In addition, the modular design could make it more difficult to inspect and maintain key components, many of which would be located within the pressurevessel at the heart of the reactor, he said.
The drywell is a large steel pressurevessel that looks like a giant upside-down pear and holds the reactor and primary pumps, and the wetwell is a large toroidal vessel that looks like a donut.
The central element will be a naphtha cracker, a stainless steel vessel that under intense heat and pressure breaks long hydrocarbons into plastics precursors.
That is a very different situation than at Fukushima Daiichi, where the fuel in three reactors is thought to have burned holes in their immediately surrounding pressure vessels, and in one case to have fallen all the way through to the bottom of the outer containment vessel.