CONSUMERS ENERGY CO

Incident Narrative

ON JANUARY 3, 2014, THE PILOT REGULATOR ON THE PRIMARY RUN OF THE WEST METER INSTALLATION AT HEMLOCK SEMICONDUCTOR ICED UP, CAUSING THE FIRST CUT REGULATOR TO OPERATE WIDE OPEN. AS A RESULT, THE FIRST CUT RELIEF VALVE (NOMINAL SIZE = 6"") ACTUATED AND VENTED GAS TO THE ATMOSPHERE THROUGH THE RELIEF STACK. THE RELIEF VALVE BLEW FOR APPROXIMATELY THREE HOURS, VENTING 3.375 MMCF (MILLION CUBIC FEET) IN THE PROCESS. FIRE DEPARTMENT PERSONNEL BLOCKED OFF A ONE-MILE SECTION OF GEDDES ROAD ADJACENT TO THE FACILITY, AND SEVERAL EMPLOYEES WERE MOVED TO ANOTHER BUILDING ON THE SITE AS A RESULT OF THE INCIDENT. MEDIA WAS ON SITE REPORTING THE INCIDENT. UPON RESPONDING, THE PILOT REGULATOR WAS THAWED AND THE FIRST CUT PRIMARY REGULATION AT THE METER INSTALLATION WAS RETURNED TO NORMAL OPERATING CONDITIONS. AS A REMEDIAL MEASURE, A HEATER WAS INSTALLED ON THE PRIMARY RUN REGULATOR & PILOT, AND CONTROL LINES WERE HEAT-WRAPPED AND INSULATED TO HELP PREVENT RE-OCCURRENCE. INCIDENT NOTIFICATION TO THE NRC WAS DELAYED BECAUSE THE RELEASE VOLUME WAS INITIALLY ESTIMATED TO BE LESS THAN 1MMCF AND THEREFORE WOULD NOT MEET THE CRITERIA FOR A FEDERALLY REPORTABLE INCIDENT. SUBSEQUENT INCIDENT INVESTIGATION AND GAS LOSS CALCULATIONS PERFORMED CONFIRMED A GAS LOSS VOLUME OF APPROXIMATELY 3.375 MMCF THEREBY MAKING THE INCIDENT REPORTABLE AND NOTIFICATION TO BOTH THE NRC AND PEAS WERE REQUIRED.