By Kim Se-jeong
The Ministry of Employment and Labor has ordered the state-run Korea Hydro and Nuclear Power Corp. (KHNP) to halt work at a nuclear reactor construction site where a gas leak killed three workers Friday.
The three were killed after inhaling nitrogen gas that leaked through a valve in the basement, according to KHNP.
An official said the ministry had ordered that work be stopped until safety measures are fully implemented.
Police confirmed the cause Saturday and identified the valve from which the gas leaked. The workers were found in the valve room in the basement of the New Gori No. 3 reactor.
The ministry also demanded that KHNP run an emergency safety inspection of all its reactors.
The move will to put the project behind schedule. The two reactors being built in the site, with a capacity of 2,800 megawatts, were expected to be operational from June 2015.
A ministry official said the KHNP must choose an inspection company that specializes in nuclear power plants and which ministry has authorized. The Occupational Safety and Health Law gives the ministry the authority to make such an order.
On Sunday, the ministry and police in Ulsan began investigations, questioning the workers who found the dead men, and others. The ministry also called in two officials from Hyundai Engineering and Construction, the main contractor.
The three workers belonged to Hyundai subcontracting companies ― two were from Daegil Construction and one from KTS Solutions.
The joint investigation team is focusing on why the workers went into the valve room when they had no reason to do so. The valve room has two pipes ― one for nitrogen and another for water.
The investigators also requested blueprints for the pipes. Police were also looking into why there were no closed-circuit television cameras outside the room.