New Structural Materials for Fast Nuclear Reactors

Abstract

The objective of this investigation is to examine the question samples to the impact of using a risk informed process in technology selection design so that the development of fast breeder reactor depends on the safety consideration in which it was pointed out that due to the design performance and evaluation beyond the design basis events the project explored the variable which could affect positively the expected average fuel burn-up , breeding ratio and decay heat removal is normally accomplished by mean of features as guard vessels and elevated pipe routing to prevent the cracked state of both core compo- nents and fuel cladding interface conditions , so that the cracked region of fuel be detected and in resisted by thermal-hydraulic analysis for estimating tem rise in fuel cladding and coolant to indicate possible provisions that can be in corporate in the design ZrFeCr alloys to uniform corrosion in temp . more than 650 with pressure 10.3 Mpa stream. Fast creep of the reactor vessel during coolant heat-up transient is another issue to be considered cor- rosion resistance of structural material can be achieved through controlling oxygen content in steel alloy. In this trend and S5140 steels are widely can be used in future fossil power plants because of their excellent high-temperature strength. They are also regarded as promising candidates for structural ma- terials for high-temperature nuclear power plants such as liquid metal-cooled fast reactors and high-temperature gas-cooled reactors. Their crack growth property is often required to evaluate the structural integrity under the pres- ence of detected or postulated flaws. In addition to fatigue crack growth property, crack growth property under creep and creep-fatigue loading is important because of high operating temperatures of these plants. As a study in the working group organized in Yermouk Industrial Complex , ex- perimental and analytical studies have been conducted on high-temperature crack growth property of representative high-quality steels. Temperature- and specimen -dependency of crack growth properties in terms of J-integral type fracture mechanics parameters were examined in detail. Standard equa- tions were derived to estimate crack growth rate as a functions of these pa- rameters. Effect of constraint on creep crack growth behavior was found to be quite large. In designing the primary system against the seismic loading one of the most important safety considerations is relative to motion of reac- tor core and control rods with in the containment affect by the site specific ground motion to seismic response . This approach may present the oppor- tunity for refinement of the reactor design by revealing components that are unnecessary or possibly over designed to component sate for requirements imposed according to current deterministic licensing requirements. The ob- jective is not only to design a sodium cooled fast reactor but to develop a systematic process to be used in design the challenge of this project is obtain- ing a reliable cost estimates in sufficient detail to test to methodology. To avoid absolutes this project will focus on comparative assessments of design and cost estimates completed in the past. the most well documented is the advanced metal reactor , since it has detailed costs at the component level and probabilistic risk assessment completed . The goal is to show meaning fuel reductions in cost and safety which will be compared to thermal reac- tor once a reasonable model has been developed areas for reduction in cost with safety aspects of the design will be determined and specific items can be addressed it expected that the methodology could be used in the design of any future reactor since the methodology will be generic. Sustainability: Concerning sustainability, the main concern was the management of the en- vironment through clean air restrictions, waste management restrictions and conservation of resources.Four general classes of nuclear fuel cycles were con- sidered: -The once through fuel cycle. -A fuel cycle with partial recycling of the bred fissile Pu. - Full plutonium recycle. - A cycle with the recycle of the transuranic el- ements. It appears that waste management is a major concern with the existing once through cycle because of the limited availability of repository space worldwide. Closed fuel cycles or recycling reactors allow some of the fuel to be reused so less of it has to be placed in a repository. Improvement in reactor performance can be achieved if thermal and fast reactors are op- erated in a coupled mode. An increase in the fuel burnup of gas cooled and water cooled thermal reactors can improve the management of the produced actinides by burning them in situ.Finally effects of radiation damage to the solid fuel contributes an increased friability of the predominantly UO2 ma- trix, resulting ultimately in the interfacial reactions lead to deterioration of the fuel cladding and eventually to contact between the liquid sodium and the fuel matrix which lead to the core melt down so a selection of improved alloy implementations were studied via TRIM code and calculating results in alloys S4337 and S 5140 were compared with a defect distributions in al- loy S316NL together with mechanical properties through mechanical tests beside the use of Macro program to the calculation of the accident pressure in a containment of fast reactor and other useful parameters to enhance the safety in the design. then an efforts toward enhancing seismic safety was being realized by the design of the system to prevent damage accumulation and seismic energy release during brittle rock failure.