Unforunately, EnglishRussia is badly translated and sometimes editorialized. Take the following line, for example: "The narrow corridor is curved so that a shock wave won’t penetrate the inside of the building."
The original Russian is "Только одна из стен - полукруглая. Это неспроста, стена является фрагментом стенки круглой шахты уходящей далеко под землю", which directly translates to "one of the walls is curved, and for a good reason: it's part of the round shaft that descends deep underground". No mention of a shockwave.
There is some comment about the shockwave in photo 4:
4. Узкий коридор входа имеет несколько поворотов, задача которых - погасить ударную волну даже при открытых дверях и недопустить попадания внутрь проникающей радиации.
В "доме" всего 1 коридор, вот его план
I don’t know Russian, but with Google translation and a little of hand editing:
4. A narrow corridor the entrance has a few turns, whose main task is to extinguish a shock wave even when the doors are open and disallow the propagation of ionizing radiation.
They probably mix the captions of the photos creatively :).
It's not good when blogspam from englishrussia.com is on the HN frontpage for hours.