• Nuclear Engineering and Technology
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• v.51 no.2
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• pp.384-393
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• 2019

An experimental validation of a nuclear forensics methodology for the source reactor-type discrimination of separated weapons-useable plutonium is presented. The methodology uses measured values of intra-element isotope ratios of plutonium and fission product contaminants. MCNP radiation transport codes were used for various reactor core modeling and fuel burnup simulations. A reactor-dependent library of intra-element isotope ratio values as a function of burnup and time since irradiation was created from the simulation results. The experimental validation of the methodology was achieved by performing two low-burnup experimental irradiations, resulting in distinct fuel samples containing sub-milligram quantities of weapons-useable plutonium. The irradiated samples were subjected to gamma and mass spectrometry to measure several intra-element isotope ratios. For each reactor in the library, a maximum likelihood calculation was utilized to compare the measured and simulated intra-element isotope ratio values, producing a likelihood value which is proportional to the probability of observing the measured ratio values, given a particular reactor in the library. The measured intra-element isotope ratio values of both irradiated samples and its comparison with the simulation predictions using maximum likelihood analyses are presented. The analyses validate the nuclear forensics methodology developed.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.299-304
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• 2024

Beyond the first nuclear age, which pitted the United States and the Soviet Union against each other, we are now in the second nuclear age, in which the decision-makers of nuclear weapons are diversified among countries large and small. India and Pakistan, two such countries, are antagonistic toward each other and possess nuclear weapons, but their nuclear posture and nuclear strategies are different. The examples of these two countries can provide clues to the future nuclear posture of North Korea, which faces South Korea. In particular, Pakistan's chosen posture of pre-emptive deterrence is a highly offensive nuclear posture that threatens to use nuclear weapons against an adversary to deter aggression. This is an option that can be accomplished even with a small nuclear arsenal that can be used as a first strike, so it seems to be the optimal posture for a nuclear-powered Pakistan to choose in response to an Indian threat. North Korea, which is outgunned by the United States and South Korea, is likely to continue to threaten to use nuclear weapons preemptively like Pakistan. However, it is expected to be defensive and quite conservative, like India, until it actually uses them to maintain its regime.

• Strategy21
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• s.31
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• pp.5-26
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• 2013

The South Korean society has experienced many changes since the sinking of ROKS Cheonan. The government reviewed its defense posture and adopted the 5·24 Measure in its relations with North Korea. As a result, the people of South Korea became more conscious of security situations on the Korean peninsula while North Korea's economy suffered badly. Meanwhile, the South Korean government has taken a flexible stance toward North Korea in terms of exchange and cooperation since September 2011. The flexible stance was to manage inter-Korea relations in a stable manner and relieve the hardships of the North Korean people while preserving the spirits and purposes of the 5·24 Measure. The UN Security Council adopted twenty-six resolutions and statements on North Korea since June 25, 1950. They include thirteen U.N. Security Council resolutions including those concerning nuclear weapons or missile programs, nine Presidential statements, and four press statements. Resolution 82, the first U.N. resolution on North Korea, came when the Korean War broke out. Resolution 825, the first one related to nuclear or missile programs, was adopted in response to North Korea's withdrawal from the NPT. Apart from these U.N. resolutions, the United States has imposed separate sanctions against North Korea. North Korea's nuclear weapons program can be considered in comparison with that of Iran in terms of the consequences they create for the regional security. The Security Council has adopted six resolutions on Iran so far. One should note that the resolutions on Iran have had much stronger sanctions compared to those imposed on North Korea. That is, while the North Korea case may be viewed as a more serious threat to international security from the perspective of nuclear weapons development or proliferation, tougher sanctions have been placed on Iran. There are two approaches that South Korea should take in addressing the related issues. First, we should aim to reduce the gap between sanctions imposed on Iran and North Korea. It is difficult to understand that a country with more serious problems is rewarded with lighter sanctions. We should take measures through the Security Council Sanctions Committee to make individuals and groups in North Korea that play a central role in developing nuclear weapons and missiles subject to additional sanctions. Second, we have to change. Other countries in the international community have become tired of North Korea's nuclear issue and now they look to South Korea for initiative. We should correctly understand this current situation and play a leading role within our capacity. Knowingly and unknowingly, the notion that the North Korean nuclear issue may be left to South Korea has been spread around the international community. Although the situation is grave, we should try to open a new horizon in ushering in the unification era by taking the initiative with confidence that there is a looming hope ahead of us. For these tasks, we should stop thinking in the old way that has been ossified for the last two decades. We should not be pushed around by neighboring great powers in dealing with North Korea related issues anymore; we should take the initiative with resolution that we will play our role at the center of four great powers and with confidence that we can do it. Based on the confidence that the Republic of Korea has become a country with enough capacity to take the initiative, we should establish a 'National Grand Strategy' representing South Korea's strategic vision that the unification is the ultimate solution to the problems related to North Korea's nuclear weapons program.

• Proceedings of the Safety Management and Science Conference
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• 1999.11a
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• pp.421-424
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• 1999

In this short report (before the authors would like to introduce an important application for one of the techniques of complex angular momentunm, say, Regge Pole approach, to nuclear fusion reaction for Light-ions: it will be reported in forthcoming papers), two kinds of thermalnuclear fusion reaction sources are introduced and discussed (A) the case of fusion: the production of neutron and target of Deuteron and (B) the case of fusion: the production of proton and target of Deuteron. Nuclear fusion reactions for Light-ions , such as the thermalnuclear energy sources and fuel cycles, are already well known. Fusion reactions are widely known as being extremly important and nationally vital (in point of view of nuclear weapons we must reconsider seriously development and building of such dangerous weapons) for our next generations in the future. This paper (a topics in review) is concerned with a simple introduction about a new nuclear fusion reaction of the above case of (B) for the second generation. Typical thermalnuclear fusion reactions which result in the release of huge amount of energy are nuclear stripping reactions:

• Nuclear industry
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• no.3
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• pp.5-30
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• 1978

• Convergence Security Journal
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• v.16 no.3_1
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• pp.107-114
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• 2016

The North Korean regime, Kim Jungun's foreign policy is changed frequently. And their military policy has no gravity. North Korea has developed nuclear weapons and long range missile. Now they have Inter-Continental Ballistic Missile. These activities redound a great threat in Korean peninsula. There are a no possibilities to give up its nuclear weapons and missile development. For the peace in Korean peninsula, we should make North Korea to abandon its nuclear himself through effective sanctions. Now China should effort to control North Korea. To reduce the threat we should coordinate the strategic interests of China and US. This study is to predict the North Korea military activities to analyze "military policies."

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.2
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• pp.219-246
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• 2017

Nuclear issue is a good example showing globalization of the international regime. The history showed nuclear weapons may cause the extinction of human races when the first nuclear bombs fell down to Japan in August, 1945 and people became increasingly eager to achieve peace. Military buildup for national security is a matter of existence in the international society. However, disarmament or arms control to secure international peace and safety which is also the purpose of the Charter of the United Nations may be the most important task for us to realize peace of the mankind. Today, disarmament, together with amicable settlement of international conflicts and collective security system, is an important means to maintain and promote international peace and safety. It might be our permanent task to realize complete disarmament but, as the Preamble of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) expressed general and complete disarmament, the international society has clarified its effort for complete disarmament. Thus, taking a look into the international regime on the nuclear issue and progress related to the nuclear issue in North Korea, the study was intended to introduce the globalization of the nuclear issue, review the international effort for nuclear disarmament based on the concept of the 'common heritage of the mankind' and with respect to the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) and controls over nuclear weapons, and then evaluate the North Korean nuclear issue, which is in direct relation with South Korea and international laws, in terms of the space law and disarmament acts. The collective security system along with policies to prevent dissemination of nuclear weapons should also be emphasized and implemented to cope with the North Korean nuclear issue.

• Journal of Contemporary Eastern Asia
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• v.14 no.2
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• pp.57-68
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• 2015

This paper examines the New York Times' reaction to the 2010 Brazil-Turkey-Iran (BTI) nuclear deal, the very last diplomatic effort before the imposition of international sanctions track over the following years. The New York Times' (NYT) coverage of the deal is examined using the Critical Discourse Analytic (CDA) approach formulated by Teun van Dijk. The results show a strong bias against the BTI deal throughout the NYT's news coverage. The overarching theme in cover-age of the deal is the imputation of malignant intentions on the part of both Iran ("to kill time to further its nuclear weapons program") and Brazil and Turkey ("to advance their own business dealings with Iran and gaining international recognition"). Also, non-relevant information is used to imply a threat of Iranian development of nuclear weapons. Moreover, the NYT leaves almost totally "unsaid" that president Obama had asked Brazilian and Turkish leaders to go to Tehran and get this deal. Therefore, the NYT basically echoed, and legitimized, discursive practices of the U.S. government on the deal.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1652-1657
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• 2021

Nuclear materials can be utilized not only for peaceful uses, but also for military purposes; hence, the international community has devoted itself to the control, management and safeguarding of nuclear materials. Nuclear materials are of varying degrees of usability for development of nuclear weapons. Thus, several methods for assessing the attractiveness of nuclear materials for nuclear weapons purposes have been proposed. When these methods are applied to unirradiated depleted, natural, and low-enriched uranium (DU, NU, and LEU), they are certainly classified as non-attractive nuclear materials. However, when nuclear material attractiveness is to be evaluated for potential radiological dispersal device (RDD) uses, it is required to develop a different method for the different aspects and factors. In the present study, we derived a novel method for evaluating nuclear material attractiveness for use in RDD development. To this end, the specific activity and dose coefficient were identified as the two sub-factors, and, in consideration of those, the mass causing detrimental health effects was determined to be the main factor impacting on nuclear materials attractiveness. Based on this factor, the attractiveness of unirradiated DU, NU, and LEU for RDD use was qualitatively compared with that of ¹³⁷Cs.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.4
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• pp.479-489
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• 2021

The Republic of Korea is expected to participate in the denuclearization verification activities by the International Atomic Energy Agency (IAEA) in case any neighboring countries declared denuclearization. In this study, samples for the verification of nuclear activities in undeclared areas were selected for the denuclearization of neighboring countries, and the appropriateness of the procedures was considered. If a country with nuclear weapons declares denuclearization, it must be accompanied by the IAEA's verification regarding nuclear materials and weapons in the declared and undeclared areas. The analysis of the process samples or on-site environmental samples and the verification of undeclared nuclear facilities and materials aid in uncovering any evidence of concealment of nuclear activity in undeclared areas. Therefore, a methodology was established for effective sampling and analysis in accordance with proper procedures. Preparations for sampling in undeclared areas were undertaken for various potential scenarios, such as, the establishment of zones according to radiation dose, methods of supplying electricity, wireless communication networks, targets of sampling according to characteristics of nuclides, manned sampling method, and unmanned sampling method. Through this, procedures were established for pre- and post-site settings in preparation for hazards and limiting factors at nuclear inspection sites.