Nuclear reactors and to closure arrangements for use therein

Claim 2

A nuclear reactor comprising: A. a pressure vessel having a wall which defines a chamber accommodating a reactor core and arranged to contain gas under pressure, B. means providing bores penetrating the wall of the pressure vessel from outside the vessel, C. closure means for the bores, D. means providing passages interconnecting the bores and the core chamber, and E. turbomachinery housed within the bores and incorporating at least one heat exchanger and an associated water-box, F. the closure means for the bore which houses a said heat exchanger of the turbomachiner comprising i. a primary closure device which provides a gastight seal across the bore, and ii. a secondary closure device extending across but not sealing the bore inwardly of the primary closure device to limit the escape of gas from the bore in the event of rupture of the primary closure device, iii. the secondary closure device being provided by the said water-box, and iv. the water-box comprising a pair of plates sealed together at their edges and shaped to provide a space between them, and v. a partition separating the space into at least two chambers.

Claim 3

A nuclear reactor according to claim 1 wherein the partition is annular and divides the space into an outer chamber radially outwards of the partition and an inner chamber radially inwards of the partition.

Claim 4

A nuclear reactor comprising: A. a pressure vessel having a wall which defines a chamber accommodating a reactor core and arranged to contain gas under pressure, B. means providing bores penetrating the wall of the pressure vessel from outside the vessel, C. closure means for the bores, D. means providing passages interconnecting the bores and the core chamber, And E. turbomachinery housed within the bores and incorporating at least one heat exchanger and an associated water-box, F. the closure means for the bore which houses a said heat exchanger of the turbomachinery comprising i. a primary closure device which provides a gas-tight seal across the bore, and ii. a secondary closure device extending across but not sealing the bore inwardly of the primary closure device to limit the escape of gas from the bore in the event of rupture of the primary closure device, iii. the secondary closure device being provided by the said water-box, iv. a section of the bore towards one end thereof being lined by a hollow cylinder having one end adjacent the said one end of the bore, v. the primary closure being sealed across the said one end of the cylinder, and vi. the water-box extending across the hollow cylinder inwardly of the primary closure device and comprising an outer plate and an inner plate, the outer plate being disposed outwardly of the inner plate with respect to the said one end of the bore, and each plate being dishshaped such as to have a convex surface directed inwards with respect to the said one end of the bore, the inner plate having a peripheral flange which is sealed to a rim formed around the periphery of the outer plate.

Claim 5

A nuclear reactor comprising: A. a pressure vessel having a wall which defines a chamber accommodating a reactor core and arranged to contain gas under pressure, B. means providing bores penetrating the wall of the pressure vessel from outside the vessel, C. closure means for the bores, D. means providing passages interconnecting the bores and the core chamber, And E. turbomachinery housed within the bores and incorporating at least one heat exchanger and an associated water-box, F. the closure means for the bore which houses a said heat exchanger of the turbomachinery comprising i. a primary closure device which provides a gas-tight seal across the bore, and ii. a secondary closure device extending across but not sealing the bore inwardly of the primary closure device to limit the escape of gas from the bore in the event of rupture of the primary closure device, iii. the secondary closure device being provided by the said water-box, iv. a section of the bore towards one end thereof being lined by a hollow cylinder having one end adjacent the said one end of the bore, v. the primary closure being sealed across the said one end of the cylinder, and vi. the water-box extending across the hollow cylinder inwardly of the primary closure device and comprising an outer plate and an inner plate, the outer plate being disposed outwardly of the inner plate with respect to the said one end of the bore, and each plate being dishshaped such as to have a convex surface directed inwards with respect to the said one end of the bore, the inner plate having a peripheral flange which is sealed to a rim formed around the periphery of the outer plate.

Claim 6

A nuclear reactor comprising: A. a pressure vessel having a wall which defines a chamber accommodating a reactor core and arranged to contain gas under pressure, B. means providing bores penetrating the wall of the pressure vessel from outside the vessel, C. closure means for the bores, D. means providing passages interconnecting the bores and core chamber, and E. turbomachinery housed within the bores and incorporating at least one heat exchanger and an associated water-box F. the closure means for the bore which houses a said heat exchanger of the turbomachinery comprising i. a primary closure device which provides a gas-tight seal across the bore, and ii. a secondary closure device extending across but not sealing the bore inwardly of the primary closure device to limit the escape of gas from the bore in the event of rupture of the primary closure device, iii. the secondary closure device being provided by the said water-box, iv. a section of the bore towards one end thereof being lined by a hollow cylinder having one end adjacent the said one end of the bore, v. the primary closure being sealed across the said one end of the cylinder, and vi. the water box extending across the hollow cylinder inwardly of the primary closure device and being provided around its periphery with an annular flange having a plurality of circumferentially spaced radially extending projections, the lining cylinder is provided internally with an annular ridge forming a seating for the flange and the water-box is supported within the lining cylinder by a plurality of spaced projections which engage the projections of the water-box on the sides remote from the ridge so as to maintain the flange in contact with the ridge, the spaces between the projections of the lining cylinder being wider than those between the circumferentially spaced water-box projections, for enabling the water-box to be fitted into its operative position within the lining cylinder by axial movement to cause the water-box projections to pass between the lining cylinder projections into engagement with the ridge, followed by a partial rotation to bring cooperating surfaces of the water-box and lining cylinder projections into engagement.

Claim 7

A nuclear reactor comprising: A. a pressure vessel having a wall which defines a chamber accommodating a reactor core and arranged to contain gas under pressure, B. means providing bores penetrating the wall of the pressure vessel from outside the vessel, C. closure means for the bores, D. means providing passages interconnecting the bores and core chamber, and E. turbomachinery housed within the bores and incorporating at least one heat exchanger and an associated water-box F. the closure means for the bore which houses a said heat exchanger of the turbomachinery comprising i. a primary closure device which provides a gas-tight seal across the bore, and ii. a secondary closure device extending across but not sealing the bore inwardly of the primary closure device to limit the escape of gas from the bore in the event of rupture of the primary closure device, iii. the secondary closure device being provided by the said water-box, iv. a section of the bore towards one end thereof being lined by a hollow cylinder having one end adjacent the said one end of the bore, v. the primary closure being sealed across the said one end of the cylinder, and vi. the water box extending across the hollow cylinder inwardly of the primary closure device and being provided around its periphery with an annular flange having a plurality of circumferentially spaced radially extending projections, the lining cylinder is provided internally with an annular ridge forming a seating for the flange and the water-box is supported within the lining cylinder by a plurality of spaced projections which engage the projections of the water-box on the sides remote from the ridge so as to maintain the flange in contact with the ridge, the spaces between the projections of the lining cylinder being wider than those between the circumferentially spaced water-box projections, for enabling the water-box to be fitted into its operative position within the lining cylinder by axial movement to cause the water-box projections to pass between the lining cylinder projections into engagement with the ridge, followed by a partial rotation to bring cooperating surfaces of the water-box and lining cylinder projections into engagement.