Analysis of Radionuclide Releases from the Fukushima Dai-ichi Nuclear Power Plant Accident Part II

Achim, Pascal; Monfort, Marguerite; Petit, G. Le; Gross, P.; Douysset, Guilhem; Taffary, T.; Blanchard, X.; Moulin, Christophe

doi:10.1007/s00024-012-0578-1

Cited by 62 publications

(44 citation statements)

References 20 publications

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“…Transfer times for the conversion of volatile iodine to particulate is on the order of several weeks; hence, gaseous iodine may provide a reservoir that can maintain and extend the influence of aerosol deposition of 131 I (cf. Uemetsu et al, 1988;Caput 1993;Achim et al, 2012;Masson et al, 2012;Kristiansen et al, 2013). Thus, the exercise below should be considered one possible endmember-based relation.…”

Section: Estimating the Influence Of 129 I Atmospheric Depositionmentioning

confidence: 99%

The 129-iodine content of subtropical Pacific waters: impact of Fukushima and other anthropogenic 129-iodine sources

et al. 2014

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Abstract.Results obtained from a dedicated radiochemistry cruise approximately 100 days after the 11 March 2011 Tohoku earthquake and subsequent disaster at the Fukushima Daiichi Nuclear Power Plant show that Fukushima derived radionuclides in the nearby ocean environment had penetrated, on average, to ≤ 250 m depth (1026.5 kg m 3 potential density surface). The excess inventory of Fukushima-derived 129 I in the region (∼150 000 km 2 ) sampled during the cruise is estimated to have been between 0.89 and 1.173 billion Bq (∼136 to ∼179 grams) of 129 I. Based on a tight tracer-tracer relation with 134 Cs (or 137 Cs) and estimates that most of the excess cesium is due to direct discharge, we infer that much of the excess 129 I is from direct (non-atmospheric deposition) discharge. After taking into account oceanic transport, we estimate the direct discharge, i.e., that directly released into the ocean, off Fukushima to have been ∼1 kg 129 I. Although this small pulse is dwarfed by the ∼90 kg of weaponstesting-derived 129 I that was released into the environment in the late 1950s and early 1960s, it should be possible to use Fukushima-derived 129 I and other radionuclides (e.g., 134,137 Cs) to study transport and entrainment processes along and across the Kuroshio Current.

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Section: Estimating the Influence Of 129 I Atmospheric Depositionmentioning

confidence: 99%

The 129-iodine content of subtropical Pacific waters: impact of Fukushima and other anthropogenic 129-iodine sources

et al. 2014

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“…64 . For nuclear warheads, the primary gamma-ray emission energy for the fissile material is 1.001 MeV.…”

Section: Overview Of Scintillation In Pet Scansmentioning

confidence: 99%

Zinc oxide nanowire gamma ray detector with high spatiotemporal resolution

et al. 2016

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To my mom, Linda.iii ACKNOWLEDGEMENTSThere are no words to express how grateful I am for all the people that have been part of my life during this journey. I could not have completed my PhD without their help, and I would first like to thank the two advisors that guided me through my graduate career.Professor Richard Mu accepted me as an REU student during my final summer as an undergraduate. After interacting with his group and getting a chance to do actual research in a lab, I changed my graduate path from computational physics to experimental physics and never looked back. Professor Mu's group has always felt like an extended family, where the members worked hard and helped each other without question. I also learned humility in his groupcelebrate the victories in the lab, but be mindful of the people and path that led to that point. I honestly can't begin to express how much I appreciate everything he has done to help me and my family over the years. He has been there through all of the ups and downs in my personal and professional life, and I am honored for the chance to continue to work with him in the future.Professor Richard Haglund accepted me into his group at Vanderbilt after I finished my Master's at Fisk University. I struggled at the beginning while trying to balance course work with research and family, and he gave me some of the best advice I've ever received. He told me that my future was in my hands and that I would fail or succeed based on my own actions. That motivated me to work harder than I had ever worked and is something I still carry with me today.I also want to thank Professor Haglund for instilling within me a deeper appreciation for the elegance of physics, from cascade lasers to perturbation theory. His depth of knowledge and work-life balance are inspiring, and I look forward to working with him in future projects. My mom and dad worked extremely hard to provide a solid foundation for me and my brother. I couldn't ask for better parents. My dad worked to provide for our family, and my mom put her career on hold to stay home with me and my brother. They encouraged us to reach for the stars and to always choose the right path, even if it was the more difficult one. I am who I am today due in large part to the sacrifices, encouragement, and love that my parents provided.

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“…Among the attempts to estimate the Fukushima radiation release employing atmospheric dispersion model and monitoring data, many obtained results directly based on the simple comparison between model outputs and measurements (e.g. Chino et al, 2011;Katata et al, 2012;Terada et al, 2012;Hirao et al, 2013;Kobayashi et al, 2013;Oza et al, 2013;Katata et al, 2014;Achim et al, 2014), while others used a more formal inverse modeling approach by introducing a cost functional and a priori estimate (e.g. Stohl et al, 2012;Winiarek et al, 2012;Saunier et al, 2013;Winiarek et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

“…The radionuclides released after the accident were detected at monitoring stations worldwide, including those of the International Monitoring System (IMS) to support the Comprehensive Nuclear-TestBan Treaty (CTBT) (Auer and Prior, 2014). Sch€ oeppner et al Stohl et al (2012), and Achim et al (2014) estimated the source terms using global monitoring data. Among the attempts to estimate the Fukushima radiation release employing atmospheric dispersion model and monitoring data, many obtained results directly based on the simple comparison between model outputs and measurements (e.g.…”

Section: Introductionmentioning

confidence: 99%

Source term estimation using air concentration measurements and a Lagrangian dispersion model – Experiments with pseudo and real cesium-137 observations from the Fukushima nuclear accident

Chai

Draxler

Stein

2015

Atmospheric Environment

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h i g h l i g h t sEmission inversion has been built based on a Lagrangian model and a cost function. Cs-137 releases from Fukushima accident were recovered using global measurements. Using ln(c) differences in the cost function is better than using concentrations. Inversion is not sensitive to observational errors or different first guesses. A temporal smoothness penalty can remove artificial variability from the results. a b s t r a c t A transfer coefficient matrix (TCM) was created in a previous study using a Lagrangian dispersion model to provide plume predictions under different emission scenarios. The TCM estimates the contribution of each emission period to all sampling locations and can be used to estimate source terms by adjusting emission rates to match the model prediction with the measurements. In this paper, the TCM is used to formulate a cost functional that measures the differences between the model predictions and the actual air concentration measurements. The cost functional also includes a background term which adds the differences between a first guess and the updated emission estimates. Uncertainties of the measurements, as well as those for the first guess of source terms are both considered in the cost functional. In addition, a penalty term is added to create a smooth temporal change in the release rate. The method is first tested with pseudo observations generated using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model at the same location and time as the actual observations. The inverse estimation system is able to accurately recover the release rates and performs better than a direct solution using singular value decomposition (SVD). It is found that computing ln(c) differences between model and observations is better than using the original concentration c differences in the cost functional. The inverse estimation results are not sensitive to artificially introduced observational errors or different first guesses. To further test the method, daily average cesium-137 air concentration measurements around the globe from the Fukushima nuclear accident are used to estimate the release of the radionuclide. Compared with the latest estimates by Katata et al. (2014), the recovered release rates successfully capture the main temporal variations. When using subsets of the measured data, the inverse estimation method still manages to identify most of the major events in the temporal profile of the release.

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Analysis of Radionuclide Releases from the Fukushima Dai-ichi Nuclear Power Plant Accident Part II

Cited by 62 publications

References 20 publications

The 129-iodine content of subtropical Pacific waters: impact of Fukushima and other anthropogenic 129-iodine sources

The 129-iodine content of subtropical Pacific waters: impact of Fukushima and other anthropogenic 129-iodine sources

Zinc oxide nanowire gamma ray detector with high spatiotemporal resolution

Source term estimation using air concentration measurements and a Lagrangian dispersion model – Experiments with pseudo and real cesium-137 observations from the Fukushima nuclear accident

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