The new reactor will be similar to the 100-mega watt Dhruva that has been operating at the Bhabha Atomic Research Centre at Trombay since 1985. Dhruva was the source of plutonium for the Pokhran blasts of May 1998.

``The basic design of the proposed reactor will be similar to that of Dhruva but appropriate modifications in the design will be incorporated based on operating experience,'' BARC scientists said.

The new reactor is expected to become operational by 2010, they said.

By that time, Dhruva would be 25 years old and the current 40-MW Cirus reactor, which is being refurbished, would also be nearing the end of its extended life.

Meanwhile, government has also approved a ``critical facility'' - a research reactor operating at almost zero watt power and used for conducting physics experiments.

Thecritical facility will help scientists carry out experiments related to the reactor physics design of the third-generation advanced heavy water reactors (Ahwrs) that will use thorium as the fuel.

In addition to the new reactor, BARC is refurbishing two of its ageing war horses - Cirus and the 43-year-old one-mega watt Apsara which is the first nuclear research reactor to be installed in Asia.

Apsara will be modified to test the basic design of a new multi-purpose research reactor (MPRR) being mooted by nuclear scientists.

BARC scientists have worked out on paper the design of a 5-10 MW multi-purpose reactor, SK Sharma, director of the reactor group at BARC, told visiting journalists of the Indian Science Writers Association.

The design will be tested first on a small scale on the 1-MW Apsara reactor, he said.

Work on Apsara modification will begin after the current refurbishing job on Cirus is over.

Commissioned in 1960, Cirus started showing signs of ageing with breakdown of equipment since 1991and the reactor was shut down in 1997.

``By the middle or end of next year, it will be back on track and may work for another 10 years,'' Sharma said.

While refurbishing Cirus, scientists will make provisions for hooking up a small desalination plant to Cirus to demonstrate the feasibility of using waste heat from Cirus to desalinate sea water, in a process called ``low temperature vacuum evaporation.''

Sharma said Cirus is likely to be completed in about two years after which the reactor is expected to provide service for another 10-15 years.

BARC's research reactors have been extensively used in neutron beam research, neutron activation analysis, neutron radiography imaging, nuclear fuel and material testing, and production of isotopes for use in medicine, agriculture and industry.