 He was Docent in nuclear physics at the Royal Institute of Technology and an employee of the Royal Swedish Academy of Sciences Institute of Physics ("Vetenskapsakademiens forskningsinstitut för fysik") from 1937 to 1945.Eklund was an associate professor ("laborator") at the Swedish National Defence Research Institute (FOA) from 1945 to 1950 and became Director of Research at the Swedish Atomic Energy Company (AB Atomenergi, Stockholm) in 1950.He became Technical Director there in 1957 and led the effort to build Sweden's first research reactor, R1.