Tritium dynamics in soils and plants grown under three irrigation regimes at a tritium processing facility in Canada

Mihok, Steve; Wilk, Marcin; Lapp, Anthony; St-Amant, Nadereh; Kwamena, N.-O.A.; Clark, Ian D.

doi:10.1016/j.jenvrad.2015.12.025

Cited by 26 publications

(13 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The SRBT case (Mihok et al, 2016) is not specific to conditions of a CANDU reactor and can be affected by the emission of organic tritiated species (to be tested), and the uncertainty of the current models (still not crop specific).…”

Section: Discussionmentioning

confidence: 99%

“…In a PHWR as CANDU is, 97 % of atmospheric emission is HTO, during the day time and night time. A CANDU reactor differs from the SRBT case (Mihok et al, 2016) where the emissions are predominately as HT, restricted to working hours (7.00 -17.00), and stopped during the weekends. There is no such a facility in Romania, but some experience for detritiation facility and other tritium bearing utility exists.…”

Section: Uncertainty Of Obt/hto Ratios For Routine Releasesmentioning

confidence: 99%

“…There is no such a facility in Romania, but some experience for detritiation facility and other tritium bearing utility exists. There are some peculiarities at SRBT which potentially can explain the results of Mihok et al (2016) and each of them will be shortly discussed in the following. The experimental errors can be eliminated because special quality assurance was taken (St-Amant, 2016).…”

Section: Uncertainty Of Obt/hto Ratios For Routine Releasesmentioning

confidence: 99%

“…A recent study (Mihok et al, 2016) presents the experimental results regarding the OBT/HTO ratios in soils and plants near a gaseous tritium light source manufacturing facility in Canada (SRBT), which emits tritium as tritiated hydrogen (HT) and HTO only during the day time and week days. The plants were irrigated with tap water (containing a tritium concentration of 5 Bq L -1 ), rain water (with a tritium concentration of 80 Bq L -1 ) and well water (with a high tritium concentration of 11000 Bq L -1 ).…”

mentioning

confidence: 99%

“…For that irrigation regime (tap and rain water), the OBT/HTO ratio in roots and tubers was about 2 and in the aerial plant parts the OBT/HTO ratio was 8. When plants were irrigated with highly contaminated water from wells, the soil and plants HTO equilibrated with about 25 % from that of irrigation water and OBT/HTO ratio in roots and tubers is 0.4 and in aerial plant parts is 1.4 (see Table 3 in Mihok et al, 2016). The experimental data show clearly that the OBT/HTO ratio is much higher than the equilibrium value of 0.7, but it is close to equilibrium when the irrigation water is highly contaminated with tritium.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Uncertainty of current understanding regarding OBT formation in plants

Melintescu

Galeriu

2017

Journal of Environmental Radioactivity

View full text Add to dashboard Cite

Radiological impact models are important tools that support nuclear safety. For tritium, a special radionuclide that readily enters the life cycle, the processes involved in its transport into the environment are complex and inadequately understood. For example, tritiated water (HTO) enters plants by leaf and root uptake and is converted to organically bound tritium (OBT) in exchangeable and non-exchangeable forms; however, the observed OBT/HTO ratios in crops exhibit large variability and contradict the current models for routine releases.Non-routine or spike releases of tritium further complicate the prediction of OBT formation.The experimental data for a short and intense atmospheric contamination of wheat are presented together with various models' predictions. The experimental data on wheat demonstrate that the OBT formation is a long process, it is dependent on receptor location and stack dynamics, there are differences between night and day releases, and the HTO dynamics in leaf and ear is a very important contributor to OBT formation.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Uncertainty Of Obt/hto Ratios For Routine Releasesmentioning

confidence: 99%

Section: Uncertainty Of Obt/hto Ratios For Routine Releasesmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Uncertainty of current understanding regarding OBT formation in plants

Melintescu

Galeriu

2017

Journal of Environmental Radioactivity

View full text Add to dashboard Cite

show abstract

Practicalities of Mainstreaming Biomarker Use – A Canadian Perspective

Mihok

McKee

2022

NATO Science for Peace and Security Series A: Chemistry and Biology

View full text Add to dashboard Cite

This paper discusses the use of biomarkers within the environmental protection framework that has evolved since the Canadian Nuclear Safety Commission (CNSC) was given a broad mandate for the protection of the environment under the Nuclear Safety and Control Act (NSCA) in 2000. Unique insights have been obtained through environmental assessments for major nuclear projects conducted under the Canadian Environmental Assessment Act, and through the Environmental Effects Monitoring (EEM) requirements at uranium mines and mills (Metal Mining Effluent Regulations under the Fisheries Act (FA)). Altogether, the Canadian nuclear sector now has 17 years of experience in applying biological evidence in decision-making. Key examples are discussed where improved effluent controls were implemented at uranium mines for three substances (U, Mo, Se) based on risk assessments and supporting biological evidence. In the case of U, potential for localized harm from the chemical toxicity rather than radiological toxicity of U was identified at three older mines through environmental risk assessment. Evidence of potential harm in the field was also obtained from a community ecology bioindicator (benthic invertebrate biodiversity). This led to the improvement of effluent controls for U that were straightforward to implement under the NSCA. In the case of Mo, the weight of evidence for potential health effects on moose and other riparian wildlife from ecological risk assessments (supported by field evidence from Sweden) prompted improved controls based on precaution and pollution prevention. A technological solution was readily available for reducing Mo in effluent and was therefore implemented. In the case of Se, population level effects in fish and individual level effects in waterfowl in the USA led to selenium risks being evaluated downstream of uranium mines. Biomarkers (larval teratogenic deformities) played a pivotal role in attributing observed effects (harm) to the probable cause (selenium accumulation in the environment). However, as technological solutions were not straightforward, effort was required to build a consensus on achievable effluent control targets in a multi-stakeholder and multi-jurisdictional context. Through site-specific research and the latest scientific literature, criteria for selenium risk evaluation and water treatment system improvements were agreed upon and implemented. Within the EEM program, similar issues have arisen in managing a robust and defensible regulatory framework for controls on multiple hazardous substances across many mining sectors. However, an initial review of biomarkers resulted in the selection of only ecologically-relevant parameters (fish health and population indicators, benthic invertebrate biodiversity) as triggers for regulatory action. Altogether, these and other parallel experiences are discussed in terms of the desirable attributes of biological effects monitoring in a Canadian regulatory context.

show abstract