India’s Power Ministry has established a committee to investigate the November 1 explosion at NTPC’s thermal power plant in Unchahar. The death toll from the blast is at 36, and dozens more workers at the plant were injured when flue gases and steam were released from a 500-MW coal-fired unit at the plant. Several remain hospitalized with severe burns.

The investigative panel was created November 6 by order of the Power Ministry, under a provision of the country’s Electricity Act 2003. It is led by P.D. Siwal, a thermal power expert from the Central Electricity Authority (CEA). The Power Ministry said it wants a report from the committee within the next month, and would like a report on the cause of the blast within the next week. The agency also asked the committee to “fix responsibility for lapses, if any,” and “to suggest remedial measures to avoid recurrence of such incidents in future.”

Other members of the investigating committee are Subir Chakraborty, director of projects for Uttar Pradesh Rajya Vidyut Utpadan Nigam Ltd. (UPRVUNL); Dhawal Prakash Antapurkar, director of steam boilers for Maharashtra; and L.D. Papney, chief engineer for thermal engineering and technology development at CEA. The order said the committee also may add other members.

NTPC, the nation’s largest utility, has its own group investigating the accident, led by S.K. Roy, the company’s executive director of operations. The explosion at the Feroze Gandhi Unchahar Thermal Power Station in Uttar Pradesh state occurred in a unit of the plant that was commissioned in March and had been operating on a trial basis since September. The 1,550-MW plant supplies electricity to nine states—Uttar Pradesh, Haryana, Himachal Pradesh, Jammu and Kashmir, Punjab, Rajasthan, Chandigarh, Delhi, and Uttarakhand—and employs about 870 workers.

The National Human Rights Commission has issued a notice to the government of Uttar Pradesh, asking for a “detailed report” on the incident from the chief secretary by mid-December.

An investigative group from the Uttar Pradesh labor department on November 3 said “gross negligence” on the part of NTPC led to the blast, although that charge has been challenged by government officials. Ministry of Power head R.K. Singh on November 2 said “I have seen everything during my physical inspection of the accident scene and I can say that there is no human negligence in the unfortunate incident.” Singh last week toured the site with state power minister Shrikant Sharma.

Though R.S. Rathee, regional executive director for NTPC, told local media on November 3 that “No one can say anything about the reasons until the probe is completed,” other NTPC officials involved in the investigation have said the accident occurred as workers were trying to remove bottom ash from beneath the furnace in the boiler unit. Pressure inside the affected unit allegedly shot up to 70 times its normal level in just a few minutes, and an emergency shut-off mechanism apparently failed to work. The pressure caused a section of economizer ductwork to fail, resulting in the explosion that released gas and steam onto the workers.

India’s NDTV on November 3 said NTPC officials have admitted that engineers were aware of the ash problem and were trying to clean the unit without shutting it down.

Shailendra Dubey, who leads the All India Power Engineers Federation, told NDTV that the unit should have been shut down for cleaning because it was new. “It was commissioned in March hurriedly … it seems work was actually not completed,” he said.

Jagmohan Singh, deputy director of the labor department, on November 3 told the Hindustan Times his group “found the formation and accumulation of clinker [residue from burned coal] in the boiler duct and the lack of its poking as the main reason for the explosion.”

Other utilities in India also are reviewing safety measures at their plants in the wake of the blast. The Karnataka Power Corporation Ltd. (KPCL) on November 7 said it has established two committees to review and audit safety measures at its coal-fired power plants. KPCL operates three thermal plants: a 1,720-MW facility in Raichur, a 1,700-MW plant in Ballari, and a 1,600-MW generating station in Yeramaras.

KPCL said senior engineers at the plants have been told to review safety practices across the facilities and submit updated operating procedures by the first week of December.

Asian News International on its Facebook page posted a video taken by a worker using a mobile phone.

The death toll is among the highest from a power-plant accident in recent years. An explosion at a hydropower station in Siberia in 2009 killed 75 people, and there were 74 deaths reported in November 2016 from the collapse of a platform at a coal-fired power plant under construction in China. Officials said it is the worst industrial accident in India since 45 people were killed by the collapse of a chimney being built at Bharat Aluminum Co.’s Korba thermal plant project in 2009.

Darrell Proctor is a POWER associate editor (@DarrellProctor1, @POWERmagazine).