Report had slammed UCC: Gas storage recipe for disaster

After studying the literature and manuals by UCC itself,the committee proved that MIC is reactive,toxic,volatile and flammable. “It is a highly hazardous and lethal material by all means of contact and is a poison,” the committee said as it found “storage of large quantities of MIC in big tanks was fraught with considerable risk”.

The committee,which submitted its report in December 1985,found that MIC was not stored as it ought to have been. “It has to be stored and handled in stainless steel of types 304 or 316,namely,good quality stainless steel,” the panel said,adding that the “UCC itself had stated that with bulk systems contamination is more likely than with tightly sealed drums”.

When the incident happened,there were three partially buried tanks in the factory at Bhopal. The committee found that tanks storing MIC have to be,for safety reasons,twice the volume of MIC to be stored. It also pointed that how the UCC itself had stated that an empty tank should be kept available at all times for transferring MIC from its storage tank on occasions of emergency.

The committee discovered that the PVH and RWH pipe lines as well as the valves were of carbon steel,which indicated a design defect. “On account of design defect,these lines also allowed back flow of the alkali solution from the VGS to travel upto the MIC tanks which made it more hazardous,” the report stated.

A further back-up report was submitted by CSIR in May 1987,but again the government did not make any use of it.

It studied that MIC had to be stored in the tanks under pressure by using nitrogen which does not react to MIC and the tank’s temperature had to be maintained below 15 degree Celsius and preferably about 0 degree Celsius. The committee dwelt at length on the operation of MIC Feed Tank,which was found in a dismal condition and was seen as the basic source of the tragedy.

The panel also found fault with the instrumentation and control system of the plant,as it stressed that the pressure in the MIC tank increased rapidly if it was contaminated with water. “But there was no high pressure alarm to alert the operator about the build-up of the pressure,” the report noted.