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Category:Letter type:DCL
MONTHYEARDCL-24-010, Nuclear Material Transaction Report for New Fuel2024-01-29029 January 2024 Nuclear Material Transaction Report for New Fuel DCL-24-009, Nuclear Material Transaction Report for New Fuel2024-01-17017 January 2024 Nuclear Material Transaction Report for New Fuel DCL-24-008, Schedule Considerations for Review of the DCPP License Renewal Application2024-01-17017 January 2024 Schedule Considerations for Review of the DCPP License Renewal Application DCL-24-004, Supplement to License Amendment Request 23-01 Revision to Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b2024-01-15015 January 2024 Supplement to License Amendment Request 23-01 Revision to Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b DCL-23-129, Nuclear Material Transaction Report for New Fuel2023-12-27027 December 2023 Nuclear Material Transaction Report for New Fuel DCL-23-122, Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation2023-12-14014 December 2023 Request for Exemption from Enhanced Weapons, Firearms Background Checks, and Security Event Notifications Implementation DCL-23-128, Emergency Plan Update2023-12-13013 December 2023 Emergency Plan Update DCL-23-125, Core Operating Limits Report for Unit 1 Cycle 252023-12-0606 December 2023 Core Operating Limits Report for Unit 1 Cycle 25 DCL-23-121, Supplement to License Amendment Request 23-03, Revision to Technical Specification3.7.8, Auxiliary Saltwater System2023-11-16016 November 2023 Supplement to License Amendment Request 23-03, Revision to Technical Specification3.7.8, Auxiliary Saltwater System DCL-23-120, License Amendment Request 23-03 Revision to Technical Specification 3.7.8, Auxiliary Saltwater (Asw) System2023-11-14014 November 2023 License Amendment Request 23-03 Revision to Technical Specification 3.7.8, Auxiliary Saltwater (Asw) System DCL-23-118, License Renewal Application2023-11-0707 November 2023 License Renewal Application DCL-2023-520, Discharge Self-Monitoring at Diablo Canyon Power Plant (DCPP)2023-10-19019 October 2023 Discharge Self-Monitoring at Diablo Canyon Power Plant (DCPP) DCL-23-103, Independent Spent Fuel Storage Installation - Withdrawal of License Amendment Request 22-01, Request for Approval of Alternative Security Measures for Early Warning System2023-10-13013 October 2023 Independent Spent Fuel Storage Installation - Withdrawal of License Amendment Request 22-01, Request for Approval of Alternative Security Measures for Early Warning System DCL-23-092, Material Status Report for the Period Ending August 31, 20232023-09-28028 September 2023 Material Status Report for the Period Ending August 31, 2023 DCL-23-077, License Amendment Request 23-02 Application to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors2023-09-27027 September 2023 License Amendment Request 23-02 Application to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors DCL-23-083, Upcoming Meeting with Nuclear Security and Incident Response Staff2023-09-13013 September 2023 Upcoming Meeting with Nuclear Security and Incident Response Staff DCL-23-078, Nuclear Material Transaction Report for New Fuel2023-09-0606 September 2023 Nuclear Material Transaction Report for New Fuel DCL-23-070, Withdrawal of Request Regarding Senior Reactor Operator License Application2023-08-16016 August 2023 Withdrawal of Request Regarding Senior Reactor Operator License Application DCL-23-068, Nuclear Material Transaction Report for New Fuel2023-08-0909 August 2023 Nuclear Material Transaction Report for New Fuel DCL-23-066, Nuclear Material Transaction Report for New Fuel2023-08-0303 August 2023 Nuclear Material Transaction Report for New Fuel DCL-23-065, Letter DCL-23-065 Request That Exam Material Be Withheld from Public Disclosure2023-07-27027 July 2023 Letter DCL-23-065 Request That Exam Material Be Withheld from Public Disclosure DCL-23-064, Nuclear Material Transaction Report for New Fuel2023-07-26026 July 2023 Nuclear Material Transaction Report for New Fuel DCL-23-054, License Amendment Request 23-01 Revision to Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b2023-07-13013 July 2023 License Amendment Request 23-01 Revision to Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b DCL-23-055, Nuclear Material Transaction Report for New Fuel2023-07-0606 July 2023 Nuclear Material Transaction Report for New Fuel DCL-23-042, Independent Spent Fuel Storage Installation, Submittal of Quality Assurance Program Description, Revision 02023-05-24024 May 2023 Independent Spent Fuel Storage Installation, Submittal of Quality Assurance Program Description, Revision 0 DCL-23-032, Independent Spent Fuel Storage Installation Docket No. 72-27, Materials License Number SNM-2514 Humboldt Bay Independent Spent Fuel Storage Installation - NRC Requested Notification of Withdrawal from Voluntary Program2023-05-22022 May 2023 Independent Spent Fuel Storage Installation Docket No. 72-27, Materials License Number SNM-2514 Humboldt Bay Independent Spent Fuel Storage Installation - NRC Requested Notification of Withdrawal from Voluntary Program DCL-23-041, 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 20222023-05-22022 May 2023 10 CFR 50.46 Annual Report of Emergency Core Cooling System Evaluation Model Changes for Peak Cladding Temperature for 2022 DCL-23-038, Revision to the Unit 1 Reactor Vessel Material Surveillance Program Withdrawal Schedule2023-05-15015 May 2023 Revision to the Unit 1 Reactor Vessel Material Surveillance Program Withdrawal Schedule DCL-23-034, 2022 Annual Nonradiological Environmental Operating Report2023-05-0101 May 2023 2022 Annual Nonradiological Environmental Operating Report DCL-23-036, 2022 Annual Radiological Environmental Operating Report2023-05-0101 May 2023 2022 Annual Radiological Environmental Operating Report DCL-23-025, 2022 Annual Radioactive Effluent Release Report2023-05-0101 May 2023 2022 Annual Radioactive Effluent Release Report DCL-2023-512, Submittal of Receiving Water Monitoring Program 2022 Annual Report2023-04-27027 April 2023 Submittal of Receiving Water Monitoring Program 2022 Annual Report DCL-23-035, Response to Request for Additional Information on Request Regarding Senior Reactor Operator License Application2023-04-24024 April 2023 Response to Request for Additional Information on Request Regarding Senior Reactor Operator License Application DCL-23-028, Technical Specification Bases, Revision 142023-04-24024 April 2023 Technical Specification Bases, Revision 14 DCL-2023-511, Report on Discharge Monitoring for the First Quarter of 20232023-04-20020 April 2023 Report on Discharge Monitoring for the First Quarter of 2023 DCL-23-031, Submittal of Annual Report of Occupational Radiation Exposure for 20222023-04-19019 April 2023 Submittal of Annual Report of Occupational Radiation Exposure for 2022 DCL-23-024, Independent Spent Fuel Storage Installation, Response to Nrg Request for Additional Information for Revision to License Amendment Request 22-01 Request for Approval of Alternative Security Measures for Early Warning System2023-04-0404 April 2023 Independent Spent Fuel Storage Installation, Response to Nrg Request for Additional Information for Revision to License Amendment Request 22-01 Request for Approval of Alternative Security Measures for Early Warning System DCL-23-022, 2023 Annual Statement of Insurance for Pacific Gas and Electric Companys Diablo Canyon Power Plant2023-03-29029 March 2023 2023 Annual Statement of Insurance for Pacific Gas and Electric Companys Diablo Canyon Power Plant DCL-23-023, Decommissioning Funding Report for Diablo Canyon Power Plant, Units 1 and 22023-03-28028 March 2023 Decommissioning Funding Report for Diablo Canyon Power Plant, Units 1 and 2 DCL-23-021, Independent Spent Fuel Storage Installation, Emergency Plan Update2023-03-23023 March 2023 Independent Spent Fuel Storage Installation, Emergency Plan Update DCL-23-020, Responses to NRC Questions Regarding License Renewal Efforts2023-03-17017 March 2023 Responses to NRC Questions Regarding License Renewal Efforts DCL-23-009, Owner'S Activity Report for Unit 2 Twenty-Third Refueling Outage2023-02-22022 February 2023 Owner'S Activity Report for Unit 2 Twenty-Third Refueling Outage DCL-23-008, Request Regarding Senior Reactor Operator License Application2023-02-22022 February 2023 Request Regarding Senior Reactor Operator License Application DCL-2023-503, Annual Sea Turtle Report2023-01-26026 January 2023 Annual Sea Turtle Report DCL-2023-502, (DCPP) 4th Quarter 2022 Report on Discharge Self-Monitoring2023-01-18018 January 2023 (DCPP) 4th Quarter 2022 Report on Discharge Self-Monitoring DCL-22-091, Revised Steam Generator Tube Inspection Report for Twenty-First Refueling Outage2022-12-20020 December 2022 Revised Steam Generator Tube Inspection Report for Twenty-First Refueling Outage DCL-22-089, Core Operating Limits Report for Unit 2 Cycle 242022-12-20020 December 2022 Core Operating Limits Report for Unit 2 Cycle 24 DCL-22-085, Request to Resume Review of the License Renewal Application or, Alternatively, for an Exemption from 10 CFR 2.109(b), Concerning a Timely Renewal Application2022-10-31031 October 2022 Request to Resume Review of the License Renewal Application or, Alternatively, for an Exemption from 10 CFR 2.109(b), Concerning a Timely Renewal Application DCL-22-041, Site-Specific Decommissioning Cost Estimate, Revision 12022-10-12012 October 2022 Site-Specific Decommissioning Cost Estimate, Revision 1 DCL-22-042, Post-Shutdown Decommissioning Activities Report, Revision 12022-10-12012 October 2022 Post-Shutdown Decommissioning Activities Report, Revision 1 2024-01-29
[Table view] Category:Periodic Monitoring Report (Radiological/Environmental)
MONTHYEARDCL-23-036, 2022 Annual Radiological Environmental Operating Report2023-05-0101 May 2023 2022 Annual Radiological Environmental Operating Report DCL-23-025, 2022 Annual Radioactive Effluent Release Report2023-05-0101 May 2023 2022 Annual Radioactive Effluent Release Report DCL-21-023, Submittal of 2020 Annual Radioactive Effluent Release Report2021-04-20020 April 2021 Submittal of 2020 Annual Radioactive Effluent Release Report DCL-20-019, Submittal of 2019 Annual Radioactive Effluent Release Report2020-04-30030 April 2020 Submittal of 2019 Annual Radioactive Effluent Release Report DCL-18-022, 2017 Annual Radiological Environmental Operating Report2018-04-26026 April 2018 2017 Annual Radiological Environmental Operating Report ML12125A3862012-04-16016 April 2012 2011 Annual Radiological Environmental Operating Report. Part 3 of 5 DCL-12-041, 2011 Annual Radiological Environmental Operating Report. Part 2 of 52012-04-16016 April 2012 2011 Annual Radiological Environmental Operating Report. Part 2 of 5 DCL-12-041, 2011 Annual Radiological Environmental Operating Report. Part 3 of 52012-04-16016 April 2012 2011 Annual Radiological Environmental Operating Report. Part 3 of 5 DCL-12-041, 2011 Annual Radiological Environmental Operating Report. Part 1 of 52012-04-16016 April 2012 2011 Annual Radiological Environmental Operating Report. Part 1 of 5 ML12125A3842012-04-16016 April 2012 2011 Annual Radiological Environmental Operating Report. Part 2 of 5 DCL-11-051, 2010 Annual Nonradiological Environmental Operating Report2011-04-28028 April 2011 2010 Annual Nonradiological Environmental Operating Report DCL-10-083, CEC-1304 Schedule 3 Part a, Environmental Information Related to Water Supply and Wastewater Discharge Annual Report2009-12-31031 December 2009 CEC-1304 Schedule 3 Part a, Environmental Information Related to Water Supply and Wastewater Discharge Annual Report ML11166A1712009-12-31031 December 2009 CEC-1304 Schedule 3 Part a, Environmental Information Related to Water Supply and Wastewater Discharge Annual Report DCL-2009-512, 2008 Annual Hazardous Waste Facility Report (Afr) - Pacific Gas & Electric Company'S Diablo Canyon Power Plant (DCPP) EPA Id No. CAD 077 966 3492009-02-27027 February 2009 2008 Annual Hazardous Waste Facility Report (Afr) - Pacific Gas & Electric Company'S Diablo Canyon Power Plant (DCPP) EPA Id No. CAD 077 966 349 DCL-2008-514, 2007 Annual Hazardous Waste Facility Report (Afr) - Pacific Gas & Electric Company'S Diablo Canyon Power Plant (DCPP) EPA Id No. CAD 077 966 3492008-02-23023 February 2008 2007 Annual Hazardous Waste Facility Report (Afr) - Pacific Gas & Electric Company'S Diablo Canyon Power Plant (DCPP) EPA Id No. CAD 077 966 349 DCL-03-141, Special Report 03-03: Seismic Event of October 18, 20032003-10-31031 October 2003 Special Report 03-03: Seismic Event of October 18, 2003 DCL-2003-530, Transmittal of First Quarter 2003 Report on Discharge Monitoring at Diablo Canyon Power Plant2003-04-18018 April 2003 Transmittal of First Quarter 2003 Report on Discharge Monitoring at Diablo Canyon Power Plant DCL-2003-501, Transmittal of Fourth Quarter 2002 Report on Discharge Monitoring at Diablo Canyon Power Plant2002-01-17017 January 2002 Transmittal of Fourth Quarter 2002 Report on Discharge Monitoring at Diablo Canyon Power Plant 2023-05-01
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PacificGas and Electric Company Lawrence F.Womack Diablo Canyon Power Plant Vice President PO. Box 56 Nuclear Services Avila Beach, CA 93424 October 31, 2003 805.545A600 Fax: 805.545A234 PG&E Letter No. DCL-03-141 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Special Report 03-03: Seismic Event of October 18, 2003
Dear Commissioners and Staff:
On October 18, 2003, at 0039 PDT, with Unit 1 and Unit 2 operating at 100 percent power, ground motion was felt and recognized as an earthquake by control room operators. The plant earthquake force monitor recorded greaterthan 0.Olg forthe seismic event. Therefore, operations personnel declared an Unusual Event.
(Reference NRC Event Notification Number 40258.) At 0330 PDT, the Unusual Event was terminated upon confirmation that no damage to the plant occurred.
This special report is submitted pursuant to Diablo Canyon Power Plant (DCPP)
Equipment Control Guideline (ECG) 51.1, "Seismic Instrumentation." This ECG requires the following actions for a seismic event: For seismic monitoring instruments actuated during a seismic event, "data shall be retrieved from actuated instruments and analyzed to determine the magnitude of the vibratory ground motion. A special report shall be prepared and submitted to the Commission ... describing the magnitude, frequency spectrum, and resultant effect upon facility features important to safety." describes the ground motion analysis, including the magnitude and frequency spectrum of this event. Enclosure 2 provides an analysis of the resultant effect upon facility features important to safety.
As this event relates to DCPP, there was no adverse effect to public health and safety, or upon facility features important to safety. Peak acceleration recorded at the Unit 1 containment base for this event was 0.012g; DCPP is designed for peak accelerations of 0.75g horizontal and 0.50g vertical.
If you have any questions, please contact me at 805-545-4600 or Lloyd Cluff at 415-973-2791.
A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Caltaway
- Comanche Peak . Diablo Canyon
- Palo Verde . South Texas Project
Document Control Desk PG&E Letter DCL-03-141 October 31, 2003 Page 2 Sincerely, eo" Q._1 Lawrence F. Womack Vice President - Nuclear Services swh/A0593059 Enclosures cc: Bruce S. Mallett, Region IV David L. ProuIx, Resident Girija S. Shukla, NRR Diablo Distribution
I Enclosure 1 PG&E Letter DCL-03-141 Diablo Canyon Power Plant Deer Canyon Earthquakes of October 18, 2003 On October 18, 2003, at 0027 and 0039 PDT, two small local magnitude (ML) 3.4 earthquakes occurred. The events were located approximately 5 km east of Diablo Canyon Power Plant (DCPP), in the region northwest of Deer Canyon.
Both earthquakes were felt in the DCPP control room; the second event triggered strong motion instruments at the plant site. The earthquakes are part of a sequence of 14 small earthquakes that occurred between October 12 and October 24, 2003.
The earthquakes were recorded by the PG&E Central Coast Seismic Network (CCSN) that has operated since 1987 as part of the PG&E Long Term Seismic Program. The CCSN data are augmented by recordings from the U.S.
Geological Survey's (USGS) Northern California Seismic Network (NCSN). The CCSN consists of 20 seismographic stations, including 5 dual-gain 3-component stations (large triangles in inset to Figure 1). The addition of the CCSN, including the 3-component stations greatly improves the accuracy of determining the earthquake location in the region around DCPP.
Figure 1 shows the Deer Canyon sequence with previous earthquakes for the period 1987 to the present. The October 2003 sequence consists of 14 earthquakes with magnitudes ranging from 0.4 to 3.4. The previous seismicity shows scattered activity across the San Luis/Pismo block; the Deer Canyon earthquakes are located within this region of previous activity (Figure 1).
Strong Ground Motion:
The two largest earthquakes were felt in the Unit 1 control room; the operators reported that the second event was the stronger. The first event did not trigger the seismic instruments. The second event did not trigger the Basic Seismic System analog recorder (Kinemetrics SMA) in the control room, however the Kinemetrics digital recorders (SSA) at the Unit 1 containment base, top of containment, the auxiliary building, and the free-field pit location (near the fitness trailer) did trigger on the second event. According to David Castleman of Kinemetrics, Inc., the SMA system worked properly; however, the system did not trigger because the containment base ground motions contained significant energy outside the 1.0 to 10.0 Hz bandwidth of the SMA trigger. An additional monitoring system, the Supplemental System, was inoperable at the time of the earthquakes; however, three temporary accelerometers (TerraTech GSR-18),
located in the Auxiliary and the Turbine buildings, recorded the second event.
1
Enclosure 1 PG&E Letter DCL-03-141 The earthquake force monitor (EFM) located in the control room measured 0.02g on the vertical component. The EFM measurement is from the sensor at the Unit 1 Containment base and does not have the DC offset removed. With the DC offset removed before filtering, the peak acceleration on the vertical component was 0.011g.
Table 2 lists the peak accelerations, peak velocities, and peak displacements of the free-field and Unit 1 containment base ground motions after the filtering and baseline corrections are applied. The peak accelerations ranged between about 1 to 2 percent g with the largest peak acceleration on the vertical component.
Regarding the frequency spectrum, the response spectra were computed for the free-field and Unit 1 containment base recordings. The 5 percent damped spectra for the free-field and Unit 1 containment base recordings are shown in Figures 2 and 3, respectively. The response spectra for this earthquake show very high frequency content that is typical for an earthquake of this magnitude.
For the free-field, the horizontal spectra peaked at about 12 Hz and the vertical spectrum peaked at about 20 Hz. For the Unit 1 containment base, the peaks are shifted to slightly lower frequencies. This shift to lower frequencies is an expected effect of the large foundation.
Conclusions The occurrence, location, and magnitude of the October 18, 2003, Deer Canyon earthquakes is not a surprise as the sequence of earthquakes is consistent with our understanding of the tectonic framework in the region around DCPP. The events occurred in the San Luis/Pismo block, which is a region of previous seismicity. Additional small earthquakes are expected to occur within this block.
The ground motions from the second event (0039 PDT) are typical for ground motions from a magnitude 3.4 earthquake at a distance of 5.0 km.
A detailed report of the Deer Canyon earthquakes, prepared by Dr. Norman Abrahamson and Ms. Marcia McLaren, PG&E Geosciences Department, is available upon request.
2
Enclosure 1 PG&E Letter DCL-03-141
-121V00 -12045' -120'30 36' A
MAGNITUDES 0-
<1.0 O 1.0+
0 2.0+
(,) 3.0+ 5-I f*
0~ 7~S 10 -
15 _,
0 5 10 15 Distance (km)
Figure 1. Map and seismic cross section showing the Deer Canyon sequence (orange circles) from October 12 through October 24, 2003, with previous earthquakes (grayed circles) from October 1987 to October 11, 2003. The data were recorded by the PG&E Central Coast Seismic network (large triangles on top figure inset; triangles with tick marks are 3-component stations) and the Northern California Seismic network (small triangles on top figure inset). Seismic stations also are shown on larger map (green triangles). Location of seismic cross section AA' is shown on map with 8-km-wide bars to mark events projected on to the cross section in bottom figure.
Quaternary faults are from PG&E (1988); selected faults are labeled. The thick gray line is the boundary of the San Luis/Pismo structural block (Lettis and others, 2001).
3
Enclosure 1 PG&E Letter DCL-03-141 0.
C 0
- 8=
0 tD a)
U Tw
.O.-
K co Frequency (Hz)
Figure 2. Response spectra at 5% damping for the free-field ground motion.
4 C Oz_
Enclosure 1 PG&E Letter DCL-03-141 NI 0
- =
0 5O 4u a) en 0.1 Frequency (Hz)
Figure 3. Response spectra at 5% damping for the Unit 1 containment base ground motion.
5
Enclosure 1 PG&E Letter DCL-03-141 Table 1: Earthquake location parameters for the Deer Canyon sequence, October 12 to 24, 2003.
Felt events are highlighted in gray.
Dist. to No. P- & Gap btwn nearest Horiz. Vert. No. P-S-wave stas. station RMS No. S-wave Error Error wave first No. Date Time (UTC) Lat Lon Depth readings (dog) (km) (sec) *MD readinas (km) (km) motions 1 10112/200313:32 28.54 35 11.97 -12C148.83 6.6 52 145 3 0.13 2.3 2 0.41 0.39 43 2 10/12/200316:57 37.60 35 12.28 -12C147.59 3.8 6 137 3 0.07 0.5 I 0.66 0.33 5 3 10/17/200313:19 14.33 35 12.49 -12C147.88 3.6 34 123 3 0.14 1.7 4 0.37 0.17 30 4 10/18/200307:27 18.37 35 12.23 -12C148.53 6.5 57 125 .3 0.12 3.4 2 0.23 0.39 101 5 10/18/200307:38 59.14 35 12.15 -12C148.52 6.7 60 127 -3 0.12 3.3 2 0.25 0.35 112 6 10/18/200307:40 49.52 3512.10 -12C147.81 3.7 6 149 4 0.05 0.4 1 3.09 1.79 5 7 10/18/200307:41 43:44 35 12.18 -12C147.92 3.7 9 147 4 0.09 1.1 1 0.85 0.44 8 8 10/18/200307:55 18.96 35 12.13 -12C147.88 3.7 16 132 4 0.12 1.3 3 0.52 0.21 11 9 10/20/200310:38 21.93 35 12.24 -12C147.97 3.6 9 146 4 0.07 1.1 I 0.61 0.31 7 10 10/20/200318:22 37.72 35 12.35 -12C148.05 3.8 9 142 3 0.07 0.9 I 0.67 0.33 8 1I 10/20/200319:28 31.85 35 15.05 -12CI44.37 8.9 46 50 4 0.10 1.5 3 0.43 0.61 15 12 10/21/200308:35 40.18 35 12.43 -12C148.00 3.6 24 125 3 0.11 1.2 2 0.54 0.25 12 13 10/21/200313:43 36.44 35 12.65 -12C148.20 3.7 37 119 3 0.12 2.6 3 0.36 0.17 41 14 10/24/200323:30 52.84 35 12.06 -12C147.73 3.4 6 147 4 0.07 0.7 0 0.52 0.33 6
- MD = duration magnitude 6
Enclosure 1 PG&E Letter DCL-03-141 Table 2. Peak ground motions values from the Basic Seismic System digital recorders (after filtering and baseline correction) 7
Enclosure 2 PG&E Letter DCL-03-141 Analysis of The Resultant Effect Upon Facility Features Important To Safety For The Seismic Event of October 18, 2003 Plant Systems Response:
Per Casualty Procedure (CP) M4, "Earthquake," a walkdown of the facility was conducted. All systems continued to operate normally, no fires were discovered. No visible damage was discovered. No alarms were received in the control room for the first seismic event; alarms received in the control room for the second seismic event are as follows:
U-1 Alarms
- Accumulator 1-3 level high; the accumulator level was high in the normal operating band (71-72 percent). The alarm came in and out several times, and returned to normal.
- Turbine supervisory instrument drawer. Bearing 5 came into alarm and returned to normal.
U-2 Alarms Turbine supervisory instrument drawer. Bearing 5 came into alarm and returned to normal.
Seismic Monitoring Instrumentation Response:
Two seismic events were felt on the plant site this date. The first event was felt at approximately 0027 with the second one at 0039. CP M4 was entered after the second event. The first event was felt but did not show any increase on the seismic monitors. The second event showed approximately 0.02g on the vertical indication of earthquake force monitor indicator, EFM-1. During the seismic event, the Unit 1 containment base appeared to have experienced ground motion about 0.02g based on initial indications; however, the Kinemetrics trigger for the control room alarm did not actuate. The nominal trigger setpoint for the Kinemetrics trigger is 0.01 g, +/- 0.002g.
The maximum acceleration at the containment base, after analysis, was determined to be 0.012g.
The Kinemetrics trigger instrument calibration was performed by the instrument vendor following this event. The as found data were within specification. In addition, the Kinemetrics trigger switch was found to be within its instrument tolerance and thus operated as designed for this low level event.
Therefore, the response by the Kinemetrics system and trigger were proper for this low level event, and were considered operable based on vendor-provided calibration data and resulting engineering evaluation.