A 47-year-old Swiss nuclear power plant was permanently shut down on Friday.

The Mühleberg nuclear plant, near Bern in Switzerland, is the first of five Swiss nuclear power reactors to be decommissioned.

The nuclear power station was officially taken offline at 12.30 Swiss local time when the last control rod was removed from between the fuel elements. This stopped the chain reaction and deactivated the reactor. It took three seconds.

The Mühleberg reactor had been in service since 1972 and provided 5% of Swiss electricity. BKW, the operator of Mühleberg plant, decided to close the plant in 2013 for business reasons.

BKW said on Friday that itwas "organisationally and financially well prepared for its largest project since the construction of [the plant] about 50 years ago". It added that the site had generated enough electricity to cover the energy consumption of Bern for more than 100 years.

"We had to reply to the question if we wanted to invest a three-digit-million figure into a long-term operation", Suzanne Thoma, the BKW CEO, said. "We reached that conclusion to not invest anymore into the nuclear plant Mühleberg."

The plant will be completely decommissioned by 200 people over a 15-year period, starting on January 6, 2020. The dismantling and destruction of equipment used for producing electricity, such as turbines, generators and condensers, will continue until October 2020. The central building will then be prepared for the dismantling, decontamination and packaging of material.

By 2024 all nuclear fuel rods will have been transported to the central interim storage facility for high-level radioactive waste in Würenlingen, northern Switzerland.

BKW says radioactivity will be eliminated from the Mühleberg site by 2031. It is expected to cost CHF1.4 billion to totally dismantle the plant and manage the radioactive waste.

Employees spoke of an "emotional moment" and of "nostalgia". "We would have been happy to operate the nuclear plant a bit longer", one said.