Report: Prepared for Taung Gold Free State (Pty) Ltd on behalf of SLR Consulting (Africa) (Pty) Ltd Limited Jeanette Gold mine Allanridge A Prospective study of the probable Radiation Impact on the Public and the Environment due to the proposed new Mine Draft Feb.2016 JC Botha 1 Report Title A Prospective study of the probable Radiation Impact on the Public and the Environment due to the proposed new Mine Status Draft J C Botha Ph.D (UOFS), former Associate Professor of Medical Prepared By Physics University of the Witwatersrand and Radiation Protection Specialist for ESKOM and AngloGold Ashanti Client SLR Consulting for Taung Gold Free State Pty Ltd The author is a retired Radiation Protection Specialist with no Declaration interest in the project other than to fulfil the contract between the Client and the Consultant Revision History Revision Change Page 2 Acronyms / Definition Abbreviations Bq Becquerel Sv Sievert EF Emission factor EIA Environmental Impact Assessment PM10 particles of an aerodynamic diameter of less than 10 ROM micrometersRun-of-Mine NNR National Nuclear Regulator TSF Tailings Storage Facility TSP Total Suspended Particulates US-EPA United States Environmental Protection Agency WRD Waste Rock Dump tpm Tons per month Tph Tons per hour Kd The volumetric distribution coefficient of the porous medium 3 Executive Summary A prospective study has been made of the probable radiation impact the uranium in the ore at the proposed new mine and tailings facility may have on the public and the environment. The results of the air quality study as well as the ground water studies performed for SLR was used in the assessment. The methodology prescribed the National Nuclear Regulator: GD 1032 has been used to perform the radiation impact assessment for the members of the Public and the Environment. The radiation dose was calculated for the inhalation of radon emanating from the proposed tailings facility and the respirable (PM10) dust containing uranium. No radiation dose could be determined for the ingestion of vegetables contaminated by mine dust or irrigated with contaminated water. A small number of the local inhabitants at Nyakallong grow their own vegetables irrigated with municipal water. The ingestion dose due to the windblown dust and contaminated water was assessed from a study performed by Bain et al who found the annual disk at various mines did not exceed about 20 µSv/a. This small number is beyond regulatory concern any way as the maximum allowable dose for a member of the public is 1000 µSv/a (with a dose constraint of 250 µSv/a per single source. The results are presented in the following table: The dose to the most exposed person Radon Dose: <2 µSv/a Dust Dose: (PM 10) <1 µSv/a Ingestion Dose 0 µSv/a Dose from Water 0 Total Dose at Present <2 µSv/a The risk of ground water pollution is also very low due to fact that the area has been subjected to mining by Harmony at Target and Pres Steyn for many years with no uranium being detected in any borehole except at Voëlpan next to Nyakallong. The uranium may be the result of acid mine drainage from the waste rock dump next to it. This water is brackish and unsuitable for drinking or irrigation. The pan is home to a few thousand Flamingos . The radiation life time risk to a member of the public is given as 4% per Sv by the International Commission for Radiation Protection. For a dose of 1 µSv/a the risk is 4.0E-8 or about 1 in a 400 million. The impact on the public is there for very small. The risk was calculated for the tailings dam in its final stage at maximum height and size and is therefore the maximum risk to the workers and the public. In terms of the risk after mitigating the risk it is already so low that it is not necessary to do any mitigation 4 The conclusion may therefore be made that the new proposed Jeanette mine and plant as well as the TSF will not have any significant impact on the public or the environment during commissioning and operation. The post closure radiation dose will be determined in conjunction with the National Nuclear Regulator who must approve the mine closure and rehabilitation program. 5 Contents Revision History .............................................................................................................................. 2 Executive Summary ........................................................................................................................ 4 1 INTRODUCTION ..................................................................................................................... 8 1.2 Brief Project Description.................................................................................................... 8 1.3 Construction Phase ........................................................................................................... 8 1.4 Operational Phase ............................................................................................................ 8 1.5 Processing Plant ............................................................................................................. 11 1.6 Post Closure. ................................................................................................................. 11 2 SCOPE AND OBJECTIVES ................................................................................................... 11 3. LEGAL REQUIREMENTS ...................................................................................................... 11 4. SITE CHARACTERIZATION .............................................................................................. 12 4.1 Demography .................................................................................................................. 12 4.2 Adjacent land use and eating Habits ............................................................................... 13 4.3 Water Catchment area .................................................................................................. 15 5. THE SOURCE TERM ......................................................................................................... 15 6. MAIN POTENTIAL EXPOSURE PATHWAYS CONSIDERED IN THIS ASSESSMENT ......... 16 6.1 Inhalation ........................................................................................................................ 17 6.2 Ingestion ......................................................................................................................... 17 6.3 External exposure. .......................................................................................................... 17 7. THE MAIN SOURCE OF INHALED RADIOACTIVITY IS RADON AND DUST FROM THE TAILINGS DAM AND OTHER SOURCES SUCH AS THE SHAFT COMPLEX AND THE WASTE ROCK DUMP ................................................................................................................................ 19 7.1 Radon dispersion modelling and Radon Inhalation Dose ................................................ 19 7.2 Dust Modelling and Inhaled dust dose ............................................................................ 22 7.3 Ingestion Dose ................................................................................................................ 23 8. GROUND WATER ............................................................................................................. 24 9. RESULTS ............................................................................................................................. 26 10. CONCLUSIONS ................................................................................................................. 28 11. RECOMMENDATIONS ...................................................................................................... 29 References ................................................................................................................................ 30 List of Tables: Table 1: The population of Nyakallong Table 2: The radioisotope content of Target Tailings material 6 Table 3: The radon dose to the critical Group (living on Tailings dam) Table 4: Annual Effective Dose and Committed Effective Dose (50 yrs.) from various ingestion pathways by Bain et al. Measurement Unit: Sv/a for D and Sv for D50 Table 5: The Chemical contents of ground or surface water. Table 6: The dose to the most exposed person Table 7: Summary of the total effective dose at conservatively selected locations for the different age groups as calculated for the Formal Urban Resident Exposure Condition from the operations of the Adjacent Harmony mines. List of Figures: Figure 1: Locality Map and Land use Figure 2: Dwellings in Nyakallong (Ptersa, 2010). Figure 3: Gardens in Nyakallong (Ptersa 2010) Figure 4: The water catchment area with the water sampling points. Figure 5: The Potential exposure pathway exposure Matrix Figure 6: The Radon flux as a function of the Radium concentration. Figure 7: The radon concentration isopleths Figure 8: The PM10 Dust Inhalation dose Distribution after Mitigation. (From the SLR Air Quality study) Figure 9: Water monitoring locations. 7 1 INTRODUCTION This report presents a prospective assessment of potential radiation impacts of this project on the public and the surrounding environment. The assessment describes the scope, relevant legislation, assessment methodology and the baseline conditions. It then considers any potentially significant environmental affects the proposed facility would have on this baseline environment; the mitigation measures required to