NPP Power Uprate and Modernization · 2010. 9. 21. · VÚJE, Inc., Okružná5, 918 64 Trnava, Slovak Republic 13 Mochovce NPP Unit 1&2 - Power Uprate Thermohydraulics and electrical

1VÚJE, Inc., Okružná 5, 918 64 Trnava, Slovak Republic

NPP Power Uprate and Modernization

French-Slovak summer schoolKocovce, 13.9 – 17.9 2010

Ing. Branislav Hatala, PhD.

[email protected]


Historical development of nuclear power


Content

Background on Power Uprates

Types of Power Uprates

Mochovce NPP Unit 1&2 Power Uprate

Safety Aspects of Power Uprate

Bohunice NPP Unit 3&4 Modernization + Power Uprate

Discussion



To increase the power output of a reactor, typically more highly enriched

uranium fuel. This enables the reactor to produce more thermal energy and

therefore more steam, driving a turbine generator to produce electricity.

In order to accomplish this, components such as pipes, valves, pumps, heat

exchangers, electrical transformers and generators, must be able to accommodate the conditions that would exist at the higher power level.

Depending on the desired increase in power level and original equipment

design, this can involve major and costly modifications to the plant such as

the replacement of main turbines.

All of these factors must be analyzed by the licensee as part of a request for a

power uprate, which is accomplished by amending the plant's operating license.



Power Uprate

Thermal reactor power increase Increase thermal efficiency of Unitupgrade

Secondary Circuit

Electricity part



Measurement uncertainty recapture power uprates

are less than 2% and are achieved by implementing enhanced techniques for calculating reactor power.

This involves the use of state-of-the-art feedwater flow measurement devices to

more precisely measure feedwater flow, which is used to calculate reactor power.

More precise measurements reduce the degree of uncertainty in the power level, which is used by analysts to predict the ability of the reactor to be safely

shutdown under postulated accident conditions.



Stretch power uprates

are typically up to 7% and are within the design capacity of the plant

without major plant modifications.

Instrumentation set-points are adjusted to achieve the higher power.

The actual value for percentage increase in power a plant can achieve and stay within the stretch power uprate category is plant-specific and depends on the

operating margins included in the design of a particular plant.



Extended power uprates

These are characterized by power increases of up to 20% , and involve significant investment into the balance of plant equipment. Large items, such

as turbines, generators and transformers are usually involved in the task.



Power uprate up to 7%

Reactor thermal power

1375 MW 1471.25 MW

Electric power

440 MW 470 MW

- without hardware changes

- without change of plant design


Mochovce NPP Unit 1&2 - Power Uprate

Power uprate up to 7%

Reactor thermal power 1375 MW 1471.25 MW

Electric power440 MW 470 MW



new type of fuel assemblies (Gd-II) (4.25% / 3.84%)

central tube

4.4% U235

4.0% U235

3.6% U235

4.0% + 3.35% Gd2O3

Enrichment



Thermohydraulics and electrical measurement

Evaluation of mass and energy balance scheme

Evaluation of the report for Ministry of Environmen t

Update of database for safety analysis calculations

Performance of safety analysis calculations

Update of Safety Report

Update of operation procedures

Steps



- performed with the aim to verify turbine margins

- performed for each turbine and generator separately

- maximal required generator gross electrical power 235 MW

- maximum steam flowrate to the turbine

- electrical devices monitoringtemperature of disconnectors coolant temperature of generator coolant temperature of exciter transformer temperature vibration of generator

Thermohydraulics and electrical measurement



- no problem for electric power increase originating from the hardware characteristics.

- limitation is only coolant circulation temperature, which depends on weather conditions such as outside temperature, humidity, wind speed ...

- mass and energy balance scheme was calculated, resulting in the new nominal thermal reactor power

The results of measurements



mass and energy balance scheme 100%T-H PARAMETRE V TEPELNEJ SCHEME I.O BLOKU ***************************************** MIESTO V POPIS MIESTA TEPLOTA TLAK PRIETOK ENTALPIA TEPELNEJ (ST. C) (MPA) (KG/S) (KJ/KG) SCHEME (*M3/H) ====================================================================== /2/ VSTUP DO REAKTORA 267.32 12.641 9245.1 1170.0 *42552. ---------------------------------------------------------------------- /3/ VYSTUP Z REAKTORA 297.88 12.360 9245.1 1329.0 *45908. ---------------------------------------------------------------------- /51/-/56/ VSTUP DO PG 297.88 12.335 1540.9 1329.0 /61/-/66/ VYSTUP Z PG 267.27 12.245 1540.9 1169.7 ---------------------------------------------------------------------- /8/ CELKOM NV DO PG 216.21 4.690 799.66 927.0 /9/ CELKOM PARA Z PG 259.92 4.690 787.66 2792.3 ====================================================================== GLOBALNE PARAMETRE: ******************* TEP.VYKON AZ (MW) 1471.25 * ROZ.TEPLOT V R (ST.C) 30.56 ---------------------------------------------------------------------- PRIKON HCC (MW) 7.48 * ROZ.TLAKOV V R (KPA) 281.4 STRATY I.O ODV.TEPLA (MW) 6.03 * ROZ.TEPLOT V PG (ST.C) 30.61 ---------------------------------------------------------------------- STRATY I.O VYM.CHL. (MW) 0.95 * PRIEM.PRIETOK HCC (M3/H) 7100.2 TEP.VYKON DO II.O (MW) 1471.75 * ROZ.TLAKOV V HCC (KPA) 436.8 ---------------------------------------------------------------------- TEP.VYK. DO ODLUHOV (MW) 2.49 * KONC.ROZ.TEPL.PG (ST.C) 7.35 TEP.VYK. DO PARY (MW) 1469.26 * ROZ.TLAKOV PG-HPK (KPA) 170.3 ----------------------------------------------------------------------

mass and energy balance scheme 107%T-H PARAMETRE V TEPELNEJ SCHEME I.O BLOKU

***************************************** MIESTO V POPIS MIESTA TEPLOTA TLAK PRIETOK ENTALPIA TEPELNEJ (ST. C) (MPA) (KG/S) (KJ/KG) SCHEME (*M3/H) ====================================================================== /2/ VSTUP DO REAKTORA 266.67 12.644 9259.3 1166.7 *42558. ---------------------------------------------------------------------- /3/ VYSTUP Z REAKTORA 295.36 12.360 9259.3 1315.2 *45642. ---------------------------------------------------------------------- /51/-/56/ VSTUP DO PG 295.35 12.335 1543.2 1315.1 /61/-/66/ VYSTUP Z PG 266.61 12.248 1543.2 1166.5 ---------------------------------------------------------------------- /8/ CELKOM NV DO PG 214.53 4.668 737.62 919.3 /9/ CELKOM PARA Z PG 259.62 4.668 733.93 2792.5 ====================================================================== GLOBALNE PARAMETRE: ******************* TEP.VYKON AZ (MW) 1375.00 * ROZ.TEPLOT V R (ST.C) 28.69 ---------------------------------------------------------------------- PRIKON HCC (MW) 7.48 * ROZ.TLAKOV V R (KPA) 283.8 STRATY I.O ODV.TEPLA (MW) 6.04 * ROZ.TEPLOT V PG (ST.C) 28.74 ---------------------------------------------------------------------- STRATY I.O VYM.CHL. (MW) 0.95 * PRIEM.PRIETOK HCC (M3/H) 7101.3 TEP.VYKON DO II.O (MW) 1375.50 * ROZ.TLAKOV V HCC (KPA) 436.5 ---------------------------------------------------------------------- TEP.VYK. DO ODLUHOV (MW) 0.79 * KONC.ROZ.TEPL.PG (ST.C) 6.99 TEP.VYK. DO PARY (MW) 1374.71 * ROZ.TLAKOV PG-HPK (KPA) 147.7 ----------------------------------------------------------------------



440

445

450

455

460

465

470

475

14 16 18 20 22 24 26 28 30 32

Cooling Water Temperature [°C]

Gro

ss E

lect

ric P

ower

[M

W]

94.8

96.8

98.8

100.8

102.8

104.8

106.8

108.8

The

rmal

Rea

ctor

Pow

er [

%]

Gross Electric Power Thermal Reactor Power

Prediction of gross electric power


Mochovce NPP Unit 1&2 - Power UprateMonthly Temperatures of Cooling Water form Cooling Towers

0

5

10

15

20

25

30

January February March April May Jun July August September October November December

Tem

pera

ture

[°C

]

Year 2004 Year 2005 Year 2006

21.8 °C


Nuclear Safety Aspects of Power Uprate

Licensing documentations

Update of Safety Analysis Report

Update of operation procedures

Definition of setpoints of safety and control systems

Documentation for Ministry of environment



In order to protect the public in case of an accident, we need to:

1. Shut down the reactor and keep it shut down

2. Keep the reactor cool after it's shut down

3. Contain the reactor coolant

Barriers

1. Fuel matrix

2. Fuel cladding

3. Primary circuit

4. Confinement



Reactor core power distribution

1

4. SKUPINA (1,4 ; MAX>

3. SKUPINA (1,2 ; 1,4>

2. SKUPINA (1,0 ; 1,2>

1. SKUPINA (1,0 ; 1,0>

Relatívny výkon prútikov

Fuel assembly power distribution

1

Relatívny výkon prútikov



Thermal power 1375 MW 1471 MW

Uncertainty 4% 2%

Fuel type Gd-2 Gd-2

Pellet power limit 325 W/cm 325 W/cm

Rod power limit 56.6 kW 56.6 kW

Average rod power 31.6 kW 33.45 kW

Average assembly power 3.9 MW 4.2 MW

Reactor overflow 42300m3/h 42300m3/h

Hot channel output 321 °C 321 °C

Assemblies output 312 °C 314 °C

∆T on reactor 28.9 °C 30.8 °C



Schema of NPP VVER-440Break location and ECCS availability


Calculation result of LOCA Max. Cladding Temperature

0

200

400

600

800

1000

1200

-50 0 50 100 150 200 250 300 350 400 450

Time [s]

Tem

pera

ture

[°C

]

VUJE, a.s. RELAP5x

•997 °C -Power uprate 107 % (1471 MW)

•989 °C -Power 100 % (1375 MW)



900

920

940

960

980

1000

1020

200 210 220 230 240 250 260 270 280 290 300

Time [s]

Tem

pera

ture

[°C

]

VUJE, a.s. RELAP5x

•997 °C -Power uprate 107 % (1471 MW)

•989 °C -Power 100 % (1375 MW)



•1200 °C Safety Limit - Regulatory acceptance cri teria

•997 °C Power uprate 107 % (1471 MW)

•989 °C Power 100 % (1375 MW)

•203 °C

•211 °C

•Safety margin


Bohunice NPP Unit 3&4

Modernization

Power Uprate


Bohunice NPP Unit 3&4 – Modernization + Power Uprate

Bohunice NPP unit 3&4 – Modernization

Thermal reactor power increase 107%

Increase thermal efficiency of Unit.

new Low Pressure Turbine Rotors

new High Pressure Turbine Rotors

new Steam Condenser

innovation of Steam flow Measuring Orifices, other minor changes



Reactor thermal power 107%

1375 MW 1471.25 MW

Electric power 113%

440 MW 500 MW

- hardware changes on secondary circuit


Bohunice NPP Unit 3&4 Modernization

Objectives

Safety

Requirements of regulatory bodies IAEA recommendationsNew knowledge and experience of the plant operatorReplacement of the obsolete part by the up to date technique

Reliability

To eliminate unplanned losses in power generation and electricity supply by equipment modernization (replacement obsolete equipment by state of the art technique)

Economy

To establish prerequisites for life extension and power upratingTo include units into the mode of secondary grid control



Scope of technical activities in the project V2 Mod ernization

I&C part –the most important part of Modernization

Modernization of the Reactor Protection System (RPS)

Modernization of the Reactor Limitation System (RLS)

Installation of the Post-Accident Monitoring System(PAMS)

Modernization of information systems

Neutron flux measurement

Reactor power control system




Electric part

Modernization of the essential power supply, category II (DG start and excitation, 0.4 kV buses, 6 kV buses)

Replacement of 400 kV switches, electrical penetrations

Stand by power supply from Madunice hydro power plant




Machinery part

Emergency core cooling and residual heat removal system

Pressurizer-B&F mode, qualification of safety valves

Essential service water system modification

Steam dump relief valves (PSA)

Ventilation and air conditioning systems

Emergency feedwater system


Conclusion



Safety Aspects of Power Uprate


36

Approved (126 NPPs)

Pending (16 NPPs)

VÚJE, Inc., Okružná 5, 918 64 Trnava, Slovak Republic

USA Uprate Programme

TYPE NPPs Uprate [%] MWtMU 44 0.4-1.7 13-65

S 65 0.9-7.0 24-239

E 20 6.3-20.0 105-579

TYPE NPP’s Uprate [%] MWtMU 8 1.6 27-57

E 8 11.9-17.0 229-521

17 179 MWt5 796 MWe

3 436 MWt1 145 MWe

Expected in 2010 – 2014 (40 NPPs)

TYPE NPP’sMU 22S 1E 17

7 198 MWt2 399 MWe


Russian Uprate Programme

Russia's nuclear plants are nowadays operating with 31 reactors generating totally 21,743 MWe. An initial proposal for a rapid expansion of nuclear capacity was based on the cost effectiveness of completing the 9 GWe of then partially

built plant. Most reactors are being uprated.

During 2010 the uprating program is expected to be completed for all VVER units except Novovoronezh 5: 4% for VVER-1000, 5% for VVER-440. Mass and

energy balance scheme was calculated, resulting in the new nominal thermal reactor power.

All RBMKs will be uprated 5% by 2013, except Leningrad 1. A major contract for upgrading Leningrad unit 4 over 2008-11 is under way, as is that for Kursk 4.

Kursk 2 & 3 with Smolensk 3 will soon follow. Kursk 1 was the first RBMK unit to be licensed for pilot operation with 5% uprate. The R&D Institute of Power

Engineering was preparing plans for 5% uprating of the later Leningrad, Kursk and Smolensk units.

Rosenergoatom is investigating further uprates of VVER-1000 units to 107 or 110% of original capacity, using Balakovo 4 as a pilot plant by 2014. This could

then be extended to other Balakovo units, then Rostov and Kalinin.


Finnish Uprate Programme

Olkiluoto 1&2 (BWR)

- Started up 1978 – 1980.

- Designed electrical power – 658 MWe (net).

- First power uprated after 30y – 860 MWe (net).

- Proposes to uprate to ~ 1000 MWe.

- As a part of this, 25 MWe PU has already been done (unit 1).

Loviisa 1&2 (PWR)

- Started up 1977 – 1980.

- Designed electrical power – 445 MWe (net).

- Already uprated to 488 MWe (net).


Swedish Uprate Programme

From 2004 – ongoing:

-Ringhals 1–4: more than 400 MWe (further uprate envisaged).

-Forsmark 1–3: ~ 370 MWe (about 190 MWe further assumption).

-Oskarshamn 1–3: ~ 320 MWe (500 MWe completely in 2013).

Spain Uprate Programme

Notable for power plants uprates – a programme to add 810 MWe (11%) to its nuclear capacity through upgrading its reactors by up to 13%.

For instance: Almaraz NPP – +5%.

Cofrentes NPP – uprated 4x to today’s 112%, final 120% expected.


NPP Paks Uprate Programme

- Four type VVER–440/213 units, installed between 1984–1987.

- Total safety evaluation of the units (Project AGNES) –accomplished in 1994.

- Over 1996–2002 – a Programme of Safety Measurements.

- Reconstruction of the secondary loop and replacements of the turbines increased electric power to 470 MWe gross.

- By increasing the heat power of the reactor (2009) – 500 MWegross output (1485 MWt).

Technical conditions, modifications needed:

New fuel introduction

Primary loop pressure controller reconstruction

Core Control Systemreconstruction

Reactor Defence System modification

Modification of the parameters of the

hydro-accumulators

Main circulator pumps (Unit 2) modification

Modification of turbines

Increasing the concentration of boric

acid in the failure systems


France Uprate Programme

In the light of operating experience, EdF uprated its four Chooz and Civaux N4 reactors from 1455 to 1500 MWe each in 2003. Over 2008-10 EdF plans to

uprate five of its 900 MWe reactors by 3%. Then in 2007 EdF announced that the twenty 1300 MWe reactors would be uprated some 7% from 2015, within

existing licence limits, and adding about 15 TWh/yr to output.

Czech Uprate Programme

- Program to boost Dukovany's gross output by 240 MWe by 2012.

- Four Dukovany units were uprated from 440 to 456 MWe gross 2005-2008 by replacing low-pressure turbines, two of them have been running at 462 MWe.

- A 38 MWe uprate of unit 3 was announced in May 2009 – bringing its total gross capacity to 500 MWe – from improved fuel, replacing the high-pressure turbine, refurbishing the generator, and I&C changes.

- Temelin 1 & 2, each performing at 994 MWe, Skoda Power modified the high pressure turbines (2004-2007) to achieve 1013 MWe gross, 963 MWe net. A further upgrade since is expected to result in 1050 MWe gross.


Belgian Uprate Programme

STATION NAME

TYPEDESIGNED

POWER (MWt )UPRATED POWER

(MWe ) netUPRATE TYPE &

POWER INCREASEDoel 2 PWR 1 192 1 311 E 10%Doel 3 PWR 2 785 3 064 E 10%

Tihange 1 PWR 2 665 2 875 E 8%Tihange 2 PWR 2 785 2 905->3 064 S/E 4.3%/10%

* till 2007

German Uprate Programme

* till 2007

STATION NAME

TYPEDESIGNED

POWER (MWt )UPRATED POWER

(MWe ) netUPRATE TYPE &

POWER INCREASEEmsland PWR 3 765 3 850 S 2.3% Grohnde PWR 3 765 3 850 S 2.3%

Isar 2 PWR 3 765 3 850->3 950 S/S 2.3%/4.9% Neckar 2 PWR 3 765 3 850->3 965 S/S 2.3%/5.3%

Phillipsburg 2 PWR 3 765 3 803->3 850->3 950 MU/S/S 1%/2.3%/4.9% Unterwesier PWR 3 733 3 900 S 4.5%


43

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Documents

NPP Power Uprate and Modernization · 2010. 9. 21. · VÚJE, Inc., Okružná5, 918 64 Trnava, Slovak Republic 13 Mochovce NPP Unit 1&2 - Power Uprate Thermohydraulics and electrical