The Experts below are selected from a list of 24 Experts worldwide ranked by ideXlab platform

Rice Aaren - One of the best experts on this subject based on the ideXlab platform.

  • Intercode Advanced Fuels and Cladding Comparison Using BISON, FRAPCON, and FEMAXI Fuel Performance Codes
    Scholar Commons, 2015
    Co-Authors: Rice Aaren
    Abstract:

    The high density uranium-based fuels are regaining popularity as the current fleet of LWR’s are showing interest in uprating plants to increase accident tolerance and performance. Fuels such as U3Si2, UN, and UC all contain a higher uranium loading and thermal conductivity than that of UO2 making them attractive in combination with an advanced cladding type such as the ceramic SiC cladding. In addition to adding more mass uranium to the core without surpassing current enrichment limits, these advanced fuels and claddings are designed with increased accident tolerance performance in a LOCA type scenario in mind. One of the possible concerns that comes with this combination of advanced fuels and cladding type is that PCMI should be avoided almost all together. From past experiments, the advanced fuels, U3Si2, UN, and UC, all show higher swelling rates than what UO2 experiences. In addition to higher swelling rates in the fuel, the SiC cladding is unyielding in nature and will crack before creeping outward with the fuel like current generation Zr based claddings will do. The combination of a fuel with higher swelling rate plus an unyielding cladding is concerning in terms of accident mitigation. Modeling the fuel and cladding based on properties found in literature can be accomplished with codes such as FRAPCON and BISON. Earlier work done on FRAPCON at USC has shown that UC with a creep model will allow the SiC cladding to remain under the suggested maximum Allowable Hoop Stress for up to 30 MWd/kgU. This was essentially the time until contact was made with the cladding. A similar implementation of UC and UN fuels into BISON has been done with comprable results. With the BISON code, a much more detailed analysis can be performed as it is a fully-coupled, transient solution which can be solved in 1, 2, and 3 dimensions. This allows for more detailed results to be drawn. This study will compare results from identical models that are implemented in both BISON and FRAPCON based on semirealistic PWR test conditions. This intercode comparison allows for further conclusions to how these advanced fuels interact mechanically with the SiC type cladding. Work has also been accomplished in the Japanese FEMAXI fuel performance code. A modified executable has been made which allows for the SiC cladding to be modeled with UO2 fuel. With all of these modified codes, PWR type simulations were run to examine how these codes modeled these advanced fuels and claddings

Aaren Rice - One of the best experts on this subject based on the ideXlab platform.

  • Intercode Advanced Fuels and Cladding Comparison Using BISON, FRAPCON, and FEMAXI Fuel Performance Codes
    2015
    Co-Authors: Aaren Rice
    Abstract:

    The high density uranium-based fuels are regaining popularity as the current fleet of LWR’s are showing interest in uprating plants to increase accident tolerance and performance. Fuels such as U3Si2, UN, and UC all contain a higher uranium loading and thermal conductivity than that of UO2 making them attractive in combination with an advanced cladding type such as the ceramic SiC cladding. In addition to adding more mass uranium to the core without surpassing current enrichment limits, these advanced fuels and claddings are designed with increased accident tolerance performance in a LOCA type scenario in mind. One of the possible concerns that comes with this combination of advanced fuels and cladding type is that PCMI should be avoided almost all together. From past experiments, the advanced fuels, U3Si2, UN, and UC, all show higher swelling rates than what UO2 experiences. In addition to higher swelling rates in the fuel, the SiC cladding is unyielding in nature and will crack before creeping outward with the fuel like current generation Zr based claddings will do. The combination of a fuel with higher swelling rate plus an unyielding cladding is concerning in terms of accident mitigation. Modeling the fuel and cladding based on properties found in literature can be accomplished with codes such as FRAPCON and BISON. Earlier work done on FRAPCON at USC has shown that UC with a creep model will allow the SiC cladding to remain under the suggested maximum Allowable Hoop Stress for up to 30 MWd/kgU. This was essentially the time until contact was made with the cladding. A similar implementation of UC and UN fuels into BISON has been done with comprable results.

E. Shashi Menon - One of the best experts on this subject based on the ideXlab platform.

  • Pipeline Stress Design
    Transmission Pipeline Calculations and Simulations Manual, 2015
    Co-Authors: E. Shashi Menon
    Abstract:

    In this chapter, we calculate the pipe wall thickness required to with stand an internal pressure in a gas and liquid pipelines using Barlow's equation. The influence of the population density of the pipeline on the required pipe wall thickness by reducing the Allowable Hoop Stress in high-population areas are explained using class locations. The range of pressures required to hydrotest pipeline sections to ensure safe operation of the pipeline and the effect of pipeline elevations was covered. The Allowable internal pressure in a pipeline was calculated depending on pipe size and material. The importance of design factor in selecting pipe wall thickness is illustrated using an example. The need for hydrostatic testing pipelines for safe operation are discussed and line fill volume calculation was introduced and its importance in batched pipelines shown.

Jian Gan - One of the best experts on this subject based on the ideXlab platform.

  • Assessment of Failure Mechanisms for GFR Vented Fuel Pins Using Hexoloy Cladding
    2008
    Co-Authors: Jian Gan
    Abstract:

    A near-term vented fuel pin concept as a back-up option for the gas-cooled fast reactor (GFR) system was evaluated. This work explored the feasibility of using mixed carbide fuel (U0.85P0.15)C with off-the-shelf monolithic SiC clad in order to meet requirements for GFR fuel with an average burnup of 10%. The Stress loading on the SiC cladding due to fuel swelling and thermal Stress due to temperature gradient were estimated based on the data from the development of carbide fuels in the 1970’s-1980’s and the materials properties for SiC tubes. The fuel swelling at the goal burnup (10%) is expected to produce a Hoop Stress of approximately 32 MPa in cladding, approaching the estimated maximum Allowable Hoop Stress (~33 MPa) for a SiC cladding reliability of 99.99%. The estimated tensile thermal Stress component (~121 MPa) near the outer surface of a monolithic SiC cladding is likely to limit its application at high temperatures.

Arazi Idrus - One of the best experts on this subject based on the ideXlab platform.

  • Strength of Tubular Members - Numerical Comparison of API RP2A to ISO Codes
    2010
    Co-Authors: Narayanan Sambu Potty, Zafarullah Nizamani, Arazi Idrus
    Abstract:

    Worldwide, currently there are three codes used for offshore jacket platform design i.e. API RP2A WSD, API RP2A LRFD and ISO 19902. Of these, the ISO code is formulated for application all over the world. API RP2A WSD is still being used for jacket platform design, not only in the Gulf of Mexico, but also in most of developing countries.API RP2A LRFD and ISO have introduced limit state design in place of working Stress design. The limit state design is followed all over the world for most of the design codes. ISO will introduce environmental load factors for each region, in its appendix. The reliability of jacket platforms is maintained in API RP2A LRFD by setting target safety factor the same as that provided in WSD designs, which means structures designed as per LRFD code will have same reliability as API RP2A WSD (which has already provided safe structures and the best available practice for design). For ISO code, the API RP2A LRFD was based as the base code of design. In this paper, the nine Stress equations of the above three codes are compared. The knowledge of the strength equations in the codes is useful for determining resistance factors for code calibration. The resistance formulations are numerically compared and the similarities and differences are determined. The member resistance formulae for local buckling, hydrostatic pressure, interaction formulae for axial compression, bending Stress, axial tension and Hoop Stress introduced in the 6th edition of WSD in 1975, have undergone major changes. In the 11th edition (1980), equations were introduced for Allowable Hoop Stress, a formula for combined effects of axial compression, bending and hydrostatic pressure. When API LRFD version was introduced in 1993, some formulae were modified. Incorporating these, the 21st edition of WSD was published in 2000. ISO 13819 was published in 1998, modified in 2007(ISO 19902). Some provisions in ISO were directly adopted from API RP2A LRFD while others improved and included.