Nuclear power stations contain numerous water storage
tanks ranging from 35 ft. to 50 ft. in diameter and as much as 50 ft. deep.
Refueling water storage tanks (RWST) contains borated water
to flood the refueling cavity during refueling as well as supply water to the
emergency core cooling system.
Read the detailed article about the deployment of an Inspector at the Palo Verde Nuclear Generating Station in the April 2015 edition of Nuclear Engineering International magazine. CLICK
For information on the Inspector
in-tank robot, please contact:
Underwater Robot Precisely Maps Water Storage Tank Floor Defects
The Inspector is a semi-autonomous, underwater robotic platform
designed to deploy
a variety of advanced, nondestructive evaluation (NDE) sensors
to over 90% of a
flat-bottom water storage tank of the type used at nuclear power
plants, and to map the position of any indications with an accuracy
of 1/8th inch (3 mm).
Surveying Nuclear Plant Storage Tank Integrity
Storage tanks at nuclear power plants are constructed of aluminum, stainless
steel or carbon steel, and all have naturally occurring electro-chemical processes
that can eventually
the metal, resulting in leaks. Defects that develop on the underside of tank
floors are particularly difficult to detect and measure.
The Nuclear Energy Institute (NEI) has recommended that all nuclear plant storage tanks undergo periodic inspection. Non-destructive evaluation (NDE) methods, such as eddy current and ultrasonic phased array are the most suitable technologies to inspect tank floor bottom plates. Using this equipment has meant taking a tank out of service by draining and ventilating it so that humans in protective clothing can enter and conduct the survey.
The Inspector Solves an Industry Problem
Inspector in-tank underwater robots perform NDE tank floor surveys
without the necessity of draining or removing a tank from service:
- Inspector robots survey and map the condition of individual tank
- Mounting options for NDE probes includes a indexable, twin-arm module.
- The navigation system can map and store the location of defects and later return
and place a sensor at the location of a defect with an accuracy of 1/8 inch (3 mm).
- Inspector robots can be deployed through a 19 inch-wide (48 cm) tank top
- Versions of the Inspector Robot are avaialble for Diesel, Petrochemical and other fluids.
Partners in NEI 09-14 Inspections
Tank survey and mapping services with Inspector robots are available through
a partnership between AREVA and Newton Labs.
AREVA is an industry leader in providing fully automated phased array ultrasonic
and equipment to perform in-service and/or pre-service examinations.
Read about the Inspector navigation process of the Inspector ▶ HERE.
Read about the sensor and tool-attachment capabilities of the Inspector ▶ HERE.