URANIUM OLYMPIC DAM · 2014. 12. 19. · Sub-level open stope has been the mining method of choice...

URANIUM

OLYMPIC DAM

LM1 ANNUAL REPORT

August 2010

BHP Billiton Olympic Dam Corporation Pty Ltd

Uranium CSG

ABN 99 007 835 761

Registered Office: Level 27, BHP Billiton Centre, 180 Lonsdale Street, Melbourne, Victoria 3000, Australia

OLYMPIC DAM

LM1 ANNUAL REPORT August 2010

DISTRIBUTION

ENVIRONMENT PROTECTION AUTHORITY (SA)

Director, Radiation Section (2 copies)

DEPARTMENT OF THE PREMIER AND CABINET

SafeWork SA

DEPARTMENT OF PRIMARY INDUSTRIES AND RESOURCES, SOUTH AUSTRALIA

Chief Inspector of Mines (2 copies)

BHP BILLITON URANIUM CSG President & COO – Olympic Dam

Vice President, HSEC

Manager, Radiation Governance

BHP BILLITON OLYMPIC DAM Asset President

Vice President, Surface

Vice President, Services

Vice President, Mining

Head of HSEC

Manager, Mine Production

Manager, Mine Development

Manager, Mine Maintenance

Manager, Mine Technical Services

Manager, Concentrator & Hydromet

Manager, Smelter and Refinery Production

Manager, Processing Maintenance

Manager, Smelter and Refinery Maintenance

Manager, Surface Technical Services

Manager, Environment and Radiation

Superintendent Radiation and Occupational Hygiene

Senior Radiation Safety Officer – Mine

Senior Radiation Safety Officer - Process

Ventilation Superintendent

Occupational Hygienist

Occupational Physician

Records Centre

This page has been intentionally left blank.

This Report has been reviewed by:

Senior Radiation Safety Officer – Process David Kruss

Senior Radiation Safety Officer – Mine James Algar

Superintendent Radiation & Occ Hygiene Cameron Lawrence

Manager – Radiation Governance Frank Harris

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August 2010 LM1 ANNUAL REPORT

Table of Contents

1 Introduction.............................................................................................3

2 Mine workings during FY10 ...................................................................4 2.1 Mining methods.................................................................................................4 2.1.1 Current Mining Method........................................................................................4 2.1.2 Stope size/shape.................................................................................................4 2.1.3 Extraction sequence............................................................................................4 2.1.4 Backfill Requirements..........................................................................................4 2.2 Mine development and Production during FY10 ............................................5 2.2.1 Mine Ventilation...................................................................................................8 2.2.2 Financial Year 2010 - Changes to Primary Ventilation Circuit.............................8 3 Planned Mine Development for FY11....................................................9 3.1 Planned Changes to Primary Ventilation Circuit during FY10 ....................12 3.2 Changes to Equipment or Process in Mine Production ..............................12 3.2.1 Changes to Mine Equipment .............................................................................12 3.2.2 Changes to Mine Procedures ............................................................................13 3.2.3 Changes to Mine Processes..............................................................................13 4 Changes to Equipment or Process in the Process Plant ..................15 4.1 Changes to Process Plant Equipment...........................................................15 4.2 Changes to Process Plant Procedures .........................................................17 5 Estimated Quantities of Radioactive Wastes .....................................18 5.1 Solid Wastes ....................................................................................................18 5.2 Gaseous Wastes..............................................................................................18 5.3 Dust and Particulate Emissions.....................................................................19 6 Conclusion............................................................................................22

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List of Figures

Figure 1: Wastes to the Tailings Storage Facility (TSF)................................................18 Figure 2: Site total emitted radon ..................................................................................19 Figure 3: Total emitted point source particulate ............................................................20 Figure 4: Total emitted uranium oxide (U3O8) from the Calciner facilities....................21

List of Tables

TABLE 1 – Actual Production Schedule FY10 ................................................................5 TABLE 2 – Actual Backfill Schedule FY10 ......................................................................6 TABLE 3 – Actual Raise Drilling Schedule FY10 ............................................................7 TABLE 4 – Actual Raise Bore Schedule FY10................................................................7 TABLE 5 – Intake and Exhaust Shafts ............................................................................8 TABLE 6 – Production Schedule FY11 ...........................................................................9 TABLE 7 – Backfill Schedule FY11 ...............................................................................10 TABLE 8 – Underground Raise Drill Schedule FY11 ....................................................11 TABLE 9 – Raise Bore Schedule FY11.........................................................................11

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1 Introduction This document is the LM1 report on radiation protection for BHP Billiton Olympic Dam. As required under the terms of the licence LM1, granted on September 28 1988 under the Radiation Protection and Control Act 1982 to mine and treat uranium bearing ores, the following information is included in this document:

• plans of Mine workings showing all existing workings and facilities for ventilation of the Mine as of 30th June 2010,

• indications of areas in which new Mine development is planned and of areas from which ore extraction is planned for the period to 30th June 2011,

• details of significant changes in Processing Plant layout, major equipment, or mill process during the twelve months ending 30th June 2010, and

• estimates of quantities of radioactive wastes produced at Olympic Dam during the twelve months ending 30th June 2010.

A separate Annual Report containing employee dose assessments, dose calculation methodologies, dose parameters and dose conversion factors for the period 1st July 2009 to 30th June 2010 will be submitted to the Radiation Protection Branch of the SA EPA in October 2010.

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2 Mine workings during FY10

2.1 Mining methods 2.1.1 Current Mining Method Sub-level open stope has been the mining method of choice at Olympic Dam since the commencement of operations in 1988. Once the stopes are mined out they are backfilled with either unconsolidated rock fill or a mixture of aggregate and binder as Cemented Aggregate Fill (CAF). The nature of the backfill material is based on future requirements of the fill mass, if it is planned to expose walls or backs in the future then CAF will be selected to backfill the stope. Conversely, if the fill mass is not going to be exposed at a later date, then the stope will be filled using rock fill.

In cycle fibrecrete is a part of the mining cycle which provides a greater level of surface support for developing drives and rehabilitation sites.

2.1.2 Stope size/shape The current stope design contains stopes of various shapes and sizes. Footprints vary from 20m by 20m to 30m by 30m. Stope height is designed as much as possible to encompass the full extent of the ore. Current stope heights generally vary from 1 to 5 lifts high (~60m to ~300m). Consequently, stope tonnages can vary from under 100,000t to in excess of 500,000t.

2.1.3 Extraction sequence The initial stope extraction sequence at Olympic Dam is defined as ‘Primary-Secondary-Tertiary’ (P/S/T). The extraction sequence was modified in 2005 to a pillarless sequence known as ‘Mining Fronts’.

The Mining Fronts extraction sequence minimises re-work caused by the need to re-access areas over time (i.e. for rehabilitation work, ventilation controls, etc.). This sequence also minimises dilution caused by CAF falling from a primary into a secondary stope and minimises ore losses caused by primary stopes CAF shadowing secondary stopes ore. Furthermore, the Mining Fronts sequence minimises any future impact of stress increase or decrease on the rock mass behaviour, thus maximising ore recovery. No remnant pillars need to be recovered in a Mining Front scenario and the operator retains the ability to close off areas upon completion of the stope extraction. Mining Fronts also provide the opportunity for consistent and systematic designs, increase the predictability, reliability and sustainability of the mining plan, and minimise the potential for ore losses.

2.1.4 Backfill Requirements There are two backfill plants utilised on site. The permanent plant produces CAF via a pug mill and utilises neutralised tailing sands, whilst the temporary plant produces CAF via a large agitator-mixing bowl and utilises quarry fines as the sand medium. Both plants are operated by BHP Billiton and a contractor delivers the CAF to surface boreholes using semi trailer bottom dump trucks. Binders (cement, fly ash and lime) are added to the CAF mixture according to the strength requirements and are sourced externally. Crushed dolomite/limestone aggregate is sourced from an onsite quarry. Water comprises both recycled process water and local saline water.

LM1 Annual Report AUGUST 2010

2.2 Mine development and Production during FY10 The actual production, backfill and raise drilling schedules for FY10 are described in Tables 1 - 4.

Table 1: Actual Production Schedule FY10 Stope Mine Area Jul-09 Aug-09 Sep-09 Oct-09 Nov-09 Dec-09 Jan-10 Feb-10 Mar-10 Apr-10 May-10 Jun-10Olive001 C 44,457 Pink115 CScarlet174 DSE 438 Scarlet152 DSE 5,888 8,781 Purple232 FBlue027 DC 14,819 Purple260 FOrange113 DC 25,912 29,472 9,219 1,906 6,274 7,635 2,624 Cyan426 FNCyan318 FN 9,987 2,795 Scarlet124 DSE 31,344 84,706 60,458 4,183 2,597 19,286 24,156 3,572 Purple242 F 58,719 10,066 Purple223 F 19,409 881 Purple214 F 39,498 49,072 5,218 Blue127 DC 22,406 35,323 9,774 Brown221 FOrange106 DNW 31,853 32,962 Olive109 C - 72,105 27,053 55,961 Pink108 C 24,420 12,756 669 Blue109 DC 46,630 91,762 59,472 16,418 727 2,211 14,371 Orange129 DC 55,358 82,105 83,143 23,049 4,709 48,648 Cyan105 FN 27,540 18,880 Blue385 DC 70,395 103,567 86,790 16,889 14,621 Purple236 F 36,950 62,631 45,517 7,978 36,761 34,627 30,331 2,880 Scarlet386 DSE 30,698 20,316 44,133 7,217 1,021 18,539 Amber501 FN 8,065 26,456 24,550 10,792 21,878 7,739 Scarlet349 DSE 7,111 21,798 32,739 827 953 24,742 Cyan153 FN 11,654 32,489 47,330 4,143 17,321 21,791 15,466 21,906 28,752 23,855 18,131 39,012 Purple210 DNW 6,489 29,181 19,490 18,842 17,477 1,863 5,699 20,446 Cyan437 FN 27,168 6,129 7,731 451 2,513 5,338 16,081 Orange102 DC 2,651 41,951 5,004 35,482 56,006 Jade301 DSE 6,976 16,580 8,929 934 41,910 Purple265 F 2,024 22,532 15,730 28,967 22,134 8,281 10,542 17,976 16,254 20,960 Jade320 DSE 5,916 13,653 4,552 39,515 Green112 DNW 15,836 12,835 29,382 38,867 8,972 8,927 22,614 26,399 22,191 Amber402 FN 9,590 18,025 20,755 27,727 17,962 16,553 23,270 28,468 19,180 10,560 Brown204 F 2,274 7,767 19,400 25,087 13,939 13,977 3,045 Jade122 DSE 4,370 2,846 13,585 20,434 25,143 2,102 Scarlet143 DSE 4,366 2,017 17,001 36,306 19,126 22,819 29,244 Orange116 DNW 4,528 13,144 14,122 18,367 35,423 8,165 Purple218 F 9,123 15,515 17,996 17,075 1,577 53,281 Green112 Surface Trucking DNW 18,844 18,023 4,301 Cyan475 FN 5,691 6,144 15,523 Orange111 DNW 8,773 7,514 5,510 6,526 Green104 DNW 4,561 18,601 17,398 29,992 Purple210 Surface Trucking DNW 4,503 12,988 Olive167 C 5,687 30,581 30,859 Olive374 C 3,861 15,750 Cyan317 FN 3,729 23,771 Blue101 DC 2,830 21,244 Purple258 F 4,418 21,428 Scarlet386 Rock Storage Stope DSE 5,233 Purple242 Rock Storage Stope F 37,876 Pink116 C 11,460

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Table 2: Actual Backfill Schedule FY10 Stope Fill Type Jul-09 Aug-09 Sep-09 Oct-09 Nov-09 Dec-09 Jan-10 Feb-10 Mar-10 Apr-10 May-10 Jun-10Jade025 CAF 10,414 782 3,968Jade315 CAF 216 7,720Purple254 CAF 26,367 15,753Cyan440 CAF 3,140 8,766Pink115 CAF 17,609 4,540

Pink115 SRF 1,414Cyan112 CAF 18,878Cyan351 CAF 19,741 6,038 40,109 1,104

Cyan351 URF 11,821 3,391Olive152 CAF 6,864 865Cyan478 CAF 34,858 10,360

Cyan478 SRF 2,593Scarlet155 CAF 51,328 9,049 31,041 969

Scarlet155 SRF 9,572 7,360Brown221 CAF 2,417 26,700Scarlet356 CAF 52,954 51,898 5,699Blue027 CAF 60,203 80,406Purple223 CAF 7,557 2,612

Purple223 URF 6,045 23,609 9,784 242Brown011 CAF 20,273 1,623Cyan426 CAF 23,437 17,890Purple214 CAF 6,700 67,787 22,051 55Pink108 CAF 25,355 16,678 75Olive001 CAF 29,108 36,490 16,843 6,611 12,938 3,143 2,433

Olive001 SRF 5,579 2,657Orange106 CAF 8,365 38,440 269Scarlet152 CAF 13,430 2,515 379 3,292 27,628 1,021 33

Scarlet152 URF 4,884 8,549 19,159Cyan105 CAF 5,789 10,002 6,037 18,432Olive109 CAF 500 17,194 34,385 19,181Amber501 CAF 19,424 7,924 7,219Orange113 CAF 10,564 10,148 44,525 38,778

Orange113 URF 7,122 3,252Purple236 CAF 15,426 19,829 20,610 2,250Scarlet174 CAF 764 16,779 43,481Blue385 CAF 19,479Scarlet124 CAF 5,995 29,648

Cyan318 URF 1,547 10,702 13,364 3,651 1,671Cyan318 SRF 10,167 2,178

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Table 3: Actual Raise Drilling Schedule FY10 Description Jul-09 Aug-09 Sep-09 Oct-09 Nov-09 Dec-09 Jan-10 Feb-10 Mar-10 Apr-10 May-10 Jun-1034 Amber 40237 Jade 12245 Blue 14827 Cyan 32627 Cyan 31732 Olive 15541 Blue 10426 Jade 30134 Green 11235 Scarlet 14327 Green 10442 Orange 11126 Olive 11432 Pink 11639 Olive 16726 Pink 11634 Amber 32246 Orange 10727 Cyan 47736 Orange 18036 Orange 11146 Purple 21035 Brown 20445 Scarlet 17441 Purple 25827 Cyan 31739 Scarlet 17445 Olive 16745 Olive 37437 Purple 21241 Purple 21031 Scarlet 14352 Cyan 12726 Orange 10226 Pink 10945 Scarlet 12835 Purple 20227 Cyan 31737 Jade 32031 Scarlet 12446 Orange 11145 Blue 10126 Jade 31529 Blue 10128 Cyan 10636 Purple 23835 Purple 21042 Orange 10246 Amber 44841 Cyan 43745 Scarlet 15445 Scarlet 154 T/Tip26 Olive 16726 Olive 155

Table 4: Actual Raise Bore Schedule FY10 Description Jul-09 Aug-09 Sep-09 Oct-09 Nov-09 Dec-09 Jan-10 Feb-10 Mar-10 Apr-10 May-10 Jun-10RB34RB34 Ext PilotRB34 Ext ReamRB31 ExtRB33

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2.2.1 Mine Ventilation The mine ventilation system is shown in the plan ODM-VNT-036-2010. Total air in circulation as of 30th July 2010 was 4200 m3/s increased from last year with the starting of the RB34 fans. A list of the air intake and exhaust shafts is shown in Table 5.

Table 5: Intake and Exhaust Shafts

INTAKES EXHAUST SHAFTS RB5 RB1 RB11 RB2 RB13 RB3 RB14 RB4 RB18 RB6 RB22 RB7 RB23 RB8 RB26 RB9 RB27 RB10 RB28 RB12

Robinson Shaft RB15 Clark Shaft RB16

Whenan Shaft RB17 Surface Decline RB19

RB20 RB21 RB24 RB29 RB30 RB34

2.2.2 Financial Year 2010 - Changes to Primary Ventilation Circuit RB34 has been commissioned in FY10. RB34 is a 4.5m diameter exhaust raise that assists RB20 in the DSE area as well as the southern rail level exhaust.


3 Planned Mine Development for FY11 Mine development will occur in those areas as outlined in the OM3 mine plan series and also shown in the overview plan ODM-ADM-122. The approximate scheduling of major Mine activities can be seen in Tables 6 - 9. Programming of the work may change with operational requirements. New stopes will be developed and brought on line as existing stopes are depleted. All stopes currently planned for FY11 are in the C, DC, DCN, DNW, DSE, F and FN Mine areas.

Table 6: Production Schedule FY11 Stope Mine Area Jul-10 Aug-10 Sep-10 Oct-10 Nov-10 Dec-10 Jan-11 Feb-11 Mar-11 Apr-11 May-11 Jun-11Blue127 DCOrange129 DCScarlet349 DSECyan153 FNPurple210 DNWCyan437 FNOrange102 DCJade301 DSEPurple265 FJade320 DSEGreen112 DNWAmber402 FNScarlet143 DSEOrange116 DNWPurple218 FCyan475 FNOrange111 DNWGreen104 DNWOlive167 COlive374 CCyan317 FNBlue101 DCPurple258 FScarlet386 Rock Storage Stope DSEPurple242 Rock Storage Stope FPink116 CScarlet349 Rock Storage Stope DSEOlive114 COlive155 CScarlet157 DSECyan127 FNOrange107 DNWPurple238 FBlue142 DCOrange180 DCNCyan326 FNCyan477 FNBlue148 DNWPurple212 DNWCyan140 FNBlue127 Rock Storage Stope DCAmber322 FNAmber521 FNPink109 COlive107 CCyan159 FNPurple225 FScarlet144 DSEScarlet154 DSEScarlet128 DSEBrown224 FPurple246 FAmber448 FNScarlet120 DSEBlue104 DCCyan359 FNJade119 DSEOrange103 DCOrange148 DCCyan106 FNScarlet151 DSEGreen114 DNW

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Table 7: Backfill Schedule FY11 Stope Fill Type Jul-10 Aug-10 Sep-10 Oct-10 Nov-10 Dec-10 Jan-11 Feb-11 Mar-11 Apr-11 May-11 Jun-11Purple232 CAFPurple223 CAFPurple223 URFOlive001 CAFScarlet152 CAFScarlet152 URFOrange113 CAFOrange113 URFPurple236 CAFScarlet174 CAFBlue385 CAFScarlet124 CAFBlue109 CAFCyan318 CAFBrown204 CAFJade122 CAFCyan437 CAFGreen112 CAFJade320 CAFScarlet349 CAFScarlet349 URFScarlet386 CAFScarlet386 URFAmber402 CAFAmber402 SRFCyan153 CAFCyan153 URFOrange102 CAFPurple210 CAFPurple210 URFCyan317 CAFCyan317 SRFCyan475 CAFCyan475 URFJade301 CAFJade301 URFJade301 SRFPurple242 CAFOlive114 CAFOlive114 URFOlive374 CAFPurple265 CAFScarlet143 CAFScarlet143 URFOlive155 CAFOlive167 CAFOrange116 CAFCyan326 CAFOrange111 CAFOrange180 CAFOrange180 URFPurple218 CAFPurple218 URFOrange107 CAFOrange107 URFOrange129 CAFOrange129 SRFPink116 CAFPink116 URFPurple212 CAFScarlet157 CAFScarlet157 SRF

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Table 8: Underground Raise Drill Schedule FY11 Description Jul-10 Aug-10 Sep-10 Oct-10 Nov-10 Dec-10 Jan-11 Feb-11 Mar-11 Apr-11 May-11 Jun-1135 Purple 202 Slot Raise - Ream 47.2594736 Orange 111 Backfill Raise - Pilot 46.126 Olive 155 Backfill Raise - Pilot 61.2236 Orange 111 Backfill Raise - Ream 43.126 Olive 155 Backfill Raise - Ream 61.2239 Blue 127 B/Fill Raise - Pilot 59.5541 Cyan 475 Backfill Raise - Pilot 108.639 Blue 127 B/Fill Raise - Ream 56.5527 Amber 521 Slot Raise - Pilot 6027 Amber 521 Slot Raise - Ream 51.63833 5.36167541 Cyan 475 Backfill Raise - Ream 61.50864 47.0913640 Blue 148 Slot Raise - Pilot 22.1 33.240 Blue 148 Slot Raise - Ream 3026 Orange 104 Backfill UGR - Pilot 215.127 Cyan 159 Slot Raise - Pilot 57.630 Orange 180 Backfill Raise Pilot 58.1227 Cyan 159 Slot Raise - Ream 54.630 Orange 180 Backfill Raise Ream 55.1226 Orange 104 Backfill UGR - Ream 68.57569 143.524337 Purple 453 Slot Raise - Pilot 23.17 51.5745 Scarlet 139 Slot Raise - Pilot 10737 Purple 453 Slot Raise - Ream 68.7445 Scarlet 139 Slot Raise - Ream 10132 Blue 104 Slot Raise - Pilot 159.82 12.3839 Scarlet 144 Backfill Raise - Pilot 54.87 039 Scarlet 144 Backfill Raise - Ream 1.302827 50.5671730 ORANGE 107 Backfill Raise - Pilot 143.4932 Blue 104 Slot Raise - Ream 157.230 ORANGE 107 Backfill Raise - Ream 143.4945 Scarlet 144 Slot Raise - Pilot 107.857 INFRA 7 Slot Raise - Pilot 76.745 Scarlet 144 Slot Raise - Ream 75.53091 26.2690957 INFRA 7 Slot Raise - Ream 70.741 Purple 225 Slot Raise - Pilot 59.25 37.7533 Blue 142 Backfill UGR - Pilot 3.53 51.9441 Purple 225 Slot Raise - Ream 9133 Blue 142 Backfill UGR - Ream 56.4745 Scarlet 151 Slot Raise - Pilot 109.326 Blue 142 Backfill UGR - Pilot 66.4345 Scarlet 151 Slot Raise - Ream 100.326 Olive 107 Slot Raise - Pilot 56.226 Blue 142 Backfill UGR - Ream 63.4326 Olive 107 Slot Raise - Ream 50.81806 2.38194431 Scarlet 128 Slot Raise - Pilot 42.41 74.9931 Scarlet 128 Slot Raise - Ream 105.426 Purple 202 Slot Raise - Pilot 80.126 Purple 202 Slot Raise - Ream 74.136 Purple 252 Slot Raise - Pilot 122.71 1939 Scarlet 120 Slot Raise - Pilot 90.38 23.0736 Brown 224 Slot Raise - Pilot 67.21 4.0936 Brown 224 Slot Raise - Ream 65.336 Purple 252 Slot Raise - Ream 132.7139 Scarlet 120 Slot Raise - Ream 104.4539 Orange 148 Slot Raise - Pilot 102.22 4.2839 Orange 148 Slot Raise - Ream 100.530 Purple 246 Slot Raise - pilot 102.0134 Green 114 Slot Raise - Pilot 203.530 Purple 246 Slot Raise - Ream 93.0137 Jade 119 Slot Raise - Pilot 7851 Orange 103 Slot Raise - Pilot 5537 Jade 119 Slot Raise - Ream 69.24853 2.75146951 Orange 103 Slot Raise - Ream 5234 Green 114 Slot Raise - Ream 50.39082 144.109246 Orange 103 Slot Raise - Pilot 24.02 21.4846 Orange 103 Slot Raise - Ream 42.5

Table 9: Raise Bore Schedule FY11 Description Jul-10 Aug-10 Sep-10 Oct-10 Nov-10 Dec-10 Jan-11 Feb-11 Mar-11 Apr-11 May-11 Jun-11RB33 Surface Raise Reaming 240 120

RB32 Surface Raise Reaming 180 180 75

RB35 Surface Raise Piloting 300 130

RB35 Surface Raise Reaming 80 180

RB33 back reaming to be completed by end of August 2010.

RB32 intake raise for A-north to commence in August 2010 and finish in October 2010.

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3.1 Planned Changes to Primary Ventilation Circuit during FY10 RB33 planned as an exhaust raise for the Cyan’s and Rail level, this project has commenced in FY09.

RB32 intake raise is to be back reamed for A-north

RB13 and RB8 to be converted to an exhaust shaft by means of installing main fans on surface. This will be necessary for the A north development.

3.2 Changes to Equipment or Process in Mine Production 3.2.1 Changes to Mine Equipment Equipment purchased during the course of the 2009/2010 year:

• For BHP Billiton Limited the following equipment was purchased and decommissioned during the reporting period:

- No change to trucking fleet

- No change to the loader fleet

- No change to forklift fleet

- Drill UJ0033 was commissioned

- Drill UJ0008 was decommissioned

- Drill UJ032 was commissioned

- Drill UJ018 was decommissioned

- Light vehicles UP299, 301, 239, 262, 266, 252, 292, 231, 242, 247, 248, 250, 253, 268, 269, 272, 285, 291, 293, 295, 310, 311 decommissioned

- Light vehicles UP342 – UP373 inclusive commissioned

• For Macmahon Underground Pty Ltd, the following equipment changes occurred:

- Jumbo DR0026 was commissioned

- Dump Truck DT0036 commissioned

- Loader LO4071 commissioned

- Shotcreter SC010 commissioned

- Shotcreter SC04 decommissioned

- Cablebolter GS04 commissioned

• For Boart Longyear Pty Ltd, there were no equipment changes.

• For Australian Raise Drilling Pty Ltd, there were no equipment changes.

• For Heading Contractors Pty Ltd, there were no equipment changes

• For Exact Mix Pty Ltd, the following equipment changes occurred for the CAF plant, quarry and batch plant:

- Water Carts SME1328, SME1325 commissioned

- Water Cart SME415 decommissioned

- Elevated work platform SME1156 commissioned


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- Elevated work platform SME524 decommissioned

- Forklifts SME1157, SME1158 commissioned

- Light vehicles PC362, PC242 commissioned

- Telehandlers SME1167, SME1178 commissioned

- Front end loaders SME1479, SME1440, SME1210, SME438 decommissioned

- Backhoe SME423 decommissioned

- Hino agi SME439 decommissioned

• Raise bore RB34 has been commissioned.

3.2.2 Changes to Mine Procedures There have been no significant changes to mine procedures that have a bearing on environmental and radiation management in the FY10 period.

3.2.3 Changes to Mine Processes Mining Method There have been no changes to the mining method in the FY10 period.

Stope size/shape There have been no changes to the stope size/shapes in the FY10 period.

Extraction sequence There have been no changes to the extraction sequence in the FY10 period.


Backfill Requirements Backfill production last year was 1.451 Mm3, a reduced amount due to the Clark Shaft Recovery. The current schedule for FY11 is 2.260 Mm3. This will be achieved by fully utilising the permanent CAF plant and using the temporary CAF plant only as required.

Studies continue to examine varying CAF mix designs to achieve different strengths, as required by Mine design.

Page 14 2BPlanned Mine Development for FY11


4 Changes to Equipment or Process in the Process Plant

4.1 Changes to Process Plant Equipment Changes that have a bearing on environmental and radiation management in the plant are shown below:

Concentrator Though there were no major changes to the Concentrator plant, the noted changes or replacements were as follows:

• Reline of tunnel 2 and 3 feeders • Mill relines completed • Svedala motor - stator overhaul • Scats Screen commissioning • Installation of On Stream Analyser to replace Multi Stream Analyser • High Compression Tailings Thickener 2 gear box replacement • Final Tail sampler installed • High Pressure Mill water tank replacement completed Hydromet Though there were no major changes to the hydro and SX plants the noted changes or replacements were as follows:

Hydromet Plant:

• Tails Leach Tank 6 & 7 commissioning

• Tails Leach Tank 1 cleaned and agitator replacement

• CCD 2 major overhaul completed

• CCD 5 gear box replacement

• Deslimes Thickener repairs

• Clarifier 2 overflow Tank reline

• Replacement of Disposals Tank 1

• Commenced a project to upgrade tails disposals (TDU)

• PLS pond reline completed

SX Plant:

• Copper SX A Train cleaned out in July 10

• Copper SX B Train cleaned out in Feb 10

• Loaded Solvent line was 100 % cleaned out in January to improve flow (line pigged)

• Ammonia recycle project completed and running larger valve trims in ammonia flow control valves in SC 3 & ST 1, St 2 & ST 3

• Pulse Column 7, 11, 5, 8 & 2 all have now been overhauled

• Uranium security upgrade completed

3BChanges to Equipment or Process in the Process Plant Page 15


• Increased feed rate to Calciner B and tested stack emissions are well below the limit

Smelter The smelter has continued to closely monitor polonium 210 (Po-210) within the process to ensure airborne radionuclide concentrations are maintained below the derived air concentration (DAC). Critical streams are assayed for Po-210 on a daily basis and the smelter project radiation technician has continued to monitor airborne activity exposures to the workforce and fume emission sources.

Of importance to note is that revert stockpiles are reducing. At the typical addition rate of 6 tonnes per hour, the remaining stockpiles are expected to be depleted by December 2010. Once the revert stocks have been depleted, small amounts of cooled and crushed Electric Furnace slag will be used as needed to maintain Electric furnace temperatures. The end of revert smelting will reduce airborne radionuclide concentrations around the Electric Furnace.

In September 2009 a new fume capture hood was installed over the slag launder between the Flash and Electric furnaces. Previously this launder was not covered, allowing fume to escape when Flash furnace slag was tapped. The new hood also assists in capturing fume escaping from the Electric furnace.

Following the Clark Shaft incident in October 2009, a major shutdown of the smelter scheduled for September 2010 was brought forward to November 2009. As part of the shutdown the Flash, Electric and Anode Furnace 3 received refractory relines. Anode Furnace 4 was relined before the shutdown. The smelter bypass stack was also replaced during the outage.

Refinery ER/EW/Gold area No changes occurred to the Refinery process flows during July 2009 to June 2010.

Analytical Laboratory No changes of note occurred to the Analytical Laboratory during July 2009 to June 2010.

Tailings Storage Facility The following were items of note for the Tailings Storage Facility.

• Commenced construction of TSF Cell 5

• EP2 taken out of service in January 2010 due to movement of some wave barriers

• Constructed a buttress at the TSF Cell 3/4 N/W corner

• Installed a dewatering bore into the mullock starter embankment for TSF Cell 3 in May 2010

• Completed 2m wall raise for EP1 with commissioning approval received June 2010.

• Installed liquor interception system TSF Cell 1 east wall in January 2010

• Repairs completed to EP5A in January 2010 and cell recommissioned in February 2010

Page 16 3BChanges to Equipment or Process in the Process Plant


4.2 Changes to Process Plant Procedures There were no significant changes to Process Plant procedures that have a bearing on environmental and radiation management for the reporting period.

3BChanges to Equipment or Process in the Process Plant Page 17


5 Estimated Quantities of Radioactive Wastes During the production of copper cathode and uranium oxide concentrate from ore mined on site, waste streams containing radioactive materials are generated. These are discussed further in the following sections.

5.1 Solid Wastes Solid wastes from the processing of ore reach the Tailings Storage Facility (TSF) in the form of tailings slurry, deposited via spigots along the edges of any of four TSF Cells. The solids consolidate over time and the liquor is either captured and transferred to a system of evaporation ponds, or is neutralised by the limestone underneath the TSF, before entering the groundwater, where it is reclaimed via a number of bores.

For the period 1st July 2009 to 30th June 2010, the mass of solid tailings produced was approximately 4,455,000 tonnes. The TSF water balance indicates that a volume of approximately 5,547,000m3 of liquor was delivered to the TSF, of which approximately 2,106,000m3 was decanted to the evaporation ponds. The data for the previous five years is shown below in Figure 1. Decreases in FY10 were due to limited production between October 2009 and May 2010 following the Clark Shaft incident and recovery.

0

1000000

2000000

3000000

4000000

5000000

6000000

7000000

8000000

9000000

10000000

FY06 FY07 FY08 FY09 FY10

Solids to TSF (t) Liquor to TAF (m3) Decanted Liquor (m3)

Figure 1: Wastes to the Tailings Storage Facility (TSF)

5.2 Gaseous Wastes Fugitive radon is emitted from all areas of site; however the most significant are the Mine ventilation raise bores, the ore stockpiles, milling activities, emission from the TSF and a component derived from ambient background concentrations.

Using the methodology derived from a review of radon source terms undertaken in 2002, the total site fugitive emission of RDP is approximately 219 TBq for the reporting period. This represents an increase over the previous reporting period’s estimation of 214 TBq, the increase is lower than normal due to the reduced production rate in FY10 as a result of the Clark Shaft incident. The increase is as a result of mine development that occurred during FY10. The previous five year radon emission activity is trended in

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Figure 2. The decreased production output for FY10 did not decrease radon emissions as only 3 percent of the total radon emission is production dependant. The remaining 97 percent of the radon emissions originate from the mine raise bores, TSF and natural background.

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Bq)

Figure 2: Site total emitted radon

5.3 Dust and Particulate Emissions Quantities of dust and particulate are generated from point-sources during the processing of ore. The principal point-sources of dust and particulate emissions are Smelter 2 (Smelter 1 only being used for the remelting of clean Refinery scrap copper), the uranium calcining facility and the Slimes Treatment Plant (STP).

Smelter 2 processes copper concentrates produced during the milling, flotation, leach and feed preparation stages of the process, and consist of a Flash Furnace (FF), an Electric Slag Reduction Furnace (EF) and two Anode Furnaces. Concentrate is fed into the FF, generating slag, blister copper and off-gas containing significant quantities of sulphur dioxide (SO2) and dust. The dust is captured within the Waste Heat Boiler (WHB) and the Electrostatic Precipitator (ESP), and either recycled to the FF, or leached and pumped to the Hydromet Tails Leach Facility.

The SO2 goes to the Acid Plant and is converted and absorbed to produce sulphuric acid. The EF takes FF slag and further reduces it to produce blister copper, slag and off-gas containing particulate. The particulate is captured via a quench tower and venturi scrubbing system, before off-gas is emitted to atmosphere. The two Anode Furnaces undertake the final fire-refining of the copper prior to casting copper anodes for use in the Refinery. The off-gas from the Anode Furnaces is treated in a gas cleaning system similar to that of the EF. All furnaces are fitted with gas cleaning system bypass stacks for use in emergency or abnormal situations.

The precipitation area of the Hydrometallurgical Plant includes two calcining furnaces, used to convert Ammonium Diuranate (ADU) to uranium oxide (U3O8). Each Calciner has a dedicated gas cleaning system to remove particulate material prior to emission to atmosphere.

4BEstimated Quantities of Radioactive Wastes Page 19


The STP (or Gold Room) treats the slimes generated during the Electro-refining process to recover gold and silver. The facility consists of a Roaster Scrubber, designed to treat various furnace off-gas streams, and a NOx Scrubber designed to treat emissions from the aciding process.

Using process control system data in coordination with isokinetic sampling, the total site particulate emission is estimated at 140,422 kg for the period 1st July 2009 to 30th June 2010. There is a decrease from last year’s figure due the reduced output of the plant in FY10 the plant during the Clark Shaft recovery. The previous five year point source particulate emission data is trended in Figure 3

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Figure 3: Total emitted point source particulate (note that a change in the calculation of particulate emissions and servicing of the main smelter stack flow measurement system in FY06 resulted in an increase in reported emissions)

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Uranium oxide emissions from the Calciners are shown in Figure 4. Uranium activity measurements from September 2009 were unavailable and activities measured from June 2009 samples were used to determine uranium emissions. The April 2010 stack test samples were not analysed as the plant was shutdown and not representative of routine operations. The uranium oxide emission and total particulate emission for the calciners was below average, again due to the 7 month period of limited production during the Clark Shaft recovery.

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3O8

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Figure 4: Total emitted uranium oxide (U3O8) from the Calciner facilities

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6 Conclusion The failure of the Clark Shaft in October 2009 heavily impacted on the production of all products.

Page 22 5BConclusion

URANIUM OLYMPIC DAM · 2014. 12. 19. · Sub-level open stope has been the mining method of choice...

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