Transcript
INTRODUCTION TO THE NECSA
PROJECT APPROVAL PROCESS AND LICENSING OF DECOMMISIONING
PROJECTS
Licensing Department
2010-08-12
Necsa’s Project Approval Process- Contents
Safety Case
Project Approval Process
Project Categorization
SHEQ-INS-0800 process
Safety Case compliance and verification
Project Approval
Example of a Safety Case for Decommissioning
heq
Project Safety Case Structure
Project Approval Process
Project Initiation
Project
Categorization
Internal Change Management Process
INS-0800 Process
1
2,3
SHEQ Approval Requirements (Safety Case)
SHEQ Approval Requirements integrated into project management plan
Compliance Verification
SHEQ Approval recommendation to SC or Authorized individual as per project cat
Y
N
Correction
Project Categorization
Categorization Element Criteria
1 Installation Existing or New?
2
SHE
Nuclear/Facility Safety Change/Modification of IROFs or
SC-SSC
3 Legislative Approval Change of Safety Envelope
4 Inventories – (Materials and Waste) Increase of material inventories/
new waste stream
5
Operating procedures, facility
arrangements and actions (including
maintenance)
Extend of change required
6 Security Increase of Security Threat
7 Safeguards Modification of existing SG
requirements
INS-0800 Process
• Meeting between Licensing Department , Project Management
Team and Discipline Specialists
• Utilization of checklist to identify project and phase specific safety
case requirements
• Identification of hold points
• Acceptance and approval of Safety Case requirements by
stakeholders
• Incorporation of Safety Case and SHEQ approval requirements into
an integrated project plan
Project Approval
Safety Case for the Decommissioning of a
Conversion Plant
• Project Management
– Project Definition, Scope and Objectives
– Project Description, Organisation and Plan
– Project QA plan
– Work Planning and Schedule
• Project Evaluation
– PEIS
– Safety analyses of planned activities
– Safety assessment
– HIRA
Safety Case for the Decommissioning of a
Conversion Plant
• Plans and Programmes
– Plans to ensure compliance to Construction Regulations
– Work procedures, work planning and training
– OTS, ISI &MP applicable during decommissioning
– Waste Management Plan
– Environmental Monitoring Plan
– Statutory Equipment Management Plan
– Building Security and Emergency Plans
– RP Programme
– Medical Surveillance and OH programme
– Plan to handle asbestos
– Commissioning and Readiness
Safety Case for the Decommissioning of a
Conversion Plant
• External Approval
– Public information
– Regulatory approval
Safety Assessment- Contents
Purpose of the assessment of decommissioning activities
Difference between safety assessment of decommissioning
activities and other planned activities.
General Assumptions
Specific Assumptions and variables
Activity specific dose calculations
Purpose of Safety Assessment
• Ensure that safety is integrated in the development of
decommissioning activities and plans(e.g. Sequence of activities)
• Optimization of protection (ALARA)
• Quantification of operator and public exposure levels in order to:
– Demonstrate compliance with safety criteria
– Identify appropriate project specific Technical Specifications, Operating Rules
and Safety (including RP) related control measures
Difference ico. Decommissioning ?
• Inventory effectively removed during shutdown
• Residual radiological conditions known- measurable/
characterization
• Decommissioning activities well defined per section/task
• Consequence of specific decommissioning activities within
characterised sections can be calculated for specific tasks with the
application of simple models
• Emphasis on deterministic hazard assessment rather than on PRA
• Only limited engineering analyses
General Assumptions
• Conservatism- unless inherent constraints are high –justification of
more realistic assumptions
• Exposure due to prevailing ambient radiological conditions as well
as radiological conditions caused by specific decommissioning
activities
• Limited credit taken for PPE.
• Annual exposure calculated as default
• Exposure via all exposure pathways are considered but could be
eliminated based on relative contribution
Specific Assumptions & Variables
• Radiological characteristics of sections/zones
– Prevailing external dose rate- at various distances
– Material at risk
• Nuclide Composition
• Physical Form e.g. Dry powder as surface contamination or in bulk
form, AMAD
• Chemical Properties e.g. Solubility (Class)
• Quantities, Concentration and prevailing levels
– Anticipated source term per decommissioning activity and AOO
Specific Assumptions & Variables
• Planned decommissioning activities per section /zone
– Main activities per section/zone required for scope of decommissioning
– Anticipated duration of main activities
– Anticipated change of radiological conditions as decommissioning
advance
• Worker Interface
– Main Worker categories per main activity defined per section/zone
– Anticipated exposure parameters applicable per Workerr category per
main task per section/zone
• Public Interface
Deterministic Hazard Assessment
18
Dose Calculation Methodology
• Inhalation Dose due to surface contamination
• Secondary Ingestion Dose due to surface Contamination
19
Inhalation Dose due to surface contamination
Dh =(C)(Rs)(Fh)(I)(t)(Eh) (Equation II.1, Annexure II, IAEA Safety Series No. 111-P-1.1)
where:
Dh = Committed effective dose in Sv a-1
C = Average surface contamination level in Bq/m2
Rs = Resuspension factor in m-1
Fh = Inhalation transfer factor for surface activity
I = Inhalation rate in m3/h ( specified as 1.2 m3/h when doing light work, ICRP 23)
t = Time in hours/a
Eh = Committed effective dose per unit intake via inhalation, in Sv/Bq
20
Secondary ingestion dose due to surface
Contamination
Dg = (C)(Rg)(t)(Eg) (Equation II.2 in IAEA Safety Series No. 111-P-1.1, but for surface
contamination)
where:
Dg = Committed effective dose, in Sv a-1
C = Average surface contamination level in Bq/m2
Rg = Secondary ingestion rate in m2/h
t = Time in hours/a
Eg = Committed effective dose per unit intake via ingestion, in Sv/Bq
21
Effective Dose
• In order to calculate the Effective dose of a specific activity it is necessary to calculate
besides the committed effective dose, also the external Dose component which could
include:
– Whole body Gamma dose
– Skin dose
– Dose to the lens of the eye
• The Effective dose is the summation of all Dose components
E=Wt.Ht
22
?
Methodology for assessing Internal dose due to volume contaminated
material?
23
Thank You!!!
top related