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

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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!!!