Nornickel is making a comprehensive, long-term effort in monitoring assets to assess the impact of permafrost thawing in the Norilsk region
Experts estimate that the area of frozen ground in Russia totals about 11 million sq km, covering almost two thirds of the country. Permafrost covers mostly Eastern Siberia and the Zabaykalsky Region. Average monthly winter temperatures range from —10 °C to —20 °C in the north of European Russia and from —40 °C to —50 °C in the northern regions of Eastern Siberia.
Nornickel operates in a permafrost environment. The Norilsk Division’s facilities are located in areas completely covered by permafrost, which can reach up to 500 m deep. The permafrost on the Kola Peninsula and in the Zabaykalsky Region can reach 25 m deep with isolated and scattered patches of thawed soil.
Permafrost is at risk of thawing as a result of global warming, which would reduce the bearing capacity of buildings and structures built upon it, eventually leading to accidents. To manage this risk, the Company pays particular attention to monitoring the condition of buildings and structures. Specifically, it:
regularly monitors the condition of foundations underneath buildings and structures built on permafrost
performs geodetic monitoring of the deformation of buildings
monitors soil temperature in buildings’ foundations
monitors whether its facilities comply with operational requirements for crawl spaces
develops recommendations and corrective action plans to ensure safe operating conditions for buildings and structures.
In 2021, the Monitoring Centre of Buildings and Structures of Norilsk Division, which carries out geotechnical monitoring and technical inspections, was upgraded, staff expanded.
Roll out of permafrost thawing monitoring
Since 2021, Nornickel has been implementing the Buildings and Structures Monitoring System project for automated monitoring of foundations and soils underneath buildings and structures, including by:
monitoring structures built on permafrost using satellite monitoring (with drone-based monitoring piloted) and early detection of any possible ground surface deformations under an agreement with Sovzond, the leading Russian space monitoring company. Satellite monitoring of structures built on permafrost, focused on four priority areas: Norilsk, Dudinka, Snezhnogorsk, and Svetlogorsk
drilling wells near buildings to update information on soils, with measuring tools installed in the wells to monitor temperature and the groundwater level (for thawed soil)
installing special sensors to monitor deformations of foundations and the temperature and humidity in crawl spaces
developing special diagnostic metrics for the condition of structures and their foundations to maximise the impact of monitoring foundation elements and soils.
Program target: 1,500 of assets, including tanks, pipelines, production facilities and administrative buildings, to be equipped with real-time sensors, which will be plugged into the
Geotechnical monitoring system
Phased roll out of permafrost-based foundations monitoring system in Norilsk Industrial District:
Phase 1 — Fuel storage facilities and other buildings hosting large groups of people or cultural heritage buildings
Phase 2 — Facilities of Norilsk Fuel and Energy Company (NTEK), tailing dams and ponds of Norilsk Division
Phase 3 — Building and structures of Norilsk Division, including main mining and processing facilities, long structures such as various pipelines (including pulp, gas and others) and railroad infrastructure as well as bridges
Phase 4 — All remaining facilities located in Norilsk Industrial area, including overpasses, pipelines and power lines
Systematic analysis of the impact of permafrost thawing on foundations:
Interferometric analysis of satellite images to identify both vertical and horizontal changes in structural elements of buildings and structures, including foundations
Geological drilling to update information on foundation soils and install special sensors for real-time thermometric monitoring of foundation soils Comparison of historical soil temperature data with up-to-date data sets
Seismoacoustic, ultrasonic, and seismic analysis of pile condition and early detection of potential structural deformations and corrosion
Geodetic survey of buildings’ structural elements for early detection of deformations (horizontal displacements and settlements)
Current activities and preliminary results
A pilot project was completed in 2021, with a digital platform developed to monitor the condition of 11 fuel tanks equipped with various types of sensors: inclinometers, thermistor strings, air humidity sensors, and groundwater level sensors
In general, most of the site area, including infrastructure facilities, covered by satellite monitoring since 2020 has proven to be stable with the values of the displacements recorded over 2020-2021 being fairly minimal and within the error margins