Patent ID: 8619942

Claim:
A radioactive debris trap ( 10 ) to be installed in a steam generator having a primary head, for the purpose of removing debris entrained in a primary flow ( 46 ) of a nuclear power plant's primary heat transport system, the debris trap ( 10 ) comprising: an open-topped box ( 36 ) comprising a bottom, a front side ( 40 ) comprising a top end and a bottom end, a back side ( 42 ) comprising a top end, a bottom end ( 38 ) and an outer surface, the open-topped box ( 36 ) further comprising a right side and a left side; an angled plate ( 44 ) positioned inside the open-topped box ( 36 ) for directing the flow ( 46 ) and the debris entrained therein into the radioactive debris trap ( 10 ), the angled plate ( 44 ) comprising a front end fixedly attached to the front side ( 40 ) of the open-topped box ( 36 ), a right side fixedly attached to the right side of the open-topped box ( 36 ), a left side fixedly attached to the left side of the open-topped box ( 36 ) and a back end, the front end of the angled plate ( 44 ) being flush with the top end of the front side of the open-topped box ( 36 ) and the back end of the angled plate ( 44 ) being proximate to both the bottom of the open-topped box ( 36 ) and the back side ( 42 ) of the open-topped box ( 36 ); a flow slot ( 22 b ) where the fluid and debris enter the radioactive debris trap ( 10 ) located between the back end of the angled plate ( 44 ) and the back side ( 42 ) of the open-topped box ( 36 ); a plurality of small holes ( 24 ) positioned across the front side ( 40 ) of the open-topped box ( 36 ) below the top end of the front side ( 40 ) of the open top box ( 36 ), the plurality of small holes ( 24 ) being sized to ensure that the gravitational force exerted on the debris entrained in the primary flow ( 46 ) is larger than the upward drag force exerted on the debris by the flow ( 46 ) itself; a settling chamber ( 48 ) located below the plurality of holes ( 24 ) and between the angled plate ( 44 ) and the bottom of the open-topped box ( 36 ); a means for fixedly attaching the radioactive debris trap ( 10 ) to the primary outlet plenum of the steam generator, said means being fixedly attached to the outer surface of the back side ( 42 ) of the open-topped box ( 36 ); and a means for removing the radioactive debris trap ( 10 ) from the steam generator without exposing personnel to excessive radiation.