Adds Maduro remarks.
A 100,000 b/d crude distillation unit at Venezuelan state-owned PdV's 635,000 b/d Amuay refinery exploded yesterday, according to a refinery manager and a labor union official on the site.
The unit was in recirculation mode when the incident occurred at 2:37pm ET.
The blast at Amuay's CD-4 is a setback in PdV's choppy efforts repair Amuay and the nearby 305,000 b/d Cardon refinery in order to boost gasoline production. Venezuela has been in the throes of a severe fuel shortage for most of this year.
The manager described the damage at Amuay as "very considerable" but said an investigation is still underway.
The union official said the incident may have been caused by a water leak that triggered a vapor blast.
The internal damages "appear initially to be so severe that the unit could be irrecoverable and may have to be rebuilt completely, but we have to wait until accident investigators complete their technical reports," the union official said. He blamed PdV for cutting safety corners in its rush to manufacture gasoline.
Amuay's CD-4 and CD-1 distillation units "should have been shut down completely when the refinery's industrial services failed on 23 October, but PdV ordered that both units be placed into recirculation mode avoid lengthy safe restart protocols," the official added.
The Amuay refinery manager confirmed that the CD-4 and CD-1 units had been in recirculation mode since water and electricity supplies to the refinery failed early this week. CD-1 is still in recirculation mode.
In familiar remarks today, President Nicolas Maduro said the refinery blast was a US-financed terrorist attack using a "powerful long-range weapon" designed to set the plant ablaze, adding that oil minister Tareck El Aissami would soon present evidence of the attack.
His government frequently blames the US and Venezuela's US-backed political opposition for infrastructure breakdowns, including electricity blackouts.
The US routinely escalates sanctions on Venezuela, but the Pentagon has dismissed military options to force Maduro out of power.
In his press conference today, Maduro said PdV has 20 days of gasoline supply, without specifying the daily consumption figure on which the estimate is based.
He pledged that all of PdV's refineries will restart gasoline production by December.
PdV has 1.3mn b/d of installed refining capacity in Venezuela, almost all of which is broken.
