Used nuclear fuel assemblies, which had been lying for decades at the bottom of Building 5, an aged and dilapidated fuel store at Russia’s Andreyeva Bay, have been removed and secured, marking a major milestone in a year-long international effort.

The European Bank of Reconstruction and Development, which manages the funds for the cleanup, reported that the complex technical operation was completed last month.

The fuel removal process at Andreyeva Bay, which began in 2017, is being carried out by SevRAO, part of Russia’s state nuclear corporation Rosatom, with financing from the bank’s Northern Dimension Environmental Partnership program. The program’s Nuclear Window effort draws together funding and technical assistance for 10 European nations

Bellona’s Alexander Nikitin, who was instrumental in drawing the world’s attention to the dangers of Andreyeva Bay, called the operation “an important step, which will allow for further cleaning of the building and the removal of remaining damaged fuel.”

He warned, however, that the Cold War relic remains hazardous and that its internal fuel storage pools must be decontaminated before the facility is harmless.

A Geiger counter measuring radiation near Andreyeva Bay's Building 5. Credit: Amund Trellevik/NRK

Andreyeva Bay opened in 1961 as a refueling station and maintenance base for Soviet nuclear submarines. Over the next quarter of a century, the site amassed some 22,000 spent nuclear fuel assemblies, many badly damaged, before it was closed in 1992 without adequate planning to handle the contamination that could emerge.

In 1982, that contamination came to the fore when the site’s now notorious Building 5 started leaking, threatening to dump a toxic stew of plutonium, uranium and other fission products into Litsa Fjord, only 50 kilometers from the Norwegian border on the Barents Sea.

Technicians at the base rushed much of that nuclear fuel into temporary containment structures at the site and cemented them in – an arrangement that over time became permanent.

Still other fuel at Andreyeva Bay was stored out in the open, unshielded from the harsh arctic elements. The conditions of neglect led many experts to fear that the radioactive morgue might spark an uncontrolled chain reaction and explode.

This slow-motion nuclear disaster continued to unfold in near secrecy until Bellona brought it to international attention in 1996, when it published a groundbreaking report on Northwest Russia’s nuclear woes.

One of the most significant problems described by the report was what remained in Building 5 after its initial leak had been stemmed: Although the intact fuel assemblies had been removed, significant volumes of radionuclides and damaged assemblies remained in the sludge of structure’s storage pools.

Tackling the removal of those dangerous remnants was complicated, as the damaged assemblies required special robots to removed them. This remote handling equipment had to be manufactured for the purpose. After tests at a mock-up facility, the damaged fuel removal was successfully completed by last month.

Following this latest operation, radiation levels at Andreyeva Bay fell by over 40 percent, which will allow for further decommissioning work within the framework of the Nuclear Window. The used fuel will be transported to Atomflot, the nuclear icebreaker port near Murmansk, for onward transportation, storage and reprocessing at the Mayak Production Association in the Southern Urals.

The EBRD, as the only international financial institution with experience funding nuclear decommissioning, has managed financing for a number of post-Soviet nuclear cleanup projects. Among those is the containment structure over Chernobyl’s stricken No 4 reactor and the Lepse nuclear service ship, which is now being dismantled near Murmansk.

The Andreyeva Bay cleanup project is expected to be complete by 2028.