This morning Don Jackson commented to Grant Minor that he believed the tank lid was still not raised high enough to safely operate the Remote Handling bridge and trolleys, despite it having been raised 0.5" yesterday to the point of engaging the limit switches (see e-log from yesterday).  Don said he believed this to be the case as a result of a visual inspection with binoculars from the outside of the tank, as well as from the views achievable with the remote cameras.

Don also believed he had caused further damage to the equipment inside the tank by orbiting with the bridge.

After a teleconference with Klaus Reiniger after lunch (Yuri Bylinski, Dan Louie, Don Jackson, Grant Minor present), the following was confirmed:

• There is a complete set of limit switches at station 1, and duplicate set at station 10 for redundancy.
• Both stations 1 and 10 have an operator upper limit switch, as well as an over-travel limit set slightly higher than the upper limit.
• The lid has traditionally been raised to the point of the upper limit switch tripping, then the lift procedure stops there.
• The wooden stick was traditionally set to just touch the roof beams with the lid at the upper limit.  This means if the stick is contacting the roof beams within 1/32nd inch or so and the upper limit trips, the lid has been raised fully.
• Klaus could only remember one incident of the lid being raised so high before tripping the upper limit that the wooden stick actually bowed under pressure from the roof beams.  In other words, this was not a normal occurrence.
• Klaus also reminded us that the limit switches have some mechanical hysteresis and need to be actuated through their full range of motion to reset them.

Don Jackson indicated that another 1/4" of clearance would be adequate to safely operate the RH equipment in his opinion.

At around 5pm Grant Minor and Ron Kuramoto reset the upper limit switches at both stations 1 and 10 by adjusting the block that both upper limit and over-travel are mounted to, see attached photos.

• A line was scribed in the primer paint to mark the original position of the limit switch mounting block.
• The bolt was loosened, and the block was raised fully to reset the switches, and then set 1/4" higher than the scribed line, measured with a Starrett scale accurate within about 1/64"
• The bolt was re-tightened.

Dan Louie and a shift operator reset the wooden stick 1/4" lower than the roof beams, this was double checked by Grant.

Dan Louie started up the system and confirmed the limit switches were properly reset.  He then raised the lid until the limit switches tripped again, confirmed by checking the illumination of the upper limit lamp (see attached photo).

After the raising of the lid, the wooden stick was confirmed to be contacting the roof beams by Grant Minor.

Dan Louie also confirmed that the master synchro counter had advanced almost exactly 250 counts (proportional to about 250 thousands of an inch).

Mechanical counter readings at each station (where accessible) were taken before and after this 1/4" rise by Dan Wright and Grant Minor:

Grant Minor had dosimeter 208 today, which was signed out at 0.61 mSv and signed in at 0.69 mSv.  Thus elevating system assessments and adjustments resulted in approximately 0.08 mSv dose.

Today Grant Minor, Dan Wright, Arthur Leung, and Dan Louie checked the height difference between the tank lid upper travel limit switch and the tank lid over travel limit switch at both stations 1 and 10.

In the attached photos, the upper travel limit is the lever on the right.  The over travel limit is the lever on the left.

The over travel limit is a safety switch designed to halt the system and lock it out if there is some problem with the upper travel limit.

The following tasks were performed:

1. The new reference positions for the brackets after the March 11th adjustment of 0.25" (see previous e-log) were scribed onto the mounting posts for Stations 1 and 10
2. The brackets at both Station 1 and Station 10 were unbolted and raised up completely to disengage the switches.  This had to be done due to mechanical hysteresis in the switches.  Dan Louie confirmed when the upper limit / over travel limit signal lamps had turned off at the control rack.
3. The Station 1 bracket was bolted up higher temporarily so that both switches were disengaged at that Station.
4. The Station 10 bracket was positioned back at the new scribed reference line from step 1.
5. A 1/8" nominal machinists parallel was slid under the lever arm of the over-travel limit switch at Station 10, and Dan Louie confirmed that the over travel lamp had turned on.
6. The Station 10 bracket was unbolted and raised to disengage both switches, and bolted in this higher position.
7. The Station 1 bracket was then positioned back at the reference line from step 1.
8. Step 5 was repeated for Station 1, confirming that the over travel lamp engaged after the 1/8" parallel was inserted under the switch.
9. Both brackets were positioned back at the reference positions from step 1 and bolted in place.

This procedure confirmed that the over travel limit switches at both stations 1 and 10 engage less than 1/8" higher than the upper limit switches.

In tank survey completed.  A few items of interest were found.  Ladders need to moved manually outboard to #5 resonators and the items noted in attached document need to be addressed.

Prior to the lid-down operation today, the Cyclotron was lowered by 0.75" and then raised again to confirm that the upper limit switches were working.  Dan Louie confirmed this from the control racks.

Maico and Grant walked around the perimeter of the cyclotron to inspect each station and ensure that there were no interferences, e.g. dial indicator rods, tread plates, etc.

The lid was lowered successfully by Gord Roy and Dan Louie.

Mechanical counter numbers recorded after lid down are shown below:

Measurements of the cyclotron magnet face gap were taken on March 15, 2013 at two locations around the tank with the cyclotron lid in the fully raised position (the lid had been raised until the upper limit switches caused the control system to stop travelling).  The purpose of the measurements is to establish an independent means of verifying correct lid height before beginning in-tank remote handling activities at the start of a shutdown period.

The height of the lid at the time of measurement was confirmed to be adequate for the bridge to perform a full orbit without any interference between the bridge or cable tray and devices on the lid.

Measurement locations were labelled using permanent marker.  A plumb-bob was used to ensure the measurement location on the upper and lower faces were aligned vertically.  The measurements were performed using a tape measure hung from the upper magnet face and read at the lower magnet face as shown.

Location #1: RH bridge entry/exit point (~50° position), Measured gap: 46-1/2" +/- 1/16"

Location #2: East side of jack station #1 (~215° position), Measured gap: 46-9/16" +/- 1/16"

Photographs of the upper limit switches on jack stations #1 and #10 were taken as shown below:

At this lid height, the reference stick on the top of the cyclotron lid was found to be touching the concrete ceiling, but was not bowed.  See photo below.

 The distance between the cyclotron tank lid and the RH bridge was then measured using a meter stick attached to the lift trolley.  The trolley was moved into the tank, and the stick raised until it contacted the tank lid.  This position was recorded, the stick was lowered, the trolley was removed from the tank, then the stick raised again to the recorded position.  A piece of aluminum angle was used to translate the measurement from the center of the trolley to the edge of the bridge as shown below:

Total Distance from RH Bridge Rail to Cyclotron Tank Lid: 15-7/16" + 6-5/16" = 21-3/4" +/- 1/8"

The copper blockers have been removed from the cyclotron and placed into the coffins.

 The Shielding and the Port Hole Covers have all been installed. No issues with the installation have caused any problems. This orbit, radial, and vertical read back continues to be an issue.

All shields, pothole covers, and ladders have been installed into the cyclotron.

2C has been successfully removed from the cyclotron and is now currently sitting in the B2 level of the RH building. A tank access was needed to feel the stuck QDL.

2C has been installed into the cyclotron.

 One of the beam spill monitor boxes was removed and placed into a lead coffin. The fields around the coffin prior to the monitor being placed in were 145 uSv/hr just above the box and 33.5 uSv/hr inside of it. A swipe was taken inside the box at this time and a count of zero was found. The tray for the monitor box was then placed into the coffin and the monitor removed from the cyclotrons. The field above the coffin with the monitor box was 1.0 Sv/hr. Safety hinted that it may be possible to put this in the decay storage tunnel. The copper block was then returned to the coffin. The fields above the the coffin were now 9 Sv/hr. The lid was returned to the coffin and returned to it storage place. The new monitor box was then installed into the Cyclotron. The box only hung up on the pins once and there was some slight difficulties unlatching. From previous experience once fully unlatched a slight tap in the latch direction seems to allow it to release easier.  Overall the installation was considered very smooth. 

During the electrical test the was no contact.  To help investigate further the Montitor box was removed from the Cyclotron. It was found to have zero counts. The issue is believed to have to do with the fit of the box but confirmation of the writing harness continuity needs to be completed. This will continue on Monday. 

Bevan Moss wrote:

One of the beam spill monitor boxes was removed and placed into a lead coffin. The fields around the coffin prior to the monitor being placed in were 145 uSv/hr just above the box and 33.5 uSv/hr inside of it. A swipe was taken inside the box at this time and a count of zero was found. The tray for the monitor box was then placed into the coffin and the monitor removed from the cyclotrons. The field above the coffin with the monitor box was 1.0 Sv/hr. Safety hinted that it may be possible to put this in the decay storage tunnel. The copper block was then returned to the coffin. The fields above the the coffin were now 9 Sv/hr. The lid was returned to the coffin and returned to it storage place. The new monitor box was then installed into the Cyclotron. The box only hung up on the pins once and there was some slight difficulties unlatching. From previous experience once fully unlatched a slight tap in the latch direction seems to allow it to release easier.  Overall the installation was considered very smooth.

all shields, porthole covers and ladder out and copper blockers in. Some conmination was found on the pads of the ladders (about a 1000 count or so) and was removed.

Day one of RH in tank work for the cyclotron (shields and blockers stuff like that) many pictures were taken.

All copper blocker removed from the cyclotron and first radiation survey done. Shields start tomorrow.

Over 50% of the shields are in some 700's left and the monitor box covers.

All shields, ladders and pothole covers are in. One rad survey left to do.

Final Radiation Survey done. All in tank work completed bridge removed from the tank.

2C has been removed from the cyclotron.

2C extraction probe has been re-installed in the cyclotron. After some problems on the first install attempt, do to a busted micro-switch that was causing the 24 Volt DC system to short out.