MACCS Best Practices as 

Applied in the 

State-of-the-Art Reactor 

Consequence Analyses 

(SOARCA) Project

Office of Nuclear Regulatory Research

NUREG/CR-7009
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MACCS Best Practices as 

Applied in the 

State-of-the-Art Reactor 

Consequence Analyses 

(SOARCA) Project

Manuscript Completed: June 2014

Date Published: August 2014

Prepared by:

Nathan Bixler, Joseph Jones, Doug Osborn, and Scott Weber

Sandia National Laboratories

Albuquerque, New Mexico 87185

Operated for the U.S. Department of Energy

Prepared for: 

U.S. Nuclear Regulatory Commission 

Office of Nuclear Regulatory Research 

Washington, DC 20555-0001

NRC Project Manager:

Jonathan Barr

NRC Job Code N6306

Office of Nuclear Regulatory Research

NUREG/CR-7009
Sandia National Laboratories is a multi-program laboratory managed and 

operated by Sandia Corporation, a wholly owned subsidiary of Lockheed 

Martin Corporation, for the U.S. Department of Energy’s National Nuclear 

Security Administration under contract DE-AC04-94AL85000.
iii

ABSTRACT

The evaluation of accident phenomena and the offsite consequences of severe reactor 

accidents has been the subject of considerable research by the U.S. Nuclear Regulatory 

Commission (NRC) over the last several decades. By applying modern analysis tools and 

techniques, a body of knowledge regarding the realistic outcomes of severe reactor accidents 

has been developed. The integrated modeling of accident progression and offsite 

consequences in the State-of-the-Art Reactor Consequence Analyses (SOARCA) project has 

created best modeling practices drawn from the collective wisdom of the severe accident 

analysis community. The objective of this document is to describe the consequence model 

improvements, modeling approach, parameter selection, and consequence analyses that 

support the SOARCA project and also explain the significance of the modeling improvements 

and approaches. This document presents a compilation of experience from using the MELCOR 

Accident Consequence Code System (MACCS) to model the offsite consequences, in terms of 

health effect risk, for NUREG-1935, “State-of-the-Art Reactor Consequence Analyses 

(SOARCA) Report.” This provides a description of how MACCS modeling capabilities were 

used to represent important aspects of radionuclide atmospheric transport, emergency 

response, and dose response to radiation exposure. Additionally, a description of choices 

among certain alternative modeling options and input parameters is provided. 

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to the requirements of the Paperwork Reduction Act of 1995 (44 USC 3501, et seq.).

PUBLIC PROTECTION NOTIFICATION

The NRC may not conduct or sponsor, and a person is not required to respond to, a request for 

information or an information collection requirement unless the requesting document displays a 

currently valid OMB control number.

v

TABLE OF CONTENTS

Section Page

ABSTRACT..........................................................................................................................iii

TABLE OF CONTENTS ........................................................................................................v

LIST OF FIGURES.............................................................................................................. vii

LIST OF TABLES.................................................................................................................ix

EXECUTIVE SUMMARY......................................................................................................xi

ACKNOWLEDGEMENTS....................................................................................................xv

ABBREVIATIONS AND ACRONYMS ............................................................................... xvii

1.0 INTRODUCTION............................................................................................ 1-1

1.1 Background ................................................................................................................. 1-1

1.2 Objective ..................................................................................................................... 1-2

1.3 Important Differences in Approach from Prior Work..................................................... 1-2

1.4 Independent Peer Review ........................................................................................... 1-3

2.0 TECHNICAL APPROACH .............................................................................. 2-1

2.1 WinMACCS ................................................................................................................. 2-3

3.0 CODE ENHANCEMENTS .............................................................................. 3-1

3.1 Increased Angular Resolution...................................................................................... 3-1

3.2 Dose Coefficient Update.............................................................................................. 3-2

3.3 Atmospheric Transport and Dispersion........................................................................ 3-2

3.4 Increased Plume Segments......................................................................................... 3-3

3.5 Increased Emergency Phase Cohorts ......................................................................... 3-3

3.6 Enhanced Treatment of Evacuation Speed and Direction............................................ 3-3

3.7 Potassium Iodide Model .............................................................................................. 3-3

3.8 Addition of Options for LCF Dose Response ............................................................... 3-3

4.0 USER-SPECIFIED INPUT CHOICES AND PARAMETERS........................... 4-1

4.1 Calculational Area ....................................................................................................... 4-1

4.1.1 Network Evacuation Model .............................................................................. 4-1

4.1.2 SECPOP.......................................................................................................... 4-3

4.2 Source Term................................................................................................................ 4-3

4.2.1 Fission Product Inventory................................................................................. 4-3

4.2.2 Particle Size Distribution .................................................................................. 4-4

4.2.3 MELMACCS .................................................................................................... 4-4

4.3 Atmospheric Transport .............................................................................................. 4-10

4.3.1 MACCS Plume Model .................................................................................... 4-12

4.3.2 Plume Rise Model.......................................................................................... 4-12

4.3.3 Plume Meander Model................................................................................... 4-13

4.3.4 Weather Sampling ......................................................................................... 4-13

4.3.5 Weather Data................................................................................................. 4-16

4.3.6 Adverse Weather ........................................................................................... 4-19

4.3.7 Dry Deposition Modeling................................................................................ 4-19

4.3.8 Wet Deposition Modeling ............................................................................... 4-20

4.3.9 Surface Roughness ....................................................................................... 4-20

4.4 Exposure Pathways................................................................................................... 4-22
vi

4.4.1 Shielding and Protection Factors ................................................................... 4-23

4.4.2 Food Ingestion Model .................................................................................... 4-25

4.5 Dose Models ............................................................................................................. 4-25

4.5.1 Dose-Response Models................................................................................. 4-25

4.5.2 Exposure and Commitment Periods............................................................... 4-26

4.5.3 Risk Factors for Cancer ................................................................................. 4-27

4.5.4 Acute Health Effects ...................................................................................... 4-30

4.6 Protective Actions...................................................................................................... 4-30

4.6.1 Emergency Planning...................................................................................... 4-30

4.6.2 Evacuation Time Estimates............................................................................ 4-32

4.6.3 Cohort Modeling ............................................................................................ 4-33

4.6.4 Cohort Response Times ................................................................................ 4-35

4.6.5 Delay to Shelter ............................................................................................. 4-37

4.6.6 Evacuation Delay........................................................................................... 4-37

4.6.7 Evacuation Phase Duration and Speed.......................................................... 4-38

4.6.8 Potassium Iodide ........................................................................................... 4-40

4.6.9 Hotspot and Normal Relocation ..................................................................... 4-41

4.6.10 Habitability ..................................................................................................... 4-42

4.7 Decontamination and Cost Parameters ..................................................................... 4-43

5.0 INSIGHTS ................................................................................................................... 5-1

6.0 REFERENCES............................................................................................................ 6-1

APPENDIX A: MACCS SURRY POWER STATION SOARCA MODELING 

PARAMETERS.............................................................................A-1

APPENDIX B: MACCS PEACH BOTTOM ATOMIC POWER STATION SOARCA 

MODELING PARAMETERS.....................................................................B-1

APPENDIX C: MACCS SOARCA MODELING PARAMETERS COMPARED TO

SAMPLE PROBLEM A INPUTS .....................................................C-1
vii

LIST OF FIGURES

Figure 2-1 Relevant MACCS exposure pathways used in SOARCA ....................................2-1

Figure 2-2 WinMACCS computational flow path...................................................................2-5

Figure 4-1 Example of WinMACCS grid showing traffic direction arrows and speed 

multipliers around Peach Bottom.........................................................................4-2

Figure 4-2 Choices of chemical groups and burnup used for Peach Bottom.........................4-5

Figure 4-3 MELCOR release paths into the environment, MELCOR time of accident 

initiation, height of ground level in MELCOR reference frame, and initial 

plume dispersion parameters ..............................................................................4-5

Figure 4-4 MELMACCS parameters for calculating deposition velocity ................................4-6

Figure 4-5 MELMACCS threshold parameters for paths and plume segments.....................4-7

Figure 4-6 Dividing the overall release into plume segments for release path 4 ...................4-7

Figure 4-7 Dividing the overall release into plume segments for release path 11 .................4-8

Figure 4-8 Definition of plume segments (release path through heat)...................................4-9

Figure 4-9 Definition of plume segments (flow rate through barium release fraction)............4-9

Figure 4-10 Peach Bottom wind rose and atmospheric stability chart, year 2006 .................4-17

Figure 4-11 Surry wind rose and atmospheric stability chart, year 2004...............................4-18

ix

LIST OF TABLES

Table 4-1 Radial distance parameter variations between SOARCA and NUREG-1150 

for the Peach Bottom site ....................................................................................4-1

Table 4-2 Evacuation parameter variations between SOARCA, Sample Problem A, 

and NUREG-1150 ...............................................................................................4-3

Table 4-3 Radionuclide classes used in SOARCA ............................................................4-10

Table 4-4 Plume model input variation between SOARCA, Sample Problem A, and 

NUREG-1150....................................................................................................4-11

Table 4-5 Plume raise inputs for SOARCA and Sample Problem A ..................................4-13

Table 4-6 Plume meander model variation between SOARCA and NUREG-1150 ............4-13

Table 4-7 Weather sampling input variation between SOARCA, Sample Problem A, 

and NUREG-1150 .............................................................................................4-15

Table 4-8 Statistical summary of raw meteorological data for SOARCA sites....................4-17

Table 4-9 Precipitation input variation between SOARCA and NUREG-1150....................4-18

Table 4-10 Particle size distribution and dry deposition velocity input variation between 

SOARCA and NUREG-1150 .............................................................................4-19

Table 4-11 Dry deposition velocities used for the SOARCA studies for each of the ten 

aerosol bins in MELCOR...................................................................................4-20

Table 4-12 Wet deposition model variation between SOARCA and NUREG-1150..............4-20

Table 4-13 Surface roughness for various land-use categories for the area surrounding 

the Peach Bottom site .......................................................................................4-21

Table 4-14 Cloudshine factor, groundshine factor, inhalation protection factor, and skin 

protection factor variations between SOARCA, Sample Problem A, and 

NUREG-1150....................................................................................................4-24

Table 4-15 Long-term groundshine factor and inhalation protection factor variations 

between SOARCA, Sample Problem A, and NUREG-1150...............................4-25

Table 4-16 SOARCA, Sample Problem A, and NUREG-1150 exposure period and 

action period input parameters ..........................................................................4-27

Table 4-17 SOARCA, Sample Problem A, and NUREG-1150 cancer input parameters......4-29

Table 4-18 SOARCA, Sample Problem A, and NUREG-1150 prompt health effects 

input parameters ...............................................................................................4-30

Table 4-19 Evacuation parameter variations between SOARCA and NUREG-1150 ...........4-31

Table 4-20 SOARCA evacuation cohorts ............................................................................4-33

Table 4-21 Cohort weighting fraction parameter variations between SOARCA, Sample 

Problem A, and NUREG-1150...........................................................................4-35

Table 4-22 Time to GE condition variations between SOARCA and NUREG-1150.............4-37

Table 4-23 Delay to shelter parameter variations between SOARCA, Sample Problem 

A, and NUREG-1150.........................................................................................4-37

Table 4-24 Evacuation delay parameter variations between SOARCA, Sample 

Problem A, and NUREG-1150...........................................................................4-38

Table 4-25 Evacuation phase duration and speed parameter variations between 

SOARCA, Sample Problem A, and NUREG-1150.............................................4-40

Table 4-26 Hotspot and normal relocation parameter variations between SOARCA, 

Sample Problem A, and NUREG-1150..............................................................4-41

Table 4-27 Long-term phase dose criterion variations between SOARCA, Sample 

Problem A, and NUREG-1150...........................................................................4-42

Table 4-28 SOARCA and NUREG-1150 action period input parameter ..............................4-43

xi

EXECUTIVE SUMMARY

The purpose of this report is to describe best practices for the MELCOR Accident Consequence 

Code System (MACCS), as implemented in the State-of-the-Art Reactor Consequence 

Analyses (SOARCA) project for the Peach Bottom Atomic Power Station and the Surry Power 

Station. By applying modern analysis tools and techniques in the SOARCA project, a body of 

knowledge regarding the realistic outcomes of severe reactor accidents has been developed 

through the integrated modeling of accident progression and offsite consequences. The 

SOARCA project provides analyses that use state-of-the-art source term and consequence 

modeling together with consideration of current operational practices and procedures. 

Collectively, this information represents the “best practice” modeling approach for using MACCS

in performing consequence analyses of severe reactor accidents in the SOARCA project. This 

best practices document provides a compilation of the parameters and inputs used in the 

SOARCA documents. It also includes additional detail on the approach to developing some of 

the input values and methodologies applied in the SOARCA studies. 

The objective of this document is to describe the consequence model improvements, modeling 

approach, parameter selection, and consequence analyses that support the SOARCA project 

analyses in NUREG-1935 [1], NUREG/CR-7110 Volume 1 [2], and NUREG/CR-7110 Volume 2 

[3]. This document also includes observations concerning the significance of key modeling 

improvements and approaches used in SOARCA and their relevance to other analyses. This 

NUREG/CR is intended to provide guidance and insights for developers and users of MACCS.

The MACCS best practice approach applied in SOARCA included: 

• Update of parameters to reflect current state of knowledge, such as the cancer risk 

factors which were updated based on Biological Effects of Ionizing Radiation 

(BEIR) V,

• MACCS code enhancements that were implemented to provide more realism in the 

analysis, such as increasing the number of plume segments, increasing angular 

resolution, increasing the maximum number of cohorts allowed, and improving the 

network evacuation model, and

• User specified choices, such as the use of site-specific emergency plan data in the 

development of emergency response related parameters.

Important parameter updates that were integrated into the MACCS models for SOARCA 

included the cancer fatality risk factors and dose response factors. In 2009, the National 

Research Council released the BEIR VII report, which is the most up-to-date study of cancer 

induction from exposure to ionizing radiation. However, because the dose coefficients used in 

the SOARCA study are from Federal Guidance Report 13 (FGR-13) and this report was 

developed using risk factors from BEIR V, the SOARCA staff made the decision to await 

Environmental Protection Agency’s (EPA’s) review of BEIR VII and subsequent update of 

FGR-13 and used BEIR V risk coefficients in SOARCA.

Many of the MACCS code enhancements were recommended by the Expert Review Panel

conducted in August 2006, prior to the commencement of the SOARCA analyses. Some of the 

panel’s recommendations on MACCS enhancements that were implemented for SOARCA 

include:
xii

• atmospheric transport and dispersion modeling improvements,

• increasing angular resolution to 64 compass directions up from 16,

• increasing the limit to 200 plume segments instead of the previous limit of 4,

• increasing the limit to 20 emergency phase cohorts instead of the original limit of 3, 

• enhancing the treatment of evacuation speed and direction to better reflect the spatial 

and temporal response of individual cohorts,

• incorporating of a potassium iodide (KI) ingestion model to account for dose reduction to 

the thyroid from inhalation of radioiodine, and

• adding several new options for latent cancer fatality (LCF) dose response.

Lastly, user specified choices are available throughout MACCS. A team of knowledgeable 

analysts developed best practice choices for each specific site. For example, the choices of 

times associated with normal and hotspot relocation depended on the specific accident scenario 

because they are based on plume arrival and on the expected resources available in the area. 

The corresponding normal and hotspot relocation doses may be established by the 

Environmental Protection Agency (EPA) or by the State where the reactor is located. The 

choices for emergency response parameters related to sheltering and evacuation require 

information from the site emergency procedures, offsite response organization emergency 

plans, and the evacuation time estimate (ETE). The choices used in SOARCA and the bases 

for selecting these values are described in this best practices document. 

Conducting a project such as SOARCA provided an opportunity to investigate consequence 

analyses at a much greater level of detail than was done for analyses performed in the past. 

Throughout the process, advanced knowledge and insights were gained that benefit the 

probabilistic risk assessment (PRA) and emergency response communities. The following

insights related to offsite consequence analyses were developed from the SOARCA project.

1. Through investigation of the importance of each chemical class, the SOARCA analyses

confirmed that the cesium group followed by the tellurium and barium/strontium groups

is generally the most important contributor to long-term and overall latent cancer fatality 

(LCF) risk when using the linear no-threshold (LNT) dose-response model. However, 

SOARCA found that the cerium group, followed by the barium/strontium group, 

dominates over the cesium group in the Peach Bottom unmitigated short term station 

blackout (STSBO) scenario without reactor core isolation cooling (RCIC) system 

blackstart1

. This scenario involves significant core-concrete interactions with insertions 

of unoxidized zirconium. Even though the cerium release is small in terms of 

percentage, it is significant in terms of activity because of its large initial inventory. This 

results in the cerium group, followed by the barium/strontium group, being the largest 

contributor to LCF risk for this scenario. This trend was not observed for any of the other 

Peach Bottom or Surry scenarios and is more likely to occur in a BWR because of the 

significantly larger quantity of zirconium in the reactor vessel of a BWR.

 1 Blackstart of the RCIC system refers to starting RCIC without any ac or dc control power. NUREG/CR-7110 

Volume 1 contains an expanded description of this scenario [2].
xiii

2. Sensitivity analyses on the effect of the surface roughness parameter show that a 

surface roughness increase from 10 cm to 60 cm results in a risk reduction of about 20% 

for the intermediate distances (10 to 50 miles) and a risk increase of about 10% within 10 

miles for the calculated LCF risks using the LNT dose-response model. The reduction in 

risk for the two truncation dose-response models reported in SOARCA is generally 

greater than 20%.

3. The development of emergency response parameters based on site-specific data 

obtained from the emergency plan and offsite response organizations enables realistic 

modeling of the response of the public. The results of the analyses show that for the 

selected SOARCA scenarios, the emergency response is very effective within the 

evacuation zone during the emergency phase. The risks are very small and entirely 

represent the non-evacuating population, with the exception of the Surry STSBO with a

thermally induced steam generator tube rupture (TISGTR) accident scenario in which the 

release starts much earlier than in the others. 

4. Using the LNT dose-response model, the largest contributor to LCF risk for most

scenarios is the long-term risk incurred after the emergency phase, and this risk is 

controlled by the habitability criterion.

5. Increasing the number of aerosol bins and accounting for deposition velocity as a 

function of particle size has a significant effect on the results. The effect is comparable 

to specifying a single deposition velocity of 0.3 cm/s; which reduces ground 

concentrations by about a factor of 3 at the distances reported in SOARCA compared 

with the NUREG-1150 methodology of using a single value of 1 cm/s. 

6. Increasing the number of compass sectors from 16 to 64 does not significantly affect 

LCF risk calculated using the LNT dose-response model. There would likely be a 

greater effect on LCF risk using the truncation dose-response models; however these 

calculations were not performed.

7. Increasing the number of plume segments has a small effect on calculated LCF risk

using the LNT dose-response model. There would likely be a greater effect on LCF risk 

using the truncation dose-response models; however these calculations were not 

performed.

8. Insight from the evaluation of seismic activity on emergency response (ER) shows the 

effect to be site-specific. For Peach Bottom, the seismic event’s impact on ER has an 

insignificant effect on health consequences primarily because the damage to 

infrastructure in this EPZ is projected to be limited to a few roadway sections. For Surry, 

the overall impact on the ER from the seismic activity is significant with regard to the 

damage to infrastructure; however, because this damage occurs in the developed areas 

which are beyond 5 miles from the plant, there is no appreciable effect on health 

consequences. Although the ER is impacted considerably by the postulated seismic 

event, the effect on overall risk is not significant, and the prompt fatality risk remains

zero. 

9. Sensitivity analyses on the size of the evacuation area were performed for two 

scenarios: the Peach Bottom unmitigated STSBO and the Surry unmitigated ISLOCA. 

These sensitivities show that the effect of expanding the size of the evacuation area is 
xiv

site-specific and scenario-specific. For the Peach Bottom unmitigated STSBO, 

expanding the size of the evacuation area decreases individual LCF risk beyond the 10-

mile radius but increases individual LCF risk within 10 miles. The increase in risk to the 

population residing within 10 miles occurs because of the increased traffic congestion 

which is caused by the larger evacuation. For areas with a radius greater than 20 miles, 

the risk reduction associated with increasing the size of the evacuation area is slight. 

For the Surry unmitigated ISLOCA, the results show very little benefit from evacuation of 

areas beyond 10 miles.
xv

ACKNOWLEDGMENTS

Contributions to this best practices document were received from NRC and Sandia National 

Laboratories (SNL) project managers and technical experts dedicated to the production of a 

valuable resource for the user community. Information received from the 2006 Expert Review 

Panel influenced the MACCS best practices. The Peer Review Committee for the SOARCA 

project provided insights and information that also influenced the best practices. The NRC 

Project Manager, Jonathan Barr, provided the leadership to ensure this project met the 

objectives of the program. Numerous NRC staff provided technical insights supporting key 

elements of the document. SNL technical staff worked with these experts to develop the criteria 

and document the approach that was used in SOARCA and described in this report. 

xvii

ABBREVIATIONS AND ACRONYMS

BEF Biological Effectiveness Factors

BEIR Biological Effects of Ionizing Radiations

BWR Boiling Water Reactor

CDF Core Damage Frequency

CPI Consumer Price Index

CSARP Cooperative Severe Accident Research Program

DOE U.S. Department of Energy

DRF Dose Reduction Factor

EAL Emergency Action Level

EAS Emergency Alert System

EOP Emergency Operating Procedure

EP Emergency Preparedness

EPA U.S. Environmental Protection Agency

EPZ Emergency Planning Zone

ER Emergency Response

ESPMUL Evacuation Speed Multiplier

ETE Evacuation Time Estimate

FGR Federal Guidance Report

GE General Emergency

GUI Graphical User Interface

HPS Health Physics Society

ICRP International Commission on Radiation Protection

ISLOCA Interfacing Systems Loss of Coolant Accident

LCF Latent Cancer Fatality

LET Linear Energy Transfer

LHS Latin Hypercube Sampling

LNT Linear No Threshold

LOCA Loss of Coolant Accident

LTSBO Long Term Station Blackout

MACCS MELCOR Accident Consequence Code System 

ORNL Oak Ridge National Laboratory

ORO Offsite Response Organization

PAG Protective Action Guide

PAR Protective Action Recommendation

PRA Probabilistic Risk Assessment

PRC Peer Review Committee

RCIC Reactor Core Isolation Cooling system

ROP Reactor Oversight Program

SAE Site Area Emergency

SAMA Severe Accident Mitigation Alternatives

SAMG Severe Accident Management Guidelines

SECPOP SECtor POPulation and Economic Estimator

SNL Sandia National Laboratories

SOARCA State-of-the-Art Reactor Consequence Analyses project

STSBO Short Term Station Blackout

TISGTR Thermally Induced Steam Generator Tube Rupture

TSC Technical Support Center

USBGR U.S. Background

1-1

1.0 INTRODUCTION

The NRC initiated the State-of-the-Art Reactor Consequence Analyses (SOARCA) project to 

develop best estimates of the offsite radiological health consequences for potential severe 

reactor accidents for two pilot plants: the Peach Bottom Atomic Power Station and the Surry 

Power Station. The SOARCA project provides analyses that use state-of-the-art source term 

and consequence modeling together with consideration of current operational practices and 

procedures. Specifically, SOARCA assessed the benefits of 10 CFR 50.54(hh) equipment and 

procedures that have become institutionalized in the last decade. By applying modern analysis 

tools and techniques and updated parameters in the SOARCA project, a body of knowledge 

regarding the realistic outcomes of severe reactor accidents has been developed. As a result, 

the application of the MELCOR Accident Consequence Code System (MACCS) in the SOARCA 

project represents the “best practice” modeling approach for using MACCS in performing 

consequence analyses. It should be noted that some of the model and parameter choices used 

in SOARCA may not be optimal for other consequence analyses, depending on their objectives 

and the types of results to be reported. Discussion is provided to help the MACCS user 

determine which of the SOARCA model and parameter choices might be useful for other 

applications. 

SOARCA presents the NRC’s most detailed and realistic severe accident analysis to date. This 

document describes MACCS best practices used in SOARCA [1] for the Peach Bottom Atomic 

Power Station [2] and the Surry Power Station [3]. The term ‘best practice’ as used in this 

document describes the modeling approaches and parameter choices. 

A compilation of experience from using MACCS to model offsite consequences, in terms of 

health effect risks for SOARCA, is presented herein. The document describes the use of 

updated parameters, MACCS code enhancements, and specific parameter selection in 

establishing best practices. The MACCS modeling capabilities are described with regard to 

important aspects of radionuclide atmospheric transport, emergency response, and dose 

response to radiation exposure. A description of choices among alternative modeling options 

and input parameters is provided. Insights are drawn from the application of these MACCS

approaches, enhancements, and parameters in the SOARCA project.

As a follow-on to the SOARCA study, NRC conducted an uncertainty analysis of the unmitigated 

long term station blackout (LTSBO) for the Peach Bottom site. Many of the uncertain 

parameters implemented in the Peach Bottom uncertainty analysis were selected based on the 

insights identified in this best practices document. The Peach Bottom uncertainty analysis 

evaluated the robustness of the SOARCA deterministic results and conclusions, and developed

insights into the overall sensitivity of the SOARCA results to uncertainty in key modeling inputs. 

Insights gained from this uncertainty analysis are documented in NUREG/CR-7155 [4]. 

1.1 Background

MACCS was developed at Sandia National Laboratories (SNL) for the NRC. Its primary use is

in performing PRAs for commercial nuclear reactors to evaluate the impact of accidental 

atmospheric releases of radiological materials on humans and on the surrounding environment.

MACCS has been widely distributed and used by the NRC and its subcontractors, private 

industry, and throughout the U.S. Department of Energy (DOE) complex. It has also been 

distributed to members of the Cooperative Severe Accident Research Program (CSARP) and 

other international organizations. 
1-2

In 2001, the NRC initiated an effort to create a Windows-based interface and framework for 

performing consequence analyses using the MACCS model. This effort was intended to 

address the following needs:

• To simplify the effort required to create or modify input files;

• To improve quality assurance by reducing the likelihood of user errors in performing 

consequence analyses;

• To enable the user to conveniently account for uncertainties in input data with the goal of 

making uncertainty assessments routine; and

• To replace the original batch framework with a Windows-based framework.

The result of this development effort is WinMACCS, which now provides a user friendly interface 

to the MACCS code. WinMACCS is currently integrated with MACCS, COMIDA2, and LHS 

(Latin Hypercube Sampling) to perform the required functionality. The original MACCS

framework was preserved, and MACCS can still be run in a stand-alone fashion as a batch 

process if desired. 

1.2 Objective

The objective of this document is to describe the consequence model improvements, modeling 

approach, parameter selection, and consequence analyses that support the SOARCA project 

analyses in NUREG-1935 [1], NUREG/CR-7110 Volume 1 [2] and NUREG/CR-7110 Volume 2 

[3]. This document also explains the significance of key modeling improvements and 

approaches used in SOARCA.

1.3 Important Differences in Approach from Prior Work

The SOARCA project staff made enhancements to MACCS to address recommendations from 

NRC staff and the SOARCA Expert Panel review [6]. The code enhancements for SOARCA 

were primarily to improve model fidelity, code performance, and functionality. These 

enhancements had a significant effect on the fidelity of the analyses performed in the SOARCA 

project, facilitating for instance, the modeling of an increased number of plume segments, 64 

sectors for wind direction and atmospheric transport, and emergency response in much greater 

detail than in previous analyses. Selected improvements to the MACCS code are described 

below:

• atmospheric transport and dispersion modeling improvements (e.g., morning and 

afternoon mixing heights, alternative Briggs plume rise model, alternative plume 

meander model based on NRC Regulatory Guide 1.145 [34], an alternative way to 

specify plume buoyancy parameters, and an alternative long-range plume spreading 

model),

• capability to treat wind directions in up to 64 compass directions (i.e., instead of 16),

• higher limits on several input parameters (e.g., a limit of 200 plume segments instead of 

the previous limit of 4),

• more emergency phase cohorts, up to 20 instead of the original limit of 3, to allow

variations in emergency response for different segments of the population,
1-3

• enhancements in the treatment of evacuation speed and direction to better reflect the 

spatial and temporal response of individual cohorts,

• incorporation of a potassium iodide (KI) ingestion model to account for dose reduction to 

the thyroid from inhalation of radioiodine,

• capability to run on a cluster of computers instead of an individual processor, and

• the addition of several new options for latent cancer fatality (LCF) dose response (i.e., 

user-input annual truncation values, user-input annual truncation values with a lifetime 

restriction, and a very flexible piecewise-linear model).

Specific aspects of the consequence modeling in SOARCA that depart from NUREG-1150 [7]

and MACCS Sample Problem A are described in Section 3.0 and Section 4.0. NUREG-1150 

values are taken from NUREG/CR-4551 Volume 2, Rev. 1, Part 7 [8] and contain values for one 

of the Peach Bottom accident scenarios. Sample Problem A is taken from the MACCS users’ 

manual (NUREG/CR-6613) and contains parameters from NUREG-1150 for one of the Surry 

accident scenarios. However, it is important to note that Sample Problem A departs from 

NUREG-1150 choices to demonstrate two new features in MACCS that were not available in 

the original MACCS code. These new features were a lookup table for dispersion parameters 

and the use of the COMIDA2 food ingestion model. In addition, Sample Problem A mistakenly 

designated a 5% fraction of the population to be in the non-evacuating cohort; whereas,

NUREG-1150 used 0.5% for this fraction. Many of the tabulated values below show differences 

between Peach Bottom (from NUREG/CR-4551) and Surry (from NUREG/CR-6613). Some of 

these differences are related to differences in the two plants and the surrounding sites, (e.g., 

shielding and protection factors); other differences are due to demonstration of new models in 

MACCS (e.g., using the dispersion lookup-table feature introduced in MACCS instead of the 

original power-law formulation). Appendix C provides a list of all MACCS input parameters for 

the Surry and Peach Bottom SOARCA unmitigated LTSBO calculations and associated MACCS

Sample Problem A (Surry) and NUREG-1150 (Peach Bottom) values.

1.4 Independent Peer Review

Two independent review groups were established for the SOARCA project. The first group was 

an expert panel convened in a public meeting forum on August 21-24, 2006. The purpose of

the meeting was to determine whether the MELCOR and MACCS modeling approach was 

consistent with the project objectives to use state-of-the art modeling with emphasis on realism 

in phenomenological and system treatments. The review was conducted by two panels drawn

from the nuclear industry and the DOE national laboratory complex with recognized expertise in

the MELCOR and MACCS numerical simulation tools. Observations and recommendations 

specific to each model were provided. The experts found the MELCOR code and the proposed 

approach for application of the codes (i.e., best practices) to be generally appropriate for 

performing realistic predictions of accident progression and source term for the SOARCA 

project. The experts found the MACCS code and the proposed approach to applying it to be 

generally appropriate for performing realistic predictions of offsite consequences for the 

SOARCA project [6].

The second review was conducted by a formal Peer Review Committee (PRC) of internationally 

renowned experts established in 2009 to evaluate and suggest improvements to the SOARCA 

project. The PRC evaluated the project approach, assumptions, results, and conclusions. To 
1-4

support the peer review, a series of PRC meetings were held where NRC and SNL staff 

presented technical details regarding the MELCOR accident progression modeling, emergency 

preparedness (EP), and MACCS consequence modeling. The PRC was provided draft 

documents for review prior to the meetings. Technical discussions were conducted on all major 

topics such as the accident sequence selection and screening process, seismic analysis, 

emergency response, angular resolution, and code validation. 

The PRC reviewed the modeling approach, parameter development, parameter selection, and 

consequence results. The PRC provided insights and identified gaps and issues for 

consideration throughout the project. The final letter of each PRC member is provided in 

Appendix B to NUREG-1935 [1]. A detailed summary of the peer review, including staff 

resolutions to individual PRC comments may be found in “Summary Report: Peer Review of the 

State-of-the Art Reactor Consequence Analyses (SOARCA) Project Results” [5]. Some of the 

PRC items regarding the consequence analyses are discussed within this document. This

MACCS best practices document was not included in the PRC review because it was completed 

after the publication of the SOARCA project primary documentation: NUREG-1935 and 

NUREG/CR-7110 Volumes 1 and 2 [1][2][3]. 
2-1

2.0 TECHNICAL APPROACH

MACCS [12] is a consequence analysis code for evaluating the impacts of atmospheric releases

of radioactive aerosols and vapors on human health and the environment. The code includes 

all of the relevant dose pathways: cloudshine, inhalation, skin contamination, resuspension,

groundshine, and ingestion. Figure 2-1 provides a graphic showing the atmospheric transport 

processes and dose pathways modeled by MACCS. Because MACCS is primarily a PRA tool, 

it accounts for the uncertainty in weather that is inherent with a hypothetical accident that could 

occur at some unknown point in the future. WinMACCS is a user-friendly front end to MACCS

that facilitates the selection of input parameters, sampling of uncertain inputs, and performs 

post-processing of results. The SOARCA calculations used WinMACCS Version 3.6 and 

MACCS Version 2.5 for offsite consequence calculations. 

The best practice approach applied in SOARCA is discussed in subsequent sections of this 

document. Best practices were applied in three different ways:

1. Update of parameters to reflect current state of knowledge such as the cancer risk 

factors based on Biological Effects of Ionizing Radiation (BEIR) V

2. Code enhancements that were implemented to provide more realism in the analysis,

such as the increased angular resolution to 64 sectors from the original 16 sectors

3. User specified practices such as the use of site-specific emergency plan data in the 

development of emergency response related parameters

To demonstrate the application of the best practices, the parameters are described with regard 

to the LTSBO scenario for each site. It should be understood that parameters are scenariospecific, and the LTSBO presents only one set of parameters. NUREG/CR-7110 Volumes 1 

and 2 include the parameters for all of the scenarios [2] [3].

Figure 2-1 Relevant MACCS exposure pathways used in SOARCA
2-2

The basic consequence analysis approach used in SOARCA included the following activities:

• The NRC obtained raw weather data for two years from each of the two SOARCA sites. 

NRC determined, based largely on data recovery, which of the two years was more 

suitable for use in SOARCA. An NRC meteorologist filled in the missing hours of data 

using standard guidelines from NRC regulatory guides and processed the data for 16, 

32, 48, and 64 compass directions. SNL performed consistency checks on the weather 

data and created the final files that were used as MACCS input, choosing 64 compass 

sectors for all of the SOARCA calculations. 

• SNL generated the site files using SECPOP2000 [28]. Site files were initially created for 

16 compass sectors, which was the only angular resolution supported by the code at the 

time. WinMACCS was then used to interpolate the site data onto the 64 compass sector

grid that was used for the SOARCA consequence analyses. 

• The NRC, SNL, and Brookhaven National Laboratory reviewed the MACCS parameters 

to determine the values to be used for the SOARCA project for the two plant sites. A 

table of parameters was created of the NUREG-1150 values, Sample Problem A values, 

and the value used in the SOARCA calculations. Appendix C provides a list of all 

MACCS SOARCA LTSBO input parameters and their associated Sample Problem A or 

NUREG-1150 values.

• Source terms were generated with the MELCOR code and interpreted with MELMACCS

which is a program used to create a MACCS radionuclide input file from the MELCOR 

output file. MELMACCS extracts information from the MELCOR plot file and converts it 

into MACCS input values. The MELMACCS user affects the interpretation of the 

MELCOR results in several ways, including associating MELCOR mass values with an 

ORIGEN output that allows masses of chemical classes to be converted to activities of 

individual radionuclides, the chemical classes that are to be included in the analysis, 

estimation of aerosol deposition velocities, and the timeframes to be used for each 

plume segment. A standard process was developed to digest each of the MELCOR 

source terms in a consistent fashion. 

• A detailed emergency response model was developed. NRC staff met with the sites to 

discuss the emergency action levels for each of the accident sequences to support 

development of the emergency response timelines, which in turn were converted into 

WinMACCS parameters. Emergency response timelines were established for each 

accident sequence. Emergency phase cohorts were established to represent unique 

segments of the population who respond in a similar manner. Six emergency phase 

cohorts were defined in SOARCA whereas previous studies defined only two or three 

cohorts (e.g., an evacuating and a non-evacuating cohort). Use of additional cohorts in 

SOARCA allowed greater fidelity in modeling the emergency response of the public.

• The network evacuation model was used to represent the site-specific evacuation 

routes. This implemented the WinMACCS capability to overlay the MACCS grid onto 

roadway maps. Expected evacuation travel directions were defined within each grid cell

for the site emergency planning zones (EPZs). The network evacuation model also 

allowed the use of speed multipliers to adjust the flow of traffic to better represent urban 

and rural traffic flow. 
2-3

• The consequence analyses were conducted using WinMACCS. The results were 

interpreted with respect to individual prompt fatality risk and individual latent cancer 

fatality risk in order to quantify the risk. Some comparisons were made with the results 

presented in the 1982 Siting Study [14]. 

2.1 WinMACCS

WinMACCS is the user interface to MACCS allowing greater user friendliness in the 

development of the analysis model. Some of the activities applied through WinMACCS for 

SOARCA are described below:

• Analysts modified input parameters and model settings. Both settings and parameters

can be saved in the project database.

• Analysts imported source term data and other inputs into the database. This option was 

used in conjunction with MELMACCS to create consequence models for each of the 

accident scenarios.

• Analysts executed multiple MACCS simulations. WinMACCS builds the MACCS input 

files using the values saved in the project database. The cyclical file capability in 

WinMACCS was used to execute multiple simulations.

• Analysts ran groups of simulations on a Windows cluster. This option was used to run 

several calculations simultaneously and to minimize the time needed for computing the 

consequence analyses. This option was used most often to run a group of dose

response models and accident scenarios simultaneously.

WinMACCS is linked with the following executable files:

• Latin Hypercube Sampling (LHS) generates values for uncertain input variables. This 

capability was not used in the SOARCA baseline study, but is being used in the 

SOARCA uncertainty analysis of the unmitigated Peach Bottom LTSBO scenario.

• COMIDA2 is a semi-dynamic food chain model that estimates annual concentrations 

(essentially food-pathway dose coefficients) given a set of radionuclides and transfer 

coefficients for each crop type considered. COMIDA2 can be run in deterministic or 

uncertain modes. Sampling in the uncertain mode is performed in conjunction with LHS. 

This capability was not used in the SOARCA study because the food pathway was not 

treated. The rationale for excluding the ingestion pathway is that food is plentiful in the 

U.S. and alternative food production can easily compensate for the lack of production in 

a contaminated area. Furthermore, the U.S. population is generally averse to 

consuming food containing even small amounts of contamination. Most, if not all, 

consumers would go out of their way to find uncontaminated food and such food would 

be in adequate supply. 

• PopMod reads an ASCII site file (e.g., a file created by SECPOP2000). PopMod creates 

a new population file containing more compass sectors. The work of PopMod is 

primarily interpolation and reformatting. No new information is added to the site data file 

that is created. PopMod was written to allow WinMACCS to support more compass 

directions by reformatting a site data file created by SECPOP2000. At the time of the 

SOARCA study, SECPOP2000 only supported 16 compass sectors; a new version now 
2-4

supports up to 64 compass sectors. PopMod was used in the SOARCA study to convert 

16-sector site files to ones with 64 compass sectors.

• Dose coefficient utility is used to create dose coefficients to calculate doses for a set of 

organs from radionuclide exposures corresponding to a set of exposure pathways. This 

utility can modify data from a standard dose coefficient file, including sampling from 

distributions to account for uncertainty in dose coefficients. This utility works in 

conjunction with LHS when sampling is to be performed. It was not used in the 

SOARCA study, but is being used in the SOARCA uncertainty analysis of the 

unmitigated Peach Bottom LTSBO scenario.

MACCS is the modeling engine and can be initiated by WinMACCS or from a command prompt 

window. 

WinMACCS is linked with the following data files: 

• Project Files are data files managed by WinMACCS and include a set of auxiliary files, 

such as the site file, the meteorological data file, the COMIDA2 binary file(s), and the 

dose coefficient file(s). The project files also consist of input files created by WinMACCS 

and output files primarily created by MACCS.

• Project Database is an Access 2000 database file that is modified by WinMACCS. This 

file contains all the project settings and parameter values that define the project.

• The meteorological data file contains one year of meteorological data that includes 

hourly, half-hourly, or quarter-hourly wind direction and speed, stability class, and 

precipitation rate data and seasonal morning and afternoon mixing height data.

• Dose coefficient files contain the dose coefficients needed to convert concentrations or 

activities into organ or effective doses. One dose coefficient file is needed for the linear 

no threshold (LNT) dose-response model; a set of 51 files are needed for truncation

dose-response models.

• The site file contains population, land use, and economic data for a specific site.

• The Comida2 binary file is used to define food-chain dose coefficients. Food-chain 

modeling was not performed in the SOARCA study.

Figure 2-2 provides a graphical representation of how WinMACCS interacts with MACCS, 

COMIDA2, LHS, PopMod, the project files, and the project database.
2-5

Figure 2-2 WinMACCS computational flow path

3-1

3.0 CODE ENHANCEMENTS

Multiple MACCS code enhancements were implemented as part of the SOARCA project. The

subsequent sections describe the parameters that were adjusted or updated to support the 

analyses. Important code enhancements included:

• increased angular resolution to 64 sectors from the original 16 sectors,

• updated dose coefficients and cancer risk factors, 

• atmospheric transport and dispersion modeling improvements,

• increased the plume segment limit to 200 instead of the previous limit of 4,

• increased number of emergency phase cohorts to 20 instead of the previous limit of 3, 

• enhanced treatment of evacuation speed and direction to better reflect the spatial and 

temporal response of individual cohorts,

• added potassium iodide (KI) ingestion model to account for dose reduction to the thyroid 

from inhalation of radioiodine, and

• added new options for LCF dose response.

3.1 Increased Angular Resolution

MACCS was originally structured with an angular grid divided into 16 compass directions. The 

expert panel review discussed in Section 1.4 recommended an increase in the number of 

compass directions to enhance model fidelity. This recommendation was addressed by 

enabling MACCS to treat 32, 48, or 64 compass sectors in addition to the original 16. SOARCA 

used the highest resolution option of 64 compass sectors. Moreover, to be consistent with the 

higher spatial resolution, wind directions were tabulated with the 64 compass sector resolution 

using hourly time averaging periods for the weather data. MACCS currently allows 15, 30, and 

60 minute time averaging periods for the weather data, but the data that were available for the 

two sites were only for hourly time periods.

The expectation was that peak doses during an accident should be reduced when angular 

resolution is increased, especially when maximum advantage is taken of potential hourly wind 

shifts in the meteorological data. This is because MACCS allows each plume segment to travel 

only in the direction of the wind at the beginning of its release. Finer angular resolution means 

that the wind is more likely to shift from one sector to another during successive hours. 

Increased angular resolution was expected to have a significant effect on prompt fatality risk 

and to have some effect on LCF risk. Prompt fatality risk is based on a highly nonlinear doseresponse curve, so a reduction in the estimated peak dose can significantly reduce the 

estimated risk. LCF risk using the LNT dose-response assumption can be insensitive to peak 

doses as long as total population doses are relatively unaffected. In other words, better 

accounting for variations in wind direction can lead to smaller individual doses, but those doses 

are spread over a larger segment of the population, which may result in approximately the same 

LCF risk. LCF risk based on a threshold type dose-response relationship, like prompt fatality 

risk, is expected to be much more sensitive to angular resolution.
3-2

For SOARCA, 64 compass directions were used together with hourly plume segments to take 

advantage of potential wind shifts in the meteorological data. A sensitivity study based on the 

Peach Bottom site indicated less than a 10% reduction in LCF risk when switching from 16 to 64 

compass sectors. Prompt fatality risk was essentially zero for all of the SOARCA accident 

scenarios due to the relatively small releases calculated by MELCOR for the scenarios studied 

in SOARCA. 

The one accident scenario that produced nonzero values for prompt fatality risk is the Surry

interfacing systems loss of coolant accident (ISLOCA), and the risks for that scenario were 

trivial (i.e., ~10-6 per event). The extent to which the added realism of capturing wind shifts 

affected the low prompt-fatality risks reported for this sequence is not known. However, it is 

certain that capturing wind shifts reduced the estimated prompt fatality risks compared with 

methodologies used in previous studies, such as NUREG-1150. For accident sequences 

producing somewhat larger source terms than the ones considered in SOARCA, the effect of 64 

compass sectors combined with hourly or more frequent plume segments could easily have a 

significant effect on predicted prompt fatality risk. Similarly, higher spatial resolution is expected 

to have a significant effect on threshold-type dose-response models because these models 

estimate higher risks when peak doses are large for a smaller population than when smaller 

doses are spread over a larger population.

3.2 Dose Coefficient Update

MACCS analyses for NRC applications prior to SOARCA used dose coefficients based on the 

International Commission on Radiological Protection (ICRP) publications ICRP 26 [36] and 

ICRP 30 [37]. The SOARCA project used the dose coefficients provided in FGR-13 [39], which 

are based on ICRP-72 published in 1996 [38]. Thus the dose coefficients used in SOARCA 

were updated from previous studies. 

Several adjustments were made to the dose coefficients based on recommendations from Dr. 

Keith Eckerman in the 2012 Oak Ridge National Laboratory (ORNL) memo [24]. They include 

the following: (1) a relative biological effectiveness factor (RBE) of 10 was used for high linear 

energy transfer (LET) radiation (alpha particles) in the breast instead of the standard radiation 

weighting factor of 20, and (2) an RBE of 1 for high-LET radiation was used for the bone marrow 

instead of the standard value of 20. These adjustments were made to account for specific 

cancer types (i.e., breast cancer and leukemia, respectively) associated with these two organs 

and were implemented in a special version of the FGR-13 dose coefficient file. In addition, the 

dose coefficients for the pancreas were copied into the dose coefficients for the bladder wall as 

a workaround. Dr. Eckerman recommended that the pancreas be used as the surrogate organ 

to associate with residual cancers. MACCS reads a hardwired set of organs, and the set 

includes bladder wall but not pancreas. Rather than modifying the MACCS code, the dose 

coefficients for pancreas were copied into the organ labeled bladder wall and bladder wall was 

associated with residual cancers.

3.3 Atmospheric Transport and Dispersion

The atmospheric transport and dispersion modeling improvements were structured to allow 

morning and afternoon mixing heights, an alternative Briggs plume rise model, an alternative 

plume meander model based on NRC Regulatory Guide 1.145 [34], an alternative way to 

specify plume buoyancy parameters, and an alternative long-range plume spreading model. 
3-3

3.4 Increased Plume Segments

The number of allowable plume segments in MACCS was increased from 4 to 200. This 

enhancement allowed significant releases to be broken up into 1-hour plume segments. 

MACCS allows each plume segment to travel in only one compass direction based on the 

weather data at the time that plume segment is released. More plume segments can better 

represent plume transport and dispersion due to possible changes in the weather (such as the 

wind direction) during the release. Longer plume segments were sometimes used for trivial 

releases, such as those where the segment content is a very small fraction of the total release. 

Finer resolution of these releases was not necessary to maintain the fidelity of the calculation. 

The MELCOR analyses provided the amount of each chemical element group in each aerosol

bin for each plume segment.

3.5 Increased Emergency Phase Cohorts

The number of emergency phase cohorts was increased from 3 to 20. For each site, six cohorts 

were established, each of which represents a discrete segment of the population that has 

similar response characteristics. The use of six cohorts provided greater fidelity in the treatment 

of emergency response than was possible with the original version of MACCS.

3.6 Enhanced Treatment of Evacuation Speed and Direction

Enhancements in the treatment of evacuation speed and direction were implemented to better 

reflect the spatial and temporal response of individual cohorts. While the network evacuation 

model in MACCS has been available for some time, it has been made considerably easier to 

use by the development of WinMACCS, which provides a graphic interface for the user to input 

speed and direction variations for each evacuating cohort. The original version of MACCS

allowed the input of direction at the grid element level; however, this required the analyst to 

input the data in a table that represented the grid. As discussed later in Section 4.1.1, the 

network evacuation model now allows this information to be input directly onto the grid using a 

layer that shows the roadway network underlying the analysis area. 

3.7 Potassium Iodide Model

A potassium iodide (KI) model was added to MACCS to account specifically for the 

implementation of a KI program. The purpose of the KI is to saturate the thyroid gland with 

stable iodine so that further uptake of radioiodine by the thyroid is diminished. If taken at the 

right time, the KI can nearly eliminate doses to the thyroid gland from inhaled radioiodine. 

Assumptions regarding the fraction of residents expected to ingest KI and the efficacy of the KI 

are input into the model. 

3.8 Addition of Options for LCF Dose Response

Additional options for user-input of LCF dose response included a yearly truncation value, userinput yearly truncation value with a lifetime limit, and a piece-wise linear model. 

4-1

4.0 USER-SPECIFIED INPUT CHOICES AND PARAMETERS

In addition to the code enhancements, many of the input variables and parameter updates used 

for consequence analysis in SOARCA were evaluated and revised for the specific application. 

The SOARCA team reviewed all of the MACCS parameters to determine which parameters 

should be adjusted for the SOARCA project and which values did not require adjustment (e.g., 

breathing rate). The team compiled tables of parameters which included NUREG-1150 values, 

MACCS Sample Problem A values, and the SOARCA user selected value to support the review. 

These tables are provided in Appendix C. The best practices discussed in this section are not 

values to be used in MACCS in all cases. Many of the values discussed are site-specific to 

Peach Bottom and Surry. Other choices made in SOARCA may not have significant benefit in 

some other analyses. Some guidance is provided on the effect of model and parameter choices 

made in SOARCA.

4.1 Calculational Area

MACCS calculates results based on a polar-coordinate spatial grid. The region potentially 

affected by a release is represented with an (r, θ) grid system centered on the location of the 

release. The radius, r, represents downwind distance. The angle, θ, is the angular offset from 

north in the clockwise direction.

The number of radial intervals as well as the radial boundary distances, input with the variable 

SPAEND, in SOARCA are the same as the values used in NUREG-1150, except for three of the 

first five radial rings. NUREG-1150 used different radial distances for each plant; whereas, 

SOARCA used Surry values taken from NUREG-1150 for both plants. Table 4-1 shows the first 

six radial distances used in SOARCA and used in NUREG-1150 for Peach Bottom. The 

complete list of boundary distances is provided in Appendix C. 

Table 4-1 Radial distance parameter variations between SOARCA and NUREG-1150

for the Peach Bottom site

Variable Description SOARCA NUREG-1150

Peach Bottom

SPAEND

Radial distances for grid boundaries (km (mi))

Ring 1 0.16 km (0.1 mi) 0.40 km (0.25 mi)

Ring 2 0.52 (0.33) 0.82 (0.5)

Ring 3 1.21 (0.75) 1.21 (0.75)

Ring 4 1.61 (1.0) 1.61 (1.0)

Ring 5 2.13 (1.33) 2.43 (1.5)

Ring 6 3.22 (2.0) 3.22 (2.0)

4.1.1 Network Evacuation Model

The network evacuation model in MACCS is now implemented via WinMACCS, which provides 

a graphic interface for the user to input speed and direction variations for each evacuating 

cohort. To develop the input used in SOARCA, the evacuation routes were reviewed to 

determine the expected direction evacuees would travel. The evacuation area was mapped 

onto a grid with 64 compass sectors and 15 radii. The direction for each grid element was 

selected based on the expected roadways that would be used in the evacuation. Speed 

adjustment factors were applied to speed up or slow down evacuees depending on whether 

congestion was expected (in urban areas) or whether free flow was expected (in rural areas). 
4-2

An example of the Network Evacuation Model directional arrows and speed adjustment factors 

for the Peach Bottom site is shown in Figure 4-1. One evacuation network at each site was 

developed and used for all accident sequences except the seismic sensitivity analyses. A 

separate evacuation network was implemented for the seismic sensitivity analyses to represent 

the loss of parts of the roadway network and loss of traffic signals. The response timing and 

evacuation speed parameters were developed specifically for each accident sequence. 

Figure 4-1 Example of WinMACCS grid showing traffic direction arrows and speed 

multipliers around Peach Bottom

Table 4-2 shows the evacuation parameters used in SOARCA, Sample Problem A and NUREG1150. As identified in the table, the evacuation type (EVATYP) for SOARCA was the 

NETWORK evacuation model. Previous analyses implemented the RADIAL evacuation model 

where the evacuees are represented as traveling along the centerline (centerpoint) of each 

sector until they are out of the evacuation area, in part because the original NETWORK 

evacuation model was cumbersome to implement. In SOARCA, the CENTERPOINT option 
4-3

was selected for evacuee movement because it is the only option allowed when evacuation 

speeds are specified to vary by phase. 

Table 4-2 Evacuation parameter variations between SOARCA, Sample Problem A,

and NUREG-1150

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

EVATYP Evacuation Type NETWORK NETWORK RADIAL RADIAL

TRAVELPOINT Evacuee Movement 

Option CENTERPOINT CENTERPOINT BOUNDARY Not used in MACCS model

4.1.2 SECPOP

In the SOARCA analyses, site files were initially created using SECPOP2000 to estimate the 

population within 50 miles of each plant for 16 compass sectors, which is the only angular 

resolution supported by that code. The population for each site was projected from 2000 to 

2005, the SOARCA project target year, using a national population growth multiplier of 1.0533 

obtained from the U.S. Census Bureau. SECPOP2000 interpolates U.S. Census data at the 

block level2 onto a MACCS grid. The economic values are from the Bureau of Economic 

Analysis (BEA) for the year 2002 and are tabulated at the county level. These values were 

scaled to 2005 dollars by applying a multiplier of 1.0900, which is the ratio of the consumer price 

index (CPI) for 2005 to the value for 2002. WinMACCS was then used to interpolate the site 

files onto a 64-compass-sector grid that was used for the SOARCA consequence analyses. 

Population values for transients, schools, and special facilities were obtained from the 

evacuation time estimate (ETE).

4.2 Source Term

The specification of the release characteristics is designated as a "source term," and can 

consist of multiple Gaussian plumes. The radioactive materials released are modeled as being 

dispersed in the atmosphere while being transported by the prevailing wind. During transport, 

whether or not there is precipitation, aerosols can be modeled as being deposited on the 

ground. If contamination levels exceed user-specified criteria, mitigative actions can be 

triggered to limit radiation exposures. 

4.2.1 Fission Product Inventory

Fuel burnup at the time of the 1982 Siting Study was much lower than current practice. The 

inventory used for the SOARCA evaluation at Peach Bottom was based on current fuel cycle 

practices. SOARCA assumes that each accident scenario occurs mid-cycle. For Peach 

Bottom, SOARCA used an ORIGEN calculation based on medium burnup: 49 MW-days/kg 

peak fuel rod at mid-cycle for Peach Bottom Unit 2 [42]. For Surry, a mid-cycle calculation of 

the fission product inventory considering current fuel cycle practices was not available. Instead, 

the core decay heat and fission product inventories were calculated using results from a 

SCALE/ORIGEN calculation based on end-of-cycle [40]. A burnup of 65 MW-days/kg for the 

peak fuel rod was assumed. The high burnup fission product inventory was slightly 

conservative relative to best estimate values and significantly larger for some isotopes than the 

low burnup values used in earlier studies [41]. The decay heats, masses, and activities as a 

 2 Census blocks are the smallest geographic area for which the Census Bureau collects and tabulates decennial 

census data and are formed by streets, roads, railroads, streams and other bodies of water, other visible physical and 

cultural features, and the legal boundaries shown on Census Bureau maps.
4-4

function of time were processed and consistently used as inputs to MELCOR to define decay 

heat and as inputs to MELMACCS to define the radionuclide inventory. 

4.2.2 Particle Size Distribution

Consequence analyses of commercial nuclear reactor units prior to SOARCA used a single 

deposition velocity to represent all particle sizes and all radionuclide groups. In other words, all 

aerosols were assumed to deposit at the same velocity. The SOARCA project implemented 

advancements in the MELCOR to MACCS interface using MELMACCS to provide binned 

particle size information for each of the radionuclide groups. Particle size distribution data are 

provided for Surry in Appendix A, Table A-3 and for Peach Bottom in Appendix B, Table B-3. 

4.2.3 MELMACCS

MELMACCS is a Windows based program developed by SNL in 2002 that is used to create a 

MACCS source term input file from the MELCOR plot file. MELMACCS version 1.7.0 was used 

in the SOARCA project. MELCOR plot files contain large amounts of data, only a small fraction 

of which is needed for MACCS calculations. The MELMACCS software was created to provide 

an interface utility between MELCOR and MACCS to extract and evaluate the required source 

term data for a consequence analysis.

 

MELMACCS obtains two classes of data from the MELCOR plot files. The first is 

time-independent data, which are data that remain constant throughout the MELCOR 

calculation. Examples are initial masses of each chemical group and flow paths to the 

environment. The second class is time-dependent data, which is written to the MELCOR plot 

file for each plot file time step. The plot file time step is defined by the MELCOR user. 

Examples of these data are fluid temperatures and flow rates for a flow path to the environment 

and the released mass of each chemical group for a flow path into the environment.

MELMACCS uses a graphical user interface (GUI) to allow the user to convert one MELCOR 

plot file into a source term input file (.INP) for MACCS. The inputs contained in this file are used

in the ATMOS portion of MACCS. 

Prior to MELMACCS converting the MELCOR plot file, the user must first specify inputs that are 

needed to create the MACCS file, but are not provided by MELCOR. These inputs are:

• the radionuclide classes to include,

• high, medium, or low burnup fuel and the type of reactor (PWR or BWR),

• time of accident initiation in the MELCOR time frame,

• grade (ground height) relative to the MELCOR coordinate system,

• building height and initial plume width and height for building wake calculations,

• parameters and choices used to estimate deposition velocities,

• mass-fraction thresholds for paths and plume segments to be considered, and

• time intervals for plume segments.

The MELMACCS inputs used for SOARCA are illustrated for the Peach Bottom LTSBO in 

Figure 4-2 through Figure 4-9. Figure 4-2 shows that all nine of the standard chemical groups 

were selected and a medium burnup calculated specifically for Peach Bottom was chosen. This 

same inventory was used to define the decay heat levels in the MELCOR calculation.
4-5

Figure 4-2 Choices of chemical groups and burnup used for Peach Bottom

Figure 4-3 shows that the accident starts at time = 0.0 seconds in the MELCOR time frame and 

that ground level (grade) is at -4.04 meters in the MELCOR reference frame. The Peach 

Bottom reactor building is 50 meters high, and the initial plume dispersion parameters are 

chosen to be 11.6 meters and 23.3 meters in the crosswind and vertical dimensions, 

respectively. 

Figure 4-3 MELCOR release paths into the environment, MELCOR time of accident 

initiation, height of ground level in MELCOR reference frame, and initial 

plume dispersion parameters
4-6

Figure 4-4 shows the choices used to calculate deposition velocity. Two optional models for 

deposition velocity are available. The one used in SOARCA is considered to be the better 

option for smaller size aerosols: Calculate deposition velocities based on expert elicitation data

[18]. With this option, the user must specify three additional parameters. The first is surface 

roughness. This was chosen to be 0.1 meters (10 cm) in all SOARCA cases except the 

sensitivity analysis in which it was set to be 60 cm. Wind speed was chosen to be 2.2 m/s, 

which is very close to the average wind speed at both the Peach Bottom and Surry sites. 

Finally, the quantile was chosen to be 0.5, which represents a median or best-estimate value 

from the expert elicitation. The option to Disable deposition velocity results in MACCS file was 

not selected. This choice causes MELMACCS to write deposition velocity information onto the 

output file. 

Figure 4-4 MELMACCS parameters for calculating deposition velocity

Figure 4-5 shows two parameters that control which of the MELCOR paths are displayed and 

which plume segments are considered. The first of these causes flow paths to be evaluated

only when more than 0.001 (0.1%) of the total release of any chemical group occurs through a 

flow path. Of the 15 flow paths in the MELCOR analysis of the SOARCA Peach Bottom 

unmitigated LTSBO, only two of them (i.e., flow path 4 – refueling bay blowout panels to the 

environment and flow path 11 – reactor building equipment lock door at 135-feet to the 

environment) have a significant release according to this threshold criterion. The second 

parameter causes a plume segment to be evaluated if any of the chemical groups in that 

segment contribute 0.001 (0.1%) to the total release of that chemical group. 

Figure 4-6 shows the timing of release for each of the chemical groups on a log scale, as 

calculated by MELCOR for release path 4; the dominant release path. The release begins at 

about 72,000 seconds (20 hours) and ends at 172,800 seconds (48 hours), when the MELCOR 

calculation is terminated. The Auto Insert function is used to automatically split the release into 

3600 second (1 hour) plume segments, which is shown as a set of vertical black lines dividing 
4-7

the time period into segments. The values selected on this screen are saved by clicking the 

Apply button. This creates 28 plume segments for release path 4.

Figure 4-5 MELMACCS threshold parameters for paths and plume segments

Figure 4-6 Dividing the overall release into plume segments for release path 4
4-8

A similar process is applied for release path 11, as shown in Figure 4-7. However, only the first 

plume segment from release path 11 meets the threshold criterion specified in Figure 4-5, so 

only one additional plume segment is created. This is the first plume segment shown in 

Figure 4-7; no significant release occurs through this flow path after the initial release. 

Furthermore, only noble gas releases are significant through this release path.

Figure 4-7 Dividing the overall release into plume segments for release path 11

The description of the plume segments, as defined by the user, is shown in Figure 4-8 and 

Figure 4-9. The first column in Figure 4-8 shows which MELCOR release path corresponds to

the specified MACCS plume segment. The second and third columns define the timing of the 

release. The fourth column contains the initial release height measured above grade. Columns 

five (Figure 4-8) through seven (see Figure 4-9 for columns six and seven) provide values used 

to determine plume buoyancy. The final nine columns provide release fractions of each 

chemical group. Three of these last nine columns are shown in Figure 4-9. All of the 

information contained in Figure 4-8 and Figure 4-9 plus additional data defining the deposition 

velocity for each aerosol bin, default values for deposition flags, initial plume dimensions for 

each plume segment, a particle size distribution for each chemical group, a default value of 

REFTIM for each plume segment, and fission product inventory data are contained in the 

MELMACCS output file.
4-9

Figure 4-8 Definition of plume segments (release path through heat)

Figure 4-9 Definition of plume segments (flow rate through barium release fraction)

Cesium iodide (CsI) and cesium molybdate (Cs2MoO4) are included in the release calculation 

performed by MELMACCS. The activities contained in CsI are split into Class 2, cesium (Cs), 

and Class 4, halogens (I), and the activities in Cs2MoO4 are split into Class 2 and Class 7, 

molybdenum (Mo). These results are then used to calculate the total fractional releases of the 

core inventory for cesium, iodine, and molybdenum.
4-10

For the SOARCA scenarios, each of the radionuclide classes listed in Table 4-3 were 

considered for environmental impacts. Class 10, uranium (U), Class 11, more volatile main 

group (Cd), and Class 12, less volatile main group (Sn), were not considered in the 

environmental impacts because these classes do not contain any isotopes that are considered 

to be important in a consequence analysis. MACCS analyses for commercial nuclear reactors 

usually use the 60 radionuclides that were evaluated to be important for health effects in the 

NUREG-1150 study; however, the NUREG-1150 study implicitly included a set of nine 

daughters that are now treated explicitly. Thus, 69 radionuclides are included in MACCS

analyses of commercial nuclear reactors.

For additional information regarding these radionuclide classes and the isotopes used in the 

consequence analyses for Peach Bottom and Surry, see Table A-1 in NUREG/CR-7110 Volume 

1 [2], and Table B-1 in NUREG/CR-7110 Volume 2 [3], respectively. 

Table 4-3 Radionuclide classes used in SOARCA

Class Name Representative Member Elements

1 Noble Gas Xe He, Ne, Ar, Kr, Xe, Rn, H, N

2 Alkali Metals Cs Li, Na, K, Rb, Cs, Fr, Cu

3 Alkali Earths Ba Be, Mg, Ca, Sr, Ba, Ra, Es, Fm

4 Halogens I F, Cl, Br, I, At

5 Chalcogens Te O, S, Se, Te, Po

6 Platinoids Ru Ru, Rh, Pd, Re, Os, Ir, Pt, Au, Ni

7 Early Transition 

Elements Mo V, Cr, Fe, Co, Mn, Nb, Mo, Tc, Ta, W

8 Tetravalent Ce Ti, Zr, Hf, Ce, Th, Pa, Np, Pu, C

9 Trivalents La

Al, Sc, Y, La, Ac, Pr, Nd, Pm, Sm, Eu, 

Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Am, 

Cm, Bk, Cf

4.3 Atmospheric Transport

Plume dispersion during downwind transport in MACCS is modeled using a segmented 

Gaussian plume model. This model uses a normal (i.e., Gaussian) distribution for air 

concentration in the crosswind and vertical dimensions. The Gaussian plume equations depend

on the wind speed, atmospheric stability class, the effect of surface roughness, release height, 

and the height of the mixing layer. 

The Gaussian plume model uses two spatially dependent dispersion parameters, sigma-y and 

sigma-z, to estimate the atmospheric dispersion. These parameters can be specified in two 

ways in MACCS: as power-law functions or with lookup tables. The dispersion parameters are 

specified for each stability class. The SOARCA project used the power-law functions, as 

specified with the DISPMD variable. The long-range distance-based model was chosen, which 

means that the same power-law functions were used at all downwind distances. This choice 

was made largely to facilitate uncertainty analyses to be performed in a follow-on study.

Table 4-4 shows the Gaussian plume model input variations between SOARCA, Sample 

Problem A, and NUREG-1150 for Peach Bottom. Sample Problem A used the weather lookup 

tables while NUREG-1150 used power-law function values from Dobbins [13]. SOARCA used 

power-law function values from a more recent evaluation of expert elicitation data [18]. A 

comparison of all the values for the power-law function can be found in Appendix C. 
4-11

The SOARCA project used the MACCS diurnal mixing height model. This model allows for two 

values of mixing height for each of the four seasons of the year. The first of these two values

corresponds to the morning (minimum) mixing height and the second to the afternoon 

(maximum) mixing height. The start day of each weather sequence determines the season in

which that sequence lies.

Table 4-4 Plume model input variation between SOARCA, Sample Problem A, and 

NUREG-1150

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

BNDWND Boundary Wind Speed 

(m/sec) 2.2 2.2 5 0.5

CYSIGA

Linear Coefficient for sigma-y

Stability Class A 0.7507 0.7507

Weather 

lookup table

0.3658

Stability Class B 0.7507 0.7507 0.2751

Stability Class C 0.4063 0.4063 0.2089

Stability Class D 0.2779 0.2779 0.1474

Stability Class E 0.2158 0.2158 0.1046

Stability Class F 0.2158 0.2158 0.0722

CYSIGB

Exponential Term for sigma-y

Stability Class A 0.866 0.866

Weather 

lookup table

0.9301

Stability Class B 0.866 0.866 0.9301

Stability Class C 0.865 0.865 0.9301

Stability Class D 0.881 0.881 0.9301

Stability Class E 0.866 0.866 0.9301

Stability Class F 0.866 0.866 0.9301

CZSIGA

Linear Coefficient for sigma-z

Stability Class A 0.0361 0.0361

Weather 

lookup table

0.00025

Stability Class B 0.0361 0.0361 0.0019

Stability Class C 0.2036 0.2036 0.2

Stability Class D 0.2636 0.2636 0.3

Stability Class E 0.2463 0.2463 0.4

Stability Class F 0.2463 0.2463 0.2

CZSIGB

Exponential Term for sigma-z

Stability Class A 1.277 1.277

Weather 

lookup table

2.125

Stability Class B 1.277 1.277 1.6021

Stability Class C 0.859 0.859 0.8543

Stability Class D 0.751 0.751 0.6532

Stability Class E 0.619 0.619 0.6021

Stability Class F 0.619 0.619 0.602

DISPMD Dispersion Model Flag LRDIST LRDIST

Not available in 

the MACCS

1.12 model

Not available in 

the MACCS 

model
4-12

4.3.1 MACCS Plume Model

In NUREG-1150, the option was used to include wind shift and wind rotation (IPLUME=2). In 

SOARCA, the option to include wind rotation was not available because the network evacuation 

model was employed, and these two options are incompatible. Instead wind shift without 

rotation was chosen (IPLUME=3). 

The wind shift option allows each plume segment to travel in the direction that the wind is 

blowing at the time point represented by the plume segment. This option was used in both 

NUREG-1150 and in SOARCA. Furthermore, in SOARCA, maximum advantage was taken of 

the effects of wind shifts by splitting the release into hourly plume segments. By matching the 

duration of each plume segment with the averaging period for wind data, the realistic treatment 

of the effect of fluctuations in wind directions on local exposures is exploited. 

Wind rotation serves the purpose of maximizing information while minimizing computational 

work. For each weather trial, wind rotation considers the possibility that, for otherwise similar 

conditions, the wind could have blown in any of the compass directions. Thus, MACCS

evaluates the consequences that would have resulted for each wind direction, but accounts for 

the relative frequency that the wind blows in each compass direction based on the wind rose. A 

separate wind rose is computed for each weather bin, so only similar conditions are considered 

in applying wind rotation. 

There are two reasons why wind rotation was not used in SOARCA. First, wind rotation is 

incompatible with network evacuation. The wind rotation model assumes that, other than 

population density, the problem is axisymmetric. This is not true when using the network 

evacuation model. MACCS prevents the user from pairing these two modeling options. The 

second reason is that the wind rotation model assumes that similar wind shifts would occur 

regardless of the initial wind direction. In other words, when wind rotation is employed, wind 

shifts for each subsequent plume segment following the initial plume segment are the same 

relative to the initial direction. This assumption becomes more dubious as more plume 

segments are employed. This is a key difference between NUREG-1150 and SOARCA. 

NUREG-1150 used two plume segments for all but one of the five plants and used three plume 

segments for Zion; SOARCA used between about 30 and 200 plume segments for each 

scenario. The assumption that the pattern of directions is independent of the initial wind 

direction is better justified when using two plume segments than when using more than a few

plume segments. 

4.3.2 Plume Rise Model

Two models for plume rise currently exist in MACCS and both are based on the work of Briggs 

[50], [51]. The more recently implemented model has been demonstrated to better approximate 

the actual rise of a plume. This more recent model was used in SOARCA but was not available 

at the time of NUREG-1150. 

The current version of MACCS also allows two ways of inputting the parameters that are used 

for estimating plume buoyancy. The original method, which was used in NUREG-1150, 

estimates buoyancy based on the rate of latent heat release in the plume. The rate of latent 

heat release is proportional to the difference between the temperatures of the plume and of the 

surrounding air. The second method, which is used in SOARCA, estimates buoyancy based on 

the mass rate of release and the density of the plume being released. The second method is 

considered superior when releases contain significant quantities of hydrogen, as they 

sometimes do during a severe accident because it accounts for density differences induced by 

both temperature and molecular weight.
4-13

To escape the building wake, a plume must overcome the turbulent wake effects of the reactor 

building. This is modeled in MACCS with an equation that depends on the building height and 

on the amount of buoyancy in the plume. The equation compares the actual wind speed with a 

critical wind speed that is just large enough to trap the plume. Based on this comparison, the 

plume either rises due to its buoyancy or is released at its initial elevation. 

Two additional dispersion parameters, an initial sigma-y and sigma-z, are used to define the 

initial size of the plume as it is released. These initial values are calculated based on the height 

and width of the reactor or other building from which the release occurs. Table 4-5 provides the 

initial dispersion parameters used in SOARCA and for Sample Problem A. As seen in 

Table 4-5, it appears the only difference in the Surry values between SOARCA and Sample 

Problem A is the number of significant figures used. Both the Surry and the Peach Bottom 

values are consistent with those used in NUREG-1150 for those reactors.

Table 4-5 Plume raise inputs for SOARCA and Sample Problem A

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A

(Surry)

SIGYINIT Initial Sigma-y for All 

Plume Segments (m) 9.3 11.6 9.302

SIGZINIT Initial Sigma-z for All 

Plume Segments (m) 23.3 23.3 23.26

4.3.3 Plume Meander Model

Plume meander was not treated in SOARCA. The NRC Regulatory Guide 1.145 plume 

meander model [34] was considered, but it would have had a minimal impact on the predicted 

doses for even the closest residents to the sites because this model only affects the plume 

dimensions at relatively short distances. Table 4-6 shows the variations of the plume meander 

inputs between SOARCA, Sample Problem A, and NUREG-1150. The changes reflect the 

decision to not account for plume meander in SOARCA.

Table 4-6 Plume meander model variation between SOARCA and NUREG-1150

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

TIMBAS Time Base for Plume 

Expansion Factor (sec) Not Used Not Used 600 600

XPFAC1 Base Time for Meander 

Expansion Factor Not Used Not Used 0.2 0.2

XPFAC2 Breakpoint for Expansion 

Factor Model Not Used Not Used 0.25 0.25

4.3.4 Weather Sampling

Weather binning is an approach used in MACCS to categorize similar sets of weather data 

based on wind speed3

, stability class, and the occurrence of precipitation. The weather 

sampling strategy adopted for SOARCA uses the nonuniform weather-binning approach in 

MACCS. This approach, which allows the user to specify a different number of random samples 

 3 With regard to wind direction, the assumption is that sampling within each weather bin is sufficient to adequately 

represent the wind rose for that bin. Accounting for the fact that each plume segment travels in its own direction, 

this assumption should be satisfied.
4-14

for each bin, has been available since MACCS was first released [12] but was not used in 

previous studies. 

In the SOARCA project, the same weather binning structure was defined as in NUREG-1150 

and Sample Problem A, which consisted of 16 predefined bins for combinations of stability class 

and wind speed and 20 user-defined bins for rain occurring before the plume travels 32 km (20 

miles). The rain bins differentiate rain intensity and the distance the plume travels before rain 

begins. The parameters used to define the rain bins are the same as those used in NUREG1150 and documented in the MACCS User’s Manual [12]. An approach called uniform weather 

bin sampling was used in NUREG-1150 and in Sample Problem A. Four weather sequences 

were sampled per bin, resulting in a nominal 144 weather trials. In some cases, a bin contained 

fewer than 4 weather sequences, resulting in a total number of weather trials less than 144 

(e.g., 135 for Surry). In conjunction with this sampling method, an additional strategy called 

wind rotation was used. Wind rotation expands the set of weather trials by a factor of 16 (i.e., 

the number of compass sectors used in the analysis) by reevaluating the results for each 

weather trial assuming that the wind had blown in each of the other compass directions. The 

consequences for each wind direction are assigned a probability that accounts for the wind rose 

probability. In effect, this strategy results in 16 x 144 = 2304 nominal weather trials (e.g., 2160 

for Surry). 

For the nonuniform weather sampling strategy approach adopted in SOARCA, the number of 

trials selected from each bin is the maximum of 12 trials and 10 percent of the number of trials 

in the bin. Some bins contain fewer than 12 trials. In those cases, all of the trials within the bin 

are used for sampling. This strategy results in roughly 1,000 weather trials for both Peach 

Bottom and Surry. Table 4-7 shows the variations of the weather sampling inputs between 

SOARCA Surry and Peach Bottom. MACCS does not allow wind rotation in conjunction with 

one of the other models used in SOARCA, network evacuation. Thus, expanding the number of 

weather trials by the number of compass sectors was not used in SOARCA, which is one of the 

main reasons that the number of weather trials was significantly increased. 
4-15

Table 4-7 Weather sampling input variation between SOARCA, Sample Problem A,

and NUREG-1150

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

INWGHT

Number of Samples for Each Bin Used for Nonuniform Weather Bin Sampling

Bin 1 12 71

44 44

Bin 2 14 42

Bin 3 12 12

Bin 4 39 52

Bin 5 85 57

Bin 6 94 74

Bin 7 16 21

Bin 8 12 12

Bin 9 27 49

Bin 10 134 103

Bin 11 119 77

Bin 12 74 35

Bin 13 92 51

Bin 14 43 75

Bin 15 12 14

Bin 16 12 4

Bin 17 37 44

Bin 18 12 12

Bin 19 13 17

Bin 20 17 24

Bin 21 14 24

Bin 22 12 12

Bin 23 6 4

Bin 24 6 8

Bin 25 12 12

Bin 26 12 12

Bin 27 12 12

Bin 28 1 1

Bin 29 5 3

Bin 30 6 5

Bin 31 5 4

Bin 32 12 12

Bin 33 5 1

Bin 34 12 7

Bin 35 12 9

Bin 36 12 12

NSBINS Number of Weather 

Bins to Sample 36 36 36 36

 4 The value 4 is actually assigned to the variable NSMPLS, which is used to uniformly select 4 weather trials from 

each bin. This would be expected to result in 4 x 36 = 144 weather trials; however, some bins do not contain 4 

hours of weather data and the net result is that fewer than 144 weather trials are actually performed. For example, 

135 weather trials were performed in Sample Problem A.
4-16

4.3.5 Weather Data

Meteorological data used in the SOARCA project consisted of one year of hourly meteorological 

data for each site (i.e., 8,760 hourly data points per site for each meteorological parameter). 

This was primarily accomplished via a cooperative effort between the licensee, the NRC, and 

SNL. Each licensee provided two years of data from onsite meteorological tower observations. 

Stability class data were derived from temperature measurements at two elevations on the site 

meteorological towers. The specific year of data chosen for each reactor was based on data 

recovery (e.g., greater than 90 percent being desirable) and proximity to the target year for 

SOARCA, which was 2005. Different trends (e.g., wind-rose pattern and hours of precipitation) 

between the years were evaluated and estimated to have a relatively minor (i.e., less than ±10

percent) effect on the final results. 

Well over 90 percent of the weather data used in SOARCA was actual site weather data. The 

missing data were bridged by following the “Procedures for Substituting Values for Missing 

National Weather Service Meteorological Data for Use in Regulatory Air Quality Models” [29]. 

The meteorological data parameters were formatted for the MACCS computer code.

The NRC staff ensured a joint data recovery rate above 90 percent (i.e., all parameters were 

measured for a given hour for at least 90 percent of the hours of the year), which is in 

accordance with the NRC Regulatory Guide 1.23, Revision 1 [31], for the wind speed, wind 

direction, and atmospheric stability parameters. The staff performed quality assurance 

evaluations of all meteorological data using the methodology described in NUREG-0917 [30]. In 

addition, atmospheric stability was evaluated to determine if the time of occurrence and duration 

of reported stability conditions were generally consistent with expected meteorological 

conditions (e.g., neutral and slightly stable conditions predominated during the year with stable 

and neutral conditions occurring at night and unstable and neutral conditions occurring during 

the day). The mixing height data were retrieved from the U.S. Environmental Protection 

Agency’s (EPA’s) SCRAM database using data from the years 1984 through 1992. Data 

needed for MACCS includes 10-meter wind speed, 10-meter wind direction (in 64 compass 

directions for the SOARCA analyses), stability class (i.e., Pasquill-Gifford stability class using 

representative values of 1 through 6 for stability classes A through F/G), hourly precipitation, 

and diurnal (morning and afternoon) seasonal mixing heights. 

Boundary weather was implemented for all of the SOARCA consequence analyses, but it was 

imposed beyond the outer boundary (i.e., 50 miles) for which results are reported. Thus, the 

choice of boundary weather had no influence on the consequence results that are reported in 

SOARCA. The Peach Bottom [2] and Surry [3] reports provide the specific parameters chosen 

to describe the boundary weather. They are also included in Appendix C.

Table 4-8 presents a summary of the meteorological statistical data and shows that the annual 

average 10-m wind speeds were generally low, ranging from 2.02 to 2.27 meters per second

(m/s) at Surry and 2.12 to 2.17 m/s at Peach Bottom. The atmospheric stability frequencies 

were found to be consistent with expected meteorological conditions. The neutral and slightly 

stable conditions predominated during the year, with stable and neutral conditions occurring at 

night and unstable and neutral conditions occurring during the day. 
4-17

 

0.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

N

NNE

NE

ENE

E

ESE

SE

SSE

S

SSW

SW

WSW

W

WNW

NW

NNW

Figure 4-10 and Figure 4-11 show the wind direction (i.e., wind rose) that the wind blows 

towards and atmospheric stability (i.e., unstable,5 neutral,6 and stable7

) conditions for the years 

that were used in the SOARCA consequence analyses (i.e., 2006 for Peach Bottom and 2004 

for Surry). Figure 4-10 and Figure 4-11 show the Pasquill-Gifford stability categories in terms of 

unstable conditions (categories A through C), neutral stability (category D), and stable 

conditions (categories E and F) for the two weather years used in SOARCA on an hourly basis. 

The trends shown in the figures are expected, which is that unstable conditions occur during 

daylight hours, peaking around mid-day, and stable conditions primarily occur during nighttime 

hours. Neutral conditions are more frequent at the Surry site than at the Peach Bottom site, 

primarily because cloud cover is more frequent at Surry. 

Table 4-8 Statistical summary of raw meteorological data for SOARCA sites

Parameter Peach Bottom Surry

Year 2005 Year 2006 Year 2001 Year 2004†

Average Wind Speed (m/s) 2.17 2.12 2.02 2.27

Yearly Precipitation (hr)

(% of Annual Weather)

588

(6.7%)

593

(6.8%)

388

(4.4%)

521

(5.9%)

Atmospheric 

Stability (%)

Unstable 21.43 17.75* 7.09 3.94

Neutral 63.97 24.57* 69.67 77.59

Stable 14.60 57.68* 23.24 18.47

Joint Data Recovery (%) 97.53 99.25 99.58 99.24

† Year 2004, as used in the Surry meteorological analysis, is a leap year (8,784 total hourly data 

points versus 8,760 hourly data points for a regular annual period).

* Subsequent analysis of Peach Bottom 2006 meteorological data revealed that atmospheric stability 

distribution data in this table was incorrectly reported in NUREG-1935 Table 2, however the correct 

data was used in the analyses. The corrected data is presented here.

Figure 4-10 Peach Bottom wind rose and atmospheric stability chart, year 2006

 5 This corresponds to Pasquill-Gifford stability classes A, B, and C. 6 This corresponds to Pasquill-Gifford stability class D. 7 This corresponds to Pasquill-Gifford stability classes E, F, and G.
4-18

 

0.00%

2.00%

4.00%

6.00%

8.00%

10.00%

12.00%

N

NNE

NE

ENE

E

ESE

SE

SSE

S

SSW

SW

WSW

W

WNW

NW

NNW

 

-50

0

50

100

150

200

250

300

350

400

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Hour of the Day

Number of Occurrences

Unstable

Neutral

Stable

Figure 4-11 Surry wind rose and atmospheric stability chart, year 2004

Table 4-9 shows the variations of the precipitation inputs between SOARCA, Sample 

Problem A, and NUREG-1150 for Peach Bottom. The values used in SOARCA are identical to 

those in Sample Problem A because there was no good reason to change them. In particular, 

boundary weather was implemented at the outer edge of the grid, well beyond the distances 

where results were presented, so the presence of boundary rain did not affect any of the 

reported results. The choice of rain distances and intensities did affect the weather sampling 

used in the SOARCA study, but these choices were considered to be reasonable. Since 

essentially no early fatalities were calculated in SOARCA, the definitions of the rain bins should 

have had a negligible effect on the reported results. The value for the boundary rain rate, 5 

mm/hr, was used in Sample Problem A to ensure that nearly all of the radionuclides would 

deposit before leaving the computational domain. This choice clearly introduces a conservative 

bias and is not always appropriate, especially when the computational grid has a radius 

significantly less than the 1000-mi radius used in Sample Problem A. 

Table 4-9 Precipitation input variation between SOARCA and NUREG-1150

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

BNDRAN Boundary Weather 

Rain Rate (mm/hr) 5 5 5 0

RNDSTS

Endpoints of Rain Distance Intervals (km)

Interval 1 3.22 3.22 3.22 3.22

Interval 2 5.63 5.63 5.63 5.63

Interval 3 11.27 11.27 11.27 11.27

Interval 4 20.92 20.92 20.92 20.92

Interval 5 32.19 32.19 32.19 40.23

Interval 6 N/A N/A N/A 80.47

RNRATE

Rain Intensity Breakpoints for Weather Binning (mm/hr)

Intensity 1 2 2 2 1

Intensity 2 4 4 4 2

Intensity 3 6 6 6 3
4-19

4.3.6 Adverse Weather

Adverse weather is typically defined as rain, ice, or snow that affects the response of the public 

during an emergency. A normal weather winter day was selected for the analysis. However,

because real weather data was used in the calculation, the travel speed of each cohort is 

reduced when adverse weather occurs. The evacuation speed multiplier (ESPMUL) parameter 

in WinMACCS is used to reduce travel speed when precipitation is occurring, as indicated from 

the meteorological weather file. The ESPMUL factor was set at 0.7, which effectively slows 

down the evacuating public to 70 percent of the established travel speed during the time

precipitation occurs. The SOARCA team estimated this value through review of existing ETE 

guidance [20].

Impacts of adverse weather can vary based on the region and familiarity of the drivers with the 

weather condition; therefore, the factors provided in NUREG/CR-7002, “Criteria for 

Development of Evacuation Time Estimate Studies,” [20] to adjust roadway speed and capacity 

depend on the weather conditions that may be experienced. The weather capacity factors in 

NUREG/CR-7002 apply to roadway capacity and speed, which when considered together, show 

that the 0.7 value for ESPMUL is reasonable. 

4.3.7 Dry Deposition Modeling

Table 4-10 shows the particle size distribution and dry deposition velocity input variation used in 

SOARCA, Sample Problem A, and NUREG-1150. As indicated in the table, particle size 

distribution data are provided in Tables A-3 and B-3 in the appendices. 

As shown in Table 4-11, the SOARCA project used the 10 aerosol bins defined in MELCOR to 

represent the dependence of deposition velocity on aerosol size. In connection with aerosol 

size distribution data for each chemical group, the modeling allows the deposition velocity 

behavior to be different for each chemical group. 

Table 4-10 Particle size distribution and dry deposition velocity input variation 

between SOARCA and NUREG-1150

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150 

Peach Bottom

NPSGRP Number of Particle 

Size Groups 10 10 1 1

PSDIST

Particle Size 

Distribution by 

Group

MELMACCS data

Appendix A

Table A-3

MELMACCS data

Appendix B

Table B-3

1. for all 

groups

1. for all 

groups

VDEPOS

Dry Deposition Velocities (m/sec)

Aerosol Bin 1 5.35E-04 5.35E-04

0.01 0.01

Aerosol Bin 2 4.91E-04 4.91E-04

Aerosol Bin 3 6.43E-04 6.43E-04

Aerosol Bin 4 1.08E-03 1.08E-03

Aerosol Bin 5 2.12E-03 2.12E-03

Aerosol Bin 6 4.34E-03 4.34E-03

Aerosol Bin 7 8.37E-03 8.37E-03

Aerosol Bin 8 1.37E-02 1.37E-02

Aerosol Bin 9 1.70E-02 1.70E-02

Aerosol Bin 10 1.70E-02 1.70E-02
4-20

Table 4-11 Dry deposition velocities used for the SOARCA studies for each of the ten 

aerosol bins in MELCOR

Mass Median Aerosol Diameter

(mm)

Deposition Velocity 

(cm/s)

0.15 0.053

0.29 0.049

0.53 0.064

0.99 0.11

1.8 0.21

3.4 0.43

6.4 0.84

11.9 1.4

22.1 1.7

41.2 1.7

4.3.8 Wet Deposition Modeling

Wet deposition is an important phenomenon that strongly affects atmospheric transport. Under 

heavy rains, wet deposition rapidly depletes the plume. Even under light rains, the plume is 

depleted much faster than by dry deposition alone. The wet deposition process can produce 

concentrated deposits on the ground and create what is often referred to as a hotspot (i.e., an 

area of higher radioactivity than the surrounding areas). While rain occurs less than 10% of the 

time for most of the U.S., it can significantly affect consequence calculations when it does occur. 

For SOARCA, parameters used in the wet deposition model were reevaluated from those used

in NUREG-1150. Both the linear and exponential coefficients for washout (CWASH1 and 

CWASH2, respectively) were modified based on expert elicitation data [18]. Table 4-12 shows 

the CWASH1 and CWASH2 variables used in SOARCA and NUREG-1150. The values in 

Sample Problem A are identical to those in NUREG-1150.

Table 4-12 Wet deposition model variation between SOARCA and NUREG-1150

Variable Description SOARCA NUREG-1150

CWASH1 Linear Coefficient for 

Washout 1.89x10-5 9.50x10-5

CWASH2 Exponential Term for 

Washout 0.664 0.80

4.3.9 Surface Roughness

Surface roughness affects both vertical dispersion and dry deposition velocities. All of the 

SOARCA base case analyses, for both sites, used a surface roughness length of 10 cm. The 

value of 10 cm for surface roughness is the same as the value used in NUREG-1150 [7] and in 

Sample Problem A. The area surrounding Surry may be characterized by a mosaic of surface 

water, forests, farmland, suburban areas, and urban areas. The James River covers a 

significant fraction of the EPZ. The value of 10 cm used in the base case was representative of 

the farmland and river. Woodland forests and urban areas also make up a significant fraction of 

the area and have a mean surface roughness of about 20 to 100 cm. An intermediate choice 

representing the average between cornfields and woodland forest, about 50 to 60 cm, might 

also have been a reasonable choice for this area. Because the river dominates the landscape 
4-21

and the urban areas are across the river, which is 2 to 3 miles wide in some areas, the lower 

value of 10 cm was chosen for this site.

Peach Bottom is located directly adjacent to the Susquehanna River near the southern border of 

Pennsylvania. As seen in Table 4-13, the area surrounding Peach Bottom is characterized by a 

mosaic of forests, farmland mostly used to grow corn, suburban areas, and several stone 

quarries. Farmland and forests are the major land-use categories. Each of these land-use 

types correspond to a typical surface roughness or a range of surface roughness as shown in 

[19]. 

Table 4-13 Surface roughness for various land-use categories for the area 

surrounding the Peach Bottom site

Land-Use Category Surface Roughness 

(cm)

Farmland recently plowed 1

Farmland with mature corn 10

Suburban housing 5 to 20

Suburban institutional buildings 70

Woodland forests 20 to 100

Stone quarries 50 to 200

For Peach Bottom, the value of 10 cm used in the base case is representative of the corn fields

that make up a significant fraction of the countryside surrounding the Peach Bottom site. 

Woodland forests also make up a significant fraction of the area and have a mean surface 

roughness of about 20 to 100 cm. An intermediate choice representing the average between 

cornfields and woodland forest, about 30 to 60 cm, is also a reasonable choice for this area.

For Peach Bottom, a sensitivity analysis was performed as part of the SOARCA study using a

60-cm surface roughness.

The surface roughness sensitivity analysis showed that an increase from 10 cm to 60 cm results 

in a risk reduction of about 20% for the intermediate distances (10 to 50 miles) and a risk 

increase of about 10% within 10 miles for the predicted LCF risks using LNT dose-response [2].

Generally the risk is lower when a higher value of surface roughness is assumed. Because the 

overall effect of surface roughness was determined to be relatively small, a similar study was 

not performed for Surry. 

The effect of surface roughness on vertical dispersion has traditionally been modeled by means 

of a multiplicative factor. The empirical expression for this factor is the ratio of surface 

roughness at the site in question to a standard value of surface roughness to the 1/5th power. 

Most of the data upon which empirical dispersion models have been based were taken at a site 

characterized by prairie grass [17], which was estimated to have a surface roughness of 3 cm. 

Thus, the empirical equation used to scale vertical dispersion uses the actual surface roughness 

divided by 3 cm to the 1/5th power. The standard multiplicative factor corresponding to a 10 cm 

surface roughness is (10 / 3)0.2 = 1.27, which is the value used in all of the base-case analyses

presented in SOARCA. A surface roughness length of 60 cm corresponds to a multiplicative 

factor of 1.82, which was used in the surface roughness sensitivity analysis presented in 

NUREG/CR-7110 Volume 1, Section 7.3.7. 

The effect of surface roughness on deposition velocity has been characterized by Bixler et al.

[18] based on expert elicitation data [15]. Bixler et al. provides a set of correlations for 

estimating deposition velocity as a function of aerosol diameter, wind speed, surface roughness, 
4-22

and percentile representing degree of belief by the experts. Based on these results, the best 

estimate for the 50th percentile correlation is as follows:

ln(vd) = −3.112 + 0.992 ∙ ln�dp� + 0.190 ∙ [ln�dp�]

2 − 0.072 ∙ [ln�dp�]3 + 5.922 ∙ z0 − 6.314 ∙ z0

2

+ 0.169 ∙ v

where:

vd = deposition velocity (cm/s)

dp = aerosol diameter (μm)

z0 = surface roughness (m)

v = mean wind speed (m/s)

This correlation is valid for aerosol diameters up to about 20 μm and surface roughness up to 

about 60 cm.

For elevated releases, enhanced vertical dispersion increases the ground level concentrations 

close to the point of release because the plume spreads down to the ground more quickly. The 

MACCS results show that ground level concentrations and resulting doses are greater for the 

sensitivity case within about 4 miles of the plant; at greater distances the ground level doses are 

smaller for the sensitivity case. At intermediate distances, enhanced vertical dispersion reduces 

ground level concentrations because the plume spreads more rapidly in the vertical dimension 

and, as a result, becomes more dilute at ground level. At long distances, the ground level 

concentrations are about the same because the plume becomes well mixed within the mixing 

layer where the plume is confined. 

Compounding the effect of increased surface roughness on vertical dispersion is the fact that 

the deposition velocity is also increased. This leads to more deposition at shorter distances and 

faster depletion of the plume. As a result, ground concentrations at short distances are 

increased and those at longer distances are diminished. The breakpoint between short and 

long distances depends on the application, but it is generally at a distance greater than 80 km 

(50 miles). Thus, for the distances reported in SOARCA, higher deposition velocities (larger 

surface roughness) result in larger long-term doses because they are proportional to deposition. 

From this discussion, the overall trend corresponding to a larger surface roughness is not clear. 

Increased dispersion tends to diminish doses, while increased deposition velocity tends to 

increase them. The general trend observed in the SOARCA study is that increased surface 

roughness decreases average individual LCF risk within a 50-mile region. The effect is about 

10% for LNT and greater than 20% for the two truncation dose-response models. 

4.4 Exposure Pathways

For SOARCA, the exposure pathways considered during the emergency phase period are 

cloudshine, groundshine, and direct and resuspension inhalation. Mitigative actions can be 

specified for the emergency phase such as evacuation, sheltering, and relocation based on 

dose projections.

The exposure pathways for the long-term phase are groundshine, resuspension inhalation, and 

food and water ingestion. Only the groundshine and resuspension inhalation exposure 

pathways were considered in SOARCA because adequate supplies of uncontaminated food and 

water are available in the U.S.; contaminated food and water would not need to be consumed.
4-23

4.4.1 Shielding and Protection Factors

In MACCS, shielding and protection factors are specified for each dose pathway and directly 

affect the doses received by individuals at each location. The shielding factors are used as 

multipliers on the dose that a person would receive if there were no shielding or protection. 

Thus, a shielding factor of one represents the limiting case of a person receiving the full dose 

(i.e., standing outdoors and completely unprotected from the exposure); a shielding factor of 

zero represents the limiting case of complete shielding from the exposure. The shielding factors 

used in the MACCS calculation are clearly important because the doses received are directly 

proportional to these factors.

Three types of activity: normal, sheltering, and evacuation, are evaluated for each dose 

pathway. In this context, normal activity refers to a combination of activities that are averaged 

over a week and over the population, including being indoors at home, commuting, being 

indoors at work, and being outdoors. Table 4-14 shows the cloudshine shielding factor, 

groundshine shielding factor, inhalation protection factor, and skin protection factor variables 

used in SOARCA, Sample Problem A, and NUREG-1150. Appendix C provides a full 

comparison of the differences between NUREG-1150 and SOARCA. 

Shielding factors applied to evacuation, normal activity, and sheltering for each relevant dose 

pathway (i.e., inhalation, deposition onto skin, cloudshine, and groundshine) were evaluated for 

each site based on values used in NUREG-1150 [7] and NUREG/CR-6953, Volume 1 [11]. The 

normal activity values assume that the average person spends 19 percent of the day outdoors 

and 81 percent of the day indoors [45]. 

Each parameter (CSFACT, GSHFAC, PROTIN, and SKPFAC) can be specified for each cohort

in WinMACCS. In the SOARCA study, shielding values for Cohorts 1, 2, 3, 5, and 6 are 

identical. Cohort 4 which corresponds to populations in special facilities, has different shielding 

values because of the larger, more robust buildings that are used for these facilities.
4-24

Table 4-14 Cloudshine factor, groundshine factor, inhalation protection factor, and 

skin protection factor variations between SOARCA, Sample Problem A, and 

NUREG-1150

Variable Description

SOARCA 

Surry

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

CSFACT

Cloudshine Shielding Factors

Evacuation Shielding 

Factor for All but Cohort 4 1 1 1 1

Normal Activity Shielding 

Factor for All but Cohort 4 0.68 0.6 0.75 0.75

Sheltering Shielding Factor 

for All but Cohort 4 0.6 0.5 0.6 0.5

Evacuation Shielding 

Factor for Cohort 4 1 1 This cohort was 

not used

This cohort was 

not used

Normal Activity Shielding 

Factor for Cohort 4 0.31 0.31 This cohort was 

not used

This cohort was 

not used

Sheltering Shielding Factor 

for Cohort 4 0.31 0.31 This cohort was 

not used

This cohort was 

not used

GSHFAC

Groundshine Shielding Factors

Evacuation Shielding 

Factor for All but Cohort 4 0.5 0.5 0.5 0.5

Normal Activity Shielding 

Factor for All but Cohort 4 0.26 0.18 0.33 0.33

Sheltering Shielding Factor 

for All but Cohort 4 0.2 0.1 0.2 0.1

Evacuation Shielding 

Factor for Cohort 4 0.5 0.5 This cohort was 

not used

This cohort was 

not used

Normal Activity Shielding 

Factor for Cohort 4 0.05 0.05 This cohort was 

not used

This cohort was 

not used

Sheltering Shielding Factor 

for Cohort 4 0.05 0.05 This cohort was 

not used

This cohort was 

not used

PROTIN [E]

Inhalation Protection Factor 

– evacuation for all but 

Cohort 4

0.98 0.98 1 1

PROTIN [N]

Inhalation Protection Factor 

- normal activity for all but 

Cohort 4

0.46 0.46 0.41 0.41

PROTIN [S]

Inhalation Protection Factor 

– sheltering for all but 

Cohort 4

0.33 0.33 0.33 0.33

PROTIN [E] Inhalation Protection Factor 

– evacuation for Cohort 4 0.98 0.98 This cohort was 

not used

This cohort was 

not used

PROTIN [N] Inhalation Protection Factor -

normal activity for Cohort 4 0.33 0.33 This cohort was not used

This cohort was 

not used

PROTIN [S] Inhalation Protection Factor 

– sheltering for Cohort 4 0.33 0.33 This cohort was 

not used

This cohort was 

not used

SKPFAC [E] Skin Protection Factors –

evacuation for all but Cohort 4 0.98 0.98 1 1

SKPFAC [N]

Skin Protection Factors -

normal activity for all but 

Cohort 4

0.46 0.46 0.41 0.41

SKPFAC [S] Skin Protection Factors –

sheltering for all cohorts 0.33 0.33 0.33 0.33

SKPFAC [E] Skin Protection Factors –

evacuation for Cohort 4 0.98 0.98 This cohort was 

not used

This cohort was 

not used

SKPFAC [N] Skin Protection Factors -

normal activity Cohort 4 0.33 0.33 This cohort was 

not used

This cohort was 

not used
4-25

Table 4-15 shows the long-term groundshine protection factor and inhalation protection factor 

variables used in SOARCA, Sample Problem A, and NUREG-1150. The values used in 

SOARCA are identical to the normal activity values used for the emergency phase shown in 

Table 4-14. Likewise the values used in NUREG-1150 are identical to the normal activity values 

used in the emergency phase.

Table 4-15 Long-term groundshine factor and inhalation protection factor variations 

between SOARCA, Sample Problem A, and NUREG-1150

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150 

Peach Bottom

LGSHFAC Long-Term Groundshine 

Protection Factor 0.26 0.18 0.33 0.33

LPROTIN Long-Term Inhalation 

Protection Factor 0.46 0.46 0.41 0.41

4.4.2 Food Ingestion Model

The ingestion pathway was not treated in SOARCA. An underlying assumption in SOARCA 

was that uncontaminated food and water supplies are abundant within the United States, and it 

is unlikely that the public would eat radioactively contaminated food. Thus, the MACCS ‘No 

Food Model’ option was used for all consequence analyses. Including the COMIDA2 food 

ingestion model would not have affected the results presented in the SOARCA study because 

the reported risks do not include societal doses from ingestion or to decontamination workers. 

4.5 Dose Models

The SOARCA results of the consequence analyses are presented in terms of probabilities and 

risks to members of the public for each of the accident scenarios identified [2], [3]. Both 

conditional probabilities and scenario-specific risks (the product of accident frequency and 

conditional probability) of health effects for individuals were tabulated. The conditional 

probabilities assume that the accident occurs and show the probabilities of health effects

occurring to individuals as a result of the accident. The scenario-specific risks are the product 

of the accident frequency and the conditional probabilities. The scenario-specific risks are the 

likelihood of receiving a fatal cancer or early fatality for an average individual living within a 

specified radius of the plant per year of plant operation.

The metrics in SOARCA were LCF risk and early fatality risk to residents in circular regions 

surrounding the plant. The risks were averaged over the entire residential population within the 

circular region. The risk values represent the predicted number of fatalities for the three choices 

of dose truncation level divided by the population. These risk metrics account for the 

distribution of the population within the circular region and for the interplay between the 

population distribution and the wind rose probabilities. 

4.5.1 Dose-Response Models

Risk results in SOARCA are presented for three dose-response assumptions including: 

1. LNT hypothesis; 

2. Linear dose response but with a dose truncation level of 620 mrem/yr, i.e., the 

U.S. average natural background dose combined with average annual medical dose [44]

(USBGR); and 
4-26

3. Linear dose response but with a dose truncation level based on the Health Physics 

Society’s (HPS) position paper that there is a dose below which, due to uncertainties, a 

quantified risk should not be assigned, which is 5 rem/yr with a lifetime limit of 10 rem

[35]. 

A 10 mrem/yr dose truncation level was also investigated, but it produced results that were only

slightly lower than with the LNT assumption, and thus were not included in the final version of 

the SOARCA documents.

4.5.2 Exposure and Commitment Periods

The exposure period for internal pathways, inhalation and ingestion, is the period of time when 

the inhalation or ingestion occurs; however, doses can continue over a person’s entire lifetime 

following the exposure. The period of time over which doses are received from an internal 

pathway is accounted for in the construction of dose coefficients by integrating the doses over a 

finite period, representing a person’s lifetime, called a dose commitment period, which is usually 

taken to be 50 years when calculating internal pathway dose coefficients for adults. The implicit 

assumption is that the average adult lives for an additional 50 years following the exposure. 

Because ingestion (i.e., food and water uptake) doses were not included, inhalation is the only 

internal pathway that is treated in SOARCA. A significant portion of the exposures during the 

emergency phase are from inhalation. As explained above, these exposures are assumed to 

lead to doses over the commitment period, which is the next 50 years following the exposure. 

However, depending on the radionuclide inhaled, the doses received may diminish rapidly and 

become negligible for most of the dose commitment period.

Most of the exposures during the long-term phase are from groundshine; a small fraction is from 

inhalation of resuspended aerosols. Since groundshine is an external pathway, doses received 

are concurrent with the exposure, whereas, exposures from inhalation during each year of the 

long-term phase contribute to doses received over the subsequent 50-year commitment period. 

Doses received in the first year thus correspond to:

• all of the dose from external exposure during the emergency phase,

• most of the dose from internal exposure during the emergency phase,

• all of the dose from external exposure during the first year of the long-term phase, and

• most of the dose from internal exposure during the first year of the long-term phase.

Doses received in the second and subsequent years correspond to:

• a fraction of the dose from internal exposure during all previous years plus most of the 

dose from internal exposure during that year, and

• all of the dose from external exposure during that year. 

Table 4-16 shows the parameter updates between SOARCA, Sample Problem A, and NUREG1150 for the exposure period. NUREG-1150 and Sample Problem A used the maximum value 

of exposure period allowed by MACCS, 1010 seconds, which is approximately 317 years. More 

recent analyses have used exposure periods chosen to be the same as the commitment period. 

In SOARCA, 1.58x109 seconds (50 years) was chosen. 
4-27

Table 4-16 SOARCA, Sample Problem A, and NUREG-1150 exposure period and action 

period input parameters

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

EXPTIM Maximum Exposure 

Time (sec) 1.58x109 1.58x109 1010 1010

4.5.3 Risk Factors for Cancer

Cancer risk factors used in the 1982 Siting Study [14] are presumed to have come from the

National Research Council’s Committee on the BEIR III report, which was published in 1980 

and would have been the latest available at the time. Cancer risk factors in the SOARCA study 

are based on BEIR V [27], which was published in 1990. These risk factors include seven 

organ specific cancers plus residual cancers that are not accounted for directly. Based on 

Table 4-4 in BEIR V, the BEIR V risk factors are about a factor of 3-5 higher, on average, than 

those from BEIR III, and are dependent upon the exposure duration and cancer type. 

In 2009, the National Research Council released the BEIR VII report, which is the most up-todate study of cancer induction from exposure to ionizing radiation. However, because the dose 

coefficients used in the SOARCA study are from Federal Guidance Report 13 (FGR-13) and this 

report was developed using risk factors from BEIR V, it was decided to use risk factors from 

BEIR V rather than BEIR VII. The SOARCA staff made the decision to await EPA’s review of 

BEIR VII and subsequent update of FGR-13 before implementing BEIR VII risk coefficients. 

The dose coefficients used in the SOARCA analyses are based on FGR-13 [25]. This guidance 

report also recommended changes to the biological effectiveness factors (BEFs) for alpha 

radiation for two of the organs used to estimate latent cancer health effects to be consistent with 

the way the risk factors for cancers associated with those organs were evaluated. The two 

organs are bone marrow and breast. For these organs, the RBE factors for alpha radiation 

were changed from the standard value of 20 to 1 and 10, respectively. Doses to these organs 

are used to evaluate occurrences of leukemia and breast cancer, respectively. The choice of 

BEFs for these organs follows EPA Guidance (EPA 402-R-93-076 [26]). 

The dose to the pancreas was used as a surrogate for dose to soft tissue to estimate residual 

cancers following the recommendations of Dr. Keith Eckerman in the 2012 Oak Ridge National 

Laboratory (ORNL) memo [24]. Because MACCS does not currently read the data for the 

pancreas from the dose coefficient file, a workaround was created. Values of the dose 

coefficients for the pancreas were copied into the organ called bladder wall. Thus, residual 

cancers are associated with the organ called bladder wall, which actually contains dose 

coefficients for the pancreas. 

The ORNL memo [24] also recommended risk factors for latent health effects that come from 

BEIR V [27], and are consistent with the modified dose coefficient file described in the preceding 

paragraph. These risk factors include seven organ specific cancers plus residual cancers that 

are not accounted for directly. 

A dose and dose rate effectiveness factor was applied to all doses in the late phase of the 

offsite consequence calculation and to those doses in the early phase that were less than 

20 rem (0.2 Sv) to the whole body. This factor, which appears in the denominator, accounts for 

the fact that protracted low doses are believed to be less effective in causing cancers than acute 
4-28

doses. The dose and dose rate effectiveness factor for all cancers except for the breast was 

2.0, and for the breast, it was 1.0, as recommended in the BEIR V report.

SOARCA added an additional cancer, liver cancer, and changed the name for cancer of the 

gastrointestinal tract, ‘GI’ in NUREG-1150, to colon cancer in SOARCA. Table 4-17 shows the 

updates between SOARCA unmitigated long-term station blackout (LTSBO) scenarios and 

NUREG-1150 for cancer risk factors. Also, the naming convention used for residual cancers 

(i.e., all other cancers not listed in ACNAME for SOARCA in Table 4-17) in SOARCA is different 

than what was used for NUREG-1150. A complete comparison of cancer risk factors is 

provided in Appendix C.

The cancer fatality risk factors for SOARCA listed in Table 4-17 (CFRISK) were updated from 

those in NUREG-1150 and Sample Problem A. The risk factors used in NUREG-1150 are 

attributed to BEIR III; the ones used in SOARCA are from BEIR V. Sample Problem A updated 

the risk factors to values from BEIR V, but those values are not fully traceable. The ORNL 

memo, “Risk Coefficients for SOARCA Project” [24] provides a basis for the risk factors used in 

SOARCA, which are taken from FGR-13 and have their origin in the BEIR V report. Notice that 

the Sample Problem A risk factors are similar but somewhat different than those used in 

SOARCA. The cancer injury risk factors used in SOARCA are listed in Table 4-17 (CIRISK) and

have the same heritage as the cancer fatality risk factors. However, cancer injuries are not 

reported in SOARCA and so these values have no influence on the published results.

The critical organ for the EARLY phase (CRIORG) is the same as the critical organ for the 

CHRONC phase (CRTOCR). The critical organ used in SOARCA is listed in Table 4-17

(CRIORG) and is similar to the critical organ in NUREG-1150 and Sample Problem A (i.e., both 

represent effective doses). The change in nomenclature corresponds to the fact that different 

tissue weighting factors were used to determine the effective doses for NUREG-1150 and 

Sample Problem A. The tissue weighting factors used in NUREG-1150 are based on ICRP-30;

for SOARCA, they are based on the more current ICRP-60 and are consistent with FGR-13. 

The cancer dose-response linear and quadratic factors for SOARCA, listed in Table 4-17

(DOSEFA and DOSEFB, respectively) are consistent with those used in Sample Problem A and 

are taken from BEIR V, which recommends a linear dose-response model for all cancer types. 

These factors are updated from the values used in NUREG-1150, which are taken from 

BEIR III, which recommends a linear-quadratic dose response model for all cancer types except 

thyroid and breast. BEIR III recommends a linear dose-response for thyroid and breast 

cancers. 
4-29

Table 4-17 SOARCA, Sample Problem A, and NUREG-1150 cancer input parameters

Variable Description

SOARCA 

Surry

LTSBO

SOARCA

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150 

Peach Bottom

ACNAME

Latent Cancer Effect

Cancer Type 1 LEUKEMIA LEUKEMIA LEUKEMIA LEUKEMIA

Cancer Type 2 BONE BONE BONE BONE

Cancer Type 3 BREAST BREAST BREAST BREAST

Cancer Type 4 LUNG LUNG LUNG LUNG

Cancer Type 5 THYROID THYROID THYROID THYROID

Cancer Type 6 LIVER LIVER GI GI

Cancer Type 7 COLON COLON OTHER OTHER

Cancer Type 8 RESIDUAL RESIDUAL N/A N/A

CFRISK

Lifetime Cancer Fatality Risk Factors

Cancer Type 1 0.0111 0.0111 0.0097 0.0037

Cancer Type 2 0.00019 0.00019 0.0009 0.00015

Cancer Type 3 0.00506 0.00506 0.0054 0.006

Cancer Type 4 0.0198 0.0198 0.0155 0.0051

Cancer Type 5 0.000648 0.000648 0.00072 0.00072

Cancer Type 6 0.003 0.003 0.0336 0.015

Cancer Type 7 0.0208 0.0208 0.0276 0.0075

Cancer Type 8 0.0493 0.0493 N/A N/A

CIRISK

Lifetime Cancer Injury Risk Factors

Cancer Type 1 0.0113 0.0113 0 0.0037

Cancer Type 2 0.000271 0.000271 0 0.00015

Cancer Type 3 0.0101 0.0101 0.017 0.017

Cancer Type 4 0.0208 0.0208 0 0.0057

Cancer Type 5 0.00648 0.00648 0.0072 0.0072

Cancer Type 6 0.00316 0.00316 0 0.025

Cancer Type 7 0.0378 0.0378 0 0.013

Cancer Type 8 0.169 0.169 N/A N/A

CRIORG Critical Organ for 

EARLY Phase L-ICRP60ED L-ICRP60ED L-EDEWBODY L-EDEWBODY

CRTOCR Critical Organ for 

CHRONC Phase L-ICRP60ED L-ICRP60ED L-EDEWBODY L-EDEWBODY

DOSEFA Cancer Dose-Response 

Linear Factors 1 for all organs 1 for all organs 1 for all organs

1 for THYROID 

and BREAST

0.39 for all other 

organs

DOSEFB Cancer Dose-Response 

Quadratic Factors 0 for all organs 0 for all organs 0 for all organs

0 for THYROID 

and BREAST

0.61 for all other 

organs

ORGFLG Doses to be Calculated 

for Specified Organ

All TRUE for 

FGR-13

All TRUE for 

DOSFAC2 

except for 

A-Lower LI and 

L-Liver, which 

are FALSE

All TRUE for FGR13

All TRUE for 

DOSFAC2 except 

for A-Lower LI and 

L-Liver, which are 

FALSE

All TRUE except 

for A-Lower LI 

and L-Liver, which 

are FALSE

Not available 

in the MACCS 

model
4-30

4.5.4 Acute Health Effects

Parameters representing four types of acute health effects are derived from expert elicitation 

data [47]. Three of these are potentially fatal, including the hematopoietic, gastrointestinal, and 

pulmonary syndromes. Pneumonitis represents an injury. Table 4-18 shows the parameter 

updates between SOARCA, Sample Problem A, and NUREG-1150 for these four acute health 

effects. Six other acute injuries were not considered in the expert elicitation, so the parameters 

used in NUREG-1150 were maintained in SOARCA since newer information was not available. 

Table 4-18 SOARCA, Sample Problem A, and NUREG-1150 prompt health effects input 

parameters

Variable Description

SOARCA 

Surry

LTSBO

SOARCA

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

EFFACA

LD50 for Early Fatality Types

A-RED MARR 5.6 5.6 3.8 4

A-LUNGS 23.5 23.5 10 10

A-STOMACH 12.1 12.1 Not used N/A

LOWER-LI N/A N/A 15 15

EFFACB

Shape Factor for Early Fatality Types

A-RED MARR 6.1 6.1 5 6

A-LUNGS 9.6 9.6 7 7

A-STOMACH 9.3 9.3 Not used N/A

LOWER-LI N/A N/A 10 10

EFFTHR

Threshold Dose to Target Organ

A-RED MARR 2.32 2.32 1.5 1.5

A-LUNGS 13.6 13.6 5 5

A-STOMACH 6.5 6.5 Not used N/A

LOWER-LI N/A N/A 8 7.5

EIFACA

LD50 For Early Injuries

PNEUMONITIS 16.6 16.6 10 10

EIFACB Shape Factor for Early Injuries

PNEUMONITIS 7.3 7.3 7 7

EITHRE Early Injury Dose Threshold

PNEUMONITIS 9.2 9.2 5 5

RISTHR Risk Threshold for 

Fatality Radius Output 0 0 0 Not available in the 

MACCS model

4.6 Protective Actions

The development of WinMACCS allowed the SOARCA project to model protective actions in a 

more detailed and more realistic manner using site-specific information (e.g., using the network 

evacuation model for the SOARCA Surry and Peach Bottom LTSBO scenarios). The analysis 

included modeling of the timing of onsite and offsite decisions and implementation of protective 

actions applied to multiple population segments called cohorts. 

4.6.1 Emergency Planning

WinMACCS facilitates implementation of multiple cohorts and using the network evacuation 

model to obtain a more realistic treatment of emergency response. This added functionality

required data that had not previously been developed for consequence analyses. 
4-31

Emergency response programs for nuclear power plants are designed to protect public health 

and safety in the unlikely event of a radiological accident. These emergency response 

programs are developed, tested, and evaluated and are in place as an element of defense in 

depth. These programs include detailed emergency response planning in place within the 

10-mile EPZ with consideration that such planning provides a substantial base for expansion of 

response efforts in the event that this proves necessary [9]. Site-specific information, such as 

emergency action level timing from the sites and planned siren activation, was obtained from 

the plant and from offsite response organizations (OROs). This information was used to support 

development of timelines by which protective actions would likely be implemented, including 

early actions such as evacuation of schools following declaration of a site area emergency. 

Historically, the evacuation area has been chosen to represent the EPZ and did not consider 

shadow evacuation (i.e., evacuation of people not residing within the officially declared 

evacuation area). The SOARCA analyses consider a shadow evacuation beyond the EPZ out 

to a distance of 20 miles from the plant and evacuating to a 30-mile radius. This results in the 

outermost evacuees traveling 10 miles beyond their initial location. For dose calculation 

purposes, evacuees are treated in the model as traveling to a point 30 miles from the site, at 

which point they are assumed not to receive any further dose. This treatment was implemented 

to be consistent with previous calculations (e.g., NUREG-1150) in which evacuees moved 

10 miles beyond the evacuation zone. The LASMOV variable defines the outermost ring in 

which evacuees will receive exposures during evacuation. LASMOV was set at ring 17 as 

shown in Table 4-19 which corresponded to 30 miles. The NUMEVA variable defines the 

number of concentric rings in which evacuation and/or sheltering can occur for the resident 

population. NUMEVA was set at ring 15 as shown in Table 4-19 to allow protective actions to 

be modeled to a distance of 20 miles. 

Table 4-19 Evacuation parameter variations between SOARCA and NUREG-1150

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG1150 Peach 

Bottom

LASMOV Last Ring in 

Movement Zone 17 17 15 15

NUMEVA

Outer Boundary of 

Evacuation/Shelter 

Region

Cohort 1 – 15

Cohorts 2 to 5 - 12

Cohort 1 – 15

Cohorts 2 to 5 - 12 12 12

For each site, six cohorts were established. Use of a larger number of cohorts allows the 

analyst to more realistically represent the response of the public than when MACCS was limited 

to three cohorts. In SOARCA, the accident was assumed to occur when school is in session, 

thus one cohort was established for schoolchildren within the EPZ. Other cohorts from within 

the EPZ included the general public, special facilities, the evacuation tail, and a non-evacuating 

cohort. An additional cohort was established for shadow evacuees from areas beyond the EPZ. 

These cohorts are discussed further in Section 4.6.3.

The non-evacuating cohort represents a small fraction (0.5 percent in this case) of the 

population who may choose not to evacuate when directed to do so. Research has shown that 

a fraction of the population refuse to evacuate when under evacuation orders [10]. However, 

there is little quantifiable data available regarding these non-evacuees. In the draft documents 

for NUREG-1150, a 5 percent value for non-evacuees was initially used; however, this value 

was changed to 0.5 percent for the final NUREG-1150 document [7]. In Sample Problem A, a 5 

percent value is identified [12] and this likely came from the draft NUREG-1150 document. 
4-32

SOARCA was the first application to use more than three cohorts in MACCS. During early 

planning meetings with the model experts, it was suggested that a maximum of six cohorts 

should be used in the analysis to ensure that model run times would be manageable. In more 

recent, non-SOARCA applications, as many as 12 cohorts have been modeled. Computer run 

times increase roughly in proportion to the number of cohorts. Therefore, although six cohorts 

were used in SOARCA, a more general best practice is to define as many cohorts as needed to 

represent the response characteristics of the population within the EPZ. When modeling an 

EPZ, the general public might be divided into multiple cohorts with unique response 

characteristics to represent the evacuation distribution. Additionally, an amusement park,

summer beach population, or other large transient population can be modeled as a separate 

cohort when present within an EPZ. However, the user should understand that MACCS treats 

all cohorts as residents, assigning dose and decontamination cost values as if they live within 

the area.

4.6.2 Evacuation Time Estimates

WinMACCS input parameters related to response characteristics of the public were developed 

primarily from documentation of the site-specific ETE, which is required to be developed and 

updated by the licensee under 10 CFR 50.47 (b)(10), “Emergency Plans.” ETEs provide the 

time required to evacuate various sectors and distances within the EPZ for transient and 

permanent residents and provide information to develop speeds and response timing for 

evacuating cohorts. The ETEs provided the mobilization times and travel times of different 

segments of the population as well as evacuation routing information.

The guidance in NUREG/CR-7002 [20] describes the detail included in an ETE study. Important 

information in an ETE study includes demographic and response data for the following four 

population segments and may be readily converted into cohorts, if appropriate:

1. Permanent Residents and Transient Population – permanent residents include all people 

having a residence in the area. The transient population includes tourists, shoppers, 

employees, etc., who visit but do not reside in the area.

2. Transit Dependent Permanent Residents – permanent residents who do not have 

access to a vehicle or are dependent upon help from outside the home to evacuate. 

This group depends upon public transportation to evacuate, which can take additional 

time to implement.

3. Special Facility Residents – residents of nursing homes, assisted living centers, and 

those confined to hospitals, jails, prisons, etc. These facilities require specialized 

vehicles to support the evacuation, the availability of which is facility-specific. Some 

facilities have onsite vehicles while most have contracts in place for offsite resources to 

support an evacuation if needed. The time to mobilize and evacuate this population 

group should be considered separately from the general public.

4. Schools – all private and public educational facilities within the EPZ. Colleges and 

universities should be assessed on a case by case basis, recognizing that college 

students typically have access to a vehicle. If there are not enough buses to evacuate 

schools in a single trip, return trips should be considered, and this affects the response 

characteristics for the cohort.

The ETE typically includes about 10 scenarios which vary by season, day of the week, time of 

day, weather conditions, special events, roadway impact, or other EPZ-specific situations. The 
4-33

scenario-specific data are used in the MACCS analyses. For example, when a summer or 

weekend scenario is analyzed, there may be no need to develop a school related cohort. In 

SOARCA, a winter weekday scenario was modeled and included residents at work and children 

at school at the time of declaration of the emergency. The selection of the scenario should be 

site-specific and be consistent with the objectives of the analysis undertaken.

Although consequence modeling has evolved to allow the use of multiple cohorts and can 

address many individual aspects of each cohort, the approach to modeling evacuations using 

the ETE is not direct. Evacuations include mobilizing and evacuating the public over a period of 

time, which is best modeled as a distribution of data. MACCS requires this distribution of data 

be converted into discrete events. In SOARCA for example, upon the sounding of the sirens 

and issuance of the emergency alert system (EAS) messaging, all members of the public are

modeled as sheltering and 1 hour later they enter the roadway network together at the same 

time and begin to evacuate. Research on existing evacuations for technological hazards has 

shown that the evacuating public actually enters the roadway network over a period of time [10]. 

To better approximate the time dependence of evacuees entering the roadway, analysts can 

divide the general public into multiple smaller groups with incremental response characteristics 

to better represent the evacuating public as a distribution. 

4.6.3 Cohort Modeling

As described earlier, the advancements in MACCS allow for discrete analysis of individual 

segments of the population by establishing many cohorts. The number of cohorts is limited but 

to a relatively large number (20), but there is diminishing value in establishing a large number of 

cohorts because the response characteristics begin to overlap within the evacuation period and 

the effects on different cohorts become indistinguishable. SOARCA was the first application to 

use more than three cohorts. The cohorts used in SOARCA are shown in Table 4-20.

Table 4-20 SOARCA evacuation cohorts

Peach Bottom Surry

Cohort 1 0 to 10 Public 0 to 10 Public

Cohort 2 10 to 20 Shadow 10 to 20 Shadow

Cohort 3 0 to 10 Schools and 0 to 10 Shadow* 0 to 10 Schools

Cohort 4 0 to 10 Special Facilities 0 to 10 Special Facilities

Cohort 5 0 to 10 Tail 0 to 10 Tail

Cohort 6 Non-Evacuating Public Non-Evacuating Public

* At Peach Bottom, sirens are sounded at the Site Area Emergency (SAE). This action provides broad 

notification to the general public and would be expected to cause a shadow evacuation from within the EPZ.

Surry sirens are not sounded at SAE.

Cohorts were established to represent members of the public who may evacuate early, 

evacuate late, those who refuse to evacuate, and those who evacuate from areas not under an 

evacuation order (e.g., the shadow evacuation). Cohort descriptions are provided below: 

Cohort 1: 0 to 10 Public. This cohort included the general public residing within the EPZ. The 

entire general public was modeled as a single cohort.

Cohort 2: 10 to 20 Shadow. This cohort included a shadow evacuation from the 10 to 20 mile 

area, just beyond the EPZ. A shadow evacuation occurs when members of the public evacuate 

from areas that are not under official evacuation orders and typically begin when a large scale 

evacuation is ordered [10]. It was assumed that 20 percent of the residents in the area beyond 
4-34

the EPZ would evacuate without being ordered to do so. This value was obtained from results 

of a telephone survey of residents of EPZs conducted by the NRC in 2008 [16]. For the 

SOARCA sites, which are largely rural, the 20 percent shadow evacuation from the area beyond 

the EPZ had no measurable effect on the evacuation of the EPZ residents. 

Cohort 3: 0 to 10 Schools and 0 to 10 Shadow. This cohort included elementary, middle, and 

high school student populations within the EPZ. Schools receive early and direct warning from 

OROs and have response plans in place to support busing of students out of the EPZ. The ETE 

provides considerable detail regarding schools including the number of schools, student and 

staff population, number of buses required to evacuate the students, and the ETE which 

considers whether return trips are required. 

A 0 to 10 mile shadow evacuation was included for the Peach Bottom site because sirens are 

sounded at the SAE. This is a local decision implemented by the OROs. The shadow 

evacuation would begin early, about the same time as the evacuation of the schools. Because 

the 0 to 10 shadow would evacuate at about the same time as the schools, only one cohort was 

used to represent the two population groups for the Peach Bottom analysis. 

Cohort 4: 0 to 10 Special Facilities. The special facilities population includes residents of 

hospitals, nursing homes, prisons, etc. In an emergency, special facilities would be evacuated 

individually over a period of time based upon available transportation and the number of return 

trips needed to evacuate a facility. Special facilities were modeled as a single cohort. It was 

determined that an appropriate representation of this cohort in the modeling would be to start 

the evacuation later in the event and apply shielding factors consistent with the types of 

structures within which these residents reside. The percent of population of this cohort is often 

relatively small, therefore it may not be beneficial to separate the special facilities into multiple 

cohorts. 

Cohort 5: 0 to 10 Tail. The 0 to 10 tail is defined as the last 10 percent of the public to 

evacuate [22] from the 10 mile EPZ. The evacuation tail takes longer to evacuate for valid 

reasons, such as shutting down farming or manufacturing operations, performing other time 

consuming actions prior to evacuating, or they may have missed the initial notification.

Cohort 6: Non-Evacuating Public. This cohort represents a portion of the public from 0 to 

10 miles who may refuse to evacuate. It is assumed to be 0.5 percent of the population who are 

modeled as though they are performing normal activities. This percentage of the population that 

does not evacuate is consistent with research on large scale evacuations that has shown a 

small percentage of the public refuses to evacuate [10]. 

Table 4-21 shows the cohort weighting parameters used in SOARCA, Sample Problem A, and

NUREG-1150. As indicated in the table, only two cohorts were used in Sample Problem A with 

percentages of 95 percent for the general public and 5 percent for the non-evacuating public. 

The percentages were adjusted to 99.5% and 0.5%, respectively, in the final NUREG-1150 

report. In SOARCA the population fractions were developed based on the actual site population 

data. The 0 to 10 public was expected to be the cohort of greatest interest; therefore, Cohort 1 

was defined as the 0 to 10 public and has the same response characteristics as Cohort 2

shadow evacuation, which is the cohort that extends the greatest distance and defines the limits 

of the array. Thus, within the WinMACCS input file, Cohorts 1 and 2 were defined to meet the 

requirement that maximum distance be established with the first cohort. The WinMACCS model 

input parameters for Cohort 1 were extended from the plant out to 20 miles, and Cohort 2 

extends from the plant out to 10 miles. In the WinMACCS input file, Cohort 1 is input as 20 
4-35

percent of the population from 0 to 20 miles. This captures the 20 percent of the population 

between 10 and 20 miles involved in the shadow evacuation beyond the EPZ. The combination 

of Cohorts 1 and 2 from 0 to 10 miles in the WinMACCS model represent all of the 0 to 10 

public cohort defined above. For the remaining cohorts, application of parameters in the 

WinMACCS model is direct, and the population fractions directly correspond to the cohort 

descriptions. 

To calculate the population fractions, shadow populations were assessed first as 20 percent of 

the population. After subtracting the shadow, non-evacuee, special needs, and schools, 10 

percent of the remaining population in each region was assumed as the evacuation tail, and the 

remainder was used as the total for the general public. 

Table 4-21 Cohort weighting fraction parameter variations between SOARCA, Sample 

Problem A, and NUREG-1150

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150 

Peach Bottom

WTFRAC

Weighting Fraction Applicable to this Scenario

Cohort 1 0.2 0.2 0.95 0.995

Cohort 2 0.535 0.355 0.05 0.005

Cohort 3 0.193 0.372

These cohorts

were not used

These cohorts

were not used Cohort 4 0.007 0.006

Cohort 5 0.06 0.062

Cohort 6 0.005 0.005

When MACCS implements the cohort function, the population fractions are distributed uniformly. 

For example, a school population cohort of 10 percent would be treated in MACCS as though 

the school population was a uniformly distributed fraction of the EPZ population. In reality, the 

schools are clustered with local populations of a few hundred students each. It is not expected 

that the uniform distribution of population fractions would have a noticeable effect on the risk 

results for the SOARCA analyses. An improvement added to MACCS after the SOARCA 

project is the SUMPOP feature which allows cohorts such as schools, special facilities, or other 

populations, to be modeled precisely within the grid element wherein the facility is located.

4.6.4 Cohort Response Times

As required by 10 CFR Part 50, “Domestic Licensing of Production and Utilization Facilities,” 

OROs develop emergency response plans for implementation in the event of a nuclear power 

plant accident. These plans are regularly drilled and inspected biennially (every two years) 

through a demonstration exercise performed with the licensee. In biennial exercises, ORO 

personnel demonstrate timely decision making and the ability to implement public protective 

actions. Emergency plans escalate response activities in accordance with a classification 

scheme based on EALs. Preplanned actions are implemented at each classification level, 

including Unusual Event, Alert, Site Area Emergency (SAE), and General Emergency (GE). 

Public protective actions are required at the GE level, but offsite emergency plans commonly 

include precautionary protective actions at the SAE level and sometimes at the Alert level, and 

these actions should be considered in the modeling. For example, at Peach Bottom the ORO 

emergency plans include sounding sirens at the SAE to inform the public that an incident has 

occurred and they should monitor EAS stations for updated information. For Surry, the ORO 

emergency plan includes notifying schools at the SAE, but sirens are only sounded for a GE.
4-36

The time to receive notification was based on the assumption that sirens will sound when 

needed. The NRC Reactor Oversight Program (ROP) data for siren performance for Peach 

Bottom shows an average siren performance indicator of 99.8 percent and 99.9 percent for 

Surry, indicating that sirens will perform when needed. The ROP information is available for all 

EPZs. 

Loss of power accidents result in the loss of power to some offsite areas of the EPZ and may 

affect siren performance when backup batteries are not available. However, it may be 

reasonable to expect that the power will be available in parts of the 10 mile EPZ. For those 

areas where the power outage affects sirens, route alerting would be conducted by OROs to

alert residents. The analyst should determine whether any delay should be included to 

represent additional time for implementation of backup notification methods.

Adjustments may be made to the evacuation speeds based on review of population densities 

and capacity limits in the roadway network. The baseline speed is typically assigned to the 

general public cohort and then adjusted using speed adjustment factors. In SOARCA these 

adjustments ranged from 75 percent to 150 percent of the average speed, as appropriate for the 

rural and urban areas. The ETE often identifies specific routes where congestion will occur, and 

this information is useful in estimating the speed adjustment factors.

Using the information and approach described above, the evacuation timing and speeds for 

each cohort were developed. Selected input parameters for WinMACCS are described below:

• Delay to shelter (DLTSHL) represents a delay from the time of the start of the accident 

until cohorts enter a shelter. 

• Delay to evacuation (DLTEVA) represents the length of the sheltering period from the 

time a cohort enters a shelter until the point at which it begins to evacuate. 

• The speed (ESPEED) is assigned for each of the three phases (Early, Middle, and Late)

used in WinMACCS. 

• Duration of beginning phase (DURBEG) is the duration assigned to the beginning phase 

of the evacuation and may be assigned uniquely for each cohort. This period begins 

when the sheltering period ends.

• Duration of middle phase (DURMID) is the duration assigned to the middle phase of the 

evacuation and may be assigned uniquely for each cohort. This period begins when the

beginning phase (DURBEG) ends.

The initial response parameter in MACCS is OALARM, which defines the time at which 

notification is given to off-site emergency response officials to initiate protective measures for 

the surrounding population. This time is a function of the accident sequence and is traditionally 

implemented as the time sirens sound notifying the public. However, because early protective 

actions are implemented at Peach Bottom with the notification of the schools at SAE, OALARM 

was not implemented in the traditional manner for SOARCA because MACCS does not allow 

the movement of cohorts before OALARM. Therefore, for SOARCA, OALARM was measured 

from accident initiation and was set at 0.0. Table 4-22 shows the time selected for OALARM in 

SOARCA, Sample Problem A, and NUREG-1150, as documented in NUREG/CR-4551 [8] for 
4-37

one of the Peach Bottom source terms. OALARM can be a useful parameter if multiple 

analyses are being performed and the response timeline is being adjusted. However, users 

should review the values for OALARM carefully when implementing this parameter because it 

can be misunderstood.

Table 4-22 Time to GE condition variations between SOARCA and NUREG-1150

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

OALARM

Elapsed Time from 

Accident Initiation to Notify 

the Public (sec)

0.0 0.0 1,300 14,000

4.6.5 Delay to Shelter

The delay to shelter (DLTSHL) defines the duration it takes for the residents within the EPZ to 

receive the alert and notification and enter a shelter [12]. The shelter is typically assumed to be 

their residence or workplace, not a separate facility. Table 4-23 shows the delay to shelter

parameters used in SOARCA, Sample Problem A, and NUREG-1150. As indicated, Cohort 3

(Schools), is notified directly by the ORO in about 15 minutes. The OROs sound the sirens and 

issue EAS messages which provide the notification to the remaining cohorts. The baseline 

DLTSHL value for Peach Bottom is 1.5 hours, and 2.75 hours for Surry. The time for these 

actions is represented in the table below.

Table 4-23 Delay to shelter parameter variations between SOARCA, Sample Problem 

A, and NUREG-1150

Variable Description

SOARCA 

Surry

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A

(Surry)

NUREG-1150

Peach Bottom

DLTSHL

Delay from Alarm Time to Shelter (sec)

Cohort 1 9,900 5,400 7,200 0

Cohort 2 9,900 5,400 N/A N/A

Cohort 3 900 900

These cohorts

were not used

These cohorts

were not used Cohort 4 9,900 5,400

Cohort 5 9,900 5,400

Cohort 6 N/A N/A

4.6.6 Evacuation Delay

Delay to evacuation (DLTEVA) defines the duration of the sheltering period that occurs before 

evacuation of residents begins [12]. Delay to evacuation might be affected by a delay in 

response to the evacuation order, a need to wait for the return of commuters, a need to wait for 

public transportation, a need to shut down operations prior to leaving work, etc. Research 

shows that delay is not uniform with most of the evacuees experiencing a small delay (e.g., 90 

percent of the public evacuates in about 60 percent of the response time) [11], [22]. As 

described earlier, there is high confidence in the alert and notification system to warn the public; 

however, response of the public is a function of the time to receive the notification and the time 

to prepare to evacuate [49]. Table 4-24 shows the evacuation delay parameters used in 

SOARCA, Sample Problem A, and NUREG-1150.
4-38

Table 4-24 Evacuation delay parameter variations between SOARCA, Sample Problem 

A, and NUREG-1150

Variable Description

SOARCA 

Surry

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A

(Surry)

NUREG-1150

Peach Bottom

DLTEVA

Delay from Beginning of Shelter to Evacuation (sec)

Cohort 1 3,600 3,600 0 0

Cohort 2 3,600 3,600 N/A N/A

Cohort 3 3,600 2,700 These cohorts

were not used

These cohorts

were not used Cohort 4 39,600 15,300

Cohort 5 39,600 15,300

Cohort 6 N/A N/A

Cohorts 1 and 2 together represent the 0-10 public and 10-20 shadow, and the baseline 

DLTEVA value is one hour. This value is supported by the ORNL-6615 study, which provided 

empirical data showing that most of the public is mobilized in about an hour [49]. The shadow 

evacuation, Cohort 2, is aligned with the general public evacuation of Cohort 1.

Cohort 3 represents the schools and the 0-10 shadow evacuation for Peach Bottom and 

represents only the schools for Surry. The 0-10 shadow has the same response characteristics 

because this cohort has been defined in SOARCA as evacuating when the schools evacuate. 

The 0-10 shadow at Peach Bottom evacuates spontaneously (i.e., prior to receiving an 

evacuation order) when the emergency is communicated to the residents of the EPZ via the 

sirens and emergency evacuation system messaging for the SAE. Shadow evacuation of the 

public has been demonstrated to begin quickly for industrial accidents [10]. For Peach Bottom, 

a baseline value of 45 minutes was used because schools are notified early and are prepared to 

evacuate when the official order is issued. The Pennsylvania emergency management plan 

explains that evacuation can be implemented for an SAE or a GE. The early warning for 

schools provides time for buses to mobilize and be ready if an evacuation were to be ordered. 

Evacuation drills at schools demonstrate the ability to prepare and move students quickly. For 

Surry, upon receipt of the declaration of SAE by the site, the Virginia Department of Emergency 

Management would notify the schools in accordance with the offsite emergency response plan. 

It is assumed schools are notified at SAE and begin sheltering in about 15 minutes. Buses 

would be mobilized, and it is assumed schools begin evacuating 1 hour after the shelter period. 

Cohort 4 represents special facilities that can take longer as a whole than the general public. It 

was determined that the best representation of this cohort in the modeling is to evacuate with 

the tail and apply shielding factors consistent with the types of structures within which these 

residents reside. 

Cohort 5 is the evacuation tail, which by definition begins evacuating at the end of the general 

public evacuation. For Peach Bottom, the baseline value of 4.25 hours was based on the sitespecific evacuation time estimate (ETE) study which showed that 90% of the population had 

completed the evacuation in 4.25 hours. Using the evacuation data provided in the Surry ETE 

study, 90 percent of the evacuation of the EPZ is complete at approximately 11 hours into the 

evacuation, and this corresponds to the departure time for the 0 to 10 Tail. 

4.6.7 Evacuation Phase Duration and Speed

Departure speeds and durations of the beginning and middle periods for MACCS were also 

developed from the Surry and Peach Bottom ETE studies. Table 4-25 shows the evacuation 

phase duration and speed parameters used in SOARCA and NUREG-1150. As shown in the 
4-39

table, the DURBEG and DURMID values were established for each cohort, whereas in NUREG1150 and Sample Problem A, fewer cohorts were used and generic values were applied. The 

values in SOARCA were based on the response characteristics developed for the cohorts. 

ESPEEDs specific to each cohort were used in the analyses. For the late phase, an ESPEED 

of 20 mph was applied to all cohorts because at this point in the evacuation, they are well 

beyond the EPZ where traffic is less congested. In NUREG-1150 and Sample Problem A, 

generic speed values were used.

The duration and speed values were based on evacuation of a full 10 mile EPZ beginning with 

the initial alert and notification. This implementation was necessary because the protective 

action modeling could not be synchronized with the MACCS weather trials which totaled about

1,000 for each site. This modeling approach represents the current expected Peach Bottom 

protective action to evacuate the full EPZ, but most sites, including Surry, would typically 

implement a keyhole evacuation of a smaller area and expand to a full EPZ only if necessary 

based on the source term release data. A keyhole evacuation model was added to MACCS 

after the SOARCA project was completed and will be released in a future version of MACCS.

This model allows the user to define the evacuation region with the radius of the inner, circular 

area, the number of sectors to evacuate beyond the circular area, and the outer radius of the 

evacuation area. The keyhole is centered on the initial wind direction but then expands as the 

wind changes direction in subsequent hours.
4-40

Table 4-25 Evacuation phase duration and speed parameter variations between 

SOARCA, Sample Problem A, and NUREG-1150

Variable Description

SOARCA 

Surry

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A

(Surry)

NUREG-1150

Peach Bottom

DURBEG

Duration of Beginning of Evacuation Phase (sec)

Cohort 1 900 900 86,400 N/A

Cohort 2 900 900 N/A N/A

Cohort 3 900 3,600

These cohorts

were not used

These cohorts

were not used

Cohort 4 3,600 1,800

Cohort 5 3,600 1,800

Cohort 6 N/A N/A

DURMID

Duration of Middle of Evacuation Phase (sec)

Cohort 1 35,100 10,800 0 N/A

Cohort 2 35,100 10,800 N/A N/A

Cohort 3 1,800 1,800

These cohorts

were not used

These cohorts Cohort 4 were not used 3,600 1,800

Cohort 5 3,600 1,800

Cohort 6 N/A N/A

ESPEED

Evaluation Speed (m/s)

Initial Evacuation Phase

Cohort 1 2.235 2.235 1.8 4.8

Middle Evacuation Phase

Cohort 1 0.447 1.341 1.8 4.8

Late Evacuation Phase

Cohort 1 8.941 8.941 1.8 4.8

Initial Evacuation Phase

Cohort 2 2.235 2.235 1.8 N/A

Middle Evacuation Phase

Cohort 2 0.447 1.341 1.8 N/A

Late Evacuation Phase

Cohort 2 8.941 8.941 1.8 N/A

Initial Evacuation Phase

Cohort 3 4.47 8.941

These cohorts

were not used

These cohorts

were not used

Middle Evacuation Phase

Cohort 3 4.47 8.941

Late Evacuation Phase

Cohort 3 8.941 8.941

Initial Evacuation Phase

Cohort 4 0.447 1.341

Middle Evacuation Phase

Cohort 4 4.47 8.941

Late Evacuation Phase

Cohort 4 8.941 8.941

Initial Evacuation Phase

Cohort 5 0.447 1.341

Middle Evacuation Phase

Cohort 5 4.47 8.941

Late Evacuation Phase

Cohort 5 8.941 8.941

Cohort 6 N/A N/A

4.6.8 Potassium Iodide

The purpose of using potassium iodide (KI) as a protective measure is to saturate the thyroid 

gland with stable iodine so that further uptake of radioiodine by the thyroid is diminished. If 

taken at the right time, the KI can nearly eliminate doses to the thyroid gland from inhaled 

radioiodine. Ingestion of KI should be modeled for residents near plants where KI has been 
4-41

distributed by the State or local government. The States distribute KI within the EPZ at the 

Peach Bottom and Surry sites and KI ingestion was therefore considered in SOARCA. It was 

assumed that half of the residents within the EPZ take KI and some of these residents do not 

take KI at the optimal time (i.e., shortly before to immediately after plume arrival), so the efficacy 

was selected as 70 percent (i.e., the thyroid dose from inhaled radioiodine is reduced by 70 

percent).

The KI model was not available for the consequence analyses in NUREG-1150 and thus a 

comparison of the MACCS inputs for the population taking KI and efficacy of KI cannot be 

made.

4.6.9 Hotspot and Normal Relocation

Hotspot and normal relocation are additional protective actions implemented by OROs. In 

addition to evacuation, residents would be relocated from areas during the accident where the 

dose exceeds the emergency phase protective action criteria based on EPA Protective Action 

Guides (PAGs) [23]. OROs would determine the affected areas based on dose projections 

using State, utility, and Federal agency computer models and field measurements. Hotspot and 

normal relocation models are included in the MACCS code to reflect this activity. These models 

include dose from cloudshine, groundshine, direct inhalation, and resuspension inhalation. 

When these models are applied within the MACCS calculation, individuals who would be 

relocated because their projected total dose from these pathways exceeds the protective action 

criteria, are prevented from receiving any additional dose during the emergency phase. 

Table 4-26 shows the hotspot and normal relocation parameters used in SOARCA, Sample 

Problem A, and NUREG-1150.

Table 4-26 Hotspot and normal relocation parameter variations between SOARCA, 

Sample Problem A, and NUREG-1150

Variable Description

SOARCA 

Surry

LTSBO

SOARCA

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

DOSHOT Hot-Spot Relocation Dose 

Threshold (Sv) 0.05 0.05 0.5 0.5

DOSNRM Normal Relocation Dose 

Threshold (Sv) 0.01 0.005 0.25 0.25

TIMHOT Hotspot Relocation Time 

(sec) 86,400 43,200 43,200 43,200

TIMNRM Normal Relocation Time 

(sec) 129,600 86,400 86,400 86,400

In MACCS, hotspot relocation is performed first and normal relocation second. The choices of 

times associated with normal and hotspot relocation depended on the specific accident scenario 

because they are based on plume arrival. The scenario-specific time for completion of the 

relocation includes the time for response personnel to identify the involved area, for them to 

notify the residents within that area that relocation is necessary, and for the residents to remove 

themselves from the area. Because the timing of relocation is keyed to plume arrival, there is 

always a period of exposure prior to initiation of relocation. The relocation times used in 

SOARCA were 12 hours for hotspot and 24 hours for normal relocation for Peach Bottom and 

24 hours for hotspot and 36 hours for normal relocation for Surry. The values for Surry are 

longer than Peach Bottom because the population density is greater and the area north and 

east of the plant is heavily urban. This would require additional resources to notify residents

and support relocating them out of the affected area. Notifying and relocating the larger 

population would be expected to take a longer time. 
4-42

In SOARCA, this application affects the non-evacuating cohort and the public beyond the EPZ

who have not already evacuated. These population groups were relocated from areas where 

the projected dose during the emergency phase exceeded a set of two upper bounds. These 

bounds were based on a range of protective action guide dose levels published by EPA, which 

is 1 to 5 rem [23]. In SOARCA, the upper limit of this range (5 rem) was used to trigger hot-spot 

relocation for both Surry and Peach Bottom, and the lower limit of this range (1 rem) was used 

to trigger normal relocation for Surry, while 0.5 rem was used for Peach Bottom to be consistent 

with the Pennsylvania habitability criterion. 

4.6.10 Habitability

Habitability is the consequence model parameter that is used to establish the dose level at 

which residents are allowed to return to their homes during the long-term phase. In the MACCS

code, habitability applies to everyone, not just evacuees. The MACCS CHRONC model 

implements user-defined habitability criterion. Habitability decision making with MACCS can 

result in three possible outcomes:

1. land is immediately habitable,

2. land will be habitable after decontamination, 

3. land will be habitable after a combination of decontamination and interdiction, and 

4. land cannot be made habitable, or it is not cost effective to do so, so the land is 

condemned.

States may establish a specific criterion for long-term habitability, although most states adhere 

to the EPA guidelines, which specify a maximum allowable dose of 2 rem in the first year and 

0.5 rem per year thereafter. A draft EPA recommendation [32] used in NUREG-1150 has 

traditionally been implemented in MACCS as a cumulative 4 rem over the first 5 years (2 rem in 

the first year + 4 years x 0.5 rem/year) of exposure. Some States expect to implement a more 

strict habitability criterion. For instance, Pennsylvania establishes a 0.5 rem per year limit

beginning in the first year, and this value was used in the Peach Bottom analysis. The long 

term habitability criteria used in NUREG-1150 of 0.04 Sv (4 rem) over a 5 year period [7] was

used for the Surry MACCS analyses [3]. Table 4-27 shows the long-term phase dose criterion 

variables used in SOARCA, Sample Problem A, and NUREG-1150. 

Table 4-27 Long-term phase dose criterion variations between SOARCA, Sample 

Problem A, and NUREG-1150

Variable Description

SOARCA 

Surry

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

DSCRLT Long-Term Phase 

Dose Criterion (Sv) 0.04 0.005 0.04 0.04

If the property cannot be made habitable within 30 years or if the cost of reclaiming habitability 

of the property exceeds the cost of condemning it, the property will be condemned and 

permanently withdrawn from use. 

Table 4-28 shows the parameters chosen for SOARCA, Sample Problem A, and NUREG-1150 

for the exposure period. As explained above, the habitability criterion used for Peach Bottom is 

a 0.005 Sv (500 mrem) in each year. Thus, the exposure period is one year (3.16x107

seconds). For Surry, the EPA recommendation is implemented as 0.04 Sv (4 rem) in 5 years 
4-43

(1.58x108 sec). This latter criterion was used for both Surry and Peach Bottom in NUREG-1150

and Sample Problem A.

Table 4-28 SOARCA and NUREG-1150 action period input parameter

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150 

Peach Bottom

TMPACT Time Action Period 

Ends (sec) 1.58x108 3.16x107 1.58x108 1.58x108

4.7 Decontamination and Cost Parameters

Decontamination parameters were based on values from NUREG-1150 [7] and were not

reviewed for SOARCA because SOARCA did not calculate economic consequences; thus cost 

decisions were only used to support the habitability decisions in the model. The cost 

parameters associated with decontamination were escalated to account for inflation using the 

CPI. These parameters affect decisions on whether contaminated areas can be restored to 

habitability and therefore affect predicted doses and health effect risks. Two levels of 

decontamination represented by dose reduction factors (DRF) of 3 and 15 were considered in 

SOARCA and were the same as in NUREG-1150. 

The user should understand that use of two DRFs provides a level of conservatism because for 

any area where a DRF of 3 is insufficient, the model applies the much higher DRF of 15, which 

costs more to implement than a DRF of 3. For example, if the model calculates the need for a 

DRF of greater than 3 but less than 15, such as a DRF of 4, the full cost for a DRF of 15 is 

applied. As a best practice it may be appropriate to include an intermediate DRF. Analysts 

should review the basis and applicability of the decontamination and cost parameters for sitespecific analyses. 

5-1

5.0 INSIGHTS

Conducting a project such as SOARCA provided an opportunity to investigate consequence 

analyses at a much greater level of detail than was done for analyses performed in the past. 

Throughout the process, advanced knowledge and insights were gained that benefit the PRA 

and emergency response communities. The following insights related to offsite consequence 

analyses were developed from the SOARCA project.

1. Through investigation of the importance of each chemical class, the SOARCA analyses 

confirmed that the cesium group followed by the tellurium and barium/strontium groups, 

is generally the most important contributor to long-term and overall LCF risk when using 

the LNT dose-response model. However, SOARCA found that the cerium group, 

followed by the barium/strontium group, dominates over the cesium group in the Peach 

Bottom unmitigated STSBO scenario without RCIC blackstart. This scenario involves

significant core-concrete interactions with insertions of unoxidized zirconium. Even 

though the cerium release is small in terms of percentage, it is significant in terms of 

activity because of its large initial inventory. This results in the cerium group, followed by 

the barium/strontium group, being the largest contributor to LCF risk for this scenario. 

This trend was not observed for any of the other Peach Bottom or Surry scenarios and is 

more likely to occur in a BWR scenario because of the significantly larger quantity of 

zirconium in the reactor vessel of a BWR. As shown below, and discussed in detail in 

NUREG/CR-7110, for the Peach Bottom STSBO without RCIC blackstart, cesium is the 

third most important chemical group whereas it is first in all other scenarios. Chemical 

groups not listed contribute less than a few percent to the overall LCF risk for the 

specified scenarios.

a. For the Peach Bottom unmitigated LTSBO, the order of importance beyond the 

EPZ is cesium, tellurium, barium/strontium, cerium, and iodine. 

b. For the Peach Bottom unmitigated STSBO with RCIC blackstart, the order of 

importance beyond the EPZ is cesium, tellurium, barium/strontium, and cerium.

c. For the Peach Bottom unmitigated STSBO without RCIC blackstart, the order of 

importance beyond the EPZ is cerium, barium/strontium, cesium, and tellurium.

d. For the Surry unmitigated ISLOCA, the order of importance beyond the EPZ is 

cesium, tellurium, and iodine.

2. Sensitivity analyses on the effect of the surface roughness parameter show that a 

surface roughness increase from 10 cm to 60 cm results in a risk reduction of about 20% 

for the intermediate distances (10 to 50 miles) and a risk increase of about 10% within 10 

miles for the calculated LCF risks using the LNT dose-response model. The reduction in 

risk for the two truncation dose-response models reported in SOARCA is generally 

greater than 20%.

3. The development of emergency response parameters based on site-specific data 

obtained from the emergency plan and offsite response organizations enables realistic 

modeling of the response of the public. The results of the analyses show that for the 

selected SOARCA scenarios, the emergency response is very effective within the 

evacuation zone during the emergency phase. The risks are very small and entirely 
5-2

represent the non-evacuating population, with the exception of the Surry STSBO with a 

TISGTR accident scenario in which the release starts much earlier than in the others. 

4. Using the LNT dose-response model, the largest contributor to LCF risk for most

scenarios is the long-term risk incurred after the emergency phase, and this risk is 

controlled by the habitability criterion.

5. Increasing the number of aerosol bins and accounting for the deposition velocity as a 

function of particle size has a significant effect on the results. The effect is comparable 

to specifying a single deposition velocity of 0.3 cm/s; which reduces ground 

concentrations by about a factor of 3 at the distances reported in SOARCA compared 

with the NUREG-1150 methodology of using a single value of 1 cm/s. 

6. Increasing the number of compass sectors from 16 to 64 does not significantly affect 

LCF risk calculated using the LNT dose-response model. There would likely be a 

greater effect on LCF risk using the truncation dose-response models; however these 

calculations were not performed.

7. Increasing the number of plume segments has a small effect on calculated LCF risk 

using the LNT dose-response model. There would likely be a greater effect on LCF risk 

using the truncation dose-response models; however these calculations were not 

performed.

8. Insight from the evaluation of seismic activity on emergency response (ER) shows the 

effect to be site-specific. For Peach Bottom, the seismic event’s impact on ER has an 

insignificant effect on health consequences primarily because the damage to 

infrastructure in this EPZ is projected to be limited to a few roadway sections. For Surry, 

the overall impact on the ER from the seismic activity is significant with regard to the 

damage to infrastructure; however, because this damage occurs in the developed areas 

which are beyond 5 miles from the plant, there is no appreciable effect on health 

consequences. Although the ER is impacted considerably by the postulated seismic 

event, the effect on overall risk is not significant, and the prompt fatality risk remains

zero.

9. Sensitivity analyses on the size of the evacuation area were performed for two 

scenarios: the Peach Bottom unmitigated STSBO and the Surry unmitigated ISLOCA. 

These sensitivities show that the effect of expanding the size of the evacuation area is 

site-specific and scenario-specific. For the Peach Bottom unmitigated STSBO, 

expanding the size of the evacuation area decreases individual LCF risk beyond the 10-

mile radius but increases individual LCF risk within 10 miles. The increase in risk to the 

population residing within 10 miles occurs because of the increased traffic congestion 

which is caused by the larger evacuation. For areas with a radius greater than 20 miles, 

the risk reduction associated with increasing the size of the evacuation area is slight. 

For the Surry unmitigated ISLOCA, the results show very little benefit from evacuation of 

areas beyond 10 miles.
6-1

6.0 REFERENCES

[1] Nuclear Regulatory Commission ((U.S.) (NRC). NUREG-1935, "State-of-the-Art 

Reactor Consequence Analyses (SOARCA) Report," Washington, D.C.: NRC, 2012.

[2] Nuclear Regulatory Commission ((U.S.) (NRC). NUREG/CR-7110 Volume 1, "Stateof-the-Art Reactor Consequence Analysis Project Volume 1: Peach Bottom 

Integrated Analysis," Revision 1, Washington D.C.: NRC, 2013.

[3] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-7110 Volume 2, "Stateof-the-Art Reactor Consequence Analysis Project Volume 2: Surry Integrated 

Analysis," Revision 1, Washington D.C.: NRC, 2013.

[4] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-7155, “State-of-the-Art 

Reactor Consequence Analyses Project: Uncertainty Analysis of the Unmitigated 

Long-Term Station Blackout of the Peach Bottom Atomic Power Station,” 

Washington D.C.: NRC, 2014.

[5] Jones, J.A., “Summary Report: Peer Review of the State-of-the Art Reactor

Consequence Analyses (SOARCA) Project,” SAND2012-3714, Sandia National

Laboratories: Albuquerque, NM. May 2012. ML121250030, Washington D.C.: NRC,

May, 2012.

[6] Laur, M.N., "Meeting with Sandia National Laboratories and an Expert Panel on 

MELCOR/MACCS Codes in Support of the State of the Art Reactor Consequence 

Analysis Project," Memo to J.T. Yerokun. ML062500079, Washington D.C.: NRC, 

September, 2006.

[7] Nuclear Regulatory Commission (U.S.) (NRC). NUREG-1150, "Severe Accident 

Risks: An Assessment for Five U.S. Nuclear Power Plants," Washington D.C.: 

NRC, 1990.

[8] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-4551, Volume 2, Rev. 1, 

Part 7, "Evaluation of Severe Accident Risks: Quantification of Major Input 

Parameters, MACCS Input." Washington D.C.: NRC, 1990.

[9] Nuclear Regulatory Commission (U.S.) (NRC). NUREG-0654/FEMA-REP-1, Rev. 1, 

“Criteria for Preparation and Evaluation of Radiological Emergency Response Plans 

and Preparedness in Support of Nuclear Power Plants,” Washington D.C.: NRC,

November 1980.

[10] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-6864, "Identification and 

Analysis of Factors Affecting Emergency Evacuations," Washington D.C.: NRC,

January 2005. 

[11] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-6953 Volume 1, "Review 

of NUREG-0654, Supplement 3, “Criteria for Protective Action Recommendations for 

Severe Accidents," Washington D.C.: NRC, December 2007.

[12] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-6613, “Code Manual for 

MACCS: Volume 1, User’s Guide,” Washington D.C.: NRC, 1998.
6-2

[13] Dobbins, R.A., “Atmospheric Motion and Air Pollution, John Wiley & Sons, New 

York, NY, 1979.

[14] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-2239, “Technical 

Guidance for Siting Criteria Development,” Washington D.C.: NRC, 1982.

[15] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-6244, “Probabilistic 

Accident Consequence Uncertainty Analysis, Dispersion and Deposition Uncertainty 

Analysis,” Washington D.C.: NRC, 1994.

[16] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-6953 Volume 2, “Review 

of NUREG-0654, Supplement 3, ‘Criteria for Protective Action Recommendations for 

Severe Accidents’ – Focus Group and Telephone Survey,” Washington D.C.: NRC,

2008.

[17] Haugen, D. A. (Ed.), “Project Prairie Grass: A Field Program in Diffusion.” No. 59, 

Vol. III, Report AFCRC-TR-58-235, Air Force Cambridge Research Center. 1959.

[18] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-7161, “Evaluation of 

Distributions Representing Important Non-Site-Specific Parameters in Offsite 

Consequence Analysis,” Washington D.C.: NRC, 2013.

[19] Whelan, G., D.L. Strenge, J.G. Droppo Jr., B.L. Steelman, and J.W. Buck, “The 

Remedial Action Priority System (RAPS): Mathematical Formulations,” 

DOE/RL-87-09, Pacific Northwest Laboratory Richland, WA. August 1987.

[20] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-7002, 

SAND2010-0016P. "Criteria for Development of Evacuation time Estimate Studies," 

Washington D.C.: NRC, November 2011.

[21] Nuclear Regulatory Commission (U.S.) (NRC). Update to Supplement 3 to 

NUREG-0654/FEMA-REP-1, Rev. 1, "Criteria for Protective Action 

Recommendations for Severe Accidents," Washington D.C.: NRC, March 2010.

[22] Wolshon, Brian, J. Jones, and F. Walton. "The Evacuation Tail and Its Effect on 

Evacuation Decision Making," Journal of Emergency Management. 

January/February 2010, Volume 8, Number 1. 201.

[23] Environmental Protection Agency (U.S.) (EPA). EPA-400-R-92-001, “Manual of 

Protective Action Guides and Protective Actions for Nuclear Incidents,” 

Washington D.C.: EPA, May 1992.

[24] Eckerman, K.F., Letter Report, “Radiation Dose and Health Risk Estimation: 

Technincal Basis for the State-of-the-Art Reactor Consequence Analysis Project,” 

ML12159A259, Oak Ridge National Laboratory: Oak Ridge, TN, January 2012.

[25] Environmental Protection Agency (U.S.) (EPA). EPA 402-C-99-001, Federal 

Guidance Report 13, “Cancer Risk Coefficients for Environmental Exposure to 

Radionuclides, Updates and Supplements,” CD Supplement, Rev 1, Prepared by 
6-3

Oak Ridge National Laboratory, Oak Ridge, TN, for Office of Air and Radiation, 

Washington D.C.: EPA, April 2002.

[26] Environmental Protection Agency (U.S.) (EPA). EPA 402-R-93-076, “Estimating 

Radiogenic Cancer Risk,” Washington D.C.: EPA, June 1994.

[27] National Academy of Sciences, “Health Effects of Exposure to Low Levels of Ionizing 

Radiation: BEIR V,” National Research Council, National Academy Press, 

Washington D.C., 1990.

[28] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-6525 Rev. 1, 

SAND2003-1648P, “SECPOP2000: Sector Population, Land Fraction, and 

Economic Estimation Program,” Washington D.C.: NRC, 2003.

[29] Atkinson, D. and R.F. Lee, “Procedures for Substituting Values for Missing NWS 

Meteorological Data for Use in Regulatory Air Quality Models,” July 7, 1992, 

http://www.rflee.com/RFL_Pages/missdata.pdf.

[30] Nuclear Regulatory Commission (U.S.) (NRC). NUREG-0917, “Nuclear Regulatory 

Commission Staff Computer Programs for Use With Meteorological Data,” 

Washington D.C.: NRC, July 1982.

 

[31] Nuclear Regulatory Commission (U.S.) (NRC). RG 1.23, Rev. 1, “Meteorological 

Monitoring Programs for Nuclear Power Plants,” Washington D.C.: NRC, 2007.

[32] Environmental Protection Agency (U.S.) (EPA). “Manual of Protective Action Guides 

and Protective Actions for Nuclear Incidents - DRAFT,” Washington D.C.:

EPA, 1989.

[33] Vierow, K., et al., "Peer Review Comment Resolution Report," ML11118A0620. 

Washington D.C.: NRC, July 2011.

[34] Nuclear Regulatory Commission (U.S.) (NRC). RG 1.145, Rev. 1, “Atmospheric 

Dispersion Models for Potential Accident Consequence Assessments at Nuclear 

Power Plants,” Washington D.C.: NRC, November 1982.

[35] Health Physics Society (U.S.) (HPS). PS010-1, “Position Statement of the Health 

Physics Society - Radiation Risk in Perspective,“ McClean, VA: HPS, 2004.

[36] International Commission on Radiological Protection (ICRP). ICRP 26, 

“Recommendations of the International Commission on Radiological Protection,” 

Volume 1 No. 3, Pergamon Press Elmsford, NY, 1977.

[37] International Commission on Radiological Protection (ICRP). ICRP 30, “Limits for 

Intakes of Radionuclides by Workers,” Volume 6 No. 2/3, Pergamon Press Elmsford, 

NY, 1981.

[38] International Commission on Radiological Protection (ICRP). ICRP 72, “Agedependent Dose to the Members of the Public from Intake of Radionuclides Part 5 –

Compilation of Ingestion and Inhalation Coefficients,” Volume 26 No. 1, Elsevier, 

New York, NY, 1996.
6-4

[39] Environmental Protection Agency (U.S.) (EPA). EPA 402-R-99-001, “Cancer Risk 

Coefficients for Environmental Exposure to Radionuclides – Federal Guidance 

Report 13,” Washington D.C.: EPA, September 1999.

[40] Oak Ridge National Laboratory (ORNL). ORNL/TM-2005/39, “SCALE: A Modular 

Code System for Performing Standardized Computer Analyses for Licensing 

Evaluations – Version 5.1, Volumes I – III,” ORNL: Oak Ridge, TN, November 2006.

[41] Scott, G. A., M.T. Leonard, P. Longmire, R.O. Gauntt, A. Goldmann, D.A. Powers, 

“Accident Source Terms for Pressurized Water Reactors with High Burnup Cores 

Calculated using MELCOR 1.8.5,” SAND2008-6664, Sandia National Laboratories: 

Albuquerque, NM, 2008.

[42] Electric Power Research Institute (EPRI). EPRI-NP-971, “Core Design and 

Operating Data for Cycle 3 of Peach Bottom 2,” EPRI: Palo Alto, CA, April, 1981.

[43] Nuclear Regulatory Commission (U.S.) (NRC). NRC Order EA-02-026, “Order for 

Interim Safeguards and Security Compensatory Measures,” Washington D.C.: NRC, 

February 2002.

[44] National Council on Radiation Protection & Measurements (NRCP) Repot No. 160, 

“Ionizing Radiation Exposure of the Population of the United States, ISBN 978-0-

929600-98-7, Bethesda, MD: NCRP, 2009.

[45] Wheeler, T., G. Wyss, and F. Harper, “Cassini Spacecraft Uncertainty Analysis Data 

and Methodology Review and Update Volume 1: Updated Parameter Uncertainty 

Models for the Consequence Analysis,” SAND2000-2719/1, Sandia National 

Laboratories: Albuquerque, NM. November, 2000.

[46] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-6526, "Probabilistic 

Accident Consequence Uncertainty Analysis, Uncertainty Assessment for Deposited 

Material and External Doses," Washington D.C.: NRC, 1997.

[47] Nuclear Regulatory Commission (U.S.) (NRC). NUREG/CR-6545, "Probabilistic 

Accident Consequence Uncertainty Analysis, Early Health Effects Uncertainty 

Assessment, " Washington D.C.: NRC, 1997.

[48] Gregory, J.J., et al., "Task 5 Letter Report: MACCS Uncertainty Analysis of EARLY 

Exposure Results," 2000.

[49] Rogers, G.O., et al., "Evaluating Protective Actions for Chemical Agent 

Emergencies," ORNL-6615 Oak Ridge National Laboratory, Oak Ridge, TN, 1990.

[50] Hanna, S.R., G.A. Briggs, and R.P. Hosker, Jr, “Handbook on Atmospheric 

Diffusion,” DOE/TIC-11223, U.S. Department of Energy, Washington D.C., 1982.

[51] Briggs, G.A., “Plume Rise and Bouyancy Effects,” DOE/TIC-27601, U.S. Department 

of Energy, Washington D.C., 1984.
A-1

APPENDIX A: MACCS SURRY POWER STATION SOARCA 

MODELING PARAMETERS

A-3

SURRY INPUT PARAMETERS FOR SOARCA

The input parameters used for the SOARCA LTSBO, STSBO, ISLOCA, TISGTR mitigated and 

unmitigated scenarios are shown in this appendix in tabular form. Table A-1 contains the more 

general ATMOS input parameters used for these three scenarios. Table A-2 through Table A-4 

contain specific inputs related to the source terms that were extracted from MELCOR results via 

the MELMACCS code. Table A-5 contains general EARLY input parameters. Table A-6 and 

Table A-7 contain parameters associated with the network evacuation model that was used to 

treat emergency response. Table A-8 contains the evacuation direction parameters. Table A-9 

contains the CHRONC input parameters.

Table A-1 ATMOS input parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

APLFRC

Method of 

Applying Release 

Fraction

PARENT PARENT PARENT PARENT PARENT

ATNAM1

Title Describing 

the ATMOS 

Assumptions

SOARCA Surry 

Unmitigated 

LTSBO

SOARCA Surry 

Unmitigated 

STSBO

SOARCA Surry 

Unmitigated 

STSBO

SOARCA Surry 

Mitigated TISGTR

SOARCA Surry 

Unmitigated 

TISGTR

ATNAM2 Title Describing 

the Source Term

Surry source 

term for 

unmitigated longterm station 

blackout.

Surry source term 

for unmitigated 

short-term station 

blackout.

Surry source term 

for unmitigated 

short-term station 

blackout.

Surry source term 

for mitigated, 

thermally-induced, 

steam-generatortube rupture

Surry source 

term for

unmitigated 

short-term station 

blackout.

BNDMXH

Boundary 

Weather Mixing 

Layer Height

1000 1000 1000 1000 1000

BNDRAN

Boundary 

Weather Rain 

Rate

5 5 5 5 5

BNDWND Boundary Wind 

Speed 2.2 2.2 2.2 2.2 2.2

BRKPNT

Breakpoint Time 

for Plume 

Meander

3600 3600 3600 3600 3600

BUILDH

Building Height 

for all Plume 

Segments

50 50 50 50 50

CORINV

Isotopic Inventory 

at Time of 

Reactor 

Shutdown

from MELMACCS from MELMACCS from MELMACCS from MELMACCS from MELMACCS

CORSCA

Linear Scaling 

Factor on Core 

Inventory

1 1 1 1 1

CWASH1 Linear Coefficient 

for Washout 1.89E-05 1.89E-05 1.89E-05 1.89E-05 1.89E-05

CWASH2 Exponential Term 

for Washout 0.664 0.664 0.664 0.664 0.664

CYSIGA Linear Coefficient 

for sigma-y

Stability Class 

A 0.7507 0.7507 0.7507 0.7507 0.7507

Stability Class 

B 0.7507 0.7507 0.7507 0.7507 0.7507
A-4

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

CYSIGA Stability Class 

C 0.4063 0.4063 0.4063 0.4063 0.4063

Stability Class 

D 0.2779 0.2779 0.2779 0.2779 0.2779

Stability Class 

E 0.2158 0.2158 0.2158 0.2158 0.2158

Stability Class 

F 0.2158 0.2158 0.2158 0.2158 0.2158

CYSIGB Exponential Term

for sigma-y

Stability Class 

A 0.866 0.866 0.866 0.866 0.866

Stability Class 

B 0.866 0.866 0.866 0.866 0.866

Stability Class 

C 0.865 0.865 0.865 0.865 0.865

Stability Class 

D 0.881 0.881 0.881 0.881 0.881

Stability Class 

E 0.866 0.866 0.866 0.866 0.866

Stability Class 

F 0.866 0.866 0.866 0.866 0.866

CZSIGA Linear Coefficient 

for sigma-z

Stability Class 

A 0.0361 0.0361 0.0361 0.0361 0.0361

Stability Class 

B 0.0361 0.0361 0.0361 0.0361 0.0361

Stability Class 

C 0.2036 0.2036 0.2036 0.2036 0.2036

Stability Class 

D 0.2636 0.2636 0.2636 0.2636 0.2636

Stability Class 

E 0.2463 0.2463 0.2463 0.2463 0.2463

Stability Class 

F 0.2463 0.2463 0.2463 0.2463 0.2463

CZSIGB Exponential Term

for sigma-z

Stability Class 

A 1.277 1.277 1.277 1.277 1.277

Stability Class 

B 1.277 1.277 1.277 1.277 1.277

Stability Class 

C 0.859 0.859 0.859 0.859 0.859

Stability Class 

D 0.751 0.751 0.751 0.751 0.751

Stability Class 

E 0.619 0.619 0.619 0.619 0.619

Stability Class 

F 0.619 0.619 0.619 0.619 0.619

DISPMD Dispersion Model 

Flag LRDIST LRDIST LRDIST LRDIST LRDIST

DRYDEP Dry Deposition 

Flag

Xe = .FALSE.

Other Groups = 

.TRUE.

Xe = .FALSE.

Other Groups = 

.TRUE.

Xe = .FALSE.

Other Groups = 

.TRUE.

Xe = .FALSE.

Other Groups = 

.TRUE.

Xe = .FALSE.

Other Groups = 

.TRUE.

ENDAT1

Control flag 

indicating only 

ATMOS is to be 

run

.FALSE. .FALSE. .FALSE. .FALSE. .FALSE.

Table A-1 ATMOS input parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios (continued)
A-5

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

GRPNAM

Names of the 

Chemical 

Classes (Used by 

WinMACCS)

Chemical Class 

1 Xe Xe Xe Xe Xe

Chemical Class 

2 Cs Cs Cs Cs Cs

Chemical Class 

3 Ba Ba Ba Ba Ba

Chemical Class 

4 I I I I I

Chemical Class 

5 Te Te Te Te Te

Chemical Class 

6 Ru Ru Ru Ru Ru

Chemical Class 

7 Mo Mo Mo Mo Mo

Chemical Class 

8 Ce Ce Ce Ce Ce

Chemical Class 

9 La La La La La

IBDSTB

Boundary 

Weather Stability 

Class Index

4 4 4 4 4

IDEBUG

Debug Switch for 

Extra Debugging 

Print

0 0 0 0 0

IGROUP

Definition of 

Radionuclide 

Group Numbers

1 = Xe 1 = Xe 1 = Xe 1 = Xe 1 = Xe

2 = Cs 2 = Cs 2 = Cs 2 = Cs 2 = Cs

3 = Ba 3 = Ba 3 = Ba 3 = Ba 3 = Ba

4 = I 4 = I 4 = I 4 = I 4 = I

5 = Te 5 = Te 5 = Te 5 = Te 5 = Te

6 = Ru 6 = Ru 6 = Ru 6 = Ru 6 = Ru

7 = Mo 7 = Mo 7 = Mo 7 = Mo 7 = Mo

8 = Ce 8 = Ce 8 = Ce 8 = Ce 8 = Ce

9 = La 9 = La 9 = La 9 = La 9 = La

INWGHT

Number of 

Samples for Each 

Bin Used for 

Nonuniform 

Weather Bin 

Sampling

Bin 1 12 12 12 12 12

Bin 2 14 14 14 14 14

Bin 3 12 12 12 12 12

Bin 4 39 39 39 39 39

Bin 5 85 85 85 85 85

Bin 6 94 94 94 94 94

Bin 7 16 16 16 16 16

Bin 8 12 12 12 12 12

Bin 9 27 27 27 27 27

Bin 10 134 134 134 134 134

Bin 11 119 119 119 119 119

Table A-1 ATMOS input parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios (continued)
A-6

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

INWGHT Bin 12 74 74 74 74 74

Bin 13 92 92 92 92 92

Bin 14 43 43 43 43 43

Bin 15 12 12 12 12 12

Bin 16 12 12 12 12 12

Bin 17 37 37 37 37 37

Bin 18 12 12 12 12 12

Bin 19 13 13 13 13 13

Bin 20 17 17 17 17 17

Bin 21 14 14 14 14 14

Bin 22 12 12 12 12 12

Bin 23 6 6 6 6 6

Bin 24 6 6 6 6 6

Bin 25 12 12 12 12 12

Bin 26 12 12 12 12 12

Bin 27 12 12 12 12 12

Bin 28 1 1 1 1 1

Bin 29 5 5 5 5 5

Bin 30 6 6 6 6 6

Bin 31 5 5 5 5 5

Bin 32 12 12 12 12 12

Bin 33 5 5 5 5 5

Bin 34 12 12 12 12 12

Bin 35 12 12 12 12 12

Bin 36 12 12 12 12 12

IRSEED

Seed for Random 

Number 

Generator

79 79 79 79 79

LATITU Latitude of Power 

Plant 37 ̊ 9' 56" 37 ̊ 9' 56" 37 ̊ 9' 56" 37 ̊ 9' 56" 37 ̊ 9' 56"

LIMSPA

Last Interval for 

Measured 

Weather

25 25 25 25 25

LONGIT Longitude of 

Power Plant 76 ̊ 41' 54" 76 ̊ 41' 54" 76 ̊ 41' 54" 76 ̊ 41' 54" 76 ̊ 41' 54"

MAXGRP

Number of 

Radionuclide 

Groups

9 9 9 9 9

MAXHGT Flag for Mixing 

Height DAY_AND_NIGHT DAY_AND_NIGHT DAY_AND_NIGHT DAY_AND_NIGHT DAY_AND_NIGHT

MAXRIS Selection of Risk 

Dominant Plume 3 3 1 1 1

METCOD

Meteorological 

Sampling Option 

Code

2 2 2 2 2

MNDMOD Plume Meander 

Model Flag OFF OFF OFF OFF OFF

NAMSTB List of Pseudo 

stable Nuclides

Isotope 1 I-129 I-129 I-129 I-129 I-129

Isotope 2 Xe-131m Xe-131m Xe-131m Xe-131m Xe-131m

Isotope 3 Xe-133m Xe-133m Xe-133m Xe-133m Xe-133m

Isotope 4 Cs-135 Cs-135 Cs-135 Cs-135 Cs-135

Table A-1 ATMOS input parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios (continued)
A-7

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

NAMSTB Isotope 5 Sm-147 Sm-147 Sm-147 Sm-147 Sm-147

Isotope 6 U-234 U-234 U-234 U-234 U-234

Isotope 7 U-235 U-235 U-235 U-235 U-235

Isotope 8 U-236 U-236 U-236 U-236 U-236

Isotope 9 U-237 U-237 U-237 U-237 U-237

Isotope 10 Np-237 Np-237 Np-237 Np-237 Np-237

Isotope 11 Rb-87 Rb-87 Rb-87 Rb-87 Rb-87

Isotope 12 Zr-93 Zr-93 Zr-93 Zr-93 Zr-93

Isotope 13 Nb-93m Nb-93m Nb-93m Nb-93m Nb-93m

Isotope 14 Nb-95m Nb-95m Nb-95m Nb-95m Nb-95m

Isotope 15 Tc-99 Tc-99 Tc-99 Tc-99 Tc-99

Isotope 16 Pm-147 Pm-147 Pm-147 Pm-147 Pm-147

NPSGRP

Number of 

Particle Size 

Groups

10 10 10 10 10

NRINTN

Number of Rain 

Intensity 

Breakpoints

3 3 3 3 3

NRNINT Number of Rain 

Distance Intervals 5 5 5 5 5

NSBINS

Number of 

Weather Bins to 

Sample

36 36 36 36 36

NUCNAM Radionuclide 

Names See Table 4-3 See Table 4-3 See Table 4-3 See Table 4-3 See Table 4-3

NUCOUT

Radionuclide 

Used in 

Dispersion Print

Cs-137 Cs-137 Cs-137 Cs-137 Cs-137

NUMCOR

Number of 

Compass Sectors 

in the Grid

64 64 64 64 64

NUMISO Number of 

Radionuclides 69 69 69 69 69

NUMRAD Number of Radial 

Spatial Intervals 26 26 26 26 26

NUMREL

Number of 

Released Plume 

Segments

28 24 24 49 24

NUMSTB

Number of 

Defined Pseudo 

stable 

Radionuclides

16 16 16 16 16

OALARM

Time to Reach 

General 

Emergency 

Conditions

0 0 0 0 0

PDELAY Plume Release 

Times

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

PLHEAT Plume Heat 

Contents

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

PLHITE Plume Release 

Heights

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

PLMDEN Plume Mass 

Density

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

PLMFLA Plume Mass Flow 

Rate

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

Table A-1 ATMOS input parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios (continued)
A-8

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

PLMMOD Flag for Plume 

Rise Input Option DENSITY DENSITY DENSITY DENSITY DENSITY

PLUDUR Plume Segment 

Durations

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table A-2)

PSDIST

Particle Size 

Distribution by 

Group

MELMACCS Data 

(See Table A-3)

MELMACCS Data 

(See Table A-3)

MELMACCS Data 

(See Table A-3)

MELMACCS Data 

(See Table A-3)

MELMACCS Data 

(See Table A-3)

REFTIM Plume Reference 

Time Point

0. for first

0.5 for 

subsequent

0. for first

0.5 for 

subsequent

0. for first

0.5 for subsequent

0. for first

0.5 for 

subsequent

0. for first

0.5 for 

subsequent

RELFRC

Release 

Fractions of the 

Source Term

MELMACCS Data 

(See Table A-4)

MELMACCS Data 

(See Table A-4)

MELMACCS Data 

(See Table A-4)

MELMACCS Data 

(See Table A-4)

MELMACCS Data 

(See Table A-4)

RNDSTS Endpoints of Rain 

Distance Intervals

Interval 1 3.22 3.22 3.22 3.22 3.22

Interval 2 5.63 5.63 5.63 5.63 5.63

Interval 3 11.27 11.27 11.27 11.27 11.27

Interval 4 20.92 20.92 20.92 20.92 20.92

Interval 5 32.19 32.19 32.19 32.19 32.19

RNRATE

Rain Intensity 

Breakpoints for 

Weather Binning

Intensity 1 2 2 2 2 2

Intensity 2 4 4 4 4 4

Intensity 3 6 6 6 6 6

SCLADP Scaling Factor for 

A-D Plume Rise 1.0 1.0 1.0 1.0 1.0

SCLCRW

Scaling Factor for 

Critical Wind 

Speed

1.0 1.0 1.0 1.0 1.0

SCLEFP Scaling Factor for 

E-F Plume Rise 1.0 1.0 1.0 1.0 1.0

SIGYINIT

Initial Sigma-y for 

All Plume 

Segments

9.3 9.3 9.3 9.3 9.3

SIGZINIT

Initial Sigma-z 

for All Plume 

Segments

23.3 23.3 23.3 23.3 23.3

SPAEND

Radial distances 

for grid 

boundaries

Ring 1 0.16 0.16 0.16 0.16 0.16

Ring 2 0.52 0.52 0.52 0.52 0.52

Ring 3 1.21 1.21 1.21 1.21 1.21

Ring 4 1.61 1.61 1.61 1.61 1.61

Ring 5 2.13 2.13 2.13 2.13 2.13

Ring 6 3.22 3.22 3.22 3.22 3.22

Ring 7 4.02 4.02 4.02 4.02 4.02

Ring 8 4.83 4.83 4.83 4.83 4.83

Ring 9 5.63 5.63 5.63 5.63 5.63

Ring 10 8.05 8.05 8.05 8.05 8.05

Ring 11 11.27 11.27 11.27 11.27 11.27

Ring 12 16.09 16.09 16.09 16.09 16.09

Table A-1 ATMOS input parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios (continued)
A-9

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

SPAEND Ring 13 20.92 20.92 20.92 20.92 20.92

Ring 14 25.75 25.75 25.75 25.75 25.75

Ring 15 32.19 32.19 32.19 32.19 32.19

Ring 16 40.23 40.23 40.23 40.23 40.23

Ring 17 48.28 48.28 48.28 48.28 48.28

Ring 18 64.37 64.37 64.37 64.37 64.37

Ring 19 80.47 80.47 80.47 80.47 80.47

Ring 20 112.65 112.65 112.65 112.65 112.65

Ring 21 160.93 160.93 160.93 160.93 160.93

Ring 22 241.14 241.14 241.14 241.14 241.14

Ring 23 321.87 321.87 321.87 321.87 321.87

Ring 24 563.27 563.27 563.27 563.27 563.27

Ring 25 804.67 804.67 804.67 804.67 804.67

Ring 26 1609.34 1609.34 1609.34 1609.34 1609.34

TIMBAS

Time Base for 

Plume Expansion 

Factor

600 600 600 600 600

VDEPOS Dry Deposition 

Velocities

Aerosol Bin 1 5.35E-04 5.35E-04 5.35E-04 5.35E-04 5.35E-04

Aerosol Bin 2 4.91E-04 4.91E-04 4.91E-04 4.91E-04 4.91E-04

Aerosol Bin 3 6.43E-04 6.43E-04 6.43E-04 6.43E-04 6.43E-04

Aerosol Bin 4 1.08E-03 1.08E-03 1.08E-03 1.08E-03 1.08E-03

Aerosol Bin 5 2.12E-03 2.12E-03 2.12E-03 2.12E-03 2.12E-03

Aerosol Bin 6 4.34E-03 4.34E-03 4.34E-03 4.34E-03 4.34E-03

Aerosol Bin 7 8.37E-03 8.37E-03 8.37E-03 8.37E-03 8.37E-03

Aerosol Bin 8 1.37E-02 1.37E-02 1.37E-02 1.37E-02 1.37E-02

Aerosol Bin 9 1.70E-02 1.70E-02 1.70E-02 1.70E-02 1.70E-02

Aerosol Bin 10 1.70E-02 1.70E-02 1.70E-02 1.70E-02 1.70E-02

WETDEP Wet Deposition 

Flag

Xe = .FALSE.

Other groups = 

.TRUE.

Xe = .FALSE.

Other groups = 

.TRUE.

Xe = .FALSE.

Other groups = 

.TRUE.

Xe = .FALSE.

Other groups = 

.TRUE.

Xe = .FALSE.

Other groups = 

.TRUE.

XPFAC1

Base Time for 

Meander 

Expansion Factor

0.2 0.2 0.2 0.2 0.2

XPFAC2

Breakpoint for 

Expansion Factor 

Model

0.25 0.25 0.25 0.25 0.25

YSCALE

Scale Factor for 

Horizontal 

Dispersion

1 1 1 1 1

ZSCALE

Scale Factor for 

Vertical 

Dispersion

1.27 1.27 1.27 1.27 1.27

Table A-1 ATMOS input parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios (continued)
A-10

Table A-2 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios

Surry LTSBO

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

1 1.63E+05 5.11E+04 8.40E+00 1.77E-01 4.85E-01 3.60E+03

2 1.67E+05 1.14E+05 8.40E+00 3.89E-01 4.83E-01 3.60E+03

3 1.70E+05 2.07E+05 8.40E+00 7.01E-01 4.81E-01 3.60E+03

4 1.74E+05 3.05E+05 8.40E+00 1.02E+00 4.79E-01 3.60E+03

5 1.77E+05 3.81E+05 8.40E+00 1.27E+00 4.76E-01 3.72E+03

6 1.81E+05 4.44E+05 8.40E+00 1.46E+00 4.74E-01 3.48E+03

7 1.85E+05 4.82E+05 8.40E+00 1.57E+00 4.72E-01 3.60E+03

8 1.88E+05 5.07E+05 8.40E+00 1.63E+00 4.70E-01 3.60E+03

9 1.92E+05 5.25E+05 8.40E+00 1.67E+00 4.69E-01 3.60E+03

10 1.95E+05 5.38E+05 8.40E+00 1.70E+00 4.67E-01 3.60E+03

11 1.99E+05 5.48E+05 8.40E+00 1.72E+00 4.65E-01 3.60E+03

12 2.03E+05 5.59E+05 8.40E+00 1.73E+00 4.63E-01 3.60E+03

13 2.06E+05 5.71E+05 8.40E+00 1.76E+00 4.62E-01 3.60E+03

14 2.10E+05 5.75E+05 8.40E+00 1.75E+00 4.60E-01 3.60E+03

15 2.13E+05 5.79E+05 8.40E+00 1.75E+00 4.58E-01 3.60E+03

16 2.17E+05 5.85E+05 8.40E+00 1.75E+00 4.57E-01 3.60E+03

17 2.21E+05 5.94E+05 8.40E+00 1.77E+00 4.55E-01 3.60E+03

18 2.24E+05 6.02E+05 8.40E+00 1.78E+00 4.54E-01 3.60E+03

19 2.28E+05 6.11E+05 8.40E+00 1.79E+00 4.52E-01 3.60E+03

20 2.31E+05 6.17E+05 8.40E+00 1.80E+00 4.51E-01 3.60E+03

21 2.35E+05 6.22E+05 8.40E+00 1.80E+00 4.50E-01 3.60E+03

22 2.39E+05 6.33E+05 8.40E+00 1.81E+00 4.48E-01 3.60E+03

23 2.42E+05 6.56E+05 8.40E+00 1.81E+00 4.42E-01 3.60E+03

24 2.46E+05 6.52E+05 8.40E+00 1.76E+00 4.39E-01 3.60E+03

25 2.49E+05 6.46E+05 8.40E+00 1.71E+00 4.36E-01 3.60E+03

26 2.53E+05 6.37E+05 8.40E+00 1.66E+00 4.34E-01 3.72E+03

27 2.57E+05 6.30E+05 8.40E+00 1.62E+00 4.32E-01 2.40E+03

28 2.59E+05 6.27E+05 8.40E+00 1.60E+00 4.31E-01 1.20E+02
A-11

Surry STSBO

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

1 9.19E+04 5.78E+04 8.40E+00 4.84E-01 1.97E-01 3.72E+03

2 9.56E+04 1.49E+05 8.40E+00 4.81E-01 5.03E-01 3.48E+03

3 9.91E+04 2.84E+05 8.40E+00 4.78E-01 9.44E-01 3.72E+03

4 1.03E+05 4.10E+05 8.40E+00 4.76E-01 1.35E+00 3.48E+03

5 1.06E+05 5.07E+05 8.40E+00 4.73E-01 1.64E+00 3.60E+03

6 1.10E+05 5.66E+05 8.40E+00 4.71E-01 1.81E+00 3.60E+03

7 1.14E+05 6.01E+05 8.40E+00 4.68E-01 1.90E+00 3.72E+03

8 1.17E+05 6.23E+05 8.40E+00 4.66E-01 1.95E+00 3.60E+03

9 1.21E+05 6.39E+05 8.40E+00 4.64E-01 1.97E+00 3.60E+03

10 1.24E+05 6.53E+05 8.40E+00 4.62E-01 2.00E+00 3.60E+03

11 1.28E+05 6.63E+05 8.40E+00 4.60E-01 2.01E+00 3.48E+03

12 1.32E+05 6.71E+05 8.40E+00 4.58E-01 2.01E+00 3.60E+03

13 1.35E+05 6.78E+05 8.40E+00 4.56E-01 2.01E+00 3.72E+03

14 1.39E+05 6.84E+05 8.40E+00 4.54E-01 2.01E+00 3.48E+03

15 1.42E+05 6.90E+05 8.40E+00 4.53E-01 2.01E+00 3.60E+03

16 1.46E+05 6.96E+05 8.40E+00 4.51E-01 2.01E+00 3.72E+03

17 1.50E+05 7.04E+05 8.40E+00 4.49E-01 2.02E+00 3.60E+03

18 1.53E+05 7.09E+05 8.40E+00 4.48E-01 2.02E+00 3.48E+03

19 1.57E+05 7.26E+05 8.40E+00 4.44E-01 2.01E+00 3.60E+03

20 1.60E+05 7.34E+05 8.40E+00 4.38E-01 1.96E+00 3.60E+03

21 1.64E+05 7.26E+05 8.40E+00 4.35E-01 1.90E+00 3.72E+03

22 1.68E+05 7.16E+05 8.40E+00 4.32E-01 1.84E+00 3.48E+03

23 1.71E+05 7.08E+05 8.40E+00 4.30E-01 1.80E+00 1.68E+03

24 1.73E+05 7.05E+05 8.40E+00 4.30E-01 1.78E+00 1.20E+02

Table A-2 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated 

and unmitigated TISGTR scenarios (continued)

 

 
A-12

Surry ISLOCA

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

1 4.59E+04 3.65E+05 2.17E+01 1.07E+00 1.83E+01 4.20E+03

2 4.59E+04 3.65E+05 2.17E+01 1.07E+00 1.83E+01 4.20E+03

3 4.83E+04 7.72E+04 7.90E+00 8.94E-01 1.05E+00 4.20E+03

4 4.83E+04 2.66E+05 5.64E+00 5.77E-01 6.65E-01 4.20E+03

5 4.86E+04 5.34E+03 6.39E-01 4.54E-01 1.13E-02 3.90E+03

6 4.86E+04 7.64E+05 4.91E+00 5.51E-01 1.75E+00 3.90E+03

7 5.01E+04 5.28E+05 4.91E+00 5.10E-01 1.66E+00 3.00E+02

8 5.01E+04 6.68E+05 2.17E+01 1.00E+00 1.68E+01 3.30E+03

9 5.01E+04 6.68E+05 2.17E+01 1.00E+00 1.68E+01 3.30E+03

10 5.04E+04 4.32E+05 4.91E+00 5.09E-01 1.14E+00 3.00E+03

11 5.25E+04 4.90E+05 4.91E+00 6.22E-01 2.13E+00 3.60E+03

12 5.25E+04 6.64E+04 7.90E+00 9.09E-01 1.23E+00 3.60E+03

13 5.25E+04 1.92E+05 5.64E+00 5.99E-01 8.21E-01 3.60E+03

14 5.34E+04 4.39E+05 4.91E+00 3.72E-01 1.11E+00 3.60E+03

15 5.34E+04 4.47E+05 2.17E+01 1.04E+00 1.76E+01 3.90E+03

16 5.34E+04 4.47E+05 2.17E+01 1.04E+00 1.76E+01 3.90E+03

17 5.61E+04 4.13E+05 4.91E+00 6.57E-01 2.03E+00 3.60E+03

18 5.61E+04 6.61E+04 7.90E+00 9.11E-01 1.21E+00 3.60E+03

19 5.61E+04 1.56E+05 5.64E+00 6.86E-01 8.55E-01 3.60E+03

20 5.70E+04 5.58E+04 4.91E+00 4.25E-01 1.47E-01 3.60E+03

21 5.73E+04 2.91E+05 2.17E+01 1.08E+00 1.75E+01 3.30E+03

22 5.73E+04 2.91E+05 2.17E+01 1.08E+00 1.75E+01 3.30E+03

23 5.97E+04 1.67E+04 4.91E+00 1.07E+00 8.97E-01 3.60E+03

24 5.97E+04 2.33E+04 7.90E+00 1.03E+00 8.08E-01 3.60E+03

25 5.97E+04 1.34E+04 5.64E+00 1.06E+00 6.77E-01 3.60E+03

26 6.06E+04 1.58E+04 2.17E+01 1.15E+00 1.83E+01 3.90E+03

27 6.06E+04 1.58E+04 2.17E+01 1.15E+00 1.83E+01 3.90E+03

28 6.45E+04 -2.35E+04 2.17E+01 1.16E+00 1.82E+01 3.30E+03

29 6.45E+04 -2.35E+04 2.17E+01 1.16E+00 1.82E+01 3.30E+03

30 7.02E+04 3.67E+02 4.91E+00 1.14E+00 5.20E-02 3.60E+03

31 7.02E+04 4.58E+03 7.90E+00 1.12E+00 3.38E-01 3.60E+03

32 7.02E+04 4.68E+02 5.64E+00 1.16E+00 2.11E-01 3.60E+03

33 7.17E+04 8.31E+00 1.20E+00 8.27E-01 5.62E-05 3.60E+03

34 7.17E+04 6.12E+04 3.38E+00 1.12E+00 7.11E+00 3.30E+03

35 7.50E+04 5.92E+04 3.38E+00 1.12E+00 7.12E+00 3.90E+03

36 7.53E+04 1.03E+01 1.20E+00 8.56E-01 1.19E-04 3.60E+03

37 7.89E+04 1.30E+01 1.20E+00 8.51E-01 1.39E-04 3.60E+03

38 7.89E+04 5.68E+04 3.38E+00 1.12E+00 7.13E+00 3.60E+03

39 8.10E+04 1.35E+03 4.91E+00 1.12E+00 1.80E-01 3.60E+03

40 8.10E+04 5.49E+02 5.64E+00 1.14E+00 1.38E-01 3.60E+03

41 8.22E+04 4.76E+02 4.91E+00 9.18E-01 1.47E-01 3.60E+03

42 8.25E+04 1.63E+01 1.20E+00 8.39E-01 1.50E-04 3.60E+03

43 8.25E+04 5.54E+04 3.38E+00 1.12E+00 7.14E+00 3.30E+03

44 8.46E+04 1.51E+03 4.91E+00 1.12E+00 1.60E-01 3.60E+03

45 8.46E+04 5.91E+02 5.64E+00 1.15E+00 1.52E-01 3.60E+03

46 8.58E+04 5.41E+04 3.38E+00 1.12E+00 7.65E+00 4.20E+03

Table A-2 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated 

and unmitigated TISGTR scenarios (continued)

 

 
A-13

Surry ISLOCA

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

47 9.00E+04 5.16E+04 3.38E+00 1.12E+00 7.15E+00 3.60E+03

48 9.18E+04 3.12E+03 4.91E+00 1.14E+00 2.60E-01 4.35E+03

49 9.36E+04 2.07E+03 4.91E+00 1.04E+00 6.92E-02 3.60E+03

50 9.36E+04 5.03E+04 3.38E+00 1.12E+00 7.16E+00 3.60E+03

51 9.62E+04 3.43E+03 4.91E+00 1.12E+00 4.74E-01 3.75E+03

52 9.62E+04 1.16E+03 5.64E+00 1.13E+00 1.93E-01 3.75E+03

53 9.72E+04 4.88E+04 3.38E+00 1.12E+00 7.17E+00 3.60E+03

54 1.01E+05 4.70E+04 3.38E+00 1.13E+00 7.17E+00 3.60E+03

55 1.03E+05 3.37E+03 4.91E+00 1.12E+00 3.66E-01 4.50E+03

56 1.04E+05 4.53E+04 3.38E+00 1.13E+00 7.18E+00 3.60E+03

57 1.07E+05 5.20E+03 4.91E+00 1.10E+00 5.49E-01 2.70E+03

58 1.08E+05 4.48E+04 3.38E+00 1.13E+00 7.18E+00 3.60E+03

59 1.10E+05 6.56E+03 4.91E+00 1.11E+00 6.23E-01 4.50E+03

60 1.12E+05 4.27E+04 3.38E+00 1.13E+00 7.19E+00 3.60E+03

61 1.14E+05 8.29E+03 4.91E+00 1.13E+00 6.96E-01 3.60E+03

62 1.15E+05 4.04E+04 3.38E+00 1.13E+00 7.20E+00 3.60E+03

63 1.18E+05 1.41E+04 4.91E+00 1.12E+00 7.79E-01 3.60E+03

64 1.18E+05 4.19E+03 5.64E+00 1.12E+00 2.50E-01 3.60E+03

65 1.19E+05 3.78E+04 3.38E+00 1.13E+00 7.21E+00 3.60E+03

66 1.22E+05 2.59E+04 4.91E+00 1.07E+00 9.14E-01 3.60E+03

67 1.22E+05 7.68E+03 5.64E+00 1.07E+00 3.05E-01 3.60E+03

68 1.22E+05 6.05E+03 4.91E+00 9.36E-01 2.44E-01 3.60E+03

69 1.25E+05 2.95E+04 4.91E+00 1.04E+00 9.47E-01 2.70E+03

70 1.25E+05 8.85E+03 5.64E+00 1.02E+00 3.20E-01 2.70E+03

71 1.26E+05 9.16E+03 4.91E+00 8.37E-01 2.63E-01 3.60E+03

72 1.28E+05 3.05E+04 4.91E+00 1.08E+00 9.52E-01 4.50E+03

73 1.28E+05 5.90E+03 7.90E+00 1.10E+00 3.51E-01 4.50E+03

74 1.28E+05 9.19E+03 5.64E+00 1.06E+00 3.22E-01 4.50E+03

75 1.30E+05 1.78E+04 4.91E+00 8.29E-01 3.61E-01 3.60E+03

76 1.30E+05 3.40E+04 3.38E+00 1.14E+00 7.23E+00 3.60E+03

77 1.32E+05 4.56E+04 4.91E+00 1.02E+00 1.06E+00 2.70E+03

78 1.32E+05 8.92E+03 7.90E+00 1.09E+00 4.36E-01 2.70E+03

79 1.33E+05 3.27E+04 4.91E+00 8.54E-01 6.85E-01 3.60E+03

80 1.35E+05 4.78E+04 4.91E+00 1.06E+00 1.10E+00 3.60E+03

81 1.35E+05 1.02E+04 7.90E+00 1.08E+00 4.68E-01 3.60E+03

82 1.35E+05 1.51E+04 5.64E+00 1.01E+00 3.96E-01 3.60E+03

83 1.37E+05 3.49E+04 4.91E+00 8.44E-01 7.07E-01 3.60E+03

84 1.39E+05 4.88E+04 4.91E+00 1.09E+00 1.11E+00 3.60E+03

85 1.39E+05 1.56E+04 5.64E+00 1.07E+00 4.05E-01 3.60E+03

86 1.40E+05 3.80E+04 4.91E+00 8.90E-01 7.59E-01 3.60E+03

87 1.42E+05 5.31E+04 4.91E+00 1.05E+00 1.16E+00 4.50E+03

88 1.42E+05 1.72E+04 5.64E+00 1.02E+00 4.22E-01 4.50E+03

89 1.44E+05 4.67E+04 4.91E+00 8.54E-01 9.27E-01 3.60E+03

90 1.47E+05 5.61E+04 4.91E+00 1.01E+00 1.19E+00 2.70E+03

91 1.48E+05 5.53E+04 4.91E+00 8.60E-01 1.09E+00 3.60E+03

92 1.49E+05 5.79E+04 4.91E+00 1.06E+00 1.22E+00 3.60E+03

Table A-2 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated 

and unmitigated TISGTR scenarios (continued)

 

 
A-14

Surry ISLOCA

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

93 1.51E+05 5.47E+04 4.91E+00 8.62E-01 1.08E+00 3.60E+03

94 1.53E+05 5.64E+04 4.91E+00 1.08E+00 1.21E+00 3.60E+03

95 1.55E+05 5.22E+04 4.91E+00 8.62E-01 1.04E+00 3.60E+03

96 1.57E+05 5.42E+04 4.91E+00 1.10E+00 1.19E+00 3.60E+03

97 1.58E+05 5.03E+04 4.91E+00 8.64E-01 1.02E+00 3.60E+03

98 1.60E+05 4.98E+04 4.91E+00 1.05E+00 1.14E+00 4.50E+03

99 1.60E+05 1.27E+04 7.90E+00 1.08E+00 5.15E-01 4.50E+03

100 1.60E+05 1.65E+04 5.64E+00 1.03E+00 4.25E-01 4.50E+03

101 1.62E+05 3.94E+04 4.91E+00 8.64E-01 8.23E-01 3.60E+03

102 1.62E+05 2.78E+04 3.38E+00 1.14E+00 7.27E+00 3.60E+03

103 1.65E+05 3.89E+04 4.91E+00 1.08E+00 9.95E-01 2.70E+03

104 1.65E+05 1.06E+04 7.90E+00 1.08E+00 4.70E-01 2.70E+03

105 1.66E+05 2.81E+04 4.91E+00 8.65E-01 6.22E-01 3.60E+03

106 1.67E+05 3.70E+04 4.91E+00 1.11E+00 9.62E-01 3.60E+03

107 1.69E+05 2.69E+04 4.91E+00 8.69E-01 6.18E-01 3.60E+03

Table A-2 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated 

and unmitigated TISGTR scenarios (continued)

 

 
A-15

Surry Mitigated TISGTR

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

1 10600 4.32E+01 8.4 0.73919 4.11E-04 3619.6

2 12800 8.88E+05 24.643 0.29498 1.0716 3639.9

3 14220 8.97E+01 8.4 0.6666 7.40E-04 3600.4

4 16440 6.76E+04 24.643 0.3208 0.091864 3600.1

5 17820 1.12E+02 8.4 0.64171 8.13E-04 3599.9

6 20040 6.10E+04 24.643 0.2937 0.08302 3599.9

7 21420 1.28E+02 8.4 0.62148 8.23E-04 3600

8 23640 5.47E+04 24.643 0.28461 0.074318 3600

9 25020 1.48E+02 8.4 0.60385 8.97E-04 3599.9

10 27240 5.95E+04 24.643 0.33478 0.088723 3600.1

11 28620 1.21E+02 8.4 0.6199 8.26E-04 3660.1

12 30840 4.60E+04 24.643 0.33994 0.069402 3600.1

13 34440 2.31E+04 24.643 0.3649 0.039585 3599.9

14 38040 7.49E+03 24.643 0.40498 0.01627 3600

15 41640 3.83E+02 24.643 0.71955 0.002878 3600

16 52440 1.49E+03 24.643 0.71162 0.007903 3600

17 56040 1.24E+04 24.643 0.50849 0.036427 3599.9

18 59640 2.03E+04 24.643 0.42415 0.045113 3600.2

19 63240 2.50E+04 24.643 0.41032 0.05232 3599.9

20 66840 2.88E+04 24.643 0.40342 0.058182 3600

21 70440 3.23E+04 24.643 0.39798 0.063655 3600.1

22 74040 3.58E+04 24.643 0.39336 0.069014 3599.8

23 77640 3.92E+04 24.643 0.38949 0.074187 3600

24 81240 4.26E+04 24.643 0.38619 0.079248 3600.2

25 84840 4.41E+04 24.643 0.38476 0.081656 3599.9

26 88440 4.63E+04 24.643 0.3831 0.085028 3600

27 92040 4.86E+04 24.643 0.38153 0.088779 3599.9

28 95640 5.10E+04 24.643 0.38011 0.09261 3600

29 99240 5.34E+04 24.643 0.37894 0.096455 3600.1

30 1.03E+05 5.58E+04 24.643 0.37793 0.10035 3600.1

31 1.06E+05 5.83E+04 24.643 0.37704 0.10438 3600

32 1.10E+05 6.08E+04 24.643 0.3762 0.10847 3599.9

33 1.14E+05 6.33E+04 24.643 0.37533 0.11268 3600.1

34 1.17E+05 6.58E+04 24.643 0.37489 0.11697 3600.1

35 1.21E+05 6.83E+04 24.643 0.37457 0.12131 3599.8

36 1.24E+05 7.09E+04 24.643 0.37437 0.12571 3600

37 1.28E+05 7.34E+04 24.643 0.37426 0.13016 3600.1

38 1.32E+05 7.59E+04 24.643 0.37422 0.13468 3600

39 1.35E+05 7.84E+04 24.643 0.37428 0.13924 3600

40 1.39E+05 8.09E+04 24.643 0.37442 0.14384 3599.9

41 1.42E+05 8.33E+04 24.643 0.37464 0.14848 3600.2

42 1.46E+05 8.58E+04 24.643 0.37494 0.15318 3599.9

43 1.50E+05 8.82E+04 24.643 0.3753 0.15791 3600.1

44 1.53E+05 9.06E+04 24.643 0.37573 0.16268 3599.9

45 1.57E+05 9.30E+04 24.643 0.37623 0.1675 3599.8

46 1.60E+05 9.53E+04 24.643 0.37687 0.17236 3600.3

47 1.64E+05 9.76E+04 24.643 0.37757 0.17724 3599.7

Table A-2 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated 

and unmitigated TISGTR scenarios (continued)

 

 
A-16

Surry Mitigated TISGTR

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

48 1.68E+05 9.98E+04 24.643 0.37832 0.18216 3600.1

49 1.71E+05 1.01E+05 24.643 0.37889 0.1857 1560.1

Table A-2 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated 

and unmitigated TISGTR scenarios (continued)

 

 
A-17

Surry Unmitigated TISGTR

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

1 10600 4.32E+01 8.4 7.39E-01 4.11E-04 3619.6

2 12800 8.88E+05 24.643 2.95E-01 1.07E+00 3639.9

3 14220 8.97E+01 8.4 6.67E-01 7.40E-04 3600.4

4 16440 6.76E+04 24.643 3.21E-01 9.19E-02 3600.1

5 17820 1.12E+02 8.4 6.42E-01 8.13E-04 3599.9

6 20040 6.10E+04 24.643 2.94E-01 8.30E-02 3599.9

7 21420 1.28E+02 8.4 6.21E-01 8.23E-04 3600

8 23640 5.47E+04 24.643 2.85E-01 7.43E-02 3600

9 25020 1.48E+02 8.4 6.04E-01 8.97E-04 3599.9

10 27240 6.21E+04 24.643 3.45E-01 9.66E-02 3600

11 28620 2.00E+02 8.4 5.80E-01 1.08E-03 3660

12 30840 6.41E+04 24.643 3.64E-01 1.06E-01 3600

13 32280 2.26E+02 8.4 5.66E-01 1.12E-03 3600.2

14 34440 6.88E+04 24.643 3.62E-01 1.12E-01 3600.1

15 35880 2.45E+02 8.4 5.60E-01 1.18E-03 3600

16 38040 7.38E+04 24.643 3.58E-01 1.18E-01 3600.1

17 39480 2.63E+02 8.4 5.55E-01 1.24E-03 3600

18 41640 7.87E+04 24.643 3.55E-01 1.24E-01 3599.9

19 43080 2.85E+02 8.4 5.49E-01 1.31E-03 3600

20 45240 8.38E+04 24.643 3.53E-01 1.29E-01 3600.1

21 46680 3.07E+02 8.4 5.43E-01 1.37E-03 3600.1

22 48840 8.93E+04 24.643 3.55E-01 1.36E-01 3600.1

23 50280 3.30E+02 8.4 5.39E-01 1.43E-03 3600

24 52440 9.51E+04 24.643 3.52E-01 1.42E-01 3599.8

25 53880 3.54E+02 8.4 5.35E-01 1.51E-03 3600

26 56040 1.01E+05 24.643 3.48E-01 1.49E-01 3600

27 57480 3.80E+02 8.4 5.31E-01 1.60E-03 3599.9

28 59640 1.08E+05 24.643 3.45E-01 1.55E-01 3600

29 61080 4.06E+02 8.4 5.28E-01 1.66E-03 3600

30 63240 1.15E+05 24.643 3.42E-01 1.63E-01 3600.1

31 64680 4.33E+02 8.4 5.24E-01 1.74E-03 3599.8

32 66840 1.22E+05 24.643 3.39E-01 1.70E-01 3600

33 68280 4.62E+02 8.4 5.21E-01 1.83E-03 3600.3

34 70440 1.29E+05 24.643 3.36E-01 1.78E-01 3599.9

35 71880 4.91E+02 8.4 5.18E-01 1.92E-03 3599.9

36 74040 1.37E+05 24.643 3.33E-01 1.86E-01 3600.1

37 75480 5.21E+02 8.4 5.14E-01 2.01E-03 3600

38 77640 1.45E+05 24.643 3.31E-01 1.95E-01 3600

39 79080 5.53E+02 8.4 5.11E-01 2.10E-03 3600

40 81240 1.53E+05 24.643 3.29E-01 2.03E-01 3600.1

41 82680 5.84E+02 8.4 5.08E-01 2.18E-03 3599.8

42 84840 1.61E+05 24.643 3.27E-01 2.12E-01 3599.8

43 86280 6.16E+02 8.4 5.05E-01 2.27E-03 3600.3

44 88440 1.68E+05 24.643 3.26E-01 2.20E-01 3600.2

45 89880 6.49E+02 8.4 5.02E-01 2.36E-03 3600

46 92040 1.76E+05 24.643 3.24E-01 2.29E-01 3599.9

Table A-2 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated 

and unmitigated TISGTR scenarios (continued)

 

 
A-18

Surry Unmitigated TISGTR

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

47 93480 6.82E+02 8.4 4.99E-01 2.45E-03 3599.8

48 95640 1.85E+05 24.643 3.23E-01 2.38E-01 3599.8

49 97080 7.16E+02 8.4 4.97E-01 2.55E-03 3600

50 99240 1.93E+05 24.643 3.22E-01 2.47E-01 3600.3

51 1.00E+05 4.91E+04 8.4 4.94E-01 1.72E-01 3720

52 1.01E+05 7.49E+02 8.4 4.94E-01 2.63E-03 3600

53 1.03E+05 2.00E+05 24.643 3.21E-01 2.55E-01 3600

54 1.04E+05 1.57E+05 8.4 4.91E-01 5.45E-01 3480.1

55 1.04E+05 7.79E+02 8.4 4.91E-01 2.71E-03 3600.1

56 1.06E+05 2.06E+05 24.643 3.20E-01 2.62E-01 3600

57 1.08E+05 2.85E+05 8.4 4.89E-01 9.81E-01 3720

58 1.08E+05 8.02E+02 8.4 4.89E-01 2.76E-03 3600.1

59 1.10E+05 2.11E+05 24.643 3.20E-01 2.67E-01 3600

60 1.11E+05 4.00E+05 8.4 4.87E-01 1.36E+00 3599.9

61 1.11E+05 8.20E+02 8.4 4.87E-01 2.79E-03 3600

62 1.14E+05 2.13E+05 24.643 3.19E-01 2.70E-01 3600

63 1.15E+05 4.77E+05 8.4 4.85E-01 1.61E+00 3480.3

64 1.15E+05 8.33E+02 8.4 4.85E-01 2.79E-03 3561.3

65 1.17E+05 2.15E+05 24.643 3.18E-01 2.71E-01 3600

66 1.18E+05 5.32E+05 8.4 4.83E-01 1.77E+00 3719.9

67 1.19E+05 8.45E+02 8.4 4.83E-01 2.86E-03 3638.5

68 1.21E+05 2.17E+05 24.643 3.18E-01 2.72E-01 3599.8

69 1.22E+05 5.65E+05 8.4 4.81E-01 1.86E+00 3599.8

70 1.22E+05 8.53E+02 8.4 4.81E-01 2.82E-03 3600.1

71 1.24E+05 2.18E+05 24.643 3.17E-01 2.73E-01 3600.2

72 1.26E+05 5.85E+05 8.4 4.79E-01 1.91E+00 3600.2

73 1.26E+05 8.61E+02 8.4 4.79E-01 2.81E-03 3600.1

74 1.28E+05 2.19E+05 24.643 3.17E-01 2.73E-01 3599.9

75 1.29E+05 5.98E+05 8.4 4.77E-01 1.94E+00 3480

76 1.29E+05 8.68E+02 8.4 4.77E-01 2.81E-03 3600

77 1.32E+05 2.19E+05 24.643 3.16E-01 2.74E-01 3600

78 1.33E+05 6.08E+05 8.4 4.75E-01 1.95E+00 3600.1

79 1.33E+05 8.74E+02 8.4 4.75E-01 2.81E-03 3599.7

80 1.35E+05 2.20E+05 24.643 3.16E-01 2.74E-01 3600.1

81 1.36E+05 6.17E+05 8.4 4.73E-01 1.97E+00 3599.9

82 1.37E+05 8.80E+02 8.4 4.73E-01 2.80E-03 3600.1

83 1.39E+05 2.20E+05 24.643 3.16E-01 2.74E-01 3600

84 1.40E+05 6.26E+05 8.4 4.72E-01 1.98E+00 3720.1

85 1.40E+05 8.87E+02 8.4 4.72E-01 2.80E-03 3600

86 1.42E+05 2.21E+05 24.643 3.15E-01 2.74E-01 3599.9

87 1.44E+05 6.60E+05 8.4 4.67E-01 2.03E+00 3479.8

88 1.44E+05 9.08E+02 8.4 4.67E-01 2.78E-03 3600.1

89 1.46E+05 2.19E+05 24.643 3.15E-01 2.71E-01 3599.8

90 1.47E+05 6.75E+05 8.4 4.62E-01 2.01E+00 3720.1

91 1.47E+05 9.18E+02 8.4 4.62E-01 2.73E-03 3600

92 1.50E+05 2.15E+05 24.643 3.15E-01 2.67E-01 3600.3

Table A-2 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated 

and unmitigated TISGTR scenarios (continued)

 

 
A-19

Surry Unmitigated TISGTR

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

93 1.51E+05 6.74E+05 8.4 4.60E-01 1.97E+00 3479.9

94 1.51E+05 9.15E+02 8.4 4.60E-01 2.67E-03 3600

95 1.53E+05 2.12E+05 24.643 3.14E-01 2.62E-01 3599.7

96 1.54E+05 6.72E+05 8.4 4.57E-01 1.94E+00 3600

97 1.55E+05 9.11E+02 8.4 4.57E-01 2.62E-03 3600

98 1.57E+05 2.08E+05 24.643 3.14E-01 2.57E-01 3600.4

99 1.58E+05 6.69E+05 8.4 4.55E-01 1.90E+00 3600.2

100 1.58E+05 9.05E+02 8.4 4.55E-01 2.57E-03 3600.1

101 1.60E+05 2.05E+05 24.643 3.14E-01 2.52E-01 3599.6

102 1.62E+05 6.65E+05 8.4 4.53E-01 1.86E+00 3719.9

103 1.62E+05 8.98E+02 8.4 4.53E-01 2.51E-03 3599.8

104 1.64E+05 2.01E+05 24.643 3.14E-01 2.48E-01 3600

105 1.65E+05 6.60E+05 8.4 4.51E-01 1.83E+00 3480

106 1.65E+05 8.90E+02 8.4 4.51E-01 2.46E-03 3600.3

107 1.68E+05 1.98E+05 24.643 3.13E-01 2.43E-01 3600.3

108 1.69E+05 6.55E+05 8.4 4.49E-01 1.79E+00 3600

109 1.69E+05 8.82E+02 8.4 4.49E-01 2.41E-03 3599.8

110 1.71E+05 1.95E+05 24.643 3.13E-01 2.40E-01 1559.9

111 1.72E+05 6.52E+05 8.4 4.49E-01 1.77E+00 359.91

112 1.73E+05 8.77E+02 8.4 4.48E-01 2.38E-03 120

113 1.73E+05 6.52E+05 8.4 4.48E-01 1.77E+00 119.89

114 1.73E+05 8.78E+02 8.4 4.48E-01 2.38E-03 119.89

115 1.73E+05 1.95E+05 24.643 3.13E-01 2.38E-01 119.89

Table A-2 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated 

and unmitigated TISGTR scenarios (continued)

 

 
A-20

Table A-3 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios

Surry LTSBO

Class Bin 1 Bin 2 Bin 3 Bin 4 Bin 5 Bin 6 Bin 7 Bin 8 Bin 9 Bin 10

Xe 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01

Cs 1.73E-03 1.26E-02 6.19E-02 2.00E-01 3.36E-01 2.52E-01 1.09E-01 2.37E-02 2.32E-03 1.05E-03

Ba 6.94E-03 3.56E-02 1.35E-01 3.69E-01 3.45E-01 8.98E-02 1.49E-02 2.50E-03 2.54E-04 3.58E-04

I 6.47E-03 3.22E-02 1.21E-01 3.28E-01 3.57E-01 1.32E-01 1.85E-02 1.95E-03 3.19E-04 1.44E-03

Te 7.53E-03 3.45E-02 1.31E-01 3.49E-01 3.40E-01 1.14E-01 1.86E-02 2.44E-03 2.44E-04 1.34E-03

Ru 8.80E-03 3.73E-02 1.35E-01 3.24E-01 3.13E-01 1.27E-01 2.71E-02 1.02E-02 3.38E-03 1.40E-02

Mo 2.39E-04 3.89E-03 2.78E-02 1.01E-01 2.67E-01 3.30E-01 1.98E-01 6.34E-02 8.46E-03 3.76E-04

Ce 7.52E-03 3.22E-02 1.15E-01 2.85E-01 3.34E-01 1.73E-01 3.59E-02 7.97E-03 1.65E-03 8.02E-03

La 4.89E-03 2.37E-02 9.23E-02 2.54E-01 3.44E-01 2.04E-01 6.15E-02 1.20E-02 1.34E-03 2.86E-03

Table A-3 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios (continued)

Surry STSBO

Class Bin 1 Bin 2 Bin 3 Bin 4 Bin 5 Bin 6 Bin 7 Bin 8 Bin 9 Bin 10

Xe 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01

Cs 1.22E-03 1.01E-02 5.26E-02 1.73E-01 3.33E-01 2.86E-01 1.21E-01 2.05E-02 1.15E-03 1.19E-03

Ba 7.02E-03 3.61E-02 1.42E-01 3.43E-01 3.18E-01 1.19E-01 2.65E-02 3.58E-03 2.58E-04 4.40E-03

I 6.19E-03 2.94E-02 1.06E-01 2.66E-01 3.44E-01 2.03E-01 3.96E-02 2.54E-03 1.97E-04 2.36E-03

Te 4.03E-03 2.31E-02 9.45E-02 2.70E-01 3.62E-01 1.94E-01 4.57E-02 4.65E-03 2.33E-04 1.50E-03

Ru 5.15E-03 2.69E-02 1.07E-01 2.75E-01 3.43E-01 1.80E-01 4.05E-02 6.86E-03 1.67E-03 1.36E-02

Mo 2.51E-04 4.22E-03 3.10E-02 1.14E-01 2.91E-01 3.42E-01 1.78E-01 3.66E-02 2.37E-03 9.36E-05

Ce 5.06E-03 2.57E-02 9.95E-02 2.57E-01 3.41E-01 2.04E-01 4.92E-02 6.85E-03 1.30E-03 9.52E-03

La 3.14E-03 1.80E-02 7.61E-02 2.18E-01 3.44E-01 2.45E-01 8.08E-02 1.18E-02 7.95E-04 2.68E-03
A-21

Table A-3 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios (continued)

Surry ISLOCA

Class Bin 1 Bin 2 Bin 3 Bin 4 Bin 5 Bin 6 Bin 7 Bin 8 Bin 9 Bin 10

Xe 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01

Cs 9.37E-03 2.56E-02 6.96E-02 2.73E-01 4.01E-01 1.78E-01 4.04E-02 2.62E-03 4.33E-05 5.48E-04

Ba 2.23E-02 4.72E-02 1.38E-01 2.92E-01 3.24E-01 1.41E-01 3.05E-02 2.46E-03 7.74E-05 2.58E-03

I 9.15E-03 2.41E-02 7.56E-02 2.81E-01 3.96E-01 1.72E-01 3.85E-02 2.53E-03 4.28E-05 6.21E-04

Te 1.28E-02 3.01E-02 8.65E-02 2.83E-01 3.82E-01 1.65E-01 3.72E-02 2.50E-03 4.58E-05 5.42E-04

Ru 1.13E-02 3.05E-02 9.69E-02 2.91E-01 3.75E-01 1.59E-01 3.34E-02 2.13E-03 3.54E-05 4.80E-04

Mo 1.02E-02 2.46E-02 6.13E-02 2.34E-01 3.80E-01 2.16E-01 6.41E-02 8.89E-03 7.41E-04 3.93E-04

Ce 7.90E-03 3.31E-02 2.20E-01 4.00E-01 1.92E-01 8.59E-02 4.09E-02 1.27E-02 1.26E-03 6.03E-03

La 2.07E-02 4.49E-02 2.46E-01 3.92E-01 1.74E-01 7.55E-02 3.43E-02 9.34E-03 8.08E-04 2.15E-03

.

Table A-3 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios (continued)

Surry Mitigated TISGTR

Class Bin 1 Bin 2 Bin 3 Bin 4 Bin 5 Bin 6 Bin 7 Bin 8 Bin 9 Bin 10

Xe 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01

Cs 2.39E-02 3.93E-02 6.33E-02 2.06E-01 3.47E-01 2.16E-01 7.68E-02 2.30E-02 4.35E-03 6.63E-04

Ba 1.29E-02 1.87E-02 5.47E-02 2.44E-01 4.15E-01 1.96E-01 4.50E-02 1.17E-02 2.38E-03 3.65E-04

I 3.45E-02 4.99E-02 6.35E-02 2.09E-01 3.47E-01 2.03E-01 6.82E-02 2.00E-02 3.72E-03 5.92E-04

Te 1.50E-02 2.65E-02 5.69E-02 2.17E-01 3.69E-01 2.16E-01 7.29E-02 2.20E-02 4.16E-03 6.11E-04

Ru 1.60E-03 5.33E-03 3.94E-02 2.20E-01 4.24E-01 2.24E-01 6.31E-02 1.87E-02 3.45E-03 4.43E-04

Mo 1.61E-02 5.22E-02 6.90E-02 2.98E-01 4.12E-01 1.16E-01 2.79E-02 6.85E-03 1.28E-03 1.92E-04

Ce 1.27E-03 8.45E-03 7.31E-02 2.80E-01 4.20E-01 1.79E-01 2.96E-02 7.03E-03 2.00E-03 2.70E-04

La 8.71E-03 2.82E-02 8.14E-02 2.99E-01 4.07E-01 1.45E-01 2.36E-02 5.32E-03 1.43E-03 1.89E-04
A-22

Table A-3 Plume parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios (continued)

Surry Unmitigated TISGTR

Class Bin 1 Bin 2 Bin 3 Bin 4 Bin 5 Bin 6 Bin 7 Bin 8 Bin 9 Bin 10

Xe 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01 1.00E-01

Cs 4.84E-03 1.55E-02 5.85E-02 1.91E-01 4.04E-01 2.69E-01 5.05E-02 5.54E-03 7.83E-04 1.17E-04

Ba 6.37E-03 2.58E-02 8.09E-02 2.35E-01 3.81E-01 2.25E-01 4.35E-02 2.94E-03 2.34E-04 4.00E-05

I 1.14E-02 2.75E-02 6.76E-02 2.02E-01 3.54E-01 2.49E-01 7.56E-02 1.12E-02 1.36E-03 2.20E-04

Te 8.56E-03 2.61E-02 7.12E-02 2.00E-01 3.56E-01 2.59E-01 7.19E-02 7.63E-03 6.94E-04 1.06E-04

Ru 1.80E-03 6.34E-03 4.20E-02 2.21E-01 4.19E-01 2.23E-01 6.39E-02 1.89E-02 3.48E-03 4.41E-04

Mo 3.95E-03 1.86E-02 6.60E-02 1.76E-01 3.29E-01 2.92E-01 1.04E-01 1.05E-02 3.31E-04 8.27E-05

Ce 4.18E-03 2.17E-02 9.15E-02 2.48E-01 3.59E-01 2.03E-01 5.65E-02 1.35E-02 2.38E-03 2.42E-04

La 2.27E-03 1.47E-02 6.50E-02 2.00E-01 3.99E-01 2.64E-01 5.12E-02 3.73E-03 2.51E-04 2.79E-05
A-23

Table A-4 Release fraction parameters used in the Surry LTSBO, STSBO, ISLOCA, 

and mitigated and unmitigated TISGTR scenarios

Surry LTSBO

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

1 3.36E-03 3.50E-06 5.31E-07 3.62E-05 5.09E-05 7.77E-08 2.69E-07 1.93E-07 1.21E-08

2 7.20E-03 7.08E-06 1.03E-06 7.43E-05 1.04E-04 1.52E-07 5.22E-07 3.77E-07 2.42E-08

3 1.27E-02 1.17E-05 1.64E-06 1.24E-04 1.75E-04 2.44E-07 8.35E-07 6.06E-07 3.96E-08

4 1.80E-02 1.55E-05 2.17E-06 1.66E-04 2.36E-04 3.18E-07 1.09E-06 7.92E-07 5.28E-08

5 2.24E-02 1.79E-05 2.51E-06 1.94E-04 2.79E-04 3.63E-07 1.23E-06 9.05E-07 6.15E-08

6 2.35E-02 1.76E-05 2.47E-06 1.91E-04 2.78E-04 3.50E-07 1.19E-06 8.74E-07 6.07E-08

7 2.55E-02 1.79E-05 2.52E-06 1.96E-04 2.87E-04 3.50E-07 1.18E-06 8.75E-07 6.20E-08

8 2.59E-02 1.71E-05 2.41E-06 1.88E-04 2.79E-04 3.27E-07 1.10E-06 8.20E-07 5.94E-08

9 2.58E-02 1.60E-05 2.27E-06 1.78E-04 2.66E-04 3.02E-07 1.01E-06 7.57E-07 5.62E-08

10 2.54E-02 1.49E-05 2.12E-06 1.67E-04 2.54E-04 2.76E-07 9.16E-07 6.93E-07 5.27E-08

11 2.50E-02 1.39E-05 1.98E-06 1.57E-04 2.42E-04 2.51E-07 8.29E-07 6.33E-07 4.94E-08

12 2.45E-02 1.29E-05 1.86E-06 1.48E-04 2.32E-04 2.29E-07 7.50E-07 5.79E-07 4.64E-08

13 2.42E-02 1.21E-05 1.75E-06 1.40E-04 2.25E-04 2.10E-07 6.81E-07 5.32E-07 4.38E-08

14 2.34E-02 1.12E-05 1.62E-06 1.30E-04 2.16E-04 1.90E-07 6.09E-07 4.82E-07 4.08E-08

15 2.27E-02 1.04E-05 1.52E-06 1.22E-04 2.09E-04 1.72E-07 5.45E-07 4.37E-07 3.81E-08

16 2.21E-02 9.69E-06 1.42E-06 1.15E-04 2.03E-04 1.56E-07 4.88E-07 3.98E-07 3.59E-08

17 2.16E-02 9.11E-06 1.35E-06 1.09E-04 2.00E-04 1.43E-07 4.40E-07 3.66E-07 3.40E-08

18 2.11E-02 8.57E-06 1.27E-06 1.04E-04 1.98E-04 1.31E-07 3.96E-07 3.36E-07 3.22E-08

19 2.06E-02 8.08E-06 1.21E-06 9.86E-05 1.98E-04 1.20E-07 3.55E-07 3.09E-07 3.07E-08

20 2.00E-02 7.60E-06 1.15E-06 9.37E-05 1.97E-04 1.09E-07 3.17E-07 2.83E-07 2.91E-08

21 1.94E-02 7.17E-06 1.09E-06 8.93E-05 1.97E-04 1.00E-07 2.83E-07 2.60E-07 2.76E-08

22 1.90E-02 6.81E-06 1.04E-06 8.56E-05 1.99E-04 9.19E-08 2.54E-07 2.40E-07 2.64E-08

23 1.87E-02 6.57E-06 9.94E-07 8.34E-05 2.04E-04 8.55E-08 2.31E-07 2.24E-07 2.56E-08

24 1.81E-02 6.23E-06 9.12E-07 7.96E-05 2.08E-04 7.79E-08 2.06E-07 2.05E-07 2.44E-08

25 1.75E-02 5.91E-06 8.37E-07 7.63E-05 2.17E-04 7.08E-08 1.83E-07 1.88E-07 2.32E-08

26 1.75E-02 5.82E-06 7.95E-07 7.57E-05 2.40E-04 6.64E-08 1.68E-07 1.77E-07 2.28E-08

27 1.10E-02 3.62E-06 4.78E-07 4.73E-05 1.67E-04 3.94E-08 9.86E-08 1.06E-07 1.41E-08

28 5.41E-04 1.78E-07 2.32E-08 2.33E-06 8.68E-06 1.90E-09 4.73E-09 5.10E-09 6.93E-10
A-24

Table A-4 Release fraction parameters used in the Surry LTSBO, STSBO, ISLOCA, 

and mitigated and unmitigated TISGTR scenarios (continued)

Surry Unmitigated STSBO

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

1 3.86E-03 6.41E-06 1.13E-06 5.54E-05 8.81E-05 1.60E-07 6.91E-07 2.84E-07 1.18E-08

2 8.94E-03 1.38E-05 2.41E-06 1.24E-04 1.85E-04 3.30E-07 1.41E-06 5.85E-07 2.51E-08

3 1.74E-02 2.53E-05 4.36E-06 2.35E-04 3.28E-04 5.74E-07 2.42E-06 1.02E-06 4.52E-08

4 2.26E-02 3.11E-05 5.28E-06 3.00E-04 3.88E-04 6.68E-07 2.79E-06 1.19E-06 5.43E-08

5 2.77E-02 3.66E-05 6.12E-06 3.64E-04 4.39E-04 7.39E-07 3.05E-06 1.32E-06 6.21E-08

6 2.96E-02 3.78E-05 6.20E-06 3.89E-04 4.33E-04 7.14E-07 2.91E-06 1.28E-06 6.21E-08

7 3.10E-02 3.83E-05 6.20E-06 4.05E-04 4.21E-04 6.79E-07 2.73E-06 1.21E-06 6.13E-08

8 2.98E-02 3.50E-05 5.70E-06 3.78E-04 3.77E-04 5.92E-07 2.35E-06 1.06E-06 5.56E-08

9 2.93E-02 3.30E-05 5.41E-06 3.64E-04 3.47E-04 5.31E-07 2.08E-06 9.54E-07 5.19E-08

10 2.86E-02 3.12E-05 5.14E-06 3.51E-04 3.20E-04 4.76E-07 1.83E-06 8.58E-07 4.85E-08

11 2.69E-02 2.85E-05 4.72E-06 3.27E-04 2.84E-04 4.12E-07 1.55E-06 7.44E-07 4.38E-08

12 2.70E-02 2.79E-05 4.64E-06 3.27E-04 2.71E-04 3.81E-07 1.40E-06 6.90E-07 4.23E-08

13 2.70E-02 2.74E-05 4.52E-06 3.27E-04 2.58E-04 3.52E-07 1.27E-06 6.38E-07 4.09E-08

14 2.44E-02 2.45E-05 4.01E-06 2.97E-04 2.23E-04 2.95E-07 1.04E-06 5.36E-07 3.59E-08

15 2.44E-02 2.43E-05 3.95E-06 2.99E-04 2.14E-04 2.74E-07 9.45E-07 5.00E-07 3.50E-08

16 2.44E-02 2.42E-05 3.90E-06 3.02E-04 2.06E-04 2.54E-07 8.57E-07 4.65E-07 3.41E-08

17 2.28E-02 2.26E-05 3.62E-06 2.86E-04 1.86E-04 2.21E-07 7.32E-07 4.07E-07 3.13E-08

18 2.13E-02 2.07E-05 3.29E-06 2.64E-04 1.69E-04 1.93E-07 6.25E-07 3.56E-07 2.87E-08

19 2.14E-02 1.99E-05 3.12E-06 2.55E-04 1.65E-04 1.82E-07 5.78E-07 3.37E-07 2.84E-08

20 2.08E-02 1.84E-05 2.81E-06 2.37E-04 1.56E-04 1.65E-07 5.15E-07 3.07E-07 2.72E-08

21 2.07E-02 1.74E-05 2.60E-06 2.25E-04 1.52E-04 1.53E-07 4.70E-07 2.87E-07 2.67E-08

22 1.87E-02 1.50E-05 2.24E-06 1.95E-04 1.33E-04 1.29E-07 3.90E-07 2.43E-07 2.38E-08

23 8.79E-03 6.81E-06 1.06E-06 8.87E-05 6.16E-05 5.77E-08 1.73E-07 1.09E-07 1.11E-08

24 6.22E-04 4.76E-07 7.62E-08 6.21E-06 4.33E-06 4.01E-09 1.20E-08 7.59E-09 7.84E-10
A-25

Surry ISLOCA

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

1 1.69E-01 4.06E-05 3.31E-07 2.78E-04 2.62E-04 2.94E-07 5.76E-06 3.45E-11 3.18E-11

2 1.69E-01 4.06E-05 3.31E-07 2.78E-04 2.62E-04 2.94E-07 5.76E-06 3.45E-11 3.18E-11

3 3.74E-02 1.90E-03 7.82E-06 1.38E-02 1.17E-02 1.88E-05 2.58E-04 2.12E-09 1.97E-09

4 6.30E-02 3.39E-03 1.38E-05 2.50E-02 2.12E-02 3.49E-05 4.59E-04 3.94E-09 3.67E-09

5 1.84E-03 9.89E-05 3.27E-07 6.88E-04 5.85E-04 7.40E-07 1.42E-05 8.74E-11 8.20E-11

6 1.67E-01 9.01E-03 3.57E-05 6.62E-02 5.65E-02 9.23E-05 1.22E-03 1.04E-08 9.74E-09

7 1.47E-02 8.96E-04 2.50E-06 6.76E-03 5.66E-03 1.07E-05 1.19E-04 1.15E-09 1.06E-09

8 9.90E-02 2.71E-05 1.22E-07 2.20E-04 2.02E-04 4.19E-07 3.30E-06 4.77E-11 4.49E-11

9 9.90E-02 2.71E-05 1.22E-07 2.20E-04 2.02E-04 4.19E-07 3.30E-06 4.77E-11 4.49E-11

10 3.66E-02 1.88E-03 9.81E-06 1.55E-02 1.40E-02 2.90E-05 2.23E-04 3.34E-09 3.23E-09

11 2.36E-02 8.73E-04 6.97E-06 8.57E-03 5.73E-03 2.66E-05 7.64E-05 4.00E-09 3.78E-09

12 6.07E-03 2.36E-04 1.58E-06 2.13E-03 1.59E-03 5.53E-06 2.43E-05 7.65E-10 7.22E-10

13 8.81E-03 3.27E-04 2.62E-06 3.21E-03 2.14E-03 1.01E-05 2.86E-05 1.51E-09 1.42E-09

14 1.27E-02 3.65E-04 3.51E-06 3.78E-03 2.43E-03 1.45E-05 2.81E-05 2.15E-09 2.03E-09

15 2.21E-02 3.33E-06 3.81E-08 3.55E-05 2.30E-05 1.35E-07 2.38E-07 2.11E-11 1.99E-11

16 2.21E-02 3.33E-06 3.81E-08 3.55E-05 2.30E-05 1.35E-07 2.38E-07 2.11E-11 1.99E-11

17 3.61E-03 1.05E-04 2.45E-06 1.19E-03 6.08E-04 1.11E-06 5.30E-06 3.37E-10 3.19E-10

18 1.09E-03 3.24E-05 5.70E-07 3.58E-04 2.14E-04 7.16E-07 1.91E-06 1.57E-10 1.51E-10

19 1.59E-03 4.62E-05 1.01E-06 5.22E-04 2.64E-04 4.84E-07 2.31E-06 1.47E-10 1.39E-10

20 8.99E-04 2.72E-05 1.12E-06 2.49E-04 1.63E-04 2.26E-07 2.06E-06 3.31E-11 3.18E-11

21 4.73E-03 4.89E-07 1.06E-08 5.62E-06 2.16E-06 2.40E-09 2.06E-08 4.53E-13 4.29E-13

22 4.73E-03 4.89E-07 1.06E-08 5.62E-06 2.16E-06 2.40E-09 2.06E-08 4.53E-13 4.29E-13

23 4.37E-04 3.08E-05 6.50E-07 3.07E-04 1.69E-04 2.27E-07 2.26E-06 8.01E-11 7.47E-11

24 2.90E-04 1.65E-05 3.66E-07 1.67E-04 8.59E-05 1.20E-07 1.16E-06 3.72E-11 3.47E-11

25 2.85E-04 2.04E-05 4.43E-07 2.02E-04 1.12E-04 1.54E-07 1.52E-06 5.24E-11 4.88E-11

26 3.46E-03 1.77E-06 3.53E-08 1.71E-05 1.09E-05 2.35E-08 1.44E-07 8.27E-12 7.63E-12

27 3.46E-03 1.77E-06 3.53E-08 1.71E-05 1.09E-05 2.35E-08 1.44E-07 8.27E-12 7.63E-12

28 2.90E-03 5.23E-07 1.14E-08 5.29E-06 4.57E-06 2.77E-08 4.48E-08 6.73E-12 6.33E-12

29 2.90E-03 5.23E-07 1.14E-08 5.29E-06 4.57E-06 2.77E-08 4.48E-08 6.73E-12 6.33E-12

30 8.94E-07 7.45E-08 9.77E-09 8.72E-07 7.60E-07 7.71E-10 2.91E-09 3.71E-08 1.60E-09

31 2.09E-06 7.89E-08 4.17E-09 8.23E-07 7.30E-07 3.00E-09 5.91E-09 1.06E-08 4.58E-10

32 4.25E-07 3.00E-08 3.70E-09 3.56E-07 3.13E-07 3.82E-10 1.34E-09 1.38E-08 5.95E-10

33 3.73E-08 1.25E-08 2.61E-08 3.42E-08 3.02E-08 2.92E-10 1.20E-09 1.49E-08 6.30E-10

34 8.35E-06 3.37E-07 2.33E-08 4.01E-06 4.02E-06 4.75E-09 1.44E-08 6.59E-08 2.92E-09

35 5.24E-06 9.34E-07 4.54E-08 1.26E-05 1.02E-05 2.62E-09 1.10E-08 1.21E-07 7.04E-09

36 7.76E-08 2.01E-08 4.12E-08 5.86E-08 5.57E-08 4.56E-10 1.92E-09 2.31E-08 1.02E-09

37 8.87E-08 1.69E-08 3.45E-08 5.16E-08 5.16E-08 3.75E-10 1.59E-09 1.90E-08 8.71E-10

38 3.99E-06 1.23E-06 4.35E-08 1.70E-05 1.02E-05 5.72E-10 4.81E-09 1.22E-07 7.92E-09

39 9.39E-07 5.34E-07 9.40E-09 7.47E-06 2.62E-06 8.00E-11 1.16E-09 2.53E-08 1.84E-09

40 3.58E-07 2.00E-07 3.63E-09 2.80E-06 9.87E-07 4.37E-11 3.49E-10 9.88E-09 7.14E-10

41 3.80E-07 2.20E-07 3.55E-09 3.10E-06 8.90E-07 4.37E-11 3.49E-10 1.04E-08 7.33E-10

42 9.27E-08 1.24E-08 2.47E-08 4.36E-08 4.04E-08 2.64E-10 1.13E-09 1.35E-08 6.41E-10

43 2.47E-06 1.26E-06 2.33E-08 1.76E-05 5.90E-06 2.28E-10 2.41E-09 6.36E-08 4.57E-09

44 1.39E-06 8.23E-07 1.15E-08 1.16E-05 2.19E-06 1.31E-10 9.31E-10 3.72E-08 2.54E-09

45 4.47E-07 2.60E-07 3.59E-09 3.65E-06 6.80E-07 4.00E-11 3.49E-10 1.15E-08 7.93E-10

46 3.47E-06 4.51E-06 2.63E-08 6.35E-05 6.90E-06 1.99E-10 3.79E-09 5.78E-08 5.02E-09

47 1.86E-06 7.33E-06 1.40E-08 1.03E-04 4.64E-06 7.55E-11 2.40E-09 2.60E-08 2.93E-09

48 1.46E-06 1.06E-05 8.87E-09 1.49E-04 4.47E-06 6.55E-11 1.51E-09 1.70E-08 2.13E-09

Table A-4 Release fraction parameters used in the Surry LTSBO, STSBO, ISLOCA, 

and mitigated and unmitigated TISGTR scenarios (continued)
A-26

Surry ISLOCA

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

49 8.05E-07 5.46E-06 5.14E-09 7.72E-05 2.39E-06 2.18E-11 8.73E-10 9.83E-09 1.22E-09

50 1.58E-06 9.65E-06 9.89E-09 1.36E-04 4.27E-06 5.26E-11 1.68E-09 1.81E-08 2.18E-09

51 4.49E-06 1.58E-05 3.21E-08 2.23E-04 7.14E-06 1.38E-10 2.68E-09 4.08E-08 3.39E-09

52 1.42E-06 5.42E-06 9.50E-09 7.66E-05 2.40E-06 4.73E-11 8.15E-10 1.25E-08 1.07E-09

53 3.41E-06 2.10E-05 1.54E-08 2.97E-04 8.60E-06 8.75E-11 2.32E-09 2.37E-08 2.73E-09

54 1.62E-06 2.08E-05 7.31E-09 2.94E-04 1.02E-05 2.64E-11 1.48E-09 9.50E-09 1.65E-09

55 1.74E-06 1.73E-05 9.86E-09 2.44E-04 2.12E-05 2.91E-11 1.51E-09 8.71E-09 1.76E-09

56 1.48E-06 1.69E-05 7.56E-09 2.38E-04 1.55E-05 1.84E-11 1.28E-09 7.19E-09 1.43E-09

57 1.91E-06 1.46E-05 1.53E-08 2.06E-04 3.25E-05 2.18E-11 1.86E-09 8.41E-09 1.82E-09

58 2.08E-06 1.43E-05 1.61E-08 2.03E-04 3.50E-05 2.17E-11 1.83E-09 8.76E-09 1.90E-09

59 3.90E-06 1.14E-05 4.19E-08 1.62E-04 1.05E-04 3.64E-11 3.96E-09 1.48E-08 3.48E-09

60 2.34E-06 6.81E-06 2.39E-08 9.61E-05 5.96E-05 2.07E-11 2.26E-09 8.55E-09 2.01E-09

61 3.84E-06 2.35E-06 6.81E-08 3.29E-05 1.65E-04 2.18E-11 4.89E-09 1.24E-08 3.20E-09

62 2.23E-06 1.70E-06 3.51E-08 2.38E-05 8.65E-05 1.64E-11 2.60E-09 7.05E-09 1.79E-09

63 5.29E-06 7.39E-07 1.45E-07 9.87E-06 3.54E-04 5.09E-11 8.85E-09 1.48E-08 4.12E-09

64 1.60E-06 2.27E-07 4.38E-08 3.02E-06 1.07E-04 1.09E-11 2.79E-09 4.46E-09 1.25E-09

65 1.73E-06 3.55E-07 4.23E-08 4.84E-06 1.02E-04 1.08E-11 2.64E-09 4.78E-09 1.31E-09

66 7.61E-06 8.07E-07 1.97E-07 1.01E-05 7.22E-04 3.64E-11 1.86E-08 1.84E-08 5.55E-09

67 2.27E-06 2.41E-07 5.90E-08 3.02E-06 2.15E-04 7.28E-12 5.47E-09 5.49E-09 1.66E-09

68 2.29E-06 2.46E-07 7.59E-08 3.04E-06 2.40E-04 1.46E-11 6.26E-09 5.34E-09 1.65E-09

69 6.29E-06 6.79E-07 2.28E-06 7.93E-06 7.39E-04 2.18E-11 2.33E-08 1.31E-08 4.25E-09

70 1.91E-06 2.07E-07 6.78E-07 2.41E-06 2.25E-04 1.09E-11 7.16E-09 3.99E-09 1.30E-09

71 3.40E-06 3.77E-07 2.55E-06 4.26E-06 2.86E-04 1.09E-11 1.48E-08 6.70E-09 2.24E-09

72 1.06E-05 1.09E-06 8.55E-06 1.24E-05 4.93E-04 3.64E-11 4.28E-08 1.86E-08 6.51E-09

73 2.33E-06 2.44E-07 1.90E-06 2.73E-06 1.41E-04 9.09E-12 9.78E-09 4.22E-09 1.45E-09

74 3.29E-06 3.39E-07 2.66E-06 3.83E-06 1.54E-04 1.46E-11 1.32E-08 5.77E-09 2.02E-09

75 5.54E-06 4.65E-07 2.61E-06 5.58E-06 1.88E-04 1.82E-11 1.42E-08 8.30E-09 2.98E-09

76 5.90E-07 5.81E-08 4.53E-07 6.57E-07 2.80E-05 1.99E-12 2.28E-09 9.98E-10 3.48E-10

77 8.43E-06 5.09E-07 6.02E-07 6.76E-06 1.37E-04 1.46E-11 7.33E-09 1.00E-08 3.68E-09

78 2.00E-06 1.33E-07 3.32E-07 1.71E-06 4.54E-05 3.64E-12 2.71E-09 2.55E-09 9.28E-10

79 9.52E-06 6.24E-07 6.17E-07 8.24E-06 1.26E-04 1.82E-11 9.72E-09 1.08E-08 4.09E-09

80 1.12E-05 8.62E-07 6.30E-07 1.13E-05 1.43E-04 2.18E-11 1.41E-08 1.19E-08 4.68E-09

81 2.97E-06 2.06E-07 1.84E-07 2.72E-06 3.90E-05 9.09E-12 3.32E-09 3.18E-09 1.23E-09

82 3.60E-06 2.74E-07 2.02E-07 3.62E-06 4.59E-05 3.64E-12 4.42E-09 3.81E-09 1.50E-09

83 9.49E-06 1.10E-06 5.06E-07 1.47E-05 1.19E-04 1.82E-11 1.48E-08 9.45E-09 3.88E-09

84 1.08E-05 2.89E-06 6.09E-07 3.97E-05 1.39E-04 1.46E-11 2.06E-08 1.00E-08 4.28E-09

85 3.49E-06 9.30E-07 1.97E-07 1.28E-05 4.50E-05 0.00E+00 6.64E-09 3.24E-09 1.39E-09

86 9.67E-06 6.08E-06 5.08E-07 8.46E-05 1.38E-04 1.09E-11 2.20E-08 7.74E-09 3.43E-09

87 1.38E-05 1.78E-05 5.18E-07 2.49E-04 1.97E-04 7.28E-12 3.85E-08 9.01E-09 4.16E-09

88 4.51E-06 5.79E-06 1.69E-07 8.11E-05 6.44E-05 1.09E-11 1.26E-08 2.95E-09 1.36E-09

89 1.12E-05 1.43E-05 3.66E-07 2.00E-04 1.69E-04 7.28E-12 3.56E-08 6.76E-09 3.20E-09

90 8.43E-06 1.74E-06 2.92E-07 2.29E-05 1.43E-04 1.46E-11 2.86E-08 4.49E-09 2.22E-09

91 1.27E-05 2.41E-06 4.58E-07 3.15E-05 2.09E-04 1.09E-11 4.58E-08 6.39E-09 3.23E-09

92 1.14E-05 2.90E-06 3.97E-07 3.83E-05 1.90E-04 0.00E+00 4.71E-08 5.45E-09 2.84E-09

93 1.23E-05 4.49E-06 4.21E-07 6.02E-05 2.17E-04 7.28E-12 6.01E-08 5.66E-09 3.05E-09

94 1.09E-05 5.55E-06 4.05E-07 7.52E-05 1.76E-04 1.46E-11 6.30E-08 4.81E-09 2.68E-09

95 1.16E-05 7.72E-06 4.75E-07 1.05E-04 1.43E-04 3.64E-12 8.27E-08 4.96E-09 2.85E-09

Table A-4 Release fraction parameters used in the Surry LTSBO, STSBO, ISLOCA, 

and mitigated and unmitigated TISGTR scenarios (continued)
A-27

Surry ISLOCA

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

96 1.04E-05 7.01E-06 4.54E-07 9.55E-05 6.92E-05 7.28E-12 9.58E-08 4.26E-09 2.52E-09

97 1.12E-05 5.40E-06 5.25E-07 7.21E-05 2.49E-05 0.00E+00 1.45E-07 4.48E-09 2.72E-09

98 1.21E-05 4.81E-06 5.16E-07 6.34E-05 1.31E-05 3.64E-11 9.60E-05 4.34E-09 2.74E-09

99 3.57E-06 1.41E-06 1.57E-07 1.87E-05 4.95E-06 7.28E-12 1.72E-05 1.30E-09 8.06E-10

100 4.02E-06 1.59E-06 1.72E-07 2.10E-05 4.36E-06 3.64E-12 3.17E-05 1.44E-09 9.10E-10

101 9.43E-06 4.23E-06 3.34E-07 5.63E-05 1.08E-05 4.37E-11 1.02E-04 3.11E-09 2.03E-09

102 1.29E-06 4.87E-07 5.19E-08 6.43E-06 1.39E-06 2.10E-12 7.90E-06 4.29E-10 2.70E-10

103 6.71E-06 3.05E-06 1.26E-07 4.09E-05 8.04E-06 5.09E-11 7.34E-06 1.95E-09 1.37E-09

104 1.90E-06 8.34E-07 3.97E-08 1.12E-05 2.07E-06 7.28E-12 9.25E-06 5.33E-10 3.65E-10

105 7.76E-06 2.48E-06 1.35E-07 3.25E-05 9.91E-06 7.28E-11 6.71E-06 2.16E-09 1.55E-09

106 8.48E-06 1.70E-06 1.43E-07 2.11E-05 1.16E-05 5.82E-11 5.76E-06 2.26E-09 1.67E-09

107 7.34E-06 1.64E-06 1.28E-07 2.05E-05 1.09E-05 5.82E-11 4.12E-06 1.95E-09 1.47E-09

Table A-4 Release fraction parameters used in the Surry LTSBO, STSBO, ISLOCA, 

and mitigated and unmitigated TISGTR scenarios (continued)
A-28

Surry Mitigated TISGTR

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

1 2.59E-06 1.08E-06 9.51E-09 9.49E-07 9.10E-07 4.72E-09 2.76E-07 9.80E-14 9.80E-14

2 0.055065 0.00187 1.69E-05 0.00218 0.00138 7.61E-06 4.68E-04 1.91E-10 1.90E-10

3 1.89E-05 4.81E-06 2.49E-08 4.65E-06 4.80E-06 1.09E-07 1.28E-06 1.85E-12 1.85E-12

4 0.002275 2.77E-04 2.55E-06 2.81E-04 2.88E-04 9.07E-06 7.27E-05 2.37E-10 2.37E-10

5 2.62E-05 7.31E-06 5.41E-08 7.33E-06 7.52E-06 1.97E-07 1.93E-06 4.79E-12 4.79E-12

6 0.013924 7.47E-04 2.18E-05 0.00103 0.00105 6.80E-05 1.96E-04 1.81E-09 1.81E-09

7 3.05E-05 6.87E-06 8.66E-08 7.48E-06 7.63E-06 2.82E-07 1.81E-06 7.39E-12 7.44E-12

8 0.011313 8.78E-04 4.59E-05 0.00132 0.00149 1.29E-04 2.25E-04 6.95E-08 4.28E-09

9 3.40E-05 5.25E-06 8.35E-07 6.06E-06 6.27E-06 3.27E-07 1.38E-06 1.53E-07 2.77E-09

10 0.001501 1.26E-04 5.64E-05 8.95E-05 9.78E-05 1.47E-05 3.38E-05 9.75E-06 2.06E-07

11 3.17E-05 8.52E-07 4.11E-07 9.50E-07 9.84E-07 5.43E-08 2.24E-07 8.03E-08 1.64E-09

12 4.35E-04 5.64E-06 5.95E-07 5.57E-05 2.36E-06 3.33E-08 4.74E-07 6.44E-08 4.02E-09

13 2.18E-04 3.60E-06 3.96E-08 4.98E-05 8.47E-07 1.02E-09 1.96E-08 2.16E-09 7.28E-10

14 1.29E-04 1.75E-06 6.61E-09 2.47E-05 3.21E-07 1.31E-10 2.21E-09 3.47E-10 1.66E-10

15 1.83E-06 1.58E-08 4.37E-11 2.23E-07 2.79E-09 0 0 3.64E-12 1.39E-12

16 1.85E-06 1.30E-08 1.75E-10 1.81E-07 7.45E-09 0 9.71E-08 4.55E-12 4.41E-12

17 6.48E-06 1.12E-07 6.32E-09 1.58E-06 2.22E-07 0 4.21E-06 1.47E-10 1.46E-10

18 8.20E-07 1.03E-07 1.36E-08 1.46E-06 2.74E-07 0 8.92E-06 2.76E-10 2.81E-10

19 5.22E-08 1.03E-07 1.59E-08 1.46E-06 1.98E-07 0 1.01E-05 3.06E-10 3.09E-10

20 7.45E-09 9.31E-08 1.59E-08 1.32E-06 1.29E-07 0 9.80E-06 2.97E-10 3.00E-10

21 0 8.66E-08 1.58E-08 1.23E-06 8.66E-08 0 9.43E-06 2.88E-10 2.92E-10

22 0 7.92E-08 1.55E-08 1.12E-06 6.01E-08 0 9.02E-06 2.79E-10 2.83E-10

23 0 7.08E-08 1.53E-08 1.00E-06 4.05E-08 0 8.70E-06 2.73E-10 2.76E-10

24 0 6.29E-08 1.49E-08 8.83E-07 2.93E-08 0 8.27E-06 2.62E-10 2.66E-10

25 0 5.40E-08 1.43E-08 7.66E-07 2.10E-08 0 7.75E-06 2.48E-10 2.51E-10

26 0 4.80E-08 1.37E-08 6.77E-07 1.54E-08 0 7.30E-06 2.35E-10 2.38E-10

27 0 4.38E-08 1.32E-08 6.17E-07 1.21E-08 0 6.94E-06 2.22E-10 2.25E-10

28 0 3.91E-08 1.31E-08 5.54E-07 8.85E-09 0 6.78E-06 2.16E-10 2.19E-10

29 0 3.73E-08 1.28E-08 5.23E-07 8.38E-09 0 6.56E-06 2.08E-10 2.10E-10

30 0 3.40E-08 1.26E-08 4.84E-07 7.45E-09 0 6.38E-06 1.98E-10 2.02E-10

31 0 3.03E-08 1.25E-08 4.27E-07 6.52E-09 0 6.25E-06 1.95E-10 1.96E-10

32 0 2.56E-08 1.19E-08 3.66E-07 4.66E-09 0 5.92E-06 1.81E-10 1.84E-10

33 0 2.33E-08 1.13E-08 3.24E-07 3.26E-09 0 5.54E-06 1.67E-10 1.69E-10

34 7.45E-09 2.00E-08 1.13E-08 2.83E-07 3.26E-09 0 5.52E-06 1.63E-10 1.66E-10

35 3.73E-08 1.72E-08 1.13E-08 2.46E-07 1.86E-09 0 5.48E-06 1.60E-10 1.62E-10

36 1.42E-07 1.49E-08 1.13E-08 2.14E-07 1.40E-09 0 5.41E-06 1.56E-10 1.58E-10

37 1.71E-07 1.35E-08 1.13E-08 1.88E-07 1.86E-09 0 5.35E-06 1.52E-10 1.54E-10

38 8.20E-08 1.16E-08 1.12E-08 1.64E-07 9.31E-10 0 5.25E-06 1.47E-10 1.50E-10

39 3.73E-08 1.02E-08 1.14E-08 1.44E-07 9.31E-10 0 5.28E-06 1.47E-10 1.49E-10

40 7.45E-09 8.85E-09 1.05E-08 1.24E-07 9.31E-10 0 4.82E-06 1.33E-10 1.34E-10

41 7.45E-09 7.45E-09 1.07E-08 1.09E-07 9.31E-10 0 4.89E-06 1.32E-10 1.34E-10

42 0 6.98E-09 1.17E-08 9.59E-08 4.66E-10 0 5.26E-06 1.41E-10 1.43E-10

43 0 6.05E-09 1.19E-08 8.52E-08 9.31E-10 0 5.31E-06 1.42E-10 1.43E-10

44 0 5.12E-09 1.20E-08 7.45E-08 0 0 5.30E-06 1.38E-10 1.41E-10

45 0 4.66E-09 1.17E-08 6.47E-08 9.31E-10 0 5.13E-06 1.33E-10 1.35E-10

46 0 4.19E-09 1.11E-08 5.68E-08 4.66E-10 0 4.84E-06 1.25E-10 1.26E-10

47 0 3.26E-09 1.10E-08 4.94E-08 0 0 4.74E-06 1.21E-10 1.22E-10

Table A-4 Release fraction parameters used in the Surry LTSBO, STSBO, ISLOCA, 

and mitigated and unmitigated TISGTR scenarios (continued)
A-29

Surry Mitigated TISGTR

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

48 0 2.79E-09 1.04E-08 4.28E-08 0 0 4.43E-06 1.11E-10 1.13E-10

49 0 1.40E-09 4.38E-09 1.68E-08 0 0 1.85E-06 4.64E-11 4.69E-11

Table A-4 Release fraction parameters used in the Surry LTSBO, STSBO, ISLOCA, 

and mitigated and unmitigated TISGTR scenarios (continued)
A-30

Surry Unmitigated TISGTR

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

1 2.59E-06 1.08E-06 9.51E-09 9.49E-07 9.10E-07 4.72E-09 2.76E-07 9.80E-14 9.80E-14

2 0.055065 0.00187 1.69E-05 0.002182 0.001379 7.61E-06 4.68E-04 1.91E-10 1.90E-10

3 1.89E-05 4.81E-06 2.49E-08 4.65E-06 4.80E-06 1.09E-07 1.28E-06 1.85E-12 1.85E-12

4 0.0022745 2.77E-04 2.55E-06 2.81E-04 2.88E-04 9.07E-06 7.27E-05 2.37E-10 2.37E-10

5 2.62E-05 7.31E-06 5.41E-08 7.33E-06 7.52E-06 1.97E-07 1.93E-06 4.79E-12 4.79E-12

6 0.013924 7.47E-04 2.18E-05 0.001034 0.001054 6.80E-05 1.96E-04 1.81E-09 1.81E-09

7 3.05E-05 6.87E-06 8.66E-08 7.48E-06 7.63E-06 2.82E-07 1.81E-06 7.39E-12 7.44E-12

8 0.011313 8.78E-04 4.59E-05 0.001322 0.001489 1.29E-04 2.25E-04 6.95E-08 4.28E-09

9 3.40E-05 5.25E-06 8.35E-07 6.06E-06 6.27E-06 3.27E-07 1.38E-06 1.53E-07 2.77E-09

10 0.0024109 1.36E-04 6.16E-05 1.07E-04 1.10E-04 1.53E-05 3.62E-05 1.07E-05 2.30E-07

11 3.79E-05 3.39E-06 1.63E-06 3.74E-06 3.87E-06 2.17E-07 8.92E-07 3.21E-07 6.45E-09

12 0.0032437 2.29E-05 1.02E-05 5.99E-05 3.03E-05 1.24E-06 5.31E-06 1.93E-06 5.04E-08

13 3.79E-05 1.72E-06 8.32E-07 2.00E-06 2.00E-06 1.10E-07 4.51E-07 1.63E-07 3.38E-09

14 0.0034168 1.21E-05 4.71E-06 4.71E-05 2.04E-05 6.96E-07 2.52E-06 1.04E-06 2.50E-08

15 3.83E-05 8.91E-07 4.25E-07 1.18E-06 1.08E-06 5.69E-08 2.30E-07 8.46E-08 1.78E-09

16 0.0035156 9.70E-06 2.59E-06 6.63E-05 1.50E-05 4.16E-07 1.44E-06 6.22E-07 1.56E-08

17 3.87E-05 5.65E-07 2.56E-07 1.13E-06 7.06E-07 3.48E-08 1.39E-07 5.17E-08 1.11E-09

18 0.0035655 1.17E-05 1.73E-06 1.18E-04 1.35E-05 2.82E-07 9.46E-07 4.21E-07 1.11E-08

19 3.91E-05 4.54E-07 1.74E-07 1.76E-06 5.49E-07 2.41E-08 9.42E-08 3.58E-08 7.89E-10

20 0.0036008 1.74E-05 1.40E-06 2.12E-04 1.55E-05 2.06E-07 8.74E-05 3.08E-07 8.68E-09

21 3.94E-05 4.56E-07 1.30E-07 3.02E-06 5.05E-07 1.80E-08 1.33E-06 2.68E-08 6.09E-10

22 0.0036017 6.49E-06 1.52E-06 6.58E-05 1.81E-05 1.63E-07 0 2.46E-07 7.91E-09

23 3.97E-05 3.95E-07 1.06E-07 2.90E-06 5.28E-07 1.44E-08 0 2.15E-08 5.11E-10

24 0.003629 5.13E-06 1.29E-06 5.19E-05 1.97E-05 1.32E-07 0 1.98E-07 6.77E-09

25 3.99E-05 3.18E-07 8.60E-08 2.42E-06 5.49E-07 1.13E-08 0 1.69E-08 4.22E-10

26 0.0036535 4.56E-06 1.05E-06 4.91E-05 2.30E-05 9.99E-08 0 1.51E-07 5.56E-09

27 4.02E-05 2.38E-07 6.51E-08 1.89E-06 5.63E-07 8.25E-09 0 1.23E-08 3.25E-10

28 0.0036759 3.98E-06 8.17E-07 4.55E-05 2.68E-05 7.08E-08 0 1.08E-07 4.40E-09

29 4.04E-05 1.72E-07 4.75E-08 1.42E-06 5.90E-07 5.75E-09 0 8.62E-09 2.42E-10

30 0.0036984 3.46E-06 6.34E-07 4.15E-05 2.88E-05 5.00E-08 0 7.63E-08 3.54E-09

31 4.06E-05 1.27E-07 3.54E-08 1.10E-06 6.34E-07 4.06E-09 0 6.09E-09 1.84E-10

32 0.0037173 2.96E-06 5.20E-07 3.66E-05 2.78E-05 3.61E-08 0 5.56E-08 2.94E-09

33 4.08E-05 9.77E-08 2.77E-08 8.82E-07 6.72E-07 2.96E-09 0 4.45E-09 1.47E-10

34 0.0037368 2.10E-06 4.41E-07 2.59E-05 2.41E-05 2.71E-08 0 4.20E-08 2.52E-09

35 4.09E-05 7.75E-08 2.26E-08 7.27E-07 6.80E-07 2.23E-09 0 3.36E-09 1.22E-10

36 0.0037562 1.30E-06 4.02E-07 1.55E-05 2.15E-05 2.09E-08 0 3.27E-08 2.22E-09

37 4.10E-05 6.28E-08 1.93E-08 6.11E-07 6.74E-07 1.72E-09 0 2.61E-09 1.05E-10

38 0.0037724 9.50E-07 3.74E-07 1.13E-05 1.90E-05 1.64E-08 0 2.59E-08 1.97E-09

39 4.11E-05 5.15E-08 1.70E-08 5.16E-07 6.56E-07 1.35E-09 0 2.06E-09 9.24E-11

40 0.003791 7.33E-07 3.50E-07 8.66E-06 1.66E-05 1.32E-08 0 2.09E-08 1.78E-09

41 4.12E-05 4.26E-08 1.54E-08 4.37E-07 6.29E-07 1.08E-09 0 1.65E-09 8.26E-11

42 0.0038074 7.72E-07 3.26E-07 9.60E-06 1.44E-05 1.06E-08 0 1.71E-08 1.63E-09

43 4.13E-05 3.62E-08 1.42E-08 3.82E-07 5.92E-07 8.73E-10 0 1.35E-09 7.50E-11

44 0.0038235 8.27E-07 3.04E-07 1.07E-05 1.27E-05 8.67E-09 0 1.41E-08 1.50E-09

45 4.14E-05 3.19E-08 1.32E-08 3.48E-07 5.51E-07 7.13E-10 0 1.11E-09 6.89E-11

46 0.0038394 8.64E-07 2.85E-07 1.14E-05 1.13E-05 7.17E-09 0 1.18E-08 1.38E-09

47 4.14E-05 2.89E-08 1.24E-08 3.26E-07 5.09E-07 5.88E-10 0 9.20E-10 6.38E-11

48 0.0038542 9.01E-07 2.60E-07 1.21E-05 9.93E-06 5.97E-09 0 9.97E-09 1.29E-09

Table A-4 Release fraction parameters used in the Surry LTSBO, STSBO, ISLOCA, 

and mitigated and unmitigated TISGTR scenarios (continued)
A-31

Surry Unmitigated TISGTR

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

49 4.14E-05 2.68E-08 1.17E-08 3.13E-07 4.67E-07 4.90E-10 0 7.72E-10 5.97E-11

50 0.0038672 9.73E-07 2.41E-07 1.32E-05 8.72E-06 5.04E-09 0 8.50E-09 1.21E-09

51 0.0027853 1.70E-06 7.38E-07 2.05E-05 2.83E-05 2.71E-08 0 4.32E-08 3.75E-09

52 4.14E-05 2.54E-08 1.10E-08 3.05E-07 4.25E-07 4.10E-10 0 6.53E-10 5.61E-11

53 0.0038613 1.06E-06 2.32E-07 1.45E-05 7.72E-06 4.21E-09 0 7.25E-09 1.13E-09

54 0.0079969 4.70E-06 2.04E-06 5.80E-05 7.49E-05 6.69E-08 0 1.08E-07 1.03E-08

55 4.11E-05 2.42E-08 1.05E-08 2.98E-07 3.85E-07 3.44E-10 0 5.54E-10 5.27E-11

56 0.0038298 1.21E-06 2.37E-07 1.68E-05 6.85E-06 3.54E-09 0 6.20E-09 1.06E-09

57 0.014864 8.52E-06 3.71E-06 1.07E-04 1.27E-04 1.06E-07 0 1.73E-07 1.82E-08

58 4.04E-05 2.32E-08 1.01E-08 2.92E-07 3.46E-07 2.89E-10 0 4.70E-10 4.95E-11

59 0.0037684 1.42E-06 2.26E-07 1.98E-05 6.07E-06 2.97E-09 0 5.29E-09 1.00E-09

60 0.019254 1.09E-05 4.74E-06 1.40E-04 1.51E-04 1.18E-07 0 1.95E-07 2.27E-08

61 3.95E-05 2.23E-08 9.71E-09 2.86E-07 3.09E-07 2.42E-10 0 3.99E-10 4.66E-11

62 0.0036753 1.40E-06 2.17E-07 1.95E-05 5.40E-06 2.47E-09 0 4.56E-09 9.52E-10

63 0.021255 1.19E-05 5.18E-06 1.56E-04 1.53E-04 1.13E-07 0 1.89E-07 2.44E-08

64 3.80E-05 2.13E-08 9.25E-09 2.78E-07 2.73E-07 2.01E-10 0 3.36E-10 4.34E-11

65 0.0035692 1.41E-06 2.08E-07 1.97E-05 4.86E-06 2.10E-09 0 3.94E-09 9.06E-10

66 0.024223 1.35E-05 5.88E-06 1.79E-04 1.61E-04 1.12E-07 0 1.90E-07 2.71E-08

67 3.75E-05 2.09E-08 9.11E-09 2.77E-07 2.49E-07 1.73E-10 0 2.93E-10 4.20E-11

68 0.0034562 1.38E-06 1.99E-07 1.94E-05 4.46E-06 1.76E-09 0 3.43E-09 8.66E-10

69 0.023745 1.32E-05 5.76E-06 1.77E-04 1.48E-04 9.61E-08 0 1.66E-07 2.62E-08

70 3.58E-05 2.00E-08 8.69E-09 2.68E-07 2.22E-07 1.45E-10 0 2.49E-10 3.96E-11

71 0.0033394 1.34E-06 1.92E-07 1.88E-05 4.10E-06 1.54E-09 0 3.02E-09 8.35E-10

72 0.023485 1.32E-05 5.72E-06 1.78E-04 1.38E-04 8.37E-08 0 1.47E-07 2.58E-08

73 3.45E-05 1.94E-08 8.41E-09 2.62E-07 2.02E-07 1.23E-10 0 2.16E-10 3.79E-11

74 0.0032239 1.32E-06 1.86E-07 1.86E-05 3.80E-06 1.27E-09 0 2.67E-09 8.07E-10

75 0.0222 1.26E-05 5.45E-06 1.71E-04 1.24E-04 7.02E-08 0 1.26E-07 2.43E-08

76 3.33E-05 1.88E-08 8.16E-09 2.57E-07 1.85E-07 1.04E-10 0 1.88E-10 3.64E-11

77 0.0031118 1.25E-06 1.80E-07 1.76E-05 3.54E-06 1.09E-09 0 2.37E-09 7.81E-10

78 0.022319 1.26E-05 5.53E-06 1.73E-04 1.19E-04 6.29E-08 0 1.16E-07 2.46E-08

79 3.20E-05 1.80E-08 7.94E-09 2.48E-07 1.70E-07 8.97E-11 0 1.65E-10 3.52E-11

80 0.0030011 1.16E-06 1.74E-07 1.63E-05 3.33E-06 9.60E-10 0 2.12E-09 7.58E-10

81 0.021661 1.19E-05 5.44E-06 1.64E-04 1.12E-04 5.46E-08 0 1.03E-07 2.41E-08

82 3.08E-05 1.68E-08 7.75E-09 2.33E-07 1.58E-07 7.70E-11 0 1.46E-10 3.42E-11

83 0.0028905 1.11E-06 1.68E-07 1.57E-05 3.18E-06 8.44E-10 0 1.91E-09 7.35E-10

84 0.021648 1.16E-05 5.52E-06 1.61E-04 1.09E-04 4.88E-08 0 9.50E-08 2.43E-08

85 2.96E-05 1.59E-08 7.56E-09 2.20E-07 1.49E-07 6.65E-11 0 1.30E-10 3.33E-11

86 0.0027884 1.05E-06 1.64E-07 1.49E-05 3.06E-06 6.69E-10 0 1.74E-09 7.19E-10

87 0.020122 1.07E-05 5.24E-06 1.49E-04 1.00E-04 4.10E-08 0 8.24E-08 2.31E-08

88 2.86E-05 1.52E-08 7.44E-09 2.12E-07 1.42E-07 5.80E-11 0 1.17E-10 3.28E-11

89 0.0026983 8.68E-07 1.62E-07 1.23E-05 3.03E-06 6.26E-10 0 1.62E-09 7.16E-10

90 0.020926 1.13E-05 5.58E-06 1.59E-04 1.05E-04 3.89E-08 0 8.09E-08 2.46E-08

91 2.75E-05 1.49E-08 7.34E-09 2.09E-07 1.38E-07 5.09E-11 0 1.06E-10 3.24E-11

92 0.0025999 8.47E-07 1.58E-07 1.20E-05 3.11E-06 5.82E-10 0 1.51E-09 7.08E-10

93 0.018819 1.05E-05 5.14E-06 1.48E-04 9.61E-05 3.20E-08 0 6.88E-08 2.27E-08

94 2.64E-05 1.48E-08 7.21E-09 2.08E-07 1.35E-07 4.46E-11 0 9.64E-11 3.19E-11

95 0.002504 8.43E-07 1.54E-07 1.20E-05 3.28E-06 4.80E-10 0 1.40E-09 6.99E-10

Table A-4 Release fraction parameters used in the Surry LTSBO, STSBO, ISLOCA, 

and mitigated and unmitigated TISGTR scenarios (continued)
A-32

Surry Unmitigated TISGTR

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

96 0.018722 1.09E-05 5.22E-06 1.53E-04 9.93E-05 2.91E-08 0 6.51E-08 2.32E-08

97 2.53E-05 1.47E-08 7.07E-09 2.08E-07 1.35E-07 3.90E-11 0 8.77E-11 3.14E-11

98 0.0024121 7.11E-07 1.49E-07 1.01E-05 3.52E-06 4.51E-10 0 1.31E-09 6.95E-10

99 0.017989 1.10E-05 5.10E-06 1.55E-04 1.01E-04 2.55E-08 0 5.97E-08 2.29E-08

100 2.43E-05 1.48E-08 6.88E-09 2.10E-07 1.37E-07 3.42E-11 0 8.03E-11 3.10E-11

101 0.0023166 6.38E-07 1.17E-07 9.05E-06 3.94E-06 3.64E-10 0 1.23E-09 6.87E-10

102 0.017843 1.15E-05 4.96E-06 1.63E-04 1.09E-04 2.31E-08 0 5.66E-08 2.34E-08

103 2.33E-05 1.50E-08 6.47E-09 2.13E-07 1.43E-07 3.00E-11 0 7.37E-11 3.06E-11

104 0.0022242 6.10E-07 1.11E-07 8.66E-06 4.47E-06 3.35E-10 0 1.15E-09 6.80E-10

105 0.016027 1.09E-05 4.35E-06 1.55E-04 1.10E-04 1.90E-08 0 4.89E-08 2.16E-08

106 2.23E-05 1.53E-08 6.05E-09 2.17E-07 1.53E-07 2.63E-11 0 6.80E-11 3.02E-11

107 0.0021344 6.16E-07 1.05E-07 8.75E-06 5.07E-06 2.91E-10 0 1.09E-09 6.72E-10

108 0.015927 1.15E-05 4.24E-06 1.63E-04 1.24E-04 1.73E-08 0 4.70E-08 2.22E-08

109 2.14E-05 1.55E-08 5.69E-09 2.20E-07 1.67E-07 2.32E-11 0 6.29E-11 2.98E-11

110 8.98E-04 2.63E-07 4.40E-08 3.73E-06 2.41E-06 1.31E-10 0 4.51E-10 2.89E-10

111 0.0015566 1.16E-06 4.11E-07 1.65E-05 1.30E-05 1.61E-09 0 4.51E-09 2.20E-09

112 6.97E-07 5.20E-10 1.84E-10 7.39E-09 5.86E-09 6.82E-13 0 1.88E-12 9.88E-13

113 5.17E-04 3.86E-07 1.36E-07 5.49E-06 4.38E-06 5.33E-10 0 1.50E-09 7.34E-10

114 6.96E-07 5.20E-10 1.83E-10 7.39E-09 5.89E-09 6.82E-13 0 1.99E-12 9.88E-13

115 6.84E-05 2.00E-08 3.33E-09 2.86E-07 1.91E-07 0 0 3.27E-11 2.23E-11

Table A-4 Release fraction parameters used in the Surry LTSBO, STSBO, ISLOCA, 

and mitigated and unmitigated TISGTR scenarios (continued)
A-33

Table A-5 EARLY parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR Scenarios

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

ACNAME Latent Cancer 

Effect

Cancer 

Type 1 LEUKEMIA LEUKEMIA LEUKEMIA LEUKEMIA LEUKEMIA

Cancer 

Type 2 BONE BONE BONE BONE BONE

Cancer 

Type 3 BREAST BREAST BREAST BREAST BREAST

Cancer 

Type 4 LUNG LUNG LUNG LUNG LUNG

Cancer 

Type 5 THYROID THYROID THYROID THYROID THYROID

Cancer 

Type 6 LIVER LIVER LIVER LIVER LIVER

Cancer 

Type 7 COLON COLON COLON COLON COLON

Cancer 

Type 8 RESIDUAL RESIDUAL RESIDUAL RESIDUAL RESIDUAL

ACSUSC

Population 

Susceptible to 

Cancer

1.0 for all 

cancers

1.0 for all 

cancers

1.0 for all 

cancers

1.0 for all 

cancers

1.0 for all 

cancers

ACTHRE

Linear DoseResponse 

Threshold

0 0 0 0 0

BRRATE

Breathing Rate 

(for all activity 

types)

0.000266 0.000266 0.000266 0.000266 0.000266

CFRISK

Lifetime Cancer 

Fatality Risk 

Factors

Cancer 

Type 1 0.0111 0.0111 0.0111 0.0111 0.0111

Cancer 

Type 2 0.00019 0.00019 0.00019 0.00019 0.00019

Cancer 

Type 3 0.00506 0.00506 0.00506 0.00506 0.00506

Cancer 

Type 4 0.0198 0.0198 0.0198 0.0198 0.0198

Cancer 

Type 5 0.000648 0.000648 0.000648 0.000648 0.000648

Cancer 

Type 6 0.003 0.003 0.003 0.003 0.003

Cancer 

Type 7 0.0208 0.0208 0.0208 0.0208 0.0208

Cancer 

Type 8 0.0493 0.0493 0.0493 0.0493 0.0493
A-34

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

CIRISK

Lifetime Cancer 

Injury Risk 

Factors

Cancer 

Type 1 0.0113 0.0113 0.0113 0.0113 0.0113

Cancer 

Type 2 0.000271 2.71E-04 2.71E-04 2.71E-04 2.71E-04

Cancer 

Type 3 0.0101 0.0101 0.0101 0.0101 0.0101

Cancer 

Type 4 0.0208 0.0208 0.0208 0.0208 0.0208

Cancer 

Type 5 0.00648 0.00648 0.00648 0.00648 0.00648

Cancer 

Type 6 0.00316 0.00316 0.00316 0.00316 0.00316

Cancer 

Type 7 0.0378 0.0378 0.0378 0.0378 0.0378

Cancer 

Type 8 0.169 0.169 0.169 0.169 0.169

CRIORG

Critical Organ 

for EARLY 

Phase

L-ICRP60ED L-ICRP60ED L-ICRP60ED L-ICRP60ED L-ICRP60ED

CSFACT

Cloudshine 

Shielding 

Factors

Evacuation

Shielding Factor for 

All but Cohort 4

1 1 1 1 1

Normal Activity 

Shielding Factor for 

All but Cohort 4

0.68 0.68 0.68 0.68 0.68

Sheltering Shielding 

Factor for All but 

Cohort 4

0.6 0.6 0.6 0.6 0.6

Evacuation 

Shielding Factor for 

Cohort 4

1 1 1 1 1

Normal Activity 

Shielding Factor for 

Cohort 4

0.31 0.31 0.31 0.31 0.31

Sheltering Shielding 

Factor for Cohort 4 0.31 0.31 0.31 0.31 0.31

DCF_FILE Name of Dose 

Coefficient File

FGR13GyEquiv

DCF.INP

FGR13GyEquiv

DCF.INP

FGR13GyEquiv

DCF.INP

FGR13GyEquiv

DCF.INP

FGR13GyEquiv

DCF.INP

DDREFA

DoseDependent 

Reduction 

Factor

Cancer 

Type 1 2 2 2 2 2

Cancer 

Type 2 2 2 2 2 2

Cancer 

Type 3 1 1 1 1 1

Cancer 

Type 4 2 2 2 2 2

Table A-5 EARLY parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated and 

unmitigated TISGTR Scenarios (continued)
A-35

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

DDREFA Cancer 

Type 5 2 2 2 2 2

Cancer 

Type 6 2 2 2 2 2

Cancer 

Type 7 2 2 2 2 2

Cancer 

Type 8 2 2 2 2 2

DDTHRE

Threshold for 

Applying DoseDependent 

Reduction Factor

0.2 0.2 0.2 0.2 0.2

DLTSHL

Delay from 

Alarm Time to 

Shelter

Cohort 1 9900 9900 9900 9900 9900

Cohort 2 9900 9900 9900 9900 9900

Cohort 3 900 900 900 900 900

Cohort 4 9900 9900 9900 9900 9900

Cohort 5 9900 9900 9900 9900 9900

Cohort 6 N/A N/A N/A N/A N/A

DLTEVA

Delay from 

Beginning of 

Shelter to 

Evacuation

Cohort 1 3600 3600 3600 3600 3600

Cohort 2 3600 3600 3600 3600 3600

Cohort 3 3600 3600 6300 3600 3600

Cohort 4 39600 39600 39600 39600 39600

Cohort 5 39600 39600 39600 39600 39600

Cohort 6 N/A N/A N/A N/A N/A

DOSEFA

Cancer DoseResponse Linear 

Factors

1 for all 

organs

1 for all 

organs

1 for all 

organs

1 for all 

organs 1 for all organs

DOSEFB

Cancer DoseResponse 

Quadratic Factors

0 for all 

organs

0 for all 

organs

0 for all 

organs

0 for all 

organs 0 for all organs

DOSHOT

Hot-Spot 

Relocation Dose 

Threshold

0.05 0.05 0.05 0.05 0.05

DOSMOD Dose-Response 

Model Flag AT AT AT AT AT

DOSNRM Normal Relocation 

Dose Threshold 0.01 0.01 0.01 0.01 0.01

DURBEG

Duration of 

Beginning of 

Evacuation Phase

Cohort 1 900 900 900 900 900

Cohort 2 900 900 900 900 900

Cohort 3 900 900 900 900 900

Cohort 4 3600 3600 3600 3600 3600

Cohort 5 3600 3600 3600 3600 3600

Cohort 6 N/A N/A N/A N/A N/A

Table A-5 EARLY parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated and 

unmitigated TISGTR Scenarios (continued)
A-36

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

DURMID

Duration of 

Middle of 

Evacuation 

Phase

Cohort 1 35100 35100 35100 35100 35100

Cohort 2 35100 35100 35100 35100 35100

Cohort 3 1800 1800 1800 1800 1800

Cohort 4 3600 3600 3600 3600 3600

Cohort 5 3600 3600 3600 3600 3600

Cohort 6 N/A N/A N/A N/A N/A

EANAM1

Text Describing 

the EARLY 

Assumptions

SOARCA 

Surry LTSBO 

Calculation

SOARCA Surry 

STSBO 

Calculation

SOARCA 

Surry STSBO

ISLOCA

Calculation

SOARCA Surry 

STSBO with

TI-SGTR 

Calculation

SOARCA Surry 

STSBO with 

TI-SGTR

Calculation

EANAM2

Text Describing 

the Emergency 

Response

Cohort 1 Group 1 Group 1 Group 1 Group 1 Group 1

Cohort 2 Group 2 Group 2 Group 2 Group 2 Group 2

Cohort 3 Group 3 Group 3 Group 3 Group 3 Group 3

Cohort 4 Group 4 Group 4 Group 4 Group 4 Group 4

Cohort 5 Group 5 Group 5 Group 5 Group 5 Group 5

Cohort 6 Group 6 Group 6 Group 6 Group 6 Group 6

EFFACA LD50 for Early 

Fatality Types

A-RED MARR 5.6 5.6 5.6 5.6 5.6

A-LUNGS 23.5 23.5 23.5 23.5 23.5

A-STOMACH 12.1 12.1 12.1 12.1 12.1

EFFACB

Shape Factor for 

Early Fatality 

Types

A-RED MARR 6.1 6.1 6.1 6.1 6.1

A-LUNGS 9.6 9.6 9.6 9.6 9.6

A-STOMACH 9.3 9.3 9.3 9.3 9.3

EFFACY Efficacy of the KI 

Ingestion 0.7 0.7 0.7 0.7 0.7

EFFTHR Threshold Dose to 

Target Organ

A-RED MARR 2.32 2.32 2.32 2.32 2.32

A-LUNGS 13.6 13.6 13.6 13.6 13.6

A-STOMACH 6.5 6.5 6.5 6.5 6.5

EIFACA LD50 For Early 

Injuries

PRODROMAL 

VOMIT 2 2 2 2 2

DIARRHEA 3 3 3 3 3

PNEUMONITIS 16.6 16.6 16.6 16.6 16.6

SKIN 

ERYTHRMA 6 6 6 6 6

TRANSEPIDERMAL 20 20 20 20 20

THYROIDITIS 240 240 240 240 240

HYPOTHYROIDISM 60 60 60 60 60

Table A-5 EARLY parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated and 

unmitigated TISGTR Scenarios (continued)
A-37

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

EIFACB Shape Factor for 

Early Injuries

PRODROMAL 

VOMIT 3 3 3 3 3

DIARRHEA 2.5 2.5 2.5 2.5 2.5

PNEUMONITIS 7.3 7.3 7.3 7.3 7.3

SKIN 

ERYTHRMA 5 5 5 5 5

TRANSEPIDERMAL 5 5 5 5 5

THYROIDITIS 2 2 2 2 2

HYPOTHYROIDISM 1.3 1.3 1.3 1.3 1.3

EINAME

Early Injury Effect 

Names and 

Corresponding 

Organ

PRODROMAL 

VOMIT A-STOMACH A-STOMACH A-STOMACH A-STOMACH A-STOMACH

DIARRHEA A-STOMACH A-STOMACH A-STOMACH A-STOMACH A-STOMACH

PNEUMONITIS A-LUNGS A-LUNGS A-LUNGS A-LUNGS A-LUNGS

SKIN 

ERYTHRMA A-SKIN A-SKIN A-SKIN A-SKIN A-SKIN

TRANSEPIDERMAL A-SKIN A-SKIN A-SKIN A-SKIN A-SKIN

THYROIDITIS A-THYROID A-THYROID A-THYROID A-THYROID A-THYROID

HYPOTHYROIDISM A-THYROID A-THYROID A-THYROID A-THYROID A-THYROID

EISUSC

Susceptible 

Population 

Fraction

1. for all 

health 

effects

1. for all health 

effects

1. for all 

health 

effects

1. for all health 

effects

1. for all health 

effects

EITHRE Early Injury Dose 

Threshold

PRODROMAL 

VOMIT 0.5 0.5 0.5 0.5 0.5

DIARRHEA 1 1 1 1 1

PNEUMONITIS 9.2 9.2 9.2 9.2 9.2

SKIN 

ERYTHRMA 3 3 3 3 3

TRANSEPIDERMAL 10 10 10 10 10

THYROIDITIS 40 40 40 40 40

HYPOTHYROIDISM 2 2 2 2 2

ENDAT2

Control flag 

indicating only 

ATMOS and 

EARLY are to 

be run

.FALSE. .FALSE. .FALSE. .FALSE. .FALSE.

ENDEMP

Time Duration 

for the 

Emergency 

Phase

604800 604800 604800 604800 604800

ESPEED Evaluation 

Speed

Initial 

Evacuation 

Phase, 

Cohort 1

2.235 2.235 2.235 2.235 2.235

Table A-5 EARLY parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated and 

unmitigated TISGTR Scenarios (continued)
A-38

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

ESPEED

Middle 

Evacuation 

Phase, 

Cohort 1

0.447 0.447 0.447 0.447 0.447

Late 

Evacuation 

Phase, 

Cohort 1

8.941 8.941 8.941 8.941 8.941

Initial 

Evacuation 

Phase, 

Cohort 2

2.235 2.235 2.235 2.235 2.235

Middle 

Evacuation 

Phase, 

Cohort 2

0.447 0.447 0.447 0.447 0.447

Late 

Evacuation 

Phase, 

Cohort 2

8.941 8.941 8.941 8.941 8.941

Initial 

Evacuation 

Phase, 

Cohort 3

4.47 4.47 4.47 4.47 4.47

Middle 

Evacuation 

Phase, 

Cohort 3

4.47 4.47 4.47 4.47 4.47

Late 

Evacuation 

Phase, 

Cohort 3

8.941 8.941 8.941 8.941 8.941

Initial 

Evacuation 

Phase, 

Cohort 4

0.447 0.447 0.447 0.447 0.447

Middle 

Evacuation 

Phase, 

Cohort 4

4.47 4.47 4.47 4.47 4.47

Late 

Evacuation 

Phase, 

Cohort 4

8.941 8.941 8.941 8.941 8.941

Initial 

Evacuation 

Phase, 

Cohort 5

0.447 0.447 0.447 0.447 0.447

Middle 

Evacuation 

Phase, 

Cohort 5

4.47 4.47 4.47 4.47 4.47

Table A-5 EARLY parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated and 

unmitigated TISGTR Scenarios (continued)
A-39

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

ESPEED

Late 

Evacuation 

Phase, 

Cohort 5

8.941 8.941 8.941 8.941 8.941

Cohort 6 N/A N/A N/A N/A N/A

ESPGRD

Speed Multiplier 

to Account for 

Grid-Level 

Variations in 

Road Network

Table A-6

Table A-7

Table A-6

Table A-7

Table A-6

Table A-7

Table A-6

Table A-7

Table A-6

Table A-7

ESPMUL

Speed Multiplier 

Employed 

During 

Precipitation

0.7 0.7 0.7 0.7 0.7

EVATYP Evacuation 

Type NETWORK NETWORK NETWORK NETWORK NETWORK

GSHFAC

Groundshine 

Shielding 

Factors

Evacuation 

Shielding 

Factor for All 

but Cohort 4

0.5 0.5 0.5 0.5 0.5

Normal 

Activity 

Shielding 

Factor for All 

but Cohort 4

0.26 0.26 0.26 0.26 0.26

Sheltering 

Shielding 

Factor for All 

but Cohort 4

0.2 0.2 0.2 0.2 0.2

Evacuation 

Shielding 

Factor for 

Cohort 4

0.5 0.5 0.5 0.5 0.5

Normal 

Activity 

Shielding 

Factor for 

Cohort 4

0.05 0.05 0.05 0.05 0.05

Sheltering 

Shielding 

Factor for 

Cohort 4

0.05 0.05 0.05 0.05 0.05

IDIREC

Direction in 

Network 

Evacuation 

Model

Table A-8 Table A-8 Table A-8 Table A-8 Table A-8

IPLUME Plume Model 

Dispersion Code 3 3 3 3 3

KIMODL Model Flag for 

KI Ingestion KI KI KI KI KI

Table A-5 EARLY parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated and 

unmitigated TISGTR Scenarios (continued)
A-40

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

LASMOV Last Ring in 

Movement Zone 17 17 17 17 17

NUMACA

Number of 

Latent Cancer 

Health Effects

8 8 8 8 8

NUMEFA Number of Early 

Fatality Effects 3 3 3 3 3

NUMEIN Number of Early 

Injury Effects 7 7 7 7 7

NUMEVA

Outer Boundary of 

Evacuation/Shelter 

Region

Cohort 1 - 15

Cohorts 2 to 

5 - 12

Cohort 1 - 15

Cohorts 2 to 

5 - 12

Cohort 1 - 15

Cohorts 2 to 

5 - 12

Cohort 1 - 15

Cohorts 2 to 

5 - 12

Cohort 1 - 15

Cohorts 2 to 

5 - 12

NUMFIN

Number of Fine 

Grid 

Subdivisions

7 7 7 7 7

ORGFLG

Doses to be 

Calculated for 

Specified Organ

All TRUE for 

FGR-13

All TRUE for 

DOSFAC2 

except for ALower LI and 

L-Liver, which 

are FALSE

All TRUE for 

FGR-13

All TRUE for 

DOSFAC2 

except for ALower LI and LLiver, which are 

FALSE

All TRUE for 

FGR-13

All TRUE for 

DOSFAC2 

except for ALower LI and 

L-Liver, which 

are FALSE

All TRUE for 

FGR-13

All TRUE for 

DOSFAC2 

except for ALower LI and LLiver, which are 

FALSE

All TRUE for 

FGR-13

All TRUE for 

DOSFAC2 

except for ALower LI and LLiver, which are 

FALSE

OVRRID

Wind Rose 

Probability 

Override

.FALSE. .FALSE. .FALSE. .FALSE. .FALSE.

POPFLG Population 

Distribution Flag FILE FILE FILE FILE FILE

POPFRAC

Population 

Fraction Ingesting 

KI

Cohort 2 - 1.0

Cohort 1, 

3-6 - 0.0

Cohort 2 - 1.0

Cohort 1, 

3-6 - 0.0

Cohort 2 - 1.0

Cohort 1, 

3-6 - 0.0

Cohort 2 - 1.0

Cohort 1, 

3-6 - 0.0

Cohort 2 - 1.0

Cohort 1, 

3-6 - 0.0

PROTIN 

[E]

Inhalation 

Protection Factor 

– evacuation for 

all but Cohort 4

0.98 0.98 0.98 0.98 0.98

PROTIN 

[N]

Inhalation 

Protection Factor -

normal activity for 

all but Cohort 4

0.46 0.46 0.46 0.46 0.46

PROTIN 

[S]

Inhalation 

Protection Factor 

– sheltering for all 

but Cohort 4

0.33 0.33 0.33 0.33 0.33

PROTIN 

[E]

Inhalation 

Protection Factor 

– evacuation for 

Cohort 4

0.98 0.98 0.98 0.98 0.98

PROTIN 

[N]

Inhalation 

Protection Factor -

normal activity for 

Cohort 4

0.33 0.33 0.33 0.33 0.33

PROTIN 

[S]

Inhalation 

Protection Factor 

– sheltering for 

Cohort 4

0.33 0.33 0.33 0.33 0.33

REFPNT

Reference Time 

Point (ARRIVAL 

or SCRAM)

ALARM ALARM ALARM ALARM ALARM

Table A-5 EARLY parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated and 

unmitigated TISGTR Scenarios (continued)
A-41

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

RESCON

Emergency phase 

resuspension 

coefficient

0.0001 0.0001 0.0001 0.0001 0.0001

RESHAF

Resuspension

Concentration 

Half-Life

182000 182000 182000 182000 182000

RISCAT Risk by WeatherCategory Flag .FALSE. .FALSE. .FALSE. .FALSE. .FALSE.

RISTHR Risk Threshold for 

Fatality Radius 0 0 0 0 0

SKPFAC 

[E]

Skin Protection 

Factors –

evacuation for all 

cohorts

0.98 0.98 0.98 0.98 0.98

SKPFAC 

[N]

Skin Protection 

Factors - normal 

activity for all but 

Cohort 4

0.46 0.46 0.46 0.46 0.46

SKPFAC 

[S]

Skin Protection 

Factors –

sheltering for all 

cohorts

0.33 0.33 0.33 0.33 0.33

SKPFAC 

[N]

Skin Protection 

Factors - normal 

activity Cohort 4

0.33 0.33 0.33 0.33 0.33

TIMHOT Hotspot

Relocation Time 86400 86400 86400 86400 86400

TIMNRM Normal Relocation 

Time 129600 129600 129600 129600 129600

TRAVEL

POINT

Evacuee 

Movement Option

CENTER

POINT

CENTER

POINT

CENTER

POINT

CENTER

POINT

CENTER

POINT

WTFRAC

Weighting 

Fraction 

Applicable to this 

Scenario

Cohort 1 0.2 0.2 0.2 0.2 0.2

Cohort 2 0.535 0.535 0.535 0.535 0.535

Cohort 3 0.193 0.193 0.193 0.193 0.193

Cohort 4 0.007 0.007 0.007 0.007 0.007

Cohort 5 0.060 0.060 0.060 0.060 0.060

Cohort 6 0.005 0.005 0.005 0.005 0.005

WTNAME Type of Weighting 

for Cohorts PEOPLE PEOPLE PEOPLE PEOPLE PEOPLE

Table A-5 EARLY parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated and 

unmitigated TISGTR Scenarios (continued)
A-42

Table A-6 Grid-level evacuation speed multipliers used in the Surry LTSBO, STSBO,

ISLOCA, and mitigated and unmitigated TISGTR scenarios for cohorts 1-2

Compass Sector

Radial 

Ring 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

4 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

5 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

6 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

7 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

8 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

9 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

10 1 1 1 1 1 1 3 3 3 3 3 3 3 3 3 3

11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

12 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

13 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

14 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

15 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

16 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

17 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
A-43

Table A-6 Grid-level evacuation speed multipliers used in the Surry LTSBO, STSBO, 

ISLOCA, and mitigated and unmitigated TISGTR scenarios for cohorts 1-2

(continued)

Compass Sector

Radial 

Ring 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

1 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

4 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

5 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

6 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

7 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

8 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

9 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

10 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

11 1 1 1 1 1 1 3 3 3 3 3 3 3 3 3 3

12 1 1 1 1 1 1 1 3 3 3 3 3 3 3 3 3

13 1 1 1 1 1 1 1 3 3 3 3 3 3 3 3 3

14 1 1 1 1 1 1 1 3 3 3 3 3 3 3 3 3

15 1 1 1 1 1 1 1 1 3 3 3 3 3 3 3 3

16 1 1 1 1 1 1 1 1 1 3 3 3 3 3 3 3

17 1 1 1 1 1 1 3 3 3 3 3 3 3 3 3 3
A-44

Table A-6 Grid-level evacuation speed multipliers used in the Surry LTSBO, STSBO, 

ISLOCA, and mitigated and unmitigated TISGTR scenarios for cohorts 1-2

(continued)

Compass Sector

Radial 

Ring 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

1 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

4 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

5 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

6 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

7 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

8 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

9 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

10 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

11 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

12 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

13 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

14 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

15 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

16 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

17 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
A-45

Table A-6 Grid-level evacuation speed multipliers used in the Surry LTSBO, STSBO, 

ISLOCA, and mitigated and unmitigated TISGTR scenarios for cohorts 1-2

(continued)

Compass Sector

Radial 

Ring 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

1 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

4 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

5 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

6 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

7 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

8 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

9 3 3 3 3 3 3 3 1 1 1 1 3 3 3 3 3

10 3 3 3 3 3 3 3 1 1 1 1 1 1 1 1 1

11 3 3 3 3 3 3 3 1 1 1 1 1 1 1 1 1

12 3 3 3 3 3 3 3 1 1 1 1 1 1 1 1 1

13 3 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1

14 3 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1

15 3 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1

16 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1 1

17 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1 1
A-46

Table A-7 Grid-level evacuation speed multipliers used in the Surry LTSBO, STSBO,

ISLOCA, and mitigated and unmitigated TISGTR scenarios for cohorts 3-5

Compass Sector

Radial 

Ring 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

4 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

5 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

6 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

7 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

8 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

9 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

10 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2

11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

12 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

13 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

14 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

15 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

16 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

17 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
A-47

Compass Sector

Radial 

Ring 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

4 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

5 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

6 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

7 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

8 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

9 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

10 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

11 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2

12 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2

13 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2

14 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2

15 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2

16 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2

17 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2

Table A-7 Grid-level evacuation speed multipliers used in the Surry LTSBO, STSBO, ISLOCA, 

and mitigated and unmitigated TISGTR scenarios for cohorts 3-5 (continued)
A-48

Compass Sector

Radial 

Ring 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

4 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

5 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

6 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

7 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

8 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

9 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

10 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

11 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

12 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

13 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

14 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

15 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

16 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

17 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

Table A-7 Grid-level evacuation speed multipliers used in the Surry LTSBO, STSBO, ISLOCA, 

and mitigated and unmitigated TISGTR scenarios for cohorts 3-5 (continued)
A-49

Compass Sector

Radial 

Ring 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

4 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

5 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

6 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

7 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

8 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

9 2 2 2 2 2 2 2 1 1 1 1 2 2 2 2 2

10 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1

11 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1

12 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1

13 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1

14 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1

15 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1

16 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1

17 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1

Table A-7 Grid-level evacuation speed multipliers used in the Surry LTSBO, STSBO, ISLOCA, 

and mitigated and unmitigated TISGTR scenarios for cohorts 3-5 (continued)
A-50

Table A-8 Evacuation direction parameters used in the Surry LTSBO, STSBO,

ISLOCA, and mitigated and unmitigated TISGTR scenarios

Compass Sector

Radial 

Ring 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

4 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2

5 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2

6 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2

7 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

8 1 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1

9 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

10 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 4

12 1 1 1 1 4 4 4 4 2 2 2 2 2 1 1 1

13 1 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1

14 4 4 2 2 2 2 2 1 4 4 4 4 1 2 2 2

15 1 2 2 2 1 1 4 4 4 4 4 4 4 1 1 1

16 2 2 1 4 4 4 4 1 1 1 1 1 1 1 1 1

17 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
A-51

Table A-8 Evacuation direction parameters used in the Surry LTSBO, STSBO, 

ISLOCA, and mitigated and unmitigated TISGTR scenarios (continued)

Compass Sector

Radial 

Ring 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

3 1 1 1 1 1 4 4 4 4 2 2 2 1 1 1 1

4 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1

5 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1

6 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1

7 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

8 1 1 1 1 1 1 1 1 2 2 2 1 1 2 2 2

9 1 1 1 1 1 1 1 1 1 1 2 2 2 1 1 1

10 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 1

11 4 4 4 4 4 4 1 1 1 1 1 1 1 2 2 2

12 1 1 1 1 4 4 1 1 1 1 1 1 1 1 1 1

13 1 1 1 1 1 4 1 1 1 1 2 2 1 1 1 1

14 2 2 2 2 1 4 4 1 1 2 2 2 1 1 1 1

15 1 2 2 2 2 1 1 4 1 2 2 2 1 4 4 4

16 1 1 2 2 1 1 4 2 1 1 1 1 1 1 1 1

17 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
A-52

Table A-8 Evacuation direction parameters used in the Surry LTSBO, STSBO, 

ISLOCA, and mitigated and unmitigated TISGTR scenarios (continued)

Compass Sector

Radial 

Ring 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

3 4 4 4 4 4 4 4 4 4 1 1 1 1 1 1 1

4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

5 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

7 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

8 1 1 4 4 4 4 1 1 1 1 1 1 1 1 1 1

9 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

10 1 1 1 2 2 2 1 1 1 4 4 4 4 4 4 4

11 2 2 2 2 2 1 1 4 4 2 2 1 1 1 1 1

12 1 1 1 1 1 1 1 4 4 2 2 1 1 1 1 4

13 1 1 1 1 1 1 2 2 1 2 1 4 4 2 2 1

14 1 4 4 4 4 2 2 2 1 2 1 2 2 2 2 2

15 1 1 4 1 1 1 1 1 1 1 1 1 1 1 1 4

16 1 1 1 2 2 2 2 2 2 2 2 2 1 1 1 1

17 4 4 4 4 4 4 2 2 2 1 1 1 2 2 2 1
A-53

Table A-8 Evacuation direction parameters used in the Surry LTSBO, STSBO, 

ISLOCA, and mitigated and unmitigated TISGTR scenarios (continued)

Compass Sector

Radial 

Ring 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

5 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

7 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

8 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

9 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

10 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1

11 1 4 4 4 4 1 1 1 1 1 1 1 1 1 1 1

12 4 4 4 4 1 1 1 1 1 1 1 1 1 1 1 1

13 4 4 4 1 1 2 1 1 2 2 1 1 1 1 1 1

14 1 1 4 4 2 2 2 2 2 2 2 2 2 1 1 4

15 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

16 1 1 1 1 1 1 2 2 2 2 2 1 4 4 4 2

17 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
A-54

Table A-9 CHRONC input parameters used in the Surry LTSBO, STSBO, ISLOCA, and 

mitigated and unmitigated TISGTR scenarios

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

CHNAME CHRONC Problem 

Identification

Surry with no 

Food-Chain 

Modeling

Surry with no 

Food-Chain 

Modeling

Surry with no 

Food-Chain 

Modeling

Surry with no 

Food-Chain 

Modeling

Surry with no 

Food-Chain 

Modeling

CDFRM Farmland Decontamination 

Cost

Level 1 1330 1330 1330 1330 1330

Level 2 2960 2960 2960 2960 2960

CDNFRM Nonfarmland

Decontamination Cost

Level 1 7110 7110 7110 7110 7110

Level 2 19000 19000 19000 19000 19000

CRTOCR Critical Organ for CHRONC 

Phase L-ICRP60ED L-ICRP60ED LICRP60ED L-ICRP60ED L-ICRP60ED

DPRATE Property Depreciation Rate 0.2 0.2 0.2 0.2 0.2

DLBCST Hourly Labor Cost for 

Decontamination Worker 84000 84000 84000 84000 84000

DPFRCT Farm Production Dairy 

Fraction Surry site file Surry site file Surry site file Surry site file Surry site file

DSCRLT Long-Term Phase Dose 

Criterion 0.04 0.04 0.04 0.04 0.04

DSCRTI Intermediate-Phase Dose 

Criterion 100000 100000 100000 100000 100000

DSRATE Societal Discount Rate for 

Property 0.12 0.12 0.12 0.12 0.12

DSRFCT Decontamination Factors

Level 1 3 3 3 3 3

Level 2 15 15 15 15 15

DUR_INTPHAS Duration of the 

Intermediate Phase 0 0 0 0 0

EVACST Emergency Phase Cost of 

Evacuation/Relocation 172 172 172 172 172

EXPTIM Maximum Exposure Time 1580000000 1580000000 1580000000 1580000000 1580000000

FDPATH COMIDA2 vs. MACCS 

Food Model Switch OFF OFF OFF OFF OFF

FRACLD Fraction of Area that is Land Surry site file Surry site file Surry site file Surry site file Surry site file

FRCFRM Fraction of Area Used for 

Farming Surry site file Surry site file Surry site file Surry site file Surry site file

FRFDL Fraction of Decontamination 

Cost for Labor

Level 1 0.3 0.3 0.3 0.3 0.3

Level 2 0.35 0.35 0.35 0.35 0.35

FRFIM Farm Wealth 

Improvements Fraction 0.25 0.25 0.25 0.25 0.25

FRMPRD Average Annual Farm 

Production Surry site file Surry site file Surry site file Surry site file Surry site file

FRNFIM Nonfarm Wealth 

Improvements Fraction 0.8 0.8 0.8 0.8 0.8

FRNFDL Nonfarm Labor Cost Fraction

Level 1 0.7 0.7 0.7 0.7 0.7

Level 2 0.5 0.5 0.5 0.5 0.5
A-55

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

GWCOEF Long-Term Groundshine 

Coefficients

Term 1 0.5 0.5 0.5 0.5 0.5

Term 2 0.5 0.5 0.5 0.5 0.5

KSWTCH Diagnostic Output Option 

Switch 0 0 0 0 0

LBRRATE Long-Term Breathing Rate 0.000266 0.000266 0.000266 0.000266 0.000266

LGSHFAC Long-Term Groundshine 

Protection Factor 0.26 0.26 0.26 0.26 0.26

LPROTIN Long-Term Inhalation 

Protection Factor 0.46 0.46 0.46 0.46 0.46

LVLDEC Number of 

Decontamination Levels 2 2 2 2 2

NGWTRM

Number of Terms in 

Groundshine Weathering 

Equation

2 2 2 2 2

NRWTRM

Number of Terms in 

Resuspension Weathering 

Equation

3 3 3 3 3

POPCST Per Capita Cost of LongTerm Relocation 12000 12000 12000 12000 12000

RELCST Relocation Cost per 

Person-Day 172 172 172 172 172

RWCOEF Long-Term Resuspension 

Factor Coefficients

Term 1 0.00001 0.00001 0.00001 0.00001 0.00001

Term 2 0.0000001 0.0000001 0.0000001 0.0000001 0.0000001

Term 3 0.000000001 0.000000001 0.000000001 0.000000001 0.000000001

TFWKF

Fraction Farmland Worker 

Time in Contaminated 

Zone

Level 1 0.1 0.1 0.1 0.1 0.1

Level 2 0.33 0.33 0.33 0.33 0.33

TFWKNF

Fraction Nonfarmland

Worker Time in 

Contaminated Zone

Level 1 0.33 0.33 0.33 0.33 0.33

Level 2 0.33 0.33 0.33 0.33 0.33

TGWHLF Groundshine Weathering 

Half-Lives

Term 1 16000000 16000000 16000000 16000000 16000000

Term 2 2800000000 2800000000 2800000000 2800000000 2800000000

TIMDEC Decontamination Times

Level 1 5184000 5184000 5184000 5184000 5184000

Level 2 10368000 10368000 10368000 10368000 10368000

TMPACT Time Action Period Ends 158000000 158000000 158000000 158000000 158000000

TRWHLF Resuspension Weathering 

Half-Lives

Term 1 16000000 16000000 16000000 16000000 16000000

Term 2 160000000 160000000 160000000 160000000 160000000

Term 3 1600000000 1600000000 1600000000 1600000000 1600000000

Table A-9 CHRONC input parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated 

and unmitigated TISGTR scenarios (continued)
A-56

Variable Description LTSBO STSBO ISLOCA TISGTR 

Mitigated

TISGTR 

Unmitigated

VALWF Value of Farm Wealth 6900 6900 6900 6900 6900

VALWNF Value of Nonfarm Wealth 220000 220000 220000 220000 220000

Table A-9 CHRONC input parameters used in the Surry LTSBO, STSBO, ISLOCA, and mitigated 

and unmitigated TISGTR scenarios (continued)
B-1

APPENDIX B: MACCS PEACH BOTTOM ATOMIC POWER STATION 

SOARCA MODELING PARAMETERS

B-3

PEACH BOTTOM INPUT PARAMETERS FOR SOARCA

The input parameters used for the SOARCA Peach Bottom unmitigated LTSBO scenario and 

the STSBO with and without RCIC blackstart are shown in this appendix in tabular form. Table 

B-1 contains the more general ATMOS input parameters used for these three scenarios. Table 

B-2 through Table B-4 contain specific inputs related to the source terms that were extracted 

from MELCOR results via the MELMACCS code. Table B-5 contains general EARLY input 

parameters. Table B-6 and Table B-7 contain parameters associated with the network 

evacuation model that was used to treat emergency response. Table B-8 contains the 

CHRONC input parameters.

Table B-1 ATMOS input parameters used in the Peach Bottom unmitigated LTSBO 

and STSBO with and without RCIC blackstart scenarios

Variable Description LTSBO STSBO with RCIC 

Blackstart

STSBO without 

RCIC Blackstart

APLFRC Method of Applying 

Release Fraction PARENT PARENT PARENT

ATNAM1 Title Describing the 

ATMOS Assumptions

SOARCA PB 

Source Term LongTerm SBO

SOARCA PB 

Source Term ShortTerm SBO

SOARCA PB 

Source Term ShortTerm SBO

ATNAM2 Title Describing the 

Source Term

Peach Bottom 

source term for 

long term station 

blackout.

Peach Bottom 

source term for 

short term station 

blackout.

Peach Bottom 

source term for 

short term station 

blackout.

BNDMXH Boundary Weather Mixing 

Layer Height 1000 1000 1000

BNDRAN Boundary Weather Rain 

Rate 5 5 5

BNDWND Boundary Wind Speed 2.2 2.2 2.2

BRKPNT Breakpoint Time for 

Plume Meander 3600 3600 3600

BUILDH Building Height for all 

Plume Segments 50 50 50

CORINV Isotopic Inventory at Time 

of Reactor Shutdown from MELMACCS from MELMACCS from MELMACCS

CORSCA Linear Scaling Factor on 

Core Inventory 1 1 1

CWASH1 Linear Coefficient for 

Washout 1.89E-05 1.89E-05 1.89E-05

CWASH2 Exponential Term for

Washout 0.664 0.664 0.664

CYSIGA Linear Coefficient for 

sigma-y

Stability Class A 0.7507 0.7507 0.7507

Stability Class B 0.7507 0.7507 0.7507

Stability Class C 0.4063 0.4063 0.4063

Stability Class D 0.2779 0.2779 0.2779

Stability Class E 0.2158 0.2158 0.2158

Stability Class F 0.2158 0.2158 0.2158
B-4

Variable Description LTSBO STSBO with RCIC 

Blackstart

STSBO without 

RCIC Blackstart

CYSIGB Exponential Term

for sigma-y

Stability Class A 0.866 0.866 0.866

Stability Class B 0.866 0.866 0.866

Stability Class C 0.865 0.865 0.865

Stability Class D 0.881 0.881 0.881

Stability Class E 0.866 0.866 0.866

Stability Class F 0.866 0.866 0.866

CZSIGA Linear Coefficient for 

sigma-z

Stability Class A 0.0361 0.0361 0.0361

Stability Class B 0.0361 0.0361 0.0361

Stability Class C 0.2036 0.2036 0.2036

Stability Class D 0.2636 0.2636 0.2636

Stability Class E 0.2463 0.2463 0.2463

Stability Class F 0.2463 0.2463 0.2463

CZSIGB Exponential Term

for sigma-z

Stability Class A 1.277 1.277 1.277

Stability Class B 1.277 1.277 1.277

Stability Class C 0.859 0.859 0.859

Stability Class D 0.751 0.751 0.751

Stability Class E 0.619 0.619 0.619

Stability Class F 0.619 0.619 0.619

DISPMD Dispersion Model Flag LRDIST LRDIST LRDIST

DRYDEP Dry Deposition Flag

Xe = .FALSE.

Other Groups =

.TRUE.

Xe = .FALSE.

Other Groups = 

.TRUE.

Xe = .FALSE.

Other Groups = 

.TRUE.

ENDAT1 Control flag indicating only 

ATMOS is to be run .FALSE. .FALSE. .FALSE.

GRPNAM

Names of the Chemical 

Classes (Used by 

WinMACCS)

Chemical Class 1 Xe Xe Xe

Chemical Class 2 Cs Cs Cs

Chemical Class 3 Ba Ba Ba

Chemical Class 4 I I I

Chemical Class 5 Te Te Te

Chemical Class 6 Ru Ru Ru

Chemical Class 7 Mo Mo Mo

Chemical Class 8 Ce Ce Ce

Chemical Class 9 La La La

IBDSTB Boundary Weather 

Stability Class Index 4 4 4

IDEBUG Debug Switch for Extra 

Debugging Print 0 0 0

Table B-1 ATMOS input parameters used in the Peach Bottom unmitigated LTSBO and STSBO 

with and without RCIC blackstart scenarios (continued)
B-5

Variable Description LTSBO STSBO with RCIC 

Blackstart

STSBO without 

RCIC Blackstart

IGROUP Definition of Radionuclide 

Group Numbers 1 = Xe 1 = Xe 1 = Xe

2 = Cs 2 = Cs 2 = Cs

3 = Ba 3 = Ba 3 = Ba

4 = I 4 = I 4 = I

5 = Te 5 = Te 5 = Te

6 = Ru 6 = Ru 6 = Ru

7 = Mo 7 = Mo 7 = Mo

8 = Ce 8 = Ce 8 = Ce

9 = La 9 = La 9 = La

INWGHT

Number of Samples for Each 

Bin Used for Nonuniform 

Weather Bin Sampling

Bin 1 71 71 71

Bin 2 42 42 42

Bin 3 12 12 12

Bin 4 52 52 52

Bin 5 57 57 57

Bin 6 74 74 74

Bin 7 21 21 21

Bin 8 12 12 12

Bin 9 49 49 49

Bin 10 103 103 103

Bin 11 77 77 77

Bin 12 35 35 35

Bin 13 51 51 51

Bin 14 75 75 75

Bin 15 14 14 14

Bin 16 4 4 4

Bin 17 44 44 44

Bin 18 12 12 12

Bin 19 17 17 17

Bin 20 24 24 24

Bin 21 24 24 24

Bin 22 12 12 12

Bin 23 4 4 4

Bin 24 8 8 8

Bin 25 12 12 12

Bin 26 12 12 12

Bin 27 12 12 12

Bin 28 1 1 1

Bin 29 3 3 3

Bin 30 5 5 5

Bin 31 4 4 4

Bin 32 12 12 12

Bin 33 1 1 1

Bin 34 7 7 7

Bin 35 9 9 9

Table B-1 ATMOS input parameters used in the Peach Bottom unmitigated LTSBO and STSBO 

with and without RCIC blackstart scenarios (continued)
B-6

Bin 36 12 12 12

Variable Description LTSBO STSBO with RCIC 

Blackstart

STSBO without 

RCIC Blackstart

IRSEED Seed for Random Number 

Generator 79 79 79

LATITU Latitude of Power Plant 39 ̊ 45' 32" 39 ̊ 45' 32" 39 ̊ 45' 32"

LIMSPA Last Interval for Measured 

Weather 25 25 25

LONGIT Longitude of Power Plant 76 ̊ 16' 09" 76 ̊ 16' 09" 76 ̊ 16' 09"

MAXGRP Number of Radionuclide 

Groups 9 9 9

MAXHGT Flag for Mixing Height DAY_AND_NIGHT DAY_AND_NIGHT DAY_AND_NIGHT

MAXRIS Selection of Risk 

Dominant Plume 2 1 9

METCOD Meteorological Sampling 

Option Code 2 2 2

MNDMOD Plume Meander Model 

Flag OFF OFF OFF

NAMSTB List of Pseudostable 

Nuclides

Isotope 1 I-129 I-129 I-129

Isotope 2 Xe-131m Xe-131m Xe-131m

Isotope 3 Xe-133m Xe-133m Xe-133m

Isotope 4 Cs-135 Cs-135 Cs-135

Isotope 5 Sm-147 Sm-147 Sm-147

Isotope 6 U-234 U-234 U-234

Isotope 7 U-235 U-235 U-235

Isotope 8 U-236 U-236 U-236

Isotope 9 U-237 U-237 U-237

Isotope 10 Np-237 Np-237 Np-237

Isotope 11 Rb-87 Rb-87 Rb-87

Isotope 12 Zr-93 Zr-93 Zr-93

Isotope 13 Nb-93m Nb-93m Nb-93m

Isotope 14 Nb-95m Nb-95m Nb-95m

Isotope 15 Tc-99 Tc-99 Tc-99

Isotope 16 Pm-147 Pm-147 Pm-147

NPSGRP Number of Particle Size 

Groups 10 10 10

NRINTN Number of Rain Intensity 

Breakpoints 3 3 3

NRNINT Number of Rain Distance 

Intervals 5 5 5

NSBINS Number of Weather Bins 

to Sample 36 36 36

NUCNAM Radionuclide Names See Table 4-3 See Table 4-3 See Table 4-3

NUCOUT Radionuclide Used in 

Dispersion Print Cs-137 Cs-137 Cs-137

NUMCOR Number of Compass 

Sectors in the Grid 64 64 64

NUMISO Number of Radionuclides 69 69 69

NUMRAD Number of Radial Spatial 

Intervals 26 26 26

NUMREL # Released Plume sgmnts 29 33 86

Table B-1 ATMOS input parameters used in the Peach Bottom unmitigated LTSBO and 

STSBO with and without RCIC blackstart scenarios (continued)
B-7

Variable Description LTSBO STSBO with RCIC 

Blackstart

STSBO without 

RCIC Blackstart

NUMSTB

Number of Defined 

Pseudostable 

Radionuclides

16 16 16

OALARM Time to Reach General 

Emergency Conditions 0 0 0

PDELAY Plume Release Times MELMACCS Data 

(See Table B-2)

MELMACCS Data 

(See Table B-2)

MELMACCS Data 

(See Table B-2)

PLHEAT Plume Heat Contents MELMACCS Data 

(See Table B-2)

MELMACCS Data 

(See Table B-2)

MELMACCS Data 

(See Table B-2)

PLHITE Plume Release Heights MELMACCS Data 

(See Table B-2)

MELMACCS Data 

(See Table B-2)

MELMACCS Data 

(See Table B-2)

PLMDEN Plume Mass Density MELMACCS Data 

(See Table B-2)

MELMACCS Data 

(See Table B-2)

MELMACCS Data 

(See Table B-2)

PLMFLA Plume Mass Flow Rate MELMACCS Data 

(See Table B-2)

MELMACCS Data 

(See Table B-2)

MELMACCS Data 

(See Table B-2)

PLMMOD Flag for Plume Rise Input 

Option DENSITY DENSITY DENSITY

PLUDUR Plume Segment Durations MELMACCS Data 

(See Table B-2)

MELMACCS Data 

(See Table B-2)

MELMACCS Data 

(See Table B-2)

PSDIST Particle Size Distribution 

by Group

MELMACCS Data 

(See Table B-3)

MELMACCS Data 

(See Table B-3)

MELMACCS Data 

(See Table B-3)

REFTIM Plume Reference Time 

Point

0. for first

0.5 for subsequent

0. for first

0.5 for subsequent

0. for first

0.5 for subsequent

RELFRC Release Fractions of the 

Source Term

MELMACCS Data 

(See Table B-4)

MELMACCS Data 

(See Table B-4)

MELMACCS Data 

(See Table B-4)

RNDSTS Endpoints of Rain 

Distance Intervals

Interval 1 3.22 3.22 3.22

Interval 2 5.63 5.63 5.63

Interval 3 11.27 11.27 11.27

Interval 4 20.92 20.92 20.92

Interval 5 32.19 32.19 32.19

RNRATE Rain Intensity Breakpoints 

for Weather Binning

Intensity 1 2 2 2

Intensity 2 4 4 4

Intensity 3 6 6 6

SCLADP Scaling Factor for A-D 

Plume Rise 1.0 1.0 1.0

SCLCRW Scaling Factor for Critical 

Wind Speed 1.0 1.0 1.0

SCLEFP Scaling Factor for E-F 

Plume Rise 1.0 1.0 1.0

SIGYINIT Initial Sigma-y for All 

Plume Segments 11.6 11.6 11.6

SIGYINIT Initial Sigma-z for All 

Plume Segments 23.3 23.3 23.3

SPAEND Radial distances for grid 

boundaries

Ring 1 0.16 0.16 0.16

Ring 2 0.52 0.52 0.52

Table B-1 ATMOS input parameters used in the Peach Bottom unmitigated LTSBO and 

STSBO with and without RCIC blackstart scenarios (continued)
B-8

Variable Description LTSBO STSBO with RCIC 

Blackstart

STSBO without 

RCIC Blackstart

SPAEND Ring 3 1.21 1.21 1.21

Ring 4 1.61 1.61 1.61

Ring 5 2.13 2.13 2.13

Ring 6 3.22 3.22 3.22

Ring 7 4.02 4.02 4.02

Ring 8 4.83 4.83 4.83

Ring 9 5.63 5.63 5.63

Ring 10 8.05 8.05 8.05

Ring 11 11.27 11.27 11.27

Ring 12 16.09 16.09 16.09

Ring 13 20.92 20.92 20.92

Ring 14 25.75 25.75 25.75

Ring 15 32.19 32.19 32.19

Ring 16 40.23 40.23 40.23

Ring 17 48.28 48.28 48.28

Ring 18 64.37 64.37 64.37

Ring 19 80.47 80.47 80.47

Ring 20 112.65 112.65 112.65

Ring 21 160.93 160.93 160.93

Ring 22 241.14 241.14 241.14

Ring 23 321.87 321.87 321.87

Ring 24 563.27 563.27 563.27

Ring 25 804.67 804.67 804.67

Ring 26 1609.34 1609.34 1609.34

TIMBAS Time Base for Plume 

Expansion Factor 36000 36000 36000

VDEPOS Dry Deposition Velocities

Aerosol Bin 1 5.35E-04 5.35E-04 5.35E-04

Aerosol Bin 2 4.91E-04 4.91E-04 4.91E-04

Aerosol Bin 3 6.43E-04 6.43E-04 6.43E-04

Aerosol Bin 4 1.08E-03 1.08E-03 1.08E-03

Aerosol Bin 5 2.12E-03 2.12E-03 2.12E-03

Aerosol Bin 6 4.34E-03 4.34E-03 4.34E-03

Aerosol Bin 7 8.37E-03 8.37E-03 8.37E-03

Aerosol Bin 8 1.37E-02 1.37E-02 1.37E-02

Aerosol Bin 9 1.70E-02 1.70E-02 1.70E-02

Aerosol Bin 10 1.70E-02 1.70E-02 1.70E-02

WETDEP Wet Deposition Flag

Xe = .FALSE.

Other groups = 

.TRUE.

Xe = .FALSE.

Other groups = 

.TRUE.

Xe = .FALSE.

Other groups = 

.TRUE.

XPFAC1 Base Time for Meander 

Expansion Factor 0.01 0.01 0.01

XPFAC2 Breakpoint for Expansion 

Factor Model 0.01 0.01 0.01

YSCALE Scale Factor for 

Horizontal Dispersion 1 1 1

ZSCALE Scale Factor for Vertical 

Dispersion 1.27 1.27 1.27

Table B-1 ATMOS input parameters used in the Peach Bottom unmitigated LTSBO and 

STSBO with and without RCIC blackstart scenarios (continued)
B-9

Table B-2 Plume parameters used in the Peach Bottom unmitigated LTSBO and 

STSBO with and without RCIC blackstart scenarios

Peach Bottom LTSBO

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

1 7.20E+04 9.18E+06 3.96E+01 9.28E-01 1.46E+02 3.60E+03

2 7.22E+04 6.96E+05 4.00E+00 5.44E-01 6.87E+00 3.66E+03

3 7.56E+04 4.87E+06 3.96E+01 9.84E-01 1.40E+02 3.60E+03

4 7.92E+04 4.37E+06 3.96E+01 9.96E-01 1.35E+02 3.60E+03

5 8.28E+04 3.68E+06 3.96E+01 1.01E+00 1.29E+02 3.74E+03

6 8.66E+04 3.08E+06 3.96E+01 1.03E+00 1.20E+02 3.60E+03

7 9.02E+04 2.66E+06 3.96E+01 1.04E+00 1.14E+02 3.60E+03

8 9.38E+04 2.21E+06 3.96E+01 1.06E+00 1.08E+02 3.60E+03

9 9.74E+04 1.94E+06 3.96E+01 1.06E+00 1.03E+02 3.60E+03

10 1.01E+05 1.75E+06 3.96E+01 1.07E+00 9.96E+01 3.60E+03

11 1.05E+05 1.58E+06 3.96E+01 1.08E+00 9.63E+01 3.60E+03

12 1.08E+05 1.48E+06 3.96E+01 1.08E+00 9.42E+01 3.60E+03

13 1.12E+05 1.45E+06 3.96E+01 1.08E+00 9.32E+01 3.60E+03

14 1.15E+05 1.40E+06 3.96E+01 1.08E+00 9.20E+01 3.60E+03

15 1.19E+05 1.36E+06 3.96E+01 1.09E+00 9.10E+01 3.60E+03

16 1.23E+05 1.33E+06 3.96E+01 1.09E+00 9.01E+01 3.60E+03

17 1.26E+05 1.30E+06 3.96E+01 1.09E+00 8.95E+01 3.60E+03

18 1.30E+05 1.28E+06 3.96E+01 1.09E+00 8.90E+01 3.60E+03

19 1.33E+05 1.27E+06 3.96E+01 1.09E+00 8.86E+01 3.60E+03

20 1.37E+05 1.26E+06 3.96E+01 1.09E+00 8.83E+01 3.60E+03

21 1.41E+05 1.25E+06 3.96E+01 1.09E+00 8.81E+01 3.60E+03

22 1.44E+05 1.25E+06 3.96E+01 1.09E+00 8.79E+01 3.60E+03

23 1.48E+05 1.25E+06 3.96E+01 1.09E+00 8.79E+01 3.60E+03

24 1.51E+05 1.24E+06 3.96E+01 1.09E+00 8.78E+01 3.60E+03

25 1.55E+05 1.24E+06 3.96E+01 1.09E+00 8.77E+01 3.60E+03

26 1.59E+05 1.24E+06 3.96E+01 1.09E+00 8.76E+01 3.60E+03

27 1.62E+05 1.24E+06 3.96E+01 1.09E+00 8.75E+01 3.60E+03

28 1.66E+05 1.24E+06 3.96E+01 1.09E+00 8.74E+01 3.60E+03

29 1.69E+05 1.24E+06 3.96E+01 1.09E+00 8.73E+01 3.42E+03
B-10

Table B-2 Plume parameters used in the Peach Bottom unmitigated LTSBO and 

STSBO with and without RCIC blackstart scenarios (continued)

Peach Bottom STSBO with RCIC Blackstart

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

1 6.09E+04 8.80E+06 3.96E+01 9.42E-01 1.40E+02 3.60E+03

2 6.09E+04 9.39E+05 4.00E+00 6.17E-01 6.61E+00 3.60E+03

3 6.45E+04 3.69E+06 3.96E+01 1.01E+00 1.29E+02 3.60E+03

4 6.81E+04 3.63E+06 3.96E+01 1.02E+00 1.27E+02 3.60E+03

5 7.17E+04 3.18E+06 3.96E+01 1.03E+00 1.22E+02 3.63E+03

6 7.54E+04 2.84E+06 3.96E+01 1.04E+00 1.17E+02 3.60E+03

7 7.90E+04 2.45E+06 3.96E+01 1.05E+00 1.11E+02 3.60E+03

8 8.26E+04 2.11E+06 3.96E+01 1.06E+00 1.06E+02 3.60E+03

9 8.62E+04 1.91E+06 3.96E+01 1.07E+00 1.03E+02 3.60E+03

10 8.98E+04 1.73E+06 3.96E+01 1.07E+00 9.92E+01 3.60E+03

11 9.34E+04 1.58E+06 3.96E+01 1.08E+00 9.64E+01 3.60E+03

12 9.70E+04 1.48E+06 3.96E+01 1.08E+00 9.43E+01 3.60E+03

13 1.01E+05 1.41E+06 3.96E+01 1.08E+00 9.29E+01 3.60E+03

14 1.04E+05 1.36E+06 3.96E+01 1.08E+00 9.18E+01 3.60E+03

15 1.08E+05 1.33E+06 3.96E+01 1.09E+00 9.09E+01 3.60E+03

16 1.11E+05 1.30E+06 3.96E+01 1.09E+00 9.02E+01 3.60E+03

17 1.15E+05 1.34E+06 3.96E+01 1.09E+00 9.09E+01 3.60E+03

18 1.19E+05 1.28E+06 3.96E+01 1.09E+00 9.11E+01 3.60E+03

19 1.22E+05 1.27E+06 3.96E+01 1.09E+00 8.92E+01 3.60E+03

20 1.26E+05 1.27E+06 3.96E+01 1.09E+00 8.90E+01 3.60E+03

21 1.29E+05 1.26E+06 3.96E+01 1.09E+00 8.87E+01 3.60E+03

22 1.33E+05 1.26E+06 3.96E+01 1.09E+00 8.85E+01 3.60E+03

23 1.37E+05 1.26E+06 3.96E+01 1.09E+00 8.84E+01 3.60E+03

24 1.40E+05 1.25E+06 3.96E+01 1.09E+00 8.83E+01 3.60E+03

25 1.44E+05 1.25E+06 3.96E+01 1.09E+00 8.82E+01 3.60E+03

26 1.47E+05 1.25E+06 3.96E+01 1.09E+00 8.81E+01 3.60E+03

27 1.51E+05 1.25E+06 3.96E+01 1.09E+00 8.80E+01 3.60E+03

28 1.55E+05 1.25E+06 3.96E+01 1.09E+00 8.80E+01 3.60E+03

29 1.58E+05 1.25E+06 3.96E+01 1.09E+00 8.78E+01 3.60E+03

30 1.62E+05 1.24E+06 3.96E+01 1.09E+00 8.78E+01 3.60E+03

31 1.65E+05 1.24E+06 3.96E+01 1.09E+00 8.77E+01 3.60E+03

32 1.69E+05 1.24E+06 3.96E+01 1.09E+00 8.76E+01 3.60E+03

33 1.73E+05 1.24E+06 3.96E+01 1.09E+00 6.56E+01 2.40E+02
B-11

Table B-2 Plume parameters used in the Peach Bottom unmitigated LTSBO and 

STSBO with and without RCIC blackstart scenarios (continued)

Peach Bottom STSBO without RCIC Blackstart

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

1 2.93E+04 1.94E+00 1.75E+01 1.11E+00 1.94E+00 3.60E+03

2 3.05E+04 4.02E+01 3.96E+01 6.64E-01 4.02E+01 3.60E+03

3 3.05E+04 2.17E+01 4.00E+00 6.43E-01 2.17E+01 3.60E+03

4 3.12E+04 1.44E+02 3.96E+01 9.81E-01 1.44E+02 3.66E+03

5 3.41E+04 8.34E+00 4.00E+00 5.24E-01 8.34E+00 3.62E+03

6 3.48E+04 1.18E+02 3.96E+01 1.05E+00 1.18E+02 3.56E+03

7 3.77E+04 3.85E+00 4.00E+00 5.49E-01 3.85E+00 3.60E+03

8 3.84E+04 1.04E+02 3.96E+01 1.07E+00 1.04E+02 3.60E+03

9 4.01E+04 1.75E+00 1.75E+01 1.11E+00 1.75E+00 3.60E+03

10 4.13E+04 2.65E+00 4.00E+00 4.72E-01 2.65E+00 3.60E+03

11 4.20E+04 9.13E+01 3.96E+01 1.09E+00 9.13E+01 3.60E+03

12 4.37E+04 3.34E+00 1.75E+01 1.11E+00 3.34E+00 3.60E+03

13 4.56E+04 8.39E+01 3.96E+01 1.11E+00 8.39E+01 3.60E+03

14 4.73E+04 3.59E+00 1.75E+01 1.11E+00 3.59E+00 3.60E+03

15 4.92E+04 8.17E+01 3.96E+01 1.11E+00 8.17E+01 3.60E+03

16 5.09E+04 3.58E+00 1.75E+01 1.11E+00 3.58E+00 3.60E+03

17 5.28E+04 8.04E+01 3.96E+01 1.11E+00 8.04E+01 3.60E+03

18 5.45E+04 3.51E+00 1.75E+01 1.11E+00 3.51E+00 3.60E+03

19 5.64E+04 7.92E+01 3.96E+01 1.12E+00 7.92E+01 3.60E+03

20 5.81E+04 3.41E+00 1.75E+01 1.11E+00 3.41E+00 3.60E+03

21 6.00E+04 7.82E+01 3.96E+01 1.12E+00 7.82E+01 3.60E+03

22 6.17E+04 3.31E+00 1.75E+01 1.12E+00 3.31E+00 3.60E+03

23 6.36E+04 7.75E+01 3.96E+01 1.12E+00 7.75E+01 3.60E+03

24 6.53E+04 3.21E+00 1.75E+01 1.12E+00 3.21E+00 3.60E+03

25 6.72E+04 7.73E+01 3.96E+01 1.12E+00 7.73E+01 3.60E+03

26 6.89E+04 3.14E+00 1.75E+01 1.12E+00 3.14E+00 3.63E+03

27 7.08E+04 7.77E+01 3.96E+01 1.12E+00 7.77E+01 3.60E+03

28 7.25E+04 3.16E+00 1.75E+01 1.12E+00 3.16E+00 3.60E+03

29 7.44E+04 7.77E+01 3.96E+01 1.12E+00 7.77E+01 3.60E+03

30 7.61E+04 3.22E+00 1.75E+01 1.12E+00 3.22E+00 3.60E+03

31 7.80E+04 7.90E+01 3.96E+01 1.12E+00 7.90E+01 3.60E+03

32 7.97E+04 3.35E+00 1.75E+01 1.11E+00 3.35E+00 3.60E+03

33 8.16E+04 8.60E+01 3.96E+01 1.11E+00 8.60E+01 3.60E+03

34 8.33E+04 3.81E+00 1.75E+01 1.11E+00 3.81E+00 3.60E+03

35 8.52E+04 8.83E+01 3.96E+01 1.11E+00 8.83E+01 3.72E+03

36 8.69E+04 4.19E+00 1.75E+01 1.10E+00 4.19E+00 3.60E+03

37 8.82E+04 5.96E-01 3.96E+01 1.11E+00 5.96E-01 3.60E+03

38 8.89E+04 8.60E+01 3.96E+01 1.11E+00 8.60E+01 3.60E+03

39 9.05E+04 4.47E+00 1.75E+01 1.09E+00 4.47E+00 3.60E+03

40 9.18E+04 5.99E-01 3.96E+01 1.11E+00 5.99E-01 3.60E+03

41 9.25E+04 8.72E+01 3.96E+01 1.11E+00 8.72E+01 3.60E+03

42 9.41E+04 4.68E+00 1.75E+01 1.09E+00 4.68E+00 3.60E+03

43 9.54E+04 6.12E-01 3.96E+01 1.11E+00 6.12E-01 3.60E+03

44 9.61E+04 8.79E+01 3.96E+01 1.11E+00 8.79E+01 3.60E+03
B-12

45 9.77E+04 4.89E+00 1.75E+01 1.08E+00 4.89E+00 3.60E+03

46 9.97E+04 8.85E+01 3.96E+01 1.11E+00 8.85E+01 3.60E+03

Plume 

Segment PDELAY PLHEAT PLHITE PLMDEN PLMFLA PLUDUR

47 1.01E+05 5.05E+00 1.75E+01 1.08E+00 5.05E+00 3.60E+03

48 1.03E+05 8.89E+01 3.96E+01 1.10E+00 8.89E+01 3.60E+03

49 1.05E+05 5.18E+00 1.75E+01 1.08E+00 5.18E+00 3.60E+03

50 1.07E+05 8.93E+01 3.96E+01 1.10E+00 8.93E+01 3.60E+03

51 1.09E+05 5.28E+00 1.75E+01 1.07E+00 5.28E+00 3.60E+03

52 1.11E+05 8.95E+01 3.96E+01 1.10E+00 8.95E+01 3.60E+03

53 1.12E+05 5.34E+00 1.75E+01 1.07E+00 5.34E+00 3.60E+03

54 1.14E+05 8.97E+01 3.96E+01 1.10E+00 8.97E+01 3.60E+03

55 1.16E+05 5.39E+00 1.75E+01 1.07E+00 5.39E+00 3.60E+03

56 1.18E+05 8.99E+01 3.96E+01 1.10E+00 8.99E+01 3.60E+03

57 1.19E+05 5.44E+00 1.75E+01 1.07E+00 5.44E+00 3.60E+03

58 1.21E+05 9.00E+01 3.96E+01 1.10E+00 9.00E+01 3.60E+03

59 1.23E+05 5.47E+00 1.75E+01 1.07E+00 5.47E+00 3.60E+03

60 1.25E+05 9.01E+01 3.96E+01 1.10E+00 9.01E+01 3.60E+03

61 1.27E+05 5.50E+00 1.75E+01 1.07E+00 5.50E+00 3.60E+03

62 1.29E+05 9.02E+01 3.96E+01 1.10E+00 9.02E+01 3.60E+03

63 1.30E+05 5.53E+00 1.75E+01 1.07E+00 5.53E+00 3.60E+03

64 1.32E+05 9.01E+01 3.96E+01 1.10E+00 9.01E+01 3.60E+03

65 1.34E+05 5.56E+00 1.75E+01 1.06E+00 5.56E+00 3.60E+03

66 1.36E+05 9.02E+01 3.96E+01 1.10E+00 9.02E+01 3.60E+03

67 1.37E+05 5.57E+00 1.75E+01 1.06E+00 5.57E+00 3.60E+03

68 1.39E+05 9.03E+01 3.96E+01 1.10E+00 9.03E+01 3.60E+03

69 1.41E+05 5.59E+00 1.75E+01 1.06E+00 5.59E+00 3.60E+03

70 1.43E+05 9.03E+01 3.96E+01 1.10E+00 9.03E+01 3.60E+03

71 1.45E+05 5.60E+00 1.75E+01 1.06E+00 5.60E+00 3.60E+03

72 1.47E+05 9.03E+01 3.96E+01 1.10E+00 9.03E+01 3.60E+03

73 1.48E+05 5.62E+00 1.75E+01 1.06E+00 5.62E+00 3.60E+03

74 1.50E+05 9.03E+01 3.96E+01 1.10E+00 9.03E+01 3.60E+03

75 1.52E+05 5.63E+00 1.75E+01 1.06E+00 5.63E+00 3.60E+03

76 1.54E+05 9.03E+01 3.96E+01 1.10E+00 9.03E+01 3.60E+03

77 1.55E+05 5.64E+00 1.75E+01 1.06E+00 5.64E+00 3.60E+03

78 1.57E+05 9.02E+01 3.96E+01 1.10E+00 9.02E+01 3.60E+03

79 1.59E+05 5.65E+00 1.75E+01 1.06E+00 5.65E+00 3.60E+03

80 1.61E+05 9.02E+01 3.96E+01 1.10E+00 9.02E+01 3.60E+03

81 1.63E+05 5.66E+00 1.75E+01 1.06E+00 5.66E+00 3.60E+03

82 1.65E+05 9.01E+01 3.96E+01 1.10E+00 9.01E+01 3.60E+03

83 1.66E+05 5.68E+00 1.75E+01 1.06E+00 5.68E+00 3.60E+03

84 1.68E+05 9.00E+01 3.96E+01 1.10E+00 9.00E+01 3.60E+03

85 1.70E+05 5.68E+00 1.75E+01 1.06E+00 5.68E+00 3.06E+03

86 1.72E+05 8.98E+01 3.96E+01 1.10E+00 8.98E+01 1.08E+03

Table B-2 Plume parameters used in the Peach Bottom unmitigated LTSBO and STSBO 

with and without RCIC blackstart scenarios (continued)
B-13

Table B-3 Plume parameters used in the Peach Bottom unmitigated LTSBO and 

STSBO with and without RCIC blackstart scenarios

Peach Bottom LTSBO

Class Bin 1 Bin 2 Bin 3 Bin 4 Bin 5 Bin 6 Bin 7 Bin 8 Bin 9 Bin 10

Xe 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000

Cs 0.1171 0.1602 0.3303 0.3061 0.0575 0.0180 0.0071 0.0025 0.0009 0.0004

Ba 0.0412 0.2230 0.4450 0.2275 0.0486 0.0111 0.0030 0.0005 0.0001 0.0001

I 0.0231 0.1503 0.5219 0.2579 0.0333 0.0102 0.0027 0.0005 0.0001 0.0000

Te 0.0286 0.1370 0.4603 0.2779 0.0643 0.0249 0.0059 0.0009 0.0002 0.0001

Ru 0.0393 0.1512 0.3597 0.2682 0.1214 0.0484 0.0104 0.0011 0.0002 0.0001

Mo 0.1553 0.1638 0.2563 0.3259 0.0649 0.0202 0.0087 0.0033 0.0012 0.0005

Ce 0.0306 0.1930 0.4357 0.2427 0.0708 0.0218 0.0047 0.0005 0.0001 0.0001

La 0.0235 0.1473 0.3990 0.2664 0.1109 0.0433 0.0089 0.0007 0.0000 0.0000

Table B-3 Plume parameters used in the Peach Bottom unmitigated LTSBO and 

STSBO with and without RCIC blackstart scenarios (continued)

Peach Bottom STSBO with RCIC Blackstart

Class Bin 1 Bin 2 Bin 3 Bin 4 Bin 5 Bin 6 Bin 7 Bin 8 Bin 9 Bin 10

Xe 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000

Cs 0.1704 0.1914 0.2388 0.2874 0.0796 0.0169 0.0094 0.0039 0.0017 0.0005

Ba 0.0303 0.1751 0.4211 0.3035 0.0581 0.0084 0.0023 0.0008 0.0003 0.0001

I 0.0322 0.1958 0.4343 0.2527 0.0634 0.0164 0.0040 0.0008 0.0003 0.0001

Te 0.0499 0.1770 0.3605 0.2675 0.0987 0.0353 0.0088 0.0016 0.0005 0.0001

Ru 0.0501 0.1443 0.2997 0.3035 0.1406 0.0480 0.0114 0.0017 0.0005 0.0001

Mo 0.2081 0.1901 0.1871 0.2966 0.0834 0.0167 0.0108 0.0047 0.0021 0.0006

Ce 0.0188 0.1393 0.4164 0.3264 0.0786 0.0164 0.0034 0.0005 0.0001 0.0001

La 0.0218 0.1333 0.3404 0.3148 0.1352 0.0442 0.0093 0.0008 0.0001 0.0000

Table B-3 Plume parameters used in the Peach Bottom unmitigated LTSBO and 

STSBO with and without RCIC blackstart scenarios (continued)

Peach Bottom STSBO without RCIC Blackstart

Class Bin 1 Bin 2 Bin 3 Bin 4 Bin 5 Bin 6 Bin 7 Bin 8 Bin 9 Bin 10

Xe 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000 0.1000

Cs 0.0288 0.2922 0.2076 0.2174 0.1847 0.0587 0.0089 0.0012 0.0002 0.0003

Ba 0.0178 0.0546 0.1120 0.3364 0.3641 0.0994 0.0135 0.0018 0.0002 0.0001

I 0.0282 0.5160 0.2181 0.1261 0.0864 0.0217 0.0023 0.0003 0.0003 0.0006

Te 0.0393 0.3360 0.2596 0.2010 0.1225 0.0376 0.0034 0.0004 0.0001 0.0001

Ru 0.0323 0.0946 0.1503 0.2915 0.2935 0.1127 0.0209 0.0036 0.0005 0.0003

Mo 0.0300 0.1217 0.1995 0.2859 0.2584 0.0880 0.0141 0.0020 0.0002 0.0002

Ce 0.0219 0.0558 0.1024 0.3281 0.3666 0.1076 0.0151 0.0021 0.0002 0.0002

La 0.0203 0.0724 0.1218 0.3231 0.3501 0.0976 0.0127 0.0016 0.0002 0.0002
B-14

Table B-4 Release fraction parameters used in the Peach Bottom unmitigated LTSBO 

and STSBO with and without RCIC blackstart scenarios

Peach Bottom LTSBO

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

1 8.75E-01 2.32E-03 1.17E-03 1.65E-03 1.73E-03 1.31E-06 6.39E-04 1.32E-05 1.91E-06

2 7.93E-02 3.29E-04 2.01E-05 4.99E-05 1.27E-04 9.46E-08 9.48E-05 1.85E-07 2.79E-08

3 1.71E-02 2.47E-04 3.24E-03 2.27E-03 4.00E-04 7.92E-07 2.52E-05 4.90E-05 3.49E-06

4 3.23E-03 1.39E-04 5.75E-04 1.10E-03 3.01E-04 7.10E-07 1.65E-05 1.01E-05 2.83E-06

5 7.40E-04 4.24E-04 1.48E-04 6.08E-03 7.48E-03 4.11E-07 7.67E-06 3.23E-06 2.40E-06

6 9.39E-04 2.61E-04 1.15E-04 3.64E-03 1.76E-03 4.13E-07 6.80E-06 2.46E-06 2.05E-06

7 6.99E-04 1.06E-04 7.24E-05 1.22E-03 2.99E-03 4.31E-07 6.98E-06 2.13E-06 1.95E-06

8 2.97E-04 6.06E-05 6.33E-05 5.46E-04 7.42E-04 4.12E-07 6.36E-06 1.74E-06 1.64E-06

9 1.39E-04 8.02E-05 2.80E-05 8.82E-04 3.63E-04 4.13E-07 5.89E-06 1.23E-06 1.18E-06

10 8.46E-05 7.28E-05 2.15E-05 8.05E-04 4.03E-04 4.21E-07 5.29E-06 1.71E-06 1.69E-06

11 5.97E-05 5.33E-05 1.02E-05 5.08E-04 2.82E-04 4.19E-07 5.07E-06 1.65E-06 1.63E-06

12 4.96E-05 3.33E-05 4.59E-06 1.56E-04 2.06E-04 4.11E-07 5.63E-06 1.57E-06 1.55E-06

13 4.42E-05 3.02E-05 5.34E-06 9.41E-05 2.47E-04 4.01E-07 6.04E-06 1.45E-06 1.44E-06

14 3.96E-05 2.74E-05 1.36E-05 7.53E-05 3.13E-04 3.94E-07 5.77E-06 1.35E-06 1.34E-06

15 3.59E-05 2.63E-05 2.23E-05 6.53E-05 4.07E-04 3.84E-07 5.62E-06 1.26E-06 1.25E-06

16 3.34E-05 2.66E-05 5.12E-06 6.08E-05 3.28E-04 3.78E-07 5.74E-06 1.19E-06 1.18E-06

17 3.06E-05 2.76E-05 4.04E-06 6.02E-05 3.34E-04 3.70E-07 5.98E-06 1.12E-06 1.11E-06

18 2.93E-05 2.85E-05 4.33E-06 5.94E-05 3.93E-04 3.62E-07 6.36E-06 1.05E-06 1.04E-06

19 2.71E-05 3.00E-05 4.34E-06 6.02E-05 3.89E-04 3.53E-07 6.84E-06 9.87E-07 9.83E-07

20 2.55E-05 3.23E-05 8.15E-06 6.31E-05 2.78E-04 3.44E-07 7.41E-06 9.35E-07 9.31E-07

21 2.27E-05 3.47E-05 1.38E-05 6.71E-05 2.68E-04 3.35E-07 8.10E-06 8.90E-07 8.86E-07

22 2.11E-05 3.65E-05 5.32E-06 7.33E-05 2.96E-04 3.07E-07 8.54E-06 8.51E-07 8.47E-07

23 2.05E-05 4.15E-05 5.60E-06 8.51E-05 3.42E-04 3.09E-07 9.73E-06 8.15E-07 8.12E-07

24 1.95E-05 4.67E-05 5.86E-06 1.02E-04 3.42E-04 3.06E-07 1.09E-05 7.82E-07 7.78E-07

25 1.86E-05 5.16E-05 6.03E-06 1.27E-04 3.43E-04 2.99E-07 1.18E-05 7.53E-07 7.50E-07

26 1.82E-05 5.72E-05 6.11E-06 1.61E-04 3.53E-04 2.92E-07 1.28E-05 7.26E-07 7.23E-07

27 1.74E-05 6.10E-05 6.32E-06 2.05E-04 3.79E-04 2.86E-07 1.31E-05 6.99E-07 6.96E-07

28 1.67E-05 3.25E-05 6.38E-06 1.11E-04 3.51E-04 2.79E-07 6.72E-06 6.75E-07 6.72E-07

29 1.54E-05 2.55E-05 6.04E-06 7.60E-05 1.98E-04 2.59E-07 5.37E-06 6.19E-07 6.16E-07
B-15

Table B-4 Release fraction parameters used in the Peach Bottom unmitigated LTSBO 

and STSBO with and without RCIC blackstart scenarios (continued)

Peach Bottom STSBO with RCIC Blackstart

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

1 8.60E-01 2.42E-03 1.66E-03 1.90E-03 2.29E-03 1.20E-06 6.56E-04 1.68E-05 2.13E-06

2 8.85E-02 4.22E-04 3.99E-05 7.02E-05 2.09E-04 1.32E-07 1.20E-04 2.40E-07 3.26E-08

3 2.02E-02 2.15E-04 4.28E-03 2.29E-03 8.33E-04 4.01E-07 1.76E-05 7.56E-05 3.61E-06

4 5.32E-03 1.02E-04 5.37E-04 1.07E-03 3.48E-04 3.81E-07 7.97E-06 1.00E-05 2.41E-06

5 1.51E-03 6.39E-05 8.13E-05 6.60E-04 2.14E-04 3.61E-07 5.06E-06 3.33E-06 2.45E-06

6 8.70E-04 1.26E-04 4.44E-05 1.75E-03 1.75E-03 2.84E-07 3.25E-06 2.42E-06 2.15E-06

7 8.32E-04 7.58E-05 5.18E-05 1.05E-03 7.84E-04 2.15E-07 2.03E-06 2.14E-06 1.90E-06

8 4.41E-04 1.04E-04 4.80E-05 1.50E-03 6.51E-04 2.40E-07 1.70E-06 1.28E-06 1.16E-06

9 2.13E-04 4.35E-05 5.05E-05 5.72E-04 1.71E-03 2.57E-07 1.61E-06 1.80E-06 1.75E-06

10 1.20E-04 2.69E-05 5.92E-05 3.06E-04 7.49E-04 2.65E-07 1.71E-06 1.71E-06 1.68E-06

11 7.74E-05 1.51E-05 2.86E-05 9.63E-05 2.02E-04 2.67E-07 2.06E-06 1.61E-06 1.60E-06

12 4.05E-05 1.61E-05 3.02E-05 7.74E-05 1.96E-04 2.66E-07 2.56E-06 1.51E-06 1.50E-06

13 4.17E-05 1.40E-05 2.40E-05 6.22E-05 2.37E-04 2.62E-07 2.53E-06 1.40E-06 1.39E-06

14 5.76E-05 1.33E-05 3.86E-05 5.33E-05 3.01E-04 2.59E-07 2.49E-06 1.31E-06 1.30E-06

15 5.39E-05 1.29E-05 5.58E-05 4.97E-05 3.54E-04 2.56E-07 2.42E-06 1.23E-06 1.22E-06

16 4.91E-05 1.31E-05 1.47E-05 4.81E-05 2.81E-04 2.49E-07 2.49E-06 1.16E-06 1.15E-06

17 4.75E-05 4.58E-05 5.74E-05 3.28E-04 9.72E-04 3.29E-07 6.42E-06 1.09E-06 1.08E-06

18 4.05E-05 2.05E-05 1.58E-05 1.52E-04 5.36E-04 2.12E-07 2.83E-06 1.02E-06 1.01E-06

19 3.79E-05 1.84E-05 6.90E-06 1.27E-04 2.59E-04 2.10E-07 2.71E-06 9.75E-07 9.68E-07

20 3.53E-05 1.56E-05 7.82E-06 6.08E-05 2.72E-04 2.05E-07 3.13E-06 9.28E-07 9.22E-07

21 3.25E-05 1.68E-05 8.97E-06 5.73E-05 1.65E-04 1.88E-07 3.55E-06 8.86E-07 8.80E-07

22 2.99E-05 1.87E-05 7.47E-06 6.39E-05 1.64E-04 1.71E-07 3.99E-06 8.47E-07 8.41E-07

23 2.83E-05 2.15E-05 4.55E-06 7.57E-05 1.81E-04 1.69E-07 4.60E-06 8.11E-07 8.06E-07

24 2.66E-05 2.48E-05 4.35E-06 9.32E-05 2.02E-04 1.65E-07 5.26E-06 7.80E-07 7.75E-07

25 2.49E-05 2.88E-05 4.28E-06 1.17E-04 2.28E-04 1.61E-07 5.96E-06 7.50E-07 7.46E-07

26 2.35E-05 3.33E-05 4.23E-06 1.50E-04 2.59E-04 1.57E-07 6.64E-06 7.22E-07 7.18E-07

27 2.22E-05 3.17E-05 4.17E-06 8.83E-05 2.95E-04 1.54E-07 7.34E-06 6.96E-07 6.92E-07

28 2.09E-05 3.06E-05 4.11E-06 6.29E-05 1.87E-04 1.50E-07 7.47E-06 6.70E-07 6.66E-07

29 1.96E-05 2.42E-05 4.06E-06 7.08E-05 1.19E-04 1.45E-07 5.43E-06 6.45E-07 6.42E-07

30 1.85E-05 2.15E-05 4.01E-06 8.06E-05 1.19E-04 1.42E-07 4.46E-06 6.24E-07 6.21E-07

31 1.76E-05 1.40E-05 3.96E-06 9.33E-05 1.21E-04 1.39E-07 2.02E-06 6.03E-07 6.00E-07

32 1.66E-05 1.50E-05 3.92E-06 1.09E-04 1.22E-04 1.36E-07 2.04E-06 5.83E-07 5.80E-07

33 1.01E-06 1.06E-06 2.59E-07 7.85E-06 8.25E-06 9.00E-09 1.39E-07 3.82E-08 3.80E-08
B-16

Peach Bottom STSBO without RCIC Blackstart

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

1 1.13E-03 5.67E-06 9.10E-05 1.11E-05 9.18E-06 4.79E-09 1.41E-06 8.74E-06 1.16E-07

2 5.21E-01 2.40E-03 2.98E-02 3.75E-03 3.58E-03 2.58E-06 6.15E-04 2.95E-03 3.72E-05

3 7.48E-02 3.61E-04 1.09E-02 1.29E-03 9.89E-04 2.26E-07 7.37E-05 8.41E-04 1.41E-05

4 1.98E-01 8.81E-04 3.80E-02 4.19E-03 3.15E-03 3.02E-07 1.49E-04 2.66E-03 4.90E-05

5 3.70E-03 8.13E-05 1.69E-04 2.12E-04 2.11E-04 8.78E-09 1.58E-05 7.26E-06 4.70E-07

6 2.01E-02 3.61E-04 1.18E-03 8.66E-04 8.98E-04 5.36E-08 7.27E-05 6.02E-05 2.34E-06

7 1.16E-03 5.96E-05 5.39E-04 1.03E-04 7.69E-05 3.28E-09 1.33E-05 2.25E-06 1.84E-07

8 1.08E-02 4.65E-04 3.59E-03 6.22E-04 3.91E-04 3.09E-08 1.09E-04 3.11E-05 1.48E-06

9 1.12E-03 7.34E-06 1.01E-04 1.63E-05 1.36E-05 3.48E-09 1.66E-06 7.42E-06 1.20E-07

10 5.67E-04 3.23E-05 6.83E-05 1.24E-05 3.72E-05 1.82E-09 8.03E-06 1.37E-06 1.05E-07

11 6.67E-03 2.46E-04 5.78E-04 1.27E-04 4.14E-04 1.88E-08 5.93E-05 1.84E-05 9.53E-07

12 1.95E-03 1.55E-05 1.70E-04 2.80E-05 2.78E-05 5.78E-09 3.57E-06 1.20E-05 2.05E-07

13 5.32E-03 2.57E-04 8.56E-04 2.24E-04 1.99E-04 1.34E-08 5.84E-05 1.05E-05 8.08E-07

14 1.95E-03 1.91E-05 1.71E-04 3.02E-05 2.88E-05 5.45E-09 4.37E-06 1.10E-05 2.00E-07

15 5.01E-03 2.81E-04 1.58E-03 4.31E-04 1.25E-04 1.07E-08 6.18E-05 8.28E-06 8.70E-07

16 1.81E-03 2.17E-05 1.76E-04 3.38E-05 2.65E-05 4.75E-09 4.92E-06 9.33E-06 1.85E-07

17 4.78E-03 2.98E-04 1.18E-03 4.10E-04 1.11E-04 9.07E-09 6.94E-05 7.01E-06 1.12E-06

18 1.66E-03 2.39E-05 1.65E-04 3.66E-05 2.39E-05 4.07E-09 5.45E-06 7.79E-06 1.75E-07

19 4.60E-03 3.20E-04 4.99E-04 5.76E-04 1.05E-04 7.47E-09 7.33E-05 5.77E-06 1.05E-06

20 1.51E-03 2.55E-05 1.45E-04 4.10E-05 2.16E-05 3.46E-09 5.82E-06 6.46E-06 1.63E-07

21 4.40E-03 2.53E-04 7.84E-04 5.51E-04 1.00E-04 6.58E-09 5.32E-05 4.84E-06 9.73E-07

22 1.38E-03 2.56E-05 1.34E-04 4.37E-05 1.95E-05 2.95E-09 5.76E-06 5.36E-06 1.51E-07

23 4.23E-03 2.36E-04 1.13E-03 3.10E-04 9.64E-05 5.95E-09 5.24E-05 4.13E-06 9.16E-07

24 1.26E-03 2.51E-05 1.30E-04 4.04E-05 1.77E-05 2.51E-09 5.66E-06 4.45E-06 1.40E-07

25 4.11E-03 2.21E-04 6.95E-04 4.65E-05 1.03E-04 5.46E-09 5.58E-05 3.58E-06 8.67E-07

26 1.17E-03 2.47E-05 1.17E-04 3.42E-05 1.64E-05 2.17E-09 5.66E-06 3.74E-06 1.31E-07

27 3.96E-03 2.34E-04 8.36E-05 4.40E-05 1.19E-04 5.02E-09 5.98E-05 3.10E-06 8.24E-07

28 1.11E-03 2.13E-05 8.54E-05 2.53E-05 1.37E-05 1.63E-09 4.98E-06 2.73E-06 1.06E-07

29 3.89E-03 2.44E-04 5.21E-05 5.61E-05 1.44E-04 4.51E-09 6.33E-05 2.47E-06 7.83E-07

30 1.07E-03 1.91E-05 6.14E-05 1.89E-05 1.21E-05 1.23E-09 4.56E-06 1.97E-06 8.78E-08

31 4.12E-03 2.36E-04 3.97E-05 8.28E-05 1.83E-04 4.41E-09 6.07E-05 2.03E-06 7.60E-07

32 1.07E-03 1.91E-05 4.95E-05 1.80E-05 1.30E-05 1.05E-09 4.62E-06 1.60E-06 8.31E-08

33 9.23E-03 1.43E-04 3.99E-05 5.78E-04 2.49E-04 3.51E-09 2.73E-05 2.15E-06 8.15E-07

34 1.24E-03 2.04E-05 4.70E-05 2.90E-05 1.71E-05 1.04E-09 4.77E-06 1.54E-06 9.33E-08

35 7.72E-03 3.45E-04 7.37E-05 4.52E-03 4.74E-04 3.31E-09 1.42E-05 3.19E-06 7.50E-07

36 1.38E-03 3.17E-05 4.54E-05 2.02E-04 3.07E-05 1.03E-09 4.80E-06 1.48E-06 1.04E-07

37 3.22E-05 9.69E-06 6.78E-07 1.42E-04 9.97E-06 2.30E-11 1.35E-07 2.05E-08 4.80E-09

38 4.20E-03 1.54E-03 8.71E-05 2.28E-02 1.69E-03 3.07E-09 1.89E-05 2.77E-06 6.85E-07

39 1.38E-03 6.87E-05 4.21E-05 7.82E-04 7.56E-05 9.79E-10 4.74E-06 1.36E-06 1.10E-07

40 2.06E-05 1.04E-05 3.48E-07 1.56E-04 1.99E-05 1.55E-11 1.08E-07 1.30E-08 4.52E-09

41 2.80E-03 1.48E-03 4.78E-05 2.21E-02 3.45E-03 2.18E-09 1.55E-05 1.70E-06 6.50E-07

42 1.32E-03 1.02E-04 3.79E-05 1.31E-03 1.79E-04 9.09E-10 4.56E-06 1.22E-06 1.14E-07

43 1.50E-05 8.34E-06 3.61E-07 1.24E-04 4.99E-05 1.48E-11 1.14E-07 9.31E-09 4.34E-09

44 2.02E-03 1.09E-03 5.50E-05 1.61E-02 8.02E-03 2.14E-09 1.68E-05 1.30E-06 6.17E-07

45 1.24E-03 1.20E-04 3.44E-05 1.60E-03 4.07E-04 8.48E-10 4.46E-06 1.09E-06 1.18E-07

46 1.47E-03 6.02E-04 8.16E-05 8.38E-03 9.10E-03 2.10E-09 1.91E-05 1.15E-06 5.85E-07

Table B-4 Release fraction parameters used in the Peach Bottom unmitigated LTSBO 

and STSBO with and without RCIC blackstart scenarios (continued)
B-17

47 1.14E-03 1.21E-04 3.21E-05 1.63E-03 6.55E-04 7.90E-10 4.44E-06 9.64E-07 1.19E-07

Peach Bottom STSBO without RCIC Blackstart

Plume 

Segment Xe Cs Ba I Te Ru Mo Ce La

48 1.09E-03 3.24E-04 1.06E-04 4.00E-03 1.11E-02 1.94E-09 1.95E-05 1.03E-06 5.55E-07

49 1.02E-03 1.13E-04 3.06E-05 1.51E-03 9.56E-04 7.32E-10 4.43E-06 8.44E-07 1.20E-07

50 8.15E-04 1.99E-04 9.58E-05 1.94E-03 1.45E-02 1.92E-09 2.07E-05 9.29E-07 5.30E-07

51 9.09E-04 1.01E-04 2.89E-05 1.32E-03 1.29E-03 6.76E-10 4.43E-06 7.34E-07 1.19E-07

52 6.24E-04 1.37E-04 9.13E-05 1.02E-03 7.55E-03 1.77E-09 1.95E-05 8.48E-07 5.07E-07

53 7.96E-04 8.88E-05 2.73E-05 1.13E-03 1.33E-03 6.23E-10 4.39E-06 6.34E-07 1.17E-07

54 4.85E-04 1.21E-04 1.08E-04 7.21E-04 3.31E-03 1.77E-09 2.02E-05 7.73E-07 4.86E-07

55 6.92E-04 7.77E-05 2.66E-05 9.60E-04 1.22E-03 5.78E-10 4.37E-06 5.48E-07 1.14E-07

56 3.85E-04 1.17E-04 1.29E-04 6.32E-04 1.97E-03 1.74E-09 2.06E-05 7.12E-07 4.67E-07

57 6.00E-04 6.84E-05 2.66E-05 8.14E-04 1.08E-03 5.39E-10 4.37E-06 4.74E-07 1.12E-07

58 3.12E-04 1.16E-04 9.57E-05 6.42E-04 1.57E-03 1.66E-09 1.99E-05 6.61E-07 4.50E-07

59 5.16E-04 6.05E-05 2.53E-05 6.92E-04 9.41E-04 5.04E-10 4.35E-06 4.11E-07 1.09E-07

60 2.58E-04 1.20E-04 4.82E-05 6.56E-04 1.55E-03 1.64E-09 2.08E-05 5.93E-07 4.34E-07

61 4.43E-04 5.39E-05 2.24E-05 5.88E-04 8.29E-04 4.73E-10 4.36E-06 3.56E-07 1.06E-07

62 2.17E-04 8.83E-05 2.79E-05 2.00E-04 1.60E-03 1.59E-09 2.01E-05 5.49E-07 4.19E-07

63 3.80E-04 4.74E-05 1.93E-05 4.89E-04 7.40E-04 4.47E-10 4.34E-06 3.09E-07 1.03E-07

64 1.86E-04 8.44E-05 2.10E-05 1.31E-04 1.72E-03 1.58E-09 2.01E-05 5.17E-07 4.04E-07

65 3.25E-04 4.20E-05 1.65E-05 4.04E-04 6.72E-04 4.25E-10 4.34E-06 2.70E-07 9.95E-08

66 1.62E-04 8.79E-05 1.92E-05 1.06E-04 1.92E-03 1.60E-09 2.15E-05 4.88E-07 3.91E-07

67 2.77E-04 3.76E-05 1.42E-05 3.33E-04 6.24E-04 4.08E-10 4.38E-06 2.37E-07 9.64E-08

68 1.41E-04 8.52E-05 1.77E-05 8.70E-05 1.86E-03 1.51E-09 2.10E-05 4.63E-07 3.79E-07

69 2.36E-04 3.41E-05 1.22E-05 2.74E-04 5.78E-04 3.92E-10 4.42E-06 2.09E-07 9.35E-08

70 1.24E-04 8.90E-05 1.77E-05 7.19E-05 1.22E-03 1.54E-09 2.23E-05 4.38E-07 3.66E-07

71 2.01E-04 3.12E-05 1.06E-05 2.25E-04 5.18E-04 3.79E-10 4.48E-06 1.86E-07 9.06E-08

72 1.11E-04 9.11E-05 1.76E-05 5.95E-05 1.07E-03 1.53E-09 2.30E-05 4.18E-07 3.55E-07

73 1.71E-04 2.90E-05 9.30E-06 1.85E-04 4.61E-04 3.68E-10 4.56E-06 1.66E-07 8.78E-08

74 9.89E-05 9.35E-05 1.73E-05 4.94E-05 6.69E-04 1.55E-09 2.38E-05 4.00E-07 3.46E-07

75 1.46E-04 2.73E-05 8.22E-06 1.52E-04 4.02E-04 3.61E-10 4.67E-06 1.50E-07 8.52E-08

76 8.89E-05 9.70E-05 1.59E-05 4.12E-05 6.33E-04 1.56E-09 2.49E-05 3.85E-07 3.38E-07

77 1.24E-04 2.61E-05 7.29E-06 1.25E-04 3.52E-04 3.55E-10 4.80E-06 1.36E-07 8.28E-08

78 7.95E-05 9.99E-05 1.46E-05 3.43E-05 6.44E-04 1.57E-09 2.58E-05 3.71E-07 3.30E-07

79 1.05E-04 2.52E-05 6.49E-06 1.03E-04 3.12E-04 3.51E-10 4.94E-06 1.24E-07 8.06E-08

80 7.25E-05 9.60E-05 1.36E-05 2.87E-05 6.22E-04 1.50E-09 2.49E-05 3.61E-07 3.26E-07

81 8.96E-05 2.44E-05 5.81E-06 8.46E-05 2.78E-04 3.47E-10 5.04E-06 1.15E-07 7.87E-08

82 6.69E-05 9.50E-05 1.31E-05 2.42E-05 6.00E-04 1.56E-09 2.49E-05 3.55E-07 3.23E-07

83 7.62E-05 2.37E-05 5.24E-06 6.95E-05 2.50E-04 3.45E-10 5.12E-06 1.06E-07 7.71E-08

84 6.12E-05 9.83E-05 1.35E-05 2.04E-05 6.25E-04 1.62E-09 2.67E-05 3.49E-07 3.22E-07

85 5.57E-05 1.98E-05 4.09E-06 4.92E-05 1.96E-04 2.94E-10 4.46E-06 8.52E-08 6.45E-08

86 1.73E-05 3.07E-05 4.19E-06 5.48E-06 1.96E-04 5.06E-10 8.72E-06 1.03E-07 9.65E-08

Table B-4 Release fraction parameters used in the Peach Bottom unmitigated LTSBO 

and STSBO with and without RCIC blackstart scenarios (continued)
B-18

Table B-5 EARLY parameters used in the Peach Bottom unmitigated LTSBO and 

STSBO with and without RCIC blackstart scenarios

Variable Description LTSBO STSBO with RCIC 

Blackstart

STSBO without 

RCIC Blackstart

ACNAME Latent Cancer Effect

Cancer Type 1 LEUKEMIA LEUKEMIA LEUKEMIA

Cancer Type 2 BONE BONE BONE

Cancer Type 3 BREAST BREAST BREAST

Cancer Type 4 LUNG LUNG LUNG

Cancer Type 5 THYROID THYROID THYROID

Cancer Type 6 LIVER LIVER LIVER

Cancer Type 7 COLON COLON COLON

Cancer Type 8 RESIDUAL RESIDUAL RESIDUAL

ACSUSC Population Susceptible to 

Cancer 1.0 for all cancers 1.0 for all cancers 1.0 for all cancers

ACTHRE Linear Dose-Response 

Threshold 0 0 0

BRRATE Breathing Rate (for all 

activity types) 0.000266 0.000266 0.000266

CFRISK Lifetime Cancer Fatality 

Risk Factors

Cancer Type 1 0.0111 0.0111 0.0111

Cancer Type 2 0.00019 0.00019 0.00019

Cancer Type 3 0.00506 0.00506 0.00506

Cancer Type 4 0.0198 0.0198 0.0198

Cancer Type 5 0.000648 0.000648 0.000648

Cancer Type 6 0.003 0.003 0.003

Cancer Type 7 0.0208 0.0208 0.0208

Cancer Type 8 0.0493 0.0493 0.0493

CIRISK Lifetime Cancer Injury Risk 

Factors

Cancer Type 1 0.0113 0.0113 0.0113

Cancer Type 2 0.000271 0.000271 0.000271

Cancer Type 3 0.0101 0.0101 0.0101

Cancer Type 4 0.0208 0.0208 0.0208

Cancer Type 5 0.00648 0.00648 0.00648

Cancer Type 6 0.00316 0.00316 0.00316

Cancer Type 7 0.0378 0.0378 0.0378

Cancer Type 8 0.169 0.169 0.169

CRIORG Critical Organ for EARLY 

Phase L-ICRP60ED L-ICRP60ED L-ICRP60ED

CSFACT Cloudshine Shielding 

Factors

Evacuation Shielding 

Factor for All but Cohort 4 1 1 1

Normal Activity 

Shielding Factor for All 

but Cohort 4

0.6 0.6 0.6

Sheltering Shielding 

Factor for All but Cohort 4 0.5 0.5 0.5
B-19

Variable Description LTSBO STSBO with RCIC 

Blackstart

STSBO without 

RCIC Blackstart

CSFACT Evacuation Shielding 

Factor for Cohort 4 1 1 1

Normal Activity 

Shielding Factor for 

Cohort 4

0.31 0.31 0.31

Sheltering Shielding 

Factor for Cohort 4 0.31 0.31 0.31

DCF_FILE Name of Dose Coefficient

File

FGR13GyEquivDCF

.INP

FGR13GyEquivDCF

.INP

FGR13GyEquivDCF

.INP

DDREFA Dose-Dependent 

Reduction Factor

Cancer Type 1 2 2 2

Cancer Type 2 2 2 2

Cancer Type 3 1 1 1

Cancer Type 4 2 2 2

Cancer Type 5 2 2 2

Cancer Type 6 2 2 2

Cancer Type 7 2 2 2

Cancer Type 8 2 2 2

DDTHRE

Threshold for Applying 

Dose-Dependent 

Reduction Factor

0.2 0.2 0.2

DLTSHL Delay from Alarm Time to 

Shelter

Cohort 1 5400 3600 3600

Cohort 2 5400 3600 3600

Cohort 3 900 900 900

Cohort 4 5400 3600 3600

Cohort 5 5400 3600 3600

Cohort 6 N/A N/A N/A

DLTEVA Delay from Beginning of 

Shelter to Evacuation

Cohort 1 3600 3600 3600

Cohort 2 3600 3600 3600

Cohort 3 2700 2700 2700

Cohort 4 15300 15300 15300

Cohort 5 15300 15300 15300

Cohort 6 N/A N/A N/A

DOSEFA Cancer Dose-Response 

Linear Factors 1 for all organs 1 for all organs 1 for all organs

DOSEFB Cancer Dose-Response 

Quadratic Factors 0 for all organs 0 for all organs 0 for all organs

DOSHOT Hot-Spot Relocation Dose 

Threshold 0.05 0.05 0.05

DOSMOD Dose-Response Model 

Flag LNT, AT LNT, AT LNT, AT

DOSNRM Normal Relocation Dose 

Threshold 0.005 0.005 0.005

DURBEG Duration of Beginning of 

Evacuation Phase

Cohort 1 900 900 900

Table B-5 EARLY parameters used in the Peach Bottom unmitigated LTSBO and STSBO 

with and without RCIC blackstart scenarios (continued)
B-20

Variable Description LTSBO STSBO with RCIC 

Blackstart

STSBO without 

RCIC Blackstart

DURBEG Cohort 2 900 900 900

Cohort 3 3600 3600 3600

Cohort 4 1800 1800 1800

Cohort 5 1800 1800 1800

Cohort 6 N/A N/A N/A

DURMID Duration of Middle of 

Evacuation Phase 10800

Cohort 1 10800 10800 10800

Cohort 2 10800 10800 10800

Cohort 3 1800 1800 1800

Cohort 4 1800 1800 1800

Cohort 5 1800 1800 1800

Cohort 6 N/A N/A N/A

EANAM1 Text Describing the 

EARLY Assumptions

SOARCA 

calculation for 

Peach Bottom 

LTSBO, EARLY 

input

SOARCA 

calculation for 

Peach Bottom 

STSBO, EARLY 

input

SOARCA 

calculation for 

Peach Bottom 

STSBO, EARLY 

input

EANAM2 Text Describing the 

Emergency Response

Cohort 1 Group 1 Group 1 Group 1

Cohort 2 Group 2 Group 2 Group 2

Cohort 3 Group 3 Group 3 Group 3

Cohort 4 Group 4 Group 4 Group 4

Cohort 5 Group 5 Group 5 Group 5

Cohort 6 Group 6 Group 6 Group 6

EFFACA LD50 for Early Fatality 

Types

A-RED MARR 5.6 5.6 5.6

A-LUNGS 23.5 23.5 23.5

A-STOMACH 12.1 12.1 12.1

EFFACB Shape Factor for Early 

Fatality Types

A-RED MARR 6.1 6.1 6.1

A-LUNGS 9.6 9.6 9.6

A-STOMACH 9.3 9.3 9.3

EFFACY Efficacy of the KI Ingestion 0.7 0.7 0.7

EFFTHR Threshold Dose to Target 

Organ

A-RED MARR 2.32 2.32 2.32

A-LUNGS 13.6 13.6 13.6

A-STOMACH 6.5 6.5 6.5

EIFACA LD50 For Early Injuries

PRODROMAL VOMIT 2 2 2

DIARRHEA 3 3 3

PNEUMONITIS 16.6 16.6 16.6

SKIN ERYTHRMA 6 6 6

TRANSEPIDERMAL 20 20 20

THYROIDITIS 240 240 240

Table B-5 EARLY parameters used in the Peach Bottom unmitigated LTSBO and STSBO 

with and without RCIC blackstart scenarios (continued)
B-21

Variable Description LTSBO STSBO with RCIC 

Blackstart

STSBO without 

RCIC Blackstart

EIFACA HYPOTHYROIDISM 60 60 60

EIFACB Shape Factor for Early 

Injuries

PRODROMAL VOMIT 3 3 3

DIARRHEA 2.5 2.5 2.5

PNEUMONITIS 7.3 7.3 7.3

SKIN ERYTHRMA 5 5 5

TRANSEPIDERMAL 5 5 5

THYROIDITIS 2 2 2

HYPOTHYROIDISM 1.3 1.3 1.3

EINAME Early Injury Effect Names 

and Corresponding Organ

PRODROMAL VOMIT A-STOMACH A-STOMACH A-STOMACH

DIARRHEA A-STOMACH A-STOMACH A-STOMACH

PNEUMONITIS A-LUNGS A-LUNGS A-LUNGS

SKIN ERYTHRMA A-SKIN A-SKIN A-SKIN

TRANSEPIDERMAL A-SKIN A-SKIN A-SKIN

THYROIDITIS A-THYROID A-THYROID A-THYROID

HYPOTHYROIDISM A-THYROID A-THYROID A-THYROID

EISUSC Susceptible Population 

Fraction

1. for all health 

effects

1. for all health 

effects

1. for all health 

effects

EITHRE Early Injury Dose 

Threshold

PRODROMAL VOMIT 0.5 0.5 0.5

DIARRHEA 1 1 1

PNEUMONITIS 9.2 9.2 9.2

SKIN ERYTHRMA 3 3 3

TRANSEPIDERMAL 10 10 10

THYROIDITIS 40 40 40

HYPOTHYROIDISM 2 2 2

ENDAT2 Control flag indicating only 

ATMOS and EARLY are to be run .FALSE. .FALSE. .FALSE.

ENDEMP Time Duration for the 

Emergency Phase 604800 604800 604800

ESPEED Evaluation Speed

Initial Evacuation 

Phase, Cohort 1 2.235 2.235 2.235

Middle Evacuation 

Phase, Cohort 1 1.341 1.341 1.341

Late Evacuation 

Phase, Cohort 1 8.941 8.941 8.941

Initial Evacuation 

Phase, Cohort 2 2.235 2.235 2.235

Middle Evacuation 

Phase, Cohort 2 1.341 1.341 1.341

Late Evacuation 

Phase, Cohort 2 8.941 8.941 8.941

Initial Evacuation 

Phase, Cohort 3 8.941 8.941 8.941

Middle Evacuation 

Phase, Cohort 3 8.941 8.941 8.941

Table B-5 EARLY parameters used in the Peach Bottom unmitigated LTSBO and STSBO 

with and without RCIC blackstart scenarios (continued)
B-22

Variable Description LTSBO STSBO with RCIC 

Blackstart

STSBO without 

RCIC Blackstart

ESPEED Late Evacuation 

Phase, Cohort 3 8.941 8.941 8.941

Initial Evacuation 

Phase, Cohort 4 1.341 1.341 1.341

Middle Evacuation 

Phase, Cohort 4 8.941 8.941 8.941

Late Evacuation 

Phase, Cohort 4 8.941 8.941 8.941

Initial Evacuation 

Phase, Cohort 5 1.341 1.341 1.341

Middle Evacuation 

Phase, Cohort 5 8.941 8.941 8.941

Late Evacuation 

Phase, Cohort 5 8.941 8.941 8.941

Cohort 6 N/A N/A N/A

ESPGRD

Speed Multiplier to Account 

for Grid-Level Variations in 

Road Network

Table B-6 Table B-6 Table B-6

ESPMUL Speed Multiplier Employed 

During Precipitation 0.7 0.7 0.7

EVATYP Evacuation Type NETWORK NETWORK NETWORK

GSHFAC Groundshine Shielding 

Factors

Evacuation Shielding 

Factor for All but Cohort 

4

0.5 0.5 0.5

Normal Activity 

Shielding Factor for All 

but Cohort 4

0.18 0.18 0.18

Sheltering Shielding 

Factor for All but Cohort 

4

0.1 0.1 0.1

Evacuation Shielding 

Factor for Cohort 4 0.5 0.5 0.5

Normal Activity 

Shielding Factor for 

Cohort 4

0.05 0.05 0.05

Sheltering Shielding 

Factor for Cohort 4 0.05 0.05 0.05

IDIREC Direction in Network 

Evacuation Model Table B-7 Table B-7 Table B-7

IPLUME Plume Model Dispersion 

Code 3 3 3

KIMODL Model Flag for KI Ingestion KI KI KI

LASMOV Last Ring in Movement 

Zone 17 17 17

NUMACA Number of Latent Cancer 

Health Effects 8 8 8

NUMEFA Number of Early Fatality 

Effects 3 3 3

NUMEIN Number of Early Injury 

Effects 7 7 7

NUMEVA Outer Boundary of 

Evacuation/Shelter Region

Cohort 1 - 15

Cohorts 2 to 5 - 12

Cohort 1 - 15

Cohorts 2 to 5 - 12

Cohort 1 - 15

Cohorts 2 to 5 - 12

Table B-5 EARLY parameters used in the Peach Bottom unmitigated LTSBO and STSBO 

with and without RCIC blackstart scenarios (continued)
B-23

Variable Description LTSBO STSBO with RCIC 

Blackstart

STSBO without 

RCIC Blackstart

NUMFIN Number of Fine Grid 

Subdivisions 7 7 7

ORGFLG Doses to be Calculated for 

Specified Organ

All TRUE for 

FGR-13

All TRUE for 

DOSFAC2 except 

for A-Lower LI and 

L-Liver, which are 

FALSE

All TRUE for FGR-13

All TRUE for 

DOSFAC2 except for 

A-Lower LI and 

L-Liver, which are 

FALSE

All TRUE for FGR-13

All TRUE for 

DOSFAC2 except for 

A-Lower LI and 

L-Liver, which are 

FALSE

OVRRID Wind Rose Probability 

Override .FALSE. .FALSE. .FALSE.

POPFLG Population Distribution 

Flag FILE FILE FILE

POPFRAC Population Fraction 

Ingesting KI

Cohort 1 and 2 - 1.0

Cohort 3 to 6 - 0.0

Cohort 1 and 2 - 1.0

Cohort 3 to 6 - 0.1

Cohort 1 and 2 - 1.0

Cohort 3 to 6 - 0.1

PROTIN 

[E]

Inhalation Protection 

Factor – evacuation for all 

cohorts but cohort 4

0.98 0.98 0.98

PROTIN 

[N]

Inhalation Protection 

Factor - normal activity for 

all cohorts except Cohort 4

0.46 0.46 0.46

PROTIN 

[N]

Inhalation Protection 

Factor - normal activity for 

Cohort 4

0.33 0.33 0.33

PROTIN 

[S]

Inhalation Protection 

Factor - sheltering for all 

cohorts

0.33 0.33 0.33

REFPNT Reference Time Point 

(ARRIVAL or SCRAM) ALARM ALARM ALARM

RESCON Emergency phase 

resuspension coefficient 0.0001 0.0001 0.0001

RESHAF Resuspension 

Concentration Half-Life 182000 182000 182000

RISCAT Risk by Weather-Category 

Flag .FALSE. .FALSE. .FALSE.

RISTHR Risk Threshold for Fatality 

Radius 0 0 0

SKPFAC 

[E]

Skin Protection Factors –

evacuation for all cohorts 0.98 0.98 0.98

SKPFAC 

[N]

Skin Protection Factors -

normal activity for all 

cohorts but cohort 4

0.46 0.46 0.46

SKPFAC 

[N]

Skin Protection Factors -

normal activity for cohort 4 0.33 0.33 0.33

SKPFAC 

[S]

Skin Protection Factors –

sheltering for all cohorts 0.33 0.33 0.33

TIMHOT Hotspot Relocation Time 43200 43200 43200

TIMNRM Normal Relocation Time 86400 86400 86400

TRAVEL 

POINT Evacuee Movement Option CENTERPOINT CENTERPOINT CENTERPOINT

WTFRAC WTFRAC for Scenario 

Cohort 1 0.2 0.2 0.2

Cohort 2 0.355 0.355 0.355

Cohort 3 0.372 0.372 0.372

Table B-5 EARLY parameters used in the Peach Bottom unmitigated LTSBO and STSBO 

with and without RCIC blackstart scenarios (continued)
B-24

Variable Description LTSBO STSBO with RCIC 

Blackstart

STSBO without 

RCIC Blackstart

WTFRAC Cohort 4 0.006 0.006 0.006

Cohort 5 0.062 0.062 0.062

Cohort 6 0.005 0.005 0.005

WTNAME Type of Weighting for 

Cohorts PEOPLE PEOPLE PEOPLE

Table B-5 EARLY parameters used in the Peach Bottom unmitigated LTSBO and STSBO 

with and without RCIC blackstart scenarios (continued)
B-25

Table B-6 Grid-level evacuation speed multipliers used in the Peach Bottom 

unmitigated LTSBO and STSBO with and without RCIC blackstart scenarios

Compass Sector

Radial Ring 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

2 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

3 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

4 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

5 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

6 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

7 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

8 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

9 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

10 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

11 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

12 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

13 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

14 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

15 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

16 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

17 0.75 0.75 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

Table B-6 Grid-level evacuation speed multipliers used in the Peach Bottom 

unmitigated LTSBO and STSBO with and without RCIC blackstart scenarios

(continued)

Compass Sector

Radial Ring 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

1 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

2 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

3 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

4 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

5 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

6 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

7 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

8 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

9 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

10 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

11 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

12 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

13 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

14 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.50 1.50 1.50 1.50 1.50 1.50 1.00 1.00

15 1.00 1.00 1.00 1.00 1.00 1.50 1.50 1.50 1.00 1.00 1.00 1.00 1.00 1.50 1.50 1.50

16 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

17 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
B-26

Table B-6 Grid-level evacuation speed multipliers used in the Peach Bottom 

unmitigated LTSBO and STSBO with and without RCIC blackstart scenarios

(continued)

Compass Sector

Radial Ring 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

1 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

2 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

3 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

4 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

5 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

6 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

7 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

8 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

9 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

10 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

11 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

12 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

13 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

14 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

15 1.50 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

16 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

17 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

Table B-6 Grid-level evacuation speed multipliers used in the Peach Bottom 

unmitigated LTSBO and STSBO with and without RCIC blackstart scenarios

(continued)

Compass Sector

Radial Ring 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

1 100 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

2 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

3 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

4 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

5 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

6 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

7 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

8 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

9 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

10 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

11 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

12 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

13 1.00 1.00 1.00 1.00 1.00 1.00 0.75 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

14 1.00 1.00 1.00 1.00 1.00 1.00 0.75 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

15 1.00 1.00 1.00 1.00 1.00 1.00 0.75 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

16 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75

17 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.75 0.75 0.75
B-27

Table B-7 Evacuation direction parameters used in the Peach Bottom unmitigated 

LTSBO and STSBO with and without RCIC blackstart scenarios

Compass Sector

Radial 

Ring 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

3 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1

4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

5 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4

6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 1

7 2 2 1 2 2 1 2 2 1 4 2 1 4 2 2 1

8 1 4 1 1 4 2 1 4 2 1 1 4 2 2 1 1

9 1 1 4 2 1 1 2 1 1 4 1 4 1 4 1 1

10 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

11 1 1 4 2 1 4 2 1 4 4 2 1 4 2 1 4

12 2 1 1 4 1 1 4 1 4 4 2 1 4 2 1 1

13 1 1 4 1 4 2 1 1 2 1 4 4 2 2 1 1

14 1 1 4 1 1 1 2 1 2 1 2 1 1 2 1 1

15 1 1 4 2 2 2 1 1 1 1 1 1 1 1 1 1

16 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4

17 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

Table B-7 Evacuation direction parameters used in the Peach Bottom unmitigated 

LTSBO and STSBO with and without RCIC blackstart scenarios (continued)

Compass Sector

Radial Ring 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

3 1 1 1 1 1 1 1 1 2 1 4 4 4 4 2 2

4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

5 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 1

6 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2

7 1 1 1 1 1 1 1 1 1 1 2 2 1 4 4 2

8 2 1 1 1 4 4 4 1 1 1 1 1 1 4 1 4

9 1 2 1 1 1 4 4 4 1 1 4 1 2 2 2 1

10 1 1 1 1 1 1 1 1 1 1 1 1 1 4 4 4

11 4 2 2 2 2 2 2 1 4 4 1 1 4 2 2 1

12 4 4 2 2 2 1 4 1 2 1 2 2 1 4 4 2

13 1 1 1 1 1 2 1 2 2 1 1 2 1 4 2 2

14 1 1 1 1 1 4 1 1 1 1 2 1 4 1 1 1

15 1 1 1 1 1 1 1 4 4 4 2 2 2 1 1 1

16 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

17 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
B-28

Table B-7 Evacuation direction parameters used in the Peach Bottom unmitigated 

LTSBO and STSBO with and without RCIC blackstart scenarios (continued)

Compass Sector

Radial Ring 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

3 2 2 2 1 1 1 4 4 4 4 2 2 2 1 1 1

4 4 2 2 1 1 1 1 4 4 4 2 2 1 4 4 2

5 1 1 1 1 2 1 4 4 2 2 1 4 4 2 2 1

6 2 2 1 1 1 1 2 1 1 4 2 2 1 2 1 4

7 1 1 1 1 4 4 2 2 1 1 4 4 1 1 4 1

8 2 1 4 4 2 1 2 1 2 1 4 2 1 4 2 1

9 1 2 1 4 2 1 2 1 2 1 1 4 1 4 1 4

10 2 2 2 2 1 2 1 4 2 1 1 1 4 2 1 4

11 1 1 4 2 1 4 1 4 2 1 4 1 1 2 1 1

12 2 1 1 4 4 2 1 1 1 1 4 1 1 1 1 4

13 1 4 2 1 4 4 1 1 4 2 1 1 2 1 2 1

14 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1

15 1 1 1 1 1 1 1 1 1 1 1 4 1 2 1 1

16 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

17 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

Table B-7 Evacuation direction parameters used in the Peach Bottom unmitigated 

LTSBO and STSBO with and without RCIC blackstart scenarios (continued)

Compass Sector

Radial Ring 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

3 1 1 1 1 1 1 1 1 1 1 1 1 1 4 1 1

4 1 4 4 2 1 1 4 2 1 4 4 4 4 4 1 1

5 4 4 2 2 1 4 4 2 1 1 1 1 1 1 1 1

6 4 2 2 1 4 4 4 4 4 4 4 1 1 1 1 1

7 4 2 2 1 4 4 4 4 4 4 1 1 1 1 1 1

8 1 4 2 1 4 4 4 2 2 1 1 1 1 1 2 2

9 4 2 2 1 4 2 1 4 1 4 1 1 1 2 2 2

10 4 2 2 1 1 1 1 1 4 4 1 1 1 1 1 1

11 4 4 4 2 2 2 1 4 4 4 2 2 1 4 2 2

12 4 4 2 2 2 2 1 4 2 1 1 2 2 1 4 2

13 4 4 2 2 2 1 1 4 2 1 4 2 1 4 1 1

14 1 4 4 2 2 1 1 4 1 4 1 1 1 1 1 1

15 1 4 2 1 2 1 1 2 1 1 2 2 2 1 2 1

16 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

17 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
B-29

Table B-8 CHRONC input parameters used in the Peach Bottom unmitigated LTSBO 

and STSBO with and without RCIC blackstart scenarios

Variable Description LTSBO STSBO with 

RCIC Blackstart

STSBO 

without RCIC 

Blackstart

CHNAME CHRONC Problem Identification

Peach Bottom 

with no FoodChain 

Modeling

Peach Bottom 

with no FoodChain Modeling

Peach Bottom 

with no FoodChain Modeling

CDFRM Farmland Decontamination Cost

Level 1 1330 1330 1330

Level 2 2960 2960 2960

CDNFRM Nonfarmland Decontamination Cost

Level 1 7110 7110 7110

Level 2 19000 19000 19000

CRTOCR Critical Organ for CHRONC Phase L-ICRP60ED L-ICRP60ED L-ICRP60ED

DPRATE Property Depreciation Rate 0.2 0.2 0.2

DLBCST Hourly Labor Cost for 

Decontamination Worker 84000 84000 84000

DPFRCT Farm Production Dairy Fraction Peach Bottom 

Site File

Peach Bottom 

Site File

Peach Bottom 

Site File

DSCRLT Long-Term Phase Dose Criterion 0.005 0.005 0.005

DSCRTI Intermediate-Phase Dose Criterion 100000 100000 100000

DSRATE Societal Discount Rate for Property 0.12 0.12 0.12

DSRFCT Decontamination Factors

Level 1 3 3 3

Level 2 15 15 15

DUR_INTPHAS Duration of the Intermediate Phase 0 0 0

EVACST Emergency Phase Cost of 

Evac./Reloc. 172 172 172

EXPTIM Maximum Exposure Time 1580000000 1580000000 1580000000

FDPATH COMIDA2 vs. MACCS Food Model 

Switch OFF OFF OFF

FRACLD Fraction of Area that is Land Peach Bottom 

Site File

Peach Bottom 

Site File

Peach Bottom 

Site File

FRCFRM Fraction of Area Used for Farming Peach Bottom 

Site File

Peach Bottom 

Site File

Peach Bottom 

Site File

FRFDL Fraction of Decontamination Cost for 

Labor

Level 1 0.3 0.3 0.3

Level 2 0.35 0.35 0.35

FRFIM Farm Wealth Improvements Fraction 0.25 0.25 0.25

FRMPRD Average Annual Farm Production Peach Bottom 

Site File

Peach Bottom 

Site File

Peach Bottom 

Site File

FRNFIM Nonfarm Wealth Improvements 

Fraction 0.8 0.8 0.8

FRNFDL Nonfarm Labor Cost Fraction

Level 1 0.7 0.7 0.7

Level 2 0.5 0.5 0.5

GWCOEF Long-Term Groundshine Coefficients

Term 1 0.5 0.5 0.5

Term 2 0.5 0.5 0.5

KSWTCH Diagnostic Output Option Switch 0 0 0

LBRRATE Long-Term Breathing Rate 0.000266 0.000266 0.000266
B-30

Variable Description LTSBO STSBO with 

RCIC Blackstart

STSBO 

without RCIC 

Blackstart

LGSHFAC Long-Term Groundshine Protection 

Factor 0.18 0.18 0.18

LPROTIN Long-Term Inhalation Protection 

Factor 0.46 0.46 0.46

LVLDEC Number of Decontamination Levels 2 2 2

NGWTRM Number of Terms in Groundshine 

Weathering Equation 2 2 2

NRWTRM Number of Terms in Resuspension 

Weathering Equation 3 3 3

POPCST Per Capita Cost of Long-Term 

Relocation 12000 12000 12000

RELCST Relocation Cost per Person-Day 172 172 172

RWCOEF Long-Term Resuspension Factor 

Coefficients

Term 1 0.00001 0.00001 0.00001

Term 2 0.0000001 0.0000001 0.0000001

Term 3 0.00000001 0.00000001 0.00000001

TFWKF Fraction Farmland Worker Time in 

Contaminated Zone

Level 1 0.1 0.1 0.1

Level 2 0.33 0.33 0.33

TFWKNF Fraction Nonfarmland Worker Time 

in Contaminated Zone

Level 1 0.33 0.33 0.33

Level 2 0.33 0.33 0.33

TGWHLF Groundshine Weathering Half-Lives

Term 1 16000000 16000000 16000000

Term 2 2800000000 2800000000 2800000000

TIMDEC Decontamination Times

Level 1 5184000 5184000 5184000

Level 2 10368000 10368000 10368000

TMPACT Time Action Period Ends 31600000 31600000 31600000

TRWHLF Resuspension Weathering Half-Lives

Term 1 16000000 16000000 16000000

Term 2 160000000 160000000 160000000

Term 3 1600000000 1600000000 1600000000

VALWF Value of Farm Wealth 9040 9040 9040

VALWNF Value of Nonfarm Wealth 210000 210000 210000

Table B-8 CHRONC input parameters used in the Peach Bottom unmitigated LTSBO and 

STSBO with and without RCIC blackstart scenarios (continued)
C-1

APPENDIX C: MACCS SOARCA MODELING PARAMETERS 

COMPARED TO SAMPLE PROBLEM A INPUTS

C-3

SOARCA INPUT PARAMETERS FOR CONSEQUENCE ANALYSIS

The input parameters used for the SOARCA Surry and Peach Bottom accident scenarios are 

compared with the MACCS Sample Problem A input parameters where applicable for the 

ATMOS, EARLY, and CHRONC modules. Non-site-specific input parameters in Sample 

Problem A which differ from the SOARCA input parameters are discussed within the main 

document. Table C-1 is a comparison of the ATMOS input parameters. Table C-2 is a 

comparison of the EARLY input parameters. Table C-3 is a comparison of the CHRONC input 

parameters. Table C-4 provides the list of radionuclides used in Sample Problem A. Table C-5 

and Table C-6 provide the release fraction data for the Surry Sample Problem A and NUREG1150, Peach Bottom inputs, respectively.

The MACCS Sample Problem A – Surry input parameters are based on a NUREG-1150 Surry

MACCS deck and are documented in NUREG/CR-6613, “Code Manual for MACCS: Volume 1, 

User’s Guide.” This MACCS input deck is provided in the MACCS Version 1.13.1 download. 

The NUREG-1150 Peach Bottom input parameters are taken from a Peach Bottom MACCS 

deck documented in NUREG/CR-4551 Volume 2, Revision 1, Part 7, “Evaluation of Severe 

Accident Risks: Quantification of Major Input Parameters, MACCS Input.” 
C-4

Table C-1 ATMOS input parameters used in the SOARCA accident scenarios 

compared with the MACCS Sample Problem A inputs

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

APLFRC Method of Applying 

Release Fraction PARENT PARENT PARENT PARENT

ATNAM1 Title Describing the 

ATMOS Assumptions

SOARCA Surry 

Unmitigated 

LTSBO

SOARCA Peach 

Bottom Source 

Term LTSBO

Surry

ATMOS Input 

for Final 

NUREG-1150 

Calculation

ATNAM2 Title Describing the Source 

Term

Surry source 

term for the 

unmitigated 

long-term 

station 

blackout.

Peach Bottom 

source term for 

the unmitigated 

long-term station 

blackout.

Second 

Draft 

NUREG1150, worst 

case 

source term 

for early 

fatalities

NUREG-1150 

Peach Bottom 

source term 

PB-15-1

BNDMXH Boundary Weather Mixing 

Layer Height (m) 1000 1000 1000 1000

BNDRAN Boundary Weather Rain 

Rate (mm/hr) 5 5 5 0

BNDWND Boundary Wind Speed

(m/sec) 2.2 2.2 5 0.5

BRKPNT Breakpoint Time for Plume 

Meander (sec) 3600 3600 3600 3600

BUILDH Building Height for all 

Plume Segments (m) 50 50 50 50

CORINV Isotopic Inventory at Time 

of Reactor Shutdown (Bq)

from 

MELMACCS 

from 

MELMACCS 

NUREG1150 Surry 

source term

NUREG-1150 

Peach Bottom 

source term PB15-1

CORSCA Linear Scaling Factor on 

Core Inventory 1 1 0.715 0.92

CWASH1 Linear Coefficient for 

Washout 1.89E-05 1.89E-05 9.50E-05 9.50E-05

CWASH2 Exponential Term for 

Washout 0.664 0.664 0.8 0.8

CYSIGA

Linear Coefficient for 

sigma-y

Stability Class A 0.7507 0.7507

Note 1

0.3658

Stability Class B 0.7507 0.7507 0.2751

Stability Class C 0.4063 0.4063 0.2089

Stability Class D 0.2779 0.2779 0.1474

Stability Class E 0.2158 0.2158 0.1046

Stability Class F 0.2158 0.2158 0.0722

CYSIGB

Exponential Term for 

sigma-y

Stability Class A 0.866 0.866

Note 1

0.9301

Stability Class B 0.866 0.866 0.9301

Stability Class C 0.865 0.865 0.9301

Stability Class D 0.881 0.881 0.9301

Stability Class E 0.866 0.866 0.9301

Stability Class F 0.866 0.866 0.9301
C-5

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

CZSIGA

Linear Coefficient for 

sigma-z

Stability Class A 0.0361 0.0361

Note 1

0.00025

Stability Class B 0.0361 0.0361 0.0019

Stability Class C 0.2036 0.2036 0.2

Stability Class D 0.2636 0.2636 0.3

Stability Class E 0.2463 0.2463 0.4

Stability Class F 0.2463 0.2463 0.2

CZSIGB

Exponential Term for 

sigma-z

Stability Class A 1.277 1.277

Note 1

2.125

Stability Class B 1.277 1.277 1.6021

Stability Class C 0.859 0.859 0.8543

Stability Class D 0.751 0.751 0.6532

Stability Class E 0.619 0.619 0.6021

Stability Class F 0.619 0.619 0.602

DISPMD Dispersion Model Flag LRDIST LRDIST Note 2 Note 2

DRYDEP Dry Deposition Flag

Xe = .FALSE. Xe = .FALSE. Xe = 

.FALSE. Xe = .FALSE.

Other Groups = 

.TRUE.

Other Groups = 

.TRUE.

Other 

Groups = 

.TRUE.

Other Groups = 

.TRUE.

ENDAT1 Control flag indicating only 

ATMOS is to be run .FALSE. .FALSE. .FALSE. .FALSE.

GRPNAM

Names of the Chemical 

Classes (Used by 

WinMACCS)

Chemical Class 1 Xe Xe

Note 2 Note 2

Chemical Class 2 Cs Cs

Chemical Class 3 Ba Ba

Chemical Class 4 I I

Chemical Class 5 Te Te

Chemical Class 6 Ru Ru

Chemical Class 7 Mo Mo

Chemical Class 8 Ce Ce

Chemical Class 9 La La

IBDSTB Boundary Weather Stability 

Class Index 4 4 4 1

IDEBUG Debug Switch for Extra 

Debugging Print 0 0 0 0

IGROUP

Definition of Radionuclide 

Group Numbers 1 = Xe 1 = Xe 1 = Xe 1 = Xe

2 = Cs 2 = Cs 2 = I 2 = I

3 = Ba 3 = Ba 3 = Cs 3 = Cs

4 = I 4 = I 4 = Te 4 = Te

5 = Te 5 = Te 5 = Sr 5 = Sr

6 = Ru 6 = Ru 6 = Mo 6 = Mo

7 = Mo 7 = Mo 7 = La 7 = La

8 = Ce 8 = Ce 8 = Ce 8 = Ce

9 = La 9 = La 9 = Ba 9 = Ba

Table C-1 ATMOS input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-6

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

INWGHT

Number of Samples for Each 

Bin Used for Nonuniform 

Weather Bin Sampling

Bin 1 12 71

Note 1 Note 3

Bin 2 14 42

Bin 3 12 12

Bin 4 39 52

Bin 5 85 57

Bin 6 94 74

Bin 7 16 21

Bin 8 12 12

Bin 9 27 49

Bin 10 134 103

Bin 11 119 77

Bin 12 74 35

Bin 13 92 51

Bin 14 43 75

Bin 15 12 14

Bin 16 12 4

Bin 17 37 44

Bin 18 12 12

Bin 19 13 17

Bin 20 17 24

Bin 21 14 24

Bin 22 12 12

Bin 23 6 4

Bin 24 6 8

Bin 25 12 12

Bin 26 12 12

Bin 27 12 12

Bin 28 1 1

Bin 29 5 3

Bin 30 6 5

Bin 31 5 4

Bin 32 12 12

Bin 33 5 1

Bin 34 12 7

Bin 35 12 9

Bin 36 12 12

IRSEED Seed for Random Number 

Generator 79 79 79 1

LATITU Latitude of Power Plant 37 ̊ 9' 56" 39 ̊ 45' 32" Note 2 Note 2

LIMSPA Last Interval for Measured 

Weather 25 25 25 25

LONGIT Longitude of Power Plant 76 ̊ 41' 54" 76 ̊ 16' 09" Note 2 Note 2

MAXGRP Number of Radionuclide 

Groups 9 9 9 9

Table C-1 ATMOS input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-7

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

MAXHGT Flag for Mixing Height DAY_AND_NIGHT DAY_AND_NIGHT Note 2 Note 2

MAXRIS Selection of Risk Dominant 

Plume 3 2 1 1

METCOD Meteorological Sampling 

Option Code 2 2 2 2

MNDMOD Plume Meander Model Flag OFF OFF Note 2 Note 2

NAMSTB

List of Pseudo stable 

Nuclides

Isotope 1 I-129 I-129 I-129

Note 3

Isotope 2 Xe-131m Xe-131m Xe-131m

Isotope 3 Xe-133m Xe-133m Xe-133m

Isotope 4 Cs-135 Cs-135 Xe-135m

Isotope 5 Sm-147 Sm-147 Cs-135

Isotope 6 U-234 U-234 Sm-147

Isotope 7 U-235 U-235 U-234

Isotope 8 U-236 U-236 U-235

Isotope 9 U-237 U-237 U-236

Isotope 10 Np-237 Np-237 U-237

Isotope 11 Rb-87 Rb-87 Np-237

Isotope 12 Zr-93 Zr-93 Rb-87

Isotope 13 Nb-93m Nb-93m Ba-137m

Isotope 14 Nb-95m Nb-95m Rb-88

Isotope 15 Tc-99 Tc-99 Y-91m

Isotope 16 Pm-147 Pm-147 Zr-93

Isotope 17 N/A N/A Nb-93m

Isotope 18 N/A N/A Nb-95m

Isotope 19 N/A N/A Nb-97

Isotope 20 N/A N/A Nb-97m

Isotope 21 N/A N/A Tc-99

Isotope 22 N/A N/A Rh-103

Isotope 23 N/A N/A Rh-106

Isotope 24 N/A N/A Te-131

Isotope 25 N/A N/A Pr-144

Isotope 26 N/A N/A Pr-144m

Isotope 27 N/A N/A Pm-147

NPSGRP Number of Particle Size 

Groups 10 10 1 1

NRINTN Number of Rain Intensity 

Breakpoints 3 3 3 3

NRNINT Number of Rain Distance 

Intervals 5 5 5 6

NSBINS Number of Weather Bins to 

Sample 36 36 Note 1 6

NUCNAM Radionuclide Names See Table 4-2 See Table 4-2 See Table C.4 See Table C.4

NUCOUT Radionuclide Used in 

Dispersion Print Cs-137 Cs-137 Cs-137 Cs-137

NUMCOR Number of Compass 

Sectors in the Grid 64 64 Note 2 Note 2

NUMISO Number of Radionuclides 69 69 60 60

Table C-1 ATMOS input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-8

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

NUMRAD Number of Radial Spatial 

Intervals 26 26 26 26

NUMREL Number of Released Plume 

Segments 28 29 2 2

NUMSTB Number of Defined Pseudo 

stable Radionuclides 16 16 27 0

OALARM Time to Reach General 

Emergency Conditions (sec) 0 0 1300 14000

PDELAY Plume Release Times (sec) MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table B-2)

3700.0, 

10000.0

25100.0, 

25800.0

PLHEAT Plume Heat Contents (W) MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table B-2)

3.7E+06, 

1.7E+05

1.4E+07, 

1.49E+06

PLHITE Plume Release Heights (m) MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table B-2) 0.0, 0.0 30.0, 30.0

PLMDEN Plume Mass Density

(kg/m3)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table B-2) Note 2 Note 2

PLMFLA Plume Mass Flow Rate

(kg/s)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table B-2) Note 2 Note 2

PLMMOD Flag for Plume Rise Input 

Option DENSITY DENSITY Note 2 Note 2

PLUDUR Plume Segment Durations

(sec)

MELMACCS Data 

(See Table A-2)

MELMACCS Data 

(See Table B-2)

1800.0, 

22000.0 240.0, 14000.0

PSDIST Particle Size Distribution by 

Group

MELMACCS Data 

(See Table A-3)

MELMACCS Data 

(See Table B-3)

1. for all 

groups

1. for all 

groups

REFTIM Plume Reference Time 

Point

0. for first 0. for first 0. for first 0. for first

0.5 for 

subsequent

0.5 for 

subsequent

0.5 for 

subsequent

0.5 for 

subsequent

RELFRC Release Fractions of the 

Source Term

MELMACCS Data 

(See Table A-4)

MELMACCS Data 

(See Table B-4) See Table C.5 See Table C.6

RNDSTS

Endpoints of Rain Distance 

Intervals (km)

Interval 1 3.22 3.22 3.22 3.22

Interval 2 5.63 5.63 5.63 5.63

Interval 3 11.27 11.27 11.27 11.27

Interval 4 20.92 20.92 20.92 20.92

Interval 5 32.19 32.19 32.19 40.23

Interval 6 N/A N/A N/A 80.47

RNRATE

Rain Intensity Breakpoints 

for Weather Binning

(mm/hr)

Intensity 1 2 2 2 1

Intensity 2 4 4 4 2

Intensity 3 6 6 6 3

SCLADP Scaling Factor for A-D 

Plume Rise 1 1 1 1

SCLCRW Scaling Factor for Critical 

Wind Speed 1 1 1 1

SCLEFP Scaling Factor for E-F 

Plume Rise 1 1 1 1

SIGYINIT Initial Sigma-y for All Plume 

Segments (m) 9.3 11.6 9.302 Note 3

Table C-1 ATMOS input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-9

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

SIGZINIT Initial Sigma-z for All 

Plume Segments (m) 23.3 23.3 23.26 Note 3

SPAEND

Radial distances for grid 

boundaries (km)

Ring 1 0.16 0.16 0.16 0.40

Ring 2 0.52 0.52 0.52 0.82

Ring 3 1.21 1.21 1.21 1.21

Ring 4 1.61 1.61 1.61 1.61

Ring 5 2.13 2.13 2.13 2.43

Ring 6 3.22 3.22 3.22 3.22

Ring 7 4.02 4.02 4.02 4.02

Ring 8 4.83 4.83 4.83 4.83

Ring 9 5.63 5.63 5.63 5.63

Ring 10 8.05 8.05 8.05 8.05

Ring 11 11.27 11.27 11.27 11.27

Ring 12 16.09 16.09 16.09 16.09

Ring 13 20.92 20.92 20.92 20.92

Ring 14 25.75 25.75 25.75 25.75

Ring 15 32.19 32.19 32.19 32.19

Ring 16 40.23 40.23 40.23 40.23

Ring 17 48.28 48.28 48.28 48.28

Ring 18 64.37 64.37 64.37 64.37

Ring 19 80.47 80.47 80.47 80.47

Ring 20 112.65 112.65 112.65 112.65

Ring 21 160.93 160.93 160.93 160.93

Ring 22 241.14 241.14 241.14 241.14

Ring 23 321.87 321.87 321.87 321.87

Ring 24 563.27 563.27 563.27 563.27

Ring 25 804.67 804.67 804.67 804.67

Ring 26 1609.34 1609.34 1609.34 1609.34

TIMBAS Time Base for Plume 

Expansion Factor (sec) 600 36000 600 600

VDEPOS

Dry Deposition Velocities

(m/sec)

Aerosol Bin 1 5.35E-04 5.35E-04

0.01 0.01

Aerosol Bin 2 4.91E-04 4.91E-04

Aerosol Bin 3 6.43E-04 6.43E-04

Aerosol Bin 4 1.08E-03 1.08E-03

Aerosol Bin 5 2.12E-03 2.12E-03

Aerosol Bin 6 4.34E-03 4.34E-03

Aerosol Bin 7 8.37E-03 8.37E-03

Aerosol Bin 8 1.37E-02 1.37E-02

Aerosol Bin 9 1.70E-02 1.70E-02

Aerosol Bin 10 1.70E-02 1.70E-02

WETDEP Wet Deposition Flag

Xe = .FALSE. Xe = .FALSE. Xe = .FALSE. Xe = .FALSE.

Other groups = 

.TRUE.

Other groups = 

.TRUE.

Other groups = 

.TRUE.

Other groups = 

.TRUE.

Table C-1 ATMOS input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-10

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

XPFAC1 Base Time for Meander 

Expansion Factor 0.2 0.01 0.2 0.2

XPFAC2 Breakpoint for Expansion 

Factor Model 0.25 0.01 0.25 0.25

YSCALE Scale Factor for Horizontal 

Dispersion 1 1 1 1

ZSCALE Scale Factor for Vertical 

Dispersion 1.27 1.27 1.27 1.27

Note 1: A weather lookup table was used for Sample Problem A – Surry

Note 2: This variable was not available for this MACCS model

Note 3: This variable was not provide for Sample Problem A – Peach Bottom

Table C-1 ATMOS input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-11

Table C-2 EARLY input parameters used in the SOARCA accident scenarios 

compared with the MACCS Sample Problem A inputs

Variable Description SOARCA Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

ACNAME

Latent Cancer Effect

Cancer Type 1 LEUKEMIA LEUKEMIA LEUKEMIA LEUKEMIA

Cancer Type 2 BONE BONE BONE BONE

Cancer Type 3 BREAST BREAST BREAST BREAST

Cancer Type 4 LUNG LUNG LUNG LUNG

Cancer Type 5 THYROID THYROID THYROID THYROID

Cancer Type 6 LIVER LIVER GI GI

Cancer Type 7 COLON COLON OTHER OTHER

Cancer Type 8 RESIDUAL RESIDUAL N/A N/A

ACSUSC Population Susceptible to 

Cancer

1.0 for all 

cancers

1.0 for all 

cancers

1.0 for all 

cancers

1.0 for all 

cancers

ACTHRE Linear Dose-Response 

Threshold 0 0 0 1.5

BRRATE Breathing Rate (for all 

activity types) (m3/sec) 0.000266 0.000266 0.000266 0.000266

CFRISK

Lifetime Cancer Fatality 

Risk Factors

Cancer Type 1 0.0111 0.0111 0.0097 0.0037

Cancer Type 2 0.00019 0.00019 0.0009 0.00015

Cancer Type 3 0.00506 0.00506 0.0054 0.006

Cancer Type 4 0.0198 0.0198 0.0155 0.0051

Cancer Type 5 0.000648 0.000648 0.00072 0.00072

Cancer Type 6 0.003 0.003 0.0336 0.015

Cancer Type 7 0.0208 0.0208 0.0276 0.0075

Cancer Type 8 0.0493 0.0493 N/A N/A

CIRISK

Lifetime Cancer Injury Risk 

Factors

Cancer Type 1 0.0113 0.0113 0 0.0037

Cancer Type 2 0.000271 0.000271 0 0.00015

Cancer Type 3 0.0101 0.0101 0.017 0.017

Cancer Type 4 0.0208 0.0208 0 0.0057

Cancer Type 5 0.00648 0.00648 0.0072 0.0072

Cancer Type 6 0.00316 0.00316 0 0.025

Cancer Type 7 0.0378 0.0378 0 0.013

Cancer Type 8 0.169 0.169 N/A N/A

CRIORG Critical Organ for EARLY 

Phase L-ICRP60ED L-ICRP60ED L-EDEWBODY L-EDEWBODY

CSFACT

Cloudshine Shielding 

Factors

Evacuation Shielding 

Factor for All but Cohort 4 1 1 1 1

Normal Activity Shielding 

Factor for All but Cohort 4 0.68 0.6 0.75 0.75

Sheltering Shielding Factor 

for All but Cohort 4 0.6 0.5 0.6 0.5
C-12

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

CSFACT

Evacuation Shielding 

Factor for Cohort 4 1 1 Note 4 Note 4

Normal Activity Shielding 

Factor for Cohort 4 0.31 0.31 Note 4 Note 4

Sheltering Shielding Factor 

for Cohort 4 0.31 0.31 Note 4 Note 4

DCF_FILE Name of Dose Coefficient

File

FGR13GyEquivDC

F.INP

FGR13GyEquiv

DCF.INP dosdata.inp dosdata.inp

DDREFA

Dose-Dependent 

Reduction Factor

Cancer Type 1 2 2 2 Note 2

Cancer Type 2 2 2 2 Note 2

Cancer Type 3 1 1 1 Note 2

Cancer Type 4 2 2 2 Note 2

Cancer Type 5 2 2 1 Note 2

Cancer Type 6 2 2 2 Note 2

Cancer Type 7 2 2 2 Note 2

Cancer Type 8 2 2 N/A N/A

DDTHRE

Threshold for Applying 

Dose-Dependent 

Reduction Factor

0.2 0.2 0.2 Note 2

DLTSHL

Delay from Alarm Time to 

Shelter

Cohort 1 9900 5400 7200 0

Cohort 2 9900 5400 7200 Note 4

Cohort 3 900 900 Note 4 Note 4

Cohort 4 9900 5400 Note 4 Note 4

Cohort 5 9900 5400 Note 4 Note 4

Cohort 6 N/A N/A Note 4 Note 4

DLTEVA

Delay from Beginning of 

Shelter to Evacuation (sec)

Cohort 1 3600 3600 0 0

Cohort 2 3600 3600 0 Note 4

Cohort 3 3600 2700 Note 4 Note 4

Cohort 4 39600 15300 Note 4 Note 4

Cohort 5 39600 15300 Note 4 Note 4

Cohort 6 N/A N/A Note 4 Note4

DOSEFA Cancer Dose-Response 

Linear Factors 1 for all organs 1 for all organs 1 for all

organs

1 for THYROID 

and BREAST

0.39 for all 

other organs

DOSEFB Cancer Dose-Response 

Quadratic Factors 0 for all organs 0 for all organs 0 for all organs

0 for THYROID 

and BREAST

0.61 for all 

other organs

DOSHOT Hot-Spot Relocation Dose 

Threshold (Sv) 0.05 0.05 0.5 0.5

DOSMOD Dose-Response Model 

Flag LNT, AT LNT, AT LNT LNT

Table C-2 EARLY input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-13

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

DOSNRM Normal Relocation Dose 

Threshold (Sv) 0.01 0.005 0.25 0.25

DURBEG

Duration of Beginning of 

Evacuation Phase (sec)

Cohort 1 900 900 86400 5400

Cohort 2 900 900 86400 Note 4

Cohort 3 900 3600 Note 4 Note 4

Cohort 4 3600 1800 Note 4 Note 4

Cohort 5 3600 1800 Note 4 Note 4

Cohort 6 N/A N/A Note 4 Note 4

DURMID

Duration of Middle of 

Evacuation Phase (sec)

Cohort 1 35100 10800 0 0

Cohort 2 35100 10800 0 Note 4

Cohort 3 1800 1800 Note 4 Note 4

Cohort 4 3600 1800 Note 4 Note 4

Cohort 5 3600 1800 Note 4 Note 4

Cohort 6 N/A N/A Note 4 Note 4

EANAM1 Text Describing the EARLY 

Assumptions

SOARCA Surry 

LTSBO EARLY 

input

SOARCA 

Peach Bottom 

LTSBO EARLY 

input

IN2A.INP, 

Sample 

Problem A 

of 

NUREG/C

R-4691, 

Vol.1, 

EARLY 

input

EARLY input 

for final 

NUREG-1150 

calculations

EANAM2

Text Describing the 

Emergency Response

Cohort 1 Group 1 Group 1

Evacuation 

within 10 

miles, 

relocation 

models 

apply 

elsewhere

Evacuation 

within 10 miles 

with hotspot 

and normal 

relocation

Cohort 2 Group 2 Group 2

No 

evacuation, 

relocation 

models 

apply 

everywhere

Note 4

Cohort 3 Group 3 Group 3 Note 4 Note 4

Cohort 4 Group 4 Group 4 Note 4 Note 4

Cohort 5 Group 5 Group 5 Note 4 Note 4

Cohort 6 Group 6 Group 6 Note 4 Note 4

EFFACA

LD50 for Early Fatality 

Types

A-RED MARR 5.6 5.6 3.8 4

A-LUNGS 23.5 23.5 10 10

Table C-2 EARLY input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-14

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

EFFACA

A-STOMACH 12.1 12.1 Note 5 N/A

LOWER-LI N/A N/A Note 5 15

EFFACB

Shape Factor for Early 

Fatality Types

A-RED MARR 6.1 6.1 5 6

A-LUNGS 9.6 9.6 7 7

A-STOMACH 9.3 9.3 Note 5 N/A

LOWER-LI N/A N/A Note 5 10

EFFACY Efficacy of the KI Ingestion 0.7 0.7 Note 2 Note 2

EFFTHR

Threshold Dose to Target 

Organ

A-RED MARR 2.32 2.32 1.5 1.5

A-LUNGS 13.6 13.6 5 5

A-STOMACH 6.5 6.5 Note 5 N/A

LOWER-LI N/A N/A Note 5 7.5

EIFACA

LD50 For Early Injuries

PRODROMAL VOMIT 2 2 2 2

DIARRHEA 3 3 3 3

PNEUMONITIS 16.6 16.6 10 10

SKIN ERYTHRMA 6 6 6 6

TRANSEPIDERMAL 20 20 20 20

THYROIDITIS 240 240 240 240

HYPOTHYROIDISM 60 60 60 60

EIFACB

Shape Factor for Early 

Injuries

PRODROMAL VOMIT 3 3 3 3

DIARRHEA 2.5 2.5 2.5 2.5

PNEUMONITIS 7.3 7.3 7 7

SKIN ERYTHRMA 5 5 5 5

TRANSEPIDERMAL 5 5 5 5

THYROIDITIS 2 2 2 2

HYPOTHYROIDISM 1.3 1.3 1.3 1.3

EINAME

Early Injury Effect Names 

and Corresponding Organ

PRODROMAL VOMIT A-STOMACH A-STOMACH A-STOMACH STOMACH

DIARRHEA A-STOMACH A-STOMACH A-STOMACH STOMACH

PNEUMONITIS A-LUNGS A-LUNGS A-LUNGS LUNGS

SKIN ERYTHRMA A-SKIN A-SKIN A-SKIN SKIN

TRANSEPIDERMAL A-SKIN A-SKIN A-SKIN SKIN

THYROIDITIS A-THYROID A-THYROID A-THYROID THYROID

HYPOTHYROIDISM A-THYROID A-THYROID A-THYROID THYROID

EISUSC Susceptible Population 

Fraction

1. for all health 

effects

1. for all health 

effects

1. for all 

health 

effects

1. for all health 

effects

Table C-2 EARLY input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-15

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

EITHRE

Early Injury Dose 

Threshold

PRODROMAL VOMIT 0.5 0.5 0.5 0.5

DIARRHEA 1 1 1 1

PNEUMONITIS 9.2 9.2 5 5

SKIN ERYTHRMA 3 3 3 3

TRANSEPIDERMAL 10 10 10 10

THYROIDITIS 40 40 40 40

HYPOTHYROIDISM 2 2 2 2

ENDAT2

Control flag indicating only 

ATMOS and EARLY are to 

be run

.FALSE. .FALSE. .FALSE. .FALSE.

ENDEMP Time Duration for the 

Emergency Phase (sec) 604800 604800 604800 604800

ESPEED

Evaluation Speed (m/s)

Initial Evacuation Phase, 

Cohort 1 2.235 2.235 1.8 4.8

Middle Evacuation Phase, 

Cohort 1 0.447 1.341 1.8 4.8

Late Evacuation Phase, 

Cohort 1 8.941 8.941 1.8 4.8

Initial Evacuation Phase, 

Cohort 2 2.235 2.235 1.8 Note 4

Middle Evacuation Phase, 

Cohort 2 0.447 1.341 1.8 Note 4

Late Evacuation Phase, 

Cohort 2 8.941 8.941 1.8 Note 4

Initial Evacuation Phase, 

Cohort 3 4.47 8.941 Note 4 Note 4

Middle Evacuation Phase, 

Cohort 3 4.47 8.941 Note 4 Note 4

Late Evacuation Phase, 

Cohort 3 8.941 8.941 Note 4 Note 4

Initial Evacuation Phase, 

Cohort 4 0.447 1.341 Note 4 Note 4

Middle Evacuation Phase, 

Cohort 4 4.47 8.941 Note 4 Note 4

Late Evacuation Phase, 

Cohort 4 8.941 8.941 Note 4 Note 4

Initial Evacuation Phase, 

Cohort 5 0.447 1.341 Note 4 Note 4

Middle Evacuation Phase, 

Cohort 5 4.47 8.941 Note 4 Note 4

Late Evacuation Phase, 

Cohort 5 8.941 8.941 Note 4 Note 4

Cohort 6 N/A N/A Note 4 Note 4

ESPGRD

Speed Multiplier to Account 

for Grid-Level Variations in 

Road Network

Table A-6

Table A-7 Table B-6 Note 2 Note 2

ESPMUL Speed Multiplier Employed 

During Precipitation 0.7 0.7 Note 2 Note 2

EVATYP Evacuation Type NETWORK NETWORK RADIAL RADIAL

Table C-2 EARLY input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-16

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

GSHFAC

Groundshine Shielding 

Factors

Evacuation Shielding 

Factor for All but Cohort 4 0.5 0.5 0.5 0.5

Normal Activity Shielding 

Factor for All but Cohort 4 0.26 0.18 0.33 0.33

Sheltering Shielding Factor 

for All but Cohort 4 0.2 0.1 0.2 0.1

Evacuation Shielding 

Factor for Cohort 4 0.5 0.5 Note 4 Note 4

Normal Activity Shielding 

Factor for Cohort 4 0.05 0.05 Note 4 Note 4

Sheltering Shielding Factor 

for Cohort 4 0.05 0.05 Note 4 Note 4

IDIREC Direction in Network 

Evacuation Model Table A-8 Table B-7 Note 2 Note 2

IPLUME Plume Model Dispersion 

Code 3 3 2 2

KIMODL Model Flag for KI Ingestion KI KI Note 2 Note 2

LASMOV Last Ring in Movement 

Zone 17 17

15 for 

cohort 1 15

0 for cohort 2

NUMACA Number of Latent Cancer 

Health Effects 8 8 7 7

NUMEFA Number of Early Fatality 

Effects 3 3 2 3

NUMEIN Number of Early Injury 

Effects 7 7 7 7

NUMEVA Outer Boundary of 

Evacuation/Shelter Region

Cohort 1 - 15 Cohort 1 - 15

12 12

Cohorts 2 to 5 - 12 Cohorts 2 to 6 -

12

NUMFIN Number of Fine Grid 

Subdivisions 7 7 7 7

ORGFLG Doses to be Calculated for 

Specified Organ

All TRUE for 

FGR-13

All TRUE for 

FGR-13

All TRUE for 

DOSFAC2 

except for ALower LI and LLiver, which are 

FALSE

All TRUE 

except for 

A-Lower LI 

and L-Liver, 

which are 

FALSE

Note 2

All TRUE for 

DOSFAC2 

except for ALower LI and LLiver, which are 

FALSE

OVRRID Wind Rose Probability 

Override .FALSE. .FALSE. .FALSE. .FALSE.

POPFLG Population Distribution Flag FILE FILE FILE FILE

POPFRAC Population Fraction 

Ingesting KI

Cohort 2 - 1.0 Cohort 1 and 2 - 1.0

Note 2 Note 2

Cohort 1, 3-6 - 0.0 Cohort 3 to 6 -

0.0

PROTIN [E]

Inhalation Protection Factor 

– evacuation for all but 

Cohort 4

0.98 0.98 1 1

PROTIN [N]

Inhalation Protection Factor 

- normal activity for all but 

Cohort 4

0.46 0.46 0.41 0.41

PROTIN [S]

Inhalation Protection Factor 

– sheltering for all but 

Cohort 4

0.33 0.33 0.33 0.33

Table C-2 EARLY input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-17

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

PROTIN [E] Inhalation Protection Factor 

– evacuation for Cohort 4 0.98 0.98 Note 4 Note 4 

PROTIN [N] Inhalation Protection Factor -

normal activity for Cohort 4 0.33 0.33 Note 4 Note 4

PROTIN [S] Inhalation Protection Factor 

– sheltering for Cohort 4 0.33 0.33 Note 4 Note 4

REFPNT Reference Time Point 

(ARRIVAL or SCRAM) ALARM ALARM ALARM Note 2

RESCON Emergency phase 

resuspension coefficient 0.0001 0.0001 0.0001 0.0001

RESHAF

Resuspension 

Concentration Half-Life

(sec)

182000 182000 182000 182000

RISCAT Risk by Weather-Category 

Flag .FALSE. .FALSE. .FALSE. .FALSE.

RISTHR Risk Threshold for Fatality 

Radius 0 0 Note 2 Note 2

SKPFAC [E] Skin Protection Factors –

evacuation for all but Cohort 4 0.98 0.98 1 1

SKPFAC [N]

Skin Protection Factors -

normal activity for all but 

Cohort 4

0.46 0.46 0.41 0.41

SKPFAC [S] Skin Protection Factors –

sheltering for all cohorts 0.33 0.33 0.33 0.33

SKPFAC [E] Skin Protection Factors –

evacuation for Cohort 4 0.98 0.98 Note 4 Note 4

SKPFAC [N] Skin Protection Factors -

normal activity Cohort 4 0.33 0.33 Note 4 Note 4

TIMHOT Hotspot Relocation Time

(sec) 86400 43200 43200 43200

TIMNRM Normal Relocation Time

(sec) 129600 86400 86400 86400

TRAVELPOINT Evacuee Movement Option CENTERPOINT CENTERPOIN

T BOUNDARY Note 2

WTFRAC

Weighting Fraction 

Applicable to this Scenario

Cohort 1 0.2 0.2 0.95 0.995

Cohort 2 0.535 0.355 0.05 0.005

Cohort 3 0.193 0.372 Note 4 Note 4

Cohort 4 0.007 0.006 Note 4 Note 4

Cohort 5 0.06 0.062 Note 4 Note 4

Cohort 6 0.005 0.005 Note 4 Note 4

WTNAME Type of Weighting for 

Cohorts PEOPLE PEOPLE PEOPLE PEOPLE

Note 4: This cohort was not used for this MACCS model

Note 5: This variable was not used in Sample Problem A – Surry 

Table C-2 EARLY input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-18

Table C-3 CHRONC input parameters used in the SOARCA accident scenarios 

compared with the MACCS Sample Problem A inputs

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

CHNAME CHRONC Problem 

Identification

Surry with no 

Food-Chain 

Modeling

Peach Bottom 

with no FoodChain 

Modeling

IN3A_N.INP, 

Sample Problem 

A, "New" 

COMIDA2-based 

food model

CHRONC input 

for final 

NUREG-1150 

calculations

CDFRM

Farmland Decontamination 

Cost ($/hectare)

Level 1 1330 1330 562.5 562.5

Level 2 2960 2960 1250 1250

CDNFRM

Nonfarmland

Decontamination Cost

($/person)

Level 1 7110 7110 3000 3000

Level 2 19000 19000 8000 8000

CRTOCR Critical Organ for CHRONC 

Phase L-ICRP60ED L-ICRP60ED L-EDEWBODY L-EDEWBODY

DPRATE Property Depreciation Rate 0.2 0.2 0.2 0.2

DLBCST

Hourly Labor Cost for 

Decontamination Worker

($/man-year)

84000 84000 35000 35000

DPFRCT Farm Production Dairy 

Fraction Note 6 Note 6 Note 6 Note 6

DSCRLT Long-Term Phase Dose 

Criterion (Sv) 0.04 0.005 0.04 0.04

DSCRTI Intermediate-Phase Dose 

Criterion (Sv) 100000 100000 100000 100000

DSRATE Societal Discount Rate for 

Property 0.12 0.12 0.12 0.12

DSRFCT

Decontamination Factors

Level 1 3 3 3 3

Level 2 15 15 15 15

DUR_INTPHAS Duration of the Intermediate 

Phase 0 0 0 0

EVACST

Emergency Phase Cost of 

Evacuation/Relocation

($/person-day)

172 172 27 27

EXPTIM Maximum Exposure Time

(sec) 1580000000 1580000000 10000000000 10000000000

FDPATH COMIDA2 vs. MACCS Food 

Model Switch OFF OFF NEW Note 7

FRACLD Fraction of Area that is Land Note 6 Note 6 Note 6 Note 6

FRCFRM Fraction of Area Used for 

Farming Note 6 Note 6 Note 6 Note 6

FRFDL

Fraction of Decontamination 

Cost for Labor

Level 1 0.3 0.3 0.3 0.3

Level 2 0.35 0.35 0.35 0.35

FRFIM Farm Wealth Improvements 

Fraction 0.25 0.25 0.25 0.25
C-19

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

FRMPRD Average Annual Farm 

Production Note 6 Note 6 Note 6 Note 6

FRNFIM Nonfarm Wealth 

Improvements Fraction 0.8 0.8 0.8 0.8

FRNFDL

Nonfarm Labor Cost Fraction

Level 1 0.7 0.7 0.7 0.7

Level 2 0.5 0.5 0.5 0.5

GWCOEF

Long-Term Groundshine 

Coefficients

Term 1 0.5 0.5 0.5 0.5

Term 2 0.5 0.5 0.5 0.5

KSWTCH Diagnostic Output Option 

Switch 0 0 0 0

LBRRATE Long-Term Breathing Rate

(m3/sec) 0.000266 0.000266 0.000266 0.000266

LGSHFAC Long-Term Groundshine 

Protection Factor 0.26 0.18 0.33 0.33

LPROTIN Long-Term Inhalation 

Protection Factor 0.46 0.46 0.41 0.41

LVLDEC Number of Decontamination 

Levels 2 2 2 2

NGWTRM

Number of Terms in 

Groundshine Weathering 

Equation

2 2 2 2

NRWTRM

Number of Terms in 

Resuspension Weathering 

Equation

3 3 3 3

POPCST Per Capita Cost of LongTerm Relocation ($/person) 12000 12000 5000 5000

RELCST Relocation Cost per PersonDay ($/person-day) 172 172 27 27

RWCOEF

Long-Term Resuspension 

Factor Coefficients

Term 1 0.00001 0.00001 0.00001 0.00001

Term 2 0.0000001 0.0000001 0.0000001 0.0000001

Term 3 0.000000001 0.00000001 0.000000001 0.000000001

TFWKF

Fraction Farmland Worker 

Time in Contaminated Zone

Level 1 0.1 0.1 0.1 0.1

Level 2 0.33 0.33 0.33 0.33

TFWKNF

Fraction Nonfarmland Worker 

Time in Contaminated Zone

Level 1 0.33 0.33 0.33 0.33

Level 2 0.33 0.33 0.33 0.33

TGWHLF

Groundshine Weathering 

Half-Lives (sec)

Term 1 16000000 16000000 16000000 16000000

Term 2 2800000000 2800000000 2800000000 2800000000

Table C-3 CHRONC input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-20

Variable Description

SOARCA 

Surry 

LTSBO

SOARCA 

Peach Bottom 

LTSBO

Sample 

Problem A 

(Surry)

NUREG-1150

Peach Bottom

TIMDEC

Decontamination Times (sec)

Level 1 5184000 5184000 5184000 5184000

Level 2 10368000 10368000 10368000 10368000

TMPACT Time Action Period Ends

(sec) 158000000 31600000 158000000 158000000

TRWHLF

Resuspension Weathering 

Half-Lives (sec)

Term 1 16000000 16000000 16000000 16000000

Term 2 160000000 160000000 160000000 160000000

Term 3 1600000000 1600000000 1600000000 1600000000

VALWF Value of Farm Wealth

($/hectare) 6900 9040 2613 3421

VALWNF Value of Nonfarm Wealth

($/person) 220000 210000 84000 78000

Note 6: Value is site-specific and provided in the respective site file

Note 7: COMIDA2 was not available for NUREG-1150. Instead a MACCS food model was 

used.

Table C-4 Sample Problem A radionuclide names

Co-58 Te-131m Zr-95 La-141

Co-60 Te-132 Zr-97 La-142

Kr-85 I-131 Nb-95 Ce-141

Kr-85m I-132 Mo-99 Ce-143

Kr-87 I-133 Tc-99m Ce-144

Kr-88 I-134 Ru-103 Pr-143

Rb-86 I-135 Ru-105 Nd-147

Sr-89 Xe-133 Ru-106 Np-239

Sr-90 Xe-135 Rh-105 Pu-238

Sr-91 Cs-134 Sb-127 Pu-239

Sr-92 Cs-136 Sb-129 Pu-240

Y-90 Cs-137 Te-127 Pu-241

Y-91 Ba-139 Te-127m Am-241

Y-92 Ba-140 Te-129 Cm-242

Y-93 La-140 Te-129m Cm-244

Table C-3 CHRONC input parameters used in the SOARCA accident scenarios compared 

with the MACCS Sample Problem A inputs (continued)
C-21

Table C-5 Sample Problem A – Surry environmental source term release fractions

Xe I Cs Te Sr Ru La Ce Ba

Plume

segment 1 1.0E+00 6.8E-01 6.4E-01 1.7E-01 4.2E-03 2.3E-03 1.6E-04 4.0E-04 6.3E-03

Plume

segment 2 4.3E-03 9.5E-03 2.4E-03 1.4E-01 6.8E-02 4.7E-04 6.8E-03 7.1E-03 5.4E-02

Table C-6 Sample Problem A – Peach Bottom environmental source term release 

fractions

Xe I Cs Te Sr Ru La Ce Ba

Plume

segment 1 6.6E-01 8.5E-03 9.4E-03 1.9E-02 2.6E-02 3.5E-03 2.8E-03 5.4E-03 2.6E-02

Plume

segment 2 3.4E-01 4.9E-01 5.4E-01 6.1E-01 7.2E-01 9.3E-03 6.2E-02 1.2E-01 6.20E-01




UNITED STATES

NUCLEAR REGULATORY COMMISSION

WASHINGTON, DC 20555-0001

------------------

OFFICIAL BUSINESS
NUREG/CR

-7009MACCS Best Practices as Applied in the State-of-the-Art Reactor 

Consequence Analyses (SOARCA) Project