On Oct 7^th, during the Mini Shutdown, the T2 cooling package was uncovered to investigate the Cu-ALCW water leak dripping into the 1A Tunnel.

The Target shield block was lifted and found that top of the monolith was dry.  Uncovering the east side of the cooling package directly above the vertical services on the south wall revealed a pin hole leak at a 1/2” 45^o copper elbow on the return line circuit of the T2 cooling package.

The cooling package was turned off followed by valving off the Cu-ALCW service lines leading up to the cooling package to let the Tunnel floor dry over night.

On Oct 8^th, the Tunnel floor was dry and Cu-ALCW service lines feeding the cooling package were drained from the Tunnel by placing a 5 gallon pail under the drain lines filling it about 1/3 full until it stopped.

Mel Good was brought in to replace the faulty elbow.  The Cu-ALCW was then turned back on with no obvious leaks.  At 16:00 approximately 1.5 hours after the repair, I went into the 1A tunnel to inspect for water leaks at the isolation valves and saw water dripping down the vertical piping on the south wall again.   

Another leak was found on the 90^o elbow just ahead of the replaced 45^o elbow. There appeared to 2-3 fine mists spraying out towards the adjacent copper elbow (look at the end of the cable tie on the following photos).

The Cu-ALCW lines leading up to cooling package were again valved off to let the Tunnel floor dry up over night.

On Oct 9^th, the Cu-ALCW lines leading up to the cooling package were again drained followed by replacing the faulty 90^o elbow. The elbow was fitted with new pieces to improve the configuration. We noticed that old copper pieces were worn thin. These damaged parts measured 20,000 c/m on the 44-2 and 40 c/m on the RM-14 monitors and were taken to the RH H/cell lab for inspection.

The T2 cooling package turned on ok about 1.5 hours after repairing the 2^nd water leak.

Mel Good received 0.03mSv over the two day repair. 

I received 0.10 mSv over three days, picking up 0.05mSv on Oct 7^th in the Tunnel where the fields were 200-300uSv/Hr by the isolation valves.  The next the day levels dropped to 40uSv/Hr.  There was no contamination found on the Tunnel floor, however 80,000 c/m on the RM14  and 50,000 c/m on the 44-2 monitors were found on the swipes taken at the bottom edge of the concrete shield blocks.

NOTE: the Cu-ALCW service lines leading up to the T2 cooling package feeds the following 4 devices; Collimator A, Collimator B, the T2 monolith cooling and the Target water heat exchanger.

On Sep. 3^rd during the 6 hr maintenance day, Doug Preddy & I went into the 1A tunnel under “controlled access” to investigate a water leak that triggered the Water Detection Sensors.  It was also noticed that the Cu-ALCW tank level was losing water.

Water was found to be leaking down the south wall chase where the T2 water package goes up the wall. Drip rate was ~1 drip every 15 seconds.

In the late afternoon of Sep. 9^th;

Day one of the 1.5 day maintenance, the tunnel was surveyed by Fiona H. see RPG for field map & floor swipe results. 

Doug, John McKinnon & I set up a plastic sheet with a funnel connected to a 8ft. lg. poly-flow tubing to direct leaking water from the T2 into the south gutter.  This set up was left over night for the floor to dry up and resume the water leak investigation. See photos.

On Sep. 10^th;

@ 08:30 about 70% of the 1A tunnel floor had dried up and the diverted water into the south side gutter had travelled to the T1 area.

The T2 cooling package was then turned off followed by valving off the Cu-ALCW feeding the T2 cooling package. A few more strips of red tuck tape were added to secure the temporary plastic diversion sheet.

@ 11:30 the x-strip graph (T/W  MS 230) of the Cu-ALCW tank level showed that the leak had stopped and leveled off.

@ 13:15 the 1A tunnel floor had dried up with no water seen dripping from the vertical chase.  Doug also mentioned that the “water sensors” that were activated reflected this. The Cu-ALCW was then valved back on to the T2 cooling package and within 3 minutes water began dripping from the south wall vertical service chase which now appeared to about  1 drip/sec.

Fiona took a water sample (20 ml vial) from the drips and also found ~ 1000 c/m (44-2 monitor) on the tacky mat just on the inside of 1A tunnel door.  The 1A Tunnel and South TNF were then locked-up by Derek H., Violeta T. & Doug.   The T2 cooling package was turned back on ok.  Will try to repair this water leak during the Oct. mini shutdown.

 A 5lb roll of 347SS sheet was received today.  This alloy is to be used for the target windows of the new T1 and T2 beryllium target cassettes that will be manufactured in the near future.  The material was ordered from Alloys International (PO# TR206407).  A mill spec report was included with the material, a scanned copy is attached in PDF format.  The roll will be stored in the meson hall RH hot cell lab office on the shelving above the work bench.

The 4" Marman flange clamp (IRH0001) labeled "Clamp A",  as used in the testing detailed in Document-114623 Release 1, has been disassembled.  The parts were used to build a TRH1257 clamp which uses the new TRH1259 jaw with 0.480" jaw root width.  This new clamp has been labeled "TRH1257-#01", and will be tested with Helicoflex H-303654 seals in the near future.

The T2 cooling system was refilled with water via the expansion tank until the tank level read approximately 38 cm.

The system pump was restarted. All sensors displayed acceptable nominal values. Demin flow was tuned to 1.0 gpm.

No leaks or abnormalities observed - system running normally.

A safety walkaround was completed for the Meson Hall Hot/Warm Cells.

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

Main deficiencies identified:

• Hot Cells:
  • Operator station phone not working (help ticket created)
  • Nuclear ventilation pressure delta - measured lower than last time

Secondary flow sensor B1A:T2CS:FGSEC:RDFLOW on the T2 cooling station suddenly became very noisy at around 11 pm, 01 September 2024.

The sensor reading would fluctuate from 0-150 gpm which is beyond typical noise levels for these sensors (~2gpm).

The noise spontaneously ended at around 4 am, 05 September 2024.

The noise likely originated from some stuck debris preventing the paddle wheel from turning normally that got spontaneously dislodged.

Alternatively, changes in the environment temperature could have broken some electrical contact that recovered when the temperature cooled over the weekend. We will make a note to look into this sensor in the coming shutdown and perform preventative replacement of components.

(UPDATE: see ELOG 359, FGSEC serviced)