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Andra-experiences
Cigéo project -Safety issues
GEOSAF–II Meeting, 29 May 2014
S. Voinis
DMR/DIR/14-0108
Content
1. General schedule
2. Cigeo’s general layout
3. Safety Case in the industrial design phase and preparing
the Application for Licensing
DMR/DIR/14-0108 GEOSAF–II Meeting, 29 May 2014
THE SAFETY CONTEXT - References
:
The “nuclear transparency”
A new legal framework
the Nuclear Safety Authority (ASN) an
independent administrative authority.
The Nuclear Safety Authority monitors
compliance with the general rules and
special prescriptions as regards nuclear
safety and radiation protection to which
are subject: the basic nuclear installations
Two key Acts for the regulator and for Andra
Sustainable management of
radioactive materials and waste
draws up a roadmap for radioactive
waste management in France, regardless
of its activity level and its nature.
states that disposal in deep geological
formations is the reference solution for
management of high-level, long-lived
radioactive waste
Andra’s missions and key endpoints.
A key decree published in November
2007:
Key milestones for nuclear facilities
From licensing to decommissioning
Particularity of Disposal
Files to be provided
French Act of 13 June 2006 French Act of 28 June 2006
and its decree’s ( key milestones .. )
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From “Preliminary” reviews
Reference design phase /application
for construction
• Precise reference design for the facility
• Operational and post closure safety
assessment
Illustration Cigéo :
Establishment of Andra “Dossiers” and examination by ASN at each key
stage of the disposal programme development
Review for
License
application of
Cigeo
Periodic dialogue with regulator and TSO a long time before Licensing
Conceptualisation and sites
investigations
• Potential formations/site criteria
• Design options
• safety approach-
• Preliminary assessments
Site characterisation and
Feasibility phase
• Formation characterisation URL
• More detailed safety assessment
• Focusing on post closure safety
• Operational safety preliminary analysis
Preparing the licensing
• Focusing on operational safety
• Compare repository options verifying that
Post-closure safety is not altered
Two intermediate reviews
by regulator
1. Intermediate report “OIC”
2. DAIE 2001
Key review according to the
French Act of 1991:
Feasibility assessment Dossier
2005
Intermediate
reviews
“ Dossier 2009”
“Dossier 2012”
Decree 2007
Interm
ediate files
GEOSAF–II Meeting, 29 May 2014 DMR/DIR/14-0108
A Step by Step Legal Framework
with Intermediate Milestones
and Reviews by Regulator
2009 - 2010 2011 2013 2014 1991 2005 1999 2001 2012
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Andra presents the actions to be taken following the
public debate on the Cigéo project – 5 May, 2014
DMR/DIR/14-0108
Four major changes
The integration of a pilot industrial phase when the facility
starts up
The establishment of a regularly revised master plan for
disposal operations
The involvement of civil society in the project
Changes to the calendar
2015: submission of the Safety Demonstration, of the Retrievability
options file, and first draft of the master plan
2017: full license application, and beginning of amenity works
2020: construction
2025: commissioning, starting with the industrial pilot phase
GEOSAF–II Meeting, 29 May 2014
General schedule
for French Deep Geological Repository Cigeo
DMR/DIR/14-0108
GEOSAF–II Meeting, 29 May 2014
2017 2020 Commissioning, starting with the
industrial pilot phase 2015
Full Licence application Options files
Content
1. General schedule
2. Cigeo’s general layout
3. Safety case in the industrial design phase and preparing
the Application for Licensing
DMR/DIR/14-0108 GEOSAF–II Meeting, 29 May 2014
The Cigéo project – the layout
The underground facility is hosted 500 m deep in thick
argillite (hard clay) formation
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HLW disposal 2075-2140
ILW disposal 2025-2085
U/G facilities
Ventilation and
service shafts
Surface Facilities
Waste transfer ramp
and service ramp
HLW disposal 2025-2040
Waste
preparation
facility
Construction
support
facility
2012 Preliminary design View of the repository after
100 years in operation
GEOSAF–II Meeting, 29 May 2014
Main design principles
Each category of waste in a separate zone
HLW(High Level Waste)
IL-LLW (Intermediate Level- Long Life Waste)
Keep construction area and operation area separate
Separate access facilities
Separate power and information network
Separate ventilation system
Generally speaking, an incident in one area should have no
consequence on the other area
Twin tunnels interconnected
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Cigéo Inventory
(m3)
Produced and
stored in 2010
HLW 10,059 27%
ILW 70,200 57%
Cigéo Project Waste Inventory
• By law only end waste can be disposed of;
• Provision in design to enable future
evolution such as potential direct disposal
of spent fuel (SF).
Vitrified HLW Clads, ends Solidified
effluents
Maintenance
waste
Activated
waste and
ITER
ILW - long lived
CEA Cadarache
Areva La Hague
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IL-LLW disposal packages /development of prototypes
Before emplacement, IL-LLW might be
grouped into precast concrete
rectangular robust containers
Prototype manufacturing Support tests
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IL-LLW disposal vaults
IL-LLW disposal vaults are horizontal tunnels located at the middle of the
host clay layer:
Thick concrete lining to limit long term deformations;
Ventilation of IL-LLW repository cells as long as they are not closed.
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Stacking of IL-LLW in disposal vaults
Emplacement/retrieval equipments is being developed and prototyped
Pre-stacking
technique
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HLW disposal packages and cells
Before emplacement, HLW will be placed
in robust overpack
Ceramic
skids for
easy
handling
Handling
Interface
Vitrified HLW
Stainless
Canister
And disposed of in lined horizontal micro-
tunnels
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Transfer of radioactive waste by ramp and cable car
• Extrapolation of existing technology
• Technology exists even for very high loads
• Emergency braking is easier than with a vertical shaft
• Advantages
• Favourable for fire issue (limited source of fire in ramp, low thermal load in ramp)
• Emergency brakes can be tested easily
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Detailed study completed a for cable
funicular system (including
emergency brakes mounted on cart)
Progressive development of the facility
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Nuclear area
Nuclear ventilation
Construction area
Twin tube design for higher
safety and service
• Emergency access and exit
possible within each area
• Electrical and data network
can be doubled in separate
galleries
GEOSAF–II Meeting, 29 May 2014
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Nuclear area
Nuclear ventilation
Construction area
Progressive development of the facility
GEOSAF–II Meeting, 29 May 2014
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Nuclear area
Nuclear ventilation
Construction area
Progressive development of the facility
GEOSAF–II Meeting, 29 May 2014
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Nuclear area
Nuclear ventilation
Construction area
Closed area
Progressive development of the facility
GEOSAF–II Meeting, 29 May 2014
Progressive development of the facility
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Nuclear area
Nuclear ventilation
Construction area
Closed area
GEOSAF–II Meeting, 29 May 2014
Progressive development of the facility
DMR/DIR/14-0108
Nuclear area
Nuclear ventilation
Construction area
Closed area
GEOSAF–II Meeting, 29 May 2014
Progressive development of the facility
DMR/DIR/14-0108
Nuclear area
Nuclear ventilation
Construction area
Closed area
GEOSAF–II Meeting, 29 May 2014
DMR/DIR/14-0108
Transfer of waste packages from surface to the
underground repository
GEOSAF–II Meeting, 29 May 2014
Content
1. General schedule
2. Cigeo’s general layout
3. Safety case in the industrial design phase
DMR/DIR/14-0108 GEOSAF–II Meeting, 29 May 2014
Safety approach : a global approach with key steps
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Framework and Safety Strategy Regulatory framework/guidance
Strategy - Context
Compliance of the safety level with the objectives to be reached
Waste package
characteristics
Technological
and design
knowledge
Site
Characteristics
Functions
Required (AF)
Scientific
knowledge
Normal Evolution
Scenario
Impact in normal operation (indicators)
Impact of incidental / accidental scenarios ( indicators) Impact of normal and altered scenarios (indicators)
Incidental /accidental
scenarios
Normal operation
Risk analysis (AR) Analysis of uncertainties (AQS)
Altered Evolution
Scenarios
Operational safety Post closure safety
Safety Assessment
Data input – Assessment basis
GEOSAF–II Meeting, 29 May 2014
Key issues towards post-closure safety
A new state of knowledge after ten years of supplementary work in
R&D and experiences in the Bure URL since the publishing of the
“dossier 2005”:
Identification of remaining uncertainties
Reassessment to check that remaining uncertainties are managed either by
technical design components or by scenarios
Industrial feasibility of sealing
Post-closure assessment in coherence with the industrial layout:
This task is all the more important so as during the industrial design
development phase, the layout of the facility may be optimised and design
options may be closed or left open.
The impact of intermediate design evolutions on the post-closure safety must
be controlled :
Post-closure functions /requirements to be fulfilled by the design
DMR/DIR/14-0108 GEOSAF–II Meeting, 29 May 2014
Classical nuclear facilities versus underground repository
Some similar practices
Operational Safety functions
Confining radioactivity in order to
prevent dispersion risks
Protecting people against irradiation
Maintaining sub criticality
Releasing the residual thermal pressure
of the waste
Managing radiolysis gases
GEOSAF–II Meeting, 29 May 2014
Typology of Risks
Internal nuclear risks
Irradiation,
Contamination,
Criticality,
Heating up,
Radiolysis.
Internal non nuclear risks
(conventional risks) :
Fire,
Handling,
Explosion,
Chemical risk,
Auxiliary losses,
Internal flooding,
Human factor.
External risks
Earthquakes, Air Traffic, Flooding,
Climatic Conditions, etc.
DMR/DIR/14-0108
Nuclear safety authority guidance (seismic, fire, criticality, external events... )
Dedicated to operational safety :
external events : seismic, plane crash , flooding…
internal hazards : criticality, fire…
Need to adapt some of the rules currently applied to surface nuclear facilities to an underground
nuclear one (e.g. fire)
Other security and mining guidance to be taken into account
Need to adapt “ classical guidance” to take into account
the underground characteristics
Illustration on Fire Guidance
Two apparently “divergent”
approaches :
Nuclear approach
Fire barriers and confinement
to prevent contamination by
dangerous products
Underground construction/tunnel
approach
Smoke extraction to allow
evacuation of persons and
action of firemen
Necessity of reconciling these two approaches
Guidelines set up by Andra with the
contribution of fire experts
from nuclear operators
AREVA, CEA, EDF
from various bodies :
institute for industrial risks
(INERIS),
center for tunnel studies (CETU)
firemen.
DMR/DIR/14-0108 GEOSAF–II Meeting, 29 May 2014
Objectives and Functional Requirements to be
reached
Objectives
OS 1: Protection of the live and health of the persons present in the installations
OS 2: Preservation of the environment (including protection of the nearby population)
OS 3: Maintaining safety functions
OS 4: Maintaining the industrial activities and the installations
Declined into sub-objectives and associated requirements
Performance criteria are proposed for each of the identified requirements
Wherever possible, a specific reference value is used.
It is issued from
Applicable regulations, if available,
Or the other guideline texts,
Or the feedback from experience and the experts’ opinions.
For example
Requirements in connection with workers
possibility of evacuating,
distance of evacuation (400m maximum),
fire resistance of the galleries
more than the evacuation duration in terms of structures resistance, flame and warm gas tightness
In the absence of complete applicable regulations, all theses reference
values will have to be justified to the regulators (Nuclear Authority, Civil
Protection Authorities)
DMR/DIR/14-0029 31 OCDE - AEN - 11 février 2014
1st
line of defence : minimize the risk of any start of fire and its spreading :
Limitation of the fire load when designing the fixed and mobile equipments,
For example, transfer of nuclear waste using cable car in the ramp
Limitation of the areas having a high fire risk
For example, limitation of underground maintenance and storage areas as much as
practically achievable
2nd
line of defence : detection of fire and early fire fighting :
Implementation of detection devices as close as possible to the potential hazard sources
Implementation of fire-fighting systems to limit the spreading of fire
For example, in board automatic fire fighting system on vehicles
3rd
line of defence : control of fire and limitation of its consequences :
To be implemented according to the reference fires and the selected “envelope” scenarios :
Ventilation and smoke extraction systems, managed from a central control room
Presence of fire compartments, especially for areas entailing a risk of radioactive
substances dispersion or for areas presenting a major fire hazard
electrical rooms for example, which feature major fire loads and ignition
sources
Presence of passageways to evacuate persons and to enable access for fire-fighting
and rescue teams
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Fire guidance : apply the principle of defence-in-depth
commonly used in the nuclear industry
GEOSAF–II Meeting, 29 May 2014
Preparing for and ensuring, the transition to an industrial mode of
construction and operation, and thus:
Demonstrating the effectiveness of the proposed techniques,
Those that are not commonly used in other industries
Duration of the underground facility over the usual duration for nuclear
facilities ( upper 100 y)
Sealing industrial feasibility
Because operational safety is part of the licensing process, and must be adequately
considered in the design, and documented for the licensing :
Risks both for surface and underground facilities
Scenarios impacts
Demonstrators
Requirements during construction
Monitoring requirements
Preliminary waste acceptance…
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CIGEO’s Safety Challenging Issues
CIGEO’s Safety Challenging Issues
Some aspects have to be developed further prior to 2015
Potential failure of the first containment barrier
Co-activity risks (construction + nuclear operation)
Fire risks
=>industrial design brings answers to these issues
Other risks
No major obstacle identified for the license application during the review of the D2009
Complements have to be provided by in the license application in order to demonstrate the
safety of the operational phase
GEOSAF–II Meeting, 29 May 2014 DMR/DIR/14-0108
Illustration on co-activity
management :
Facility designed to ensure
physical separation of nuclear and
construction operation during the
whole life of the facility
Construction
zone
Establishment of containment Systems
Main requirements:
Maintain a level of contamination as low as possible in premises
Avoid the direct contact of the workers with not stuffy radioactive substances.
Objective of "zero" measures in internal exposure by dusts, discharges and radioactive
particles and exposure from gases the lowest possible.
Maintain the durability of at least a system of containment between zones contaminated
on one hand, and not contaminated zones on the other hand
CIGEO’s Safety Challenging Issues
GEOSAF–II Meeting, 29 May 2014 DMR/DIR/14-0108
1st
containment system : disposal waste package
2nd
containment system :
Depending on primary waste package (e.g. only one
containment system for vitrified waste )
For ILW : depending on the “zone” and the scenario:
Ramp, galleries, disposal cells …
2nd
containment system: necessary, unless guarantees made on 1st
system operate at least based on two effective barriers in all
situations (normal, degraded, incidental and accidental)
Objectives in Ramp and galleries :
« Zéro » contamination during normal functioning
Limited contamination for incidental/accidental scenarios
Objectives regarding ILW disposal Cells
Provisions on dynamic containment systems in specific sectors in
case of failure of the static containment
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Design options
HEPA filter
Fire Risk in an underground nuclear facility
Measures to reduce the risks of exothermic reaction involving some waste
(asphalts, sodium, magnesium's)
Possible limits of acceptability of such waste on the Center towards the safety in
operation
Identification of the reference scenario
Mitigation of fire according to the defense in depth principle
The future design options will identify besides measures to insure the static seclusion of
the parcel of waste in the diverse
CIGEO’s Safety Challenging Issues
DMR/DIR/14-0108
GEOSAF–II Meeting, 29 May 2014
Design features (Intermediate Level-Long Life Waste
disposal cell)
IL-LLW Cell :
Segmentation fire in cell
handling => design
equipment, detection and
fixed fire-fighting, fire
resistance of the package
fire during the transfer and
implementation of the
package stack => gear
design transfer (self
extinguishing system), fire
resistance of package
DMR/DIR/14-0029 38 OCDE - AEN - 11 février 2014
Design principle applied to fire management- Evacuation and
rescue operations in case of fire in the underground facility
In case of fire
Underground design includes twin tunnels (patterns of parallel galleries)
These galleries are interconnected
Passageways to evacuate workers
Smoke free escape route
Presence of two passageways
Access for firefighting and rescue operations
Two access free in all installation and situation
Fire fighting equipment in installation
DMR/DIR/14-0029 39 OCDE - AEN - 11 février 2014
Incidental Situation: evacuation and rescue in the ramp
Passageways to evacuate workers :
Smoke free escape route
Presence of two passageways
Access for firefighting and rescue
operations :
Two access free in all installation and
situation
Fire fighting equipment in installation
DMR/DIR/14-0029 42 OCDE - AEN - 11 février 2014
The need for demonstrators
DMR/DIR/14-0108
Nuclear Waste Package Transfer & Emplacement technologies
are very well known processes throughout the nuclear industry (on road, on rail or
at sea and also commonly in nuclear surface facilities),
… but they have to be adapted to the underground conditions prevailing
in a Deep Geological Disposal
The main goals of the R&D programme in view od demonstration of
safety on the waste packages and their related emplacement systems
are :
to prove the mechanical feasibility of the various waste package emplacement
processes thanks to the design, construction and test of a full scale industrial
prototype,
the compatibility of the processes with the various pre-determined waste,
Engineering a completely proven operational solution, for such
concepts…
is not only a technical challenge with many issues still pending,
but it is also a progressive and slow process of confidence building with the various
stakeholders (, evaluators, national and local political representatives, NGO’s,
public at large, etc...),
the real systems qualification will take place in due time in-situ (i.e. underground)
before start-up or in the industrial phase.
GEOSAF–II Meeting, 29 May 2014
Waste Package Handling
Emplacement
and Retrieval
Tests
ILW
HLW
Design of Incline Transfer System
(Surface to U/G)
Technical tests to support the
DMR/DIR/14-0108 GEOSAF–II Meeting, 29 May 2014
In situ Tests
Sealing Technology and Demonstration
Tests
Full Scale Test
DOPAS* European
Project (Demonstration
of plugs and seals)
Key issues towards licensing : technical feasibility
DMR/DIR/14-0108 GEOSAF–II Meeting, 29 May 2014
List of references
The National Inventory of Radioactive Materials and Waste 2012 - In summary_
http://www.andra.fr/download/andra-international-en/document/editions/466a.PDF
Only available in French :
Synthesis Repot for public Debate : Centre industriel de stockage réversible profond de
déchets radioactifs en meuse/haute-marne - Dossier du maître d’ouvrage -
http://www.andra.fr/download/site-principal/document/editions/504.pdf
Dossier 2009: Options de sûreté du stockage en formation géologique profonde -
http://www.andra.fr/download/site-principal/document/editions/392.pdf
Presentations at various conferences :
e.g. IAEA Regional Workshop on Engineering for Safe Geological Repository Construction
and Operation- Peine 23-27 September 2013
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