The Comprehensive evaluation of safety and economics is important, when designing large scale welded structures such as a spherical tank.
As it has been increasingly required to evaluate the safety of welded structures as a quantitative fracture probability, reliability analysis procedures for brittle fracture have been widely applied based on probabilistic fracture mechanics, Monte Carlo simulation method and so on. On the other hand, it has been also required to optimize the fabrication cost. Therefore, optimization procedures including nonlinear programming and linear programming have been proposed for design analysis.
In this paper, applying reliability analysis procedures based on WES2805 combining Monte Carlo simulation and nonlinear programming termed SUMT for a typical spherical tank design, the relationship between the brittle fracture probability and the material cost is evaluated.
Following findings for reliability analysis are obtained.
(1) The relationships between fracture probability and steel cost are almost linear for typical steels of SPV50, SPV32 and SPV24. Therefore, the optimum selection of steel can be made by using the quantified relationship.
(2) A selection index for steel cost is represented by the value of (steel cost)/(allowable stress).
(3) A selection index for fracture probability may be represented by the value of (allowable stress)/(fracture toughness) and its correction term considering flaw size-plate thickness ratio.

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Effects of Mn and Cr addition on tensile properties and low temperature toughness have been investigated with extra hevavy gauge pressure vessel steel plates that have the chemical composition of 0.12% C-1.4%Mn-0.3%Mo-0.75% Ni, then the results have been discussed with metallurgical view points.
The Cr addition, not less effectively than the increase of Mn content, increases the tensile strength at both room temperature and 350°C, with less deterioration of Charpy absored energy. With the cooling rates that are equivalent to those at quenching of such extra heavy gauge plates as 150mm thick, the Cr addition works to suppress the elevation of starting temperatures of bainitic transformation (Bs). This suppression of elevation of Bs could be the reason for the improvement of tensile strength with Cr addition. The Cr addition also changes the morphology of cementite in the region surrounded by acicular ferrite (carbide free bainite) form lamellar one to small sized granular one. This morphological change of cementite could lighten the deterioration of the Charpy absorbed energy through lowering the possibilities of crack initiation.

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JAERI and RIKEN SPring-8 project team is constructing a synchrotron radiation facility (SPring-8: Super Photon ring-8GeV), the largest in the facilities existing and planning in the world. This facility, which aims at achieving high brilliance photon beams in the range from soft X-ray to hard X-ray, is expected to be played a role as a center of excellence for general study for the light science, and fundamental science to establish the advanced technologies such as ultra large scale integration, new materials and life science. In this review, the summary of the SPrig-8 is described and then the accelerators constituting the facility in more details. The ultra-high vacuum system for the facility is described with great emphasis on problems in the design and production and the thought for them. Finally, applications of the synchrotron radiation to the industry and fundamental science are also described.

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SC on Standardization, which is organized under the Committee on Elevated Temperature Design in High Pressure Institute of Japan, has been conducting the study to introduce design by analysis into elevated temperature structural design code in Japan.
In order to identify the differences in code provisions of design by analysis and design by formula, SC on Standardization has been conducting the comparison of ASME Boiler & Pressure Vessel Code Sec. III NB/NC and Sec. VIII Div. 1/Div. 2.
It has shown from the comparison that design by analysis requires strict strength evaluation including secondary stress and peak stress, which may cause fatigue failure and thermal ratchetting. In case of design by analysis, larger allowable stresses for primary membrane stress and wider options in configuration are permitted based on detailed stress analysis, accompanied by extensive examinations, than in case of design by formula.

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Among various types of quick closure devices specified in JIS B 8284, there is yoke type. In the case of yoke type, the cover plates are supported by the frame as shown in Fig. 1 and this type of closures is used, in particular, for ultra high pressure services such as HIP and CIP processes.
The yoke type is further subgrouped to rectangular frame type and obround frame type. In Part 5 of this series of article the design calculation equations for rectangular frame type is explained.

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