Irradiation and Cooling Process Effects on Material Barrier Analysis Based on Plutonium Composition of LWR

2013 ◽  
Vol 772 ◽  
pp. 513-518
Author(s):  
Sidik Permana ◽  
Novi Trian ◽  
Abdul Waris ◽  
Su'ud Zaki ◽  
I. Mail ◽  
...  

Nuclear fuel utilization program from front-end up to back-end processes especially spent fuel management have been monitored and safeguarded by the IAEA in order to ensure the utilization of nuclear fuels from all nuclear facilities including nuclear fuel reprocessing facilities are dedicated only for civil and peaceful purposes. Nuclear fuel production processes including reactor criticality condition is one of the major topics in term of nuclear fuel sustainability which related to energy security issues. Meanwhile, reduction level or preventing processes of nuclear fuel utilization from its potential risk from nuclear explosive purposes should be also strengthened and prioritized. To increase the intrinsic proliferation resistance of nuclear fuel, one of the potential ways is by increasing the material barrier level such as isotopic barrier. In case of plutonium, increasing the intrinsic properties of plutonium isotopes can be used by increasing material barrier of even mass number (Pu-238, Pu-240 and Pu-242). In this study, the effect of different irradiation process during reactor operation which related to discharged fuel burnup have been used and decay time to analyzed its dependeny to plutonium production as well as plutonium production dependency to decay or cooling time processes. Fuel production analysis of the reactor are based on the spent fuel of light water reactor (LWR) with different discharged fuel burnup (33 GWd/t, 50 GWd/t and 60 GWd/t) and different decay or cooling time process (1 to 30 years cooling time). Fuel behavior optimization of LWR design are obtained by using ORIGEN code by employing some modules for analyzing fuel production dependencies to burnup and decay time processes. In this study, two parameters for investigating the material barriers are adopted such as decay heat (DH) and spontaneous fission neutron (SFN) compositions. The compositions of DH and SFN are sensitive to the composition of isotopic plutonium especially more sensitive to even mass plutonium composition. Higher discharged fuel burnup level produces more even mass plutonium compositions and effectively reduce Pu-239 production because of more fissile Pu-239 are consumed for higher burnup. Isotopic Pu-238 gives the highest DH contributor, while Isotope Pu-240 obtains the highest contribution of SFN followed by other plutonium isotopes. DH and SFN compositions of plutonium can be increased effectively by increasing burnup process. Longer decay time is also effective to increase SFN compositions because of its dependency to all even mass plutonium while it gives less DH compositions because of its dependency to the contribution of Pu-238.

Author(s):  
G. S. You ◽  
W. M. Choung ◽  
J. H. Ku ◽  
S. I. Moon ◽  
H. D. Kim

The Korea Atomic Energy Research Institute (KAERI) has been developing pyroprocess for the dry conditioning of PWR spent nuclear fuels since 1997. The ACPF (Advanced spent fuel Conditioning Process Facility) was developed for volume reduction research on spent PWR fuel. Several years later, the PRIDE (PyRoprocess Integrated inactive Demonstration) facility was also developed for SFR fuel utilization research by pyroprocessing. An integrated full pyroprocess was used in the PRIDE facility. Presently another pyroprocess facility, ESPF (Engineering Scale Pyroprocess Demonstration Facility), is being conceptually designed for the future demonstration of an engineering-scale pyroprocess.


2006 ◽  
Vol 985 ◽  
Author(s):  
Jeffrey A. Fortner ◽  
A. Jeremy Kropf ◽  
James L. Jerden ◽  
James C. Cunnane

AbstractPerformance assessment models of the U. S. repository at Yucca Mountain, Nevada suggest that neptunium from spent nuclear fuel is a potentially important dose contributor. A scientific understanding of how the UO2 matrix of spent nuclear fuel impacts the oxidative dissolution and reductive precipitation of Np is needed to predict the behavior of Np at the fuel surface during aqueous corrosion. Neptunium would most likely be transported as aqueous Np(V) species, but for this to occur it must first be oxidized from the Np(IV) state found within the parent spent nuclear fuel. In this paper we present synchrotron x-ray absorption spectroscopy and microscopy findings that illuminate the resultant local chemistry of neptunium and plutonium within uranium oxide spent nuclear fuel before and after corrosive alteration in an air-saturated aqueous environment. We find the Pu and Np in unaltered spent fuel to have a +4 oxidation state and an environment consistent with solid-solution in the UO2 matrix. During corrosion in an air-saturated aqueous environment, the uranium matrix is converted to uranyl (UO22+) mineral assemblage that is depleted in Np and Pu relative to the parent fuel. The transition from U(IV) in the fuel to a fully U(VI) character across the corrosion front is not sharp, but occurs over a transition zone of ∼ 50 micrometers. We find evidence of a thin (∼ 20 micrometer) layer that is enriched in Pu and Np within a predominantly U(IV) environment on the fuel side of the transition zone. These experimental observations are consistent with available data for the standard reduction potentials for NpO2+/Np4+ and UO22+/U4+ couples, which indicate that Np(IV) may not be effectively oxidized to Np(V) at the corrosion potential of uranium dioxide spent nuclear fuel in air-saturated aqueous solutions.


MRS Advances ◽  
2018 ◽  
Vol 3 (19) ◽  
pp. 991-1003 ◽  
Author(s):  
Evaristo J. Bonano ◽  
Elena A. Kalinina ◽  
Peter N. Swift

ABSTRACTCurrent practice for commercial spent nuclear fuel management in the United States of America (US) includes storage of spent fuel in both pools and dry storage cask systems at nuclear power plants. Most storage pools are filled to their operational capacity, and management of the approximately 2,200 metric tons of spent fuel newly discharged each year requires transferring older and cooler fuel from pools into dry storage. In the absence of a repository that can accept spent fuel for permanent disposal, projections indicate that the US will have approximately 134,000 metric tons of spent fuel in dry storage by mid-century when the last plants in the current reactor fleet are decommissioned. Current designs for storage systems rely on large dual-purpose (storage and transportation) canisters that are not optimized for disposal. Various options exist in the US for improving integration of management practices across the entire back end of the nuclear fuel cycle.


Author(s):  
A. Fenenko

During the last twenty years Washington has used the “counter-proliferation strategy” in Korean Peninsula. The Americans demanded that North Korea eliminate its nuclear arsenals and plutonium production facilities under the watchful eye of the “five powers’ commission” or the IAEA. Pyongyang's recent military provocation may now raise the specter of the United States or even South Korea delivering non-nuclear strikes against its nuclear facilities. That would give the USA an opportunity to raise the question of whether certain regimes should be allowed to acquire nuclear weapons or even to develop nuclear fuel cycle capacity. The last crises demonstrated that under certain circumstances North Korea could also initiate a military conflict in East Asia.


2018 ◽  
Vol 20 (2) ◽  
pp. 69 ◽  
Author(s):  
Ihda Husnayani ◽  
Pande Made Udiyani

Reaktor Daya Eksperimental (RDE) is a 10 MWth pebble-bed High Temperature Gas-cooled Reactor that is planned to be constructed by National Nuclear Energy Agency of Indonesia (BATAN) in Puspiptek complex, Tangerang Selatan. RDE utilizes low enriched UO2 fuel coated by TRISO layers and loaded into the core by means of multipass loading scheme. Determination of radionuclide characteristics of RDE spent fuel; such as activity, thermal power, neutron and photon release rates; are very important because those characteristics are crucial to be used as a base for evaluating the safety of spent fuel handling system and storage tank. This study is aimed to investigate the radionuclide characteristics of RDE spent fuel at the end of cycle and during the first 5 years cooling time in spent fuel storage. The method used to investigate the radionuclide characteristics is burnup calculation using ORIGEN2.1 code. In performing the ORIGEN2.1 calculation, one pebble fuel was assumed to be irradiated in the core for 5 cycles and then decayed for 5 years. At the end of the fifth cycle, it is obtained that the total activity, thermal power, neutron production, and photon release rates from all radionuclides inside one spent fuel are approximately 105.68 curies, 0.41 watts, 2.65 x 103 neutrons/second, and 1.79 x 104 photons/second, respectively. The results for the radionuclides characteristics during the first 5 years cooling time in the spent fuel storage show that the radioactivity characteristics from all radionuclides are rapidly decreasing at the first year and then slowly decreasing at the second until the fifth year of cooling time. The results obtained in this study can provide data for safety evaluation of fuel handling and spent fuel storage, such as the calculation of sourceterm, radiation dose rate, and the determination of radiation shielding.Keywords: RDE, spent fuel, radionuclide activity, thermal power, neutron production, photon releaserates KARAKTERISTIK RADIONUKLIDA DI DALAM BAHAN BAKAR RDE. Reaktor Daya Eksperimental (RDE) adalah reaktor tipe Reaktor Temperatur Tinggi Berpendingin Gas dengan daya termal 10MW yang akan dibangun oleh BadanTenagaNuklirNasional (BATAN) di kawasanPuspiptek, Tangerang Selatan. RDE menggunakan bahan bakar UO2 yang dilapisi dengan lapisan TRISO dan dimasukkan ke dalam teras RDE menurut skema multipass (5 siklus). Penentuan karakteristik radionuklida di dalam bahan bakar RDE; seperti aktivitas, daya termal, laju produksi neutron dan pelepasan foton; adalah sangat penting karena informasi karakteristik ini diperlukan sebagai dasar untuk melakukan evaluasi keselamatan system penanganan dan penyimpanan bahan bakar bekas. Penelitian ini bertujuan untuk menganalisis karakteristik radionuklida bahanbakar RDE setelah 5 siklus dan pada 5 tahun pertama pendinginan ditempat penyimpanan bahan bakar bekas. Metode yang digunakan dalam menghitung karakteristik radionuklida adalah menggunakan program ORIGEN2.1. Satu bola bahan bakar RDE diasumsikan diiradiasi selama 5 siklus dan kemudian meluruh selama 5 tahun. Pada akhir siklus, diperoleh hasil aktivitas total, daya termal, laju produksi neutron dan pelepasan foton dari seluruh radionuklida di dalam satu bola bahan bakar RDE sebesar 105,68 curies, 0,41 watts, 2,65 x 103 neutron/detik, dan 1,79 x 104 foton/detik. Hasil untuk karakteristik radionuklida selama 5 tahun penyimpanan menunjukkan bahwa karakteristik radioktivitas radionuklida menurun dengan cepat pada tahun pertama dan kemudian menurun lebih lambat pada tahun kedua hingga tahun kelima. Hasil perhitungan karakteristik radionuklida dari penelitian ini dapat digunakan sebagai basis untuk analisis keselamatan penanganan dan penyimpanan bahan bakarbekas RDE.Kata kunci:RDE, bahan bakar bekas, aktivitas radionuklida, daya termal, produksi neutron, laju foton


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