Chernobyl updates: Stable fuel particles, solid waste disposal

More than 40 years after the meltdown of Unit 4 at Ukraine's Chernobyl nuclear power plant, research into radioactive material at the site continues, as do efforts toward cleanup and decommissioning.

In a paper published in the March 2026 issue of the Journal of Hazardous Materials and disseminated widely last week, a team of researchers from the Leibniz University Hannover and Helmholtz-Zentrum Dresden-Rossendorf research laboratory revealed that the fuel components of six "hot particles"-pieces of radioactive debris resulting from the Chernobyl explosion-appeared structurally stable, with the fissile material bound within the particles.

The stability of hot particles: The hot particles examined included remnants with properties similar to those of uranium dioxide fuel, particles created when the fuel melted and fused with its protective zirconium shielding, and uranium oxides produced when the reactor's graphite moderator caught fire.

The research team subjected each type of particle to X-ray diffraction analysis and found that for each one, the crystalline structures of the fuel material were intact, suggesting that fissile material from these particles had not escaped into the surrounding environment to any significant degree and was more stable than expected.

While the team noted that further research was warranted, as only six particles were studied and every particle can behave differently, the paper stated that such research could promote the development of new waste management and containment strategies at affected sites.

This is not the first time researchers have investigated the stability of hot particles from the Chernobyl accident. A 1995 paper from the International Atomic Energy Agency hypothesized that structural matrices inside fuel particles could prevent radionuclides from migrating into the environment.

It also is not the first case of surprising findings from Chernobyl hot particles: A paper published in the September 2004 issue of Mycological Research found that microfungi were attracted to and capable of breaking down and absorbing material from graphite-infused particles.

The ICSRM ships waste: News of the fuel particle research findings followed a different update from the firm currently overseeing the Chernobyl nuclear power plant. On September 17, State Specialized Enterprise "Chornobyl NPP" announced that the site's Industrial Complex for Solid Radioactive Waste Management (ICSRM) had sent its first seven packages of low- and intermediate-level radioactive waste for disposal.

The ICSRM began operations in May after years of construction, licensing, and testing, but it had been proposed decades before. The ISCRM was designed to treat waste left over from Chernobyl's pre-1986 operations along with waste produced by the decommissioning of Unit 4.

With the ICSRM functioning, three facilities for treating, processing, and handling radioactive waste now are active at the Chernobyl site:

• The ICSRM.
• The Liquid Radioactive Waste Treatment Plant (LRTP).
• The Complex for Manufacturing Metal Drums and Reinforced Concrete Containers (CMD&C).

Prior to the ICSRM starting operations, solid waste was stored on site at Chernobyl's Solid Radioactive Waste Storage Facility. The ICSRM's processed waste will go to the Specially Equipped Near-Surface Disposal Facility for Solid Radioactive Waste (ENSDF), part of the Vector industrial complex that was constructed 20 kilometers west of Chernobyl as a site for near-surface storage of waste from the accident.

The decommissioning of Chernobyl has been progressing according to a four-stage process. Plant operators expect the fourth and final stage-the dismantling of reactor equipment-to be completed sometime around 2065.