Are spent fuel rods radioactive and are the spent fuel rods cooling pools discharging radioactive water (tritium) into the environment?
Sure.Are spent fuel rods radioactive
There is nearly no tritium in the spent fuel pools, and the water is not getting into the environment unless there is an accident. There is no chain reaction happening in the spent fuel pool so the neutron flux is small. Traces of tritium can come from the fuel rods.and are the spent fuel rods cooling pools discharging radioactive water (tritium) into the environment?
Yes. Spent or used fuel contains the unused fuel, the fission products (2 atoms per fission), and the transmuted fuel and non-fuel components. In the early years of commercial nuclear energy, the fuel was discharge with burnups (GWD/tU) of about 25-33 GWd/tU, or roughly 2.5-3.3% FIMA (fissioned initial metal (U) atoms). In modern times, discharge burnups are at least 2x greater, with batch burnups being something like 50-60 GWd/tU (or 5 to 6% FIMA). Since there are regulatory/statutory limits on peak rod burnup, or peak pellet burnup, the actual discharge burnup is slightly less, although technically, the fuel could continue to higher burnups. Within a batch of fuel, there is a relatively broad range of burnup due to the axial and radial gradients in the core/fuel, with the most severe gradients being on the periphery of the core (typically one row in from the outermost assemblies and the corner assemblies in a PWR). The BWR situation is more complicated because control elements, which are inserted part-time in the core during operation for reactivity control, cause local radial and axial gradients in the fuel closest to the control elements (control blades).Are spent fuel rods radioactive
In the early days of the industry, before wide of Zr alloys (Zircaloy-2 (in BWRs) and Zircaloy-4 (in PWRs)), cladding was often made of 304, 347 and 348 stainless steel. Tritium from fission would leak out of the fuel rods into the coolant, and into the spent fuel pool following discharge. Some older plants have had issues with tritium in ground water onsite. Since tritium decays over time (half life ~12.3 years), a lot of the tritium from 50-60 years ago has decayed, and otherwise at very low levels, generally less than regulatory limits.are the spent fuel rods cooling pools discharging radioactive water (tritium) into the environment?
I provided the context of LWR (both PWR/VVER and BWR), since that is the greatest volume of spent fuel in the US and Eu, but that could apply to CANDU. AGR and Magnox fuel is similar, but different, and of course there are fast reactor fuels and research reactor fuels."Spent fuel rods" from exactly what kind of reactor? See https://en.citizendium.org/wiki/Nuclear_power_reconsidered for some of the options. A discussion without knowing exactly what reactor is kind of, well, makes me wonder.