After the Fukushima Daiichi nuclear accident, municipal solid waste (MSW) contaminated with radiocesium was generated. In Japan, approximately 80% of MSW by weight has been incinerated. As consequence, radiocesium was retained in incineration residue after the accident. Among the incineration residues, fly ash with high radioactivity was transported to an interim storage facility and special treatment has been carried out. While, bottom ash with radioactivity levels of <8000 Bq kg wet has been directly deposited in conventional MSW landfills. The radiocesium leaching from bottom ash is low, but the reason for this low leaching remains unclear. In this study, leaching tests and microscopic observations of bottom ash containing stable Cs were conducted to investigate the mechanism making Cs leaching low. It is noted that the ash used was simulated ash created from combusting refuse derived fuel (RDF) to which stable Cs was added, not real radioactive ash. Based on pH dependence testing, the Cs leaching increased as the pH decreased. The amount of Cs leached in the neutral range was 2-4% mass of the total content. Electron probe microanalysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy confirmed that certain particles in bottom ash contain concentrated Cs. These particles were found to comprise aluminum, silicon, potassium, and oxygen at their core, surrounded by concentrated Cs. Raman microscopy suggested that these particles are microcline. Co-heating of microcline with Cs carbonate led to the condensation of Cs in a manner similar to particles observed in bottom ash, and Cs was captured in a glassy substance formed on the microcline surface, which reduced the leaching of Cs.

Using the discontinuous Galerkin method in the SLIM modelling framework, we study the transport in the Scheldt basin and adjacent coastal area of radionuclides possibly emitted by Doel nuclear power plant in the aftermath of an accident. The contamination pathways taken into consideration are direct liquid releases into the water and deposition via the atmosphere. In past nuclear accidents, several radionuclides were released, among which, I and Cs were considered herein. The hydrodynamics and atmospheric conditions are selected to simulate the worst-case scenario in the domain of interest. The radionuclide deposition towards the North Sea results in I and Cs being transported to the Belgian coastal region. In case of deposition towards the river, radioactivity from upstream tributaries can reach the estuary within days. Direct liquid releases spread downstream until the mouth of the estuary after about few weeks and extend upstream into the Scheldt River. In all cases, due to tidal influence, the estuary becomes most vulnerable, with radioactivity potentially circulating for over a month. Additionally, higher river discharge resulted in decreased radioactivity levels in the estuary.

The final disposal of NORM wastes in conventional landfill generally determines problems of acceptance by the landfill operators, since their willingness to accept Naturally Occurring Radioactive Material (NORM) is often limited due to their concern about the radiological risks and reluctance of the local community to have at local landfills material that despite being cleared is still perceived as 'radioactive'. In order to raise awareness among landfill operators, and also among other stakeholders on the actual radiological risk of exempted or cleared NORM wastes, it is of interest to estimate the mass of annual wastes containing NORM that can be disposed of in a landfill for conventional waste complying with the annual dose criterion of 1 mSv. A methodology was developed considering a hypothetical homogeneous large landfill and assuming that NORM wastes are delivered with an initial activity concentration of 1 kBq kg. The methodology uses exposure scenarios and assumptions from Radiation Protection 122 Part 2, the codes RESRAD-ONSITE and OFFSITE, and the most recent dose coefficients from ICRP. The exposure scenarios considered are the "worker handling NORM at an active landfill" and "members of the public living near an active landfill", For these scenarios, screening levels (called Operational Levels in this work) in terms of activity concentration fulfilling the annual dose criterion of 1 mSv, for members of the public (including all ICRP age groups) and workers at a landfill, have been calculated for each decay chain segments using a generic and conservative approach. The Operational Levels evaluated in this work are almost independent from the landfill size and are relevant to the landfills complying the EU directive 1999/31 requirements. The obtained Operational Levels (OL) are all higher than 1 kBq kg, for U-238 and Th-232 series radionuclides and 10 Bq g for K-40, which are the general clearance levels adopted in the European Union. The estimated OLs range between 2 kBq kg (for Th-232sec) and about 150 kBq kg (for Po-210). For the U-238 decay chain, the segments with the smallest OLs values are U-238sec (OL = 2.5 kBq kg) and Ra-226+ (OL = 3.7 kBq kg). For Th-232 chain, the most critical segments are Th-232sec and Th-228+ (OL = 3.8 kBq kg). As regards the mass of annual NORM wastes that can be disposed of in a conventional landfill, the levels obtained for Po-210, Pb-210+ and K-40 indicate that from the radiological point of view limitations to the annual admissible mass may occur only for large activity concentrations (i.e. 40 kBq kg and above). For the other segments, instead, limitations can occur for activity concentration levels in residues above 2 kBq kg.

The Yenisei is the largest river in the Northern Hemisphere receiving controlled radioactive discharges from nuclear facilities. The paper presents a comparative study of temporal trends of artificial radionuclides plutonium (Pu) and radiocesium (Cs), and a natural isotope of the essential macronutrient potassium (K) in samples of three commercial fish species (Northern pike, Baikal grayling, and Siberian dace) occupying different positions in a trophic network in the Yenisei River (Siberia, Russia). Samples of fish were caught in the Yenisei in 2011-2020 during a period of significant changes in controlled radioactive releases into the river. The study has shown no increase in plutonium concentration in fish samples within two years after the upsurge in controlled Pu discharge into the river (2018-2020). Average activity concentration of Pu (mBq∙kg d.w., range, mean ± sd) in muscle of grayling (0.6-31.8, 10.9 ± 8.6) was higher (p < 0.01) than in muscle of dace (1.0-4.4, 2.4 ± 1.2) and pike (1.1-11, 3.8 ± 2.9). This can be attributed to the feeding of grayling on benthic invertebrates rich in Pu. The concentration of Pu tended to increase in muscle of pike with the increasing size of the fish. Average activity concentration of Cs (Bq∙kg d.w., range, mean ± sd) in muscle of pike, a piscivorous fish (1.8-23.4, 7.7 ± 5.1), was significantly higher (p < 0.001) than the average activity concentration of Cs in muscle of dace (0.7-5.7, 2.7 ± 1.6) and grayling (1.3-7.2, 2.5 ± 1.7). A similar effect was revealed for K. This can be attributed to biomagnification of Cs and K in food chains. The results will draw a baseline for assessment of dose-dependent ecological risks for wild fish itself and fish consumers, add field-based facts to the fundamental knowledge of behavior of artificial radionuclides in freshwater food chains, and suggests a hypothesis for consequent experimental studies.

Radon studies were conducted in two Canadian cities, in Halifax, Nova Scotia, and Winnipeg, Manitoba, to evaluate trends in indoor radon before and after the 2010 National Building Code of Canada was adopted into the legally binding provincial building codes in 2011. Participants were recruited in neighbourhoods characterized by newer housing developments. A postcard campaign in each city offered free radon testing to every house in the target areas, and free testing kits were mailed to study participants. Indoor radon measurements and house questionnaires were completed by 225 eligible participants in Halifax and 171 eligible participants in Winnipeg, using alpha-track radon detectors deployed for three months during the heating season in 2021-2022. Multivariate logistic regression analyses were conducted to evaluate the association between indoor radon and the period of construction, the area in contact with the ground, the number of storeys, the type of heating system, the water source, and the type of ventilation. These analyses were focussed on the detached study houses because the majority of the participants lived in a detached house, and significant associations were identified for the period of construction and the floor where the radon detector was located. An odds ratio of 1.91 (1.04-3.50) for the detached Halifax study houses built after 2011 was associated with having a higher than geometric mean radon concentration (p = 0.033), nearly double the likelihood. There was no evidence of significant change in the indoor radon after 2011 in the detached Winnipeg study houses. A lower likelihood - almost half - for measurement conducted on a main/upper floor compared to in the basement was associated with a radon concentration above the respective geometric mean for each city: an odds ratio of 0.48 (0.27-0.86) for the detached Halifax study houses (p = 0.012), and of 0.45 (0.32-0.64) for the detached Winnipeg study houses (p = 0.022). Radon is the second most important cause of lung cancer, after smoking, and the results of this study support strengthening the radon preventive measures required in new low-rise housing to reduce the associated lung cancer burden in Canada.

The activity concentrations of natural radionuclides in water, soil, cassava, cocoyam and yam grown in two mining districts and a non-mining district in Ghana were determined using a high-resolution gamma spectroscopy system with high-purity germanium detector. The estimated absorbed dose for soil from Amansie, Konongo, and Mampong were 206 nGy/h, 224 nGy/h and 198 nGy/h, respectively, which were all above 60 nGy/h set by the United Nations Scientific Committee on the Effects of Atomic Radiation. The soil-to-plant transfer factors (TF) for ³⁸U, ³Th, and ⁴⁰K ranged from 0.11 to 1.11, 0.03 to 2.39, and 0.03 to 22.07, respectively. The results showed that the highest TF for U and Th were 1.11 and 2.39, respectively in cassava. There was no significant variation in the TF of U and Th among the soils in the different communities. The estimated transfer factors for U and Th for cassava, cocoyam and yam were higher than that reported by the International Atomic Energy Agency.

Radon is a carcinogenic gas that cannot be detected by the five senses and poses a significant health threat, particularly in the form of lung cancer, to individuals living in all enclosed buildings worldwide. The aims of this study are to (1) measure Indoor Radon Concentrations (IRCs) in 117 buildings in İzmir, Turkey, (2) investigate and model the relationship between the IRCs and Geological Units (GUs) and Active Faults (AFs), and (3) compare the IRC values with the European Indoor Radon Reference Level (EIRRL) (200 Bq/m³) to identify areas that pose a potential health risk for lung cancer due to elevated Indoor Radon Levels (IRLs). The IRCs were measured using Solid State Nuclear Track Detectors (SSNTDs) in 117 buildings. These measurements were conducted between February 2013 and March 2013. The IRCs were visualized on a map along with the GUs and AFs, and a geological cross-section was generated from the data represented on this map. The IRCs in 117 buildings were geostatistically modeled in conjunction with AFs. Generally, the highest IRCs were found in locations proximal to AFs, with an increase in IRLs observed parallel to the AFs's directions. The highest IRC (487 Bq/m³) was recorded in a building located on alluvium derived primarily from volcanic rocks, whereas the lowest concentration (28 Bq/m³) was observed in a building situated on alluvium predominantly derived from sedimentary rocks. The statistical parameters (minimum: 28 Bq/m³, maximum: 487 Bq/m³, arithmetic mean: 210 Bq/m³) of the IRCs were established. In İzmir, IRCs in 59 out of 117 buildings, representing approximately 50% of the sampled structures, were found to exceed the recommended EIRRL of 200 Bq/m³. It is imperative that IRCs in all enclosed buildings be regularly and periodically monitored by relevant authorities, and mitigation measures should be implemented in locations where IRLs exceed the threshold value of 200 Bq/m³.

The spatial distribution of radon and the relevance of the placement of radon detectors relative to the entry path of radon-containing air in an experimental room was investigated. A radon emanation source was used from which the air was transported with a constant air flow into the room. The radon contaminated air was released under a floor element used for electrical wiring which has multiple holes connecting to the inner volume of the room. At 36 equally spaced lattice points in the room the radon activity concentration was measured with two different solid-state nuclear track detectors of type Radonova Radtrak and Radonova Rapidos. The radon exposure on the detectors was accumulated over 72 days. Additionally, an electronic measurement device of type Saphymo AlphaGUARD was used as reference. It indicated a radon exposition of 475(1)kBq h/m. The detectors of type Radtrak had a mean exposition of 564(36)kBq h/m and the ones of type Rapidos 496(15)kBq h/m. Except for one outlier both types of detector showed a homogeneous distribution of radon in the room. Therefore, we have shown that under these experimental conditions the placement of the radon detector does not significantly influence the measurement result.

A necessary condition for the sustainable development of nuclear power is the safe disposal of vitrified high-level radioactive waste from the processing of spent nuclear fuel in underground repositories. Their safety depends on the rate of radionuclide transport by groundwater from the repository to the biosphere. A significant fraction of the radionuclides is carried by groundwater in colloidal form. The radionuclide-bearing colloid (radiocolloid) is the most mobile and therefore the most ecologically hazardous form of radionuclide transport. The radiocolloid can be retained mechanically in the rock if the colloid particle size is larger than diameter of rock pore channels. Transport of radionuclide-bearing colloid by groundwater is considered. (1) A technique for determining the size distribution of pore channels in the rock is developed. It is based on measurements of the gas permeability of rock samples at different pressures. (2) The technique is applied to rock samples from the Nizhnekanskiy Massif (Russia), which has been selected for the development of a high-level radioactive waste repository. (3) Simulated radionuclide-bearing colloids were obtained by water leaching of aged aluminum phosphate glass with radionuclide simulants. The glass composition is similar to that used for vitrification of liquid HLW at the Russian radiochemical plant. (4) The size distribution of the colloid was determined by filtering the leachates through membranes of different pore sizes. (5) Mechanical retention of the colloid by the rock is estimated theoretically. The estimation is based on size distributions of colloid particles and diameters of pore channels in the rock. It is shown that 99% of the colloidal form of the actinide simulants (Ce, Nd, U) can be mechanically retained in the rock of the Nizhnekanskiy Massif.

We present results from the laboratory experiments performed to study the behaviour of dense plumes in porous media using Caesium Nitrate (CsNO) as the solute. Specifically, we consider the case of fixed volume release of a dense fluid into a saturated porous medium of lighter density. Our experiments consider the injection volume and concentration of CsNO and the porous medium permeability as experimental variables. Our measurements show that the plume length and volume increase with time approximately as t. The mean concentration of the plume decreases with time as plume monotonically dilutes due to continuous mixing with the surrounding. From our measurements and with the help of dimensionless scaling, we present empirical models for the length, volume and mean concentration of the plume. Our results may be used to gain preliminary insights into the spatio-temporal evolution of plumes formed in the subsurface environment.

The presence of fractures in the surrounding rocks of a radioactive waste disposal repository is recognized as a potential pathway for radionuclides to enter the public domain. As is well known, radionuclides transported by groundwater exhibit increased mobility in fractures, with flow velocities significantly faster than those in the pore spaces of the surrounding rock matrix. The principal objective of this study is to investigate the mobility of Sr, Cs, U, and Pu in fractures and their fate in the groundwater environment. Concurrently, batch and transport experiments were conducted to determine the sorption coefficients and transport parameters of each radionuclide. The results demonstrated that the adsorption and desorption isotherms of each radionuclide could be quantitatively described using the Freundlich isotherm. The hysteresis area "S" formed by the adsorption and desorption isotherm was utilized to quantify the irreversibility of the four radionuclides on granite particles, with a ranking of Pu > Cs > Sr > U. The distribution coefficients (real K) of the four radionuclides varied by 2-3 orders of magnitude, but the tendencies and concentrations of Sr, Cs, U, and Pu in the sampling holes were not significantly different. These findings suggest that it is essential to introduce the first-order rate constant (α) and consider the kinetic process of adsorption to describe their migration process in granite single fractures. The sorbed concentrations of radionuclides on the surface of the upper and lower granite matrix were positively correlated with "real K × α × time," while their concentrations in water flow were opposite. The irreversibility of radionuclides is another critical factor. The greater the irreversibility of radionuclides, the more challenging it is for them to desorb, resulting in a higher sorbed concentration remaining on the surface of the granite matrix and a smaller concentration in the water flow.

Bricks and tiles crafted from fired red clay are extensively utilized in everyday construction activities. However, red clay inherently contains radon gas, a radioactive substance that could potentially endanger human health. Hence, investigating the radon emission patterns of red clay post high-temperature treatment holds significant importance. This study examines the pore structure of red clay following high-temperature treatment through nitrogen adsorption and analyzes the radon release patterns. Findings reveal that the radon release rate from red clay initially rises, then declines with increasing temperature, peaking at 200 °C, registering at 0.0127 Bq/(m s). The pore structure significantly influences radon exhalation, with connectivity and micropore volume demonstrating linear correlations with radon exhalation rate, with correlation coefficients of 0.96 and 0.78, respectively. This research offers valuable insights into radon radiation in structures made of red clay.

Any major nuclear facility must ensure the conservation of biodiversity regarding radiation protection of biota. A special concern is for tritium (H) and radiocarbon (C) transfer in wild mammals, birds and reptiles. Hydrogen and carbon are the main components of biological tissues and enter the life cycle. The present study improves the scientific bases of a previous model, analyses the uncertainty of input parameters and tests the model for a larger range of mammals and birds. The biological and metabolic half-times for organically bound tritium (OBT) and C are linked with energy metabolism and recent results are revised in relation with metabolic scaling. A large data base regarding basal metabolic rate (BMR), field metabolic rate (FMR), and organ mass is used for input information of the present model, which considers brain as a separate compartment. Metabolic energy partition in organs of active animal is defined and the factors affecting the metabolic rate are analysed. Body and ambient temperature, diet and habitat, and phylogeny are important factors considered in animal adaptation to environment. The available experimental data for carbon turnover rates in animals are analysed and it is observed that the experimental conditions are not appropriate for wild animals. The link between C and Cs turnover rate is analysed and the present metabolic approach is successfully tested for mammals and reptiles. Considering animal adaptation and the large data base for Cs, the radiological impact of accidental releases of H and C on biota can be pursued in the future research.

A model of radionuclide transfer in freshwater bodies, along with dosimetric models for estimating doses to aquatic biota species (including phytoplankton, zooplankton, zoobenthos, and fish), is presented. The results of the reconstruction of radiation doses to aquatic organisms living in the closed (non-flowing, lentic) Lake Uruskul, located in the vicinity of the Kyshtym accident, are provided. The contributions of the main dose-forming radionuclides, as well as both internal and external exposures, to the doses received by aquatic organisms over the 50 years following the Kyshtym accident are discussed. It is shown that benthic organisms received the highest doses (2.6-8.3 Gy per day), while zooplankton experienced somewhat lower doses (up to 3.3 Gy per day). Fish received doses of up to 4 mGy per day during the first 100 days. Phytoplankton, with doses reaching up to 0.5 Gy per day, occupied an intermediate position in this sequence. These doses could lead to long-term radiation effects.

This study focuses on public exposure to natural radioactivity caused by the inhalation of radon and thoron progeny in homes in Franceville, Moanda and Mounana in Gabon. The equilibrium factor (F) between thoron and its progeny was determined experimentally for a proper estimate of the effective dose. In order to assess internal exposure due to radon and thoron progeny, 150 passive radon-thoron discriminative detectors (RADUET) and thoron progeny monitors were deployed for about 3 months in the above-mentioned towns. The results of the measurements obtained showed that the average concentrations of thoron progeny (EETC) were 1.54 ± 0.08 Bq m, 3.05 ± 0.09 Bq m and 1.84 ± 0.11 Bq m in Franceville, Moanda and Mounana, respectively. The ranges of the measured thoron equilibrium factors were 0.004-0.710, 0.005-0.750, and 0.006-0.794 in Franceville, Moanda and Mounana, respectively. The arithmetic and geometric mean values were, respectively, 0.183 and 0.117 in Franceville, 0.184 and 0.122 in Moanda, and 0.221 and 0.140 in Mounana. The experimentally determined equilibrium factor (F) allowed us to compare the value of the experimentally determined effective dose with the theoretically determined one calculated using the equilibrium factor proposed by United Nation Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 2000 report. F values were around 6-11 times greater than the UNSCEAR typical value. The ranges, arithmetic and geometric mean EERC values determined were 30.40-55.60 Bq m, 24.00 ± 0.90 Bq m and 41.68 (1.00) in Franceville, 36.40-62.50 Bq m, 45.30 ± 0.70 Bq m and 44.72 (1.00) in Moanda, and 35.00-90.00 Bq m, 50.00 ± 2.00 Bq m and 48.50 (1.00) in Mounana. The mean values of the annual effective inhalation dose due to thoron progeny determined using F were 0.32 mSv (compared to 0.049 mSv), 0.63 mSv (compared to 0.103 mSv), and 0.39 mSv (compared to 0.055 mSv) in Franceville, Moanda and Mounana, respectively. The main conclusion of this study is that indirect estimations of thoron progeny concentrations considerably underestimate the estimation of the annual effective inhalation dose.

The present study aimed to develop a Monte Carlo model to estimate the annual effective dose due to radon exposure sourced by radon gas in the walls and floor of a standard model room. With the purpose of developing a tool for radon level assessment in dwellings and workplaces, Geant4 toolkit was used to simulate the energy deposited by gamma rays emitted by radioactive radon progeny in a water phantom positioned at three different locations within the model room. The energy deposition was then used to estimate the annual effective dose through a deterministic approach. The simulation outcomes showed good agreement with experimental data, with the ratio between the simulated and the experimental data displaying the overestimation by a factor of approximately 1.09. Both simulation and experimental data fell within the same range, with a relative deviation of 7.7%. Additionally, the influence of various parameters, such as receptor position in the room, wall, and floor thicknesses, wall cover, and building material bulk density, on the annual effective dose due to radon inhalation in the room was evaluated. Geant4 Monte Carlo toolkit proved to be a reliable tool for radon modeling in real exposure situations.

This study analyzed the transport and deposition of Pb across Asia, particularly focused on Japan, from 2012 to 2015, used an atmospheric transport model that combines WRF and HIRAT. Results indicated that modeled deposition fluxes aligned well with observation data. The average deposition flux in Asia is 17.2 Bq m⁻ month⁻, showed significant seasonal variation. Along the Sea of Japan, the four-year average was 27.0 Bq m⁻ month⁻, with winter peaks in Hokkaido and Tohoku-Hokuriku and summer peaks in Kyushu. The calculation results showed distinct seasonal transport routes. During summer in Kyushu, southerly and westerly winds from southern China (e.g., Guangdong and Fujian) transported Pb-enriched air masses. Stationary fronts carried these air masses from the southwestern Chinese basin, leading to intensified deposition. In winter, along the northern Japan Sea coast, high Pb deposition events were closely associated with the East Asian winter monsoon, characterized by East Asian troughs and Siberian highs. Strong northwesterly winds from Siberia transported Pb-enriched air masses to the Hokkaido and Tohoku-Hokuriku coastal regions, resulting in significant deposition. Approximately 47% of the high winter Pb deposition events originated from the Kazakhstan-Xinjiang border, while the remaining 53% came from eastern Siberia.

This study investigated the activity concentrations of Ra, Th, and K and their soil-to-plant transfer factors in some medicinal plants located in Nepal. The geometric mean values of soil-to-plant transfer factors (TFs) for Ra, Th, and K were 0.37, 0.96, and 3.50, respectively. This indicated that medicinal plants absorbed the highest amount of K from the soil, followed by Th, while Ra was absorbed the least. The average radium equivalent activities for medicinal plants (189 Bq/kg) and associated soils (182 Bq/kg) were within the international acceptable limit of 370 Bq/kg. According to the activity concentrations found in the medicinal plants, they do not present any radiological health hazards unless consumed in excessive quantities; however, continuous investigations are essential.

Public concerns over environmental protection have increased after Fukushima accident. The soil-plant transfer factor (Fv) is a critical parameter for environmental risk assessment. Cs Fv values determined in acid Brazilian soils could be two orders of magnitude higher than Fv values measured in soils affected by the Chernobyl accident. This paper studied the behaviour of Sr in Brazilian soils where very few Sr Fv data is available. All classes of studied soils (Ferralsol, Acrisol and Nitisol) showed that more than 80% of total Sr in soils remains potentially mobile, mainly at the bioavailable phase, more than 2 years after soil contamination in an experiment conducted in lysimeters. Higher Sr Fv for maize and cabbage was observed in the acid soils with low content of exchangeable Ca, lower Fv values occurred at Nitisol, the subtropical soil type. It seems that the behaviour of Sr in these soils are mainly controlled by ionic competition mechanisms occurring for root uptake and sorption sites, with stable Sr and major nutrients (Ca, Mg and K). The mineralogy also seems to play a relevant role, since goethite rich clay soil presented Sr Fv values higher one or two orders of magnitude than Sr Fv values observed at clayed soil goethite rich with trace of vermiculite, for all studied crops. The high rate of Sr migration down the soil profiles observed for the studied soils during the 2 first years after contamination suggests a high rate of transfer to groundwater, even transfer to leafy crop group can be also a relevant pathway. In the present study, maize, among other plant species, presented the lowest Fv values, even when compared with maize cultivated in temperate soil. Our results suggest that stable Sr may not be a very good analogue of Sr for determining plant Fv values: geometric mean of stable Sr Fv for maize was Fv = 6.3E-1 ± 2.1E0 (n = 8) and for Sr was Fv = 1.8E-2 ± 2.5E0 (n = 16), geometric mean of stable Sr Fv for cabbage was Fv = 1.4E0 ± 3.9E0 (n = 17) and for Sr was Fv = 7.9E-1 ± 4.4E0 (n = 18).

To meet the rising demand for cereal-based food products, it is essential to create parent lines for hybrid development. Evaluating the sensitivity of maize genotypes to gamma rays is critical for successful mass irradiation to induce mutations. This study aimed to assess how maize genotypes respond to gamma radiation and determine an effective dosage for mutation breeding. Six maize genotypes were subjected to gamma radiation doses ranging from 0 to 750 Gy (s) Co. The irradiated seeds were evaluated in controlled conditions and then planted in the field for the assessment of physio-agronomic traits. The lethal dose (LD50) was established based on the germination rate of the M1 generation. Results demonstrated a decrease in germination percentage, plant height, survival rate, root length, and plant photosynthetic rate with escalating gamma radiation doses. The mean LD, determined from the germination data, was 254.3 Gy. The radiation dosage range of 206.71-301.95 Gy proved effective in influencing both quantitative and qualitative characteristics. These findings provide valuable insights into the efficient utilization of gamma radiation in expediting the development of promising parent lines, which can be instrumental in hybridization efforts to produce superior maize varieties.