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This paper gives an extensive analysis on the characterization of xenon isotopic ratios for various nuclear reactors and nuclear explosions through neutronic depletion codes. The results of the characterization can be used for discriminating the sources of the xenon isotopes’ release among the nuclear explosions and nuclear reactors. The considered sources of the xenon radionuclides do not only include PWR, CANDU, and nuclear explosions using uranium and plutonium bombs, but also IRT-200 and 5MWe Yongbyon (MAGNOX reactor) research reactors operated in North Korea. A new data base (DB) on xenon isotopic activity ratios was produced using the results of the characterization, which can be used in discrimination of the sources of xenon isotopes. The results of the study show that 5MWe Yongbyon reactor has quite different characteristics in 135Xe/133Xe ratio from the PWRs and the nuclear reactors have different characteristics in 135Xe/133Xe ratios from the nuclear explosions.

Science and Technology Conference (SnT) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is committed to advancing the scientific and technological progress of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), relying on scientific and technological innovation to strengthen the treaty verification system capabilities of CTBT and accelerating the progress of its entry into force. As seismology is an important means for nuclear-test-ban monitoring, and the scientific advances of the SnT conference is helpful to review the development of earthquake science and technology, this paper systematically analyzes the scientific topic setting and the advances of seismic event discrimination research in the SnT conference. The analysis showed that the themes of “the earth as a complex system” and “advances in sensors, networks and processing”, as well as the seismological approaches of the nuclear-test-ban monitoring, attracted more attention. Seismic event discrimination remains a critical CTBT-related seismology problem, and the same is the focus of attention in the applied research on the North Korean nuclear test series, while new technologies such as deep learning and machine learning have shown a rapid development trend in event discrimination research.

Onsite measurements are the standard for establishing geological conditions and related transport properties. However, making direct measurements is not always possible, either because a location is too remote, too vast, or access is outright denied. The latter is typically the case at nuclear test sites, or military installations. Here we describe a systematic method to characterize geology and estimate fracture width, spacing, tortuosity, permeability, and porosity at locations where direct measurements cannot be made. Fractures are treated as fractals with their respective fractal dimensions determined using surface images. Tortuosity in the geological matrix (i.e., bulk media) is determined using rock class with the latter also being used to determine distributions for permeability and porosity. The approach is tested using areal images and rock class for the Nevada Test Site and validated by comparison to field and core measurements. Past work has shown that testing a nuclear weapon underground can affect not only the migration time for gases to the surface but also their isotopic ratios. Accurately modeling gas transport and isotopic fractionation requires knowledge of the geology. However, suspected tests are typically conducted at sites to which the international community has no access. Plain Language Summary: Subsurface geology affects processes that affect aquifer recharge, land‐atmosphere gas transport, seismic conditions and stability. Onsite measurements are the standard for establishing the geological conditions at a particular location. However, accessing a location is not always possible and in situations like these, other methods with which to estimate subsurface conditions are needed. This is particularly true for the sites at which suspected nuclear tests take place, or other locations to which access is restricted. Here we provide a systematic way for estimating the geology at such locations that is based on open source data. Key Points: It is not always possible to gain access to a site where understanding the local geology is importantWe provide a systematic way to estimate fracture width, spacing, tortuosity, permeability, and porosity using areal images and rock classThe approach is validated with an analysis of the Nevada Test Site and comparison of the results to field and core measurements [ABSTRACT FROM AUTHOR]

This study investigates the impact of North Korea’s nuclear tests on Asian stock markets. Two approaches are used separately in order to identify how stock market returns and volatilities change immediately after the nuclear tests. We find that the Chinese stock market tends to be more sensitive to unexpected shocks from North Korea’s nuclear tests than other Asian stock markets. However, relatively, the Japanese stock market is little influenced by the nuclear tests though Japan is not only geographically close to North Korea but also politically vigilant to North Korea’s nuclear threats. Also, we find that strengthened return correlations (linearity) do not necessarily increase stock return volatilities.

Iran lies in an earthquake belt, and many Iranians have highlighted memories of natural disasters. While visiting Bam, a city destroyed by a severe earthquake, my team and I realized that some inhabitants attribute the disaster to nuclear tests. These rumours were also heard from the survivors of the earthquake in Sarpol-e Zahab in 2018. Looking deeper into the roots of nuclear rumours, I found the origin of rumours about the unnatural cause of the earthquake many years earlier, before the 1979 revolution and in the Tabas 1978 disaster. In this article, the nuclear folklore around earthquakes in Iran has been investigated. Analysing public opinion about disasters without considering their perceptions, rumours, and folklore is not complete. The current study reveals an overlooked mechanism based on the long-term dictatorship and untrustful media have made understanding the disasters complicated in the country. [ABSTRACT FROM AUTHOR]

The 6th nuclear test of North Korea on September 3, 2017 produced an mb 6.1 artificial earthquake and significant surface deformations detectable from satellite observations. Wang et al. (2018) have reported the surface displacement of the Mt. Mantap caused by the explosion by applying offset-tracking method to TerraSAR-X SAR images. Based on the assumption of elastic behaviour of the mountain body, they have modelled the rise and collapse of the mountain and suggested the location, depth and energy of the explosion. However, we suspect that the surface displacement might be caused by landslide in which case the elastic modelling would be misleading. In this paper, we use both SAR interferometry and offset-tracking method to quantify the elastic and random deformation caused by the explosion. The 3-D displacement vectors around the rim of the explosion, where the inter-ferometric coherence is maintained, were obtained by using three ALOS-2 interferograms acquired in different orbits. Only east-west component of the displacement vector was valid due to orbital characteristics, which indicates the explosive tendency of the bedrock of up to 25 cm in the rim of the mountain. Deformation on the ruptured zone, where the interferometric coherence is lost, was detected through visual inspection and offset tracking by using two pairs of high-resolution ALOS-2 and TerraSAR-X images. It showed up to 3.5 m displacement on the mountain slope towards the direction of gravity, which is similar to the results of Wang et al. (2018). However, we have visually identified many stable points and features that have not moved at all in the mountain flank surrounded by active surface deformation, which is believed to be stable bedrocks and outcrops. This implies that the displacements observed by the offset method in the mountain flank of the ruptured zone were mostly of landslides caused by the topsoil and boulder stones. It is suggested that elastic behaviour of the mountain body due to the 6th nuclear test of North Korea is unidentifiable and the subsequent modelling might be invalid in the mountain flank of the ruptured zone where surface motion from landslides is dominant. [ABSTRACT FROM AUTHOR]

In this essay, the author explores whether nuclear catastrophe is beyond the reach of art. A documentary photographer, she reflects on her own work capturing the lives of those who lived downwind of the nuclear tests conducted at the Nevada Test Site in the United States. Many years after being immersed in the project for a decade, and documenting the effects of 1,000 nuclear devices that had exploded above this population, the author finally arrives at the answer to her question. [ABSTRACT FROM AUTHOR]

In this interview, former Los Alamos National Laboratory director Siegfried S. Hecker details one of the world’s great nonproliferation stories—the effort to secure the Semipalatinsk Test Site in Kazakhstan. He recounts his visit to the Russian nuclear weapons labs in early 1992, after the collapse of the Soviet Union, when he found underfunded scientists who were indifferent to the cleanup of the testing site in the now-independent Kazakhstan and doubtful that the site would pose a security threat. Hecker talks about how he was able to organize engineers and nuclear scientists in the United States, Russia, and Kazakhstan to come together in a 15-year, $150-million effort to secure many of the tunnels and test areas at the sprawling Semipalatinsk Test Site. [ABSTRACT FROM PUBLISHER]

The idea that ordinary people might contribute to verification of arms control treaties is not new; abstract discussions of the concept date back decades. But powerful and portable electronic devices have spread so widely in recent years that societal verification now seems an imminent reality. Motivated individuals might, for instance, collect treaty-relevant data through onboard sensors that smartphones can carry and then transmit the information to multilateral verification bodies or, as is already happening, share it online with global communities that subject it to crowdsourced analysis. But will societal verification generate enthusiasm in the developed and developing worlds alike? What legal protections must be established for participants? And will information gathered through societal verification ultimately prove useful and trustworthy? Three authors explore these emerging questions: from Burkina Faso and representing the Preparatory Commission for the Comprehensive Nuclear Test Ban Treaty Organization, Lassina Zerbo; from the United States, research fellow Nima Gerami (2013); and from Malaysia, nuclear engineer Jamal Khaer Ibrahim (2013). [ABSTRACT FROM AUTHOR]

Monitoring seismic activity in the north Korean Peninsula (NKP) is important not only for understanding the characteristics of tectonic earthquakes but also for monitoring anthropogenic seismic events. To more effectively investigate seismic properties, reliable seismic velocity models are essential. However, the seismic velocity structures of the region have not been well constrained due to a lack of available seismic data. This study presents 1-D velocity models for both the inland and offshore (western East Sea) of the NKP. We constrained the models based on the results of a Bayesian inversion process using Rayleigh wave dispersion data, which were measured from ambient noise cross-correlations between stations in the southern Korean Peninsula and northeast China. The proposed models were evaluated by performing full moment tensor inversion for the 2013 Democratic People's Republic of Korea (DPRK) nuclear test. Using the composite model consisting of both inland and offshore models resulted in consistently higher goodness of fit to observed waveforms than previous models. This indicates that seismic monitoring can be improved by using the proposed models, which resolve propagation effects along different paths in the NKP region. [ABSTRACT FROM AUTHOR]

This article challenges the stereotype that North Korea's foreign policy is difficult to predict and thus can only be subjected to ex post study. Based on the naive Bayesian method, we establish a short‐term prediction model for North Korea's nuclear and missile tests using international news reports from North Korean media between 2006 and 2018 as a dataset. The test results show that the overall accuracy rate of the model's predictions of North Korean historical activity is greater than 80%, and its robustness is strong. To solve the problem of relatively delayed data collection, we use the Seasonal Autoregressive Integrated Moving Average (SARIMA) time series analysis method to simulate the values of feature sets. The estimated data are statistically reliable, and the prediction accuracy is high. This study proves that although the DPRK is extremely closed, it is possible to make relatively accurate predictions of its behavior using appropriate methods. The modeling approach in this paper can provide inspiration for developing general approaches to national behavior prediction. [ABSTRACT FROM AUTHOR]

Three soil depth profiles of 210Pb, 137Cs and 40K at different areas of Algeria were studied. The soil sampling areas are near the location where the French nuclear tests took place at 1960–1966. The two depth soil profiles were collected at Ghardaia region and the third one at Reggane region. The vertical distributions of radionuclides at the two soil depth profiles from Ghardaia region are different, probably due to the different soil composition. The soil depth profile from sandy soil show uniformity in the distribution of radionuclides without a clear maximum (peak). The soil depth profile that characterised by silty sand show a clear peak at 20–50 cm depth for all studied radioactive nuclides, while the observed activities are two times higher than the corresponding values in sandy soil samples. More specifically in Ghardaia region the 210Pb, 137Cs, 40K activity concentrations ranged between 27 and 50 Bq kg−1, 0.2 and 3 Bq kg−1 and 75 and 90 Bq kg−1 respectively in sandy soil type and between 37 and 75 Bq kg−1, 4 and 6 Bq kg−1 and 140 and 180 Bq kg−1 respectively in silty sand soil type. Finally, the third depth soil profile collected from Reggane site presents a completely different distribution of the studied radionuclides. The activity concentrations of 210Pb, 137Cs, 40K ranged between 37 and 51 Bq kg−1, 0.16 and 0.39 Bq kg−1 and 120 and 309 Bq kg−1 respectively. Three peaks in the 137Cs distribution revealed, were most probably, Chernobyl related 137Cs accounts for the surface peak, while the deeper peaks are connected to the weapons fallout. [ABSTRACT FROM AUTHOR]

After years-long research, Indian scientists carried out a successful nuclear explosion on May 18, 1974 in the Rajastan desert. Although Indian officials immediately stated that it was a „peaceful nuclear explosion“, and that they did not intend to make a nuclear weapon, India had become the 6th nuclear power and the first non-aligned country to come into „the nuclear club“. This lead to a strong criticism on the international stage, especially by Pakistan, as well as by great powers and some non-aligned countries. As a member of the Non-aligned Movement, closely aligned with India, Yugoslavia carefully tracked statements and explanations given by Indian officials, systematically noted and analyzed responses of individual countries, and calmly created its own view toward the Indian nuclear test. Yugoslav diplomacy promptly congratulated India its huge technological success, defending the right of all countries, including India, to develop research in the field of nuclear energy, thereby granting full trust to Indian official statements that they did not intend to use their achievements in military purposes. Further, the Indian nuclear explosion resurrected the previous nuclear ambitions of Yugoslav state leadership, primarily of Josip Broz Tito. The Yugoslav nuclear program was relaunched, including the examination of possibilities for exploiting nuclear energy for military purposes. Yugoslav leaders expected great help from India in this matter, so they undertook efforts to intensify cooperation between the two countries in the field of nuclear energy, and to spread that cooperation to other non-aligned countries. However, Indian assistance, being much less than expected, did not contribute to the Yugoslav nuclear program, which, owing to many weaknesses, produced modest results in civilian research, and did not achieve any success in the military field.

Los Alamos has a long history of participation in active experiments in space beginning with the Teak nuclear test in 1958. Above-ground nuclear testing stopped in 1962 because of the Partial Test Ban Treaty, and a program of non-nuclear chemical release experiments began in 1968. Los Alamos has participated in nearly 100 non-nuclear experiments in space, the last being the NASA-sponsored strontium and europium doped barium thermite releases in the Arecibo beam in July of 1992. The rationale for these experiments ranged from studying basic plasma processes such as gradient- driven structuring and velocity-space instabilities to illuminating the convection of plasmas in the ionosphere and polar cap to ionospheric depletion experiments to the B.E.A.R. 1-MeV neutral particle beam (NPB) test in 1989. This report reviews the objectives, techniques and diagnostics of Los Alamos participation in active experiments in space.