Reconstruction of radiation dose rate profiles by autonomous robot with active learning and Gaussian process regression

EVALUATION OF RADIATION DOSE RATE OF RSG-GAS REACTOR. The RSG-GAS reactor has been operated for 30 years. Since the nuclear reactor has been operated for a long time, aging process on its components may occur. One important parameter for maintaining the safety level of the RSG-GAS reactor is to maintain radiation exposure as low as possible, especially in the working area. The evaluation results should be able to demonstrate that the radiation exposure of the RSG-GAS is still safe for workers, communities and the surrounding environments. The purpose of this study is to evaluate radiation exposure in the working area to ensure that the operation of RSG-GAS is still safe for the next 10 years. The scope of this work is confirming the calculation results with the measured radiation dose in the RSG-GAS reactor working area. Measurement of radiation exposure is done by using the installed equipments at some points in the RSG-GAS working area and a portable radiation exposure measurement equipment. The calculations include performance of a modeling and analysis of dose rate distribution based on the composition and geometry data of RSG-GAS by using MCNP. The analysis results show that the maximum dose rate at Level 0 m working area of RSG-GAS reactor is 3.0 mSv/h with a deviation of 6%, which is relatively close to the measurement value. The evaluation results show that the dose rate in RSG-GAS working area is below the limit value established by the Nuclear Energy Regulatory Agency of Indonesia (BAPETEN) of 10 mSv/h (for the average effective dose of 20 mSv/year). Therefore, it is concluded that the dose rate in RSG-GAS working area is safe for personnel..Kata kunci: dose rates, RSG-GAS, radiation safety, MCNP.

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Conceptual Shield Design for Boron Neutron Capture Therapy Facility Using Monte Carlo N-Particle Extended Simulator with Kartini Research Reactor as Neutron Source

ASEAN Journal on Science and Technology for Development ◽

10.29037/ajstd.532 ◽

2020 ◽

Vol 35 (3) ◽

pp. 177-181

Author(s):

Afifah Hana Tsurayya ◽

Azzam Zukhrofani Iman ◽

R. Yosi Aprian Sari ◽

Arief Fauzi ◽

Gede Sutresna Wijaya

Keyword(s):

Monte Carlo ◽

Radiation Dose ◽

Dose Rate ◽

Neutron Source ◽

Gamma Ray ◽

Outer Part ◽

Radiation Shielding ◽

Radiation Dose Rate ◽

Boron Neutron Capture ◽

Radiation Workers

The research aims to measure the radiation dose rate over the radiation shielding which is made of paraffin and aluminium and to determine the best shield material for the safety of radiation workers. The examination used MCNP (Monte Carlo N-Particle) simulator to model the BNCT neutron source and the shield. The shield should reduce radiation to less than the dose limit of 10.42 µSv/h, which is assumed to be the most conservative limit when the duration of workers is 1920 h. The first design resulted in a radiation dose rate which was still greater than the limit. Therefore, optimization was done by adding the lead on the outer part of the shield. After optimization by adding the lead with certain layers, the radiation dose rate decreased, with the largest dose being 57.60 µSv/h. Some locations over the limit could be overcome by other radiation protection aspects such as distance and time. The paraffin blocks were covered by aluminium to keep the shield structure. The lead was used to absorb the gamma ray which resulted from the interaction between the neutrons and aluminium.

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Chemical vapor deposited diamond radiation detectors for ultrahigh radiation dose‐rate measurements: Response to subnanosecond, 16‐MeV electron pulses

Review of Scientific Instruments ◽

10.1063/1.1146077 ◽

1995 ◽

Vol 66 (12) ◽

pp. 5516-5521 ◽

Cited By ~ 6

Author(s):

S. Han ◽

R. S. Wagner ◽

J. Joseph ◽

M. A. Plano ◽

M. Dale Moyer

Keyword(s):

Radiation Dose ◽

Dose Rate ◽

Chemical Vapor ◽

Radiation Detectors ◽

Radiation Dose Rate ◽

Chemical Vapor Deposited ◽

Electron Pulses

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The rain induced gamma-radiation dose rate enhancement at Järvselja SMEAR station

10.5194/egusphere-egu21-15644 ◽

2021 ◽

Author(s):

Urmas Hõrrak ◽

Xuemeng Chen ◽

Kristo Hõrrak ◽

Uko Rand ◽

Kaupo Komsaare ◽

...

Keyword(s):

Radiation Dose ◽

Gamma Radiation ◽

Dose Rate ◽

Atmospheric Aerosol ◽

Aerosol Particles ◽

Aerosol Formation ◽

Radiation Dose Rate ◽

Air Mass ◽

Rate Enhancement ◽

Gamma Radiation Dose

The SMEAR Estonia station (58.277663 N, 27.308266 E, 36 m a.s.l.) was established in south-east of Estonia at the J&#228;rvselja Experimental Forestry in 2012 to investigate the atmosphere-biosphere interactions and atmospheric aerosol formation and growth.In summer 2019, the gamma-radiation monitor GammaTRACER XL2-3 (Saphymo GmbH) was set up at J&#228;rvselja station and the rain sensor DRD11A (Vaisala Oyj) in autumn 2019. These devices enable to measure the gamma-radiation dose rate and precipitation intensity, which affect the ionization rate of atmospheric air close to ground, with high accuracy and time resolution, and complement our measurement system of atmospheric ions and aerosol particles.The gamma-radiation dose rate measurements at about 1.2 m above the ground reveled on relatively steady background about 70 nSv/h occasional events with increase up to about 110 nSv/h, which correlated well with rainfall intensity. Commonly such events last 3-4 hours, but in specific meteorological situation with continuous long-lasting rain and air mass movement from southerly directions the effect can last 2-3 days, resulting in gradual increase in gamma-radiation dose rate level during about 24 h.Such a phenomenon is known to occur due to wet deposition of radioactive aerosol particles during rain, namely due to the radon (222 Rn) short-lived daughter progeny products (Po-218, Pb-214, Bi-214) attached to atmospheric aerosol particles. The radon (222 Rn) daughter progeny involvement is confirmed by simultaneous gamma-spectrometric measurements with SARA AGS711F (Envinet GmbH) at T&#245;ravere station (58&#176; 15' 52,9" N, 26&#176; 27' 42,1", 72 m), located about 50.3 km west from the J&#228;rvselja SMEAR station. The gamma dose rates showed very similar temporal behavior when both stations were affected by the same air mass with precipitation zone passing over the stations.To our best knowledge, the details of rain-induced enhancement of gamma-radiation dose rate and atmospheric processes behind the phenomenon are not well known and are worth future investigations. The events of rain induced gamma-radiation dose rate enhancement at J&#228;rvselja SMEAR and T&#245;ravere station are analyzed and discussed in more detail in the presentation and the spatial representativity of the phenomenon is estimated based on the gamma-radiation monitoring network data of Estonian Early Warning System.

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