Smoke Event in AGS Ring

1
Take 5 for Safety

• Smoke Event in AGS Ring
• Collider-Accelerator Department
• 3-10-2009

2
Smoke Event in AGS Timeline, March 4, 2009

• 0900 A-fan-house duct smoke detector reported
  to Maintenance Coordinator as impaired for metal
  grinding and welding work in I5 area of the AGS
  Ring
• 1100 - Walk down of job performed by Maintenance
  Coordinator with 2 welders and a RCD tech
• The issue of spray and use of welding blankets
  was specifically discussed
• One welder is the fire watch
• 1115 - Grinding of welds to remove old mounting
  plates starts
• HEPA filtered radioactive-material-vacuum used to
  collect most of the direct spray
• 1145 - Grinding completed no problems with spray
  or smoke noted
• 1200 Two welders leave for lunch no sign of
  smoke
• 1205 - RCD tech leaves for lunch no sign of
  smoke
• 1218 - Smoke detector alarm and Fire/Rescue
  initially responded to C-fan house
• 1231 - Nothing found at C-fan house, Fire/Rescue
  continues to investigate
• 1232 - Noted that the fire alarm computer
  indicates A-fan-house smoke as source of alarm
• 1233 - Employee reports smoke in south wiring
  tunnel going into the Westinghouse area
• 1330 Employee reports odor near I5
• 1400 - Fire/Rescue group locates source of the
  smoke smoldering pipe insulation at the I5 work
  area
• Command post moved closer to area
• 1500 - Fire/Rescue reports that the emergency
  situation in the AGS has cleared

3
Causal Analysis The Five Whys

• Problem Statement
• Work involving metal grinding in the AGS Ring
  causes pipe wrapping and insulation to smolder
• 1) Why did the smoldering occur?
• An ember from a nearby metal grinding process
  burned the pipe wrapping and went unnoticed by
  workers

4
Causal Analysis The Five Whys

• 2) Why were the pipe, the ember and the smoke and
  odor from smoldering insulation not observed?
• Pipe The smoldering pipe insulation was 7 from
  the work
• During the job site walk-down by the Maintenance
  Coordinator for combustible material and during
  the metal grinding work, the pipe was obscured
  from view
• Ember The welder and the fire watch were focused
  on the immediate work area
• The welder indicated to the Maintenance
  Coordinator that embers would not travel far due
  to using a thin blade
• Smoke and Odor The welders waited about 15
  minutes after the grinding work stopped and
  before leaving for lunch
• The odor was first observed by others about 30
  minutes after the welders left
• The smoke alarm in the fan house also occurred
  about 30 minutes after the grinding work stopped

5
Causal Analysis The Five Whys

• 3) Why didnt the fire watch wait 60 minutes?
• The welder and the fire watch felt that based on
  their experience, grinding work was not a
  significant fire-watch issue, grinding embers
  did not travel far and the Requirements Checklist
  on the Hot Work Permit applied to welding and not
  grinding

6
Causal Analysis The Five Whys

• 4) Why do the welders think this way?
• The Hot Work Permit is ambiguous about applying
  the Requirements Checklist to metal grinding
• There is unclear terminology on the Hot Work
  Permit
• There are several fire-watch intervals on the Hot
  Work Permit (e.g., 4 hours and 60 minutes)
• There is no place to initial the Hot Work Permit
  if work is stopped for lunch and resumed later
• Part 1 of the Hot Work Permit, which does not go
  to the worksite, contains an instruction for
  welders to initial the checklist that
  instruction should be on Part 2, which is posted
  at the site
• Checkboxes are used even though a blank checkbox
  could be an oversight
• Signoffs on the Hot Work Permit are not required
  by the fire watch
• The SBMS Fire Safety Subject Area does not
  identify grinding as requiring a Hot Work Permit
• BNLs computer based Fire-Watch Training is
  outdated and does not clearly state the different
  activities that would require a permit
• The fire watch time requirements in the Subject
  Area contradict both the training and the permit
• Detailed instructions for fire watch duties do
  not accompany the Hot Work Permit, but are listed
  with brevity in SBMS
• Completing each section of the Hot Work Permit
  does not have a corresponding instruction in SBMS

7
Causal Analysis The Five Whys

• 5) Why are there weaknesses in the Standards
  Based Management System?
• Past training or experience is relied upon but
  people forget all the rules after a few days
• In this case, it was use of the Hot Work Permit
• Maintaining the SBMS up to date is problematic
  for a small employer
• The size and scope of SBMS is too broad to
  maintain using our current approach
• SBMS is not human-performance friendly
• Welders and other users of the Hot Work Permit
  became overconfident and were not reminded about
  the specific dangers and controls for metal
  grinding on the Hot Work Permit itself

8
Causal Analysis Conclusions

• This programmatic deficiency is a good example of
  a latent organizational weakness
• The program puts workers in a knowledge based
  performance mode where the risk of an error
  resulting in an unwanted event is too high (1
  out of 100) and is unacceptable