Consistency Among the Results of the ASPIS Iron88, PCA Replica, and PCA ORNL Benchmark Experiments

Figures & data

TABLE I Drawbacks Identified in the SINBAD Benchmark Documentation for the ASPIS Iron88, PCA ORNL, and PCA Replica Benchmarks

Benchmark/Quality	Additional Information Needed on
PCA ORNL	Approximate modeling of neutron source (material test reactor with a 93% ^235U fuel elements), and quality evaluation (not done yet)
ASPIS PCA Replica ♦♦♦	Setup of the activation foils, rear wall of the ASPIS cave, and water tank [bowing effects ^55Mn(n,γ)]
ASPIS Iron88 ~ ♦♦♦	Detector arrangement (e.g., stacking), gaps between the slabs, absolute calibration of neutron source and dilution factor, and effect of the cave walls

Fig. 1. ASPIS Iron88 experimental configuration.

Fig. 2. PCA ORNL 12/13 experimental configuration.

Fig. 3. Layout of the PCA Replica 12/13 experimental configuration.

TABLE II Experimental and Computational Nuclear Data Uncertainties for the Reaction Rates Measured in the ASPIS Iron88 Benchmark

ASPIS Iron88	Uncertainty (%)
	Experimental	Computation Nuclear Data
		JEFF-3.3	ENDF/B-VII.1	JENDL-4.0
^197Au(n,γ): 26 cm	4.2	5.1	9.9	9.2
46 cm	4.2	4.3	8.8	8.8
62 cm	4.2	3.7	8.1	8.5
^103Rh(n,n’):26 cm	5.1	6.4	7.8	8.6
62 cm	5.1	11.7	18.7	14.9
^115In(n,n’): 26 cm	4.5	6.6	10.5	14.8
62 cm	4.7	10.5	15.0	17.8
^32S(n,p): 26 cm	6.5	13.3	11.5	17.2
52 cm	6.5	25.0	20.8	35.0
62 cm	8.6	29.3	25.1	42.9
^27Al(n,α): 26 cm	4.7	18.8	31.5	29.5

TABLE III Experimental and Computational Nuclear Data Uncertainties for the Reaction Rates Measured in the PCA Replica Benchmark

PCA Replica	Uncertainty (%)
	Experimental	Computation Nuclear Data
		JEFF-3.3	ENDF/B-VIII.0
^103Rh(n,n’): 59 cm	5.0	8.0	8.0
^115In(n,n’): 26 cm	4.4	9.7	9.0
^32S(n,p): 49 cm	5.7	10.6	9.9
59 cm	5.5	11.6	11.8

Fig. 4. ASPIS Iron88 benchmark: C/E ratios for the ¹⁰³Rh(n,n’) and ¹¹⁵In(n,n’) reaction rates calculated using the MCNP code and cross sections from the FENDL-3.2 and 2.1, JEFF-3.3, ENDF/B-VIII.0, and JENDL-4.0u evaluations. Dashed lines delimit the ±1σ measurement standard deviations. Examples of ±1σ computational (nuclear data) uncertainties calculated using the SUSD3D codes are shown.

Fig. 5. PCA Replica and PCA ORNL benchmarks: C/E ratios for the ¹⁰³Rh, ¹¹⁵In, and ³²S/⁵⁸Ni activation foils calculated using the MCNP code and cross sections from the FENDL-3.2 and 2.1, JEFF-3.3, ENDF/B-VIII.0, and JENDL-4.0u evaluations. Dashed lines delimit the ±1σ measurement standard deviations. (c) Comparison of the C/Es for two reactions having approximately similar thresholds: ³²S(n,α) (ASPIS Iron88) and ⁵⁸Ni(n,p) (PCA Replica).

Fig. 6. Comparison of the ASPIS Iron88 and PCA Replica benchmark results for the ³²S reaction rates. (a) C/E ratios calculated using the MCNP code and cross sections from the FENDL-3.2 and 2.1, JEFF-3.3, ENDF/B-VIII.0, and JENDL-4.0u evaluations. Dashed lines delimit the ±1σ measurement standard deviations. (b) Sensitivity of the ³²S(n,p) reaction rates at the deepest measurement positions in the ASPIS Iron88 (position A14 at 74 cm) and PCA Replica (position A7 at 59 cm) benchmarks to the ⁵⁶Fe inelastic and elastic cross sections. Legend: “Fe88_S_A14 Inel Fe56” stands for the sensitivity of the ³²S reaction rate at position A14 to the inelastic cross section of ⁵⁶Fe, etc.

Fig. 7. Comparison of the ASPIS Iron88 and PCA Replica benchmark results for the ¹¹⁵In reaction rates. (a) C/E ratios calculated using the MCNP code and cross sections from the FENDL-3.2 and 2.1, JEFF-3.3, ENDF/B-VIII.0, and JENDL-4.0u evaluations. Dashed lines delimit the ±1σ measurement standard deviations. (b) Sensitivity of the ¹¹⁵In reaction rates at the deepest measurement positions in the ASPIS Iron88 (position A11 at 57 cm) and PCA Replica (position A7 at 59 cm) benchmarks to ⁵⁶Fe inelastic and elastic cross sections. Legend: “Fe88_In_A11 Inel Fe56” stands for the sensitivity of the ¹¹⁵In reaction rate at position A11 to the inelastic cross section of ⁵⁶Fe.

Fig. 8. Comparison of the ASPIS Iron88 and PCA Replica benchmark results for the ¹⁰³Rh reaction rates. (a) C/E ratios calculated using the MCNP code and cross sections from the FENDL-3.2 and 2.1, JEFF-3.3, ENDF/B-VIII.0, and JENDL-4.0u evaluations. Dashed lines delimit the ±1σ measurement standard deviations. (b) Sensitivity of the ¹⁰³Rh reaction rates at the deepest measurement positions in the ASPIS Iron88 (position A14 at 74 cm) and PCA Replica (position A7 at 59 cm) benchmarks to ⁵⁶Fe inelastic and elastic cross sections. Legend: “Fe88_Rh_A14 Inel Fe56” stands for the sensitivity of the ¹⁰³Rh reaction rate at position A14 to the inelastic cross section of ⁵⁶Fe, etc.

Fig. 9. Sensitivity of the ³²Al(n,α), ⁵⁸Ni(n,p), ¹⁰³Rh(n,n’), and ¹¹⁵In(n,n’) reaction rates at the measurement position D6 (~50 cm) in the PCA ORNL benchmark to the ⁵⁶Fe inelastic cross sections calculated using the MCNP6 code.

Fig. 10. The ASPIS Iron88 and PCA ORNL benchmarks: C/E ratios for the ²⁷Al(n,α) reaction rates calculated using the MCNP code and cross sections from the FENDL-3.2 and 2.1, JEFF-3.3, ENDF/B-VIII.0, and JENDL-4.0u evaluations. Dashed lines delimit the ±1σ measurement standard deviations. Examples of ±1σ computational (nuclear data) uncertainties calculated using the SUSD3D codes are shown.

Fig. 11. Sensitivity of the ²⁷Al(n,α) reaction rate at the deepest measurement positions in the ASPIS Iron88 and PCA ORNL benchmarks to ⁵⁶Fe inelastic cross sections.