# Transuranic Transmutation and Criticality Calculation Sensitivity to Heterogeneous Lattice Effects - 12391

## Abstract

Using Mixed Oxide (MOX) fuel in traditional Pressurized Water Reactor (PWR) assemblies has been researched at length and has shown to provide the benefit of transmutation and targets the amount and toxicity of high level waste needed to be managed. Advanced MOX concepts using enriched Uranium Dioxide (UO{sub 2}) are required for multiple recycling of plutonium. The use of MOX and ordinary UO{sub 2} fuel in the same assembly as well as unfueled rods and assembly edge effects contrasts with the unit cell computational assumption of a uniform infinite array of rods. While a deterministic method of calculating the Dancoff factor has traditionally been employed in fuel assembly analysis due to the lighter computational and modeling requirements, this research seeks to determine the validity of the uniform, infinite lattice assumption with respect to Dancoff factor and determine the magnitude of the impact of nonuniform lattice effects on fuel assembly criticality calculations as well as transuranic isotope production and transmutation. This research explored the pin-to-pin interaction in a non-uniform lattice of MOX fuel rods and UO{sub 2} fuel rods through the impact of the calculated Dancoff factors from the deterministic method used in SCALE versus the Monte Carlo method used inmore »

- Authors:

- United States Military Academy, West Point, New York 10996 (United States)
- University of South Carolina, Columbia, South Carolina 29208 (United States)

- Publication Date:

- Research Org.:
- WM Symposia, 1628 E. Southern Avenue, Suite 9-332, Tempe, AZ 85282 (United States)

- OSTI Identifier:
- 22293636

- Report Number(s):
- INIS-US-14-WM-12391

TRN: US14V1292115160

- Resource Type:
- Conference

- Resource Relation:
- Conference: WM2012: Waste Management 2012 conference on improving the future in waste management, Phoenix, AZ (United States), 26 Feb - 1 Mar 2012; Other Information: Country of input: France; 6 refs.

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; 21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; 12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; AMERICIUM 241; EIGENVALUES; ENRICHED URANIUM; FUEL ASSEMBLIES; FUEL RODS; HIGH-LEVEL RADIOACTIVE WASTES; INTERACTIONS; MIXED OXIDE FUELS; MONTE CARLO METHOD; PLUTONIUM 238; PLUTONIUM 239; PLUTONIUM 242; PWR TYPE REACTORS; SENSITIVITY; SPECTRA; TOXICITY; TRANSMUTATION; URANIUM 238; URANIUM DIOXIDE

### Citation Formats

```
Barbaras, Sean A., and Knight, Travis W.
```*Transuranic Transmutation and Criticality Calculation Sensitivity to Heterogeneous Lattice Effects - 12391*. United States: N. p., 2012.
Web.

```
Barbaras, Sean A., & Knight, Travis W.
```*Transuranic Transmutation and Criticality Calculation Sensitivity to Heterogeneous Lattice Effects - 12391*. United States.

```
Barbaras, Sean A., and Knight, Travis W. Sun .
"Transuranic Transmutation and Criticality Calculation Sensitivity to Heterogeneous Lattice Effects - 12391". United States.
```

```
@article{osti_22293636,
```

title = {Transuranic Transmutation and Criticality Calculation Sensitivity to Heterogeneous Lattice Effects - 12391},

author = {Barbaras, Sean A. and Knight, Travis W.},

abstractNote = {Using Mixed Oxide (MOX) fuel in traditional Pressurized Water Reactor (PWR) assemblies has been researched at length and has shown to provide the benefit of transmutation and targets the amount and toxicity of high level waste needed to be managed. Advanced MOX concepts using enriched Uranium Dioxide (UO{sub 2}) are required for multiple recycling of plutonium. The use of MOX and ordinary UO{sub 2} fuel in the same assembly as well as unfueled rods and assembly edge effects contrasts with the unit cell computational assumption of a uniform infinite array of rods. While a deterministic method of calculating the Dancoff factor has traditionally been employed in fuel assembly analysis due to the lighter computational and modeling requirements, this research seeks to determine the validity of the uniform, infinite lattice assumption with respect to Dancoff factor and determine the magnitude of the impact of nonuniform lattice effects on fuel assembly criticality calculations as well as transuranic isotope production and transmutation. This research explored the pin-to-pin interaction in a non-uniform lattice of MOX fuel rods and UO{sub 2} fuel rods through the impact of the calculated Dancoff factors from the deterministic method used in SCALE versus the Monte Carlo method used in the code DANCOFF-MC. Using the Monte Carlo method takes into account the non-uniform lattice effects of having neighboring fuel rods with different cross-sectional spectra whereas the Dancoff factor calculated by SCALE assumes a uniform, infinite lattice of one fuel rod type. Differences in eigenvalue calculations as a function of burnup are present between the two methods of Dancoff factor calculation. The percent difference is greatest at low burnup and then becomes smaller throughout the cycle. Differences in the transmutation rate of transuranic isotopes in the MOX fuel are also present between the Dancoff factor calculation methods. The largest difference is in Pu-239, Pu-242, and Am-241 composition whereas U-238, Pu-242, and Pu-238 composition was not changed by taking into account the non-homogenous lattice effects. Heterogeneous lattice effects do change the calculated eigenvalue and transmutation rate in a non-uniform lattice of MOX fuel rods and UO{sub 2} fuel. However, the uncertainty in the ENDF data used by SCALE in these calculations is large enough that the infinite lattice assumption remains valid. (authors)},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2012},

month = {7}

}