R. Periäfiez et al. 
Environmental Modelling and Software 122 (2019) 104523 
"able 4 
°ransport models linked with hydrodynamic models. Transport of radionuclides only in solute is denoted by S, in suspended sediments by SS and in bottom sediments by BS. 
Dimensions Density Sediment Ice Radionuclide Radionuclide 
stratification transport transport phases transport mode 
Eulerian 
Eulerian 
Eulerian 
Eulerian 
Eulerian 
Eulerian 
Eulerian 
Eulerian 
Eulerian 
Lagrangian 
Lagrangian 
Eulerian 
Eulerian 
Eulerian 
Prandle (1984) 
mishi and Trent (1992) 
Abril and Garcia-Leön (1993) 
Harms (1997) 
Margvelashvily et al. (1997) 
Zheleznyak et al. (1992) 
Koziy et al. (1998) 
Aldridge (1998) 
Derjäfiez (1999) 
<obayashi et al. (2007) 
Choi et al. (2013) 
Misumi et al. (2014) 
Higashi et al. (2015) 
Maderich et al. (2017) 
Table 5 
Stand-alone transport models, Transport of radionuclides only in solute is denoted by 5, in suspended sediments by SS and in bottom sediments by BS. 
Dimension Hydrodynamics Time Sediment Radionuclide Transfer to 
averaging transport transport biota 
Tidal model Tidal No Ss No 
Tidal model 1 year No S-SS-BS No 
Mike21 1 year Yes S-SS-BS No 
Mike21 1 year Yes 5-SS-BS Yes 
MRICOM 1 month Yes 5-55 No 
Diagnostic 1 year Yer 85 Ver 
Breton and Salomon (1995) 
"yons et al. (1998)/CUMBRIA 
Goshawk et al. (2003)/MEAD 
Gleizon and McDonald (2010)/MARISA 
Vakano et al. (2010) 
Nakano and Povinec (2012)/LAMER 
Table 6 
30x models. CR is a concentration factor. 
Number of Daughter Transfer to Dose 
. boxes products biota assessment 
MARINA I 14 No CR sea food ingestion 
CEC (1990) sea sprays, sediments 
A HH 
MARINA II 72 No CR sea food ingestion 
EC (2002) sea sprays, sediments 
A 
NRPA 129 No CR sea food ingestion 
‘osjpe et al. (2002) sea sprays, sediments 
EEE - vb A a ————— 
PC-CREAM-08 55 No CR sea food ingestion 
Smith and Simmonds (2009) inhalation of sea sprays 
(beach)sediments 
HH nd dr A A 
MOIRA 55 IR sea food ingestion 
Monte (2011) sea sprays, sediments 
SENSE nn A —— 
50SEIDON 4 Yes sea food ingestion 
epicard et al. (1998) 
ep SEA AED LLLLLLL),,))LLL HH 
DOSEIDON-R Variable Yes CR/dynamic sea food ingestion 
Lepicard et al. (2004) 
patch. The !37Cs concentrations in the surface, intermediate, and deep 
layers reduced to the pre-Fukushima values over the North Pacific 
some 2.5 years after the Fukushima accident. Similar conclusions were 
also obtained by Rossi et al. (2013, 2014): the Fukushima plume 
was rapidiy diluted within the Kuroshio system over a time-scale of 
a few months, Over the subsequent decades a significant amount of 
Fukushima-derived radionuclides will spread across the North Pacific 
basin. The model estimated that a component of Fukushima !57Cs 
was injected into the interior ocean via subduction, before eventu- 
ally returning to the surface by coastal upwelling along the west 
coast of North America. The comparison of !97Cs measurements along 
line P, placed about 1500 km west British Columbia, Canada (Smith 
et al., 2017), with modelling (Rossi et al., 2013, 2014; Tsubono et al., 
2016) showed good agreement. Some discrepancies in the calculated 
time evolution of concentrations could be explained because of the 
assumption that releases occurred solely by direct discharges from 
FDNPP (Rossi et al., 2013, 2014). Simulations with both sources (at- 
mospheric deposition and direct release) matched ocean measurements 
well (Tsubono et al.. 2016). The relevance of atmospheric deposition 
was also studied by other authors (Honda et al., 2012), finding that 
‘he high!?7Cs concentrations detected in surface waters north of 40° 
N one month after the accident should be attributed to atmospheric 
deposition. 
The residence time of !27Cs in the shelf was estimated, using a 
model, as 43416 days (Dietze and Kriest, 2012). The effective horizontal 
diffusivities on the shelf and effective diffusivity for cross-shelf trans- 
port were evaluated as well. As discussed in Section 5.2, these authors 
highlighted the effects of numerical (artificial) diffusion which appears 
in Eulerian transport models, 
It was found, using a Lagrangian model, that the Kuroshio current 
acts as a barrier (Rypina et al., 2013), as previously described by Jayne 
et al. (2009), which prevents the migration of radionuclides released 
from Fukushima towards the south (they would not travel south beyond 
the latitude of Tokyo). Instead, they are transported towards the central 
Pacific, 
Other modelling studies, using an Eulerian model (Estournel et al., 
2012), indicated that radionuclides stay close to the coastline for 
relatively long times and suggested the role of freshwater discharges