Letter Sequence Other |
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Results
Other: ML20083M935, ML20084H457, ML20084P594, ML20092D927, ML20094R400, ML20096C908, ML20106B579, ML20107K230, ML20112D736, ML20126C521, ML20127K137, ML20127N695, ML20128N286, ML20132G502, ML20154A542, ML20235N112
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MONTHYEARML20083M9351984-04-12012 April 1984
Discusses Problems W/Pcrv Prestressing Sys & Resultant Insp Test Results.Liftoff Tests Show Tendon Sys Operable.Nrc Permission to Return to Power Operation from Present Refueling Outage Requested by 840418
Project stage: Other
ML20084H4571984-04-25025 April 1984
Forwards Relaxation Curves for Prestressed Concrete Reactor Vessel Tendon Sys,In Response to 840419 Request.No Immediate Mechanism for Controlling Sleeve Atmosphere Provided.Areas W/Indicated Corrosion Regreased
Project stage: Other
ML20084P5941984-05-0707 May 1984
Forwards Pcrv Tendon Sys Relaxation Curves Containing Min Design Lines,Per H Polk 840503 Telcon Request
Project stage: Other
ML20092D9271984-06-15015 June 1984
Responds to Requesting Details of Proposed Tendon Surveillance Program.Program Consists of Load Cell Data & Visual Insps.Surveillance Started on 840601.Program Developed Using Reg Guide 1.35 as Ref
Project stage: Other
ML20093J1171984-07-20020 July 1984
Forwards Rev 2 to Updated FSAR for Fort St Vrain.Rev Includes Safety Evaluations Either in Support of License Amends or in Support of Conclusions That Changes Did Not Involve Unreviewed Safety Question
Project stage: Request
ML20094R4001984-08-0909 August 1984
Confirms 840806 Telcon on Tech Spec Change Request Re Tendon Corrosion & Anchor Assembly Surveillance.Tech Spec Change Request Will Be Submitted by 840930
Project stage: Other
ML20096C9081984-08-20020 August 1984
Responds to Re Possible Design Mods to Pcrv Tendons & Details of Evaluations & Schedule of Completion of Repts Detailing Results of Metallurgical Exams.Actions Necessary to Evaluate Design Mods for Pcrv Listed
Project stage: Other
ML20107K2301984-10-18018 October 1984
Updates Tendon Investigations & Corrosion Prevention Programs.Efforts Concentrated on Corrosion Prevention Methods Rather than Detailed Moisture Measurements
Project stage: Other
ML20112D7361984-12-14014 December 1984
Forwards Tendon Accessibility Info,Rationale for Tendon Surveillance & Info Re Corrosion Mechanism in Response to 840720 & 1029 Requests for Addl Info.Tendons Considered Acceptable If No Major Mods Necessary
Project stage: Other
ML20106B6131985-01-31031 January 1985
Discusses Visual Insp of Top Longitudinal Tendons,Per 850115 Meeting Request.Visual Insp of 30% of Longitudinal Tendons for Buttonheads Noted.Inconsistency Exists Between Last Mapping of Raised Buttonheads & Current Insp Results
Project stage: Meeting
ML20106B5791985-01-31031 January 1985
Submits Plans for Implementing Interim Tendon Surveillance Program,In Response to Concerns.Surveillance Program Will Be Based on Proposed Tech Spec SR 5.2.2,submitted in DW Warembourg
Project stage: Other
ML20132G5021985-03-12012 March 1985
Evaluation of CRD Mechanism & Reserve Shutdown Sys Failures & Pcrv Tendon Degradation Issues Prior to Fort St Vrain Restart
Project stage: Other
ML20128N2861985-05-20020 May 1985
Informs of Intent to Conduct Addl Insps of Random Sample of Pcrv Bottom Head Longitudinal Tendon Anchor Assemblies. Thirty-four Longitudinal Bottom End Caps Accessible.Ten End Caps Will Be Removed & Inspected
Project stage: Other
ML20126C5211985-05-23023 May 1985
Discusses Investigation of Methods to Control Tendon Corrosion Involving Establishment of Nitrogen Blanket on Pcrv Tendon Sys.Establishing & Maintaining Overall Nitrogen Blanket Sys for Tendons Highly Questionable
Project stage: Other
ML20127K1371985-06-0707 June 1985
Discusses Insp of 10 Bottom Longitudinal Tendon End Caps. Tendons Visually & Magnetic Particle Inspected for Evidence of Corrosion,Concavity,Water,Apparent Failures & Cracking.No Raised Buttonheads Found.All Tests Negative
Project stage: Other
ML20127N6951985-06-14014 June 1985
Elaborates on Util Commitments to Listed Plant Activities, Including CRD Mechanism Temp Recording,Requalification, Surveillance & Preventative Maint,Backup Reactor Shutdown Procedure,Tendons & Pcrv Integrity & Electrical Sys
Project stage: Other
ML20138A8071985-07-0202 July 1985
Forwards Updated Safety Evaluation Accepting Util Commitments Re Tendon Surveillance as Basis for Restart. Util Will Incorporate Modified Tendon Surveillance Program Into Tech Specs & Provide Results 6 Months After Restart
Project stage: Approval
ML20138A8551985-07-0202 July 1985
Safety Evaluation Accepting Util Tendon Surveillance Proposal.Proposal Will Lead to Maintaining Structural Integrity of Reactor Vessel.Plant Structurally Ready for Restart
Project stage: Approval
ML20132G4501985-07-0808 July 1985
Forwards Safety Evaluation Re Pcrv Prestressing Tendon Wire Corrosion Problems.Submittals & 0614 Acceptably Resolve Concerns.Lasl Evaluation Rept Encl
Project stage: Approval
ML20132G4761985-07-0808 July 1985
Safety Evaluation Re Pcrv Tendon Corrosion Investigation & Proposed Remedy.Tendon Surveillance Proposal Acceptable
Project stage: Approval
ML20235N1121987-07-0909 July 1987
Forwards Lasl Technical Evaluation Rept, Technical Assistance for Fort St Vrain Task Ii:Pcrv & Pcrv Tendon Evaluation, Final Rept
Project stage: Other
ML20154A5421988-08-30030 August 1988
Requests Addl Info Re Rev 7 to Schedule Commitment Items on Pcrv Tendon Surveillance Involving Provision of Schedule for Conducting Evaluation within 45 Days for Pcrv Tendon Degradation
Project stage: Other
1985-01-31
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Text
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h PublicService
.iio s.,*.
Company of Colorado 16805 WCR 19 1/2, Platteville, Colorado 80651 June 7, 1985 Fort St. Vrain Unit No. 1 P-85193 Regional Administrator Region IV ff,3 ggggg U. S. Nuclear Regulatory Commission j
611 Ryan Plaza Drive, Seite 1000
/I
! M l 8E Arlington, Texas 76011 6
M Attention: Mr. Eric H. Johnson Docket No. 50-267
SUBJECT:
Fort St. Vrain Additional Tendon Inspection
REFERENCES:
- 1) PSC Letter, D. W. Warembourg to E. H. Johnson, dated 5/~20/85 (P-85176)
- 2) IFE Information Notice 85-10 (G-85053)
- 3) I&E Information Notice 85-10 Supplement 1 (G-85098)
Dear Mr. Johnson:
As per Reference 1, ten of the bottom longitudinal tendon end caps were removed for inspection.
The visual inspection consisted of examining the tendon end caps, prestressing anchor assembly stressing washer, shims, bearing plate and buttonheads for evidence of general corrosion, concavity, water or apparent failures. The inspection showed no evidence of concavity, cracking, water, or general corrosion.
No raised buttonheads were found during this inspection.
To insure that there was no cracking similar to that at Farley, five y
(6 ]
of the anchor assemblies were magnetic particle inspected for cracking. The tendons inspected were VM1, VI3, Vill, VM17, VM18, VM22, VI27, VM31, VI34 and VI38. The tendons which were subjected to v
the examination were VM1, VM17, VM22, VM31 and VI34.
gh 8506270277 850607
)b PDR ADOCK 05000267
/
G PDR
Due to bleedout associated with liquid penetrant tests, Public Service Company considers magnetic particle testing to be more sensitive for this application. The magnetic particle tests showed-no discontinuities.
During this inspection, no visible evidence of pitting was found in the tendon caps. As per Reference 3, a galvanic cell was established at Farley between their galvanized caps and the stressing washers.
The zinc in Farley's prostressing system was essential in the establishment of the galvanic cell, which resulted in stressing washer failure. Since we have no zinc coated components associated with our prestressing system and based on all previous inspections to date, it is Public Service Company of Colorado's conclusion that Fort St. Vrain'is not susceptible nor exhibiting evidence of zinc related galvanic cell corrosion.
If you have any further questions, please do not hesitate to contact Mr. M. H. Holmes at (303) 571-8409.
Very truly yours, D. rv. rviAm D. W. Warembourg, 9
Manager, Nuclear Engineering Division
- Ref. Corrosion Engineering by Fontana/Greene, 1978.
DWW/MJF/ksc Attachments
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