"The hot tests revealed that the level of radioactivity of a small part of the radioactive waste accumulated during the NPP utilization period was above the radioactivity values used during the design phase, therefore, safe handling of such waste requires additional measures," the Ignalina utility said in a press release.
According to the statement, the issue is currently a subject of negotiations with the project contractor, Russian-capital Germany company Nukem Technologies.
"The project contract envisages a budget for additional tasks, which can be used for risks in connection to possible deviations from the initial data. This way, the overall contract value will not change," reads the communique.
The company also said that it was aiming to ensure timely implementation of all additional instruments to be able to start industrial utilization of the complex in November of 2018, as envisaged in the NPP decommissioning schedule.
Last October, the Lithuanian State Nuclear Power Safety Inspectorate (VATESI) gave the green light to the INPP to start hot-testing its radioactive waste sorting and storage complex. This involved sorting radioactive waste to test the equipment.
The new storage facility, worth almost 200 million euros, was built by Nukem Technologies, a German company controlled by Russia's nuclear energy giant Rosatom, and the casks were manufactured by Germany's GNS.
The Ignalina plant, which was the first in the world to close Soviet-built RBMK-type reactors that are considered unsafe by the West, is to be fully decommissioned by 2038.
In line with its pre-accession commitments to the European Union, Lithuania shut down the first unit of the Soviet-era facility in late 2004 and closed the second unit at the end of 2009.