Dams & Frozen Core Dams

NUNA has been and continues to be involved with the majority of the resource companies operating in Nunavut and the Northwest Territories providing dam and dike construction services.

NUNA designed and assembled its own plant for the construction of frozen core dams.  Designed to accurately monitor the moisture content and temperature of core granular material prior to placement, the plant can produce up to 3,000 tonnes per 24-hour shift.  Structurally and environmentally sound, frozen core dams provide the most efficient and reliable control of tailings and other materials.

NUNA key projects

Leslie Long Lake Frozen Core Dam
BHP Billiton Diamonds Inc., Ekati Diamond Mine, Northwest Territories, Canada

NUNA constructed the EBA Engineering CEA award-winning Leslie Long Lake dam located at BHP Billiton Diamond's  Ekati Diamond Mine.  NUNA's work comprised the construction of the 800 m long frozen core dam including key trench excavation and preparation, HDPE liner installation, production and placement of core material which required the supply and operation of an asphalt plant for the mixing of the core material. The installation of aggregate crushing and asphalt facility commenced January 1998 and the structure was completed early April 1998. The dam was constructed to contain 100 million m3 of processed kimberlite. Thermosyphons were installed to provide passive refrigeration to the dam structure. 

Processed Kimberlite Containment Dam
Initial Dam Construction & Subsequent Raises
Diavik Diamond Mines Inc., Northwest Territories, Canada 

Lac de Gras Constructors (LDGC), a partnership (between Nuna Logistics Limited and Peter Kiewit & Sons) has been involved as Contractor for Diavik Diamond Mines since the eary stages.  One of the several projects by LDGC comprised the initial construction of 5.5 linear km of containment and subsequent raising of the PKC dam (5 m–15 m lifts) which entailed blasting and excavation of the key trench to bedrock and/or permafrost, leveling with till material, placement of HDPE liner locked in with a till plug.  Structure comprised of rock fill, liner bedding, liner and placement of rock fill for thermal protection.

 

NUNA constructed the CEA AWARD-WINNING 800 m Leslie Long Lake frozen core dam for the containment of 100 million m3 of processed kimberlite, Ekati Diamond Mine, BHP Billiton Diamonds Inc.

Frozen core dam technology has proven to be a successful cost effective method of earth dam construction utilizing what is perhaps the most abundant natural resource in the Arctic - cold weather!