Northern Dynasty Receives Positive Preliminary Assessment Technical Report for Globally Significant Pebble Copper-Gold-Molybdenum Project in Southwest Alaska Wardrop completes independent Preliminary Assessment report based on concept, pre‐feasibility and
Wardrop completes independent Preliminary Assessment report based on concept, pre‐feasibility and feasibility‐level study programs completed by Pebble Partnership and Northern Dynasty
Preliminary Assessment describes and assigns potential economic value to three mine development cases comprising 25, 45 and 78 years of open pit mining and a nominal processing rate of 200,000 tons per day
For the Pebble Project, the 45‐year Reference Case yields a 14.2% pre‐tax IRR, a 6.2‐year payback on initial capital investment of $4.7 billion and a $6.1 billion pre‐tax NPV at a 7% discount rate and long‐term metal prices. At current prevailing metal prices, the 45‐year Reference Case yields a 23.2% pre‐tax IRR, a 3.2‐year payback on initial capital investment and a $15.7 billion pre‐tax NPV at a 7% discount rate
For Northern Dynasty’s 50% share of the project, the 45‐year Reference Case yields an 18% pre‐tax and 15.4% post‐tax IRR, a 4.7‐year pre‐tax and 5.3‐year post‐tax payback on initial capital investment and a $3.6 billion pre‐tax and $2.4 billion post‐tax NPV at a 7% discount rate and long‐term metal prices.
At current prevailing metal prices, the 45‐year Reference Case yields a 30.2% pre‐tax and 25.1% post‐tax IRR, a 2.6‐year pre‐tax and 3.1‐year post‐tax payback on initial capital investment and an $8.3 billion pre‐tax and $5.6 billion post‐tax NPV at a 7% discount rate for Northern Dynasty’s 50% interest
The 45‐year Reference Case produces 31 B lb copper, 30 M oz gold, 1.4 B lb molybdenum, 140 M oz silver, 1.2 M kg rhenium and 907,000 oz palladium while mining only 32% of the mineral resource
For the 45‐year Reference Case, cash costs per payable lb of copper after by‐product credits total –$0.11 February 23, 2011, Vancouver, BC – A National Instrument 43-101-compliant Technical Report on a Preliminary Assessment of the Pebble Copper-Gold-Molybdenum Project (the “Pebble Project”) in southwest Alaska, completed for Northern Dynasty Minerals Ltd. (TSX: NDM; NYSE Amex: NAK) by Wardrop, a Tetra Tech Company (“Wardrop”), confirms that Pebble is an economically robust project with the potential to become one of the most important metal producers of the 21st century. The Preliminary Assessment updates and substantially revises project economic analysis last done by Northern Dynasty in 2004, and so constitutes a material change for which a material change report containing the full executive summary will be shortly filed at www.sedar.com and at www.northerndynasty.com, along with a complete copy of the Technical Report.
The Preliminary Assessment is based on Wardrop’s comprehensive review of recent engineering and technical studies undertaken principally by the Pebble Limited Partnership (the “Pebble Partnership”) and by Northern Dynasty. The economic assessments and other opinions expressed in the Preliminary Assessment are strictly those of Northern Dynasty and Wardrop, and do not reflect the views of any other stakeholder in the project. The Pebble Partnership continues to separately undertake detailed engineering studies toward the completion of a Prefeasibility Report for the Pebble Project as contemplated by the 2007 Limited Partnership Agreement, including ongoing programs to engage project stakeholders in the planning process. As such, any project which is ultimately put forward by the Pebble Partnership for permitting under the National Environmental Policy Act (NEPA) may differ from those mine models presented in the Preliminary Assessment.
“The Pebble Project is among a handful of mineral projects around the world with the potential to meaningfully enhance global production of copper, gold and molybdenum at a time when worldwide demand is increasingly outstripping supply,” said Northern Dynasty President & CEO Ron Thiessen. “After many years of exhaustive geological, environmental and socioeconomic study, as well as intensive engineering effort, this Preliminary Assessment confirms Pebble’s potential as a modern, world-class mine that provides decades of benefits to shareholders, to the people and communities of Alaska, and to the U.S. and global economies.”
The Preliminary Assessment describes and assigns potential economic value for three successive development cases:
1. An Investment Decision Case (“IDC Case”), which describes an initial 25-year open pit mine life upon which a decision to initiate mine permitting, construction and operations may be based;
2. A Reference Case, which is based on 45 years of open pit mine production; and
3. A Resource Case, which is based on 78 years of open pit mine production and seeks to assess the longerterm value of the project in current dollars.
The 25-year IDC Case is the only scenario for which a tailings storage facility has been comprehensively engineered, although preliminary engineering studies have identified a number of suitable sites nearby to receive tailings after 25 years. Ongoing investigations undertaken during the first 25 years of mining, including construction of an early access shaft, would determine the optimal mining method and plan for subsequent phases of development.
For the purposes of its Preliminary Assessment, Wardrop has selected the 45-year Reference Case as its base case. All currency values are in US dollars. Production rates are stated in imperial tons.
A Preliminary Assessment is preliminary in nature, and includes Inferred mineral resources that are considered too speculative geologically to have economic considerations applied to them that would enable them to be categorized as mineral reserves. There is no assurance that the Preliminary Assessment will be realized.
Preliminary Assessment Key Findings
- At a 0.30% CuEQ1 cutoff, the Pebble mineral resource comprises:
5.94 billion tonnes of Measured and Indicated resources grading 0.78% CuEQ2, and containing o 55 billion pounds of copper, 67 million ounces of gold, and 3.3 billion pounds of molybdenum; and o 4.84 billion tonnes of Inferred resources grading 0.53% CuEQ, and containing 25.6 billion pounds of copper, 40.4 million ounces of gold, and 2.3 billion pounds of molybdenum.
- The Pebble deposit supports open pit mining utilizing conventional drill, blast and truck-haul methods, with an initial mine life of 25 years and potential for mine extensions to 78 years and beyond.
- The potential exists for underground block cave development at a mining rate of 150,000 tons per day to emerge as the preferred mining method for phases of development beyond 25 years.
- The process plant employs conventional crush-grind-float technology and equipment with a nominal throughput of 200,000 tons per day, as well as secondary gold recovery. Average mill throughput for the first 25 years would be 219,000 tons per day, rising to 229,000 tons per day for the 45-year and 78-year cases.
1 The Preliminary Assessment is based on mineral resources announced by Northern Dynasty in a news release dated February 1, 2010. The mineral resources fall within a volume or shell defined by long-term metal price estimates of $2.50/lb copper, $900/oz gold and $25/lb molybdenum. Mineral resources that are not mineral reserves do not have demonstrated economic viability.
Copper equivalent calculations for this resource estimate used metal prices of $1.85/lb for copper, $902/oz for gold and $12.50/lb for molybdenum, and metallurgical recoveries of 85% for copper 69.6% for gold, and 77.8% for molybdenum in the Pebble West area and 89.3% for copper, 76.8% for gold, 83.7% for molybdenum in the Pebble East area. Recovery values reflect average results of metallurgical testwork completed to the date of the February 1, 2010 estimate and are subject to revision pending ongoing metallurgical studies. Revenue is calculated for each metal based on grades, recoveries and selected metal prices; accumulated revenues are then divided by the revenue at 1% copper. Recoveries for gold and molybdenum are normalized to the copper recovery as shown below:
CuEq (Pebble West) = Cu % + (Au g/t x 69.6%/85% x 29.00/40.79) + (Mo % x 77.8%/85% x 75.58/40.79)
CuEq (Pebble East) = Cu% + (Au g/t x 76.8%/89.3% x 29.00/40.79)+ (Mo % x 83.7%/89.3% x 5.58/40.79)
2 Individual grades for each metal, as well as estimates for Measured and Indicated resources, are shown in the Mineral Resources section below.
- Other project facilities and infrastructure include: a 378 megawatt natural gas-fired turbine plant at the mine site; an 86-mile transportation corridor to Cook Inlet for road and pipeline rights-of-way; and a new deepwater port on Cook Inlet.
- Construction of the Pebble Project would take four years, and employ a peak labour force of 2,080. The operations workforce averages 1,120 over the first 25 years of mining.
- The 45-year Reference Case processes 3.8 billion tons of material with a strip ratio of 2.1:1 and average grades of 0.46% copper, 0.011 oz gold per ton and 214 ppm molybdenum.
- The 45-year Reference Case produces 31 billion lb copper, 30 million oz gold, 1.4 billion lb molybdenum, 140 million oz silver, 1.2 million kg rhenium and 907,000 oz palladium, while mining 32% of the total Pebble mineral resource.
- Economic valuations are expressed in US dollars in real terms utilizing long-term metal prices of $2.50/lb copper, $1,050/oz gold, $13.50/lb molybdenum, $15/oz silver, $3,000/kg rhenium and $490/oz palladium.
- Annual cash flows are calculated and subsequently discounted at a rate of 7%. Market convention generally uses a discount rate of 8% for copper and other base metal projects and 5% for gold and other precious metal projects. Given the large contribution of gold to total revenues at Pebble, a 7% blended discount rate has been selected.
- For the Pebble Project, the 45-year Reference Case yields a 14.2% pre-tax Internal Rate of Return (IRR), a 6.2-year payback on initial capital investment and a $6.1 billion pre-tax Net Present Value (NPV) at long-term metal prices and a 7% discount rate. At current prevailing metal prices, the 45-year Reference Case yields a 23.2% pre-tax IRR, a 3.2-year payback on initial capital investment and a $15.7 billion pre-tax NPV at a 7% discount rate.
- For Northern Dynasty’s 50% interest in the Pebble Project, the 45-year Reference Case yields an 18% pre-tax and 15.4% post-tax IRR, a 4.7-year pre-tax and 5.3-year post-tax payback on initial capital investment, and a $3.6 billion pre-tax and $2.4 billion post-tax NPV at a 7% discount rate at long-term metal prices. At current prevailing metal prices, Northern Dynasty’s 50% interest in the Pebble Project yields an 30.2% pre-tax and 25.1% post-tax IRR, a 2.6-year pre-tax and 3.1-year post-tax payback on initial capital investment and an $8.3 billion pre-tax and $5.6 billion post-tax NPV at a 7% discount rate.
- Initial capital expenditures for all three development cases are estimated at $4.7 billion, excluding capital costs associated with outsourced power, road and port infrastructure. Sustaining capital requirements for the 45-year Reference Case are estimated to be $6.14 billion.
- Operating costs for the 45-year Reference Case average $966 million per year and total $43.5 billion over the life of the mine. Operating costs per ton milled average $11.55 for the 45-year Reference Case, while cash costs per payable pound of copper, after by-product credits, are -$0.11.
- Net Smelter Return (NSR) for the 45-year Reference Case averages $2.67 billion per year and totals $120.2 billion over the life of mine. NSR per ton milled for the 45-year Reference Case averages $31.91.
- For the 45-year Reference Case, 56% of NSR would be derived from copper, 24% from gold, 16% from molybdenum and 4% from other metals (silver, rhenium and palladium).
Pebble Project Development Overview
Mine Site Development As described in the Preliminary Assessment, the Pebble deposit supports an open pit mine utilizing conventional drill, blast and truck-haul methods, with an initial life of 25 years and potential for mine extensions to 78 years and beyond. Phases of mine development beyond 25 years would require separate permitting and development decisions to be made in the future, based on prevailing conditions at the time and the accumulated experience gained from developing and operating the initial phase of the Pebble Project. Near-surface mineral resources in the western portion of the deposit are most efficiently developed through open pit methods, but the potential exists for underground mining (in particular block caving) to emerge as the preferred mining method for subsequent phases of development. Given its size, structure and polymetallic nature, the Pebble deposit presents a great deal of flexibility in near-term and long-term development options.
Of the three development cases, the 25-year IDC Case is the most comprehensively engineered. It seeks to mine near-surface resources for rapid payback, primarily in Measured and Indicated categories but also including a small proportion (16%) of Inferred material. This initial phase of mining processes about two billion tons of material or less than 20% of the total Pebble mineral resource. As such, it is not considered to be ideal for assessing the potential long-term economic value of the Pebble Project.
The level of engineering applied to the 45-year Reference Case is similar to that in the 25-year IDC Case, with the exception of detailed engineering associated with tailings storage after year 25. This extended phase of mining processes some 3.8 billion tons of material (or 32% of the total Pebble mineral resource), primarily in Measured and Indicated categories in the western portion of the deposit. Inferred resources comprise 28% of the total volume mined. Wardrop selected the 45-year Reference Case as the base case for its Preliminary Assessment due to the enhanced level of development of the Pebble mineral resource within a timeframe that makes a significant contribution to the project’s NPV. However, the 45-year Reference Case in itself is not an optimized mine plan. The 78-year Resource Case is based on a continuation of mining methods, costs and assumptions that inform the 25-year IDC Case and the 45-year Reference Case. By developing some 55% of the Pebble mineral resource over eight decades, it is intended to demonstrate the longer-term value of the Pebble Project. The 78-year Resource Case processes some 6.5 billion tons of material, primarily in Measured and Indicated categories from both the western and eastern portions of the Pebble deposit. Inferred resources comprise 33% of the total volume mined. While the economic valuation of all three development cases is based on open pit mining only, a detailed description of underground block cave mine design, operations, costs and production at a mining rate of 150,000 tons per day is also provided in the Preliminary Assessment.
The Pebble process plant, as described in the Preliminary Assessment, employs conventional crush-grind-float technology and equipment, as well as secondary gold recovery, with a nominal throughput of 200,000 tons per day and the potential to process up to 275,000 tons per day in certain years. Annual throughput averages 219,000 tons per day for the 25-year IDC Case, and 229,000 tons per day for the 45-year Reference Case and 78-year Resource Case.
The grinding circuit comprises two 40 ft x 25 ft @ 29 megawatt semi-autogenous grinding (SAG) mills and four 26 ft x 40 ft @ 16.4 megawatt ball mills. The concentrator produces a copper-gold concentrate containing 26% copper and 18 grams gold per dry tonne, as well as a 52% molybdenum concentrate and gold doré. It is anticipated that the Pebble Partnership would construct a molybdenum autoclave plant offshore to treat the molybdenum concentrate, thereby realizing enhanced value through improved pricing for rhenium and additional copper recovery.
Mine schedules have been developed for the life of mine in each development case, setting out volumes of mineralized and non-mineralized material, densities, tons, dilution, grades of contained metals (copper, gold, molybdenum) and material hardness. A key aspect of these schedules is the annual plant throughput tonnage, which is defined by the grindability of the mineralized material. The rate of production in any given year is derived by that tonnage which utilizes all available energy for which the plant has been designed (909 GWh/a). The production limit of 275,000 tons per day is therefore determined by the SAG mill hydraulic limit. Accordingly, the annual processing rate fluctuates over the mine life as the hardness of the mill feed varies. Other mine-site facilities and installations include tailings storage, rock storage, a 378 megawatt combined-cycle natural gas-fired turbine plant, as well as shop, office and camp buildings.
Pebble mine-site layout for the 25-year IDC Case
Copper-gold concentrate produced at Pebble is transported via a slurry pipeline to a new deep-water port on Cook Inlet. There it is de-watered and bulk shipped to offshore smelters. Other products of the process plant are gold doré, which would be flown to market from an existing aviation facility at Iliamna, and molybdenum concentrate, which would be bagged and trucked to the port for shipment.
Process tailings are stored behind purpose-built embankments during mining, and thereafter in the pit. A mine life extension beyond 25 years would require a second tailings storage facility (TSF) to be developed; topographical and land status conditions in the project area present a number of nearby siting opportunities. Engineering has been undertaken to a preliminary level for TSF sites with sufficient capacity to receive mine tailings after 25 years.
The TSF option selected for the 25-year IDC Case is Site G, located approximately three miles west of the open pit. The TSF impoundment would be created by three embankments. The north embankment is constructed initially to a height of approximately 200 feet and raised each year, while the south and east embankments would be built later in the mine life as the impoundment fills. The ultimate height of the north embankment is approximately 685 feet, while ultimate heights for the south and east embankments are approximately 450 feet and 100 feet, respectively.
A site-wide water surplus is forecast at the Pebble Project over the life of the mine. All surplus water would be treated to meet prevailing regulatory standards for water quality and the protection of aquatic life, and released to optimize downstream flow conditions for fish and aquatic habitat.
Infrastructure Development As described in the Preliminary Assessment, an 86-mile transportation corridor would be developed to link the Pebble mine site to a new deep-water port on Cook Inlet, 66 miles to the east, as shown on the local infrastructure map. The transportation corridor includes a two-lane, all-weather permanent access road, whose primary purpose is to transport freight by conventional highway tractors and trailers. The transportation corridor also includes four buried, parallel pipelines, including:
- a copper-gold concentrate slurry pipeline from the mine site to the port;
- a return water pipeline from the port site to the mine;
- a natural gas pipeline from the port site to the mine to fuel a natural gas-fired generating plant at the mine site; and
- a diesel fuel pipeline from the port site to the mine.
Pebble transportation corridor and port site location
A new, permanent deep-water port developed at the entrance to Iniskin Bay on Cook Inlet would serve as a product load-out facility, and facilitate in-bound fuel, equipment and supply shipments. Facilities at the port include a barge dock, deep-sea ship dock, container storage and a handling area for containers. Infrastructure components at the port site include a power generation plant, accommodation and maintenance facilities, offices, fuel storage and transfer facilities. On an annual basis, the port would accommodate shipping of 1.1 million tons of concentrate in Handymax vessels of approximately 50,000 tons, as well as diesel fuel and container barges of equipment and supplies.
Project planning assumes that the nearby Cook Inlet gasfield does not currently have adequate natural gas supplies to meet project needs. Natural gas would be sourced from other regions of Alaska and transported by pipeline from the Kenai Peninsula across Cook Inlet via a sea-bottom line to the port site and along the transportation corridor to the mine site. An alternative is the importation of liquefied natural gas (LNG) directly to the port site. Diesel fuel would be transported via pipeline from the port fuel storage facility to the mine site. In addition to fuelling mobile mining equipment and other rolling stock, emergency electrical generators also operate on diesel fuel.
Project Workforce Construction of the Pebble Project is projected to take four years, with a peak labour force of 2,080. The operations workforce is projected to average 1,120 over the initial 25-year life of the mine, with longer-term labour requirements to be determined by the mine development alternatives selected. Both construction and operations workforces would be accommodated in project camps at the mine site and the port site, and work on a rotational basis. The Pebble Partnership has stated its intention to maximize local and Alaskan hire at the Pebble Project, and is developing a workforce development plan to accomplish this goal.
Production Profiles
The 45-year Reference Case processes 3.8 billion tons of mineralized material, with a strip ratio of 2.1:1 and average grades of 0.46% copper, 0.011 oz gold per ton and 214 ppm molybdenum. Metallurgical recoveries average 87.9% for copper, 71.3% for gold and 87.9% for molybdenum. Over the life of mine, the 45-year Reference Case produces 30.5 billion lb of copper, 30.3 million oz of gold and 1.4 billion lb of molybdenum, as well as 140 million oz of silver, 1.2 million kg of rhenium and 907,000 oz of palladium.
Production results for all three development cases are presented in the table below:
| Item | Unit | IDC | Reference | Resource |
|---|---|---|---|---|
| Case | Case | Case | ||
| Mine Life | years | 25 | 45 | 78 |
| Mining Method | Open Pit | Open Pit | Open Pit | |
| Strip Ratio | waste : ore | 1.5 | 2.1 | 2.6 |
| Processing Rate | M ton / yr | 80 | 84 | 84 |
| Total Processed | M ton | 1,990 | 3,767 | 6,528 |
| % of M+I+I Resource | % | 17 | 32 | 55 |
| Copper Eq. Grade | % | 0.72 | 0.83 | 0.84 |
| Copper Grade | % | 0.38 | 0.46 | 0.46 |
| Gold Grade | oz / ton | 0.012 | 0.011 | 0.011 |
| Molybdenum Grade | ppm | 182 | 214 | 243 |
| Copper Recovery | % | 86.6 | 87.9 | 88.4 |
| Gold Recovery | % | 71.5 | 71.3 | 71.2 |
| Molybdenum Recovery | % | 84.8 | 87.9 | 89.4 |
| Copper Eq. Recovered | M lb | 24,483 | 54,129 | 96,357 |
| Copper Recovered | M lb | 12,944 | 30,494 | 53,437 |
| Gold Recovered | 000 oz | 16,391 | 30,307 | 50,133 |
| Molybdenum Recovered | M lb | 616 | 1,420 | 2,835 |
| Peak Annual Copper Recovered | M lb | 822 | 1,157 | 1,096 |
| Peak Annual Gold Recovered | 000 oz | 1,038 | 1,127 | 1,088 |
| Peak Annual Molybdenum Recovered | M lb | 43 | 56 | 62 |
| Avg Annual Copper Recovered | M lb | 518 | 678 | 685 |
| Avg Annual Gold Recovered | 000 oz | 656 | 673 | 643 |
| Avg Annual Molybdenum Recovered | M lb | 25 | 32 | 36 |
| 26% Cu-Au Concentrate Produced | 000’s dmt | 22,582 | 53,200 | 93,225 |
| 52% Mo Concentrate Produced | 000’s dmt | 537 | 1,239 | 2,473 |
Financial Valuation
Pebble Project Economic valuations for all three development cases presented in the Preliminary Assessment are expressed in US dollars in real terms. The valuation date for NPV, IRR and other financial results is at the commencement of project construction.
Long-term and current prevailing metal prices applied to the financial model for each of the development cases are outlined in the table below:
| Metal Type | Unit | Long Term Metal Prices | Current | |
|---|---|---|---|---|
| Prevailing | ||||
| Metal Prices | ||||
| Copper | $/lb | 2.50 | 4.00 | |
| Gold | $/oz | 1,050 | 1,350 | |
| Molybdenum | $/lb | 13.50 | 15.00 | |
| Silver | $/oz | 15.00 | 28.00 | |
| Rhenium | $/kg | 3,000 | 3,000 | |
| Palladium | $/oz | 490 | 490 |
Net Smelter Return (NSR) statistics at long-term metal prices for all three development cases are provided in the table below:
| Description | Unit | IDC Case | Reference Case | Resource Case | |||
|---|---|---|---|---|---|---|---|
| 25 years | 45 years | 78 years | |||||
| NSR LOM | $ M | 54,637 | 120,197 | 213,970 | |||
| NSR Annual Average | $ M | 2,185 | 2,671 | 2,743 | |||
| Copper | % | 52 | 55 | 55 | |||
| Gold | % | 29 | 24 | 22 | |||
| Molybdenum | % | 15 | 16 | 18 | |||
| Other | % | 4 | 5 | 5 | |||
| NSR per ton milled | $ / ton | 27.45 | 31.91 | 32.78 |
Annual cash flows are calculated and subsequently discounted at a rate of 7%. Market convention generally uses a discount rate of 8% for copper and other base metal projects and 5% for gold and other precious metal projects. Given the large contribution of gold to total revenues at the Pebble Project, a 7% blended discount rate has been selected. Financial results for all three development cases are summarized below:
| Item | Unit | IDC Case | Reference Case | Resource Case | |||||
|---|---|---|---|---|---|---|---|---|---|
| Mine Life | years | 25 | 45 | 78 | |||||
| Initial Capital | $ M | 4,695 | 4,695 | 4,695 | |||||
| LOM Sustaining Capital | $ M | 3,204 | 6,140 | 11,727 | |||||
| LOM NSR | $ M | 54,637 | 120,197 | 213,970 | |||||
| NSR Per Ton | $ / ton | 27.45 | 31.91 | 32.78 | |||||
| LOM Operating Cost | $ M | 22,208 | 43,489 | 96,063 | |||||
| Operating Cost Per Ton | $ / ton | 11.16 | 11.55 | 14.72 | |||||
| C1 Copper Cost | $ / lb | -0.10 | -0.11 | 0.21 | |||||
| LOM Pre-Tax Net Cash Flow | $ M | 20,123 | 55,278 | 87,329 | |||||
| Long-term Metal Prices | |||||||||
| Pre-Tax NPV at 7% | $ M | 3,837 | 6,129 | 6,812 | |||||
| Pre-Tax IRR | % | 13.4% | 14.2% | 14.5% | |||||
| Pre-Tax Payback | years | 6.5 | 6.2 | 6.1 | |||||
| Current Prevailing Metal Prices | |||||||||
| Pre-Tax NPV at 7% | $ M | 11,410 | 15,709 | 16,864 | |||||
| Pre-Tax IRR | % | 22.6% | 23.2% | 23.3% | |||||
| Pre-Tax Payback | years | 3.2 | 3.2 | 3.2 |
Pre-tax results are before income taxes but after net profits interest (NPI) royalty and local production taxes.
C1 Copper Cost is the cash cost per payable pound of copper (including operating costs and realization charges) after by-product credits Annual pre-tax cash flows for the 45-year Reference Case are illustrated in the figure below.
Northern Dynasty’s 50% Interest Under the terms of the Pebble Limited Partnership Agreement, Anglo American is required to elect to commit $1.425 to $1.5 billion in staged investments in order to retain its 50% interest in the Pebble Project. If a feasibility study for the project is completed after 2011, Anglo American’s overall funding requirement increases from $1.425 billion to $1.5 billion. A significant proportion of Anglo American’s financial contribution is expected to be applied to initial capital costs to construct the mine, thereby reducing Northern Dynasty’s capital requirements. In order to calculate an NPV and IRR estimate for Northern Dynasty’s 50% interest in the Pebble Project under this scenario, it is necessary to adjust Northern Dynasty’s share of initial capital costs. For the purpose of this calculation, it is assumed that $1 billion of Anglo American’s funding requirement would be applied to the Pebble Project’s capital cost for construction. To the end of 2010, Anglo American has invested some $325 million to advance the Pebble Project.
Inasmuch as Northern Dynasty is in a position to calculate taxes payable for its portion of profits associated with development of the Pebble Project, financial results for Northern Dynasty’s 50% interest in the project have been presented on a pre-tax and post-tax basis, and at long-term and current prevailing metal prices, in the table below:
| Item | Unit | IDC Case | Reference Case | Resource Case | |||||
|---|---|---|---|---|---|---|---|---|---|
| Long-term Metal Prices | |||||||||
| Pre-Tax NPV at 7% | $ M | 2,403 | 3,550 | 3,891 | |||||
| Pre-Tax IRR | % | 17.3 | 18.0 | 18.4 | |||||
| Pre-Tax Payback | years | 4.9 | 4.7 | 4.6 | |||||
| Current Prevailing Metal Prices | |||||||||
| Pre-Tax NPV at 7% | $ M | 6,190 | 8,339 | 8,917 | |||||
| Pre-Tax IRR | % | 29.5 | 30.2 | 30.4 | |||||
| Pre-Tax Payback | years | 2.7 | 2.6 | 2.6 | |||||
| Long-term Metal Prices | |||||||||
| Post-Tax NPV at 7% | $ M | 1,559 | 2,358 | 2,650 | |||||
| Post-Tax IRR | % | 14.6 | 15.4 | 15.8 | |||||
| Post-Tax Payback | years | 5.6 | 5.3 | 5.3 | |||||
| Current Prevailing Metal Prices | |||||||||
| Post-Tax NPV at 7% | $ M | 4,141 | 5,561 | 6,002 | |||||
| Post-Tax IRR | % | 24.5 | 25.1 | 25.4 | |||||
| Post-Tax Payback | years | 3.1 | 3.1 | 3.0 |
Pre-tax results are before income taxes but after NPI royalty and local production taxes.
The impact of various discount rates on Northern Dynasty’s 50% share of the Pebble Project’s pre-tax NPV7, and its sensitivity to a range of copper and gold prices (both individually and combined with other metal prices held constant) is presented in the table below. Life of Mine cash flow for Northern Dynasty’s 50% is $7,535 million for the 25-year IDC Case, $19,818 million for the 45-year Reference Case and $31,583 million for the 78-year Resource Case.
| Item | Unit | IDC Case | Reference Case | Resource Case | ||||
|---|---|---|---|---|---|---|---|---|
| Discount Rate | ||||||||
| NPV at 5% | $M | 2,491 | 4,164 | 4,877 | ||||
| NPV at 7% | $M | 1,559 | 2,358 | 2,650 | ||||
| NPV at 8% | $M | 1,213 | 1,774 | 1,975 | ||||
| NPV at 10% | $M | 689 | 976 | 1,087 | ||||
| Copper Price (Gold $1050/oz, Mo $13.50/lb) | ||||||||
| 2.50 | $M | 1,559 | 2,358 | 2,650 | ||||
| 2.75 | $M | 1,893 | 2,776 | 3,089 | ||||
| 3.00 | $M | 2,226 | 3,192 | 3,525 | ||||
| 3.25 | $M | 2,557 | 3,605 | 3,955 | ||||
| 3.50 | $M | 2,874 | 4,006 | 4,375 | ||||
| 3.75 | $M | 3,188 | 4,404 | 4,792 | ||||
| 4.00 | $M | 3,499 | 4,796 | 5,201 | ||||
| 4.25 | $M | 3,802 | 5,181 | 5,605 | ||||
| Gold Price (Copper $2.50/lb, Mo $13.50/lb) | ||||||||
| 1050 | $M | 1,559 | 2,358 | 2,650 | ||||
| 1100 | $M | 1,646 | 2,459 | 2,755 | ||||
| 1150 | $M | 1,733 | 2,560 | 2,860 | ||||
| 1200 | $M | 1,820 | 2,660 | 2,964 | ||||
| 1250 | $M | 1,906 | 2,760 | 3,068 | ||||
| 1300 | $M | 1,993 | 2,861 | 3,172 | ||||
| 1350 | $M | 2,079 | 2,961 | 3,276 | ||||
| 1400 | $M | 2,166 | 3,061 | 3,380 | ||||
| Combined Copper and Gold Price (Mo $13.50/lb) | ||||||||
| 2.50 / 1050 | $M | 1,559 | 2,358 | 2,650 | ||||
| 2.75 / 1100 | $M | 1,980 | 2,876 | 3,193 | ||||
| 3.00 / 1150 | $M | 2,399 | 3,391 | 3,732 | ||||
| 3.25 / 1200 | $M | 2,804 | 3,895 | 4,255 | ||||
| 3.50 / 1250 | $M | 3,200 | 4,389 | 4,771 | ||||
| 3.75 / 1300 | $M | 3,590 | 4,873 | 5,276 | ||||
| 4.00 / 1350 | $M | 3,971 | 5,350 | 5,776 | ||||
| 4.25 / 1400 | $M | 4,351 | 5,827 | 6,276 |
Capital and Operating Costs
Initial and Sustaining Capital All three development cases presented in the Preliminary Assessment have the same initial capital requirement of $4.7 billion. This includes:
- direct field costs for executing the project;
- indirect costs associated with the design, construction and commissioning of new facilities;
- owner’s support costs for corporate, environmental, permitting and staffing; and
- capital costs to completion of construction and commissioning at the end of Year -1.
The capital cost estimate has been developed over a series of project stages and is largely based on first principles estimates. Quantities have been derived for project components for which productivity and labour rates have been estimated for specific trades. As a result, the capital cost estimate approaches a pre-feasibility level of accuracy. It has been anticipated in the financial valuation that the Pebble Partnership would enter into strategic partnerships as needed to develop, finance and operate a number of infrastructure assets – including the transportation corridor (port and road) and the power plant. Each financial case also considers that the Pebble Partnership would construct a molybdenum autoclave plant offshore to treat the molybdenum concentrate, and thereby realize enhanced value through improved pricing for rhenium and additional copper recovery. Other costs include owner’s costs and an overall capital cost contingency of 17.7%.
The initial capital cost for all three development cases is shown in the table below:
| Area | Cost ($M) | ||
|---|---|---|---|
| Mining | 430.8 | ||
| Processing | 1,389.3 | ||
| Other Infrastructure | 422.0 | ||
| Tailings | 294.0 | ||
| Pipelines | 97.5 | ||
| Access Road * | 162.0 | ||
| Port Infrastructure * | 154.5 | ||
| Power Generation * | 534.1 | ||
| Indirect Costs | 1,406.8 | ||
| Contingency | 865.7 | ||
| Molybdenum Autoclave | 374.2 | ||
| Less: Escalation/ De-Escalation | (121.1) | ||
| Less: Outsourced Infrastructure * | (1,315.0) | ||
| Total | 4,694.8 |
*Outsourced infrastructure, including associated indirects and contingencies
Sustaining capital requirements (in $M) for all three development cases are shown in the table below:
| Area | IDC Case | Reference Case | Resource Case | ||||
|---|---|---|---|---|---|---|---|
| Open Pit | 2,047 | 3,286 | 7,225 | ||||
| Processing | 146 | 230 | 517 | ||||
| Infrastructure | 12 | 165 | 165 | ||||
| Waste Management | 846 | 2,211 | 3,364 | ||||
| Other | 70 | 104 | 180 | ||||
| Molybdenum Autoclave | 83 | 144 | 276 | ||||
| Total | 3,204 | 6,140 | 11,727 |
Operating Costs Life of mine unit operating costs for the 45-year Reference Case are estimated to be $11.55 per ton milled. This includes all costs associated with open pit mining of mineralized and non-mineralized material, processing of mill feed to a final concentrate and all services required to support the operation. This estimate has been prepared as an annual cost for each year of the project from plant start-up to mine closure. Operating costs are based on estimated process plant throughput rates, which range depending on the grindability of the material fed to the process plant. Life of mine unit operating costs for all three development cases are presented in the table below:
| Description | Unit | IDC Case | Reference Case | Resource Case | ||||
|---|---|---|---|---|---|---|---|---|
| Total Operating Costs | $M | 22,208 | 43,489 | 96,063 | ||||
| Open Pit | $ / ton | 3.83 | 4.30 | 7.19 | ||||
| Process | $ / ton | 4.50 | 4.60 | 4.93 | ||||
| Transportation | $ / ton | 0.97 | 0.91 | 0.91 | ||||
| Environmental | $ / ton | 0.30 | 0.29 | 0.31 | ||||
| G&A | $ / ton | 1.56 | 1.45 | 1.38 | ||||
| Total Operating Costs per ton milled | $ / ton | 11.16 | 11.55 | 14.72 |
Costs of ocean freight for the transportation of final concentrate to off-shore smelters, as well as all smelter and other offsite charges, are summarized in the table below:
| Description | Unit | IDC Case | Reference Case | Resource Case | ||||
|---|---|---|---|---|---|---|---|---|
| Offsite Charges | ||||||||
| Total Offsite Charges | $ M | 4,752 | 11,089 | 19,938 | ||||
| Offsite Charges per ton milled | $ / ton | 2.39 | 2.94 | 3.05 | ||||
| Cash Cost Analysis | ||||||||
| Offsite Charges | $/lb | 0.38 | 0.38 | 0.39 | ||||
| Operating Costs | $/lb | 1.79 | 1.48 | 1.87 | ||||
| Copper Cash Cost | $/lb | 2.17 | 1.86 | 2.26 | ||||
| By-Product Credits | $/lb | -2.27 | -1.97 | -2.05 | ||||
| C1 Copper Cost | $/lb | -0.10 | -0.11 | 0.21 |
Annual costs for the 45-year Reference Case are summarized in the figure below.