A proposed nuclear power plant will cost $1.9 billion to build and then will produce cash flows of $270 million a year for 15 years. After that period (in year 15), it must be decommissioned at a cost of $870 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 project NPV if the discount rate is 4%?

b. What if the discount rate is 18%