Research On The Reactor Physics Analysis Methods And Characteristics Of Traveling Wave Reactor

Traveling wave reactor (TWR) is an innovative nuclear system, which isbased on the design concept of dynamic breed-and-burn equilibrium of fissilenuclides at the orient location of reactor core. In the whole life of TWR, thereactivity changes little and the shapes of important reactor characteristicsremain constant but move along the core. Natural uranium, depleted uraniumand discharged fuel of pressurized-water reactor (PWR) can be utilized as freshfuel in TWR, which proposes a new resolved method for uranium resourcesutilization and discharged fuel reprocessing. At present, the internationalresearch for TWR is in concept exploration. In order to accelerate the technicaldevelopment and the engineering application of TWR, we select TWR for thestudy and the main contents are as follows:The core analysis methods for TWR have been researched. Compar ed withthe traditional reactor, TWR features higher fuel depletion, stronger coreheterogenization, more geometric grid, which force the present code to face thegreat challenges in precision and efficiency. Based on in-depth study of highburnup calculation characteristics of TWR, and applying analytic functionexpansion nodal method(AFEN), a fuel management code called HANDF-E hasbeen developed. HANDF-E has adopted some speedup methods, includingLyusternik-Wagner method, internal-external cooperation iterative method,OpenMP parallel method etc. At the same time, HANDF-E has the ability ofmacroscopic burnup calculation, pin power reconstruction, thermal hydraulicfeedback calculation, shuffling material etc. In some cases, HANDF-E is notconvergent and two stabilization techniques are introduced to resolve theinstability problem. One is the truncation approximation and the other is theTaylor expansion. The precision of HANDF-E is confirmed in many numericaltests, and the calculation efficiency is greatly improved at the same time.Reactor characteristics and core design methods are studied for axial TWR.By using HANDF-E code, the thesis studies the effects of different degree offuel enrichment and zirconium content of metal fuel, different types of nuclearfuels and coolant on the physics characteristics of a long life TWR and the effects of different length, enrichment of startup region and radial dimension onthe steady performance of TWR. Based on the results, a new axial TWR coredesign has been proposed, which satisfies the requirement of small excessreactivity swing and important reactor characteristics moving along the axialdirection with constant distribution.Core design methods and fuel shuffling scheme are studied for radial TWR.The calculation results by HANDF-E show that the key parameters for a longlife radial TWR are height of the core activity areas as well as the axial breedingthickness. Based on this, a full life of60years radial TWR core design andpreliminary radial fuel shuffling scheme in decades are proposed.The analysis methods and development code systems in this thesis can beapplied to TWR in the future and the proposed core designs will provide goodreference to the engineering application of axial and radial core design.