EE WAS OPENING THE SUCTION VALVE ON #4 SETTLER OVERFLOW PUMP AND FELT A STRAIN IN RIGHT GROIN. HE AWOKE THE NEXT MORNING AND NOTICED SORENESS AND SWELLING IN HIS GROIN. HE THEN CONTACTED THE PLANT NURSE AND LET HER CHECK HIM OUT. NURSE SENT HIM TO DOCTOR WHO DIAGNOSED HIM WITH STRAINOF THE GROIN. HE WAS PLACED ON RESTRICTED DUTY AND RETURNED TO WORK THAT NIGHT.