Tri-State completes extensive upgrades at Nucla coal plant

While Tri-State Generation and Transmission Assn.’s 100-MW Nucla coal plant in southwest Colorado was off line in 2013 for about two months during spring and fall ”shoulder” periods, plant employees tackled a long list of maintenance and capital projects.

During the outages, extensive repairs and upgrades were completed at the plant’s coal receiving and reclaim areas, Tri-State said in a Dec. 13 blog posting.

“Having the available personnel and extra time during the outages allowed us to get a lot more done than we usually have time to complete during our typical two-week fall outage,” said Steve Sullivan, plant manager at Nucla. “In view of us taking on all those projects that we don’t normally do in-house, I am particularly proud of our employees’ excellent safety record this year.”

The station conducted its spring outage from March 15 through June 7. The plant was brought off line as a coal conservation measure while permitting was completed for a new mining site at nearby New Horizon mine. The fall outage, which is normally two weeks in length, was extended from Sept. 13 until Nov. 14 to allow time for coal deliveries to begin from the new mining site.

During both spring and fall outages, plant personnel performed extensive maintenance and repair work on duct systems, air heater refurbishment and instrument calibration. A major project nearing completion is the conveyor belt guarding project that is expected to be well under budget when it is finished before year-end.

A major undertaking during the fall outage was component replacement and extensive repairs to the station’s coal receiving and reclaim areas, including belt replacements, chute modifications and the rebuilding of coal feeders and conveyers.

Another significant capital project during the fall that involved many Nucla employees was the replacement of the obsolete input/output interface cards that directly link the plant’s Ovation digital control system to ancillary field devices throughout the facility.

Sullivan said that a year-long conveyer belt machine guarding project was originally planned for completion by an outside contract firm. “But, we took a look at their proposed design and determined that we could build it better in house,” Sullivan said. “This project, which provides safety barriers around belts for OSHA compliance, is expected to be completed by the end of the year, well below its projected budget figure.”

Nucla is a circulating fluidized-bed combustion facility built in the 1980s. The nearby New Horizon strip mine is operated by the Western Fuels Assn., which supplies mining and fuel procurement services to various members. The mine is listed with the U.S. Mine Safety and Health Administration under Western Fuels-Colorado LLC. It produced only 154,996 tons of coal in the first nine months of this year, according to MSHA figures, well off the pace from output in all of 2012 of 353,398 tons and in 2011 of 360,009 tons.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.