New Delhi: The toll in the blast at state-run NTPC Ltd’s Unchahar power plant in Raebareli, Uttar Pradesh, has risen to 32, chairman and managing director Gurdeep Singh said on Friday.
The blast occurred in the boiler area of the recently commissioned 500 megawatt (MW) unit of the 1,550MW coal-fuelled plant (about 110km from state capital Lucknow) that supplies electricity to Uttar Pradesh, Haryana, Himachal Pradesh, Jammu and Kashmir, Punjab, Rajasthan, Chandigarh, Delhi and Uttarakhand.
According to NTPC, the explosion, which has affected 80 people, happened during attempts to remove the bottom ash from beneath the furnace through a controlled operation of poking. Pressure went up, resulting in the economizer section opening up. This resulted in the sudden release of gas and steam.
Mint reported on Friday that executive director (operations) S.K. Roy is heading a committee to investigate the incident wherein the economizer duct blew, releasing flue gas and steam. The committee will submit its report within a month.
“The inquiry committee has started its work… Till the time all facts are in front, till then to say something will be more of a conjecture,” Singh said at a press conference.
The equipment for the plant was supplied by state-run Bharat Heavy Electricals Ltd (Bhel). NTPC operates 46 units of 500MW across its power projects, with a majority of the machinery supplied by Bhel, India’s largest power generation equipment manufacturer.
“This unit is designed, manufactured, supplied, constructed and commissioned by Bhel,” Singh said.
The Uttar Pradesh government has ordered an inquiry to determine within seven days the cause of the blast at the Unchahar plant. Also, the National Human Rights Commission (NHRC) has served a notice to the UP government over the deaths. “We will be taking all corrective actions, whether it is design related, whether it is construction related, whether it is operation related,” Singh said.
In response to Mint’s query on whether it was a standard practice to remove the ash when the boiler was operational, Singh said, “There can’t be a yes or no answer as far as this one is concerned.” He added that based on experience, “poking type of action” clears the ash.
“But if it is observed that it is kind of unmanageable and is in severe condition, then the boiler is stopped and then it is cleared,” Singh said.
As part of the standard operating procedure, it is the call of the personnel on the ground to assess the situation and then decide the course of action.
The unit, which was to be commissioned in December 2016, was finally commissioned in March 2017 and the commercial operation date got delayed from April 2017 to September 2017.
“So it has been done after full inspection,” Singh said.
India’s largest power generation utility runs 105 coal-fuelled units, with its projects accounting for 16%, or 51,635MW, of the country’s installed power generation capacity of 329,298.27MW.
In response to another Mint query on boilers not being shut down to boost plant availability factor (PAF), Singh said, “As far as availability is concerned, we don’t get carried away with this. Our instructions are very clear… and I cannot recall any point in the last two years that we would have said: don’t stop the unit.”
“Let me just inform that this team which was at the site was very experienced and trained and they have worked in different power plants,” Singh said. “If human error has happened, that will also come out in the enquiry,” he added.