- The Fukushima accident triggered a major reassessment of nuclear plant robustness and improvements. Over 1500 potential improvements were identified and consolidated into 209 across 72 plants. - Top improvements included enhancing seismic protection of systems, spent fuel pool upgrades, and adding emergency diesel generators. New solutions like filtered venting systems and batteries provide benefits. - The presentation discussed newer venting system designs, high energy density systems using supercritical CO2, passive heat exchangers for spent fuel pools, and lithium-ion batteries as replacements for lead-acid batteries. These solutions can increase plant robustness.

2. New solutions for NPPNew solutions for NPP
Robustness Improvement
Dr. Alexander Wolski
Director, Strategic Projects
BULATOM Conference 2013BULATOM Conference 2013
Varna, June 5

3. Fukushima Impact on the IndustryFukushima – Impact on the Industry
► Has triggered a major re-assessment of
robustness of nuclear stations
► First round of evaluations has been► First round of evaluations has been
finished
► Improvement areas and strategies have► p o e e t a eas a d st ateg es a e
been identified
► Implementation of upgrades has started
world-wide
► New solutions can provide substantial
b fitbenefits
“We must re-think everything we already have thought
again, from the beginning”
(Angela Merkel, March 2011)

4. Improvements Database
G i C t i ti d C R f i
REMOO, 2012
Ljubljana
Grouping, Categorization and Cross-Referencing
SEISMIC
►> 1500 d t i t General
FLOODING
General
Flooding protection engineering features/structures, e.g. dykes
EXTREME WEATHER CONDITIONS
ELECTRICAL SYSTEMS
►> 1500 raw data improvements
►Condensed to 209 across 72 plants
Almaraz ■■
Asco ■■
Emergency diesel generator (EDG) (Primary)
Mobile diesel generator (MDG)
…
Batteries
HEAT REMOVAL SYSTEMS
General
Belene ■■
Borssele ■
Safety injection systems
…
Spent fuel pool
Mobile pumps
ACCIDENT MANAGEMENT
General
…
…
PWR / VVER ■
BWR
General
Staffing
Procedures (Development & updating)
…
Hydrogen analysis and mitigation
Ex-vessel cooling
OTHER / GENERAL
Vandellos II ■
Zaporizhzhya ■■■■■■
PHWR ♦
UNGG / AGR / Magnox ○
RBMK ‡
OTHER / GENERAL
…
RBMK ‡

5. Improvements Database
Interface - Overview
REMOO, 2012
Ljubljana
Interface - Overview

6. Improvements Database
A I t Sit
REMOO, 2012
Ljubljana
Average Improvements per Site

7. Improvements Database/Matrix Results
REMOO, 2012
Ljubljana
Improvements Database/Matrix Results
COUNT BY CATEGORY
SEISMIC (GENERAL)
HEAT REMOVAL
OTHER
EXTREME WEATHER CONDITIONS
FLOODING
ELECTRICAL POWER
EXTREME WEATHER CONDITIONS
0 500 1000 1500 2000 2500
ACCIDENT MANAGEMENT

8. Improvements Database
Top 10 Improvements
REMOO, 2012
Ljubljana
Improvement BWR GCR PWR VVER Others
1 Seismic survivability of relevant SSCs 99 99 11 33 11
Top 10 Improvements
1 Seismic survivability of relevant SSCs 99 99 11 33 11
2
Seismic Margin Assessment (SMA) / Seismic -
PSA
24 44 33 14 11
SSC used for flooding protection (dykes,
3
mountable flood walls, building seals, air inlets,
doors, flood valves, check valves, mobile pumps,
etc.)
13 88 66 11 31
4
Diesel and lube oil supplies (volume, versatility,
40 17 22 29 774
pp ( , y,
diversity, etc.)
40 17 22 29 77
5 SAMGs 11 53 99 11 26
6
Add more EDGs (preferably separated /
independent)
60 14 44 43 15independent)
7
Filtered containment venting (pressure relief),
possibly seismically qualified 44 24 29 22 27
8
Access to site and specific areas, transport and
l i ti t ft i f t t d 22 33 34 49 168 logistics management after infrastructure damage
due to external events (incl. weather)
22 33 34 49 16
9
EFW bunkered system protected against floods
and earthquakes
111 23 55 78 19
10 Flooding survivability of relevant SSCs 1010 55 23 46 73

9. Filtered Venting Systemg y
► First filters developed and tested were dry filters► First filters developed and tested were dry filters
(implemented in Germany and France)
► Industry today seems to prefer wet filtration solutions► Industry today seems to prefer wet filtration solutions
► Current SA calculations show
• Higher temperatures (> 250 ºC)Higher temperatures ( 250 C)
• Varying loads of residual heat
► Passive Functionality of wet filters cannot be guaranteedy g
under all conditions
► Modern stainless steel HEPA filters are available from
applications in the Nuclear Weapons Industry and Fuel
Enrichment Plants

10. Maximised Filtration Area
HEPA grade filters (99.9% @ 0.3 microns).
1,57 m2 footprint
44 m2 filtration surface per m3
“German Filter” from the 80’s
8,8 m2 footprint
1 3 m2 filtration surface per m3 p1,3 m2 filtration surface per m3

11. Variable Solutions – Example VVER 1000 (320)
► Aerosols remain in
Containment
► Replacement of existing
aerosol filters – no
additional space requiredadditional space required
► No additional penetrations
► 100% backup possiblep p
► 2nd venting possible
► Solution for VVER 440
(230) developed(230) developed

12. High Energy Density – Supercritical CO2
> Example: Sandia National Laboratory‘s100 kW shaft power test bench
2
100 kW
Turbo-electric
generator-
compressor
unit
CompressorsCompressors
sufficient for
pumping ~2.5 MWth
of decay heatof decay heat

13. Smart Heat Exchanger – self-powered, passive
Power Box
Air Cooler
Power Box
Air Cooler
M
G
Optional power forp p
air cooling
Pool cooling
t
Pool cooling
Spent Fuel Pool
70 – 95 °C
system system

14. Pb-Batteries – Last Century Technologyy gy
► Mature technology for large energy► Mature technology for large energy
storage based on Li-Fe Batteries
► Li-Fe substantially superior to standard
consumer products (LiCoO2 / LiMn2O4 orconsumer products (LiCoO2 / LiMn2O4 or
LiNiO2)

15. 200 V / 1000 Ah Module
Temperature 0°C / + 45°C -30°C / +60°C
Humidity < 85 % at 25°C < 90%
Reduced Pressure > 53 kPa > 11.6 kPa
Cells 100 X Varta Vb 2410 16 x 5 = 80 LiFe
Weight 10 760 kg 3 360 kg ( 69%)Weight 10,760 kg 3,360 kg (-69%)
Self Discharge 3% / month < 1% / month
Discharge rate (1 hr) 53% 99%g ( )
Charging mode CV
30% in fast charge
CV or CC
100% @ 3x nominal current
C l d Lif 20 >> 20 i NPPCalendar Life 20 years >> 20 years in NPP
Cycle Life >1200 cycles > 6000 cycles
Footprint 7.97 m2 2.24 m2 (-72%)Footprint 7.97 m 2.24 m ( 72%)

16. WorleyParsons Qualification for Li-Fey Q
► Nuclear requirements from conventional lead batteries have been► Nuclear requirements from conventional lead batteries have been
transferred to new technology
• IEE 535-20006, Qualification of Class1E Storage Batteries for Nuclear Power
Stations
• IEEE 344-2004, Recommended Practice for Seismic Qualification of Class 1E
Equipment
• KTA 3703, Emergency Poawer Facilities with Batteries and AC/DC converters, g y
• HP-031-01, Russian Design Stanfard for Earthquake resistant NPP
► Existing conventional requirements for have been added
• IEC 60896-11, Stationary lead-acid batteries – General requirements and
methods of test
• IEC 450-2010, Recommended practice for Maintenance, Testing and
Replacement of vented lead acid batteries for stationary applicationsReplacement of vented lead-acid batteries for stationary applications
► Qualification and Testing Program developed and under execution
► Third Party review by credited TSO organizationy y g

17. Li-Fe Batteries – Advantagesg
► Higher Capacity Discharge (100% @ 30 minutes discharge► Higher Capacity Discharge (100% @ 30 minutes discharge
► No hazardous gases (no dedicated ventilation system
► Non-explosive, even in direct flames
► Real time monitoring
► No maintenance, no monitoring / re-filling of water
► 1/3 of the floor space 1/3 of the weight► 1/3 of the floor space, 1/3 of the weight
► Capacity stable at low temperature and after thousands of cycles
► Almost no self-discharge
► Large Battery packs are available with a
capacity of 24 MWhr and a maximum
discharge capacity of 6 MW (20’ container)

18. Applications in Nuclear Power Plantspp
► Replacement of existing batteries► Replacement of existing batteries
• Increase battery capacity by a factor of 3
• Reduce stationary hazards
R d i t i t• Reduce maintenance requirements
► Buffering the start-up of Emergency Diesel Generators
• Instantaneous start-up of emergency power systemp g y p y
• Relaxation of diesel engine start-up time requirements
► Gas-Turbine-Generators
• GTG are highly reliable under severe conditions but have start-up times of 45 to
60 seconds
• GTG can be operated with various fuels
• GTG are much smaller and contain less parts
• GTG have minimum maintenance requirements
► New self-sustained diverse SBO electricity supply► New self sustained diverse SBO electricity supply
• 24 MWhr in a simple container

19. WorleyParsons Nuclear Services
Improve Example for new solution developmentImprove – Example for new solution development
Steam-driven auxiliary feedwater pump
St d d l ti f W ti h PWRStandard solution for Westinghouse PWR
Transfer of concept and experience to other designs
RELAP model developed and feasibility demonstrated for VVER 1000
Core Cooling without External Power Supply at 6 bar
N d i t ith t illi tNew pump designs operate without auxilliary systems
On-going developments:
Combination with Power-Box
Condensation and re-use of driving steam
Additi l l t i l t dAdditional electrical power generated
Almost “closed-cycle”; minimum makeup water required

20. Thank you!Thank you!y