Ramana, Makhijani: Look Before You Go Nuclear | Columns
Cowboy State plans to host a multibillion-dollar “demonstration” nuclear power plant – TerraPower’s Natrium Reactor. The long history of similar nuclear reactors, dating back to 1951, indicates that Wyoming will likely end up with a nuclear lemon on its hands.
The design of the Natrium reactor, which uses molten sodium as a coolant (water is used in most existing commercial nuclear reactors), is likely to be problematic. Sodium reacts violently with water and burns if exposed to air, a serious vulnerability. A sodium fire, a few months after the reactor started generating electricity, shut down the Japanese demonstration reactor at Monju.
With 1,200 megawatts, the French Superphénix was the largest sodium-cooled reactor, designed to demonstrate commercial feasibility. Plagued by operational problems, including a major sodium leak, it was shut down in 1998 after 14 years, operating at an average capacity of less than 7% of the 80-90% required for commercial operation. Other sodium-cooled reactors have also experienced leaks, which are very difficult to avoid due to the chemical interactions between sodium and the stainless steel used in various reactor components. Finally, sodium, being opaque, makes it notoriously difficult to maintain and repair reactors.
Sodium-cooled reactors can experience rapid surges that are difficult to control. Under severe conditions, an uncontrolled chain reaction can even lead to an explosion. Such a runaway reaction was the central cause of the Chernobyl reactor explosion in 1986, although it was a reactor of a different design. After Chernobyl, Germany’s sodium-cooled Kalkar reactor, roughly the same size as the Natrium project, was abandoned without ever being commissioned, although it was complete.