INEEL Advanced Test Reactor (ATR) Accidents 1991 to 1999

 

1991

May 20; Advanced Test Reactor fuel element fell from handling tool to water storage canal floor.

June 4;   ATR reactor scrammed due to under voltage to coolant pump.

Aug.13;   ATR reactor scrammed due to loss of power to coolant pump.

Oct.14;    ATR reactor scrammed due to low coolant pressure caused by malfunctioning

                         temperature control valve.

Oct.16;   ATR reactor scrammed again due to low coolant pressure caused by another

                         malfunctioning temperature control valve.

1992

Jan.16;     Advanced Test Reactor spilled 350 gallons of sulfuric acid into the "cold" waste  pond;

Apr. 12;  Advanced Test Reactor was scrammed when a diesel generator supply power failed;

1993

Jan.4;   Advanced Test Reactor scrammed.  During a lC-W loop experiment, a scram  occurred  due  to loss of  flow signal because of an operator error.  The operator did not properly follow the  procedure and a  reset button was depressed which  caused  the loop pumps to turn off and  the reactor scrammed.

Sept. 8; A damaged C cell battery was found in the ATR reactor vessel outside of the core region and

             removed; a thorough inspection of the vessel revealed no other debris and the vessel was

             closed up. 

Sept. 13; Crushed parts of a flashlight were found inside the ATR reactor vessel, but outside the core

            region and no debris was found on the fuel.  Detailed inspections were conducted including

            the use of an underwater camera video system, but other missing flashlight parts were not

            found.  Reactor operation was delayed for more than two days and in-vessel inspections will

             be  performed following each nuclear re_qualification testing event.

1994

April 4;  During refueling of the Advanced Test Reactor, 19 workers received internal radiation

            exposure caused by underwater control rod cutting operations in preparations for disposal.

              Workers using a remote control saw were cutting through a control rod of hafnium and

             aluminum and either the saw arced or hit the hafnium which got into bubbles of hydrogen and

            rose to the surface of the pool. The highest dose was 2 mRem.  Hafnium has a half life of 45

            days.   The facility was evacuated.  OCAW union said exposure was 1.3 REM and

            internal uptake of 96 microcurie of hafnium-181.

1995

July 3; Several pipefitters working at the Advanced Test Reactor were exposed to 50,000 counts per

             minute by over a dozen isotopes because their anti-contamination (anti-c) clothing provided

             inadequate protection in the work environment.  In another event, a DOE Environmental

             Health Representative was contaminated while conducting an inspection of the check valve

             work that was            the subject of previous pipefitter contamination.  In both cases the Pro-Tech

             2000 anti-c clothing  did not prevent the migration of graphite particles through the material

             or protect individuals  during bending, kneeling, extreme temperatures, or presence of

             contaminated liquids.

Aug. 24; The Advanced Test Reactor Emergency Fire Water Injection System would be rendered

             inoperable during a design basis earthquake.  The purpose of the injection system is to pump

 water into the reactor core to prevent irradiated fuel elements from being uncovered in the event  of a loss-of-coolant accident or a complete loss of coolant flow during an earthquake.

1997

Feb.24; Advanced Test Reactor accident resulted in 410 pounds of Freon when a scaffold fell on and broke a chiller unit line.  Operators attempting to use self-contained breathing apparatus found five to be unusable.  Freon, according to NIOSH is immediately dangerous to life or health in concentrations as low as 2 ppm.

Feb.27; DOE imposed $25,000 civil penalty on Lockheed Martin Idaho Technologies under the Price

Anderson Act for multiple failures to maintain radiation exposures as low as reasonably achievable.

Mar.1; A Test Reactor Area Technician received a whole body neutron exposure of 1865 millirem

             the month of April and the source of the exposure could not be determined.

Mar.13; Two cesium-137 sources containing 27.5 mCi and 12 mCi with a potential dose rate of 111 mrem/hr were lost and a search was unable to determine their location.

April 27; Advanced Test Reactor spent fuel element fell off handling device during transfer from reactor to storage pool.

Oct 25; Advanced Test Reactor operators discover five holes in gas-tight reactor confinement boundary (during operations) that subcontractors had left unfilled.  This breached the reactor gas-tight confinement boundary.  A similar event occurred on December 16, 1996 at the same location.

1998

Jan 12; The Advanced Test Reactor at the Test Reactor Area had an uncontrolled shutdown after a secondary coolant line system piping leaked.

1999

Feb. 17; Advanced Test Reactor operators found that a flux trap target capsule holder assembly had been rotated 90 degrees from its intended position since 1994. Miss orientation of the targets could have caused a variation of the neutron flux peaking  within the flux trap resulting in operating the advanced test reactor outside its safety authorization basis.

March 22; Advanced Test Reactor crane dropped a 400 pound irradiated inpile tube assembly being lifted from the reactor core and narrowly missed hitting a worker.  The uncontrolled fall damaged the storage well and docking plate.