I had my first interview recently after passing the Math/Science test. I didn't make it past the interview.
The interviewers grilled me on mechanical concepts, which I didn't really expect. Before the interview they do ask you to review the CANDU system(thats exactly what I was told), so I focussed on the engineering physics part of CANDU.
During the interview they asked ques such as what equipment operators use, questions about pumps, valves, heat exchangers, theory behind turbines. A few electrical questions such as transformers, voltages of generators. It also includes typical behavioral questions.
I underestimated what topics they would be covering.
I feel really upset after the interview, I thought I could make it. Based on all the requirements for the position and reading the operator preview document on their website, I felt I was prepared since I have an Electrical Engineering degree. I felt the interview would focus on behavioral, but I was wrong. I felt it was a bit unfair since the focus was on mechanical concepts specifically fluid mechanics.