While conducting a site investigation at the Shearon Harris Nuclear Power Plant in North Carolina, workers found that a pipe on the site property was leaking onto the soil. The leaking isolation valve, 3WN-38, allowed nearly 10,000 gallons of water to escape onto the surrounding area. The water contained some 5,780 picocuries per liter of radioactive tritium. The valve was secured and the leak was stopped, but not before over 800,000 becquerels of radiation were released.
Tritium is a radioactive form of hydrogen which has a half-life of 12.3 years and is capable of moving through soil quickly. While tritium can be found in gaseous form, it is almost always found as water, or “tritiated” water. The EPA standard for tritium in drinking water is 20,000 picocuries per liter.
Source: NRC Event Notifications