Japan Self-Defense Force officers prepare for a clean-up at a radiation affected area in Nihonmatsu, Fukushima Prefecture in northern Japan, March 15, 2011. Panic swept Tokyo on Tuesday after a rise in radioactive levels around an earthquake-hit nuclear power plant north of the city, causing some to leave the capital or stock up on food and supplies.

A dominant view in the government is that South Africa has no choice but to opt for nuclear because no other energy source, except coal – the dirtiest carbon emitter – can affordably provide the baseload power the country needs.

The triple whammy Japanese earthquake, tsunami and nuclear incident may test the bounds of this resolve. Public sentiment has been influenced by televised images of explosions at the Fukushima nuclear plant.

The global political compass may be tilting away from the axis of easy presidential visits to France to discuss matters nuclear, but the degree of wobble has yet to be ascertained. From Switzerland and Germany to Thailand and India, the events in Japan are causing a rethink of nations’ nuclear plans – although nations such as the US have reiterated their support for nuclear.

Like most energy sources, nuclear would not survive without a government leg-up. Funding assistance traditionally comes via sweeteners of export credit assistance by countries exporting nuclear technology. This doesn’t make nuclear a cheap option, or one preferred by financiers. In South Africa, the debate has hinged largely on the cost of providing new nuclear capacity compared with other power sources.

The integrated resource plan (IRP) 2010 is due out by April, outlining a roadmap over 20 years of the government’s preferred energy mix. A draft released at the end of last year proposed an energy mix in 2030 of 47 percent coal, 16 percent renewables and 14 percent nuclear.

Following numerous public objections, the drafters went back to work, devising a nuclear-free scenario, inflating the costs of nuclear by 40 percent.

It found that the cost of the non-nuclear option was higher than a preferred scenario that included nuclear with costs adjusted 40 percent higher. Not surprising, as planners upped the input of gas turbines in the non-nuclear option in order to meet the country’s baseload requirements.

A pro-nuclear executive told me recently the increase of nuclear costs by 40 percent was somewhat arbitrary.

In other words, arbitrary remodelling of IRP scenarios done by a pro-nuclear government has resulted in a financial argument for nuclear. How would the results have differed if nuclear costs were inflated by, say, 50 percent? Or if different assumptions were made about oil and gas prices?

The events in Japan, which has a long history of alleged nuclear cover-ups, are now likely to shift the South African nuclear debate back to the basics of safety, inasmuch as nuclear lobbyists believe it is unreasonable to question the safety of the entire nuclear industry as a result. While South Africa lies far from the earthquake-prone Rim of Fire, we now know that the risk of nuclear meltdown is not simply a historical footnote consigned to Three Mile Island in 1979 and Chernobyl in 1986.

South Africa’s biggest nuclear risks may not stem from earthquakes, but it has safety issues of its own that have never been addressed transparently, among them the failure to provide raw data on routine emissions from the Pelindaba and Koeberg nuclear facilities in recent years.

There are also questions about the impact of releasing low-level nuclear waste into the Crocodile River system, whether the population of the Witwatersrand has been exposed to radioactive radon, an ageing system at Pelindaba, and the tricky issue of tailings from uranium mining, among many others.

It remains to be seen whether the explosions have been forceful enough to shake these skeletons out of South Africa’s closet.