Uranium in Poland: Resources and Recovery from Low-Grade Ores

The presented studies deal with an assessment of the possibility of uranium recovery from the low-grade uranium resources in Poland. Uranium was leached from the ground uranium ores with efficiencies in 81–100% range that depend on the type of ore and leaching solution used. In the next step, the post-leaching solution was treated by the solvent extraction or ion exchange chromatography to separate uranium from other metals present in the ore. The novel routes of leaching by using membrane methods were examined. The final product, “yellow cake,” was obtained in precipitation step. The studies of precipitation of uranium as ammonium diuranate or uranium peroxide from diluted uranium solutions are presented in this chapter. The work was completed with tentative economic analysis and environmental impact assessment along with radiation protection issues connected to uranium production

Dose assessment intercomparisons within the RENEB network using G0-lymphocyte prematurely condensed chromosomes (PCC assay)

Purpose: Dose assessment intercomparisons within the RENEB network were performed for triage biodosimetry analyzing G0-lymphocyte PCC for harmonization, standardization and optimization of the PCC assay. Materials and methods: Comparative analysis among different partners for dose assessment included shipment of PCC-slides and captured images to construct dose-response curves for up to 6 Gy c-rays. Accident simulation exercises were performed to assess the suitability of the PCC assay by detecting speed of analysis and minimum number of cells required for categorization of potentially exposed individuals. Results: Calibration data based on Giemsa-stained fragments in excess of 46 PCC were obtained by different partners using galleries of PCC images for each dose-point. Mean values derived from all scores yielded a linear dose-response with approximately 4 excess-fragments/cell/Gy. To unify scoring criteria, exercises were carried out using coded PCC-slides and/or coded irradiated blood samples. Analysis of samples received 24 h post-exposure was successfully performed using Giemsa staining (1 excess-fragment/cell/Gy) or centromere/telomere FISH-staining for dicentrics. Conclusions: Dose assessments by RENEB partners using appropriate calibration curves were mostly in good agreement. The PCC assay is quick and reliable for whole- or partial-body triage biodosimetry by scoring excess-fragments or dicentrics in G0-lymphocytes. Particularly, analysis of Giemsa-stained excess PCC-fragments is simple, inexpensive and its automation could increase throughput and scoring objectivity of the PCC assay

RENEB accident simulation exercise

Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event. Materials and methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results obtained from all other participants. The exercise was performed over 27 weeks and involved the network consisting of 28 institutes: 21 RENEB members, four candidates and three non-RENEB partners. Results: The duration of a single exercise never exceeded 10 days, while the response from the assisting laboratories never came later than within half a day. During each week of the exercise, around 4500 samples were reported by all service laboratories (SL) to be examined and 54 scenarios were coherently estimated by all laboratories (the standard deviation from the mean of all SL answers for a given scenario category and a set of data was not larger than 3 patient codes). Conclusions: Each participant received training in both the role of a reference laboratory (activating the network) and of a service laboratory (responding to an activation request). The procedures in the case of radiological event were successfully established and tested

RENEB intercomparison exercises analyzing micronuclei (Cytokinesis-block Micronucleus Assay)

Purpose: In the framework of the ‘Realizing the European Network of Biodosimetry’ (RENEB) project, two intercomparison exercises were conducted to assess the suitability of an optimized version of the cytokinesis-block micronucleus assay, and to evaluate the capacity of a large laboratory network performing biodosimetry for radiation emergency triages. Twelve European institutions participated in the first exercise, and four non-RENEB labs were added in the second one. Materials and methods: Irradiated blood samples were shipped to participating labs, whose task was to culture these samples and provide a blind dose estimate. Micronucleus analysis was performed by automated, semi-automated and manual procedures. Results: The dose estimates provided by network laboratories were in good agreement with true administered doses. The most accurate estimates were reported for low dose points (== 2.7 Gy) a larger variation in estimates was observed, though in the second exercise the number of acceptable estimates increased satisfactorily. Higher accuracy was achieved with the semi-automated method. Conclusion: The results of the two exercises performed by our network demonstrate that the micronucleus assay is a useful tool for large-scale radiation emergencies, and can be successfully implemented within a large network of laboratories

Uncertainty of fast biological radiation dose assessment for emergency response scenarios

Purpose: Reliable dose estimation is an important factor in appropriate dosimetric triage categorization of exposed individuals to support radiation emergency response. Materials and Methods: Following work done under the EU FP7 MULTIBIODOSE and RENEB projects, formal methods for defining uncertainties on biological dose estimates are compared using simulated and real data from recent exercises. Results: The results demonstrate that a Bayesian method of uncertainty assessment is the most appropriate, even in the absence of detailed prior information. The relative accuracy and relevance of techniques for calculating uncertainty and combining assay results to produce single dose and uncertainty estimates is further discussed. Conclusions: Finally, it is demonstrated that whatever uncertainty estimation method is employed, ignoring the uncertainty on fast dose assessments can have an important impact on rapid biodosimetric categorization

RENEB intercomparisons applying the conventional Dicentric Chromosome Assay (DCA)

Purpose: Two quality controlled inter-laboratory exercises were organized within the EU project ‘Realizing the European Network of Biodosimetry (RENEB)’ to further optimize the dicentric chromosome assay (DCA) and to identify needs for training and harmonization activities within the RENEB network. Materials and methods: The general study design included blood shipment, sample processing, analysis of chromosome aberrations and radiation dose assessment. After manual scoring of dicentric chromosomes in different cell numbers dose estimations and corresponding 95% confidence intervals were submitted by the participants. Results: The shipment of blood samples to the partners in the European Community (EU) were performed successfully. Outside the EU unacceptable delays occurred. The results of the dose estimation demonstrate a very successful classification of the blood samples in medically relevant groups. In comparison to the 1st exercise the 2nd intercomparison showed an improvement in the accuracy of dose estimations especially for the high dose point. Conclusions: In case of a large-scale radiological incident, the pooling of ressources by networks can enhance the rapid classification of individuals in medically relevant treatment groups based on the DCA. The performance of the RENEB network as a whole has clearly benefited from harmonization processes and specific training activities for the network partners

Integration of new biological and physical retrospective dosimetry methods into EU emergency response plans : joint RENEB and EURADOS inter-laboratory comparisons

Purpose: RENEB, 'Realising the European Network of Biodosimetry and Physical Retrospective Dosimetry,' is a network for research and emergency response mutual assistance in biodosimetry within the EU. Within this extremely active network, a number of new dosimetry methods have recently been proposed or developed. There is a requirement to test and/or validate these candidate techniques and inter-comparison exercises are a well-established method for such validation. Materials and methods: The authors present details of inter-comparisons of four such new methods: dicentric chromosome analysis including telomere and centromere staining; the gene expression assay carried out in whole blood; Raman spectroscopy on blood lymphocytes, and detection of radiation induced thermoluminescent signals in glass screens taken from mobile phones. Results: In general the results show good agreement between the laboratories and methods within the expected levels of uncertainty, and thus demonstrate that there is a lot of potential for each of the candidate techniques. Conclusions: Further work is required before the new methods can be included within the suite of reliable dosimetry methods for use by RENEB partners and others in routine and emergency response scenarios

Investigation of the influence of calibration practices on cytogenetic laboratory performance for dose estimation

Purpose: In the frame of the QA program of RENEB, an inter-laboratory comparison (ILC) of calibration sources used in biological dosimetry was achieved to investigate the influence of calibration practices and protocols on the results of the dose estimation performance as a first step to harmonization and standardization of dosimetry and irradiation practices in the European biological dosimetry network. Materials and methods: Delivered doses by irradiation facilities used by RENEB partners were determined with EPR/alanine dosimetry system. Dosimeters were irradiated in the same conditions as blood samples. A short survey was also performed to collect the information needed for the data analysis and evaluate the diversity of practices. Results: For most of partners the deviation of delivered dose from the targeted dose remains below 10%. Deviations larger than 10% were observed for five facilities out of 21. Origins of the largest discrepancies were identified. Correction actions were evaluated as satisfactory. The re-evaluation of some ILC results for the fluorescence in situ hybridization (FISH) and premature chromosome condensation (PCC) assays has been performed leading to an improvement of the overall performances. Conclusions: This work has shown the importance of dosimetry in radiobiology studies and the needs of harmonization, standardization in irradiation and dosimetry practices and educational training for biologists using ionizing radiation

The rapid interphase chromosome assay (RICA) implementation: comparison with other PCC methods

A report is presented on the advantages of the rapid interphase chromosome assay (RICA) and the difficulties that may be met while implementing this method for application in biological dosimetry. The RICA test can be applied on unstimulated human lymphocytes; this is an advantage in comparison with the dicentric chromosomes or micronucleus tests. In the former two tests, stimulated lymphocytes are examined and hence, 48 h more are needed to obtain cells traversing the cell cycle. Due to the use of unstimulated nondividing cells, higher numbers of cells are available for RICA analysis than for dicentric chromosomes or micronuclei tests. Moreover, the method can be applied after exposure to ionizing radiation doses in excess of 5 Gy. Such doses cause a significant cell cycle delay or result in the loss of G2 phase and mitotic cells because of apoptosis. Therefore, the traditional biodosimetry based on the evaluation of the incidence of damage to chromosomes is very difficult to carry out. This is due to the lack of an adequate number of mitotic cells for analysis. RICA is free of this disadvantage. An automatic microscope can be used to retrieve cell images; automatic image analysis can also be used