Introduction to Nuclear Instrumentation

2020 ◽  
pp. 19-36
Author(s):  
Douglas S. McGregor ◽  
J. Kenneth Shultis
Keyword(s):  
Nuclear Instrumentation

Nuclear Instrumentation Systems in Prototype Fast Breeder Reactor

2004 ◽  
Author(s):  
P. M. Vijayakumaran ◽  
C. P. Nagaraj ◽  
C. Paramasivan Pillai ◽  
R. Ramakrishnan ◽  
M. Sivaramakrishna
Keyword(s):  
Neutron Flux ◽  
Early Warning System ◽  
Warning System ◽  
Radiation Monitoring ◽  
Fast Breeder Reactor ◽  
Delayed Neutrons ◽  
The Core ◽  
Flux Monitoring ◽  
Nuclear Instrumentation ◽  
Fission Chambers

The nuclear instrumentation systems of the Prototype Fast Breeder Reactor (PFBR) primarily comprise of global Neutron Flux Monitoring, Failed Fuel Detection & Location, Radiation Monitoring and Post-Accident Monitoring. High temperature fission chambers are provided at in-vessel locations for monitoring neutron flux. Failed fuel detection and location is by monitoring the cover gas for fission gases and primary sodium for delayed neutrons. Signals of the core monitoring detectors are used to initiate SCRAM to protect the reactor from various postulated initiating events. Radiation levels in all potentially radioactive areas are monitored to act as an early warning system to keep the release of radioactivity to the environment and exposure to personnel well below the permissible limits. Fission Chambers and Gamma Ionisation Chambers are located in the reactor vault concrete for monitoring the neutron flux and gamma radiation levels during and after an accident.

scholarly journals Gamma Radiation Applied in Euterpe oleraceae Pulps

2020 ◽  
pp. 134-145
Author(s):  
Lucia Maria Jaeger de Carvalho ◽  
Bruno Paranhos ◽  
Edgar Francisco Oliveira de Jesus ◽  
José Luiz Viana de Carvalho
Keyword(s):  
Antioxidant Capacity ◽  
Rio De Janeiro ◽  
Antioxidant Properties ◽  
Total Phenolic ◽  
Low Doses ◽  
Plastic Bags ◽  
Freeze Dried ◽  
Total Anthocyanins ◽  
The City ◽  
Nuclear Instrumentation

Aims: The aim of this work was to evaluate the optimal radiation dose to maintain the antioxidant capacity of conventional and organic acaí freeze-dried pulps. Study Design: All analyses were conducted in sextuplicate for each experiment. Place and Duration of Study: Were conducted at the LATAIA and the irradiation processes at the Laboratory of Nuclear Instrumentation, UFRJ, Rio de Janeiro, Brazil. The study was carried out from July, 2018 to March, 2020. Methodology: Frozen acaí pulps from two commercial brands, one of them organic and other conventional were used and purchased in the city of Rio de Janeiro, packed in plastic bags containing 1 kg. For each brand, frozen pulps (5 kg) were thawed at 4ºC, opened and homogenized. Samples were subdivided into aliquots ranging from 20 to 300 g for the assays and frozen inside the plastic bags until analyses. A Cobalt 60, Gammacell irradiator was used and doses of 1.25. 2.5. 3.75 and 5 kGy were applied in the in natura pulps. Antioxidant capacity was performed by the ORAC and DPPH methods and, phenolic compounds by Folin Ciocalteau method and, total anthocyanins and majority anthocyanidins by HPLC. Results: Anthocyanins increases at irradiaton dose up to 3.75 kGy in organic açaí but it was not significant in conventional acaí irradiated at low doses (1.25 to 3.75 kGy). Our results suggested that irradiation doses up to 5 kGy do not decrease total phenolic or anthocyanin contents nor the pulp antioxidant activity compared with non-irradiated pulps. The results showed irradiation did not reduce these analytes, and even increased in the organic acaí. Conclusion: The study evidenced that gamma irradiation can be an alternative safe process for fruit pulps preservation. We conclude that irradiation doses up to 5 kGy can be used in acaí without harming its antioxidant properties.

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