Andra-experiences - gnssn.iaea.orggnssn.iaea.org/RTWS/general/Shared Documents/Waste...

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

Siting: underground and surface facilites


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 .. )

GEOSAF–II Meeting, 29 May 2014 DMR/DIR/14-0108

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


A Step by Step Legal Framework

with Intermediate Milestones

and Reviews by Regulator

2009 - 2010 2011 2013 2014 1991 2005 1999 2001 2012


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


General schedule

for French Deep Geological Repository Cigeo

DMR/DIR/14-0108


2017 2020 Commissioning, starting with the

industrial pilot phase 2015

Full Licence application Options files

Content

1. General schedule


3. Safety case in the industrial design phase and preparing

the Application for Licensing


The Cigéo project – the layout

The underground facility is hosted 500 m deep in thick

argillite (hard clay) formation

DMR/DIR/14-0108

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


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


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


IL-LLW disposal packages /development of prototypes

Before emplacement, IL-LLW might be

grouped into precast concrete

rectangular robust containers

Prototype manufacturing Support tests


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.


Stacking of IL-LLW in disposal vaults

Emplacement/retrieval equipments is being developed and prototyped

Pre-stacking

technique


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


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


Detailed study completed a for cable

funicular system (including

emergency brakes mounted on cart)

Progressive development of the facility

DMR/DIR/14-0108

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


DMR/DIR/14-0108

Nuclear area

Nuclear ventilation

Construction area



DMR/DIR/14-0108

Nuclear area

Nuclear ventilation

Construction area

Closed area



DMR/DIR/14-0108

Transfer of waste packages from surface to the

underground repository


Content

1. General schedule


3. Safety case in the industrial design phase


Safety approach : a global approach with key steps

DMR/DIR/14-0108

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


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


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


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.


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

DMR/DIR/14-0108

Fire guidance : apply the principle of defence-in-depth

commonly used in the nuclear industry


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…


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


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



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


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


DMR/DIR/14-0108


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


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


Incidental Situation: evacuation of workers


Incidental Situation: rescue


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


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.


Waste Package Handling

Emplacement

and Retrieval

Tests

ILW

HLW

Design of Incline Transfer System

(Surface to U/G)

Technical tests to support the


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


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 -


Presentations at various conferences :

e.g. IAEA Regional Workshop on Engineering for Safe Geological Repository Construction

and Operation- Peine 23-27 September 2013



















Thank for your attention


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