After removing the previously found extraction electrode and other suspect components the field at the manipulator tongs (in front of the window) in still 3mSv\h.

I have been through every bin etc in the hc and even emptied the dust seperator canister of the vacuum. I will use the camera to look under the table and inside the vacuum cleaner itself...these are really the only possibilities left.

HALCW pump ITC:MP1 and MP2 phase current draw measurement result: water supplied to both station. MP1: Black 17.0A, blue 16.9A, red 16.7A.   MP2: black 17.3A, blue17.8A, red 17.3A.    The results are good.  No concern on both motors.

 ITW/ITE water system manual valves water small leak inspection and repairing job is done. Small water drippings have been found on ITE: manual supply and return(valve stems).  ITW: 2A window supply(valve stem), collimator supply(valve stem),EE return(valve stem), HS supply and return(valve stems), tube heater supply and return(valve stems). all small leaks are repaired. 

After waste transfer, I did a SHC field measurement from TH through top flange opening. The general field around manipulator maintenance working area is 550 to 650 usv/hr(0.4 to 0.5 meters above table). some area on work table where target fragile material stayed before have 1.0 to 1.3 m/sv (closing to contact measurement). The spreading of target material dusts deposited on table, and affected the whole cell field in my view. 

HALCW resin can loop two filters have been replaced. no water leak on after job check.

Chole and I finished ITW water signals interlock. No issue.

Service of  Parker 1/4 quick connectors in ITW and ITE have been done.  all 28 female connectors were serviced. o- rings and valve stem in quick connectors were replaced. the serviced connectors have been installed back to ITW and ITE.  Visually inspected all connectors with flowing through them. No leak, and they function well. 

To prevent TP bearings seize during shut down, ITW:TP3,TP4, TP1S TP4S have been started since March 06th. They work fine.  The plan is to switch them off this Thursday, and restart them in May before ITW in use.

ITE water signals interlock annual check is done today. all interlocks work . No issue.

TCS water system filters annual replacement has been done. Plant group Dan Tower finished the job and updated the inspection tags .

2 broken lights of NHC were replaced in Target Hall. see pics attached.

Adam and I did  spent target pail and its lifting jigs load test this morning.  The load for full pail test is 263 lbs and for empty pail is 69 lbs. pail and all jigs passed the test.

On March 27 remote end 9342 was installed on the west position (right hand as viewed by operator) and arm 9764 removed and moved to anteroom.

Previous to this installation, arm 9342 received tensioning of the elevation twist pulley block and tightening of the tong cable opening via the tong cable drum. Tong opening was reduced to roughly 2" to achieve tension in the tong cable such that slack upon release of the system was reduced and tong cable didn't hop pulley in elevation/twist pulley block (this 2"opening is not enough to grasp the air ratchet but is suff. for holding a target...right manip will have to hold the air tool for now. It is also notable when dealing with the tong cable system that slack can cause the tong cable to hop off the secondary pulley in the wrist joint (where two cables run through a secondary pulley that has no retention feature).

Notable during this repair was the fact the the lock-down set screws on the elevation/twist pulley block were missing. These lock down the tensioning screws once the block has been tensioned. New set screws were installed after elevation twist cables were tensioned to their nominal value of 15 in lbs.

It is my recommendation that, when the spare remote arm is fixed and there is a window that this arm come back out and the tong cable be replaced (we have 6 on hand).

Tong cable on remote arm 9**4 has be relocated onto its pulleys and tong opening adjusted at the tong cable drum by changing the position of the tong cable screws by two positions (tightened/closed) such that the air tool will fit in the tong and some of the slack in the tong system has been taking up.

An attempt was made to also adjust the elevation twist pulley block which would also aid in taking up slack in the tong system however, the elevation twist pulley block was already and the end of its adjustment. Elevation twist cables are measuring 10 in lbs, the nominal value that they should be at is 15.

Tong system has been cycled multiple times and the tong cable itself looks good. This arm should be good for service however, I recommend a new pulley block be ordered and the new one dimensional compared to the existing. If they are the same we may consider shortening the new pulley block to achieve a window for tensioning, after which I would recommend the pulley blocks be swapped...swapping should only take place after 9342 has had the tong cable replaced and we can be more confident in its operational state, or in the 2026 shutdown in allowed.

TM4 was moved from Safe Module Parking to the North Hot Cell today.

Refilled TCS:TK2 from 11" to 28.8 ".

A safety walkaround was completed for the ISAC Hot Cells and Target Hall Areas.

The resulting spreadsheet can be found on DocuShare as Document-242733.

Main deficiencies identified:

• Hot Cells:
  • Overdue fire extinguisher inspection
  • NHC oil level depleted - to be filled
  • SHC breathable air certification expired (may have been checked but just not updated - to follow up)
  • SHC left manipulator tong cable snapped (planned May 22 repair)
• Target Hall:
  • NHC depression indicator calibration expired and reading is 0 (requested mech services to check this in Oct 2024)

Action has been, or will be, taken on all deficiencies.

Findings

• During April 2025 safety walk ID: 2796 , it was noted that the oil level in NHC window oil expansion tank was below the indicator range.
• previous safety walks from July, October, Jan 2024 did not show any issues, but this was not a recorded item, only to check for leaks 
• No visible leaks from the exterior can be seen. 
• No air gap can be seen inside the window, so it is completely filled
• Last fill date September 28, 2022, no notes of finding a leak prior to, or after the fill
  •  ID: 2369 Entry time: Wednesday, September 28, 2022, 13:15

NHC Window Oil Filling

• Oil used was from a separate pail labeled Hot Cell Window Oil, believed to have come from the 55gal mother pail containing Penreco Drakeol 10 B LT Mineral Oil NF
• Nitrogen supply needle valve was closed to prevent oil from blocking this line
• Oil was filled from the removed pressure relief valve position which deviates from the procedure previously used ( ID: 2369 )
  
  • This was done to avoid oil from entering nitrogen supply line and limit oil from entering pressure gauge 
  • Valve from previous fill location (alleged old accumulator location) was also open to encourage better breathing
• ~1,775mL added via squeeze bottle before oil was seen in the indicator tube. Another ~1100mL was added via squeeze bottle to bring oil fill indicator to the previous 2022 fill mark that is about halfway up the tube. 2,875mL Total
  • This is considerably more oil added than in 2022 (1.5L)
  • Location of oil level and fill date marked on indicator tube and on reservoir  with blue Sharpie 
• Accumulator valve closed, Pressure relieve valve re-installed, nitrogen supply line valve opened 
  • 1.8 inH2O reached in ~10 minutes. 2.2inH2O was indicated the next morning 

Notes

• Oil level check on quarterly safety walks will be added
• Increased checking interval during the first quarter will be performed 
• Unrelated NHC entries in 2024 did not note any oil leaks, so not sure where 2.5L+ of oil has gone in 2.5 years
• SHC window oil level has remained about halfway up the indicator tube. 

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May 12, 2025 - Aaron Tam 

Oil fill check 

• Two observations were made on the oil level. Once on May 6th with ~0.5cm below mark and may 12th ~1cm below mark
  • Photos uploaded 
• Nitrogen pressure is higher than last recorded at 3.1 inH2O
• I have a suspicion that a large gas bubble exists above the window in a separate holding tank. More observations to come 

Remote end 9352 replaced with end 9764 due to signs of an issue with the tong cable (tong opening excessively large and slack in cable on one side). Upon replacement tong opening on 9764 also opened larger then the remote end was set to. Everything is operational but this phenomenon indicates the handle cable system on operator side must be where the excess is coming for. This is further indicted but the position of the locking screw on the handle cable drum on the operator side, typically ccw of the hole location but now cw of the locking hole location. When there is a two week period between target changes in the NHC I would suggest swapping this operator arm with the spare.