UI Conditional Test: Repeat

I have a UI repeat and need to check if a variable is null to properly fill a TD, if I remove the conditionals the variable is displayed correctly but for this verification situation I am not getting any way to make the when test does it work correctly, is there any way to check inside a ui: repeat? Here is the code below:

<ui:repeat var="ossada" value="#{sessionOssadaController.ossadas}"
    varStatus="status">
    <tr>
        <td>#{ossada.codigoOssada}</td>
        <c:choose>
                <c:when test="#{empty ossada.codigoOssada} ">
                    <td>#{ossada.sexo}</td>
                </c:when>
                <c:otherwise>
                    <td>Nao Cadastrado</td>
                </c:otherwise>
        </c:choose>
    </tr>
</ui:repeat>