I think viva voce would be a rare type of assessment for after the bomb, for some reason, always thought it would only be for extension english two students. But some possible questions you can be asked might include:
1)Why have you chosen these particular related texts?
2)What are the key concepts that you can derive from a study of the collection of texts as a whole-considering the philosophical, scientific, religious and economic paradigms?
3)How has the analysis of these after the bomb texts transformed your way of thinking?
4)What is the significance of the distinctive textual mediums used by the texts to convey contextual concerns about after the bomb?
Just some ideas, if you could give us more specific information about this assessment task, might be able to come up with better questions
Hope this helps