Permafrost not cause of oil spill in Norilsk | Polarjournal
Due to a faulty construction and insufficient maintenance, one of the biggest oil disasters occurred on May 29, 2020, in which 21,000 tons of fuel flowed into the environment. (Photo: Denis Kozhevnikov)

The reason for the spill of diesel fuel of the Norilsk-Taimyr Energy Company was violations during the construction and operation of the tank plant. This was the conclusion reached by the state technical surveillance authority “Rostekhnadzor” after the oil spill. No signs of melting permafrost were found under the foundation of the reservoir from which 21,000 tons of fuel had leaked.

A large part of the spilled diesel fuel flowed into the River Ambarnaya and was then partially absorbed. (Photo: Marine Rescue Service)

The report notes that the specialists carried out technical and geological investigations of the soil base in the collapse zone. They discovered design weaknesses and defects in the construction of the post foundation of the storage tank. As a result, some of the posts did not rest on the rocky ground, resulting in an uneven distribution of the load. In addition, “no signs of worsening permafrost were found under the foundation and in the adjacent area,” the report said.

“Rostekhnadzor” noted that the tank was taken out of service for repair in 2015 and had not been inspected even after its recommissioning began in 2019, as the supervisory authorities were not informed. This means that the storage tank has not been under state supervision since 2015. In particular, production control in the company was insufficiently organised. Regular technical testing of the foundation and geotechnical observation were not carried out.

In the wider vicinity of the damaged storage tank, the soil had to be removed over a large area. (Foto: Kirill Kukhmar)

“According to preliminary findings, the accident was the result of ‘technical and organisational violations’ committed both during the construction of the storage tank and during its operation,” the ministry said in a statement.

The investigation also found violations in the activities of the commission of experts working with the storage tank. The Commission authorised the operation of the tank by September 2022 and issued a recommendation allowing for an increase in the level of the tank by a quarter.

The summary of the final results and the signing of the technical investigation of the accident will take place at the last meeting of the Commission in the Yenisei department of Rostechnadzor. It will take place today, Friday 13 November.

Previously, Norilsk Nickel had announced the melting of permafrost under the foundation of the reservoir as the cause of the accident. As a result of the sinking of the base supports of the storage tank in May 2020, 21,000 tons of diesel fuel ran into streams and the Ambarnaya River, as well as into the ground. “Rosprirodnadzor” has estimated the environmental damage at 148 billion rubles (12.6 billion euros). Norilsk Nickel denies the extent and extent of the damage.

Heiner Kubny, PolarJournal

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