Text For Citation: 02 Item/Group: 003 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 recogn ized 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 the m at high velocity - was not implemented in such a way as to protect employees f rom the hazard of an explosion caused by venting large amounts of natural gas in to areas where it could accumulate and where, or in close proximity to where, ig nition sources existed. The following conditions and practices contributed to th e existence of this hazard: the vent pipe configured close to and below scaffold ing, in close proximity to the Power Generation Building, in the area immediatel y east of the two approximately 115 foot tall Heat Recovery Steam Generators (HR SGs) and well below the tops of all of those structures; the failure to eliminat e open flame ignition sources, including but not limited to propane heaters; con struction work occurring during the gas blow process; individuals other than tho se essential to conducting the gas blows working in the area during the gas blow process; and the inability to readily control the amount and pressure of gas fl owing through the main gas fuel line. On February 7, 2010, employees were exposed to serious or fa tal impact and other injuries from an explosion hazard created when a large amou nt of natural gas was blown at high velocity through CT#2 Pilot Gas Filter Separ ator "A" Vent Pipe (561- SEP-2000A) into the area immediately east of HRSG numbe r 2 and close to buildings, scaffolding, partially enclosed work areas, and othe r structures that were adjacent to the Power Generation Building in which employ ees worked and in or around in which open flame ignition sources, including but not limited to propane heaters, existed, construction work was occurring, and nu merous employees non-essential to conducting the gas blow were working. When nat ural 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 a ll other nearby structures, or horizontally to a location away from structures t hat could inhibit the adequate dispersal of the gas; ensure that any and all ign ition sources are eliminated; ensure that any and all construction activity ceas es during the gas blow process; ensure that all workers other than those essenti al to conducting the gas blows are removed from the building and area around whi ch the gas blows are occurring; and ensure the use of devices to control the amo unt and pressure of gas vented, such as a fast closing pipe shut-off valve and a gas pressure control valve.