Due to multiple rumors about what really happened at the construction site of the Belarusian nuclear power plant First Deputy Director General of the Russian state nuclear engineering corporation Rosatom Alexander Lokshin, who oversees the project, has decided to make a few comments about the situation. The interview has been published on the Rosatom website.
On the night of 9-10 July a subcontractor was relocating the reactor vessel from one support assembly to another. Naturally, it was done outside the reactor compartment building because preparations for inserting the reactor vessel into the power-generating unit were still underway. The reactor vessel was supposed to be moved by about ten meters without changing its horizontal alignment. However, during rigging operations the subcontractor failed to precisely follow the instructions. As a result, the reactor vessel was slanted when it was hoisted.
The reactor vessel is 11 meters long. It was lifted by about 4 meters when the hoisting crane experienced a malfunction. The lifted reactor vessel stayed like that for over half an hour. Slanting grew gradually all the time and in the end the reactor vessel slipped inside the rigging and touched the ground while hanging at an angle.
The entire process was filmed without interruptions and the tensions on the hoisting crane hook were recorded. Even when the reactor vessel touched the ground, the main weight of the product — over two thirds — was still hoisted by the crane. This is why it is not a good idea to resort to words like “crashed” or “dropped” while talking about the event because such words distort what happened since the reactor vessel moved as slow as a man walks.
Why the events were disclosed only now?
The nuclear engineering industry follows clear-cut instructions and regulations, which determine what events are to be reported to oversight agencies and the general public. These rules describe the scale of the damage or impact on personnel, equipment, and environment. In this case there was no event that damaged anything. At best we can talk about painting erased by metallic straps due to friction.
Do you want to say that no violations happened?
I said right away that instructions concerning the rigging of the cargo were not followed to the letter. The subcontractor has been punished, its personnel have been laid off and will never be allowed to work at out nuclear sites. But it was done not because something happened to the reactor vessel. Their mistakes stopped the equipment installation process. Moreover, mass media now doubt the advisability of using this reactor vessel, which can be seen at least as damage to the reputation. It is what we hold these people and the subcontractor as a whole accountable for.
As far as the reactor vessel is concerned, it has suffered no essential impact that could change its qualities. Instrument measurements and calculations convincingly demonstrate that the maximum impact the reactor vessel experienced was many times below the limit and 1.5 times below even the effects the reactor vessel is designed to handle non-stop for 60 years of normal operation.
Nevertheless, in order to dispel even a shadow of a doubt of the customer, we have decided to do additional testing. Specialists of the design company OKB Gidropress and the manufacturing company Atommash have performed control measurements, including ultrasound scanning and non-destructive testing of welded seams. The results confirm that the state of the reactor vessel has experienced no changes.
What are you going to do now?
Results of all the tests have been handed over to the customer. We are absolutely convinced that there are no technical obstacles to using the reactor vessel as it is. But we understand that the general public acceptance of nuclear projects is a high priority along with safety and reliability. We concede that the customer may decide not to use the reactor vessel in order to stop the wave of rumors and hype among part of the population.
If the customer decides so, we will take this decision into consideration because we understand the special importance of public acceptance during the construction of the country's first nuclear power plant. Then the first power-generating unit will get the reactor vessel initially intended for the second unit. This reactor vessel is nearly ready. But the customer has yet to make this decision. Such a decision will definitely shift the timeline for completing the construction of the power-generating unit.