Question

the earliest nuclear fission reactions required the action of an operator to shut down safely in the event of a problem. today, scientists have designed passively safe nuclear reactors that require no human intervention to shut down safely. which of the following best describes why the design of fission reactors has changed?a. the scientists that developed the first nuclear power plants did not care about safety.b. the scientists that design modern nuclear reactors do not look at earlier designs.c. scientists have applied what they learned from early nuclear plants to create better designs.d. scientists working on the first nuclear power plants did not know how nuclear fission worked.

Explanation:

Early nuclear fission reactors needed human operator action to shut down safely, while modern ones are passively safe. This change comes from scientists using knowledge gained from early nuclear plant operations to improve reactor designs over time. Option A is incorrect because early scientists did care about safety, they just had less developed designs. Option B is wrong because modern designs build on earlier ones. Option D is false as early scientists understood nuclear fission basics to build the first plants.

Answer:

C. Scientists have applied what they learned from early nuclear plants to create better designs.