• 방사성폐기물학회지
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• 제19권4호
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• pp.421-433
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• 2021

The present multidisciplinary study, which is a nexus of engineering and political science, investigates how the modernization of Non-Strategic Nuclear Weapons (NSNWs) affects the IAEA safeguards system based on the likelihood of the use of nuclear weapons. To this end, this study examines the characteristics of modernized NSNWs using Monte Carlo techniques. The results thus obtained show that 10 kt NSNWs with a Circular Error Probability (CEP) of 10 m can destroy the target as effectively as a 500 kt weapon with a CEP of 100 m. The IAEA safeguards system shows that the Significant Quantity (SQ) of 1 of plutonium is 8 kg, a parameter that was established when strategic nuclear weapons were dominant. However, the results of this study indicate that in recent years, low-yield nuclear weapons such as NSNWs have been more strategically interesting than strategic nuclear weapons as NSNWs require less plutonium than strategic nuclear weapons. Therefore, we would like to conclude that reducing the SQ of plutonium can result in more robust safeguards and non-proliferation strategies.

• 대한화학회지
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• 제43권3호
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• pp.280-285
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• 1999

이온크로마토그래피를 이용하여 Pu 화학종의 분리방법을 검토하였다. 환원제(KI, $NaNO_2$) 또는 산화제(KBrO_3$)를 사용하여 Pu의 산화수를 조절한 후 1-octanesulfonate 와 ${\alpha}$-HiBA 용리액을 사용하는 동적계에서 $PuO_2^{2+},\; PC^{4+}$ 및 $Pu^{3+}$의 화학종을 각각 안정하게 개별분리하였다. Iodide와 nitrite를 동시에 사용하여 Pu 화학종들을 $Pu^{3+}$까지 환원한 다음 이온크로마토그래피로 안정하게 분리하였다.

• Nuclear Engineering and Technology
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• 제50권1호
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• pp.140-144
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• 2018

Isotopic analyses of plutonium and low-enriched uranium mixtures with particle sizes of $0.6-3.3{\mu}m$ were performed using thermal ionization mass spectrometry with a continuous heating method to verify its effectiveness for the accurate analysis of minor isotopes without sample pretreatment. The mixed particles used in this study were prepared from a mixed solution of plutonium (SRM 947) and uranium (U010, $^{235}U$ 1% enriched) reference materials. The isotope ratios for plutonium in the individual mixed particles, including $^{238}Pu/^{239}Pu$, $^{241}Pu/^{239}Pu$ as well as $^{240}Pu/^{239}Pu$, and $^{242}Pu/^{239}Pu$, were in good agreement with the certified values despite the isobaric interference of $^{238}U$ and $^{241}Am$. The isotope ratios for uranium in the mixed particles also agreed well with the certified values within the range of error. However, the isotope ratios for minor isotopes, such as $^{234}U$ and $^{236}U$, in the particles with diameters of less than approximately $1.8{\mu}m$ could not be measured because numbers of $^{234}U$ and $^{236}U$ atoms in analyzed particles are too low. These results indicate that thermal ionization mass spectrometry with a continuous heating method is applicable for the analysis of trace amounts of plutonium isotopes, including $^{238}Pu$ and $^{241}Pu$, despite the presence of the respective isobars $^{238}U$ and $^{241}Am$ in the microsamples.

• 방사성폐기물학회지
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• 제18권1호
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• pp.83-90
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• 2020

흑연 동위원소 비율법(GIRM)은 비핵화 검증 도구로써 흑연감속로의 플루토늄 생산량을 예측하는데 사용된다. 원자로가 가동되면 ²³⁸U의 중성자 포획 반응에 의해 플루토늄이 생성되어 축적되고 동시에 흑연 내 불순물도 핵반응을 통해 다른 핵종으로 바뀌기 때문에 플루토늄의 생성량과 불순물의 농도는 일정한 상관 관계를 갖는다. 이러한 상관관계에도 불구하고 어느 특정 시점에서의 불순물의 농도는 불순물의 초기 농도에 의존하기 때문에 불순물의 초기 농도가 알려지지 않으면 불순물의 절대 농도만으로 플루토늄 생산량을 예측하는 것은 불가능하다. 그러나 불순물의 초기 동위원소 비율은 초기 불순물 농도에 상관없이 알려져 있기 때문에 불순물의 동위원소 비율과 플루토늄 생산량의 관계는 흑연감속로에서 플루토늄 생성량을 예측하는 유용한 도구가 될 수 있다. 흑연동위원소 비율법의 지표 원소로 Boron, Lithium, Chlorine, Titanium, Uranium 등이 이용되는 것으로 알려져 있다. 위 지표원소의 동위원소 비와 플루토늄 생성량 사이의 상관 관계가 초기 불순물 농도에 의존하지 않는지를 네 가지 다른 흑연 불순물 조성을 이용하여 평가하였다. ¹⁰B/¹¹B, ³⁶Cl/³⁵Cl, ⁴⁸Ti/⁴⁹Ti, ²³⁵U/²³⁸U은 흑연의 초기 불순물 농도에 상관없이 누적 플루토늄 생성량과 일관된 상관 관계를 갖는다. 이러한 원소들은 다른 원소의 핵반응에 의해 해당 원소의 동위원소가 생성되지 않기 때문이다. 반면 ⁶Li/⁷Li과 플루토늄 생성량의 상관관계는 흑연 내 불순물의 초기 농도에 의존한다. ⁷Li은 ⁶Li의 중성자 포획 반응에 의해서 생성되기도 하지만 ¹⁰B의 (n, α)반응으로도 생성되는 것이 더 지배적이기 때문에 ¹⁰B의 초기 농도가 ⁷Li의 생성량에 영향을 미치는 것이다. 따라서 Lithium은 흑연 동위원소 비율법을 위한 지표 원소로 적절하지 않음을 알 수 있다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 춘계학술발표회논문집(2)
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• pp.627-632
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• 1998

Using an ammonium oxalate-ammonium sulfate electrolyte, a simple, quantitative, and fast technique for preparing sources for analytical alpha spectrometry was developed. To determine the optimum conditions for plating plutonium, parameters such as current density .and pH of electrolyte affacting the electrodeposition of the plutonium have been investigated. An optimized electrodeposition step for the determination of plutonium has been validated with a result of application to IAEA-Reference Soils. The new method of fallout Pu determination has been applied to environmental samples such as soil, sediment and moss samples in Korea.

• Nuclear Engineering and Technology
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• 제51권5호
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• pp.1398-1405
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• 2019

We use a molecular dynamics simulation to explore thermal transport in oxide nuclear fuels with point defects. The effect of vacancy and substitutional defects on the thermal conductivity of plutonium dioxide and uranium dioxide is investigated. It is found that the thermal conductivities of these fuels are reduced significantly by the presence of small amount of vacancy defects; 0.1% oxygen vacancy reduces the thermal conductivity of plutonium dioxide by more than 10%. The missing of larger atoms has a more detrimental impact on the thermal conductivity of actinide oxides. In uranium dioxide, for example, 0.1% uranium vacancies decrease the thermal conductivity by 24.6% while the same concentration of oxygen vacancies decreases the thermal conductivity by 19.4%. However, uranium substitution has a minimal effect on the thermal conductivity; 1.0% uranium substitution decreases the thermal conductivity of plutonium dioxide only by 1.5%.

• Nuclear Engineering and Technology
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• 제48권1호
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• pp.274-284
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• 2016

Purpose: The purpose of this work is to describe the spectrometric analysis of gaseous cloud formation over reactor mixed uranium-and-plutonium (UP) fuel $(U_{0.8}Pu_{0.2})O_2$ samples heated to a temperature $>2,000^{\circ}C$, and thus forecast and evaluate radiation hazards threatening humans who cope with the consequences of any accident at a fission reactor loaded by UP mixed oxide $(U_{0.8}Pu_{0.2})O_2$, such as a mixture of 80% U and 20% Pu in weight. Materials and methods: The UP nuclear fuel samples were heated up to a temperature of over $2,000^{\circ}C$ in a suitable assembly (apparatus) at out-of-pile experiments' implementation, the experimental in-depth study of metabolism of active materials in living organisms by means of artificial irradiation of pigs by plutonium. Spectrometric measurements were carried out on the different exposed organs and tissues of pigs for the further estimation of human internal exposure by nuclear materials released from the core of a fission reactor fueled with UP mixed oxide. Results: The main results of the research described are the following: (1) following the research on the influence of mixed fuel fission products (radioactive isotopes being formed during reactor operation as a result of nuclear decay of elements included into the fuel composition) on living organisms, the authors determined the quantities of plutonium dioxide ($PuO_2$) that penetrated into blood and lay in the pulmonary region, liver, skeleton and other tissues; and (2) experiments confirmed that the output speed of plutonium out of the basic precipitation locations is very small. On the strength of the experimental evidence, the authors suggest that the biological output of plutonium can be disregarded in the process of evaluation of the internal irradiation doses.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2017년도 추계학술논문요약집
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• pp.137-138
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• 2017

The spectroscopic reference data for plutonium at different temperatures are necessary information for the chemical speciation and evaluation of thermodynamic data at elevated temperature. This work is the initial step to extend research activities for understanding the plutonium chemistry in aquatic solutions at high temperature. The hydrolysis of Pu(III) and the solubility of Pu(III) hydroxide at the elevated temperature will be discussed.

• Nuclear Engineering and Technology
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• 제16권4호
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• pp.224-229
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• 1984

• Mass Spectrometry Letters
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• 제6권3호
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• pp.75-79
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• 2015

Suitable analytical procedures for the bulk analysis of ultra-trace amounts of uranium and plutonium have been developed using multi-collector inductively coupled mass spectrometry (MC-ICP-MS). The quantification and determination of the isotopic ratios of uranium and plutonium in three simulated swipe samples, a swipe blank, and a process blank were performed to validate the analytical performance. The analytical results for the simulated swipe samples were in good agreement with the certified values, based on the measurement quality goals for the analysis of bulk environmental samples recommended by the International Atomic Energy Agency (IAEA)