a statement. "We took those concerns to heart."

Later, conflicts over the release of clouds of sulfuric acid led the company to buy out and relocate the entire immediate Cheshire community. Still, the urea solution is new technology that effectively removes the risk of a gaseous ammonia release.

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Chlorine hazard warning sign (Photo courtesy Idaho Health and Safety Standards)
Chlorine gas is the other hazardous substance the coalition warns against in its report. Some power plants use chlorine gas as a biocide against algae and slime in cooling towers or mussels and clams in intake water pipes that can increase corrosion and mineral buildup, and cut heat transfer.

Orum points out that less hazardous alternatives to chlorine gas at power plants include chlorine bleach or bromine. "Additional approaches include ultraviolet light, pulsed electric power, filtration, and anti-fouling surface coatings. Power plants frequently use more than one method to filter or treat water," the report states.

But today, 24 power plants account for two-thirds of the people in danger, the report documents, and in 10 states more than 100,000 people live in danger of emergency chemical releases from power plants. These states are California, Texas, Florida, Illinois, Minnesota, Pennsylvania, Missouri, Rhode Island, Virginia, and New Jersey.

In a worst case scenario, ammonia or chlorine gas would drift downwind in a ground-level toxic plume. Numerous federal agencies and other experts have warned that terrorist might target facilities that use hazardous chemicals.

"It would be prudent for power companies to adopt safer alternatives to ammonia and chlorine gas," said George Sorvalis of the Working Group on Community Right-to-Know. "Many power plants are already using safer chemicals to achieve the same results without putting workers and communities at risk. Better safe than sorry."