Dave Pushka

1
Flare Liquid Argon Off-Axis Detector Tank

• Will It work Yes!
• Tank is 90 identical to the hundreds of LNG and
  LN2 double wall cryogenic tanks built world wide
  by multiple construction contractors.
• Materials of construction (9 Nickel steel) are
  completely understood and have been since the
  1950s.
• Steel plate thickness increases due the higher
  specific gravity of LAr (LAr s.g. 1.4 verses
  0.6 for LNG or NH3 ) have been understood for at
  least a century.
• Flare tank is smaller (at 225,000 bbl) than the
  largest LNG tanks (_at_ 1,000,000 bbl) but larger
  than many petrochemical (ethane, butane, propane,
  butadiene, ammonia) tanks.
• Heat Leak for a standard insulated tank is well
  understood
• API 620 Q is the applicable code for these tanks.
  

2
Flare Liquid Argon Off-Axis Detector Tank

• What will it cost
• Budget Cost of Standard suspended deck tank
  11,000,000
• Inflation of budget cost by 20 2,200,000
• Inflation of old estimate due to steel market
  2,600,000
• Inflate to reflect a double roof tank (not
  s.d.) 2,000,000
• Non-standard Flare specific tank requirements
• Elevator to attic 800,000
• Stairways (4) 1,000,000
• Habitable Attic 17,000 sf _at_ 300/sq ft
  5,100,000
• Door Sheets 200,000
• Access Ways 200,000
• Detector Support Structure 6,000,000
• Work Platforms for detector installation
  1,000,000
• Total Estimate (with all standard caveats)
  32,100,000

3
Flare Liquid Argon Off-Axis Detector Tank

• What is Known
• Desired Volume (tank capacity and aspect ratio)
• Loads from the sense wires and sense wire weight
• Allowable deflections on the roof and tank walls
  due to detector loads
• Materials of construction suitable for the cold
  detector specific structural elements
• Suitable non-destructive examination (NDE)
  techniques to use to compensate for the fact that
  hydro-testing of the inner tank does not exceed
  (or match) the static loads from the LAr due to
  the high specific density of the LAr
• Physicist desires for electronics and access to
  electronics at the top of the tank, between the
  inner and outer roofs.

4
Flare Liquid Argon Off-Axis Detector Tank

• What is Known
• Tank and Mechanical Loads from High Voltage
  system (but current estimates are being refined)
• Heat Leak due to detector feed thru and wiring
  (but may change as designs develop)
• Relative cool-down rate of the detector (fast
  time constant) and the tank (slow time constant).
  Believed to be understood and not likely to
  result in wire breakage.

5
Flare Liquid Argon Off-Axis Detector Tank

• What is Unknown
• Soil conditions (site information not yet
  received) which is necessary for proper
  foundation design and an accurate cost estimate.
• Site topography which is necessary for performing
  a vapor dispersion study for the accidental
  release of LAr from the tank due to an accident.
• Construction cost changes due to the site
  accessibility (this may increase or decrease the
  actual costs by a few percent).
• Loads applied to the tank structure from the High
  Voltage planes and field shaping structure
  (estimated to be 20 of the total)
• Best design (we have a workable conceptual
  design) for the structural members used for
  supporting the top of the detector.
• Optimum number and locations of door sheets and
  temporary access ways to be used during detector
  construction.

6
Flare Liquid Argon Off-Axis Detector Tank

• What is Unknown
• Tank heat leak (known relatively well) and
  refrigerator sizing (known) Fixed versus
  operating cost / benefit analysis
• Thermal insulation versus electrical power
  infrastructure
• Heat leak due to detector feed thru and wiring
  and chimneys
• Tank temporary openings and detector installation
• Tank cleaning pre and post detector construction
• Walking-working surfaces for detector
  construction
• How wind and other loads on the outer tank affect
  the detector
• Ullage space / refrigerator controls / detector
  readout wire length
• Ventilation of the attic versus ODH
  classification

7
Flare Liquid Argon Off-Axis Detector Tank

• Full Detector Design Development Plan
• We intend to develop a complete conceptual design
  of the tank and detector (designer effort for
  developing a solid model has only just started in
  the last few hours)
• Details addressing reasonable solutions to the
  unknown items (construction access, optimum
  roof structure, chimney locations, high
  voltage plane and field shaping loads, tank shell
  stiffeners, dimensions of the electronics attic,
  ullage space, requirements for cleaning of tank,
  internals needed for detector construction
  including life safety, etc.) will be developed
• Scott Menary is pursuing site specific
  information such as soil bearing capacity,
  topography, etc.
• Cost estimate will be updated to reflect the
  details worked out in this tank design
  development plan.

8
Flare Liquid Argon Off-Axis Detector Tank

• How to Measure the Unknowns
• Unknowns are two types
• Unresolved design details - these will be covered
  by the steps in the preceding Detector
  Development Plan
• Site specific information needed for foundation
  design and vapor dispersion studies - these
  criteria have been assigned to Scott Menary
  (along with other site specific questions) for
  answers.
• We do not yet know about the unknown unknowns but
  will develop a plan for addressing them when the
  unknown unknowns become known unknowns.

9
Flare Liquid Argon Off-Axis Detector Tank

• Disaster Scenarios (During Construction)
• Adequate provisions for installing the detector
  safely are not included in the initial design and
  result in a schedule delay while corrective
  measures are implemented.
• Poor planning of the detector installation
  sequence requires either
• Longer duration for detector construction
• Higher detector installation labor costs
• Additional temporary tank access port
  installations
• Construction accidents by either our tank vendor,
  site prep contractor, or ourselves.

10
Flare Liquid Argon Off-Axis Detector Tank

• Disaster Scenario (In Operation)
• The absolute worse case disaster scenario is the
  uncontrolled rapid release of Liquid Argon
• Potential for Loss of life
• Significant financial loss (value of the LAr)
• A similar event happened with LNG in the 1940s
  in Cleveland which led to the development of 9
  Ni steels for cryogenic applications
• Standard Industry Mitigation Measures include
• Spill Control Berm (Included in our design)
• Vapor Dispersion Studies (planned work)
• Roll Over (which may be possible with a single
  component liquid) of the tank contents could
  release large quantities of gaseous argon.
• Solution will be addressed by adequate mixing of
  the contents as is done with LNG facilities.
• Loss of Argon would NOT require an environmental
  clean-up.

11
Flare Liquid Argon Off-Axis Detector Tank

• Assembly-
• Assembly of the tank (foundation, outer tank
  floor shell roof, inner tank floor shell
  roof, internal structure specific to the
  detector, hydro-testing, NDE, insulation and
  re-opening of door sheets) would be performed by
  a contractor much as the fabrication of the
  Mini-Boone sphere was accomplished. This will
  take approximately 18 months.
• Detector Installation would follow with the tank
  contractor largely de-mobilized.
• Upon completion of the majority of the detector
  installation (at least completion of the portions
  requiring grade level access to the inner tank),
  the tank erector would re-mobilize, close door
  sheets and grade level man-ways, perform NDE on
  the new weld joints, insulate (or re-insulate),
  and close up the vessel.
• Purging and cool-down (refer to RLS talk).

12
Flare Liquid Argon Off-Axis Detector Tank

• Issues to Integrate
• Tank and Mechanical Loads from Detector
• Tank Heat Leak and Refrigerator Sizing Initial
  verses Operating cost / benefit analysis
  including electrical power infrastructure as well
  as electrical energy costs.
• Heat Leak due to detector feed thru and wiring
• Tank Temporary Openings and Detector Installation
• Tank Cleaning pre and post detector construction
• Walking-working surfaces for detector
  construction
• How wind and other external loads on the outer
  tank affect the detector
• Ullage space / refrigerator controls / detector
  readout wire length
• Relative cool-down rate of the detector (fast
  time constant) and the tank (slow time constant).
• Ventilation of the attic verses ODH
  classification

13
Flare Liquid Argon Off-Axis Detector Tank

• What will it cost
• Integration will be addressed during the design
  phase.
• Labor cost. Estimate 1/3 FTE for the duration of
  the design development. Not everything will be
  performed by one individual as the topics vary
  across several disciplines