Perhaps you should try some spelling variations:
"stable salt reactor" » "stable spent reactor", "stable shunt reactor", "stable a reactor", "table salt reactor", "stable small reactor", "stable set reactor"
"stable fast reactor" » "table fast reactor", "stable fault reactor", "state fast reactor"

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"stable salt reactor\") OR (\"stable fast reactor\"))".
• Removing quotes may allow a broader search: (( stable salt reactor ) OR ( stable fast reactor )).
• Adding a wildcard symbol may retrieve word variants: (("stable salt reactor") OR ("stable fast reactor"))*.