Lawrence Livermore National Laboratory


Proactive Maintenance Saves NIF Shot Time and Money

For Nick Jize, the difference between proactive and reactive maintenance is like the difference between getting regular physicals and waiting until you need the EMTs to take you to the emergency room.

“Our goal is to maximize NIF shot opportunities by predicting and preventing equipment failures before they occur,” Jize (pronounced Jeeze) said. “We want to be in control of the equipment, not let the equipment be in control of us.”

Jize, NIF’s facility operations and maintenance manager, has more than 20 years of experience in reliability management and is considered an industry leader in Reliability Centered Maintenance (RCM) and predictive maintenance. His job is to ensure that all conventional facility equipment and utilities are ready for laser shot operations 24 hours a day, seven days a week.

Nick JizeNick Jize

And by using RCM and other industry best-practices processes and tools, Jize and his team are helping keep NIF running at an ever-increasing pace—NIF completed 31 target shots in February at a rate of more than 7.5 shots a week—while also saving millions of dollars in avoided downtime and unnecessary maintenance. Since 2011, RCM and a companion program called Condition Based Maintenance (CBM) have saved more than $2 million, and they are projected to save nearly $3.5 million by 2017. The programs use non-intrusive techniques such as vibration analysis, oil analysis, and ultrasonic lubrication, and the elimination of ineffective preventive maintenance tasks.

“The RCM program is a decision process to determine what needs to be done based on the function of the equipment,” Jize said. “We look at the failure modes of each piece of equipment, and we look at the criticality of the function it performs to determine the best maintenance path to follow.

“So it’s function-based, not equipment-based,” he said. “Let’s say we have two identical motors in the facility—one provides power for a cooling pump for critical electronics supporting the laser, while the other one supplies an infrequently used sump pump. We’re not going to treat all equipment the same. That’s where function-based comes in: there will be a lot more cost to the facility if the cooling pump fails than if the sump pump goes out. So it’s a different maintenance strategy based on function rather than the equipment itself.”

A key asset condition management tool used by the Facility Operations and Maintenance (FOM) group is vibration analysis, used to assess the health of critical pumps and motors in order to mitigate failures and plan for repairs with as much notice as possible. “Vibration analysis allows you to predict what’s failing and how it’s failing, and potentially how much longer you have before you need to do something about that failure,” Jize said.

“We also use our vibration analyzer to perform precision alignment and balancing whenever we replace motors or fans,” he said. “The analyzer provides information about rotating machinery, indicating the condition of a bearing, co-alignment of the motors and pumps, adequacy of equipment mounting, and proper balancing —all of which affect the reliability of rotating equipment.

“When we install the equipment we get a baseline of the vibration signature, make the necessary adjustments, and take the baseline again until we’re satisfied that we’ve installed the equipment properly. Then we go out every quarter or so and take another vibration signature, and based on how the vibration spectrum is changing we can tell whether a bearing is failing, or if the motor has some imbalances, and so forth”

Technicians Align Motor and PumpFacility Operations and Maintenance technicians Santiago Tordil (left) and Mario Jimenez perform precision alignment on the NIF central plant motor and pump set.

The RCM program paid big dividends toward the end of last year, when a routine monthly vibration analysis detected incipient failures on one of the motors in the laser amplifier cooling system. The motor was placed on a watch list and scheduled for weekly vibration analysis; subsequent tests revealed a significant rise in low-frequency vibrations indicating further bearing deterioration and looseness. At that point, the FOM Team received management approval to replace the motor before it failed.

“Vibration analysis said it’s about to go,” Jize said, “and it wasn’t worth the risk to keep it in operation. If it failed at an inopportune moment it would impact facility costs a lot more than the cost of replacing the motor.”

Vibration analysis allowed sufficient time to have a well-planned replacement strategy using the NIF “Formula 1” operational approach, based on the quick teamwork of Formula 1 race car pit crews. The FOM and Transport and Handling (T&H) teams replaced and commissioned the motor in a four-hour window between shots, taking less than three hours to complete the task. Previously the process, in a reactive mode, could have required a full eight-hour shift.

Electrician Installs AccelerometerFOM electrician Ernie Montano installs an accelerometer on a power amplifier circulating fan motor on NIF’s 5th floor mezzanine. The vibrations detected by the accelerometer will be read remotely and could provide an early warning of potential problems requiring more detailed vibration analysis or possibly an emergency shutdown.

“This proactive approach prevented at least eight hours of shot delays had the motor failed at an inopportune time while we were preparing for a shot,” Jize said. “And the Formula 1 process avoided at least two hours of shot delays, for a one-time savings of about $80,000.”

Condition Based Maintenance, or CBM, differs from time based preventive maintenance by taking into account the condition of the equipment in determining the need for maintenance. “Time based preventive maintenance includes the things you might do on a periodic basis, such as changing oil every so often,” Jize said. “CBM would say let’s look at the condition of the oil and change it only when it’s starting to go bad.

“Lubrication for motors is another example. Based on manufacturer’s recommendations, we used to go in and pump in three to six pumps of lubricant per bearing every quarter. It turned out that that was way more than what we needed for this operation. Now we use ultrasonic oil analysis to determine if lubrication is needed or not.

“The ultrasonic device is attached to the Zerk fitting and allows the technician to listen to the bearing as he is applying the lubrication. By doing this, the technician can determine how much lubrication to add and when to stop adding lubricant. Now we no longer are filling our motor windings with grease as we have in the past; we used to find the windings full of grease in our post-failure analysis, so we eliminated that issue and our motors are lasting longer now.

“We use precision ultrasonic lubrication for all our motor bearing lubrication,” he said. “This technology alone has doubled the life of our AMP cooling motors. CBM can also be used to verify findings. We use oil analysis to monitor the health of our rotating equipment and as a way to confirm any diagnoses from our vibration analysis data. For example, if vibration analysis indicates that we are seeing some bearing deterioration, we should be able to confirm this with an increase in the metallic contents of the oil.”

The FOM Team performs about 6,000 preventive maintenance work orders a year at an estimated average of four hours per work order. About 25 percent of all maintenance tasks have gone through a rigorous RCM analysis to evaluate cost effectiveness and value, resulting in the elimination of hundreds of hours of ineffective preventive maintenance. In addition, the team has reduced the time spent doing reactive maintenance by 50 percent.

Jize said RCM evaluations of the remaining maintenance tasks are in progress; the reviews already are saving several hundred thousand dollars a year. And expansion of NIF’s RCM and CBM efforts are planned for 2015 and the years that follow.

Jize credited the members of these teams for keeping NIF operating smoothly and efficiently: the Maintenance Integration Group, Beamline Systems system managers, FOM system managers, the FOM Work Center, and the Transport & Handling Work Center.