Dear Jesse, To the left is a greatly simplified depiction of a Light Water Reactor core. The core is only the beginning of Light Water reactor complexity. Chris Mowry of Babcock & Wilcox told Robert Bryce
"We estimate there would be between 500 and 1,000 jobs at the site throughout the three-year field construction period."That gives us somewhere from 2.5 to 5 million hours of labor on site to construct the B&W mPower reactor and its facility. This is no small project and suggests something of the daunting complexity of building a large reactor will also confront the builders of small Light Water Reactors. If factory labor is several times more efficient than on site construction labor, B&W has failed to move enough labor from the reactor site to the the factory. Thus the small Light Water Reactor proves to be something of a disappointment in that it will not offer an economic advantage compared to larger reactors. Chris Mowery stated,
The B&W mPower reactor uses the best features and elements of existing Generation III+ technology. This is technology with which the NRC is familiar, and for which NRC regulatory and licensing protocol already exists. By avoiding the use of new Generation IV technology concepts, we will ensure that the NRC is reviewing designs and reactor technology that it already has the ability to license.It would appear that B&W believed that it had a choice between Generation III+ and Generation IV nuclear technology and chosen the former because of a perceived weakness of the NRC to assess new nuclear Generation IV technologies..
The major advantage of a small reactor would be that it would allow for the transfer of labor from the reactor site to the factory. Professor Andrew Kadak,, who teaches nuclear engineering at MIT, has pointed out what happens when labor is transferred to the construction site to the factory.
Building a reactor in a factory should save construction time, says Kadak. He estimates that what takes eight hours to do in the field could be done in just one hour in a factory. Once the reactor is manufactured, it would then be shipped to the site of a power plant along with the necessary containment walls, turbines for generating electricity, control systems, and so on.
The great advantage of China and India in the construction of Generation II and Generation III reactors is that it is labor intensive and their labor costs are low. In order for European and American nuclear power to be cost competitive with the power produced in China and India, labor must be used with factory like efficiency. Thus if tasks requiring a day can be completed in on hour, all through the construction system,labor consts can be dramatically lowered.
In addition to moving reactor construction labor from the construction site to the factory, reactor design must be simplified and the production system automated. We have already noted the relative complexity of Generation II and III reactor cores. Here is the design of an extremely simple, low cost and safe Generation IV Molten Salt Reactor core. The core is basically made up of two hollow cylinders, one inside of the other. This core design is light weigh because it lacks internal structure, and because, unlike the Light Water mPower Reactor the Molten Salt Reactor operates under atmospheric pressure.
The Molten Salt Reactor (MSR) is not just simpler, it is more compact. It can be housed in a smaller structure. Compact cores mean smaller housing. The MSR cannot explode, that means a smaller containment structure is required. The late Edward Teller, proposed locating MSRs underground for safety. Underground locations also protect against terrorists attacks via truck bombs or aircraft. Underground locations mean that massive and labor intensive containment structures are not required.
Of course some features of the MSR are not as simple as this core design. But it would appear that the MSR concept holds real promise of lowering reactor labor costs, while significantly adding to nuclear safety, and offering a sustainable nuclear technology that could provide high levels of energy to human society for hundreds of thousands and perhaps millions of years.