Download - Rebak GE EPRI AFC Florida 2015 02 17
Imagination at work
Ferritic Steels as Accident Tolerant Fuel Cladding for Commercial Light Water Reactors
FOURTH EPRI/INL/DOE JOINT WORKSHOP ON ACCIDENT TOLERANT FUEL
17-18 February 2015, St. Petersburg, Florida
Raul B. Rebak
GE Global Research, Schenectady, NY
GE team is/will be focused on cladding material, no fuel development
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015 2
Approach of GE Research
•Demonstrate that stainless iron based bulk alloys or Advanced Steels can be used as fuel cladding materials in commercial nuclear reactors
•The proposed material should be as good as Zr alloys (or better than Zr alloys) under normal operation conditions
1. Resistant to general corrosion and environmental cracking under normal operation conditions
2. Resistant to radiation damage
•The proposed Advanced Steels should be able to outperform the containment the fuel in the case of an accident scenario (e.g. LOCA) as compared to the current Zr alloys
1. Better mechanical strength at higher temperature
2. Enhanced retention of fission products (no cracking)
3. Improved reaction kinetics with steam
4. Lower generation of hydrogen gas when reacting with steam
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015
We are currently in Phase 1B
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015
Technology and Manufacturing Readiness Levels for Advanced Steel Cladding
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TRL 5 – Component in a Representative Environment
TRL 6 - Prototype in a Representative Environment
TRL 7 - Prototype in an Operational Environment
TRL 8 – System Qualification
TRL 1 – Basic Principles Observed
TRL 2 - Concept Formulation
TRL 3 - Proof of Concept
TRL 4 – Component in the Laboratory
End of Phase 1A
2022
Lead Fuel Assembly
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015
Approach to Study and Rate the Steels
Regulatory Analysis, Fuel Economy
Fabrication Capabilities
Environmental Degradation Under Accident Scenarios
Environmental Degradation Under Normal Operation Conditions
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Work to be Done in Phase 1B to Mature Feasibility Concepts
Follow Guidelines per INL/EXT-13-29957, FCRD-FUEL-2013-000264, LWR ATF Performance Metrics
1. Environmental Confirmatory Testing (e.g. Quench Test, Fretting, etc.)
2. Irradiation Testing at ATR
3. Evaluate Tube Fabrication and Manufacturability
4. Early Economical Feasibility for the new fuel concept
5. Preliminary Performance and Safety Assessment
• Evaluate Neutronics
• Thermal Hydraulics
• Scoping Analysis for Bounding Transients or Accidents
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Materials Selected to Study
Alloy Nominal Composition
A Zirc-2 UNS R60802 Zr + 1.2-1.7 Sn + 0.07-0.2 Fe + 0.05-0.15 Cr + 0.03-0.08 Ni
B Ferritic steel T91 K90901
Fe + 9 Cr + 1 Mo + 0.2 V
C Ferritic steel HT9 S42100
Fe + 12 Cr + 1 Mo + 0.5 Ni + 0.5 W + 0.3 V
D Nano ferritic alloys -NFA
e.g. 14YWT; Fe + 14 Cr + 0.4 Ti + 3 W + 0.25 Y2O3
E MA956 or UNS S67956 Fe + 18.5-21.5 Cr + 3.75-5.75 Al + 0.2-0.6 Ti + 0.3-0.7 Y2O3
G APMT Fe + 22 Cr + 5 Al + 3 Mo
H Super ferritic, e.g. 4C54, Ebrite S44627
Fe + 25-27.5 Cr + 1 Mo + 0.17 (Ni + Cu)
J Alloy 33 – UNS R20033 33 Cr + 32 Fe + 31 Ni + 1.6 Mo + 0.6Cu + 0.4 N
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Behavior of Candidate Steels in Simulated Normal Operation Conditions
Behavior of Candidate Steels in Simulated Normal Operation Conditions
1) Crack Propagation Studies
2) One Year Exposure to High
Temperature Water
3) Electrochemical Tests
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015
Crack Propagation Studies
GE Rebak DOE Project, FCRD AFC Integration Meeting, 26-August-2014 11
Specimen ID
Material Condition Hours Tested
C642 Nano-ferritic As-rec’d 4,970 hours
C646 HT-9, irradiated 38.7 dpa 4,533 hours
C647 HT-9 21% cold forged 8,585 hours
C648 APMT 23% cold forged 10,500+ hours
C649 T91 23% cold forged 4,624 hours
C680 HT-9, irradiated 7 dpa 1,312 hours
C689 HT-9, irradiated 38.7 dpa 4,300+ hours
C690 9% Cr ferritic 30% cold forged 2,457 hours
C691 20% Cr ferritic 20% cold forged 69 hours
C692 Alloy 33 20% cold forged 3,300+ hours
C709 APMT As-received 700+ hours
C710 Nano-ferritic As-received 500+ hours
Compact Tension Specimen of HT9 neutron irradiated to 36.9 dpa and tested in 288°C Water + 2 ppm O2 up to a stress intensity of 38 ksi√in
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In chromium ferritic alloys a crack may propagate under cyclic loading (fatigue) but it stops growing as the load cycling frequency is decreased
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015
Compact Tension Specimen of 23% cold worked APMT tested in 288°C Water + 2 ppm O2 up to a stress intensity of 40 ksi√in
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In chromium ferritic alloys a crack may propagate under cyclic loading (fatigue) but it stops growing as the load cycling frequency is decreased
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015
1.E-09
1.E-08
1.E-07
1.E-06
1.E-05
00.0020.0040.0060.0080.01
Cra
ck G
row
th R
ate
, mm
/s
Frequency, Hz
K=40 ksi/in, R=0.5
K=30 ksi/in, R=0.5
Crack Arrest as FrequencyIs Decreased in Ferritic Steels
c648 - 0.5CT of APMT, 23% CW
30 ksiin, 2 ppm O2, 30 ppb SO4
1-Year Exposure of Coupons to High Temperature Water
Simulated BWR, Normal Water Chemistry (2000 ppb O2), 288°C
1) Zirc-2
2) T91
3) HT9
4) 14YWT NFA
5) MA956
6) APMT
7) Ebrite
8) Alloy 33
GE Rebak DOE Project, FCRD AFC Integration Meeting, 26-August-2014 14
1-Year Exposure at 288°C Water + 2 ppm O2
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• The rate of mass gain decreased at the exposure time increased
• The highest mass gain was for Zirc-2 coupons
• APMT offers some of the lowest mass gains as a function of time
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015
366 days exposure to 288°C Water
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T91, RB2, X10,000 HT9, RC2, X10,000 NFA, RD2, X10,000
MA956, RE2, X10,000 APMT, RG2, X10,000 Alloy 33, RJ2, X10,000
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015
1-Year Exposure at 288°C Water + 2 ppm O2
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• Stable corrosion potentials as a function of immersion time
• The lowest Ecorr was for Zirc-2
• All the iron containing alloys had a similar Ecorr, the lowest being for T91
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015
Redox kinetics on APMT, NFA and Alloy 33 alloys behaves similarly to 304 SS or X-750 in high temperature water
Corrosion Potential of Zirc-2, 304SS, X-750, APMT, Alloy 33, NFA and Pt under different water chemistry conditions
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Tip: To navigate between the first level copy and the first level bullet, use the Indent and Outdent button on the Home Ribbon. Once you are on the second, and third level bullets, you can Tab and Shift-Tab to go back and forth between the bullet levels.
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015
Under UV illumination the ECP shift of the advanced steels is in the opposite direction as the one on Zirc-2 suggesting that APMT will not suffer Shadow Corrosion
Corrosion Potential response of several materials under UV illumination in 288°C water containing 1 ppm O2
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Tip: To navigate between the first level copy and the first level bullet, use the Indent and Outdent button on the Home Ribbon. Once you are on the second, and third level bullets, you can Tab and Shift-Tab to go back and forth between the bullet levels.
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015
Reactions with Steam, Resistance under Accident Conditions
Reactions with Steam, tested at GE Research
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Reactions with Steam, tested at GE Research
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Appearance after 24 h in 100% steam at 800°C
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X100, Zirc-2
X500, APMT
Negligible steam attack in the Fe-Cr-Al alloy Polishing marks still visible
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015
Fabrication Evaluations
Current Sandvik Fabrication Status
Evaluate the cold forming properties of APMT tubing
by cold pilgering and cold drawing.
The target for the study is to
1. Understand the limitations when cold forming
APMT tubing
• Manufacture a APMT tube with as small dimension as possible, the aim is to reach 15 x 1 mm
• If the cold forming trials are successful a tube of 1 m will be delivered with the smallest dimensions achieved
Irradiation Tests at the INL-ATR
Fuel Properties Used in Neutronics Analysis
Development
Lead Fuel Type
Cladding
Type
Fuel OD
(in)
Total
Fuel
Height
(in)
Enriched
Fuel
Height (in)
Enrichment
(% U-235)
Density
(g/cc)
GE UO2 APMT /
Alloy 33 0.3235 4 3.2 4.90% 10.631
Images of Fuel Provided by INL
INL ATR Tests to demonstrate chemical compatibility between fuel and cladding
• 300-400°C Cladding temperature
• 300-400 W/cm LHGR • 20, 80 GWd/mT Burnup
• < 1700°C fuel centerline
temperature
Rodlets fabricated by INL
using material provided by GE Research
Fuel Fabricated by GE-GNF
Rebak GE-DOE, EPRI AFC Workshop, 17-February-2015
Tests at ATR started on 11-02-2015
Storage of Spent (Used) Fuel
Prediction for 100 Years Storage in Dry Casks
Repository
5-10 years
40-100 years
10,000 years? 1,000,000 years?
Summary and Conclusions
Summary and Conclusions
1) The proposed advanced steels are better than zirconium alloys under normal operation conditions
• Resistant to general corrosion and environmental cracking
• Resistant to shadow corrosion
• Resistant to radiation damage
2) The advanced steels outperform the zirconium alloys under accident conditions
• Better mechanical strength at higher temperature
• Enhanced retention of fission products
• Improved reaction kinetics with steam
• Lower generation of hydrogen gas when reacting with steam
3) Other Areas • Irradiation studies at ATR (dry and water loop)
• Neutronics, thermal hydraulics
• Tritium Release
• Long term storage of spent fuel in dry casks
• Fabrication of tubing • Economics
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Acknowledgements This material is based upon work supported by the Dept. of Energy [National Nuclear Security Administration] under Award Number DE-NE0008221. This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
GE Tasks and Deliverables for FY2015-2016
Task Who 1QFY15 2QFY15 3QFY15 4QFY15 1QFY16 2QFY16 3QFY16 4QFY16
Task 1.1: Envormental Degradation Under Normal Opeation Conditions
Resitance to Environmental Cracking GE
Resistance to Fretting GE
Task 1.2: Behavior of materials under accident conditions
Superheated Steam Tests up to 1000°C GE
Superheated Steam Tests > 1000°C ORNL
Quenching tests GE, ORNL
Task 1.3: Behavior of materials under proton irradiation conditions
Effect of irradiation on microstructure U.Mich
Effect of irradiation on environmental cracking susceptibility U.Mich
Task 1.4: ATR Test
PIE analysis after intermediate irradiation INL, LANL
Task 1 Milestone: are advanced steels environmentally suitable?
Task 2.1: Develop tube fabrication parameters GE, Sandvik
Task 2.2: Evaluate optimal cladding composition, burst tests ORNL
Task 2 Milestone: Can FeCrAl tubes be fabricated in small diameter with thin walls
Deliverable: A Fabrication Feasibility Report
Task 3.1: Themal Hydraulics and Neutronic Calculations BNL, ORNL
Task 3.2: Data preparation for LTR/LTA Plan for 2022 Insertion GE, BNL, ORNL
Deliverable: A Report on LTR/LTA Insertion Plan GE
Deliverable: A Report on ATF advanced steel cladding feasibility vs. against metrics GE
Deliverable: Technical Quarterly Reports GE