Possible Clues:

• Puzzlement
• Mix-up
• Before new merger, business in a muddle
• One against possible energy source? Shame!
• The sort of mess that melting together produces at last
• Perplexity in study on nuclear reaction
• The muddle of a hundred on the melt
• Study nuclear process in chaos
• It¿s all over the place when Con joins up
• Puzzlement ... or a hint to getting the 10 words on the perimeter of this puzzle