Tritium Studies Project Synthesis Report

About the report

The Tritium Studies Project Synthesis Report is the summary report of a series of research studies being produced by the Canadian Nuclear Safety Commission (CNSC) under its Tritium Studies Project. The goal of the research is to expand the body of knowledge on tritium and to further enhance regulatory oversight of tritium-related activities in Canada. The synthesis report summarizes the studies and provides overall conclusions and recommendations. The report was updated at the request of the Commission to reflect intervener comments from the June 2010 Commission Meeting and to expand the explanation for the recommended limit for tritium in groundwater. The revised report was released in January 2011.

Highlights

The main conclusion of the Tritium Studies Project is that Canada's regulatory framework has been effective in protecting the health and safety of Canadians. Canadian facilities are currently using best practices for tritium, with effective control being achieved through a variety of mechanisms.

The Synthesis report recommends that the CNSC undertake the following actions.

To make the regulation of tritium even safer:

  • Establish a multi-stakeholder, tritium working group to assist with epidemiology studies examining lifetime exposure to tritium at low doses and to consider additional studies in radiobiology and dosimetry, including review of the radiation weighting factor for tritium.
  • Continue its research into the chemical forms of tritium in human and animal foods while assessing the sensitivity of dose estimates to high amounts of organically bound tritium in some food items.

To protect future drinking water resources:

  • Address groundwater protection issues at existing facilities at the policy level in consultation with the provinces. In the interim, CNSC staff is drafting regulatory documents providing expectations for groundwater protection, and providing guidance on contaminated site assessments. 
  • Address groundwater protection issues for all new Class I Nuclear Facilities that release tritium to the atmosphere by considering new design requirements, including: 
    • a design objective for tritium level in groundwater of 100 Bq/L
    • a controlled zone of sufficient size to ensure that the design objective of 100 Bq/L would be achieved at the perimeter given discharges of tritium to the atmosphere under normal operations
    • design criteria for release points (stacks) to ensure the effective dispersion of tritium in an atmospheric plume and to minimize environmental contamination.

To enhance environmental compliance monitoring:

  • Undertake work to identify factors that need to be taken into account for adequate calibration of active and passive air samplers for tritium. In the interim, licensees should be requested to provide data on the uncertainty in current measurements.

Read the report: Tritium Studies Project Synthesis Report (PDF)