Exploring LTO for NPP

Bohunice and SAM for

NPPs Mochovce and

Bohunice

Country report - Slovakia

Ludovit Kupca Head of LTO project team

Nuclear Engineering Division

Engineering Department, SE, a.s.

Meeting of the Technical Working Group on Life Management

of Nuclear Power Plants, 22-24 February 2017, Vienna

2

Slovenske elektrarne Nuclear overview – Bohunice Units 3,4

Bas

ic o

ve

rvie

w

Key h

igh

lig

hts

• New installed equipment (TGs, Generators with higher output) 505

MWe/ unit

• High UCF, low UCLF

• Likely to operate 30 more years

• Modern new digital safety system (RPS, ESFAS) by AREVA

• Generating and selling the heat to the surrounding municipalities

• Area of population supporting nuclear technology and region with a

nuclear tradition

• Location: western Slovakia near to Trnava

• Two units VVER 440/V-213 PWR

• Commissioning date: 1984 and 1985

• Expected decommissioning date: 2044 and 2045

• Gross capacity: 2 x 505 MWe

• Net capacity: 2 x 471 MWe

• Fuel type: Enriched uranium 4,87%

3

Slovenske elektrarne Nuclear overview – Mochovce Units 1,2

Bas

ic o

ve

rvie

w

Key h

igh

lig

hts

• Location: southern Slovakia, between the towns Nitra and Levice

• Two units VVER 440/V-213 PWR

• Commissioning date: 1998 and 2000

• Gross capacity: 2 x 470 MWe

• Net capacity: 2 x 436 MWe

• Expected decommissioning date: 2058 and 2060

• Fuel type: Enriched uranium 4,87%

• The youngest VVER440 in the world

• Potential to uprate up to 505 MWe/unit (currently planned

after EMO 3/4 commissioning)

• Modern I&C and safety system by SIEMENS

• Area of population supporting nuclear technology

4

Responsibilities of executive officers

PROCUREMENT OF WORKS, SERVICES & MATERIALS

PROCUREMENT STRATEGY, POLICIES, OPTIMISATION &

CONTINUOUS IMPROVEMENT

DESIGN TO COST

Energy Management Director – Juraj Chren PRODUCTION OPTIMIZATION

PRODUCTION SCHEDULING

DISPATCHING CENTRE, PRODUCTION EVALUATION

METERING DATA MANAGEMENT

FUELS & HEAT

REGULATORY AND PORTFOLIO MANAGEMENT

Procurement Director – Robert Štofko

Market and Regulatory Director –

Branislav Strýček

AFC Director – Georgios Karavas PLANNING & COST CONTROL, APPROVAL OF THE

INVESTMENT PLAN (SIP) AND INVESTMENT PROJECTS

NPP Operation Director – Milan Molnár NUCLEAR OPERATION SUPPORT

MAINTENANCE COORDINATION

NUCLEAR TRAINING

EQUIPMENT RELIABILITY

FUEL CYCLE AND RADIOACTIVE WASTE

MO34 OPERATION PREPARATION

INTERNAL COMMUNICATION NUCLEAR

Nuclear Engineering Director –

Vladivoj Řezník NUCLEAR TECHNOLOGY

BASIC DESIGN CONFIGURATION – DESIGN

AUTHORITY

TECHNICAL NUCLEAR ENGINEERING – AGEING, LTO

NUCLEAR SAFETY ASSESSMENT

NDT AND SERVICES

INVESTMENT PROJECTS MANAGEMENT

TECHNICAL & PROJECT DOCUMENTATION CENTRE

COORDINATION & PLANNING

Nuclear Safety & Radiation Protection

Manager – Jozef Tomek NUCLEAR SAFETY, RADIATION PROTECTION,

EMERGENCY PREPAREDNESS

LICENSING & REGULATORY AFFAIRS

CONTINUOUS IMPROVEMENT

IMS and Nuclear Oversight Director –

Ľubomír Krenický QUALITY ASSURANCE

DOCUMENTATION CENTER AND TECHNICAL

INFORMATION

HEALTH & SAFETY AND ENVIRONMENT

NUCLEAR OVERSIGHT

CORPORATE INDEPENDENT OVERSIGHT

Procurement Manager – Peter Čambál

Human Resources and Organization

Director – Jana Kollárová PLANNING AND COMPENSATION

HR BUSINESS PARTNERING

HR DEVELOPMENT

ORGANIZATION AND HR ADMINISTRATION

Generation Director – Jaroslav Holubec NUCLEAR POWER PLANTS OPERATION

EBO NPP Director – Martin Mráz

External Relations and Sustainability

Manager – Miroslav Šarišský INTERNAL AND EXTERNAL COMMUNICATION NUCLEAR

SECURITY

INTERNAL AUDIT

ICT

SERVICES

Operational Performance Optimization

Manager – Jaroslav Holubec PLANNING, MONITORING AND CONTINUOUS

IMPROVEMENT

MONITORING AND CONTINUOUS IMPROVEMENT

PROJECT MANAGEMENT

MATERIAL MANAGEMENT AND LOGISTICS

WAREHOUSE MANAGEMENT

EMO NPP Director – Miroslav Tokár

General Director – Bohumil Kratochvíl MO34 PROJECT MANAGEMENT SUPERVISION

EXTERNAL RELATIONS AND SUSTAINABILITY

NPP COMMUNICATIONS

LEGAL AND CORPORATE AFFAIRS

Availability

Unit 3

Unit 4

UCF [%]

75.0 86.7 89.3 88.1 89.9 94.2 93.7 93.9

86.8

2007 2008 2009 2010 2011 2012 2013 2014 2015

80.0 79.6 88.9 90.3 93.4 90.3 94.5 94.6 94.4

2007 2008 2009 2010 2011 2012 2013 2014 2015

Bohunice

WANO PWR 3y top decile 2014 – 92,52

WANO PWR 3y top decile 2014 – 92,52

Availability Mochovce

UCF [%]

UCF [%]

90.1 91.0 82.6

91.6 93.3 92.6 93.3 92.6 91.6

2007 2008 2009 2010 2011 2012 2013 2014 2015

91.3 88.3 91.6 85.3

92.5 92.0 94.2 89.2 94.4

2007 2008 2009 2010 2011 2012 2013 2014 2015

WANO PWR 3y top decile 2014 – 92,52

WANO PWR 3y top decile 2014 – 92,52

Unit 1

Unit 2

Directive SE/SM-310 – Engineering Process Definition

Configuration management

En

gin

eeri

ng

pro

ces

s

Long term operation - Ageing management

Project management

Project management Research and development

Management of the activities and projects that subject is science, research and innovation

Integration and coordination of a wide range of activities to ensure project implementation from

its approval to completion and delivery into operation and subsequent evaluation

Specifies, monitors the performance and status of equipment, evaluates the status of key equipment and

suggests their preventive maintenance or replacement.

Coordinates the licensing of long term operation. Long term operation can be considered as configuration

management after termination the designed lifetime.

Combines and coordinates activities to ensure the integrity of the power plant to achieve the objectives of SE

a.s. by managing of technical changes and further development of the technology infrastructure.

Under configuration management process is also included role of Design Authority.

8

Nuclear Design Engineering

Krajmer Imrich (3)

23100 Nuclear Design Engineering

125

Dušan Líška

23110 Nuclear Technology

22

Bartovič Ivan

23120 Basic Design Configuration – DA

11

Borák Ján

23130 Technical Nuclear Engineering

14

Gajdoš Martin

23140 Nuclear Safety Evaluation

15

Haršány Jozef

23150 Technical Revisions and Services

60

*systemization valid from 1.3.2016

• Main activities of department: • Solving of complex technical issues in project

design, materials and reliability of nuclear power plants;

• Preparation and compilation of design changes proposals, including the establishment of their priority and assumption of financial expenses;

• Design management of nuclear power plants and assurance of its integrity;

• Set up strategy for maintaining SE, a.s. nuclear power plants;

• Analysis of causes of equipment failure and proposals for its elimination;

• Seismic monitoring of locations of nuclear power plants and prepare proposals for seismic reinforcement of the installation;

• International cooperation in the field of nuclear engineering;

• Check of classified components of primary circuit; • Perform function of main corporate metrologies

and geodesist; • Performance and evaluation of ISI and NDT

program on RPV, MCP, SG, etc on EBO, EMO12,

MO34 and many more activities…

Nuclear Power Plant Bohunice

Unit 3,4

Strategy is to operate power plant until 2045 (60

years of operation), respecting state of the art

level of safety.

LTO has been approved by Regulatory Authority.

Major running projects:

• Safety Improvements –Implementation of Actions

from Stress Tests, Backup supply,

• Long Term Operation Program:

• Essential service water routes replacement

• Replacement of SORR system (RRCS)

• Control rods cables replacement

• Monitoring of selected primary SCs operating

loads

Nuclear Power Plant Mochovce

Unit 1,2

Strategy is to complete ongoing safety measures,

consequently to do modernization of main

components and power uprate as well.

Major running projects:

• Safety Improvements –EMO Severe accidents

management, Implementation of Actions from Stress

Tests, Seismic reevaluation of EMO12-new figure of

seismic loading, Completion of 400kV switch breakers

in Unit 1 and 2

• Modernization - Modernization and innovation of

safety systems SORR (RRCS), Replacement AKRB-

03 (SEJVAL) - phase 2 (Dosimetric I&C System)

• Other - System of liquid radioactive concentrates

treatment

11

Long Term Operation

Nuclear Power Plant Bohunice

0

10

20

30

40

50

60

70

80

90

100

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60

Campaing

Tk

fZ

K [

°C

]

Tkfin Tkf15 Tkf25 Tkf35

Tka

Why LTO? Considered design lifetime is 30 years.

• Assets utilization for longer period from 30 to 60 years.

• Good condition of main technological components such as RPV, SGs, MCP..

• EBO safety modernization program finished in 2008.

• EBO power uprate to 505 MWe in 2010.

• NPPs low total costs of electricity production.

• Short discounted pay back period.

13

Continued refurbishments and upgrades confirm

trend of safety, reliability, and performance improvements

Modernization program

Power Uprate 2x76 MW uprate

Severe Accident Management Project

LTO licensing process

Optimized programs of In-service inspections

LTO measures implementation

Stress Tests action plan implementation

Enhancing V-2 nuclear safety and seismic upgrading (2002 – 2008) approximatelly 110 tasks:

SEISMIC RESISTANCE IMPROVEMENT- New acceleration value in free field is 0.34 g (originally 0.1 g)

FIRE SAFETY MEASURES

NUCLEAR AND OPERATIONAL SAFETY IMPROVEMENTS – new RPS, RLS RTS, TELEPERM XS, ex-core measurement, exchange of section and

auxiliary switchboards, exchange and extension of technology information systems

Optimizing of operational controls for key components of the main primary system was implemented between 2007 and 2015. The

inspection interval for the following SSCs: Reactor Pressure Vessel, Main Insulation Valves, Main Circulation Pumps, Pressurizer, Primary

Circuit Pipes, Boric Acid Tank Storage, Bubbling Tank.

Maximum continuous nominal output of reactor is 505 MWe per unit of NPP EBO = 107% nominal output that

was achieved by implementation of measures on Turbines, Main Condenser, Generators, Unit Transformer,

Primary Circuit – I&C, Cooling Towers etc.

• External coolability of RPV – In-

vessel retention strategy

• Controlled depressurization of RCS in

the onset of severe accident

• Containment Hydrogen management

- Installation of PARs

• Containment Vacuum breaker

• Alternative coolant system -RPV

corium flooding, Containment spray,

Spent fuel flooding

• Alternative electric power system

• I&C capabilities needed for SAM

• Long term heat removal

Elaboration and submission

of documents to NRA SR

according to Slovak law

requirements.

After the accident in Fukushima Daiichi NPP, the European Council asked National Regulatory Authorities (on 24 to 25 March 2011) for

performance of stress tests in all nuclear power plants in Europe. The stress tests and their evaluation were made according to the

ENSREG definition of the task in three fields.

• Increase of resistance of SE nuclear units against extreme external events

• Increase of time reserve to ensure basic safety functions in case of the station blackout or loss of ultimate heat sink

• Severe accident management and minimization of their radiation consequences

It includes the execution of measures from the

finding of the licensing process and the necessary

measures for the assurance of safe and reliable

operation for the following 30 years. The program

includes the modernisation, renovation and

replacement of such systems and components,

whose physical or moral lifetime has been spent.

Commission on assessment of ISI

RPV, SG, RCP, MIV

Main primary piping

Secondary piping

Pressurizer

Reactor building

Corrosion monitoring

Cables

Main condenser,

TG Base+Hall Building

ESW piping, tower

Central pumping

station building

Chemical Water

Treatment Building

Auxiliary Operating

Systems Building

In terms of main SSCs technical conditions, AMPs demonstrate

feasibility of plant long term operation

Reactor internals

Diesel generator

building

Ageing management programs

15

Ageing management program Example of cable degradation on +14,7m

color change

„cut“ crack crack

„cut“ contact (hot parts)

Valve: 2RA52S08 (W51-WS-12078)

Cable: 1-C5HKE-V 12Cx1,5

History: 2004 – installation; 2010 – removal

Damage: color change / jacket crumbling

Jacket EaB: 95,9% (new 180%; criterion >50%)

Failure

reason

↑T + oil vapour impact

+ contact with hot parts

16

Essential Service Water (ESW) Buried piping - The conclusions of studies

• Insulations are entirely after their lifetime

• Seismic resistance of all external ESW piping distributions in the ground is sufficient provided that the external piping insulation

is not damaged and piping itself is not degraded by corrosion

17

Acceptance letter sent by

UJD on 25 Nov 2014

2011 2012 2013 2014 2009

LT

O lic

ensin

g p

rogra

mm

e

QA

& L

TO

licensin

g

org

aniz

ation

LTO

feasibility study

Draft LTO database

Review of time limited ageing analyses (TLAAs)

Review of plant ageing management programmes (AMPs)

Handling with RW & spent fuel

Review of plant programmes that are dealing with

safety relevant short lived SC

Met

ho

do

logy

for

sele

ctio

n a

nd

eva

luat

ion

of

SSC

s

con

dit

ion

s w

ith

re

spe

ct t

o L

TO li

cen

sin

g p

roce

ss

Review of plant operating procedures (with respect to LTO)

LTO radiological (enviro) impact

SAR update

Final report

Summary report

Independent review of plant LTO licensing programme

Implementation

of corrective

measures from

findings of LTO

licensing

programme

IAEA OSART

Nov 2010

First LTO kickoff meeting:

7 July 2010

2010

Co

rpo

rate

LTO

str

ateg

y :

LT

O o

rgch

art,

mai

n g

oal

s, t

asks

;

info

rmat

ion

for

pla

nt

man

ager

mee

tin

g

Review of knowledge retention system (w.r. to LTO)

IAEA OSART

FU Jun 2012

Selection of

SSCs for LTO

2015 2025

Review of

documentation by UJD

(Mar–Oct 2014)

LTO licensing

18

LTO Evaluation Phase Documentation

PROJECT

MANAGER

LICENSING MECHANICAL ELECTRICAL I&C STRUCTURAL

Steering Committee

Engineering Director

Plant director

Nuclear Engineering

Manager

19

Nuclear regulator license statement

for NPP Bohunice

• SE presented to Nuclear Regulatory Authority Action plan on corrective

measures for Bohunice V2 long-term operation program on 19/11/2014

• Nuclear Regulatory Authority Acceptance Letter was signed and

sent to Slovenské elektrárne on 25/11/2014.

• Nuclear Regulatory Authority agrees with the measures proposed by

SE and they will carry out inspections to check status of corrective

measures performance.

• Subject to fulfilment of tasks within given deadlines, Nuclear Regulatory

Authority does not consider necessary to modify the existing

operating license for operation of NPP V2 issued by the Authority´s

Decision No. 275/2008.

• Slovenské elektrárne is obliged to inform Nuclear Regulatory Authority

about the performance of tasks of the Action Plan regularly once a year.

20

LTO measures implementation

Measures from findings

21

LTO hardware modifications program

Innovation of piping systems

Reconstruction of the 400kV substations

Innovation of heat exchangers

Lifetime of primary and secondary circuit extension

Implementation project outputs to ensure the levels of nuclear safety in line with trends in safety requirements in the world

Replacement of essential service water piping

Electrical switchboards innovation direct current and 1st category (it was not included in the original modernization program)

Replacement of 6 kV and 0.4 kV cables

Replacement of electrical protection of drivers 6 kV, outlets to transformers 6/0.4 kV

Replacement the CRD (HRK) cables

Innovation of operational electrical and I&C systems

Gradual replacement of

operational I&C and Electro

with application of new digital

systems due to absence of

the original spare parts.

Replacement of I.O. and II.O. due to FAC and other

degradation mechanism. Replacement of 400 kV components due to end

of its lifetime and lack of spare parts.

Replacement of heat exchangers which are

at the end of original designed lifetime due to

erosion and corrosion.

Replacement of

I.O equipment's

after its

designed

lifetime,

qualification –

valves,

exchangers... Replacement of cladding for spent fuel pit and storage in

shaft no. 1 due to degradation mechanism.

Replacement of essential service water piping placed

underground due to end of lifetime of isolated layer and

subsequent corrosion effect. (internal and external )

Replacement of section direct switchboards and system for emergency power supply -

1 category due to lack of spare parts.

Replacement of 6 kV and 0.4 kV

cables based on ageing

management output and end of

designed lifetime.

LTO output – replacement of 6 kV electric circuit due to

end of lifetime and lack of spare parts.

Innovation of ventilation systems Replacement of obsolete systems

Replacement of cables from control rods due to thermal

degradation.

22

Modification of Essential Service Water

Scope of modification:

Section A,B

• Replacement of existing ESW and NESW* piping,

laying down the new piping in a topsoil channel

• Replacement of shut-off valves DN600 and other

valves of smaller dimension

• Sealing of cooling towers pools Realization in May 2016 during common outage of

units 3/4 with duration of 5 days for each ESW

system.

Section C- Piping rehabilitation

Realization started in September 2015, completed

during plant operation

Section C

Return piping of ESW

from cooling towers

to the inlet

into the pumping

station

(by gravitation)

Section B

Return piping of ESW

from the outlet from

the concrete monolith

to cooling

towers

Section A Discharge

of ESW

and NESW from

pumping station to

the inlet into the

concrete monolith

23

Modification of Essential Service Water

Section C- Piping rehabilitation

Uncovering of the piping places, no longer than

9m

Removal of the original bitumen insulation from

the piping

Cleaning of the piping surface

Performance of NDT examinations

Application of “cold sleeves” in parts where local

material reduction is larger than the reduction

prescribed by the STN 13 1010 standard

Insulation of the entire piping system STOPAQ

Wrapping band + Outer wrap – mechanical

insulation tape

Concrete and the backfilling of excavations

Application of the cathodical protection

New buried piping to ESW fan cooling towers Central pumping station

EBO10155 – Modifications on Essential Service Water

25

Innovation of Control Rods System

Conventional area Hermetic zone

Power cabling

Signal cabling

IPR EBO 10117 – Replacement of V2 NPP Emergency Control Rod Assembly (ECRA) Cabling

IPR EBO 10043 LTO P11 – Replacement of Reactor Rod Control System

Main and emergency control rooms

Reactor safety systems AKNT,

AKE, RLS, RPS, BREAKER

Power supply

Upper reactor plenum

ECRA drive mechanism

Room of cabinets

Control rod testing stand

Communication cabling

Operational reactor systems

RCS, TVER, SRV, KVRK and plant technological computer

system TPS

• System safety reclassification from safety class „II“ to „III“ (from category „A“ to „B“ per STN IEC 61226) under approval of NRA

• Alignment with EMO12,MO34, EDU

Position indicators and control switches

• Power cabling for electromotor of ECRA • Signal cabling for ECRA position sensors • Hermetic cabling penetrations • Cable connectors on reactor postament • Special cables from reactor postament to ECRA drive mechanism and

position sensors • Cable connectors on ECRA drive mechanism and position sensors

Innovation of Control Rods System

Project is coordinated with implementation of emergency control rod cables replacement

completed in regular outages in 2016

EBO10043/11

– replacement

of CRS

New cabinets SORR – GO4/2016

New Reactor Protection and Control

System – GO4/2016 New operator desk controllers

Old operator desk controllers

Old Reactor Protection and Control System –

GO4/2016

28

Severe Accident Management

Nuclear Power Plant Bohunice and Mochovce 1,2

Long term heat removal

Severe accident management Bohunice 2009-2013 and in Mochovce 2011-2016

Alternative electric power system

External coolability of RPV – In-vessel retention strategy

Containment Hydrogen management - Installation of PARs

Controlled depressurization of RCS in the onset of severe accident

Containment Vacuum breaker

Alternative coolant system -RPV corium flooding, Containment spray, Spent

fuel flooding

I&C capabilities needed for severe accident management

Implementation of Safety Upgrading Measures in the

Area of

Mitigation of Severe

Accidents

30

In-vessel retention strategy

Measures to flooding reactor shaft

31

Primary circuit depressurization

32

Passive hydrogen recombinators

Containment Hydrogen management

33

Emergency Response Center

ERC Bunker

ERC Radiation - group

ERC TSC - group

ERC SAM - operators

34

Hermetic zone - Vacuum breaker

35

Emergency coolant source

36

Water supply by fire brigade sources

37

Stress tests - immediately implemented measures

38

Alternative electric power system

39

I&C System for Severe Accident Management

– Instrumentation for Severe Accident conditions (PAMS + dedicated severe accident measurements)

– Control of equipment considered essential for severe accident management

– Dedicated SAM control panel in the unit control room and Emergency response center

40

Long term heat removal

– Recovery strategy of existing systems for long term heat removal during SA conditions adopted

– Existing systems for containment spray and essential feed water system modified for SA conditions

– New pipelines are designed to ensure the ultimate coolant delivery to the reactor cavity, spent fuel pool

and alternative coolant system tanks (make up)

41

END OF PRESENTATION

Thank you for your kind attention.