Mothers for Nuclear is a pro-nuclear energy group founded and run by Kristin Zaitz and Heather Hoff, two employees of Diablo Canyon Power Plant, the last nuclear power plant in California. Zaitz and Hoff started the group when the plant came under pressure from government regulators in 2015, which resulted in the plant being scheduled to close in 2024. Zaitz and Hoff are continuing to try to reverse the closure and are advocating for increased development of nuclear power throughout the United States and around the world. They argue that nuclear energy is the most efficient form of energy production in terms of financial and environmental costs, and they specifically seek to challenge left-wing environmentalist objections to nuclear energy.
Mothers for Nuclear has three international chapters: Mothers for Nuclear Canada, Mums for Nuclear UK, and Mothers for Nuclear Deutschland, Osterreich, Schweiz (Germany, Austria, and Switzerland). Mothers for Nuclear has also attended events in China and Turkey. 
Mothers for Nuclear was founded by Kristin Zaitz and Heather Hoff, two employees of the Diablo Canyon Power Plant, the only remaining nuclear plant in California after the shutdown of the San Onofre plant in 2012.  Both have said that they previously opposed nuclear power and took jobs reluctantly. Zaitz studied engineering in college and had a highly influential professor who often criticized nuclear power in class. Hoff was born near Three Mile Island, the site of the most famous nuclear accident in the United States and was warned by her uncle that power plant employees were exposed to radiation and would often die prematurely of cancer. 
Zaitz and Hoff both became convinced of the efficiency and environmental benefits of nuclear power as they worked at Diablo Canyon Power Plant. The plant’s opening was opposed by California Governor Jerry Brown (D) and attracted a protest which resulted in 2,000 arrests. The plant has continued to attract controversy ever since. With the rise of natural gas and highly subsidized renewable energy in California, political pressure has increased to shut down the plant. 
In 2015, Pacific Gas and Electric (PG&E), the company which owns Diablo Canyon Power Plant, applied to renew its operating license from the U.S. Nuclear Regulatory Commission and its environmental permit from the California State Lands Commission to continue absorbing and expelling 2.5 billion gallons of seawater each day. At the time, the plant produced 8% of California’s electricity, and 25% of the state’s non-carbon-emitting energy. Then-Lieutenant Governor Gavin Newsom (D-CA) chaired the California commission and stated that the power plant likely wouldn’t survive past the mid-2020s. 
In 2016, Zeitz became connected to Environmental Progress, an organization run by journalist Michael Shellenberger, who spoke out in favor of the Diablo Canyon Power Plant. At one of the organization’s events, Zeitz met up with Hoff, and the two began to coordinate with local businesses, unions, and non-profits to support the power plant. On Earth Day, they formed Mothers for Nuclear to continue their efforts and expand into broader nuclear power advocacy throughout the United States and internationally.  PG&E was aware of their activism and permitted it, though the company did not explicitly endorse Zeitz and Hoff’s views. 
Later in 2016, PG&E announced that it would shut down the Diablo Canyon Power Plant due to a lack of financial viability. The plant was facing decreased demand due to “community-choice aggregation,” a California policy which permitted localities to choose the sources of their electricity; many towns chose environmentalist-aligned energy production over nuclear power despite being provided at the same cost through the state. PG&E also faced increased regulatory costs due to a 2015 California bill which requires the state to produce half of its energy with renewable sources, which would force PG&E to increase its renewable energy production. 
Mothers for Nuclear list three partner organizations: World Nuclear Energy Day, Students for Nuclear Energy, and Generation Atomic.