Chernobyl Nuclear Power Plant under construction

In 1970, the very year when the town of Pripyat was founded, they started building the first of the four reactors at the Chernobyl Nuclear Power Plant. This one was ready to operate in 1977, as is the book that I found and brought with me from Pripyat (Again, I find it better to mention that I intend to give it to the Chernobyl Museum in Kiev  when I'm done translating it.). .

This photo is a shot of a photography featured in this book, and according to the accompanying text, it shows some part of the ChNPP under construction. I don't recognise these cylinders, so currently I'm looking to find out what they are.