Neutron Balance Analysis for Sustainability of Breed-and-Burn Reactors

Heidet, Florent; Greenspan, E.

doi:10.13182/nse10-114

Cited by 30 publications

(34 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was initially developed to estimate the minimum burnup required to establish the breed-and-burn mode and the maximum attainable burnup before ∞ k drops below unity (Heidet and Greenspan, 2012). In this study, the neutron balance analysis provides a fair comparison of the neutronic performance expected from the various blanket fuel options.…”

Section: Neutron Balancementioning

confidence: 99%

“…In this study, the neutron balance analysis provides a fair comparison of the neutronic performance expected from the various blanket fuel options. This comparison is based on a simple model represented by a 0-D fully homogenized unit cell with reflective boundary conditions (Heidet and Greenspan, 2012). The volume fraction occupied by fuel, gap, cladding, and coolant is assumed to be 37.5%, 12.5%, 22.0%, and 28.0%, respectively.…”

Section: Neutron Balancementioning

confidence: 99%

“…The minimum average burnup required for sustaining the B&B mode of operation is close to 20% Fissions per Initial Metal Atom (FIMA). This corresponds to a peak radiation damage on the cladding of ∼500 Displacements per Atom (DPA) (Hou et al, 2016;Heidet and Greenspan, 2012). However, the maximum radiation damage that cladding materials have been exposed to so far in a fast reactor is ∼200 DPA.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Improved resource utilization by advanced burner reactors with breed-and-burn blankets

Zhang

Fratoni

Greenspan

2018

Progress in Nuclear Energy

Self Cite

View full text Add to dashboard Cite

A B S T R A C TPrevious studies assessed the feasibility of designing Sodium-cooled Fast Reactors (SFR) in a novel Seed-andBlanket (S&B) configuration in which a significant fraction of the core power is generated by a radial metallic thorium-fueled blanket that operates in the Breed-and-Burn (B&B) mode. The radiation damage on the cladding material in both seed and blanket does not exceed the presently acceptable constraint of 200 Displacements per Atom (DPA). This paper investigates a number of blanket fuel options other than metallic thorium fuel, including thorium dioxide fuel, thorium hydride fuel, thorium nitride Fully Ceramic Encapsulated (FCM) fuel, and Pressurized Water Reactor (PWR) Used Nuclear Fuel (UNF) after limited reprocessing. Since the neutron spectrum of the oxide fueled blanket is softer than that of the reference metallic thorium fueled blanket, it can discharge its fuel at an average burnup of around 110 MWd/kg versus 65 MWd/kg of the metallic thorium. The two thorium hydride fueled blankets feature an even softer neutron spectrum than the oxide fueled blanket and, therefore, a higher average discharge burnup -192 MWd/kg and 245 MWd/kg when the H-to-Th ratio is, respectively, 0.5 and 2.0. The FCM fuel is composed of SiC matrix and cladding that is expected to self-anneal the neutrons induced damage. With the assumption that the FCM fuel will indeed be proven not limited by radiation damage, its discharge burnup could be up to 482 MWd/kg. As a result, the corresponding thorium utilization is the highest of all options examined -close to 80 times the utilization of natural uranium in present Light Water Reactors (LWRs). The amount of Trans-Th isotopes accumulated in the thorium blanket per unit of generated electricity decreases as the blanket fuel is discharged at a higher burnup. Therefore, a higher discharge blanket burnup results in lower long-term radioactivity and radiotoxicity. It is also found that the 232 U/ 233 U ratio in the discharged thorium fuel is over 3 times higher in the thorium hydride than in the other blankets thus improving the thorium-hydride blanket's proliferation resistance. Softening of the blanket spectrum leads to softening of the seed spectrum region interfacing with the blanket and this enables to discharge the seed fuel at a higher average burnup. The higher discharge burnup of the seed fuel reduces the required reprocessing and fuel fabrication capacities per unit of generated electricity. The cores having softer neutron spectrum blankets also feature less positive feedback to sodium voiding and much more negative Doppler coefficient. When PWR UNF is used after limited reprocessing to fuel the blanket, the subcritical blanket driven by the excess neutrons from the seed can discharge this fuel at an average burnup of ∼120 MWd/kg. Combined with the burnup in the first stage PWRs, this two-stage energy system can achieve an accumulated uranium burnup of ∼170 MWd/kg. This increases the fuel utilization of natural uranium by a factor of three relative to oncethroug...

show abstract

Section: Neutron Balancementioning

confidence: 99%

Section: Neutron Balancementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Improved resource utilization by advanced burner reactors with breed-and-burn blankets

Zhang

Fratoni

Greenspan

2018

Progress in Nuclear Energy

Self Cite

View full text Add to dashboard Cite

show abstract

“…This scenario was developed because the core performance characteristics of the breed-andburn operation with thorium-based fuel were impractical [16,17]. In this study, the TRU recovered from the Pressurized Water Reactor (PWR) used nuclear fuel with a discharge burnup of 50 GWd/t was considered as fissile material and the TRU vector used is provided in Table 3.1.…”

Section: Fuel Conversion Scenariosmentioning

confidence: 99%

Feasibility study on AFR-100 fuel conversion from uranium-based fuel to thorium-based fuel

Heidet¹,

Kim²,

Grandy³

2012

View full text Add to dashboard Cite

show abstract

“…6 However, in order to sustain the B&B mode of operation, it is necessary to fission at least~20% of the initial depleted uranium feed. 7 An average burnup of 20% fissions per initial metal atom (FIMA) corresponds to a peak discharge burnup of up to 30% FIMA and the peak radiation damage on the cladding material in the vicinity of 500 displacements per atom 8,9 (dpa). The maximum neutroninduced radiation damage to which cladding and structural materials have been exposed at the Fast Flux Test Facility (FFTF) so far is approximately 200 dpa (Ref.…”

Section: Introductionmentioning

confidence: 99%

Advanced Burner Reactors with Breed-and-Burn Thorium Blankets for Improved Economics and Resource Utilization

2017

Self Cite

View full text Add to dashboard Cite

-This paper assesses the feasibility of designing seed-and-blanket (S&B) sodium-cooled fast reactor (SFR) cores to generate a significant fraction of the core power from radial thorium-fueled blankets that operate in the breed-and-burn (B&B) mode. The radiation damage on the cladding material in both seed and blanket does not exceed the presently acceptable constraint of 200 displacements per atom (dpa). The S&B core is designed to have an elongated seed (or driver) to maximize the fraction of neutrons that radially leak into the subcritical B&B blanket and reduce the neutron loss via axial leakage. A specific objective of this study is to maximize the fraction of core power generated by the B&B blanket that is proportional to the neutron leakage rate from the seed to the blanket. Since the blanket feed fuel is very inexpensive and requires no reprocessing and remote fuel fabrication, a larger fraction of power from the blanket will result in a lower fuel cycle cost per unit of electricity generated by the SFR core. It is found possible to design the seed of the S&B core to have a lower transuranics (TRU) conversion ratio (CR) than a conventional advanced burner reactor (ABR) core without deteriorating core safety. This is due to the unique synergism between a low CR seed and the B&B thorium blanket. The benefits of the synergism are maximized when using an annular seed surrounded by inner and outer thorium blankets. Two high-performance S&B cores are designed to benefit from the annular seed concept: (1) an ultra-long-cycle core having a CR = 0.5 seed and a cycle length of~7 effective full-power years (EFPYs) and (2) a high-transmutation core having a TRU CR of 0.0. The TRU transmutation rate of the latter core is comparable to that of the reference ABR with a CR of 0.5, and the thorium blanket can generate close to 60% of the core power. Because of the high blanket power fraction along with the high discharge burnup of the CR = 0 seed, the reprocessing capacity per unit of core power required by this S&B core is only approximately 1/6th that of the reference ABR core with a TRU CR of 0.5. Although the seed fuel CR is nearly zero, the burnup reactivity swing is low enough to enable a cycle length of more than 4 EFPYs. This is attributed to a combination of reactivity gain in the thorium blankets over the cycle and the relatively high heavy metal inventory. Moreover, despite the very low leakage, the S&B cores feature a less positive coolant reactivity coefficient and large enough negative Doppler coefficient even when using nonfertile fuel for the seed, because of the unique physics properties of the 233 U and Th in the thorium blankets. With the long cycles, the S&B SFR is expected to have a higher capacity factor, and therefore a lower cost of electricity, than conventional ABRs. The discharge burnup of the thorium blanket fuel is typically 70 MWd/kg such that the thorium fuel utilization is approximately 12 times that of natural uranium in light water reactors. A sensitivity study is subsequently un...

show abstract

Neutron Balance Analysis for Sustainability of Breed-and-Burn Reactors

Cited by 30 publications

References 7 publications

Improved resource utilization by advanced burner reactors with breed-and-burn blankets

Improved resource utilization by advanced burner reactors with breed-and-burn blankets

Feasibility study on AFR-100 fuel conversion from uranium-based fuel to thorium-based fuel

Advanced Burner Reactors with Breed-and-Burn Thorium Blankets for Improved Economics and Resource Utilization

Contact Info

Product

Resources

About