The future of nuclear power has been dealt a nasty blow by Japan’s Fukushima crisis — on the eve of the 25th anniversary of the Chernobyl disaster — which has forced the first cancellations of six planned reactors.

The crisis has already had considerable political impact in countries such as Germany, while forcing countries from Europe to China to delay their power programs while reviewing safety rules. But this week two reactors planned for Texas and four in Italy have been shelved or cancelled in what is the most dramatic fallout so far for the industry outside of Japan’s Fukushima disaster.

Including the four damaged reactors at Fukushima, that’s 10 current or planned power plants gone, with the future of the other two at Fukushima very doubtful.

American power group NRG Inc got publicity in Australia this morning with its announcement yesterday that it is dropping plans to build two nuclear reactors in Texas.

But the more important decision came in Italy where the country’s Senate on Wednesday night, our time, approved a proposal made a day earlier by the Berlusconi government to indefinitely shelve plans to build four reactors, which were to cost  $US26 billion between 2013 and 2030. The government had tabled the proposal in the senate on Tuesday, so the Australian media missed it.

The first reactor was to have been completed in 2020, but no more.

While the cynical in Italy say the proposal is aimed at undermining a referendum in June on the question of the country returning to nuclear power, it will be almost impossible for Berlusconi to renege on the deal. The government was facing defeat at the referendum (which would have also been another vote on the prime minister). Naturally the government says that vote is now not needed

The decision, which now goes to the lower house for a vote, means Italy’s current 80% sourcing of its energy needs from fossil fuels (oil, coal and gas) won’t change, leaving unchanged the 20% share currently held by renewables, such as solar, geothermal and hydro. It also means Italy will find it next to impossible to reduce its carbon consumption by a significant amount in coming years, and will also increase the costs for other EU members of cutting their levels.

Economic Development Minister Paolo Romani was quoted as saying Italy would reconsider nuclear power “when Europe as a whole takes decisions shared by all countries”, referring to planned “stress tests” on European nuclear power stations.

“Fukushima has shown us that major accidents are possible. I don’t say that voluntarily, having said that I was and remain pro-nuclear,” Romani said in a media interview. “Nuclear power is not culturally acceptable at the moment.” That is, the voters don’t want it.

Italy closed its old reactors after the Chernobyl disaster.

The NRG decision was interesting because the two plants it has cancelled were among the four identified by the US government in 2005 for support by way of loans and funding guarantees. But a combination of a gas glut, falling electricity prices and a weak outlook for future demand meant the plants were becoming doubtful. The killer blow was Fukushima, which has ruined the outlook for nuclear power in Japan.

NRG was building the plants in co-operation with its Japanese partner, Toshiba, which was responsible for building two of the six reactors at Fukushima plant of Tokyo Electric Power, which was in turn involved in helping finance the NRG project. (No wonder it’s a goner, given Tokyo Electric’s future is very much in doubt).

“The tragic nuclear incident in Japan has introduced multiple uncertainties around new nuclear development in the United States which have had the effect of dramatically reducing the probability that STP 3 and 4 can be successfully developed in a timely fashion,” said David Crane, president and CEO of NRG in the company’s statement. “We continue to believe both in the absolute necessity of a US nuclear renaissance and that STP 3&4 is the best new nuclear development project in the country bar none.

“However, the extraordinary challenges facing US nuclear development in the present circumstance and the very considerable financial resources expended by NRG on the project over the past five years make it impossible for us to justify to our shareholders any further financial participation in the development of the STP project.”

The next big test for nuclear power outside of Japan will probably come in June in Germany at the end three-month moratorium ordered by Chancellor Angela Merkel. Her government will decide by mid-June how long the country’s 17 nuclear power reactors are allowed to remain online and how that decision will shape the future German energy mix. There’s talk she wants to abandon any idea of new nuclear power plants or continuing with some of the old ones to improve her government’s electoral appeal.

Her government lost power in the German state of Barden Wurttemberg in late March on the issue of nuclear power, with the Greens winning control of the government in coalition with the Social Democrats. It was the first time in 68 years that Merkel’s conservative party had lost power in the state that is the richest and the heartland of German manufacturing and industry.