公开(公告)号：US5479464A

公开(公告)日：1995-12-26

申请号：US298503

申请日：1994-08-30

Applicant: Edmund E. DeMario ,  Charles N. Lawson ,  Raymond G. Zakrzwski ,  Ivan Klima

Inventor： Edmund E. DeMario ,  Charles N. Lawson ,  Raymond G. Zakrzwski ,  Ivan Klima

IPC: G21C3/334 ,  G21C5/06

CPC classification number: G21C3/334 ,  G21Y2002/201 ,  G21Y2002/302 ,  G21Y2002/304 ,  G21Y2004/30 ,  G21Y2004/301 ,  Y02E30/40

Abstract: An expandable top nozzle for a nuclear fuel assembly having zircaloy thimble tubes has a cylindrical barrel and an assembly slidable in the barrel which includes a hub and a thin rod ejection plate fixed in spaced relation to the hub by support tubes through which the control rods extend. The support tubes extend through the hub and a spring retainer plate biased against an annular shoulder in the barrel by helical compression springs concentrically mounted with the support tubes in counterbores in the hub and spring retainer plate. A centrally located instrument guide robe has a spring loaded plunger which extends through the spring retainer plate and sets the height of an RCCA below the top of the barrel despite expansion and compression of the nozzle with changes in thimble robe length relative to the other internals. The top nozzle is removably attached to a fuel assembly by tubular inserts fixed to the thimble robes and having collapsed fingers with an annular outward bulge adjacent the free end. With the collapsed fingers inserted in the apertures in the rod ejection plate, lock tubes are pushed through the support tubes to spread the collapsed fingers of the inserts into engagement with circumferential grooves in the apertures.

Abstract translation: 用于具有锆石顶针管的核燃料组件的可扩展顶部喷嘴具有圆柱形筒体和在筒体中可滑动的组件，该组件包括轮毂和通过支撑管与支承管间隔开固定的细杆弹出板，控制杆通过支撑管延伸 。 支撑管延伸穿过轮毂和弹簧保持板，该弹簧保持板通过同心地安装在支撑管中的螺旋压缩弹簧偏压在筒体中的环形肩部上，该支撑管位于轮毂和弹簧保持板中的沉孔中。 中心位置的仪器导向罩具有弹簧加载的柱塞，其延伸穿过弹簧保持板，并且将RCCA的高度设置在筒的顶部之下，尽管喷嘴的扩张和压缩相对于其它内部件的套管长度的变化。 顶部喷嘴通过固定到套管的管状插入件可拆卸地附接到燃料组件，并且具有邻近自由端的具有环形向外凸起的折叠式手指。 当折叠的手指插入到杆排出板的孔中时，锁定管被推动通过支撑管，以将插入物的折叠的指状物分散成与孔中的周向槽接合。