Silkwood is an effective little-guy(here, gal)-vs-corporate-Moloch drama. Scripted by Nora Ephron and Alice Arlen it is based on real, although conjecture-clouded, events that happened to whistleblower Karen Silkwood who was exposed to radiation at an Oklahoma nuclear facility where she worked, and as a result became an activist for worker safety over shareholder profits.
With strong performances by Meryl Streep in the lead and Cher as her lesbian friend (both actresses were Oscar-nominated but neither won), it is a sadly moving film, being neither manipulative, patronising or simplistic, Nichols' adherence to the conventions of mainstream cinema and era-typical undercurrents of conspiracy-theory paranoia notwithstanding.
FYI: The perils of nuclear energy were much to the fore during the 1970s and '80s. For related subject matter see The China Syndrome (1979).