Letter Sequence Other |
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Results
Other: B10079, Discusses Position on Asymmetric LOCA Loads,In Response to NRC .Reactor Cavity Seal Will Not Be Subjected to Forces Creating Missile Hazard for Max pipe-break Opening Considered in WCAP-9558 & WCAP-9558,Revision 1, ML14184A106, ML15223A533, ML15238B097, ML17174B193, ML17207A438, ML17326A274, ML17338B145, ML18079B047, ML19208D035, ML19209A772, ML19209A773, ML19209B556, ML19209B989, ML19242A701, ML19247A568, ML19247B242, ML19249E918, ML19250C244, ML19259C125, ML19259C826, ML19259D694, ML19260D661, ML19262B585, ML19275A183, ML19275A432, ML19275A437, ML19275A443, ML19275A446, ML19296A786, ML19339C073, ML19347B263, ML20003A697
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MONTHYEARML19259C1251979-06-0606 June 1979 Responds to NRC .Discusses New Design for Reactor Cavity Annulus Seal Ring Support Sys.Describes Interim Operating Procedure Until New Sys Installed Project stage: Other ML19247A5681979-07-0505 July 1979 Notifies of Status of Rept on Reactor Cavity Annulus Seal. Most PWR Users Remove Ring During Normal Operation.Others Store Seal Ring in Raised Position During Normal Operation Project stage: Other ML15245A1061979-07-18018 July 1979 Discusses Review of Re Potential of Reactor Cavity Annulus Seal Ring to Become Destructive Missile. Requests Demonstration That Seal Ring Is Not Destructive or Removal of Seal Ring No Later than Next Refueling Outage Project stage: Approval ML19242A7011979-07-18018 July 1979 Requests Addl Info Demonstrating That Seal Ring Cannot Become Destructive Misile During lon-term Operation or Statement That Seal Ring Will Be Removed by Next Refueling Outage Project stage: Other ML19259C8261979-07-19019 July 1979 Advises That 780202 Response Has Been Reviewed Re Potential for Reactor Cavity Annulus Seal Ring to Become Destructive Missile in Loca.Requests Analysis Demonstrating Safe Conditions & Statement Re Seal Ring Removal Project stage: Other ML19247B2421979-07-26026 July 1979 Responds to Re Reactor Cavity Annulus Seal Ring. Requests Analysis of Seal Ring Effect on Other Containment Safety Components Should Ring Become Missile.Statement Promising Seal Ring Removal Before Next Refueling Outage Project stage: Other ML17244A8471979-09-0505 September 1979 Discusses Completion of Review of Response to Re Potential for Reactor Cavity Annulus Seal Ring to Become Destructive Missile in Event of LOCA Pipe Break Inside Reactor Cavity.Response Resolves Issue Project stage: Approval ML18043B0421979-09-0505 September 1979 Discusses Completion of Review of Response to Re Potential for Reactor Cavity Annulus Seal Ring to Become Destructive Missile in Event of LOCA Pipe Break Inside Reactor Cavity Project stage: Approval ML19275A4371979-09-11011 September 1979 Notifies That Util Response to NRC Acceptably Resolves Issue Re Potential for Reactor Cavity Annulus Seal Ring to Become Destructive Missile During LOCA Project stage: Other ML19208D0351979-09-11011 September 1979 Discusses Util Re Potential for Reactor Cavity Annulus Seal to Become Destructive Missile During Loca. Removal During Operation Is Acceptable Pending NRC Approval & Installation of Seal Ring Support Sys Project stage: Other ML19275A4321979-09-11011 September 1979 Notifies That Util Response to NRC Acceptably Resolves Issue Re Potential for Reactor Cavity Annulus Seal Ring to Become Destructive Missile During LOCA Project stage: Other ML17207A4381979-09-11011 September 1979 Notifies That Util Response to NRC Acceptably Resolves Issue Re Potential for Reactor Cavity Annulus Seal Ring to Become Destructive Missile During LOCA Project stage: Other ML19275A4431979-09-11011 September 1979 Notifies That Util Response to NRC Acceptably Resolves Issue Re Potential Issue for Reactor Cavity Annulus Seal Ring to Become Destructive Missile During LOCA Project stage: Other ML19275A4461979-09-11011 September 1979 Notifies That Util Response to NRC Acceptably Resolves Issue Re Potential for Reactor Cavity Annulus Seal Ring to Become Destructive Missile During LOCA Project stage: Other ML18079B0471979-09-18018 September 1979 Responds to Util Answer to NRC Re Reactor Cavity Seal Ring Generic Issue.Util Answer Acceptably Resolves Issue Project stage: Other ML17174B1931979-09-18018 September 1979 Notifies That Util Response to NRC Re Potential for Reactor Cavity Annulus Seal Ring to Become Destructive Missile During LOCA Acceptably Resolves Problem Project stage: Other ML17338B1451979-09-18018 September 1979 Responds to Util Answer to NRC Re Reactor Cavity Seal Ring Generic Issue.Util Answer Acceptably Resolves Issue Project stage: Other ML19209A7721979-09-18018 September 1979 Responds to Util Answer to NRC Re Reactor Cavity Seal Ring Generic Issue.Util Answer Acceptably Resolves Issue Project stage: Other ML19209A7731979-09-18018 September 1979 Responds to Util Answer to NRC Re Reactor Cavity Seal Ring Generic Issue.Util Answer Acceptably Resolves Issue Project stage: Other ML17326A2741979-09-18018 September 1979 Responds to Util Answer to NRC Re Reactor Cavity Seal Ring Generic Issue.Util Answer Acceptably Resolves Issue Project stage: Other ML19249E9181979-09-18018 September 1979 Notifies Util That Response to NRC Re Potential for Reactor Cavity Annulus Seal Ring to Become Destructive Missile During LOCA Acceptably Resolves Problem Project stage: Other ML14184A1061979-09-18018 September 1979 Notifies That Util Response to NRC Re Potential for Reactor Cavity Annulus Seal Ring to Become Destructive Missile During LOCA Acceptably Resolves Problem Project stage: Other ML19275A1831979-09-26026 September 1979 Submits Addl Info Omitted from Potential of Reactor Cavity Annulus Seal Ring to Become Destructive Missile in Event of LOCA Pipe Break Inside Reactor Cavity Project stage: Other ML19209B5561979-09-27027 September 1979 Responds to .Reactor Cavity Seal Ring Will Be Removed from Normal Operation No Later than Next Refueling Outage.Outage Is Scheduled for May-June 1980 Project stage: Other ML19209B9891979-09-28028 September 1979 Ack Receipt of NRC Re Reactor Cavity Annulus Seal Ring.Util Will Take Necessary Action to Preclude Seal Ring Becoming Potential Missile.Action Will Begin No Later than Fourth Refueling Shutdown Scheduled for Fall 1980 Project stage: Other ML19259D6941979-10-0202 October 1979 Responds to 780202 Response Re Potential for Reactor Cavity Annulus Seal Ring to Become Destructive Missile in Event of LOCA Pipe Break Inside Reactor Cavity.Response Inadequate. Must Demonstrate Safety or Remove Ring Project stage: Other ML19275A9151979-10-0202 October 1979 Discusses Review of Response to .Requests Demonstration That Seal Ring Cannot Become Destructive Missile During long-term Operation & That Public Health & Safety Is Not Threatened Project stage: Approval ML15223A5331979-10-11011 October 1979 Ack Receipt of .Ltr Did Not Provide Required Responses.Response Should Demonstrate That Seal Ring Cannot Become Destructive Missile.Info Requested within 30 Days of Ltr Receipt Project stage: Other ML19250C2441979-10-30030 October 1979 Informs of Resolution of Reactor Cavity Ring Seal Generic Issue Project stage: Other ML19254F9311979-11-0909 November 1979 Responds to 791002 Request for Info Re PWR Reactor Vessel Seal Ring Missile Problem.Seal Ring Cannot Become Destructive Missile During Continued long-term Operation & Poses No Threat to Public Health & Safety Project stage: Request ML19262B5851979-12-20020 December 1979 Advises That Seal Ring Should Be Removed Following Each Refueling Outage by Raising Ring More than 12 Ft Above Cavity Floor,In Response to NRC 791002 Request.Util Does Not Concur W/Nrc Belief That Ring Could Become Missile Project stage: Other ML19260D6611980-01-26026 January 1980 Responds to Re NRC 791002 Request to Evaluate Potential for Reactor Cavity Annulus Seal Ring to Become Destructive Missile During LOCA Pipe Break Inside Reactor Cavity.No Further Action Required Project stage: Other ML19296A7861980-01-28028 January 1980 Accepts Util 790927 Commitment to Remove Reactor Cavity Seal Ring During Normal Operations Prior to Startup Following Next Refueling Outage.Commitment Resolves Issue Discussed in NRC Project stage: Other ML19260E2921980-02-0404 February 1980 Notifies That NRC Has Completed Review of Util 791220 Response Re Potential for Reactor Cavity Annulus Seal Ring to Become Destructive Missile in Event of LOCA Pipe Break Inside Reactor Cavity.Response Acceptably Resolves Issue Project stage: Approval ML15238B0971980-04-30030 April 1980 Notifies That Removal & Storage of Reactor Cavity Seal Ring Satisfactorily Resolves Safety Issue Identified in NRC Project stage: Other ML19316A8251980-05-0808 May 1980 Advises That Review of of 790926 Response to NRC Re Potential Destructive Consequence for Annulus Seal Ring in Event of LOCA Pipe Break Is Complete.Decision Not to Use Seal Ring Except During Refueling Is Acceptable Project stage: Approval ML19347B2631980-09-29029 September 1980 Responds to Re Proposed Reactor Cavity Annual Seal Plate Storage.Relocation to Storage Area Remote from Differential Pressures Generated within Reactor Cavity Following Postulated LOCA Is Acceptable Project stage: Other ML18139A5651980-09-30030 September 1980 Responds to NRC Request for Updated Status Rept on Reactor Vessel Flange Seal Ring Analysis.Westinghouse Owners Group Study Offers Rationale for Not Requiring Installation of Pipe Break Restraints Project stage: Request B10079, Discusses Position on Asymmetric LOCA Loads,In Response to NRC .Reactor Cavity Seal Will Not Be Subjected to Forces Creating Missile Hazard for Max pipe-break Opening Considered in WCAP-9558 & WCAP-9558,Revision 11980-10-0303 October 1980 Discusses Position on Asymmetric LOCA Loads,In Response to NRC .Reactor Cavity Seal Will Not Be Subjected to Forces Creating Missile Hazard for Max pipe-break Opening Considered in WCAP-9558 & WCAP-9558,Revision 1 Project stage: Other ML19339C0731980-10-30030 October 1980 Verifies That Seal Ring Has Been Removed from Cavity Annulus Area & Is Not Potential Missile Hazard.Concludes That Safety Issue Has Been Satisfactorily Resolved Project stage: Other ML20003A6971981-01-21021 January 1981 Notifies of Satisfactory Resolution of Safety Issue Re Potential for Reactor Cavity Annulus Seal Ring or Biological Shielding within Reactor Cavity to Become Missile in Event of LOCA Project stage: Other 1979-09-26
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'o UNITED STATES b
[ 'yp[r. y ',,g NUCLEAR REGULATORY COMMISSION x
E WASHINGTON, D. C. 20555 7
% bQ /g July 26,1979 Jocket tio. 50-29 Mr. Robert fi. Groce Licensing Engineer Yankee Atomic Electric Company 20 Turnpike Road Westboro, Massachusetts 01581
Dear Mr. Groce:
We have reviewed your response to our letter dated February 2,1978, in regard to the potential for the reactor cavity annulus seal ring to become a destructive missile in the event of a loss-of-coolant accident pipe break inside the reactor cavity.
In your response, you indicated that in the event of a large coolant pipe rupture the subsequent ECCS analysis takes no credit for control rod insertion. Therefore, damage to the control rod drive mechanisms (CRDM) would not affect the safe shutdown of the reactor subsequent to a loss-of-coolant accident as previously analyzed.
However, the role of CRDM for the safe shutdown of the reactor for small break LOCA has not been addressed.
Moreover, you have not analyzed the effects of the seal ring, should it become a missile, on other safety related components located inside the containment. Therefore, pursuant to 10 CFR 50.54 (f) of the Conmission's regulations, you are requested to (a) demonstrate by appropriate analysis that the seal ring cannot become a destructive missile during continued long-tenn operation and that it poses no threat to the health and safety of the public; or (b) furnish a statement that the seal ring will be removed by no later than the next refueling outage.
Please respond within 60 days of your receipt of this letter.
irgcerely,
])
n%d Dennis L. Ziemaa, Chief Operating Reactors Branch #2 Division of Operating Reactors cc:
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[1;)(j O[2 290808 6
4 Mr. Robert H. Groce July 26,1979 cc Mr. Lawrence E. Minnick, President Yankee Atomic Electric Company 20 Turnpike Road
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Westboro, Massachusetts 01581 Greenfield Community College 1 College Drive Greenfield, Massachusetts 01301 4