# Presentation: 118323

## 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 1950’s.
- 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 (@ 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.

## 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 @ $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

## 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.

## 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.

## 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.

## 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

## 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.

## 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.

## 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.

## 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 1940’s 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.

## 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).

## 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

## 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