Embrittlement database

The embrittlement database (EDB) (Wang and Subramani, 2007) is a database of raw material embrittlement test data compiled from US power... 

The US NRC is currently engaged in an effort to develop a modern, web-based embrittlement database named the Radiation Embrittlement Archive Project (REAP) (Klasky et al, 2013). The objective is to address previous database sustainability issues (e.g., the challenge of keeping data retrievable... 

Wang J and Subramani R (2007), PR-EDB Power Reactor Embrittlement Database, Version 3, ORNL/TM-2006/605, August, Oak Ridge National Laboratory, Oak Ridge, TN. 

To identify the flux effect in the embrittlement database generated by Rolls Royce (RR), they performed a comprehensive evaluation of their database in terms of flux effect following the procedure shown in Fig. 11.9. They first fit a simple functional form of AHv = A-J dose) to the data of individual heat irradiated at the same condition (flux and temperature) but at different fluences in their database to obtain A values for each specific condition. Then the A values were plotted as a function of irradiation temperature to obtain an expression of a temperature-dependent A value model. This model was used to estimate the A values at a specific irradiation temperature, for example 290 °C, to make a comparison of A values for a specific heat at different flux conditions. The results show that there is a consistent flux effect in the A values for the low-Cu materials examined. 

There are many parameters in the above set of equations. However, reasonably estimated values have been assigned to most of the parameters, as shown above, and those values are fixed throughout the calibration process. The only parameters fitted to the embrittlement database are the total permanent sink strength, 5, and the solute trap concentration, The final form of the vacancy concentration as a function of flux is not necessarily visible in the equations, but it is schematically plotted in Rg. 11.11. Note that the contribution of thermal vacancies is not considered in the current modeling as indicated in the figure. 

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