FAIRBANKS—Golden Valley Electric Association released a rough timeline of its continued closure of its Healy Unit 2 coal plant Friday, saying it expects the plant to be closed for at least four to six months.

The recently reopened coal plant was shut down March 3 when an explosion occurred in the plant's coal feed system. No one was injured in the fire, but it forced GVEA to shut the plant indefinitely while the cause of the fire is determined and damage assessed.

The coal plant had only two weeks earlier passed its 45-day commissioning test. GVEA brought the plant back online for the first time in 16 years in May 2015 after purchasing the plant from the Alaska Industrial Development Export Authority in 2012, planning to renovate and reopen it as a clean coal plant.

At the time of the fire, GVEA spokeswoman Corinne Bradish said it was too soon to tell how long Healy Unit 2 would be closed down. After two weeks, however, the utility released information saying repairs will likely take "four to six months or longer, if needed."

The fire in the coal feed system caused damage to the fan that transports pulverized coal dust from the pulverizer to the boiler, according to the GVEA notice. The explosion was caused by a coal "puff," an industry term for when a heat source ignites built-up coal dust in the air, GVEA said at the time of the fire.

The cause behind the heat source that led to the fire will be investigated during the closure in conjunction with the damage assessment and repairs. The investigation of the cause will be undertaken by an outside party, according to GVEA.

The results of the investigation are expected to be completed within four to six months.

The energy utility hopes to cut down on excessive closure time by moving up the time frame of a planned three-month closure originally scheduled for this summer to tie in new electrical equipment. That tie-in will now take place during the current closure.

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