Fermilab

What is tritium?
Tritium is a hydrogen atom that has an additional two neutrons in the nucleus. It is a weakly radioactive hydrogen isotope with a half-life of 12.3 years. When tritium decays into ordinary helium, it emits low-energy particles called beta particles.

Although tritium can be a gas, its most common form is in water. People can be harmed by regularly drinking water that contains high levels of tritium over many years.

The Earth's atmosphere contains low levels of tritium produced naturally when cosmic rays strike air molecules. At Fermilab, small amounts of tritium are produced as a byproduct of accelerator operations.

Does the tritium at Fermilab constitute a health risk to employees or neighbors?
No. The low levels found in surface water on the Fermilab site are extremely low compared to what is safe for a lifetime of continuous exposure to tritium.

The main hazard associated with tritium is internal exposure through ingestion, but the surface water at Fermilab is not used as drinking water and poses no threat to drinking water.

Even if a person were to drink surface water on the Fermilab site, the body excretes ingested tritium in about two weeks. Tritium is only harmful if it is ingested in large amounts over long periods of time. In that case, high doses of tritium over a sustained period can cause cancer.

To keep people safe, federal agencies set limits on the amount of tritium in water. The U.S. Department of Energy has set a limit of 1,900 picocuries per milliliter for tritium in surface water. Federal drinking water standards set a limit of 20 picocuries per milliliter.

Is there tritium in the creeks leaving the Fermilab site?
We occasionally detect low levels of tritium in Indian Creek, well below the water standards that Fermilab is required to meet. In the 35-year history of our environmental monitoring program at Fermilab, we detected very small amounts of tritium in Indian Creek for the first time in November 2005. We measured levels of tritium at 3.3 picocuries per milliliter in a water sample taken from Indian Creek just inside the Fermilab property. We never have detected tritium in samples taken from Ferry Creek and Kress Creek to date. Typical tritium concentrations in on-site ponds are less than three picocuries per millimeter. The federal surface water standards for tritium is 1,900 picocuries per milliliter.

We frequently update a Web page with results from samples taken from the three creeks leaving the Fermilab site: Indian Creek, Ferry Creek and Kress Creek. Fermilab is committed to keeping releases of tritium well below the required limits.

What steps did you take after the detection of tritium in Indian Creek in 2005?
We took a series of steps to reduce the possibility for tritium to get into Indian Creek and keep the levels of tritium in the ponds on the Fermilab site as low as reasonably achievable (see this webpage), both now and in the future. Occasional low-level discharges from on-site ponds could occur after heavy rain storms.

Where does the tritium on the Fermilab site come from?
Tritium is a byproduct of accelerator operations at Fermilab. Water with low levels of tritium is pumped out of the accelerator tunnels and used in our onsite industrial cooling systems and cooling ponds. The tritium found in Indian Creek stems from the NuMI/MINOS experiment, which began in February 2005. The accelerators that provide proton beams for these experiments run at higher intensity than in the past.

Where can you get more information?
If you have any concerns or questions about tritium at Fermilab, please call Fermilab's Office of Communication at 630-840-3351. We welcome your questions and will be pleased to provide additional information.