test 2

blah blah blah....

Randomly checked on the nuclear ventilation for the Meson Hall Hotcells and discovered they were not running again (both magnahelic gauges displayed zero). Attempted to restart the fan manually and the control box seems to not be working. Matt McClean has been contacted and they will look into the problem.

The nuclear ventilation is currently not running in the RHMH hot cells.

 The west side manipulator was removed from the hot cell using the new manipulator removal frame.  The operation went smoothly and required about one hour with two operators after everything had been prepared.  No contamination was found on the manipulator thru-tube or slave arm.  Only 50cpm were measured on the wrist assembly of the slave end.

All water was removed from the base of the target hole in the T1 monolith using a suction tube device and wypalls.  Video inspection was performed and revealed standing water in the unused 4" beam line pipe facing south as well as on the bellows on the M13 beam line.  (Photos attached)

Vacuum group is currently pumping down on the T1 volume to remove the remainder of the water.

 Four water sensors have been installed on top of the T1 monolith.  These water sensors were wired and brought to the area during the 2014 shutdown, but installation was delayed so that the top of the monolith could be painted first.  The sensor labels (attached to the sensor cable) are: T1, T2, T6, and T8.  The location of each sensor is documented on the diagram below.  Two photos of the top of the monolith are also attached.  Doug Preddy has been notified.

Water was purged from the T1 and T2 targets using compressed air.  The water is stored in a labeled bucket on the BL1A blocks near the T2 cooling package.  The bucket is approximately 100µSv/hr on contact and 10µSv/hr at 0.5m.  Isaac's coveralls had 500cpm on them after this job and were dropped off at active laundry.  Keith had no contamination on his coveralls.

The T2 cooling package was visually inspected today after blocks were removed.  With the cooling package off the following leaks were observed:

- Collimator A return line ball valve: ~ 2 drops / second
- Collimator B return line ball valve: ~ 1 drop / 3 seconds

The cooling package was then started and the following leaks were observed:

- T2 heat exchanger secondary side, north end ball valve (CuALCW):  ~ 1 drop / sec
- Target water return line ball valve above reservoir: very slow leak, wet but no drips visible

These leaks explain the water found in the tunnel, and the slow drop in T2 expansion tank level.  However it is a little mysterious why four valves all failed around the same time on two different water systems..

The copper active supply to the T2 area will be valved off to stop the leaks, and the valves will be serviced or replaced during this shutdown.

 A water leak developed this morning from a city water supply line at a hose connection near the T2 expansion tank.  Water was observed to be dripping off the mezzanine onto the plastic sheet covering the T2 cooling package.  The leak has been stopped and the leaky fitting is being repaired by Carston Frasden.

The T2 cooling package was inspected: small amount of water on the top of the plastic sheet, no water visible below the plastic, and all package components were dry.
The T2 expansion tank level was checked: no change.

 Today I noticed a "NOT OK" signal from T2 water expansion tank warning level sensor.  I checked the water level in the tank and confirmed that the water level in the tank had indeed dropped.  The water package is currently not connected to the target so it is not possible for this water to enter the beam line.  

My initial suspicion is that the female Hansen fittings are leaking.  If this is the case, the water will be leaking onto the top of the T2 monolith.  The water lines were disconnected from the target on April 12, 2012 and at that time the expansion tank level was checked and confirmed to be full.   Approximately 7 liters of water has been lost since that time.  If the leak rate is steady this equates to 166mL per day.

I will investigate further on Monday morning.  If the cause of the leak is not obvious, a thorough investigation will have to wait until the M20 front end is covered as radiation levels are high around the T2 monolith and cooling package areas.  The current water level in the expansion tank has been recorded, and will be checked again Monday morning in order to see if the level is still decreasing and at what rate.

 After approval from RPG, the water drained from the suck tube, which was stored in a bucket in the RH lab active sink area, was released to the active drain.  Even after rinsing, the bucket still had a slight field from the base, so it has been labelled and will be kept in the active sink area.

Water detecting strips were installed around the T1 and T2 areas today with Doug Preddy and contractors from SMT Research.  Four sensors were installed at various locations on each cooling package.  Four sensors were installed on the top surface of the T2 monolith.  In addition, four sensors were routed for future installation at the T1 monolith (it is currently covered by blocks and requires cleaning and painting before sensor installation).

See the attached PDF for sensor ID numbers and placement specifics.

Photos are attached of the sensors installed around the T2 monolith and cooling package.

Six 5 gallon pails were transferred this morning from a temporary storage bunker in the Warm Cell to the Rad Waste Pit for long term storage.  The pails contain various BL1A active waste from the East Hot Cell including dozens of irradiated beryllium and graphite targets.  The field from the pails ranged from 0.1 to 9mSv/hr at 0.5m.  The work was performed according to the clean-out procedure (Document-142965).  Photographs and records of the pail contents, field, weight, etc have been uploaded to Docushare Collection #20185 and hard paper copies were given to RPG.

All remaining waste in the east hot cell is too large to fit into 5 gallon pails, so it must be packaged in a 55 gallon drum.  Some long items will need to be cut in the cell before hand.

The field on the hot cell roof is now less than 5uSv/hr in working areas, and a maximum of 55uSv/hr at 0.5m above the east hot cell opening.  The field was previously > 50uSv/hr in some working areas, and > 200uSv/hr above the opening.

Before and after photos of the hot cell interior are included below:

Since the previous E-Log the following tasks have been completed:

- Panel spacer rods installed at 4 locations in each tank (two top, two bottom at approximately 1/3 and 2/3 the way across)
- Spacer rods expanded only slightly to begin compressing the rubber window spacers while still leaving at least a 8mm gap between window and frame
- Window and frame around seal area masked off with masking tape
- Sealant was applied from the outside using a plastic cone tip with a copper tube attachment to allow sealant injection to the bottom of the sealant cavity.  The process involved having one person inside the tank to make sure the sealant cavity was completely filled with no voids. A total of 42 of the 20oz. sausages were required.  Two spare unopened sausages remain.

The sealant will now be left for 2 weeks to cure before water is added to the tank.

The following tasks were completed over the past 2 weeks:

- Aquarium Technology Ltd. (UK) was contacted regarding best method for replacing window seal.  A detailed procedure was provided (attached below)
- The warm cell windows were determined to be acrylic, not glass.  Estimated weight: 450lb per panel

- All water in the warm cell windows was released to grassy area outside the lab after approval from Gord Wood (OH&S) and Joe Mildenberger (RPG)
- Warm cell was cleaned up and blocks were configured to make fields as low as possible in the work area around the windows (~2micro Sv/hr max field around windows).  No contamination found on warm cell floor.
- The old seal around each window was cut mechanically with a thin blade
- The panel spacer rods were removed  (most were constructed of SS and Al, however a couple were mild steel and were badly corroded)
- The window panels were separated from the frame using a rubber mallet and moved to the center of the tank (the panels were not removed from the tanks for this repair)
- The old seal material was removed from the panels and the aluminum frame using WD40 or mineral spirits to help break it down (this was a very tedious and unpleasant task)
- Pitting due to corrosion was found in various places on the aluminum frame.  It appeared to be worst where mild steel spacer rods were used, and also worse at weld locations (see attached photo).  Max depth of pits ~1/8"
- The corrosion was cleaned as much as possible using a wire brush then rags with mineral spirits
- A final clean of sealing surfaces was done with isopropyl alcohol
- A deep pit (~1/4" deep) was found on the inside of the inside of the aluminum frame on the west tank, south window (see attached photo)
- This pit, as well as some other smaller ones on the same side were filled with Dow Corning 791 sealant material

- Rubber stand-offs (Digi-Key #SJ5009-0-ND) were installed on the frame side in the center of the sealing faces (3 top, 3 bottom)
- The panels were moved back into place resting on 3/8" thick aluminum spacers (see attached photo).  These replaced spacers of the same size and material that were slightly corroded

The following tasks remain to be completed:

- Install panel spacer rods (mild steel rods to be replaced with SS or Al)
- Apply sealant to all panels from outside the tank as detailed in the procedure using 20oz pneumatic applicator caulk gun (PO: TR206556)
- Install corrosion inhibiting pads inside tank.  Will use 6 pads per tank, (4x McMaster 3609K2 & 2x McMaster 3590K2 per tank)
- Perform final clean of inside of windows and tank
- After 14 days cure time fill tanks with city water and allow to sit to check for leaks
- If leak tight, use water in tanks to back-flush the sand filter
- Refill tanks and start pump with filter in normal mode
- Occasionally check for water leaks and check status of pitting inside tank over the coming months/years
- Also monitor corrosion inhibiting pads and replace or change materials if necessary

Summarized Seal Replacement Procedure provided by Aquarium Technology Ltd:

1) Cut out the viewing panel entirely and mechanically clean all sealant traces from both the panel and the frame bearing faces of the tank structure

2) Degrease all sealing surfaces with something like pure petroleum spirit (mineral spirit) which won't harm the acrylic

3) Reinstall the clean viewing panel spacing it off the frame bearing face by around 10mm using self adhesive rubber stand-offs  (depending on panel flatness likely no more than 3 needed along the top and bottom)

4) Brace the panel in place, mask off the frame and panel, and then inject Dow Corning 791 sealant from the outside.  Ensure that the sealant goes in under pressure, fully wets both surfaces, and completely fills the void.

5) Allow the sealant to cure for 10-14 days before filling the tanks

The warm cell water window tanks were filled on September 17 after 2 weeks of curing time.  A water leak was found coming from the seals of a plastic pipe joining the two tanks near the top.  This was repaired using rubber gaskets and quick cure caulking.  The tank was refilled on September 18 and no longer leaked from that location.  The sand filter was backflushed with the water exhausted to the grass area outside the hot cell lab until the water ran clear.  The pump was then started with the water circulating normally through the filter.  Small water leaks were observed coming from 3 of the 4 plastic ball valves on the filter loop piping.  These leaks stopped after approximately 3 days of continuous running, and are still leak tight now.

During this repair job it was observed that the support wheels for the warm cell manipulators are crumbling and should be replaced before the next time the manipulators are used.

A trial run of remote removal of the UCN target was performed using the shielded target cask (TTA0335) developed in 2020.  The work took place between Feb 9 - 17 under work permit C2021-02-09-1.

The procedure in work instruction Document-187117 R1 was followed. Draining and purging of the water system as well as venting of helium from the target crypt was performed by Tony Hessels.  The remainder of the procedure was carried out by Keith Ng, Maico Dalla Valle, and Isaac Earle.  A maximum field of 1.7mSv/hr was measured at 0.5m from the bare target;  This is higher than the approximate 500uSv/hr field that was expected, however dose incurred during the work was minimal (Isaac: 0.05mSv, Maico: 0.03mSv, Keith: 0.03mSv).

The cask aligned well to the target arm and no modifications to the cask or UCN hardware were required to carry out the procedure.  A few updates will be required to the work instruction document based on discoveries made during the procedure; notably: 

• Cask to be installed on the west side of where the water tubing connections for the crypt flange are located;  As a result the cask lid will be installed after the cask base (with target forearm inside) is removed from the rails
• Shims are not required under blocks TTA0550 and TTA0555 in order to clear the top of the cask (the concrete and steel supports for these blocks are higher than in the UCN area shielding model)
• In addition to the six 3/8"-16 bolts for the water manifold, two shoulders screws (one on each side of the manifold) must also be removed to allow the two halves to separate

The work instruction document will be updated to include the changes above, as well as other minor updates and extra figures. 

After testing, the target forearm was reinstalled and all connections re-made.  Leak checking of the water connections and crypt flange as well as testing of the target thermocouple signals is to be arranged by the UCN Group.  The cask has been stored on top of concrete shielding on the B2 level north-east of the UCN experimental area.

Various photos taken during the procedure are attached.

Uncovered T2 monolith and transferred M20BB to hot cell using flask.

Field at 0.5m from beam blocker while being lifted with flask: 21,700μSv/hr (using pole monitor) 

Field above hole after removing M20BB: 9000μSv/hr

The level sensor for the active sump in the RH lab was tested.
The level sensor is working properly and is operational.
 

blah blah blah.... fjda;jfeowifjoajglfa;nafg