The nuclear industry is built upon numerous and redundant safety systems and measures to protect public health and safety, plant personnel and equipment. One such protective system present across all U.S. nuclear power plants is a robust environmental program. The program encompasses monitoring pathways, including the air, ground and water for small releases of radioactivity. During normal nuclear power operations, water containing trace amounts of radioactive materials is released in a controlled manner. Known as effluents (materials discharged to the environment), these releases are continuously monitored and sampled to ensure compliance with effluent release requirements by the U.S. Nuclear Regulatory Commission (NRC), the Environmental Protection Agency (EPA) and local and state agencies.
Utilities that operate nuclear plants must begin radiological environmental monitoring at least three years before the plant starts operating and continue throughout the plant’s lifetime. Since 1923, Duke Energy has had an environmental monitoring program to ensure the health and safety of the public and to ensure plant operations cause minimal impact to the environment. In fact, Duke was one of the first utilities nationwide to launch an environmental and air program (the company’s environmental programs were started with mosquito control and were designed to help control nuisance populations of lake-breeding mosquitoes in the Catawba River Valley). Today at nuclear sites, these programs sample and monitor for both off-site and on-site radioactive material, such as tritium, and allows for the early detection of any signs of system or equipment leakage.
Tritium, an isotope of hydrogen, is found naturally in water everywhere and is a byproduct of electricity generation at nuclear power plants. Like hydrogen, tritium can bond with oxygen to form water. When this happens, the resulting water (called “tritiated water”) is slightly radioactive. The properties of tritium are very useful and are produced commercially in concentrated quantities for use in such self-luminescent devices as exit signs, aircraft dials and wristwatches. In addition, tritium is one of the least radioactive substances and must be ingested in large amounts to pose any health risks (if ingested, tritium can be a low-energy internal hazard). To put it into context, if a person consumed two liters of tritiated water per day for an entire year, this would be equal to a radiological dose of eight millirem (using EPA dose model assumptions). A millirem is a measurement of the amount of radiation received by a person. For comparison, if a person had a chest x-ray you would receive about 6-10 millirem. On average, individuals annually receive about 360 millirem from all sources, including background and medical sources of radiation.
To preserve the integrity of systems that carry radioactive fluids and gases, the industry’s environmental program also includes a comprehensive inspection and maintenance program. Radiation samplers and monitors are positioned at locations around each plant and are part of nuclear station operations. Sampling and analysis of area vegetation, drinking water (even crops that have been irrigated with water), fish, soil and milk is also performed as part of this program. Each nuclear station in the U.S. is required to submit a report to the NRC on its environmental monitoring programs and sampling results. Reports are available to the public on the NRC website.
Duke Energy takes its role as an environmental steward very seriously and has strict environmental monitoring programs to monitor such releases. In 2006 Duke Energy became part of an industry wide voluntary program to enhance industry groundwater protection and communications with local officials about the results of monitoring. Both short- and long-term actions were identified and implemented to comply with this initiative, including the installation of additional monitoring wells. While unplanned releases of tritium and other radioactive material have occurred at U.S. nuclear energy facilities in recent years, it’s been determined that there have been no impact to public health and safety. Significant improvements have been implemented to find solutions to improve groundwater protection monitoring across the industry. In light of industry experience, Duke Energy is continuously working to further validate and enhance processes/programs as appropriate and is committed to using natural resources and energy efficiently to reduce resource consumption, waste, discharges and emissions. We strive to improve our operations with a focus on preventing environmental and safety incidents and preserving public safety.
Further reading:
For more information on the industry’s perspective on the environment click here to be routed to the Nuclear Energy Institute's website.
For a fact sheet on environmental monitoring click here to be routed to the NRC's website.
For more information on tritium, radiation protetction limits and drinking water standards, click here.
