ML23075A332

Containment 2008

ML23075A332
Person / Time
Site:	Palisades
Issue date:	03/16/2023
From:	Jack Giessner, Kenneth Kolaczyk NRC/RGN-III, NRC/NRR/DRO/IRAB
To:
References
Download: ML23075A332 (15)

Text

Palisades Nuclear Plant Trapped in Containment August 6, 2008 Jack Giessner, RIII

Agenda

• The Event

• Special Inspection Team - Insights and Findings

• Lessons Learned - Inspector Safety

• Questions

Anatomy of an Accident

• Accidents are almost always the cumulative result of a chain of apparently minor deviations from known standards, practices, and procedures.

Hop Howlett II, Industrial Operators Guide

• This was an Event, not an Accident, that had many of the accident precursors present

The Event (Background)

• Plant shutdown for maintenance

• Containment entry for visual inspection

• Second entry of the evening to finish inspection

• NRC IP 71111.20 for inspection

The Event (Timeline)

• August 5, 2008: 2000 - Reactor shutdown for control rod drive work

• 2100 First Containment entry for visual inspection, WBGT between 92-98 F

- heat stress index 115 F

• August 6: 0025 Second entry of the evening to finish inspection (Stay time 30 minutes)

• 0030 Phone system goes down (unknown to team)

• 0040 Scaffold team exits, leaves outer door partially open (unknown to team)

• 0053 Airlock exit not successful

• 0100 Attempt at phone failed

• 0115 Escape hatch attempt fails

• 0130 Partial removal of Anti Cs; water bottle use

• 0145 Cycle shield cooling pump discharge valve in attempt to notify CR

• 0155 Another team of scaffolders enters containment and team exits

Personnel Airlock Inner Door Personnel Airlock Outer Door Escape Hatch The Event - Barriers Broken

• Failure to close outer hatch of Personnel Air Lock - lack of procedures; operator aid control

• Phone system down - no backup plan

• Escape hatch failed to operate - material condition; acceptance of deficient issues

• Heat stress control monitor - overall access control

The Event - Barriers Remaining

• Actions to mitigate heat stress - bottled water; removal of Anti-Cs

• Low Dose Area = Cool Area = Area near hatch

• Attempts to signal Control Room

• Timing/Luck - Another Group enters containment Accident does not occur

Special Inspection Team - Insights and Findings

• Containment Access Control - inadequate procedures

• Emergency Escape hatch not being maintained IAW design

• No procedure for operating the hatches +

Training and operator aids ineffective for airlocks

• Heat stress control program - turned over to OSHA per MOU

Lessons Learned - Inspector Safety

• High industrial safety risk evolutions

- You CAN ensure your own safety

- Spend time needed to understand the program (even if there is no direct tie to nuclear safety)

• High industrial safety risk programs

- Confined space

- Heat Stress

- Fall Protection

- Electrical Safety

- Heavy Loads

Lessons Learned - Inspector Safety

• Must be able to do your job - and you must be safe

• Think about surrounding and think about worse case contingencies

Next Week:

Callaway Disputed Violation