Nuclear Plume Dispersion

1. Development of computer program for
calculation of projected dose in the off-site
Area for Design Based and Beyond Design
Based Accidents at NPPs.
PRESENTED BY: TALHA JAVED
SUPERVISOR: Mr. QAISAR NADEEM
CO-SUPERVISOR: Dr. HASEEB-ur-REHMAN

2. MOTIVATION
 NPPs release radioactive effluents in environment under normal and emergency
situation.
 While atmospheric Releases In NPP’s emergency conditions:
 Projection of dose to offsite locations is quite important.
 Make decision based on the exposure of general public like:
 Evacuation.
 Shelter.
 Precautions etc.
 We need tools to project offsite doses and suggest required actions to Decision
Making Authorities.

3. SCOPE & OBJECTIVES
 EDSS is designed to:
 Predict offsite dose dispersion upto 25km radius due to radioactive effluent releases
specific to CHASNUPP site.
 Tabulated data of dose at required locations.
 Visual representation of dose dispersion and identifying the areas of high dose.
 Assist Decision Makers in making decision regarding general public.
 EDSS is designed to be used at CHASNUPP site and needs to be independent of
any internet facility usage.

4. WHY WE NEEDED TO DEVELOP EDSS
EDSS is a site specific tool(CHASNUPP) and we were called for help in developing a
software utility for predicting off-site doses due to atmospheric releases of
radioactive effluents.
Currently client is using INTERASS for this purpose which is based on Gaussian Plume
Model which has its inherent limitations like:
 Recommended for 10 km radius.
 Wind direction and speed is assumed to be constant along the track of plume.
 Recommended for wind velocities greater than 3 m/sec which is not the case for
CHASNUPP.

5. LITRATURE REVIEW
 EMERGENCY: is a serious, unexpected, and often dangerous situation requiring
immediate remedial action.
The IAEA guidelines suggest the following emergency classes:
 Alert: is declared once something uncertain, or a decrease in the level of protection has
been detected, but no action is needed to protect those residing off-site
 Site Area Emergency: is declared when the population at the site needs to prepare for
taking protective actions and other response actions and monitoring needs to be
conducted in the vicinity of the facility
 General Emergency: is declared when protective actions and other response actions
need to be taken immediately to protect the public which resides off-site.

6. LITRATURE REVIEW
 GAUSSINA PLUME MODEL: A simple model used for finding the concentration of
pollutant at some specific point due to atmospheric release of pollutant. Considers the
Gaussian distribution of Plume about the vertical axis.
Where,
Χ = Pollutant concentration at specific point (ML-3)
Q = Emission rate (MT-1)
V = Wind velocity in down wind direction(LT-1)
σx, σy = Dispersion Coefficients (L)

7. LITRATURE REVIEW
 LANGRANGIAN PARTICLE MODEL: considers fictitious particles and tracks their
movement by stochastically picking the required data at specific location.
 The mass of pollutant emitted is divided in a given number of computational particles
which are just fictitious and have no practical existence.
 Each of these particles moves in the atmospheric fluid with the same velocity as that of
fluid and the velocity used consists of two components:
 Mean wind velocity provided by meteorological model at the specific point
 Fluctuation in velocity calculated stochastically

8. LITRATURE REVIEW
 CALMET: is a meteorological processor and generates a 3D wind field which is used by
LAPMOD as an input for calculating Concentrations at different point
 3D Wind field is generated based on:
 Terrain data
 Meteorological data consisting of wind speed, temperature, pressure etc.
 What is 3D wind Field?
A three dimensional meteorology profile which divides the whole 3D volume into small 3D
regions and considers each individual volume is having a separate met-Station which provides
metrology data at each region.
The data is constant for each region and changes as the region changes while the data in each
region is calculated by CALMET from the input data.

9. LITRATURE REVIEW
 LAPMOD: is a software based on Langrangian Particle model and is used for
calculating concentrations (ML-3) of effluents at respective point and requires
following inputs:
 3D wind field as generated by CALMET.
 Source emission profile which consists of detail of each specie, concentration, time of
release etc. at the source location.
 Points where we want to know the concentrations of effluents.

10. INTRODUCTION TO EDSS
 EDSS is a software utility for prediction offsite doses and is basically an integration
of different utilities performing various steps for predicting dose dispersion. The
utilities include:
 CALMET for generating 3D wind field based on Weather profiles and Geodetic data.
 LAPMOD and dose factors for calculation of dose dispersion based on CALMET and
Source data input.

11. INTRODUCTION TO EDSS
 Main Window:
 Buttons
 Site map of CHASNUPP FOR
visual presentation of dose
Dispersion
 Legends for various dose limits.

12. INTRODUCTION TO EDSS
 Inputs to EDSS.
 Run Period
 Met Data
 Source Data
 LAPMOD Control File
 Outputs:
 Submersion and deposition Concentration files.
 Submersion Dose, Deposition Dose and Total Dose files.

13. INTRODUCTION TO EDSS
 INPUTS TO EDSS:
 Run Period:
 Project Name.
 Location.
 Starting time and Duration

14. INTRODUCTION TO EDSS
 INPUTS TO EDSS:
 Met Button: Weather profile
 Manual input: manual entry of data from meteorological
instrumentations installed nearby.
o Surface Data.
o Upper Air Data
 Station Data Files: that are obtained from Meteorological
station.
o 1 surface data File.
o 2 Upper air Data Files.
 Existing files: Premade CALMET.DAT file.
 Note:- At the end of this step a CALMET.DAT file is
generated.

15. INTRODUCTION TO EDSS
 Running CALMET: Creates a 3D wind field in form of CALMET.DAT file which is
used by LAPMOD for predicting dose.
 Inputs required for CALMET are:
 Geodetic Data: Consists of Terrain information of Area.
 EDSS is site Specific so GEO.DAT file is fixed.
 Weather Profile: As created in this step.

16. INTRODUCTION TO EDSS
 INPUTS TO EDSS:
 Source Button: Information of Source Type
and Emission Parameters
 Source Definition:
o Name of Source(Stack)
o Coordinates
o Type of Source
 Radioactive Species being released: from a
library of 50 species provided.

17. INTRODUCTION TO EDSS
 INPUTS TO EDSS:
 Source Button: Information of Source Type
and Emission Parameters
 Emission Profile: Properties of emission at
each time step.
o Temperature
o Velocity
o Activity of each specie
 EDSS generates a file of emission data as
source.inp which is used by LAPMOD for
dose calculations

18. INTRODUCTION TO EDSS
 INPUTS TO EDSS:
 Running LAPMOD: LAPMOD uses following inputs for
calculations of Concentrations at respective grid
locations.
 CALMET.DAT file for meteorological data. As LAPMOD is
designed to use this file.
 Source.inp file for emission data.
 LAPMOD Control file for importing the settings for
running software.
 Generates following files as output:
 Submersion concentration
 Deposition Concentration.

19. INTRODUCTION TO EDSS
 LAPMOD Control file consists of following information:
 Start Date and Time
 Number of Particles Emitted
 Plume Rise Type
 Grid Lower-Left and Top-Right Corner Coordinated
 Time Step for writing output files
 Location of Output Files
 Format of Output Files
 The LAPMOD Control file is fixed for easiness and EDSS automatically updates some
parameters that are required to be updated in each run while most of the parameters
are fixed.

20. INTRODUCTION TO EDSS
 OUTPUT OF EDSS:
 EDSS uses following for Dose Calculations:
 Submersion Concentration files.
 Deposition Concentration files.
 Hotspot Dose Factors library
o Submersion Dose factor
o Deposition Dose factor.
 EDSS Calculated and stores following Doses is
separate files:
 Submersion Dose
 Deposition Dose
 Total Dose

21. WORKS TO BE PERFORMED NEXT
Main Tasks:
 Source Term estimation incorporation.
 As in SBOs we need so.
 Introduce Reverse Modeling in EDSS.
 To calculate Source data from doses measured at some offsite location.
Auxiliary Tasks:
 Making the EDSS’s visualization more better and user friendly.
 Develop argument based input mechanism.
 Making EDSS compatible for CHASNUPP.
 Develop users manual for EDSS.

22. PROJECT TIMELINE
Activity
Number Description of Activities
Starting
Time
Ending
Time
A001 Literature Review 10/12/2020 11/16/2020
A002 Understanding the Project 11/16/2020 12/21/2020
A003 Do Trial runs on EDSS 12/28/2020 1/11/2021
A004 Gather info regarding Theoretical Methods for Source Term Estimation 1/11/2021 2/15/2021
A005 Implement Theoretical methods for Source Term Estimation in EDSS 2/15/2021 4/5/2021
A006 Learn Inverse Modeling in LAPMOD 4/5/2021 5/3/2021
A007 Implement Inverse Modeling technique for Source Term Estimation in EDSS 5/3/2021 6/28/2021
A008 Improve EDSS for being user friendly 6/28/2021 8/2/2021
A009 Make EDSS compatible for CHASNUPP Site 8/2/2021 9/6/2021
A010 Develop User's Manual for EDSS 9/6/2021 9/27/2021
A011 Develop Thesis Report 9/27/2021 11/8/2021

23. PROJECT TIMELINE
35
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49
28
56
35
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21
42
10/12/2020 1/20/2021 4/30/2021 8/8/2021 11/16/2021
A001
A003
A005
A007
A009
A011
DATE
ACTIVITY
NUMBER
Project Timeline

24. WHAT I HAVE ACOMPLISHED
 Literature Review.
 Overview of Current progress on the project.
 Theoretical Methods for Source term estimation:
 Calculation of Source parameters while the detection system at NPP site is halted due to
some reason.
 How can we estimate Source parameters?
o Use reverse modeling for dose calculated at some distant location. As used by PAKs NPP Hungary
which uses ERM software based on Langrangian Particle model and calculates source parameters form
dose measured at some point by using Reverse modeling technique[1]
o Use theoretical values provided in Regulatory guides.
o Use some relations depending on Burnup, Time of operation, Type of fuel etc.
[1] https://www.osti.gov/etdeweb/servlets/purl/20658881

25. EMERGENCY DECISION SUPPORT SYSTEM
 Any queries?

26. THANK YOU