CONTAINMENT VESSEL FOR REACTOR TANK

摘要

1388336 Nuclear reactors SIEMENS AG 18 May 1973 [19 May 1972] 23950/73 Heading G6C A protective casing 12 for surrounding the pressure vessel 1 of a PWR nuclear reactor comprises two parts 13, 14 one of which has lugs 15 which pass between pressure vessel pipe unions 5 and connect the two parts together. In the embodiment shown, the parts 13, 14 are connected together by keys 17 which co-operate with keyways in the lower part 13 and the lugs 15 depending from the upper part 14. The region of the connection is surrounded by a ring 20 to prevent opening of the joint under pressure. A catch ring 23 is secured to the upper end 22 of the casing 12 by serrations 21 forming a bayonet joint, and extends over a catch cover 24 mounted above the pressure vessel cover 7. Projections 28 on the pressure vessel 1 support the latter on the upper edge 18 of the lower casing part 13 while the casing 12 rests on the surrounding concrete biological shield 33 by means of a ring 29. A thermally-insulating layer 35 surrounds the casing 12 and the space between the layer 35 and the shielding 33 may be ventilated by cool air. Bellows seals 40, 41 prevent water, utilized to flood the reactor for refuelling, from penetrating around the casing 12. The cylindrical portion of the lower part 13 is of laminated construction. In another embodiment (Fig. 3, not shown), the casing is suspended from the biological shield by means of projections (50) extending from the lugs into locating members (51, 52) in a steel frame (54) set in the shield. Also, pipes (56-59) pass through the casing 12 to permit monitoring of the pressure vessel 1 by means of ultra-sonic equipment or sensitive microphones. In another embodiment (Fig. 5, not shown), the catch ring is enlarged to form a hood. In a further embodiment (Fig. 6, not shown), the lugs (15) are integral with the lower casing part (13), the catch ring (23) is integral with the upper casing part (14) and the two casing parts are secured together by means of serrations (66) forming a bayonet joint.