The effect of chemical speciation on the impact of¹²⁹I discharges to atmosphere from BNFL Sellafield, Cumbria

Abstract

Abstract. lM I is produced through neutron-induced fission of 23i U and neutron capture reactions with the fission products 1!S Te and nn Te in the cores of nuclear reactors. This typically constitutes about 1% of the total fission products, depending on fuel bum-up. Whilst is not released in routine discharges from nuclear power plants it is released during reprocessing. The ability to model '"1 behaviour (important for prospective assessments) has been relatively poor. This is due both to variability in the reported behaviour of iodine, which may be related to abundance and physico-chemical form, and to the relative paucity of data for ,29 1. The primary aims of this study are to measure environmental concentrations of '"l around Sellafield; to establish whether the chemical species of iodine in air differs as a function of the source term, and; to determine concomitant values for model parameters defining 129 1 transport through the environment. Some differences in the environmental transport of are observed, albeit slight, apparently related to source term. These findings suggest that a source-specific approach may be appropriate. The critical group dose arising from l "l is estimated to be about 1.4 uSv a" 1 to adults and 3.2 uSv a" 1 to infants.

Temporal variation in <sup>129</sup>I and <sup>127</sup>I in aerosols from Xi'an, China: influence of East Asian monsoon and heavy haze events

“…The lowest N( 129 I) (< 0.1×10 5 atoms m −3 ) in aerosols have been found at two high-altitude sites of the Alps (about 3000 m above the sea level). (2) The high values beyond 10 8 atoms m −3 have been reported at the sites directly contaminated either by nuclear reprocessing plants, such as Hanford, Sellafield and the reprocessing plant (WAK) at Karlsruhe, or by the Fukushima nuclear accident in 2011 (Brauer et al, 1973;Jackson et al, 2002;Wershofen and Aumann, 1989;Xu et al, 2015).…”

Temporal variation of &lt;sup&gt;129&lt;/sup&gt;I and &lt;sup&gt;127&lt;/sup&gt;I in aerosols from Xi'an, China: influence of East Asian monsoon and heavy haze events

“…The lowest 129 I (< 0.1×10 5 atoms m -3 ) in aerosols have been found at two high altitude sites of Alps mountains (about 3000 m above the sea level). 2) The high values beyond 1000×10 5 atoms m -3 have been reported at the sites directly contaminated either by nuclear reprocessing plants, such as Hanford, Sellafield and WAK at Karlsruhe, or by Fukushima nuclear accident in 2011 (Brauer et al, 1973;Jackson et al, 2002;Wershofen and Aumann, 1989;Xu et al, 2015). 3) In between, aerosol 129 I within the range from 10×10 5 atoms m -3 to 1000×10 5 atoms m -3 , are mainly found in the sites and periods with global fallout from atmospheric nuclear weapon testing, and indirectly contaminations from nuclear fuel reprocessing plants (Brauer et al, 1973;Englund et al, 2010;Kadowaki et al, 2018;Tsukada et al, 1991;Zhang et al, 2016).…”

Ultra-Sensitive Determination of Particulate, Gaseous Inorganic and Organic Iodine-129 and Iodine-127 in Ambient Air

“…Studies on particulate and gaseous species of atmospheric 129 I mainly focus on either the period immediately after global atmospheric nuclear weapon testing and nuclear accidents, or the regions adjacent to nuclear reprocessing plants, nuclear testing sites, and locations of nuclear accidents. − However, in the areas remote from nuclear facilities and accidents, atmospheric 129 I studies mainly focus on particulate species and precipitation. ,,,− Field observations on gaseous 129 I are very sparse in ambient air due to extremely low concentrations and lack of available sampling techniques and sensitive detection technology, resulting in an inadequate understanding of the transport process and transformation mechanism of airborne radioactive iodine. To serve nuclear safety monitoring and environmental tracing applications using the long-lived anthropogenic 129 I, this work aims to develop an effective method for speciation analysis of 129 I and 127 I in the air by sequential collection of particulate, gaseous inorganic and organic forms of iodine, followed by chemical separation and measurement of 127 I by ICP–MS and 129 I by AMS.…”