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Category:REPORTABLE OCCURRENCE REPORT (SEE ALSO AO LER)
MONTHYEARML20077B4731991-05-10010 May 1991 Ro:On 910507,operator Failed to Perform Surveillances & Channel Tests for All 6 Scram Channels & 2 Interlocks Prior to Reactor Operation.Caused by Personnel Error. Tailgate Meeting Held & Mods to Hardware Initiated ML20212Q6971986-08-26026 August 1986 Ro:On 860821,during Prestartup,Source Interlock Operated But Failed to Prevent Movement of Control Rods.Caused by Temporary Loss of Electrical Contact in Logic Circuits. Movement Restored Proper Electrical Contact ML20136H3291985-11-13013 November 1985 Ro:On 851112,wide-range Log Channel Malfunctioned During Operation of Reactor.Caused by Faulty Calibr Switch in Log Channel.Switch Adjusted & Reactor Operated at Several Power Levels Up to 95 Kw ML20114B3221985-01-14014 January 1985 Ro:On 850107,while Taking Unit to 95 Kw Power,Period Meter Indicated Period Decreasing W/Log Power Trace Levelling & Linear Power Trace Rising.Caused by wide-range Log Channel Malfunction.Manual Scram Initiated & Reactor Secured ML20101M8491984-12-10010 December 1984 Ro:On 841203,wide-range Log Channel Malfunctioned,Resulting in Manual Scram.Cause Traced to Resistor in Filter on Detector High Voltage Supply.Repairs & Testing in Progress ML20065R4001982-10-20020 October 1982 Ro:On 821006,malfunction of Eberline AMS-3 Continuous Air Monitor Pump Caused Pump to Be Inoperable for Approx 1-h.No Loss of Significant Signals Indicated.Pump Repaired.Changes to Procedures or Equipment Under Review ML20137G4501981-03-24024 March 1981 Ro:During walk-through of Operator Training Program, O-ring Seal of Filter Holder Found Not Seated Properly Causing Partial Bypass of Filter for Air Sucked Into instrument.Filter-in Lock Adjusted ML20137G4461977-06-23023 June 1977 Ro:On 770621,radioactive Source Containing 200 Mci Cs-137 Recovered from Brine Well 33.Incident Described in ML20137H3841976-01-12012 January 1976 Ro:On 760106,operator Left Console Key in Switch So That Reactor Not Secured Per Tech Specs.Key Withdrawn from Console.Incident Discussed W/Operators & Large Red Plastic Tag Attached to Key to Make It More Visible ML20137G8161973-02-16016 February 1973 Ro:On 730125,available Excess Reactivity of Core Exceeded Tech Specs Limit.Caused by Change in Worth of Control Rods. Rearrangement of Core Configuration Initiated to Reduce Available Excess Reactivity ML20137G7931971-11-22022 November 1971 Ro:On 711022,during Startup of Reactor,Period Limiting Signal Unavailable for Servo Sys Which Continued to Raise Rod Causing Rapid Rise of Power.While Reactor Manually Scrammed,Reactor Period Less than Min Allowed in Tech Specs 1991-05-10
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20205K3851998-12-31031 December 1998 Dow Triga Research Reactor Annual Rept for 1998. with ML20203A1031998-02-11011 February 1998 Safety Evaluation Supporting Amend 8 to License R-108 ML20217P6341997-12-31031 December 1997 Dow Triga Research Reactor Annual Rept - 1997 ML20210R1221997-08-19019 August 1997 Safety Evaluation Supporting Amend 7 to License R-108 ML20137C5401996-12-31031 December 1996 Dow Triga Research Reactor Annual Rept - 1996 ML20101F2761995-12-31031 December 1995 Dow Triga Research Reactor Annual Rept - 1995 ML20081F1491994-12-31031 December 1994 Dow Triga Research Reactor Annual Rept-1994 ML20063G7291993-12-31031 December 1993 Dow Triga Research Reactor Annual Rept for 1993 ML20127B4661992-12-31031 December 1992 Dow Triga Research Reactor Annual Rept 1992 ML20141M0461991-12-31031 December 1991 Dow Triga Research Reactor Annual Rept - 1991 ML20077B4731991-05-10010 May 1991 Ro:On 910507,operator Failed to Perform Surveillances & Channel Tests for All 6 Scram Channels & 2 Interlocks Prior to Reactor Operation.Caused by Personnel Error. Tailgate Meeting Held & Mods to Hardware Initiated ML20081M7561991-03-26026 March 1991 Dow Triga Research Reactor Annual Rept - 1991, Covering May - Dec 1990 Period ML20062F7491990-11-19019 November 1990 Microprocessor-Based I&C Sys for Dow Triga Research Reactor ML20081E0901990-06-30030 June 1990 Dow Triga Research Reactor Annual Rept - 1990 ML20006B6581990-01-19019 January 1990 Ro:On 900116,wide Range Log Channel Failed While Reactor Taken to Power.Caused by Poor Connection in Rotary Switch in Wide Range Log Channel.Authorization to Replace Entire Control Console Initiated in Early Jan 1990 ML19354D5871989-12-21021 December 1989 Ro:On 891220,wide Range Log Channel Failed While Reactor Was Being Taken to Power.Caused by Poor Connection in Rotary Switch in Log Channel.Switch Repaired & Reactor Returned to Operation ML20246J5981989-04-30030 April 1989 Safety Evaluation Report Related to the Renewal of the Facility License for the Research Reactor at the Dow Chemical Company ML20237L4561987-08-14014 August 1987 Dow Triga Research Reactor Requalification Program ML20210S6051987-02-0909 February 1987 Revised Licensed Operator Requalification Program for Facility ML20214C5491986-12-31031 December 1986 Dow Triga Research Reactor Requalification Program ML20214C5411986-12-31031 December 1986 Dow Triga Research Reactor Environ Rept ML20214C5351986-12-31031 December 1986 SAR for Dow Triga Research Reactor 300 Kw ML20212Q6971986-08-26026 August 1986 Ro:On 860821,during Prestartup,Source Interlock Operated But Failed to Prevent Movement of Control Rods.Caused by Temporary Loss of Electrical Contact in Logic Circuits. Movement Restored Proper Electrical Contact ML20214C5121985-12-31031 December 1985 Dow Chemical Co,1985 Annual Rept ML20136H3291985-11-13013 November 1985 Ro:On 851112,wide-range Log Channel Malfunctioned During Operation of Reactor.Caused by Faulty Calibr Switch in Log Channel.Switch Adjusted & Reactor Operated at Several Power Levels Up to 95 Kw ML20114B3221985-01-14014 January 1985 Ro:On 850107,while Taking Unit to 95 Kw Power,Period Meter Indicated Period Decreasing W/Log Power Trace Levelling & Linear Power Trace Rising.Caused by wide-range Log Channel Malfunction.Manual Scram Initiated & Reactor Secured ML20101M8491984-12-10010 December 1984 Ro:On 841203,wide-range Log Channel Malfunctioned,Resulting in Manual Scram.Cause Traced to Resistor in Filter on Detector High Voltage Supply.Repairs & Testing in Progress ML20065R4001982-10-20020 October 1982 Ro:On 821006,malfunction of Eberline AMS-3 Continuous Air Monitor Pump Caused Pump to Be Inoperable for Approx 1-h.No Loss of Significant Signals Indicated.Pump Repaired.Changes to Procedures or Equipment Under Review ML20052E2361982-04-28028 April 1982 RO: on 820421,instructions Given to Disconnect Power Supply & Single Lead to Compensated Ion Chamber.Incident in Violation of Tech Specs Requiring Two Linear Safety Channels Operating While Reactor Is Operating ML20137G4501981-03-24024 March 1981 Ro:During walk-through of Operator Training Program, O-ring Seal of Filter Holder Found Not Seated Properly Causing Partial Bypass of Filter for Air Sucked Into instrument.Filter-in Lock Adjusted ML20137G4461977-06-23023 June 1977 Ro:On 770621,radioactive Source Containing 200 Mci Cs-137 Recovered from Brine Well 33.Incident Described in ML20137H3841976-01-12012 January 1976 Ro:On 760106,operator Left Console Key in Switch So That Reactor Not Secured Per Tech Specs.Key Withdrawn from Console.Incident Discussed W/Operators & Large Red Plastic Tag Attached to Key to Make It More Visible ML20137G8161973-02-16016 February 1973 Ro:On 730125,available Excess Reactivity of Core Exceeded Tech Specs Limit.Caused by Change in Worth of Control Rods. Rearrangement of Core Configuration Initiated to Reduce Available Excess Reactivity ML20137G7931971-11-22022 November 1971 Ro:On 711022,during Startup of Reactor,Period Limiting Signal Unavailable for Servo Sys Which Continued to Raise Rod Causing Rapid Rise of Power.While Reactor Manually Scrammed,Reactor Period Less than Min Allowed in Tech Specs 1998-02-11
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DOW CHEMICAL U.S.A. hM August 26, 1986 MICHIGAN DIVISION MIDLAND,. MICHIGAN 48640 Mr. James C. Keppler U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 DOW TRIGA RESEARCH REACTOR, LICENSE R-108, DOCKET 55-264
Dear Mr. Keppler:
This letter reports an event which is described in section D.(1) of the operating license of the Dow TRIGA Research Reactor.
NUCLEAR SYSTEM: Source Interlock SAFETY FUNCTION: Prevent withdrawal of control elements with less than two neutron induced counts per second on the startup channel. '
CONDITION: During pre-startup checkout on Augut 21, 1986 the source interlock operated, given the proper signal, but failed to prevent the movement of the control
- rods.
The pre-startup checkout was halted while the operation of the interlock was reviewed. The interlock was reset and a signal was again provided which operated the source interlock. At this time the interlock did prevent the movement of the control rods. The interlock system was examined, relays and connections were removed and inspected, the system was returned to working order and was tested three times. At each time the proper interlock was achieved.
The failure was ascribed to a temporary loss of electrical contact in the logic circuits, which use plug-in relays. Subsequent inspection and movement restored the proper electrics.1 contacts and the system, af ter testing, was returned to service, mY
/,!Y , 1 8609080001 860826 PDR ADOCK 05000264 S PDR %
AUG 2 91986 I AN OPERATING UNIT of' THE DOW C#4EMICAL COMPANY
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, h-i Mr. James C. Keppler U.S. Nuclear Regulatory Commission August 26, 1986 Page 2 A telephone report was made to the duty officer at llegion III on the afternoon of August 21, 1986.
Yours,
- G&) /6L C. W. Kocher Reactor Supervisor Analytical Laboratories 1602 Building cc: L. W. Rampy Chairman, Radiation Safety Committee The Dow Chemical Company 1803 Building Midland, MI 48674 D. L. Berry Chairman, Reactor Operations Committee The Dow Chemical Company 1602 Building Midland, MI 48674 i
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