Technetium-99 incident at USP: understand the radioactive material and its medical importance in the country

An incident involving radioactive material was recorded in one of the units of the Institute for Energy and Nuclear Research (Ipen) in São Paulo, involving two professionals from the institution. The fact generated concern given the crucial role of the institute in Brazilian health.

The incident occurred on May 29th and its confirmation was released on Thursday night (11/6) by the National Nuclear Energy Commission (CNEN). The Ipen installation is located on the campus of the University of São Paulo (USP).

According to information released by CNEN, the episode involved the detection of traces of technetium-99. The presence of the substance was noticed during the process of removing biological sensors from an autoclave, an essential piece of equipment in the manufacture of compound radiopharmaceuticals used in diagnostic tests and cancer therapies.

The situation took place specifically at the institute’s Radiopharmacy Center. This division is responsible for the development and distribution of a wide range of radiopharmaceuticals essential for imaging procedures and oncological treatments in hospitals, clinics and research centers throughout Brazil. The uninterrupted supply of these materials by Ipen is vital, as the interruption could impact millions of patients annually who depend on these diagnostics and therapies for their treatment.

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Also according to the CNEN note, the two employees involved, classified as Occupationally Exposed Individuals (IOEs), were subjected to specialized exams, such as the Full Body Counter.

The results of these tests indicated that the amounts of radioactivity detected were minimal, confirming that there was no internal contamination in the workers. The contamination was restricted to the controlled area of ​​the institute’s Radiopharmacy Center, ensuring that it did not spread outside the restricted environment.

Ipen plays an irreplaceable role by supplying 430 clinics and hospitals across the country, enabling around 2 million medical procedures each year. Most of these interventions are directly linked to the diagnosis and treatment of patients fighting cancer.

After the incident, the internal report detailing the incident was sent for evaluation by the National Nuclear Safety Authority (ANSN), the regulatory body responsible for nuclear supervision in the country.

The National Nuclear Safety Authority (ANSN) informed, in a statement, that the Ipen Radiopharmacy Center has a valid and active operating license.

In its inspection and regulatory monitoring activities for licensed facilities, ANSN issued a notification, establishing a deadline of June 18, 2026 for Ipen to comply with the requirements presented.

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This notification guarantees the institute the right to adversarial proceedings and full defense. Any additional measures will only be determined after an in-depth technical analysis of the information and documents that will be presented by Ipen.

The disclosure of the details of the incident occurred after the Union of Workers in the Federal Public Service in the State of São Paulo (Sindsef-SP) and the Association of Ipen Servers (Assipen) officially requested information from the institute’s management and CNEN about what happened and the actions taken.

Understand technetium-99: the radioactive substance in question

Technetium, represented by the chemical symbol Tc, is a silvery-gray radioactive metallic element in the periodic table.

According to the US Environmental Protection Agency (EPA), technetium is found in tiny quantities in nature, in the Earth’s crust, but its large-scale production occurs primarily in specialized laboratories.

The technetium-99 isotope is generated during the operation of nuclear reactors and is also a residue of atomic weapons detonations.

Technetium-99m is a variation of Tc-99 with a shorter shelf life. This specific form is widely used as a diagnostic tool in medicine, as it does not persist for a long period in the human body or the environment.

Technetium-99m represents the most widely used medical isotope globally, acting as an essential radioactive tracer for the diagnosis of various health conditions.

When injected into patients, special cameras are used to capture images, allowing visualization of the presence of technetium in the body and helping to identify anomalies.