1 BROOKHAVEN SCIENCE ASSOCIATES 2009 DOE Accelerator Safety Workshop BNL S-band LINAC Fire Safety Concerns August 19, 2009 A. Ackerman

2 BROOKHAVEN SCIENCE ASSOCIATES BNL S-Band Electron LINAC’s ‘S-Band’ Electron LINAC’s 2 – 4 GHz range Klystron Modulators contain a Pulsed Forming Network – supply high voltage & current pulse to klystron –Capacitors (store energy) –Inductors (shape the pulse; filters) –Thyratron (switch) –~150 lbs of plastic, oil, plastic insulated wire Four S-Band LINAC’s on site National Synchrotron Light Source (NSLS) Source Development Laboratory (SDL) Accelerator Test Facility (ATF) Laser Electron Accelerator Facility (LEAF) SLAC Design

3 BROOKHAVEN SCIENCE ASSOCIATES BNL S-Band LINAC’s Fire History Three significant capacitor fires NSLS: 1999; ~$95k loss SDL: 2003; ~$10k loss ATF: 2009; ~$100k loss Lessons from 1999 Too much combustible material Capacitors not well suited to application –Air bubbles develop; Dielectric fluid not well distributed; Arcing results in fire Difference between operation and arcing is subtle –Cannot prevent first arc, can discontinue power after the first event Capacitors do not need forced air cooling Need positive mechanism for power disruption (emergency stops)

4 BROOKHAVEN SCIENCE ASSOCIATES BNL S-Band LINAC’s Fire History Corrective actions from 1999 Use Glastic Maintenance program for capacitor; different model Arc detection Smoke detection Audio monitoring Emergency power shut off switches Response procedures No fire suppression –Minimize fire damage –Keep adequate replacement parts

5 BROOKHAVEN SCIENCE ASSOCIATES Accelerator Test Facility (ATF; Bldg 820) Overview Accelerator Test Facility 70 MeV electron Linear Accelerator (LINAC) Four beam lines Electron / Laser interaction research / testing S-Band LINAC 2 Klystrons

6 BROOKHAVEN SCIENCE ASSOCIATES ATF; The Fire

7 BROOKHAVEN SCIENCE ASSOCIATES Accelerator Test Facility (ATF; Bldg 820) Fire Investigation Investigation team; 8 members; BNL Incident description Causal analysis –7 causal factors; o Root, Direct, 5 contributing Judgments of need; 5 statements –ATF design review for restart –Site wide corrective action closure –Facility transfer –Design & maintenance stds; (HV) –ATF operator qualification Final Report; dated April 9, 2009 Comprehensive, well organized, concise Good basis for Corrective Action Planning

8 BROOKHAVEN SCIENCE ASSOCIATES ATF Fire Corrective Action Planning Committee Progress Corrective Action Planning Committee formed Scope –Review investigation report; focus on causal analysis –Develop corrective action plan to address judgments of need 9 members; BNL Corrective action plan ‘strategy’ determined o High voltage (HV) pulsed power focus o Institutional issues focus Initial report complete; includes HV Pulsed Power Corrective Action Plan DOE Lessons Learned document completed; distributed soon

9 BROOKHAVEN SCIENCE ASSOCIATES ATF Fire Corrective Action Planning HV Pulsed Power Working Group formed 8 members; 7 BNL; 1 ORNL Charge: 3 ‘phases’ –Return ATF to safe operation; design review; 08/31/2009 –Fire safety design review; 4 S-Band LINACS –Establish review, design, control, & maintenance requirements for HV pulsed power on site.

10 BROOKHAVEN SCIENCE ASSOCIATES ATF Fire Corrective Action Planning ATF Conduct of Operations Review Working Group formed 3 members; BNL 2 meetings completed; third scheduled Charge: –Review ATF Conduct of Operations program for effectiveness and compliance with DOE Order Change 2

11 BROOKHAVEN SCIENCE ASSOCIATES ATF Fire Corrective Action Planning More to come ‘Immediate’ need focused on BNL HV Pulsed Power Understand the systems in place and the risks they present Apply consistent controls (fire or arc detection, procedures, disconnects …) Establish maintenance criteria Assure adequate rigor in ‘Conduct of Operations’ Institutional need focused on management systems, policy, … sharing information and resources organizing management changes defining and meeting the resource needs for accelerator (or other facility level equipment) maintenance and operation implementing complete and consistent corrective actions establishing standards for equipment design and maintenance

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