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Decommissioning Projects - South/Central America

(last updated 17 Nov 2019)


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Argentina   flag

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Malargüe · Los Gigantes
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Argentina, General

Journalists publish investigation on abandoned open pit mines in Argentina

A team of journalists of the Forum of Argentine Journalism (Fopea) published an exhaustive investigation on open pit mining. Fopea verified that there are at least 75 abandoned mines left all over the country, ignored by the national government. There are no registries, neither official maps nor data. But people are living and used to live at these sites.
The investigation team of Fopea visited five abandoned mines in Argentina, among them the former uranium mines of Los Colorados (La Rioja) and Los Adobes (Chubut). The journalists also discuss the uranium exploration and the imminent reopening of the Sierra Pintada mine in San Rafael (Mendoza), the tailings of which are accumulated in Malargüe. (Los Andes Feb. 3, 2010)

> El día después de las minas, peligro sin control (Foro de Periodismo Argentino - in Spanish)

CNEA releases environmental assessment of reclamation of former uranium mine and mill sites in Argentina

> Download: Proyecto de Restitucion Ambiental de la Mineria del Uranio (PRAMU): EVALUACION AMBIENTAL, Documento Marco, 03 Diciembre de 2005 (in Spanish): CNEA · World Bank
> Download: Argentina: Uranium mining Environmental restoration Project, Environmental assessment - Executive Summary, January 2006 (in English): World Bank

Argentina: Plans for reclamation of uranium mining sites with World Bank loan

The Argentinian Nuclear Energy Commission (CNEA) plans to reclaim the former uranium mining sites in the country with the help of a World Bank loan. In a first stage, the efforts shall be concentrated on the site of Malargüe (Mendoza), and in a second stage on Córdoba and Los Gigantes (Córdoba), and others. The total reclamation cost is estimated at US$ 25 million.
On July 31, 2008, the World Bank Board of Executive Directors approved a US$30 million loan to support an environmental program designed to assist the Government of Argentina, specifically the National Atomic Energy Commission (CNEA), to meet its legal obligations to remediate closed uranium mines and milling facilities in a permanent manner, consistent with internationally accepted standards for the safe disposal and handling of hazardous materials. The Mining Environmental Restoration Program will finance investments to remediate the closed uranium processing site in Malargüe, Mendoza, and will provide technical assistance for the planning and engineering design of up to seven additional sites.

Project description: Argentina-Mining Decontamination Project (World Bank)
Project data (World Bank)

Proyecto de Restitución Ambiental de la Minería del Uranio (PRAMU) (CNEA)




Malargüe (Mendoza)

Reclamation of Malargüe uranium mill tailings completed: The encapsulation of uranium tailings deposited in Malargüe has been completed. This information, although not officially confirmed, transcended from sources within the scope of the National Atomic Energy Commission. Finally, after the World Bank granted a loan of US $ 30 million for its completion, the 700,000 tons of uranium mining waste from the Huemul mine in Malargüe and the Sierra Pintada mine in San Rafael, which are only 1,000 Meters away from San Martín Square, are encapsulated. According to the urban planning of the Municipality of Malargüe, the site will be landscaped and will have environmental monitoring done by the CNEA and the supervision of the RNA. (Los Andes Apr. 19, 2017)
The surface of the site was converted to a public parc. (Los Andes Sep. 15, 2017)

Reclamation work on the Malargüe uranium mill tailings started on March 17, 2003, with preparation of the disposal site for the tailings. The work is co-financed by the World Bank. (Los Andes April 7, June 16, 2003)

> See also: Argentina: Plans for reclamation of uranium mining sites with World Bank loan



Los Gigantes

Los Gigantes (Córdoba)

Waste from closed Dioxitek UO2 plant in Córdoba to be dumped on former Los Gigantes uranium mine site: The amount of 58,000 tonnes of radioactive waste is to be transported from the closed Dioxitek UO2 plant in Córdoba to the former Los Gigantes uranium mine site, according to a document submitted by CNEA to the World Bank. Althouth the Los Gigantes mine ceased operations in 1990, no remediation works were carried out yet. (La Voz Dec. 20, 2015)

Residents complain about lack of progress with reclamation of Los Gigantes uranium mine - 25 years after mining ceased: The residents of Villa Carlos Paz and Tanti are claiming for years assurances that the former uranium deposit of Los Gigantes (30 kilometers from the cities) does not contaminate the watershed of the San Roque. The mine operated until 1990 but there are tons of materials piled up in the area [in particular 2.4 million t of heap leach residue].
The National Atomic Energy Commission (CNEA) through the Environmental Restoration Program of Uranium Mining (Pramu), funded by the World Bank is supposed to manage the situation. But the community now says it has no information that anything happens at all.
For Alicia Morales Lamberti, holder of the Chair for Environmental Law and Natural Resources of the National University of Córdoba, the problem is that the implementation of the program is "very slow" and that, unlike the provisions for Sierra Pintada (Mendoza) is "maintenance only". (La Nacion Oct. 1, 2015)

> See also: Argentina: Plans for reclamation of uranium mining sites with World Bank loan


Brazil   flag

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Poços de Caldas
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Minas Gerais

Poços de Caldas

Poços de Caldas (Minas Gerais)

> View deposit info · decommissioning data

CNEN establishes "action plan" for inspection of Poços de Caldas tailings dam: The National Nuclear Energy Commission (CNEN) has decided to establish an action plan for the regulatory control of the tailings dam at the Nuclear Industries of Brazil (INB), located in the municipality of Caldas, in southern Brazil. Minas Gerais. Ordinance for this purpose is published today (23) in the Official Gazette of the Union.
The ordinance stipulates that within a period of 360 days, CNEN shall update the regulations on the Safety of Dam-Retaining Systems containing Radionuclides, in order to adapt it to the National Policy on Dam Safety (PNSB) provided for in Law n. 12,334, of September 20, 2010.
CNEN shall also adopt, within 180 days, necessary measures to intensify dam inspection activities, which may be done by requesting assignment from other organs, by signing agreements or cooperation agreements, or by contracting of specialized private agents.
The document also says that CNEN should monitor all measures to be implemented by INB related to the restructuring of the tailings dam monitoring system, "concomitantly with the deadlines given to INB, analyzing the projects in a timely manner (before their execution), as well as accompanying the execution of the work". (Jornal Estado de Minas May 23, 2019)

Public Prosecutor's Office issues proposal for agreement with INB and regulator CNEN on necessary improvement of management of Poços de Caldas tailings: The Federal Public Prosecutor's Office (MPF) in Pouso Alegre (MG) sent the National Nuclear Energy Commission (CNEN) and the Brazilian Nuclear Industries (INB) a proposal for a Conduct Adjustment Agreement (TAC) that provides for measures to increase inspection and of the tailings dam safety of the Mineral Treatment Unit in Caldas (MG). Representatives of CNEN, the body that regulates the activities of INB and MPF, inspected the dam at the beginning of the month.
According to the Federal Public Ministry, the emergency plan presented by INB did not comply with recommendations made by the agency. According to the MPF, the document did not provide, for example, the realization of simulated emergency situations in conjunction with municipalities, Civil Defense, dam safety team, employees of the enterprise and population comprised in the Autosave Zone (ZAS).
In the TAC proposal submitted last Tuesday (23), the MPF listed a series of obligations to be assumed by CNEN regarding the establishment of a routine and inspection planning not only in relation to the Caldas dam, but also to any similar structure existing in the country or that may be installed. Also according to the MPF, it was found that, although CNEN had a legal obligation to supervise the safety of nuclear waste dams, this duty had not been fulfilled due to a lack of adequate standards and even qualified personnel.
Regarding INB, the agreement establishes deadlines for compliance with various measures, including the complete restructuring of the dam monitoring system, the improvement of the flood map of the tailings mass in the event of an eventual rupture of the structure, the verification of internal trainings of officials and employees, and the installation of alert mechanisms and evacuation plans in communities within the self-rescue zone. The proposed agreement also establishes the imposition of a fine based on the assumption of non-compliance with the obligations envisaged. (Globo Apr. 24, 2019 - emphasis added)

On Nov. 8, 2019, INB announced that it signed the Conduct Adjustment Agreement (TAC) with the Federal Public Prosecutor (MPF) regarding the tailings dam of the company's unit in Caldas, Minas Gerais.

Emergency measures to prevent failure of tailings dam not fully implemented at former Poços de Caldas uranium mine, Federal Public Prosecutor's Office finds: A preliminary analysis by the Federal Public Prosecutor's Office (MPF) revealed that state-owned Nuclear Industries of Brazil (INB), linked to the Ministry of Mines and Energy, did not fully comply with recommendations made at the beginning of February for the nuclear waste dam located in the municipality of Caldas, in the south of Minas Gerais. Despite the pending issues, the emergency action plan (Paemb) was delivered. The state company presented the document last Friday (Mar. 29), one day before the deadline stipulated in the recommendation.
Given the lack of information on the measures taken, MPF prosecutors inspected the dam on Thursday (Apr. 4), which includes a depleted uranium mine in 1995.
According to the MPF, among the necessary measures that have not yet been met are the delivery of copies of the Paemb to authorities and public agencies and proof of training and simulations made with the municipal Civil Defense, employees and the population that lives in the zone of self-saving, this is in any area that would be flooded in less than 30 minutes in case of breakage or that is situated at a distance of less than 10 kilometers. According to the MPF, the installation of alarm systems has not been proven either. (Jornal Estado de Minas Apr. 5, 2019)

INB delivers emergency plan to prevent failure of tailings dam at former Poços de Caldas uranium mine: Indústrias Nucleares do Brasil (INB), a company responsible for water dams and radioactive waste tailings, in Caldas (MG), delivered an emergency security plan for the region on Friday (Mar. 29). The document was handed over to the Federal Prosecutor's Office, which now must review the plan before it is implemented.
The creation of the emergency plan was a request of the MPF after a study by the Federal University of Ouro Preto (Ufop) to point out a risk of disruption in the tailings dam, which contains radioactive materials.
The emergency plan should detail to the residents of Caldas and Poços de Caldas the risks and the measures being taken to avoid the dam rupture. Details of the plan have not yet been disclosed by the INB. (Globo Mar. 29, 2019)

Federal Public Prosecutor's Office calls for emergency measures to prevent failure of tailings dam at former Poços de Caldas uranium mine: The Federal Public Prosecutor's Office (MPF) has recommended to the President of the Indústrias Nucleares do Brasil (INB) and to the President of the National Nuclear Energy Commission (CNEN) that, by March 30, all necessary steps be taken to fully implement the Emergency Action Plan for Dams (Paemb) on the tailings dam of the Mineral Treatment Unit (UTM), located in the municipality of Caldas, south of the state.
This dam contains radioactive material resulting from the first uranium mine operated in Brazil.
The exploration lasted from 1982 to 1995, when it was closed, on the grounds that the activities were economically unfeasible. Even after the end of the mine, the mine pit containing mud with radioactive waste, a decontaminated ore processing plant, dozens of equipment, and the dam with thousands of tons of uranium, thorium and radium waste remains in the mine.

In September of last year, INB noted that an "unusual event" occurred at the UTM-Caldas dam, which was immediately communicated to CNEN and the Brazilian Institute of the Environment (IBAMA) . Such an event consisted of turbidity and reduction of water flow at the outlet of the overflow pipe system of the structure. Also, actions were immediately initiated to investigate the causes of the event, by collecting special samples and intensifying the field inspections and reading the dam instrumentation.
A technical report produced by an emergency contractor at the Federal University of Ouro Preto (UFOP) concluded that the overflow pipe system of the tailings dam is seriously compromised and that the infiltrations found on its walls favor the occurrence of so-called piping.
Piping is a process of internal erosion that damages the structure of the dam, increasing the probability of rupture, which requires immediate measures of correction and intervention [view here].

About two weeks ago, representatives of the Brazilian Nuclear Industries presented to the MPF the measures that are being implemented as a matter of urgency to change the mechanism of the overflow pipe dam system, preceded by a provisional auxiliary system, as well as the Paemb and the schedule of its Implementation. Regarding the Paemb, no concrete action has been taken so far.
For the Federal Public Prosecutor's Office, the relevance and complexity of the facts, already worrying about the possibility of rupture of the structure, are more serious when the tailings are considered to consist of radioactive material.
The closure of uranium exploration activities occurred in 1995, without concrete measures being taken to decommission UTM-Caldas and environmental recovery for the damages caused. The omission of INB led the Federal Public Prosecutor to file a Public Civil Action No. 4106-80.2015.4.01.3826 , in the year 2015, to demand the full environmental recovery in the area of the project. "The longer this situation lasts, the lack of concrete measures for decommissioning and environmental recovery, the greater the exposure of the environment (fauna and flora) and the population to the risk of serious and harmful events," warns MPF.

Transparency - Another point addressed in the recommendation concerns the need and the right of the populations neighboring the project, which can be affected in the event of a possible rupture, to receive information about the dam situation in clear and accessible language.
Therefore, the MPF recommended that in five days, INB and CNEN should be widely disseminated to civil society, especially to communities that may be directly affected by a possible incident, about the risks they are exposed to.
The information should cover both the "unusual event" occurred on Sep. 25, 2018, indicating the characteristics and causes of the occurrence, as well as the potential risks arising from the situation in which the dam structure is located, the measures taken by the entrepreneur to stabilization of the enterprise and the content of the Emergency Action Plan (SAP). (MPF Feb. 7, 2019)

The latest Federal Public Prosecutor's Office action in this case apparently was triggered by the Brumadinho tailings dam disaster on Jan. 25, 2019 (see details).

INB presents reclamation plan for former Poços de Caldas uranium mine

On June 26, the Indústrias Nucleares do Brasil present the Plan for Recovery of Degraded Areas - PRAD to the population and authorities of Caldas, where it ran the first uranium mine in the country. The proposal is the result of a two-year study addressing hydrogeological, geochemical, and radiological aspects, conducted by the multinational contractor of INB, Golder Associates.
The program provides for the recovery of the environment of the area comprising the mine, industrial facilities and tailings dam. According to Golder, the environmental restoration of the area involves funds of about Real 400 million [US$ 192 million] in work that will extend over nearly two decades. (INB June 26, 2012)

Water treatment at former Poços de Caldas uranium mine site needs improvement, study shows

"[...] The water samples obtained from waste rock piles showed high uranium concentrations (5.62 mg L-1), high manganese values (75 mg L-1) and low average pH values (3.4).
The evaluation of the water quality at the point considered the limit between the Ore Treatment Unit of the Brazilian Nuclear Industries and the environment (Consulta Creek) indicated contamination by fluoride, manganese, uranium and zinc.
The Antas reservoir showed seasonal variations in water quality, with mean concentrations for fluoride (0.50 mg L-1), sulfate (16 mg L-1) and hardness (20 mg L-1) which were low in January, evidencing the effect of rainwater flowing into the system.
The concentrations for fluoride, sulfate and manganese were close or above to the limits established by current legislation at the point where the treated mining effluent was discharged and downstream from this point.
This study demonstrated that the effluent discharged by the UTM affected the quality of the water in the Antas reservoir, and thus the treatments currently used for effluent need to be reviewed. "

Evaluation of surface water quality in aquatic bodies under the influence of uranium mining (MG, Brazil), by Rodgher S, de Azevedo H, Ferrari CR, et al., in: Environmental Monitoring and Assessment, ahead of print, June 21, 2012

Justice orders cleanup of former Poços de Caldas uranium mine

From 1982 to 1995, INB's uranium mill at Caldas produced 1200 tonnes of uranium ore concentrate (yellow cake). Although closed for 15 years, decommissioning still has not started, causing contamination fears. The former open pit currently forms an acidic lake of 1200 metres diameter and 180 metres depth. The complex comprises the disused uranium mill, the uranium mill tailings basin, and deposits of radioactive materials - approximately 11,000 tonnes of uranium and thorium concentrate, among others - that had been transferred to the site during two decades from the (zirconium processing) plant of Santo Amaro (São Paulo). (O Estado Jan. 31, 2011)


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