Agency to study blocks used at Sago
Federal scientists have agreed to a special study of the foam blocks used to seal a closed-off mine area where the explosion that caused the Sago Mine disaster may have occurred.
The National Institute for Occupational Safety and Health will perform the review at the request of West Virginia mine safety regulators.
The U.S. Mine Safety and Health Administration and the state Office of Miners Health, Safety and Training had asked NIOSH for special assistance to investigate the Sago disaster.
“We will be planning to do so,” said NIOSH spokesman Fred Blosser. “We will meet with the state and MSHA to see what they have in mind.”
Twelve miners died and a 13th was critically injured after an explosion ripped through the Upshur County mine early on Jan. 2.
Sago was the worst mining disaster in West Virginia in nearly 40 years, and was the first in a string of fatal coal accidents that has rocked the state.
On Thursday, Democratic House members said they would host a forum in Washington, D.C., on Monday that will include testimony from families of Sago victims and miners who previously worked at the International Coal Group operation.
“The upcoming mine safety forum will be an opportunity for citizens of our nation’s coalfields to share with members of Congress and the public their unique perspective on the lives of miners and the working conditions in our mines,” said Rep. Nick J. Rahall, a West Virginia Democrat who is helping to organize the forum.
Rahall is the lead House sponsor of the West Virginia congressional delegation’s bill to force MSHA to write tougher new mine rescue and safety regulations.
ICG officials believe that the explosion occurred in an area of the Sago Mine that had been closed just weeks before the disaster.
The company had been producing coal from the area, but closed it off after repeated roof falls made the work too dangerous, according to state mining records.
On Oct. 14, state officials had approved the company’s plan to seal off the area using “Omega blocks,” a product described as resembling dense plastic foam.
A state inspector examined the seals on Dec. 12 and found that they were properly constructed, according to state records.
“The seals may be closed,” wrote John Collins, the state inspector. “The seals are built as approved.”
United Mine Workers safety officials have questioned the use of the Omega block seals, saying that the blocks may not have been strong enough to meet federal regulations.
MSHA rules require all seals to be built using “solid concrete blocks.” Alternate materials may be used only if they will withstand 20 pounds per square inch of pressure, the MSHA rules state.
In a 1993 report, NIOSH examined the use of various materials for seals in underground mines.
Companies frequently seal mined-out or abandoned areas to “eliminate the need to ventilate them,” NIOSH said in the report.
If areas are sealed, mine operators no longer have to test them for methane or conduct pre-shift examinations to determine they are safe.
“Seals also are used to isolate fire zones or areas susceptible to spontaneous combustion,” NIOSH said in its 1993 report. “Therefore, the mine seals must be capable of isolating these areas of the mine from the active workings.”
NIOSH recommended that seals be able to control gas or air exchanges between the sealed an open areas of a mine, to prevent toxic or flammable gases from entering active workings.
Also, seals should be capable of preventing an explosion initiated on one side from propagating to the other side, NIOSH said.
NIOSH tested various seal materials by blowing them up at a testing facility in Pennsylvania.
The tests indicated that the Omega blocks would meet MSHA standards, surviving a blast of 20 pounds per square inch, the NIOSH report said.
NIOSH tested a model called Omega 384 blocks, described as “glass-fiber, reinforced lightweight block.”
It is not clear if the Omega blocks used at Sago were the same as those tested by NIOSH.
In a summary of its research on the topic, NIOSH praised cement seals that were used in the U.S. Steel Gary 50 Mine in Pineville. When an explosion occurred there in June 1995, the cement seals, “effectively contained the explosion, thereby sparing the miners working nearby,” MSHA said.
J. Davitt McAteer, Gov. Joe Manchin’s mine safety adviser, said that the Omega block tests and the Sago investigation could indicate a larger safety problem that will need to be addressed.
“It raises a very broad question,” McAteer said during a legislative briefing last month.
“If we are encountering ignitions in the sealed areas, do we have to rethink what we’re doing in those areas?” he said. “That would be a big undertaking.”
To contact staff writer Ken Ward Jr., use e-mail or call 348-1702.