What to do with half mill?

Father in law just called me complaining that he's only getting less than half a percent on his money in a credit union savings account. He and his wife are in their lower 80s. Six kids. Wants to know what else he could do with his money to gain more interest but with very little risk. Both are relatively healthy at this point. Pretty certain they have no recurring debt. House and vehicles are paid off.

Advice?