|
|---|
Category:REPORTABLE OCCURRENCE REPORT (SEE ALSO AO LER)
MONTHYEARML20210P3051999-08-0505 August 1999
Ro:On 990708,credible Single Failure in SR Temp Sys Could Result in Loss of Capability of Temp Sys to Protect Limiting Safety Sys Settings.Single Failure Is Loss of 15 V DC Power Supply.Mod Request 134 to Temp Sys Was Submitted
ML20209E9771999-07-0808 July 1999
Preliminary Rept of non-routine Occurence Re Identification of Possible Single Failure for Safety Related Temperature Sys on 990706.Low Temperature Auto Rundown Proposed & Problem Rept Initiated to Document Review of Event
ML20196B2091998-11-25025 November 1998
RO Update:On 981028,reactor Was Shutdown Upon Discovery That RB Ventilation Dampers Would Not Automatically Close.Damper Cylinder Was Repaired on 981102 & Reactor Operation Resumed on 981103
ML20154J6761998-10-0909 October 1998
RO 20:on 980925,Reactor Operators Made Error at Ford Nuclear Reactor in Implementing Calorimetry Procedures to Raise Power Level.Upon Discovery of Error Made in Linear Level Setpoint Reactor Power Was Reduced by 1% to Compensate
ML20153H0841998-09-28028 September 1998
Special Rept:On 980925,inadequate Procedure Implementation Resulted in Possible steady-state Reactor Operation at 2.02 MW Thermal Power.Interim Reactor Manager Reviewed Calorimeter Data & Did Not See Any Obvious Errors
ML20151Z1571998-09-17017 September 1998
Revised Ro:On 980817,980811 Event Re Slow Inward Drift of CR Reoccurred.Caused by Worn Worm Gear & Missing Full Turn of Worm Thread.Installed & Tested Drive Gear Coupling. Previously Submitted Ltr Rept Dtd 980911,deleted Text
ML20151W6391998-09-11011 September 1998
Special Rept:On 980811,swing Shift Operators Noted That CR Would Slowly Drift Inwards When in Manual Control with CR low-raise Switch in Neutral.Cr lower-raise Switch Was Removed,Inspected & Cleaned,Then Reinstalled & Tested
ML20236W0781998-07-30030 July 1998
RO 19:on 980720,determined That Reactor Was Operating W/ Inoperable Alarm Circuit on Bridge Radiation Monitor.Caused by Spurious Alarms Due to Temp & Humidity Sensitivity. Maint Procedures CP-216 & CP-219 Were Modified
ML20236T0741998-07-23023 July 1998
Non-routine Rept:On 971112,reactor Operators Shut Down Ford Nuclear Reactor to Remove Piece of Polyethylene Irradiation Container.Caused by Lack of Oversight.Method Will Be Adopted to Track Quartz & Polyethylene Samples
ML20236S2921998-07-20020 July 1998
RO-19:on 980720,reactor Operation w/in-operable Alarm Circuit on Bridge Radiation Monitor,Was Disabled.Caused by Spurious Alarms Due to Temperature & Humidity Sensitivity. Reactor Shutdown Pending Further Investigation
ML20248L5931998-06-0303 June 1998
Ro:On 980510,discovered 75 Gallon Loss of Pool Water to Radioactive Liquid Retention Tank Sys.Caused by Leak in One of Two Resin Columns Comprising B Hot Demineralizer (Hot Di) Sys.Modified Operating Procedure OP-211 Encl
ML20057F4521993-10-0606 October 1993
Follow-up on RO 18,dtd 930805 Re Release of low-level Radioactive Water from RB to Drain Tiles Around Foundation of Bldg.Line from Foundation Tiles Drains to Reactor Cold Sump,Through Which Water Released Permanently Sealed
ML20128D4641992-11-25025 November 1992
Ro:On 921124,control Rod Interlock Sys Removed from Reactor Control Sys.Caused by Wiring Error Made During Mod That Disabled Interlock That Drops Reactor Out of Automatic Control.Control Rod Withdrawn to 23 Inches
ML20058N7841990-08-0606 August 1990
RO 13:on 900721,tritium Content in Heavy Water Tank in Excess of 50 Ci.Samples Sent to Kms Fusion.Health Physics Procedure 107 Corrected to Reflect Correct Density of Heavy Water
ML20246F3881989-05-0303 May 1989
RO 12:on 881227,concentrations of I-131 & Xe-133 Discovered in Reactor Pool Water.Caused by B&W Element 204 Releasing Fission Products.B&W Contacted to Review Mfg Process.Air Samples Will Be Taken Above Pool on Monthly Basis
1999-08-05
[Table view]
Category:TEXT-SAFETY REPORT
MONTHYEARML20210P3051999-08-0505 August 1999
Ro:On 990708,credible Single Failure in SR Temp Sys Could Result in Loss of Capability of Temp Sys to Protect Limiting Safety Sys Settings.Single Failure Is Loss of 15 V DC Power Supply.Mod Request 134 to Temp Sys Was Submitted
ML20209E9771999-07-0808 July 1999
Preliminary Rept of non-routine Occurence Re Identification of Possible Single Failure for Safety Related Temperature Sys on 990706.Low Temperature Auto Rundown Proposed & Problem Rept Initiated to Document Review of Event
ML20205B0631998-12-31031 December 1998
Rept of Reactor Operations for Jan-Dec 1998 for Ford Nuclear Reactor Michigan Memorial - Phoenix Project Univ of Michigan,Ann Arbor. with
ML20206P3021998-12-31031 December 1998
Revised Rept of Reactor Operations for Jan-Dec 1998 for Ford Nuclear Reactor Michigan Memorial - Phoenix Project Univ of Mi,Ann Arbor
ML20196B2091998-11-25025 November 1998
RO Update:On 981028,reactor Was Shutdown Upon Discovery That RB Ventilation Dampers Would Not Automatically Close.Damper Cylinder Was Repaired on 981102 & Reactor Operation Resumed on 981103
ML20155J1131998-10-29029 October 1998
Part 21 Rept Re Failure of EDs to Automatically Close.Cause Due to Discovery That Air Cylinder That Operates RB Ventilation Supply & EDs Was Hanging Up.Reactor Will Remain Shut Down Until Damper Cylinder Is Repaired
ML20154J6761998-10-0909 October 1998
RO 20:on 980925,Reactor Operators Made Error at Ford Nuclear Reactor in Implementing Calorimetry Procedures to Raise Power Level.Upon Discovery of Error Made in Linear Level Setpoint Reactor Power Was Reduced by 1% to Compensate
ML20153H0841998-09-28028 September 1998
Special Rept:On 980925,inadequate Procedure Implementation Resulted in Possible steady-state Reactor Operation at 2.02 MW Thermal Power.Interim Reactor Manager Reviewed Calorimeter Data & Did Not See Any Obvious Errors
ML20151Z2701998-09-17017 September 1998
Safety Evaluation Supporting Amend 45 to License R-28
ML20151Z1571998-09-17017 September 1998
Revised Ro:On 980817,980811 Event Re Slow Inward Drift of CR Reoccurred.Caused by Worn Worm Gear & Missing Full Turn of Worm Thread.Installed & Tested Drive Gear Coupling. Previously Submitted Ltr Rept Dtd 980911,deleted Text
ML20151W6391998-09-11011 September 1998
Special Rept:On 980811,swing Shift Operators Noted That CR Would Slowly Drift Inwards When in Manual Control with CR low-raise Switch in Neutral.Cr lower-raise Switch Was Removed,Inspected & Cleaned,Then Reinstalled & Tested
ML20236W0781998-07-30030 July 1998
RO 19:on 980720,determined That Reactor Was Operating W/ Inoperable Alarm Circuit on Bridge Radiation Monitor.Caused by Spurious Alarms Due to Temp & Humidity Sensitivity. Maint Procedures CP-216 & CP-219 Were Modified
ML20236T0741998-07-23023 July 1998
Non-routine Rept:On 971112,reactor Operators Shut Down Ford Nuclear Reactor to Remove Piece of Polyethylene Irradiation Container.Caused by Lack of Oversight.Method Will Be Adopted to Track Quartz & Polyethylene Samples
ML20236T0801998-07-23023 July 1998
Development of Model Characterizing Heat Transfer in MTR Fueled Ford Nuclear Reactor
ML20236S2921998-07-20020 July 1998
RO-19:on 980720,reactor Operation w/in-operable Alarm Circuit on Bridge Radiation Monitor,Was Disabled.Caused by Spurious Alarms Due to Temperature & Humidity Sensitivity. Reactor Shutdown Pending Further Investigation
ML20248L5931998-06-0303 June 1998
Ro:On 980510,discovered 75 Gallon Loss of Pool Water to Radioactive Liquid Retention Tank Sys.Caused by Leak in One of Two Resin Columns Comprising B Hot Demineralizer (Hot Di) Sys.Modified Operating Procedure OP-211 Encl
ML20217K8811998-04-23023 April 1998
Corrected First Page of Safety Evaluation Supporting Amend 44 to License R-28,changing Date in First Paragraph to 970930 & Date in Second Paragraph to Oct 1996
ML20216J3501998-04-16016 April 1998
Safety Evaluation Supporting Amend 44 to License R-28
ML20217H1891997-12-31031 December 1997
Rept of Reactor Operations Jan-Dec 1997 for Ford Michigan Memorial - Phoenix Project Univ of Mi Ann Arbor
ML20137F2251996-12-31031 December 1996
Rept of Reactor Operation Jan-Dec 1996 for Ford Nuclear Reactor Mi Memorial - Phoenix Project Univ of Mi Ann Arbor
ML20137K7671996-12-31031 December 1996
Annual Rept of Reactor Operations for Period 960101-1231
ML20057F4521993-10-0606 October 1993
Follow-up on RO 18,dtd 930805 Re Release of low-level Radioactive Water from RB to Drain Tiles Around Foundation of Bldg.Line from Foundation Tiles Drains to Reactor Cold Sump,Through Which Water Released Permanently Sealed
ML20059M3161993-08-0101 August 1993
Rev 2 to Safety Analysis
ML20128D4641992-11-25025 November 1992
Ro:On 921124,control Rod Interlock Sys Removed from Reactor Control Sys.Caused by Wiring Error Made During Mod That Disabled Interlock That Drops Reactor Out of Automatic Control.Control Rod Withdrawn to 23 Inches
ML20058N7841990-08-0606 August 1990
RO 13:on 900721,tritium Content in Heavy Water Tank in Excess of 50 Ci.Samples Sent to Kms Fusion.Health Physics Procedure 107 Corrected to Reflect Correct Density of Heavy Water
ML20055H1141990-07-18018 July 1990
Requalification Program Ford Nuclear Reactor
ML20245F9791989-08-0404 August 1989
Safety Evaluation Supporting Amend 33 to License R-28
ML20246F3881989-05-0303 May 1989
RO 12:on 881227,concentrations of I-131 & Xe-133 Discovered in Reactor Pool Water.Caused by B&W Element 204 Releasing Fission Products.B&W Contacted to Review Mfg Process.Air Samples Will Be Taken Above Pool on Monthly Basis
ML20150C6951987-12-31031 December 1987
Rept of Reactor Operations,1987
ML20236U2031987-11-24024 November 1987
Safety Evaluation Supporting Amend 32 to License R-28
ML20141N1111986-02-24024 February 1986
Safety Evaluation Supporting Amend 31 to License R-28
ML20136G8911985-11-0505 November 1985
Safety Evaluation Supporting Amend 30 to License R-28
ML20126M2631985-07-31031 July 1985
Safety Evaluation Report Related to the Renewal of the Operating License for the Training and Research Reactor at the University of Michigan.Docket No. 50-2.(University of Michigan)
ML20138L5791984-06-30030 June 1984
Low Enrichment Fuel Evaluation & Analysis Program Summary Rept for Jan 1983 - June 1984
ML20138L5731982-12-31031 December 1982
Low Enrichment Fuel Evaluation & Analysis Program Summary Rept for CY81 & CY82
ML20138L5621980-12-31031 December 1980
Low Enrichment Fuel Evaluation & Analysis Program Summary Rept for CY80
ML20138L5491980-03-10010 March 1980
Cycle 184 Reactor Operations Summary Rept for 800226-0310
ML20138L5241979-12-31031 December 1979
Low Enrichment Fuel Evaluation & Analysis Program Summary Rept for CY79
ML20148D8151978-10-13013 October 1978
Safety Evaluation Rept Supporting Amend 26 to Facil Oper Lic R-28 Concluding That an Increase from 1 Mw to 2 Mw in Maximum Allowed Pwr of Fnr w/10-plate Fuel Assemblies in E,W & Core Positions Is Acceptable
ML20148C8061978-10-12012 October 1978
Safety Evaluation Supporting Amend 25 to License R-28
ML20138L5181978-04-20020 April 1978
Revised Safety Analysis:Utilization of Intermetallic U Aluminide (UAI3,UAI4,UAI2) & U Oxide (U308) Cermet Fuel Cores in Ford Nuclear Reactor
1999-08-05
[Table view] |
Text
C/ .
es- ,/. .
/G Ml08 Mill / 6 ' WiffHR/
nQ fe < MICHIGAN MEMORIAL-PHOENIX PROJECT gg PHOENIX MEMORIAL LABORATORY FOP.D NUCLEAR REACTOR ANN ARBOR, MICHIGAN 48109-2100 5 August 1999 Docket 50-2 License R-28 U.S. Nuclear Regulatory Commission Document Control Room Washington,DC 20555 Re: Final Report of Non-routine Occurrence - Identification of a Single Failure Mode for the Safety Related Temperature System This report is to inform the Commission of a condition involving a credible single failure in the safety related Temperature System that could result in the loss of the capability of the Temperature System to protect Limiting Safety System Settings. The condition was discovered while designing an upgrade to the system and reported initially on July 8,1999. This is the final report on the occurrence per Technical Specifications 6.6, Reporting Requirements.
Temperature System The Temperature System uses resistance temperature detectors (RTDs) as the sensing element. These RTDs are connected to a resistance bridge to provide a 4-20 mA current loop. This 4--20 mA current loop is dropped across a precision 250 ohm resistor to provide the voltage signal necessary to drive the temperature recorder. The temperature recorder has pre-set alarms that provide the required technical specification action upon reaching a Limiting Safety System Setting. The resistance bridge and 4-20 mA current loop are driven by a +15V DC power supply. This 15V DC power supply is powered from 110V AC Reactor Control Power and has a fuse for overload protection.
Summary ofSingle Failure The single failure mode is a loss of the 15 V DC power supply which results in loss of temperature indication. This prohibits the Required Safety Channel functions listed in Technical Specification 3.2.1, Reactor Safety System for Reactor Coolant Inlet Temperature, Reactor Pool Temperature, and Reactor Coolant Exit Temperature. Loss of these functions would be a reportable occurrence as defined in Technical Specification 1.0, Defmitions. A blown fuse is credible and as such the design of the temperature system should incorporate this failure mode. The failure to identify this system response was a design oversight when the 15 V DC power supply was initially installed.
Safety implications A failure of this nature should be promptly observed by the Console Operator and would result in a Manual Shutdown of the reactor per facility Operating Procedure 109, Responses to Scrams Alarms, and Abnormal /
Conditions. Although there exist plausible scenarios whereby the temperature limits within Technical Specification /)
2.1, Safety Limits, could be exceeded prior to operator action in the event of a loss of the 15 V DC power supply, these do not constitute a safety concern since temperatures in the primary coolant would remain well below any temperature that couldjeopardize the integrity of the fuel clad. A review of facility records indicates that a failure of this type has not occurred in the past.
Corrective Action
[h4 Modification Request No.134 to the Temperature System included a Low Temperature Auto Rundown to eliminate this single failure mode. This modification was approved by the Safety Review Committee prior to its installation.
zw2$ f~ t istopher W. Becker h -
Nuclear Reactor Laboratory Manager Phone: (734) 764-6224 Fax: (734) 936-1571 File: Correspondence 99-029 i NRC Correspondence 1999 l
C:\My Documents \CW13ecker\ Letter File \99-029. doc 9908120151 990005 PDR ADOCK 05000002 - - - - ---- - - -
PDR rax: (734) 936-1571 www.umich.edu/~mmpp/
f r . ,u. . u .,-. , , m .._ , .. . _ ,
[