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Revealing the Green Side of Nuclear Energy

Above: A peregrine falcon perches on equipment outside the reactor building of the Three Mile Island nuclear power plant. Photo courtesy of Exelon Corp.

Insight Web Extra

September 2010

Nuclear Power Plants Closely Monitored
To Protect the Environment

If the environment had its own page on a social media website, it would “friend” nuclear energy.  

In a sense, it already has. A pair of bald eagles last spring chose the Three Mile Island nuclear plant in Pennsylvania as their nesting place, joining pairs of peregrine falcons and osprey that already had taken up residence. In fact, TMI’s feathered friends are among many species of flora and fauna—including those threatened or endangered—that are thriving in the protected habitat around nuclear power plants.

Nuclear plants like Exelon’s TMI stand alongside such other low-carbon energy sources as wind turbines, hydropower and solar energy. All of them help keep the air clean because they produce no greenhouse gases or regulated pollutants while generating electricity. 

The environmental benefits of nuclear energy also encompass air, earth and water—and their inhabitants. PSE&G, which operates three reactors along the Delaware River in New Jersey, developed wetlands nearby to provide habitat for diverse species. AEP’s Cook nuclear plant on the shore of Lake Michigan exercises careful stewardship over one of the largest freshwater dune formations in the world. Southern California Edison Co. (SCE), which operates the San Onofre nuclear power plant, built a 175-acre artificial reef for giant kelp to foster populations of coastal fish species. And in parched Arizona, the Palo Verde nuclear plant operated by APS processes municipal sewage effluent at its Water Reclamation Facility and uses the reclaimed water to cool the plant. A similar plan is in the works for two reactors that FPL plans to build in Florida.

Kelp smallElectric power companies that operate nuclear plants engage in a wide range of environmental programs. Southern California Edison Co. (SCE), which operates the San Onofre plant, built a 175-acre articial reef for giant kelp to foster populations of coastal fish species. Photo courtesy of SCE.

The clean-air benefits of America’s 104 reactors are widely known, and there is almost universal recognition among policymakers that expansion of nuclear energy is needed to help combat climate change. However, nuclear energy’s environmental attributes extend beyond clean air, protection of endangered species and stewardship of sensitive lands near the facilities. 

Under federal regulations, all nuclear power plants have stringent environmental monitoring programs to ensure there are no negative effects from plant operations. The U.S. Nuclear Regulatory Commission requires electric utilities to begin these programs at nuclear plant sites at least three years before the plant starts operating. Because radiation is naturally present in the environment, the pre-operational monitoring is designed to establish a baseline the company later will use to ensure that the plant’s impact on the environment remains minimal. The NRC requires nuclear plants to submit a report each year on the results of their monitoring programs.

Environmental monitoring in the nuclear energy industry has drawn attention recently because of occasional leaks of slightly radioactive water at several plants. There has been no impact on public safety or the environment as a result of leaks, but public trust has been shaken in some cases. In 2006, the nuclear industry adopted a program to enhance groundwater monitoring at each nuclear plant site. 

The program includes better communication with the public.

“The electric companies that operate nuclear power plants have gone out to stakeholders to discuss ground water protection programs and, more often than not, they have ended up explaining their environmental monitoring programs,” said Kathleen Yhip, who manages the industry’s groundwater protection program for the Nuclear Energy Institute (NEI). “We have found that few people are familiar with environmental programs at nuclear power plants.” Yhip is on loan to NEI from Southern California Edison Co., where she is manager of external and regulatory affairs. 

The annual environmental monitoring reports are available to the public through the NRC, which posts them on its website. “Whether they are comprehensible to the public is another matter,” Yhip said, adding that a typical report is lengthy, technical and packed with data required by the regulator.

Since nuclear power plants are industrial sites, they also are subject to environmental reporting requirements mandated by the U.S. Environmental Protection agency and the state environmental agencies. These include industrial waste discharges (Clean Water Act), air emissions (Clean Air Act), chemical inventory reporting (Emergency Planning Community Right-to-Know Act), hazardous waste disposal (Resource Conservation Recovery Act), storage tank management, spill prevention (Oil Pollution Act) and a communications and chemical control program for the potentially hazardous materials used on site (OSHA).

Environmental Scientists Protect Ecosystems at Nuclear Power Plants

Jerrold McCormick is an environmentalist with the credentials to prove it—bachelor’s and master’s degrees in environmental management and a career dedicated to the complex task of protecting ecosystems. Ask McCormick why an environmental scientist would choose a career in nuclear energy, and his answer is simple and direct: “I wanted to work on something that is part of the solution.”

McCormick is a senior environmental scientist at PPL Corp.’s Susquehanna nuclear power plant, which is perched solidly on a hilltop overlooking the scenic Susquehanna River in northeastern Pennsylvania. From the diverse opportunities open to someone with his credentials, he opted for nuclear energy because it has one of the smallest environmental footprints of any energy source, yet produces vast amounts of electricity. Two reactors at Susquehanna provide enough electricity annually for about two million homes.

McCormick is one of hundreds of employees in the nuclear industry who specialize in environmental science, health physics, radiation protection, waste management and other disciplines whose direct role is protecting public safety and the environment. Along with federal and state regulators, the industry’s environmental experts provide a system of checks and balances to ensure that nuclear power plants continue to be good neighbors and responsible stewards of their surroundings.

Environmental Monitoring Begins Before a Plant Starts Operating

Health physicist Harry Riley, who manages Susquehanna’s radiological environmental monitoring program, arrived at the site fresh from college in 1978 when the plant was still under construction. “This place was just a hole in the ground,” Riley said. Although plant operation was still a few years away, he accepted a job at the new plant site over several other offers because he wanted to start at someplace new.  

Susquehanna’s radiological environmental monitoring program already was under way. It started in 1972, when the 1,200-acre site in Luzerne County, Pa., was a typical construction site with no industrial activities involving radiological materials. By the time the first reactor started commercial operation in 1983, PPL’s environmental monitoring program had established a 10-year baseline of data to use for comparison purposes throughout the plant’s operation. Riley estimates that the plant has accumulated some 100,000 data points of environmental information to match against that baseline.

Radiological environmental monitoring programs look for any changes in radiation levels that may be attributed to plant operation. They also pick up fluctuations in the natural, or “background” radiation, present at the site. At Susquehanna, for example, radon levels fluctuate from year to year depending on how much of the naturally occurring radioactive gas moves up through the ground to the air above.

Safe drinking water is essential, both onsite and off. Susquehanna draws its drinking water from two wells near the plant, both of which are monitored.

The town of Danville draws its water from the Susquehanna River downstream of the nuclear plant. Every 20 minutes, an automatic sampler captures three representative samples of drinking water that have been processed through the Danville Municipal Water Authority’s treatment facility. Scientists from Ecology III Inc., an independent environmental research and services firm in Berwick, Pa., collect the samples weekly and combine them into a monthly sample. The combined monthly sample then is sent to independent offsite labs to test for the presence of any radioactivity above that normally found in the local environment. Spreading out the samples over a month’s time helps ensure that the test results give a reliable picture of the power plant’s effects, if any, on local drinking water.

A fisherman relaxes near PPL's Susquehanna nuclear power plant, waiting for a bite on his line. Photo courtesy of PPL.

Fishing is a popular activity in Pennsylvania, and the area near the plant attracts anglers whenever the weather is right. On a humid summer morning, with an overcast sky, three fishermen staked out positions on the shores of Lake Took-a-While and leisurely cast their lines, hoping to land a nice largemouth bass or trout. Their fishing spot is part of the Susquehanna Riverlands Environmental Preserve, adjacent to the plant. The sandy soil under the fishermen’s feet, the lake water and the fish all have been sampled, studied and verified as unaffected by nuclear plant operations.  

PPL also monitors crops that have been irrigated with water taken from the Susquehanna River downstream of the plant, conducting a survey of the area every year to determine which farms irrigated with river water and which crops received the water. If a field is used for more than one crop a year, the first and any subsequent crops that year are sampled and tested.

Susquehanna’s environmental monitoring program also tests milk from local dairy farms.

Nuclear Plants Expand Monitoring of Groundwater

Some electric companies have detected higher-than-expected levels of the radioactive element tritium at nuclear power plant sites as a result of leaks or other unplanned releases. Tritium is a mildly radioactive form of hydrogen that is produced naturally in the upper atmosphere. Rain carries it to the Earth’s surface, and it is found in water everywhere. Tritium is used commercially in a variety of products, such as exit signs, gun sights and aviation runway lights. It also is a byproduct of nuclear power plant operations.
Environmental scientists prepare to take a sample from one of the groundwater monitoring wells at PPL's Susquehanna plant. Left to right: Harry Riley and Jerrold McCormick of PPL; Lyle Harvey of Ecology III.

Environmental scientists prepare to take a sample from one of the groundwater monitoring wells at PPL's Susquehanna plant. Left to right: Harry Riley and Jerrold McCormick of PPL; Lyle Harvey of Ecology III.  Photo courtesy of PPL. 


At facilities where leaks have occurred, state and federal officials have evaluated the situations and determined there are no public health consequences resulting from the leaks. For example, water taken from a residential drinking water well near the Braidwood nuclear plant in Illinois several years ago contained about 1,600 picocuries of tritium per liter—significantly higher than expected for that well, indicating an unintended release from the plant. To put this amount in perspective, EPA standards allow drinking water to contain up to 20,000 picocuries of tritium per liter—more than 12 times the amount found in the Braidwood sample. 

A radiation expert from Texas A&M University, speaking earlier this year at a U.S. Nuclear Regulatory Commission workshop, stressed the importance of putting the tritium leaks in perspective.

“I come from the medical area, where very large doses [of radiation] are used,” said Dan Reece, director of the Nuclear Science Center and professor of nuclear engineering, whose expertise includes radiation dose assessment and medical application of isotopes. “Moderate doses of radiation produce trivial risk. …The utilities should clean up the leaks, but it should not be considered a health risk to the public.” 

In January, Entergy’s Vermont Yankee plant detected a leak of water containing tritium from two separate pipes inside a concrete tunnel using wells installed as part of the groundwater monitoring program. Due in part to a clogged drain, water containing tritium seeped through an unsealed joint in the tunnel wall to the soil and eventually the groundwater. The leak was stopped and Entergy implemented a groundwater remediation plan at the plant that involved pumping the contaminated water to the surface for filtering and storage for use in the plant. That process was successful in steadily reducing the concentration of tritium in the site's groundwater.

Given the high-profile nature of the leak in Vermont, the state’s department of health said, “There is no immediate threat to public health, but this event is of high concern because it signals an unscheduled and unintended release or leak of radioactive materials.” No detectable tritium levels were found in any drinking water well samples or in Connecticut River water as a result of the release.

Entergy also has stated its intention to be an industry leader in tritium leak prevention and mitigation, announcing a six-point groundwater protection initiative. The company has begun implementation of more than 50 actions toward that goal, many of which have already been completed. 

Safety is the public’s overarching concern about nuclear energy, and public trust is a crucial element for the industry. In some cases, that trust has been shaken. The elevated tritium level discovered in the well near the Braidwood plant was traced back to a spill that occurred on plant property several years earlier. Because the event had no safety significance, the company at the time did not notify local officials. Understandably, the officials were dismayed when they ultimately learned about the tritium release. This event served as a wake-up call to the nuclear energy industry that communications with the public needed improvement.

In 2006, the nuclear industry adopted a voluntary initiative to enhance groundwater protection and communications about the results of the monitoring. Companies that operate nuclear power plants installed additional monitoring wells at nuclear power plants and have taken other actions to enhance their understanding of the plant’s hydrology and the potential for leaks to occur. In addition, all companies operating nuclear power plants have enhanced their communications to ensure they keep the public and state and local officials well informed.

“The industry takes seriously its responsibility as stewards of the environment and as neighbors in the communities in which we operate. We have a zero tolerance standard for allowing any radioactive releases to reach groundwater,” said Anthony Pietrangelo, senior vice president and chief nuclear officer at the Nuclear Energy Institute.

SCE’s Yhip is managing the ground water protection initiative for NEI.

“Prior to the new industry program, most plants only tested groundwater where it is a source of drinking water,” Yhip said. Those monitoring wells are off-site. “Now we’re monitoring groundwater whether or not it is a source of drinking water, and we’re monitoring it closer to the plant so we’ll get an early indication of any leaks before the water gets off the site.”

Under the industry program, Susquehanna tripled the number of groundwater monitoring wells on PPL-controlled property, Riley said, determining the most effective locations for the monitoring wells through a meticulous assessment process.

Although industry initiatives are voluntary, the NRC factors them into its plant inspections and notes in its inspection reports—also publicly available—how well each plant has met the requirements of the initiative. 

A recently completed industry peer assessment found that all 104 nuclear plants have completed major actions that significantly enhanced their monitoring of ground water, said Ralph Andersen, chief health physicist at NEI. A summary report on the lessons learned from the recently completed industry-wide peer assessments will be provided to the NRC.

State Environmental Protection Officials Monitor Nuclear Power Plants

In addition to the NRC’s resident inspectors, the Pennsylvania Bureau of Radiation Protection (PaBRP) assigns a nuclear engineer to each of the state’s five nuclear plants and conducts its own environmental monitoring programs, said Tonda Lewis, the PaBRP’s radiation protection program supervisor. The engineers conduct inspections, review operating procedures and keep up to date on the plants’ environmental monitoring programs. 

The radiological environmental monitoring program for Susquehanna includes testing split samples of river water and milk, with a portion of each sample going to a lab chosen by PPL and to the state’s laboratory for independent analysis. Four air monitors—two of them co-located with PPL monitors—capture particulates in the air around the plant to be tested weekly for radioactivity. 

The PaBRP also monitors environmental dosimeters at 30 locations, ranging from about one to 15 miles away from the plant, to check for any increase in radioactivity in the general environment that could be attributed to plant operations. In addition, the PaBRP has begun testing samples of groundwater taken from tritium monitoring wells on the Susquehanna plant site.

Lewis said the state of Pennsylvania has a good relationship with all of its nuclear plants. “Susquehanna, in particular, has always been really good about keeping us informed,” she said.


The clean-air benefits of nuclear energy have become well known, amid growing concern about climate change. Every year, nuclear energy prevents the emission of 650 million metric tons of carbon dioxide—nearly as much CO2 as is released from all U.S. passenger cars—by taking the place of fossil-fueled electricity generation that otherwise would be used. Nuclear energy also prevents the emission of 500,000 tons of nitrogen oxide and two million tons of sulfur dioxide annually in the United States. 

Despite these environmental benefits, few members of the public are aware that nuclear power plant sites are among the most thoroughly studied and monitored industrial environments in the nation. The nuclear industry’s rigorous environmental monitoring programs—along with the dedicated professionals who implement those—help ensure that the plants are operated safely and cause no harm to the surrounding community or the environment.

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