The Uranium Corporation of India Limited (UCIL) was established in 1967 as a public sector enterprise, under the administrative control of the Department of Atomic Energy, with the objective of Mining and Processing of uranium ore to produce uranium concentrate. UCIL started it’s operations in 1968 at Jaduguda with uranium ore mining and a processing plant, each of 1,000 metric tonnes per day (MTPD) capacity.

To meet the growing demand of uranium for nuclear power, UCIL has expanded its activities both in mining and processing plants . The focus has been on efficiency, cost effectiveness as well as on environmental safety. The new mine has been opened at Narwapahar. The processing plant at Jadguda has been expanded to process this extra ore. Now the overall processing capacity of the Uranium Mill is 2090 MTPD. Jaduguda mine is being deepened by sinking a III stage shaft to sustain the mine production. The operating units under UCIL at present are : Underground Mines at Jaduguda, Bhatin Narwapahar; Ore Processing Plant at Jaduguda for producing Uranium concentrate, and Plants for uranium mineral recovery from copper tailings at Mosaboni & Rakha. All the units are located in Singhbum (East) Dist. Bihar.

The New Mine

The Narwapahar mine, 12 km north west of Jaduguda, is one of the most modern mines in the country. The mine is designed to produce 1000 tonnes of ore per day. Trackless mining equipment are in use for the first time in the country. Mine development progress rates of over 300 meters per month have been achieved and the underground out-put per man shift is about 1.9 tonnes, which is considered to be best in the country.

The Narwapahar mine is worked by a decline and a vertical shaft. The decline has the advantage that heavy equipment can be lowered to the working area without dismantling. The shaft is used for hoisting ore and movement of personnel .
 
 

New Deposits

A few uranium deposits have been found to be promising in different parts of the country and these are at different stages of evaluation. The large sand stone type deposit discovered in cretaceous tertiary sedimentary basin at Domiasiat in the State of Meghalaya has been planned for the next commercial exploitation. Different mining methods and extraction techniques have been studied to find the most suitable alternative keeping the cost and the environmental impact as low as possible.

Jaduguda Mine Expansion

Jaduguda Mine is the first mine opened by UCIL in 1968. Ore body in Jaduguda has been prospected upto a depth of about 800 m below surface and it is expected that it would continue further in depth.

The main entry to the mine is through a circular shaft . The shaft has been sunk to a depth of 640 m in two stages – first stage from surface to 315 m and second stage from 315 m to 640 m. As ore upto the second stage is depleting, UCIL has planned to deepen the mine further.

An auxiliary IIIrd stage shaft has been planned for mining ore lying below 555 ML to a depth of 900 m. The main features are similar to the main shaft. The shaft sinking has been completed and it lined with concrete.

Jaduguda Mill Expansion

The Mill expansion planning and implementation has been carried out with in-house expertise. Specific emphasis has been given on adoption of new technology, automation and instrumentation, proper integration with old system for minimum extra manpower requirement and better environmental control. Efficient new equipment such as steep inclined conveyor, hi-rate thickener, horizontal belt filter and spray drier have been incorporated. PLC based centralized control systems have been installed in plant. Enclosed magnesium diuranate spray drying plant with a remote controlled packing system has also been installed.

A new dust extraction system has been installed in the ore crushing plant. In the fine ore handling area also, dry fog system has been adopted for dust suppression. All liquor tanks have been covered and new efficient ventilation system has been installed in chemical house, housing filtration, extraction and precipitation units.

Uranium is extracted from ore in the Jaduguda Mill by hydro-metallurgical process. After three stages of crushing, the crushed ore undergoes two stages of wet grinding. This slurry is pumped for leaching uranium in leaching vessels. The uranium rich liquor is obtained by filtration and purified and concentrated employing ion exchange resins. The Uranium is then precipitated from this concentrated liquor as magnesium diuranate also known as yellow cake. This is thickened, washed, filtered, dried and packed in drums. These are then transported to the Nuclear Fuel Complex (NFC) at Hyderabad for further processing into nuclear fuel.

UCIL's Environment Friendly Efforts

Two types of wastes - liquid and filtered solids depleted in uranium - are generated in ore processing. This neutralised slurry is classified and coarse fractions are pumped back to the mines as back-fill. The fine particles are pumped to a tailings pond, where the slime settles. The clear liquor is decanted off and sent for treatment.

In Jaduguda the first tailings pond was constructed in the nearby valley around one kilometre away from the tailings treatment plant. After this pond got filled up, two more ponds were constructed.

UCIL has implemented a composite scheme for reclamation of water and effluent re-treatment to make the final discharged effluent, environmentally benign.

Mine water from all mines is collected, clarified and re-used in ore processing plant.

Tailings pond effluent is clarified and a part of this is sent to the plant for re-use. Rest is retreated, clarified, settled and precipitates are sent to tailings pond. The clear effluent is monitored and is clean enough to be discharged to the environment.

With implementation of the Effluent Reclamation Scheme (ERS) the fresh water consumption for industrial use has gone down.

Ore mining and processing, like any other industrial activity would have some impact on the environment. Efforts are made to ensure that the effect on environment is minimum and remains below the specifications provided by national and international expert bodies.

To achieve this objective, at Jaduguda, an independent Health Physics Unit regularly monitors the concentration levels and discharges, if any. It ensures that the activity is not polluting the environment. The Environmental Survey Laboratory collects the environmental samples for analysis for surveillance of environment. This includes :

Radon-222, an inert radioactive gas with a short half life of 3.8 days, occurs in nature. It is associated with mines exhaust, tailings pond and the milling operations. Though the level of radon in an air-conditioned concrete house could well be above the levels encountered in the mines, radon gas is further diluted by adequate ventilation in the mines. The ventilation system has been designed to bring the radon level to acceptable levels, accepted by international and national standards. Radon is not a problem near the tailings pond because of natural dilution.

Environmental gamma radiation measurements carried out at different locations upto about 25 kms. around Jaduguda indicate that there is virtually no impact of UCIL’s operations on the environmental radiation. The natural regional background exposure level in this region varies from 782 to 1586 micro Gray/yr with an average of 1106 micro Gray/yr. In-fact the allowable gamma radiation level for public exposure from nuclear industry is 1000 micro Gray/year above the natural regional background level.

Effect on Aquatic System

As explained earlier, all discharges from UCIL are treated and monitored and are kept within allowable limits. Health Physics Unit regularly collects various environmental samples for analysis around and Jaduguda area. The mean values of uranium, radium and pH of different aquatic streams and down stream of tailings pond confirm that the effectof UCIL’s operation on aquatic system is negligible.
 
 

Conclusion

With a committed programme of the country to increase the nuclear power generation capacity, the demand for uranium is expected to go up steadily. UCIL is taking all steps to increase the uranium production to keep pace with the country’s uranium requirements.

UCIL is well aware of its responsibilities to ensure that there should be least impact of its activities on environment. The regular monitoring indicates that the impact on environment because of UCIL’s operation is negligible.

With its safe and environment friendly operations, UCIL could be a role model for other industrial units to follow.

* Late Mr. J.L. Bhasin former CMD of Uranium Corporation of India Ltd.