Western University, corrosion awareness day 2021, Corrosion of lead pipes, used nuclear fuel containers, and steel-reinforced concrete.
Contributors: Arthur Situm, Lila Laundry-Mottiar, Claire Tully, Saman Nikpour, Yolanda Hedberg, Jamie Noël
Images from: Thalia Standish, Canadian Nuclear Safety Commission, Ontario Power Generation, Nuclear Waste Management Organization, SNC-Lavalin
Historical Pipe Corrosion in London, Ontario
In London, Ontario, there has been a history of lead pipes being used for drinking water distribution. Many homes have had them replaced but there is a possibility that some still remain. Lead pipes are susceptible to corrosion due to the ions present in water, which can cause the lead to leach out of the piping and into the water. To try to prevent this leaching, some of the lead pipes were exchanged with copper pipes. However, the new connection of copper to lead accelerated the problem through galvanic corrosion. This is a very big issue, as lead can be very toxic to the body. Ingestion of lead can result in reproductive toxicity, anemia, kidney and brain damage. In 2016, it was reported that more than 200 homes had lead pipes replaced and the city estimated that about 4,350 full lead services remain in London homes. If your home was built before 1953, you should check out the water service because there is a possibility it could still be lead.
The Long-term Storage of Canada’s Spent Nuclear Fuel
About 15 percent of Canada’s electricity comes from nuclear power. Once the power is harnessed in the nuclear fuel plants, the produced used fuel bundles require storage until they are no longer radioactive. There are approximately 2.9 million used fuel bundles that require permanent storage. That’s enough to fill eight hockey rinks from the ice to the top of the boards. The used fuel bundles are stored first in pools, also known as wet storage, and then in dry storage. During this time, the radioactivity of the bundle significantly decreases. The radioactivity of these bundles will diminish after approximately 100,000 years. Therefore, we need a long-term storage solution. The Nuclear Waste Management Organization in Canada suggests the commission of a deep geological repository, in which the used fuel will be placed in copper-coated and carbon steel reinforced canisters. These copper-coated canisters will be put in bentonite clay boxes and be placed 500 meters below ground in Canada’s host rock. Scientists and engineers study the corrosion of these canisters to ensure that Canada’s groundwaters do not reach the fuel bundles, which could lead to the possible contamination of the surrounding environment.
The Corrosion of Steel-Reinforced Concrete by Road Salt
In the winter, we use road salt to lower the melting point of ice. Doing this helps increase the safety of our roads by keeping them free of ice but there are drawbacks, one of which is the corrosion of metal parts of vehicles. Moreover, as the ice melts, the salty water from the road seeps into the steel reinforced concrete of bridges, accelerating the corrosion of the steel rebar within the bridge and eventually causing the surrounding concrete to break off in a process known as spalling. This damage is costly, as it typically requires the replacement of the concrete structures, and, if left unchecked, can lead to safety concerns. The Gardiner Expressway in Toronto is a notable example. In 2012, after multiple instances, where sections of concrete fell onto the road (and in one case a car was even struck), it was estimated by the city that a backlog of over half a billion dollars worth of repairs had occurred.