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The delegation included many high-ranking officials like Thai Phung Ne, Government Special Envoy; Le Quang Hung, Director of the Agency for State Control of Quality Construction and senior officials of Quang Nam province.
After over one hour of the survey, the delegation met to discuss measures to deal with the leaks.
Officials assured that no more leaks will come from the biggest dam in central Vietnam--after the EVN adjusted repair methods where only a couple of days ago--30 liters of water per second was gushing out, as compared to seven liters per second now.
They also said that the dam will release water to the dead level by mid-April and full repairs will be complete before the flood season.
Tran Van Hai, chief of the EVN’s Hydro-power Project Management Board 3, said that water was being discharged at the speed of 230cu.m/second. If it doesn’t rain, the reservoir will fall to the dead level (140m) in the next two weeks. At that time, leaks will be fixed.
Dinh Van Thu, Vice Chair of Quang Nam province, said that the province authorities agreed with the Ministry of Industry and Trade’s plan.
Dr. Nguyen Bach Phuc, Director of the HCM City Electric-Electronics-IT Institute cum Chair of the HCM City Association for Sci-Tech Consultation, also said that the reservoir must be released to the bottom immediately to seek reasons and fix errors in order to ensure the safety for people in the downstream areas.
He said that the halt of the Song Tranh 2 plant would not remarkably affect EVN’s operation because this plant accounts for nearly 1 percent of the total power system.
Dr. Pham Hong Giang, Chair of the Vietnam Association for Big Dams and Water Resource Development, said that the most effective solution to deal with leakage at the Song Tranh 2 dam is using the geomembrane technology, which does not require water discharge.
Dr. Dao Trong Tu, former Vice Secretary General of the Mekong River Association, proposed that the Vietnam Association for Big Dams and Water Resource Development to hold a field-trip to evaluate the leaks at the Song Tranh 2 dam.
The 96m-high dam, part of the hydropower plant in Quang Nam Province that began operations in January 2011, is capable of holding 729 million cubic meters of water.
Minor quakes, measuring 3 on the Richter scale, were recorded in the surrounding area earlier in 2011.
The plant has passed its first State assessment which allowed it to run at part of its total capacity while awaiting full assessment in May.
Water has been leaking from the dam since February 2012, worsening in the last 10 days.
Water was flowing out through so-called "thermal gaps" — small openings placed between concrete blocks to prevent cracking in the heat, according to the Ministry of Industry and Trade.
While denying any faults in design and construction, officials of the Electricity Construction Consultancy Company 1 admitted that "water leakage outside the dam was abnormal."
Water holes were designed to receive water absorbed from inside the dam's concrete walls (concrete is not an absolute waterproof material) into water ditches before it could leak out of the dam, he said.
Initial assessment by experts from the Ministry of Industry and Trade, EVN and the State Council for Assessment and Acceptance of Construction Works showed some water holes were blocked, resulting in water leaking from thermal gaps.
The Ministry said most of the blocked water holes had been cleared, which reduced water leakage and the unblocking process was expected to finish by the end of March.
Le Ha
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