The Democratic Republic of Congo has authorised the startup of an experimental nuclear reactor that has been mothballed for more than a quarter of a century.

"The government has given its agreement to restarting the Trico II reactor," the official account of Thursday's cabinet meeting said.

The one-megawatt reactor began operations in March 1973 in the Regional Centre for Nuclear Research of Kinshasa (CREN-K), near the capital's university.

But it has not operated since 1994 for lack of funds.

The government also "authorised the minister of scientific research to inform" the International Atomic Energy Agency (IAEA), according to the cabinet report, seen by AFP on Friday.

CREN-K was established in 1959, in the twilight of Belgian colonial rule, to carry out medical, biological and industrial research.

Its director, Professor Vincent Lukanda, in an interview with AFP in 2017, said the amount of uranium or fissile material in the centre was a state secret but acknowledged it was "very dangerous."

In 2007, uranium bars were stolen from the facility, triggering international concern that the material could be diverted for military use or terrorism.

The reactor comes under IAEA inspection rules. The agency carries out regular checks on stocks of and stores of fissile material.

The is also located on a hillside exposed to erosion by tropical rain and potential landslips.