1. Nuclear Fuel Development Status and Prospect
Sep. 30, 2014
JEON, Kyeong Lak

2. Great global challenges of the 21th century
Ref. Richard Smalley, Energy & Nanotechnology Conf., Houston, May 3, 2003

3. Contents Introduction I Basic Issues in Fuel Development II
Fuel Development Status in KNF
III
Fuel Performance IV
Nuclear Fuels in Future V
Closing Remarks VI

4. Nuclear Plant v.s. Fossil Plant
I. Introduction
Nuclear Plant v.s. Fossil Plant
Nuclear power reactors based on the fission process are characterized in comparison with fossil plants by
High energy density
Radiation hazard and decay heat from fission products

5. Fuel Cost Portion by Electric Power Source Nuclear Fuel Cycle Elements
Enrichment
44%
Conversion 7%
Mining & Milling
33%
Fabrication
16%
Highly engineered product
Specifically designed for reactor type & each fuel load
Licensed by the authority in the host country

6. Nuclear Power Plants in Korea
Hanbit Site
Wolsong Site
Hanul Site
Kori Site
Seoul
Daejeon
KNF 1 6 12
W 14x14
(Kori 1)
W 16x16
(Kori 2)
W 17x17
OPR1000 11
Type In
Operation
Under
Construction
Total 4 30
CANDU 23 7
APR1400
Hanul 1, 2, 3, 4, 5, 6
Shin-Hanul 1,2
(Under Construction)
Wolsong 1, 2, 3, 4
Shin-Wolsong 1, 2 (Under Construction)
Kori 1, 2, 3, 4
Shin-Kori 1,2, 3,4,5,6
(Under Construction)
Hanbit 1, 2, 3, 4, 5, 6 6

7. Construction & Operation of NPPs in Korea
Construction (~10 yrs)
BOP Design
K-E&C (AE)
NSSS Design
K-E&C (SD)
Core Design
KNF (ICD)
Equip. Mf’g
DHIC
Construct.
(H, D, S….)
Test
KHNP
Fuel Fab.
KNF
Engineering
Construction & Mf’g
Operation(~60 yrs)
Core Design
& Fuel Fab.
KNF
Maintenance
KHNP/KPS
Operation
KHNP
* AE: Architect Engineering
SD: System Design
ICD: Initial Core Design

8. Nuclear Fuel Production in KNF
14x14 OFA
16x16 ACE7
17x17 ACE7
16x16 PLUS7
CANDU fuel

9. Fuel Engineering Overview
UO2 Powder
Top Nozzle
Core Design &
Safety Analysis
UO2 Pellet
Spacer Grids
Bottom Nozzle
Cladding Tube
Fuel Rod
Fuel Assembly
NPP Operation Support 9

10. Major Fields in Fuel & Core Design
Safety Analysis
Fuel Design
Nuclear Design
Nuclear Physics
T/H Design
T/H,
Fluid
Fuel Rod
Design
Cladding Mat’ls
Ceramic
FA Mech.
Mechanics
(Stress,Vib.,FEM,FSI..)
Fluid, Thermal

11. II. Basic Issues in Fuel Development
Development Objectives
Safety : Thermal Margin
DNB Margin
LOCA Margin
Economy : Burnup Performance
High Burnup
Long Cycle
Reliability : Mechanical Integrity
Structural Robustness, Fretting Wear, Irradiation Growth, Corrosion, etc.
Debris Filtering
Shipping & Handling

12. Development Phases Licensing In-Pile Tests Out-of-Pile Tests
Component & Assembly
Design
Out-of-Pile Tests
In-Pile Tests
Licensing
Detail Design
Manufacturing Process Development
Out-of-Pile Tests of Components & Assembly
Lead Test Assembly Manufacturing
LTA In-Pile Tests
Licensing for Commercial
Implementation
Conceptual Design
of Mat’l & Components
Scoping tests

13. PWR Fuel Assembly Fuel Rods : 236 Guide Tubes : 4 Fuel Rods : 264
W type
(14OFA,16ACE7,17ACE7)
PLUS7(16x16)
Fuel Rods : 236
Guide Tubes : 4
Instr. Tube : 1
Top Nozzle : 1
Bot. Nozzle : 1
Zirc. S/G : 9
Inconel S/G : 2
P-Grid : 1
Fuel Rods : 264
Guide Tubes : 24
Instr. Tube : 1
Top Nozzle : 1
Bot. Nozzle : 1
Zirc. S/G : 6+5
Inconel S/G : 2
P-Grid : 1

14. Fuel Rod Fuel Rod Pellet Cladding Tube Plenum Spring Optimization
Length, Diameter
Fuel Enrichment, Axial Blanket
Burnable Absorber
Pellet
Dish & Chamfer, D/H
Grain size, Densification
Missing Pellet Surface, PCI/PCMI
Property Degradation with Burnup
Cladding Tube
Corrosion, Creep, Fatigue, Irrad. growth
Plenum Spring Optimization
Plenum volume, Shipping & handling load
End Plug Welding
Defect Free & Inspection
Variable Pitch
Plenum Spring
Axial Blanket
Advanced Cladding
Long Solid End Plug

15. Mid Grid Improve DNB & LOCA Margin & Low Pressure Drop
Optimized Mixing Vane
Reduce CIPS
Minimize azimuthal temp. distribution
Spring & Dimples
Fretting Resistance
Transverse Stamping
Irradiation Growth
Anti-Hangup & Tear Resistant Outer Strap
Vertical
Diagonal (Low ∆P)
Conformal
I - Spring

16. ※ Vane Shape ※ Vane Pattern No Net Unbalanced Hydraulic Torque
No Unbalanced Lateral Force
 No Fuel Assembly Vibration
Split Vane
Side-supported
Combined

17. Intermediate Flow Mixing Grid
Improve DNB & LOCA Margin
Dimples
Fretting wear margin
Transverse Stamping
Irradiation Growth
Important DNB margin zone
Active fuel length
Power
distribution
Coolant temp.
IFM Grid
Mixing vane

18. Guide Thimble Straight and thick thimble
Prevent incomplete RCCA insertion
Irradiation Growth
Outer Guide tube
Dashpot Tube
Swaged
(Dashpot)
Insert
Swaged v.s. MONOBLOC
Swaged Type
Tube-in-Tube

19. Top Nozzle Removable No loose parts, No screw failure
Stainless Steel Casting

20. Bottom Nozzle Debris Filter Low Pressure Drop with Double Chamfer
Stainless Steel Casting

21. Debris Filter GuardianTM Grid TrapperTM bottom nozzle
Protective Grid with DFBN Flow Holes

22. Fuel Cladding Tube

24. Poolside Examination FA Length FA Bowing/Twist Spacer Grid Width
Controller
Inspection
Stand
X-Y-Z Inspection Table
FA to be
Inspected
DAQ
& Analysis
FA Length
FA Bowing/Twist
Spacer Grid Width
FR Length
FR Diameter
FR Bowing
FR Oxide Layer Thickness

25. III. Fuel Development Status in KNF
Fuel Development Strategy
고유 핵연료
확보기
(’05~’15)
HIPER16, 17 Fuel
X-Gen Design Code
Technology
Innovation
Patented Tech.
3rd Gen. Fuel
Technology
Development
(’99~’04)
Improved Tech.
Joint R&D with W
PLUS7 & ACE7 Fuel
2nd Gen. Fuel
Technology
Initiative
(80’s ~ 90’s)
Import Proven Tech.
Established Tech.
1st Gen. Fuel
Fuel
Import
(70’s ~ 80’s)
0th Gen. Fuel

26. Technology Transfer from Foreign Venders
1st Generation Fuel
Technology Transfer from Foreign Venders
PWR Fuel Design & Manufacturing
PWR Fuel Design & Mfg Technology Transfer in 1985
Started W Type Fuel Supply from 1989
Started OPR1000 Fuel Supply from 1994
Started Production of Zr Alloy Tubes from 2009
Localized PWR Fuel Components Except
Enriched UF6
Feeder Materials of Grid Straps and Bars

27. Develop Advanced Fuel with Foreign Partner
2nd Generation Fuel
Develop Advanced Fuel with Foreign Partner
Joint Development Team Was Organized to Develop Design, Mfg Technology, Out-of-Pile Tests and LTA Fabrication
2nd Generation Fuel Includes
PLUS7 for OPR 1000 & APR 1400 from 1999
16 and 17ACE7 for W16 and W17 Type Plants from 2001
Status
LTA Developments Completed for PLUS7, 16ACE7, and 17ACE7
LTA Irradiation Completed and Hotcell Examination Ongoing
PLUS7 : Region Implementation from 2006
16ACE7 : Region Implementation from 2008
17ACE7 : Region Implementation from 2009

28. Fuel Rod with High Burnup Capability
PLUS7
Fuel Rod with High Burnup Capability
Reduced Rod Bow
Top Inconel Grid
Removable
Top Nozzle
Mid-Grid(9) with Mixing Vanes
GT (4)
IT (1)
Bottom Inconel Grid with High Burnup Capability
Spacer Grid
Debris Filtering
Protective Grid
Debris Filtering
Bottom Nozzle

29. 16 & 17ACE7 Integral Clamp Top Nozzle (ICTN) Inconel Top Grid IFMs
- Reduced Rod Bow
Integral Clamp
Top Nozzle (ICTN)
- No Potential for Loose Parts
Enhanced Mid Grids
- Thermal Margin
- Fretting Margin
Fuel Rod
- High Burnup
- ZIRLOTM
Inconel Bottom Grid
IFMs
Tube-in-Tube
- IRI Free
Debris Filtering
(DFBN, Protective Grid,
Long End Cap))
- Increase Debris Filtering

30. Advanced Fuel Supply
Advanced Fuel
Project
Year 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14
PLUS7TM Fuel
(OPRs & APR1400s)
Detail Design
Out-of-Pile Tests
LTAs
In-Reactor
Reload Batch Loading
16ACE7TM Fuel
(W16x16 Type Plant)
Detail Design
Out-of-Pile Tests
LTAs
In-Reactor
Reload Batch Loading
17ACE7TM Fuel
(W17x17 Type Plants)
Detail Design
Out-of-Pile Tests
LTAs
In-Reactor
Reload Batch Loading
The irradiation data, experiences and VOC will be feedback
continuously to PLUS7, ACE7 and further development.

31. Develop Leading Edge Fuel Technology
3rd Generation Fuel
Develop Leading Edge Fuel Technology
Utilize Fuel Technologies & Operating Experiences Accumulated through the 1st and 2nd Generation Fuels
3rd Generation Fuel Includes
HiPER16 for OPR 1000 & APR 1400 from 2005
HiPER17 for W17X17 Type Plants from 2008
Status
Completed LTA Developments for HiPER16 & HiPER17
LTAs In-Reactor Verification
8 LTAs of HiPER16 at Hanul #6 from July 2011
4 LTAs of HiPER17 at Hanbit #2 from Nov. 2014

32. HiPER 16 HiPER 17 SMART Design Concept High Performance Efficiency
Reliability
Concepts &
Components
of HiPER
Component / Material
HANA Alloy
Integrated Top Nozzle
Anti Fretting Wear Grid
Robust Guide Tube…

33. Overall Development Schedule
Item Year
’05
’06
’07
’08
’09
’10
’11
’12
’13
’14
’15
’16
’17
HiPER 16 Fuel Development
Component Development
Test Assembly Fabrication
Out-of-pile Test & Final Design
LTA Fabrication
In-Reactor Verification Test
HiPER 17 Fuel Development
Component Development
Test Assembly Fabrication
Out-of-pile Test & Final Design
LTA Fabrication
In-Reactor Verification Test
SMART Fuel Development
Component Development
Test Assembly Fabrication
Out-of-pile Test & Final Design
Standard Design Approval

34. IV. Fuel Performance
Fuel Failure Rate

35. PWR Fuel Failure Root Cause
GTRF
Corrosion
Duty Related
Debris
Fab.
Unknown
U.S.
GTRF
Corrosion
Others
Debris
Fab.
Unknown
Korea
Mechanism
Grid-to-Rod
Fretting
Corrosion
Duty Related
Debris
Fabrication
Others
Unknown
Ref. KHNP-EPRI fuel reliability program workshop, Korea (2013)

36. Fuel Failure due to Grid-to-Rod Fretting Wear

37. Debris induced Fuel Failure

38. V. Nuclear Fuels in Future
TMI-2, 1979
Chernobyl, 1986
Fukushima I, 2011

39. Behavior of Fuel Materials
B. Cheng, “Accident Tolerant Fuel Technology”, KHNP-EPRI Fuel Reliability Program Workshop, Daejeon, Sep., 2012.

40. Accident Tolerant Fuel
Cladding Tube
SiC
Steel(FeCrAl), Mo,….
Coating
Ref.: K.A. Terrani et. al, EHPG, Norway (2013) & J. of Nuclear Materials (2012)

41. Fuel pellets Microencapsulated fuels
Higher density fuel (metal, nitride, silicide)
Microencapsulated fuels:
Fully Ceramic Microencapsulated Fuel
Metal Matrix Microencapsulated Fuel
Ref.: K.A. Terrani et. al, EHPG, Norway (2013) & J. of Nuclear Materials (2012)

42. Safe Shutdown & Cooling
VI. Closing Remarks
Normal
Operation
Transient
Condition
Design Basis
Accident
Beyond-Design
Basis Accident
Safe Shutdown & Cooling
Accident Tolerant
High Performance
Zero Defect
Public Acceptance?

43. TVEL
Partners in Power !!!