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Alexandro Rocha ScislewskiDistrict of Caetité - DICAE

Coordination of Nuclear Facilities - CODINBrazilian Nuclear Energy Commission - CNEN

Highlights of Uranium Production in Brazil

14-18 October 2019Prague and Dolni Rozinka, Czech Republic

Interregional Workshop on Case Study of Conventional Uranium Production from Exploration to ClosureIAEA Technical Cooperation Project INT2019International Atomic Energy Agency – IAEA

Paulo Renato Barbosa Marinho Coordination of Nuclear Facilities - CODIN

Brazilian Nuclear Energy Commission - CNEN

THE BRAZILIAN NUCLEAR POLICY

According to the Brazilian Constitution (1988):

The Union holds the monopoly of the survey, mining, milling, exploration and exploitation of nuclear minerals, as well as of the

activities related to industrialization and commerce of nuclear minerals and materials – state owned companies

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Licensing of Nuclear Mining Facilities (Brazil)

By Law definition, all the uranium and thorium mining and milling facilities are considered nuclear installations.

Nuclear installations are subject to both:

1 – A Nuclear License, by CNEN; and(Ministry of Science, Technology, Innovation and Communication)

2 – An Environmental License, by the Brazilian Institute for the Environmentand Renewable Natural Resources – IBAMA), with the participation of stateand local environmental agencies.(Ministry of Environment)

PB

RR AP

AM

AC

PA

RO

MT

MS

MA

TO

GOMG

BA

SP

PR

SC

RS

ES

RJ

DF

SE

RN

PEAL

PICE

Sta. Quitéria

Caetité/Lagoa Real

Poços deCaldas

• First brazilian Uranium mine;• Operated from 1982 to 1995;• Status – finished operation and

evaluating process of remediation andclosure

• Actually, the only uranium mine in operation;

• Status – in operation since 2000

Uranium Mining and Milling Facilities in Brazil

• Status – in process of comissioning;• The largest discovered uranium

reserve in Brazil) and uranium is inter-mixed with phosphates

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Caldas – Operation History

• The installation was operated by state-owned company: Nuclear Industries of Brazil (INB)

• 1982 to 1995: Operation phase

• Open pit mining / sulfuric acid leaching

Mine PitChemical Processing Plant

Caldas – Current situation

• Liquid effluent treatment plant still in operation

• Main sources of contamination:– Mine pit

– Waste rock piles

– Tailings dam

– Ore processing and storage facilities

WASTE ROCK PILES

FLOODED MINE PIT

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Caldas – Technical challenges

• The mining site high precipitation rates

• Acid Mine Drainage + High precipitation rates great volumes of water need be treated (heavy metals and radionuclides) before release.

• Large amounts of sludge need to be disposed off (containing radionuclides and heavy metals)

• Radiological control of the site is maintained by the Operator, especially at effluent discharge points– Waste dam – Units of treatment of rainwater drainage from mining area and

waste rock piles

Caldas – Challenges for decommissioning

• Funding mechanism for decommissioning and remediation needs to be well defined

• Compliance endpoints are established on a case by case basis

• Political and psychosocial aspects involved– Although operation ceased in 1995, population is still concerned

– AMD and presumed watershed contamination are always on the local news, raising population concern

– Population believes in unconfirmed high levels of cancer occurrence

– The municipality created a multidisciplinary group to assess local water bodies in terms of radiological, chemical and biological contamination, which includes the regulators

– Need to establish a structured, systematic, long term communication and a stakeholder involvement programme

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Caetité – uranium mining and milling facility

Open Pit Mine

Waste Rock Pile

Tailing Ponds and Recycling Effluent Tanks

Milling Facility

The site low precipitation rates: ~ 650 mm/year

• Operated by state-owned company: Brazilian Nuclear Industries (INB)

• The facility has been in operation in Caetité since 2000

• Has produced a total of approximately 4000 tons of U3O8

• Reserves of 100,000 t of U3O8

• Remediation activities and operation of the facility are performedsimultaneously, in order to prevent future legacy. Good practices

Caetité – general information

Source: https://www.unece.org/fileadmin/DAM/energy/se/pdfs/UNFC/ws_IAEA_CYTED_UNECE_Oct12_Lisbon/17_Gomerio.pdf, http://www.inb.gov.br/pt-br/Media-Center/Galeria-de-Imagens , International Workshop on Uranium Mine Safety-IAEA TC Project BRA/9/057-Rio de Janeiro 2014 - INB

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Open pit mine

Milling Area

Tailing Ponds

Heap Leaching

Pile

Waste Rock Pile

Caetité – mining/milling waste management

Waste Rock

Photo source: INB

Caetité – remediation of waste rock pile

Measures to ensure long term stability:– The waste rock pile is being built on a natural slope of a dry valley in

order to ensure the geological and geotechnical stability

– The rain water infiltration is directed to a sump by an underlyingdrainage system. After monitoring, the collected effluents can either betreated or directly discharged to the environment

– The leached ore is emplaced into specific sectors of the waste rockpiles so that such material remains encapsulated, in order to reducethe transport of fine material due to infiltration

Leached Ore

Waste Rock

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Caetité – remediation of waste rock pile

Installation biodegradable blanket

Topsoil cover

Revegetation

• The main steps of remediation of Waste Rock Pile are:– After waste rock and leached ore piles reach the final elevation, they

are covered with a semi-compacted layer of soil (clay)

– After sealing with the clay layer, the topsoil cover is emplaced andrevegetation is carried out. This procedure aims to prevent erosion ofthe surface layer.

Photos source: INB

Caetité – remediation of the tailing ponds

• Tailing ponds characteristics:– HDPE-lined ponds with a drainage

system which retains the solid phase and allows the recycling of the liquid

– When the ponds are full, they will be closed with compacted clay and topsoil covers, and revegetated

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Caetité – remediation of the tailing ponds

• Remediation of the pond slopes:– During the operation of the facility the slopes of the ponds are

covered with topsoil and revegetated (simultaneous decommissioning and remediation)

2011 2013

Photos source: INB

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