Nuclear reactors

Claim 1

A GRAPHITE MODERATOR STRUCTURE FOR A NUCLEAR REACTOR COMPRISING STACKS OF UNIFORM RIGHT PRISMATIC GRAPHITE BLOCKS POSITIONED IN LAYERS EXTENDING IN THE DIRECTION OF THE LENGTHS OF THE BLOCKS, THE BLOCKS DEFINING COOLANT CHANNELS PARALLEL TO THEIR LENGTH, AND HAVING MINIMUM WIGNER GROWTH PROPERTIES IN THE DIRECTION OF THEIR LENGTH, AND PAIRS OF GRAPHITE TILES SEPARATING ADJACENT END FACES OF THE BLOCKS, THE TILES BEING ARRANGED SO THAT FIRST, THEY FORM TWO LAYERS BETWEEN EACH LAYER OF BLOCKS WITH THEIR PRINCIPAL FACES PARALLEL TO THE END FACES OF THE BLOCKS, SECOND, THAT ALL THE TILES IN ANY ONE LAYER HAVING MINIMUM WIGNER GROWTH PROPERTIES IN A DIRECTION WHICH IS ONE CO-ORDINATE AXIS NORMAL TO THE LONGITUDINAL AXES OF THE BLOCKS AND THAT ALL THE TILES IN THE ADJACENT LAYERS HAVE MINUMUM WIGNER GROWTH PROPERTIES IN A DIRECTION WHICH IS THE OTHER COORDINATE AXIS NORMAL TO THE LONGITUDINAL AXIS, THIRD, THE PRINCIPAL FACES OF THE TILES AND THE END FACES OF THE BLOCKS ARE PROVIDED WITH MEANS DEFINING INTERLOCKING KEYS AND KEYWAYS PARALLEL TO BOTH SAID CO-ORDINATE AXES, FOURTH, THE SIDE WALLS OF SAID TILES WHICH ARE NORMAL TO THE DIRECTION OFF MINIMUM WIGNER GROWTH IN THEIR RESPECTIVE TILES BUTT TOGETHER AND THE OTHER SIDE WALLS ARE SPACED APART, FIFTH, THE LENGTH OF THE SIDE WALLS OF THE TILES LYING ALONG THE DIRECTION OF MINIMUM WIGNER GROWTH IS GREATER THAN THE PARALLEL DIMENSIONS OF THE VERTICAL BLOCKS ABOVE AND BELOW AND IS EQUAL TO THE REQUIRED LATTICE PITCH OF THE COOLANT CHANNELS, AND SIXTH, THE TILES HAVE MEANS DEFINING APERTURES CO-AXIAL WITH AND OF SIMILAR SIZE TO SAID COOLANT CHANNELS.