Method of avoiding or inhibiting intermixing of the atmosphere which exists in an enclosed space with a gaseous substance present in the same space

Claim 2

In a method of avoiding explosive mixtures of hydrogen with air, or of hydrogen with air and steam in the atmosphere within the safety containment of a nuclear reactor in the course of accidents, said safety containment having an upper area and a lower area containing atmospheres of different densities, the improvement comprising reducing the density of the atmosphere in the upper area of said safety containment and increasing the density of the atmosphere in said lower area so as to produce in said safety containment a substantially stable atmosphere stratified into superposed layers of non-explosive mixtures of hydrogen, air and steam so as to prevent further intermixing between hydrogen and oxygen of the air, caused by convection between said lower area and said upper area and avoid said explosive mixtures.

Claim 3

In a method of avoiding explosive mixtures of hydrogen with air, or of hydrogen with air and steam in the atmosphere within the safety containment of a nuclear reactor in the course of accidents, said safety containment having an upper area and a lower area containing atmospheres of different densities, the improvement comprising increasing the density of the atmosphere in said lower area so as to produce in said safety containment a substantially stable atmosphere stratified into superposed layers of mixture of hydrogen, air and steam so as to prevent further intermixing between hydrogen and oxygen of the air caused by convection between said lower area and said upper area and avoid said explosive mixtures.

Claim 4

In a method of avoiding explosive mixtures of hydrogen with air, or of hydrogen with air and steam in the atmosphere within the safety containment of a nuclear reactor in the course of accidents, said safety containment having an upper area and a lower area containing atmospheres of different densities, the improvement comprising increasing the density of the atmosphere in said lower area so as to produce in said safety containment a substantially stable atmosphere stratified into superposed layers of mixture of hydrogen, air and steam so as to prevent further intermixing between hydrogen and oxygen of the air caused by convection between said lower area and said upper area and avoid said explosive mixtures.

Claim 5

In a method of avoiding explosive mixtures of hydrogen with air, or of hydrogen with air and steam in the atmosphere within the safety containment of a nuclear reactor in the course of accidents, said safety containment having an upper area and a lower area containing atmospheres of different densities, the improvement comprising reducing the density of the atmosphere in the upper area of said safety containment and increasing the density of the atmosphere in said lower area so as to produce in said safety containment a substantially stable atmosphere stratified into superposed layers of non-explosive mixtures of hydrogen, air and steam so as to prevent further intermixing between hydrogen and oxygen of the air caused by convection between said lower area and said upper area and to avoid said explosive mixtures, said reducing step and said increasing step each including supplying gas to the atmosphere of a respective area of the safety containment.

Claim 6

In a method of avoiding explosive mixtures of hydrogen with air, or of hydrogen with air and steam in the atmosphere within the safety containment of a nuclear reactor in the course of accidents, said safety containment having an upper area and a lower area containing atmospheres of different densities, the improvement comprising reducing the density of the atmosphere in the upper area of said safety containment and increasing the density of the atmosphere in said lower area so as to produce in said safety containment a substantially stable atmosphere stratified into superposed layers of non-explosive mixtures of hydrogen, air and steam so as to prevent further intermixing between hydrogen and oxygen of the air caused by convection between said lower area and said upper area and to avoid said explosive mixtures, said reducing step and said increasing step each including supplying gas to the atmosphere of a respective area of the safety containment.

Claim 7

In a method of avoiding explosive mixtures of hydrogen with air, or of hydrogen with air and steam in the atmosphere within the safety containment of a nuclear reactor in the course of accidents, said safety containment having an upper area and a lower area containing atmospheres of different densities, the improvement comprising reducing the density of the atmosphere in the upper area of said safety containment and increasing the density of the atmosphere in said lower area so as to produce in said safety containment a substantially stable atmosphere stratified into superposed layers of non-explosive mixtures of hydrogen, air and steam so as to prevent further intermixing between hydrogen and oxygen of the air, caused by convection between said lower area and said upper area and to avoid said explosive mixtures, said reducing step including supplying heat to said upper area, said increasing step including substracting heat from said lower area.

Claim 8

In a method of avoiding explosive mixtures of hydrogen with air, or of hydrogen with air and steam in the atmosphere within the safety containment of a nuclear reactor in the course of accidents, said safety containment having an upper area and a lower area containing atmospheres of different densities, the improvement comprising reducing the density of the atmosphere in the upper area of said safety containment and increasing the density of the atmosphere in said lower area so as to produce in said safety containment a substantially stable atmosphere stratified into superposed layers of non-explosive mixtures of hydrogen, air and steam so as to prevent further intermixing between hydrogen and oxygen of the air, caused by convection between said lower area and said upper area and to avoid said explosive mixtures, said reducing step including supplying heat to said upper area, said increasing step including substracting heat from said lower area.

Claim 9

The method as claimed in claim 1, wherein the density of the atmosphere is reduced in the upper area of the safety containment by supplying a gas or a gas mixture.

Claim 10

The method as claimed in claim 5, wherein the gas supplied is an inert gas.

Claim 11

The method as claimed in claim 1, wherein the density of the atmosphere in the upper area is reduced by raising the temperature of the atmosphere in said upper area.

Claim 12

The method as claimed in claim 7, wherein a fluid medium whose temperature is higher than the temperature of the atmosphere in the upper area of the safety is supplied to the upper area of the safety to raise the temperature of the atmosphere therein.

Claim 13

The method as claimed in claim 7, wherein at least one heating means arranged in the upper area of the safety containment is used to raise the temperature of the atmosphere.

Claim 14

The method as claimed in claim 7, wherein said safety containment is enclosed by wall means, said wall means being heated at least partially to raise the temperature of the atmosphere in the upper area of the safety containment.

Claim 15

The method as claimed in claim 10, wherein the increase in temperature is effected directly or indirectly from outside.

Claim 16

The method as claimed in claim 1, wherein the density of the atmosphere in said upper area is reduced by feeding a fluid medium into said upper area and by raising the temperature of the atmosphere in said upper area of the safety containment.

Claim 17

The method as claimed in claim 1, wherein the density of the atmosphere in said lower area is increased by feeding a gas or a gas mixture into the lower area of the safety containment.

Claim 18

The method as claimed in claim 13, wherein the gas used is an inert gas.

Claim 19

The method as claimed in claim 1, wherein the density of the atmosphere in said lower area is increased by lowering the temperature of the atmosphere in the lower area of the safety containment.

Claim 20

The method as claimed in claim 15, wherein a fluid medium whose temperature is lower than the temperature of the atmosphere in the lower area of the safety containment is supplied to the lower area of the safety containment to lower the temperature of the atmosphere therein.

Claim 21

The method as claimed on claim 15, wherein said safety containment is enclosed by wall means, said wall means being cooled at least partially to the lower temperature in the lower area of the safety containment.

Claim 22

The method as claimed in claim 16, wherein the lowering of the temperature is effected directly or indirectly from outside.

Claim 23

The method as claimed in claim 1, wherein the density of the atmosphere in said lower area is increased by feeding a fluid medium into the lower area of the safety containment and by lowering the temperature of the atmosphere in the lower area of the safety containment.