Seifert Master Thesis

General Concept(s)

Discussion of Serpent2 flow functionality, possible uses, pitfalls, and workarounds. How it differs from batch-wise reprocessing. Discuss usefulness over batchwise (Xe-135 in batchwise is not removed until after depletion, meaning more captures occur by Xe-135 than would have happened if removed continuously).

Use Serpent2 build-in flows and binary restarts to create "piping" where material decays naturally while not in core. How does this differ from MSBR analysis as a single unit geometry analyzed in SaltProc where piping volume is included in core volume? Does it improve result by providing more accuracy to location of DNP decay? Does a smaller "mesh" of materials allow for better results?

Thesis Sections

• Abstract
• Introduction
• Literature Review
  • Accounting for material decay in piping
  • Serpent2 continuous removal
  • Serpent2 restart scripts
  • Methods of tracking DNPs in MSRs
    • GenFOAM?
    • Moltres?
  • Batchwise removal methods in Serpent2
  • SaltProc
  • MSBR
• Methods
• Results
• Conclusions

Results to Discuss

• Explanation of flow functionality
• Discussion of cyclic flow effects (breaks depletion); workarounds
• Explanation of why type 1 approximations necessary given removal fraction
• Type 1 cycle-time-decay approximation
• Type 1 linear generation approximation
• Type 2 different approaches and non-physicality
• Discussion of when each type could be used (pros/cons)

Results to be Generated

• Isotope-importance based type 1 MSBR approximation
• Difference plots along with mass plots for type 1 approximations
• N-steps for different type 1 approximations
• Type 1 approximations at different starting positions (BOC vs SS)
• Implementation of Serpent2 built-in flows in SaltProc
• Separation of MSBR into core and piping material difference in results
  • Difference from single-material model
  • Discuss validty of slug flow approximation (no mixing of materials)
  • DNP groups SS locations
  • Difference in neutronic parameters
  • Mesh refinement analysis (cost vs accuracy)
  • Analysis of separate parts of the core

Possible Things to Add

• Neutronics parameters for different type 1 approximations
• Comparison of MSBR with SaltProc, subdivided materials, and with CFD