Question: In how many nuclear power projects of Washington Nuclear Project  the Energy Northwest started construction?
Sentence (from "WNP-1 and WNP-4"): WNP-1, WNP-2 and WNP-3 were part of the original 1968 plan, with WNP-4 (a twin to WNP-1 and located at the same site) and WNP-5 (a twin to WNP-3, in similar fashion) added in the early 1970s.
Relevant evidence: No