Thermal-spectrum reactors

The international group has identified six Generation rV reactor systems for development. All of these reactors should be ready for deployment by 2030. The fast neutron spectrum reactors can use the fuel values of all of the fissile and fertile transuranic isotopes in reprocessed fuel. This does not occur in the current thermal spectrum reactors. Producing energy... 

Gas cooling was originally chosen for thermal-spectrum reactors because it provided a means of removing heat from a reactor core without... 

Water cooled thermal-spectrum reactors for electricity production with optional desalination or heating bottoming cycles, including ... 

One of the concepts, the water cooled ELENA (1), is being designed for district heating as its primary function. Another two concepts, the water cooled UNITHERM (2) and the sodium cooled RAPID (3), are being designed for a variety of applications, including cogeneration options with potable water and/or district heat production. All three concepts are sized for remotely sited towns of several tens to one hundred thousand populations two are water cooled thermal spectrum reactors, one is a sodium cooled fast spectrum reactor. Their characteristics are summarized in Table 3. 

Generically, these eould be fast reactors with multiple recycle of all transuranics in the uranium fuel cycle as well as high conversion thermal spectrum reactors with multiple recycle of in the thorium fuel cycle. 

Reloads for thermal-spectrum reactors (that are net consumers of fissile mass) plus... 

The two primary removal mechanisms for fissile plutonium ( Pu and 2 Pu) are fission and radiative capture. Net fissile destruction rates are shown in Figure A-9 for irradiations in the five reactor spectra. At low exposure, the net fissile rates are somewhat higher in thermal spectrum reactors. At exposures in excess of about 650 GWD/MT, higher fissile destruction rates are achieved in fast (LMR) or epithermal (HTGR) spectrum reactors. 

Figure A-11 illustrates the growth in parasitic absorber plutonium isotopes with exposure in the five reactor spectra. The three thermal spectrum reactor types (BWR, CANDU, and PWR) all achieve about 20% parasitic absorber fraction at an exposure of about 300 GWD/MT. The epithermal spectrum HTGR achieves a 20% parasitic absorber fraction at an exposure of about 450 GWD/MT. The fast spectrum LMR achieves 20% parasitic absorber fraction at an exposure of about 475 GWD/MT.

Y. Okano, S. Koshizuka and Y. Oka, Direct-Cycle, Supercritical-Pressure, Light-Water-Cooled Thermal Spectrum Reactor with Double Tube Water Rods, Proc. PHYSOR 96, Vol. 2, 11-20 (1996)... 

The plant dynamics of the Super LWR were understood by plant transient analyses. Although the Super LWR is a thermal spectrum reactor, the reactor power is not very sensitive to the flow rate because the water rods with large volume fraction mitigate fluctuation of the average water density. Based on the plant transient analyses and also referring to LWRs and FPPs, the plant control system of the Super LWR was designed and tuned. Finally, the adequacy of the control system was assessed by plant stability analyses. 

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