# Sensitivity Analysis and Uncertainty Quantification Applied to the Feynman Y and Sm _{2}

## Abstract

Neutron multiplicity counting (NMC) experiments are frequently used to perform non-destructive assay (NDA) of special nuclear material (SNM), but MCNPR© code simulations of the counting distribution that were performed by Miller have revealed over-calibration in the value of the Pu-239ν¯. Mattingly has demonstrated the procedure for deterministic calculations of the counting distribution moments and O’Brien implemented a first-order, adjoint-based sensitivity analysis (SA) methodology applied to the counting distribution moments. In this report, these techniques are used to apply SA/uncertainty quantification (UQ) to the Feynman *Y* and Sm _{2}, which are ratios of the counting distribution moments. Sm _{2} is less sensitive to the cross sections than *Y* and therefore has less variance due to covariance in the cross sections than *Y*.

- Authors:

- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

- Publication Date:

- Research Org.:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

- Sponsoring Org.:
- USDOE National Nuclear Security Administration (NNSA)

- OSTI Identifier:
- 1481111

- Report Number(s):
- LA-UR-18-30511

- DOE Contract Number:
- AC52-06NA25396

- Resource Type:
- Technical Report

- Country of Publication:
- United States

- Language:
- English

### Citation Formats

```
Clark, Alexander Rich.
```*Sensitivity Analysis and Uncertainty Quantification Applied to the Feynman Y and Sm2*. United States: N. p., 2018.
Web. doi:10.2172/1481111.

```
Clark, Alexander Rich.
```*Sensitivity Analysis and Uncertainty Quantification Applied to the Feynman Y and Sm2*. United States. doi:10.2172/1481111.

```
Clark, Alexander Rich. Fri .
"Sensitivity Analysis and Uncertainty Quantification Applied to the Feynman Y and Sm2". United States. doi:10.2172/1481111. https://www.osti.gov/servlets/purl/1481111.
```

```
@article{osti_1481111,
```

title = {Sensitivity Analysis and Uncertainty Quantification Applied to the Feynman Y and Sm2},

author = {Clark, Alexander Rich},

abstractNote = {Neutron multiplicity counting (NMC) experiments are frequently used to perform non-destructive assay (NDA) of special nuclear material (SNM), but MCNPR© code simulations of the counting distribution that were performed by Miller have revealed over-calibration in the value of the Pu-239ν¯. Mattingly has demonstrated the procedure for deterministic calculations of the counting distribution moments and O’Brien implemented a first-order, adjoint-based sensitivity analysis (SA) methodology applied to the counting distribution moments. In this report, these techniques are used to apply SA/uncertainty quantification (UQ) to the Feynman Y and Sm2, which are ratios of the counting distribution moments. Sm2 is less sensitive to the cross sections than Y and therefore has less variance due to covariance in the cross sections than Y.},

doi = {10.2172/1481111},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2018},

month = {11}

}