The European Union's nuclear regulators and the
European Commission on Thursday failed to reach consensus on "stress tests" for nuclear power plants proposed after Japan's reactor crisis, dpa reported.
The open-ended negotiations are set to resume next week in Prague.
"Content is more important than timing," EU Energy Commissioner Guenther Oettinger said. "The public expects credible stress tests covering a wide range of risks and safety issues. This is what we are working on."
The nuclear meltdown scare that Japan faced at its Fukushima nuclear plant in the wake of a magnitude-9.0 earthquake and ensuing tsunami led to a renewed debate on nuclear safety around the world.
EU leaders in March decided to recommend that member states carry out voluntary stress tests. They tasked the national regulators and the European Commission with drafting common assessment standards, with a view to launching the tests in the second half of 2011.
But there are differences between member states and Oettinger on what should be tested for.
Oettinger has insisted that plants be assessed not just on how they would withstand natural disasters, but also man-made ones - particularly terrorist attacks.
That has met resistance from some member states because of the commission's simultaneous demand for the tests' outcome to be made public, according to Oettinger spokeswoman Marlene Holzner.
The commission has insisted on transparency because it cannot force member states to fix problems found at their nuclear plants, but believes the public will do so if the issues come to light.
Holzner has said that Oettinger is willing to compromise on the issue, since it is "obvious" that publicizing measures put in place to protect against terrorist attacks would not make sense.
But the commissioner has warned that he is ready to take the issue back to EU leaders if agreement is not reached.
Thursday's discussion saw "progress" being made, "but no final decision has been taken," Oettinger's office said.
The commission and the European Nuclear Safety Regulators Group will now hold a two-day meeting starting next Thursday in Prague.
A total of 143 nuclear power plants are currently operational in fourteen of the EU's 27 countries, with another six under construction and 15 proposed.