EPR Time for for lessons learned - NNR

EPR – Time for for

lessons learned

1st NNR REGULATORY INFORMATION CONFERENCE

Pretoria – 05 -07 October 2016

DR. Yves GUENON

Matthieu MAURIN

1ST NNR REGULATORY INFORMATION CONFERENCE 05 - 07 October 2016 – Proprietary information AREVA - 2

Agenda

EPR Design safety principle

EPR Commissioning status Lessons Learned

1st NNR REGULATORY INFORMATION CONFERENCE 05-07 October 2016 – Proprietary information AREVA 3

General arrangement of the buildings (typical)

Turbine building

Fuel

building

Reactor

building

Diesel

Generator

building

safeguards

buildings

Diesel Generator

building

Pumping

Station

Waste building

Nuclear

auxiliary

building


EPR reactor main characteristics

Power:

Core thermal power : 4590 MWth

Generated electrical power : About 1650 MWe

High efficiency : up to 37 %

Target Design Availability : > 91 % (EUR methodology)

Short outages

Prevention of Reactor trips

Radiation Protection

Low collective dose : < 0.5 man.Sievert/yr

Fuel cycle length: up to 24 months

Design service life: 60 years

Reduced operating costs


EPR reactor main primary system: proven design components

Integrating decades of experience

Primary System with a 4-loop configuration

Well known design, close

to existing plants

Main components enlarged as compared to those in operation

Increased grace period in case

of transients and accidents

Extensive use of forgings with integrated nozzles

Improved component quality

with less welds

Materials resistant to corrosion and cracking

RPV

2 SGs

PZR

2 SGs

4 MCPs

RPV: Reactor Pressure Vessel, SGs: Steam Generators

MCPs: Main Coolant Pumps, PZR: Pressurizer


Generation I Generation III Generation II

First

reactor

prototypes

“Commercial”

power

reactors

Advanced

reactors with

improved

safety and

performance

1950 1970 > 2005

60-year evolution of nuclear reactor design

EPR design safety principle


Topics relevant to EPR robustness

Protection against external hazards

Protection against internal hazards

Severe accidents mitigation

Post Fukushima related issues


Core meltdown

accidents

(Three Miles

Island)

Dispersal of

radioactive

material (Chernobyl)

Malevolent acts

(9/11)

Limit the risk of a core meltdown

probability of core meltdown divided

by 10 between the Generation II and

the Generation III

Eliminate the risk of any

consequences on surrounding

population and environment

(especially limiting long term

consequences)

Protect against malevolent acts, for

example, ensure that a commercial

airplane crash will not cause a severe

accident

A

B

C

Past events, driving high safety objectives


Protection against external hazards

Airplane crash protection (reactor building, fuel building and two out of four safeguard buildings) that allows to protect against commercial airplane crash

Protection against external flooding

Geographical separation of redundant safeguard buildings


Protection against internal hazards

1

2

3 4

Redundant trains are fully separated (4 different buildings)


Complementary safety systems

Ensuring the highest level of safety

with complementary systems

Diversity of safety systems

Safety systems from different origins (eg, suppliers, characteristics…) to prevent from single failure

Redundancy against single failure

If one safety system fails, another can ensure 100% of the safety functions

1

4

E.g. redundant

safety systems

E.g. 2 different

types of

Emergency

Diesel generator

Complementary

of active and

passive

systems

Multiple layers of protection – redundant, diversified, & complementary


Severe accidents mitigation

Taken into account in the design on a deterministic basis

Practical elimination of accidents that would lead to large early releases (dedicated primary system depressurization valves, Hydrogen passive recombiners with reactor building free volume, dry reactor pit…)

Low pressure core melt sequences taken into account without any probabilistic cut off frequency : core catcher


Post Fukushima event analysis

IRWST2 (1800 m3)

EFWS1 tanks

(4x400 m3)

Fire fighting

tank

(2600 m3)

Systems required to mitigate post-Fukushima like event are by design protected from external hazard (flooding, earthquake):

Water proof emergency and station black-out diesel buildings

Water proof safeguard buildings (I&C, electrical switchboards, mechanical components)

Diversified ultimate heat sink safety classified


Main outcomes of the post-Fukushima stress tests for the EPR

Stress tests performed in Europe following

European directives highlighted the intrinsic

Robustness of the EPR design:

In France, the National Authority ASN reported that “the

enhanced design of [the EPR™ reactor] ensures already

an improved robustness with respect to the severe

accident”

In Finland, STUK (Safety Authority) highlighted in its final

report that “Earthquakes and flooding are included in the

design to ensure safety functions to a high level of

confidence”


In line with IAEA safety standards, the EPR design was developed in accordance with:

The Technical Guidelines issued by the French Safety Authority (ASN)

The Western European Nuclear Regulator Association (WENRA) for new power reactors

The European Utility Requirements (EUR)

A design reviewed in the framework of international organization

http://annual-report.asn.fr/index.html


Benefiting from a worldwide licensing experience

国家核安全局 NNSA

2016 2012 2009 2005 2007

To receive support during licensing process from experienced

Safety Authority, which already performed similar evaluation

http://annual-report.asn.fr/index.html


EPR Commissioning last and crucial step for full design validation

Starts at the end of the construction phase

To demonstrate that the behavior of the plant

as built is in compliance with the design

assumptions and the license conditions

Covers the full range of plant conditions

required in the design and the safety case with the

tests and initial operation of all the plant’s

components and systems

Encompass all functions of the operation

organization

To demonstrate the adequate functioning of all systems


EPR Commissioning follows a ramp-up plan Divided in 4 phases

An experienced and proven methodology is key to ensure smooth and successful commissioning

Fuel Loading

1 2 3 4

COMPONENT

S & SYSTEMS

SYSTEM

INTERACTIONS

ALL SYSTEMS

OPERATIONAL ALL SYSTEMS AT

FULL POWER

COLD TESTS HOT TESTS

Responsibility transferred

to operator

Operating

license is issued

Validation of hot tests

& Safety Authority authorization to load fuel


EPR Progress update

© AREVA 1 2 3 4

COMPONENT

S & SYSTEMS

SYSTEM

INTERACTIONS

COLD TESTS HOT TESTS

ALL SYSTEMS

OPERATIONAL ALL SYSTEMS AT

FULL POWER


Lessons Learned

Current EPR projects are implemented in very different environments and conditions (countries / utilities / supply chains / regulators)

This brings a high value to our lessons learned

Some recommendations

Manage all lessons learned with a dedicated process ! (not only technical)

Build on a mature reference design :

EPR design is mature, and now confirmed through commissioning

Reference design allows a smoother licensing process and international cooperation

Adaptation of EPR reference design to tropicalized conditions is validated

Rely on a stable set of regulatory rules (as standardized as possible)

Use a realistic and transparent planning for development phase

Anticipation and Preparation are key:

Public acceptance

Work with customer and partners on other / early contracts for building confidence and solve

potential cultural differences

Early involvement of future owner operator in the project

Support the supply chain development (or revitalization) with a rigorous methodology

Human Capacity Building is needed at all levels


The value of lessons learned: Reactor building construction

Construction

duration (# months)

126

4

16

139

10

TSN1 OL3

Slab +1,5m

Start of inner

containment

Gusset

pouring

1st concrete

Dome lifting

24

47

EPR Time for for lessons learned - NNR

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