Forwards AEOD/S803, AEOD Concerns Re Power Oscillation Event at LaSalle 2 (BWR-5). Rept Details AEOD Concerns Re Facility Power Oscillation Event of 880309.Significant Concerns & Associated Recommendations ListedML20155F804 |
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LaSalle |
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06/08/1988 |
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From: |
Jordan E NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
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To: |
Beckjord E, Murley T Office of Nuclear Reactor Regulation, NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
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ML20155F805 |
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References |
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REF-GTECI-B-19, REF-GTECI-B-59, REF-GTECI-ES, REF-GTECI-TH, TASK-B-19, TASK-B-59, TASK-OR AEOD-S803, NUDOCS 8806170060 |
Download: ML20155F804 (6) |
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Category:INTERNAL OR EXTERNAL MEMORANDUM
MONTHYEARML20217M5311999-10-25025 October 1999 Notification of 991103 Meeting with Util in Rockville,Md to Discuss Licensee Analytical Approach in Design of Pipe Supports at Plant ML20217C9051999-10-12012 October 1999 Forwards SER Input Approving License Request for Amend to Plant,Units 1 & 2.Licensee Proposal to Modify Definition of Core Alteration in Section 1.0 of TS & Update Sections 3/4.1,3.4.3 & 3/4.9 to Reflect Proposed Definition Change ML20211K8611999-09-0101 September 1999 Informs That There Has Been Some Confusion Re Recently Issued ODCM Generic Section Rev Which Needs to Be Clarified. Clarifications Are Listed ML20210P1361999-08-0404 August 1999 Notification of 990817 Meeting with Util in Rockville, Maryland to Discuss Status of Licensing Actions Submitted by Comm Ed & Plan for Proposed Licensing Workshop ML20237E3131998-08-26026 August 1998 Forwards for Public Release,Info Re NRC SMM Held on 980714-15.Summary of January 1998 NRC SMM & Watch List Removal Evaluation Factors Also Encl ML20237D9721998-08-11011 August 1998 Notification of Cancelled Licensee Meeting W/Util on 980903 to Discuss Effectiveness of Performance Improvement Initiatives & Progress Toward LaSalle Unit 1 Restart ML20237D9751998-08-11011 August 1998 Notification of Cancelled Licensee Meeting W/Util to Discuss Effectiveness of Performance Improvement Initiatives & Progress Toward LaSalle Unit 1 Restart ML20237D9821998-08-11011 August 1998 Notification of Licensee Meeting W/Util on 980915 to Discuss Status of LaSalle Unit 1 & Performance Improvement & Restart Plans for LaSalle Unit 2 ML20216H6971998-03-17017 March 1998 Notification of 980326 Meeting W/Commonwealth Edison Co in Lisle,Il to Discuss Comed Request to Consolidate near-site Emergency Operations Facility Into Single Central EOF ML20198N7961998-01-13013 January 1998 Confirms Rev to Time of NRC Oversight Panel Meeting for LaSalle County Station.Meeting Will Be Conducted on 980126 in Lisle,Il to Discuss Status & Effectiveness of Restart Plan Plant Performance Improvement Actions ML20197A8901997-12-16016 December 1997 Forwards Plant Restart Action Plan,For Review & Approval. Restart Action Plan Status Will Be Updated on as Required Basis ML20217D4261997-09-30030 September 1997 Informs of Scheduled Visits W/Nuclear Services at Gpu on Nov 14th & Visit at Commonwealth Edison on Dec 3rd & Would Like to Receive Any Info Available.Supporting Documentation Encl ML20211D6721997-09-15015 September 1997 Provides NRR Concurrence to Remove Big Rock Point from SALP Program,To Extend Current Point Beach SALP Cycle from 15 to 19 Months & to Extend Current LaSalle County Station SALP Cycle to Approx Six Months Following Restart of Either Unit ML20211D7661997-09-0303 September 1997 Informs of Intent & Rationale for Extending Current LaSalle County Station SALP Cycle to Approx Six Months Following Restart of Either Unit ML20217D5461997-04-18018 April 1997 Forwards Partially Withheld Background Briefing Package in Preparation for 970425 Meeting Between Comed & Commission IA-97-178, Forwards Partially Withheld Background Briefing Package in Preparation for 970425 Meeting Between Comed & Commission1997-04-18018 April 1997 Forwards Partially Withheld Background Briefing Package in Preparation for 970425 Meeting Between Comed & Commission ML20147J2391997-04-0909 April 1997 Notification of Meeting on 970416 W/Util in Rockville,Md to Discuss Overall Response & Present Addl Details Re Performance Indicators Used to Monitor Performance Stations ML20136C1031997-03-0606 March 1997 Forwards Correspondence Transmitted Via Internet to J Zwolinski from P Blanch During 970102-31.Requests Correspondence Be Placed in PDR ML20138J7671997-02-0505 February 1997 Informs That NRC Plans to Administer Generic Fundamentals Exam Section of Written Operator Licenseing Exam on 970409. Ltr W/Copy to Chief,Operator Licensing Branch Must Be Submitted to Listed Address in Order to Register Personnel ML20149M6901997-01-19019 January 1997 Notification of 970128 Meeting W/Commonwealth Edison Co to Discuss Licensee Proposed Program for Use of Mixed Oxide Fuel ML20134E8811996-12-27027 December 1996 Submits Dates Requested Re Plants ML20134E9141996-12-18018 December 1996 Discusses Highlights of Independent Self Assessment Exit Meeting ML20134E9071996-12-17017 December 1996 Submits Draft Highlights on Licensee Independent Self Assessment Exit Meeting & Decision to Extend Outages ML20134E8261996-12-16016 December 1996 Forwards Highlights from Exit Meeting for LaSalle Independent Safety Assessment ML20134E8401996-12-16016 December 1996 Discusses Highlights from LaSalle Independent Safety Assessment Exit Mtg ML20134E8581996-12-16016 December 1996 Forwards Highlights from Exit Meeting for LaSalle Independent Safety Assessment ML20210N4271996-12-0202 December 1996 Informs About Drop in Meeting on 961203 for Update on Industry Restructuring & Deregulation,Unicom Strategic Planning & Mixed Oxide Fuel ML20217D5421996-11-27027 November 1996 Forwards Partially Withheld Background Briefing Package in Preparation for 961203 Meeting Between Comed,Nuclear Strategic Services & Chairman Jackson ML20129J4781996-11-0404 November 1996 Summarizes 961030 Operating Reactors Events Briefing 96-14 Re Notification of Senior Managers from Commission,Oe,Aeod, Res,Nrr & Regional Offices of Selected Events That Occurred Since 961023 Briefing.List of Attendees Encl ML20210N3761996-08-12012 August 1996 Informs About Meeting on 960513 to Brief Chairman Jackson on Comed Response to Deregulation ML20217D4761996-07-31031 July 1996 Forwards Background Briefing Package in Prepartion of 960813 Meeting Between Commonwealth Edison Co & Chairman Jackson. Purpose of Visit to Discuss Recent Organizational Changes at Comed & Company Mgt Focus for Immediate Future ML20210N3381996-05-14014 May 1996 Discusses Courtesy Visit to Ceco on 960513 Re Listed Plants ML20210N2681995-11-13013 November 1995 Discusses Paritially Withheld Chairman Briefing by Ceco on 951116 ML20217D5321995-11-0909 November 1995 Forwards Partially Withheld Background Briefing Package in Preparation for 951116 Meeting Between Commission & Senior Comed Mgt.Purpose of Visit to Discuss Performance at Each of Sites & Challenges & Issues Needed to Be Addressed ML20210N3971995-10-12012 October 1995 Informs of Courtesy Visit on 951011 to Util to Discuss Listed Topics.List of Attendees Encl ML20210N3701995-10-0505 October 1995 Forwards Background Briefing Package in Preparation for 951011 Meeting W/Company Executives & Chairmam Jackson ML20134B5061994-04-13013 April 1994 Submits Plants Which Will Be Discussed in Categories Indicated Re Results of Screening Meetings for June 1994. Partially Deleted ML20059H2941994-01-21021 January 1994 Notification of Significant Licensee Meeting W/Util on 940201 in Lisle,Il to Discuss Failure to Take Prompt C/A for Hardened Grease in 4 Kv & 6.9 Kv Circuit Breakers Following 10CFR21 Notification & Oct 1992 Breaker Failure ML20058N4811993-12-15015 December 1993 Informs of Decision to Expand Senior Mgt Oversight of Selected Plants,Per Recent Meeting W/J Martin & H Miller. Lists Assignment of Managers,Effective Immediately IR 05000373/19930331993-11-23023 November 1993 Notification of 931130 Enforcement Conference in Region III Ofc to Discuss Fitness for Duty Issue as Discussed in Insp Repts 50-373/93-33 & 50-374/93-33 ML20062J4501993-10-27027 October 1993 Requests Addl Info Re Proposed EAL Changes in Util Generating Station Emergency Plan Annexes.Proposed EALs Reviewed Against Guidance in NUMARC/NESP-007,rev 2, Methodology for Development of Eals ML20059A4651993-10-20020 October 1993 Notification of Significant Licensee Meeting W/Util in Glen Ellyn,Il on 931104 to Review Status of Util Initiatives on QA & Corporate Engineering Support ML20057F2751993-10-13013 October 1993 Notification of 931021 Meeting W/Util in Rockville,Md to Discuss Util Mod to Address NRC Bulletin 93-03, Resolution of Issues Re Reactor Vessel Water Level Instrumentation in BWR, for Plant ML20057C9801993-09-27027 September 1993 Discusses 930927 Press Conference Re J O'Connor Announcement That Util Settled Six Rate Matters & Appeals Before Illinois Courts & Commerce Commission by Agreeing to Refund Listed Amount to Customers Over Next 12 Months ML20128E4961993-02-0505 February 1993 Notification of 930211 Meeting W/Util in Chicago,Il to Discuss Elimination of Operating Basis Earthquake Requirements for Pipe Ruptures ML20128C2901993-01-29029 January 1993 Notification of 930201 Meeting W/Licensee in Rockville,Md to Discuss Current Status of Licensing Activities at Plant ML20058K1361989-08-29029 August 1989 Lists Conclusions Reached at 890822 Meeting on Owners Group Improved Tech Specs,Including Surveillance Requirement 3.0.5 & pressure-temp Limits & Leakage Detection Sys ML20245C5871989-04-24024 April 1989 Notification of 890509 Meeting W/Util in Rockville,Md to Discuss Static O-Ring Differential Pressure Switches ML20245B6191989-04-15015 April 1989 Forwards Evaluation Rept Re BWR Overfill Events Resulting in Steam Line Flooding.All Events Included Reactor Depressurization Followed by Uncontrolled Condensate or Condensate Booster Pumps Injection or Both ML20245B7501989-04-15015 April 1989 Forwards Engineering Evaluation Rept on BWR Overfill Events Resulting in Flooding of Steam Lines.Potential for Equipment Damage Believed to Exist & Any Damage Occurring Should Be Fixed Prior to Restart 1999-09-01
[Table view] Category:MEMORANDUMS-CORRESPONDENCE
MONTHYEARML20217M5311999-10-25025 October 1999 Notification of 991103 Meeting with Util in Rockville,Md to Discuss Licensee Analytical Approach in Design of Pipe Supports at Plant ML20217C9051999-10-12012 October 1999 Forwards SER Input Approving License Request for Amend to Plant,Units 1 & 2.Licensee Proposal to Modify Definition of Core Alteration in Section 1.0 of TS & Update Sections 3/4.1,3.4.3 & 3/4.9 to Reflect Proposed Definition Change ML20211K8611999-09-0101 September 1999 Informs That There Has Been Some Confusion Re Recently Issued ODCM Generic Section Rev Which Needs to Be Clarified. Clarifications Are Listed ML20210P1361999-08-0404 August 1999 Notification of 990817 Meeting with Util in Rockville, Maryland to Discuss Status of Licensing Actions Submitted by Comm Ed & Plan for Proposed Licensing Workshop ML20237E3131998-08-26026 August 1998 Forwards for Public Release,Info Re NRC SMM Held on 980714-15.Summary of January 1998 NRC SMM & Watch List Removal Evaluation Factors Also Encl ML20237D9721998-08-11011 August 1998 Notification of Cancelled Licensee Meeting W/Util on 980903 to Discuss Effectiveness of Performance Improvement Initiatives & Progress Toward LaSalle Unit 1 Restart ML20237D9751998-08-11011 August 1998 Notification of Cancelled Licensee Meeting W/Util to Discuss Effectiveness of Performance Improvement Initiatives & Progress Toward LaSalle Unit 1 Restart ML20237D9821998-08-11011 August 1998 Notification of Licensee Meeting W/Util on 980915 to Discuss Status of LaSalle Unit 1 & Performance Improvement & Restart Plans for LaSalle Unit 2 ML20216H6971998-03-17017 March 1998 Notification of 980326 Meeting W/Commonwealth Edison Co in Lisle,Il to Discuss Comed Request to Consolidate near-site Emergency Operations Facility Into Single Central EOF ML20198N7961998-01-13013 January 1998 Confirms Rev to Time of NRC Oversight Panel Meeting for LaSalle County Station.Meeting Will Be Conducted on 980126 in Lisle,Il to Discuss Status & Effectiveness of Restart Plan Plant Performance Improvement Actions ML20197A8901997-12-16016 December 1997 Forwards Plant Restart Action Plan,For Review & Approval. Restart Action Plan Status Will Be Updated on as Required Basis ML20217D4261997-09-30030 September 1997 Informs of Scheduled Visits W/Nuclear Services at Gpu on Nov 14th & Visit at Commonwealth Edison on Dec 3rd & Would Like to Receive Any Info Available.Supporting Documentation Encl ML20211D6721997-09-15015 September 1997 Provides NRR Concurrence to Remove Big Rock Point from SALP Program,To Extend Current Point Beach SALP Cycle from 15 to 19 Months & to Extend Current LaSalle County Station SALP Cycle to Approx Six Months Following Restart of Either Unit ML20211D7661997-09-0303 September 1997 Informs of Intent & Rationale for Extending Current LaSalle County Station SALP Cycle to Approx Six Months Following Restart of Either Unit ML20217D5461997-04-18018 April 1997 Forwards Partially Withheld Background Briefing Package in Preparation for 970425 Meeting Between Comed & Commission IA-97-178, Forwards Partially Withheld Background Briefing Package in Preparation for 970425 Meeting Between Comed & Commission1997-04-18018 April 1997 Forwards Partially Withheld Background Briefing Package in Preparation for 970425 Meeting Between Comed & Commission ML20147J2391997-04-0909 April 1997 Notification of Meeting on 970416 W/Util in Rockville,Md to Discuss Overall Response & Present Addl Details Re Performance Indicators Used to Monitor Performance Stations ML20136C1031997-03-0606 March 1997 Forwards Correspondence Transmitted Via Internet to J Zwolinski from P Blanch During 970102-31.Requests Correspondence Be Placed in PDR ML20138J7671997-02-0505 February 1997 Informs That NRC Plans to Administer Generic Fundamentals Exam Section of Written Operator Licenseing Exam on 970409. Ltr W/Copy to Chief,Operator Licensing Branch Must Be Submitted to Listed Address in Order to Register Personnel ML20149M6901997-01-19019 January 1997 Notification of 970128 Meeting W/Commonwealth Edison Co to Discuss Licensee Proposed Program for Use of Mixed Oxide Fuel ML20134E8811996-12-27027 December 1996 Submits Dates Requested Re Plants ML20134E9141996-12-18018 December 1996 Discusses Highlights of Independent Self Assessment Exit Meeting ML20134E9071996-12-17017 December 1996 Submits Draft Highlights on Licensee Independent Self Assessment Exit Meeting & Decision to Extend Outages ML20134E8261996-12-16016 December 1996 Forwards Highlights from Exit Meeting for LaSalle Independent Safety Assessment ML20134E8401996-12-16016 December 1996 Discusses Highlights from LaSalle Independent Safety Assessment Exit Mtg ML20134E8581996-12-16016 December 1996 Forwards Highlights from Exit Meeting for LaSalle Independent Safety Assessment ML20210N4271996-12-0202 December 1996 Informs About Drop in Meeting on 961203 for Update on Industry Restructuring & Deregulation,Unicom Strategic Planning & Mixed Oxide Fuel ML20217D5421996-11-27027 November 1996 Forwards Partially Withheld Background Briefing Package in Preparation for 961203 Meeting Between Comed,Nuclear Strategic Services & Chairman Jackson ML20129J4781996-11-0404 November 1996 Summarizes 961030 Operating Reactors Events Briefing 96-14 Re Notification of Senior Managers from Commission,Oe,Aeod, Res,Nrr & Regional Offices of Selected Events That Occurred Since 961023 Briefing.List of Attendees Encl ML20210N3761996-08-12012 August 1996 Informs About Meeting on 960513 to Brief Chairman Jackson on Comed Response to Deregulation ML20217D4761996-07-31031 July 1996 Forwards Background Briefing Package in Prepartion of 960813 Meeting Between Commonwealth Edison Co & Chairman Jackson. Purpose of Visit to Discuss Recent Organizational Changes at Comed & Company Mgt Focus for Immediate Future ML20210N3381996-05-14014 May 1996 Discusses Courtesy Visit to Ceco on 960513 Re Listed Plants ML20210N2681995-11-13013 November 1995 Discusses Paritially Withheld Chairman Briefing by Ceco on 951116 ML20217D5321995-11-0909 November 1995 Forwards Partially Withheld Background Briefing Package in Preparation for 951116 Meeting Between Commission & Senior Comed Mgt.Purpose of Visit to Discuss Performance at Each of Sites & Challenges & Issues Needed to Be Addressed ML20210N3971995-10-12012 October 1995 Informs of Courtesy Visit on 951011 to Util to Discuss Listed Topics.List of Attendees Encl ML20210N3701995-10-0505 October 1995 Forwards Background Briefing Package in Preparation for 951011 Meeting W/Company Executives & Chairmam Jackson ML20134B5061994-04-13013 April 1994 Submits Plants Which Will Be Discussed in Categories Indicated Re Results of Screening Meetings for June 1994. Partially Deleted ML20059H2941994-01-21021 January 1994 Notification of Significant Licensee Meeting W/Util on 940201 in Lisle,Il to Discuss Failure to Take Prompt C/A for Hardened Grease in 4 Kv & 6.9 Kv Circuit Breakers Following 10CFR21 Notification & Oct 1992 Breaker Failure ML20058N4811993-12-15015 December 1993 Informs of Decision to Expand Senior Mgt Oversight of Selected Plants,Per Recent Meeting W/J Martin & H Miller. Lists Assignment of Managers,Effective Immediately IR 05000373/19930331993-11-23023 November 1993 Notification of 931130 Enforcement Conference in Region III Ofc to Discuss Fitness for Duty Issue as Discussed in Insp Repts 50-373/93-33 & 50-374/93-33 ML20062J4501993-10-27027 October 1993 Requests Addl Info Re Proposed EAL Changes in Util Generating Station Emergency Plan Annexes.Proposed EALs Reviewed Against Guidance in NUMARC/NESP-007,rev 2, Methodology for Development of Eals ML20059A4651993-10-20020 October 1993 Notification of Significant Licensee Meeting W/Util in Glen Ellyn,Il on 931104 to Review Status of Util Initiatives on QA & Corporate Engineering Support ML20057F2751993-10-13013 October 1993 Notification of 931021 Meeting W/Util in Rockville,Md to Discuss Util Mod to Address NRC Bulletin 93-03, Resolution of Issues Re Reactor Vessel Water Level Instrumentation in BWR, for Plant ML20057C9801993-09-27027 September 1993 Discusses 930927 Press Conference Re J O'Connor Announcement That Util Settled Six Rate Matters & Appeals Before Illinois Courts & Commerce Commission by Agreeing to Refund Listed Amount to Customers Over Next 12 Months ML20128E4961993-02-0505 February 1993 Notification of 930211 Meeting W/Util in Chicago,Il to Discuss Elimination of Operating Basis Earthquake Requirements for Pipe Ruptures ML20128C2901993-01-29029 January 1993 Notification of 930201 Meeting W/Licensee in Rockville,Md to Discuss Current Status of Licensing Activities at Plant ML20058K1361989-08-29029 August 1989 Lists Conclusions Reached at 890822 Meeting on Owners Group Improved Tech Specs,Including Surveillance Requirement 3.0.5 & pressure-temp Limits & Leakage Detection Sys ML20245C5871989-04-24024 April 1989 Notification of 890509 Meeting W/Util in Rockville,Md to Discuss Static O-Ring Differential Pressure Switches ML20245B6191989-04-15015 April 1989 Forwards Evaluation Rept Re BWR Overfill Events Resulting in Steam Line Flooding.All Events Included Reactor Depressurization Followed by Uncontrolled Condensate or Condensate Booster Pumps Injection or Both ML20245B7501989-04-15015 April 1989 Forwards Engineering Evaluation Rept on BWR Overfill Events Resulting in Flooding of Steam Lines.Potential for Equipment Damage Believed to Exist & Any Damage Occurring Should Be Fixed Prior to Restart 1999-09-01
[Table view] |
Text
b s 5 l Y KIC p .k UNITED STATES l
- g NUCLEAR REGULATORY COMMISSION ;
-l w AssiNoTos, o. c. 20sss r.
\ **"* / JUN 0 81968 j MEMORANDUM FOR: Thomas E. Murley, Director Office of Nuclear Reactor Regulation I
Eric S. Beck,iord, Director Office of Nuclear Regulatory Research FROM: Edward L. Jordan, Director Office for Analysis and Evaluation of Operational Data SUEJECT: AE0D CONCERNS REGAPDING THE MARCH 9, 1988 POWER OSCILLATION EVENT AT LASALLE 2 Enclosed is an AE00 Special Report detailing our concerns about the LaSalle 2 power oscillation event of March 9,1988. We have reviewed calculations performed by Brookhaven on the BWR Nuclear Plant Analyzer, as well as the licensee's LER and other foreign and U.S. infonnation. Although this is the first event of this type at a domestic reactor, similar events have occurred in foreign reactors. Based on this review, we classify this event as an important precursor event with significant safety concerns. Our most !
significant concerns and associated recomendations are described below. l
- 1. The laSalle event raises questions about the adequacy of the analysis used to meet the cora stability requirements of GDC-12 when both l recirculation pumps are tripped. The event also points out the '
difficulties the operators face in rapid diagnosis of and response to an event which readily promotes significant complicating factors such as j subsequent loss of feedwater heating and reactor water level fluctuations. ;
Simple and unambiguous procedures are needed to assure prompt proper l operator response which ensures compliance with GDC-12. GE SIL 380 does i not provide adequate guidance.
l
- 2. During startup and shutdown, BWCs routinely enter regions of potential thermal-hydraulic-neutron kinetics instability. This operation can be l
avoided without large impact on plant operations by nrodifying plant !
operating procedures to increase recirculation flow slightly early in the startup and by inserting control rods sooner during shutdcen.
Several foreign reactors operate with power / flow operating restrictions that avoid the unstable region. Addit %lly, reduction or loss of forced recirculation flow during plarc hansients can result in the plant entering regions of potential instability. Prudent operator action is '
needed to restore stable plant operation and to avoid actions which could l initiate events with more significant consequences. For example, restart of recirculation pumps following loss of feedwater heating or MSIV closure i could result in additional reactivity insei tion while the reactor was exhibiting power oscillations.
- 3. This event has implications regarding the reactor transient response to a recirculation pump trip during an ATWS. In par;icular, the power oscilla-tions may substantially exceed previously predicted values and thus raise ouestions regarding previous fuel integrity etaluations.
8806170060 88060s gDR ADOCK 05000374 PDR
Thomas E. Murley i l
Conclusion l
The March 9 LaSalle event indicates serious deficiencies in the core stability l analysis for LaSalle and perhaps other BWRs. Further, such undamped power '
oscillations call for prompt operator recognition and action, yet at LaSalle, operators were not trained to recognize or respond to such oscillations.
Adequate plant procedures did not exist at LaSalle, and few, if any, plant simulators in the U.S. are capable of modeling these typm of oscillations. l i
It is not at all clear at this time that we understand ) . nature end potential !
consequence of such power oscillations considering such factors as improper or :
I no operator action, alternative core configurations and equipment failures, or divergent localized power oscillations. Since it will take time to thoroughly analyze and understand the LaSalle event and its implications on other BWRs, we j conclude that, at least in this interim period, action is warranted to minimize i the potential for core instability. Our recommendations in this regard are '
presented below.
We anticipate a written response to these recommendations within 45 days as discussed in NRC Manual Chapter 0515. ,
Recommendation to NRR l Pending a full understanding of tne LaSalle event and its implications, we i believe that all BWRs should be required to; l (a) Immediately insert control rods to below the 80% rod line following reduction or loss of recirculation flow or other transients which result in entry into potentially unstable regions of the power / flow map.
(b) Increase recirculation flow during routine reactor startups and insert some control rods prior to reducing recirculation flow below 50% during shutdowns to avoid operation in potentially unstable areas of the power /
flow map.
(c) Immediately scram the reactor if (a) or (b) above are not successful.
Reconnendation to RES Review resolution of GIs B-19 and B-59 and ATWS mitigation in light of the LaSalle operating experience.
Please let me know if we can provide any clarification or additional assis-tance. If you have questions regarding the enclosed Special Report, please call Jack Rosenthal on x24440.
D(,ginal $6aed By:
E: D 'Judan Edward L. Jordan, Director Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated Distribution: See next page
- DSP:AE0D *DSP:AE0D *DSP:AE0D *DSP:AE00 *D:DSP:AE0D DD:AE0D *D:AE00 JKauffman:md Glanik JRosenthal VBenroya TNovak CJHeltemes ELJordan 6/ /88 6/ /88 6/ /88 6/ /88 6/ /88 6/ /88 6/q/88
Thomas E. Murley Conclusion The March 9 LaSalle event indicates serious deficiencies in the core stability analysis for LaSalle and perhaps other BWRs. Further, such undamped power oscillations call for prompt operator recognition and action, yet at LaSalle, operators were not trained to recognize or respond to such oscillations.
Adequate plant procedures did not exist at LaSalle, and few, if any, plant i simulators in the U.S. are capable of modeling these types of oscillations.
It is not at all clear at this time that we understand the nature and potential consequence of such power oscillations considering such factors as improper or no operator action, alternative core configurations and equipment failures, or divergent localized power oscillations. Since it will take time to thoroughly analyze and understand the LaSalle event and its implications on other BWRs, we conclude that, at least in this interim period, action is warranted to minimize the potential for core instability. Our recommendations in this regard are presented below.
[/>
. jg Recomendations
- 1. Pending a full understanding of the LaSalle event and its implications, we believe that all BWRs should be required to:
(a) Immediately insert control rods to below the 80% rod line following loss of all recirculation flow or other transients which result in entry into potentially unstable regions of the power / flow map.
(b) Increase recirculation flow during routine reactor startups and insert some control rods prior to reducing recirculation flow below 50% durir.g shutdowns to avoid operation in potentially unstable areas of the power / flow map.
(c) Immediately scram the reactor if (a) or (b) above are not successful.
frA
- 2. NRR should revisit GIs 8-19 and B-59 and ATWS mitigation in light of the LaSalle operating experience.
Please let me know if we can provide any clarification or additional assis-tance. If you have questions regarding the enclosed Engineering Evaluation, please call Jack Rosenthal on x24440.
Edward L. Jordan, Director Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated -
5 gsSS'f
/
Distribution: VSte//o Z Dy dr T h 24 b &3 <Gfds , 7 tub j RR MTaylor CHeltemes AE0D R/F JKauffman jf ROAR R/F JPartlow TNovak JRosenthal MWilliams M ,
EJordan VBena roya Glanik KBlack WLanp15ing L Pha MR$
7
- DSP:AE0D *DSP:AE00 *DSP:AE00 *DSP:AE0D *D: :AEOD DD:AE00 .ED JKauffman:md Glanik JRosenthal VBenroya vak CJHeltemes ELJordaji 6/ /88 6/ /88 6/ /88 6/ /88 6 ')i/88 6/ /86
/ /
109 6/
8 [/
Thomas E. Murley 3. This event has apparent implications regarding reactor response to recirculation pump trip during an ATWS. In particular, it is not clear where the power oscillations would peak and whether fuel would be damaged.
Recomendation Issue a generic communication which would require all BWRs to:
a) Immediately insert control rods to below the 80% rod line following loss >
of all recirculation flow, trip of a recirculation pump, or loss of feedwater heatina.
b) Increase recirct. tion flow during routine reactor startups and insert :
some control rods prior to reducing recirculation flow during shutdowns to l avoid operation in potentially unstable areas of the power / flow map.
c) Immediately scram the reactor if a) or b) above are not successful in l preventing and suppressing oscillations.
Under separate correspondence, we are recommending that RES revisit GIs B-19 and B-59 and ATWS mitigation in light of the LaSalle operating experience.
Conclusion Adequate justification exists for an appropriate generic communication that ensures prudent operations. In addition, adequate justification exists for revisiting the technical bases of previously resolved issues in light of the LaSalle operating experience.
Edward L. Jordan, Director Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated Distribution: I PDR MTaylor CHeltemes AE0D R/F JKauffman l ROAB R/F SEbneter TNovak JRosenthal MWilliams Edordan WLanning VBenaroya Glanik KBlack SEE PREVIOUS CONCURRENCE
- DSP:AE0D* DSP:AEOD* DSP:AE0D* DSP: qBp* 0:DSP:@D DD:AE00 0:AEOD JKauffman:md Glanik JRosenthal ena oya ovak W CJHeltemes Edordan 4/ /R0 4/ /88 4/ /88 /88 9/88 4/ /88 4/ /88 i
I
Thomas E. Murley Recomendation Issue a generic comunication which would require all BWRs to:
Imediately implement procedures to scram the plant on loss of all forced circulation.
Based on the LaSalle event, imediately train plant operators regarding the magnitude of the power oscillations observed, the short time to onset of these oscillations, and the factors which contribute to core instability.
Imediately implement the requirements of GE SIL 380, regardless of calculated decay catio, until improved analytical methods are approved by the NRC.
Implement procedures which prevent routine operation in or near the unstable region and which address operator response to transients which put the reactor in the unstable region.
Recommendation Because of current reliance on operator action to meet GDCs 10 and 12, perform a thorough, integrated review of procedures, operator training, Control Room aids, and instrumentation used for response to and identification of power oscillation events.
Recommendation On a lower priority, revisit Generic Issues B-19 and B-59 and the BWR ATWS mitigation studies in light of the LaSalle operating experience.
Conclusion Adequate justification exists for an appropriate generic comunication that ensures prudent operations. In addition, adequate justification exists for revisting the technical bases of previously resolved issues in light of the LaSalle operating experience and for performing a review of items required for adequate operator response to power oscillation events.
Edward L. Jordon, Director- ,
Office for Analysis and Evaluation of Operational Data '
Enclosure:
As stated Distribution: -
FDR MTaylor CHeltemes AE0D R/F JKauffman R0AB R/F SEbneter TNovak JRosenthal PWilliams !
Edordan WLanning Benaroya Glanik KBlack ;
DSP:AEOD D E0D F5P:AE0D DSP: E00 D:DSP:AE0D DD:AEOD D:AE0D JKauffman:md iLatik JRosenthal VBenaroya TNovak CJHeltemes EJordan 4/d/88 y-4/,7//88 4/g/88 4/1%/88 4/ /88 4/ /88 4/ /88
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Thoms E. Murley l Di ibution: J
. p ROAB"R/F AE0D R/F VStello JTaylor JSniezek Dross TSpets TMartin i ERossi EJordan MTaylor JPartlow WLanning CHeltemes TNovak VBenaroya JRosenthal Glanik-JKauffman MWilliams KBlack LPhillips MRing i
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