{"operation":"document","citation":"PHMSA FIR, Williams Partners Operating LLC, 2014-03-31","title":"Failure Report- Williams Partners Operating LLC 3/31/14","source_type":"incident","agency":"Pipeline and Hazardous Materials Safety Administration","status":"historical","official":true,"published_on":"2016-04-29","effective_on":"2014-03-31","summary":"Williams Partners Operating LLC; Natural Gas; WA; failure 2014-03-31; apparent cause: Incorrect Operation.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-fir-failure-report-williams-partners-operating-llc-33114.json","markdown":"https://regulus.evalyn.ai/document/phmsa-fir-failure-report-williams-partners-operating-llc-33114.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-fir-failure-report-williams-partners-operating-llc-33114","source_url":"https://www.phmsa.dot.gov/safety-reports/failure-report-williams-partners-operating-llc-33114","body":"<<<PAGE 1>>>\n\nFailure Investigation Report – Liquefied Natural Gas (LNG) Peak Shaving Plant, Plymouth,\nWashington\nDOT US Department of Transportation\nPHMSA OPS Pipeline and Hazardous Materials Safety Administration\nOffice of Pipeline Safety, Western Region\nWUTC Washington Utilities and Transportation Commission (PHMSA Interstate Agent)\nPrincipal Investigator Scott Rukke, WUTC\nSenior Accident\nPeter Katchmar, PHMSA\nInvestigator\nRegion Director Chris Hoidal, PHMSA\nDate of Report 4/28/2016\nSubject Failure Investigation Report – Liquefied Natural Gas (LNG)\nPeak Shaving Plant, Plymouth, Washington\nOperated by Williams Partners Operating, LLC\nOperator, Location, & Consequences\nDate of Failure 03/31/2014\nCommodity Released City/County & State OpID & Operator\nName\nNatural Gas (both in liquid and gaseous states)\nPlymouth (Unincorporated)/Benton County, WA\n39054 - Williams Partners Operating LLC\nUnit # & Unit Name 1155 – Williams Partners, Plymouth LNG\nSMART Activity # 149816\nMilepost / Location Milepost 175.0\nType of Failure Operator Error - Vessel and piping failure from detonation caused\nby internal auto-ignition due to a purge that failed to remove a gas-\nair mixture from the system.\nFatalities 0\nInjuries 5\nDescription of area\nimpacted\nTotal Costs $45,749,300\nContained within the plant grounds except for some ejected debris\nthat caused damage to the adjacent railroad tracks.\nPage 1 of 11\n\n<<<PAGE 2>>>\n\nFailure Investigation Report – Liquefied Natural Gas (LNG) Peak Shaving Plant, Plymouth,\nWashington\nExecutive Summary\nOn Monday, March 31, 2014, at approximately 8:19 a.m. PDT, the Plymouth-Liquefied Natural\nGas (LNG) Peak Shaving Plant experienced a catastrophic failure and a resulting explosion on a\nportion of the facility’s LNG-1 purification and regeneration system. The failure occurred during\nroutine annual liquefaction startup operations. The failure initiated in the piping between adsorber\nvessel D20A and the salt bath heater D-40 used to heat the gas for adsorber regeneration. Five\nemployees were injured and treated on site and one employee was flown to the hospital for\nadditional treatment with burns. An emergency shutdown was activated and plant personnel were\nevacuated.\nDebris from adsorber D20A and the associated piping caused extensive damages to the\nsurrounding plant facilities, including penetration of the outer shell of the LNG-1 storage tank, a\ndent to the inner shell of the LNG-1 storage tank, the air scrubber to the Saturn Turbine\ncompressor, above ground gas transmission piping at the compressor station, the LNG-1\nrefrigerant tower, regeneration compressor and coolers, boil-off compressor, various plant\ncommunication systems and cables, backup generator, and the surrounding buildings and\nstructures including the control room. Furthermore, the Burlington Northern RR tracks which were\nlocated outside plant grounds were damaged by ejected debris.\nThe penetration of the outer shell of the LNG-1 storage tank caused the Perlite insulation between\nthe annulus of the inner and outer tanks of the storage tank to be compromised, thereby allowing\nLNG “boil-off” gas to escape. Boil-off gas is the product of the constantly vaporizing LNG\npresent in the inner tank which is open at the top. It was unknown whether boil off gas was\noriginating directly from a debris-caused penetration of the inner tank shell of LNG-1 or was\nmigrating through the top of the inner tank, through the annulus between the two tanks, and out the\npenetration of the outer tank. Regardless, a decision was made to evacuate the town of Plymouth\nand the surrounding communities within a two-mile radius. It was later confirmed that the inner\ntank of LNG-1 was not penetrated. The inner tank did sustain a minor dent, which was repaired.\nAdditionally, a protruding one half-inch diameter instrumentation pipe located near the bottom of\nthe LNG-1 tank was damaged. This allowed LNG to release in a spray and vaporize. There was\nno pooling of the LNG and there was no resulting vapor (methane) cloud that left the plant. As\nsoon as the plant was made safe, Williams’ personnel donned cryogenic suits, entered the facility\nand closed the valve between the damaged pipe and LNG-1 tank wall, shutting off the LNG release\nat the tank. The release continued for approximately 25 hours and an estimated 9.3 barrels per\nhour or a total of 234 barrels was released.\nThe Washington Utilities and Transportation Commission (WUTC) and Pipeline and Hazardous\nMaterials Safety Administration (PHMSA) responded to the event and conducted a combined\ninvestigation into the apparent and contributory causes of the failure.\nThe apparent cause of the failure was determined to be the auto-ignition of a gas-air mixture left in\nthe piping after the pack and purge that was conducted on March 18, 2014. This pack and purge\noccurred 13 days prior to liquefaction start-up.\nPage 2 of 11\n\n<<<PAGE 3>>>\n\nFailure Investigation Report – Liquefied Natural Gas (LNG) Peak Shaving Plant, Plymouth,\nWashington\nPipeline System Overview\nThe Plymouth Peak Shaving Plant is a storage facility in the middle of the Williams Northwest\nPipeline System, a primary artery for the transmission of natural gas to the Pacific Northwest and\nIntermountain Region. The pipeline is an approximately 3,900-mile, bidirectional transmission\nsystem crossing the states of Washington, Oregon, Idaho, Wyoming, Utah, and Colorado.\nNorthwest's system provides access to British Columbia, Alberta, Rocky Mountain, and San Juan\nBasin gas supplies.\nThe LNG plant is a peak shaving storage facility that takes gas from the pipeline system in the\nspring and summer months, liquefies it, stores it, then vaporizes it during periods of high demand\nin the fall and winter months. The process of liquefying natural gas reduces the gas volume 600 to\n1. That is, 600 cubic feet of natural gas becomes 1 cubic foot of LNG, and vice-versa, 1 cubic foot\nof LNG will expand to 600 cubic feet of natural gas when vaporized. The LNG process allows for\nan economic way to store natural gas for vaporization and distribution at a later date when demand\nincreases.\nThe Plymouth LNG Peak Shaving Plant\nThe Plymouth plant consists of two separate LNG plants, LNG-1 and LNG-2. There is a\ncompression station inside the plant fence consisting of four reciprocating compressors and one\nSaturn Turbine compressor. The LNG portion of the plant is a peak shaving facility that takes\npipeline natural gas from the Northwest Pipeline (NWPL) interstate transmission system, removes\nCO2 and water vapor, then liquefies and stores the product (methane) for future vaporization and\ncompression back into the NWPL system during periods of peak demand. It includes two 90 foot\ntall storage tanks with a capacity of 1.2 billion standard cubic feet (Bscf) (14.5 million gallons) of\nLNG each. The liquefaction process consists of two, 6 million cubic feet per day (MMCFD)\nrefrigeration towers, each operated as an integrated cascade loop system. The facility includes\nfour (4) vaporizers rated at 75 MMCFD. LNG boil-off within the storage tanks is captured and re-\ninjected into the pipeline system. LNG-1 was placed in operation in 1975 and LNG-2 was placed\nin operation in 1979. Both LNG-1 and LNG-2 share the use of the four vaporizers.\nLNG-1 Purification and Regeneration System (Failure Origin Site)\nThe purification and regeneration system is a subsystem of the LNG process consisting of two\nmolecular sieve adsorber towers, a regeneration gas heater, also referred to as the salt bath heater\n(SBH), a regeneration compressor, hot and cold dust filters, and associated pipe and valving. The\nsystem removes water vapor and CO2 prior to the gas being liquefied.1\nThe adsorption process occurs as a precursor to the liquefaction phase of operation. It is a time\nbased cycle between the two adsorber towers which allows one adsorber to remove water and CO2\nand the other adsorber to regenerate or be cleaned using gas that has been heated by passing\nthrough the gas heater. This process ensures that a continuous stream of purified gas enters into\nthe refrigeration towers where the liquefaction occurs.\n1 In order to liquefy, natural gas needs to be almost pure methane. Adsorbers are vessels which contain media that\nremoves carbon dioxide and moisture when the pipeline quality natural gas is passed through them. Adsorbers are also\nknown as molecular sieves.\nPage 3 of 11\n\n<<<PAGE 4>>>\n\nFailure Investigation Report – Liquefied Natural Gas (LNG) Peak Shaving Plant, Plymouth,\nWashington\nThe regeneration cycle initiates when one of the two adsorbers times out during purification. The\ninlet and outlet valves for the standby adsorber open to allow passage of the feed gas stream which\nthen brings that adsorber on-line. The inlet and outlet valves of the adsorber to be regenerated\nclose and the regeneration inlet and outlet valves open. A lateral from the main feed gas discharge,\ndownstream of the adsorber gas filter, allows a portion of the feed gas to pass through the\nregeneration gas heater. The discharge of the regeneration gas heater passes through the adsorber\nselected for regeneration. The passage of the heated gas allows the release of the impurities from\nthe media. The heated gas then carries the impurities out of the adsorber. Discharge from the\nadsorber then passes through the regeneration gas filter and cooler before entering the regeneration\ngas compressor. The regeneration gas compressor pressurizes the gas stream to the main pipeline\npressure and discharges to the boil-off and regeneration gas header and returns it to the pipeline.\nEvents leading up to the Failure\nThe following is a timeline of the significant events that led up to the failure that occurred on the\nmorning of March 31, 2014. This information was excerpted from pages 5-6 of the Root Cause\nFailure Analysis (RCFA) submitted by Williams dated October 29, 2015.\nPHMSA/WUTC added emphasis by [ … ].\nNovember 1, 2013 – Three manual valves were removed around hot dust filter (D-45) allowing air\n(containing 20.9% Oxygen) to enter the LNG-1 purification and regeneration system.\nMarch 18, 2014 – Three manual valves were installed around D-45 and pressure purging was performed\nfrom ~100 psig down to ~5 psig a total of three times [with natural gas]. Because the blowdowns for each\npressure purge were only done to ~5 psig instead of the industry recognized 0-1 psig, oxygen remained in the\nsystem. The valve configuration (see appendix B) outlined in the procedure combined with the nested piping\nconfiguration around the adsorbers also made blowing down to 0-1 psig a must. The system was left at ~5\npsig after the 3rd and final pressure purge. [A valve slowly leaked natural gas into the system after the purge.\nThe pressure rose to 53 psig and remained constant until March 31, 2014.]\nMarch 30, 2014 – Regeneration Salt Bath Heater (D-40) was started and slowly brought up to its full\noperating temperature of 550 degrees F.\nMarch 31, 2014, 7:48-8:08 a.m. –Plymouth operators pressure system up to 685 psig. This pressurization\nadded heat to the system due to the compression of the air and natural gas mixture still contained within.\nMarch 31, 2014, 8:14 a.m. – Regeneration compressor started and confirmed running.\nMarch 31, 2014, 8:15 a.m. – Plymouth Board Operator commands the system to align valves for normal\noperation using the distributed control system (DCS). As automated valves align they allow flow through the\nsystem.\nMarch 31, 2014, 8:15 a.m. – Shortly after the command is given via the DCS to align valves, [V400D on the\ninlet side of the Salt Bath Heater (SBH) opens and allows the gas-air mixture that was trapped on either side\nof this valve to flow] the flammable mixture of air and natural gas enters the D-40 salt bath heater where it\nauto-ignites. This ignition created a rolling detonation, against the flow of gas, through the flammable zone\nin the direction of the D-20A adsorber. The pressure wave generated by the detonation nearest D-20A then\nentered D-20A and failed the vessel by rapid over-pressurization releasing natural gas to the atmosphere\nwhere it ignited creating a large deflagration.\nPage 4 of 11\n\n<<<PAGE 5>>>\n\nFailure Investigation Report – Liquefied Natural Gas (LNG) Peak Shaving Plant, Plymouth,\nWashington\nMarch 31, 2014 – Immediately following the failure, the plant was shut down, evacuated, and incident\ncommand established with the help of local emergency responders.\nEvents on the morning of March 31, 2014\nNormal start time for all plant personnel is 6:30 a.m. At 6:45 a.m. an all-employee meeting was\nheld in the main administrative building to plan out the work week. It lasted approximately an\nhour. During the meeting, the start-up of the purification system for LNG-1 and LNG-2 was\ndiscussed. The schedule goals were to start LNG-1 on Tuesday, April 1, morning and LNG-2 on\nWednesday, April 2, morning.\nAfter the meeting, the employees involved in the purification loop start-up went through the policy\nand procedures manual and pulled the procedures for starting the liquefaction process for LNG-1.\nThe procedures were copied and provided to each employee. The employees went to the control\nroom to initiate the start-up of the purification loop for LNG-1. There were newer employees as\nwell as a couple of more experienced staff in the group. On-the-job training is an important\nmethod of ensuring that newer employees learn the correct actions for accomplishing different\ntasks at the plant.\nThree technicians went to the control room and the other two went to the compressor building.\nThe start-up procedures require the manual opening of different valves. Technicians in the control\nroom directed technicians in the field by radio to perform each separate step in the start-up\nprocedure. Once the purification system was pressured up, everyone but two technicians returned\nto the control room. The two technicians in the LNG-1 compressor building, adjacent to the\nadsorber towers, were to watch and listen for the start of the regeneration (Regen) compressor.\nThe compressor started and appeared to be running correctly for a minute or two. At this point,\none of the employees in the control room issued the command to start the regeneration process\nwhich aligned the valves in their correct orientation for purification. Valve D-400 (hot valve),\ndownstream of the salt bath heater (SBH) opened allowing the gas-air mixture to flow into the\nSBH where the mixture auto-ignited. The initial explosion caused the piping immediately\nupstream of the SBH to fail catastrophically. A rolling detonation occurred inside the piping from\nthe SBH propagating backward against the flow of gas until it reached the bottom of adsorber D-\n20A. The failed piping showed evidence that the pipe failure occurred from forces internal to the\npipe. The post-accident analysis showed there were multiple explosions inside the piping before\nthe pressure wave reached the adsorber, at which time the adsorber experienced a brittle failure.\nFrom the metallurgical analysis it was deduced that the adsorber failed due to an overloading event\nand there was no evidence of combustion internal to the adsorber. The pressure at the D-20A\nadsorber was estimated to have reached as high as 1,774 psig. Once the adsorber failed, the gas\nreleased then ignited, causing an explosion which propelled the pieces of the adsorber in all\ndirections.\nOne of the two employees who were in the compressor building sustained burns. He was able to\nextricate himself from the debris and walk to the administrative building, where other employees\nassisted with first aid. He was air-lifted to a hospital. Four other employees sustained minor\ninjuries.\nAfter the explosion, all of the employees evacuated the area. The station emergency shutdown\n(ESD) switch was pulled by one of the evacuating employees and the plant ESD switch was pulled\nby personnel in the administrative building.\nPage 5 of 11\n\n<<<PAGE 6>>>\n\nFailure Investigation Report – Liquefied Natural Gas (LNG) Peak Shaving Plant, Plymouth,\nWashington\nEmergency Response\nImmediately after the explosion, the plant manager called 911 to report it. The plant manager then\nwent back to his office and called Williams Gas Control and told them, “This is not a drill. The\nLNG Plant has experienced an explosion. There is fire and smoke in the adsorber area and there is\nblowing gas from the pipeline compressor area.” He then called Williams Director of Operations\nand told him about the explosion and fire. He then told the Field Office Administrator to start the\nevacuation process.\nAt 9:10 a.m., a representative of Umatilla County, OR, called the National Response Center,\n(NRC) (report number 1078318) and reported a natural gas explosion and fire. It was also reported\nthat approximately 200 private citizens were evacuated. As soon as PHMSA received this\nnotification, calls were placed to the Oregon Public Utilities Commission, who were not aware of\nthe incident. After a minute of discussion, when the Columbia River area was mentioned, it was\ndecided that the call more than likely had to do with the LNG facility near Plymouth, WA, directly\nacross the Columbia River from Umatilla, OR.\nAt 9:27 a.m., a representative from Williams Northwest Pipeline called the NRC (Report Number\n1078325). It was reported that at 8:31 a.m., an explosion occurred at a natural gas compressor\nstation (storage for LNG). The caller stated that the cause of the explosion was unknown, believed\nto possibly have been from a heater blowing up; there was an ongoing fire at the facility, and that\nthe plant had been evacuated; there was a reported injury, it was unknown whether the individual\nwas transported to a hospital, and injuries were believed to be minor.\nDuring this time, PHMSA personnel were in contact with WUTC, PHMSA’s State partner for\nnatural gas and hazardous liquid pipeline inspection in the State of Washington. WUTC had\nalready received a call from Williams and had already deployed an inspector to respond to the\nevent.\nDue to the 911 call, local fire departments, police agencies and county emergency services\npersonnel were dispatched to the LNG Plant. First on scene were firefighters and ambulances.\nAfter talking with the plant personnel, it was decided to move everyone to a more remote point. It\nwas also decided to evacuate citizens within an approximate two mile radius of the plant, which\nincluded most of the citizens of Plymouth, Washington. An incident command center was set up\nat the weigh station at the crossing of Hwy 14 and Plymouth Road. A representative from WUTC\narrived in the early afternoon of March 31, 2014, and a PHMSA representative arrived the next\nmorning. The investigation into the cause of the event was initiated.\nSummary of Return-to-Service\nWilliams has worked closely with WUTC and PHMSA during the investigation and the\nreconstruction of the LNG-1 side of the plant. All known contributory factors identified during the\ninvestigation were either “designed out” of the reconstructed LNG facility or were addressed by\nwriting and implementing new detailed procedural requirements.\nThe following changes were implemented to reduce the possibility of a similar accident recurring:\nPage 6 of 11\n\n<<<PAGE 7>>>\n\nFailure Investigation Report – Liquefied Natural Gas (LNG) Peak Shaving Plant, Plymouth,\nWashington\n1. Modification of the purge process to include piping and purge points designed to remove\nall possible dead-legs.\na. Design piping to ensure a full flow-through path for purge gas through the\npurification loop piping during the purge process.\nb. Implement detailed purge procedures to allow safe, successful and repeatable\nactions by employees.\n2. Combining the LNG-1 and LNG-2 purification loops into one purification loop with three\nadsorbers.\n3. Removal of the salt bath heater involved in the incident and replacement with a new “tight\nwound helical coil” heater that does not use a salt bath. This allows for more consistent\nheat distribution to the gas.\n4. Modification of the start-up procedure to start the process heater after the system has been\nbrought up to pressure and normal flow has been established.\n5. 6. 7. Moving the control room away from the process area.\nAdding additional archiving capability to plant control room systems.\nFull engineering review and analysis of process operating procedures.\nInvestigation Details\nWUTC and PHMSA collaborated on this investigation. WUTC provided continuous oversight of\nthe assessment and removal of the failed portions of the piping and adsorber of specific interest to\nthe metallurgists, and of the plant reconstruction and tank repair. PHMSA personnel monitored\nWilliams’ actions and remained in contact with WUTC throughout the accident investigation and\nthe plant reconstruction period. All employees who were at the plant on March 31, 2014, were\ninterviewed except the one individual who was admitted to the hospital. Original design\ndocuments, maintenance records, procedures, and records of modifications made over the years\nwere reviewed and analyzed. Williams contracted with different experts to analyze different\naspects of the event. WUTC and PHMSA have reviewed and analyzed all reports submitted. The\nfollowing was excerpted from the Williams’ RCFA, pages 4-5.\n“In response to the March 31, 2014 incident, Williams assembled an investigation team of various\ndisciplines including employees and consultants. This portion of the report describes the tasks of\neach consultant and how those results aided the investigation.\nABS Consulting (Evidence Preservation) – Brought on-site immediately to maintain chain of\ncustody of all evidence gathered during the investigation. With debris scattered throughout the plant\nsite, ABS Consulting was tasked with collecting, cataloguing and maintaining custody of all\nevidence.\nStress Engineering Services (Metallurgical Consultant) – SES performed metallurgical analysis\nof fragments from adsorber D-20A in their shop in Houston, TX and confirmed that proper\nmaterials and construction methods for the era in which the vessel was manufactured were used.\nAdditionally the report prepared by SES concluded that while there were multiple ‘points of\ninterest’ there was no combustion internal to D-20A, meaning that the vessel was likely exposed to\nrapid over-pressurization.\nPage 7 of 11\n\n<<<PAGE 8>>>\n\nFailure Investigation Report – Liquefied Natural Gas (LNG) Peak Shaving Plant, Plymouth,\nWashington\nFauske & Associated (Auto-Ignition Testing) – The Chicago based team was enlisted to perform\nAuto-Ignition Testing of natural gas at increasing pressures. Based on the Plymouth plant inlet\ncomposition the morning of the incident, Fauske tested a similar composition at pressures ranging\nfrom atmosphere (in order to prove their experimental setup) up to 700 psia (Plymouth Plant\npressure on the morning of the incident). They concluded that the auto-ignition temperature of\nnatural gas drops with increasing pressure and that at the pressures immediately preceding the\nincident auto-ignition could occur as low as at 680 °F.\nThe Williams’ investigation team reviewed this report and agreed with Fauske’s conclusions.\nABS Consulting (Blast Modeling) – While gathering evidence details, ABS generated a damage\nreport, noting where damage had occurred in the process area. ABS then created a 3-D model of\nthe process area and ran simulations of internal detonations at various locations throughout the\nprocess area while monitoring internal pressure throughout the system. That pressure data was then\nused to determine areas of expected damage based on each detonation location. The expected\ndamage was then compared to actual damage observed in the field, in particular 4” piping\nconnecting the adsorber to the Salt Bath Heater which had failed from the inside outwards rather\nthan by external impact. The best matching detonation location was on the inlet of the regeneration\ngas heater.”\nWilliams also contracted with additional experts to evaluate LNG-1’s storage tank for damage:\n DBI, Inc. Quality Inspection and Consulting Services – performed an out-of-service API-\n653 inspection on the LNG-1 tank.\n G2MT, LLC - was contracted to perform a residual stress analysis of a dented region on the\nLNG-1 tank.\n Stress Engineering Services (Metallurgical Consultant) – performed a Fitness- For-Service\nassessment on the dent in the LNG-1 tank prior to return-to-service.\nAll final reports submitted by the various consultants are on file with PHMSA.\nWilliams submitted an accounting of gas lost which is summarized in the table below on a\nmonthly as well as overall basis.\nPage 8 of 11\n\n<<<PAGE 9>>>\n\nFailure Investigation Report – Liquefied Natural Gas (LNG) Peak Shaving Plant, Plymouth,\nWashington\nInvestigators requested a summary of damaged facilities that occurred as a result of the LNG Plant\nevent. Following is an accounting of facilities impacted that was submitted by Williams:\n1. “Systems affected\na. T1 LNG Storage\ni. Incident debris penetrated the outer tank shell.\nii. LNG contained in Tank 1 was transferred to T2.\niii. Tank was warmed up, nitrogen purged, then air purged while being\nvented to atmosphere.\nPage 9 of 11\n\n<<<PAGE 10>>>\n\nFailure Investigation Report – Liquefied Natural Gas (LNG) Peak Shaving Plant, Plymouth,\nWashington\nb. BOG (Boil-off Gas)\ni. Piping from LNG tanks to BOG compression was damaged during the\nincident.\nii. LNG-1 BOG compression was damaged during the incident.\niii. LNG tanks T1 and T2 were vented to atmosphere while repairs were made.\nc. LNG Vaporization/Send-out\ni. PSV, recycle, and casing vent piping for three (five total) of the\nLNG send-out pumps returns to T1. Having T1 out of service renders\nthe pumps unusable.\nd. LNG-1 Liquefaction\ni. Damage was sustained to the cold box.\nii. Communications, lighting, power, and hazardous gas systems were\ndamaged in the incident.\niii. The LNG-1 motor building was extensively damaged and had to be\ndemolished.\niv. BOG, regen, and MR (Mixed Refrigerant) compression were\ndamaged in the incident.\nv. The control room and tech shop adjacent to LNG-1 were damaged.\nvi. Incident debris damaged the radiator for the emergency generator.\nvii. Piping and structural steel in the pipe rack adjacent to the incident\narea was damaged.\nviii. Plant office building was damaged by debris.\nix. Maintenance shop was damaged by debris.\nx. LNG-1 Adsorbers were damaged during the incident.\nxi. Air coolers for compression (BOG, MR, Regen) and regeneration\ngas were damaged in the incident.\nxii. Refrigeration process vessels were damaged in the incident.\ne. LNG2 Liquefaction\ni. Common process and utility piping systems to LNG-1 and LNG2 were\ndamaged during the incident.\nii. Cable tray at the LNG2 cold box was struck by incident debris.\nf. MR\ni. ii. g. Vent Gas\ni. i. Piping to LNG-1 and LNG2 was damaged during the incident.\nBOG piping to the MR Mix tanks was damaged during the incident.\nVent gas piping was damaged during the incident.\nh. NWP Pipeline Compression\nDamage was sustained to the Saturn air inlet filter, housing bellows, and\nbuilding.\nii. Damage was sustained to NWP compression piping.”\nPage 10 of 11\n\n<<<PAGE 11>>>\n\nFailure Investigation Report – Liquefied Natural Gas (LNG) Peak Shaving Plant, Plymouth,\nWashington\nFindings and Contributing Factors\nWUTC and PHMSA find the following:\nThe primary cause of this failure was a substandard purge performed after leaving the\nLNG-1 purification loop open to the atmosphere from November 1, 2013, to March 18,\n2014. A flammable gas-air mixture remained in the system which then entered the salt\nbath heater and auto-ignited during start-up.\nContributory Causes:\n1. 2. 3. 4. The start-up sequence in the written procedure contributed to the event. The start-up of the\nsalt bath heater combined with the rapid pressurization of the gas-air mixture in the system\nfrom 53 psig to 685 psig allowed conditions to exist that were within the temperature and\npressure range for auto-ignition to occur.\nThe purge and pack procedure utilized by the employees on March 18, 2014, did not\nprovide a sufficient amount of detail to assure successful and repeatable results.\nPrevious purge and pack operations may have at times utilized additional purge points at or\nnear the adsorbers.\nThe low toughness of the adsorber metal allowed it to fail in a brittle manner causing\nfragmentation.\nAppendices\nA Plymouth Final Report Photos\nB NRC Report #1\nC NRC Report #2\nD Operator Accident/Incident Report to PHMSA\nE Williams Root Cause Failure Analysis (On file with PHMSA)\nF ABS Consulting (Evidence Preservation) (On file with PHMSA)\nG Stress Engineering Services (Metallurgical Analysis) (On file with PHMSA)\nH Fauske and Associates (Auto-Ignition Testing) (On file with PHMSA)\nI ABS Consulting (Blast Modeling) (On file with PHMSA)\nJ DBI, Inc. Quality Inspection and Consulting Services (Out-of-Service API-653\nInspection) (On file with PHMSA)\nK G2MT, LLC (Residual Stress Analysis) (On file with PHMSA)\nL Stress Engineering Services (Dented Wall Assessment) (On file with PHMSA)\nPage 11 of 11\n\n<<<PAGE 12>>>\n\nPlymouth WA LNG plant overview. Approximate Two Mile Radius in Red Circle.\nPre-Event LNG Plant Overview.\nPage 1 of 11\n\n<<<PAGE 13>>>\n\nAerial view taken shortly after the failure. Looking South toward Columbia River.\nAerial view taken shortly after the failure. Fires still burning. Perlite insulation leakage from the penetrated\nouter LNG-1 storage tank. Control room lower left.\nPage 2 of 11\n\n<<<PAGE 14>>>\n\nView of the outer shell penetration of the LNG-1 storage tank, looking east. Leaking 1/2-inch LNG instrument\nline lower left side of tank. V-shaped ice formation above outer shell penetration. Perlite insulation on ground\nlower left.\nClose up of the pipe configuration where the spray of LNG was in the picture above.\nPage 3 of 11\n\n<<<PAGE 15>>>\n\nControl room – center left. LNG-1 compressor building center right, refrigerant tower to the left of the\ncompressor building. Natural gas fires from severed purification loop piping near the failed adsorber.\nView from inside the Compressor Building where 2 employees were listening for the compressor start-up. The\nfailed adsorber was on the outside of the back wall in this picture. The employee that was hospitalized with\nburns was in this area. Red arrow points to a hard hat.\nPage 4 of 11\n\n<<<PAGE 16>>>\n\nLooking SE towards the failure site from in front of the Control Room. One of the twin adsorbers lying on its\nside. Compressor building in center-back. Refrigerant tower top-left. Use burned truck as reference.\nView of the control room looking west. Use burned truck as reference.\nPage 5 of 11\n\n<<<PAGE 17>>>\n\nView of the failure site looking east from inside the control room.\nInside of the control room view through the window. Looking west.\nPage 6 of 11\n\n<<<PAGE 18>>>\n\nRemnants of the failed adsorber base center. Refrigerant tower top center. Large piece of debris from the\nfailed adsorber embedded in the center of tower.\nLNG-1 Salt Bath Heater where auto-ignition initiated. Red arrow indicates a failure point in the 4-inch heater\ngas inlet. The piping is blown outward and down. It would normally be behind the heater and up on the pipe\nrack. Looking Northeast. The LNG-2 storage tank in the background.\nPage 7 of 11\n\n<<<PAGE 19>>>\n\nAnother view of the Salt Bath Heater. The 4-inch gas inlet piping denoted with red arrows. The piping is\nblown to the left of the heater. Looking northwest.\nThe LNG-2 Salt Bath Heater which was identical to the LNG-1 Salt Bath Heater. The 4-inch inlet gas piping is\npainted black.\nPage 8 of 11\n\n<<<PAGE 20>>>\n\nLNG-1 and LNG-2 purification systems. Looking northeast. Undamaged LNG-2 adsorbers, refrigerant tower\nand Salt Bath Heater center left.\nLNG-2 Adsorbers – undamaged – identical to LNG-1 adsorbers pre-event.\nPage 9 of 11\n\n<<<PAGE 21>>>\n\nFailed piping reassembled in secured evidence yard placed in as close to original piping configuration as\npossible. Stakes are placed at pipe rack cross members. Close observation reveals numerous internal failures\nof the piping caused by “rolling detonation”. The 4” Salt Bath Heater inlet piping is placed next to the 6”\noutlet Salt Bath Heater piping. The pallets hold all of the small fragmented pieces of the 4” pipe.\nThis picture is in the opposite direction as the last picture. Notice the adsorbers in the background.\nPage 10 of 11\n\n<<<PAGE 22>>>\n\nOverview of evidence yard.\nPage 11 of 11\n\n<<<PAGE 23>>>\n\nTeleDetail http://hmis.phmsa.dot.gov/hmis/telephonics/Teledetail.aspx?showresul...\nHMIS->INCIDENTS->TELEPHONICS\n(Version 4.0.0 PROD ) Rules of Behavior Home Logout Menu\n[Return to Search]\nNRC Number: 1078318\nCall Date: 03/31/2014 Call Time: 12:10:00\nCaller Information\nFirst Name: Last Name:\nCompany Name:\nAddress:\nCity: State:\nCountry: Zip:\nPhone 1: Phone 2:\nOrganization Type: Confidential: Yes No No Response\nIs caller the spiller? Yes No No Response\nDischarger Information\nFirst Name: Last Name:\nCompany Name:\nAddress:\nCity: State:\nCountry: Zip:\nPhone 1: Phone 2:\nOrganization Type:\nSpill Information\nState: County:\nNearest City: Zip Code:\nLocation\nSpill Date: (mm/dd/yyyy) Spill Time: (24hh:mm:ss)\nDTG Type:\nIncident Type Reported Incident Type\nDescription\nMaterials Involved\nMaterial / Chris Name Chris Code Total Qty. Water Qty.\nNATURAL GAS ONG 1 CUBIC FEET 0 UNKNOWN AMOUNT\nMedium Type:\nAdditional Medium Information:\nInjuries: Fatalites:\nEvacuations: Yes No Unknown No. of Evacuations:\nDamages: Yes No Unknown Damage Amount:\nFederal Agency Notified: Yes No Unknown State Agency Notified: Yes No Unknown\nOther Agency Notified: Yes No Unknown\nRemedial Actions\n1 of 2 2/24/2015 9:42 AM\n\n<<<PAGE 24>>>\n\nTeleDetail http://hmis.phmsa.dot.gov/hmis/telephonics/Teledetail.aspx?showresul...\nAdditional Info\nLatitude\nDegrees: Minutes: Seconds: Quadrant:\nLongitude\nDegrees: Minutes: Seconds: Quadrant:\nDistance from City: Direction:\nSection: Township:\nRange: Milepost:\nRescinded Comments (max 250 characters)\n1..1 of 1\n2 of 2 2/24/2015 9:42 AM\n\n<<<PAGE 25>>>\n\nTeleDetail http://hmis.phmsa.dot.gov/hmis/telephonics/Teledetail.aspx?showresul...\nHMIS->INCIDENTS->TELEPHONICS\n(Version 4.0.0 PROD ) Rules of Behavior Home Logout Menu\n[Return to Search]\nNRC Number: 1078325\nCall Date: 03/31/2014 Call Time: 12:27:00\nCaller Information\nFirst Name: Last Name:\nCompany Name:\nAddress:\nCity: State:\nCountry: Zip:\nPhone 1: Phone 2:\nOrganization Type: Confidential: Yes No No Response\nIs caller the spiller? Yes No No Response\nDischarger Information\nFirst Name: Last Name:\nCompany Name:\nAddress:\nCity: State:\nCountry: Zip:\nPhone 1: Phone 2:\nOrganization Type:\nSpill Information\nState: County:\nNearest City: Zip Code:\nLocation\nSpill Date: (mm/dd/yyyy) Spill Time: (24hh:mm:ss)\nDTG Type:\nIncident Type Reported Incident Type\nDescription\nMaterials Involved\nMaterial / Chris Name Chris Code Total Qty. Water Qty.\nLIQUEFIED NATURAL GAS LNG 0 UNKNOWN AMOUNT 0 UNKNOWN AMOUNT\nMedium Type:\nAdditional Medium Information:\nInjuries: Fatalites:\nEvacuations: Yes No Unknown No. of Evacuations:\nDamages: Yes No Unknown Damage Amount:\nFederal Agency Notified: Yes No Unknown State Agency Notified: Yes No Unknown\nOther Agency Notified: Yes No Unknown\nRemedial Actions\n1 of 2 2/24/2015 9:45 AM\n\n<<<PAGE 26>>>\n\nTeleDetail http://hmis.phmsa.dot.gov/hmis/telephonics/Teledetail.aspx?showresul...\nAdditional Info\nLatitude\nDegrees: Minutes: Seconds: Quadrant:\nLongitude\nDegrees: Minutes: Seconds: Quadrant:\nDistance from City: Direction:\nSection: Township:\nRange: Milepost:\nRescinded Comments (max 250 characters)\n1..1 of 1\n2 of 2 2/24/2015 9:45 AM\n\n<<<PAGE 27>>>\n\nNOTICE: This report is required by 49 CFR Part 191. Failure to report can result in a civil penalty not to\nexceed 100,000 for each violation for each day that such violation persists except that the maximum civil\npenalty shall not exceed $1,000,000 as provided in 49 USC 60122.\nOMB NO: 2137-0522\nEXPIRATION DATE: 10/31/2017\nReport Date: 05/06/2014\n20140002\n-\nNo.\n15014\nU.S Department of Transportation\nPipeline and Hazardous Materials Safety Administration\n**updated - old value was\n15013\n--------------------------------------------------\n(DOT Use Only)\nINCIDENT REPORT –\nLIQUEFIED NATURAL GAS (LNG) FACILITIES\nA federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply\nwith a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a current valid\nOMB Control Number. Send comments regarding this collection of information, including suggestions for reducing the burden to: Information Collection\nClearance Officer, PHMSA, Office of Pipeline Safety (PHP-30) 1200 New Jersey Avenue, SE, Washington, D.C. 20590.\nINSTRUCTIONS\nImportant: Please read the separate instructions for completing this form before you begin. They clarify the information requested and provide specific\nexamples. If you do not have a copy of the instructions, you can obtain one from the PHMSA Pipeline Safety Community Web Page at\nhttp://www.phmsa.dot.gov/pipeline/library/forms.\nPART A - KEY REPORT INFORMATION\nOriginal: Supplemental: Final:\nYes\n**updated -\nReport Type: (select all that apply)\nYes\nold value\nwas\nNULL\nLast Revision Date: 03/25/2016\n1. Operator's OPS-issued Operator Identification Number (OPID): 39054\n2. Name of Operator WILLIAMS PARTNERS OPERATING LLC\n3. Address of Operator:\n3a. Street Address ONE WILLIAMS CENTER\n3b. City TULSA\n3c. State Oklahoma\n3d. Zip Code: 74172\n4. Local time (24-hr clock) and date of the Incident: 03/31/2014 08:19\n5. National Response Center Report Number: 1078325\n6. Local time (24-hr clock) and date of initial telephonic report to the\nNational Response Center (if reported): 03/31/2014 09:23\n7. Incident resulted from:\nUnintentional release of commodity Yes\nIntentional release of commodity No\nEmergency shutdown No\nReasons other than the above No\n- Describe:\n8. Commodity released: (select only one, based on predominant volume\nreleased) Natural Gas while being handled in gaseous phase\n- Other Commodity Name:\n9. Estimated volume of commodity released unintentionally - Thousand\nCubic Feet (MCF): 14,000.00\n10. Estimated volume of intentional and controlled release/blowdown -\nThousand Cubic Feet (MCF) 154,200.00\n11. Estimated volume of liquid spilled to the ground (Barrels):\n12. Were there fatalities? No\n- If Yes, specify the number in each category:\n12a. Operator employees\n12b. Contractor employees working for the Operator\n12c. Non-Operator emergency responders\n12d. General public\n12e. Total fatalities (sum of above)\n13. Were there injuries requiring inpatient hospitalization? Yes\n- If Yes, specify the number in each category:\n13a. Operator employees 1\n13b. Contractor employees working for the Operator 0\n13c. Non-Operator emergency responders 0\nForm PHMSA F 7100.3 Reproduction of this form is permitted\nPage 1 of 5\n\n<<<PAGE 28>>>\n\n13d. General public 0\n13e. Total injuries (sum of above) 1\n14. Was the LNG Facility shut down due to the incident? Yes\n- If No, Explain:\n- If Yes, complete Questions 14a and 14b: (use local time, 24-hr clock)\n14a. Local time and date of shutdown 03/31/2014 08:19\n14b. Local time LNG Facility restarted 03/15/2016 08:15\n- Still shut down? (* Supplemental Report Required)\n15. Was there an ignition? Yes\n16. Was there an explosion? Yes\n17. Number of general public evacuated: 150\n18. Number of operator/contractor personnel evacuated: 18\nPART B - ADDITIONAL FACILITY INFORMATION\n1. Facility Information:\nLNG FACILITY / PLANT\nName of LNG Plant / Facility Plymouth LNG Peak Shaving Plant\nNPMSLNG ID\nPlant / Facility Status In Service\nPlant / Facility Location\nState Washington\nLatitude\nLongitude\nProcess\nLiquefaction/Vaporization Rate (MMCF/D) at the time of the\nIncident 0\nNumber of Vaporizers in service at the time of the Incident 0\nTotal Capacity (MMCF/D) 300\nLNG Source (list all that apply)\nTruck\nRailroad\nShip/Barge\nLiquefaction Yes\nInterstat","truncated":true,"body_characters":48228}