Looking at their usage last year, an appropriate Q1 amount seems to be 150K. Then we could add it to the list for Q2 decision at the next meeting. Ray On 10/9/15, 11:07 AM, "[email protected] on behalf of [email protected]" <[email protected] on behalf of [email protected]> wrote:

Hello,

A yearly allocation for the LCRC cluster has been requested with the following updated information:

Submitter/PI: Yiqi Yu Project Name: SHARP_ARC Division: NE, MCS Project title: Multi-physics Simulation of SFR Core Radial Expansion with SHARP Associated funding: DOE-NE Advanced Reactor Concepts Other Systems: NE Division clusters, MCS Cosmea cluster Science: Sodium-cooled fast-spectrum nuclear reactors (SFRs), when compared to water-cooled reactors for commercial electric generation in the U.S., have demonstrated a superior capability to effectively utilize nuclear fuel, reduce the radiotoxicity of the associated used fuel, and reduce the time required to isolate the associated nuclear waste from the biosphere from many millennia to a couple centuries. Argonne¹s SFR concepts rely on passive feedbacks for reactor safety. The reactor should remain safe even during highly unlikely scenarios for long periods of time without the need for human intervention. By careful design choices, any disturbance in the reactor operation that causes the nuclear fuel and coolant to heat up should cause decrease the nuclear fission reaction rates and cause the reactor to shut itself down. The heat generated by radionuclide decay can be then be removed by natural circulation of the coolant.

One mechanism by which the reactor shuts itself down is radial core expansion: as the structural support materials heat and expand, the core grows wider and neutrons tend to leak outside the core rather than being absorbed by the fuel inside the core. Simulating this phenomenon requires multi-physics analysis: neutron transport, fluid dynamics and heat transfer, and structural mechanics. Conventional approaches employ a multi-step process for integrating these physics, and the fluid and structural mechanics calculations are conventionally 1-D.

In FY14,we successfully performed first-of-a-kind simulations with the SHARP toolkit, including multigroup neutron transport with PROTEUS, computational fluid dynamics simulations with Nek5000, and finite-element based structural mechanics with DIABLO. These physics codes were integrated to predict the reactor¹s response to the deforming geometry. In FY15, we improved upon our demonstrated modeling capability with SHARP, and begin to address validation issues. In FY16,We will implant our new model in SHARP and apply SHARP for different multi-physics problems.

Project description: SHARP is a subset project under Nuclear Energy Advanced Modeling and Simulation (NEAMS), which aims at developing a versatile tool being developed for integrated multi-physics simulation capability for the design and analysis of future-generation nuclear power plants and for modeling the core of a wide variety of reactor types under various scenarios. For some scenario, it is necessary to perform coupled neutronic, structural mechanics and thermal-hydraulic calculations, such as radial core expansion. The primary driver for radial core expansion is the thermal expansion of the assembly ducts and their contact and interaction with other assemblies, load pads and restraint rings. The structures internal to the assembly are usually ignored and are assumed to slide with regards to the duct. However, CFD simulation requires considerable computational cost. Applying a porous media model whose solution requires less computational time to calculate the duct wall temperature distribution in wire wrap fuel rod assemblies became a better choice. The code PROTEOUS, Nek5000 and Diablo will be used for the project. A demonstrational calculation has been performed on LCRC.The expected number of this project is around 15. Industry partnership: Project URL: http://energy.gov/ne/advanced-modeling-simulation/advanced-nuclear-reactor s Current FY Hours Used: undetermined amount

New FY Requested allocation: 800000 Q1: 200000 Q2: 200000 Q3: 200000 Q4: 200000

Justification: Nek5000 and PROTEOUS-SN used in this project both have good scalability. PROTEUS-SN¹s parallel methodology permits the efficient decomposition of the problem by both space and angle, permitting large problems to run efficiently on hundreds of thousands of cores. PROTEUS-SN can also be used in serial or on smaller compute clusters (10¹s to 100¹s of cores) for smaller homogenized problems.Nek5000 can even scale to > 290,000 processors. Storage requirements: 4 TB would provide convenience, considering the relatively large number of collaborators working simultaneously.

Thank You,

The LCRC Accounts System