Radiochemical Assays of Irradiated VVER-440 Fuel for Use in Spent Fuel Burnup Credit Activities

The Effect of Fuel Burnup and Dispersed Water Intrusion on the Criticality of Spent High-Level Nuclear Fuel in a Geologic Repository

MRS Proceedings ◽

10.1557/proc-333-445 ◽

1993 ◽

Vol 333 ◽

Author(s):

William G. Culbreth ◽

Paige R. Zielinski

Keyword(s):

Fuel Burnup ◽

Spent Fuel ◽

Geologic Repository ◽

Chain Reaction ◽

Worst Case ◽

Mixture Ratio ◽

Waste Package ◽

Radiological Data ◽

A Chain ◽

High Level

ABSTRACTStudies of the spent fuel waste package have been conducted through the use of a Monte-Carlo neutron simulation program to determine the ability of the fuel to sustain a chain reaction. These studies have included fuel burnup and the effect of water mists on criticality. Results were compared with previous studies.In many criticality studies of spent fuel waste packages, fresh fuel with an enrichment as high as 4.5% is used as the conservative (worst) case. The actual spent fuel has a certain amount of “burnup” that decreases the concentration of fissile uranium and increases the amount of radionuclides present. The LWR Radiological Data Base from OCRWM has been used to determine the relative radionuclide ratios and KENO 5.a was used to calculate values of the effective multiplication factor, keff.1Spent fuel is not capable of sustaining a chain reaction unless a suitable moderator, such as water, is present. A completely flooded container has been treated as the worst case for criticality. Results of a previous report that demonstrated that keff actually peaked at a water-to-mixture ratio of 13% were analyzed for validity. In the present study, these results did not occur in the SCP waste package container.

Download Full-text

Validation of the Onsite Used Operational Code Against Burnup Measurement

Journal of Nuclear Engineering and Radiation Science ◽

10.1115/1.4034570 ◽

2016 ◽

Vol 3 (1) ◽

Author(s):

Michal Koleška ◽

Michal Šunka ◽

Jaroslav Ernest

Keyword(s):

Experimental Data ◽

Fission Product ◽

Research Reactor ◽

Fuel Burnup ◽

Spent Fuel ◽

Axial Distribution ◽

Operational Code ◽

Spectrometric System ◽

Type Fuel

A spectrometric system was developed for spent fuel burnup evaluations at the LVR-15 research reactor, which employed highly enriched (36%) IRT-2M-type fuel. Such a system allows the measurement of fission product axial distribution by measuring certain nuclides, such as Cs137, Cs134, and their ratios, respectively. Within the paper, a comparison between experimental data provided by the spectrometric system and calculations in operational code called NODER is provided.

Download Full-text

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.772.513 ◽

2013 ◽

Vol 772 ◽

pp. 513-518

Author(s):

Sidik Permana ◽

Novi Trian ◽

Abdul Waris ◽

Su'ud Zaki ◽

I. Mail ◽

...

Keyword(s):

Nuclear Fuel ◽

Decay Time ◽

Cooling Time ◽

Fuel Burnup ◽

Fuel Utilization ◽

Spent Fuel ◽

Nuclear Facilities ◽

Fuel Production ◽

Plutonium Isotopes ◽

Plutonium Production

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.

Download Full-text