Under environmental agreements with the U.S. Environmental Protection Agency and other parties done in 2011, and to address operational challenges and reduce costs, the Tennessee Valley Authority idled the coal-fired Johnsonville Units 7-10 on March 1, and plans to idle Johnsonville Units 5-6 and Colbert Unit 5 by Oct. 1.
Also, two coal-fired units at John Sevier will be retired by Dec. 31, 2012, the remaining two units at John Sevier will be idled by Dec. 31, 2012, and Johnsonville Units 1-4 will be retired by Dec. 31, 2017, TVA noted in its May 4 Form 10-Q quarterly report. “Several of these idle dates are earlier than the retirement dates required by the Environmental Agreements as well as earlier than the expected date for coal-fired plant compliance with the Mercury and Air Toxics Standards (‘MATS’),” TVA added.
TVA’s November 2011 Form 10-K report shows Johnsonville as a ten-unit coal plant with 1,206 MW of total net summer capacity. Colbert is a five-unit coal plant with 1,184 MW of net summer capacity. John Sevier is a four-unit, 704-MW (net summer) coal plant.
Inactive units may be in three categories: retired, mothballed or inactive reserve. Retired units are unavailable for service and are not expected to return to service in the future. Mothballed units are unavailable for service but can be brought back into service after some repairs with appropriate amount of notification, typically weeks or months. Inactive reserve is the state in which a unit is unavailable for service but can be brought back into service after some minor repairs in a relatively short duration of time, typically measured in days. TVA refers to units which are in inactive reserve or mothballed status as idled.
There are a number of other changes underway at non-coal units across the TVA system, the May 4 Form 10-Q said.
Watts Bar Nuclear Plant Unit 2 – After experiencing lower than expected productivity, TVA management established a team in October 2011 to develop an Estimate to Completion (ETC) that details work remaining to complete Unit 2. In conjunction with the ETC, an analysis to identify those factors contributing to schedule delay and higher costs of the project was also initiated. Findings of the seven-month ETC show additional funding of $1.5bn to $2bn needed to complete Unit 2, putting the total estimated cost of completion at $4bn to $4.5bn. The estimated time to complete Unit 2 is between September and December 2015. The new estimate also adds an allowance for addressing impacts associated with the Fukushima nuclear disaster in Japan and other potential risks. “TVA continues to believe that the completion of Watts Bar Unit 2 is the correct option,” said the Form 10-Q.
Bellefonte Nuclear Plant – Delays in the schedule for the completion of Watts Bar Unit 2 will affect the timing of the commencement of construction of Bellefonte Unit 1 which, as provided in the TVA Board’s approval of the Bellefonte Unit 1 project in August 2011, will not begin until after initial fuel loading at Watts Bar Unit 2. TVA said it does not anticipate that delays to Watts Bar Unit 2 will have a significant adverse impact on TVA’s ability to provide for the power needs of its customers, due to factors such as the lower forecasted outlook for electricity demand as well as the impacts of energy efficiency and demand response initiatives.
Browns Ferry Nuclear Plant – A new cooling tower for Browns Ferry had been scheduled to go into operation in the summer of 2011. TVA now expects the new cooling tower to be completed in 2012. The additional cooling capacity is expected to be available this summer and will help keep TVA from having to reduce generation at Browns Ferry due to thermal issues it has run into in the past.
Raccoon Mountain Pumped-Storage Plant – An inspection of the Raccoon Mountain Unit 2 turbine in March found cracking in the rotor poles and the rotor rim. Because the same type of cracking led to the catastrophic failure of a similar unit in Europe, Units 1 and 4 were also taken out of service during March for inspections. Similar conditions were found on Units 1 and 4. These three units, with a net summer capacity of 1,212 MW, which are utilized to balance the transmission system as well as generate power, are not expected to return to service for several months. TVA plans to dispatch generation from other TVA units and purchase power to compensate for this loss. No unusual findings were detected during an inspection of Unit 3 last year and this unit remains in service. Unit 3 will be re-inspected in the future. The net summer dependable capability of the four units at Raccoon Mountain is 1,616 MW.
Allen and Gallatin combustion turbines – Effective May 1, four simple cycle combustion turbine units at TVA’s Allen plant, with a total net summer capability of 64 MW, and two simple cycle combustion turbine units at Gallatin, with a total net summer capability of 130 MW, have temporarily been designated as unavailable for operation until repairs are done. Restoration projects to return the units to active service are being planned for the fall of 2012 through the spring of 2014.
John Sevier Combined Cycle Facility – John Sevier CCF was connected to the TVA electrical grid for the first time on Dec. 17, 2011, and began commercial operations on April 30.
New renewable projects – The contracts for 535 MW of renewable power from four wind power contracts with third-party providers began in January. These newly added wind power sources are among contracts TVA has entered into with eight wind farms from a 2008 Request for Proposals for more renewable and clean energy, bringing the maximum capacity to 950 MW. In the three and six months ended March 31, TVA received 891 million kWh and 1,243 million kWh, respectively, under all of these agreements.
Fuel inventories have increased $114m since Sept. 30, 2011, due primarily to lower-than-planned coal-fired generation, the Form 10-Q noted. Lower coal-fired generation is the result of lower overall generation due to the weather and lower than expected economic growth as well as a shift in generation sources due to lower natural gas prices.