Tag: safety

Engineering Division pilots equipment protection interlock system for Berkeley Lab user endstations

Engineering Division pilots equipment protection interlock system for Berkeley Lab user endstations

A new user-configurable equipment protection interlock system that helps protect scientific equipment and users will provide more flexibility and reliability while improving safety at the Lab.

Equipment protection interlock systems are a vital component of the infrastructure for many types of scientific equipment and facilities, especially at Berkeley Lab facilities like the Advanced Light Source (ALS), BELLA, and the Joint Genome Institute. These specialized interlock systems control the mechanisms that prevent unsafe conditions when using equipment. Actions like protecting beamline slits and components from overheating fall to interlock systems that have been custom-configured to meet the specific requirements of equipment and experiments. The Engineering Division is currently piloting a system for Berkeley Lab that will make setting up and using equipment protection system interlocks safer, faster, and more consistent—with minimal training and no need for coding on the user side.

This new tool has been developed at the ALS in collaboration with the European Synchrotron Radiation Facility (ESRF). The underlying idea for the interlock system comes from ESRF, where more than 400 of the devices are already in use. When Ernesto Paiser, ALS Instrument Software Support Group Lead, formerly of ESRF, arrived at Berkeley Lab, he saw an opportunity to implement a similar system that would provide increased reliability and flexibility while improving safety and efficiency.

“When I started at the Lab,” says Paiser, “I was immediately confronted with numerous challenges related to the equipment protection system (EPS). One of the most significant issues was how complex and inaccessible the system was for end users when they needed to define or modify interlock requirements at the end stations. Even a minor request often required changes to the main front-end interlock program. Each modification triggered a full system retest, regardless of the scope of the change. In many cases, by the time the work was completed, the original request was no longer needed, yet the changes remained permanently embedded in the system.”

Read more on the LBL website

Image: Ernesto Paiser, ALS Instrument Software Support Group Lead, pictured with the new no-code interlock system.

Credit: Engineering Division

X-rays look at nuclear fuel cladding with new detail

X-rays look at nuclear fuel cladding with new detail

Micro-beam measurements at the Swiss Light Source SLS have enabled insights into the crystal structure of hydrides that promote cracks in nuclear fuel cladding. This fundamental knowledge of the material properties of cladding will help assess safety during storage.

For over seventy years, zirconium alloys have been used as cladding for nuclear fuel rods. This cladding provides a structural support for the nuclear fuel pellets and an initial barrier to stop fission products escaping into the reactor water during operation. During its long history, which includes extensive research and development advances, reactor type zirconium alloys have proved themselves as an extremely successful material for this application.

Yet they have a well-known nemesis: hydrogen. When submerged in water during operation in a reactor, at the hot surface of the fuel rod water molecules split into hydrogen and oxygen. Some of this hydrogen then diffuses into the cladding. It makes its way through the cladding until – when the concentration and conditions are right – it precipitates to form chemical compounds known as zirconium-hydrides. These hydrides make the material brittle and prone to cracking. Now, using the Swiss Light Source SLS, researchers were able to shed new light on the interplay between cracking and hydride formation.

Using a technique called synchrotron micro-beam X-ray diffraction, the researchers could study the structure of hydrides during the growth of cracks in fuel cladding at a new level of detail. “Through thermomechanical tests, we could control extremely slow crack propagations. Discovering at such high spatial resolution which hydride formations actually occurred made all the challenges of the material preparation worthwhile,” says study first author, Aaron Colldeweih who designed the thermomechanical testing procedure as part of his PhD project at PSI.

One of the things they discovered was that an unexpected type of hydride was present at the crack tip. This type of hydride, known as gamma-hydride has a slightly different crystal structure and stoichiometry to the type more commonly present, known as delta-hydride, “There has been a lot of discussion about gamma-hydrides: whether they are stable and whether they exist at all. Here we could show that with certain applied stresses you create gamma-hydrides that are stable,” says Johannes Bertsch, who leads the Nuclear Fuels Group in the Laboratory of Nuclear Materials at PSI.

Read more on the PSI website

Image: Malgorzata Makowska, scientist at the MicroXAS beamline of the SLS, carefully positions a standard material for setup calibration on the sample manipulator in front of the X-ray beam.

Credit: Paul Scherrer Institute / Mahir Dzambegovic