Progress of the JT-60 SA Toroidal Field coils tests in the
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www.cea.fr www.cea.fr Progress of the JT-60 SA Toroidal Field coils tests in the Cold Test Facility W. Abdel Maksoud L. Genini, D. Ciazynski, Y. Huang, L. Vieillard
Progress of the JT-60 SA Toroidal Field coils tests in the
Diapositive 1Toroidal Field coils tests in the
Cold Test Facility
W. Abdel Maksoud
TFC tests in the Cold Test Facility
The JT-60 SA TF coils Cold Test Facility main goals are : -
Mitigate the manufacturing risks by testing the coils in nominal
conditions of temperature
(5 K) and current (25.7 kA) - Check a certain number of
performances of the TF coils : DC/AC insulation, cooling down
characterization, RRR of the conductor, pressure drop in the
winding pack, etc. - Measure the temperature margin of the TF coils
against a quench
MT25 – Amsterdam - 28/08/2017 3W. Abdel Maksoud
Tesing progress
Coils integrated in the Tokamak: 9?
- Wed-Af-Po3.02 : P. Decool, “Completion of the French JT-60SA
Toroïdal Field Magnet Contribution” - Mon-Af-Or4 : G.M. Polli,
“Completion of ENEA’s procurement for 9 TF coils of JT-60SA
tokamak“
MT25 – Amsterdam - 28/08/2017 4W. Abdel Maksoud
Warm tests
TESTS RESULTS SUMMARY
Visual checks - Minor: marks and scratches on the casing surface -
Major: holes on casing straight leg corresponding to weld
defects
created during the electron beam-welding phase repaired or to be
repaired by WT
Temperature sensors checks - Major: non working sensor dismounted
and repaired by CEA
DC insulation at 3 kV - Major: insulation fault at the soldering
point of the terminal voltage
taps of TFC01 repaired by ASG - Major: insulation fault on TFC08
under investigation
Expected values TFC10 TFC11 TFC01 TFC12 TFC03 TFC13 TFC14 TFC04
TFC05 TFC15 TFC06 TFC16 TFC07 TFC08
Visual checks OK/NOK
DC insulation at 3 kV > 0.5 G
Leak test at 20 bars < 10E-8 Pa.m3/s
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Cooling down
Cooling down duration - Since TFC12 (4th coil tested) a nominal
cooling down duration of 7-8 days has been achieved by CTF
for all coils
Pollution level during cooling down - From TFC10 to TFC13 (except
TFC12)
pollution clogging's has been observed below 200 K. Between 1 and 3
evacuations has been made each time to clean the coil and be able
to continue the cooling down
- GE visually observed oil traces in WT casing tubes of TFC14 and
applied since then a cleaning procedure with Methyl Ethyl Cetone.
No pollution clogging observed in CTF for TFC14, 15 and 16.
- Low level of pollution for ASG coils TFC04, TFC06 and TFC07 but
very high for TFC05. Same cleaning procedure for all coils random
level of pollution
0
1
2
3
4
5
6
7
8
9
Pressure drop (bar) due to pollution clogging at 170 K before
evacuation
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Tests at 5 K (no current)
TESTS RESULTS SUMMARY
DC insulation at 3 kV - TFC01 & TFC08 DC faults same as 300 K -
Major: insulation fault during the DC test of TFC07 at 5 K current
tests cancelled and postponed to
after investigations and repair. Cooling down induced a crack in
the insulation of the joints area creating a short cut with the
ground conductive paint repaired by ASG waiting for 2nd
campaign
As the 3 DC tests faults were visible first under vacuum and not
air, DC tests in vacuum were added to the testing procedure
beginning from TFC07
Expected values TFC10 TFC11 TFC01 TFC12 TFC03 TFC13 TFC14 TFC04
TFC05 TFC15 TFC06 TFC16 TFC07 TFC08
RRR > 100
DC insulation at 3 kV > 0.5 G
AC insulation (4 kHz, 0.5 kV, 1.5 s) 85 ± 15 %
Pressure drop (24 g/s, 4 bar, 5 K) 600 mbar ± 15 %
ΔT = Tout - Tin < 0.4 K
MT25 – Amsterdam - 28/08/2017 7W. Abdel Maksoud
Tests at 5 K (no current)
TESTS RESULTS SUMMARY
ΔT inlet-outlet value - Between 0.6 K and 0.9 K for all the coils
due to a low cooling efficiency of the casing pipes inducing
40% of heat loads transfer to the winding should be within
specification in Tokamak operation
Expected values TFC10 TFC11 TFC01 TFC12 TFC03 TFC13 TFC14 TFC04
TFC05 TFC15 TFC06 TFC16 TFC07 TFC08
RRR > 100
DC insulation at 3 kV > 0.5 G
AC insulation (4 kHz, 0.5 kV, 1.5 s) 85 ± 15 %
Pressure drop (24 g/s, 4 bar, 5 K) 600 mbar ± 15 %
ΔT = Tout - Tin < 0.4 K
0.4
0.5
0.6
0.7
0.8
0.9
1
Tests at 5 K and 25.7 kA
QUENCH TEMPERATURE TESTS RESULTS
- Due to the too high inlet-outlet ΔT, a dynamic procedure for
Tquench measurement has been implemented instead of the static
one
- For all the tested coils, the measured quench temperature is
between 7.44 K and 7.52 K. These values are in agreement with the
expected values computed thanks to the Tcs measurements made on the
TF coils conductor and well above the minimum required value in the
Tokamak (> 7.3 K)
MT25 – Amsterdam - 28/08/2017 9W. Abdel Maksoud
Tests at 5 K and 25.7 kA
QUENCH INITIATION
*Daniel Ciazynski *Valerio Tomarchio / Yawei Huang
57 % of quench initiated on side pancakes VS 29 % on central
pancakes
Quench location
Inlet temperature
DP type
TFC10_2 DP1 - Side
TFC07 TBD TBD TBD
- Tue-Af-Po2.03 : D. Ciazynski, “analysis of early quench
development in jt-60sa toroidal field coils tested in the cold test
facility”
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Tests at 5 K and 25.7 kA
QUENCH PROPAGATION
Understanding the complex experimental physical behavior of the
JT-60SA TF coils quench and modelling it is an important step in
quench understanding that could be useful for JT-60SA operation and
the protection and stability designs of ITER and DEMO.
- Thu-Af-Po4.02 : Y. Huang, “Numerical modelling of the quench
propagation phase in the JT-60SA TF coils tested in CTF” -
Thu-Af-Po4.02 : S. Nicollet, “parametric analyses of jt-60sa tf
coil in cold test facility with supermagnet code“ - Tue-Af-Po2.03 :
F. Bonne, “Dynamical Cryodistribution Model of the JT-60SA Toroidal
Field Coil in Cold Test Facility”
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Tests at 5 K and 25.7 kA
INTER PANCAKE JOINT MEASUREMENTS
- All the inter pancake joint values are well within the
specifications : < 10 n for the total value and < 5 n for the
highest one
0.96 1.35 1.13 0.7 1.43
0.74 1.3 1.57 1.23 1.15 0.88 1.04 1.36
2.98 3.53 3.79
4.76
TFC10 TFC11 TFC01 TFC12 TFC03 TFC13 TFC14 TFC04 TFC05 TFC15 TFC06
TFC16 TFC07 TFC08
DPs interjoint resistance (n)
Conclusion
The JT-60 SA TF coils cold tests allowed to :
- Successfully cool down and test 13 JT-60SA TF coils under nominal
conditions of temperature (5 K) and current (25.7 kA)
- Validate major performances of the TFCs like quenching
temperature (between 7.44 K and 7.52 K) and joint resistances (
< 2 n)
- Find and solve or repair a certain number of non-conformities
that could have caused major problems during the Tokamak operation
like:
- Identify pollution clogging inside the coils during cooling down
and find a procedure to clean the coils and proceed the cooling
down
- Identify DC faults on 3 coils: 2 have been repaired, the 3rd is
under investigation and one will be re-cold tested after
repair
- Better understand and model the quench behavior of the coils
(sometimes unexpected) through deep scientific experimental
analysis and several modelling studies
13 TFCs tested with success 5 coils left!
MT25 – Amsterdam - 28/08/2017 13W. Abdel Maksoud
Thank you for your attention