NV ENERGY

Incident Narrative

ON MARCH 22, 2018 AT 20:17, THE RENO FIRE DEPARTMENT WAS NOTIFIED OF A BUILDING FIRE AT 624 EUREKA AVENUE IN RENO, NEVADA. AT 20:25 NV ENERGY (NVE) WAS CONTACTED BY THE CITY OF RENO PUBLIC SAFETY DISPATCH NOTIFYING OF A ""WORKING FIRE"" AT 624 EUREKA AVENUE IN RENO, NEVADA. NVE GAS DISPATCH SENDS GAS SERVICEMEN TO INVESTIGATE. AT 20:51 THE CITY OF RENO PUBLIC SAFETY DISPATCH CONTACTED NVE AGAIN TO REPORT THAT THERE WAS AN EXPLOSION AT THIS LOCATION, POSSIBLY FROM THE FURNACE. AT 21:02 THE FIRST NVE PERSONNEL ARRIVE AT THE SITE AND FOUND THE HOME AT 624 EUREKA AVE DAMAGED BY WHAT APPEARED TO BE A GAS EXPLOSION WITH INDICATIONS OF UNDERGROUND GAS READINGS. RENO FIRE DEPARTMENT AND NVE PERSONNEL EVACUATE THE NEIGHBORHOOD AND MONITOR GAS CONCENTRATIONS WHILE OTHER NVE PERSONNEL EXPOSE THE SERVICE TEE AND SECURE THE GAS LEAK. THE LEAK OCCURRED AT THE THREADED JOINT BETWEEN A 3/4"" BLACK IRON PIPE NIPPLE AND A 3/4"" BLACK IRON 90 DEGREE ELBOW AT THE SERVICE TEE CONNECTION TO 614 EUREKA AVENUE. BASED UPON THE RENO FIRE DEPARTMENT INCIDENT REPORT, NATURAL GAS LEAKING FROM THE SERVICE TEE APPEARS TO HAVE TRAVELED THROUGH A SERVICE TRENCH INTO THE BASEMENT OF 624 EUREKA. THE LEAKING GAS WAS IGNITED IN THE BASEMENT BY THE FURNACE, EXPLODED, AND DAMAGED THE HOME. TWO INDIVIDUALS WERE IN THE RESIDENCE AT THE TIME OF THE EXPLOSION BUT NO INJURIES WERE SUSTAINED. THE CAUSE OF THE FAILURE IS STILL UNDER INVESTIGATION AND A SUPPLEMENTAL REPORT WILL BE FILED WHEN THE CAUSE IS DETERMINED. AT 22:36 THE NVE DUTY SUPERVISOR ON SCENE DETERMINED THAT THE PROPERTY DAMAGE COSTS WOULD EXCEED $50,000. THE INITIAL NOTIFICATION TO THE NATIONAL RESPONSE CENTER (NRC) WAS MADE AT 22:49 AND WAS GIVEN NRC INCIDENT REPORT # 1207485. NVE PROVIDED AN UPDATE TO THE NRC ON MARCH 23, 2018 AT 15:44 AND WAS GIVEN NRC INCIDENT REPORT # 1207546. SUPPLEMENTAL UPDATE: FURTHER ANALYSIS HAS DETERMINED THAT THE PIPE-TO-ELBOW JOINT FAILED DUE TO OVERLOAD FROM AN EXTERNAL BENDING LOAD AND NOT DUE TO A MATERIAL OR MANUFACTURING DEFECT ASSOCIATED WITH THE PIPES OR FITTINGS. THE EXTERNAL BENDING LOAD AT THE FAILED PIPE-TO-ELBOW JOINT OCCURRED AS A RESULT OF LOADING IMPARTED TO THIS JOINT DURING COMPACTION AROUND THE TEMPORARY SERVICE CONNECTION. NV ENERGY'S CONTRACTOR WAS PERFORMING BACKFILL AND COMPACTION ACTIVITIES ON THIS TEMPORARY SERVICE CONNECTION ONE DAY PRIOR TO THE INCIDENT OCCURRING. FINAL UPDATE: ANALYSIS HAS CONCLUDED AND THE INCIDENT WAS CAUSED BY A LEAK FROM A CRACK IN THE BLACK IRON PIPE USED FOR THE TEMPORARY SERVICE CONNECTION FOR THE NEIGHBORING PROPERTY 614 EUREKA AVENUE. THE GAS MIGRATED INTO THE BASEMENT OF THE INCIDENT HOUSE WHERE IT FOUND AN IGNITION SOURCE, MOST LIKELY THE HOUSE FURNACE. THE DIRECT CAUSE OF THE CRACK IN THE PIPE WAS MECHANICAL OVERLOADING OF THE HORIZONTAL SECTION OF THE TEMPORARY SERVICE CONNECTION. THE MECHANICAL OVERLOADING WAS LIKELY CAUSED DURING COMPACTION OF SAND AROUND THE TEMPORARY SERVICE CONNECTION, DUE TO INSUFFICIENT COVER (SAND ABOVE THE PIPE) DURING COMPACTION.