Notable Event at Jefferson Labs Central Helium Liquefier

Notable Event at Jefferson Lab’s Central Helium Liquefier Pressurized U- Tube Near-Miss Bert Manzlak, CSP

Thomas Jefferson National Accelerator Facility one of 17 national laboratories funded by US Department of Energy

Where is Jefferson Lab Newport News, Virginia 900 miles / 1450 km 14 hours drive Femi Lab 370 miles / 600 km 7 hours drive New York City 180 miles / 290 km 3 hours Washington, DC

Jefferson Lab Located in Newport News, Virginia is 5 - 45 minutes from: Norfolk / 30 Newport News / 5 Williamsburg / 30 Virginia Beach / 45

12 Ge. V Upgrade Project The completion of the 12 Ge. V Upgrade of CEBAF was ranked the highest priority in the 2007 NSAC Long Range Plan. New Hall Upgrade arc magnets and supplies Add 5 cryomodules CHL upgrade 20 cryomodules Add arc 20 cryomodules Add 5 cryomodules Enhanced capabilities in existing Halls • • $338 M DOE project (FY 09 -17) $9 M Va. contribution Currently - Nnearing completion Commissioning – In progress

Central Helium Liquifier

Portion of CHL #1

U-Tube / Bayonet Near Miss Event CEBAF 12 Ge. V cryogenic system upgrade evolution – remove and installing U -tubes (and bayonets) More than one this day One a “No Fit” needing machining … a decision to continue with the next two THEN began the MISCOMMUNICATIONS SEQUENCES

Senior CHL operator Three person crew Supervisor Lead engineer Crane operator Systems engineer

Engineering Drawing / Dummy Bayonet

Event Summarized • Original bayonet work plan changed • The plan changed however the step sequence was not revisited • Communications was less than adequate between working crew / Supervisor / field engineer and control room operator • Result - wrong bayonet location was identified

Event Summarized • After retaining cap was removed from top of flange the stainless steel (dummy bayonet / cap) ejected upwards ~ 25 feet (7. 62 m) Landing ~ 3 feet (0. 91 m) from crew Its size: 3 inches (76. 2 mm) diameter 3. 5 feet (1. 07 m) length ~ 25 lbs. (~ 11. 3 kg) weighs

The Notable Event • The cryogenic header being worked on: – Operational pressure (at the time of event) 3 atmospheres (~ 304 KPa) – Safe removal pressure (historical) 1 - 1. 5 atmospheres ( ~ 152 KPa) There were no injuries

After the Event • Event reported to ESH&Q Division / Laboratory Director / Department of Energy • Engineering Management Stopped ALL work on U-tubes Prior to Restart Complete & sign off on a NEW first ever Operational Safety Procedure “Bayonet Installation and Removal”

After the Event • All Hands Meeting with the Engineering Division Cryogenic Group • Review new OSP and Lessons Learned • Work Control (CHL work list) generated CTLis – “Continued CHL 1/CHL 2 U-Tube Configuration” / OSP • Engineering Division “Stand Down” Review work control documents

Event Investigation • Internal formal investigation team assembled (five members) • JLab Notable Event Report (ENG-13 -1023) – Root Cause – Contributing Causes – Extent of Condition – Corrective Actions – Lessons Learned – Associate Director (signature) Acceptance/Acknowledgement of Facts

Root Cause Communication - Less than Adequate (LTA) Hand gestures were made to indicate the next work location. This vague indicator allowed the lead engineer and technical leader to misunderstand which bayonet was to be removed

Contributing Causes • Human Performance (LTA) (Skill Based Error) – Failure to follow their (un formalized) work practices – confirming proper location/pressure of the new bayonet location prior to start of rework • Work Planning (LTA) No formal Task Hazard Analysis, OSP / Only desktop procedures

Contributing Causes • Work Planning (LTA) Schedule was a contributing factor. Lead operator was trying to take on too many tasks / multi-tasking while in the control booth. Not fully focused and had he been would have been on the floor sooner and potentially able to recognize the error • Design (LTA) No method to verify on the floor, that bayonet was or not energized, reliance on information from Control Room

Extent of Condition Conduct an extent of condition check on Physics Division operations – A new Operational Safety Procedure “Physics Division Cryogenic Bayonet Installation and Removal” Highest Risk Code Before Mitigation - 3 Highest Risk Code After Mitgation - 2

Corrective Actions • Develop and approve OSPs for U-Tube Operations Activities • Conduct all-hands meeting with Cryogenic Group and review OSP and Lessons Learned • Close out CTLis (work planning tool) and re-enter “Continues CHL 1/CHL 2 U-tube Configuration) – (including new work procedure and OSP)

Corrective Actions • Install “Nupro” type valves on Cryogenic bayonet flanges (with available ports) at first opportunity • Write new work procedure to handle valves w/o local valve pressure reading that involves restraints

Lessons Learned • When possible, pressure systems should have method of confirming the presence of hazardous store or residual energy local to the equipment and planned task. • Use work planning tools, especially when multiple work groups. Consider check lists / equipment maps with formal procedures. • When designing system that may be a source of potential hazardous energy, consider local shut off and monitoring mechanisms for works to confirm safety of the task.

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