A new concept for nuclear power

Llewellyn King

Saturday, Sept. 15, 2012 | 2:01 a.m.

The company that has revolutionized war in the air with Predator drones wants to do the same thing for nuclear power. It wants to soar away from today’s reactor designs, rooted in the 1950s and the beliefs of Adm. Hyman G. Rickover, father of the nuclear Navy and by extension the nuclear industry.

Rickover’s legacy is the light water reactor, the technology in over 400 reactors making electricity around the world. But to the scientists at General Atomics (GA) in San Diego, Calif., the light water reactor is yesterday’s machine, like the land-line telephone, the radial aircraft engine, mechanical calculators and the silent movie.

GA, where the Predator was born along with a number of other “disruptive” technologies, believes it is time to shed the past and build new reactors that answer the concerns that have swirled around light water for decades.

Call it the new, improved, front wheel-drive reactor.

GA’s entry into the nuclear stakes — which are hot again because of Department of Energy interest in small modular reactors (SMRs) — is the Energy Multiplier Module (EM2) as in “e-m-squared.” It is derived from over 50 years of the company’s R&D on modular high-temperature reactors. If EM2 works as its enthusiastic designers believe it will, then nuclear power generation will be changed in the way that the Predator has changed warfare.

To the EM2 team, the old days of boiling water at relatively low temperatures to create steam to turn a turbine is first-generation technology: It is the technology of the 19th century with nuclear replacing coal in steam generation starting in the 1950s.

The EM2 uses helium to cool the reactor and directly drive the turbine with gas heated to 856 degrees Centigrade — more than twice the light water temperature. The helium will turn an enclosed turbine at an incredible 6,000 to 12,000 revolutions per minute for 30 years before the reactor has to be shut down. By contrast, conventional reactors have to be shut down and refueled every 18 months.

The company believes that the time is at hand for a new reactor with better physics leading to competitive economics, waste remediation and long life cycle.

GA believes that it has the scientific insight to manufacture the unique fuel for the EM2, a so-called fast reactor, and to clad it in silicon carbide.

The EM2 is designed to produce 240 megawatts of electricity, but a smaller 71-MWe version will come first. The cost of EM2 electricity is expected to be about half that from today’s water reactors. Most light water reactors are in the 1200 MWe range.

The GA plan is that the EM2 will be as revolutionary as some of its other high-tech products including the rail gun, an electromagnetic weapon; magnetic-levitating cargo pallets at docks; an electromagnetic launch system for aircraft on the USS Gerald R. Ford; and, of course, the Predator.

Because of the high operating temperatures of the EM2, it will be able to discharge waste heat easily and will not have to be located near abundant water, like rivers, bays and oceans.

It will use uranium as a starter fuel, enriched to 12 percent of fissile uranium 235 to get a neutron flux going, but after that it will burn nuclear waste or depleted uranium. It will effectively eliminate the nuclear waste issue and multiply the power gained from uranium fuel by a factor of 262 times over today’s water-cooled reactors.

The essence of a fast reactor is the high energy of the neutrons, ergo their ability to react with the fissile material left in nuclear waste and depleted uranium. Being a fast reactor, EM2 will both burn up nuclear waste and generate enough radioactive “seed” during its operational cycle to refuel another reactor.

The largest problem facing EM2, and other new reactors, is the lack of enthusiasm in the utility customer base. Natural gas is cheap and utilities would rather use that than go to new nuclear regime of any kind, let alone a machine that is revolutionary through and through.

So to raise the money — in this case about $4 billion — to build a demonstration reactor, GA is looking outside the utility customer base and the United States. It is talking to sovereign wealth funds, and sometimes directly to foreign governments, that want to secure the disruptive technologies of the future.

Llewellyn King is executive producer and host of “White House Chronicle” on PBS.