KEEPING RADIATION MANAGEMENT AT BEVERLEY URANIUM MINE AT BEST PRACTICE; PLANS, RESPONSES AND OUTCOMES

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1 Radiation Protection in Australasia Vol. 29, No. 2 ARPS35 Conference Paper KEEPING RADIATION MANAGEMENT AT BEVERLEY URANIUM MINE AT BEST PRACTICE; PLANS, RESPONSES AND OUTCOMES S Kutty, P H Woods,*, E Dayal,, A Jagger, Heathgate Resources Pty Ltd, Suite 1 Level 4, 25 Grenfell Street, Adelaide SA 5000 * currently IAEA, Vienna International Centre, PO Box 100, A-1400 Vienna, Austria currently CQMI, Rockhampton Mater Hospital, Spencer Street, Rockhampton Qld 4700; currently Paladin Africa, Kayelekera Mine, Karonga District, Malawi Presented at the 35th annual conference of the Australian Radiation Protection Society, Adelaide, October 2010 ABSTRACT The Beverley Uranium Mine, located approximately 550 km north of Adelaide, South Australia, opened in 2000 and has since maintained a good record in radiological protection. The Radiation Management Plan and Radioactive Waste Management Plan for the Beverley Mine have been subject to continuous improvement since the mine opened. In with several years of monitoring, operations and review to draw on, these plans underwent a significant revision to bring them in-line with evolving government expectations: in particular to satisfy the requirements of the 2005 ARPANSA Code of Practice 1. In this major revision of the plans a risk-based approach was adopted, allowing radiation protection to be refined to emphasise effort where it was most important to reduce risks. These revised plans were formally adopted in early 2010 and late 2009 respectively. Selected illustrative results of personal and area radiation monitoring over the last 9 to 10 years are presented along with some of the physical and procedural improvements to radiation management at the site. The use of investigation and action levels guides the response to aboveroutine radiation levels is illustrated, with practical steps that resulted on specific occasions. 4 INTRODUCTION Heathgate Resources Pty Ltd (Heathgate) operates the technologically advanced in situ recovery (ISR) Beverley Uranium Mine located about 550 km north of Adelaide, South Australia, on the arid plains between the northern Flinders Ranges and Lake Frome. Following release of an Environmental Impact Statement in and other approvals, the mine was approved in 1999 and opened in Among the regulatory documents requiring approval were the first Radiation Management Plan (RMP) and Radioactive Waste Management Plan (RWMP). General descriptions of operations and of environmental and radiological protection at Beverley have been published by a number of authors 3-6. In brief, mining is undertaken by the circulation of acidified natural groundwater to which an oxidising agent (hydrogen peroxide) has been added to dissolve uranium in situ within the mineralised aquifer zones, via a series of 150 and 100 mm diameter wells between approximately 100 and 150 m depth. This mining solution is passed through ion exchange columns in the processing plant where the uranium is preferentially absorbed, after which the mining solution is re-fortified and returned to the wellfields. Typically 50 to 100 circulations are undertaken in any mining area until the maximum economically viable amount of uranium has been removed (ranging from about 50% to >90%, averaging about 60-70%). All processing is undertaken for the Beverley Mine at the Beverley Processing Plant; however, for the satellite mines of Beverley North, when the resin in the ion exchange columns is fully loaded with uranium it is transported by tanker truck

2 to Beverley. Uranium is eluted from the resin using a brine (NaCl) solution then precipitated as Uranium Ore Concentrate (in our case uranyl peroxide); resin is reconditioned and reused. The concentrate is then rinsed, centrifuged and dried to a yellow powder for drumming and sold for use in electricity production under a strict safeguard regime overseen by the Australian Government s Australian Safeguards and Non-Proliferation Office (ASNO). Since 2001 Beverley has produced from approximately 500 to just over 1000 tonnes per year of Uranium Ore Concentrate (expressed as U 3 O 8 ); this represents around 5-10% of Australia s production in those years. Production from the original Beverley discoveries diminished in 2011, and ongoing production is largely from nearby deposits found in the last few years 6, 7. REGULATION AND LICENSING Radiation protection at Heathgate s operations is regulated under the South Australian Radiation Protection and Control Act Heathgate holds Licence Number LM4 issued under Section 24 of that Act. Explicit in the licence condition is that the Licensee shall comply with 2005 ARPANSA Code of Practice ( the Code ) 1 and any amendments thereof or any codes, standards or recommendations substituted therefor. Associated with the licence are the RMP and RWMP, which must be approved by the regulator administering the Act, currently the Radiation Protection Branch (RPB) within the South Australian Environment Protection Authority (EPA). For recent operations, both Authorisation to Construct and Authorisation to Operate are required for processing plants and wellfields, following the Code. EXTENSION OF MINING AND MAJOR REVIEW OF RADIATION PLANS Since the discovery and mining of the original Beverley uranium resources, additional deposits have been discovered in the area and mining is extending over a larger area. Uranium deposits have been found in the Tertiary Namba Formation 8 and the Tertiary Eyre Formation and Cretaceous sediments 9. The first expansion was to adjacent deposits that were mined essentially as an extension of the original Beverley mine, with applications and approvals in and respectively. The RMP and RWMP for the Beverley Mine have been subject to continuous improvement since the mine opened. In , with several years of monitoring, operations and review to 5 draw on, these plans underwent a significant revision to bring them in-line with evolving government expectations, in particular to satisfy the requirements of the Code 1. In this major revision of the plans, a risk-based approach was adopted that allowed radiation protection to be refined to emphasise effort where it was most important to reduce risks. A second expansion to the Beverley North Project was applied for in and approved in Initial mining there is via two satellite plants named Pepegoona and Pannikan, with trucking of uranium-bearing resin back to Beverley for final processing (more detail below). Minor revisions only were required of the RMP and RWMP to accommodate these satellite mines. RADIATION MANAGEMENT PLAN The relevant Radiation Management Plan (RMP) at Beverley is currently version 2.3, i.e. the third minor revision of the second version (first complete revision). This numbering system is important both for approvals (so the relevant document is referred to), and for good practice general document control. All the recent RMP (and RWMP) revisions have been done in-house by the radiation protection team, which consists of one Senior Radiation Advisor and one or two Radiation Advisors. In addition, the environment and safety teams are expected to have a good level of radiation protection understanding and assist from time to time with radiological clearances and other simple procedures. The sections of the RMP are set out in Table 1. Investigation and Action Levels To ensure that the radiation doses received by the employees working at the mine site are As Low As Reasonably Achievable (ALARA) internal investigation and action levels have been implemented. These are explained in the text of the plan and set out in tabular form in Table 2. The limits set for each exposure pathway are based on annual dose limits. When the radiation monitoring results indicate that the levels of radiation measured have exceeded the internal investigation level, an investigation is triggered to find out the reasons for the elevated readings. When the radiation level exceeds the action level immediate steps are taken to rectify the problems that are responsible for the elevated readings. Investigation levels are set lower than

3 Section Section Title Notes 1 Scope 2 Introduction Overview of the operation, review process for RMP 3 Location and Environment Includes notes on the 2008 and 2010 expansions and baseline information 4 Brief Description of the Operation 5 Main Components of Operation and Associated Radiation Exposure Main Beverley processing plant, associated facilities, satellite mine facilities at Beverley North Covers the wellfields with drilling and mining operations there, supervised and controlled areas of the Beverley processing plant, associated facilities, sealed sources and radiation generating apparatus (bore hole geophysical logging sources, X-ray fluorescence analysers, prompt fission neutron geophysical tools), solid and liquid waste management areas, satellite facilities 6 Administrative Controls 17 subsections covering various aspects, e.g. training, permitting, inductions 7 Transport of Radioactive Materials Final product (uranyl peroxide, a form of yellowcake), samples, bore hole logging sources 8 Risk Assessment and Control Includes a large tabulated risk assessment prior to and with controls 9 Occupational Dose Details methodology and reporting Assessment 10 Radiation Monitoring Description of the radiation monitoring program 11 Quality Assurance Such as calibrations, inspections, preventative maintenance 12 Record Keeping and Reporting Includes weekly, monthly quarterly and annual radiation reports (quarterly and annual are provided to the regulators) 13 Review and Auditing Includes commitment to triennial external review, next due in Bibliography Appendices 13 appendices including figures, background data, monitoring details, standard operating procedures and detailed drawings Table 1 Contents of Beverley Uranium Mine RMP 6

4 Pathway/Unit Low-Level Alpha (LLA) Dust Area/Operator In areas that require wearing of respiratory protection (Drier and Packing Room) Investigation Level Action Level 4 13 Bq m -3 Rest of the areas Drier Operator 1 13 Radon Decay Products (RnD) J m -3 All areas/operators 2 7 Gamma Dose Rate Sv hr -1 All areas Alpha Surface Contamination Bq cm -2 Clean areas (offices, change rooms etc) Plant Supervised Area and Wellfield 4 Visible dust Plant Controlled Area (Drier and Packing Room) 10 Visible dust Table 2 Beverley Internal Investigation and Action Levels action levels, and act as early warning prior to exposure increasing to levels that may be problematic. The internal investigation and action levels that are currently being used at the mine site are given in Table 2. All routine and special (e.g. associated with a confined space entry requiring a Radiation Work Permit, one of the administrative controls) monitoring results are compared to the appropriate Investigation and Action Levels; where results are graphed, one or both limits is included in the graph for quick comparison. In routine reports to company management, all results above an Investigation or Action Level are highlighted, and the results of the ensuing investigation summarised. Often in the case of an Investigation Level exceedence some action is also undertaken, although sometimes the occurrence is noted if it was due, for example, to lack of wind to disperse RnD. In the event that an Action Level is exceeded, action is mandatory and must be documented. If of sufficient importance, radiation investigations are formalised as part of the site Incident Management System; lesser investigations are recorded within the Radiation Protection Section. Three examples of historic graphed data are shown in Figures 1, 2 and 3. 7 Figure 1 shows the LLA activity measurement for drier operators, obtained using personal dust sampling measurements. Although no operator received doses even close to occupational health limits, activities were not as low as reasonably achievable. In this case, a major capital improvement program was instituted in 2002, greatly improving the containment of LAA dust. A new, lower investigation level was then instituted, and concentrations have generally been below that level ever since, with notable improvement since late For Figure 2, a number of values over the Investigation Level of LLA Activity in the drier and packing rooms are apparent; improvements to the operation are reflected in the lower absolute values and less frequent exceedences in more recent years. Figure 3 shows areas where the precautions taken from the beginning of operations have been entirely adequate to keep general area LLA dust activities well below the investigation level. Reporting Reports containing information on the results of radiation monitoring carried out and the doses received by the employees are made available to senior management personnel of Heathgate as well

5 14 12 LLAA (Bqm-3) Current Investigation Level 1 Bqm Dec Nov Nov Nov Nov-08 Drier Operator Figure 1 LLA activity measurement for drier operators 12.0 Investigation Level for Drier & Packing Room 10.0 LLAA (Bqm-3) Drier Packing Room Packing Warehouse Figure 2 LLA Activity in the drier and packing rooms measured with positional dust samplers 8

6 0.40 Investigation level 0.30 LLAA (Bqm-3) Plant Wellfield Office Areas Figure 3 General Area LLA dust activities measured with positional dust samplers as to the various regulatory authorities. The reports prepared by the radiation advisors are: Weekly Radiation Reports Monthly Radiation Reports Quarterly Occupational Radiation Reports and Annual Occupational Radiation Reports. The South Australian Environment Protection Authority has indicated that the Annual Occupational Radiation Reports will shortly become available to the general public. Heathgate has anticipated this for some time and supports the initiative. A summary of occupational doses over the years of operation is given in Table 3 and as quarterly amounts in Figure 4. Note that in Figure 4 it is the pro-rata of the 20uSv/yr average annual dose limit that is shown, not the 50mSv/ yr maximum annual dose limit. The slightly elevated maximum dose during 2006 was due to some maintenance issues with the drier, since corrected, that resulted in higher than usual LLA dust dose contributions (but still only a fraction of the dose limit), coupled with the removal of using respiratory protection factor for LLA dust dose contributions of drier operators. 9 Year Average worker dose Maximum. worker dose Table 3 Summary of Occupational Doses, Beverley Mine, msv/yr RADIOACTIVE WASTE MANAGEMENT PLAN As with the RMP, the relevant Radioactive Waste Management Plan (RWMP) at Beverley is currently version 2.3, with a similar revision history. Its contents are set out in Table 4. As can be seen by comparing Tables 1 and 4, there are many parallels between the RMP and RWMP as well as their separate purposes. Much of the information on the surrounding environment is drawn from the original environmental documentation associated with the Beverley Extension and Beverley North approvals 2, 10-13, and their various supporting documents provided in

7 5 Total Effective Dose (msv) Pro-rata Designated Employee Dose Limit ( 20 msv/year) (5mSv/qtr) Average Max Figure 4 Summary of Quarterly Occupational Doses part by specialist environmental consultants. Because of the In Situ Recovery style of mining at the Beverley Mines, and in particular the approved disposal of liquid waste in the minedout Beverley aquifer, considerable detail is given on the hydrogeological setting of the area and the approach to groundwater monitoring. For detail, please refer to the Mining and Rehabilitation Programs 11, 13 and other publications 4, 5, 6, 15. Low-Level Waste Disposal Typical low level radioactive contaminated waste comprises of used PPE, filters, parts, equipment and other waste which has had for contact with the processing stream. Fourteen LLW disposal cells have been constructed to date; eleven of those had been completed and capped. Early cells were 10m x 10m x 6m (depth); later cells 30m x 10m x 6m. The base is compacted clay, sloped to one corner with an observation pipe that can be used to remove rainwater that may enter an open pit and allow post-closure monitoring of the pit. A 1.5mm thick polyethene plastic liner is used to line the sides of the pit, and folds over the top of the waste when the pit is full. Drummed waste is stacked two drums high around the perimeter of the pit, and loose material placed in the centre. The plastic upper liner is covered with a further compacted clay layer, and filled to a slight dome above the former ground level. An earthen cover of minimum 2m is created. Completion 10 reports for each disposal cell are prepared, as per the RWMP, and submitted to the EPA as a record of the construction, contents and closure of the cells. Various stages of construction and closure are illustrated in Plates 1 to 4. CONCLUSION In line with governmental, societal and our own expectations, good practice and continual improvement have been applied to radiation protection at Beverley Uranium Mine since planning and construction. All radiation doses associated with the enterprise have been well within the appropriate limits, with stable or decreasing doses since operations commenced. With ongoing good management this positive outcome can be expected to be maintained through all operational and later decommissioning stages. REFERENCES 1. ARPANSA (2005) Code of Practice: Radiation Protection and Radioactive Waste Management in Mining and Mineral Processing. Radiation Protection Series Publication No.9 2. Heathgate Resources Pty Ltd Beverley Uranium Mine: Environmental Impact Statement Main Report. Heathgate Resources, June 1998, Adelaide 3. Paulka, S Environmental management and regulation at an Australian In Situ Acid Leach

8 Section Section Title Notes 1 Scope 2 Introduction Overview of the operation, review process for RWMP 3 Environment Includes notes on the 2008 and 2010 expansions and baseline information 4 Brief Description of the Operation Main Beverley processing plant, associated facilities, satellite mine facilities at Beverley North 5 Main Components of Operation and Associated Wastes 6 Waste Management and Disposal Systems Covers the wellfields with drilling and mining operations there, supervised and controlled areas of the Beverley processing plant, associated facilities, solid and liquid waste management areas, satellite facilities Covers solid waste management and disposal, including the approved Low Level Radioactive Waste (LLW) disposal facility, liquid waste management disposal (evaporative concentration and injection into the Beverley mine aquifer) and satellite facilities (including communal drilling mud disposal pits) Final product (uranyl peroxide, a form of yellowcake), samples, bore hole logging sources Includes a large tabulated risk assessment prior to and with controls Description of the radiation monitoring program 7 Decommissioning and Rehabilitation 8 Risk Assessment and Control 9 Monitoring and Dose Assessment 10 Administrative Controls 11 Training Programmes Such as calibrations, inspections, preventative maintenance 12 Record Keeping and Reporting Includes weekly, monthly quarterly and annual radiation reports (quarterly and annual are provided to the regulators) 13 Review and Auditing Includes commitment to triennial external review, next due in Bibliography Appendices 17 appendices including figures, background data, monitoring details, Bachmann reporting criteria, dose calculation methodology, incident management and detailed drawings Table 4 Contents of Beverley Uranium Mine RMP 11

9 Plate 1 LLW cell during lining Plate 2 LLW cell lined and partially filled 12

10 Plate 3 LLW cell during capping plastic in place, compacted clayey earth to follow Plate 4 LLW cell fully capped 13

11 Uranium Mine: Beverley. Papers Presented at an IAEA Technical Meeting, Saskatoon, Canada, June Published as an Annex in Best Practice in Environmental Management of Uranium Mining, International Atomic Energy Agency, Vienna, IAEA Nuclear Energy Series; No. NF-T-1.2, (ISSN ). 4. Jeuken, B, Märten, H., Phillips, R Uranium ISL Operation and Water Management under the Arid Climate Conditions at Beverley, Australia. In Mine Water and the Environment (Proceedings 10th IMWA Congress); Rapantova, N., Hrkal, Z., Eds.; VSB-Technical University of Ostrava: Karlsbad, Czech Republic, 2008; pp Märten, H., Phillips, R., Woods, P., (in press): Environmental Management of the Beverley Uranium Mine. International Atomic Energy Agency, Low environmental impact uranium mining and remediation: 15 years of multinational experience through Uranium Mine Remediation Exchange Group, IAEA- TECDOC-Number to be assigned, IAEA, Vienna 6. Woods, P. (2011). Sustainability aspects of the Beverley Uranium Mines. AusIMM Bulletin, Melbourne, June 2011 (No.3), pp Märten, H., Phillips, R. & Woods, P. (2012). New Uranium ISR Satellites at Beverley North, South Australia, in The New Uranium Mining Boom, ed. B. Merkel and M. Schipek, pp Springer Berlin Heidelberg, DOI: / _3 8. Curtis, J.L, Brunt, D.A., & Binks P.J. (1990): Tertiary palaeochannel uranium deposits of South Australia, in Geology of the Mineral Deposits of Australia and Papua New Guinea; Ed. F.E. Hughes. The Australasian Institute of Mining and Metallurgy (Melbourne) Monograph No.14(2), pp Stoian L.M. (2010): Palynology of Mesozoic and Cenozoic sediments of the Eromanga and Lake Eyre basins: results from recent drilling in the northwest Frome Embayment. MESA Journal v. 57, pp Heathgate Mining proposal for Proposed Extension of Beverley Mine. Prepared for Heathgate Resources Pty Ltd by URS Australia Pty Ltd, ref , 21 December Heathgate Beverley Mine Mining and Rehabilitation Program. Heathgate Resources document MP-011 Version 6.0, 30 September Heathgate Beverley North Project Mining Lease Proposal and Draft Public Environment Report. Prepared for Heathgate Resources Pty Ltd by URS Australia Pty Ltd, ref , 8 April Heathgate Beverley North Mine Mining and Rehabilitation Program. Heathgate Resources document MP-020 Version 10.0, 27 January Bachmann, H Report of independent review of reporting procedures for the SA uranium mining industry. Report for the SA Minister for Mineral Resources Development, August Armstrong D. & Jeuken, B Management of in-situ recovery (ISR) mining fluids in a closed aquifer system. Abstracts of the International Mine Water Conference, October 2009, Pretoria, South Africa. pp