Pressurized water reactors spent fuel

Chadwick PH, Mcgowan IR (1972) Determination of plutonium and uranium in mixed oxide fuels by sequential redox titration. Talanta 19 1335 Charlton SW, Stanbro WD (2001) Monitors for the prediction of alternate nuclear material concentrations for pressurized water reactor spent fuel. Nucl Technol 136(l) 24-36... 

Table 1. Chemical compositions (ivr%) of low-pressured water reactor (LWR) spent fuel and uraninite from Oldo reactors 10. 16 and Cigar Luke...

Nuclear power plants in the United States use light water moderated nuclear reactors (LWR) that produce the steam to generate electricity. The fuel elements for boiling water reactors and pressurized water reactors (PWR) are nearly the same. The fuel is uranium dioxide enriched with 3 % and this produces a nearly uniform spent fuel, which would be the feed for domestic fuel reprocessing. 

Figure 13.18 Water-dilution volumes for radionuclides in spent fuel discharged from a l-GW(f>) pressurized-water reactor as a function of decay time. After J. Choi and H.

Figure 13.19 Water-dilution volumes for radionuclides in spent-fuel reprocessing wastes formed by operating a l-GW( -) pressurized-water reactor for one year, plotted as a function of decay time. After J. Choi and H. Pigford, Water dilution volumes for high-level wastes, ANS Transactions 39, p. 176. Copyright 1981 by the American Nuclear Society,...

The requirements of ANSI/ANS 8.1 specify that calculational methods for away-from-reactor criticality safety analyses be validated against experimental measurements. If credit is to be taken for the reduced reactivity of burned or spent fuel relative to its original fresh composition, it is necessary to benchmark computational methods used in determining such reactivity worth against spent fuel reactivity measurements. This report summarizes a portion of the ongoing effort to benchmark away-from-reactor criticality analysis methods using critical configurations from commercial pressurized- water reactors (PWR). 

Abstract The chapter is devoted to the practical application of the fission process, mainly in nuclear reactors. After a historical discussion covering the natural reactors at Oklo and the first attempts to build artificial reactors, the fimdamental principles of chain reactions are discussed. In this context chain reactions with fast and thermal neutrons are covered as well as the process of neutron moderation. Criticality concepts (fission factor 77, criticality factor k) are discussed as well as reactor kinetics and the role of delayed neutrons. Examples of specific nuclear reactor types are presented briefly research reactors (TRIGA and ILL High Flux Reactor), and some reactor types used to drive nuclear power stations (pressurized water reactor [PWR], boiling water reactor [BWR], Reaktor Bolshoi Moshchnosti Kanalny [RBMK], fast breeder reactor [FBR]). The new concept of the accelerator-driven systems (ADS) is presented. The principle of fission weapons is outlined. Finally, the nuclear fuel cycle is briefly covered from mining, chemical isolation of the fuel and preparation of the fuel elements to reprocessing the spent fuel and conditioning for deposit in a final repository. 

The relative amounts of the various actinide nuclides in spent fuel as a function of time after discharge from a pressurized water reactor (PWR) are shown in O Fig. 61.27... 

The nuclidic and elemental composition of spent fuel will vary depending on the history of operation of the reactor and the extent of fuel bumup where burnup is usually expressed in terms of megawatt-days per metric ton (MW d/t). As a result, the radionuclide content of spent fuel from thermal reactors can vary in composition not only from reactor type to reactor type (pressurized water reactor, boiling water reactor, high-temperature gas reactor, etc.) but also... 

Choi, Fl.B., B.W. Rhee, and Fl.S. Park. 1997. Physics Study on Direct Use of Spent Pressurized Water Reactor Fuel in CANDU (DUPIC). Nuclear Sceince and Engineering 126, 80-93. 

For serial plants with the BN GT-300 on Russian sites, MOX fuel recycled from pressurized water reactor (PWR or WER) or RBMK spent fuel could be used. 

The plutonium from pressurized water reactor (PWR) spent fuel after 25 years of cooling is used as a make-up fuel for the SPINNOR/VSPINNOR. The consideration is that, if PWR spent fuel is used without cooling, then it contains a relatively high portion of " Pu, which decays to If the reactors are designed for the use of plutonium from PWR spent fuel... 

The reference fuel for the pressure-tube type of SCWR is a mix of thorium and plutonium (which is extracted from the spent light water reactor (LWR) fuel). On average, the weight percentage of plutonium is 13% in the fuel (Wojtazek, 2015). With the high neutron economy of the heavy water moderator, other fuel mixes can also be accommodated. Studies have demonstrated the feasibility of using low enriched uranium (LEU) of 7% (Yetisir et al., 2012) a mix of LEU at 7.5% with Th a mix of transuranics at 21 wt% with Th (Winkel et al., 2013) or a mix of Pu at 8%, Th, and U (at 2 wt%) extracted from the SCWR fuel (Magill et al., 2011). 

Reactivity changes and plutonium isotopic compositions were first examined for a commercial pressurized water reactor (PWR) operating on a low enrichment (3.2 wt% equilibrium fuel cycle. The results aided in understanding the significance of a number of approximations made in this assessment. The results also provided some perspective on the plutonium composition in spent conunercial reactor fuels. 

The most efficient matrix for retention of actinides and fission products is the uraninite mineral. However, it has been shown that other matricies such as apatite, clay minerals, zirconium silicates, and oxides (Fe, Mn) may also be important in the retention of fission products and actinides. For example, Pu was stored in apatite (Bros et al. 1996) and chlorite (Bros et al. 1993) in the core of the reactor 10. In the core of the reactors, between uraninite grains, 20-200 (j.m-sized metallic aggregates containing fissiogenic Ru, Rh, and Te associated with As, Pb, and S were found. These aggregates also exist in spent fuels of water-pressured type reactor plants, suggesting their analogy with spent fuels. 

The baseline process, including the pressure sintering step, was demonstrated with both simulated high level waste and under hot cell conditions using a waste solution prepared from typical spent light water reactor fuel. A batch contacting method using sodium titanate was also evaluated, but the overall decontamination factor was much lower than obtained in the column process. 

Krypton and xenon removal. The number of curies of krypton and xenon per megagram (metric ton) of spent fuel from pressurized-water, liquid-metal fast-breeder, and high-temperature gas-cooled reactors from Tables 8.7, 8.8, and 8.9 are listed in Table 10.5, together with the number of standard liters per megagram, assuming atomic weights of 85 and 133 for krypton and xenon. 

The composition of boron carbide is approximately 80 atomic percent boron. The material is often considered as a source of boron, without the high reactivity of the latter. Like boron, B4C has a high neutron capture cross-section for thermal neutrons and a low secondary gamma radiation. As such, it provides an excellent neutron absorber and is used extensively to control the neutron flux in nuclear fission reactors, such as the boiling water, pressurized water, and fast breeding reactors. It is also used for the compact storage of spent fuel rods.l l... 

I) Concrete containment 2) Containment steel shell 3) Polar crane 4) Reactor pressure vessel S) Control rod drive mechanism 6) Spent fuel pool 7) Refuelling machine 8) Steam generator 9) Pressurizer 10) Pressurizer relief tank 11) Main coolant pump 12) Main steam line 13) Feedwater line 14) Concrete shield IS) Accumulator 16) Personnel lock 17) Mate rials lock 18) Lifting gantry 19) Fresh fuel assembly storage 20) Borated water storage tank 21) Residual heat cooler 22) Component cooler 23) Safety injection pump (By courtesy of Siemens/KWU)... 

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