1. SAFRAN
Workshop on the Application of the IAEA Methodology and Safety Assessment Framework (SAFRAN) Tool for the Safety Case (SC) and Safety Assessment (SA) for Predisposal Management of Disused Sealed Radioactive Sources (DSRS)
Athens, GREECE
23-27 June 2014

2. SAFRAN
A software package for assessing radiological safety of pre-disposal waste management activities

3. Purpose of SAFRAN
Implements methodologies developed within the SADRWMS project. It provides aid in:
Describing predisposal radioactive waste management activities in a systematic way,
Conducting the safety assessment with clear documentation of the methodology, assumptions, input data and models,
Establishing a traceable and transparent record of the safety basis for decisions on proposed waste management solutions,
Demonstrating clear consideration of and compliance with national and international safety standards and recommendations.

4. Benefits of SAFRAN
Implements methodologies that have been conciliated at international level – IAEA standards.
Facilitates performing iterations of the Safety Asessment, for example in case of upgrades of facilities, if new waste streams appear, etc.
Several experts can work more effectively in the same safety assessment. SAFRAN facilitates exchange of experience through sharing projects and databases.
Facilitates regulatory review by providing a transparent representation of all SA components. The regulator can use the SAFRAN projects in independent safety assessments.
SAFRAN can be used for creating generic safety assessments.
Overview of SAFRAN Tool 4

5. History of the development (1)
The tool development started in April 2005
In the frame of the IAEA project: SADRWMS – Safety Assessment Driving Radioactive Management Solutions
From April 2007 it was introduced in another IAEA project: DeSa – Safety Assessment in Decommissioning
From 2008 – Sponsoring from SSM (Sweden), NDA (UK) and IRSN (France)

6. History of the development (2)
From April development of a new User Interface and new Calculation Tool based on Ecolego.
Development of website for downloading the tool.
Development of first version of User Guide in Wiki language.
AUGUST 2010 – RELEASE OF VERSION 1.0
Testing by Studsvik AB
Preparation of User Guide and Tutorials
Some improvements in the Safety Assessment Module

7. Test Cases Development of specifications: Treatment plant in Vinca,
IAEA training courses: Slovenia, Croatia, Moscow, Belarus, Chile and Cuba,
Development of specifications for decommissioning: Decommissioning of a nuclear laboratory in the US.
Waste Treatment Plant and Storage facility of the Leningrad Nuclear Power Plant,
Treatment Plant in Studsvik – 2 iterations (Sweden),
National waste treatment and storage facility in Thailand.

8. SAFRAN components SAFREQ Report System description Safety Assessment
Site features, waste producers, waste streams
Safety Assessment
Normal Operation, Accidents
Report
Regulatory Framework
SAFCALC
DATABASE

9. System Description For each configuration Site Facilities
Rooms
Areas (Storage or Processing)
Physical elements
Safety elements
Waste Management Activities
Processes
Check for clearance
Waste Producers
Primary Waste Components
Waste Streams

10. Types of safety elements
Site selection
Safety functions
Limits and conditions
Mantainance requirements
Operational procedures
Emergency procedures
Management systems
Can be linked to physical elements and assessments

11. Waste management activities
Description
Output(s) from activities
Reduction factors
One and only one WMA can be assigned to an area

12. Reduction factors
Define how the activity changes the waste properties: Volume, mass and activity
Sorting of waste
Output
Volume
Massa
Activity
Combustible
5 %
Non combustible
95 %

13. Check for clearance
Possible to make comparisons of activity concentrations in the waste components against IAEA´s and user defined clearance criteria
Clearance criteria are defined for unconditional clearance of solid materials and expressed in Bq/g

14. Processes
A process is a sequence of WMAs which can be used in defition of Waste Streams (WS)

15. Waste Streams
Waste streams represent the fate of waste components through different steps of processing, storing and clearing of wastes
Consider changes of waste properties in these steps.

17. SAFRAN components SAFREQ Report System description Safety Assessment
Site features, waste producers, waste streams
Safety Assessment
Normal operation, accidents
Report
Regulatory Framework
SAFCALC
DATABASE

18. Regulatory Framework Regulatory requirements
Criteria Doses in during normal operation (Sv/y) and accidents (Sv).
Workers and members of the public
Several regulatory frameworks can be added to a project, for example IAEA and national, and all can be used in the SA

19. SAFRAN components SAFREQ Report System description Safety Assessment
Site features, waste producers, waste streams
Safety Assessment
Normal operation, accidents
Report
Regulatory Framework
SAFCALC
DATABASE

20. Assessment types For normal operation and accidents.
Doses to workers and members of the public.
Radiological impacts indoors and outdoors.

21. Assessment context Link to one or more Regulatory Frameworks
Purpose – select from a list or add own
Scope – Define which facilites, rooms and areas will be included in the SA and at what level the assessment is carried out
Approach
PIEs will be defined or only PIE types will be used.
Include or not a step for Screening of Hazards.
Compliance with Safety Requirements will be assessed or not?

22. Graded approach to the assessments
Impacts
Optional step
calculations for standardized conservative
exposure situations
Screening or Hazards
calculations for specified endpoints and expecific exposure conditions
Dose Assessment

23. Safety Assessment for Normal Operation
Endpoints definition – several endpoints that can be optionally linked to one or more regulatory criteria
Indoors and Outdoors
Dose (Sv/y) or Other
Scenarios
Relevant or not relevant
Bounded or not (if bounding scenarios are defined)
Quantitative or qualitative
Indoors or outdoors
Radiological consequences
Indoors: Direct external exposure and exposure by inhalation or Other
Outdoors: Releases to air, liquid discharges or Other

24. Normal operation scenarios
Impacts are classified by their location and type:
Inside the facility (workers exposure)
Direct external exposure and exposure via inhalation,
Other;
Outside the facility (public exposure):
Releases to air,
Liquid discharges,
Other.
In case of assessment of scenarios for normal operation conditions, the SAFRAN classifies arising impacts by their location and radiological impact type. Basing on this classification, SAFRAN selects appropriate procedure and model for calculation of impacts.

25. Screening of hazards and Hazard Quotient
Screening of hazards – implementation of the graded approach;
For screening of hazards SAFRAN uses the concept of hazard quotient (HQ)
The graded approach means that the scope and level of detail of the safety assessment carried out for any particular facility or activity shall be consistent with the magnitude of the possible radiation risks arising from the facility or activity. Therefore the SAFRAN includes procedure for the screening of hazards in order to identify and direct efforts towards all significant and relevant hazards for the facility or activity. Screening out - means that the hazard associated impact is evaluated to be sufficiently low that does not need for any further assessment. Hazard screening allows reducing of number of scenarios to be further assessed.
HQ is comparison of particular scenario generated impact against the impact which can be considered as being insignificant and therefore could be screened out from further consideration.
The impacts can be assessed qualitatively or quantitatively. Qualitative methods usually are used when the magnitude of the impact is either very high or very low. For situations in between usually there is a need for quantification of the impacts.
For example, SAFRAN comes with a default scale of hazards for normal operation scenarios with five categories: Very Low, Low, Medium, High and Very High. The assumed correspondence between these categories and the Hazard Quotients (HQ) are shown in the table.

26. HQ: External irradiation and inhalation
SAFRAN default values:
Screening dose to worker is 0.1 mSv/y,
Annual worker exposure time is 2000 h/y (i.e. working time is 8 h per day, 5 days per week and 50 weeks per year).
User may set its own value for screening dose rate basing on actual conditions to be assessed.

27. HQ: Releases to atmosphere
SAFRAN default values:
Screening dose to member of the public is 0.01 mSv/y,
Release to dose calculation factors (mSv/Bq) are based on the IAEA Safety Report Series No. 19 defined Generic Environmental Model;
User may set its own value for screening release rate basing on actual conditions to be assessed.
The Generic Environmental Model for releases into atmosphere are based on assumptions that are expecting being sufficiently conservative for most of usually encountered practices.
The similar approach is used for screening of hazards associated with liquid discharges.

28. Dose assessments If scenario is not screened out basing on HQ
dose rate (inside facility)
release / discharge (outside facility)
then dose calculation is performed;
Calculation continues with already identified impacting parameters (dose rate, release / discharge rate).

29. Dose assessments (cont.)
External irradiation and inhalation:
User defines actual exposure time:
Releases to atmosphere / Liquid discharges
SAFRAN includes database of release to dose conversion factors:

31. Dose assessments (cont.)
Releases to atmosphere / Liquid discharges
SAFRAN includes database of release to dose conversion factors;
SAFRAN includes SAFCALC tool where IAEA Safety Reports Series No. 19 models are implemented and can be used with user defined parameters;
User values of DCF.

32. Safety Assessment for Accidents
PIE types
External natural
External human induced
Internal
Endpoints definition – several endpoints that can be optionally linked to one or more criteria
Indoors and Outdoors
Dose (Sv) or Other
Scenarios and impacts
PIEs
Scenarios
Impacts

33. Assessments for accidents
PIE Type
PIE 1
PIE n
Scenario 1
Scenario n
Scenario m
Impact 1
Impact n
Impact m
Screening of hazards
Endpoint 1
Endpoint n
Ass Case 1
Ass Case n

34. Default scale of probabilities
PIE properties
Relevant or not
Probability (per year or during facility lifetime)
Qualitative: Very Low, Low, Medium, High, Very High
Quantitative: Probability of occuring at least once
Default scale of probabilities
Qualitative
Category
Probability during lifetime
Annual probability
1/y
Very High
> 95 %
> 3,0E-02
High
75-95 %
1,4E ,0E-02
Medium
5-75 %
5,0E ,4E-02
Low
0,1-5 %
1,0E ,0E-04
Very Low
< 0,1 %
< 1,0E-05

35. Scenario properties Relevant or not
The probability may or not be the same as the probability of the linked PIE
Several scenarios may be linked to the same PIE, but a scenario can have only one PIE
A scenario may have several impacts and several scenarios can be linked with the same impact

36. Properties of impacts from accidents
Relevant or not relevant
Bounded or not (currently practically not used)
Quantitative or qualitative
Indoors or outdoors
Radiological consequences
Indoors: Releases to air, increased direct external exposure and Other
Outdoors: Releases to air, liquid discharges or Other
If the same endpoint is assigned to several impacts of the same scenario, then for this endpoint SAFRAN will also calculate the sum of the doses from all impacts.

37. Potentially Affected Inventory (PAI)
Also known as Material At Risk
Is the radionuclide inventory or amount, in Bq, that can be affected during an accident.
Examples
The PAI for an accident consisting of dropping a waste package equals the total activity in the package.
The PAI for an accident during a processing activity equals the activity involved in one instance of the activity

38. Calculation of PAI
For Storage Areas the PAI is the total activity present in the Area, i.e. the summa over all stored Waste Components.
For Processing Areas the PAI is the Capacity of the Processing Activity (m3) multiplyied by the radionuclide concentration in the waste. For each processing activity SAFRAN calculates two PAI values, using the concentrations in the waste before and after the activity. The user has to choose between these.
In the PAI calculation for an Area, all Waste Streams passing through this Area are considered.
In the PAI calculation for a Room all areas in this Room are considered.
In the PAI calculation for a Facility all Rooms in this Facility are considered.

39. Release Fractions
Release Fraction (RF) is the fraction of the Potential Affected Inventory that is released to air during the accident.
The RF depends on the Waste Form, the Radionuclide and the Type of Effect of the accident.
Values of RF are given in the SAFRAN Database.
It is assumed that RF correspond to respirable fractions.

40. Analysis of the results
Comparison of hazards.
Comparison of doses against regulatory criteria – assessment of compliance.
Definition of modifications of the facilities, waste management activities, existing and new safety elements.

41. Example of Probability-Consequence plots
HQ/Prob
Very Low
Low
Medium
High
Very High
<0.1
SC3
0.1- 1
SC4
1-10
SC2
10-100
>100
SC1

42. SAFRAN components SAFREQ Report System description Safety Assessment
Site features, waste producers, waste streams
Safety Assessment
Normal operation, accidents
Report
Regulatory Framework
SAFCALC
DATABASE

43. Models available in SAFCALC
IAEA SR-19 models: screening models for routine releases to the atmosphere, lakes, rivers, estuarines and coastal areas.
Model for accidental releases to the atmosphere.
Model for accidental releases inside a room.
Simple dosimetry models: point source, disc, cylinder, cube (with and without shielding)

44. Uncertainty analysis
Probabilistic simulations using Monte Carlo random sampling and Latin Hypercube sampling.
Sensititivy analyses using regressions, correlations and variance based methods.

45. SAFRAN components SAFREQ Report System description Safety Assessment
Site features, waste producers, waste streams
Safety Assessment
Normal operation, accidents
Report
Regulatory Framework
SAFCALC
DATABASE

46. Database Radionuclide half lives. Clearance levels.
Gamma constants – dose rates at 1 m from a point source.
Screening dose rates for Normal and accidental situations.
Screening release rates for Normal operation.
Screening releases for accidental situations.
Release Fractions.
Dispersion factors.
Dose Conversion Factors for Normal and accidental situations.

47. SAFRAN components SAFREQ Report System description Safety Assessment
Site features, waste producers, waste streams
Safety Assessment
Normal operation, accidents
Report
Regulatory Framework
SAFCALC
DATABASE

48. SAFRAN website www.safran.facilia.se
Free download of the software and documentation
Online User Guide
Tutorials
SAFRAN projects – TNIT test case
GOSA
Discussion Forum