Two methods were developed to estimate updated mean seismic hazard for existing probabilistic seismic hazard analyses (PSHAs) due to a change in the ground motion model (GMM). Both methods were used to estimate updated hazard at nuclear power plant (NPP) sites in the Central and Eastern United States (CEUS) for a change from the Electric Power Research Institute (EPRI) 2013 GMM to the Next Generation Attenuation (NGA)-East GMM. These methods present efficient tools to inform decisions on whether to perform a full PSHA revision or other detailed evaluations, especially when a large number of sites must be analyzed. A Simplified Hazard (SiHaz) method was developed to estimate mean hazard explicitly using a reduced PSHA logic tree that incorporates the updated GMM and potential changes in the site response model. An alternative scaling method was independently developed to be applied directly to current CEUS NPP hazard. Both methods were validated using updated PSHA results at several sites. Estimates at 46 NPP sites using both methods showed good agreement for mean annual frequencies of exceedance between 1E-4 and 1E-5/yr.

开发了两种方法来估计由于地震动模型（GMM）的变化而导致的现有概率地震危险性分析（PSHA）的更新平均地震危险性。两种方法都用于估计美国中部和东部（CEUS）的核电站（NUS）站点的最新危害，这是从电力研究所（EPRI）2013 GMM到下一代衰减（NGA）-东部的变化GMM。这些方法提供了有效的工具，可为是否执行完整的PSHA修订或其他详细评估提供决策依据，尤其是在必须分析大量站点时。开发了一种简化危害（SiHaz）方法，使用简化的PSHA逻辑树显式估计平均危害，该逻辑树结合了更新的GMM和现场响应模型中的潜在变化。独立开发了一种替代缩放方法，可直接应用于当前的CEUS NPP危害。两种方法均在多个地点使用更新的PSHA结果进行了验证。使用这两种方法对46个NPP站点进行的估算表明，年平均超出频率在1E-4和1E-5 / yr之间有很好的一致性。