DCL-15-027, Diablo Canyon Power Plant Er Changes Reflected in the Environmental Report Update Amendment 2. Part 8 of 9
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EVENT PROBABILITY NAME ZPRS2F 9.98E-01 DB4F 5.64E-03 IPCET2 1.20E-01 ' Diablo Canyon Power Plant License Renewal Application TABLE F.5-28 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP LEVEL 2 (ST2)1 IMPORTANCE LIST REVIEW RISK DESCRIPTION POTENTIAL SAMAS REDUCTION WORTH 1.01 E+OO Inadvertent pressurizer spray For scenarios that include fire induced pressurizer spray through aux or normal path: All actuation induced LOCAs, many of the contributors components impacted initially have an RHR pump available for mitigation.
Failure to trip the deadheaded pump before it is damaged leads to loss of heat removal capability and subsequent containment overpressurization.
A potential means of precluding the need to trip the RHR pumps would be to install a normally open CCW flow bypass line around the RHR Hx outlet valve. This would ensure that minimum cooling flow would be available to prevent damage to the RHR pumps when they are running with the RCS at high pressure (SAMA 1 ). 1.01 E+OO 125V DC BUS F -LONG TERM This is an intermediate SF for DF4, which represents the (TRAIN 11): 125V DC VITAL unavailability of DC bus F. An alternate DC generator POWER BUSES: Train OF-could be used to either power critical DC buses or to (BTC11=S, BTC121=F) directly power critical DC equipment (SAMA 1 0). The generator would have to be stored in a seismically qualified area. 1.01 E+OO INDUCED RCS HOT LEG OR They include primarily large magnitude seismic events SURGE LINE FAILURE: RCS at and fire events in which 480V switchgear room cooling setpoint pressure, Seal LOCA, fails. Given that this SF is associated with a large scale smallest leak size, no CST seismic event (greater than 1. 75g), a new mitigating resupply , no RCS failures system capable of responding after seismic events -(potentially up to 4g) is considered to be required.
Such a system would include a 4KV power source, a core spray type injection system (with a qualified PORV) capable of spraying the core for cooling until the reactor cavity is flooded to a level above TAF, a connection to a large seismically qualified source of water (wells or seawater), and a heat exchanger system (SAMA 4). For the fire Page F-223
EVENT PROBABILITY NAME ZPRSI1 2.80E-01 DB2H 5.64E-03 DF4 5.64E-03 ZSVHES 5.80E-03 Diablo Canyon Power Plant License Renewal Application TABLE F.5-28 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP LEVEL 2 (ST2)1 IMPORTANCE LIST REVIEW ------------
-RISK DESCRIPTION POTENTIAL SAMAS REDUCTION WORTH events, the action to align portable switchgear ventilation is credited, (instrumentation required for diagnosis is not degraded) and it fails. Loss of all AC power is considered to be an adequate cue to credit the alignment of an additional mitigation strategy, such as the use of portable, engine driven, high pressure RCS and SG injection pumps (SAMA 18). 1.01 E+OO Operator action to terminate Addressed in the Level 1 importance list. spurious Sl: Instrumentation OK 1.01 E+OO 125V DC VITAL* POWER This is an intermediate SF for DH10, which represents BUSES: Train DH -BTC132=S, the unavailability of DC bus H. An alternate DC BTC131=F generator could be used to either power critical DC buses or to directly power critical DC equipment (SAMA 1 0). The generator would have to be stored in a seismically qualified area. 1.01 E+OO 125V DC BUS F -LONG TERM This SF represents the unavailability of DC bus F. An (TRAIN 11 ): BTC11 =S, alternate DC generator could be used to either power BTC121=F critical DC buses or to directly power critical DC equipment (SAMA 1 0). The generator would have to be stored in a seismically qualified area. 1.01 E+OO 480V Switchgear Ventilation
-Addressed in the Level 1 importance list. Operator Action: No fire damage to flow switches Page F-224 EVENT PROBABILITY NAME OG230S 6.63E-01 AWBB 6.23E-03 Diablo Canyon Power Plant License Renewal Application TABLE F.5-2B APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP LEVEL 2 (ST2)1 IMPORTANCE LIST REVIEW RISK DESCRIPTION POTENTIAL SAMAS REDUCTION WORTH 1.01 E+OO AVAILABILITY OF POWER This SF represents the failure of offsite power from the FROM 230 KV OFFSITE GRID: 230KV source in a fire event. The scenario including this 52HG15 impacted -for scenario SF are typically associated with fires in the 4-A-1 area ZTRY22F1 (Chemical Lab Area, G Bus Compartment).
In these cases, the fire impacts RHR pump 1-1 and 480V bus Gin combination with the random failue of DG 1-1 and fire induced failue of 4KV bus G. The result is a failure of power to the DG fuel oil system, which leads to an SBO as it is also combined with a failure to align the backup power supply to the fuel oil system. DCPP has a viable recovery option for this typs of event, but the action to perform the task is impacted by degraded instrumentation and it has failed. These types of events could also potentially be mitigated through the use of portable, engine driven, high pressure RCS and SG injection pumps (SAMA 18). 1.01 E+OO SUPPORT FOR THE TOP AND This SF represents the failure of MD AFW pump 13 given MOP 1-2 UNAVAILABLE the unavailability of the other two pumps. A potential approach to restoring SG makeup would be to provide an engine driven SG makeup pump that can be aligned in time to mitigate loss of SG makeup scenarios (SAMA 2). Page F-225 EVENT PROBABILITY NAME GYG 5.65E-02 SIZCR4 8.73E-01 Cl4 1.03E-01 Diablo Canyon Power Plant License Renewal Application TABLE F.S-28 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP LEVEL 2 {ST2)1 IMPORTANCE LIST REVIEW RISK DESCRIPTION POTENTIAL SAMAS REDUCTION WORTH 1.01 E+OO 1/3 DIESELS UNAVAILABLE This is an intermediate SF for TG1 and similar SFs, which (BUS G) represent the unavailability of DG 2-1. The SF appears in the importance list, but it is related to non-minimal failures that do not directly impact the sequence of events. No SAMAs are required.
1.01 E+OO TOP EVENT Sl: 8976, 8974B, This SF represents the failure of the Sl top event given and all ZSI2 components fire impact on the RWST suction and recirculation valves. impacted The sequences that include this SF often include RHR pump failure due to the failure to trip the pumps when operating in the "deadhead" condition.
A potential means of precluding the need to trip the RHR pumps would be to install a normally open CCW flow bypass line around the RHR Hx outlet valve. This would ensure that minimum cooling flow would be available to prevent damage to the RHR pumps when they are running with the RCS at high pressure (SAMA 1 ). 1.01 E+OO SSPS Trains A and B Not Avail This represents failure of containment isolation when both but Manual Recovery Avail SSPS trains are unavailable.
The primary contributors to these scenarios are flooding events that lead to failure of all three DC batteries/buses.
Credit is already taken for manual isolation of the flooding event. A portable DC generator could be used to directly power critical loads in the event that batteries have failed (SAMA 1 0). Page F-226 I ! I EVENT PROBABILITY NAME PRA1A 1.96E-01 GH4F 3.52E-02 Diablo Canyon Power Plant License Renewal Application TABLE F.S-28 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP LEVEL 2 (ST2)1 IMPORTANCE LIST REVIEW RISK DESCRIPTION POTENTIAL SAMAS REDUCTION WORTH 1.01 E+OO PRESSURE RELIEF: PR Failed This SF represents the fire related failures of PORV 474 due to PORV 474 8000A faiure-block valve 8000A. The scenarios generally include for fire area 9A either a failure to swap recirculation mode or failure to trip deadheaded RHR pumps to prevent pump damage. Automating the swap to recirculation mode could improve the reliability of the function (SAMA 7). A potential means of precluding the need to trip the RHR pumps would be to install a normally open CCW flow bypass line around the RHR Hx outlet valve. This would ensure that minimum cooling flow would be available to prevent damage to the RHR pumps when they are running with the RCS at high pressure (SAMA 1 ). 1.01 E+OO UNIT 1 BUS H DIESEL This SF represents the failure of DG 1-1 given success of GENERATOR:
DG 1-1 (BUS H) DG 1-2 (and bypass of DG 1-3). In top contributors, the : GF-B,GG-S failure of DG 1-1 is combined with fire induced failure of Sl pump 1-2, leaving no adequate high pressure injection supply to mitigate the fire induced LOCA. Cross-tie from the opposite unit is available, but common cause failures would likely limit the credit associated with including the capability in the model. Installation of a self-contained, independent swing diesel, not dependent on external support systems, would provide increased defense in depth and should be considered for loss of onsite emergency AC power sources (SAMA 15). Page F-227 I EVENT PROBABILITY NAME AWS4 1.61 E-02 ZSG234 9.83E-01 IPCET1 7.20E-01 Diablo Canyon Power Plant License Renewal Application TABLE F.5-28 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP LEVEL 2 (ST2)1 IMPORTANCE LIST REVIEW ----RISK DESCRIPTION POTENTIAL SAMAS REDUCTION WORTH 1.01 E+OO SUPPORT FOR BOTH MOP'S This is an intermediate SF for AW4S. The primary UNAVAILABLE contributors containing this SF are LOOP and SBO seismic events in which MD AFW is failed due to power dependencies.
Subsequent to the TO AFW failure, feed and bleed is unavailable due to loss of po_wer to one PORV and loss of instrument air for the other. Providing a backup air supply to PORV PCV 474 could reduce the feed and bleed failures associated with loss of instrument air (SAMA 5). Also, a more robust seismically-resistant 4kV power source (SAMA 4 or SAMA 15) can provide some benefit. 1.01 E+OO PCV-19 spuriously opens due to This SF represents the failure of PCV-19 to open for fire: fire impact PCV-20, PCV-21 steam relief given fire impact on the other 3 ADVs. Many and PCV-22 of the scenarios that include this SF also include failure of the charging pumps due to loss of cooling to the pumps, which impacts mitigation of a fire induced LOCA. In these cases, instrumentation for diagnosis is degraded and there is limited time for the 30 minute alternate cooling alignment from fire water. A potential imporovement would be to provide a hard pipe connection between the fire water system and the charging pump cooling lines to simplify the alignment and reduce the time required for the action (SAMA 23). 1.01 E+OO INDUCED RCS HOT LEG OR This SF represents the probability of failure of the RCS SURGE LINE FAILURE hot leg or surge line after core damage, which occurs for a diverse range of events. A potential means of preventing these failures would be to provide an independent means of adding water to the RCS at high pressure. These types of events could also potentially be mitigated through the use of portable, engine driven, high Page F-228
-EVENT PROBABILITY NAME TD1 1.61 E-02 BB1H 1.42E-02 GYF 5.65E-02 Diablo Canyon Power Plant License Renewal Application TABLE F.5-2B APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP LEVEL 2 (ST2)1 IMPORTANCE LIST REVIEW RISK DESCRIPTION POTENTIAL SAMAS REDUCTION
- WORTH pressure RCS and SG injection pumps (SAMA 18). 1.01 E+OO SEISMIC TD AFW PUMP -This SF represents the failure of the turbine driven AFW SCT=F pump in seismic events. Most of the contributors are related to large magnitude events. Given that this SF is associated with a large scale seismic event (greater than 1.75g), a new mitigating system capable of responding after seismic events (potentially up to 4g) is considered to be required.
Such a system would include a 4KV power source, a core spray type injection system (with a qualified PORV) capable of spraying the core for cooling until the reactor cavity is flooded to a level above TAF, a connection to a large seismically qualified source of water (wells or seawater), and a heat exchanger system (SAMA 4). 1.01 E+OO Train 2H fails with Recovery -Addressed in the Level 1 importance list. TH=S 1.01 E+OO DEG 2-3 GENERATOR This is an intermediate SF for TF1 and similar SFs, which FAILURE (1/3): 1/3 DIESELS represent the unavailability of DG 2-3. The SF appears in UNAVAILABLE (BUS F) the importance list, but it is related to non-minimal failures that do not directly impact the sequence of events. No SAMAs are required.
Page F-229 TABLE F.S-28 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP LEVEL 2 (ST2)1 IMPORTANCE LIST REVIEW EVENT PROBABILITY RISK NAME REDUCTION WORTH F02AZ 4.34E-03 1.01 E+OO SOP6 9.97E-01 1.01 E+OO 1 ST2 refers to the Small Early release category.
Diablo Canyon Power Plant License Renewal Application DESCRIPTION POTENTIAL SAMAS FUEL OIL TRANSFER A portable diesel fuel oil transfer pump is already SYSTEM: SUPPORT FOR available.
The risk importance of this split fraction would TRAIN 0-1 AVAIL; FIRE fall below the review threshold if its use were credited in INDUCED FAILURE OF TRAIN the model. No SAMA is required.
0-2 SEIS6, Hazard Levels: This SF represents the loss of all offsite power and is 3.00E+OO to 3.99E+OO based on the 230kV switchyard seismic fragility, which is significantly stronger than the 500kV switch yard seismic fragility.
Given that this SF is associated with a large scale seismic event (greater than 1. 75g), a new mitigating system capable of responding after seismic events (potentially up to 4g) is considered to be required.
Such a system would include a 4KV power source, a core spray type injection system (with a qualified PORV) capable of spraying the core for cooling until the reactor cavity is flooded to a level above TAF, a connection to a large seismically qualified source of water (wells or seawater), and a heat exchanger system (SAMA 4). Page F-230 SAMA SAMA TITLE NUMBER 1 Install a Minimum CCW Cooling Flow Line Around the RHR Heat Exchanger Outlet Valve 2 Provide an Engine Driven SG Makeup Pump Diablo Canyon Power Plant License Renewal Application TABLE F.5-3 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP PHASE 1 SAMA LIST
SUMMARY
SAMA DESCRIPTION For scenarios in which an Sl signal is generated while the RCS pressure remains above the RHR low pressure interlock for extended times, it is necessary for the operators to check the status of the RHR pumps at some point after initiation and to shut them down to prevent pump damage. If CCW is flowing to the RHR heat exchangers, however, the action to trip the RHR pumps is not required to prevent pump failure. A means of preventing RHR pump failure without adding a large, early demand on the CCW system is to add a small, normally open bypass line around the RHR heat exchanger outlet valves in the CCW flowpath.
For cases in which the AFW pumps have failed and/or the support systems are failed, such as the 480V AC switchgear, providing an independent means of injecting water to the steam generators could provide the secondary side heat removal function.
Ensuring that the makeup pump can be aligned in time to mitigate early loss of AFW scenarios and that diverse pump suction supplies are available (e.g., Fire Water, Raw Water) is required to mitigate the top DCPP risks. (This SAMA is addressed by elements of the DCPP FLEX strategy.)
SOURCE COST ESTIMATE PHASE 1 BASELINE DISPOSITION PRA $3,020,424 Implementation cost is Importance List less than MACR. Retain Review for Phase II analysis.
See Section F.6.1. PRA $17,492,616 Implementation cost is Importance List greater than the MACR. Review Screened from further analysis.
Page F-231 SAMA SAMATITLE NUMBER 3 Change Procedures to Explicitly Address Vulnerability of Auto Sl 4 Seismically Qualified Response System 5 Backup Air System for PORV PCV 474 Diablo Canyon Power Plant License Renewal Application TABLE F.5-3 DCPP PHASE 1 SAMA LIST
SUMMARY
SAMA DESCRIPTION SOURCE The DCPP fire procedure already identifies PRA equipment that may be damaged for each Importance List fire area and provides guidance to mitigate Review failed equipment.
A potential enhancement would be explicitly identify that fire damage may impact auto Sl actuation and direct the operators to monitor valid instruments to ensure it functions when it is required.
For large scale seismic events, many of the PRA plant's mitigating systems may be damaged Importance List to an extent that only an independent, Review seismically durable system would be capable of preventing core damage. Such a system would include a 4KV power source, a core spray type injection header (with a qualified PORV) capable of spraying the core for cooling until the reactor cavity is flooded to a level above TAF, a connection to a large seismically qualified source of water (wells or seawater), and a heat exchanger system. (A significant portion of this SAMA's design is addressed by elements of the DCPP FLEX strategy.
One exception is that this SAMA includes a core spray-like injection for reactor cavity flooding.)
Currently, loss of offsite power results in the PRA loss of the lA system. Changing the air Importance List supply to PCV 474 (Pressurizer PORV) to a Review class I backup air supply would prevent this and reduce the loss of lA contributions to APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 COST ESTIMATE PHASE 1 BASELINE DISPOSITION
$376,342 Implementation cost is less than MACR. Retain for Phase II analysis.
See Section F.6.2. $160,001,440 Implementation cost is greater than the MACR. Screened from further analysis.
$3,133,404 Implementation cost is less than MACR. Retain for Phase II analysis.
See Section F.6.13 Page F-232 SAMA NUMBER 6 7 8 SAMATITLE Install an Additional Train of 480V Switchgear Room HVAC Automate Swap to Recirculation Protect RHR Cables in Fire Areas 6-A-2 and 6-A-3 Diablo Canyon Power Plant License Renewal Application TABLE F.5-3 DCPP PHASE 1 SAMA LIST
SUMMARY
SAMA DESCRIPTION SOURCE core damage. Alternate Switchgear Room cooling PRA procedures already exist for DCPP, but the Importance List loss of room cooling is still an important Review issue. While costly, a potential means of reducing the HVAC failure contribution would be to install an independent train of HVAC. The operators are well trained on the action PRA to transition the RCS injection systems to Importance List recirculation mode, but automating the Review process will further improve reliability and reduce the contribution of this action to core damage scenarios.
For fires in areas 6-A-2 and 6-A-3, fire PRA induced failure of the 8700A/B and the FCV-Importance List 641A/B valves lead to loss of the RHR Review system, which is critical for mitigating the fire scenarios.
Providing additional protection for the cables associated with these components in these areas could help improve the likelihood that RHR would remain available.
APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 COST ESTIMATE PHASE 1 BASELINE DISPOSITION
$9,993,910 Implementation cost is greater than the MACR. Screened from further analysis.* $10,616,468 Implementation cost is greater than the MACR. Screened from further analysis.
$1,072,493 Implementation cost is less than MACR. Retain for Phase II analysis.
See Section F.6.4. Page F-233 SAMA SAMA TITLE NUMBER 9 Install Spray Barriers to Protect the TO AFW Pump and Install a Waterproof MD AFW Pump 1 0 Alternate DC Generator 11 Install a Swing RHR Pump Diablo Canyon Power Plant License Renewal Application TABLE F.S-3 DCPP PHASE 1 SAMA LIST
SUMMARY
SAMA DESCRIPTION SOURCE For some flooding scenarios, including PRA those in fire areas 14-A and 3-Q-2, the AFW Importance List system is damaged by flood water from fire Review protection system breaks. Providing barriers to protect the TD AFW pump can reduce the likelihood that the pump will be damaged. The MD AFW pumps are susceptible to flood water incursion via ventilation ducts that must remain open to provide adequate room cooling. To protect the MD AFW pumps from these flooding events, it would be necessary to replace the existing equipment with a waterproof pump. In order to mitigate DC system failures, an PRA alternate DC generator could be used to Importance List directly power a bus (bypasses charger Review faults) or directly power critical loads (bypasses distribution failures).
The generator should be stored in a seismically qualified area so that it would potentially be available to respond in seismic scenarios.
For LOCA events in which the RHR pumps PRA have failed, but cooling flow is available to Importance List the RH R heat exchangers, the availability of Review an additional RHR pump that can be powered from any AC division would provide a means of containment heat removal. APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 COST ESTIMATE PHASE 1 BASELINE DISPOSITION
$25,520,160 Implementation cost is greater than the MACR. Screened from further analysis.
$22,572,878 Implementation cost is greater than the MACR. Screened from further
- analysis.
$75,042,192 Implementation cost is greater than the MACR. Screened from further analysis.
Page F-234 SAMA SAMA TITLE NUMBER 12 Use an Alternate EDG to Support Long Term AFW Operation and a 480V AC Cooled PDP for Primary Side Makeup 13 Not Used. 14 Protect the Letdown Isolation Capability in Fire Area 5-A-1 Diablo Canyon Power Plant License Renewal Application TABLE F.S-3 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP PHASE 1 SAMA LIST
SUMMARY
SAMA DESCRIPTION . A low cost SBO mitigatio-n strategy is to use a small, alternate EDG to power a station battery charger for steam generator level instrumentation and AFW control. In addition, if power can be supplied to a 480V AC self-cooled, high pressure positive displacement pump, primary side makeup could be maintained to make up for normal seal leakage and potentially for boil off in longer timeframes. (This SAMA is addressed by elements of the DCPP FLEX strategy.)
SOURCE COST ESTIMATE PHASE 1 BASELINE DISPOSITION PRA $13,560,218 Implementation cost is Importance List greater than the MACR. Review Screened from further analysis.
In some cases , fires in area 5-A-1 can lead PRA $5,620,896 Implementation cost is less than MACR. Retain for Phase II analysis.
See Section F.6.6. to uncontrolled letdown flow that opens a Importance List system relief valves and results in a LOCA Review path. The DCPP fire procedure already directs actions to isolate the letdown path by depowering the 8149A/B/C valves. To further reduce the risk associated with a letdown LOCA for fires in these areas, a potential enhancement would be to protect the cables associated with either LCV-459 or LCV-460 such that they could function normally and terminate/control flow through the line. Page F-235 SAMA SAMA TITLE NUMBER 15 Install a Contained Swing EDG 16 Change P raced u res to Caution About Spurious Sl Signals in Specific Fire Areas Diablo Canyon Power Plant License Renewal Application TABLE F.5-3 DCPP PHASE 1 SAMA LIST
SUMMARY
SAMA DESCRIPTION SOURCE One of the most effective means of reducing PRA SBO scenarios is to provide a diverse Importance List emergency power supply that can support Review all of the equipment normally supplied by an existing EDG. (Some of the capabilities represented by this SAMA are addressed by elements of the DCPP FLEX strategy.
One difference is that the FLEX strategy uses a portable 4 kV power supply delivered from the regional response center that would not be immediatley available.)
The DCPP fire procedure already include PRA guidance that addresses spurious actuation Importance List of equipment, but its use is not currently tied Review to specific fire areas. A potential enhancement would be to include cautions in the procedures to identify fire areas where damage could cause specific spurious actuations and identify the attachment with the mitigating steps. APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 COST ESTIMATE PHASE 1 BASELINE DISPOSITION
$146,105,155 Implementation cost is greater than the MACR. Screened from further analysis.
$372,788 Implementation cost is less than MACR. Retain for Phase II analysis.
See Section F.6.7. Page F-236 SAMA SAMA TITLE NUMBER 17 Install Flood Sensors to Mitigate Fire Protection System Pipe Breaks 18 Portable Engine Driven Primary and Secondary Side Pumps Diablo Canyon Power Plant License Renewal Application TABLE F.5-3 DCPP PHASE 1 SAMA LIST
SUMMARY
SAMA DESCRIPTION SOURCE. There are multiple scenarios related to Fire PRA Protection system pipe breaks that, if un-Importance List isolated, lead to significant equipment Review damage. In order to improve the likelihood of flood termination, water sensors could be installed in areas containing critical equipment that can be impacted by fire protection system floods, such as those containing the AFW, CCW, and RHR pumps. The water level sensor could be linked to logic that would trip the fire protection pumps and/or isolate a critical valve for scenarios where there is not a coincident fire alarm. For events such as internal floods or fires PRA that can result in the loss of multiple, critical Importance List plant functions, recovery may be easier via Review the use of portable equipment that bypasses the permanently installed equipment.
The use of portable engine driven pumps for primary and secondary side makeup can provide a means of maintaining RCS inventory and decay heat removal. Ensuring the equipment can be aligned in time to respond to loss of AFW cases, have diverse suction sources, and injection points will improve the flexibility of the enhancement. (This SAMA is addressed by elements of the DCPP FLEX strategy; however, the FLEX strategy uses a 480V AC pump powered by a portable generator for RCS makeup.) APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 COST ESTIMATE PHASE 1 BASELINE DISPOSITION
$9,610,440 Implementation cost is greater than the MACR. Screened from further analysis.
$49,473,576 Implementation cost is greater than the MACR. Screened from further analysis.
Page F-237 SAMA SAMA TITLE NUMBER 19 Primary Side Isolation Valves 20 Use Alternate Signal (such as AMSAC) to energize the 480V AC Buses that Supply the Rod Drive Motor Generator Sets 21 Change Fire Procedures to Include Fire Area Specific Guidance on Containment Isolation Valves Diablo Canyon Power Plant License Renewal Application TABLE F.5-3 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 DCPP PHASE 1 SAMA LIST
SUMMARY
SAMA DESCRIPTION The availability of primary side steam generator isolation vales would provide a simple means of isolating ruptured SGs. While secondary side isolation capability exists, these valves would help avoid challenges to secondary side integrity due to failure to rapidly cool down the primary side. In the event that the MG set breakers do not trip in an ATWS, an alternate signal, such as an AMSAC signal, could be used to depower the 480V AC supply that powers the MG sets to ensure the control rod drive units are shut down. The 480V trip could be delayed so that it is only performed after 30 seconds with a valid A TWS signal. The DCPP fire procedure already identifies equipment that may be damaged for each fire area and provides guidance to mitigate failed equipment.
A potential enhancement would be to explicitly identify the containment isolation valves that may be impacted for each fire area. Where possible, the fire procedures could direct manual actions to close the valves. In cases where manual isolation would not be desirable until after loss of equipment or core damage, a reference to other procedures, such as the Severe Accident Mitigation Guidelines could be provided.
SOURCE COST ESTIMATE PHASE 1 BASELINE DISPOSITION PRA $137,797,270 Implementation cost is Importance List greater than the MACR. Review Screened from further analysis.
PRA $11,173,059 Implementation cost is Importance List greater than the MACR. Review Screened from further analysis.
PRA $256,817 Implementation cost is Importance List less than MACR. Retain Review for Phase II analysis.
See Section F.6.8. Page F-238 SAMA SAMA TITLE NUMBER 22 Install Containment Combustible Gas Igniters 23 Enhancethe Notes: Firewater to Charging Pump Cooling Connection TABLE F.5-3 DCPP PHASE 1 SAMA LIST
SUMMARY
SAMA DESCRIPTION Early containment failure is a contributor to the LERF release category.
Although inerting containment in accident conditions could help prevent burns of combustible gases, a better solution is to install backed igniters throughout upper dome of containment.
For cases in which CCW is not available for charging pump cooling, it is possible to connect the Fire Protection system to the charging pump cooling line to provide alternate pump cooling. However , the current alignment requires the use of fire hoses and may not be viable in time stressed events, such as some fire scenarios.
By providing a hard piped connection with manual isolation valves, the alignment could be performed rapidly and the reliability of the action could potentially be improved.
SOURCE PRA Importance List Review PRA Importance List Review (1) Cost estimates are on a per unit basis Diablo Canyon Power Plant License Renewal Application APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 COST ESTIMATE PHASE 1 BASELINE DISPOSITION
$13,083,120 Implementation cost is greater than the MACR. Screened from further analysis.
$491,021 Implementation cost is less than MACR. Retain for Phase II analysis.
See Section F.6.9. Page F-239 SAMA Number 1 3 5 8 SAMA Title Install a Minimum CCW Cooling Flow Line Around the RHR Heat Exchanger Outlet Valve Change Procedures to Explicitly Address Vulnerability of Auto Sl Backup Air System for PORV PCV 474 Protect RHR Cables in Fire Areas 6-A-2 and 6-A-3 Diablo Canyon Power Plant License Renewal Application Table F.S-1 DCPP Phase 2 SAMA List Summary SAMA Description For scenarios in which an Sl signal is generated while the RCS pressure remains above the RHR low pressure interlock for extended times, it is necessary for the operators to check the status of the RHR pumps at some point after initiation and to shut them down to prevent pump damage. If CCW is flowing to the RHR heat exchangers, however, the action to trip the RHR pumps is not required to prevent pump failure. A means of preventing RHR pump failure without adding a large, early demand on the CCW system is to add a small, normally open bypass line around the RHR heat exchanger outlet valves in the CCW flowpath.
The DCPP fire procedure already identifies equipment that may be damaged for each fire area and provides guidance to mitigate failed equipment.
A potential enhancement would be explicitly identify that fire damage may impact auto Sl actuation and direct the operators to monitor valid instruments to ensure it functions when it is required.
Currently, loss of offsite power results in the loss of the lA system. Changing the air supply to PCV 474 (Pressurizer PORV) to a class I backup air supply would prevent this and reduce the loss of lA contributions to core damage. Fore fires in areas 6-A-2 and 6-A-3, fire induced failure of the 8700A/B and the FCV-641A/B valves lead to loss of the RHR system, which is critical for mitigating the fire scenarios.
Providing additional protection for the cables associated with *these components in these areas could help improve the likelihood that RHR would remain available.
Source PRA Importance List Review PRA Importance List Review PRA Importance List Review PRA Importance List Review APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Phase 2 Baseline Disposition This SAMA's net value is negative and is classified as not "cost beneficial".
This SAMA's net value is positive and is classified as potentially "cost beneficial".
This SAMA's net value is negative and is classified as not "cost beneficial".
This SAMA's net value is negative and is classified as not "cost beneficial".
Page F-240 SAMA Number 14 16 21 SAMA Title Protect the Letdown Isolation Capability in Fire Area 5-A-1 Change Procedures t o Caution About Spurious Sl Signals in Specific Fire Areas Change Fire Procedures to Include Fire Area Specific Guidance on Containment Isolation Valves Diablo Canyon Power Plant License Renewal Application Table F.S-1 DCPP Phase 2 SAMA List Summary SAMA Description In some cases, fires in area 5-A-1 can lead to uncontrolled letdown flow that opens a system relief valves and results in a LOCA path. The DCPP fire procedure already directs actions to isolate the letdown path by depowering the 8149AIB/C valves. To further reduce the risk associated with a letdown LOCA for fires in these areas, a potential enhancement would be to protect the cables associated with either LCV-459 or LCV-460 such that they could function normally and terminate/control flow through the line. The DCPP fire procedure already includes guidance that addresses spurious actuation of equipment, but its use is not currently tied to specific fire areas. A potential enhancement would be to include cautions in the procedures to identify fire areas where damage could cause specific spurious actuations and identify the attachment with the mitigating steps. The DCPP fire procedure already identifies equipment that may be damaged for each fire area and provides guidance to mitigate failed equipment.
A potential enhancement would be to explicitly identify the containment isolation valves that may be impacted for each fire area. Where possible, the fire procedures could direct manual actions to close the valves. In cases where manual isolation would not be desirable until after loss of equipment or core damage, a reference to other procedures, such as the Severe Accident Mitigation Guidelines could be provided. Source PRA Importance List Review PRA Importance List Review PRA Importance List Review APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Phase 2 Baseline Disposition This SAMA's net value is negative and is classified as not "cost beneficial". This SAMA's net value is negative and is classified as not "cost beneficial".
This SAMA's net value is positive and is classified as potentially "cost beneficial".
Page F-241 SAMA SAMA Title Number 23 Enhancethe Firewater to Charging Pump Cooling Connection Diablo Canyon Power Plant License Renewal Application Table F.S-1 DCPP Phase 2 SAMA List Summary SAMA Description Source For cases in which CCW is not available for charging pump PRA Importance cooling, it is possible to connect the Fire Protection system to List Review the charging pump cooling line to provide alternate pump cooling. However, the current alignment requires the use of fire hoses and may not be viable in time stressed events, such as some fire scenarios.
By providing a hard piped connection with manual isolation valves, the alignment could be performed rapidly and the reliability of the action could-potentially be improved.
APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Phase 2 Baseline Disposition This SAMA's net value is negative and is classified as not "cost beneficial".
Page F-242 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT2 TABLE F.7-1 SENSITIVITY OF DCPP BASELINE RISK TO PARAMETER CHANGES Parameter Meteorology Evacuation Time Evacuation Speed No Evacuation Release Height Release Heat Deposition Velocity Population Resettlement Planning Economic Inputs Rate of Return Year 2004 MET data Year 2006 MET data Description Evacuation delay time increased from 100 min to 200 min. Evacuation speed decreased from 0.76 m/s to 0.38 m/s. No evacuation or relocation in the 7 day emergency phase. Ground level release. Base case is top of containment.
Buoyant Plume. Base case is zero heat energy. Dry deposition velocity decreased from 0.01 m/sec to 0.003 m/sec Year 2045 population uniformly increased 30% No "Intermediate Phase" resettlement planning (in lieu of 6 months) 1 year "Intermediate Phase" resettlement planning (in lieu of 6 months) Generic economic inputs increased (factor of 2) 3% expected rate of return (in lieu of 7%) 12% expected rate of return (in lieu of 7%) Value of Farm and Doubled value of farm wealth (12,241 $/hectare) and non-Non-Farm Wealth farm wealth (370,506 $/person) to 24,482 $/hectare and 741,012 $/person , respectively.
Diablo Canyon Power Plant License Renewal Application Pop. Dose Cost Risk Risk A Base ABase (o/o) (Ofo) -9% -1% -11% -5% -20% 0% 0% 0% -9% 0% -10% -3% -14% 0% 20% -35% 30% 29% 6% -31% -3% 32% -2% 44% 1% -9% -1% 11% 1% 68% Page F-243 TABLE F.7-2 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 MACCS2 ECONOMIC PARAMETERS INPUTS FOR SENSITIVITY Base Case Sensitivity Variable Description Value Value DPRATEtlJ Property depreciation rate (per yr) 0.20 0.20 DSRATE(2 J Investment rate of return (per yr) 0.07 0.07 EVACST(0 J Daily cost for a person who has been evacuated
($/person-day) 58.59 117.18 RELCST(0 J Daily cost for a person who is relocated
($/person-day) 58.59 117.18 POPCST(0 J Population relocation cost ($/person) 10,850 21,700 TIMDEC(1 J Decontamination time for each level(oJ 2&4 2&12 months months CDFRM0(0 J Cost of farm decontamination for two levels of decontamination 1,221 2,442 ($/hectare)
(5 l 2,713 5,426 CDNFRM(0 J Cost of non-farm decontamination per resident person for two levels of 6,510 13,020 decontamination
($/person)(5 l 17,360 34,720 DLBCST(0 J Average cost of decontamination labor ($/man-year) 75,950 151,900 TFWKF(1 J Time workers spend in farm land contaminated areas(oJ 1/10 1/4 1/3 1/4 TFWKNF(1 J Time workers spend in non-farm land contaminated areas(oJ 1/3 1/4 1/3 1/4 VALWF0(4 J Weighted average value of farm wealth ($/hectare) 12,241 12,241 VALWNF(oJ Weighted average value of non-farm wealth ($/person) 370,506 370,506 Notes to Table F.7-2: (1) Uses NUREG/CR-4551 (Reference
- 20) value. (Zl DSRATE based on NUREG/BR-0058 (Reference 25). (3) These parameters use the NUREG/CR-4551 (Reference
- 20) value, updated to the July 2014 using the CPl. (4) VALWFO is based on the 2012 Census of Agriculture (Reference 63), Bureau of Labor Statistics (Reference 64), and Bureau of Economic Analysis (Reference
- 2) data, updated to July 2014 using the CPI for the counties within 50 miles. (5) Two decontamination levels are modeled. The first value is associated with a dose reduction factor of 3. The second value is associated with a dose reduction factor of 15. (B) VALWNF is based on 2007 data from the Bureau of Labor Statistics (Reference 64), U.S. Census Bureau (References 88 and 86), National Resources Conservation Service (Reference 87), Bureau of Economic Analysis (Reference 2), 2007 and 2012 U.S. Census of Agriculture (Reference 85 and 63), and the Journal of Monetary Economics (Reference 91). Diablo Canyon Power Plant License Renewal Application Page F-244 F.10 FIGURES APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 MLOCA, 2.1%\ LOCV,
\ TLMFW, 2.3% PLMFW, 2.6 SGTRN, 8.2% Initiator SELOCA LPCC LOSW SLOCN SGTRN LCV LOSWV L1DCG RTRIP PLMFW TTRIP TLMFW LOCV MLOCA Others Diablo Canyon Power Plant License Renewal Application Description RCP Seal LOCA Loss of Component Cooling Water system Loss of Auxiliary Salt Water System Non-lsolable Small Break LOCA Non-Isolated Steam Generator Tube Rupture Loss of Condenser Vacuum Loss of Switchgear Ventilation Loss o DC Bus G Reactor Trip Partial Loss of Main Feedwater Turbine Trip Total Loss of Main Feedwater Loss of Control Room Ventilation Medium Break LOCA Remaining Internal Events Environmental Report Diablo Canyon Power Plant Figure F.2-1 DC03 Internal Contribution to CDF by Initiating Event Page F-245 LOSW, 2.4% SELOCA, 3.7% LOSWV, 3.9% Initiator SGTRN LOSWV SELOCA LOSW SLOCN LPCC VSI LOCV Others Diablo Canyon Power Plant License Renewal Application Description APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Non-Isolated Steam Generator Tube Rupture Loss of Switchgear Ventilation RCP Seal LOCA Loss of Auxiliary Salt Water System Non-lsolable Small Break LOCA Loss of Component Cooling Water system Interfacing System LOCA at RHR Pump Suction Loss of Control Room Ventilation . Remaining Internal Events Environmental Report Diablo Canyon Power Plant Figure F.2-2 DC03 Internal Contribution to LERF by Initiating Event Page F-246 Diablo Canyon Power Plant License Renewal Application SEIS3, 5.8% SEIS2, 1.3% Initiator SEIS6 SEIS5 SEIS4 SEIS1 SEIS3 SEIS2 Description SEISMIC LEVEL 6 SEISMIC LEVEL 5 SEISMIC LEVEL 4 SEISMIC LEVEL 1 SEISMIC LEVEL 3 SEISMIC LEVEL 2 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Environmental Report Diablo Canyon Power _Plant Figure F.2-3 DC03 Seismic Contribution to CDF by Initiating Event Page F-247 Diablo Canyon Power Plant License Renewal Application SEIS3, 4.3% Initiator SEIS6 SEIS1 SEIS5 SEIS4 SEIS3 SEIS2 SEIS2, 1.0% Description SEISMIC LEVEL 6 SEISMIC LEVEL 1 SEISMIC LEVEL 5 SEISMIC LEVEL 4 SEISMIC LEVEL 3 SEISMIC LEVEL 2 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Environmental Report Diablo Canyon Power Plant Figure F.2-4 DC03 Seismic Contribution to LERF by Initiating Event Page F-248 3BB115, 4.7% Initiator 1A 6A3 7A 6A5 6A2 8G 5A1 5A4 6A1 Others Diablo Canyon Power Plant License Renewal Application Description Containment Vital Battery Charger Room Bus H Cable Spreading Room P250 Room Vital Battery Charger Room Bus G SSPS Room Vital 480VAC SWGR Room APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Non-Vital 480VAC Bus SWGR and MCC Room Vital Battery Charger Room Bus F Remaining Unit 1 Fire Areas Environmental Report Diablo Canyon Power Plant Figure F.2-5 DC03 Fire Contribution to Unit 1 CDF by Initiating Event Page F-249 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Others , 25.9% SA4,2.1%-6A2, 2.8% SAl, 2.9% Initiator 7A 6A3 1A 8G 14A 10-85 5A1 6A2 8C 6A1 6A5 5A4 5A2 Others Diablo Canyon Power Plant License Renewal Application Description Cable Spreading Room Vital Battery Charger Room Bus H Containment SSPS Room Turbine Building 12kV SWGR Room Vitai480VAC SWGR Room Vital Battery Charger Room Bus G Main Control Room Vital Battery Charger Room Bus F P250 Room Non-Vital 480VAC Bus SWGR and MCC Room Vitai480VAC SWGR Room Remaining Unit 1 Fire Areas Environmental Report Diablo Canyon Power Plant Figure F.2-6 DC03 Fire Contribution to Unit 1 LERF by Initiating Event Page F-250 6A3, 3.9% 14A 301 31 6A2 6A1 6A3 302 Others Diablo Canyon Power Plant License Renewal Application Initiator Description Turbine Building Turbine Driven AFW Pump Room Fuel Handling Building Vital Battery Charger Room Bus G Vital Battery Charger Room Bus F Vital Battery Charger Room Bus H Motor Drivn AFW Pumps Room Remaining Unit 1 Fire Areas APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Environmental Report Diablo Canyon Power Plant Figure F.2-7 DC03 Flooding Contribution to CDF by Initiating Event Page F-251 3Q2, 3.1% 38885,4.7 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Initiator Description 14A 6A1 6A2 31 3Q1 3BB85 3Q2 Others Diablo Canyon Power Plant License Renewal Application Turbine Building Vital Battery Charger Room Bus F Vital Battery Charger Room Bus G Fuel Handling Building Turbine Driven AFW Pump Room Containment Pen Area Elev 85' Motor Drivn AFW Pumps Room Remaining Unit 1 Fire Areas Environmental Report Diablo Canyon Power Plant Figure F.2-8 DC03 Flooding Contribution to LERF by Initiating Event Page F-252 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 I" .10 Cll
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APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 1. Standard for Probabilistic Risk Assessment for Nuclear Power Plant Applications. American Society of Mechanical Engineers RA-SB-2003.
Addenda to ASM RA-S-2002.
March 17, 2005 (draft). 2. Bureau of
- Economic Analysis, Regional Economic Accounts, www.bea.gov/regional, accessed September 2014. 3. Deleted. 4. Applicant's Environmental Report; Operating License Renewal Stage; H. B. Robinson Steam Electric Plant Unit No. 2. Appendix F Severe Accident Mitigation Alternatives, Letter, J. W. Moyer (CP&L) to U.S. Nuclear Regulatory Commission.
Carolina Power and Light. Application for Renewal of Operating License. June 14, 2002. Available at: http://www.nrc.gov/reactors/operating/licensing/renewal/applicationslrobinson.ht mi. 5. Applicant's Environmental Report; Operating License Renewal Stage; Harris Nuclear Plant. Appendix E Severe Accident Mitigation Alternatives.
Carolina Power and Light. November 2006. Available at:
er.pdf. 6. Quality Assurance and Verification of the MACCS Code, Version 1.5. C.A. Dobbe, E.R. Carlson, N.H. Marshall, E.S. Marwil, J.E. Tolli. Idaho National Engineering Laboratory.
NUREG/CR-5376 (EGG-2566).
1990. 7. Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports, DOE-STD-3009-94, Change Notice 3. U.S. Department of Energy. Washington, D.C. March 2006. 8. Mixing Heights, Wind Speeds, and Potential for Urban Air Pollution Throughout the Contiguous United States. AP-1 01. Holzworth, George. U.S. Environmental Protection Agency. January 1972. 9. MAAP 3.0B -Modular Accident Analysis Program for LWR Power Plants. EPRI NP-7071-CCML, Volumes 1, 2, and 3. Electric Power Research Institute.
November 1990. 10. Fire PRA Method Enhancements Additions Clarifications, and Refinements to EPRI 1019189, Section 3.7. Electric Power Research Institute.
2008. 11. EPRI HRA Calculator 4.0. 2008. Diablo Canyon Power Plant License Renewal Application Page F-255 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 12. Comparison of Average Transport and Dispersion Among a Gaussian, a Dimensional, and a Three-Dimensional Model. Mollenkamp, C.R., N.E. Bixler, C.W. Morrow, J.V. Ramsdell, Jr., and J.A. Mitchell, Lawrence Livermore National Laboratory, Atmospheric Science Division, Livermore, CA. NUREG/CR-6853, October 2004. 13. Severe Accident Mitigation Alternatives. (SAMA) Analysis Guidance Document.
Rev. A. Nuclear Energy Institute.
November 2005. 14. National Fire Protection Association 805 Standard. 2001. 15.Applicant's Environmental Report; Operating License Renewal Stage; Point Beach Nuclear Plant, Units 1 and 2. Appendix F SAMA Analysis.
Application for Renewed Operating Licenses.
Nuclear Management Company, LLC. February 2004. Available at:
beach/er.pdf 16.Application for Renewed Operating Licenses-Prairie Island Nuclear Generating Plant Units 1 and 2, Nuclear Management Company, LLC. Xcel Energy Inc., Minneapolis, Minnesota.
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1975. 18. Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants, Regulatory Guide 1.145, U.S. Nuclear Regulatory Commission, February 1983. 19. Severe Accident Risks: An Assessment for Five U.S. Nuclear Power Plants. Final Summary Report. NUREG-1150.
Vol. 1, U.S. Nuclear Regulatory Commission.
Washington, D.C. December 1990. 20. Evaluation of Severe Accident Risks: Quantification of Major Input Parameters, NUREG/CR-4551, SAND86-1309, Vol. 2, Rev. 1, Part 7. U.S. Nuclear Regulatory Commission.
Sprung, J.L., Rollstin, J.A., Helton, J.C., Jaw, H-N. Washington, D.C. December 1990. 21. Regulatory Analysis Technical Evaluation Handbook.
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1997. 22. Code Manual for MACCS2: User's-Guide.
NUREG/CR-6613, Volume 1, SAND 97-0594. U.S. Nuclear Regulatory Commission.
Chanin, D. and Young, M. May 1998. Diablo Canyon Power Plant License Renewal Application Page F-256 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 23. Sector Population, Land Fraction, and Economic Estimation Program. SECPOP2000:
NUREG/CR-6525, U.S. Nuclear Regulatory Commission.
Washington, D.C., Rev. 1, August 2003. 24. Atmospheric Relative Concentration for Control Room Radiological Habitability Assessments at Nuclear Power Plants, Regulatory Guide 1.194, U.S. Nuclear Regulatory Commission,. June 2003. 25. Regulatory Analysis Guidelines of the U.S. Nuclear Regulatory Commission.
NUREG/BR-0058, U.S. Nuclear Regulatory Commission.
Washington, D.C., Rev 4, September 2004. 26. Proposed License Renewal Interim Staff Guidance LR-ISG-2006-03:
Staff Guidance for Preparing Severe Accident Mitigation Alternatives (SAMA) Analyses, U.S. Nuclear Regulatory Commission, August 10, 2006. 27. Environmental Standard Review Plan: Section 7.2 Severe Accidents, NUREG-1555, Revision 1, U.S. Nuclear Regulatory Commission, July 2007. 28. Deleted 29. Diablo Canyon PRA (DCPRA-1988), as accepted in Supplement No. 34 to NUREG-0675, Dated June 1991. 30. Long-Term Seismic Program (LTSP) 31. Supplement No. 34 to NUREG-0675, Dated June 1991. 32.1ndividual Plant Examination of External Events for severe Accident Vulnerabilities, Generic Letter 88-20, Supplement 4, U.S. Nuclear regulatory Commission, June 28, 1991. 33.1ndividual Plant Examination Report for Diablo Canyon Power Plant Units 1 and 2 in Response to Generic Letter 88-20, Pacific Gas and Electric Company, April 1992. 34. PG&E Letter to NRC, DCL-92-084, SBO submittal, April 3, 1992. 35. DCPP PRA Containment Event Tree. Pacific Gas and Electric Company, PRA Calc. File PRA91-009, Revision 0, February 1992. 36. Staff Evaluation of the Diablo Canyon Power Plant (DCPP) Units 1 and 2, Individual Plant Examination (IPE) -Internal Events Submittal, U.S. Nuclear Regulatory Commission, June 30, 1993. Diablo Canyon Power Plant License Renewal Application Page F-257 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 37.1ndividual Plant Examination of External Events Report for Diablo Canyon Power Plant Units 1 and 2 in Response to Generic Letter 88-20 Supplement 4, Pacific Gas and Electric Company, June 1994. 38. NUREG/CR-5726, Review of the Diablo Canyon Probabilistic Risk Assessment.
Bozoki et al. August 1, 1994. 39. Reliability Study: Westinghouse Reactor Protection System. 1984-1995, NUREG/CR-5500 Vol2, INEEUEXT-97-00740.
- 40. Review of Diablo Canyon Individual Plant Examination of External Events (IPEEE) Submittal, U.S. Nuclear Regulatory Commission, December 4, 1997. 41. Common Cause Failure Parameter Estimations, NUREG/CR-5497, INEEL/EXT-97 -01328. Marshall et al. 1998. 42. NUREG/CR-5750, Rates of Initiating Events at U.S. Nuclear Power Plants: 1987-1995.
Polaski, J.P., et al. 1999. 43. DCPP PRA Model Technical Adequacy.
Probabilistic Risk Assessment, Calculation File No. C.1 0, Draft Revision 5, Pacific Gas and Electric Company. 2014. 44. Peer *Review (Certification) of the DCPP PRA model, using the WOG Peer Review Certification Guidelines, Performed in May 2000. 45. Diablo Canyon Power Plant Probabilistic Risk Assessment Peer Review Report, Final Report, August 2000. 46. Human Action Analysis-Failure Likelyhood Range Factor Calculation, Calculation File GF .2, Revision 5. 47. EDG 14 day LAR, PRA Calculation File PRA02-06, Revision 0. 48. Diablo Canyon Power Plant Probabilistic Risk Assessment, Calculation File H.4, Revision 3. 49. Evaluation of Loss of Offsite Power Events at Nuclear Plants: 1986-2003 (Draft), Draft NUREG/CR (INEEL/EXT-04-02326), S.A.Eide, C. D. Gentillon, and . T.E Wierman of IN EEL and D.M. Rasmuson of NRC. October 2004. 50. Calculation File H.3, Revision 2. 51. Re-Evaluation of Selected Split Fractions in Level 2 Model, PRA Calculation File PRA05-05, Revision 0, December 5, 2005. Diablo Canyon Power Plant License Renewal Application Page F-258 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 52. Diablo Canyon Power Plant Units 1 & 2 FSAR Update, Revision 21, September 2013. 53. Central Coastal California Seismic Imaging Project Report. Pacific Gas and Electric Company. September 2014. Available at Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML 14260A024 through ML 14260A069.
- 54. PG&E Letter No. DCL-11-005, "Report on the Analysis of the Shoreline Fault Zone, Central Coastal California," dated January 7, 2011 ("Shoreline Fault Report").
Available at ADAMS Accession No. ML 110140431. 55. Diablo Canyon Follow-On Peer Review of HRA Update, Final Report, R-1736044-1728, July 31, 2007. 56. Transmittal of Resolution/Disposition of ASME PRA Peer Review Findings for LERF for Diablo Canyon Units 1 and 2, LTR-RAM-11-07-021, November 30, 2007. 57. Common Cause Failure Database and Analysis System, NUREG/CR-6268, INEEL/EXT-97-00696. Wierman et al. September 2007. 58. Diablo Canyon Power Plant PRA Self-Assessment, ERIN P0114060001-2717 R 1, January 2008. 59. DCPP ORIGEN Calculation, Core Inventory Data, December 2008. 60. Diablo Canyon Power Plant Emergency Plan Implementing Procedure.
Emergency Classification and Emergency Plan Activation, EP G-1, Rev. 37A. January 2009. 61. Miscellaneous Systems-PRA Systems Analysis, Revision 10. 62. Susquehanna Steam Electric Station Application for License Renewal Environmental Report, Appendix E. PPL Susquehanna, LLC. August 2006. 63. U.S. Dept. of Agriculture, 2012 Census of Agriculture
-California State and County Data, AC-12-A-5, Vol. 1, Part 5, May 2014. 64. U.S. Dept. of Labor, Bureau of Labor Statistics, www.bls.gov/data/, accessed September 2014. 65. Wolf Creek Nuclear Operating Corporation.
Applicant's Environmental Report; Operating License Renewal Stage, Attachment F. Wolf Creek Nuclear Operating Corporation, Burlington, Kansas. 2006. Diablo Canyon Power Plant License Renewal Application Page F-259 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 66. WCAP-16464-NP, Westinghouse Owner's Group Mitigating Systems Performance Index Cross Comparison, Revision 0, August 2005. 67. Diablo Canyon Power Plant: Development of Evacuation Time Estimates, KLD TR-498, November 2012. 68. EPRI Report 1019194, Guidelines for Performance of Internal Flooding Probabilistic Risk Assessment, December 2009. 69. NUREG-1437, Generic Environmental Impact Statement for License Renewal of Nuclear Plants. Supplement 35, Regarding Susquehanna Steam Electric Station, Units 1 and 2. Office of Nuclear Reactor Regulation.
March, 2009. 70. NUREG-1437, Generic Environmental Impact Statement for License Renewal of Nuclear Plants. Supplement 33, Regarding Shearon Harris Nuclear Power Plant Unit 1. Office of Nuclear Reactor Regulation.
August, 2008. 71. NUREG-1437, Generic Environmental Impact Statement for License Renewal of Nuclear Plants. Supplement 13, Regarding H.B. Robinson Steam Electric Plant Unit No. 2. Office of Nuclear Reactor Regulation.
December, 2003. 72. NUREG-1437, Generic Environmental Impact Statement for License Renewal of Nuclear Plants. Supplement 23, Regarding Point Beach Nuclear Plant Units 1 and 2. Office of Nuclear Reactor Regulation.
August, 2005 73. NUREG-1437, Generic Environmental Impact Statement for License Renewal of Nuclear Plants. Supplement 39, Regarding Prairie Island Nuclear Generating Plant. Units 1 and 2. Office of Nuclear Reactor Regulation.
May, 2011. 74. NUREG-1437, Generic Environmental Impact Statement for License Renewal of Nuclear Plants. Supplement 32, Regarding Wolf Creek Generating Station. Office of Nuclear Reactor Regulation.
May, 2008. 75. DCL-1 0-150, Response to NRC Letter dated November 24, 2010, Request for Additional Information for the Applicant's Environmental Report -Operating License Renewal Stage, December 6, 2010. 76.Applicant's Environmental Report; Operating License Renewal Stage; Grand Gulf Nuclear Station. Attachment E Severe Accident Mitigation Alternatives Analysis.
Application for Renewed Operating Licenses.
Entergy Operations, November 2011. 77. NUREG-1437, Generic Environmental Impact Statement for License Renewal of Nuclear Plants. Supplement 50, Regarding Grand Gulf Nuclear Station. Unit 1. Draft Report for Comment. Office of Nuclear Reactor Regulation.
November, 2013. Diablo Canyon Power Plant License Renewal Application Page F-260 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 78. Applicant's Environmental Report; Operating License Renewal Stage; Seabrook Station, Unit 1. Attachment F Severe Accident Mitigation Alternatives Analysis.
NextEra Energy Seabrook, LLC. June 2010. 79. NUREG-1437, Generic Environmental Impact Statement for License Renewal of Nuclear Plants, Supplement 46, Regarding Seabrook Station. Second Draft Report for Comment. Office of Nuclear Reactor Regulation.
April, 2013. 80.ASME/ANS RA-Sa-2009 (American Society of Mechanical Engineers/American nuclear Society).
2009,. Addenda to ASME/ANS RA-S-2008, Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Applications.
- 81. Regulatory Guide 1.200 Revision 2, An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities, U.S. NRC, June 2008. 82. National Fire Protection Association (NFPA) 805, Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants, 2001. 83. NUREG/CR-6850, Fire PRA Methodology for Nuclear Power Facilities, September 2005. 84. PG&E Letter DCL-13-0065, License Amendment Request to Adopt NFPA 805 Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generation Plants (2001 Edition), June 26, 2013 85. U.S. Dept. of Agriculture, 2007 Census of Agriculture-United States Summary and Data, AC-07-A-51, Vol. 1, Part 51, December 2009. 86. U.S. Census Bureau, Statistical Abstract of the United States, 2012. 87. National Resources Conservation Service, Summary Report: 2007 National Resources Inventory, December 2009. 88. U.S. Census Bureau, American Housing Survey for the United States: 2007,
- September 2008. 89. U.S. Food and Drug Administration, Guidance on Contamination of Human Food and Animal Feeds: Recommendations for State and Local Agencies, FDA63FR-43402, August 1998. 90. U.S. Nuclear Regulatory Commission, State of the Art Reactor Consequence Analysis Project, NUREG/CR-7110, Rev.1, May2013. Diablo Canyon Power Plant License Renewal Application Page F-261 APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 91. Davis M.A. and Heathcote J., "The price and quantity of residential land in the United States", Journal of Monetary Economics, 54 (2595-2620), June, 2007. 92. California Department of Finance, State and County Total Population Projections, 2010-2060.
- 93. Regulatory Guide 1.17 4 Revision 2, An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis, U.S.NRC, May 2011. 94. Diablo Canyon Power Plant Administrative Procedure, TS3.NR1, Probabilistic Risk Assessment (PRA), Revision 8, August 1, 2013 95. Diablo Canyon Power Plant Administrative Work Procedure, AWP E-028, Revision 0, August 1, 2013 96. Diablo Canyon Power Plant, PRA Calculation, G.2, Revision 7 (draft) 97. Diablo Canyon Power Plant, PRA Calculation, G.?, Revision 0 (draft)
- U Rls delineated in some references may no longer be valid. Diablo Canyon Power Plant License Renewal Application Page F-262
Action Title/ Applicable SR Internal flooding -NRC IN 98-31 I SER 3-98, A0468801 Hard coded conditional HEP in top event MU APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Addendum 1 Evaluation of PRA Open Items /Issues on SAMA Process Action Description Current Status/ Importance to SAMA Application Comment AR A0468801 was written to document PG&E'S This will be None. No direct impact on current evaluation of an event at WNP-2, where a fire system considered in the model anticipated.
water hammer led to flooding of emergency core updating of the
- No expected change in core cooling system (ECCS) pump rooms. The evaluation Internal Flooding damage frequency (CDF) or was not complete by the time the 1997 PRA internal PRA. Level 2 results. flood update was performed.
This PG&E evaluation
- No expected change in the should be reviewed as part of the 1999/2000 PRA update to see if any assumptions or new insights need SAMA cost benefit analysis.
to be added to the PRA internal flooding analysis.
Originally, in the model there was one HEP for the A new conditional If the failure probability of the RWST operators to makeup to the RWST in the general prob of 0.5 was used makeup action is too low, the SAMA transient tree. During the HEP dependency study it in sensitivity study. analysis could be impacted.
was noticed that the HEP was used even if the However, a SAMA was identified to operators had failed to swap over to recirculation automate swap to recirc mode cooling. As a work around for this, a conditional (SAMA 7), which would preclude the probability of 0.1 was used. A new HEP needs to be need to refill the RWST, if developed for this situation that is more realistic.
successful.
Even if it assumed that the benefit of SAMA 7 is directly proportional to the RWST makeup HEP, a multiplier of 5 on the SAMA 7 averted cost risk (to account for the difference in proposed HEPs) would still not yield a cost beneficial result. The result of multiplying the 95 1 h percentile averted cost-risk by a factor of 5 is still far below the $10.6 million implementation cost: 5 * $1,019,665
= $5,098,325.
This issue will not change the SAMA identification process or the conclusions of the cost benefit analysis.
Diablo Canyon Power Plant Page F-263 License Renewal Application Action Title/ Applicable SR Seismic trip and PORV challenge APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Addendum 1 Evaluation of PRA Open Items /Issues on SAMA Process Action Description Current Status/ Importance to SAMA Application Comment In revision 2 of calculation file F.6, the assumption that Modeling PORV None. Insignificant impact on CDF, there was a PORV challenge on every seismic initiating challenge due to Level 2 results, and SAMA analysis. event was removed. This was because in most cases, seismic induced the plant had already tripped from the seismic event LOSP has (via seismic trip) and did not experience a load insignificant impact on rejection when 500 kV was lost. The first item is that the seismic induced this assumes the seismic trip works successfully all the CDF/LERF.
time. To be more correct, the seismic trip should be added to the model and then the effect of the seismic trip can be evaluated probabilistically.
Second item is the seismic trip has a setpoint of about 0.3 g's which is about 2/3's the way through the first seismic initiator (which goes to 0.53). This would imply that below 0.35 there should be a PORV challenge, if 500 kV was lost (which is not yet modeled).
To better model this SEIS1 initiator should be changed to 0.4, and the details of the 500 kV and seismic trip should be modeled. Note RISKMAN is limited to only six acceleration levels, so this would require re-adjusting the exist boundary between SEIS1 and SEIS2. Also note this corresponds to the double design earthquake (ODE) earthquake, which was the safe shutdown earthquake prior to the HOSGRI upgrades which put the SSE to 0.75 g's. 12/19/02 EGO Also note we do not model a PORV challenge on seismically induced LOSP, which should be adequate for SEIS 2 through 6 due to seismic trip, but maybe a noticeable contributor in SEIS1. I Diablo Canyon Power Plant Page F-264 License Renewal Application Action Title/ Applicable SR Address anchorage of relay panels in cable spreading rooms APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Addendum 1 Evaluation of PRA Open Items /Issues on SAMA Process Action Description Current Status/ Importance to SAMA Application Comment NRC letter dated 12/4/97 informed DCPP that the To confirm that an This is a documentation issue and intent of GL 88-20, supplement 4, had been met. The analysis had been no impact on the SAMA analysis.
attachment to the NRC report was a consultant's report performed of the entitled, "Technical Evaluation Report on the Submittal-anchorage of relay Only review of the Diablo Canyon Power Plant (Units 1 panels within the and 2) Individual Plant Examination Of External cable spreading room. Events," dated September, 1997. On page 28 of the consultant's report, they state in (8)(1) " .. it is unclear if the licensee performed an analysis of the anchorage of relay panels within the cable spreading room." the concern is whether this equipment is a seismic induced hazard. Please address this issue and reference documentation.
*--Diablo Canyon Power Plant Page F-265 License Renewal Application Action Title/ Applicable SR Address potential for d/g lockout from card ox Split fraction event tree rules for seismic RCP seal modeling APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Addendum 1 Evaluation of PRA Open Items /Issues on SAMA Process Action Description Current Status/ Importance to SAMA Application Comment NRC letter dated 12/4/97 informed DCPP that the Address Seismic-The electrical power reliability, intent of GL 88-20, supplement 4, had been met. The induced loss of C02 i ncluding the EDGs, has been attachment to the NRC report was a consultant's report and its impact. addressed in the SAMA analysis.
entitled, "Technical Evaluation Report On The The risk contribution due to a failure Submittal-Only Review Of The Diablo Canyon Power of EDGs from a seismically failed Plant (Units 1 and 2) individual plant examination of C02 system is expected to be minor. external events," dated September, 1997.
- No significant change in CDF or Level 2 results. Page 28 of the consultant's report, under (8)(2), they
- No significant change in the state " .. it is unclear if the analysis considered the SAMA cost benefit analysis.
potential for diesel generator (lockout or starvation) failure caused by seismically induced activation of the co-located C02 system. Also, it is unclear if the licensee analyzed the potential for icing or freezing or relays within the cable spreading room given seismically induced activation of the C02 system, or the potential for the weight of the C02 suppressant, which condenses on the cable trays, to fail safety-related cabling because of structural failure. Please address these three issues and reference documentation.
The backstop split fraction SEX is seen in sequence Need to add SF and Current results are conservative.
124 (DC01 ECCS AOT application) and others. This is rule for the scenarios Even with conservative results, this a result of the lack of a rule that looks for no CCW flow with No CCW and no was not an issue for the SAMA with AS=S but with no support for CCP 1-1. The support for CCP 1-1. analysis and resolution of the issue complementary rule exists (with no support for CCP 1-will have no significant impact on the 2). The result of this discrepancy is to give slightly application.
more conservative results since a guaranteed failure is used in this particular instance rather than a calculated split fraction.
'Update SE event tree logic with provision for no CCP 1-1 support. Diablo Canyon Power Plant Page F-266 License Renewal Application Action Title/ Applicable SR CCW model has Header 'C' and HEP combined Diablo Canyon Power Plant License Renewal Application APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Addendum 1 Evaluation of PRA Open Items /Issues on SAMA Process Action Description While researching HEPs, it was noticed that credit is taken for the operator to reduce heat loads for LLOCA (and MLOCA and SLBI), even though they may not have enough time. In other words, we are using the HEP for heat load reduction for all initiators.
For LLOCA, MLOCA and SLBI, we generally have HI-HI containment pressure ("P" signal), which will isolate CCW non-vital Header C. The various CCW calculations support one CCW pump as adequate for flow and heat loads when Header C is isolated.
This implies that failure of the HEP roughly approximates the hardware failure of Header C to isolate. To more accurately model the worth of the HEP and FCV-355 (Header C), they should probably be split out into separate items. Also note that the current modeling does not model the support for Header C automatic isolation (SSPS for "P" signal and Bus H for MOV power). This should have little affect on CDF or LERF, but will affect some basic event importances.
07/11/02 Further research during the NRC inspection also noticed FCV-355. We need to investigate if Header 'C' Isolation is required for Phase "B" actuation even if two CCW pumps are running. 11/12/02 Upon reviewing E.11 revision 9, it was noticed by AXA that the calc file talks about isolating Header 'C' (implied by INIT=SLBI for general transient) and failing to trip the RCPS should give a failure of the seals. There is logic in top event for this in RP, but no logic for it in SE. so on INIT=SLBI if the RCPS are still running, and charging has failed the rules use split fraction SE2. But it should use SE2 only if -INIT=SLBI, and if INIT=SLBI (and charging AHS failed, it should use SEF). On reviewing past calculation files it appears that it has been this way since Revision 1 and possibly Revision 0 of C.4.2. A quick review of INIT=SLBI in PLG-0637 did not clarify anything as none of the SBLI sequences showed any SE failing (almost like it was bypassed in the tree. Current Status/ Comment Revise rule for split fraction SE2 and SEF associated with SLBI initiator.
This has an. insignificant impact on the CDF/LERF.
Importance to SAMA Application Not significant since impact on CDF/Level 2 results is also insignificant.
- No significant change in CDF or Level 2 results.
- No significant change in the SAMA cost benefit analysis.
Page F-267 Diablo Canyon Power Plant License Renewal Application This page intentionally left blank. APPENDIX E ENVIRONMENTAL REPORT AMENDMENT 2 Page F-268 Affected LRA Section Table 3.3.2-5 Enclosure 3 PG&E Letter DCL-15-027 Page 1 of 2 Diablo Canyon Power Plant LRA Changes Reflected in the LRA Update Amendment 49 Reason for Change Errata. Plant-specific Note 6 was changed to Plant-specific Note 9.
I Enclosure 3 PG&E Letter DCL-15-027 Page 2 of 2 Appendix A FINAL SAFETY ANALYSIS REPORT SUPPLEMENT I Table 3.3.2-5 Auxiliary Systems-Summary of Aging Management Evaluation-Makeup Water System Component Intended Material Environment Aging Effect Aging Management NUREG-Table 1 Item Notes Type Function Requiring Program 1801 Vol. Management 21tem Tanks PB Carbon Steel Concrete Loss of material Inspection of Internal None None G , e 9 Surfaces of Miscellaneous Ducting and Piping Components (82.1.22)
Enclosure 4 PG&E Letter DCL-15-027 Page 1 of 17 Diablo Canyon Power Plant License Renewal Application, Appendix E Changes Reflected in the Amendment 2 The following LRA, Appendix E sections that were submitted by Pacific Gas and Electric Company Letter DCL-14-103, "10 CFR 54.21(b) Annual Update to the Diablo Canyon Power Plant License Renewal Application (LRA), Amendment 48 and LRA Appendix E, Applicant's Environmental Report-Operating License Renewal Stage, Amendment 1 ," Enclosure 2, dated December 22, 2014, contain reference and typographical corrections.
All corrections are shown as electronic markups (deletions crossed out and insertions italicized).
Section 2.2.2.1 Section 2.4 Sections 2.5.1 and 2.5.2 Section 2.7 Sections 2.8 and 2.8.1 Sections 2.13.5 and 2.13.6 Section 2.14 Section 3.1 Section 4.0.2 LRAAppendix E, Tables 2.13-1 and 2.13-2 have been updated.
Enclosure 4 PG&E Letter DCL-15-027 Page 2 of 17 2.2.2.1 Species and Relative Abundance ENVIRONMENTAL REPORT APPENDIX E AMENDMENT 2 In addition to the aquatic species special status species listed in Table 2.2-3, Table 2.4-1 presents a list of terrestrial special status species with the potential to occur on the Diablo Canyon lands including some freshwater species discussed above.