ML22145A493

8-6-its-been-a-busy-year-r1

ML22145A493
Person / Time
Issue date:	03/08/2022
From:	Office of Nuclear Reactor Regulation
To:
References
Download: ML22145A493 (8)

Text

Office of Nuclear Regulatory Research Its Been a Busy YearRecent Major Updates for the NRCs Accident Consequence Code System (MACCS)

NEW Postprocessing Capability

• AniMACCSplume segment animation and mapping utility 4.1 NEW Code Documentation

• Theory Manual

• User Guide

• Additional MACCS studies and reference documents NEW Code Models

• Near-Field Modelingevaluation, guidance, and new models to support modern siting applications

• HYSPLIThigh fidelity, state-of-the-art, atmospheric transport and dispersion modeling

• RDEIMalternate offsite cost estimation using gross domestic product (GDP) modeling 1

What Is MACCS and How Is It Used?

The MACCS code was developed and is used to evaluate the offsite consequences of radioactive releases to the environment

• MACCS models atmospheric transport, emergency and long-term protective actions, radioactive exposure pathways, dosimetry, health effects, and economic consequences

• MACCS outputs capture a variety of metrics, including dose, health effects, fatality risk, economic losses, and land contamination

• MACCS uses include regulatory and cost-benefit analyses, environmental reports and impact statements, plant-specific evaluations of severe accident mitigation alternatives, MACCS Code Suite U.S. Department of Energy documented safety analyses, probabilistic risk assessments, and numerous research studies

• WinMACCS 4.1MACCS Windows graphical user interface (GUI) such as the State-of-the-Art Reactor Consequence Analysis

• SECPOP 4.3.0population and economic data utility (SOARCA) Project

• MelMACCS 2.0.1MELCOR radioactive source term input utility

• AniMACCS 1.3plume segment animation and mapping utility 2

AniMACCS

• MACCS added the capability to graphically visualize atmospheric results

• AniMACCS displays plume movement and ground and air concentration over a site map

• AniMACCS allows user flexibility to modify map scale, contour colors, The AniMACCS User Guide zoom in or out, take (SAND2022-0403) was screen captures, and published in January 2022 export animation to video AniMACCS Ground Concentration Animation from SAND2020-8732 3

Near-Field Modeling Benchmark and Improvements Near-Field Code Comparison

• Recent near-field modeling improvements support computer code A

readiness to evaluate advanced reactors

• In 2020, MACCS 3.11.6 was compared to other codes, including QUIC, ARCON96, and AERMOD2 (SAND2020-2609)

• Comparison showed MACCS can be used within 500 meters (~0.3 miles) from the release location to model near-field results B

• MACCS 4.1 enhancements added plume meander and building wind-effect models to simulate or bound near-field C

assessments of other codes A. Ground-level, time-integrated /Q versus distance for AERMOD2, ARCON96, and QUIC compared with bounding MACCS calculations (Figure 5-8 from SAND2020-2609)

B. QUIC time-averaged air concentration for a vertical plane at building centerline (Figure 4-24b from SAND2020-2609)

C. QUIC time-averaged air concentration for a horizontal plane at 1 meter elevation (Figure 4-24a from SAND2020-2609) 4

HYSPLIT and RDEIM Economic Model HYSPLIT Regional Disruption Economic Impact Model (RDEIM)

• MACCS added NOAAS HYSPLIT as an optional

• MACCS added RDEIM to estimate offsite economic costs atmospheric transport and diffusion model using current state-of-practice economics

• HYSPLIT is a complete system for simulating complex

• RDEIM includes income losses due to land restrictions in atmospheric transport with both puff and particle the directly affected area, national supply chain tracking dispersion models disruptions, and economic gains due to national recovery

• Users can choose between the traditional MACCS

• Users can select the new RDEIM model, which replaces Gaussian plume segment model or the higher fidelity the MACCS loss-of-use cost output with the GDP-based HYSPLIT model capability HYSPLIT Model Deposition Map MACCS GUI RDEIM Model Selection RDEIM Model Document (SAND2020-5567) 5

Updated MACCS User Guides, Theory Manual, and Verification Report MACCS 3.10 and 4.0 User Guides (SAND2021-1588, SAND2021-8998)

• User guides published corresponding to new code releases

• User guide is intended to assist analysts in understanding both the WinMACCS GUI and MACCS inputs and outputs

• Provides guidance on getting started, parameter screens, tutorials, and required auxiliary input such as the site, meteorological, and dose conversion factor files MACCS Theory Manual (SAND2021-11535)

• Updates the previous theory manual from 1990 (NUREG/CR-4691, Vol. 2)

• Captures software improvements since MACCS 1.5

• Consolidates model descriptions contained in various historical documents

• Presents the current mathematical modeling and assumptions for MACCS modules and output results MACCS Verification Report (ADAMS Accession No. ML22026A461)

• Documents the systematic testing and verification of MACCS equations and algorithms

• Verification began with MACCS 4.0 and resulted in minor upgrades to MACCS 4.1, ensuring simulation consistency with analytic results 6

MACCS Documentation Numerous documents published 2019-2022

• AniMACCS User Guide (SAND2022-0403)

• MACCS Theory Manual (SAND2021-11535)

• MACCS 4.0 User Guide (SAND2021-8998)

• Nearfield Consequence Analysis Implementation (SAND2021-6924)

• MACCS 3.10 User Guide (SAND 2021-1588)

• MACCS Verification Report (ADAMS Accession No. ML22026A461)

• Nearfield Model Evaluation (SAND2020-2609)

• RDEIM Economic Model Description and Benchmark (SAND2020-5567)

• SOARCA Project, Sequoyah (NUREG/CR-7245) 7

Contact Information MACCS Code Distribution AJ NosekCode Distribution Manager U.S. NRC, Office of Nuclear Regulatory Research, Accident Analysis Branch https://maccs.sandia.gov/getcode.aspx

Contact:

MACCSCodes@nrc.gov MACCS Code Support https://maccs.sandia.gov/default.aspx

Contact:

wg-maccs-entity@sandia.gov 8