Help me solve this. I could not understand the problem

 

Compound U Concentration B2m Extrap. dist , Full H2) Thermal refl Migration Area koo [gU/l] 200 [cm-2] [cm] [cm2] .0308 5.90 28.0 1.87 U235(100) NH, OM ME1700 Lecture 3 HW Third problem, after Knief 4.1 and 4.2 Comparison of 2 hand calculations of a critical dimension: Use the data provided above (obtained by eye from graphs* in ARH-600 which address 100% enriched U-235 nitrate in water). Separately use both formulas below to define attainment of criticality (keff=1), viz., : = 1) Keff Koo/(1+ M2B2g) =1 for the system to be just critical, and 2) B2 B2m for system to be just critical. g = Recall that for a cylinder: = B2g [2.405/(r+)]+ [/(h+2)]2, and we are assuming infinite cylinder height. Using each method, you will need to solve for the critical radius and state the critical diameter in cm for an infinitely long cylinder with full water reflection, that you I have calculated. Compare the two results for reproducibility [e.g., discuss the quantity (B-A)/B, where A represents the result using method 1) and B represent your results using method 2)]. Bear in mind that before establishing a parametric safety limit, significant further conservatism would be applied, resulting in a much smaller diameter than you have calculated at criticality. For example, 200 g/l does not represent the most reactive concentration for this system; such a calculation would be performed for data at the most reactive concentration (roughly 290 gram/1). Beyond that, still other factors would be applied, likely in conjunction with measures for concentration control. * Graphs III.B.10(100)-1 and III.B.10(100)-2, from ARH-600