A third of the nation’s atomic power plants still have additional work to complete on computer systems to be fully ready to deal with the Y2K computer bug, this according to the Nuclear Regulatory Commission. Massachusetts Democratic Congressmember Edward Markey, a consistent critic of the NRC, said yesterday the report only confirmed his fears about the lack of preparation of nuclear plants for the Y2K bug. Markey last week questioned whether power plants are ready to deal with possible Y2K-related blackouts, after an NRC letter revealed that both emergency power generators at New Hampshire’s Seabrook nuclear plant were simultaneously inoperable for about a week. Dr. Helen Caldicott has called for all nuclear power plants to be closed before the year 2000 to avoid major problems.