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Thiessen, K. M.*; Boznar, M. Z.*; Charnock, T. W.*; Chouhan, S. L.*; Federspiel, L.; Grai, B.*; Grsic, Z.*; Helebrant, J.*; Hettrich, S.*; Hulka, J.*; et al.
Journal of Radiological Protection, 42(2), p.020502_1 - 020502_8, 2022/06
Times Cited Count:5 Percentile:83.25(Environmental Sciences)Takahara, Shogo; Charnock, T. W.*; Silva, K.*; Hwang, W. T.*; Lee, J.*; Yu, C.*; Kamboj, S.*; Yankovich, T.*; Thiessen, K. M.*
Journal of Radiological Protection, 42(2), p.020517_1 - 020517_13, 2022/06
Times Cited Count:0 Percentile:0.01(Environmental Sciences)State-of-the-art dose assessment models were applied to estimate doses to the population in urban areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. Assessment results were compared among five models, and comparisons of model predictions with actual measurements were also made. Assessments were performed using both probabilistic and deterministic approaches. Predicted dose distributions in indoor and outdoor workers from a probabilistic approach were in good agreement with the actual measurements. In addition, when the models were applied to assess the doses to a representative person, based on a concept suggested by the International Commission on Radiological Protection (ICRP), it was evident that doses to the representative person obtained with a deterministic approach were always higher than those obtained with a probabilistic approach.
Silva, K.*; Okamoto, Koji*; Ishiwatari, Yuki*; Takahara, Shogo; Promping, J.*
Journal of Nuclear Science and Technology, 52(11), p.1402 - 1416, 2015/11
Times Cited Count:3 Percentile:17.52(Nuclear Science & Technology)Silva, K.*; Okamoto, Koji*; Ishiwatari, Yuki*; Takahara, Shogo; Promping, J.*
Proceedings of 12th Probabilistic Safety Assessment and Management Conference (PSAM-12) (USB Flash Drive), 12 Pages, 2014/06
no abstracts in English
Silva, K.*; Ishiwatari, Yuki*; Takahara, Shogo
Reliability Engineering & System Safety, 123, p.110 - 122, 2014/03
Times Cited Count:15 Percentile:50.48(Engineering, Industrial)The experiences of the Fukushima Accident and also the Chernobyl Accident point out the needs to integrate the assessments of health effects, economic, social and environmental impacts of severe accidents in nuclear power plants, in order to perform a comprehensive consequence assessment. The authors introduced the cost per severe accident as an index for that purpose. The index is calculated based on the systematic accident consequence assessment method which consists of level 2 and 3 probabilistic risk assessments. In the present study, the index was used to evaluate the consequences of severe accidents of a virtual boiling water reactor. The breakdown of the cost per severe accident was provided, and the decontamination cost accounted for the greatest proportion. As applications of the index, it was used to optimize the management levels of protective actions for the public, and to evaluate the consequence-reduction effects of accident management.
Silva, K.*; Ishiwatari, Yuki*; Takahara, Shogo
Proceedings of Probabilistic Safety Assessment and Management Topical Conference; In light of the Fukushima Dai-ichi Accident (PSAM 2013) (USB Flash Drive), 10 Pages, 2013/04
The "cost per severe accident" was introduced as an index to analyze improvement of accident protection and consequence mitigation strategies. This index consists of various costs and consequences converted into monetary values. The evaluations of these costs and consequences were made based on the systematic consequence analysis using level 2 and 3 PSA. The accident sequences were taken from the results of level 2 seismic PSA. The doses to the public and the number of people affected were calculated using the level 3 PSA code OSCAAR. The data obtained from the open documents on the Fukushima Accident are used as much as possible. Sensitivity analyses are carried out to identify the sensitive assumptions or parameters to the cost per severe accident. Base on the results of the sensitivity analyses, optimized accident protection and consequence mitigation strategies are recommended taking into account the various aspects comprehensively using the cost per severe accident.
Silva, K.*; Ishiwatari, Yuki*; Takahara, Shogo
Proceedings of 2nd International Symposium on Technology for Sustainability (ISTS 2012) (USB Flash Drive), p.31 - 34, 2012/11
The authors introduced the external cost regarding severe accident as an index for severe accident consequence analysis of nuclear power plants in the previous work. In this research, we modify the calculation methods of two components of the external cost regarding severe accident; decontamination cost and health effect cost, in order to obtain more reality-based results. The decontamination cost calculation method is renewed based on data obtained from decontamination demonstration project of JAEA and land use data of Ibaraki Prefecture. Willingness to pay is used to estimate the health effect cost instead of human capital method. To investigate the effect of discount rate on severe accident consequence, sensitivity analysis was performed using discount rates from 0%, 1%, 3%, 5%. Changes of the fractions of the costs comprising the external cost regarding severe accident are very small even in the case of discount rate of 5%.
Silva, K.*; Ishiwatari, Yuki*; Takahara, Shogo
Proceedings of 20th International Conference on Nuclear Engineering and the ASME 2012 Power Conference (ICONE-20 & POWER 2012) (DVD-ROM), 9 Pages, 2012/07
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review D, 84(1), p.012006_1 - 012006_18, 2011/07
Times Cited Count:29 Percentile:73.24(Astronomy & Astrophysics)We report on the event structure and double helicity asymmetry () of jet production in longitudinally polarized collisions at = 200 GeV. Photons and charged particles were measured by the PHENIX experiment. Event structure was compared with the results from PYTHIA event generator. The production rate of reconstructed jets is satisfactorily reproduced with the next-to-leading-order perturbative QCD calculation. We measured = -0.0014 0.0037 at the lowest bin and -0.0181 0.0282 at the highest bin. The measured is compared with the predictions that assume various distributions.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Times Cited Count:184 Percentile:99.45(Physics, Nuclear)Transverse momentum distributions and yields for , and in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as and scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.
Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04
Times Cited Count:9 Percentile:49.6(Physics, Nuclear)Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to collisions.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review D, 83(5), p.052004_1 - 052004_26, 2011/03
Times Cited Count:177 Percentile:98.48(Astronomy & Astrophysics)The PHENIX experiment at RHIC has measured the invariant differential cross section for production of , , and mesons in collisions at = 200 GeV. The spectral shapes of all hadron transverse momentum distributions are well described by a Tsallis distribution functional form with only two parameters, and , determining the high and characterizing the low regions for the spectra, respectively. The integrated invariant cross sections calculated from the fitted distributions are found to be consistent with existing measurements and with statistical model predictions.
Silva, K.*; Ishiwatari, Yuki*; Takahara, Shogo
no journal, ,
no abstracts in English
Silva, K.*; Ishiwatari, Yuki*; Takahara, Shogo
no journal, ,
In this research, the authors introduce the "external cost regarding severe accident" as an index to evaluate the effect of severe accident in a nuclear power plant. This can contribute to an improvement in nuclear power plant risk evaluation which needs not only probability evaluations but also effect evaluations. To calculate the external cost regarding severe accident, typical sequences of severe accidents are picked up first. Containment failure frequency (CFF) and sourceterms of each sequence are taken from the results of level 2 PSA. The sourceterm of each sequence is input into the level 3 PSA code OSCAAR which was developed by Japan Atomic Energy Agency (JAEA). Using these outputs, the external cost regarding severe accident is calculated. The results were compared with the amount of sourceterms of each severe accident which can be one of the indexes to evaluate the effects of severe accident.
Silva, K.*; Okamoto, Koji*; Ishiwatari, Yuki*; Takahara, Shogo; Promping, J.*
no journal, ,