Picture a 33 year-old asphalt road: weathered with time, bearing the cracks and crags of decades of harmless-seeming water trickling into its crevices, freezing, expanding, breaking up the road from within.

Most people wouldn’t want to trust their car to the safety of a road like this.

And it certainly isn’t the image anyone wants to invoke when talking about critical equipment in nuclear reactors.

Action at Doel Steam Generator in Belgium. 04/29/2004 © Greenpeace / Philip Reynaers

Yet, on Friday the 13th, two leading materials scientists announced that the Belgian reactors, Doel 3 and Tihange 2, may be experiencing the nuclear equivalent in their reactor pressure vessels; essentially the piece of equipment that contains the highly radioactive nuclear fuel core being comparable to an old, busted up road.

Thousands of cracks have been discovered in the pressure vessels of both reactors. This component is required to be integrally sound, with no risk of failure, due to the potentially catastrophic nuclear disaster resulting from the failure of a pressure vessel.

As reactors age, the steel of the reactor pressure vessel is damaged – or embrittled – by radiation. According to the scientists, hydrogen from the water in the pressure vessel – which cools the nuclear fuel core – may be corroding the steel by injecting hydrogen atoms into the steel of the vessel itself, where it can accumulate and build up pressure, resulting in the steel blistering – effectively breaking up the pressure vessel from within.

Tests revealed a stunning 13 047 cracks in Doel 3; and 3 149 cracks in Tihange 2.

Action at Tihange Nuclear Power Plant in Belgium. 03/05/2014 © Philip Reynaers / GreenpeaceAfter first discovering the problem and shutting down the cracked reactors in 2012, the Belgian Federal Agency for Nuclear Control (FANC), dismissed the issue as a manufacturing problem and okayed the reactor to be start up again in 2013. They did so while acknowledging that they did not to fully understand what was happening inside the reactor steel. However, further testing revealed unexplained and unexpected embrittlement of a test steel sample. Following these findings, both reactors were shut down again since March 24, 2014.

But, the announcement of the materials scientists now go one step further: they state that the problem may well be the result of normal reactor operations. This means the cracks may be growing in size, and furthermore, that this could be endemic to the global nuclear fleet. Simply put: the findings in Belgium have serious safety implications for every nuclear reactor on the planet.

In response, the Director General of the Belgian nuclear regulator, The Federal Agency for Nuclear Control (FANC), admitted that, "This may be a global problem for the entire nuclear industry. The solution is to implement worldwide, accurate inspections of all 430 nuclear power plants.”

When the head of a federal nuclear regulator says that every reactor in the world needs to be inspected for a critical nuclear safety problem, the smart thing for national nuclear regulators to do is take immediate action. Certainly, every reactor needs to be inspected for such cracking at the earliest possible date, but no later than the next maintenance outage. 

Electrabel, operator of the Belgian reactors, has reacted to the latest news by saying that it may be willing to “sacrifice” one of its crippled reactors to scientific study; meaning they would permanently shut down the reactor and allow destructive testing in the hopes of learning more about this previously ignored or dismissed nuclear safety problem. 

Given that this phenomenon has not been sufficiently studied and is poorly understood, restarting any reactor in which cracking is found would not only constitute a nuclear experiment, it would place the public at unnecessary and unacceptable risk. There are 1.5 million people living within 30km from the Doel reactor, which is close to the Dutch border.

Every reactor needs to be inspected – and before the old, busted up nuclear road leads to yet another catastrophic nuclear disaster.

Kendra Ulrich is a Senior Energy Campaigner with Greenpeace Japan.

Eloi Glorieux is an Energy Campaigner with Greenpeace Belgium.