A proposed nuclear power plant will cost $1.4 billion to build and then will produce cash flows of $220 million a year for 15 years. After that period (in year 15), it must be decommissioned at a cost of $820 million. (Negative amounts should be indicated by a minus sign. Do not round intermediate calculations. Enter your answers in billions rounded to 3 decimal places.) a. What is the NPV of the project if the discount rate is 5% ? b. What is the NPV of the project if the discount rate is 18%