Kova was selected to provide engineering and quality control services for design, fabrication and installation of permanent mine opening covers for the Beaverlodge area near Uranium City, Saskatchewan. The Beaverlodge area includes a large decommissioned mining and milling site as well as a number of satellite mining sites. Each site has a number of openings for a production shaft and multiple vent raises. Each uncovered opening poses a substantial risk to residents and visitors of the area.
The uranium mines operated as a federal government crown corporation from 1952 to 1982 to supply uranium primarily for cold war era nuclear material requirements. The mines were decommissioned over a period from 1983 to 1985. Many mine openings were left open or covered haphazardly with concrete reinforced with scrap metals (train rail steel, drilling rods, etc.). As the majority of existing concrete covers were undocumented, a decision was made to replace all existing covers and uncovered openings with stainless steel covers to maximize useful lifespan.
Kova’s cover design considers corrosion allowance and material selection to provide a useful lifespan of as many as 1200 years between cover replacement.
Kova’s on-site engineering staff examine each opening location with local contractors and regulators to mutually agree on the ideal placement for rock anchors and size of each cover. Field information for fabrication drawings is gathered using conventional methods complimented with laser scanning using a Leica ScanStation P40 and proprietary scanning tools to better inform office-based drafting and engineering personnel.
Engineering design is completed using a combination of traditional calculation methods complimented with computer-aided design methods including finite element analysis (FEA). Drafting work considers the organic shapes of the rock formation captured during scanning, and the detailed FEA work. The resulting work product is a fabrication drawing set for the most material and labour efficient, safe and long-lasting cover that is commercially available today.
Kova’s scope for the project included shop inspections using visual and liquid penetrant inspection techniques as well as field review following installation and pickling operations. Kova’s final work product includes a formal report certifying the cover is ready for service.
The typical work schedule includes gathering information during the summer, completing design work and receiving regulatory approval during the fall, fabricating shop components and transporting during the winter, and installing and completing field review in the summer.
This project was started in 2015 and is currently ongoing with 18 covers either installed and field reviewed or slated for installation during the 2018 summer construction season.