RLL is a Ronan Engineering term that stands for "Radiation Low Level." RLL technology utilizes up to a total of 0.9 mCi (0.033 GBq) of cesium source. In comparison, some conventional density gamma gauges use source sizes with a hunderd times more activity to make the same measurement. Because of these very low-levels of activity, and their simplicity of design, Ronan systems are the safest gamma gauges on the market. The NRC recognized this in 1999 when Ronan Engineering attained certification for the first RLL source design.
There are three types of RLL Source Holders; the RLL-1, RLL-1A, and the RLL-2. The RLL-1 utilizes from one to ten 0.09 mCi (0.003 GBq) cesium capsules, while the RLL-1A utilizes a single 0.9 mCi (0.033 GBq) cesium capsule. The RLL-2 is a strip source holder which accomodates up to a total of 100 µCi (0.004 GBq) cesium 137.
- Periodic shutter check. Per NRC guidelines, shutters are not required on source holders with less than 1 mCi (0.037 GBq) of cesium.
- No Radiation Safety Officer and/or Special Radiation Training is Required by NRC
- No Licensed Radiation Person is Required to Install, Commission or Move On-Site
Other advantages include:
- 0.5 mrem/hr @ 12"
- Lower Disposal Cost Than Conventional, Higher Intensity Type Gages
- Lead Free Option Available
- Fire Resistant Design Available
- Less Risk to users
- Less Documentation to Maintain
The only regulatory difference between the RLL-1 and the RLL-1A is that the RLL-1 does not require a Leak Test, whereas the RLL-1A requires a leak test every three years. This exemption from leak tests is an advantage for the RLL-1. However, because it utilizes multiple capsules, and the RLL-1A utilizes only one capsule, the RLL-1 is more expensive than the RLL-1A.
Ronan sizes the source to last a minimum of 15 years, usually 20- 30 years. We guarantee a minimum of 15 years on all sources.
Total Cost of Ownership
Even though the initial equipment cost may be approximately 10% higher than conventional gamma gauges, the return on investment is almost immediate. The differential in equipment costs are offset by lower installation costs (RLL sources do NOT require licensed personal to install, commission or move them… conventional sources require licensed personal.) On-going maintenance costs are also lower as the RLL does NOT require periodic leak tests (RLL-1) or shutter checks as conventional sources do.
- The RLL Type Gauge is Approximately 100 lbs (45 kg), Lighter Than Conventional Type Gamma Gauges and as Such are Easier to Install...No Supports Required on Smaller, Lighter Piping
- The RLL is Smaller in Overall Dimensions (6 in, 15 cm) Than Conventional Type Gamma Gauges
- Dependable, Reliable, Repeatable Measurement That is Easy to Install, Calibrate and Maintain
Ronan can utilize low-level technology because our only focus is on non-contact measurement gauges. We use extra sensitive scintillation type detectors. We cut and polish the crystals at our facility. We utilize spring pressure to hold the crystal securely to the photo-multiplier tube. We do not use cements, glue or grease that can degrade or break the connection between the crystal and photo-multiplier tube. Ronan typically uses larger crystal sizes, which enables us to measure a larger sample of the product in the pipe. Ronan’s microprocessor utilizes the latest technology in the industry.
