RESRAD-BUILD Presentations

Environmental Science Division

Argonne National Laboratory

April 11-12, 2011

RESRAD-BUILD Workshop

2

RESRAD-BUILD Workshop Overview

Introduction to RESRAD-BUILD– Comparison of RESRAD and RESRAD-BUILD

– History of RESRAD-BUILD development

– Overview of RESRAD-BUILD pathways

– Pathways considered

– Sources and receptors considered

– Building Geometry

– Code requirements

– Supporting documentation

Demonstration

3

RESRAD-BUILD Workshop Overview

Methodology– Time integration– Source Geometry– Source/Receptor Specification– Coordinate system– Source removal and injection– Air flow model– Dose calculations for each pathway– Special models for tritium and radon– Guideline Development

Output ResultsProblem Solving TechniquesVerification of RESRAD-BUILDRESRAD-BUILD Configuration Control

Introduction to RESRAD-BUILD

5

Comparison of RESRAD and RESRAD-BUILD

RESRAD (soil) and RESRAD-BUILD (building) codes address different contamination sources and uses: – Soil contamination which might lead

to contamination of food and water through movement by natural processes

– Building contamination in man-made products and air-flows which might lead to exposure during normal building occupancy or D&D activities

6

History of RESRAD-BUILD Development

Motivation for RESRAD-BULD– Increased D&D activity

– Limitations of regulatory guidelines

– Movement towards dose-based release criteria

Development History of RESRAD-BUILD– DOS version released Dec. 1994

– Windows version released July 1996

– Uncertainty module upgraded Sep 2000

– Currently at version 3.5

7

The Potential Problem with Concentration Based Regulations

8

Removal of contaminated material– Time (source life time)

– Fraction

Fate of removed material– Disposed of

– Released in to air

Fate of material released to air– Deposition of surfaces

• Resuspension

– Moved by air circulation• From room to room

• Out of building

Processes Considered in RESRAD-BUILD

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External– Direct

– Deposition

– Immersion

Ingestion– Direct

– Deposition

Inhalation– Airborne particulates

• Resuspension

– Radon

Pathways Considered in RESRAD-BUILD

10

Sources and Receptors Considered

Four distinct source types– Point

– Line

– Area• Circular

• Rectangular

– Volume• Cylindrical

• Rectangular prism

Ability to co-locate sources– Area source above a volume source

– Hot-spot in an area source

Up to 10 sources in a single run

Up to 10 receptors in a single run

11

Building Geometry in RESRAD-BUILD

1-RoomWarehouse

2-Room House

3-Room House

2-StoryHouse 2-Story Building with

2 Rooms on the First Floor3-StoryHouse

2-Story Housewith Basement

(No air exchangebetween basement

and outdoors)

12

RESRAD-BUILD Computer Requirements

Microsoft Windows platform– Windows 2000

– Windows XP

– Windows Vista

Requires active internet connection for download– http://www.evs.anl.gov/resrad/

19 MB downloadable file

Current Version: RESRAD-BUILD 3.5

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RESRAD-BUILD Manual Version 3

Updated descriptions of sources, receptors and roomsUpdated users guide Procedure for performing probabilistic analysisMathematical modelsParameter descriptions

– Name– Range– Default

• Deterministic• Probabilistic

– Measurement Methodology

RESRAD-BUILD Demonstration

15

RESRAD-BUILD Problem Demonstration

RESRAD-BUILD Methodology

17

RESRAD-BUILD Time integrated Dose Calculations

Calculates an average concentration of the radionuclide over the exposure duration– Average calculation based on the

number of integration points selected

– Larger number of integration points are required for longer exposure times or short source lifetimes

– Integration point set to 1 calculates the instantaneous dose and projects the dose over the entire exposure duration• May overestimate the dose when the

source lifetime is small

18

Source Geometry

Source Types– Point

– Line

– Area

– Volume

Source Geometry– Area source

• Circular

• Rectangular

– Volume source• Cylindrical

• Rectangular

19

Receptor & Source Specifications

Receptor– Room in which he/she is located

• 1, 2, 3– Center point of receptor

• X, Y, Z coordinates in space• Usually 1 m above “floor”

Point source– Room in which it is located– X, Y, Z coordinates in space

Line source– Room in which it is located– Center point of line source

• X, Y, Z coordinates in space– Length of the source– Orientation of source

• X, Y or Z

(0,0,0)

(1,1,1)

2m

(1,1,-1)

X

20

Area Source Specifications

Area source– Room in which it is located

• 1, 2, or 3

– Center point of the source• X, Y, Z coordinates in space

– Direction normal or perpendicular to the surface of the source

– Circular source• Area of the source

– Rectangular source• Lengths of sides

(0,1,1)

Y Direction

3.3 m

10 m

(3,2,2)

24 m2

X

Z

21

Volume Source Specifications

Volume source– All area source specifications from

previous slide• Room in which it is located• Center point of the source• Direction normal or perpendicular to the

surface of the source• Area of circular source• Lengths of sides of rectangular source

– Number of regions in the third dimension• Up to 5 regions

– Region 1 will be closest to (0,0,0)

– Region where contamination exists• Only 1 contaminated region per source

– Thickness, density and erosion rate of each region

(0,1,1)

Y Direction

3.3 m

10 m

(3,2,2)

24 m2

X

Z

22

RESRAD-BUILD Coordinate System

Rectangular coordinate system

Origin of coordinate system is chosen by the user – Not specified in the code

– Should not coincide with the center of a volume source

– For any volume source, the region closest to the origin has to be region 1

Helpful Hints– Have a drawing of the rooms

you want to model

– Base distances from a room corner

– Negative Z distances couldinfer a building with a basement

(0,0,2)Z

(2,0,2)

(3,0,3)Y

(4,1,2)X

(0,0,0)

Z

X

Y

23

“Rotated” Coordinate Systems

Coordinate systems may be rotated (with respect to the walls) – For example, if a contaminated

pipe runs along the diagonal of a room

If multiple sources are present then RESRAD-BUILD may have to be run more than once.– If the sources can not all be

described by the same coordinate system

Source

ReceptorSour

ce

24

Models the release of the radionuclides from the source to the air

– Building renovation– Building occupancy

The airflow in the building will transport the airborne nuclides from room to room

Nuclides will deposit and will be resuspended

Pathways considered– External

• Submersion, deposited nuclides

– Inhalation– Ingestion

• Deposited nuclides

Source Injection to Air Pathways

25

RESRAD-BUILD One Room Air Flow Model

V dC/dt = I - QC - VC + VCP - DVC + RDVC / ( R+)

Change of Activity in the room

Injection Rate

Exchange with outside

Decay in Air

Decay of parent in Air

Deposition

Resuspension

26

Three Room Air Flow Model

27

Source Removal/Injection - Point, Line, Area Sources

Source removal and injection treated the same for point, line and area

Parameters affecting source removal– Removable fraction– Source lifetime

Parameters affecting source injection– Source lifetime– Removable fraction– Air fraction

Source is linearly removed over the source lifetime– “Erosion Rate” or removal rate

• Removable Fraction/ Source Lifetime• 20% over 10 years

– 2% per year

Radioactive decay occurs simultaneously

Removable fraction

Fraction remaining “fixed”

Fraction remaining “fixed”

Air fraction × Removable fraction

Lifetime

Removed from building

28

Source Removal/Injection-Volume Source

In a multi-region source, the regions erode in order– Region 1 first, region 2 next and so on– User specifies the regions– Region 1 is closest to 0,0,0

• Used to compute direct external radiation

Removal calculated using the erosion rate (cm/d), area (m2) and the bulk density of the material (g/cc)

Injecting calculated by applying the air fraction to the quantity removed

(1,1,1)

Region 1 Region 2

(2,1,1)

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Calculation of Injection Rate

5 m2 Area Source U-238 @ 100 pCi/m2

Source lifetime =3650 days Removable fraction =0.1 (10%) Air fraction =0.01 (1%) Calculate the injection rate Calculate the amount of U-238 remaining

after 10 years (neglect radioactive decay)

● Total Activity● 5*100 = 500 pCi of U-238

● Removal rate per day● 500*0.1/3650 = 0.0137 pCi/day

● Injection rate● 0.0137*0.01/24/60/60 = 1.59E-9 pCi/s

● Total activity remaining● 100*0.9 = 90 pCi/m2

30

RESRAD-BUILD Example 1

Input the following into RESRAD-BUILD and compare the results with the last slide.– 5 m2 Area Source– U-238 @ 100 pCi/m2

– Source lifetime = 3650 days– Removable fraction = 0.1– Air fraction =0.01– evaluation time of 10 years– Run the code and check the code

calculated values of • injection rate

– View Last Detailed Output

• the amount of U-238 remaining after 10 years

– View Last Report

31

Direct External Pathway

FGR 12 External Dose conversion FactorsCorrected for:

– Finite area

– Finite thickness

– Density

– Shielding • thickness

• density

• material

32

The Direct External Pathway

A single shield is allowed between each source receptor pair– 10 Sources– 10 Receptors– 100 Source shield combinations

Users may wish to use a composite shield if multiple shields are present

Shielding by uncontaminated regions of volume sources is also modeled– thickness– density– region 1 is closest to origin

33

Direct Ingestion Pathway

Receptor MUST be in the same room as the source

Removable fraction must be greater than 0

Models the incidental ingestion of contaminated material

FGR 11 dose conversion factors

User must ensure mass balance– See next slide

34

Calculation of Direct Ingestion

RESRAD-BUILD does not perform a mass balance when computing the direct ingestion dose

– Can end up modeling a situation where the quantity ingested is more than the removable part or even the entire source

Direct ingestion rate is the fraction of the removable portion of the source ingested per hour (point, line, area)

Direct ingestion rate is in grams per hour for volume sources of the portion that is removable

30

locationreceptor at fraction Time ctionIndoor Fra duration Exposure 24

(hours) locationreceptor at Time

nnniI DCFStD RateIngestionTime Ingestion)(

35

Inhalation

Models the inhalation of particulates

Removable fraction and Air fraction determine respirable fraction– Only removable fraction ×

airborne fraction is considered in the inhalation dose

– Balance of the removable material is removed from the building and is not considered in RESRAD-BUILD

Includes resuspension of deposited material

Air quality model is used to estimate the airborne concentration

36

Inhalation

Source and receptor may be in different rooms

Does not depend on exact location within the room

Inhalation dose based on 1 m particle size

FGR 11 inhalation dose conversion factors

Dose is integrated over the exposure duration– Average concentration in

air over the exposure duration

37

Ingestion of deposited material

Models indirect ingestion of particulates deposited from air– Ingestion dose dependents

on removable fraction and air fraction

– If material is removed but not airborne RESRAD-BUILD will ignore this portion

Air quality model calculates the concentration of the deposited radionuclides

Ingestion rate for indirect ingestion is in units of m2

per hour

38

Ingestion of deposited material

Source and receptor may be in different rooms

Does not depend on exact location within the room

FGR 11 Ingestion dose conversion factors

Dose is integrated over the exposure duration– Average deposited

concentration over the exposure duration

Dose from direct ingestion and indirect ingestion are summed and reported as a single ingestion dose– direct and indirect

ingestion rates can be independently set to zero

39

External exposure from air borne and deposited nuclides

External dose from– Deposition

– Submersion

– dependents on air fraction and removable fraction

Air quality model calculates the concentration in air and the concentration of the deposited radionuclides

FGR 12 external dose conversion factors

Dose from deposition corrected for finite area

No shielding considered in the deposition dose

40

External exposure from air borne and deposited nuclides

Source and receptor may be in different rooms

Not based on exact location within a room

Dose from submersion is small compared to deposition

Dose is integrated over the exposure duration– Average deposited

concentration over the exposure duration

41

RESRAD-BUILD Example 2

Demonstration of the air pathways 1 Source, 3 ReceptorsModel Ra-226 using a point source -10 pCi 2 Room model

– Room 1 36 m2

– Room 2 100 m2

Source 1 in room 1 (5, 5, 0)Receptor 1 in room 1 (1, 1, 1)Receptor 2 in room 2 (3, -5, 1)Receptor 3 in room 2 (6, -8, 1)What is the external, inhalation and

ingestion dose to receptors 2 and 3?How do the doses compare with the dose

to receptor 1?

Source 1

Receptor 1

Receptor 2

Receptor 3

42

RESRAD-BUILD Example 2

Sensitivity on– release fraction– air fraction– lifetime

With and without direct ingestion– for all receptors

With and without shielding from wall between rooms– Sensitivity on density– Can vary material type

Default air exchangeHigh air exchange between rooms

Source 1

Receptor 1

Receptor 2

Receptor 3

43

Special Models for H-3: Point Line & Area

Point, Line, Area Sources– Modeled similar to other

radionuclides– Removable fraction should be set

to 1 to model the complete release of tritium vapor (HTO)

– Air fraction should be set to 0.1– Deposition velocity of HTO should

be set to 0• There will be no deposition• Resuspension rate not considered• Indirect ingestion rate not

considered

Dermal absorption is modeled by increasing the inhalation dose by 50%

Air fraction

Removable fraction

Fraction remaining “fixed”

Fraction remaining “fixed”

44

Special Models for H-3: Volume Source

Models the vaporization of HTO– Assume equilibrium conditions– Diffusion of HTO from the source

to the indoor air– As humidity increases diffusion

decreases– Larger the moisture content

lower the H-3 content in the water

Fraction available for vaporization– Default 1.0

H-3 in solid form is released through erosion

Pathways considered– Inhalation– Ingestion– Dermal absorption

Wet Zone ThicknessDry Zone Thickness

45

Special Models for Radon

Point, Line and Area– Calculation of the injection rate is

similar to other point line and area sources.

– Uses the emanation fraction for the release fraction.

Volume Source– Models the diffusion of radon from

a single contaminated region through up to 4 uncontaminated regions.

– Source is only in ONE room• Can not diffuse the source into two

roomsRadon Flux

Radon Flux

46

RESRAD-BUILD: Risk Calculations

RESRAD-BUILD allows users to calculate cancer risk– FGR 13 mortality

– FGR 13 morbidity

– HEAST 2001 morbidity

– User library

Methodology is the same as the dose calculations– Same external model

– Same injection model

– Same air quality model

47

Guideline Development

Users must develop guideline values for each source type

Units of guideline values– Activity per mass (Volume

Source)• pCi/g

– Activity per area (Area Source)• DPM/m2

– Activity per length (Line Source)• pCi/m

– Activity (Point Source)

Use RESRAD-BUILD to develop DSRi(t)

)()(

tDSR

HtG

i

Ei

Gi(t) Single Radionuclide GuidelineHE Dose Limit (25 mrem/yr)DSRi(t) Dose to Source Ratio

(mrem/yr // Unit Concentration)

48

Output Results

RESRAD-BUILD provides users with graphical and text based results– Summary report provides

• Parameter Used

• Source term

• Dose

– Detailed Report• Intermediate calculations

involving airflow

• Injection rates

• External dose parameters

– Graphical Results• Interactive plotting

Problem Solving Techniques

50

Multiple Receptors in a Building

RESRAD-BUILD can be used to model multiple receptors in a building to obtain a collective dose

More realistically model a single individual performing multiple tasks at multiple locations

0.9 0.5

1.0

0.3 0.2

.5

51

Co-Locate Volume and Surface Sources

With up to 10 sources available in a single run, RESRAD-BUILD can allow users to model surface contamination and volumetric contamination in a single run

Use the same coordinates and source parameters to co-locate a volume and a surface source

52

Building Occupancy vs. Building Renovation

Building Occupancy Scenarios– Low release over a long

period of time

– Material that is more likely to become airborne

– Exposure duration is typically one year

Building Renovation– Large release over a short

time

– Airborne fraction lower than building occupancy

– Exposure duration 30 to 90 days

53

Multi-Room Air-Flow Model Input

Easy way to provide air-flow into the RESRAD-BUILD Computer Code

Automatically calculates room exchange rates, and overall building air exchange rate

Allows users to visualize airflow within a building

Provide instantaneous feedback when airflows are inconsistent

54

RESRAD-BUILD Example 3

Model the following scenario in RESRAD-BUILD– Pu-239 in a laboratory hood

– Laboratory• 36 m2 , 2.5 meters

– Laboratory hood• 1 m2 , 3 meters

– Hallway • 30 m2, 2.5 meters

– Air-flow is from the hallway to the room and out through the laboratory hood• There is no airflow from the hood

into either the room or the hallway

Laboratory

Laboratoryhood

Hal

lway

Receptor 1Receptor 2

55

Three-Dimensional Display

Allows users to visually place sources and receptors to model building geometry

Sources and receptors are color coded to room location

Sources are displayed as icons and do not represent the entire source– Volume Source: Square– Area Source: Circle– Line Source: Thin

Rectangle– Point Source: Point

56

Dose Conversion and Slope Factors

Shared Nuclide Dose Conversion Factor Database– Access to more complete set of nuclides

– Ability to construct “site-specific” DCF libraries

– Ability to use in both RESRAD and RESRAD-BUILD

– Editor has no equilibrium assumptions built in

– RESRAD-BUILD automatically constructs DCFs with a 30-day half-life cutoff equilibrium assumption

Risk calculation– Uses same exposure time for dose and risk

– Risk slope factors are applied

RESRAD-BUILD Probabilistic Demonstration

58

RESRAD-BUILD Probabilistic Demonstration

Use question 7 from deterministic workbook– Inhalation rate

– Removable fractions for all five sources

– Air release fractions for all five sources• Correlate?

Turn off Radon pathway to speed up calculations?

Verification of RESAD-BUILD

60

Internal Verification of RESRAD-BUILD

Published internal verification report October 2001

Compared RESRAD-BUILD calculations with those given in the users manual using MS Excel– Tritium model

– Radon model

– Direct ingestion

– Inhalation

– Indirect ingestion

Benchmarked external model with MCNP

61

Independent Verification of RESRAD-BUILD

Completed by Tetra Tech NUS Inc. March 2003

Provided verification of the: – Supporting radionuclide

database

– Input parameters

– Individual pathways

– Uncertainty Modules

Quality Assurance &

Quality Control

63

RESRAD-BUILD QA/QC Program

Changes to RESRAD-BUILD must be approved by the Project Leader and Program Manager

A modification must be reviewed by:– An independent scientist or programmer

– The Project Systems Analyst

– The Project Leader

– The Program Manager

All modifications are reviewed prior to release by all programmers

RESRAD-BUILD source code stored in Visual Source Safe to allowing for version control

64

Thank You For Attending!!!!

E-mail: RESRAD@anl.gov

Web Site: http://www.evs.anl.gov/RESRAD