The CIA told Congress yesterday that there’s cause for concern about the Y2K bug compromising the safety of aging Soviet-era nuclear power plants in Russia and Ukraine. The risk of an accident is low, said Lawrence Gershwin of the CIA, but still higher that usual because computer problems could be aggravated by power failures. A worst-case scenario would result in a meltdown and possible release of radioactive fission gases. Making all the Soviet-designed power systems immune to computer problems is “not feasible,” according to Gershwin. In addition to Russia and Ukraine, China and Indonesia are the major countries most likely to experience serious Y2K problems.