STUDY ON THE HULL CONSTRUCTION AROUND THE REACTOR OF NUCLEAR SHIPS (in Japanese)
: hull construction around the marine reactor is important in the study of the hull construction to ensure the safety of nuclear ships. A series of model experiments on hull structure were carried out. Experiments on antiimpact characteristics of high tensile steel plating were concerned with the collision-resistive construction of ship sides. According to the results of collision test of shipstructure models, carried out previously, it was found that the cross stiffened structure with thicker plating than usual was effective from the view point of collision-resistance. Three types of elemental models of cross stiffened structure, square plate, square plate stiffened with single-beam lattice, and square plate stiffened with three-beam lattice, were investigated under impact loading quantitatively. The anti-impact characteristics of high tensile steel plating and those of mild steel plating were compared. The energy absorption of high tensile steel models for unit deflection was greater than that of mild steel models. Thus, improved anti-impact characteristics might be expected by using high tensile steel plating. To protect safely the reactor, when nuclear shlp stranding, it is necessary to study the ultimate strength of ordinary double bottom structure. The preliminary experiment for the locally compressive strength of the double bottom structure was projected as follows: instability of double bottom element; instability of single floor element companled wlth bending; and instability of vertical members in double bottom companied with bending. On loading the vertical member in double bottom structure with compressive force, the mode of failure varies notably due to its load area. Experiments on the synthesis of the containment vessel and the hull construction were performed. When a water-cooled reactor mounted on a nuclear ship suffers a damage by accident, bursting out high pressure steam, there is a danger that the radioactive fusion products come out, too. It is necessary to prevent bursting-out of the nuclear substance in any circumstances. As a measure against this problem, the reactor is generally placed in the high pressure resisting container suspended in the hull as an independent vessel. The volume of the container of this type is limited, and the inner pressure is inevitably high. The weight of the container made of thick plates is naturally heavy. In order to meet this problem, using a part of the hull as a container by constructing the part so as to endure a high pressure was considered. The available volume of the container of this type would be two or three times as large as that of the independent type. However, the inner pressure of the container of this type is over 5 kg/cm/sup 2/. The structure of the container enduring this pressure must be much stronger than that of the ordinary hull. The safety factor of this type of construction must be confirmed in order to put it into practice. Therefore, various tests were carried out by using models similar to the actual containers, and analyses were made, based upon the tests results, in order to prepare for construction of future nuclear ships. The first test was made to determine the ultimate strength of the ordinary hull structure of a 70,000 DW tanker. The test results revealed that the buckling of the corner of the transverse web ring is the most important factor in hull construction, and that by improving this part, the strength of the hull would be much increased. It was also found that the safety factor of the structure of the hull should be about 2. The second test was carried out to improve the corner design of the transverse web ring. When the corner radius of the transverse ring was smaller than the web depth, there was little difference in the breaking strength of statical compression even if the corner radius was further decreased. The ultimate strength of the transverse web ring was increased when the tripping bracket was fitted at the corner. Fundamental data concerning the estimation of the ultimate strength of the web ring and the way
- Research Organization:
- Nuclear-Powered Ship Research Assn. of Japan, Tokyo
- NSA Number:
- NSA-17-015401
- OSTI ID:
- 4756144
- Report Number(s):
- NP-12553
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-63
- Country of Publication:
- Country unknown/Code not available
- Language:
- Japanese
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