During the normal operation of nuclear power plants and nuclear processing facilities, machinery, building materials, and other things can become radioactive even if they never come into physical contact with radioactive material. What causes this?

Nuclear power plants function by harnessing the energy released from controlled nuclear reactions. One of the less-known but critical phenomena occurring in these facilities is neutron activation. Imagine tiny particles, called neutrons, whizzing through a nuclear reactor. These neutrons can sometimes be captured by the nuclei of stable materials such as the structural components or tools within the plant. When this happens, the materials themselves can become radioactive.
This transformation occurs through a process known as neutron activation, which is an inadvertent byproduct of nuclear fission—the process that powers the reactor. Neutron activation can make everyday instruments and building parts a source of radiation, creating significant consequences for safety and waste management. This is one reason why nuclear power plants employ robust shielding and monitoring systems, to ensure that the radiation does not pose a threat to workers or the public. Furthermore, understanding and managing neutron activation is essential for the decommissioning of nuclear facilities, where previously non-hazardous materials must now be handled and disposed of as radioactive waste.

Radioactive materials are substances that emit radiation as they decay. This decay process involves the release of particles or energy from an unstable nucleus seeking a more stable arrangement. In our daily lives, we encounter low levels of natural radioactive materials in elements like uranium and thorium, as well as created or artificial radioactive isotopes used in medical treatments and industrial applications.
Within nuclear power plants and nuclear processing facilities, radioactive materials are meticulously controlled and utilized for energy production or other purposes. The presence of these materials requires stringent safety protocols, including specialized gear and storage to protect workers and the environment. Neutron activation can inadvertently increase the levels of radioactive material when stable structures or tools absorb free neutrons and begin to emit radiation themselves. Thus, controlling neutron activation helps in managing the levels of radioactivity and safeguarding against potential contamination or exposure incidents.

The Role of Nuclear Processing Facilities

Nuclear processing facilities are complex environments where the refinement, conversion, and management of nuclear materials take place. These might include fuel fabrication plants, reprocessing centers, and waste treatment facilities. The primary goal in these settings is to handle nuclear materials in a way that is safe, efficient, and minimizes environmental impact.

Impact of Neutron Activation

Neutron activation in these facilities can complicate processes by transforming otherwise non-radioactive materials into sources of radiation. For instance, tools, protective gear, and even structural materials can become radioactive, sometimes significantly so. Consequently, there's a need for strict monitoring and regular inspections to identify and manage any activated materials. This process ensures that radiological safety standards are met, both for the workers onsite and the surrounding communities.
Tackling the challenges posed by neutron activation takes expertise and careful planning. Nuclear processing facilities are designed with containment systems and barriers specifically to limit the spread of activated materials. Waste generated by neutron activation must be treated as radioactive and dealt with accordingly, which includes secure transportation, storage, and disposal—measures that are vital for public health and safety.