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Category:DEFICIENCY REPORTS (PER 10CFR50.55E & PART 21)
MONTHYEARML20210E3591997-03-27027 March 1997 Part 21 Rept Re Sorrento Electronics Inc Has Determined Operation & Maint Manual May Not Adequately Define Requirements for Performing Periodic Surveillance of SR Applications.Caused by Hardware Failures.Revised RM-23A ML20115J3981996-07-22022 July 1996 Interim Part 21 Rept Re 3/4 Schedule 80 Pipe Furnished to Consolidated Power Supply.Investigation Revealed Only One Nuclear Customer Involved in Sale of Matl ML20077C2801994-11-21021 November 1994 Deficiency Rept Re Defective Yokes P/N 342849 Mfg by Copes- Vulcan,Inc.Affected Utilities Notified & Defective Yokes Will Be replaced.Copes-Vulcan Also re-inspected All Yokes in Inventory & Verified Yokes Acceptability ML20056D7071993-07-15015 July 1993 Part 21 Rept Re Reportable defect-75 PSIG Relief Check Valve 1 Npt,Emd 9521844,Kepner 416C-1-75 ML20126J5961992-12-31031 December 1992 Part 21 Rept Re Potential Loss of RHR Cooling During Nozzle Dam Removal.Nozzle Dams May Create Trapped Air Column Behind Cold Leg Nozzle Dam.Mod to Nozzle Dams Currently Underway. Ltrs to Affected Utils Encl ML20094F5181991-12-23023 December 1991 Part 21 Rept Re Matl Used in Johnson Kokogawa Corp Wear Plate Blades Not Displaying Sufficient Spring Capabilities to Adequately Hold Rom Chip Pins When Rom Mounted in Socket.Util Advised That Improved Sockets Now Available ML20012A9011990-02-27027 February 1990 Suppls 900213 10CFR21 Rept Re Chilled Water Sys Operation. Evaluation of Crystal River Determined That Postulated High Energy Line Break in Intermediate Bldg May Be Subj to Steam Loads Higher than Normal Loads,Causing Rising Water Temp ML20011F5971990-02-22022 February 1990 Part 21 Rept Re Solder Connections in Abb 27/59 Relays Deteriorated Due to Thermal Stress,Causing Bonding of Printed Wiring Pattern to Glass Epoxy Circuit Board.Interim Circuit Board W/Larger Pads & Higher Wattage Will Be Used ML20011F1941990-02-22022 February 1990 Part 21 Rept Re Abb 27/59 Relay Catalog Series 211L.Solder Connections to Printed Wiring Runs on Bottom of Circuit Board Deteriorated Due to Thermal Stress.No Actual Failure Occurred & Relays to Be Changed at Next Outage ML18153C1011990-02-0202 February 1990 Part 21 Rept Re Two of Three Pc Cards in GE Type SLV11A1 Over/Undervoltage Relays Failing to Produce Output.Short Between Leads Would Result in Damage to Component 1C5. Sketch of Threshold Detection Board Encl ML17223A7451990-01-26026 January 1990 Part 21 Rept Re Backup Rings Furnished in Spare Parts Seal Kits & in 25 Gpm 4 Way Valves as Part of Actuators Made of Incorrect Matl.Rings Should Be Viton & Have Been Identified as Buna N ML20005G6831990-01-0505 January 1990 Part 21 Rept Re Installation Instructions for Grommet Use Range for Patel Conduit Seal P/N 841206.Conduit Seals in Environ Qualification Applications Inspected for Proper Wire Use Range & Grommets Replaced ML19325E0861989-10-16016 October 1989 Followup Part 21 Rept Re Class 1E Battery Chargers W/ Transformers Running at Temps Exceeding Those Used in Qualification Rept When Operating at or Near Full Load Rating of Equipment.Listed Corrective Actions Underway ML19351A2941989-10-0909 October 1989 Part 21 Rept Re Potential of Ambient Compensated Molded Case Circuit Breakers to Deviate from Published Info. Instantaneous Trip Check Will Be Instituted on All Class 1E Thermal/Magnetic Ambient Breakers Prior to Shipment ML19325C9521989-09-29029 September 1989 Part 21 Rept Re Potential Common Failure of SMB-000 & SMB-00 Cam Type Torque Switches Supplied Prior to 1981 & 1976. Vendor Recommends That Switch W/Fiber Spacer Be Replaced ML20248E0121989-09-13013 September 1989 Supplemental Part 21 Rept Re Potential Problem W/Six Specific Engine Control Devices in Air Start,Lube Oil, Jacket Water & Crankcase Sys.Initially Reported on 890429. California Controls Co Will Redesign Valve Seating ML20246P7111989-07-17017 July 1989 Part 21 Rept Re Quench Cracks in Bar of A-SA-193 Grade B7 Component.Quench Cracks Found in One Bar of Matl.Listed Purchasers Informed of Potential Defect.Next Rept Will Be Submitted When Addl Info Becomes Available ML20247D3011989-07-12012 July 1989 Part 21 Rept 10CFR21-0047 Re Control Wiring Insulation of Inner Jacket Used on General Motors Diesel Generator Sets Identified as 999 or MP Series.Encl List of Owners of Units Notified ML20245B6651989-06-15015 June 1989 Part 21 Rept 150 Re Potential Defect in Component of Dsr Standby Diesel Generator.Cause of Failure Determined to Be Combination of Insufficient Lubrication to Bushings.Listed Course of Action Recommended at Next Scheduled Engine Maint ML20246K7401989-04-26026 April 1989 Part 21 Rept Re Incorrectly Stamped Name Plates on Certain Asco Nuclear Qualified Valves.Vendor Will Contact Each Affected Facility & Furnish Correctly Stamped Plates & in Near Future Discontinue Sale of Rebuild Kits for Valves ML20244D8161989-04-13013 April 1989 Part 21 Rept Re Failure of Rosemount Transmitters.All Failed Transmitters Replaced,Inservice Test Procedure Prepared & Monthly Test of All 12 Transmitters in RCS Throughout Cycle 2 Operation Will Be Performed.Review Continuing ML20247P7991989-04-0404 April 1989 Part 21 Rept Re Atmospheric Dump Valves.Cause of Failure Speculative But Result of Piston Ring That Failed to Seal. Resolution to Problem Requires Increasing Pilot Valve Capacity & Reworking of Plug to Enlarge Pilot Flow Area ML20207N4641988-10-12012 October 1988 Part 21 Rept Re Potential Problem W/Emd 20-645E4,Type 999 Excitation Sys Circuit Breaker & Wiring.Potential for Field Circuit Breaker to Trip Due to Combined Air Temps & Field Current Exists at All Plants W/Model 999 Sys ML20205F3211988-10-10010 October 1988 Part 21 Rept Re Potential Deviation from Tech Spec Concerning Ry Indicators Due to Operating Temp Effect on Analog Meter Movement.Initially Reported on 881006.Customers Verbally Notified on 881006-07 ML20207P0451988-10-0505 October 1988 Part 21 Rept 146 Re Defect in Left Intercooler Inlet Adapter on Standby Diesel Engine Generator.Recommends Utils Inspect Left Intake Manifold Drain as Part of Operating Plan.Addl Info Expected by 881015 ML20207P0151988-10-0404 October 1988 Part 21 Rept Re Fuel Nozzle Tips in Standby Diesel Generator KSV-20-T W/Cracks Permitting Diesel Fuel to Be Sprayed Into Cylinders.Heavy Vapors Observed Emitting from Breathers on Some Cylinder Heads ML20245D9541988-09-0606 September 1988 Part 21 Rept Re Condition Involving Inconel 600 Matl Used to Fabricate Steam Generator Tube Plugs & Found to Possess Microstructure Susceptible to Stress Corrosion Cracking ML20154J4101988-05-12012 May 1988 Addendum 1 to Supplemental Part 21 Rept 145 Re Potential Problem w/F-573-156 Pressure Sensor/Lube Oil Trip.Initially Reported on 880429.Addl 1-1/8-inch Diameter W/Deep Counterbone in Pressure Head Added to Activate Valve ML18093A8281988-05-0606 May 1988 Part 21 & Deficiency Rept Re Asea Brown Boveri,Power Distribution,Inc Low Voltage K-Line Circuit Breakers. Efforts Underway to Define Quantity & Type of Component Parts That May Need to Be Replaced ML20153G0111988-05-0606 May 1988 Part 21 Rept Re Potential Defect in Bussman Buss KTK-R Fuse Blocks W/Part Numbers 2078,2079 & 2080.Purchasing Records Reviewed to Identify If Any Parts Were Actually Used or Shipped to Customers.Results Listed ML20153B6191988-04-29029 April 1988 Part 21 Rept Re Potential Defect in Component of Dsr or Dsrv Standby Diesel Generators Supplied to Utils.Recommends Return of Subj Components in Onsite Warehouse Storage & Suggests Surveillance of Devices Already Installed ML20153F9661988-04-19019 April 1988 Part 21 Rept Withdrawing 870929 Notification Re Potential Problem W/Saturable Core Transformer ML20153B2811988-02-22022 February 1988 Part 21 Rept Re Defect in Operation of Gas Monitors Using Fixed Filters.Initially Reported on 880212.Caused by Error in Software for Monitors.Vendor Testing Mod to Software & in Interim Recommends Changing Filters Every 48 H ML20196D6281988-02-10010 February 1988 Part 21 Rept Re Potential Defect in Certain Model RTF-480/120-30 Ac Line Regulating Transformers Involving Nuisance Tripping of 100 Ampere Ac Input Circuit Breaker When Initializing Unit.Breaker Should Be Replaced ML20195J7421988-01-25025 January 1988 Final Part 21 Deficiency Rept Re Potential Problem W/ Silicone rubber-insulated Cables.Based on Encl Three Test Repts,Tva Concludes That Mfg,Shipping,Receipt & Installation Practices Did Not Reduce Cable Insulation Thickness ML20149J0261987-12-21021 December 1987 Part 21 Rept Re Installation of Relay Part B8002DN in Foxboro 62H Controllers in Facilities.Subj Relay Must Be Replaced by Relay Part N0196ZN.Relay B8002DN Not Used in Any Other Plants ML20235U0271987-10-0707 October 1987 Part 21 Rept Re Westinghouse Plant Steam Generator Tubes Susceptible to High Cycle Fatigue Failure Similar to 870715 Event at North Anna Unit 1.Caused by Mean Stress in Tube & Superimposed Alternating Stress ML20235R1211987-09-29029 September 1987 Part 21 Rept Re Saturable Core Transformer Installed in Emergency Diesel Generator Set.Problem Developed in Svc. Teardown Insp Performed by Util.Results Noted Inadequate Insulation.Addl Info Will Be Provided ML20234F5261987-09-16016 September 1987 Followup Part 21 Rept Re Defective MIS-5 Actuating Fuses. Initially Reported on 870620.All Defective Fuses Will Be Replaced W/Fuses from Subsequent Lots Before Mode 4 ML20235H0041987-09-10010 September 1987 Part 21 Rept Re Nonconformance of American Insulated Wire Co & Rockbestos Co Silicone rubber-insulated Single Conductor Cables.Initially Reported on 870904.Cause Not Found. Evaluation Continuing ML20238E7721987-09-10010 September 1987 Part 21 Rept Re Special high-potential Withstand Tests on Number of Installed 14 Silicone rubber-insulated Single Conductor Cables.Initially Reported on 870904.Evaluation of Silicone Rubber Cable Continuing ML20237G5781987-08-0707 August 1987 Part 21 & Deficiency Rept 142 Re Defect in Starting Air Distributor Sys of Dsr Standby Diesel Generator.Drain Sys Will Be Permanently Installed in Start Air Distributor ML20236N7131987-08-0505 August 1987 Part 21 Rept Re Potential Problem W/Vibration in Lube Oil & Jacket Water Sys.At Rancho Seco Site,Fatigue Cracks Found in Welds of Support Members in Lubricating Oil Sys.Cracks Due to Vibration in Lube Oil Sys.Addl Preventive Action Taken ML20234C7351987-06-23023 June 1987 Supplemental Part 21 Rept Re Silicone Foam Seal Anomolies at Wolf Creek Generating Station ML17261A5301987-06-18018 June 1987 Part 21 Rept Re Potential Util Failure to Comply W/Component Containment Isolation Licensing Commitment If Proposed Mods to Component Cooling Water Sys Instituted.Utils Advised to Evaluate Containment Isolation Sys ML20215G2441987-06-16016 June 1987 Part 21 Rept Re Failure of Load Sequencing Equipment Supplied in Aug 1977 During Scheduled Testing.Caused by Open Electrical Connection on One Crimp Lug.Since 1978,insulated Lugs Used on All Equipment ML20216E4721987-05-28028 May 1987 Part 21 Rept 140 Re Potential Defect in Air Pressure Regulators Mfg by Bellofram.Dripwell Gasket May Fail Due to Mismachining of Gasket Seating Surface Causing Loss of Control Air & Starting Air Pressure ML20214A1361987-05-12012 May 1987 Part 21 Rept Re Capacity of Thermal Compensating Accumulator Being Insufficient to Compensate for Thermal Expansions of Hydraulic Fluid During Full Ambient Temp Transient Required by Customer Specs.Interim & Permanent Mods Identified ML20205R5851987-03-31031 March 1987 Part 21 & Deficiency Rept 139 Re Potential Defect in Engine Control Panel Shutdown Circuitry of Dsr & Dsrv Standby Diesel Generator.Corrective Action at Vogtle Already Implemented.Mfg Will Work W/Smud to Implement Mods ML20204F9061987-03-18018 March 1987 Amended Part 21 Rept 138 Re Potential Problem W/Static Exciter Voltage Regulator Reset Design.Initially Reported on 870311.Similar Equipment Delivered to Listed Sites.Generic Info Will Be Provided by 870331 1997-03-27
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20212J6311999-10-0101 October 1999 SER Accepting Request for Relief from ASME Boiler & Pressure Vessel Code,Section Xi,Requirements for Certain Inservice Insp at Plant,Unit 1 ML20217G3721999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Sequoyah Nuclear Plant.With ML20212F0831999-09-23023 September 1999 Safety Evaluation Granting Relief from Certain Weld Insp at Sequoyah Nuclear Plant,Units 1 & 2 Pursuant to 10CFR50.55a(a)(3)(ii) for Second 10-year ISI Interval ML20212F4761999-09-23023 September 1999 Safety Evaluation Supporting Amends 246 & 237 to Licenses DPR-77 & DPR-79,respectively ML20212C4761999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Sequoyah Nuclear Plant.With ML20210L4361999-08-0202 August 1999 Cycle 9 12-Month SG Insp Rept ML20210L4451999-07-31031 July 1999 Unit-2 Cycle 10 Voltage-Based Repair Criteria 90-Day Rept ML20216E3781999-07-31031 July 1999 Monthly Operating Repts for July 1999 for Sequoyah Nuclear Plant,Units 1 & 2.With ML20210G6631999-07-28028 July 1999 Cycle 9 90-Day ISI Summary Rept ML20196H8621999-06-30030 June 1999 NRC Regulatory Assessment & Oversight Pilot Program, Performance Indicator Data, June 1999 Rept ML20209H3831999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Sequoyah Nuclear Plant.With ML20211F9031999-06-30030 June 1999 Cycle 9 Refueling Outage ML20196J8521999-06-28028 June 1999 Safety Evaluation Authorizing Proposed Alternative to Use Iqis for Radiography Examinations as Provided for in ASME Section III,1992 Edition with 1993 Addenda,Pursuant to 10CFR50.55a(a)(3)(i) ML20195K2951999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Sequoyah Nuclear Plant,Units 1 & 2.With ML20206Q8951999-05-0505 May 1999 Rev 0 to L36 990415 802, COLR for Sequoyah Unit 2 Cycle 10 ML20206R5031999-04-30030 April 1999 Monthly Operating Repts for April 1999 for Sequoyah Units 1 & 2.With ML20205P9811999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Sequoyah Nuclear Plant,Units 1 & 2.With ML20204C3111999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Sequoyah Nuclear Plant,Units 1 & 2.With ML20205B6631999-02-28028 February 1999 Underground Storage Tank (Ust) Permanent Closure Rept, Sequoyah Nuclear Plant Security Backup DG Ust Sys ML20203H7381999-02-18018 February 1999 Safety Evaluation of Topical Rept BAW-2328, Blended U Lead Test Assembly Design Rept. Rept Acceptable Subj to Listed Conditions ML20211A2021999-01-31031 January 1999 Non-proprietary TR WCAP-15129, Depth-Based SG Tube Repair Criteria for Axial PWSCC Dented TSP Intersections ML20198S7301998-12-31031 December 1998 Cycle 10 Voltage-Based Repair Criteria 90-Day Rept ML20199G3641998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Sequoyah Nuclear Plant,Units 1 & 2.With ML20197J5621998-12-0303 December 1998 Unit 1 Cycle 9 90-Day ISI Summary Rept ML20197K1161998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Sequoyah Nuclear Plant,Units 1 & 2.With ML20195F8061998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for Sequoyah Nuclear Plant.With ML20154H6091998-09-30030 September 1998 Monthly Operating Repts for Sept 1998 for Sequoyah Nuclear Plant,Units 1 & 2.With ML20154H6251998-09-17017 September 1998 Rev 0 to Sequoyah Nuclear Plant Unit 1 Cycle 10 Colr ML20153B0881998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for Sequoyah Nuclear Plant.With ML20239A0631998-08-27027 August 1998 SER Accepting Licensee Response to GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power-Operated Gate Valves, for Sequoyah Nuclear Plant,Units 1 & 2 ML20236Y2091998-08-0707 August 1998 Safety Evaluation Accepting Relief Requests RP-03,RP-05, RP-07,RV-05 & RV-06 & Denying RV-07 & RV-08 ML20237A4411998-07-31031 July 1998 Blended Uranium Lead Test Assembly Design Rept ML20237B5221998-07-31031 July 1998 Monthly Operating Repts for July 1998 for Snp ML20236P6441998-07-10010 July 1998 LER 98-S01-00:on 980610,failure of Safeguard Sys Occurred for Which Compensatory Measures Were Not Satisfied within Required Time Period.Caused by Inadequate Security Procedure.Licensee Revised Procedure MI-134 ML20236R0051998-06-30030 June 1998 Monthly Operating Repts for June 1998 for Sequoyah Nuclear Plant ML20249A8981998-05-31031 May 1998 Monthly Operating Repts for May 1998 for Sequoyah Nuclear Plant,Units 1 & 2 ML20247L5141998-04-30030 April 1998 Monthly Operating Repts for Apr 1998 for Sequoyah Nuclear Plant ML20217K4471998-04-27027 April 1998 Safety Evaluation Supporting Requests for Relief 1-ISI-2 (Part 1),2-ISI-2 (Part 2),1-ISI-5,2-ISI-5,1-ISI-6,1-ISI-7, 2-ISI-7,ISPT-02,ISPT-04,ISPT-06,ISPT-07,ISPT-8,ISPT-01 & ISPT-05 ML20217E2221998-03-31031 March 1998 Monthly Operating Repts for Mar 1998 for Sequoyah Nuclear Plant ML20248L2611998-02-28028 February 1998 Monthly Operating Repts for Sequoyah Nuclear Plant,Units 1 & 2 ML20202J7911998-01-31031 January 1998 Monthly Operating Repts for Jan 1997 for Sequoyah Nuclear Plant,Units 1 & 2 ML20199J2571998-01-31031 January 1998 Cycle 9 Voltage-Based Repair Criteria 90-Day Rept ML20199J2441998-01-29029 January 1998 Snp Unit 2 Cycle Refueling Outage Oct 1997 ML20199F8531998-01-13013 January 1998 ASME Section XI Inservice Insp Summary Rept for Snp Unit 2 Refueling Outage Cycle 8 ML20198M1481997-12-31031 December 1997 Monthly Operating Repts for Dec 1997 for Sequoyah Nuclear Plant,Units 1 & 2 ML20199A2931997-12-31031 December 1997 Revised Monthly Operating Rept for Dec 1997 for Sequoyah Nuclear Plant,Units 1 & 2 ML20197J1011997-11-30030 November 1997 Monthly Operating Repts for Nov 1997 for Sequoyah Nuclear Plant,Units 1 & 2 ML20199C2951997-11-13013 November 1997 LER 97-S01-00:on 971017,vandalism of Electrical Cables Was Observed.Caused by Vandalism.Repaired Damaged Cables, Interviewed Personnel Having Potential for Being in Area at Time Damage Occurred & Walkdowns ML20199C7201997-10-31031 October 1997 Monthly Operating Repts for Oct 1997 for Sequoyah Nuclear Plant ML20198Q5571997-10-23023 October 1997 Rev 0 to, Sequoyah Nuclear Plant,Unit 2,Cycle 9,COLR 1999-09-30
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TENNEESEE VA CHATTAND A,TENNESSEEY37401 Ll [ AUTHORIT c.
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December 13, 1974 ogffgggd i aurassa '
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-M rA Mr. F. E. Kruesi, Director Directorate of Regulatory Operations U. S. Atomic Energy Co= mission Washington, DC 20545
Dear Mr. Kruesi:
TVA made an initial report to the AEC-DRO Region II office by telephone on October 1,1973, of a poten,tial design deficiency of Sequoyah liuclear Plant units 1 and 2 Interior Concrete Structure. On October 29, 1973, we submitted an interim report stating by mid-December 1973, a schedule of work to be done and an estimated time for submittal of a final report. The enclosed report is submitted as a second interim report on the potential design deficiency.
Very truly yours, s
/1 c J. E. Gilleland Assistant to the Manager of Power Enclosure CC (Enclosure):
Mr. Iiorman C. Moseley, Director Directorate of Regulatory Operations I
U. S. Atomic Energy Commission Region II - Suite 818 230 Peachtree Street, liW.
Atlanta, Georgia 30303 i PDR ADOCK8308290036 S 05000327 740213 PDR 4
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4: ' ENCLOSURE l
SEQUOYAH NUCLEAR PLANT REACTOR BUILDINGS - UNITS 1 AND 2 INTERIOR CONCRETE STRUCTURE POTENTIAL DESICN DEFICIENCY INTERIM REPORT NO. 2 An initial report of a potential design deficiency in the interior concrete structure of the reactor buildings for units 1 snd 2 of our Sequoyah Nuclear Plant was made by telecon to the AEC-DRO Region II Office on October 1, 1973, in compliance with 10CFR50.55(e). An interim report was submitted to AEC-DRO Headquarters on October 29, 1973. This report constic'utes the second interim report on the deficiency.
The seismic response loads of the interior concrete structure of the reactor building have been reduced; accordingly, additional structural analysis will not be required.
The effects of the shift in the location of peak response of the floor response spectra are continuing to be evaluated. A summary of the major items, with an evaluation to date is as follows:
I. ICE CONDENSER Numerous runs have been made, all of which indicate seismic loadings will either remain essentially the same or be slightly reduced.
II. AUXILIARY EQUIPMENT The regenerative heat exchanger, excess heat exchanger, and accumulators have been designed to seismic umbrella values and appear to be unaffected.
The manipulator crane appears also to be unaffected and work is continuing on other items.
III. NUCLEAR STEAM SUPPLY SYSTEM (NSSS) AND NSSS/ SUPPORTS
- a. Reactor internals have apparently been qualified to a higher seismic environment than Sequoyah and appear unaffected.
- b. SCRAM time is being evaluated; however, it is not expected to be l affected based on the above.
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- c. CRDM supports seismic loads are apparently reduced,
- d. NSSS piping seismic loads are apparently within allowables.
- e. NSSS/ supports seismic loads apparently increase; however, the supports were apparently sized for a higher seismicity plant and intreased loads appear to be within allowables.
IV. AUXILIARY PIPINC All auxiliary piping systems have not been designed to date. Those systems that have been designed are being evaluated for the revised spectra and those that have not will be designed for the revised spectra.
Complete evaluation of the design adequacy of the Reactor Building equipment and piping therein will be available by February 1,1974.
During the course of the re-analysis of the reactor building, it was determined that for seismic analysis a modulus based on expected long range concrete strengths would be more appropriate than an analysis based on 28-day design strengths (since we have found that continuing hydration does occur in the relatively massive concrete members associated with these structures). Modulus for seismic analysis shall therefore be based on previous test experience for 180-day strengths with the fly ash con-crete using the ACI 318-71 code formula in section 8.3.1.
This decision extended the problem to include all Category I structures since the 28-day specified strength was used in determining the concrete modulus for all of these structures in the original seismic analysis. We are preceeding to re-analyze all Category I structures to determine if safety related equipment and piping in the structures will be affected by this revised requirement. A schedule for this re-analysis of other Category I structures will be furnished the Commission as soon as it can be developed.
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