The following report was received from the State of
Arkansas via e-mail:
The Arkansas Department of Health was notified via telephone and e-mail on Monday, May 1, 2017, at approximately 1337 [CDT] of the licensee's general licensed device stuck shutter and the failure of the shutter mechanism. The equipment failure appears to have occurred from strong thunderstorms. The lockout procedure was verbally verified with the licensee.
The licensee's fixed gauge is a ThermoFisher Scientific, Model Number E-SFL10-XX, Serial Number SP9810, which contains approximately 1,178.42 mCi Kr-85 (approximately 43.60 GBq Kr-85).
The original activity: 1,250 mCi Kr-85 (approximately 46.25 GBq Kr-85) as of June 1, 2016. The source's Model Number is TFC-185 and the Serial Number is QC00256.
Licensee operations with the gauge are twenty-four hours a day. The gauge has a fail-safe closing shutter mechanism and the gauge immediately went into the safe mode electronically during the thunderstorm. The closed shutter position was verified by the visual colored indicators in place.
There have been no known radiation exposures to personnel and/or members of the public. There have been no known radiological health and safety concerns.
The shutter will be repaired by the manufacturer today, May 2, 2017, whom will perform a root cause analysis. The State of Arkansas is awaiting information from today's evaluation, repairs, and surveys.
The State is awaiting a 30 day written report from the licensee."
State Event Number: ARK-2017-002
- * * UPDATE ON 6/9/17 AT 1507 EDT FROM ANGIE HALL TO BETHANY CECERE * * *
The following follow-up report was received from the State of Arkansas via e-mail:
The [Arkansas] Department [of Health] has received the required thirty (30) day report from the licensee, along with the related exposure survey and service reports from the manufacturer.
The licensee states, 'We have several of these gauges that have been operating normally for several years. Due to the nature of this repair and the fact that this is the only time we have ever had to do this repair, it is my belief that a component in the device failed to operate as intended. The technician scraped paint off the surface of the shutter/flag mechanism that would help the mechanism stick to the magnet. The technician also tightened and applied thread lock to the securing hardware for the magnet. Both items should have been done at the factory.'
The manufacturer's Field Engineer (also known as Technician) stated, 'I believe the issue started with the holding magnet being loose. This may have caused the solenoid to work harder and fail, and that could have caused the board to fail.'
The manufacturer's Radiation Safety Officer stated, 'Thermo EGS Gauging LLC. is aware of the shutter mechanism failing in the closed or failing to the closed position on the TFC-185 and the TFC-190 sensors. The R&D manufacturing team has been working on a engineering project to correct this issue. We are currently in the testing phase and will manufacture all future sensors with the updated materials and parts. There is also an upgrade retrofit kit in the works for existing sensors that are demonstrating/developing this shutter issue. Currently we are sending out Field Service engineers to the customer's site to offer temporary repairs on an as needed basis.'
The Department is waiting on a response from the manufacturer concerning the above statement.
There have been no known radiological health issues, radiological exposures, safety hazards, or concerns to personnel or members of the public during this event.
Event Cause: Equipment failure/design, manufacturing, or installation error.
Corrective Action by licensee: New equipment obtained and repairs made with engineering change to system.
Reporting Requirement Information:
Arkansas State Board of Health 'Rules and Regulations for Control of Sources of Ionizing Radiation' RH-1502.f.2 and RH-402.c.
U.S. Nuclear Regulatory Commission (NRC) Regulations Title 10 CFR Section 30.50 (b) (2) - Equipment is disabled or fails to function as designed, and Title 10 CFR Section 21.21 - A failure to comply or a defect affecting a basic component that is supplied for a facility or an activity that is subject to licensing requirements.
The licensee and manufacturer reports and surveys have been sent to Randy Erickson, Regional State Agreement Officer, U.S. NRC, Region IV Office, and the NRC Headquarters Operations Center.
Note: Leak tests are not required for this type of gauge.
NMED Item Number 170231.
Notified R4DO (Rollins) and NMSS Events Notification by email.
- * * UPDATE ON 6/21/17 AT 1407 EDT FROM ANGIE HALL TO BETHANY CECERE * * *
The following follow-up report was received from the State of Arkansas via e-mail:
The Department has received clarification from the manufacturer's Radiation Safety Officer, stating in part, 'Due to a manufacturing defect of some source housing parts, about 10% of our sensors sold in the past could be affect' (affected).
He also stated, 'Our customer Baxter Healthcare is aware of this issue and unfortunately cannot provide a solution to them until their sensors develop this issue on a case by case basis.'
The Department considers this event to be closed.
Notified R4DO (Gaddy) and
NMSS Events Notification by email.