Unchahar Tragedy Is One Of The “Rarest Incidents” In The Company’s History: NTPC CMD Gurdeep Singh

Considered as one of the worst industrial accidents in the country in the past many years, the sudden malfunctioning of the boiler of the 500MW unit at Unchahar thermal power plant has left the top management of India’s largest power generator, NTPC Limited, completely startled.

NTPC chairman and managing director Gurdeep Singh on Friday (3 November) said this was one of the “rarest incident that has happened” as the company is operating a total of 105 coal-based power units, of which as many as 45 are 500MW units – similar to that of the unit six at Unchahar that exploded on Wednesday (1 November), claiming 32 lives so far with as many as 48 injured and under treatment presently. With a total installed capacity of 51,708MW, NTPC has been generating coal-based power since 1975.

Unchahar is located at Rae Bareli district of Uttar Pradesh with an installed capacity of 1,560MW, which includes 10MW solar. Just a month back, this power plant was in the news for making a national record as the 210MW unit one of Unchahar had been in continuous generation for 686 days – surpassing all performance records so far.

The last such unfortunate accident took place in 2009 when a power plant chimney under construction at BALCO’s Korba project collapsed, claiming the lives of 45 people.

Even as a three-member committee – under NTPC executive director S K Roy along with two general managers – has been constituted to look into the exact cause of the Unchahar accident, NTPC said it will take immediate corrective actions in design, construction and operations of all its future thermal power units as also the existing ones.

The report of the committee is expected in a month, but it will take anywhere between three to six months to restart the affected unit, NTPC chairman said.

Experts, with experience of working in thermal power plants, said one of the reasons could be the sudden change in the coal that is fired in the boiler (or poor coal with high ash content). They added that poor coal quality leads to high ash deposits at the funnel-shaped bottom of the furnace.

“These ash deposits are pushed out using rods (even while boiler is in operation). A similar exercise could have been carried out at Unchahar Unit 6 where the economiser section got opened up and released ash content that affected the workers.”

The NTPC chairman said the enquiry will reveal whether it was a human error, violation of a safety norm or something else. “I don’t want to say anything now on whether it was a human error, safety violation, control failure, malfunction or technical error. If I will tell you the reason then it would impose my view on the committee which will give its report in one month,” Singh said.

He, however, ruled out allegations that the unit six of Unchahar project was commissioned in any “hurry” and added that some of NTPC’s most experienced employees were maintaining the affected unit six of Unchahar, which has been designed by one of India’s most experienced and leading power equipment manufacturer – BHEL.

The company currently employs more than 22,000 people and has been bagging awards for best performer in safety operations year after year. The NTPC chairman said the report on the cause of the accident at Unchahar will be used by the company as a major input on operations and maintenance procedures being carried out at existing as also for future power plants.

With 17.73 per cent of the total national capacity, NTPC presently contributes 24 per cent of India’s total power generation. Another 19,654MW power capacity is under implementation by NTPC at various locations across the country.