• Title/Summary/Keyword: Concept of Radiation

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The Underlying Concept of the ICRU Report 39 (ICRU 보고서 39의 배경과 전망)

  • Lee, Jai-Ki
    • Journal of Radiation Protection and Research
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    • v.10 no.1
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    • pp.74-85
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    • 1985
  • The four new operational quantities for the practical determination of dose equivalents from external radiation sources, defined in the ICRU report 39, are reviewed from the viewpoint of the underlying concept, the relationship to the existing quantities, and the expected role in the radiation protection practice and in the radiation measurements.

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Intensity-modulated radiation therapy: a review with a physics perspective

  • Cho, Byungchul
    • Radiation Oncology Journal
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    • v.36 no.1
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    • pp.1-10
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    • 2018
  • Intensity-modulated radiation therapy (IMRT) has been considered the most successful development in radiation oncology since the introduction of computed tomography into treatment planning that enabled three-dimensional conformal radiotherapy in 1980s. More than three decades have passed since the concept of inverse planning was first introduced in 1982, and IMRT has become the most important and common modality in radiation therapy. This review will present developments in inverse IMRT treatment planning and IMRT delivery using multileaf collimators, along with the associated key concepts. Other relevant issues and future perspectives are also presented.

Internal Radiation Dosimetry in Radionuclide Therapy (방사성핵종을 이용한 치료에서 흡수선량의 평가)

  • Kim, Kyeong-Min;Lim, Sang-Moo
    • Nuclear Medicine and Molecular Imaging
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    • v.40 no.2
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    • pp.120-126
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    • 2006
  • Radionuclide therapy has been continued for treatment of incurable diseases for past decades. Relevant evaluation of absorbed dose in radionuclide therapy is important to predict treatment output and essential for making treatment planning to prevent unexpected radiation toxicity. Many scientists in the field related with nuclear medicine have made effort to evolve concept and technique for internal radiation dosimetry in this review, basic concept of internal radiation dosimetry is described and recent progress in method for dosimetry is introduced.

A Numerical Modelling of the tidal front in the Mid-yellow sea off Korea using a concept of Mixing rate (혼합율 개념을 이용한 서해 중부 조석전선의 수치모델)

  • 신상익;승영호
    • 한국해양학회지
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    • v.28 no.2
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    • pp.121-131
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    • 1993
  • The tidal front forming in the Mid-Yellow Sea off Korea, near Tae-An peninsular, is calculated using a 3-D general circulation model(Semtner, 1974) and the concept of mixing rate, an extension of the concept of mixing efficiency proposed by simpson & Hunter(1974). Along the north and south open boundaries, simple radiation conditions are applied. The model is run with the initial state which represents the winter condition. With imposed uniform heating by solar radiation and spatially-different vertical mixing, the model then generated the tidal front comparable to the observed one.

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Application of the Leak Before Break(LBB) Concept to a Heat Exchanger in a Nuclear Power Plant

  • Kwon, Jae-Do;Lee, Choon-Yeol;Lee, Yong-Son;Sul, Il-Chan
    • Journal of Mechanical Science and Technology
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    • v.15 no.1
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    • pp.10-20
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    • 2001
  • The leak before break(LBB) concept is difficult to apply to a structure with a thin tube that is immersed in a water environment. A heat exchanger in a nuclear power plant is such a structure. The present paper addresses an application of the LBB concept to a heat exchanger in a nuclear power plant. The minimum leaked coolant amount(approximately 37.9 liters) containing the radioactive material which can activate the radiation detector device installed in near the heat exchanger is assumed. A postulated initial flaw size that can not grow to a critical flaw size within the time period to activate the radiation detector is justified. In this case, the radiation detector can activate the warning signal caused by coolant leakage from initially postulated flaws of the heat exchanger. The nuclear plant can safely shutdown when this occurs. Since the postulated initial flaw size can not grow to the critical flaw size, the structural integrity of the heat exchanger is not impeded. Particularly the informational scenario presented in this paper discusses an actual nuclear plant.

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Simple Calculation Method as a Supplementary Radiation Safety Assessment for Facility with Radiation Generator

  • Kim, Sang-Tae
    • International Journal of Contents
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    • v.14 no.4
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    • pp.65-69
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    • 2018
  • The objective of this study was to conduct a radiation shielding analysis for the facility equipped with radiation generator. The analysis was carried out in two aspects. First, from the aspect of the effect caused by primary and leakage radiation. Second, effect of scattered radiation was evaluated by applying a simple calculation method based on a scattering rate concept since effect of scattered radiation is significantly important at maze entrance of the radiation facility. The calculated results obtained using the simple method were compared to the results calculated using Geant4 code and the measured values. The results calculated by the suggested method indicate that slight error exists in a radiation shielding analysis done at the maze entrance comparing to other two results, while the results evaluated at the outside of the maze entrance door are relatively consistent with other values.

Proposing a Simple Radiation Scale for the Public: Radiation Index

  • Cho, Gyuseong;Kim, Jong Hyun;Park, Tae Soon;Cho, Kunwoo
    • Nuclear Engineering and Technology
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    • v.49 no.3
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    • pp.598-608
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    • 2017
  • A new radiation scale is proposed. With empathy toward the vast majority of people who are not well versed in radiation and related matters, and thus suffering from misunderstanding that breeds unnecessary fear of radiation, the aim of proposing a new radiation scale, radiation index (RAIN), is to put the general public at ease with the concept of radiation. RAIN is defined in dimensionless numbers that relate any specific radiation dose to a properly defined reference level. As RAIN is expressed in plain numbers without an attached scientific unit, the public will feel comfortable with its friendly look, which in turn should help them understand radiation dose levels easily and allay their anxieties about radiation. The expanded awareness and proper understanding of radiation will empower the public to feel that they are not hopeless victims of radiation. The correspondence between RAIN and the specific accumulated dose is established. The equivalence will allow RAIN to serve as a common language of communication for the general public with which they can converse with radiation experts to discuss matters related to radiation safety, radiation diagnosis and therapy, nuclear accidents, and other related matters. Such fruitful dialogues will ultimately enhance public acceptance of radiation and associated technologies.

AMBIDEBTER Nuclear Complex - A Credible Option for Future Nuclear Energy Applications (AMBIDEXTER 원자력 복합체 - 신뢰성 있는 미래 원자력에너지 이용 방안)

  • 오세기;정근모
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1998.05a
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    • pp.235-242
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    • 1998
  • Aiming at one of decisive alternatives for long term aspect of nuclear power concerns, an integral and closed nuclear system, AMBIDEXTER (Advanced Molten-salt Break-even Inherently-safe Dual-mission Experimental and TEst Reactor) concept is under development. The AMBIDEXTER complex essentially comprises two mutually independent loops of the radiation/material transport and the heat/energy conversion, centered at the integrated reactor assembly, which enables one to utilize maximum benefits of nuclear energy under minimum risks of nuclear radiation. And it provides precious radioisotopes and radiation sources from its waste stream. Also the reactor operates at very low level of fission products inventory throughout its lifetime. The nuclear and thermalhydraulic characteristics of the molten TH/$^{233}$ U fuel salt extend the capability of the self-sustaining AMBIDEXTER fuel cycle to enhance resource security and safeguard transparency. The reactor system is consisted of a single component module of the core, heat exchangers and recirculation pumps with neither pipe connections nor active valves in between, which will significantly improve inherent features of nuclear safety. States of the core technologies associated with designing and developing the AMBIDEXTER concept are mostly available in commercialized form and thus demonstration of integral aspects of the concept should be the prime area in future R&D programs.

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