[Hallb-engineering] Fwd: Lesson Learned "FML-15-0421 Subcontractors accidentally Cut an Energized15kv Cable"
tilles at jlab.org
Thu Jun 11 15:05:27 EDT 2015
----- Forwarded Message -----
From: "Tina Johnson" <cjohnson at jlab.org>
To: "Tina Johnson" <cjohnson at jlab.org>
Sent: Thursday, June 11, 2015 1:00:05 PM
Subject: Lesson Learned "FML-15-0421 Subcontractors accidentally Cut an Energized15kv Cable"
Jefferson Lab Lessons Learned : Print Lesson
FML-15-0421 Subcontractors accidentally Cut an Energized15kv Cable
Statement of Lessons Learned
1. The lab�s work, planning, and control (WPC) process does work; it is not just a paper exercise. Plan your work and then work your plan. This incident resulted in zero injuries and a major contributor in that outcome was the contractor working to their approved activity hazard analysis (AHA).
2. If an outcome is different than expected or is hampered by unknowns or a difficult work environment, then a re-adjustment of the work plan may need considered. Stop work, gather all the known and unknown information, and then re-evaluate your plan/procedure.
3. The host employer (Jlab in this case) should inform the contract employers of certain information, relevant to the work to be performed and the safety thereof, before work begins. This transfer of information, to be made available to the contract employers, is to provide information about the design and operation of the host employer�s electrical distribution installation.
Discussion of Activities
On April 21, 2015, an electrical subcontractor for the Utilities Infrastructure Modernization (UIM) Project electrical upgrade project cut into a wrongly identified energized 15kV cable. The subcontractor�s procedure is to enter a downstream manhole and use compressed air to blow down into the conduit of the de-energized cables to determine which conduit in the manhole contains the cables to be cut. Using this method the conduit is identified, as water and mud are typically (because of the high water table) blown out of the end of the conduit into the manhole. The cable is then marked in the manhole, and a remote hydraulic cutter head is attached. The subcontractor electrician then exits the manhole and remotely actuates the hydraulic cutter after all workers are clear. On this cable�s conduit however, there was no visible water/mud ejection when the compressed air was applied. The worker in the manhole instead used his hand to sense the flow of air, and upon being convinced he had located the correct cable conduit, the hydraulic cutter head was attached and he exited the manhole. When the cutter was actuated, there was reportedly an audible concussion, arc flash, and smoke exited from the manhole. Work was discontinued by the subcontractor crew pending notification to management. There were no injuries, and electrical services to some campus locations were momentarily impacted. The fault condition was traced out and then additional lockout/tagout (LOTO) was applied to ensure an electrical safe work condition. At this point in time a �suspend work� was authorized and lab management met for an initial meeting.
Root Causes: Procedure Less than Adequate- Procedure did not identify actions to take should the checking mechanism not give obvious results and the process did not utilize an electrical means of identification.
Procedure needs improvement: identifying cables to be cut has no second checker mechanism (for when the first checking mechanism does not give obvious results) and/or the process does not utilize an electrical means of identification.
1) Failure to apply Knowledge: Manhole as-built were not made available and/or were not in existence for the contractor�s use.
2) Labels need improvement: Many of the existing cable tags were illegible and/or information not appropriate (somewhat ambiguous) for the current electrical distribution layout.
3) Failure to apply Knowledge: Reference site drawings were not made available for the contractor�s use.
4) Work environment (manhole): The work environment may have contributed to poor human performance. The typical work environment inside a manhole at the site is challenging and may have been a contributing factor to the difficulty of the work task of cable identification. The manholes are wet, dark, cramped and sometimes obstructed from free movement, and made noisy from the peripheral equipment (gas generators and confined space blowers that are running during the confined space access).
1. Review and update, if needed, the identification procedure and AHA .
2. Submit a contract modification to have YRE to provide the lab with manhole as-builts on the manholes that they have/will enter under the UIM Electrical Distribution Upgrade project.
3. Submit a contract modification to have YRE to provide the lab with a more robust (to better withstand the environment that they will reside in) cable tag in the manholes that they have/will enter under the UIM Electrical Distribution Upgrade project. �Cables shall be identified by tags that are corrosion resistant and suitable for the environment in which that are installed. The quality of the tag must be good enough to read with portable lighting�. [National Electrical Safety Code-NESC]
4. Add any available (including the ones that are provided under the UIM project) manhole as-built to the site electrical distribution reference drawings. On future projects that involve electrical manhole access/work, make these reference drawings available to the contractor. �The host employer (Jlab in this case) should inform the contract employers of certain information, relevant to the work to be performed and the safety thereof, before work begins. This transfer of information, to be made available to the contract employers, is to provide information about the design and operation of the host employer�s electrical distribution installation.�[190.269 & 1926.950 OSHA]
5. Review the confined space training and determine if mention of this possible difficult work environment condition is warranted.
6. Review and research the cable identification procedure used at other DOE sites and also with other employers that are involved with underground medium/high voltage type work.
7. Clarify the language on the AHA to specify �test the cables�, to �test the cables at terminals� and verify LO/TO._ Ensure that the AHA captures actual work being performed and that the AHA references the contractor�s procedures.
8. Add a step to the AHA to ensure there is a review of available as-built drawings for cable identification prior to the start of work.
JLab Preventive Measures
Captured in the corrective actions above.
6/11/2015 12:52:00 PM by Johnson, Tina
See above note
6/11/2015 12:51:44 PM by Johnson, Tina
SMEs approved Lessons learned. Please share within your work group.
Summary Lesson ID: 891
Safety Related: NO
Originator: Johnson, Tina
Issued: 6/10/2015 10:37:28 AM
Approved By: Johnson, Tina
Approved On: 6/11/2015 12:51:44 PM
Source: TJNAF NE
Contact: Todd Kujawa
Queued Emails: 0
Sent Emails: 0
Viewings: 57 times Attachments
* Oxygen Deficiency Hazards (ODH)
* >50 amps OR >50 Vac OR 60Vdc AND >5 mA
* AC Electrical Equipment
* Stored energy >10 joules, capacitive, inductive, or battery
* SAF603: SAF603A FPA-70E BASIC ELECTRICAL TRAINING
* SAF603A: ELECTRICAL SAFETY AWARENESS
* SAF603N: NFPA-70E BASIC ELECTRICAL SAFETY
* SAF604: HIGH VOLTAGE IN R&D
* SAF603S: NFPA-70E for Supervisors
* SAF603M: NFPA-70E for Managers
* SAF603N1: ARC FLASH:LIVE to TELL! (ELE016EFV)
* SAF603N2: Electrical Safety:Beware of the Bite (ELE5EFV)
* SAF603N3: Electrical Safety for the Qualified Worker (ELECEFV)
* *Division Safety Officers (DSOs)
* *Safety Wardens
* *DOE Notification
* *ESH&Q Liaisons
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