agr-5/6/7 pie preparations - art.inl.gov
TRANSCRIPT
AGR-5/6/7 PIE Preparations
John D. Stempien, Ph.D.AGR TRISO Fuels PIE Technical Lead
Presented at the Gas-Cooled Reactor Program Annual ReviewJuly 14, 2020 via Videoconference from Idaho National Laboratory
• Basic capsule and fuel properties
• Major PIE objectives
• Preliminary prioritization of activities and capsules
• Major PIE activities flow chart
• Destructive and non-destructive PIE
• Special considerations for Capsule 1
• Number of tests/compacts for statistics
• Air/moisture ingress testing
• Preliminary schedules
Outline
2
Irradiation Test Train and Fuel
Capsule Nominal Packing Fraction (%)
Number of Compacts
1 40 90
2 25 32
3 25 24
4 25 24
5 40 24
3
• Values below were taken from the irradiation test plan (PLN-5245, INL/MIS-17-43095)
Pre-test Predicted Irradiation Conditions
CapsulePacking Fraction
(%)
Number of Compacts
TA Peak (°C)
TAVA(°C)
TA Min(°C)
Burnup(% FIMA)
Fast Fluence(1025 n/m2, E>0.18 MeV)
1 40 90 1350 1100 760 11.5 6.3
2 25 32 1000 910 710 18.0 6.8
3 25 24 1480 1380 1060 18.0 7.2
4 25 24 990 910 760 16.5 6.0
5 40 24 890 780 600 10.8 3.4
4
1. Evaluate and characterize unexpected Capsule 1 behavior.
2. Verify acceptable performance and behavior of the fuel under normal irradiation conditions (Capsules 2, 4, and 5).
3. Evaluate performance and characterize behavior of fuel under high irradiation temperatures (Capsule 3).
4. Conduct post-irradiation high-temperature testing in helium to verify acceptable fuel performance under conduction cool-down accidents.
5. Perform oxidation testing to characterize fuel behavior during exposure to air or moisture at nominal and accident temperatures.
Major PIE Objectives
PLN-6110 draft under review. Will be released no later than August 2020.
5
Preliminary Activities and Capsule Prioritization
Priority Capsule(s) Remarks
1 1 Identify the cause(s) of in-pile TRISO failures. Capsule 1 contains 90 of the 194 compacts in the experiment. In-pile fission gas release indicates that significant fuel failure occurred in this capsule.
2 2, 5, 4
Confirm that intact AGR-5/6 TRISO fuel behaves in-pile and in safety testing like previous fuel from AGR-1 and AGR-2. Confirm that any AGR-5/6 SiC and/or TRISO failures occur under similar conditions (i.e., prior irradiation history and/or safety-test temperatures) and via the same mechanisms as failed fuel from AGR-1 and AGR-2.Confirm that the phenomena affecting performance in AGR-1 and AGR-2 are the same phenomena affecting AGR-5/6 performance.
3 All Establish fuel compact and TRISO particle performance under oxidizing conditions in air and moisture.
4 3 Analyze high-temperature margin test fuel to determine the effects of high-average irradiation temperatures on in-pile performance and post-irradiation accident performance.
6
Major PIE ActivitiesPackage test
train for shipment from ATR to
HFEF
Receive test train at HFEF
Test train exterior visual inspection and photography
Cut test train and separate capsules
Capsule disassembly
Test train precision gamma
scanning
Test train neutron radiography
Capsule components
recovery
Graphite holder metrology then
PGS
Spacers, disks, and insulators gamma
counting
Fuel compacts metrology
Metal components leaching and
leachate analysis
Axial PGS scans
PGS tomography
Graphite holders burn
leach
Fuel compacts PGS
Ceramic components
leaching
Graphite components
burn-leaching
Destructive exams and
heating tests
7
Requirements Documents for Test Train Inspection, Disassembly, and Metrology
8
• Fuel compacts
• Graphite holders
• Miscellaneous capsule components
Shells including heads and through-tubes
Gas lines and thermocouples
Spacers, disks, insulators, gamma “heaters”, Capsule 1 wave spring
• Disassembly equipment has been designed and is underconstruction
Capsule Components Recovery for Fission Product Analysis
9
• Gamma scanning:
Holder and compact gamma-emitter inventories measured using the Precision Gamma Scanner (PGS)
Spatial variations in holder gamma-emitter inventories via Gamma Emission Computed Tomography (GECT) to help locate compacts with SiC failure(s)
• Neutron radiography, especially on Capsule 1, to look for signs of degradation of fuel or capsule
• Metrology of holders and compacts to feed dimensions back into the thermal analyses
Non-destructive Holder and Compact Exams
10
• Leach metallic capsule components (e.g., shells, heads, through-tubes, spacers, gas lines, TCs)
• Leach equipment designs under review
• Dry gamma counting then leaching (ceramic) or burn-leaching non-metallic (carbonaceous) spacers, discs, and insulators
• Compact holders burn-leach for Sr-90
Non-fuel Destructive Fission Product Analyses
11
• Exams will be mostly the same as in prior PIE campaigns• Compact ceramography• Safety/heating testing in inert and oxidizing (see PLN-5934) atmospheres with and without
sample reirradiation in NRAD Primarily isothermal testing Some cyclic testing may be performed No plans to repeat conduction-cooldown transient temperature testing
• As-irradiated and post-heating test deconsolidation-leach-burn-leach (DLBL)• Burnup measurements via inductively-coupled-mass-spectrometry (ICP-MS) methods• As-irradiated and post-safety test particle gamma counting and microanalysis (e.g., optical and
electron microscopy, x-ray, etc.)
Fuel Compacts Destructive Exams
12
• Inspecting external and internal surfaces, brazes, gas lines, TCs
• Condition of graphite holder and compacts unknown until disassembled
• Options if compacts do not push out of holder Section holder and perform ceramography on holder/compact cross sections
Utilize new, multi-axis mill to machine-out compacts
PGS scanning with fuel in place (scan ~tangent to holder surface and rotate holder for full circumferential scan)
• Want to know mechanism of TRISO failure, but quantifying all TRISO failures probably not necessary or feasible
• Given ~half of the AGR-5/6/7 fuel is in Capsule 1, option to screen compacts for TRISO failure via NRAD reirradiation and heating?
Special Considerations for Capsule 1
13
• Want to demonstrate TRISO failure rate of 6E-4 or better under core conduction cooldown (T = 1600°C) AGR-1 (1600°C tests of 33,100 particles): ≤ 9.1×10-5 at 95% confidence AGR-2 (1600°C tests of 12,704 particles): ≤ 2.4×10-4 95% confidence
• Table shows number of particles to test to demonstrate TRISO failure statistics equal to or better than 6E-4
• Limit tests >1600°C on the basis that modern HTGR peak accident temperatures < 1700°C. Based on the AGR-1 and AGR-2 safety testing campaign, between 3 and 7 tests at temperatures ≥1700°C would be reasonable
Required Number of Safety Tests
Failure fraction at 95% confidence
# of failures observed # of particles to be tested
# of Capsule 1 and/or 5 compacts, 40% particle
packing fraction
# of Capsule 2, 3, and/or 4 compacts, 25% particle
packing fraction
≤6E-40 5,000 2 31 8,000 3 45 17,500 6 8
≤2E-40 15,000 5 71 24,000 8 115 53,000 16 25
≤6E-50 50,000 15 231 79,000 24 365 175,000 52 80
14
• Note: Combined AGR-1 and AGR-2 tested 45,804 particles at 1600°C with failures ≤6.6E-5• If all or most Capsule 1 compacts are a “loss” (likely), some Capsule 3 compacts could be substituted to
cover the intermediate irradiation temperature range: ~15% of Capsule 3 compacts are 1050-1250°C ~30% of Capsule 3 compacts are 1250-1350°C
• Number of tests could be reduced if there is no discernable difference between 25 and 40% PF• Post-test destructive analysis could be limited after the first few and multiple compacts could be tested
simultaneously to increase throughput
Preliminary Plan for Inert Safety Testing
CapsulePacking Fraction
(%)
TA Peak (°C)
TAVA(°C)
TA Min (°C)
Burnup(% FIMA)
Fast Fluence(1025 n/m2,
E>0.18 MeV)
1600°C Safety Tests
1700°C Safety Tests
1800°C Safety Tests
1 40 1350 1100 760 11.5 6.3 6 – 22 25 1000 910 710 18.0 6.8 2 – 13 25 1480 1380 1060 18.0 7.2 3 2 24 25 990 910 760 16.5 6.0 2 – –5 40 890 780 600 10.8 3.4 2 – 1
Total # Compacts: 15 2 6Total # particles 43,107 4,530 17,055
15
Irradiated TRISO Fuels Testing in Air and Steam - Purpose• Safety testing of AGR fuel has only been under helium (FACS/CCCTF)
• Accident scenarios in HTGRs include depressurized conduction cooldown events such as:
Main coolant line break with air-ingress
Steam generator tube leak with moisture-ingress
• Fuel oxidation will occur when exposed to air or steam at high temperatures:
Compact matrix and particle OPyC layer oxidation
SiC generally resistant to but will slowly oxidize as well
• Oxidation of matrix and OPyC may mobilize fission products
• Exposed kernels (from as-fabricated defects or in-pile failures) vulnerable to hydrolysis
16
Goals of Air/Moisture Ingress Testing
• Test irradiated TRISO fuels in oxidizing environments representative of air and moisture ingress accidents in HTGRs
• Measure fission product releases as a function of time
• Relate fission product releases and release rates to fuel irradiation history, test conditions, and extent of fuel oxidation
• Use collected data for:
Fuel qualification and licensing
Input to and comparisons with predictive models and simulations
Reactor accident source term analysis (design-basis and/or beyond-design-basis)
17
Air Moisture Ingress eXperiment (AMIX) Simplified Schematic
*Schematic for illustrative purposes only 18
Oxidation Testing Entire Irradiated Fuel Compacts• Air/Moisture Ingress Experiment (AMIX) furnace currently under construction• Test entire fuel compacts comprised of thousands of TRISO fuel particles and heavily contaminated graphite in air and
moisture atmospheres• Acquire essential data on fuel performance under air and moisture-ingress accidents
T ≤ 1600°C 5.5E-4 < PH2O < 0.8 atm 2.0E-5 < PO2 < 0.2 atm
Out-of-cell equipment In-cell equipment 19
Air Cell at FCF
Installation at Fuel Conditioning Facility (FCF) at the Materials and Fuels Complex (MFC)
20
Gas Supply Valve Board #1, Side A
• Gas distribution
• Auto source switching based on pressure
• Air source drier
• Helium source drier and oxygen getter
21
Gas Supply Valve Board #1, Side B
• Mass flow controllers• Motor-operated valves• Helium/air mixing chambers
22
Steam generator and Steam/Helium Mixing (Board #2)• Water flow meters• Steam generator• Motor-operated valves• Helium/steam mixing• Process pressure measurements• Heat trace
23
FGMS Board (Board #3)• Board is between post-furnace air/moisture removal and FGMS• Additional air/moisture/CO2/CO gettering• Inert make-up/sweep gas to make up for condensed steam/gettered air• Flow meter to measure flow into FGMS cold traps
24
AMIX Gamma Equipment Testing and Assembly
25
Skid #1 (left) Water Supply, Skid #2 (right) Water Removal/Collection
26
AMIX Furnace Delivered to INL
27
Instrumentation and Control Cabinet #1 Under Construction
28
Cabinet #2: Furnace and Heat Trace Power/ControlFront Door and Right Side
29
Cabinet #2: Furnace and Heat Trace Power/ControlInside Rear
30
• Completed wiring 60+ thermocouples
• Constructed all “breakout boxes” andcables to/from the boxes
Other work:
31
Other work • All feedthroughs received:
Six 3” feedthroughs
One 12” feedthrough• FGMS cryotraps were built and received in April 2020
• Working on software development for gamma detectors forthermal gradient tube and particulate/zeolite filter
• Designed transfer carts needed to move transformers andlarge control cabinet to FCF basement
• Received in-cell tables and supports
32
Updated AMIX Timeline
33
• See PLN-5934Oxidation Testing
Test Purpose Specimen Type Test Condition Number of Tests
Intact Particle Performance
AGR-2 Compacts Moisture Opt: 2Air Opt: 2
AGR-2 Particles Moisture Opt: 2Air Opt: 2
AGR-5/6/7 Compacts Moisture 2Air 2
Matrix release
AGR-2 Compacts Moisture Opt: 1Air Opt: 1
AGR-5/6/7 Compacts Moisture 2Air 2
AGR-3/4 matrix rings a Moisture 2 (Plus 2 opt)Air 2 (Plus 2 opt)
Graphite releaseAGR-3/4 PCEA rings Moisture 2
Air 2
AGR-3/4 IG-110 rings b Moisture Opt: 2Air Opt: 2
Exposed kernel releaseAGR-3/4 Compacts Moisture 3
Air 2
AGR-5/6/7 Compacts Moisture 3 (Plus 2 opt)Air TBD
Total 24 ca Tests might be reduced pending results of matrix release tests with AGR-5/6/7 and/or AGR-2 compacts.b Tests might be reduced or eliminated based on PCEA test results and availability of samples.c Total is for sum of H2O and O2 tests only. Tests marked TBD, opt, and helium are not included in total.
34
Preliminary AGR-5/6/7 PIE Schedule (page 1 of 3)Date Start Date End Activity Notes
February 2018 August 2020 Irradiation May extend to September 2020 due to ATR outages.August 2020 December 2020 Cooling in ATR canalJanuary 2021 January 2021 Shipment(s) to HFEF at MFC Likely two shipments but might be a single shipment .January 2021 February 2021 Test train exterior inspection Assume first test section comes mid-January. February 2021 March 2021 Test train PGS Do one section of test train in Feb, and one section in March. Do all of the test train capsules.
March 2021 April 2021 Test train NRAD May only scan capsule 1 in NRAD. Could decide to separate Capsule 1 from the others to send only Cap 1 down to NRAD.
April 2021 April 2021 Test train disassembly
April 2021 June 2021 Capsule disassembly Items removed from the capsules could be gamma scanned and leached or burn/leached after each capsule is completed. Assumes no difficulties in removing/recovering Capsule 1 compacts.
June 2021 June 2021 Compact metrologyJune 2021 July 2021 Graphite holder metrology
May 2021 December 2021 Compact PGS As soon as compacts complete both PGS and metrology, some could be shipped to ORNL, and some could be examined further at INL. Assumes 1 to 2 weeks to scan a set of 12 compacts.
August 2021 December 2021 Graphite holder PGSProbably need to push this end date out given that each holder may take 2 weeks to scan, compact scanning will also be occurring, and we cannot assume the PGS will be 100% available for AGR during this time frame.
October 2021 June 2021 PGS Report PGS report to include results from compact and graphite holder scans. Could think about splitting PGS report into two reports: compacts and holders
35
Preliminary AGR-5/6/7 PIE Schedule (page 2 of 3)Date Start Date End Activity Notes
August 2021 February 2022 AGR-5/6/7 Disassembly and Metrology Report Added two extra months to accommodate some delays.
October 2021 November 2021 Fuel compact shipment to ORNL Could begin as soon as PGS and metrology and inspection are completed probably closer to July .
July 2021 November 2021 Non-metallic capsule components gamma countingJuly 2021 August 2021 Capsule metal components leachingJuly 2021 August 2021 Capsule ceramic components leachingJuly 2021 December 2021 Capsule graphite spacers and felts burn-leach Includes all lab work, but data review/transmission may take longer.
September 2021 April 2022 Compact reirradiation screening Might be able to screen at least some Capsule 1 compacts for broken TRISO .
October 2021 July 2022 AGR-5/6/7 Fission Product Mass Balance ReportIncludes time from starting the report to getting all of the AL data and finishing the report. Report can be started with PGS data of holders and some gamma of capsule components .
October 2021 June 2022 Fuel compact ceramographyJuly 2021 January 2022 Fuel compact ceramography Report
October 2021 July 2022 Fuel compact as-irradiated DLBL Includes DLBL hot cell work, but not all IMGA and radioanalytical work .
April 2022 February 2023 Destructive burnup analysis Includes all analysis and report. Assumes use of compacts undergoing as-irradiated DLBL.
December 2021 June 2024 As-irradiated fuel particle micro analysis at ORNL
36
Preliminary AGR-5/6/7 PIE Schedule (page 3 of 3)
Date Start Date End Activity Notes
November 2021 March 2024 Fuel compact inert heating tests at INL Includes time to receive FGMS and condensation plate results. Does not include time to do any post-test PIE on compacts.
January 2022 May 2024 Fuel compact inert heating tests at ORNL Includes time to receive FGMS and condensation plate results. Does not include time to do any post-test PIE on compacts.
August 2022 May 2025 Compact oxidation tests Does not include any post-test compact destructive examsJanuary 2022 December 2024 Post-safety test compact/particle exams primarily ORNL
September 2022 September 2025 Post-oxidation test compact/particle examsOctober 2025 August 2026 Final AGR-5/6/7 PIE Report
37
38
