E-mail correspondence on the Target Hall crane fault diagnosis between October 11th and 15th:

On 15/10/2013 3:34 PM, Grant Minor wrote:

Hello all,

I spoke with the Norelco tech Mike Smith this afternoon regarding the failed thermal sensor component / circuit.  He will call Kone on holiday Monday (their office is not closed for Canadian Thanksgiving) and determine if they have a replacement module.

I explained (to the best of my understanding) the diagnosis performed by Dave Morris / controls group and the test that was done to isolate the thermal sensor unit.  Unfortunately, Mike Smith's drawings from Seattle crane contain notes and revisions that don't match the drawing that Dave Morris provided me (Seattle Crane dwg E5 - 1/1 revision 1 02-10-99), and he was unable to confirm in his opinion whether the bypass performed by Dave Morris has correctly isolated the problem components.  In addition, he believes that the bypass he performed on Wednesday isolated portions of circuitry that are inconsistent with this thermal sensor circuit.

Mike Smith will return Tuesday morning to review the bypass and schematics.  He recommended not operating the crane until he has a chance to confirm this thermal sensor issue.

From the drawings I have in hand and from discussions with Dave Morris, the failed component might be the thermistor sets inside the motor housing which are in series with the suspect module, or the module itself.  My understanding is that the crane is designed with two pairs of motors for the bridge drive, and each pair is protected by one of these thermal modules (thus there are two modules total).  Both modules would be the same age and both might be susceptible to the same failure mode.

As it is unclear to me the exact nature of the drive system failure, and I have a recommendation from Norelco to hold on operation of the crane, I must unfortunately state that the crane should not be used and we will have to wait until Tuesday to gather more information.

I am not so concerned about temporary loss of the thermal protection circuitry, as we have not had an overheating scenario in those motors in the lifetime of the crane (to my knowledge).  I am more concerned about getting 100% confirmation that we have addressed the problem.  If we attempt to use the crane and experience another failure during a lift that prevents us from placing the load down safely with the crane stuck in position over a target station, then we would be in much deeper trouble.

My apologies for this situation.

Best regards and have a good weekend,

Grant


On 11/10/2013 1:28 PM, Grant Minor wrote:
Thanks Dave,

I've contacted Norelco, Mike Smith and I are planning a path forward for further diagnosis and repair.

The crane MUST NOT be used to carry a load until it is identified whether the module or the sensors have failed, the reason for the failure, and the functionality of the thermal sensors has been restored.

Without the thermal sensor circuit we lose protection from motor overheat, an event which could have much more serious failure implications to the crane.

Cheers,

Grant

On 11/10/2013 1:04 PM, David Morris wrote:
The fault has been identified in the Target Hall Crane as a failed motor temperature module, or motor temperature sensor, on the East-West motion. The status contact in the module was bypassed allowing crane motion. There was no fault with the controls.

Dave

 SiC#46 loaded into pail 293 successfully along with other hotcell waste 

Upon visual inspection of the target, a spark-sign was spotted on the perimeter of the extraction electrode. Metallic looking material also found built up between the extraction electrode and the backing plate of the target 

Photo attached 

Nb#6 was removed from TM1...it looked very clean.

Ta#38 was installed onto TM1...fit well.

Isaac Earle did this change with supervision in an effort to cross train.

TM1 containment box was checked for damage from the "bump" it got during yesterday's move. There was new scratches on the shutter side panel. Picture to follow.

The front containment box panel was "difficult" to remove...it required a good pull to get off.

Tom Kauss inspected target hall crane below hook attachment pins and plates ITA6550-01. He certified the use of these pins and plates. The inspection of these pins and plates was in Target hall crane annual check list. It was issued as a calibration index by Isaac Earle in 2022-Feb-08.  After inspection, The inspection tag  was issued and attached to pin. Tom has an inspection record on this job. See attachments.

November 15, 2011 removed TaC#1 from TM1 and inspected TM1 for any obivous signs of trouble (Problems with EE at end of run).

Upon starting removal of the high current conductor fastener on A+ (Left oven leg) it became clear right away that the oven of the target was broken as the leg moved as soon as the fasten was loosened.

Inspection of TM1 with the target removed yeilded no obvious signs of trouble, save a piece of capton tape found on the sliding tray directly below the service tray.

September 5, 2024 -AT

• Plastic and clean target tray added to SHC 
• TM4 moved to SHC 
• TM4 containment box cover removed

September 6, 2024 - AT

• Ta#68(Spare) removed from TM4 onto clean tray 
  • top left mounting bolt fell under source tray in containment box - unretrievable
• Ta#68(Spare) moved out of SHC via toolport door 
  • SHC lift table was lower than tool port tunnel by 2". Target-on-Tray slipped back onto lift table when trying to drag it up to the tool port. Target bounced out of one locating pin, but stayed within boundaries of the tray 
  • Water also leaked out from the VCR fitting and on to the SHC lift table, and toolport. 
• Target-on-tray slid into a clean plastic bag, and then into a plastic box. 

 September 9, 2024 - AT

• Ta#68(Spare) taken out of plastic bag and water drained from waterlines
  • Target was rotated in every direction several times until no more water poured out from the VCR joints
• Ta#68(Spare) put back in box without the bag (to promote evaporation) 

October 7, 2024 - Aaron Tam 

Ta#68 HP-SIS checks performed at B1 lab, moved to anteroom, and inserted into SHC via tool port w/ Aaron Schmidt. 

Ta#68 fixed to source tray with 4 mounting bolts in order of: Right manip. holding, Top left, Right manip. removed, Bottom right, Top right, bottom left. w/ Aaron Schmidt and Brady Borrmann

• Motion was smooth, no resistance when positioning onto pins

VCR fittings done up with ample force, leak check passed

Conductor bolts installed in order of: 2 Target electrode conductors (Checked washers), 3 target Inner and outer conductors.

All bolts checked for full contact with mirror and binos. 

Electrical check failed: Dead short (look for David's ELOG for more detail when available) 

Troubleshooting while David is checking resistance: w/ Ferran

• Intermittent success with heavy manipulation of water lines
  • Loosening off Waterline bracket-to-source-tray 
  • Loosening off Bracket to water line bolts 5/32 hex's 
  • Rotating bracket towards operator (effectively raising waterlines in the back upwards) seems to yield more intermittent success, but never passing megger @ 250V 
  • Tube was inadvertently dented when handling the tube in a wrenching motion with manip tong. counterclockwise
• Target removed while David is still on the multimeter (calling for any sign of success)
  • Starting to remove Target in order of: Tightening back waterline-to-bracket 5/32 hex screws, loosening off waterline bracket, loosening off VCR nuts, 2 Target electrode conductor bolts, 3 Target inner and outer conductor bolts, Fixing bolts Top left (dropped below source tray), Bottom right...
    • (At this time David called with some success with electrical check)
  • Reversing course to verify fault has passed, target was reassembled, only finger loose on the VCR nuts.
  • Faults no longer present
  • Target removed
    •  As target was being pulled off source tray locating pins, a piece of ceramic fell onto the source tray just behind window waterlines.

Target taken out of Hotcell by Ferran. New VCR gaskets installed. Target reinserted 

Target installed no issues. Used fixing bolt used to replace dropped one. 

Leak check passed, Electrical check passed

• Notably don't have a photo of reinstalled target or source tray before 2nd install attempt. 

Containment cover reinstalled 

Ceramic piece moved into Pail #285 (suspect this is a very hot piece)

TM2 ready for move to ITE

  Note: Ta#68 had a difficult install. See E-log ID# 2698 for more info 

First look:

• Containment box cover looks the same as previous (See:ID: 2697)
• Target shows large amount of soot-like deposits (See photos for locations)
• Deposits seem to have been left on parts of the service tray as well ie.: Multipin connector 

Removal:

• Removal was smooth
• Water-line bracket fixing bolts seemed loose even before I put a tool to them 

Eyes of sides:

• Better photos of where deposits are 
• Everything else seems normal 

 Abstract:
This target has seen some irregular beam patterns 
Possibility that the beam hit the walls of the target tube or even the cooling fins
This PIE we want to investigate how the irregular beam physically affected the target 

Related ELOGS: 
ID: 2728
ID: 2698

PIE was performed by Aaron Tam, Directed by Aurelia Laxdal, Observed by Lucas Backes, Special help from Chad Fisher 

External views:

• Windows are clear of any irregularities 
• More pictures of this can be found in RH-ISAC E-log 2728

Internal Views:

• Heatshield internal
  
  • Some discolouration from heat and soot deposits.
  • This seems to be fairly clean to normal amounts - not concerning 
• Target tube
  • tube is bent with the middle higher than the sides
  • Target tube was not removed 9/64ths allen wrench could not be located for this operation 
• Target tube Exit
  • Heatshield windows were punctured to reveal the target tube entraces/exits
  • Entrance is waterline side (ITE)
• Extraction electrode parts were removed from the back off the target
  • These parts look normal
  • some of the extraction electrode would not pull out due to tight fitting parts and the investigation stopped here.

Conclusion: Target physical condition is normal as far as we could investigate 

 Post Irradiation Examination

October 9, 2024 - Aaron Tam w/ Chad Fisher, Aurelia Laxdal, and Lucas Backes 

PIE conducted by Chad with direction from Aurelia. Aaron and Lucas observing/documenting 

Goal: Thin foil target material is somewhat novel, and we should characterize the differences if there are any. 

Photos of the pre-examined target can be seen on ELOG 2697  on Tuesday October 1, 2024, when the target was removed from TM2

Notes:

• Right most inner/outer target conductor bolts was sitting proud and had threads showing, photo attached
• Some Black deposit was found on the inside of the heatshield directly below the extraction tube, and loose in powder form inside the heatshield. 
• Target tube seems to have more of a crystalline texture than previous examinations.
• When Target tube was being removed, one of the target electrode conductors broke off
• some dimple texture was found on the target tube windows and this was further explored by prying a channel through the length of one side of the tube to get a better look

Target pieces were placed loosely back within the heatshield, and the lid loosely placed back on.

Awaiting pail loading, and move to storage vault

Ta#66 post operation electrical check was done at SHC this Monday. See attachment.

On Jan. 9 we did the PIE on Ta#66. Opened the heat shield and removed the EE. The inside of the heat shield was very black with lots of flakes falling off. The target itself looked overheated, and the container looked pretty bad for a Ta target. The outside of the EE looked perfect but after removing it there was a lot of black stuff on the side and we saw that the Re foil was curled up. Jens said during the runtime that he saw something that looked like a wire in the beam path, so maybe this was it.

Electrical check and leak check at SHC. NO leak. electrical check ok.   Before target on, A is short to PQ, RU is short to HS ( 60KV bias) as we measured before.

Ta#59 has been removed from TM2 and it is now ready for electrical check.

See attachment

Ta#57 has been removed from TM4.

Ta#56 has been installed onto TM4 with new fasteners. High current fasteners torqued to 130 in lbs.

RIB "shield" has been removed in  preparation for insertion of new optics tray.

Containment box has been replaced onto TM2, interior of containment box vacuumed, and Ta#54 installed with new fasteners (high current torqued to 130 in lbs).

Ta#52 has been removed from TM$ and UCx#21 installed with new mounting and high current hardware. High current fasteners torqued to 130 in lbs.

This afternoon Ta#51 was removed from TM2 and SiC#36 installed.

All new fasteners used. High current fasteners torqued to 130 in lbs.