Fig. 1 The Holtec International HI-STORM 100 spent fuel cask system [ 37 ] More

Fig. 2 Energy spectrum of the neutron flux at various locations in the MPC where fuel rods are stored. The flux is queried at ( a ) r  =   0.50 cm, ( b ) 20 cm, ( c ) 30 cm, ( d ) 40 cm, ( e ) 50 cm, ( f ) 60 cm, ( g ) 70 cm, and ( h ) 84.3 cm (the outer edge of the fuel region). The most probabl... More

Fig. 2 Energy spectrum of the neutron flux at various locations in the MPC where fuel rods are stored. The flux is queried at ( a ) r  =   0.50 cm, ( b ) 20 cm, ( c ) 30 cm, ( d ) 40 cm, ( e ) 50 cm, ( f ) 60 cm, ( g ) 70 cm, and ( h ) 84.3 cm (the outer edge of the fuel region). The most probabl... More

Fig. 3 Angular distribution of the neutron flux at ( a ) r  =1.25 cm and at ( b ) the inner surface of the MPC ( r  =   84.3 cm) More

Fig. 4 The mean distance between interactions (MFP) of the materials appearing within the fuel region. The source flux is provided in order to identify energy ranges of greater importance. More

Fig. 5 The top-down cross-sectional view of the helium model (i.e., the cask featuring homogenized fuel), as instantiated in MCNP. From inside to out, the layers are homogeneous fuel material; helium backfill (to allow for fill and neutron streaming between the fuel and MPC shell), stainless steel... More

Fig. 6 Comparison of the neutron energy spectra between the detailed and helium models. The neutron flux is queried at ( a ) r  =   0.50 cm, ( b ) 20 cm, ( c ) 30 cm, ( d ) 40 cm, ( e ) 50 cm, ( f ) 60 cm, ( g ) 70 cm, and ( h ) 84.30 cm (the outer edge of the fuel region. More

Fig. 6 Comparison of the neutron energy spectra between the detailed and helium models. The neutron flux is queried at ( a ) r  =   0.50 cm, ( b ) 20 cm, ( c ) 30 cm, ( d ) 40 cm, ( e ) 50 cm, ( f ) 60 cm, ( g ) 70 cm, and ( h ) 84.30 cm (the outer edge of the fuel region. More

Fig. 7 Comparison of the neutron angular distributions between the helium and detailed models at ( a ) 1.25 cm from the cask centerline and at ( b ) 84.30 cm from the cask centerline (the interior surface of the MPC) More

Fig. 8 Scalar neutron flux calculated from the MCNP detailed model (solid line), compared to the scalar neutron flux through hypothetical homogenized fuel material calculated using Eq. (23) with Table 1 data (dashed line). The inset graph shows an error metric between these models. More

Fig. 9 Analytical sensitivity coefficients as a function of the cylindrical radius in the homogenized fuel region More

Fig. 10 The absolute values of the sensitivity coefficients depicted in Fig. 9 More

Fig. 11 A comparison between the sensitivity coefficients from the helium model (dotted and dashed lines) and the analytic model (solid line) More

Fig. 12 The side view of the detailed model representation of the HI-STORM 100 spent fuel cask More

Fig. 13 A top-down cross-sectional view of the MCNP detailed model representation of the HI-STROM 100 spent fuel cask showing the arrangement of fuel cells in the spent fuel cask. This image shows the extent of geometric details which range from millimeters to meters. More

Fig. 14 A cross-sectional view of a single fuel cell in the detailed model. The smaller circles are fuel rods clad with zircalloy and the larger circles represent instrument locations (which are modeled as water in the simulations). There are neutron absorbing pads made of boron-carbide and alumin... More

Fig. 15 The neutron source spectrum found using ORIGEN-S. The spectrum is generated by spontaneous fission and ( α , n ) reactions leading to a maximum value at 2.71 MeV. More

Fig. 16 The interior neutron flux spatial distribution of the detailed model. The material regions are: the fuel region (extending from 0 cm radius to 84.34 cm), the MPC (84.34 cm to 86.84 cm), the air region (86.84 cm to 95.25 cm), the concrete annulus (95.25 cm to 166.37 cm), and the carbon stee... More