Carbon-14 Management: The Implementation of Stack Emissions Monitoring at Ontario Hydro Nuclear

Abstract

The CANDU system generates higher levels of carbon-14 (14C) than any other reactor type. More than 95% of this production occurs in the moderator and most of this is captured on the moderator ion exchange column resins with a small fraction being released to the environment. In the past, OHN has depended mainly on environmental measurements of 14C to assess the impact of its emissions. In 1995, the Advisory Committee on Radiological Protection published a report, ACRP- 14, entitled: "The Management of Carbon-14 in Canadian Nuclear Facilities". The report recommended mandatory emissions monitoring at all OHN generating facilities along with reporting of 14C inventory and the provision of information on the stability of stored ion exchange resins which retain the 14C. OHN has responded by committing to implement 14C emissions monitoring by the end of 1999, reporting the OHN 14C inventory and supporting research into resin and 14C stability in storage. 'State-of-the-art' stack samplers, manufactured by a local company, BOT Engineering, have now been delivered to the various OHN locations and are either being installed or are awaiting installation.