Abstract: A nuclear power plant comprises a nuclear reactor, the nuclear reactor comprising reactor fuel elements, a reactor vessel surrounding the nuclear reactor and a primary shield surrounding the reactor vessel. The reactor fuel elements are arranged between a first height and a second height above the first height. The primary shield comprises a base portion, an intermediate portion and a top portion. The base portion has an upper height below the first height and the base portion comprises concrete. The top portion has a lower height above the second height and the top portion comprises concrete. The intermediate portion is arranged vertically between the base portion and the top portion of the primary shield. The intermediate portion comprises at least one support structure and a matrix material containing tungsten or boron, and the least one support structure extends between the top portion and the bottom portion of the primary shield.