Mitigating Nuclear Hazards - Part 5, Reactors

Nuclear reactors are used to generate electricity, make isotopes for medical diagnosis and to fight disease, and for research including space exploration and environmental science.

According to the World Nuclear Association, there are 454 operating nuclear reactors world wide and 54 under construction. In the U.S., according to the Energy Information Agency, 98 nuclear reactors operate in 30 states and 2 reactors are under construction in Georgia.

In addition to reactors still operating, many plants have retired or been dismantled, which is known as “decommissioned.” Again, according to the World Nuclear Association, 115 power reactors, 48 experimental reactors, and over 250 research reactors have been retired or decommissioned.

Uranium fuel pellets contained within rods and assemblies allow for the nuclear chain reaction of U-235 that releases neutrons and produces heat to boil water producing steam that turns a generator to produce electricity. The first nuclear reactor was built by Enrico Fermi known as the Chicago Pile-1 on December 2, 1942. The first commercial nuclear power plant to operate in the U.S. was built in 1958 near Pittsburgh, Pennsylvania. Since 1961, NASA with support from DOE used radioisotope heat decay to power deep space rockets such as the Cassini mission to Saturn.

The most common radioisotope used in medical diagnosis is technetium-99 (Tc-99), with some 40 million procedures per year, accounting for about 80% of all nuclear medicine procedures worldwide. I had this “Tech-99” test done many years ago to see how well my digestive organs function, including gall bladder, as a result of Celiac disease that’s been alleviated by my becoming gluten free.

Between 2003 to 2005, I served NRC as a Project Manager on relicensing nuclear power plants. I coordinated National Environmental Policy Act (NEPA) reviews for license renewal applications of nuclear power plants. Here is a list of license renewal applications completed by NRC. For example, I led the team to produce environmental reviews of the D.C. Cook plant on Lake Michigan near South Bend, Indiana. We compared the environmental and socioeconomic costs and benefits of continued nuclear operations as compared with all other potential sources of power generation and environmental impacts. Getting inside the nuclear power plant for inspections was a highlight.

One of the environmental impact issues that I raised concerned releases of tritium into groundwater, that were evident at D.C. Cook because Michigan state laws required groundwater monitoring of tritium. But at the time not all states required tritium or other groundwater monitoring which eventually became required by NRC. After citizens complaints, the Associated Press investigated in 2011 and NRC began requiring quarterly groundwater monitoring all all nuclear power plants and for industry to provide annual reports. Radioactive effluent and environmental monitoring reports are discussed by NRC. Here are two annual reports, A and B, provided for the D.C. Cook plant by Indiana Michigan Power.

According to NRC, “The list only includes leaks or spills where the concentration of tritium in the leak source, or in a groundwater sample was greater than 20,000 picocuries per liter (pCi/L). A tritium concentration of 20,000 pCi/L is used as the threshold for inclusion in the list because it is the drinking water standard in EPA’s Safe Drinking Water Act…. Ten sites are currently reporting tritium, from a leak or spill, in excess of 20,000 pCi/L.”

Recently, I coauthored a paper on using the fission track method for identifying naturally-occurring uranium in soil by exposing thin section samples in a USGS research reactor. Here is link to the abstract.

Several new advanced reactor designs “Gen 4” are being proposed to be safer and produce less waste. On June 4th of this week, the U.S. Senate Committee on Environment and Public Works held a hearing about advanced nuclear technology being developed world wide.

If you have basic questions about nuclear science and technology or live near a nuclear facility, here are some useful educational websites from NRC and EPA, and feel free to contact us at