دوز مورد انتظار و عدم قطعیت مرتبط و نتایج تجزیه و تحلیل حساسیت برای همه کلاسهای سناریو در ارزیابی عملکرد سال 2008 از مخازن پیشنهادی زباله های رادیو اکتیو در سطح بالا در کوه یوکای امریکایی، نوادا

Extensive work has been carried out by the U.S. Department of Energy (DOE) in the development of a proposed geologic repository at Yucca Mountain (YM), Nevada, for the disposal of high-level radioactive waste. In support of this development and an associated license application to the U.S. Nuclear Regulatory Commission (NRC), the DOE completed an extensive performance assessment (PA) for the proposed YM repository in 2008. The conceptual structure and organization of the 2008 YM PA is based on decomposing the analysis into the following scenario classes: nominal, early waste package failure, early drip shield failure, igneous intrusive, igneous eruptive, seismic ground motion, and seismic fault displacement. This presentation describes how results obtained for the individual scenario classes are brought together in the determination of expected dose to the reasonably maximally exposed individual (RMEI) specified by the NRC in the regulatory requirements for the YM repository and presents associated uncertainty and sensitivity analysis results. The following topics are addressed: (i) determination of expected dose to the RMEI from all scenario classes, (ii) expected dose and uncertainty in expected dose to the RMEI for 0 to 20,000 yr, (iii) expected dose and uncertainty in expected dose to the RMEI from for 0 to 106 yr, (iv) justification for the decomposition procedure used to estimate expected dose to the RMEI from all scenario classes, and (v) effectiveness of individual barrier systems in reducing releases from the repository and thus dose to the RMEI. The present article is part of a special issue of Reliability Engineering and System Safety devoted to the 2008 YM PA; additional articles in the issue describe other aspects of the 2008 YM PA.

The U.S. Nuclear Regulatory Commission (NRC) regulations for a high-level radioactive waste (HLW) repository at Yucca Mountain (YM), Nevada, require that the U.S. Department of Energy (DOE) demonstrate compliance with three separate and distinct radiation protection standards [1] and [2]: (i) Individual Protection Standard after Permanent Closure (10 CFR 63.311), which is based on the required characteristics of the reasonably maximally exposed individual (RMEI) as described in 10 CFR 63.312, (ii) Individual Protection Standard for Human Intrusion (10 CFR 63.321), which is based on the Human Intrusion Scenario described in 10 CFR 63.322, and (iii) Standards for Protection of Ground Water (10 CFR 63.331), which are based on the representative ground water volume specified in 10 CFR 63.332. This presentation summarizes results of analyses performed by the DOE as part of the 2008 YM performance assessment (PA) to assess compliance with the Individual Protection Standard after Permanent Closure. Compliance with this standard is demonstrated in part by estimation of the expected dose to the RMEI specified by the NRC in the regulatory requirements for the proposed YM repository ([1; 2]; [3], Section 2; [4]). Summaries of the analyses performed in the 2008 YM PA to assess compliance with the Individual Protection Standard for Human Intrusion and the Standards for Protection of Ground Water are presented in Refs. [5] and [6], respectively. The conceptual structure and organization of the 2008 YM PA are based on decomposing the analysis into the following scenario classes [3]: nominal [7] and [8], early waste package (WP) failure [9] and [10], early drip shield (DS) failure [9] and [10], igneous intrusive [11] and [12], igneous eruptive [11] and [12], seismic ground motion [13], [14] and [15], and seismic fault displacement [13] and [15]. This presentation describes how results obtained for the individual scenario classes are brought together in the determination of expected dose to the RMEI and presents associated uncertainty and sensitivity analysis results. The following topics are considered: the determination of expected dose to the RMEI from all scenario classes (Section 2), expected dose and uncertainty in expected dose to the RMEI for 0 to 20,000 yr (Section 3), expected dose and uncertainty in expected dose to the RMEI from for 0 to 106 yr (Section 4), justification for the decomposition procedure used to estimate expected dose to the RMEI from all scenario classes (Section 5), and effectiveness of individual barrier systems in reducing releases from the repository and thus dose to the RMEI (Section 6). The presentation then ends with a concluding summary discussion (Section 7).