Leak before break evaluation for main steam piping system made of SA106 Gr.C
- Korea Power Engineering Company, Seoul (Korea, Republic of)
The basis of the leak before break (LBB) concept is to demonstrate that piping will leak significantly before a double ended guillotine break (DEGB) occurs. This is demonstrated by quantifying and evaluating the leak process and prescribing safe shutdown of the plant on the basis of the monitored leak rate. The application of LBB for power plant design has reduced plant cost while improving plant integrity. Several evaluations employing LBB analysis on system piping based on DEGB design have been completed. However, the application of LBB on main steam (MS) piping, which is LBB applicable piping, has not been performed due to several uncertainties associated with occurrence of steam hammer and dynamic strain aging (DSA). The objective of this paper is to demonstrate the applicability of the LBB design concept to main steam lines manufactured with SA106 Gr.C carbon steel. Based on the material properties, including fracture toughness and tensile properties obtained from the comprehensive material tests for base and weld metals, a parametric study was performed as described in this paper. The PICEP code was used to determine leak size crack (LSC) and the FLET code was used to perform the stability assessment of MS piping. The effects of material properties obtained from tests were evaluated to determine the LBB applicability for the MS piping. It can be shown from this parametric study that the MS piping has a high possibility of design using LBB analysis.
- Research Organization:
- Nuclear Regulatory Commission, Washington, DC (United States). Div. of Engineering Technology; Electricite de France (EDF), 69 - Villeurbanne (France); Battelle, Columbus, OH (United States)
- OSTI ID:
- 489306
- Report Number(s):
- NUREG/CP--0155; CONF-9510432--; ON: TI97004806
- Country of Publication:
- United States
- Language:
- English
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