QUẢNG  NAM — A broken water valve is the suspected cause of an incident on September 13 that left two worker missing at the Sông Bung 2 Hydropower Plant in the central province of Quảng Nam.

Search and rescue forces are still working to find the missing workers, while all 20 forestry project employees in the La Êê commune lowands in Nam Giang district have made it home safety.  

Huỳnh Khánh Toàn, Vice-Chairman of the provincial people’s committee, confirmed the accident yesterday via a press conference. He said that water from the plant’s conductor tunnel swept two houses and nearly collapsed one in La Êê commune, flooding some nearby communes’ traffic roads.

He said water collapsed one steel valve of the tunnel, while the other valve remaines in tact.

Toàn also dismissed online media speculation that the dam of the plant was broken and that over 30 residents were missing.

“We had a field check last night, and I can confirm that only two workers were swept away by water while cleaning the tunnel,” he said.

“A huge volume of water also damaged two vans, a crane, five trucks, and much of the project’s equipment and material. It also flooded certain traffic roads in nearby communes,” he said.

According to the latest technical report, water from Thu Gia-Thu Bồn river system flocked rapidly to the hydropower reservoir after the 4^th storm in recent weeks, speeding at 560 cubic metre per second. Strong water flow broke one of two steel cast valves of the tunnel, sweeping every thing in side the tunnel away.

He said the 100MW (megawatt) hydro-power plant, which started operating one turbine in 2012, has stored 28 million cubic metre of water in its reservoir in preparation for operation of the second turbine later this year.

The reservoir was designed to hold 94 million cubic metres and to produce 460 million kilowatt per hour per year.  

Toàn said the tunnel was officially accepted by state agencies for water storage on September 3^rd , and it had been in the final completion process for the operation of the hydro-power plant this December.

In a urgent message sent Tuesday, Prime Minister Nguyễn Xuân Phúc asked the province, the ministries of industry and trade, the Việt Nam Electricity Group (EVN) and relevant agencies to discover the cause of the accident and to file a report before September 15^th.

The accident was the first for a hydro-power plant project in the central province.

The VNĐ5.3 trillion (US$235 million) Sông Bung 2 hydro-power plant, which was built in area of two communes – La Êê and Zuôih, both in the Nam Giang district – is one five projects built in the Vu Gia-Thu Bồn under the national energy security strategy.

The province has 62 hydropower projects with a total designed capacity of 1,600MW, and more than 820 irrigation projects with 72 reservoirs built in the river basin. However, these projects only operate at 51 per cent of designated capacity.

Toàn said the province had called search and rescue forces from the army, border guard, militia to search the missing workers: Nguyễn Minh Luân, 24, and  Đặng Văn Tuyền, 37. 

No report of property damage was given at the press conference.

The province will update with further reports on the accident.

In 2014, a tunnel in Đạ Dâng- Đạ Chomo hydroelectric power plant in Lâm Đồng Province collapsed during construction after heavy rains in the area.  — VNS