Letter Sequence Other |
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Results
Other: ML20099C963, ML20106B611, ML20112G495, ML20112G517, ML20133E335, ML20135G405, ML20141P237, ML20155G018, ML20212R258, ML20215J636, ML20216J199
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MONTHYEARML20097J8491984-09-13013 September 1984
Clarifies Re Method to Be Used to Enhance Moisture Removal If Request for Relief from 100 Psia Pcrv Pressure Restriction Granted.Helium Mass Flow Rate Through Circulator Differential Pressure Increased
Project stage: Request
ML20099C9631984-10-29029 October 1984
Ro:On 840911,moisture Discovered in Purified Helium Supply Line Wells During Installation of New Moisture Sensing Probes.Tests Indicate Leak Source Is Circulator Penetration A.Rate of Leak Approx .05 Gpm
Project stage: Other
ML20106B6111985-01-24024 January 1985
Informs That Concern W/Seriousness of Moisture Ingress Events & Other Impediments to Obtaining Realistic Plant Operation Prompted Corporate Mgt to Form Improvement Committee Under Chairmanship of Rf Walker
Project stage: Other
ML20112G5171985-01-24024 January 1985
Responds to HR Denton Identifying Requirement for Development of Plan to Implement Mods Recommended by Moisture Ingress Committee.Improvement Committee Formed to Evaluate Innovative & Substantial Plant Mods
Project stage: Other
ML20112G4951985-03-12012 March 1985
Responds to 850220-22 Requests for Addl Info Re Improvement Committee & Plant Mods Concerning Reduction of Primary Sys Moisture.Historical Background,Review Committee Responsibilities & Description of Helium Issues Encl
Project stage: Other
ML20135G4051985-09-0404 September 1985
Notifies of Mod to Helium Circulator Auxiliary Sys to Mitigate Pcrv Moisture Ingress.Digital Test Valve Removed from Main Drain Sys & Will Not Be Reinstalled
Project stage: Other
ML20133E3351985-09-20020 September 1985
Notifies of Change to One of Mods Provided in Re Helium Circulator Auxiliary Sys.Mod Designed to Mitigate Pcrv Moisture Ingress.Thermal Dispersion Type Flow Elements Removed for Evaluation by Manufacturer
Project stage: Other
ML20141P2311986-03-14014 March 1986
Forwards SER Re Util 860312 Plans for Mods to Facility in Order to Reduce Moisture Ingress Into Reactor Vessel.Design Mods Should Reduce Likelihood of Moisture Ingress
Project stage: Approval
ML20141P2371986-03-14014 March 1986
SER Re Util 860312 Plans for Mods to Facility in Order to Reduce Moisture Ingress Into Reactor Vessel.Design Mods Should Reduce Likelihood of Moisture Ingress.Licensee Committed to Conduct Further Studies If Ingress Continues
Project stage: Other
ML20155G0181986-04-0202 April 1986
Forwards Info Re Fort St Vrain Improvement Committee & Actions Taken & Under Consideration to Mitigate Moisture Ingress Into Primary Coolant Sys,Per Util 850312 Commitment
Project stage: Other
ML20216J1991987-02-0404 February 1987
Evaluation of Long-Term Effects of Moisture Ingress in Fort St Vrain Nuclear Reactor
Project stage: Other
ML20212R2581987-04-16016 April 1987
Provides NRC W/Annual Report of Actions Taken by Util or Under Consideration by Util to Mitigate Moisture Ingress Into Primary Coolant Sys,Per Item Iv.A of Encl to
Project stage: Other
ML20215J6361987-06-16016 June 1987
Forwards Advanced Science & Technology Assocs,Inc Rept Re Moisture Ingress at Facility.Agrees W/Subcontractor,Lasl, Conclusions Re Effects of Moisture Inleakage Occurrences Into Prestressed Concrete Reactor Vessel.W/O Encl
Project stage: Other
ML20216J1921987-06-17017 June 1987
Safety Evaluation Re Mods to Reduce Moisture Ingress Into Reactor Vessel.Periodic Insps & Preventive Maint Should Be Performed on Pertinent Components.Operational Performance Should Be Continuously Upgraded
Project stage: Approval
ML20216J1841987-06-17017 June 1987
Forwards Safety Evaluation & Rept Re Mods to Reduce Moisture Ingress Into Reactor Vessel.Lasl Recommends Operational Performance Be Upgraded & Reliability of Power Distribution Sys Be Improved to Reduce Frequency of Moisture Ingress
Project stage: Approval
1985-09-04
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2420 West 26th Avenue, Suite 1000, Denver, Colorado 80211 September 4, 1985 Fort St. Vrain Unit No.1 P-85285 Regional Administrator Region IV i
U.S. Nuclear Regulatory Comission SEP I ?. E 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011 Attention: Mr. Dorvin Hunter Docket No. 50-267
SUBJECT:
Modification Concerning Moisture Ingress
REFERENCE:
PSC Letter, 0. R. Lee to E. H. Johnson, dated 3/12/85 (P-85082)
Dear Mr. Hunter:
of the referenced letter provided a brief description of helium circulator auxiliary system modifications designed to mitigate PCRV moisture ingress. This letter provides notification of a change to one of those modifications. The test valve referred to as a Digital valve in the attachment has been removed from the 'A' circulator main drain system and will not be reinstalled at this time. The original conventional globe valve has been reinstalled and will be in operation for plant restart.
The test valve in the 'A' circulator and electronic controls on all
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four circulator positions were installed and limited performance testing completed prior to startup.
The electronic control in conjunction with controlling main drain strictly by the main drain to buffer helitm pressure differential has provided a significant system response improvement for the conventional globe valves.
Performance of the test valve was found to be very satisfactory in the area of response. However, after only thirty days operation, it developed significant mechanical problems which indicated a disappointingly short service life. The test valve was, therefore, removed for evaluation by the valve manufacturer and possible reliability testing.
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Should you desire further clarification of this issue, please contact Mr. M. H. Holmes at (303) 571-8409.
Very truly yours, A0$*/YLuntAW D. W. Warembourg, Manager Nuclear Engineering Division DW/ELh/deh
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