Cook Nuclear Plant Unit 1 - Event and Recovery

Transcription

1 Cook Nuclear Plant Unit 1 - Event and Recovery Presented by Gary Hatcher, CIH EEI Spring Occupational Safety and Health Committee Conference April 21-24, 2009

2 Contents Cook Unit 1 9/20/08 Main Turbine Event Event Description Unit 1 Main Turbine-Generator Overview Results of Event Response Worker Concerns OSHA Investigation Lessons Learned (Pluses and Deltas) Looking Forward 2

3 Event Description Saturday, September 20, 2008 Unit 1 reactor was manually tripped at 2005 hours due to highhigh vibration readings on all main turbine bearings with severe vibration and rumbling felt coming from outside the control room After the manual reactor trip, all control rods fully inserted and major systems functioned as designed After a main generator fire was reported, the Shift Manager implemented the Emergency Plan based on the fire in the protected area and activated the Technical Support Center at 2018 hours 3

4 Event Description Cook Unit 1 (continued) The fire was extinguished at 2028 hours and the Technical Support Center was functional at 2113 hours During the event the in-service fire water storage tank was reported empty due to a large leak from a coupling failure in the underground portion of the fire header, the fire header leak was isolated and temporary fire suppression was placed in service at 2309 hours The Site Emergency Coordinator terminated the Unusual Event and Emergency Plan on Sunday, 9/21/08 at 0409 hours 4

5 Unit 1 Main Turbine-Generator Overview High Pressure Turbine Low Pressure Turbines (3) Generator Unit 1 Began Commercial Operation August Generates 1048 Net Megawatts 2000 RPM on Turbine Designed and Build by Westinghouse 5

6 Event Description Then Now 6

7 Event Description Oil soaked steam piping and insulation Fire damaged generator instrument cables Broken insulation 7

8 Event Description Damaged exciter house Front Standard Damaged Main Turbine Thrust Bearing Damaged main turbine shaft 8

9 Event Description Damaged LP C rotor LP B rotor blade Damaged LP blades 9

10 Event Description Third Party IH monitoring of work area and site Boundary of spill area on ground floor Insulation removed from bottom of HP turbine casing Asbestos abatement tent setup on HP turbine 10

11 Response to Insulation Spill Two Plant Industrial Hygienist and a contractor s IH Technician responded immediately after the fire and incident Air sampling was started and to date 3923 air samples have been collected No samples have exceeded the PEL (even during abatement) On the night of the event all samples were low (<.01 f/cc or much less) Bulk Samples were collected and areas with positive results restricted with signs and barriers The site initiated 24 hour coverage with Safety and Health Personnel immediately after the event. This coverage continues today with plant and third party IH coverage on round the clock 12 hour shifts 11

12 Asbestos Concerns Response to asbestos concerns Plant employees Contractor s employees Communication concerns Supervisors were not communicating air monitoring results well, probably because of a lack of understanding Supervisors were not feeding back employee concerns to S&H office S&H staff were focused on managing the response Asbestos exposure issues interpreted by employees who are more familiar with working with radiation/contamination Equated any exposure as serious exposure Made assumptions regarding detection of fibers based on experience with radiation. Wanted to use smear sample on loose material Felt that clean up was a matter of shutting down area and decontaminating the entire building Employees saw little benefit in air samples 12

13 MIOSHA Visit MIOSH visited the site five days after the event as a result of employee complaints During the visit they collected several samples Four of the bulk samples were positive for ACM in small amounts <10% One sample that was positive was from a piece of material that had fallen into a previously cleared area. The Compliance Officer witnessed an employee pick up the material bare handed and place in a bucket In the closing conference MIOSHA was very complimentary of the plant s response and of what they had seen, but The plant received one citation with three parts for: Failure to clean up spills immediately Failure to assure employees used HEPA vacuum while cleaning debris Failure to dispose of ACM in sealed impermeable bags or other closed containers 13

14 Lessons Learned Plan your work and work your plan Have a detailed plan Practice and drill your plan Get help and resources quickly IH contractors Abatement workers Mobile Lab Equipment (HEPA vacuums, 6 mil plastic, tarps, decontamination equipment, disposal bags) Aggressive Communications Inside the organization Outside the organization Get Corporate Communications engaged for worker communication as well as public communications Go directly to employees. Don t rely on frontline leaders to communicate If employees don t get the information they need, they ll assume the worst Conduct employee meetings to discover their concerns and address them proactively Protect employees in a conservative manner Limit access to areas unless protected Don t rely totally on bulk testing Assume migration of material Gravity, it s the law! 14

15 Looking Forward Ongoing recovery work to repair turbine and related damage. The unit is scheduled back in service for September One year after the incident Abatement of damaged insulation, lagging and pipe supports continues Access to some areas is still limited by overhead work on the turbine There is concern that spilled oil has soaked some of the insulation that is otherwise intact. The site has begun to assess the risk of the oil soaked insulation by collecting core samples on key pipes to determine risk of fire/smoke during start up Air and bulk sampling continues, but mostly in support of the turbine work and abatement. There are still at least four air samples collected daily to verify the continued low fiber exposure levels 15

16 Questions? 16