NEW : Anti-nuclear activists warn of a potential environmental catastrophe . The San Onofre nuclear plant has been shut down since radioactive gas escaped . Score: 6 Eight of the more than 9,700 tubes in one of the unit 3 generators failed a pressure test , while six tubes in unit 2 's reactor needed to be plugged , the NRC has found . The head of the NRC says the plant wo n't restart until a cause and plan is put forward .
NEW : Anti-nuclear activists warn of a potential environmental catastrophe . The San Onofre nuclear plant has been shut down since radioactive gas escaped . Score: 6 The head of the NRC says the plant wo n't restart until a cause and plan is put forward .