NUCLEAR POWER UPDATE: TVA, B&W poised to put small modular reactors to the test. “The smaller, simpler design of modular reactors makes it possible for a power company to scatter them in more sites — maybe even a decommissioned coal plant — or to cluster them to get the effect of a full-sized reactor, proponents say. . . . Encased in its vessel, the B&W mPower reactor will be 83 feet high and 13 feet in diameter and will look something like a giant spark plug. It will have a capacity of about 180 megawatts of power compared with about 1,100 megawatts for a standard reactor. On the TVA grid, 1 megawatt powers about 585 homes, said TVA spokesman Travis Brickey. . . .Its cooling system would work on a cycle in which water cools the reactor core, boils to the top of the vessel as steam, cools, condenses and falls back to the reactor as water. This is an important safety feature because all the pumps and pipes and tanks on a typical reactor are places where leaks can happen, Hoagland said.”