[en] Plant economics is one of important items in FBR development. In present FBR design, large design factor provided in design standards is considered to be one of restriction for the improvement of FBR economics. From such a background, FBR Integrity System Code (FISC), which is for settlement of appropriate design margin, is now under development. Aim of this study is to contribute to the development of this code, and investigation study on inspection technique and flame of code for inspection has been performed. The results of this study are as follows. (1) Study of position of code for inspection. The present code, and standard for inspection and evaluation examples for risk assessment, which is one of method for margin exchange, have been investigated, and inspection accuracy, inspection interval, type of inspection and inspection procedure etc. have been extracted as the standardization item. In these items, first two items, in particular, have a large contribution to rationalization. (2) Investigation of inspection technique. Because the inspection accuracy is one of important item from study item (1), present status of Ultrasonic Testing (UT) technique, which is the one of the method used for ISI, has been investigated. And, monitoring technique, which is effective for rationalization of inspection, has been also investigated. Concerning UT, estimation of detection limit is difficult, but it is considered that detection of 1-2 mm depth crack can be detected by present UT technique. On monitoring technique, fatigue or crack monitoring can contribute to maintenance schedule. (3) Study of flame of code for inspection. Based on the above study results, the standardization items in code for inspection have been extracted, and area and flame of this code have been studied. Because FISC is considered to provide the concrete design procedures, present code and guideline such JEAC and JEAG is considered to be covered in this code. Material inspection included in design code is also included. Route for margin exchange between another code has been studied using the extracted standardization items, and flame of code for inspection has been settled preliminarily. (author)

[en] This paper describes an evaluation method of primary stress in three dimensional (3-D) structures. In 'Design by Analysis' for nuclear components, the stresses are classified into the primary and the secondary stresses. The primary stress in axisymmetric structures can be evaluated by linearization of stress distribution in the specified section, however this procedure is hardly applicable to 3-D structures from difficulties to define the evaluation section. From this reason, the alternative evaluation method is needed. In this study, the evaluation method of primary stress in 3-D structures with elastic-plastic analysis is proposed utilizing the feature of primary stress that is independent from stress redistribution. The proposed method is verified through application to example problems. (author)

[en] This paper describes an evaluation method of primary stress in three dimensional (3-D) structures. In 'Design by Analysis' for nuclear components, the stresses in structures are classified into the primary and the secondary stresses. The primary stress in axisymmetric structures can be evaluated by linearization of stress distribution in the specified section, but it is difficult to define the evaluation section in the 3-D structures, and to evaluate the primary stress with the conventional procedure. From this reason, the alternative evaluation method is needed. In this study, the evaluation method of primary stress in 3-D structures with elastic-plastic analysis is proposed utilizing the feature of primary stress that is independent from stress redistribution. The proposed method is verified through application to example problems. (author)

[en] This paper describes an evaluation method of primary stress in 3-D structures. In 'Design by Analysis' for nuclear components, the stresses in structures are classified into the primary and the secondary stresses. The primary stress in axisymmetric structures can be evaluated by linearization of stress distribution in the specified section, but it is difficult to define the evaluation section in the 3-D structures, and to evaluate the primary stress with the conventional procedure. From this reason, the alternative evaluation method is needed. In this paper, the evaluation method of primary stress in 3-D structures is presented utilizing the feature of primary stress that is independent from stress re-distribution. (author)

[en] Many efforts have been made to implement the System Based Code concept aiming at optimizing margins dispersed in existing codes and standards. Failure probability calculated based on statistical information such as a type of probability distribution, mean (or median) and variance (or standard deviation) for random variables is expected to be a promising quantitative index for margin optimization. Statistical information on material strength, which is also required to calculate the failure probability, has been already reported in JAEA-Data/Code 2015-002 'Statistical Properties of Material Strength for Reliability Evaluation of Components of Fast Reactors –Austenitic Stainless Steels–' whereas others have not been identified yet. This report provides methodologies and basic ideas to determine statistical parameters of other random variables, especially variable loads, necessary for reliability evaluation. (author)