In this paper, a comparative study of the pipe-wall thinning prediction with existing experimental data is carried out for some typical cases of flow accelerated corrosion of carbon steel. The numerical model tested in this study is the pipe-wall thinning model based on the standard k-εmodel of turbulence with the modification of high-Schmidt-number effect. The comparative study is carried out for the straight pipe flow, the pipe flow behind an orifice and the pipe flow behind a long elbow combined wit...
英字タイトル:
Investigation on Pipe-wall Thinning Prediction by Flow Accelerated Corrosion

Pipe wall thinning is one of the important degradation phenomena taking place in the nuclear power plant. Major mechanism of the mainly pipe wall thinning is Flow Accelerated Corrosion (FAC), where chemical process plays the primary role. But mechanism of FAC is not yet full y understood. Especially characteristics of oxide film formed in FAC is not well known although oxide film property would be strongly related to thinning rate in FAC. The main objective of this work is finding characteristics of oxide ...
英字タイトル:
Relation of Thinning Rate and Characterization of The Oxide Film Formed in Flow Accelerated Corrosion of Carbon Steels

After the pipe rupture accident due to the pipe wall thinning in August 2004 in Mihama-3, Japan Society of Mechanical Engineers constituted a special task for the piping wall thinning in the Power Generation Equipment Code Committee. First, they established the Rules on Pipe Wall Thinning Management providing the function, which the guideline of each company for pipe wall thinning should satisfy. Second, they are establishing the technical standards for thermal power stations, PWRs, and BWRs. In this report...

In Hamaoka Power Station, thinning management of piping system is considering earthquake In Hamaoka Power Station, thinning management of piping system is considering earthq uake resistance. Current management method is too conservative due to assumption that has large range thinning by liquid droplet impingement erosion (LDI). Therefore, we are developing reasonable earthquake safety evaluation method suited for locally-thinning caused by LDI. To understand the influence on earthquake resistance by the lo...
英字タイトル:
Seismic safety evaluation of piping system with local wall thinning by LDI(Part1)- Thinning Management of piping system in Hamaoka Power Station

For seismic safety of piping system with local thinning surface by liquid droplet impingement erosion (LDI), hybrid tests?? were conducted to the piping with locally-thinned elbow. I n this presentation, determination method of the thinning shape on the elbow is developed.To determine the thinning shape by LDI, droplet behavior at the elbow is calculated in vario us flow and piping size conditions, and collision point and velocity for each droplet is evaluated. Then, the relationship between collision cond...
英字タイトル:
Seismic safety evaluation of piping system with local wall thinning by LDI (Part 2)-Evaluation of local thinning shape by LDI

In order to evaluate seismic safety of piping systems with locally wall thinning by LDI, hybrid tests have been conducted incorporating a numerical analysis of whole s ystem with a loading test of elbow model. Seismic performance effects of wall thinning elbow were clarified by comparing three cases of different thickness elbow model s such as no defect, 50% thinning and 75% thinning. By these results, the almost same hystereses of the non-linear load displacement relations were obtained and the dam ages o...
英字タイトル:
Seismic safety evaluation of piping systems with locally wall thinning by LDI (Part3)-Seismic performance effects of elbow pipes by loading tests