The injured employee was conducting maintenance at the plant and was at the reactor slurry line to open the valve to drain the slurry out so it did not solidify. Steam in the line was turned on from the control room. When the employee went to rod out the valve, the material broke loose due to the steam pressure and sprayed hot reactor slurry onto the employee. The slurry contained phosphoric acid and ammonia. The employee sustained chemical burns to both arms and was hospitalized.