High pressure was generated with sintered diamond anvils inserted in the pressure medium of a multistage apparatus. X-ray diffraction using strong synchrotron radiation was sucessfully attempted. The X-ray transparency of the sintered diamond was unexpectedly high, and pressure of 60GPa was generated with the anvils of 0.7mm top face. Development of the technique of simultaneous measurement of electric resistance and lattice parameter under pressures up to 50GPa enabled the determination of the α→ε transition pressures of Fe-V alloys, which are useful as the pressure-fixed points in the ultrahigh pressure region.

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Through the past experiences and developments of the fabrication, inspection, and operation of nuclear power plants, it has been recognized that the Leak-Before-Break (LBB) design concept can be justified in the LWR pressure boundary pipings.
Instead of the postulated Double Ended Guillotine Break (DEGB) philosophy, a revised piping design criterion in which LBB concept is introduced, is recently under preparation in Japan, U. S. A., and European countries. In order to verify the LBB of the LWR pipings, extensive experimental and theoretical works have been conducted in many countries. One of the important subject concerning LBB verification is to establish the procedure to evaluate ductile pipe fracture, as well as the subcritical flaw growth and leakage evaluation.
At Japan Atomic Energy Research Institute, a research program to investigate the unstable ductile fracture behavior of LWR piping under bending load has been carried out as a part of the LBB verification researches site 1983. This paper summarizes the results of ductile fracture test conducted at room temperature. 6-inch diameter, sch. 80 pipes of type 304 stainless steel with a through-wall or a part-through crack were tested under bending load at room temperature. The four point bending facility of 400kN maximum load and 750mm maximum stroke respectively, which installed a compliant disk spring device, was used for the pipe tests. Tests were performed under high compliance condition using the spring device or low compliance condition without using the device and the stable or unstable pipe fracture behavior was investigated.
Pipe fracture data were obtained from the test with regard to load-displacement curve, crack extension, net section stress, J-resistance curve, and so on. Besides, the influence of the compliance on the fracture behavior was examined.
J-resistance curves obtained from the pipe tests were higher than that of the CCT specimen of type 304 stainless steel and that of 6-inch diameter STS42 carbon steel pipe specimen. The maximum load of the through-wall cracked pipes was well predicted by the net section stress approach, while the predicted loads at the crack penetration of the part-through cracked pipes were inaccurate. In the paper are also discussed the validity of the tearing instability criterion and the acceptability of the flawed piping considering LBB.

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Low cycle fatigue tests are performed in 150A and 300A SGP long elbow under displacement-controlled in-plane bending. Experimental results for deformation are compared with analytical results which are developed using thin shell theory more accurate than well-known kármán theory.
Maximum strain amplitude is obtained at φ=0°-10° in inner side and the relationship between maximum strain amplitude and fatigue crack penetrate life satisfies ASME Sec III design curve.
In this paper we propose the simplified estimating method of the fatigue crack penetrate life from displacement amplitude using the ASME Sec III div. 1 equation.

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Creep tests of Hastelloy X alloy have been performed at 900°C under internal pressure, using cylindrical specimens with an artificial defect. The purpose of this research is to investigate the effect of defect size on the creep strength.
Two kinds of cylindrical specimens were used. One was 62mm in outer diameter, 3.0mm in thickness and 240mm in length. Another was 66mm in outer diameter, 6.0mm in thickness and 240mm in length. Axial notches were machined on the outer surface of these specimens by a milling cutting. Diametral deformation of the specimen was measured during the test by dial gauges mounted on quartz rods. Creep crack growth depth was measured using the electrical potential method.
The numerical analysis using a finite element program ADINA has been performed to investigate the creep deformation around the artificial defect. Analytical model represents one-half of the cylindrical specimen which is 56.0mm in inner diameter and 3.0mm in thickness, and has the axial notch of 1.0mm in depth with infinite length. Elastic-plastic and creep analysis of this model was carried out by incremental method of the time step of 0.01 hours.
The following results are concluded from these tests and analyses. [1] The creep rupture time decreases with increasing notch length. [2] The electric potential method is very useful for measuring the creep crack growth depth. [3] The initial creep deformation around the notch is obtained from the finite element analysis.

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The seismic proof design standard for high pressure gas facilities was added to the High Pressure Gas Control Law by MINISTER OF INTERNATIONAL TRADE AND INDUSTRY, in Oct. 1981.
⌈SEISMIT-SP⌋ is a computer program developed by MITI in accordance with the law. It is used for designing of spherical tanks widely, but some limitations are settled on.
In case of large spherical tanks which volumes more than 3000m³, to use the ⌈SEISMIT-SP⌋, it is necessaly to increase thickness of shell plates around the column attached part, determind by the law, or stiffen the shell plates, and to check their local deformation
We propose a convenient method combining the ⌈SEISMIT-SP⌋ with a conventional local stress analysis method by P. P. Bijlaard, to check the above mentiond problem.

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In this paper, new manufacturing techniques of boiler tubes for large power plant by high frequency electric resistance welding (ERW) and the properties of their products are described.
The formers describe;
·the very pure steel making process and its products for ERW boiler tubes
·sheilded welding device for alloy steel tubes
·automatic heat input control system on ERW
·nondestructive inspection system.
The latters describe;
·test results about tubes manufactures such as workability, tensile properties at elevated temperature and creep rupture strength at elevated temperature
·results of test and analysis about tubes used on actual boiler of Tobata and Kimitsu cooperative power plants, which are related to scale and sludge piled up on tube surfaces, corrosion on tubes, micro structure changes on tubes, tensile properties at elevated temperature and creep rupture strength at elevated temperature.
During these analysis, we have concluded as follows;
·qualities of welded portion in ERW boiler tubes are same as base metal
·qualities of ERW boiler tubes are same or good as seamless boiler tubes
·the tube after operation has the same quality as unused material.

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