The Mining and Chemical Combine (a subsidiary of the State Corporation Rosatom) conducted a scientific-technical meeting on the subject Probabilistic Safety Assessment (PSA) of wet storage of spent nuclear fuel at the GKhK. This is the first PSA made for the object of the nuclear fuel cycle (formerly the PSA was applied for uranium-graphite reactors and nuclear power reactors).

The PSA actions for wet storage of spent nuclear fuel started two years ago when the head of Rosatom Sergey Kiriyenko took a business trip to the Mining and Chemical Combine. Considering the Fukushima events the industry leader raised the matter of prospect awaiting the GKhK wet storage of spent nuclear fuel if catastrophic earthquake of magnitude ten and greater happened and the cooling pond became hydrated.

Unlike foreign counterparties the GKhK wet storage cooling pond is divided into several independent sections. If any compartment is dehermetised or dehydrated the storage covers can be rearranged into an undamaged compartment. Moreover, even if spent nuclear fuel is completely dehydrated it can stay without breaching the fuel rods for more than 30 days. However, an additional safety barrier was developed in order to avoid the extremely unlikely situation: if a catastrophic earthquake causes dehermetisation of all storage pool independent compartments, the irrigation system will be powerful enough to ensure the necessary heat level of fuel storage as long as possible. Both the project of irrigating system and the already completed reconstruction have been the objects of probabilistic safety analysis, and mathematical models were used to calculate the work of the whole system in the most difficult situations.

Source: www.sibghk.ru