This paper discusses the creep fatigue damage assessment of high temperature piping in fast breederreactors, when assessed according to RCC-MR, ASME Subsection NH and CEGB-R5 procedures (EDF-R5). RCC-MR has specific rules for high temperature piping for insignificant and significant creep for both the primary and secondary stresses, whereas ASME-NH and R5 refer to procedures related to vessels that are to be used for piping. Failure modes considered, failure theories used, creep deformation, creep rupture, creep deformation enhanced by cyclic loading, creep ratcheting (non linear interaction of primary and secondary stresses), combining cycles for fatigue analysis, fatigue strength reduction factors with significant creep effects, creep fatigue interaction and large strains induced by dynamic events such as seismic on subsequent creep response related to high temperature piping have been compared with respect to RCC-MR, ASME-NH and R5 assessment procedures. The effect of creep and fatigue rules in RCC-MR, ASME-NH and R5 assessment procedures, when different materials are used have also been discussed. The advantages and disadvantages of linear damage rule (cycle fraction / time fraction) used in NH with that of the strain fraction used by RCC-MR and R5 has also been discussed. The effect of elastic and inelastic analysis on creep and fatigue life of piping with respect to RCC-MR, ASME-NH and R5 procedures are also discussed.
The large amounts of money being spent worldwide by the nuclear industry on the development of fast breederreactors is becoming increasingly difficult to justify... Will it ever be possible to recoup the vast sums that have been spent and the much greater sums that will need to be spent before the fast reactor can become a commercial option for electricity utilities? ... Uranium will not be suddenly exhausted or become excessively expensive ... There will be plenty of time to identify the trend ... But perhaps of greater significance to fast reactor economics than the availability of uranium is the fact that with advances in techniques for the storage of irradiated fuel from light-water reactors utilities can avoid reprocessing. The uncertain and growing costs of reprocessing are then properly loaded on the fast reactor ... In these circumstances fast reactors may never be economic ... Evangelical fervour is not a substitute for sound technical argument. In February 1984 the Comptroller and Auditor General published a terse report entitled “Development of Nuclear Power,” expressing unease about the AEA’s financial performance; and the House of Commons Committee of Public Accounts looked into the matter. The committee chairman asked AEA chairman Sir Peter Hirsch “the estimated total cost of development” of the fast breeder. Sir Peter replied: “We have spent so far about £2400 million in 1982-83 prices. The forward development programme, assuming a certain profit for it, again in 1982-83 prices, is estimated to be £1300 million, the total being £3700 million.” Asked “What have you got for all this money?” Hirsch continued:
- In solid-fuel reactors, SNF burn up is limited by fuel-clad lifetime that, in turn, limits fuel burn up and the burnout of plutonium. In non-breederreactors, SNF burn up is also economically limited, independent of the technology. Excess fissile material is in fresh fuel when it is initially placed in the reactor core. This is required to compensate for fuel burn up over time. To assure reactor control, burnable neutron absorbers are then added to the fresh fuel to avoid excess nuclear reactivity in new fuel assemblies. There is an economic cost (extra enrichment) in ―storing‖ excess fissile fuel in the new fuel assembly until it is needed toward the end of the fuel assembly lifetime. These factors fundamentally limit solid-fuel burn up.
Thermal striping is a phenomenon, which leads to random temperature fluctuations in the interface between non- isothermal streams. This fluid thermal fluctuation is transferred to the structural components in vicinity without much boundary layer attenuation. Because of the high heat transfer coefficient associated with liquid metal coolants such as sodium, the temperature fluctuations are transmitted to the adjoining structures with minimal attenuation, which eventually leads to high cycle fatigue and crack initiation, propagation and finally failure of the component. In Liquid Metal cooled Fast BreederReactors
One way to order our thinking on nonideal reactors is to consider model- ing the flow patterns in our reactors as either CSTRs or PFRs as a first approx- imation. In real reactors, however, nonideal flow patterns exist, resulting in ineffective contacting and lower conversions than in the case of ideal reactors. We must have a method of accounting for this nonideality, and to achieve this goal we use the next-higher level of approximation, which involves the use of macromixing information (RTD) (Sections 13.1 to 13.4). The next level uses microscale ( micromixing ) information to make predictions about the conver- sion in nonideal reactors. We address this third level of approximation in Sec- tions 13.6 to 13.9 and in Chapter 14.
The recent spark in interest for SMR technology is largely based off two main advantages SMRs offer over large power plants. Total capital cost is projected to be less than conventional Advanced light water reactors (ALWR) and SMRs can be used in off grid locations. Ideally SMRs would be able to be made in factory with minimal component outsourcing and the modularity of the parts will help optimize the manufacturing supply chain . Vendors also point out that the passive safety features associated with many SMR designs reduce the number of structures, systems and often include a simplified power conversion system. Currently the estimate from vendors is that in order to optimize the SMR supply chain for low cost, five to seven units must be made. Seeing as this type of technology is new there are uncertainties with how the actual cost will compare to ALWRs. The total capital cost is broken down into
Loss in the power production and saving of the fuel for both considered reactors-transmuters are of the same order of magnitude. In the mode of self-service, these values are 1 and 1.5% respectively for CANDU reactor and 1.5 and 3.5% for VVER-1000 reactor. It is necessary to note that these data of losses in the power production should be considered as approximate data. Exact data can be obtained either in experiments on reactors now in operation, or in result of precise steady-state and dynamic calculations of neutron distributions in the active core of considered reactors operating in transmutation modes.
a carrying capacity of around 320 individuals that reside in ca. 115 territories (Komdeur and Pels 2005). Group membership was assigned to each bird (>5 months old) that was seen repeatedly on a territory interacting with group members and not exhibiting primary breeding pair behaviours (Richardson et al. 2002). A pri- mary breeder status was assigned to individuals in a pair that were repeatedly seen in the same territory, stayed within close proxim- ity, had constant vocal interactions with their mate and either mate guarded (if male) or were the object of mate guarding (if female). A territory generally contains a single primary breeding pair, and approximately 50% of territories also contain additional non- primary group-members (Kingma et al. 2016). Habitat saturation forces some individuals to assume non-primary roles, as helpers or non-helpers, because of the limited breeding vacancies (Komdeur 1992).
J. Abonyi, L. Nagy, F. Szeifert: Takagi-Sugeno Fuzzy Control of Batch Polymerization Reactors, 2nd On-line World Conference on Soft Computing (WSC2), June. 1997
Molnár, F., Morász, M., Szeifert, F., Nagy, L., Chován, T.: Model based control algorithms in the CHEMIFLEX system, MKN '93, Veszprém (1993).
Advanced Nuclear Materials discusses the major classes of materials suitable for usage in nuclear fission, fusion reactors and high power accelerators, and for diverse functions in fuels. The work addresses the full panorama of contemporary international research in nuclear materials, from Actinides to Zirconium alloys. Considerable changes in the operating performance of fission reactors, along with advances in the plasma physics knowledge required for heating and controlling fusion energy reactions suggest that fission and fusion energy can be important components of the overall energy portfolio for the 21st century and beyond. Advanced materials can enable improved reactor performance via increased safety margins and design flexibility, in particular by providing increased strength, thermal creep resistance and superior corrosion and neutron radiation damage resistance.
Despite a decrease in the rate of construction of new research reactors, creation of reactor facilities for the personnel education and training will remain a crucial near-term task.
The presented reactors feature a simple design and proven engineering concepts which make the reactors cost-effective and safe and ensure their long-term operation without refueling.
This study was carried out to explore effects of antibiotics (Tylosin, Colestin) and prebiotic (enzymes) on immune status and reproduction of commercial Ross broilers breeder flock of 6000 females and 700 males to use viral vaccines (ND,AI, IB, IBD and CIA) as well as MG and MS infection by ELISA- test. Results revealed that mean ELISA titers against MS was 685±120.7, 1200.4±322.7, 924.6±99.9, 1373±168.5 and 925.7 ±133.4 at 6, 27 ,35, 44 and 61 weeks, respectively; while CV% still is below 30%. Mean ELISA titer against MG was 2891.8±146.64, 608.5±208.5, 2961±1319.5, 3199.2±1331.2 at 6th, 27th, 35th and 44th week, respectively. While CV% was 5.1 at 6 th week and increased gradually to be 48.4 %. The fluctuation in MS and
Although pure GA performs well, mostly it does not equal to TS. [1 2 ,1 3 ] have proposed the enhancement of GA for solving single VRPSD. [1 2 ] developed a permutation-based GA for VRPSD enhanced by automatically adapting the mutation probability to capture dynamic changing in population while in [1 3 ] , a new scheme based on hybrid GA with TS was proposed. In this study we propose the enhancement of GA by using Breeder GA (BGA). According to [1 4 ] , The BGA is a robust global optimization method where selection, recombination and mutation are well tuned and have a synergetic effect. To the best of our knowledge, this is the first time B G A has applied for solving VRPSD.
Seismic analysis of reactor assembly of 500 MWe pool type fast breeder is carried out to ensure that certain functional limits and RCC-MR design criteria are respected. The important functional requirements that are addressed in this paper are: (i) it should be possible to shutdown the reactor in case of demand for SCRAM from the plant protection system during a seismic event, (ii) the reactivity insertion because of possible compaction during dynamic displacements of core under seismic event and relative vertical displacements between absorber rods and fuel sub-assembly, should not result in super prompt criticality, (iii) there should not be any sodium slug impact on the top shield due to sloshing and (iv) there should not be any mechanical interaction between the adjacent shells. The primary stress limits specified in RCC-MR code are also respected.
. nonlinear processes at interfaces in heterogeneous catalysis and electrochemistry. The main goals are the development of the fundamental understanding of complex systems and to indicate the longer-term potential for exploitation of their properties to develop new reactors appropriate to such systems. This represents a necessary first step to the future application of such systems, e.g. for new routes to high-value industrial products.