23. September 2014
Nuclear power plants are stringent about safety and control. Protocols spell out the steps to resolve emergency scenarios ranging from equipment failures to loss of power to an inability to cool the reactor core, allowing crews to quickly address and prevent disasters. But what about the events that can’t be predicted?
Earthquakes, tsunamis, and other weather events and natural disasters are some of the biggest challenges facing nuclear power plant operators today, especially with the Fukushima nuclear power plant meltdown in 2011 still fresh in many minds. These are exactly the kinds of external events that nuclear power plants must prepare for, according to a recent report from the National Academy of Sciences about the lessons learned from Fukushima. And in one aspect of nuclear safety, glass is helping them do so.
Learning from Fukushima
At Fukushima, an earthquake knocked out power and the subsequent tsunami flooded equipment used to monitor, control, and cool the reactors. The radiation leak that followed was the worst nuclear disaster since Chernobyl.
The National Academy of Sciences report concludes that such large-scale natural disasters that occur outside a power plant should be a more integral part of plant safety preparations, adding to the procedures already entrenched for emergencies arising from within. Following the recent earthquake in California, some are already heeding this advice, questioning whether the Diablo Canyon nuclear power plant could withstand such an event.
Glass-to-metal sealed electrical penetration assemblies
One aspect of preparing nuclear power plants against natural disasters involves the components that feed power, control, and instrumentation cables through the containment walls of a nuclear reactor. These electrical penetration assemblies (EPAs) must maintain the pressure boundary integrity of the structure. EPAs must withstand radiation, high pressure and temperature levels, as well as unforeseen problems, such as flooding or earthquakes.
Glass-to-metal sealed EPAs developed by SCHOTT have been installed in power plants and on nuclear submarines throughout the world, and in some cases, have continued to do their job with little to no maintenance since the 1960s, when nuclear power was still in its infancy. Unlike some more traditional, organic polymer EPAs, glass-to-metal sealed EPAs don’t break down.
SCHOTT’s EPA, SCHOTT Eternaloc, has passed environmental tests including survivability in test conditions similar to an earthquake with a magnitude of 12 on the Richter scale, as well as extremely high temperatures and pressures. A new EPA, developed for the Vattenfall Forsmark 3 nuclear reactor in Sweden, is designed to maintain its integrity even after being submerged in water for 30 days at a depth of 13 meters.
It was impossible to predict the earthquake and following tsunami that created the tragedy at Fukushima. But technologies like SCHOTT EPAs exist to help reduce the risk of catastrophic natural disasters in nuclear facilities. Taking steps to increase safety protocols at our nation’s nuclear power plants ensures the safety and reliability of nuclear power in today’s world, as well as for many years to come.