A readable book about nuclear power
The first thing to note is that the book is an old one: written in the mid-1970s, revised once in the early 1980s. So if you're looking for the most up-to-date book on nuclear power, this book is not the one to seek.
That said, this book is a classic! Patterson is a nuclear physicist, so he's well qualified to write it. The book, very well written for a non-technical audience, describes nuclear reactors and how they work. Patterson then describes how they can malfunction and release radioactive debris.
At the time of his writing, he could include the accidents at Windscale in the UK and Three Mile Island in Pennsylvania. He wrote before Chernobyl and Fukushima, so those accidents are not included.
The book is informative, easy to read (especially for a complicated subject!), and "timely," despite its age. It shows that the intrinsic flaws of nuclear power were well understood 40 years ago, and the situation has not altered in fundamental ways since that time.