Investigation into Kudankulam spillage

Six workers were injured by a hot water spillage in the turbine hall of India's Kudankulam 1 during a recent maintenance outage. The regulator attributed the incident on procedural errors rather than faulty equipment.

Six workers were injured by a hot water spillage in the turbine hall of India's Kudankulam 1 during a recent maintenance outage. The regulator attributed the incident on procedural errors rather than faulty equipment.

Kudankulam (Image: NPCIL)

The accident occurred on 14 May during maintenance of a three-way hot water inlet valve to a heater loop in the turbine building of Kudankulam unit 1. Hot water spilled from the valve injuring six workers: three from plant owner Nuclear Power Corporation of India Limited (NPCIL) and three contractors.

The workers were given first aid at the plant site before being taken to a local hospital, and later transferred to another hospital for specialist treatment. The most injured workers are still receiving hospital treatment.

India's Atomic Energy Regulatory Board (AERB) has now completed a preliminary investigation into the incident and said that it resulted from inadequate draining of the hot water before dismantling of the valve began. It concluded that there was no design deficiency in the construction of the valve involved.

The incident happened during a maintenance outage at the unit which began on 12 May. Following completion of the work, the unit was restarted on 17 May.

Commissioning continues

Kudankulam 1 is one of two VVER-1000 pressurized water reactors built as part of a bilateral agreement between India and Russia signed back in 1988. Construction began in 2002 and the unit was completed in March 2011. However, its commissioning was delayed by over two years due to protests and legal action following the accident at Japan's Fukushima Daiichi plant.

The unit eventually achieved first criticality last July and was connected to the grid in October. Power output of the reactor has gradually increased and it has been running at 75% power since late January. Earlier this month, the AERB gave approval for Kudankulam 1 to be temporarily operated at 100% power during commissioning tests. NPCIL says it expects the unit to enter commercial operation next month.

The start of commercial operation of the second Kudankulam unit, which has entered the commissioning phase, is now expected in March 2015.

Researched and written
by World Nuclear News