"I cannot see any plausible political line-up that would enable a revival of nuclear power in Germany," Altmaier told Friday's edition of the Leipziger Volkszeitung regional daily.
After the 2011 Fukushima disaster in Japan, Germany embarked on an ambitious "energy revolution", deciding to phase out its nuclear power plants by the end of 2022 and bolster renewable sources of energy such as solar and wind power.
But concerns have mounted that this would entail a sharp rise in electricity prices amid difficulties in building a network able to transmit energy from the North Sea coast to the energy-hungry south of the country.
The European Union's Energy Commissioner, Günther Oettinger, told Monday's edition of the Rheinische Post regional daily that there would "still be nuclear power on the German network in 40 years."
He said there were still 140 nuclear power stations in Europe and that nuclear fusion technology was progressing rapidly. "Maybe this technology will one day be accepted in Germany," said Oettinger, who is himself German.
Altmaier also vowed to meet the deadline of finding a permanent national storage site for nuclear waste by 2030, despite continued feet-dragging and prolonged negotiations on a regional and national level.
"We are together looking country-wide," he said, adding that the search would be accelerated this year. The search would be "co-financed and jointly carried out" by Germany's nuclear energy companies, said Altmaier.
But environmentalists accused the government of plotting to dispose of German nuclear waste abroad, where safety requirements may be more lax.
According to a report in the Süddeutsche Zeitung on Friday, the government is preparing a change to the law which would legalize the export of nuclear waste to a third country.
The Environment Ministry insists the government is still planning on disposing of highly radioactive nuclear waste within Germany's borders, yet environmentalists have questioned this in the face of the new legislation.
Environment group Deutsche Umwelthilfe said the new legislation "does not conform with the [EU's] intention to prioritize domestic disposal," in a statement on Friday.
The amended law would require an agreement between Germany and a third country, and for disposal sites abroad to meet strict safety requirements, wrote the paper.