Fire broke out at an off-line nuclear power plant in Japan today, injuring one worker but releasing no radioactivity, UPI quoted the company as saying. Tokyo Electric Power Co. said smoke was detected coming from the Kashiwazaki-Kariwa plant's No. 1 reactor about 9 a.m. and the fire was extinguished a half-hour later, Kyodo news service reported. The injured worker suffered minor facial burns, firefighters said. The fire, the eighth reported since the plant's operations were suspended, started in an underground pump cabin that cools the reactor, Kyodo said. Firefighters suspect it started with organic solvent the worker was getting prepared to use in the area.