A pressurized water reactor, PWR, or a pressurized heavy water reactor, PHWR, comprising: a primary heat transport system; a secondary heat transport system; and a steam generator, wherein the steam generator comprises a radioactive debris trap for the purpose of removing debris entrained in a primary flow of the primary heat transport system, the debris trap being characterized in that it comprises: an outer cylinder comprising an outer surface, a top end, a bottom end, a back side and an opposite front side having a perimeter; an inner cylinder located within the outer cylinder and coaxial therewith, the inner cylinder comprising a top end and a bottom end; wherein the top end of the outer cylinder and the top end of the inner cylinder are both oriented upwards for receiving the primary flow within the inner cylinder; a top plate which connects the top end of the outer cylinder to the top end of the inner cylinder; a plurality of small holes located at the top end of the outer cylinder thus arranged to allow liquid to exit the debris trap, the plurality of small holes sized to allow a piece of debris of 0.017" (0.43 mm) diameter by 0.017" (0.43 mm) long to fall at a free fall velocity of at least twice the upwards vertical velocity of the flow; an annular cavity located between the outer cylinder and the inner cylinder, the annular cavity comprising a settling chamber positioned below the plurality of small holes; a bottom plate connected to the perimeter of the bottom end of the outer cylinder which encloses the radioactive debris trap; a gap located between the bottom end of the inner cylinder and the bottom plate through which primary flow with debris entrained therein enters the settling chamber; a means for fixedly connecting the radioactive debris trap to the steam generator, the means being fixedly attached to the outer surface of the outer cylinder. a primary heat transport system; a secondary heat transport system; and a steam generator, wherein the steam generator comprises a radioactive debris trap for the purpose of removing debris entrained in a primary flow of the primary heat transport system, the debris trap being characterized in that it comprises: an outer cylinder comprising an outer surface, a top end, a bottom end, a back side and an opposite front side having a perimeter; an inner cylinder located within the outer cylinder and coaxial therewith, the inner cylinder comprising a top end and a bottom end; wherein the top end of the outer cylinder and the top end of the inner cylinder are both oriented upwards for receiving the primary flow within the inner cylinder; a top plate which connects the top end of the outer cylinder to the top end of the inner cylinder; a plurality of small holes located at the top end of the outer cylinder thus arranged to allow liquid to exit the debris trap, the plurality of small holes sized to allow a piece of debris of 0.017" (0.43 mm) diameter by 0.017" (0.43 mm) long to fall at a free fall velocity of at least twice the upwards vertical velocity of the flow; an annular cavity located between the outer cylinder and the inner cylinder, the annular cavity comprising a settling chamber positioned below the plurality of small holes; a bottom plate connected to the perimeter of the bottom end of the outer cylinder which encloses the radioactive debris trap; a gap located between the bottom end of the inner cylinder and the bottom plate through which primary flow with debris entrained therein enters the settling chamber; a means for fixedly connecting the radioactive debris trap to the steam generator, the means being fixedly attached to the outer surface of the outer cylinder. an outer cylinder comprising an outer surface, a top end, a bottom end, a back side and an opposite front side having a perimeter; an inner cylinder located within the outer cylinder and coaxial therewith, the inner cylinder comprising a top end and a bottom end; wherein the top end of the outer cylinder and the top end of the inner cylinder are both oriented upwards for receiving the primary flow within the inner cylinder; a top plate which connects the top end of the outer cylinder to the top end of the inner cylinder; a plurality of small holes located at the top end of the outer cylinder thus arranged to allow liquid to exit the debris trap, the plurality of small holes sized to allow a piece of debris of 0.017" (0.43 mm) diameter by 0.017" (0.43 mm) long to fall at a free fall velocity of at least twice the upwards vertical velocity of the flow; an annular cavity located between the outer cylinder and the inner cylinder, the annular cavity comprising a settling chamber positioned below the plurality of small holes; a bottom plate connected to the perimeter of the bottom end of the outer cylinder which encloses the radioactive debris trap; a gap located between the bottom end of the inner cylinder and the bottom plate through which primary flow with debris entrained therein enters the settling chamber; a means for fixedly connecting the radioactive debris trap to the steam generator, the means being fixedly attached to the outer surface of the outer cylinder.