Uranium in Meghalaya
The Atomic Minerals Directorate for Exploration and Research is enthused by the discovery of uranium at Wakhyn in Meghalaya and the permission to prospect in the Rajiv Gandhi Tiger Sanctuary.
The AMD camp in Tiniang village.
"WE were encouraged by what we established at Lambapur... We had always called Lambapur the tip of the iceberg," said R.M. Sinha, Director, Atomic Minerals Directorate for Exploration and Research (AMD), Hyderabad, when Frontline met him on September 21. On that day, the AMD had received permission from the Union Ministry of Environment and Forests (MoEF), based on a Supreme Court order, to prospect for natural uranium in a 10 sq km area of the Rajiv Gandhi Tiger Sanctuary near Chitrial. The sanctuary is an extension of the Lambapur-Peddagattu block in Andhra Pradesh's Nalgonda district, where the AMD had already established the presence of uranium deposits.
The AMD had applied to the Board of Wildlife Management to do the exploration for uranium in the sanctuary. According to Sinha, the AMD had earlier surveyed the fringe of the sanctuary and concluded that the area had high potential. "Unless we drill in the area, we cannot prove the deposit. We have received permission to drill in a 10 sq km area [in the sanctuary]," he said.
Besides the neighbouring villages of Lambapur and Peddagattu, the AMD has discovered uranium deposits at Tummalapalle in Cuddapah district of the State. But what has buoyed Sinha is the discovery of uranium deposits at Wakhyn, a densely forested area in Meghalaya, where the turbulent Wahblei river flows. "Our concentration now, after the Singhbhum belt (in Jharkhand), is on Meghalaya. We have got deposits at Domiasiat (Kylleng-Pyndengsohiong) and Wakhyn. The sandstone rock in Meghalaya has high potential, but the ore grade is not high," he said.
On the banks of the Wahblei river in Wakhyn, checking for uranium deposits.
The aerial extent of sandstone in which the uranium mineral is lodged in the area all over Domiasiat is about 1,100 sq km. But one sq km area around Domiasiat alone has a potential of 10,000 tonnes of uranium. "From that you can deduce what a large potential exists in Meghalaya in terms of tonnage," the AMD Director said. But the grade was just 0.1 per cent, that is, 1,000 kg of ore yields only 1 kg of uranium.
Geologists of the AMD are the foot soldiers of the Department of Atomic Energy (DAE) trekking in the desert sands of Rajasthan, camping in leech- and cobra- infested forests in Meghalaya and Karnataka, climbing steep cliffs in the hills of Cuddapah district in Andhra Pradesh or traversing the beach sands of Tamil Nadu and Kerala, all in search of atomic minerals such as uranium, thorium, niobium, tantalum, yttrium, zirconium, titanium, beryllium and lithium.
The AMD started operations on July 29, 1949, as the Rare Minerals Survey Unit (RMSU) under the then Ministry of Natural Resources and Scientific Research. It was renamed Raw Materials Division (RMD) and brought under the Atomic Energy Commission (AEC) on October 3, 1950. The RMD was subsequently renamed Atomic Minerals Division in 1958, and then Atomic Minerals Directorate for Exploration and Research (AMD) during its golden jubilee in 1998. It began with a nucleus of 17 geoscientists under the stewardship of Prof. D.N. Wadia, who was then Geological Adviser to the Government of India.
R.M. Sinha, Director, AMD.
According to Dr. P. Krishnamurthy, former Regional Director, AMD, Eastern Region, Jamshedpur, the first recruitment of geologists was done by the AEC under the leadership of Dr. D.N. Wadia using the services of the Geological Survey of India and the Departments of Geology and Mining of the States and the candidates were from reputed geology departments. On October 3, 1950, at No.10, King George Avenue, the official residence of Dr. Wadia, some 50 people were recruited in different cadres, says Krishnamurthy in a pre-print of his paper to be presented at a conference to be held on January 22 to celebrate the centenary of the Mining and Metallurgical Geology Institute in Kolkata. "The Shamiana Batch, as it was popularly known, constituted the nucleus from which the RMSU, under the control of the AEC, spread out and grew in different parts of the country to explore for atomic minerals," says Krishnamurthy, who is now Consultant, Training and Development, Uranium Corporation of India Limited (UCIL).
How do the AMD geologists detect atomic minerals in sand, rock or riverbeds? Their work begins with the identification of favourable areas with the help of remote-sensing imageries or air-borne gamma-ray spectrometric survey. The geologists prepare a geological map of the area and then drill for rock samples to know the depth of occurrence of the uranium ore. The rocks are tested in the AMD's laboratories for uranium and other associated economic minerals and to understand the genetic aspects of uranium mineralisation. A simple method for recognising uranium minerals involves the use of ultra-violet lamp. If a rock were to have uranium mineralisation, it will glow under the light due to the presence of secondary uranium minerals.
Geologists assess the potential of the find in tonnes in a given area. If it is a viable deposit, the UCIL steps into the picture. It excavates the deposit by setting up mines, and mills the uranium into yellowcake, that is, magnesium diuranate, in processing plants. The Nuclear Fuel Complex (NFC) in Hyderabad sinters the yellowcake into fuel bundles to power India's 13 operating Pressurised Heavy Water Reactors.
The approximate ore grades from Kylleng-Pyndengsohiong is 0.1 per cent, Jaduguda 0.065 per cent, Banduhurang 0.03 and Lambapur 0.1 per cent. If the grade of the ore found in a particular area were 0.01 per cent and the grade of the ore in another area were to be 0.1 per cent, there would be ten times the quantity of natural uranium in the same volume of ore in the latter. "So the grade is important," the AMD Director said. In Canada, uranium ore grades are as high as 21 per cent.
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