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| 5 WASHINGTON, D. C. 20555 el SAFETY EVALVATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION TOLLUU LD150h LUMPANY DAVIS-BE5SE NUCLEAR POWER 51 ATION DOCKET NO. 50-346 During a combined ASME Section XI and pre-fueling visual inspection several "looseparts"werediscoveredintheDavis-BesseNuclearPowerStatIon(DBNFS) | | 5 WASHINGTON, D. C. 20555 el SAFETY EVALVATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION TOLLUU LD150h LUMPANY DAVIS-BE5SE NUCLEAR POWER 51 ATION DOCKET NO. 50-346 During a combined ASME Section XI and pre-fueling visual inspection several "looseparts"werediscoveredintheDavis-BesseNuclearPowerStatIon(DBNFS) |
| Unit I reactor vessel. Two pieces were determined to be from a high pressure injection / makeup (HPI) nozzle thermal sleeve. In a letter dated September 14, 1988, the licensee reported the results of field inspections, laboratory metal-lographic analysis, and fracture mechanics analyses of the cracked thermal sleeve and of the adjacent nozzle at the connection of the HPI piping to the reactor coolant system (RCS) cold leg. | | Unit I reactor vessel. Two pieces were determined to be from a high pressure injection / makeup (HPI) nozzle thermal sleeve. In a {{letter dated|date=September 14, 1988|text=letter dated September 14, 1988}}, the licensee reported the results of field inspections, laboratory metal-lographic analysis, and fracture mechanics analyses of the cracked thermal sleeve and of the adjacent nozzle at the connection of the HPI piping to the reactor coolant system (RCS) cold leg. |
| The metalleraphic analysis of the failed thermal sleeve indicates that the cracks propaga+ . by fatigue, with high cycle thermal stresses being the primary cause of crack .uwth, and flow induced vibratory stresses a secondary cause. The licensee concluded that the high cycle thermal fa'igue stresses resulted from thermal mixing of hot reactor coolant and relatively cc.d makeup flow at the outlet end of the sleeve during periods of low makeup flow. The licensee has replaceo the failed thermal sleeve with a design which will facilitate installation and reduce the effect of potential flow-induced vibration. The licensee has committed: (a) to evaluate and, as practical, increase minimum bypass flow; (b) to provide for neans of accurately setting the minimum bypass flow; and (c) to provide procedures to clearly establish administrative control of bypass flow. | | The metalleraphic analysis of the failed thermal sleeve indicates that the cracks propaga+ . by fatigue, with high cycle thermal stresses being the primary cause of crack .uwth, and flow induced vibratory stresses a secondary cause. The licensee concluded that the high cycle thermal fa'igue stresses resulted from thermal mixing of hot reactor coolant and relatively cc.d makeup flow at the outlet end of the sleeve during periods of low makeup flow. The licensee has replaceo the failed thermal sleeve with a design which will facilitate installation and reduce the effect of potential flow-induced vibration. The licensee has committed: (a) to evaluate and, as practical, increase minimum bypass flow; (b) to provide for neans of accurately setting the minimum bypass flow; and (c) to provide procedures to clearly establish administrative control of bypass flow. |
| Dye penetrant examination of the nozzle adjacent to the failed thermal sleeve revealed ru1tiple indications between the RCS weld buttons and the nozzle knuckle region with some extending over the knuckle, into the cold leg piping. Grinding away of approximately one-sixteenth inch of clad material did not remove these indications. It is believed that these indications are cracks resulting from high cycle thermal fatigue. | | Dye penetrant examination of the nozzle adjacent to the failed thermal sleeve revealed ru1tiple indications between the RCS weld buttons and the nozzle knuckle region with some extending over the knuckle, into the cold leg piping. Grinding away of approximately one-sixteenth inch of clad material did not remove these indications. It is believed that these indications are cracks resulting from high cycle thermal fatigue. |
Latest revision as of 19:46, 5 December 2021
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Category:SAFETY EVALUATION REPORT--LICENSING & RELATED ISSUES
MONTHYEARML20211B0271999-08-13013 August 1999 SER Accepting Second 10-year Interval Inservice Insp Requests for Relief RR-A16,RR-A17 & RR-B9 for Plant, Unit 1 ML20195K2871999-06-16016 June 1999 Safety Evaluation Accepting Licensee Response to GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power-Operated Gate Valves ML20199H5931999-01-20020 January 1999 Safety Evaluation Accepting Thermo-Lag Re Ampacity Derating Issues for Plant ML20155B6781998-10-28028 October 1998 Safety Evaluation Accepting Proposed Reduction in Commitment Changes in QA Program Matl Receipt Insp Process ML20236R1441998-07-15015 July 1998 SER Related to Quality Assurance Program Description Changes for Davis-Besse Nuclear Power Station,Unit 1 ML20236K3981998-06-30030 June 1998 SER Accepting in Part & Denying in Part Relief Requests from Some of ASME Section XI Requirements as Endorsed by 10CFR50.55a for Containment Insp for Davis-Besse Nuclear Power Station,Unit 1 ML20236K5131998-06-29029 June 1998 Safety Evaluation Accepting Proposed Alternate Emergency Operations Facility Location for Davis-Besse Nuclear Power Station,Unit 1 ML20198R4771998-01-13013 January 1998 SER Approving Second 10-year Interval Inservice Inspection Program Plan Requests for Relief for Davis-Besse Nuclear Power Station,Unit 1 ML20128L3001996-10-0202 October 1996 SER Supporting Dbnp IPE Process of Identifying Most Likely Severe Accidents & Severe Accident Vulnerabilities ML20058M9591993-09-28028 September 1993 SE Accepting Licensee Response to GL 89-19, Request for Action Re Resolution of USI A-47, 'Safety Implication of Control Sys in LWR Nuclear Power Plants.' ML20057A3791993-08-20020 August 1993 SE Concluding That Second 10-yr Interval Inservice Insp Program Plan for Plant Has Unacceptable Exam Sample as Discussed in Encl Inel TER ML20056G4301993-08-18018 August 1993 Safety Evaluation Re Inservice Testing Program Requests for Relief.Licensee Made Changes to Subj Program to Include Exercising & fail-safe Testing of Auxiliary Feedwater Valves AF-6451 & AF-6452,in Response to TER Anomaly 8 ML20056B2721990-08-20020 August 1990 Safety Evaluation Granting Relief from ASME Code Repair Requirements for ASME Code 3 Piping ML20248D8271989-09-29029 September 1989 Safety Evaluation Accepting Util 890228 & 0630 Submittals Presenting Proposed Designs to Comply w/10CFR50.62 ATWS Rule Requirements ML20247E6901989-09-0505 September 1989 Safety Evaluation of Audit of Facility Design for Resolution of IE Bulletin 79-27 Re Loss of non-Class IE Instrumentation & Control Power Sys Bus During Operation.Preventive Maint & Testing Program Should Be Developed for Bus Power Sources ML20247J8731989-05-18018 May 1989 Safety Evaluation Supporting Amend 133 to License NPF-3 NUREG-0660, Safety Evaluation Accepting Util 840301 & 870420 Responses to NUREG-0737,Item 1.C.1,except Where Noted in Section 21989-05-0303 May 1989 Safety Evaluation Accepting Util 840301 & 870420 Responses to NUREG-0737,Item 1.C.1,except Where Noted in Section 2 ML20196D9601988-12-0808 December 1988 Safety Evaluation Re Util Response Concerning Auxiliary Feedwater Sys Reliability Study.Util Should Ensure That Sys Mods Do Not Result in Net Reduction in Sys Reliability ML20207K7911988-10-0404 October 1988 Safety Evaluation Supporting Operation in Cycle 6 W/O Removing Flaws in Cracked HPI Nozzle ML20148D0391988-01-19019 January 1988 SER Accepting Util 831209 Response to Generic Ltr 83-28,Item 4.5.2 Re Reactor Trip reliability-on-line Testing.Unit Designed to Permit on-line Functional Testing of Diverse Trip Features of Reactor Trip Breakers ML20147C2631988-01-12012 January 1988 Safety Evaluation Accepting Util Responses to Generic Ltr 83-28,Item 2.1 (Part 1) Re Equipment Classification of Reactor Trip Sys Components ML20149F9621988-01-11011 January 1988 SER Accepting License Response to Generic Ltr 83-28,Item 2.2.1 Re Equipment Classification Programs for safety- Related Components ML20236U6531987-11-27027 November 1987 Safety Evaluation Re Effects of Errors in Util Analysis of Small Break Loca.Use of Incorrect Values in Analysis Results in Incomplete Compliance w/10CFR50,App K.Plant Poses No Risk to Public Health Due to Meeting 10CFR50.46 Requirements ML20236T3871987-11-25025 November 1987 SER Re Conformance to Reg Guide 1.97 Concerning post-accident Monitoring Instrumentation.Design Acceptable ML20211G8641987-02-11011 February 1987 Safety Evaluation Supporting Licensee Responses to Generic Ltr 83-28,Item 3.2.3, Post-Maint Testing & All Other Safety-Related Components ML20207Q6711987-01-0909 January 1987 Safety Evaluation Supporting Util Re Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock Events ML20212C9231986-08-0404 August 1986 Sser Supporting Util Reanalyses of 74 Masonry Walls ML20212G6021986-08-0404 August 1986 Safety Evaluation Accepting Util Response to NRC Request for Addl Info Re Question 29 Concerning Training for Infrequent, Critical & Difficult Tasks ML20212R3421986-06-10010 June 1986 SER Re Progress Made by Licensee in Area of Plant Maint.New Maint Organization Functioning W/No Major Weaknesses.Region III Will Continue to Monitor Maint at Plant to Assure Continued Control & Progress ML20206F3041986-05-27027 May 1986 Safety Evaluation Accepting Util Review Re Cold Pressurization of Secondary Side of Steam Generator During Testing on 850906 ML20203N9141986-04-17017 April 1986 Safety Evaluation Accepting Proposed Mods to Safety Actuation Sys Re Shared Power Supply Returns as Result of 801205 Actuation NUREG-0103, Safety Evaluation Supporting Relief from Inservice Insp Requirements of ASME Boiler & Pressure Vessel Code Requiring Quarterly Stroke Testing of RCS Valves & Denying Relief from Code Requirements for Valve RC-11 Testing1986-03-0606 March 1986 Safety Evaluation Supporting Relief from Inservice Insp Requirements of ASME Boiler & Pressure Vessel Code Requiring Quarterly Stroke Testing of RCS Valves & Denying Relief from Code Requirements for Valve RC-11 Testing ML20137J6891986-01-0808 January 1986 Safety Evaluation Supporting Util Identification of Root Causes for Spurious 850609 Steam & Feedwater Line Rupture Control Sys Low Level Actuation,Closure of MSIVs & Actions Taken to Prevent Recurrence.Plant Restart Acceptable ML20137J7031986-01-0808 January 1986 SER Supporting Util Identification of Root Causes for Source Range Nuclear Instrumentation Channels Inoperability During 850609 Steam & Feedwater Line Rupture Control Sys Low Level Actuation & Corrective Actions Taken.Plant Restart Approved ML20136B7841985-12-24024 December 1985 SER Re Util Development of Systematic & Thorough Troubleshooting Plans to Investigate 850609 Incident Leaving Redundant source-range Nuclear Instrumentation Channels Inoperable.Restart & Power Operation Now Acceptable ML20137R1611985-11-12012 November 1985 Safety Evaluation Supporting Util Responses to Generic Ltr 83-28,Items 4.2.1 & 4.2.2 Re Preventive Maint & Trending of Parameters ML20138P0681985-10-30030 October 1985 Safety Evaluation Accepting Licensee 831107 & 850709 Responses to Generic Ltr 83-28,Items 3.1.1,3.1.2,4.1 & 4.5.1 Re post-maint Testing & Reactor Trip Sys Reliability (vendor-related Mods & Sys Functional Test Description) ML20138P6391985-10-30030 October 1985 SER Re Proposed Mods to Maint Program.Licensee Should Identify Actions to Be Completed Prior to or After Restart. Region Should Actively Monitor Licensee Progress ML20133Q0441985-10-24024 October 1985 Safety Evaluation Supporting Util 831107 Response to Generic Ltr 83-28,Item 3.1.3 Re post-maint Testing (Reactor Trip Sys Components).Eg&G Technical Evaluation Rept Encl ML20062E0871982-07-29029 July 1982 Safety Evaluation Supporting Licensee Request for Relief from ASME Boiler & Pressure Vessel Code Section XI Hydrostatic Test (Insp) Requirements ML20214J2801979-12-20020 December 1979 Safety Evaluation Re Preliminary Design for Upgrading Present control-grade Anticipatory Reactor Trip Sys for Loss of Main Feedwater & Turbine Trip to safety-grade ML20125B1331968-12-16016 December 1968 Safety Evaluation Re Piqua Nuclear Power Facility Retirement.T Hamrick to J Schlesinger Encl 1999-08-13
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217K1231999-10-14014 October 1999 Revised Positions for DBNPS & Pnpp QA Program ML20217D5441999-09-30030 September 1999 Monthly Operating Rept for Sept 1999 for Davis-Besse Nuclear Power Station.With ML20211R0811999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for Davis-Besse Nuclear Power Station,Unit 1.With ML20211B0271999-08-13013 August 1999 SER Accepting Second 10-year Interval Inservice Insp Requests for Relief RR-A16,RR-A17 & RR-B9 for Plant, Unit 1 ML20210Q8541999-07-31031 July 1999 Monthly Operating Rept for July 1999 for Davis-Besse Nuclear Power Station,Unit 1.With ML20209E6231999-06-30030 June 1999 Monthly Operating Rept for June 1999 for Davis-Besse Nuclear Power Station,Unit 1.With ML20195K2871999-06-16016 June 1999 Safety Evaluation Accepting Licensee Response to GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power-Operated Gate Valves ML20195F4871999-05-31031 May 1999 Monthly Operating Rept for May 1999 for Davis-Besse Nuclear Power Station,Unit 1.With ML20207E8011999-05-19019 May 1999 Non-proprietary Rev 2 to HI-981933, Design & Licensing Rept DBNPS Unit 1 Cask Pit Rack Installation Project ML20207F4351999-05-0404 May 1999 Rev 1 to DBNPS Emergency Preparedness Evaluated Exercise Manual 990504 ML20206M6341999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for Davis-Besse Nuclear Station,Unit 1.With ML20205M2931999-03-31031 March 1999 Monthly Operating Rept for Mar 1999 for Davis-Besse Nuclear Power Station.With ML20207J1461999-02-28028 February 1999 Monthly Operating Rept for Feb 1999 for Davis-Besse Nuclear Power Station,Unit 1.With ML20199H5931999-01-20020 January 1999 Safety Evaluation Accepting Thermo-Lag Re Ampacity Derating Issues for Plant ML20204J6751998-12-31031 December 1998 1998 Annual Rept for Dbnps,Unit 1,PNPP,Unit 1 & BVPS Units 1 & 2 ML20199E2501998-12-31031 December 1998 Monthly Operating Rept for Dec 1998 for Davis-Besse Nuclear Power Station,Unit 1.With ML20206B0101998-12-31031 December 1998 1998 Annual Rept for Firstenergy Corp, for Perry Nuclear Power Plant & Davis-Besse Nuclear Power Station.Form 10-K Annual Rept to Us Securities & Exchange Commission for Fiscal Yr Ending 981231,encl ML20205K5781998-12-31031 December 1998 Waterhammer Phenomena in Containment Air Cooler Swss ML20197J3441998-11-30030 November 1998 Monthly Operating Rept for Nov 1998 for Davis-Besse Nuclear Power Station,Unit 1.With ML20195D0001998-10-31031 October 1998 Monthly Operating Rept for Oct 1998 for Davis-Besse Nuclear Power Station,Unit 1.With ML20155B6781998-10-28028 October 1998 Safety Evaluation Accepting Proposed Reduction in Commitment Changes in QA Program Matl Receipt Insp Process ML20154H5801998-09-30030 September 1998 Monthly Operating Rept for Sept 1998 for Davis-Besse Nuclear Power Station,Unit 1.With ML20151W1611998-08-31031 August 1998 Monthly Operating Rept for Aug 1998 for Dbnps.With ML20237E3171998-08-21021 August 1998 ISI Summary Rept of Eleventh Refueling Outage Activities for Davis-Besse Nuclear Power Station ML20237B1681998-07-31031 July 1998 Monthly Operating Rept for July 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20236U5011998-07-23023 July 1998 Special Rept:On 980624,Unit 1 Site Damaged by Tornado & High Winds.Alert Declared by DBNPS Staff,Dbnps Emergency Response Facilities Activiated & Special Insp Team Deployed to Site by Nrc,As Result of Event ML20236R1441998-07-15015 July 1998 SER Related to Quality Assurance Program Description Changes for Davis-Besse Nuclear Power Station,Unit 1 ML20236N7451998-06-30030 June 1998 Monthly Operating Rept for June 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20236K3981998-06-30030 June 1998 SER Accepting in Part & Denying in Part Relief Requests from Some of ASME Section XI Requirements as Endorsed by 10CFR50.55a for Containment Insp for Davis-Besse Nuclear Power Station,Unit 1 ML20236K5131998-06-29029 June 1998 Safety Evaluation Accepting Proposed Alternate Emergency Operations Facility Location for Davis-Besse Nuclear Power Station,Unit 1 ML20248F7441998-05-31031 May 1998 Reactor Vessel Working Group,Response to RAI Regarding Reactor Pressure Vessel Integrity ML20249A4121998-05-31031 May 1998 Monthly Operating Rept for May 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20196B5221998-05-23023 May 1998 10CFR50.59 Summary Rept of Facility Changes,Tests & Experiments Dbnps,Unit 1 for 960602-980523 ML20236E7581998-05-19019 May 1998 Rev 0 to Davis-Besse Unit 1 Cycle 12 Colr ML20236N7501998-04-30030 April 1998 Rev 2 to Monthly Operating Rept for Apr 1998 for Davis-Besse Nuclear Power Station,Unit ML20247F6721998-04-30030 April 1998 Monthly Operating Rept for Apr 1998 for Davis-Bess Nuclear Power Station,Unit 1 ML20249A4141998-04-30030 April 1998 Revised Monthly Operating Rept for Apr 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20217P8041998-04-0707 April 1998 11RFO OTSG ECT Insp Scope ML20216B4041998-03-31031 March 1998 Monthly Operating Rept for Mar 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20216C5131998-02-28028 February 1998 Monthly Operating Rept for Feb 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20202D3721998-01-31031 January 1998 Monthly Operating Rept for Jan 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20199G6321998-01-26026 January 1998 Rev 1 to Davis-Besse Unit 1,Cycle 11,COLR ML20198R4771998-01-13013 January 1998 SER Approving Second 10-year Interval Inservice Inspection Program Plan Requests for Relief for Davis-Besse Nuclear Power Station,Unit 1 ML20198K7931997-12-31031 December 1997 Monthly Operating Rept for Dec 1997 for Davis-Besse Nuclear Power Station,Unit 1 ML20217K6401997-12-31031 December 1997 1997 Annual Rept First Energy ML20203A3931997-11-30030 November 1997 Monthly Operating Rept for Nov 1997 for Davis-Besse Nuclear Power Plant,Unit 1 ML20198S5371997-10-31031 October 1997 Monthly Operating Rept for Oct 1997 for Davis-Besse Nuclear Power Station ML20217H7701997-09-30030 September 1997 Monthly Operating Rept for Sept 1997 for Davis-Besse Nuclear Power Station,Unit 1 ML20216H3261997-08-31031 August 1997 Monthly Operating Rept for August 1997 for DBNPS ML20217K0241997-07-31031 July 1997 Monthly Operating Rept for Jul 1997 for Davis Besse Nuclear Power Station,Unit 1 1999-09-30
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8 o NUCLEAR REGULATORY COMMISSION l
5 WASHINGTON, D. C. 20555 el SAFETY EVALVATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION TOLLUU LD150h LUMPANY DAVIS-BE5SE NUCLEAR POWER 51 ATION DOCKET NO. 50-346 During a combined ASME Section XI and pre-fueling visual inspection several "looseparts"werediscoveredintheDavis-BesseNuclearPowerStatIon(DBNFS)
Unit I reactor vessel. Two pieces were determined to be from a high pressure injection / makeup (HPI) nozzle thermal sleeve. In a letter dated September 14, 1988, the licensee reported the results of field inspections, laboratory metal-lographic analysis, and fracture mechanics analyses of the cracked thermal sleeve and of the adjacent nozzle at the connection of the HPI piping to the reactor coolant system (RCS) cold leg.
The metalleraphic analysis of the failed thermal sleeve indicates that the cracks propaga+ . by fatigue, with high cycle thermal stresses being the primary cause of crack .uwth, and flow induced vibratory stresses a secondary cause. The licensee concluded that the high cycle thermal fa'igue stresses resulted from thermal mixing of hot reactor coolant and relatively cc.d makeup flow at the outlet end of the sleeve during periods of low makeup flow. The licensee has replaceo the failed thermal sleeve with a design which will facilitate installation and reduce the effect of potential flow-induced vibration. The licensee has committed: (a) to evaluate and, as practical, increase minimum bypass flow; (b) to provide for neans of accurately setting the minimum bypass flow; and (c) to provide procedures to clearly establish administrative control of bypass flow.
Dye penetrant examination of the nozzle adjacent to the failed thermal sleeve revealed ru1tiple indications between the RCS weld buttons and the nozzle knuckle region with some extending over the knuckle, into the cold leg piping. Grinding away of approximately one-sixteenth inch of clad material did not remove these indications. It is believed that these indications are cracks resulting from high cycle thermal fatigue.
The fracture mechanics analysis indicates that high cycle thermal fatigue cracks are self limiting to a depth substantially less than the depth permitted by ASME Code when a defect is evaluated for brittle fracture considerations. The licensee's brittle fracture analysis met the margins rr. quired for continued operation in Subarticle IWB-3600 of Section XI of the ASME Code (1977 Edition through Sumer 1977 Addenda). The analysis indicates that high cycle thermally induced cracks in the HP!
nozzle with thermal sleeves intact will not grow to a size which will affect the integrity of the nozzle during the remaining life of DBNPS.
i P
~
s 2-Ultrasonic examination of the nozzle revealed no reportable indications. The licensee c intends that, based on the detection capability of the ultrasonic exami-nation, these examination results indicate that the cracks in the nozzle are shallow (less than 0.3 inches in depth) and have not penetrated through the clad into the base metal.
CONCLUSIONS:
Based on the results of the licensee's fracture mechanics analyses, the ultrasonic examination, the revised thermal sleeve design, and the licensee's commitments related to evaluation and monitoring of bypass flow, the staff concludes that DBNPS may be operated for Cycle 6 without removing the cracks in the HPI nozzle.
Principal contributor: Barry Elliot, ENTB Dated: October 4, 1988 I