András Cserháti senior expert

VVER 2013 International Conference 11-13 Nov 2013, Prague

Past, present and future of the Paks NPP in Hungary

More than 30 years before

14 Dec 1982, 21:45 Connection to grid of unit 1 2

A good chance for future

• Change in safety philosophy (late ‘70s)

– designed for Ø500 mm primary tube rupture

(loss of coolant accident, LOCA),

– functionally similar confinement to western type containments

– chance to avoid closure of NPP at joining to EU!

V-230 V-213 hermetic volume

3

First period of R&D

• VVER-440/V-213 - a robust hardware – very good and reliable basis

• Identification, elimination of weaknesses of Soviet supply – full scope training simulator Nokia+KFKI+SZTAKI+Paks NPP

– monitoring of the reactor core VERONA system

– monitoring of the reactor pressure vessel embrittlement

= surveillance program, specimen testing = neutron spectrum and fluence measurements = interpretation and prediction expert panel

– confinement air tightness examination VEIKI

– monitoring of the environment KFKI

4

- late ’80s

Second period of R&D

• Problems – availability of the Soviet/Russian institutions – growing criticism in the world against Soviet-

designed reactors = GRS Greifswald study, = IAEA EBP on RBMK and VVER safety

– some missing answers to safety design = why it done that way?

• Reaction – sharp turn to safety related questions

• Solution – AGNES project, safety enhancement program

= show the cons/pros by Europe/US conform tools = give priorities for backfitting measures

5

early ’90s -

Second period of R&D

– The task required recognition and adaptation of the computer codes, input and run Paks NPP data and finally interpretation of the results.

– The expected accuracy was also analyzed due to use non-VVER tools.

AGNES project

partly transparent Soviet methods and assumptions, closed computer codes, incomplete documentation

internationally accepted and used methodology, codes, criteria, with adequate QA

Gidropress Chief Constructor Kurchatov Institute NPP Design Bureau, Kiev

V-213

Paks NPP units

Leading Hungarian institutes with moderate foreign help, supervision

Original design

6

early ’90s -

The AGNES project

• Aims of the project:

– a state of the art report on the reassessment of the nuclear safety,

– to carry out DBA and BDBA as well as PSA-1, – to determine the safety improvement priorities.

• Results – The up-to-date analyses do not differ much

from the Soviet ones. – The plant can safely run since the extreme

conservative original design overcompensates the weak points of those analyses.

– The conservative approach makes the operation of the plant more safe, but less economical.

Advanced General and New Evaluation of Safety

The results are accepted by the IAEA and the specialists in developed countries.

7

Major safety reports/reviews

Activity/Documents 1985 1990 1995 2000 2005 2010 2015

PSAR (before construct.)

FSAR (before startup)

partial FSAR updates

AGNES project

new safety regulation

PSR for units 1&2

PSR for units 3&4

major FSAR update

annual FSAR updates TSR (stress test)

SAR – Safety Analysis Report, PSAR – preliminary SAR, FSAR – Final SAR PSR – Periodic Safety Review, TSR – Targeted Safety Reassessment

now

8

Mobile diesels

Cooling and feeding examples

Mobile feedwater to SG

9

• Summary – TSR has not revealed new

safety concerns – Ongoing safety upgrading

addresses problems raised by Fukushima

– There are no issues which question the economic viability of the plant operation

– There is no need to alter the plans concerning the construction of new nuclear units in Hungary

Targeted Safety Reassessment

10

Safety improvements

• 1996-2002: Safety enhancement program – Improvement of incident and accident management – Enhancing the reliability of the safety systems – Decreasing the loads on the items of equipment – More effective training of the operational personnel – Inspection of the containment – Improvements in the seismic resistance – Improvement in the fire safety

• 1998-2011: Management of the primary to secondary leakage (PRISE) • 2002-: Severe Accident Management

0,0E+00

5,0E-05

1,0E-04

1,5E-04

2,0E-04

2,5E-04

3,0E-04

3,5E-04

4,0E-04

4,5E-04

5,0E-04

1995 1997 1999 2001 2003 2005 2007 2009 2011

Co

re d

am

ag

e p

rob

ab

ilit

y

Sorozatok3 Sorozatok2 Sorozatok1

11

Improvement unit 1 unit 2 unit 3 unit 4

Flooding the reactor cavity ready ready 2013 2014

Electric power supply system for designated consumers

ready

ready

ready

ready

Passive autocatalytic recombiners

ready

ready

ready

ready

Reinforcement of the spent fuel pool cooling system

ready

ready 2013 ready

Dedicated instrumentation system

ready

ready 2013 2013

Severe accident management guidelines

ready ready 2013 2014

Severe Accident Management

• Present status of SAM works

12

Improvement example

• External cooling of the reactor pressure vessel – fill up the 270 m3 reactor cavity

13

Electricity production

14

Load factors unit 1: 90.8% unit 2: 85.9% unit 3: 91.9% unit 4 91.0%

NPP average: 89.9%

WANO - World Association of Nuclear Operators

15

Nuclear capacity increase

• Power uprate (past)

– the four Paks NPP units now on 108% – 440->460->500 MW

• Lifetime extension (present)

– 30+20 years – licensing is in progress

• Cycle length expansion (near future)

– shift from 12 to 15 month fuel cycle – rare shutdown, more production

• New nuclear build (future)

– political support exists – preparation started F

elix

Sock

well

C15

16

Steps graphically

lifetime extension power uprate

30 yrs +20 yrs

new build cycle length expansion

100% 108%

N N

N

t t

unit 1

unit 2

unit 3

unit 4

unit 5

unit 6

t

N

t 3

11 mo oper

1 mo stop

14 mo oper

1 mo stop

12 months cycle

15 months cycle

17

The power uprate

• Initial state – beginning of commercial operation: 440 MW

• Intermediate state – ’90s: 440460-470 MW, due to turbine

modifications, secondary circuit reconstructions, efficiency increase

• Final state – since 2006 at

every year an additional unit

440

450

460

470

480

490

500

2005 2006 2007 2008 2009

unit 1

unit 2

unit 3

unit 4

18

The power uprate

• Performance improvement program – Feasibility Study - Nov 2001

= 8% increase is possible, keeping safety barriers = achiavable only with new, upgraded fuel = the secondary circuit can receive more traffic turbine

conversion

– Concept - Oct 2002 = goal: thermal power: 1375 1485 MW, electric power: 470 500 MW = principles: untouched safety, life length, failure rate

and maintenance costs, economic return during remainder of the original life

= review of necessary modificatoins = schedule

108%

19

The power uprate

• Technical items, modifications – the introduction of new fuel assemblies – primary pressure regulator replacement – core monitoring system refurbishment – new reactor protection system set points – changes in passive emergency core cooling,

accumulator parameters – main circulating pump impeller modification (unit 2) – turbine conversion – emergency boric acid concentration increase

20

The power uprate

• Safety analyzes – all repeat for 108+4% power level, – results:

= probabilistic safety analysis: the insignificant increase in core damage frequency (1.4%)

= the limits are exceeded, a significant reduction in the existing reserve is expected.

• Licensing

– there wasn’t such a complex authorization yet! – with involvement of many administrations – multi-stage process

= permits - common principal ~, units specific ~, authorities’ (environmental, water etc) specialized ~ , fuel use ~, modification ~, operation ~

AEKI, VEIKI, Erőterv Gidropress, Kurchatov I., TVEL Turboatom

21

The power uprate

• Economics – a total of >120 MW of new capacity was

established with HUF 4.8 billion budget – 3.5 years after the investment has been profitable – 0.50 HUF/kWh cost reductions (that is 5% at the Paks 10-11 HUF/kWh price) – comparison with other investments:

types of plants mil HUF/MW bil HUF/120 MW

biomass 400 48

lignite 350 42

gas turbines 125 15

nuclear with power uprate 40 5

22

Lifetime extension

• Main preparatory steps, schedule

Program elaboration

Report on program

Authority assessment of program

Implementation of program

Operation monitoring of conditions of license

Environmental impact assessment preliminary final

2000 01 02 03 04 05 06 07 08 09 10 11 12 2032 …

Feasibility study

Unit Started 30 yrs 50 yrs

1. 1982 2012 2032

2. 1984 2014 2034

3. 1986 2016 2036

4. 1987 2017 2037

• Dates

-4 yrs -1 yr applicaton intention

23

Lifetime extension

• Parliamentary approval – 2005: accepted with 96.6% of votes

• Environmental licensing – Environmental impact assessment

– Public hearings = in HU: Paks és Kalocsa / Espoo Convention:

Nagymarton (AT), Eszék (HR), Nagyvárad (RO)

– License issued

– Green legal campaigns and consequences = Energy Club appealed the decision

= higher instance upheld with minor alterations

= Energy Club asked for a new procedure

= court refused, no more appeal possible

N

E

N P K

24

Lifetime extension

• Economics – Fully financed by the NPP – , : very profitable project

= costs: 1/3 of CCGT investment, 1/2 of CCGT O/M

– return on capital

– dividends even to 4.4x if investment

25

The C15 project

• VVER fuel cycles (operation and shutdown)

– now: 12 mo

– later: 15 mo

• Need for fuel with higher enrichment

~415-425 days operation

~320-340 days operation

instead 4.7% now 4.2% average

4,0

4,4

4,4+Gd

4,6

4,95

3,6

4,0

4,4

4,4+Gd

26

The C15 project

• For 5 years – 4 shutdowns instead 5 – +25 days/year operation – -20% maintenance cost

2012 2013 2014 2015 2016

no

w

• check the maintenance cycles,

• renew the safety assessment

Σ ~200 tasks

1

2

3

4

e.g. unit 2 in 2016 does not

shut down

27

New build fundamentals

• Power rate: grid and economy calculations – 600-1000-1600 MW What is the offer?

• Siting: Paks

vs. other

sites

• Not FOAK • 60 years

lifetime

• Light / pressurized water reactor (PWR)

• Load following capacity (50-100%)

quicker, cheaper at Paks!

28

The Paks site

Danube river

Existing units

Spare area

Cooling water intake Discharge

water

29

Paks units, bird's-eye view

30

Ministry

Government

Parliament

Preconditions, time scale

Paks-5 Paks-6

2007 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

years

studie

s 7. (2) For the start of preparation of new nuclear unit, or storage facility or extension of the existing NPPs by new unit is necessary to obtain the prior principal agreement of the Parliament. Atomic Act

licensing

bidding

construction design commis- sioning

Teller Lévai

31

Paks-II

New build - -

• Topics studied 1. Production, grid analysis 2. Energy policy, strategy 3. Economy, trade

4. Public acceptance, communication

5. Nuclear issues, environment 6. Law and licensing

• Studies completed – Feasibility study – Preliminary environmental assessment – Analysis of the storage of spent fuel and

radioactive waste from the new units

Teller Project

32

Options and types

33

New build - -

• Tasks and working areas 1. Financing, project company

= strategic studies, joint venture founding preparations

2. Bidding = BIS preparation, collection of domestic suppliers, bid evaluation

3. Deeper economic & technical studies = cooling (Danube / tower), electricity demand, energy markets,

system-wide regulatory network development and reserve analysis

4. Early licensing preparation = dose constrain, site preparation and environmental approval

5. Legal issues = regulatory procedures, role of licensee, legislation harmonization

6. Public acceptance, communication = moving visitor’s center, polling, conference series

7. Social & economic relations, embedding of project = human resources, analysis of training needs, nuclear cluster

Lévai Project

34

Thank you for attention!

35

The lecturer Education

−Moscow Power Engineering Institute – nuclear engineer, −Budapest University of Economic Sciences – engineer economist, −International courses (USA-Canada, W-Germany, Japan)

Professional experience

Date Location Position Job description

2012- Paks NPP SAR team senior technical expert yearly SAR updates, PSR, PLEX

2009-2011 Paks NPP, Lévai project

department head new nuclear build, bidding, strategic issues, types, investors

2007-2008 Paks NPP, Teller project

senior technical expert

2003-2007 Paks NPP, Damaged fuel recovery project

senior technical expert, deputy recovery leader

damaged fuel recovery preparation and implementation

2000-2003 Paks NPP, Techn. Div.

department head technical support

1995-1999 Paks NPP, Safety Div.

technical expert, team leader safety reviews, PSR

1985-1994 Paks NPP department head R&D, AGNES, technical documentation

1978-1983 Paks NPP, Nucl. Div. reactor physicist reactor physics, in-core measurements

1976-1977 ERŐTERV MTA KFKI

young engineer as the NPP employee

designer institute research institute

András Cserháti cserhati@npp.hu