US Nuclear Corp. has signed a definitive agreement to be the exclusive manufacturer of medical isotope generators for a nuclear medicine company. US Nuclear, in Canoga Park, would make the devices for MIFTEC, owned by Magneto-Inertial Fusion Technologies Inc. in Tustin. The agreement between US Nuclear and MIFTEC replaces a letter of intent between the two companies signed in December. The value of the agreement was not disclosed. Currently there are no suppliers for this equipment in the United States. US Nuclear Chief Executive Robert Goldstein said that radioisotope sales reached $9.6 billion in 2016 and are projected to hit $17 billion by 2021. “With MIFTEC’s excellent efficiency and affordability, and US Nuclear’s manufacturing capability, we believe the world market will multiply,” Goldstein said in a statement. Radioisotopes have a variety of uses in the medical field, including treatment of cancer and in medical imaging. US Nuclear has three subsidiaries: Technical Associates in Canoga Park, which makes radiation detection equipment; Overhoff Technologies in Milford, Ohio, which specializes in tritium detection equipment; and Electronic Control Concepts, also in Milford, which makes voltmeters to check industrial and medical X-ray machines. Shares in US Nuclear (UCLE) closed up 33 cents, or more than 15 percent, at $2.49 on the over-the-counter market.