Chennai, Jul 14 (IANS): The much awaited event for the Indian nuclear establishment, the first unit at Kudankulam Nuclear Power Project (KNPP) and India's 21st reactor, began the nuclear fission process Saturday night, officials of the Nuclear Power Corporation of India Ltd (NPCIL) said.

"At 23.05, the first reactor attained criticality and all the parameters are normal," a jubilant R.S.Sundar, site director of KNPP, told IANS over phone.

According to him, sustained nuclear reaction has been achieved and all parameters are as per expectations.

"After a long time, the mood here is good," he added.

Top officials of the Indian nuclear establishment, including R.K.Sinha, chairman of the Atomic Energy Commission (AEC) and secretary, department of atomic energy (DAE), and K.C.Purohit, chairman and managing director of NPCIL among others, are at Kudankulam to see the first of the two Russian-made units attain criticality in a smooth manner.

Earlier speaking to IANS, Purohit said the process towards criticality was proceeding smoothly as per the procedure laid down.

India's atomic power plant operator, NPCIL is setting up two 1,000 MW reactors with Russian technology and equipments at Kudankulam, around 650 km from Chennai.

The over Rs.17,000 crore project, which generated severe protests from the locals, has started generating heat and steam from the 163 uranium fuel bundles loaded in the reactor.

The reactor was loaded with fuel assemblies containing about 80 tonnes of uranium oxide.

On July 11 night, armed with the AERB's clearance, the KNPP started its journey towards attaining criticality.

According to officials, several low power tests will be carried out in order to verify the conformance of the reactor characteristics to design objectives.

If the reports are satisfactory, then the AERB will give its clearance for the next stage, which is phase-wise increase in reactor power level.

At the first stage, the plant will be synchronised with the southern grid when power generation touches 400 MW. That is expected to happen in 30-45 days. After necessary regulatory clearances the power generation will be increased gradually to 50 percent, 75 percent, 90 percent and finally 100 percent.

When that happens, the total installed nuclear power capacity in the country will go up to 5,780 MW.

KNPP is India's first pressurised water reactor belonging to the light water reactor category.

While the power from KNPP will be shared by the southern states, the lion's share will be for the home state Tamil Nadu, which is suffering from power deficit.

"Tamil Nadu's share of the 1,000 MW will be 463 MW. As and when the power comes to our grid, it will certainly ease the power shortage to some extent," a senior official at Tamil Nadu Generation and Distribution Corporation Ltd (TANGEDCO) told IANS.

"The utility sources power from various central power generating units at varied rates but less than Rs.3 per unit whereas the power from KNPP will be over Rs.3 per unit," he added.

As for the second unit at KNPP, he said there will be time lag of around six/eight months, Sinha told IANS.

According to Sinha, it was matter of time before the general framework agreement is signed with the Russian suppliers for the third and fourth units.

It is learnt construction work for the administrative building for the next two units is progressing at KNPP site.

According to him, the total outlay for the third and fourth units would be Rs.40,000 crore.

"The issue of liability of the suppliers in the case of an accident is one of the reasons for the signing of the agreement getting delayed," Sinha said.

On the level of local content in the proposed two units, Sinha said it is for NPCIL and the Russian parties to decide and it would be covered in the general framework agreement.

The KNPP is an outcome of the inter-governmental agreement between India and the erstwhile Soviet Union in 1988. However, construction began only in 2001 but was delayed mainly due to non-sequential supplies of components from Russian vendors.

Fearing for their safety in the wake of the nuclear accident at Fukushima in Japan in 2011, villagers in the vicinity of the Kudankulam plant, under the banner of People's Movement Against Nuclear Energy (PMANE), have been opposing the project.

City-based environmental activist G. Sundarrajan had filed a case in the apex court demanding that the KNPP be scrapped. The court dismissed the case in May and laid down 15 directions for the NPCIL, the AERB, the union environment and forest ministry, the Tamil Nadu government and the state pollution control board to follow.

KNPP site director Sundar said the other nuclear power projects under construction are Kakrapar Atomic Power Project (2x700 MW), Rajasthan Atomic Power Project (2x700 MW) and the second unit at KNPP of 1,000 MW.

When all these come into play the total nuclear power capacity in the country will be 9,580 MW, he said.