By Gregory Hale
Sometimes a company needs an incident or an extreme near miss to hammer home the importance of safety into the minds of all the workers.
Mike Broadribb knows that for a fact. He has been in two major process safety incidents.
“Sharing incidents that occur means we need to learn the lessons. Too often we share the information, but we don’t always learn,” said Broadribb, senior principal consultant at Baker Engineering and Risk Consultants in San Antonio, TX, during his Monday break out session during the 16th Process Plant Safety Symposium at the AIChE Spring Meeting and 10th Global Congress on Process Safety in New Orleans.
The one incident he focused on was with a Fluidized Catalytic Cracking Unit. When the incident occurred the unit was in the process of starting up. “Cat crackers take a long time to start up,” he said. “I had been working long hours and I was under pressure to get this unit started up because everything at the plant depended on this unit running.”
On the last day of the start up, Broadribb was doing a one-man PSSR (pre startup safety review) in addition to doing other tasks and they were getting ready for blank removal.
They were warming up the unit with steam when the workers were saying there was too much and they should reduce the amount. They reduced the steam and the blank ended up lifted out. The pipefitter was trying to clean the flange faces when he found one of the riggers collapsed and then Broadribb heard some yelling and screaming so he went out to investigate and it turned out the pipefitter collapsed. As he was running to the scene, which was at least three stories up, an instrument foreman collapsed and fell on Broadribb. They called emergency services and people were running to the scene, some the breathing apparatus and some with not. In all, eight people suffered injuries, but all survived. It turned out a pressure control valve, PCV5, ended up open to flare when it should have been closed while the blank removed. It also turned out a tailgas ended up shut off and it was routing back to the flare. The gas routing back was hydrogen sulfide (H 2S), which is a colorless gas with the characteristic foul odor of rotten eggs and is heavier than air, very poisonous, corrosive, flammable and explosive. So with the flare venting, it was sending out the H2S and the workers were dropping.
All eight workers ended up overcome by the gas and had to undergo treatment to recover. “We were very lucky,” he said.
A major crisis ended up averted, however, injuries ensued. What did Broadribb learn:
• There should be one single competent person in charge of critical tasks
• There should be positive isolation when breaking critical containment
• There should be procedures for infrequent operations (like a startup)
• Share abnormal operations knowledge
• “It’s never happened before” is not a good excuse
• There should be a proper PSSR done and not one done while doing other tasks
• Too much going on for proper control. “When you are doing a startup, you don’t want non essential personnel on the site,” Broadribb said.
“This incident changed my outlook and pursuit of process safety excellence,” Broadribb said. “I know it is an ongoing journey.”