You may want to talk with another agent about your concerns - as well as talk with a few people who live in the area. An agent can provide you with community trends within 10 miles - and trends outside the area as well. But, it would be a stretch to say the proximity to the nuclear facility was the reason for the differences.
There are plenty of very valuable homes within 10 miles of the Limerick plant. And, there are very knowledgeable and informed people who live in the communities nearby - and many who have lived in the area for all their lives.
Please research the number of nuclear accidents in the US, their frequency and severity and make an informed decision based on what you find. Don't let someone scare you unnecessarily.