Gene Sievers is taking over as manager of the Y-12 National Security Complex in Oak Ridge, Tenn., backfilling a position left vacant after his predecessor was promoted as part of the leadership shuffle that ensued when Morgan Smith retired as head of the outgoing nuclear-weapons production-site prime.

Sievers, most recently vice president of the Bechtel National-led Consolidated Nuclear Security’s (CNS) Mission Assurance organization, replaces Bill Tindal as the prime point-person at the U.S. manufacturing hub for nuclear-weapon secondary stages. 

CNS promoted Tindall to chief operating officer after the last person in that position, Michelle Reichert, was herself promoted to CNS chief executive officer to fill Smith’s spot.

Blake Scott replaced Sievers as vice president of mission assurance, CNS said in its press release. Scott was most recently senior director of lithium transformation.

Smith, CNS said through a spokesperson last month, had been considering retirement for some time before stepping down in August.

CNS is about to enter the final 12 months of its roughly $2-billion-a-year contract to manage Y-12 and the Pantex Plant in Amarillo, Texas. The National Nuclear Security Administration opted not to pick up any more options on the company’s prime contract, citing safety and management lapses including timekeeping irregularities that CNS reported up to its customer.

That set off an earlier-than-anticipated scramble for one of the biggest pots of revenue in the nuclear-weapons business, and heavyweights such as former Y-12 and Pantex prime BWX Technologies [BWXT] and Amentum, née AECOM [ACM] Technical Services, say they are in on the action. 

Likewise, Texas A&M University and the University of Tennessee System are publicly shopping their combined services to industry, though the institutions hadn’t gotten any bites at deadline Tuesday.