I doubt that alarmist beat-ups of the Japanese nuclear incident in isolation will have an enduring effect on the ASX.
However, given the circumstances of this and the Chernobyl disaster, I wouldn't be surprised to eventually see a social and regulatory global push to decommission or upgrade nuclear power plants which are:
1. Aging, and/or 2 Susceptible to earthquakes or tsunamis, and/or 3. Underdesigned by modern standards.