Text For Citation: 02 Item/Group: 004 Hazard: HEAT

Section 5(a)(1) of the Occupational Safety and Health Act of 1970: The employer did not furnish employment and a place of employment which were free from recognized hazards that were causing or likely to cause death or serious physical harm in that the method used to clean the 561 main fuel gas line pipes - blowing natural gas through them at high velocity - was not implemented in such a way as to protect employees from the hazard of an explosion caused by venting large amounts of natural gas into areas where it could accumulate and where, or in close proximity to where, ignition sources existed. The following conditions and practices contributed to the existence of this hazard: the vent pipe configured close to and below scaffolding, in close proximity to the Power Generation Building, in the area immediately east of the two approximately 115 foot tall Heat Recovery Steam Generators (HRSGs) and well below the tops of all of those structures; the failure to eliminate open flame ignition sources, including but not limited to propane heaters; construction work occurring during the gas blow process; individuals other than those essential to conducting the gas blows working in the area during the gas blow process; and the inability to readily control the amount of gas and pressure flowing through the main gas fuel line. On February 7, 2010, employees were exposed to serious or fatal impact and other injuries from an explosion hazard created when a large amount of natural gas was blown at high velocity through CT#2 Pilot Gas Filter Separator "A" Vent Pipe (561- SEP-2000A) into the area immediately east of HRSG number 2 and close to buildings, scaffolding, partially enclosed work areas, and other structures that were adjacent to the Power Generation Building in which employees worked and in or around in which open flame ignition sources, including but not limited to propane heaters, existed, construction work was occurring, and numerous employees non-essential to conducting the gas blow were working. When natural gas is chosen for this method of cleaning gas line pipes, feasible means of abatement to eliminate or materially reduce the hazard are to ensure that the vent pipe is positioned vertically and above the Power Generation Building and all other nearby structures, or horizontally to a location away from structures that could inhibit the adequate dispersal of the gas; ensure that any and all ignition sources are eliminated; ensure that any and all construction activity ceases during the gas blow process; ensure that all workers other than those essential to conducting the gas blows are removed from the building and area around which the gas blows are occurring; and ensure the use of devices to control the amount and pressure of gas vented, such as a fast closing pipe shut-off valve and gas pressure control valve.