Patent Number: 
Section: claims

1. A method of constructing a nuclear reactor module, the method comprising:providing a first formwork defining a chamber in which is mounted a nuclear reactor comprising a nuclear reactor pressure vessel configured to contain nuclear fuel when in use;providing a second formwork defining a containment structure configured to contain an internal pressure generated by an escape of coolant from a reactor coolant circuit, the first formwork being housed within the second formwork;filling one or more voids within the first formwork with concrete through at least one concrete supply pipe that extends from outside of the second formwork, through the second formwork, and through a wall of the first formwork so as to open into the one or more voids of the first formwork;forming the containment structure by filling one or more voids within the second formwork with concrete; andventing the one or more voids within the first formwork through one or more vent pipes, thereby forming a concrete support structure for the nuclear reactor,wherein the filling of the one or more voids within the second formwork occurs after the filling of the one or more voids within the first formwork. 2. The method of constructing a nuclear reactor module according to claim 1,further comprising removing at least one removable support that is configured to support at least some of the nuclear reactor during transportation. 3. The method of constructing a nuclear reactor module according to claim 1, further comprising removing at least one removable brace that is configured to support at least some of the first formwork during transportation. 4. The method of constructing a nuclear reactor module according to claim 1, further comprising:detaching the at least one concrete supply pipe after the first formwork has been filled with concrete, andremoving the at least one concrete supply pipe from the containment second formwork. 5. The method of constructing a nuclear reactor module according to claim 1,wherein the first formwork comprises at least one arrangement comprising: (i) a structural void, (ii) an expansion void disposed above the structural void, and (iii) a structural support plate disposed between the structural void and the expansion void and having at least one hole therein, andwherein the method further comprises filling the structural void with concrete to a level above the structural support plate such that the structural void is filled with structural concrete that can support a load applied to the structural support plate.