The Tokyo Electric Power Company Fukushima Dai-ichi nuclear power plant in Fukushima-Ken (Prefecture), Japan, was destroyed in March 2011 due to a massive earthquake (magnitude 9) centred offshore to the northeast of Honshu Island and the subsequent historic tsunami on 11 March 2011. Due to nuclear meltdown, damage to the buildings housing the reactors by hydrogen explosions, and the contamination of cooling water from the reactor cores, huge quantities of radioisotopes were emitted to the atmosphere and to the adjacent seawater. Fishing is currently restricted off the coast of Fukushima-Ken because intermittent surveys have found that the majority of fishery products still contain radioisotope levels exceeding the Japanese Standard Value. The Tokyo University of Marine Science and Technology has measured radioisotope levels in fishery species off Iwaki-Shi(Iwaki City), Fukushima-Ken (located south of the former nuclear power plant); these data could be used to understand the relationship between the accumulation of specific nuclides (radioisotopes) and certain species of fish, as follows:
Chapter 1 “Accumulation of a Specific Nuclide by Female Common Skete (Feminam Okamejei kenojei spp.)”
Some of these data indicated that feminam Okamejei kenojei spp. (English Name: Female Common skete; Japanese Name: KOMON KASUBE NO MESU) had a negative linear relationship between fish weight and 137Cs/134Cs ratio . Therefore, feminam Okamejei kenojei spp. have the ability to accumulate a specific nuclide (radioisotope). To date, ultracentrifugation and diffusion methods have been used to accumulate specific nuclides for atomic fuel. However, if we could utilize the ability of Okamejei kenojei spp. to accumulate a specific nuclide, we would have an additional method to obtain specific nuclides.
Chapter 2 “Total Quantity of Caesium Radioisotopes in Fish in the Fukushima-Ken Exclusive Economic Zone, Japan, in November 2012”
The total amount of caesium radioisotopes in fish biomass in the Fukushima-Ken Exclusive Economic Zone (EEZ) has not yet been reported. The Tokyo University of Marine Science and Technology has measured radioisotope levels in fishery species off Iwaki-Shi (City), Fukushima-Ken (located south of the destroyed nuclear power plant), and these data can be used to estimate the total fish biomass and the quantity of caesium radioisotopes in fish in the Fukushima-Ken EEZ. On 22 to 23 November 2012, the estimated total fish biomass in the Fukushima-Ken EEZ was 91,150,218.79 kg and the estimated total quantities of Cs-134 and Cs-137 in fish were 4,879,259,657 Bq and 8,381,002,727 Bq, respectively.
Chapter 3 “Some Fish Species in Offshore Fukushima, Japan have the Ability to Accumulate a Specific Nuclide (Radioisotope)”
[1] It is possible to accumulate or separate specific nuclides (134Cs and 137Cs) by combining Sebastes cheni (Japanese rockfish; SHIROMEBARU) and Kareius bicoloratus (Stone flounder; ISHIGAREI), and Ditrema temmincki temmincki (Surfperch; UMITANAGO) and Cynoglossus joyneri (Red tongue sole; AKASHITA BIRAME).
[2] There are differences in 134Cs and 137Cs accumulation between adult fish and fry of Paralichthys olivaceus (Bastard halibut; HIRAME). Therefore, some fish species have the ability to accumulate a specific nuclide (radioisotope).
To date, ultra-centrifugation and diffusion methods have been used to accumulate specific nuclides for atomic fuel. However, if we could use the ability of some fish species to accumulate specific nuclides, we would have additional methods to concentrate nuclides.
Chapter 4 “Possible Atomic Fuel Production through Accumulation of Specific Radioisotopes by Fish in Offshore Fukushima, Japan”
[1] The Total Fish Weight % of Okamejei kenojei (English Name: Common-skete; Japanese-Name:KOMON KASUBE) spp. and Sebastes cheni (Japanese rock fish, Japanese sea perch; SHIRO MEBARU) in this sampling in offshore Fukushima-ken,Japan were 26.6824 Weight% and 13.700005 Weight%, respectively; additionally, the fish bodies of Okamejei kenojei spp. and Sebastes cheni had 49.322578 becquerel% and 33.037159 becquerel% of 134Cs, respectively, and had 50.479187becquerel% and 31.779293 becquerel% of 137Cs, respectively. Therefore, Okamejei kenojei spp. has ability to accumulate 1.8485 times of their weight % for 134Cs and 1.92168 times of their weight% for 137Cs. However, Sebastes cheni has the ability to accumulate 2.411 times of their weight% for 134Cs and 2.3195 times of their weight% for 137Cs.
[2] It is possible to accumulate or separate specific nuclides (134Cs and 137Cs) by combining Sebastes cheni and Kareius bicoloratus (Stone flounder; ISHIGAREI), and Ditrema temmincki temmincki (Surfperch; UMITANAGO) and Cynoglossus joyneri (Red tongue sole; AKASHITA BIRAME).
[3] There are differences in 134Cs and 137Cs accumulation between adult fish and fry of Paralichthys olivaceus (Bastard halibut; HIRAME).
Therefore, some fish species have the ability to accumulate a specific nuclide (radioisotope). To date, ultra-centrifugation and diffusion methods have been used to accumulate specific nuclides for atomic fuel. However, if we could use the ability of some fish species to accumulate specific nuclides, we would have additional methods to concentrate nuclides.
