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Category:GENERAL EXTERNAL TECHNICAL REPORTS
MONTHYEARML20207E8011999-05-19019 May 1999 Non-proprietary Rev 2 to HI-981933, Design & Licensing Rept DBNPS Unit 1 Cask Pit Rack Installation Project ML20205K5781998-12-31031 December 1998 Waterhammer Phenomena in Containment Air Cooler Swss ML20217P8041998-04-0707 April 1998 11RFO OTSG ECT Insp Scope ML20196B8771996-12-16016 December 1996 First Amended & Restated Master Decommissioning Trust Agreement Dtd as of 961231 Between Toledo Edison Co & Mellon Bank ML20196B8951996-12-16016 December 1996 First Amended & Restated Master Decommissioning Trust Agreement Dtd as of 961216 Between Cleveland Electric Illuminating Co & Mellon Bank ML20134D7821996-05-0808 May 1996 Rev 1 to Instrument Drift Data Analysis Methodology & Assumptions ML20091S4311995-08-31031 August 1995 USI A-46 Seismic Evaluation Rept. W/61 Oversize Drawings ML20138J1411994-02-28028 February 1994 Rev 0 to IPEEE,A-46 & Design In-Structure Response Spectra for Selected Bldgs at Dbnps ML20067D3311993-08-31031 August 1993 Technical Evaluation Rept,Evaluation of B&Wog Pressurizer Surge Line Thermal Stratification Program to Address NRC Bulletin 88-11 ML20091P5721991-10-31031 October 1991 Reactor Containment Bldg Integrated Leak Rate Test Including,Type A,B & C Periodic Test Results ML20070Q1911991-03-25025 March 1991 NRC Form 474 Simulation Facility Certification ML20058L1891990-08-0101 August 1990 Dcrdr Human Engineering Discrepancy Repts 1988 Summary Addendum 1,Vol 1 ML20006E3671990-01-11011 January 1990 Toledo Edison Co Mark-BZ Fuel Assembly Seismic & LOCA Analysis. ML20094J0841989-12-0808 December 1989 Investigation of Acoustic Leak Monitoring for NRC Region Iii. Info Partially Deleted ML19324C1761989-10-30030 October 1989 Hpi/Makeup Nozzle Weld Overlay Repair Contingency Plan. ML19327B0161989-10-11011 October 1989 Cycle 7 LOCA Limits. ML20245K6751989-08-0202 August 1989 Rev 2 to Review 18 Month PM Items for Diesel Generator & Evaluate Extension to 30 Months ML20151Z1941988-08-11011 August 1988 Rept on Reactor Vessel Continuous Vent Line Performance, ML20234F2501988-01-0606 January 1988 Rev 3 to App R Compliance Assessmemt Rept ML20147C0851987-12-0101 December 1987 Fifth Refueling Outage Executive Summary. Related Documents Encl ML20237J9781987-08-24024 August 1987 Performance Indicators for Davis-Besse Nuclear Power Station,Salp 6,Weekly Rept 3 for Period Ending 870824 ML20214J1891987-05-0505 May 1987 Rev 2 to App R Compliance Assessment Rept ML20206J5001987-03-31031 March 1987 Dcrdr Special Study Plans for Davis-Besse ML20212G7461987-01-0707 January 1987 Rept of Emergency Evacuation Review Team on Emergency Response Plans for Perry & Davis-Besse Nuclear Power Plants ML20214E0761986-11-17017 November 1986 Auxiliary Feedwater Calculation Summary ML20211E0651986-09-26026 September 1986 Transient Assessment Program Rept,Davis-Besse Unit 1 Reactor Trip on High Flux,840302 ML20214T7501986-09-11011 September 1986 DB Small-Break LOCA Analysis Assumptions Evaluation ML20154Q6531986-02-28028 February 1986 Westinghouse Owners Group Position on Davis-Besse Event ML20141E6691985-11-30030 November 1985 B&W Owners Group Action Plan for Review of 850609 Davis-Besse Transient ML20138H4891985-11-25025 November 1985 Rev 17 to Seismic Category I Piping Sys Support & Hanger Discrepancies ML20136H0951985-11-15015 November 1985 Revised Davis-Besse Reactor Protection Sys Single Failure Analysis ML20137H3971985-11-12012 November 1985 Rev 16 to Seismic Category I Piping Sys Support & Hanger Discrepancies Summary Rept ML20137S9031985-10-29029 October 1985 Toledo Edison Davis-Besse Nuclear Power Station Unit 1 Seismic Category I Piping Sys Support & Hanger Discrepancies,Summary Rept ML20209H5861985-10-28028 October 1985 Rev 3 to Course of Action ML20137S8241985-10-22022 October 1985 Rev 14 to Seismic Category I Piping Sys & Hanger Discrepancies,Summary Rept ML20209H6481985-10-15015 October 1985 Rev 3 to Auxiliary Feedwater Pump Turbine Overspeed Trip Throttle Valve Problem ML20138J4811985-10-15015 October 1985 Seismic Category I Piping Sys Support & Hanger Discrepancies ML20133M9911985-10-0808 October 1985 Rev 12 to Seismic Category I Piping Sys Support & Hanger Discrepancies,Summary Rept ML20133K9881985-10-0404 October 1985 Independent Mgt Assessment of Toledo Edison Davis-Besse QA Program ML20138A9411985-09-24024 September 1985 Rev 10 to Safety-Related Piping Sys Support & Hanger Discrepancies, Summary Rept ML20132E4471985-09-17017 September 1985 Rev 9 to Safety-Related Piping Sys Support & Hanger Discrepancies, Summary Rept ML20137C3021985-09-0909 September 1985 Toledo Edison Co Davis-Besse Nuclear Power Station Course of Action Rept ML20137M5431985-09-0909 September 1985 Vols 1 & 2 of Davis-Besse Course of Action ML20135D7421985-09-0303 September 1985 Rev 7 to Safety-Related Piping Sys Support & Hanger Discrepancies, Summary Rept ML20133K9941985-08-30030 August 1985 Rept of Assessment of Actions at Davis-Besse Resulting from 850609 Loss of Feedwater Event ML20134Q0161985-08-27027 August 1985 Rev 6 to Safety-Related Piping Sys Support & Hanger Discrepancies, Summary Rept ML20137U3061985-08-16016 August 1985 Rev 5 to Safety-Related Piping Sys Support & Hanger Discrepancies, Summary Rept ML20134B8371985-08-0909 August 1985 Rev 4 to Safety-Related Piping Sys Support & Hangar Discrepancies, Summary Rept ML20133M3261985-07-26026 July 1985 Rev 3 to Safety-Related Piping Sys Support & Hanger Discrepancies,Summary Rept ML20126L9021985-07-0505 July 1985 Rev 1 to Action Plans 5,6 & 7, Steam & Feedwater Rupture Control Sys Trip/Msiv Closure 1999-05-19
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217K1231999-10-14014 October 1999 Revised Positions for DBNPS & Pnpp QA Program ML20217D5441999-09-30030 September 1999 Monthly Operating Rept for Sept 1999 for Davis-Besse Nuclear Power Station.With ML20211R0811999-08-31031 August 1999 Monthly Operating Rept for Aug 1999 for Davis-Besse Nuclear Power Station,Unit 1.With ML20211B0271999-08-13013 August 1999 SER Accepting Second 10-year Interval Inservice Insp Requests for Relief RR-A16,RR-A17 & RR-B9 for Plant, Unit 1 ML20210Q8541999-07-31031 July 1999 Monthly Operating Rept for July 1999 for Davis-Besse Nuclear Power Station,Unit 1.With ML20209E6231999-06-30030 June 1999 Monthly Operating Rept for June 1999 for Davis-Besse Nuclear Power Station,Unit 1.With ML20195K2871999-06-16016 June 1999 Safety Evaluation Accepting Licensee Response to GL 95-07, Pressure Locking & Thermal Binding of Safety-Related Power-Operated Gate Valves ML20195F4871999-05-31031 May 1999 Monthly Operating Rept for May 1999 for Davis-Besse Nuclear Power Station,Unit 1.With ML20207E8011999-05-19019 May 1999 Non-proprietary Rev 2 to HI-981933, Design & Licensing Rept DBNPS Unit 1 Cask Pit Rack Installation Project ML20207F4351999-05-0404 May 1999 Rev 1 to DBNPS Emergency Preparedness Evaluated Exercise Manual 990504 ML20206M6341999-04-30030 April 1999 Monthly Operating Rept for Apr 1999 for Davis-Besse Nuclear Station,Unit 1.With ML20205M2931999-03-31031 March 1999 Monthly Operating Rept for Mar 1999 for Davis-Besse Nuclear Power Station.With ML20207J1461999-02-28028 February 1999 Monthly Operating Rept for Feb 1999 for Davis-Besse Nuclear Power Station,Unit 1.With ML20199H5931999-01-20020 January 1999 Safety Evaluation Accepting Thermo-Lag Re Ampacity Derating Issues for Plant ML20204J6751998-12-31031 December 1998 1998 Annual Rept for Dbnps,Unit 1,PNPP,Unit 1 & BVPS Units 1 & 2 ML20199E2501998-12-31031 December 1998 Monthly Operating Rept for Dec 1998 for Davis-Besse Nuclear Power Station,Unit 1.With ML20206B0101998-12-31031 December 1998 1998 Annual Rept for Firstenergy Corp, for Perry Nuclear Power Plant & Davis-Besse Nuclear Power Station.Form 10-K Annual Rept to Us Securities & Exchange Commission for Fiscal Yr Ending 981231,encl ML20205K5781998-12-31031 December 1998 Waterhammer Phenomena in Containment Air Cooler Swss ML20197J3441998-11-30030 November 1998 Monthly Operating Rept for Nov 1998 for Davis-Besse Nuclear Power Station,Unit 1.With ML20195D0001998-10-31031 October 1998 Monthly Operating Rept for Oct 1998 for Davis-Besse Nuclear Power Station,Unit 1.With ML20155B6781998-10-28028 October 1998 Safety Evaluation Accepting Proposed Reduction in Commitment Changes in QA Program Matl Receipt Insp Process ML20154H5801998-09-30030 September 1998 Monthly Operating Rept for Sept 1998 for Davis-Besse Nuclear Power Station,Unit 1.With ML20151W1611998-08-31031 August 1998 Monthly Operating Rept for Aug 1998 for Dbnps.With ML20237E3171998-08-21021 August 1998 ISI Summary Rept of Eleventh Refueling Outage Activities for Davis-Besse Nuclear Power Station ML20237B1681998-07-31031 July 1998 Monthly Operating Rept for July 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20236U5011998-07-23023 July 1998 Special Rept:On 980624,Unit 1 Site Damaged by Tornado & High Winds.Alert Declared by DBNPS Staff,Dbnps Emergency Response Facilities Activiated & Special Insp Team Deployed to Site by Nrc,As Result of Event ML20236R1441998-07-15015 July 1998 SER Related to Quality Assurance Program Description Changes for Davis-Besse Nuclear Power Station,Unit 1 ML20236N7451998-06-30030 June 1998 Monthly Operating Rept for June 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20236K3981998-06-30030 June 1998 SER Accepting in Part & Denying in Part Relief Requests from Some of ASME Section XI Requirements as Endorsed by 10CFR50.55a for Containment Insp for Davis-Besse Nuclear Power Station,Unit 1 ML20236K5131998-06-29029 June 1998 Safety Evaluation Accepting Proposed Alternate Emergency Operations Facility Location for Davis-Besse Nuclear Power Station,Unit 1 ML20248F7441998-05-31031 May 1998 Reactor Vessel Working Group,Response to RAI Regarding Reactor Pressure Vessel Integrity ML20249A4121998-05-31031 May 1998 Monthly Operating Rept for May 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20196B5221998-05-23023 May 1998 10CFR50.59 Summary Rept of Facility Changes,Tests & Experiments Dbnps,Unit 1 for 960602-980523 ML20236E7581998-05-19019 May 1998 Rev 0 to Davis-Besse Unit 1 Cycle 12 Colr ML20236N7501998-04-30030 April 1998 Rev 2 to Monthly Operating Rept for Apr 1998 for Davis-Besse Nuclear Power Station,Unit ML20247F6721998-04-30030 April 1998 Monthly Operating Rept for Apr 1998 for Davis-Bess Nuclear Power Station,Unit 1 ML20249A4141998-04-30030 April 1998 Revised Monthly Operating Rept for Apr 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20217P8041998-04-0707 April 1998 11RFO OTSG ECT Insp Scope ML20216B4041998-03-31031 March 1998 Monthly Operating Rept for Mar 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20216C5131998-02-28028 February 1998 Monthly Operating Rept for Feb 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20202D3721998-01-31031 January 1998 Monthly Operating Rept for Jan 1998 for Davis-Besse Nuclear Power Station,Unit 1 ML20199G6321998-01-26026 January 1998 Rev 1 to Davis-Besse Unit 1,Cycle 11,COLR ML20198R4771998-01-13013 January 1998 SER Approving Second 10-year Interval Inservice Inspection Program Plan Requests for Relief for Davis-Besse Nuclear Power Station,Unit 1 ML20198K7931997-12-31031 December 1997 Monthly Operating Rept for Dec 1997 for Davis-Besse Nuclear Power Station,Unit 1 ML20217K6401997-12-31031 December 1997 1997 Annual Rept First Energy ML20203A3931997-11-30030 November 1997 Monthly Operating Rept for Nov 1997 for Davis-Besse Nuclear Power Plant,Unit 1 ML20198S5371997-10-31031 October 1997 Monthly Operating Rept for Oct 1997 for Davis-Besse Nuclear Power Station ML20217H7701997-09-30030 September 1997 Monthly Operating Rept for Sept 1997 for Davis-Besse Nuclear Power Station,Unit 1 ML20216H3261997-08-31031 August 1997 Monthly Operating Rept for August 1997 for DBNPS ML20217K0241997-07-31031 July 1997 Monthly Operating Rept for Jul 1997 for Davis Besse Nuclear Power Station,Unit 1 1999-09-30
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Attachm:nt to TECo let'sr Serial No. 387 dated September 16, 15 7 Revision 1 to Attachment to TECo letter
{Jx_) Serial No. 3J6 dated August 30, 1977 DAVIS-BESSE UNIT 1 ST TION AND INSTRUMENT GRol3 DING SYSTEMS SYSTEM DESIGN CRITERIA The station ground grid system at Davis-Besse is a three dimen-sional grid in the turbine and auxiliary building that consists of 4/0 and 500 MCM bare copper conductor. The vertical risers are in-stalled at a minimun of every other building column. Horizontal conductors are installed as needed to tie equipment to the station ground grid (20' to 70' horizontally). The station ground grid vertical risers are tied to the building steel at each floor as a minimum and the horizontal conductors are tied to the building steel at every other building column as a minimum. Drawing i *70, Rev. A shows some typical equipment that is tied to the station ground grid. This drawing was left with the NRC during our meeting on August 25, 1977 and a copy is attached.
The instrument grounding syctem has been installed as shown on drawing E-470, Rev. A. The inctrumentation common sianal and analog signal cable shields for the following major systems are tied to the instrument ground bus:
- 1. Reactor Protection System (RPS).
- 2. Integrated Control System (ICS).
- 3. Non-Nuclear Instrumentation (NNI).
- 4. Computer processing unit, local and remote multiplexers, typers, line printer, paper tape punch / reader, card reader, cathode ray tubes and operator keyboards.
- 5. Miscellaneous electronic control system.
The analog signal cable shields for the following major systems are tied to the instrument grcund bus:
- 1. Safety Features Acutation System (SFAS)
- 2. Steam and Feedwater Rupture Control System (SFRCS)
- 3. Steam generator level 8001220 fo o Revision 1
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- g s t i i The station ano instrument grounding systems nave been installed in
1 j accordance with the Davis-Besse Unit I design criteria and as shown t on drawing E-470, Rev. A. During the testing on these systems, the l following has been found:
l j 1. RPS, ICS and NNI; the instrument ground buses in these l
systems are intentionally tied together as shown on
- drawing E-470, Rev. A. There may be an inadvertent tie between this group of instrument ground buses and either the station ground system or the instrument ground bus
.I in the ccmputer or the miscellaneous electronic control system.
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! 2. There is an inadvertent tie between the following in- ,
strument ground bus and either the station ground system
! or the instrument ground bus in another system:
I A. Computer. ,
i B. Miscellaneous electronic control system.
l EQUIP:1ENT DESIGN CRITERIA The RPS was designed and shipped to Davis-Besse with isolated in- ,
' strument and station ground systems. The RPS has been used at all
B&W units in operation with these two buses tied together in the cabinets and then connected to the station ground gri t. The RPS is I designed to operate within specifications when installed with a j single grot.nc tns; system or with separate station and instrument grounds as stecified at Davis-Besse. The Davis-Besse grounding system meets the B&W balance-of plant (BOP) requirements for this installation. The E&W E0P requirements stated in the 205 BSAR call for a grounding system similar to that employed at Davis-Besse.
4 Th n NNI and ICS were designed to have either single or separate in-st:ument and s;ation ground systems. All B&W units in operation hare had the two ground buses in these systems tied together. The NNI and ICS caoinets and interconnecting cables to remate instruments were shipped to Davis-Besse with the two ground systems tied together.
This required Toledo Edison to work closely with B&W and Bailey field representatives to modify the~ equipment to separate the j ground buses in these systems.
l The computer and miscellaneous electronic control system were designed and shipped with separate instrument and station ground
, systems.
TheShASandSERCSandsteamgeneratorlevelsystemsweredesigned and shipped with separate instrument and station ground systems.
Only analog signal cable shields are connected to the instrument 4 ground bus. Noise tests conducted by their manufacturer (Consolidated i i Controls Corporation) indicated that these shields could be connected i to either the station or instrument ground system or they could be j
1 cit ungrounded.
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MAXIMUM GROUND FAULT CURRENTS j If a ground fault on any of the major electrical equipment, station 1 power electrical buses or transformers should occur, this fault j current would flow through the station ground system. The maximum ground fault current that could occur due to a fault on each elec-l trical system on Davis-Besse Unit 1 is as follows:
- 1. 345 KV - 21,200 amps.
- 2. 25 KV Main Generator - 8 amps. Limited by ground 4 resistor.
- 3. 13.8 KV Housepower buses - 400 amps. Limited by ground resistor.
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- 4. 4.16 KV Housepower buses - 400 amps. Limited by ground resistor.
- 5. 480 Volt Housepower buses - 21,900 amps.
j 6. 250/125 Volt DC Housepower buses are ungrounded and no j DC fault currents can flow in the station ground grid.
MAXIMLH GROUND CURRENT INDUCED VOLTAGES i
I If there is an inadvertent tie between the instrument ground system in the RPS and the station ground, loop fault current from an elcc-trical !ault could flow in the RPS instrument ground connection producing an induced voltage at the RPS system.
The largest ground currents that can flow through the wAcion i
ground system in the Cable Spreading Room ceiling would be caused i by a ground fault in the 480 V Motor Control Center (MCC) located directly above the Control / Cabinet Room at elevation 643'. The calculated ground fault current that can occur at this MCC is 4,224 I amps. The source of this ground fault current is a 1000 KVA transformer located on elevation 603' at the northside of the auxiliary building.
j This 1000 KVA transformer has a 6.75% impedance on 1 MVA base, 13.8 i KVA to 480 V, (Delta : Y) transformer with a solidly grounded neutral.
! The 13.8 KVA bus is assumed to have zero impedance up to the 480 volt transformer.
- It was found that approximately 90% of the ground fault current 1 would flow from the MCC to the 1000 KVA transformer on ene ground cables installed in the conduits with the phase cables.
In calculating this induced voltage that could be impressed on the RPS instrument ground bus, the following conservative assumptions were l made:
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- 1. ,The fault current at the MCC enters the station ground grid and flows
. through three paths to the source transformer neutral. ,
- 2. No ground fault current would be by-passed through building steel. lI
! 3. The location of the inadvertent tie between the instrument and I station ground systems was picked in an attempt to maximize the loop currents flowing in the RPS instrument ground buses.
- 4. The fault current flowing in the instrument ground bus of the RPS cabinet with the inadvertent ground returns to the source transformer across the impedance of the 500 kcm insulated instrument bus grounding cable.
l j Using the above conservative assumptions, the f ault voltage that could be impressed on the instrument ground buses would be 1.4 volts, rms, 60 Hz.
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The ground fault current that caused this voltage would be interrupted within l1 3 cycle. (50 ms.). This 1.4 volt difference between NI/RPS cabinets would i
cause 60 He current flow through the system's instrument ground. Normally, this kind of " noise" could enter the system through inductive or capacitive coupling between a ground lead carrying the noise and an analog signal lead.
I Since the degree of coupling is not known, one can assume an unlikely worst case in which there is direct coupling, with no attenuation, directly into any or all RPS 0 to 10 volt DC analog signals. The system is designed to reject such noise by a minimum of 34 db which translater to a 2500:1 power attenuation or a 50:1 voltage attentuation. With 34 db rejection, the worst effect on a trip set point will be to impose an error of less than 0.24% of the signal full range. However, when the noise is injected in such a way as to pass through
- one or more modules prior to be bistable set point module, additional attenua-i tion occurs reducing the error to less than 0.06%. Considering the assumed direct coupling, the effect is extremely conservative. It is B&W's accessment that this is not a safety concern.
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