On February 17, 2011, Wardrop, A Tetra Tech Company issued an independent 43-101 compliant Preliminary Assessment Technical Report of the Pebble Project. The Preliminary Assessment is based on concept, pre-feasibility and feasibility-level technical and engineering studies completed by the Pebble Partnership and Northern Dynasty.
Wardrop's Preliminary Assessment describes and assigns potential economic value to three successive mine development cases comprising 25, 45 and 78 years of open pit mining and a nominal processing rate of 200,000 tons per day. Wardrop selected the 45-Reference Case as the base case for its study.
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.
