Iran inaugurated the construction of an isotope production centre at the Fordow nuclear site near the city of Qom on Tuesday, Mehr news agency reported.
The ceremony was attended by Ali Akbar Salehi, the head of the Atomic Energy Organisation of Iran, according to the Mehr news agency.
The centre will research methods to produce stable isotopes, including through distillation and heat exchange. These can be used in medicine, industry and science.
The facility is expected to be built by mid-May 2020 and equipped after September of the same year.
Iran was accused of enriching uranium at the underground Fordow facility before signing a deal in 2015 to scale down its nuclear activities.
In its turn, Tehran repeatedly denied that the Fordow facility was intended to produce weapons-grade uranium, saying that it was tasked only with producing low-enriched uranium for power plants.
On 8 May, Iran announced that it was partially discontinuing some of its obligations under the JCPOA, exactly one year after the US unilaterally withdrew from the nuclear deal and re-imposed wide-ranging sanctions on the Islamic Republic.