The Commission also found shortcomings in the actions of working with the emergency tank at CHP-3 expert organization
Moscow, 10 Nov – IA Neftegaz.RU. Rostekhnadzor called the violations during the construction and operation of the reservoir as the cause of the accident at TPP-3 of the Norilsk-Taimyr energy company (NTEC, a subsidiary of Norilsk Nickel) in may 2020.
This is stated in the message of the Yenisei Department of Rostechnadzor.
According to the results of technical investigation of causes of accident, formed the act, which directed the members of the Commission on technical investigation of the accident for review.
The document contains the preliminary conclusions, the final results and the signing of the act is planned in the framework of the final meeting of the Commission November 13, 2020 in the Yenisei Department of Rostechnadzor.
Earlier it was reported that during the investigation Rostechnadzor considers 4 main versions:
- design flaws that caused an incorrect load distribution on pile Foundation,
- irregularities in the execution of construction works, which led to a poorly performed pile foundations,
- climate impact
- violation of safety requirements in the process operation of the facility.
The climatic reasons of permafrost thawing the Department ruled out, and the rest of the accident was caused by a combination of factors.
Preliminary conclusions of Rostekhnadzor:
- the accident was the result of interrelated technical and organizational violations committed both at the stage of construction of the tank, and during its operation,
- as a result of engineering-geological investigations of the Foundation soil in the area of the collapse revealed shortcomings in design and shortcomings in the construction of pile Foundation of the tank, whereby the part of the piles rested on rock, which led to uneven load distribution,
- signs of permafrost degradation under the Foundation and adjacent areas not detected
- in 2015 the tank, put in repair, in connection with state supervision was suspended
- in 2019, the operation was resumed without notification of regulatory authorities and implemented without due observance of industrial safety requirements,
- production control at the enterprise was organized at an insufficient level, periodic tehosvidetelstvovanii Foundation and geotechnical monitoring was not carried out, was not planned and was not provided performance of a complex of operations to maintain operational and serviceable condition of structures,
- after the overhaul, when carrying out hydraulic tests have gone wrong, and, as a consequence, almost 50% of the total number of piles the base of the tank received a load exceeding the carrying capacity.
The Commission also found shortcomings in the actions of working with the expert tank of the organization, not fully investigating the compliance of the project and Executive documentation for construction pile Foundation and documents proving quality of structures and materials, as well as committing several other violations.
This was the conclusion about the possibility of using the tank until September 2022, inclusive, and issued the conclusion authorizing the increase in loading by 25%.
Oil spill from the fuel tank at CHP-3 occurred at the end of may 2020
The tank collapsed due to subsidence of the supports of the vault, it resulted more than 21 thousand tons of oil products which got into the soil and water.
In early July, 2020 Rosprirodnadzor said that the damage to water objects estimated at nearly 148 billion rubles, and soil – in 738 mln.
Please note that this assessment considers overstated, calling the amount of RUB 21.4 bn, there is a trial.
At the end of October 2020 Norilsk Nickel has completed 3 major phases of the spill of petroleum products, a fully localized oil spill and when you’re done collecting the main mass of the fuel and water mixture.
To complete the cleanup and rehabilitation of contaminated after an accident lands Norilsk Nickel expects to end 2023