ATRIUM trademark 11 measures against debris fretting

The design goals to improve the debris resistance for the ATRIUM trademark 11 were met and exceed: - Improve filter efficiency for small thin wires and avoid open debris paths o The 3rd Generation FUELGUARD trademark filter is able to filter straight wires with a diameter of > 0.2mm and a length of > 8mm with nearly 100% efficiency because of the geometric configuration of the filter grid cells and corresponding frame interior walls. In addition, the filter is able to prevent thinner flexible wires from entering the filter with help from special features (twists) at the filter's entrance plane. - Reduce susceptibility of spacer grid to trap debris (which can pass filter): The spacer debris entrapment tests confirm clearly decreased debris entrapment susceptibility of the ATRIUM trademark 11 spacer in comparison with the ATRIUM trademark 10XP, XM spacers in all axial levels and test conditions. Taking into account the very good filter efficiency of the 3rd Generation FUELGUARD trademark it can be concluded that the risk of debris fretting is significantly decreased in the ATRIUM trademark 11 fuel assembly relative to previous designs. - Prevent larger debris from entering assembly from the top: The new ATRIUM trademark 11 UTP prevents debris with a diameter > 7 mm from entering the fuel assembly from the top (ATRIUM trademark 10XM > 18 mm). - Retain debris within the LTP during fuel movement and flow cycling: Most of the caught wires will remain in filter. All of the introduced measures together will significantly improve the resistance of the ATRIUM trademark 11 against debris fretting compared to precursor designs. (orig.)