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The assay intersections including capped composites and estimated true widths are provided in Table 1 and include the following highlights: (A drill hole plan map and select drill sections are attached to this news release.) "The results to date support our belief that Saramacca has the potential to be a transformational asset for the Company," said President and CEO of IAMGOLD Steve Letwin. "This exemplifies our strategy of seeking short-cycle capacity, which can add tremendous value for our shareholders at minimal incremental cost, since the deposit is only 25 kilometres away from our current infrastructure." Craig MacDougall, Senior Vice President, Exploration for IAMGOLD, stated: "I want to congratulate the exploration team for completing this important program in such a timely manner and without a reported safety incident.  The additional assay results continue to impress and highlight numerous intersections with high grades of gold over wide intervals, both enhancing our confidence in and understanding of the mineralized zones.   As previously stated, all results will be incorporated into an initial resource estimation expected for completion in Q3 2017." Drilling to date has confirmed the presence of multiple mineralized structures within an approximately 2-kilometre long and 600-metre wide corridor. Mineralization occurs in the near surface oxidized weathering profile to depths ranging from 50 to 100 metres, as well as deeper in the primary sulphide zones and remains open along strike and at depth.  In the deposit area, three mineralization styles are recognized from the drilling completed to date: breccia hosted mineralization characterized by jigsaw, crackle and matrix supported breccias; shear hosted mineralization characterized by well-developed pyritic disseminations and stringers; and irregular pyrite-quartz-carbonate veins which locally carry high gold grades. The 2017 50 x 50 metre infill drilling program has been completed and further drilling activities will await the completion of the seasonal rains which have commenced. Results to date and those still pending will be incorporated into a deposit model to support an initial National Instrument 43-101 resource estimate expected for completion by the third quarter 2017.  Additional exploration potential exists at depth and along strike and will be tested in future drilling programs. Preliminary engineering and permitting studies have commenced to support and develop future exploitation scenarios. The Saramacca project is strategically located approximately 25 kilometres southwest of the Rosebel Gold Mine milling facility. Mineralization is hosted in the Paramaka Formation within the lower part of the Marowijne Greenstone Belt, which is dominated by metamorphosed dacite, rhyolite, basalt and andesite lithologies in the project area.  These are traversed by the regional, northwest trending Saramacca shear zone, an important deformation zone for the localization of gold mineralization. The Saramacca property has been explored since the 1990's principally by Golden Star Resources Ltd. ("Golden Star") and later as a joint venture between Golden Star and Newmont Mining Corporation. Much of that work focused on the discovery and delineation of Anomaly M, which was the subject of successive auger and diamond drilling programs with over 50 diamond drill holes and over 200 auger holes completed in the anomaly area. Evaluation of this work suggests an exploration target potential of between 8 and 40 million tonnes grading between 1.0 and 1.8 g/t Au for potentially 0.5 to 1.4 million contained ounces of gold. The potential quantity and grade are conceptual in nature and insufficient exploration work has been completed to date to define a mineral resource. The property will require significant future exploration to advance to a resource stage and there can be no certainty that the exploration target will result in a mineral resource being defined. On August 30, 2016, the Company signed a letter of intent with the Government of Suriname to acquire rights to the Saramacca property, with the intent of defining a National Instrument 43-101 mineral resource within 24 months. The terms of the letter included an initial payment of $0.2 million, which enabled immediate access to the property for Rosebel's exploration team to conduct due diligence, as well as access to the data from previous exploration activity at the Saramacca property. On September 30, 2016, having been satisfied with the results of the due diligence, the Company ratified the letter of intent to acquire the Saramacca property and subsequently paid $10 million in cash and agreed to issue 3.125 million IAMGOLD common shares to the Government of Suriname in three approximately equal annual instalments on each successive anniversary of the date the right of exploration was transferred to Rosebel (December 14, 2016). In addition, the agreement provides for a potential upward adjustment to the purchase price based on the contained gold ounces identified by Rosebel in National Instrument 43-101 measured and indicated resource categories, within a certain Whittle shell within the first 24 months, to a maximum of $10 million. The Saramacca project falls within the "UJV" area as defined in an Agreement with the Government of Suriname announced on April 15, 2013.  The Agreement establishes a joint venture growth vehicle under which Rosebel would hold a 70% participating interest and the Government will acquire a 30% participating interest on a fully-paid basis. The drilling results contained in this news release have been prepared in accordance with National Instrument 43-101 Standards of Disclosure for Mineral Projects ("NI 43-101"). The "Qualified Person" responsible for the supervision of the preparation, verification and review of the technical information in this release is Ian Stockton, MAusIMM, FAIG, RP. Geo., Exploration Manager for IAMGOLD in Suriname.  He is considered a "Qualified Person" for the purposes of National Instrument 43-101 with respect to the technical information being reported on. The technical information has been included herein with the consent and prior review of the above noted Qualified Person. The information in this news release was reviewed and approved by Craig MacDougall, P.Geo., Senior Vice President, Exploration for IAMGOLD. Mr. MacDougall is a Qualified Person as defined by National Instrument 43-101. The sampling of, and assay data from, drill core is monitored through the implementation of a quality assurance - quality control (QA-QC) program designed to follow industry best practice. Drill core (HQ and NQ size) samples are selected by the IAMGOLD geologists and sawn in half with a diamond saw at the Rosebel mine site. Half of the core is retained at the site for reference purposes. Sample intervals may vary from half a metre to one and a half metres in length depending on the geological observations. Samples are transported in sealed bags to FILAB in Paramaribo, Suriname, a representative lab of ALS.  FILAB is an ISO 9001 (2008) and ISO/IEC 170250 accredited laboratory. Samples are weighed and coarse crushed to <2.5 mm, and 350-450 grams is pulverized to 85% passing <100 μm.  Samples are analyzed for gold using standard fire assay technique with a 50 gram charge and an Atomic Absorption (AA) finish. IAMGOLD inserts blanks and certified reference standard in the sample sequence for quality control.  Samples representative of the various lithologies are collected from each drill hole and measured for bulk density at the site RGM laboratory. This news release contains forward-looking statements. All statements, other than of historical fact, that address activities, events or developments that the Company believes, expects or anticipates will or may occur in the future (including, without limitation, statements regarding expected, estimated or planned gold production, cash costs, margin expansion, capital expenditures and exploration expenditures and statements regarding the estimation of mineral resources, exploration results, potential mineralization, potential mineral resources and mineral reserves) are forward-looking statements. Forward-looking statements are generally identifiable by use of the words "will", "should", "continue", "expect", "estimate", "believe", "plan" or "project" or the negative of these words or other variations on these words or comparable terminology. Forward-looking statements are subject to a number of risks and uncertainties, many of which are beyond the Company's ability to control or predict, that may cause the actual results of the Company to differ materially from those discussed in the forward-looking statements.  Factors that could cause actual results or events to differ materially from current expectations include, among other things, without limitation, failure to meet expected, estimated or planned gold production, cash costs, margin expansion, capital expenditures and exploration expenditures and failure to establish estimated mineral resources, the possibility that future exploration results will not be consistent with the Company's expectations, changes in world gold markets and other risks disclosed in IAMGOLD's most recent Form 40-F/Annual Information Form on file with the United States Securities and Exchange Commission and Canadian provincial securities regulatory authorities. Any forward-looking statement speaks only as of the date on which it is made and, except as may be required by applicable securities laws, the Company disclaims any intent or obligation to update any forward-looking statement. IAMGOLD (www.iamgold.com) is a mid-tier mining company with four operating gold mines on three continents. A solid base of strategic assets in North and South America and West Africa is complemented by development and exploration projects and continued assessment of accretive acquisition opportunities. IAMGOLD is in a strong financial position with extensive management and operational expertise. This entire news release may be accessed via fax, e-mail, IAMGOLD's website at www.iamgold.com and through CNW Group's website at www.newswire.ca. All material information on IAMGOLD can be found at www.sedar.com or at www.sec.gov.

Malet J.,Institute for Radiological Protection and Nuclear Safety | Blumenfeld L.,CEA Saclay Nuclear Research Center | Arndt S.,GRS Society for plants and Reactor Safety | Babic M.,JSI | And 9 more authors.
Nuclear Engineering and Design | Year: 2011

The influence of containment sprays on atmosphere behaviour, a sub-task of the Work Package WP12-2 CAM (Containment Atmosphere Mixing), has been investigated through benchmark exercises based on TOSQAN (IRSN) and MISTRA (CEA) experiments. These tests are being simulated with lumped-parameter (LP) and Computational Fluid Dynamics (CFD) codes. Both atmosphere depressurization and mixing are being studied in two phases: a 'thermalhydraulic part', which deals with depressurization by sprays (TOSQAN 101 and MISTRA MASPn), and a 'dynamic part', dealing with light gas stratification break-up by spray (TOSQAN 113 and MISTRA MARC2b). In the thermalhydraulic part of the benchmark, participants have found the appropriate modelling to obtain good global results in terms of experimental pressure and mean gas temperature, for both TOSQAN and MISTRA tests. It can thus be considered that code users have a good knowledge of their spray modelling parameters. On a local level, for the TOSQAN test, single droplet behaviour is found to be well estimated by some calculations, but the global modelling of multiple droplets, i.e. of the spray, specifically for the spray dilution, is questionable in some CFD calculations. It can lead to some discrepancies localized in the spray region and can thus have a high impact on the global results, since most of the heat and mass transfers occur inside this region. In the MISTRA tests, wall condensation mass flow rates and local temperatures were used for code-experiment comparison and show that improvement of the local modelling, including initial conditions determination, is needed. In this dynamic part, a general result, in both tests, is that calculations do not recover the same kinetics of the mixing. Furthermore, concerning global mixing, LP contributions seem not suitable here. For the TOSQAN benchmark, the one-phase CFD calculations recover partially the phenomena involved during the mixing, whereas the two-phase flow CFD contributions generally recover the phenomena. Moreover, one important result is also that none of the contributions finds the exact amount of helium remaining in the dome above the spray nozzle in the TOSQAN 113. Discrepancies are rather high (above 5%vol of helium). Results are thus encouraging, but the level of validation should be improved. The same kind of conclusions can be drawn for the MISTRA MARC2B tests. As a conclusion of this SARNET spray benchmark, the level of validation obtained here is encouraging for the use of spray modelling for risk analysis. However, some more detailed investigations are needed to improve model parameters and decrease the uncertainty for containment applications as well as to increase the predictability of the phenomena within the containment analyses. Further activities are well encouraged on this topic, such as numerical benchmarks on analytical separate-effect experiments. © 2011 Elsevier B.V. All rights reserved.

Di Giuli M.,Institute for Radiological Protection and Nuclear Safety | Haste T.,Institute for Radiological Protection and Nuclear Safety | Biehler R.,Institute for Radiological Protection and Nuclear Safety | Bosland L.,Institute for Radiological Protection and Nuclear Safety | And 23 more authors.
Annals of Nuclear Energy | Year: 2016

The importance of computer simulations in the assessment of nuclear plant safety systems has increased dramatically during the last three decades. The systems of interest include existing or proposed systems that operate, for example, normal operation, in design basis accident conditions, and in severe accident scenario beyond the design basis. The role of computer simulations is especially critical if one is interested in the reliability, robustness, or safety of high consequence systems that cannot be physically tested in a fully representative environment. In the European 7th Framework SARNET project, European Commission (EC) co-funded from 2008 to 2013, the Phébus FPT3 experiment was chosen as a code benchmark exercise to assess the status of the various codes used for severe accident analyses in light water reactors. The aim of the benchmark was to assess the capability of computer codes to model in an integral way the physical processes taking place during a severe accident in a pressurised water reactor (PWR), starting from the initial stages of core degradation, fission product, actinide and structural material release, their transport through the primary circuit up to the behaviour of the released fission products in the containment. The FPT3 benchmark was well supported, with participation from 16 organisations in 11 countries, using 8 different codes. The temperature history of the fuel bundle and the total hydrogen production were well captured. No code was able to reproduce accurately the final bundle state, using as bulk fuel relocation temperature, the temperature of the first significant material relocation observed during the experiment. The total volatile fission product release was well simulated, but the kinetics were generally overestimated. Concerning the modelling of semi-volatile, low-volatile and structural material release, the models need improvement, notably for Mo and Ru for which a substantial difference between bundle and fuel release was experimentally observed, due to retention in the cooler upper part of the bundle. The retention in the primary circuit was not well predicted, this was due mainly the non-prototypic formation of a boron-rich blockage in the rising line of the FPT3 steam generator, simulated in the circuit as a single external cooled U tube. The deposition mechanism and the volatility of some elements (Te, Cs, I) could be better predicted. Containment vessel thermal hydraulics, designed in the experiment to be well-mixed, were well calculated. Concerning the containment aerosol depletion rate, only stand-alone cases (in which the input data were derived from experimental data) provided acceptable results, whilst the integral cases (in which the input data came from circuit calculations) tended to largely overestimate the total aerosol airborne mass entering the containment. The disagreement of the calculated total aerosol airborne mass in the containment vessel with the measured one is due to the combination of a general underestimation of the overall circuit retention and overestimation of fission product and structural material release. Calculation of iodine chemistry in the containment turned out to be a major challenge. Its quality strongly depends on the correct prediction of chemistry speciation in the integral codes. The major difficulties are related to the presence of high fraction of iodine in gaseous form in the primary circuit during the test, which is not correctly reproduced by the codes. This inability of the codes compromised simulation of the observed iodine behaviour in the containment. In the benchmark a significant user effect was detected (different results being obtained by different users of the same code) which had to be taken into account in analysing the results. This article reports the benchmark results comparing the main parameters calculated and observed, summarising the results achieved, and identifying the areas in which understanding needs to be improved. Relevant experimental and theoretical work is under way to resolve the issues raised. © 2016 Elsevier Ltd. All rights reserved.

Chatelard P.,Institute for Radiological Protection and Nuclear Safety | Arndt S.,GRS Society for plants and Reactor Safety | Atanasova B.,INRNE | Bandini G.,ENEA | And 5 more authors.
Nuclear Engineering and Design | Year: 2014

Significant efforts are put into the assessment of the severe accident integral code ASTEC, jointly developed since several years by IRSN and GRS, either through comparison with results of the most important international experiments or through benchmarks with other severe accident simulation codes on plant applications. These efforts are done in first priority by the code developers' organisations, IRSN and GRS, and also by numerous partners, in particular in the frame of the SARNET European network. The first version of the new series ASTEC V2 had been released in July 2009 to SARNET partners. Two subsequent V2.0 code revisions, including several modelling improvements, have been then released to the same partners, respectively in 2010 and 2011. This paper summarises first the approach of ASTEC validation vs. experiments, along with a description of the validation matrix, and presents then a few examples of applications of the ASTEC V2.0-rev1 version carried out in 2011 by the SARNET users. These calculation examples are selected in a way to cover diverse aspects of severe accident phenomenology, i.e. to cover both in-vessel and ex-vessel processes, in order to provide a good picture of the current ASTEC V2 capabilities. Finally, the main lessons drawn from this joint validation task are summarised, along with an evaluation of the current physical modelling relevance and thus an identification of the ASTEC V2.0 validity domain. © 2013 Elsevier B.V.

Ammirabile L.,European Commission - Joint Research Center Ispra | Bieliauskas A.,European Commission - Joint Research Center Ispra | Bujan A.,European Commission - Joint Research Center Ispra | Toth B.,European Commission - Joint Research Center Ispra | And 7 more authors.
Nuclear Technology | Year: 2010

This paper presents an overview of the activities carried out in the framework of the SARNET project by the CIEMAT, INR, JRC/IE, GRS, UJV, and VUJE partners involved in the validation ofASTEC on fission product (FP) release and transport experiments simulating severe accident conditions in the reactor circuit and containment. These activities were mainly devoted to the analysis of the Phébus experiments, FPTO, FPT1, and FPT2, which provided fundamental reference data for the severe accident research. The ELSA, SOPHAEROS, CPA, and IODE modules were used for FP release from the bundle, transport in the circuit, containment thermal hydraulics and aerosol behavior, and iodine behavior in containment, respectively. Studies on aerosol behavior in the STORM experiments and iodine behavior in the ThAI experiments are also summarized. The paper describes not only the results of validation of some stand-alone or several coupled code modules but also the results of first integral calculations, when all the relevant modules of the ASTEC code were used to model the FP release and transport. In the integral calculations, no boundary conditions are to be defined by the code users for most of the code modules, but only at such interfaces were the boundary conditions applied in the experiment. The integral calculation allows more objective judgment about the combined uncertainties of the calculated results. Together with overview of the progress in the validation of the main ASTEC modules, this paper also points out what needs to be improved in the modeling of future ASTEC V2 code versions.

Malet J.,Institute for Radiological Protection and Nuclear Safety | Mimouni S.,Électricité de France | Manzini G.,RSE SpA | Xiao J.,Karlsruhe Institute of Technology | And 3 more authors.
Nuclear Engineering and Design | Year: 2015

This paper presents a benchmark performed in the frame of the SARNET-2 EU project, dealing with momentum transfer between a real-scale PWR spray and the surrounding gas. It presents a description of the IRSN tests on the CALIST facility, the participating codes (8 contributions), code-experiment and code-to-code comparisons. It is found that droplet velocities are almost well calculated one meter below the spray nozzle, even if the spread of the spray is not recovered and the values of the entrained gas velocity vary up to 100% from one code to another. Concerning sensitivity analysis, several 'simplifications' have been made by the contributors, especially based on the boundary conditions applied at the location where droplets are injected. It is shown here that such simplifications influence droplet and entrained gas characteristics. The next step will be to translate these conclusions in terms of variables representative of interesting parameters for nuclear safety. ©2014 Elsevier B.V. All rights reserved.

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