[en] Westinghouse has designed and built ODEN, a Critical Heat Flux (CHF) test loop for PWR applications. The ODEN test facility is a replacement to (and improvement upon) the well known former Heat Transfer Research Facility (HTRF) of Columbia University in New York City. The ODEN loop shares the laboratory infrastructure (power supply, heat sink and control room) with the well-known Westinghouse FRIGG BWR test loop. The ODEN loop is designed to cover Departure from Nucleate Boiling (DNB) testing needs for all types of PWR lattices in 5x5 or 6x6 rectangular geometry or in hexagonal test sections. The loop installation was completed in 2006 and qualification / benchmark testing versus HTRF data was completed in 2010. The ODEN CHF test loop was used to perform DNB measurements to provide an improved correlation to increase DNB margin for the Westinghouse WWER-1000 fuel design. The fuel was tested in an extensive thermal-hydraulic verification program with axially uniform test (typical cell) and two axially cosine tests (typical and thimble cells). The DNB measurements were performed at low to high pressures, low to high mass flows and include high steam quality conditions. The tests were carried out in a bundle configuration of 19 rods in a hexagonal array. The ODEN loop demonstrated high DNB data quality, and excellent agreement of the repeatability of the DNB data. The ODEN loop has now completed more than 1000 CHF data points. Following the DNB measurements, Westinghouse developed two DNB correlations. The WVHI correlation for predicting DNB for high flow conditions with all four loops in service operation, and the WVLO correlation for predicting DNB for low flow conditions for N-X loop operations. The WVHI and WVHLO correlations have been implemented in the Westinghouse 3-D thermalhydraulic sub-channel code VIPRE-W and used for comparative Steady-State Operation DNBR analyses as well as for comparative analyses of the Complete Loss of Flow, Under Frequency (CLOF UF) Transient. The CLOF UF accident is the most DNB limiting transient for a WWER-1000 core. The comparative VIPRE-W DNBR analyses carried out by Center of Reactor Core Design, Kharkov, Ukraine, clearly demonstrated that the use of the WVHI DNB correlation with the current analysis methodology allows increasing the current core design limit by 3% without any restrictions. Qualification of the correlations is ongoing for use in safety substantiation analyses for the Westinghouse WWER-1000 fuel in Ukrainian NPP´s. (authors)