There are some that would agree with drapa that the 12% is needed. The contract is not clear to me.

In cases where the language of an agreement is ambiguous, contract law stipulates that the intent and spirit of the agreement will take precedence. As a PE I have been a witness in several cases and this is the legal principle upon which these kind of cases are decided. One has to look at the intent of the agreement between Cuu and Teck when it was written.

At the time it was written I believe interests rates were in the 7-8% range and using 12% NPV was common in the mining industry as a determining factor in assessing viability. Today it is not. So for Teck to argue that the BFS did not meet their proof of viability at 12% would not hold too much credibility and would be view as a violation of the spirit and intent of their agreement. So imo, from a legal standpoint, I don`t think we have to worry about Teck rejecting the BFS on these grounds.