|
---|
Category:REPORTABLE OCCURRENCE REPORT (SEE ALSO AO LER)
MONTHYEARML20072D5071994-07-27027 July 1994 Ro:On 940722,drift of Temp Trip Setting of Primary Coolant Occurred.Suspect Drift Occurred Since 940522 Due to Failure of Compressor That Provides Bldg Compressed Air.New Equipment Ordered to Replace Current Unit ML19310A3451980-05-23023 May 1980 Ro:On 800410,heavy-water Temp Recorder TRA-D1 Was Not Recalibr After Replacement of Worn Sliding Contacts on Scanner Select Switch.Cause Not Stated.Importance of Recalibr Emphasized to Personnel ML19309F1241980-04-14014 April 1980 RO 80-02:on 800305,low Flow Scram of Flow Recorder FRA-D1 Resulted in Reactor Trip & Subsequent Shutdown.Caused by Broken Teflon Gasket Pieces Restricting Flow.Gasket Repaired & Sys Refilled 1994-07-27
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20210E9411999-07-22022 July 1999 Safety Evaluation Supporting Amend 14 to License R-97 ML20207A6541999-02-26026 February 1999 1998 Annual Rept for Ga Institute of Technology Research Reactor. New TS No Longer Require Annual Operating Rept to Be Submitted to Nrc.Rept Submitted Since Facility Under Previous TS for Portion of CY98 ML20155G9901998-11-0404 November 1998 Safety Evaluation Supporting Amend 13 to License R-97 ML20236Q0781998-06-0404 June 1998 Rev 3 to 82A9083, Ga Inst of Technology Research Reactor Decommissioning Plan ML20217K7981998-04-0202 April 1998 Safety Evaluation Supporting Amend 12 to License R-97 ML20203H0571998-02-24024 February 1998 1997 Annual Rept for Ga Institute of Technology Research Reactor ML20135D2821996-12-31031 December 1996 1996 Annual Rept for Ga Institute of Technology Research Reactor ML20106G4281996-02-27027 February 1996 Annual Rept for Ga Inst of Technology Research Reactor for CY95 ML20078A0001995-01-10010 January 1995 SAR for 5 MW Ga Tech Research Reactor, Revised from First Submittal,Apr 1994 ML20149G8581994-10-31031 October 1994 Provides NRC W/Error Notice Received from Former Software Supplier ML20072D5071994-07-27027 July 1994 Ro:On 940722,drift of Temp Trip Setting of Primary Coolant Occurred.Suspect Drift Occurred Since 940522 Due to Failure of Compressor That Provides Bldg Compressed Air.New Equipment Ordered to Replace Current Unit ML20070M9701994-04-30030 April 1994 SAR for 5 MW Georgia Tech Research Reactor. W/Financial Qualifications of Georgia Institute of Technology to Operate Georgia Tech Research Reactor ML20064N3581994-03-31031 March 1994 Nucleate Boiling Characteristics & Critical Heat Flux Occurrence in Subcooled Axial-Flow Water Sys ML20063L4971994-02-25025 February 1994 Annual Rept for Ga Inst of Technology Research Reactor ML20058L9001993-05-0404 May 1993 Part 21 Rept Consisting of Gtices Program Error Notice 93.14 Re Ibm RS6000 Computers Gt Modeler Recovery File.Resized Graphics Screen Can Not Be Completely Recovered.Lists Customers Not Notified Because of Unknown Current Addresses ML20035H0401993-04-22022 April 1993 Part 21 Rept Re Problem in Gtstrudl Computer Code,Resulting in Incorrect Answers or Job Aborts.Initially Reported on 920831.Listed Customers Not Notified Due to Unknown Current Addresses.Curve Data May Be Lost After Save/Restore Process ML20035H0671993-04-14014 April 1993 Part 21 Rept,Consisting of Error Notice Received from Former Software Supplier (Georgia Inst of Technology) Re Problem Results in Gtstrudl Computer Code.Listed,Former Customers Not Notified Due to Unknown Current Addresses ML20035G8261993-04-0101 April 1993 Part 21 Rept,Consisting of Error Notice Received from Georgia Inst of Technology Re Incorrect Answers Which May Not Be Apparent or Job Aborts in Gtstrudl Computer Code. Listed Vendors Not Notified Due to Unknown Addresses ML20034E6811993-02-22022 February 1993 Annual Rept for 1992 ML20128A1481992-09-30030 September 1992 Analyses for Conversion of Ga Tech Research Reactor from HEU to LEU Fuel ML20090B3821992-02-24024 February 1992 Annual Rept for 1991 (CY91) for Ga Institute of Technology Research Reactor ML20096H5461991-12-31031 December 1991 Corrected Pages 13 & 14 to Annual Rept,Consisting of Item 7(e) Re Max Cumulative Radiation Dose Which Could Have Been Received by Individual Continuously Present in Unrestricted Area During Reactor Operation ML20079B1551991-06-0707 June 1991 Amend to 1990 Annual Rept - Georgia Tech Research Reactor. Submittal Corrects Error in Item 1.f on Page 5 Re Changes in Plant Staff & Committee Membership ML20065S7981991-01-0202 January 1991 Requalification Program for Reactor Operators/Senior Reactor Operators,Georgia Tech Research Reactor ML20235W8571989-02-21021 February 1989 Annual Rept for 1988 ML20151C0681988-07-12012 July 1988 Safety Evaluation Supporting Amend 7 to License R-97 ML20154N0061988-04-19019 April 1988 Neely Nuclear Research Ctr Response to NRC Concerns ML20151R1981988-03-29029 March 1988 Rept of Visit to Georgia Tech Research Reactor Facility to Inspect Facilities & to Interview Operational Staff ML20148E3451988-03-14014 March 1988 Incident Rept of Cadmium Spill on 870818 ML20148F3191988-02-26026 February 1988 Annual Rept for 1987.Related Info,Including Revised Procedure 3800, Liquid Waste Disposal Sys, from Chapter 15 of Auxiliary Sys Encl ML20207T4171987-02-16016 February 1987 Annual Rept for 1986,including Operations Summary,Power Generation,Shutdowns,Unscheduled Maint on safety-related Sys & Components & Changes,Test & Experiments W/O Prior NRC Approval ML20235X1721986-12-31031 December 1986 Rev 1 to 1986 Annual Rept, Correcting Several Errors in Section 7, Environ Monitoring ML20009A1861981-03-13013 March 1981 Annual Operating Rept for 1980 ML19310A3451980-05-23023 May 1980 Ro:On 800410,heavy-water Temp Recorder TRA-D1 Was Not Recalibr After Replacement of Worn Sliding Contacts on Scanner Select Switch.Cause Not Stated.Importance of Recalibr Emphasized to Personnel ML19309F1241980-04-14014 April 1980 RO 80-02:on 800305,low Flow Scram of Flow Recorder FRA-D1 Resulted in Reactor Trip & Subsequent Shutdown.Caused by Broken Teflon Gasket Pieces Restricting Flow.Gasket Repaired & Sys Refilled ML19309F0881980-04-11011 April 1980 RO 80-1:on 791009,during ECCS Tank TD-2 Monthly Flow Rate Verification,Flow Rate Observed to Be 8 Gpm.Caused by Loose Lock Nuts Which Fix handle-to-ball Operating Shaft. Surveillance Program Will Be Strengthened ML20009A1891980-02-28028 February 1980 Annual Operating Rept for 1979 ML20009A1901979-03-0707 March 1979 Annual Operating Rept for 1978 ML20101L3751972-12-19019 December 1972 SER Approving Mod to Georgia Tech Research Reactor to Permit Operation at Increased Power Levels Up to 5 Mwt 1999-07-22
[Table view] |
Text
?O q 4
GEORGI A INSTITUTE OF TECHNOLOGY SCHOOL OF NUCLEAR ENGINEERING ATLANTA, GEORGI A 30332
' /." 16 r.!0 : 5 3 FR AN M H. N EE LY NUCLE AR RESE ARCH CENTER TELEPHONE: (404) 894 3400 April 14, 1980 U.S. Nuclear Regulatory Comission, Fagion II 101 Marietta Street, N.W. Suite 3100 Atlanta, Georgia 30303
Subject:
Licensee Event Report LER 80-2 Gentlemen:
Reference:
Docket 50-160 License R-97 At 1157 hours0.0134 days <br />0.321 hours <br />0.00191 weeks <br />4.402385e-4 months <br /> on March 5,1980 the Georgia Tech Research Reactor (GTRR) was shutdown frcm 1107 by a " Low D 0 Flow" scram. his trip came from 2
flow recorder FRA-Dl. Observation of the recorder trace indicated a step decrease in flow from 1760 gallons per minute (gpm) to 1720 Epm.
The trip point setting is specified to be 1625 gpm.
An extensive investigation was begun to detemine the cause of the flow decrease. On March 6-7, 1980 boroscopic and indirect visual examinations were made inside the reactor vessel, particularily in the vicinity of the reactor outlet nozzle. No problems were noted. On March 10, 1980, the main coolant pump MD2A was operated several times while observers stationed themselves in the process equipment room. It was detemined that system pressures were generally greater than nomal, particularly the pressure between heat exchangers HX-D1 and HX-D2 which was 3-4 psi above normal.
During each startup of the punp, metallic-sounding noises were heard from the channel head of HX-D2. Additionally, the system m ssure gages were observed to fluctuate full scale during each startup, indication a pressure e
pulse somewhere in the system.
Based upon these observations and with the concurrence of the Nuclear Safe-guards Comittee, the primry system was drained and the channel cover on HX-D2 was re::oved. Bree pieces of Teflon gasket material were found in the channel. he area of these pieces was estimated to be 36 sq. inches.
Be gasket mterial was thought to be from HX-D1 so the channel cover of this heat exchanger was removed. me gasket for Lhis cover was a full-face type and it aas founf to be damaged with missing pieces in the outlet quadrant.
Additionally, the horizontal channel separater was seen to be deflected downward, ie. toward the inlet line, appmximately 11/4 inch.
()1
//o 0FFICLE COPY h_
.. =
'h00418g
a s
.w U.S. Nuclcar Regulatory Cormtission, Region II Page 2 April 14, 1980 Two additional pieces of Teflon gasket material were removed from the pipe ccnnecting HX-D1 and HX-D2. 'Ihese accounted for all the missing gasket material. Compression marks on the gasket for HX-D1 suggested that the deflection of the partition had occurred some time ago, perhaps in 1974 when the quick closing isolation valves were first installed and tested.
We believe that the pieces of Teflon Epsket broken off from HX-D1 were carried into HX-D2. During hydraulic startup, the pieces would be randomly impacted on the tubes of HX-D2, causing a pressure pulse in the D 0 system.
2
'Ihe Teflon pieces would act to restrict the flow somewhat through the system.
When the trip point from the flow recorder FRA-D1 was checked, it was found that the sealed mercur/ contact switch that actuated the trip had loosened in its holder causing the trip to occur at approximately 1690 gpm rather than the 1625 gpm set point. The loose switch was corrected.
Repair was effected by using two hydraulic jacks to nove the partition plate back to approximately its original position. A new Teflon gasket was made with cutouts and ribs for the partition plate. On March 21, 1980, the system was refilled and on March 26, 1980, the prirnry coolant pump was started.
Flow and system pressure readings were nomal.
On April 4,1980, during hydraulic startup, a very loud " buzzing" noise was heard frcm the channel section of HX-Dl. 'Ihe channel cover was removed and it was seen that a portion of the new gasket had extruded between the par-tition plate and the channel cover. 'Ihe noise was caused by vibration of the extruded section of gasket. We believe this occurred during hydraulic start-up as the pressure " lifted" the cover slightly from the channel. On April 8, 1980, a new, 1/8" thick full face Tef1cn gasket was installed on HX-D1. The main cool-ant pump was started and the system throughly checked. Flow was nonml, pressures nomal and no unusual sounds were noted.
We believe that the problem has now been corrected. If you have any questions about this matter please advise me.
Sincerely rours,
- 1 Robert S. Kir d
Associate Dimetor RSK:lm cc: Members, Nuclear Safeguards Conmittee L.D. McDowell (2)
L.E. Weaver i
..... _. _. _. _ _. _ _