WAO10
April 12 – 16, 2010
INTEC, KAERI, Korea

Maintenance Strategyof the PEFP Proton Linear Accelerator

Dae-il Kim (dikim@kaeri.re.kr)
PEFP, KAERIContentsI.

What we have, what we have to do

II. 20-MeV experiences

III. 100-MeV plans
IV. Summary2What we have Facilities- 20MeV proton accelerator- Auxiliary parts for the accelerator- Electrical power station- Cooling station
 Experiences on 20-MeV machine- installation,- operation,- maintenance
Klystron (RFQ)

WaveguideElectrical power system utilities

Klystron (DTL) Target Station Beam Profile

4cmCooling utilities
Ion Source

LEBT

3 MeV RFQ

20 MeV DTL

3What we have to do Installation at Gyeongju site
- Disassembly of 20MeV linac- Packing and transportation- Installation
 After installation,- commissioning- operation- maintenance
TR21

Seoul

KAERI
DaejeonGyeongju

TR22
TR23

TR25

TR24

TR101

TR102
TR103

TR105

TR104

4

I.

What we have, what we have to do

II. 20-MeV experiences

III. 100-MeV plans
IV. Summary

5Installation
 Experience on the heavy but carefully treated parts- DTL tank
- Alignment- Klystron- Supporting structure- Modulator

6

Packing and Transportation
 Experience on the heavy but carefully treated parts- Klystron : Return of the spare klystron to factory- DTL tank (?) – DT alignment

7

Packing and Transportation• Inspection of parts inside oil tank after the delivery- find to the damaged components

8Maintenance Statistics

HV Trips

Other Trips

Trip Numbers

30

20

100
2005

2006

2007

2008

2009

Fiscal years

9DT Replacement Reason- Electromagnet failure at tank 3 HE / tank 4 LE side end plate- Vacuum leakage at tank 4 / 15th drift tube
- On line replacement of the DT Check after replacement- Field profile variation < 1%- Resonant frequency compensation using wall temperature < 2 deg. C
1.03

before replacement

after replacement

Normalized field .

1.02

1.01

1.00

0.99

Replaced DT position

0.98

0.97
16

11

1621

26

cell number

Drift tube replacement

Field profile before and after replacement10

Vacuum System – Commissioning stage• Vacuum system components of 20 MeV Proton Linear Accelerator
PumpComp.

ModelPumping speed

Seal

FlangeNo.

VarianTriscroll 300

250L/sViton O-ring

NW255Iwata

ISP-500B

500L/sViton O-ring

NW40

3Leybold

T1600

1600L/s

Copper

CF250

1OsakaTG1300MCAB

1300L/s

Copper

CF200

2VarianTV301 NAV

280L/s

CopperCF8"41300L/s

Copper

CF8"

6300L/s

CopperCF8"8Scroll Pump

TMP

CapaciTorr B 1300-2
NEG Pump

Saes getters
MK5Ion Pump

VarianVaclon Plus 300

At first,
we mainly used the TMP for DTL tank11

Vacuum System – Operation stage
 Change of the vacuum system operation from commissioning stage (2007)- TMP fails- Regular maintenance of the scroll pump
 Operation method- At initial evacuation, use a TMP (1 TMP/DTL tank)- At normal operation,use ion pumps as main pump (2 ion pump/DTL tank)gate valve close, turn off the TMP

TMP:
Blade broken

Scroll pump:
Replace of tip seal and bearing

12

Electrical Power Station
 22.9kV, 8MVA capacity
 VCB at the electrical power station- 8 years since manufacture- Coronal discharge at the VCB(June, 10, 2007)
 The number of permitted operation
is within the limit, but the old causes
problem
VCB and its bus bar

Newly installed one

FRP barrier

13High Voltage DC Power Supplies -100kV, 20A, <20J : 2 sets
 Arc energy limiting device : crowbar (RFQ), opening switch (DTL) Trips of the high voltage DC power supplies caused by- Malfunction of the protection circuit (DTL , 2005)- Crowbar trip due to the klystron arcs (RFQ, 2007~ 2008): high voltage connectors of the inside and outside the oil tank

Number of Trip2005

2006

2007

2008

2009

2010

30

518

13

-

-Replace the systems
with modulator
to check the modulator
performance at 2009

Change the circuit
to optical (DTL case)

Change the connector and re-adjust
the inside connector (RFQ case)

14

Installation of the Modulator• Valve direction of the cooling circuit- After installation of the cooling circuit, we could not operate the cooling circuit- The directions of the check valve and solenoid valve were reversed
INOUT

Seal

Check valve

Strainer

Solenoid valve

Blue circle : correct direction
Red circle : wrong direction

Flowmeter15

Installation of the Modulator• Inspection and test for the finding of the strange pulse- C-phase of the CH4 is the strange pulse- Ch 1: HVCM output voltage,
Ch2&Ch3&Ch4 : A&B&C phase current• Test after exchange the IGBT board- HVCM output voltage : 7.5kV- SCR voltage : 150V
- pulse width : 100us/div

16

Cooling System
 2MW, 6000lpm, 5bar : 2 sets
 Need regular maintenance – pump, heat exchanger, de-ionizer Problem : water leakage occurs many times- DTL DT cooling line
- Klystron oil tank
- RF load cooling circuit

Cleaning of theheat exchanger plate

Water leakage at klystron oil tank

Leak from the RF load cooling line joint

De-ionizer filter

17

Example of the Spare Parts Keep spare ignitron switches as a crowbar switch of the HVPS
- Original one : glass sealed type- Spare parts : ceramic sealed type
: New but unused for 6 years
 There was a problem for the unused new ignitron- Vacuum degradation and lost of the high voltage hold off capability- Disadvantage of the ceramic sealed type
 Need policy to choose the proper number, and storage periodof the spare parts

Glass sealed type

Ceramic sealed type

18

I.

What we have, what we have to do

II. 20-MeV experiences

III. 100-MeV plansIV. Summary

19

Scheduled Maintenance Regular maintenance period- August at summer season- Dec. ~ Jan. at winter seaon
 Make maintenance list, and do as the list
 List examples- Vacuum system
Scroll pump, ion pump regen., NEG regen.
- High voltage components
Insulation oils, silica Gel, keep clean- Cooling system
Grease, heat exchanger plate, DI system- Alignment of the system

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Unscheduled Maintenance Prepare spare part to reduce the down time
- Disadvantage : Many important parts should be imported- Need to decide the number of spare part
- Need to consider the unused period- Need to consider the delivery time
- Need to consider the possible rental service- It is necessary for us to get advice from other experienced lab.
 Set up the possible fault scenarios and install MPS
 Long delivery items- Klystron- Modulator- etc.

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Example of the MPS
 Modulator-105kV, 5.8MW peak, 9% duty, 1.5ms long, 60Hz
 CO2 system of the modulator as MPS- Thank to the recommendations from the SNS
Smoke
Detector

Smoke
Detector

Control Box
Enclosure safety box
CO2SuppressionHeadCO2Suppression
HeadSolenoid Valve

CO2CO2Suppression
switch22

Example of the Spare Parts
 Spare part list of the modulator- Proposed by the manufacturer- Decide items, number based on the strategy
Description
IGBT Switchplate Assembly
Rogowski Coil Main
IGBT, 1200A,3300V
IGBT Driver Board
IGBT Fibler Optic Cables
IGBT gate bypass cards
Modulator Differential Line Driver
HV Boost Transformer
Twinax Cable Terminations
Twinax Cable Terminations
Rogowski Integrator Box
Oil Filter
Fan Filter
Oil Pump Motor, 1 1/2 hp, 3500RPM
Safety Enclosure FanOil Level Switch
3Ph 30A, Y Female Recepticle
3Ph 20A, Y Female Recepticle
3Ph 20A Y Male Recepticle
Dessicant Breather Assembly
Rectifier Card Assembly
Energy Storage Capacitor
IGBT bypass 10 uF 4kV caps
IGBT 10 uF 2kV caps
1800 pF 160 kV resonating caps
900 pF 160 kV resonating caps
500 pF 180 kV output caps
50 kV resonant rectification caps
.03 uF doubler caps
DSP Control Chassis
Dynamic Fault Detection Chasis
HV connector assemblies
Switchplate Handling and Installation fixture

Price Quatity Delivery Time DynapoweroHVCM unitVendorooooooooooooooooooo

Description
FUSE, 1.00A, 250V
FUSE, 200E AMP, 5.5KV
PILOT LIGHT, AMB
PILOT LIGHT, GRN
DIODE, 1010A, 5600V, DISC, 58MM
THYRISTOR, 2100A, 4200V, DISC, 7.7MM
H/F GATE DRIVE, 6 PUL, REV
FIRING CKT LOGIC, 6/12 PLS
INTERFACE, ZFCTREGULATOR, SWTCHR, REV B MO
CURRENT IMBALANCE DETECTOR
ISOLATOR, DIFF, HIGH PRECISIONRE
H/F GATE DRIVE, 6 PUL, REV D 10K
FUSE, 7.00A, 250V
SWCH, THRM, L-185, NC REDSWCH, THRM, 356F, NC,PEPIXFMR, CNTR, 500VA, 3300:110,50/60
VALVE, BALL, 1-1/4, UNION, CPVCMETER, DIG PAN, 3-1/2, 20VDC
CNTR, 200A, 6.6KV, SF6,110VAC COIL
CURR SENS, 500A
ISOLATOR, DIFF, HIGH PRECISION RE
BRACKET, MOUNT, 1INCHVARISTOR, 1700VRMS, 6000J, BBCAP, 0.82MFD, 3300VDCRES, OHM, 15.00 190W, NON-IND
PROG CNTL, SLC500, POWER SUPPLYPROG CNTL, SLC500, PROCESSORPROG CNTL, SLC500, 7 SLOT RACKPROG CNTL, SLC500, 12KFLASHPROG CNTL, SLC500, 16 AC IN, 120V
PROG CNTL, SLC500, 8NO, 3A/120VAC
PROG CNTL, SLC500, 16 RLY OUTPROG CNTL, SLC500, 8DC IN, SINKMOUNTING BOARD, 4 POSITIONINPUT MOD, 5V LOG, 2.5-2.8Vin
CNTR, 400A, 5KV, 120/230/50/60/DC
HT EXCH, W/A, 5291CFM, 3HP
SWCH, FLOW, 1.25 BODY, 20GPM
PWR SPLY, +/-15V, 1.5A, CA SE BB
FUSE, 15A, 250V
FUSE, 4.50A, 250V

Price Quatity

Delivery Time

Dynapower

Vendorooooooooooooooooooooooooooooooo

SCR unit23

Summary• We experienced on- transportation- installation- operation- maintenancein the 20 MeV proton linear accelerator• We will plan
- make maintenance list, and do as the list for scheduled maintenance- prepare spare part to reduce the down time
for the unscheduled maintenance- consider to buy the spare part
- set up the possible fault scenarios and install MPS
in the 100 MeV proton linear accelerator

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