No abstract available

[en] The invention provides a calandria tank which can effectively absorb the difference in thermal expansion between the calandria tank barrel and the calandria tubes, and which permits the reduction of the distance between the outermost calandria tubes and the inner peripheral surface of the calandria tank barrel to the minimum required distance. The tank comprises upper and lower barrel sections having cylindrical forms with upper and lower end openings. The upper end opening of the lower barrel section is positioned opposite the lower end opening of the upper barrel section at a suitable distance from and coaxially with the latter. A tube sheet attached to the upper barrel section closes the upper opening of the barrel section, and the calandria tubes are connected at their upper ends to the tube sheet. Similarly, a lower tube sheet attached to the lower barrel section closes the lower opening of the lower barrel section, and the calandria tubes are connected at their lower ends to the lower tube sheet. A connecting mechanism joins the lower end opening of the upper barrel section and the upper end opening of the lower barrel section so as to allow an axial movement of the barrel sections with respect to each other. The connecting mechanism includes an aseismatic ring making a sliding contact with an inner surface of one of the upper and lower barrel sections and having elongated guide bores, and being attached to the other barrel section. Protrusions attached to the barrel section make sliding contact with the aseismatic ring, by engaging with the guide bores to prevent the ring from moving in a circumferential direction but, allowing the ring to move in the axial direction

[en] Description and characteristics of different types of heavy water moderated reactors. (RW)

[en] The unit described represents a connecting piece in a loading machine of the channel nuclear reactor. The connecting piece has an inflatable cuff condensation. To prevent ejection of the coolant in the reactor hall at a break in the inflatable cuff the connecting piece is fitted out with a hollow, situated below the cuff condensation; an elastic ring is mounted in it forming a cavity which is connected with the pressure source, for example, with the connecting piece cavity through an automatic vent

[en] A description is given of a cooling water intake collector for a nuclear reactor. It includes multiple sub-collectors extending out in a generally parallel manner to each other, each one having a first end and a second one separated along their length, and multiple water outlets for connecting each one to a corresponding pressure tube of the reactor. A first end tube and a second one connect the sub-collector tubes together to their first and second ends respectively. It also includes multiple collector tubes extending transversely by crossing over the sub-collector tubes and separated from each other in the direction of these tubes. Each collector tubes has a water intake for connecting to a water pump and multiple connecting tubes separated over its length and connecting each one to the corresponding sub-collector

No abstract available

[en] Purpose: To rapidly submerge a reactor core in water in a pressure tube type reactor. Constitution: Water is filled in both an inlet header and an outlet header at the initial of starting an emergency reactor core cooling device, and the water filling is swithched to one side filling after the water is filled fully in the core. Thus, the steam condensing effect at the failured port side can be raised at the initial of filling coolant to accelerate the decrease in pressure of the core. Thus, the water can be fully filled rapidly in the core, and wasteful water flowout from the failed port after the full water can be eliminated. (Kamimura, M.)

[en] The present invention relates to a miniaturized nuclear reactor utilizing pressure tube structural members comprising: a moderator containing one calandria tube contained within the moderator; one fuel channel pressure tube contained within the one calandria tube; one fuel bundle contained within the one fuel channel pressure tube; one fuel channel pressure tube pad positioned between the one calandria tube and the one fuel channel pressure tube; one horizontal exterior support pad positioned on the bottom reactor wall, one fuel bundle pad positioned between the one fuel bundle and the one fuel channel pressure tube; one vertical support pad positioned on a reactor side wall between the one calandria tube and the reactor side wall; one angular support pad positioned on a corner formed between the reactor top and the reactor side wall. (author) figs

[en] The First Report from the Select Committee on Science and Technology, 1976-77, is on the SGHWR programme. The reasons for the enquiry and the evidence given by all the interested organisations are presented. The report summarised the cases for and against the SGHWR, as presented by the different organisations and considers alternative types of reactor. Comments are made on the plant ordering procedures. The Committee's recommendations regarding the policies which should be adopted are discussed. The various memoranda submitted by the organisations taking part in the enquiry to the general purposes sub-committee are reproduced. (U.K.)

[en] Object: To enable a neutron source to be easily mounted and exchanged in a safe manner by mounting the neutron source within the pressure tube and thus dispensing with a neutron source guide duct and neutron source assembly replacement means. Structure: A neutron source assembly having an outer diameter capable of being snugly fitted into the pressure tube is used and is inserted into the pressure tube occupied by a fuel assembly by making use of fuel replacing means. The neutron source assembly is provided with upper and lower handling heads and has a cylindrical barrel, in which a neutron source is removably accommodated. For varying the neutron intensity only the neutron source may be replaced without the need of changing the whole assembly, thus resulting in less nuclear waist. (Kamimura, M.)