An investigation towards real time dose rate monitoring, and fuel rod detection in a First Generation Magnox Storage Pond (FGMSP)

Characterization of Multiple Hindered Settling Regimes in Aggregated Mineral Suspensions

“…Substantial volumes of Mg(OH) 2 rich intermediate level radioactive waste, called corroded magnox sludge (CMS), have accumulated in legacy ponds at the Sellafield nuclear decommissioning site in Cumbria, UK 35,36 . The time-line and expense of decommissioning ageing nuclear legacy buildings is highly dependent on the dewatering behaviour of Mg(OH) 2 rich suspensions, but any such spent nuclear fuel derivatives would require remote handling in a shielded hot cell for analysis.…”

Radiation Tolerance of Pseudanabaena catenata, a Cyanobacterium Relevant to the First Generation Magnox Storage Pond

“…The cultures were exposed to daily doses of ionizing radiation using a Faxitron CP-160 Cabinet X-radiator (160 kV; 6 mA; tungsten target). The FGMSP has a reported dose of 5.65 Gy h −1 associated with the sludge, and 0.15 mGy h −1 associated with the pond water (Jackson et al, 2014). A dose of 1 Gy min −1 for 19 min per day was administered to the cultures over five consecutive days to give a total dose of 95 Gy.…”

“…The early Magnox gas cooled reactors form a significant part of the UK's legacy nuclear fleet. The fuel rods used in these reactors were clad in a magnesium non-oxide (Magnox) alloy (Jensen and Nønbel, 1999;Gregson et al, 2011a,b;Jackson et al, 2014). Spent fuel rods containing this cladding have been stored in open air legacy storage ponds, including the First Generation Magnox Storage Pond (FGMSP) situated on the Sellafield site (Cumbria, United Kingdom), since the late 1950s (Jackson et al, 2014).…”

“…The fuel rods used in these reactors were clad in a magnesium non-oxide (Magnox) alloy (Jensen and Nønbel, 1999;Gregson et al, 2011a,b;Jackson et al, 2014). Spent fuel rods containing this cladding have been stored in open air legacy storage ponds, including the First Generation Magnox Storage Pond (FGMSP) situated on the Sellafield site (Cumbria, United Kingdom), since the late 1950s (Jackson et al, 2014). Within the FGMSP, fuel storage times have been longer than anticipated and the spent fuel has been subject to extensive corrosion due to the Magnox cladding and the uranium metallic fuel having limited chemical stability in water.…”

“…This extended storage has led to the formation of a high hazard radioactive environment with corroded spent nuclear fuel, pond effluent (NDA, 2016;Foster et al, 2020) and sludge (NDA, 2016). In order to provide thermal cooling and minimize further corrosion of the fuel rods and the growth of microorganisms, the pond is continuously purged with alkaline dosed demineralized water (pH ∼11.4) (Gregson et al, 2011a,b;Jackson et al, 2014). However, there is clear visible evidence for the presence of microorganisms in the pond, including events reported as "algal blooms", which are most prominent when the purge cycling is not active (Gregson et al, 2011a,b;Konovalovaite, 2019;Foster et al, 2020).…”