ARMZ, the uranium mining division of state nuclear corporation Rosatom, has announced the start of exploration work at the Dobrovolnoye uranium deposit in the Zverinogolovsky district of the Kurgan region of Russia. ARMZ subsidiary JSC Dalur received a permit for the project in June 2017, and ARMZ said yesterday that Rusburmash, its geological exploration and drilling subsidiary, plans to drill 238 wells and carry out geophysical surveys at the site.

ARMZ has said that commissioning the Dobrovolnoye deposit - which has estimated reserves of 7067 tonnes of uranium - will enable JSC Dalur to increase the volume of uranium recovery from the current 590 tonnes per year to 700 tonnes by 2025.

Anatoly Novgorodtsev, chief geologist at Rusburmash, said in the ARMZ statement that all three uranium deposits of the Trans-Urals - Dalmatovskoye, Khokhlovskoye and Dobrovolnoye - are alike in terms of their formation, mineral composition of ores, chemical composition of groundwater, and hydrogeological and geological conditions.

"Isolation of these paleovalley-related uranium resources is sufficient for borehole drilling and underground leaching," he said. "The technique of drilling and subsequent liquidation of exploratory wells that we are using means we can avoid violating the integrity of the geological massif and to conduct environmentally friendly production," he added.

Rusburmash says it plans to use a new tool for "direct determination" of uranium content at the Dobrovolnoye deposit. The tool - AMK KND-M-48 - is based on excitation of the atomic nuclei of the uranium-235 isotope contained in natural uranium using a pulsed neutron generator, and recording the flow of neutrons formed during the decay of the nuclei. The Federal Agency for Technical Regulation and Metrology approved the AMK KND-M tool in 2014. The tool enables the study of small diameter wells, has a high generator life and significantly reduces operating costs, Rusburmash says, and it also enables simultaneous registration of the uranium content and filtration characteristics of ores and ore-bearing rocks.

The company will use a drilling fluid based on bentonite clay, which penetrates 15-30 cm into aquifers and waterproofs them while drilling the wellbore. After casing the well with polyethylene pipes, the annular space 70-90 metres above the filter is waterproofed with cement mortar using sulfate-resistant Portland Cement PCT-1-50 GOST 1581-96. The rest of the annulus above the cementation interval and up to the wellhead is filled with a gel cement solution.

Nikolay Poponin, director general of Dalur, said the company has developed ways to avoid "negative environmental impacts" over its many years of using ISL mining methods.

"We live here and our children will continue to live here," he said, "and the residents of the Zverinogolovsky district have been fully engaged in discussions about the project." Journalists were shown that background radiation at the Dobrovolnoye site was 0.04 microsieverts per hour, he added.

At public hearings conducted over the past year, local residents approved the preliminary version of the Environmental Impact Assessment for the construction and operation of a pilot industrial facility for ISL mining at the Dobrovolnoye deposit, ARMZ said. This project concerns construction of the so-called 'slurry barn', it said, for the placement of used drilling fluids, as well as materials requiring a licence for the construction of nuclear facilities.

Mikhail Sheigets, head of the Zverinogolovskoye district, confirmed that most of the local residents are happy for work to start at the Dobrovolnoye deposit.

"This is a push in the development of the district, with tax cuts and job creation," he said. "Eight local residents are already working here, in the near future up to 25 jobs will be created, and then up to 200. The infrastructure and the quality of life of people will improve, and it is important that no harm to the environment will be caused by the application of this technology," he added.

ARMZ noted that, in the entire history of the development of uranium deposits in the Trans-Urals - since the discovery of the first of them, Dalmatovsky, in 1979 - there has been no single emergency. Research has shown that ore bodies have been reliably isolated from groundwater and overlying aquifers, it said.

Claims by opponents to the Dobrovolnoye project that exploratory drilling in 1988-1989 had caused damage in this regard had led to the formation of a special commission, ARMZ said. This commission has confirmed the condition of the mouths of the wells pose no hazard and the gamma radiation levels are within the normal range. There are currently no sumps on the area of the Dobrovolnoye uranium deposit, it said, and natural background radiation in the research area does not exceed 0.10 microsieverts per hour. On 18 June, representatives of the commission, which included members of local environment bodies and the general public, signed an inspection report based on the results of the survey of the Dobrovolnoye site, it said.

Researched and written by World Nuclear News

Date: Friday, 08 November 2019
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