Using OGNL, it is possible to render a single radio button using the existing radio tag.
<s:radio theme="simple" name="selectedOption" list="{optionA}"/> ... <s:radio theme="simple" name="selectedOption" list="{optionB}"/>
If you want to use some other (or no) label, you can use a map:
<s:radio theme="simple" name="selectedOption" list="#{optionA:'Value A'}"/> ... <s:radio theme="simple" name="selectedOption" list="#{optionB:'Value B'}"/>