The all too believable "Unbelievable!" Part II

[hedgehog]

Remember this accident?

Officials investigate massive Connecticut power plant explosion that killed five

MIDDLETOWN, Conn. -- Fire marshals today were preparing to start their investigation into a massive explosion that rocked an under-construction power plant where gas lines were being tested, killing at least five people.

A dozen or more others were hurt in Sunday's blast, which was so powerful it alarmed residents who heard the boom and felt tremors in their homes miles away from the Kleen Energy Systems plant here, about 20 miles south of Hartford.
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The nearly completed 620-megawatt plant is being built to produce energy primarily using natural gas, which accounts for about a fifth of the nation's electricity. Workers for the construction company, O&G Industries, were purging a gas line, clearing it of air, when the explosion occurred around 11:15 a.m. Sunday, Santostefano said.

http://www.nj.com/news/index.ssf/2010/02/officials_investigate_massive.html

Purging the line? Maybe not so much....

CSB: Unsafe Pipe Cleaning Practices Common Across Gas Energy Industry

* May 25, 2010

The practice of using flammable natural gas to clean power plant piping, which led to the fatal explosion at Connecticut-based Kleen Energy on Feb. 7, has been commonly used across the gas-fired power generating industry, CSB investigators said recently.

The explosion, which killed six workers and injured at least 50 others, occurred during a “gas blow”—a planned effort to clean out new fuel-gas piping leading to combustion turbines by directing high-pressure natural gas through the pipes and out of vents located near ground level, adjacent to the power generation building. The gas accumulated above the lower explosive limit and ignited, causing massive damage to the new billion-dollar facility, which was nearing completion.

CSB investigators will present the new findings, derived from a survey of 62 representatives from the combined-cycle gas power industry, at professional society meetings in Maryland and Connecticut this week. Thirty-nine survey respondents (63 percent) indicated their companies had at some time used flammable natural gas to blow out piping. Only one of those 39 respondents said a flare was used to safely combust the gas prior to venting to the atmosphere.

According to the survey, using natural gas to clean pipes remains the most common single practice in industry, employed by 37 percent of respondents. The other respondents reported using nitrogen, which is nonflammable, or inherently safer alternatives such as air, steam, or cleaning pigs. On Feb. 25, 2010, CSB stated that natural gas blows were “inherently unsafe” and urged industry to seek alternatives.

http://ohsonline.com/articles/2010/05/25/csb-unsafe-pipe-cleaning-practices-common-across-gas-energy-industry.aspx?admgarea=ht.RiskManagement