Pros
Lots of great people, and great engineers. Good opportunities for work at site. Employee stock program is a good long-term benefit, and helps provide transparency into company financial situation. Paid overtime is nice. A segment of upper management is trying every day to be a better engineering firm and a better employer, even though some of the old guard is slow to allow progress. Overall, a good place for a long-term, stable career as an engineer.
Cons
Not a very consistent culture; some groups are great to work for, others are miserable, depending on supervisors, clients, projects, etc. Nuclear industry is 90% paperwork, 10% engineering. Very limited in compensation and promotion structure so best performers do not always get compensated relative to their value to the company or promoted into positions which match their abilities. Even receiving a promotion does not necessarily mean increased compensation for the increased responsibility.