Mapping Radioactivity to Improve Nuclear Emergency Response

By Emmanuelle Brière
December 2010

A helicopter used by NRCan to carry sensing equipment returning after a practice radiation survey.

Over the last few years, Natural Resources Canada’s (NRCan’s) Nuclear Emergency Response Team has been active on two fronts of significant importance to public health and safety: coordinating emergency response exercises with provinces and providing a cartographic service to detect radiation following nuclear incidents. The Nuclear Emergency Response Team is the responsibility of the Geological Survey of Canada (GSC) as part of the Federal Nuclear Emergency Plan created in partnership with Health Canada (HC) and other federal departments.

Example of a Successful Incident Simulation

Last May, the team received a special request from the Regional Branch of the Environmental Control Centre for Mauricie and Centre-du-Québec (part of Quebec’s MDDEP — Ministère du Développement durable, de l'Environnement et des Parcs) to conduct a field exercise as part of an incident simulation at the Gentilly-2 nuclear station near Bécancour, about 100 km northeast of Montreal.

During the simulation, helicopters mounted with specialized detection equipment provided by NRCan flew at low altitude over the nuclear station and also the Bécancour Industrial Park in order to measure the ambient radiation. All the operational procedures of the Emergency Response Plan — including radiation mapping and the sampling and analysis of soil and surface water — were accomplished successfully.

Advantage of Radiation Emergency Mapping

Installation of radiation detection equipment in a helicopter for an airborne survey exercise.The red boxes are gamma radiation detectors, also shown is the control unit and neutron detector.

NRCan’s GSC has a long history of working with the remote measurement of radiation. In the 1960s, it pioneered the development of techniques to map the presence of naturally occurring radioactive substances — such as uranium, potassium and thorium — in rock formations. Today, these same fundamental techniques are used to improve our ability to respond to nuclear incidents.

The likelihood of a nuclear emergency is very small. But it is critical that tools and strategies be available in the event of such an emergency. Radiation itself is a natural phenomenon, and normal levels are found all around us, in the ground and in the air. The special case of the excessive radiation that could result from a reactor accident, for instance, would present a real danger to the Canadian population.

For radiation to be managed, its location must first be pinpointed. Thanks to specialized aerial surveys and ground gamma ray spectrometry, the Nuclear Emergency Response Team is able to construct a highly accurate and detailed map of radiation and determine if radiation levels are abnormally high.

“NRCan’s role is the creation of maps of radiation distribution so that one can get an idea of where the radiation is stronger and where it’s weaker,” says Henry Seywerd, physicist in the Earth Sciences Sector (ESS) of GSC. “Decision-makers can then determine what needs to be done within different geographical areas to mitigate the potential effects of an accident.”

Contributing to Provincial Emergency Procedure Exercises

Map of radiation dose distributions in the region around the Becancour industrial site and the Gentilly-II reactor as acquired by the NRCan survey. Dose levels are consistent with background levels, and are dominated by the natural radioisotopes in the stone and concrete in the area.

Should a major incident occur, mapping tools would be essential. The provinces do not themselves have these technologies but must rely on the services of the federal government. That’s when NRCan’s Nuclear Emergency Response Team is mobilized. And since an incident could happen at any time, the team is always ready.

“We are available 24 hours a day, seven days a week,” says Henry. “Our goal is to be able to provide two people as well as the equipment ready to leave Ottawa within four hours of a phone call and to travel to the incident location. We get there as quickly as possible, set up, produce the maps and help that way.”

For more information on this important work, visit the Federal Nuclear Emergency Plan.

To read about related articles, see Maps & Mapping

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