NUCLEAR POWER PLANT

1 . A nuclear power plant comprising a nuclear reactor,

the nuclear reactor comprising reactor fuel elements, the reactor fuel elements being arranged between a first height and a second height above the first height,

a reactor vessel surrounding the nuclear reactor and a primary shield surrounding the reactor vessel,

the primary shield at least forming a ring around the reactor vessel, the primary shield comprising a base portion, an intermediate portion and a top portion, the base portion, the intermediate portion and the top portion each extending continuously circumferentially around the reactor vessel, the base portion of the primary shield having an upper height at or below the first height and the base portion comprising concrete, the top portion of the primary shield having a lower height at or above the second height and the top portion comprising concrete, the intermediate portion of the primary shield being arranged vertically between the base portion and the top portion, the intermediate portion comprising at least one support structure and a matrix material containing one of tungsten, boron, silver, indium, hafnium and cadmium and the least one support structure extending between the top portion and the bottom portion of the primary shield.

2 . A nuclear power plant as claimed in claim 1 wherein the at least one support structure comprises an internal concrete member and an external concrete member, a single layer of matrix material containing one of tungsten and boron being arranged between the internal concrete member and the external concrete member,

3 . A nuclear power plant as claimed in claim 1 wherein the at least one support structure comprises an internal steel member and an external steel member, a single layer of matrix material containing one of tungsten and boron being arranged between the internal steel member and the external steel member.

4 . A nuclear power plant as claimed in claim 1 wherein the at least one support member comprises an internal steel reinforced concrete member and an external steel reinforced concrete member, a single layer of matrix material containing one of tungsten and boron being arranged between the internal steel reinforced concrete member and the external steel reinforced concrete member.

5 . A nuclear power plant as claimed in claim 1 wherein the at least one support member comprises an internal concrete member, an intermediate concrete member and an external concrete member, a first layer of matrix material containing one of tungsten and boron being arranged between the internal concrete member and the intermediate concrete member and a second layer of matrix material containing one of tungsten and boron being arranged between the intermediate concrete member and the external concrete member.

6 . A nuclear power plant as claimed in claim 1 wherein the at least one support member comprises an internal steel member, an intermediate steel member and an external steel member, a first layer of matrix material containing one of tungsten and boron being arranged between the internal steel member and the intermediate steel member and a second layer of matrix material containing one of tungsten and boron being arranged between the intermediate steel member and the external steel member.

7 . A nuclear power plant as claimed in claim 1 wherein the at least one support member comprises an internal steel reinforced concrete member, an intermediate steel reinforced concrete member and an external steel reinforced concrete member, a first layer of matrix material containing one of tungsten and boron being arranged between the internal steel reinforced concrete member and the intermediate steel reinforced concrete member and a second layer of matrix material containing one of tungsten and boron being arranged between the intermediate steel reinforced concrete member and the external steel reinforced concrete member.

8 . A nuclear power plant as claimed in claim 1 wherein the matrix material comprises a polymeric material.

9 . A nuclear power plant as claimed in claim 8 wherein the polymeric material comprises one of polypropylene and polythene.

10 . A nuclear power plant as claimed in claim 1 wherein the one of tungsten and boron is distributed throughout the matrix material as one of a powder and particles.

11 . A nuclear power plant as claimed in claim 1 wherein the primary shield comprises an internal steel lining and an external steel lining, the base portion, the intermediate portion and the top portion being sandwiched between the internal steel lining and the external steel lining.

12 . A nuclear power plant as claimed in claim 1 wherein the intermediate portion has a radially inner surface and a radially outer surface, the intermediate portion has the same vertical height at the radially outer surface as the radially inner surface.

13 . A nuclear power plant as claimed in claim 1 wherein the intermediate portion has a radially inner surface and a radially outer surface, the intermediate portion has a greater vertical height at the radially outer surface than the radially inner surface.

14 . A nuclear power plant as claimed in claim 1 wherein the intermediate portion has a radially inner surface and a radially outer surface, the intermediate portion has a greater vertical height at the radially inner surface than the radially outer surface.

15 . A nuclear power plant as claimed in claim 1 wherein a further wall surrounds the primary shield, a containment vessel surrounds the further wall and a building wall surrounds the containment vessel.

16 . A nuclear power plant as claimed in claim 1 wherein the nuclear reactor is one of a pressurised water reactor and a boiling water reactor.

17 . A nuclear power plant as claimed in claim 1 wherein the nuclear reactor is a small modular reactor.

18 . A nuclear power plant as claimed in claim 17 wherein the small modular nuclear reactor produces up to 500 MWe.

19 . A nuclear power plant as claimed in claim 18 wherein the small modular nuclear reactor produces 220 to 440 MWe.