Tritium has become an important radionuclide in commercial Pressurized Water Reactors because of its mobility and tendency to concentrate in plant systems as tritiated water during the recycling of reactor coolant. Small quantities of tritium are released in routine regulated effluents as liquid water and as water vapor. Tritium has become a focus of attention at commercial nuclear power plants in recent years due to inadvertent, low-level, chronic releases arising from routine maintenance operations and from component failures. Tritium has been observed in groundwater in the vicinity of stations. The nuclear industry has undertaken strong proactive corrective measures to prevent recurrence, and continues to eliminate emission sources through its singular focus on public safety and environmental stewardship.

This paper will discuss:

- production mechanisms for tritium,

- transport mechanisms from the reactor through plant, systems to the environment,

- examples of routine effluent releases,

- offsite doses,

- basic groundwater transport and geological issues, and

- recent nuclear industry environmental and legal ramifications.