Twenty-two people would not have lost their lives in the Nagaram pipeline blast in June if GAIL India had installed the safety features as promised to the Chief Controller of Explosives (CCOE) while seeking his approval for the project in July 2001, says the government enquiry report on the incident.
In the application submitted to CCOE on July 24, 2001, GAIL committed to set up a gas dehydration unit (GDU) at the start of the pipeline at Tatipaka to strip water and condensate from “wet” natural gas so as to prevent pipeline corrosion and leakage of inflammable condensate and gas in the open.
But it did not set up the GDU at Tatipaka, as committed while seeking CCOE permission under Manufacture, Storage & Transportation of Hazardous Chemical Rules of 1989.
“GAIL has apparently flouted the declaration to the statutory authority as well as the declared design basis by not providing GDU at Tatipaka and Mori. Absence of GDU contributed to increasing the internal corrosion rate in the pipeline,” says the report received by the Home Ministry on Thursday.
“Pipeline was designed on the basis of handling dry natural gas. However, it was being regularly used for transportation of wet gas without taking any additional precautionary measures. Wet gas contains free water, carbon dioxide, sulphur etc which induced internal corrosion in the pipeline,” it says.
The enquiry committee’s finding is that the explosion, followed by a major fire, was due to leakage of condensate and gas which was probably continuing from the night before the incident. The condensate formed vapour cloud with gas pockets, and triggered a major fire when a tea vendor lighted the stove.
“The fire flashed back to the source of leak i.e. at pipe near to the canal, resulting in the bursting and ripping away of the pipe and leading to leakage of huge quantity of hydrocarbon from the pipeline, thereby increasing the intensity of the fire,” says the probe report.
“Internal incident report of GAIL also suggests that line has been leaking due to internal corrosion because of presence of condensate in the line,” it says. Corrosion and leaks were a regular affair and the section between Tatipaka and chainage 5.8 km experienced seven leaks in last two years.
But GAIL persisted in operating this line with wet gas, despite being aware of the leaks, and resorted to makeshift repairs by small contractors who would weld clamps, sleeves or pads to cover the leaks. “No inspection was carried out in spite of repeated leaks,” says the report.
The “lapses observed” section says the “inadequate systems/ approach of GAIL in undertaking repeated repair of these high pressure lines by following temporary measures with the help of clamps/ sleeves/ pads was a factor in this accident”.
GAIL’s lack of concern was despite a September 2010 survey which found debris within the pipeline indicating that corrosion was taking place because of water and condensate. Intelligent Pigging Survey showed that corrosion was concentrated “towards the beginning of the line” but no corrective action was taken.
It suggested the use of “an effective corrosion inhibitor” along with operational cleaning/ dewatering pig runs to remove the water and condensate from the pipeline. This too was ignored by GAIL and the rate of internal corrosion got increased leading to a number of failures in the initial portion of pipeline.
The June 27 fire occurred at chainage 0.5 km and spread over a 50-metre radius, engulfing nearby dwelling units, houses and tea stalls, killing 22 people, including three women and three children, besides injuring 38 others.
When contacted, GAIL chairman and managing director B C Tripathi confirmed receiving the enquiry report and said his organisation would pursue the corrective actions suggested by the committee. “We will be filling up all the deficiencies pointed out by the committee. In fact, we have already addressed some lacunae,” he said.