Tritium emissions from Point Lepreau pose health hazard

Recently, Point Lepreau has been scrutinized for costs that could reach $294 million for its 249-day outage, its contribution to about three-quarters of NB Power’s nearly $5.4 billion debt, and whether it should be shut down. Missing from discussion, however, are the reactor’s tritium emissions and the health hazard they pose.

All CANDU reactors like Point Lepreau use heavy water to sustain a chain reaction to produce steam that drives a turbine to generate electricity, and to prevent the core from overheating and melting down. Over time, tritium, or radioactive hydrogen, builds up in the heavy water. To reduce the risk of exposing nuclear workers and the public to increasing radiation levels, the heavy water from the moderator system must be treated or replaced.

NB Power was asked if Point Lepreau’s heavy water had ever been replaced or treated. Through email, Kathleen Duguay, manager, community affairs and nuclear regulatory protocol at Point Lepreau responded as follows:

“The Station has not undergone a replacement of heavy water since the reactor began operations.”

“…we have not removed the water from the reactor and transported it to the Darlington Tritium Removal Facility for tritium removal and returned to Point Lepreau and reused in the reactor.”

This refers to the lifetime of the reactor and explains why tritium emissions from Point Lepreau are higher than other nuclear power plants in Canada.

The belief that tritium’s health risks are minimal has been refuted by Dr. Ian Fairlie, a retired radiation

Governmentʼs biologist and former head of the U.K.

Committee Examining the Radioactive Risks of Internal Emitters (CERRIE), a scientific committee on internal radiation risks.

According to Fairlie, human exposures to tritium occur when radioactive water vapour or tritium gas is inhaled, absorbed through the skin, or ingested in food and drinking water.

Once inside the body, some of the tritium attaches to proteins, fats, carbohydrates and DNA molecules to form organically-bound tritium. Unlike radioactive water which lasts for only about 10 days in adults before it is excreted, organically-bound tritium lingers, emitting radioactively for long periods, in the case of nerve tissue and DNA, for a lifetime.

NB Power’s environmental studies acknowledge local residents are exposed to tritium in water vapour, well water, seafood, dulse, wild mushrooms, berries, garden vegetables, honey hives, and seaweed for fertilizer.

Years ago, the Ontario government asked the Ontario Drinking Water Advisory Council to examine how adequately the regulatory limits of tritium in drinking water protected public health. The council compared cancer risks of tritium with those of other chemical carcinogens and recommended that the allowable limit be reduced by a factor of 350. This recommendation was never implemented.

Epidemiology studies at Canadian facilities that emit tritium find increases in cancer and birth defects, yet NB Power doesn’t measure tritium levels in people near Point Lepreau. Such studies should be done. If negative health effects are found, more detailed cohort or case-controlled studies should be conducted.

Tritium exposures are overwhelmingly internal from radioactive water and organically-bound tritium. This health hazard from Point Lepreau deserves as much attention as its financial liabilities.