BRUSSELS — The Swiss government decided Wednesday to abandon plans to build new nuclear reactors, while European Union regulators agreed on a framework for stress-testing theirs, as repercussions from the disaster in Japan continue to ripple across Europe.

The Swiss Energy Minister Doris Leuthard had suspended the approvals process for three new reactors, pending a safety review, after the accident that struck the reactors at the Fukushima Daiichi plant in Japan after the earthquake and tsunami of March 11.

On Wednesday — days after an anti-nuclear rally in Switzerland drew a large crowd of 20,000 people — the Cabinet said it had decided to make the ban permanent.

The country’s five existing reactors — which supply about 40 percent of the country’s power — would be allowed to continue operating, but would not be replaced at the end of their life span, it said. The last would go offline in 2034.

In a statement, the Cabinet said it was responding to the desires of the Swiss people to reduce risks “in the face of the severe damage that the earthquake and tsunami in Fukushima caused.”

However, it said that there was no need to shut down plants ahead of schedule, insisting that their safe operation was assured.

The lengthy phase-out will also allow time for Switzerland to develop new energy sources and improve energy efficiency, it said, adding that long-term, nuclear energy was expected to lose its competitive advantage over renewable sources of energy because the costs associated with nuclear power, such as for new safety standards and equipment, are expected to climb.

The nuclear fuel meltdowns in Japan have prompted different reactions in other parts of Europe. France, which relies on nuclear power for about 80 percent of its electricity and is a major exporter of nuclear technology, has reaffirmed its commitment to the technology. Just across the border, however, the German government reversed a previous decision to extend the life of its nuclear plants and is working on a plan to accelerate the phase out there.

Meanwhile, national regulators from across the 27-nation European Union are planning new safety tests for the 143 operating nuclear reactors in their territories.

On Wednesday, they agreed that the tests would include some man-made disasters as well as natural ones. But the European Commission said that there would be a separate process to check whether nuclear operators could adequately thwart acts of terrorism, because of sharp differences among governments about encroaching on sensitive areas of defense and security.

The E.U. energy commissioner, Günther Oettinger, said at a news conference in Brussels that the tests would be robust.

“The quality and the depth of this stress test is such as to fulfill the requirements of the European citizen to live in a safe environment,” Mr. Oettinger said. “All of this will be done in as transparent way as possible.”

Greenpeace, an environmental group that opposes nuclear power, strongly disagreed.

The tests “won’t be independent, won’t cover plans for emergencies and won’t always tell us whether some of Europe’s most obvious terrorist targets are protected or not,” said Jan Haverkamp, a nuclear policy adviser at Greenpeace.

Britain, France and the Czech Republic were among countries that had fought hardest to water down the tests, Mr. Haverkamp said.

Britain generates only around 18 percent of its electricity from nuclear power but faces the prospect of a worsening energy shortfall if it is required to shut its reactors. The Czech Republic still mines uranium for sale to nuclear power generators.

Still, atomic power remains a hugely sensitive matter after the Ukrainian nuclear disaster in Chernobyl in 1986 spread fallout across the Continent.

Although the tests remain voluntary, the European Commission recommended that the 14 member states with reactors producing electricity begin testing for so-called man-made events by June 1.

Those tests would in some cases be more rigorous than routine safety checks. For example, power plants built to withstand earthquakes of a magnitude of 6.0 on the Richter scale would be tested for earthquakes of a higher magnitude, although it would be up to the authorities in each country to define how much tougher to make the criteria.

The tests also would include peer-review teams composed of seven people, drawing from regulators from all 27 E.U. countries and the European Commission. Those teams would have leeway to conduct inspections inside nuclear plants.

According to the commission, the key goal of the tests is to prevent the kind of accident in Europe that struck the reactors at the Fukushima Daiichi plant.

The commission said nuclear operators would need to describe what would happen if their reactors lost power for “several days” and what measures were in place if primary backup systems powered by batteries also failed.

The tests would include a review of containment systems to ensure they could withstand an air crash or the explosion of a nearby oil tanker, whether as a result of an accident or a terror attack. The tests would also seek to ascertain whether there were adequate systems to put out any resulting fire from explosions occurring near nuclear power plants.

The E.U. authorities still need to set a schedule for checking whether reactors could withstand a wider range of terror attacks, possibly including cyber attacks. Those tests are far more sensitive because governments want to avoid revealing any vulnerabilities of their reactors.

The commission, the executive arm of the European Union, said that reactors failing the tests should be shut down and decommissioned if safety upgrades were too difficult or too expensive. But it acknowledged that it had no authority to order such shutdowns.

The European Commission said national operators and regulators had agreed to make their findings public, despite initial concerns in Paris and London that publishing certain information might encourage attacks. Governments would present a final report on the tests at the end of year.

Paul Geitner contributed reporting from Paris.

Article source: http://www.nytimes.com/2011/05/26/business/global/26nuclear.html?partner=rss&emc=rss