ML12292A404
| ML12292A404 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 10/17/2012 |
| From: | Ameren Missouri |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML122920434 | List: |
| References | |
| Download: ML12292A404 (34) | |
Text
ULNRC-05919 October 17, 2012 Page 1 of 34 CALLAWAY PLANT UNIT 1 LICENSE RENEWAL APPLICATION REQUEST FOR ADDITIONAL INFORMATION (RAI) RESPONSE TO ITEMS 5D, 7A, 7B, TABLES 7-1, 8-1, 9-1, AND 11-1
ULNRC-05919 October 17, 2012 Page 2 of 34 RAI 5.d:
Note 1 to Table F.3-2 states, "The current plant procedures and training meet current industry standards. There are no additional specific procedure improvements that could be identified that would affect the result of the human error probability (HEP) calculations. Therefore, no SAMA items were added to the plant specific list of SAMAs as a result of the human actions on the list of basic events with RRW greater than 1.005." This appears to imply that meeting current industry standards is sufficient to indicate that no additional SAMAs are needed.
- i. Provide additional information to justify the conclusion stated as indicated above.
ii. Explain the process used to make the determination that there are no opportunities to improve procedures and training. Include in the explanation how human error probability factors were considered (e.g., cognition, resources, timing, and stress level).
iii. Discuss whether any of the risk significant operator action failures could be addressed by options other than training or procedures such as automated functions, testing, and maintenance to reduce failure or event rates, or enhanced documentation. Specifically discuss the potential for automating the function associated with basic event OP-XHE-FO-CCWRHX (OPERATOR FAILS TO INITIATE CCW FLOW TO THE RHR HXS) identified in Table 3-2.
Callaway Response In order to perform a cost/benefit analysis of any change, the impact on the calculated Human Error Probability must be determined. Discussion with the HRA analysts indicate that based on the current structure and format of the existing procedures, any incremental improvements or changes made to training or procedures would not result in the ability to take additional credit in the HRA because in general full credit is already taken. Improvements may be possible through re-ordering steps in the EOP network to improve timing, however, since Callaway uses the standardized EOP network significant changes in EOP structure would result in compliance issues with EOP configuration control. The current standardized EOP structure is based on the deterministic safety analysis, not a PRA analysis, thus while there may be PRA improvements there are significant analysis and infrastructure changes that would have to be implemented Industry-wide to change the standardized structure. Any enhancements that could be made within the standardized structure have either already been made at Callaway or would not result in additional significant credit in the HEP determination. With no significant change to the HEP, the benefit of making the change would be negligible.
The note was not intended to state that no opportunities for improvement exist, rather that there would be no calculated dollar value benefit from any improvements made. Plant personnel are always encouraged to use the corrective action process to identify potential improvements. In addition, the PRA group reviews and actively participates in changes made to Operating Procedures to evaluate impact on the PRA as well as suggest improvements.
ULNRC-05919 October 17, 2012 Page 3 of 34 In general, operator actions credited in the Level 1 PRA, are proceduralized in the EOP and OTO procedure network. The EOP/OTO procedures address both cognition and execution as follows:
x Cognition - specifically they identify the primary cue (instrumentation or alarm needed to make the diagnosis) x Execution - specifically they identify the tasks needed to accomplish the required action).
The EOP/OTO procedures are highly trained on both in the classroom and to the extent possible in the simulator or through job performance measures. All EOPs are required to be trained on at least once every six years. In general, most EOPS are trained on several times a year in both the simulator and class room training. There is a six week training cycle and each crew will spend one week in simulator and/or class room training during each six week cycle.
The trainers review the procedures regularly to identify areas where the training crews have encountered difficulty and update the procedures accordingly. EOP/OTO Writers manual APA-ZZ-00102 is the guidance document the procedure writers follow to ensure that the procedures are written to be consistent with industry standards.
As part of the HRA task the EOP and OTO procedures are reviewed to ensure that credited operator actions in the PRA are proceduralized in the same context as the EOPS/OTOs. The HRA task accounts for the following:
x Procedure Context -Does the procedure match the modeled PRA scenario, x Procedure Structure - Response not obtained column format vs. paragraphs of instructions, x Procedure Wording - Does the procedure wording have a double negative, x Distinction of important steps (boxed, bulleted, bolded, etc),
x Time to reach the required procedure step.
If the HEP is dominated by a single failure mechanism such as an ambiguously worded statement or not enough time to reach the required procedure step, then these findings are passed back to the Callaway training department and procedure revisions are made within the limitations of standardized procedures, as applicable.
The Callaway training department maintains a listing of time critical deterministic and PRA risk significant actions in procedure APA-ZZ-00395. On a defined cycle, the deterministic operator actions are evaluated/validated in the simulator, including timing of events. There is considerable overlap in the deterministic operator actions and the PRA risk significant actions and timing information from these validations is used to evaluate the assumptions in the HRA.
This training identifies procedure ambiguities associated with the procedure guidance for most actions credited in the PRA. These completions times are not requirements but are intended to be nominal average estimates that most crews can achieve. Following the completion of a major PRA update APA-ZZ-00395 is updated.
As part of PRA Update 5, all Level 1 post-initiator operator actions were reviewed and updated to align with the current EOP/OTO procedure revisions and training. As part of this update, all
ULNRC-05919 October 17, 2012 Page 4 of 34 risk-significant scenarios were talked through with Callaway trainers and insights from recent simulator training were incorporated into the updated HRA.
The process followed for this HRA update was:
- 1. Identify - Each PRA scenario was reviewed in the context of the appropriate EOP to ensure that the as-operated plant is reflected in the HRA.
- 2. Define - As part of the definition a feasibility check was performed for each HFE. This included defining both a cognitive and execution procedure, identify the frequency and level of training, showing there is enough time to complete the action, and there are enough people available to perform all tasks associated with the initiating event.
- 3. Quantify - The HEP is quantified using the EPRI HRA approach which accounts for a combination of cognitive and execution performance shaping factors.
- 4. Uncertainty - The uncertainty is addressed both qualitatively and quantitatively in the HRA.
As part of the HRA update no procedure updates to improve the SAMA were identified.
A case was quantified to determine the benefit of automating the initiation of CCW flow to the RHR heat exchangers. This case was evaluated by setting the value of basic event OP-XHE-FO-CCWRHX to 0.0. The benefit of this modification was determined to be $62K with the 95% CDF benefit being $132K. This modification was judged to be not cost beneficial be potentially cost-beneficial with an estimated cost of $200K.
The cost of adding hardware systems to automatically perform the actions represented by important human actions is high. This cost has been shown in a number of SAMA submittals to sometimes be order(s) of magnitude higher than the benefit achieved.
Other non-procedural changes such as additional maintenance and testing would not necessarily reduce risk significant human errors. Most equipment related failures are induced by human errors during testing or maintenance. The benefits of increasing the occurrence of tests and maintenance diminish at the point where additional maintenance or restoration errors are introduced or at the point where undue wear and tear occurs. Callaway's maintenance and testing program uses vendor recommended test and maintenance intervals as well as operating experience in an attempt to optimize mechanical reliability. Randomly increasing test and maintenance over the recommended intervals is perceived to have no mechanical reliability benefit; but would pose an increase in maintenance and restoration errors as well as wear and tear.
Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.
ULNRC-05919 October 17, 2012 Page 5 of 34 RAI 7.a:
A note at the end of Table F.5-1 indicates that recent industry submittals of like-kind plants (i.e.,
Wolf Creek, South Texas, Diablo Canyon, and Seabrook) were used as a source of candidate SAMAs. The extent to which these submittals were examined is not clear, as only two SAMA candidates were identified in Table F.5-1 as being from these sources (I.e., SAMA 162 and 165). Also, it appears that a cost beneficial SAMA identified in the Diablo Canyon submittal might represent an unevaluated SAMA candidate for Callaway (Le., SAMA 24 -Prevent clearing of RCS cold leg water seals). Describe the extent to which the four cited SAMA submittals were used as sources to generate candidate SAMAs and evaluate each SAMA determined to be cost beneficial in those submittals or show how they could be screened out using criteria presented in ER Section F.6.0. If the SAMA review for a submittal has been completed, use the cost beneficial SAMAs as reported in the respective site specific volume of NUREG-1437, "Generic Environmental Impact Statement for License Renewal of Nuclear Plants."
Callaway Response This entire 7.a response is provided by this transmittal and was not part of Reference 3.
The SAMA section of the Environmental Report for each of the listed submittals was reviewed.
The site specific volume of NUREG-1437 was reviewed for those plants where one was available. For each SAMA item the descriptions and decisions of the cost/benefit analysis were reviewed for applicability and site specific cost/benefit to Callaway. The tables below show the Callaway disposition for each plant's potentially cost beneficial SAMAs.
Wolf Creek SAMA Description Callaway Disposition SAMA 2: Modify controls and operating The Callaway AEPS design already maintains procedures to permit the diesel generators at constant AC power up to the safety the Sharpe Station to be more rapidly aligned related/non-safety related separation breakers to the WCGS emergency buses in SBO with the breaker controls located in the main events. control room. The AEPS diesel generators automatically start and supply AC power up to the separation breakers on loss of the normal supply; and, if required, the manual diesel controls are also located in the main control room.
SAMA 4: Proceduralize operator actions to Callaway procedure ECA-1.2 contains perform local isolations of any valves that fail direction for operators to manually close all to close remotely in an interfacing system valves in ISLOCA pathways that are located LOCA. outside containment if the valves cannot be closed from the control room.
ULNRC-05919 October 17, 2012 Page 6 of 34 SAMA 5: Modify procedures to open SAMA 80 has been modified to indicate that emergency diesel generator room doors to procedural guidance to open doors or provide provide alternate room cooling given failure of alternate ventilation following loss of EDG the heating ventilation and air-conditioning HVAC is potentially cost beneficial.
(HVAC) supply fan.
SAMA 1: Install a permanent, dedicated SAMA 187 has been added. AEPS was generator for the NCP in order to provide RCP installed with a spare breaker that could be seal cooling in SBO events. used to supply the NCP. This SAMA is considered potentially cost beneficial.
SAMA 3: Provide the capability to cross-tie This SAMA was evaluated using case 4KV2 between 4-kilovolts (kV) AC buses in the event and was determined to have a benefit of $13K of a loss of power to one bus. with a 95% CDF benefit of $27K. Callaway SAMA 11 has been modified to consider this SAMA to be potentially cost beneficial. A physical cross-tie exists, but there is no analysis or procedures to allow its use except in specific conditions with offsite power available. Associated Costs are to develop procedures and analysis to allow use of the cross-tie with the Emergency Diesel Generators. The SAMA is already evaluated as potentially cost beneficial; however, it should be noted that the calculated benefit is somewhat under-estimated since it was evaluated only for SBO sequences.
SAMA 13: Install an alternative fuel oil tank This SAMA is included as Callaway SAMA 162 with gravity feed capability to address fuel oil and has been determined to be potentially cost transfer failure events. beneficial.
SAMA 14: Install a permanent, dedicated SAMA 188 has been added. This SAMA was generator for the NCP, and a motor-driven evaluated using case SBOMOD2 and was AFW pump and battery charger to address determined to have a benefit of $182K with a SBO events in which the TD AFW pump is 95% CDF benefit of $385K. AEPS was unavailable. installed with a spare breaker and expansion capability which could be used to supply various equipment. This SAMA is considered potentially cost beneficial.
Case SBOMOD This SAMA case was analyzed by multiplying the frequency of all SBO sequences by 1.0E-01 which represents the total failure probability of the operator errors and hardware failures associated with operation of the equipment that would be made available due to this modification.
No changes were made to support system modeling.
ULNRC-05919 October 17, 2012 Page 7 of 34 Case SBOMOD2 This SAMA case was analyzed by multiplying the frequency of all SBO sequences by 5.0E-02 which represents the total failure probability of the operator errors and hardware failures associated with operation of the equipment that would be made available due to this modification. No changes were made to support system modeling.
Case 4KV2 This SAMA case was analyzed by modifying the fault trees to include a cross-tie to the other 4KV AC bus and diesel generator. Only SBO sequences were solved and the results combined with the remainder of the baseline model results. The probability of failure for the cross-tie was assigned a probability of 5.0E-02. The cross-tie failure event was removed from cutsets containing the failures of both EDGs (including those caused by support equipment). No changes were made to support system modeling. The calculated benefit under-estimates the actual benefit since the benefit was only determined for SBO sequences. The benefit for other sequences could not be determined without extensive modifications to the PRA model.
The low benefit of this SAMA is attributed to the AEPS AC power supply that can be controlled from the main control room and the ability to have AEPS aligned to either 4KV bus and the ability to use the non-safety auxiliary feed pump.
Seabrook SAMA Description Callaway Disposition SAMA 157: Provide independent AC power This item is considered implemented at source for battery chargers Callaway. Procedures and equipment exist that will provide temporary portable power sources for the battery chargers.
SAMA 165: RWST fill from firewater during This item is considered implemented at containment injectionModify 6 inch RWST Callaway. Procedures and equipment exist to flush flange to have a 21/2-inch female fire hose connect fire water to the RWST.
adapter with isolation valve SAMA 192: Install a globe valve or flow This item is considered to be N/A for Callaway.
limiting orifice upstream in the fire protection This is a plant specific internal flooding issue system that was not identified for Callaway.
SAMA 193: Hardware change to eliminate This item is considered to be N/A for Callaway.
MOV AC power dependency This is a plant specific PRA importance issue that was not identified for Callaway.
ULNRC-05919 October 17, 2012 Page 8 of 34 South Texas Project South Texas Project has no potentially cost beneficial SAMA items.
Diablo Canyon SAMA Description Callaway Disposition SAMA 12: Improve Fire Barriers for ASW and This item is considered to be N/A for Callaway.
CCW Equipment in the Cable Spreading This is a plant specific fire related issue that Room was not identified for Callaway.
SAMA 13: Improve Cable Wrap for the This item is considered to be N/A for Callaway.
PORVs in the Cable Spreading Room This is a plant specific fire related issue that was not identified for Callaway.
SAMA 24: Prevent Clearing of RCS Cold Leg This SAMA is included as Callaway SAMA 179 Water Seals and has been determined to be potentially cost beneficial.
SAMA 25: Fill or Maintain Filled The Steam This item is considered implemented at Generators to Scrub Fission Products Callaway. The Emergency Operating Procedures contain direction to maintain steam generator level above the tubes.
Also refer to Tables 7-1, 8-1, 9-1, and 11-1 which directly follow this response.
Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 9 of 34 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway % Red.
SAMA % Red. In OS SAMA SAMA Case % Red IN Number Potential Improvement Discussion In CDF Dose Case Description Benefit Cost OECR Cost Basis Evaluation Basis for Evaluation 1 Provide additional DC battery Extended DC power 12.17% 10.87% NOSBO No Station Blackout $360K >$1M 10.49% Expert Not Cost- Cost will exceed benefit.
capacity. availability during an SBO. Events Panel Beneficial 2 Replace lead-acid batteries Extended DC power 12.17% 10.87% NOSBO No Station Blackout $360K >$1M 10.49% Expert Not Cost- Cost will exceed benefit.
with fuel cells. availability during an SBO. Events Panel Beneficial 5 Provide DC bus cross-ties. Improved availability of DC 0.30% 0.00% DC01 TDAFW no DC $1K >$199K 0.03% Expert Not Cost- Cost will exceed benefit.
power system. Dependency Panel Beneficial 11 Improve 4.16-kV bus cross- Increased availability of on- 0.26% 0.58% 4kv2 Add 4KV cross-tie $13K <$100K 0.58% Expert Potentially Physical cross-tie exists, tie ability. site AC power. capability for SBO Panel Cost- but there is no analysis or sequences Beneficial procedures to allow its use except in specific outage conditions. Cost is to develop procedures and analysis to allow use of the cross-tie. Benefit calculated is under-estimated since it was evaluated for only SBO sequences.
15 Install tornado protection on Increased availability of on- 2.65% 4.35% LOSP1 No tornado related $91K >$500K 3.38% Expert Not Cost- Cost will exceed benefit.
gas turbine generator. site AC power. LOSP Panel Beneficial 24 Bury off-site power lines. Improved off-site power 40.66% 41.30% NOLOSP Eliminate all Loss of $1.2M >$3M 35.28% Expert Not Cost- Cost will exceed benefit.
reliability during severe Offsite Power Events Panel Beneficial Previous SAMA submittals weather. have estimated approximately $1M per mile.
25 Install an independent active Improved prevention of 2.77% 0.00% LOCA12 No failures of the $48K >$1M 0.35% Expert Not Cost- Cost will exceed benefit.
or passive high pressure core melt sequences. charging or SI pumps Panel Beneficial injection system.
26 Provide an additional high Reduced frequency of core 2.77% 0.00% LOCA12 No failures of the $48K >$1M 0.35% Expert Not Cost- Cost will exceed benefit.
pressure injection pump with melt from small LOCA and charging or SI pumps Panel Beneficial independent diesel. SBO sequences.
28 Add a diverse low pressure Improved injection 3.19% 2.17% LOCA03 No failure of low $65K >$1M 1.01% Expert Not Cost- Cost will exceed benefit.
injection system. capability. pressure injection Panel Beneficial 29 Provide capability for Improved injection Potentially SAMA is judged to be low alternate injection via diesel- capability. Cost- cost, but analysis is driven fire pump. Beneficial needed to determine impacts of injection of non-borated water to RCS.
Expert Panel judged this SAMA to be potentially cost-beneficial without determining an actual benefit or cost.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 10 of 34 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway % Red.
SAMA % Red. In OS SAMA SAMA Case % Red IN Number Potential Improvement Discussion In CDF Dose Case Description Benefit Cost OECR Cost Basis Evaluation Basis for Evaluation 39 Replace two of the four Reduced common cause 2.77% 0.00% LOCA12 No failures of the $48K >$1M 0.35% Expert Not Cost- Cost will exceed benefit.
electric safety injection failure of the safety charging or SI pumps Panel Beneficial pumps with diesel-powered injection system. This pumps. SAMA was originally intended for the Westinghouse-CE System 80+, which has four trains of safety injection.
However, the intent of this SAMA is to provide diversity within the high-and l 41 Create a reactor coolant Allows low pressure 0.78% 0.00% DEPRESS No failures of $12K >$500K 0.27% Expert Not Cost- Cost will exceed benefit.
depressurization system. emergency core cooling depressurization Panel Beneficial system injection in the event of small LOCA and high-pressure safety injection failure.
43 Add redundant DC control Increased availability of 0.30% 0.00% SW01 Service Water Pumps $1K >$100K 0.06% Expert Not Cost- Cost will exceed benefit.
power for SW pumps. SW. not dependent on DC Panel Beneficial Power 46 Add a service water pump. Increased availability of 17.60% 27.72% SW02 No failures of ESW $636K >$5M 23.26% Expert Not Cost- Cost will exceed benefit.
cooling water. pumps Panel Beneficial 54 Increase charging pump lube Increased time before 0.48% 0.00% CHG01 Charging pumps not $4K >$100K 0.06% Expert Not Cost- Cost will exceed benefit.
oil capacity. charging pump failure due dependent on cooling Panel Beneficial to lube oil overheating in water.
loss of cooling water sequences.
55 Install an independent Reduced frequency of core 5.54% 0.00% RCPLOCA No RCP Seal LOCAs $94K >$1M 0.21% Expert Not Cost- Cost will exceed benefit.
reactor coolant pump seal damage from loss of Panel Beneficial Previous investigation into injection system, with component cooling water, installing such a system dedicated diesel. service water, or station concluded that operators blackout. did not have sufficient time to place the system in service prior to seal damage.
56 Install an independent Reduced frequency of core 5.54% 0.00% RCPLOCA No RCP Seal LOCAs $94K >$500K 0.21% Expert Not Cost- Cost will exceed benefit.
reactor coolant pump seal damage from loss of Panel Beneficial injection system, without component cooling water dedicated diesel. or service water, but not a station blackout.
58 Install improved reactor Reduced likelihood of 5.54% 0.00% RCPLOCA No RCP Seal LOCAs $94K >$3M 0.21% Expert Not Cost- Cost will exceed benefit.
coolant pump seals. reactor coolant pump seal Panel Beneficial LOCA.
59 Install an additional Reduced likelihood of loss 3.61% 0.00% CCW01 No failures of the CCW $59K >$1M 0.07% Expert Not Cost- Cost will exceed benefit.
component cooling water of component cooling water Pumps Panel Beneficial pump. leading to a reactor coolant pump seal LOCA.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 11 of 34 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway % Red.
SAMA % Red. In OS SAMA SAMA Case % Red IN Number Potential Improvement Discussion In CDF Dose Case Description Benefit Cost OECR Cost Basis Evaluation Basis for Evaluation 64 Implement procedure and Improved ability to cool 5.39% 0.76% FWCCW Evaluate fire water $104K <$150K 0.77%% Expert Potentially The cost estimate is for hardware modifications to residual heat removal heat 2 hookup to RHR HX Panel Cost development of a allow manual alignment of exchangers. Beneficial procedure and use of the fire water system to the temporary connections.
component cooling water Cost of permanent system, or install a modification would be component cooling water significantly higher.
header cross-tie.
65 Install a digital feed water Reduced chance of loss of 1.57% 0.00% FW01 No loss of Feedwater $29K $19M 0.49% Callaway Not Cost- Cost will exceed benefit.
upgrade. main feed water following a Events Modification Beneficial plant trip. Costs 71 Install a new condensate Increased availability of the 1.14% 0.00% CST01 CST does not deplete $18K >$2.5M 0.24% Expert Not Cost- Cost will exceed benefit.
storage tank (auxiliary auxiliary feedwater system. Panel Beneficial feedwater storage tank).
77 Provide a passive, Reduced potential for core 1.57% 0.00% FW01 No loss of Feedwater $29K $>1M 0.49% Expert Not Cost- Cost will exceed benefit.
secondary-side heat- damage due to loss-of- Events Panel Beneficial rejection loop consisting of a feedwater events.
condenser and heat sink.
79 Replace existing pilot- Increased probability of 3.43% 2.17% FB01 Only one PORV $79K >$500K 1.68% Expert Not Cost- Cost will exceed benefit.
operated relief valves with successful feed and bleed. required for Feed & Panel Beneficial larger ones, such that only Bleed one is required for successful feed and bleed.
80 Provide a redundant train or Increased availability of 6.08% 4.35% HVAC No dependencies on $156K <$100K 3.87% Expert Potentially Procedures to open doors means of ventilation. components dependent on HVAC Panel Cost or provide temporary room cooling. Beneficial ventilation may be cost beneficial for the EDGs, MDAFW pumps, and charging pumps.
Procedures for opening doors to the DC switchgear rooms exist.
87 Replace service and Elimination of instrument 0.36% 0.00% INSTAIR Eliminate all instrument $2K >$500K 0.06% Expert Not Cost- Cost will exceed benefit.
instrument air compressors air system dependence on air failures Panel Beneficial with more reliable service water cooling.
compressors which have self-contained air cooling by shaft driven fans.
91 Install a passive containment Improved containment 19.52% 36.96% CONT01 No failures due to $793K >$10M 31.32% Expert Not Cost- Cost will exceed benefit.
spray system. spray capability. containment Panel Beneficial overpressure 93 Install an unfiltered, Increased decay heat 19.52% 36.96% CONT01 No failures due to $793K >$2M 31.32% Expert Not Cost- Cost will exceed benefit.
hardened containment vent. removal capability for non- containment Panel Beneficial ATWS events, without overpressure scrubbing released fission products.
94 Install a filtered containment Increased decay heat 19.52% 36.96% CONT01 No failures due to $793K >$2M 31.32% Expert Not Cost- Cost will exceed benefit.
vent to remove decay heat. removal capability for non- containment Panel Beneficial Option 1: Gravel Bed Filter; ATWS events, with overpressure Option 2: Multiple Venturi scrubbing of released Scrubber fission products.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 12 of 34 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway % Red.
SAMA % Red. In OS SAMA SAMA Case % Red IN Number Potential Improvement Discussion In CDF Dose Case Description Benefit Cost OECR Cost Basis Evaluation Basis for Evaluation 96 Provide post-accident Reduced likelihood of 0.48% 0.00% H2BURN No hydrogen $10K >$100K 0.44% Expert Not Cost- Cost will exceed benefit.
containment inerting hydrogen and carbon burns/explosions Panel Beneficial capability. monoxide gas combustion.
97 Create a large concrete Increased cooling and MAB >$10M Note 1 Expert Not Cost- Cost will exceed benefit.
crucible with heat removal containment of molten core Panel Beneficial potential to contain molten debris. Molten core debris core debris. escaping from the vessel is contained within the crucible and a water cooling mechanism cools the molten core in the crucible, preventing melt-through of the base mat.
98 Create a core melt source Increased cooling and MAB >$10M Note 1 Expert Not Cost- Cost will exceed benefit.
reduction system. containment of molten core Panel Beneficial debris. Refractory material would be placed underneath the reactor vessel such that a molten core falling on the material would melt and combine with the material.
Subsequent spreading and heat removal from the vitrified compound would be facilitated, and concrete attack would not occur.
99 Strengthen Reduced probability of 19.52% 36.96% CONT01 No failures due to $1.2M >$10M 31.32% Expert Not Cost- Cost will exceed benefit.
primary/secondary containment over- containment Panel Beneficial containment (e.g., add pressurization. overpressure ribbing to containment shell).
100 Increase depth of the Reduced probability of MAB >$10M Note 1 Expert Not Cost- Cost will exceed benefit.
concrete base mat or use an base mat melt-through. Panel Beneficial alternate concrete material to ensure melt-through does not occur.
102 Construct a building to be Reduced probability of 19.52% 36.96% CONT01 No failures due to $1.2M >$10M 31.32% Expert Not Cost- Cost will exceed benefit.
connected to containment over- containment Panel Beneficial primary/secondary pressurization. overpressure containment and maintained at a vacuum.
104 Improve leak detection Increased piping 39.34% 2.17% LOCA05 No piping system $689K >$2M 1.03% Expert Not Cost- Cost will exceed benefit.
procedures. surveillance to identify LOCAs Panel Beneficial leaks prior to complete failure. Improved leak detection would reduce LOCA frequency.
107 Install a redundant Increased containment 19.52% 36.96% CONT01 No failures due to $1.2M >$2M 31.32% Expert Not Cost- Cost will exceed benefit.
containment spray system. heat removal ability. containment Panel Beneficial overpressure
ULNRC-05919 October 17, 2012 Enclosure 1 Page 13 of 34 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway % Red.
SAMA % Red. In OS SAMA SAMA Case % Red IN Number Potential Improvement Discussion In CDF Dose Case Description Benefit Cost OECR Cost Basis Evaluation Basis for Evaluation 108 Install an independent power Reduced hydrogen 0.48% 0.00% H2BURN No hydrogen $10K >$100K 0.44% Expert Not Cost-supply to the hydrogen detonation potential. burns/explosions Panel Beneficial control system using either new batteries, a non-safety grade portable generator, existing station batteries, or existing AC/DC independent power supplies, such as the security system diesel.
109 Install a passive hydrogen Reduced hydrogen 0.48% 0.00% H2BURN No hydrogen $10K >$100M 0.44% Expert Not Cost- Cost will exceed benefit.
control system. detonation potential. burns/explosions Panel Beneficial 110 Erect a barrier that would Reduced probability of MAB >$10M Note 1 Expert Not Cost- Cost will exceed benefit.
provide enhanced protection containment failure. Panel Beneficial of the containment walls (shell) from ejected core debris following a core melt scenario at high pressure.
111 Install additional pressure or Reduced ISLOCA 1.33% 8.70% ISLOCA No ISLOCA events $123K >$500K 7.08% Expert Not Cost- Cost will exceed benefit.
leak monitoring instruments frequency. Panel Beneficial for detection of ISLOCAs.
112 Add redundant and diverse Reduced frequency of 0.30% 0.00% CONT02 No failures of $1K >$1M Expert Not Cost- Cost will exceed benefit.
limit switches to each containment isolation containment isolation Panel Beneficial containment isolation valve. failure and ISLOCAs.
113 Increase leak testing of Reduced ISLOCA 1.33% 8.70% ISLOCA No ISLOCA events $123K >$1M 7.08% Expert Not Cost- Cost will exceed benefit.
valves in ISLOCA paths. frequency. Panel Beneficial 114 Install self-actuating Reduced frequency of 0.30% 0.00% CONT02 No failures of $1K >$500K 0.03% Expert Not Cost- Cost will exceed benefit.
containment isolation valves. isolation failure. containment isolation Panel Beneficial 115 Locate residual heat removal Reduced frequency of 1.33% 8.70% ISLOCA No ISLOCA events $123K >$1M 7.08% Expert Not Cost- Cost will exceed benefit.
(RHR) inside containment ISLOCA outside Panel Beneficial containment.
116 Ensure ISLOCA releases are Scrubbed ISLOCA 1.33% 8.70% ISLOCA No ISLOCA events $123K >$1M 7.08% Expert Not Cost- Cost would exceed benefit.
scrubbed. One method is to releases. Panel Beneficial Current plant design plug drains in potential break requires drains to be open.
areas so that break point will Analysis and license be covered with water. changes required to implement are included in the cost estimate.
119 Institute a maintenance Reduced frequency of 20.47% 63.28% NOSGTR No SGTR Events $1.4M >$3M 69.43% Expert Not Cost- Cost will exceed benefit.
practice to perform a 100% steam generator tube Panel Beneficial inspection of steam ruptures.
generator tubes during each refueling outage.
121 Increase the pressure Eliminates release pathway 20.47% 63.28% NOSGTR No SGTR Events $1.4M >$10M 69.43% Expert Not Cost- Cost will exceed benefit.
capacity of the secondary to the environment Panel Beneficial side so that a steam following a steam generator tube rupture would generator tube rupture.
not cause the relief valves to lift.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 14 of 34 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway % Red.
SAMA % Red. In OS SAMA SAMA Case % Red IN Number Potential Improvement Discussion In CDF Dose Case Description Benefit Cost OECR Cost Basis Evaluation Basis for Evaluation 122 Install a redundant spray Enhanced depressurization 20.47% 63.28% NOSGTR No SGTR Events $1.4M >$10M 69.43% Expert Not Cost- Cost will exceed benefit.
system to depressurize the capabilities during steam Panel Beneficial primary system during a generator tube rupture.
steam generator tube rupture 125 Route the discharge from the Reduced consequences of 20.47% 63.28% NOSGTR No SGTR Events $1.4M >$10M 69.43% Expert Not Cost- Cost will exceed benefit.
main steam safety valves a steam generator tube Panel Beneficial through a structure where a rupture.
water spray would condense the steam and remove most of the fission products.
126 Install a highly reliable Reduced consequences of 20.47% 63.28% NOSGTR No SGTR Events $1.4M >$10M 69.43% Expert Not Cost- Cost will exceed benefit.
(closed loop) steam a steam generator tube Panel Beneficial generator shell-side heat rupture.
removal system that relies on natural circulation and stored water sources 129 Vent main steam safety Reduced consequences of 20.47% 63.28% NOSGTR No SGTR Events $1.4M >$10M 69.43% Expert Not Cost- Cost will exceed benefit.
valves in containment. a steam generator tube Panel Beneficial Current containment rupture. design does not support this modification.
Modifications to containment and associated analysis are included in the cost estimate.
130 Add an independent boron Improved availability of 2.41% 2.17% NOATWS Eliminate all ATWS $63K >$1M 1.85% Expert Not Cost- Cost will exceed benefit.
injection system. boron injection during Panel Beneficial ATWS.
131 Add a system of relief valves Improved equipment 2.41% 2.17% NOATWS Eliminate all ATWS $63K >$2M 1.85% Expert Not Cost- Cost will exceed benefit.
to prevent equipment availability after an ATWS. Panel Beneficial damage from pressure spikes during an ATWS.
133 Install an ATWS sized filtered Increased ability to remove 2.41% 2.17% NOATWS Eliminate all ATWS $63K >$1M 1.85% Expert Not Cost- Cost will exceed benefit containment vent to remove reactor heat from ATWS Panel Beneficial decay heat. events.
136 Install motor generator set Reduced frequency of core 2.41% 2.17% NOATWS Eliminate all ATWS $63K >$500K 1.85% Expert Not Cost- Cost will exceed benefit.
trip breakers in control room. damage due to an ATWS. Panel Beneficial 147 Install digital large break Reduced probability of a 39.34% 2.17% LOCA05 No piping system $689K >$5M 1.03% Expert Not Cost- Cost will exceed benefit.
LOCA protection system. large break LOCA (a leak LOCAs Panel Beneficial before break).
153 Install secondary side guard Prevents secondary side 2.53% 0.00% NOSLB No Steam Line Breaks $51K >$1M 0.87% Expert Not Cost- Cost will exceed benefit.
pipes up to the main steam depressurization should a Panel Beneficial isolation valves. steam line break occur upstream of the main steam isolation valves.
Also guards against or prevents consequential multiple steam generator tube ruptures following a main steam line break event.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 15 of 34 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway % Red.
SAMA % Red. In OS SAMA SAMA Case % Red IN Number Potential Improvement Discussion In CDF Dose Case Description Benefit Cost OECR Cost Basis Evaluation Basis for Evaluation 160 Modifications to lessen Lower impact of flood that <$50K Expert Potentially Relatively minor impact of internal flooding propagates through the Panel Cost- modifications to door path through Control Building dumbwaiter Beneficial opening could result in dumbwaiter. lower flow to the dumbwaiter. Specific benefit could not be calculated but SAMA item is judged to be low cost and therefore potentially cost beneficial.
161 Improvements to PORV Decrease in risk due to 0.85% 0.46% PORV PORVs do not fail to $18K >$100K 0.24% Expert Not Cost- Cost will exceed benefit.
performance that will lower PORV failing to open. open Panel Beneficial the probability of failure to open.
162 Install a large volume EDG Allows transfer of EDF fuel 1.14% 7.60% EDGFUEL No EDG fuel pump $124K $150K 7.11% Wolf Creek Potentially Wolf Creek estimated cost fuel oil tank at an elevation oil to the EDG day tanks on failures Cost- of $150K is less than the greater than the EDG fuel oil failure of the fuel oil Beneficial potential benefit.
day tanks. transfer pumps.
163 Improve feedwater check Lower risk due to failures in 5.52% 2.05% FW02 Feedwater Check $127K >$500K 2.23% Expert Not Cost- Cost will exceed benefit.
valve reliability to reduce which feedwater check Valves do not fail to Panel Beneficial probability of failure to open. valves fail to open and open allow feeding of the steam generators.
164 Provide the capability to Provide backup to ESW in 5.62% 7.64% SW03 AEPS power to SW $191K >$500K 6.37% Expert Not Cost- Cost will exceed benefit.
power the normal service conditions with power only pumps Panel Beneficial water pumps from AEPS. available from AEPS.
171 Increase the size of the Ensure a supply of makeup 0.68% 0.13% LOCA04 RWST does not $13K >$100K 0.07% Expert Not Cost- Cost will exceed benefit.
RWST or otherwise improve water is available from the deplete Panel Beneficial the availability of the RWST RWST.
178 Improvements to UHS Improve availability or 3.29% 4.75% HVAC02 UHS cooling tower $113K <$100K 3.82% Expert Potentially Implementation of cooling tower electrical room mitigate loss of HVAC. % electrical room HVAC Panel Cost temporary ventilation or HVAC. does not fail. Beneficial opening of doors will be a lower cost than the calculated benefit.
179 Modify procedures such that Prevents possible thermally 0.15% 3.18% RAI7a Reduced probability $63K <$100K 4.46% Expert Potentially Implementation of the water loop seals in the induced steam generator of thermally induced Panel Cost procedure change will be RCS cold legs are not tube rupture following core steam generator tube Beneficial lower cost than benefit, cleared following core damage. failure especially if 95% CDF damage. benefit is considered.
180 Install lower amperage fuses Reduced fire risk. Potentially SAMA considered for various 14 AWG control Cost potentially cost beneficial circuits in the MCR. The Beneficial without benefit or cost majority of the modification determination since the centers around the trip circuit NFPA 805 license fuses on NB, NG, PA, PB, amendment request and PG system breakers. committed to performing the modification.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 16 of 34 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway % Red.
SAMA % Red. In OS SAMA SAMA Case % Red IN Number Potential Improvement Discussion In CDF Dose Case Description Benefit Cost OECR Cost Basis Evaluation Basis for Evaluation 181 Install redundant fuses and Reduced fire risk. Potentially SAMA considered isolation switches for MCR Cost potentially cost beneficial evacuation procedure OTO- Beneficial without benefit or cost ZZ-00001. determination since the NFPA 805 license amendment request committed to performing the modification.
182 To protect against multiple Reduced fire risk. Potentially SAMA considered spurious operation scenarios, Cost potentially cost beneficial cable runs will be changed to Beneficial without benefit or cost run a single wire in a determination since the protected metal jacket such NFPA 805 license that spurious valve opening amendment request due to a hot short affecting committed to performing the valve control circuit is the modification.
eliminated for the fire area.
This modification will be implemented in multiple fire areas.
183 Quick response sprinkler Reduced fire risk. Potentially SAMA considered heads in cable chases A-11, Cost potentially cost beneficial C-30, and C-31 will be Beneficial without benefit or cost modified to be in accordance determination since the with the applicable NFPA 805 license requirements of NFPA 13- amendment request 1976 edition. committed to performing the modification.
184 Improvements in the More reliable main steam 0.59% 0.95% SLIS Steam Line Isolation $28K >$500K 1.06% Expert Not Cost- Cost is for installation of reliability of the Steam Line line isolation. System does not fail Panel Beneficial redundant instrumentation Isolation automatic signal. system and would likely be much higher. Procedure and training already direct operators to manually back up failed automatic actuations.
185 Automate initiation of CCW More reliable than manual 3.53% 0.14% HEP Evaluate automating $62K $200K 0.11% Expert Potentially flow to the RHR heat initiation of flow to RHR CCW flow to RHR Panel Cost exchangers. HX. HXs Beneficial 186 Develop a procedure and Backup cooling water if 0.04% 0.05% FWCCW Fire water available to $1K >$1M 0.04% Expert Not Cost- Ability to do this will require obtain equipment to provide ESW/SW is lost cool CCW HX Panel Beneficial larger fire pumps.
a temporary hookup of fire water as a replacement for ESW 187 Install modification to power Another source of backup 4.07% 7.63% SBOMOD Reduce the frequency $174K $350K 7.03% Expert Potentially Already installed spare the normal charging pump power to the NCP in cases of SBO sequences. Panel Cost circuit breaker, from an existing spare of station blackout or loss Beneficial implementation requires breaker from the AEPS. of service water power and control cables.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 17 of 34 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway % Red.
SAMA % Red. In OS SAMA SAMA Case % Red IN Number Potential Improvement Discussion In CDF Dose Case Description Benefit Cost OECR Cost Basis Evaluation Basis for Evaluation 188 Install a permanent, Another source of backup 4.28% 7.63% SBOMOD2 Reduce the frequency $182K $400K 7.38% Expert Potentially AEPS was installed with a dedicated generator for the power to the NCP, DC of SBO sequences. Panel Cost spare breaker and NCP, and a motor-driven power (pump/valve control Beneficial expansion capability that AFW pump and battery and SG level could be used to supply charger to address SBO instrumentation), and various equipment.
events in which the TD AFW power to an AFW pump in pump is unavailable. cases of station blackout or loss of service water OS = off site Note 1: For SAMA items that were judged to cost significantly more than the Maximum Attainable Benefit (MAB), no calculation of the individual benefit was performed.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 18 of 34 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA SAMA 3% Disc Realistic Benefit at 95%
Number Potential Improvement Discussion Case Benefit Rate Disc Rate at 33yrs CDF Cost Cost Basis Evaluation Basis for Evaluation 1 Provide additional DC battery Extended DC power availability NOSBO $360K $588K $325K $512K $761K >$1M Expert Panel Not Cost- Cost will exceed capacity. during an SBO. Beneficial benefit.
2 Replace lead-acid batteries with fuel Extended DC power availability NOSBO $360K $588K $325K $512K $761K >$1M Expert Panel Not Cost- Cost will exceed cells. during an SBO. Beneficial benefit.
5 Provide DC bus cross-ties. Improved availability of DC DC01 $1K $1K $1K $1K $1K >$199K Expert Panel Not Cost- Cost will exceed power system. Beneficial benefit.
11 Improve 4.16-kV bus cross-tie ability. Increased availability of on-site 4kv2 $13K $20K $12K $17K $27K <$100K Expert Panel Potentially Physical cross-tie AC power. Cost-Beneficial exists, but there is no analysis or procedures to allow its use except in specific outage conditions. Cost is to develop procedures and analysis to allow use of the cross-tie.
Benefit calculated is under-estimated since it was evaluated for only SBO sequences.
15 Install tornado protection on gas Increased availability of on-site LOSP1 $91K $144K $82K $125K $192K >$500K Expert Panel Not Cost- Cost will exceed turbine generator. AC power. Beneficial benefit.
24 Bury off-site power lines. Improved off-site power reliability NOLOSP $1.2M $2.0M $1.1M $1.7M $2.6M >$3M Expert Panel Not Cost- Cost will exceed during severe weather. Beneficial benefit. Previous SAMA submittals have estimated approximately $1M per mile.
25 Install an independent active or Improved prevention of core melt LOCA12 $48K $85K $44K $75 $102 >$1M Expert Panel Not Cost- Cost will exceed passive high pressure injection sequences. Beneficial benefit.
system.
26 Provide an additional high pressure Reduced frequency of core melt LOCA12 $48K $85K $44K $75 $102 >$1M Expert Panel Not Cost- Cost will exceed injection pump with independent from small LOCA and SBO Beneficial benefit.
diesel. sequences.
28 Add a diverse low pressure injection Improved injection capability. LOCA03 $65K $111K $58K $97K $137K >$1M Expert Panel Not Cost- Cost will exceed system. Beneficial benefit.
29 Provide capability for alternate Improved injection capability. Potentially SAMA is judged to be injection via diesel-driven fire pump. Cost-Beneficial low cost, but analysis is needed to determine impacts of injection of non-borated water to RCS.
Expert Panel judged this SAMA to be potentially cost-beneficial without determining an actual benefit or cost.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 19 of 34 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA SAMA 3% Disc Realistic Benefit at 95%
Number Potential Improvement Discussion Case Benefit Rate Disc Rate at 33yrs CDF Cost Cost Basis Evaluation Basis for Evaluation 39 Replace two of the four electric safety Reduced common cause failure LOCA12 $48K $85K $44K $75 $102 >$1M Expert Panel Not Cost- Cost will exceed injection pumps with diesel-powered of the safety injection system. Beneficial benefit.
pumps. This SAMA was originally intended for the Westinghouse-CE System 80+, which has four trains of safety injection.
However, the intent of this SAMA is to provide diversity within the high- and l 41 Create a reactor coolant Allows low pressure emergency DEPRESS $12K $20K $11K $17K $25K >$500K Expert Panel Not Cost- Cost will exceed depressurization system. core cooling system injection in Beneficial benefit.
the event of small LOCA and high-pressure safety injection failure.
43 Add redundant DC control power for Increased availability of SW. SW01 $1K $2K $1K $2K $3K >$100K Expert Panel Not Cost- Cost will exceed SW pumps. Beneficial benefit.
46 Add a service water pump. Increased availability of cooling SW02 $636K $1M $575K $879K $1.3M >$5M Expert Panel Not Cost- Cost will exceed water. Beneficial benefit.
54 Increase charging pump lube oil Increased time before charging CHG01 $4K $7K $4K $6K $9K >$100K Expert Panel Not Cost- Cost will exceed capacity. pump failure due to lube oil Beneficial benefit.
overheating in loss of cooling water sequences.
55 Install an independent reactor coolant Reduced frequency of core RCPLOCA $94K $168K $85K $148K $198K >$1M Expert Panel Not Cost- Cost will exceed pump seal injection system, with damage from loss of component Beneficial benefit. Previous dedicated diesel. cooling water, service water, or investigation into station blackout. installing such a system concluded that operators did not have sufficient time to place the system in service prior to seal damage.
56 Install an independent reactor coolant Reduced frequency of core RCPLOCA $94K $168K $85K $148K $198K >$500K Expert Panel Not Cost- Cost will exceed pump seal injection system, without damage from loss of component Beneficial benefit.
dedicated diesel. cooling water or service water, but not a station blackout.
58 Install improved reactor coolant pump Reduced likelihood of reactor RCPLOCA $94K $168K $85K $148K $198K >$3M Not Cost- Cost will exceed seals. coolant pump seal LOCA. Beneficial benefit.
59 Install an additional component Reduced likelihood of loss of CCW01 $59K $106K $53K $93K $124K >$1M Cost will Not Cost- Cost will exceed cooling water pump. component cooling water leading exceed Beneficial benefit.
to a reactor coolant pump seal benefit LOCA.
64 Implement procedure and hardware Improved ability to cool residual FWCCW2 $104K $184K $94K $161K $220K <$150K Expert Panel Potentially Cost The cost estimate is modifications to allow manual heat removal heat exchangers. Beneficial for development of a alignment of the fire water system to procedure and use of the component cooling water system, temporary or install a component cooling water connections. Cost of header cross-tie. permanent modification would be significantly higher.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 20 of 34 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA SAMA 3% Disc Realistic Benefit at 95%
Number Potential Improvement Discussion Case Benefit Rate Disc Rate at 33yrs CDF Cost Cost Basis Evaluation Basis for Evaluation 65 Install a digital feed water upgrade. Reduced chance of loss of main FW01 $29K $50K $27K $44K $62K $19M Callaway Not Cost- Cost will exceed feed water following a plant trip. Modification Beneficial benefit.
Costs 71 Install a new condensate storage Increased availability of the CST01 $18K $32K $16K $28K $39K >$2.5M Expert Panel Not Cost- Cost will exceed tank (auxiliary feedwater storage auxiliary feedwater system. Beneficial benefit.
tank).
77 Provide a passive, secondary-side Reduced potential for core FW01 $29K $50K $27K $44K $62K $>1M Expert Panel Not Cost- Cost will exceed heat-rejection loop consisting of a damage due to loss-of-feedwater Beneficial benefit.
condenser and heat sink. events.
79 Replace existing pilot-operated relief Increased probability of FB01 $79K $133K $72K $117K $168K >$500K Expert Panel Not Cost- Cost will exceed valves with larger ones, such that successful feed and bleed. Beneficial benefit.
only one is required for successful feed and bleed.
80 Provide a redundant train or means Increased availability of HVAC $156K $259K $141K $227K $331K <$100K Expert Panel Potentially Cost Procedures to open of ventilation. components dependent on room Beneficial doors or provide cooling. temporary ventilation may be cost beneficial for the EDGs, MDAFW pumps, and charging pumps. Procedures for opening doors to the DC switchgear rooms exist.
87 Replace service and instrument air Elimination of instrument air INSTAIR $2K $3K $2K $$2K $4K >$500K Expert Panel Not Cost- Cost will exceed compressors with more reliable system dependence on service Beneficial benefit.
compressors which have self- water cooling.
contained air cooling by shaft driven fans.
91 Install a passive containment spray Improved containment spray CONT01 $793K $1.2M $717K $1.1M $1.7M >$10M Expert Panel Not Cost- Cost will exceed system. capability. Beneficial benefit.
93 Install an unfiltered, hardened Increased decay heat removal CONT01 $793K $1.2M $717K $1.1M $1.7M >$2M Expert Panel Not Cost- Cost will exceed containment vent. capability for non-ATWS events, Beneficial benefit.
without scrubbing released fission products.
94 Install a filtered containment vent to Increased decay heat removal CONT01 $793K $1.2M $717K $1.1M $1.7M >$2M Expert Panel Not Cost- Cost will exceed remove decay heat. Option 1: Gravel capability for non-ATWS events, Beneficial benefit.
Bed Filter; Option 2: Multiple Venturi with scrubbing of released fission Scrubber products.
96 Provide post-accident containment Reduced likelihood of hydrogen H2BURN $10K $15K $9K $13K $20K >$100K Expert Panel Not Cost- Cost will exceed inerting capability. and carbon monoxide gas Beneficial benefit.
combustion.
97 Create a large concrete crucible with Increased cooling and MAB >$10M Expert Panel Not Cost- Cost will exceed heat removal potential to contain containment of molten core Beneficial benefit.
molten core debris. debris. Molten core debris escaping from the vessel is contained within the crucible and a water cooling mechanism cools the molten core in the crucible, preventing melt-through of the base mat.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 21 of 34 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA SAMA 3% Disc Realistic Benefit at 95%
Number Potential Improvement Discussion Case Benefit Rate Disc Rate at 33yrs CDF Cost Cost Basis Evaluation Basis for Evaluation 98 Create a core melt source reduction Increased cooling and MAB >$10M Expert Panel Not Cost- Cost will exceed system. containment of molten core Beneficial benefit.
debris. Refractory material would be placed underneath the reactor vessel such that a molten core falling on the material would melt and combine with the material. Subsequent spreading and heat removal from the vitrified compound would be facilitated, and concrete attack would not occur.
99 Strengthen primary/secondary Reduced probability of CONT01 $1.2M $1.2M $717K $1.1M $1.7M >$10M Expert Panel Not Cost- Cost will exceed containment (e.g., add ribbing to containment over-pressurization. Beneficial benefit.
containment shell).
100 Increase depth of the concrete base Reduced probability of base mat MAB >$10M Expert Panel Not Cost- Cost will exceed mat or use an alternate concrete melt-through. Beneficial benefit.
material to ensure melt-through does not occur.
102 Construct a building to be connected Reduced probability of CONT01 $1.2M $1.2M $717K $1.1M $1.7M >$10M Expert Panel Not Cost- Cost will exceed to primary/secondary containment containment over-pressurization. Beneficial benefit.
and maintained at a vacuum.
104 Improve leak detection procedures. Increased piping surveillance to LOCA05 $685K $1.2M $620K $1.1M $1.5M >$2M Expert Panel Not Cost- Cost will exceed identify leaks prior to complete Beneficial benefit.
failure. Improved leak detection would reduce LOCA frequency.
107 Install a redundant containment spray Increased containment heat CONT01 $1.2M $1.2M $717K $1.1M $1.7M >$2M Expert Panel Not Cost- Cost will exceed system. removal ability. Beneficial benefit.
108 Install an independent power supply Reduced hydrogen detonation H2BURN $10K $15K $9K $13K $20K >$100K Expert Panel Not Cost-to the hydrogen control system using potential. Beneficial either new batteries, a non-safety grade portable generator, existing station batteries, or existing AC/DC independent power supplies, such as the security system diesel.
109 Install a passive hydrogen control Reduced hydrogen detonation H2BURN $10K $15K $9K $13K $20K >$100M Expert Panel Not Cost- Cost will exceed system. potential. Beneficial benefit.
110 Erect a barrier that would provide Reduced probability of MAB >$10M Expert Panel Not Cost- Cost will exceed enhanced protection of the containment failure. Beneficial benefit.
containment walls (shell) from ejected core debris following a core melt scenario at high pressure.
111 Install additional pressure or leak Reduced ISLOCA frequency. ISLOCA $123K $179K $111K $154K $259K >$500K Expert Panel Not Cost- Cost will exceed monitoring instruments for detection Beneficial benefit.
of ISLOCAs.
112 Add redundant and diverse limit Reduced frequency of CONT02 $1K $1K $1K $1K $2K >$1M Expert Panel Not Cost- Cost will exceed switches to each containment containment isolation failure and Beneficial benefit.
isolation valve. ISLOCAs.
113 Increase leak testing of valves in Reduced ISLOCA frequency. ISLOCA $123K $179K $111K $154K $259K >$1M Expert Panel Not Cost- Cost will exceed ISLOCA paths. Beneficial benefit.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 22 of 34 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA SAMA 3% Disc Realistic Benefit at 95%
Number Potential Improvement Discussion Case Benefit Rate Disc Rate at 33yrs CDF Cost Cost Basis Evaluation Basis for Evaluation 114 Install self-actuating containment Reduced frequency of isolation CONT02 $1K $1K $1K $1K $2K >$500K Expert Panel Not Cost- Cost will exceed isolation valves. failure. Beneficial benefit.
115 Locate residual heat removal (RHR) Reduced frequency of ISLOCA ISLOCA $123K $179K $111K $154K $259K >$1M Expert Panel Not Cost- Cost will exceed inside containment outside containment. Beneficial benefit.
116 Ensure ISLOCA releases are Scrubbed ISLOCA releases. ISLOCA $123K $179K $111K $154K $259K >$1M Expert Panel Not Cost- Cost would exceed scrubbed. One method is to plug Beneficial benefit. Current plant drains in potential break areas so that design requires break point will be covered with drains to be open.
water. Analysis and license changes required to implement are included in the cost estimate.
119 Institute a maintenance practice to Reduced frequency of steam NOSGTR $1.4M $2.1M $1.2M $1.8M $2.9M >$3M Expert Panel Not Cost- Cost will exceed perform a 100% inspection of steam generator tube ruptures. Beneficial benefit.
generator tubes during each refueling outage.
121 Increase the pressure capacity of the Eliminates release pathway to NOSGTR $1.4M $2.1M $1.2M $1.8M $2.9M >$10M Expert Panel Not Cost- Cost will exceed secondary side so that a steam the environment following a Beneficial benefit.
generator tube rupture would not steam generator tube rupture.
cause the relief valves to lift.
122 Install a redundant spray system to Enhanced depressurization NOSGTR $1.4M $2.1M $1.2M $1.8M $2.9M >$10M Expert Panel Not Cost- Cost will exceed depressurize the primary system capabilities during steam Beneficial benefit.
during a steam generator tube generator tube rupture.
rupture 125 Route the discharge from the main Reduced consequences of a NOSGTR $1.4M $2.1M $1.2M $1.8M $2.9M >$10M Expert Panel Not Cost- Cost will exceed steam safety valves through a steam generator tube rupture. Beneficial benefit.
structure where a water spray would condense the steam and remove most of the fission products.
126 Install a highly reliable (closed loop) Reduced consequences of a NOSGTR $1.4M $2.1M $1.2M $1.8M $2.9M >$10M Expert Panel Not Cost- Cost will exceed steam generator shell-side heat steam generator tube rupture. Beneficial benefit.
removal system that relies on natural circulation and stored water sources 129 Vent main steam safety valves in Reduced consequences of a NOSGTR $1.4M $2.1M $1.2M $1.8M $2.9M >$10M Expert Panel Not Cost- Cost will exceed containment. steam generator tube rupture. Beneficial benefit. Current containment design does not support this modification.
Modifications to containment and associated analysis are included in the cost estimate.
130 Add an independent boron injection Improved availability of boron NOATWS $63K $104K $57K $90K $134K >$1M Expert Panel Not Cost- Cost will exceed system. injection during ATWS. Beneficial benefit.
131 Add a system of relief valves to Improved equipment availability NOATWS $63K $104K $57K $90K $134K >$2M Expert Panel Not Cost- Cost will exceed prevent equipment damage from after an ATWS. Beneficial benefit.
pressure spikes during an ATWS.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 23 of 34 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA SAMA 3% Disc Realistic Benefit at 95%
Number Potential Improvement Discussion Case Benefit Rate Disc Rate at 33yrs CDF Cost Cost Basis Evaluation Basis for Evaluation 133 Install an ATWS sized filtered Increased ability to remove NOATWS $63K $104K $57K $90K $134K >$1M Expert Panel Not Cost- Cost will exceed containment vent to remove decay reactor heat from ATWS events. Beneficial benefit heat.
136 Install motor generator set trip Reduced frequency of core NOATWS $63K $104K $57K $90K $134K >$500K Expert Panel Not Cost- Cost will exceed breakers in control room. damage due to an ATWS. Beneficial benefit.
147 Install digital large break LOCA Reduced probability of a large LOCA05 $689K $1.2M $620K $1.1M $1.5M >$5M Expert Panel Not Cost- Cost will exceed protection system. break LOCA (a leak before Beneficial benefit.
break).
153 Install secondary side guard pipes up Prevents secondary side NOSLB $51K $87K $46K $77K $108K >$1M Expert Panel Not Cost- Cost will exceed to the main steam isolation valves. depressurization should a steam Beneficial benefit.
line break occur upstream of the main steam isolation valves.
Also guards against or prevents consequential multiple steam generator tube ruptures following a main steam line break event.
160 Modifications to lessen impact of Lower impact of flood that <$50K Expert Panel Potentially Relatively minor internal flooding path through Control propagates through the Cost-Beneficial modifications to door Building dumbwaiter. dumbwaiter opening could result in lower flow to the dumbwaiter. Specific benefit could not be calculated but SAMA item is judged to be low cost and therefore potentially cost beneficial.
161 Improvements to PORV performance Decrease in risk due to PORV PORV $18K $32K $16K $28K $39K >$100K Expert Panel Not Cost- Cost will exceed that will lower the probability of failure failing to open. Beneficial benefit.
to open.
162 Install a large volume EDG fuel oil Allows transfer of EDF fuel oil EDGFUEL $124K $131K $113K $156K $263K $150K Wolf Creek Potentially Wolf Creek estimated tank at an elevation greater than the to the EDG day tanks on Cost-Beneficial cost of $150K is less EDG fuel oil day tanks. failure of the fuel oil transfer than the potential pumps. benefit.
163 Improve feedwater check valve Lower risk due to failures in FW02 $127K $218K $115K $191K $270K >$500K Expert Panel Not Cost- Cost will exceed reliability to reduce probability of which feedwater check valves Beneficial benefit.
failure to open. fail to open and allow feeding of the steam generators.
164 Provide the capability to power the Provide backup to ESW in SW03 $1191K $307K $172K $267K $403K >$500K Expert Panel Not Cost- Cost will exceed normal service water pumps from conditions with power only Beneficial benefit.
AEPS. available from AEPS.
171 Increase the size of the RWST or Ensure a supply of makeup LOCA04 $13K $23K $12K $20K $27K >$100K Expert Panel Not Cost- Cost will exceed otherwise improve the availability of water is available from the Beneficial benefit.
178 Improvements to UHS cooling tower Improve availability or mitigate HVAC02 $113K $181K $102K $158K $239K <$100K Expert Panel Potentially Cost Implementation of electrical room HVAC. loss of HVAC. Beneficial temporary ventilation or opening of doors will be a lower cost than the calculated benefit.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 24 of 34 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA SAMA 3% Disc Realistic Benefit at 95%
Number Potential Improvement Discussion Case Benefit Rate Disc Rate at 33yrs CDF Cost Cost Basis Evaluation Basis for Evaluation 179 Modify procedures such that the Prevents possible thermally RAI7a $63K $87K $57K $75K $134K <$100K Expert Panel Potentially Cost Implementation of water loop seals in the RCS cold legs induced steam generator tube Beneficial procedure change are not cleared following core rupture following core damage. will be lower cost damage. than benefit, especially if 95%
CDF benefit is considered.
180 Install lower amperage fuses for Reduced fire risk. Potentially Cost SAMA considered various 14 AWG control circuits in the Beneficial potentially cost MCR. The majority of the beneficial without modification centers around the trip benefit or cost circuit fuses on NB, NG, PA, PB, and determination since PG system breakers. the NFPA 805 license amendment request committed to performing the modification.
181 Install redundant fuses and isolation Reduced fire risk. Potentially Cost SAMA considered switches for MCR evacuation Beneficial potentially cost procedure OTO-ZZ-00001. beneficial without benefit or cost determination since the NFPA 805 license amendment request committed to performing the modification.
182 To protect against multiple spurious Reduced fire risk. Potentially Cost SAMA considered operation scenarios, cable runs will Beneficial potentially cost be changed to run a single wire in a beneficial without protected metal jacket such that benefit or cost spurious valve opening due to a hot determination since short affecting the valve control circuit the NFPA 805 is eliminated for the fire area. This license amendment modification will be implemented in request committed to multiple fire areas. performing the modification.
183 Quick response sprinkler heads in Reduced fire risk. Potentially Cost SAMA considered cable chases A-11, C-30, and C-31 Beneficial potentially cost will be modified to be in accordance beneficial without with the applicable requirements of benefit or cost NFPA 13-1976 edition. determination since the NFPA 805 license amendment request committed to performing the modification.
ULNRC-05919 October 17, 2012 Enclosure 1 Page 25 of 34 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA SAMA 3% Disc Realistic Benefit at 95%
Number Potential Improvement Discussion Case Benefit Rate Disc Rate at 33yrs CDF Cost Cost Basis Evaluation Basis for Evaluation 184 Improvements in the reliability of the More reliable main steam line SLIS $28K $40K $23K $35K $55K >$500K Expert Panel Not Cost- Cost is for installation Steam Line Isolation automatic isolation. Beneficial of redundant signal. instrumentation system and would likely be much higher.
Procedure and training already direct operators to manually back up failed automatic actuations.
185 Automate initiation of CCW flow to More reliable than manual HEP $62K $112K $56K $99K $132K >$200K Expert Panel Potentially Cost the RHR heat exchangers. initiation of flow to RHR HX. Beneficial 186 Develop a procedure and obtain Backup method of removing FWCCW $1K $2K $1K $2K $2K >$1M Expert Panel Not Cost Ability to do this will equipment to provide a temporary decay heat if CCW is lost. Beneficial require larger fire hookup of fire water to the RHR heat pumps exchangers to use as a backup to CCW for removing decay heat.
187 Install modification to power the Another source of backup SBOMOD $174K $272K $157K $236K $367K $350K Expert Panel Potentially Cost Already installed normal charging pump from an power to the NCP in cases of Beneficial spare circuit breaker, existing spare breaker from the station blackout or loss of implementation AEPS. service water requires power and control cables.
188 Install a permanent, dedicated Another source of backup SBOMOD2 $182K $285K $165K $247K $385K $400K Expert Panel Potentially Cost AEPS was installed generator for the NCP, and a motor- power to the NCP, DC power Beneficial with a spare breaker driven AFW pump and battery (pump/valve control and SG and expansion charger to address SBO events in level instrumentation), and capability that could which the TD AFW pump is power to an AFW pump in be used to supply unavailable. cases of station blackout or various equipment.
loss of service water
ULNRC-05919 October 17, 2012 Page 26 of 34 Table 9-1. Callaway Plant Potentially Cost Beneficial SAMAs Callaway SAMA Number Potential Improvement Discussion Additional Discussion 11 Improve 4.16-kV bus Increased availability of Physical cross-tie exists, cross-tie ability. on-site AC power. but there is no analysis or procedures to allow its use except in specific outage conditions. Cost is to develop procedures and analysis to allow use of the cross-tie.
Benefit calculated is under-estimated since it was evaluated for only SBO sequences.
29 Provide capability for Improved injection Currently being alternate injection via capability. evaluated by plant diesel-driven fire pump. improvement program.
Would use unborated water and portable pump (fire truck).
Calculation of specific benefit of this SAMA was not performed since it is judged to be potentially low cost.
Evaluation will consider impacts of injection of non-borated water.
64 Implement procedure and Improved ability to cool Cost based on hardware modifications to residual heat removal heat development of allow manual alignment of exchangers. procedure for temporary the fire water system to the hookup of fire water to component cooling water CCW heat exchangers.
system, or install a Cost of permanent component cooling water modification would be header cross-tie. much greater.
ULNRC-05919 October 17, 2012 Page 27 of 34 Table 9-1. Callaway Plant Potentially Cost Beneficial SAMAs Callaway SAMA Number Potential Improvement Discussion Additional Discussion 80 Provide a redundant train Increased availability of Procedures to open or means of ventilation. components dependent on doors or provide room cooling. temporary ventilation may be cost beneficial for the EDGs, MDAFW pumps, and charging pumps. Procedures for opening doors to the DC switchgear rooms exist.
160 Modifications to lessen Lower impact of flood that impact of internal flooding propagates through the path through Control dumbwaiter Building dumbwaiter.
162 Install a large volume EDG Allows transfer of EDG fuel fuel oil tank at an elevation oil to the EDG day tanks greater than the EDG fuel on failure of the fuel oil oil day tanks. transfer pumps.
178 Improvements to UHS Improve availability or Implementation of cooling tower electrical mitigate loss of HVAC. temporary ventilation or room HVAC. opening of doors will be a lower cost than the calculated benefit.
179 Modify procedures such Prevents possible Implementation of that the water loop seals in thermally induced steam procedure change will the RCS cold legs are not generator tube rupture be lower cost than cleared following core following core damage. benefit, especially if damage. 95% CDF benefit is considered.
ULNRC-05919 October 17, 2012 Page 28 of 34 Table 9-1. Callaway Plant Potentially Cost Beneficial SAMAs Callaway SAMA Number Potential Improvement Discussion Additional Discussion 180 Install lower amperage Reduced fire risk. SAMA considered fuses for various 14 AWG potentially cost control circuits in the MCR. beneficial without benefit The majority of the or cost determination modification centers since the NFPA 805 around the trip circuit fuses license amendment on NB, NG, PA, PB, and request committed to PG system breakers. performing the modification.
181 Install redundant fuses and Reduced fire risk. SAMA considered isolation switches for MCR potentially cost evacuation procedure beneficial without benefit OTO-ZZ-00001. or cost determination since the NFPA 805 license amendment request committed to performing the modification.
182 To protect against multiple Reduced fire risk. SAMA considered spurious operation potentially cost scenarios, cable runs will beneficial without benefit be changed to run a single or cost determination wire in a protected metal since the NFPA 805 jacket such that spurious license amendment valve opening due to a hot request committed to short affecting the valve performing the control circuit is eliminated modification.
for the fire area. This modification will be implemented in multiple fire areas.
ULNRC-05919 October 17, 2012 Page 29 of 34 Table 9-1. Callaway Plant Potentially Cost Beneficial SAMAs Callaway SAMA Number Potential Improvement Discussion Additional Discussion 183 Quick response sprinkler Reduced fire risk. SAMA considered heads in cable chases A- potentially cost 11, C-30, and C-31 will be beneficial without benefit modified to be in or cost determination accordance with the since the NFPA 805 applicable requirements of license amendment NFPA 13-1976 edition. request committed to performing the modification.
185 Automate initiation of CCW More reliable than manual flow to the RHR heat initiation of flow to RHR exchangers. HX.
187 Install modification to Another source of backup Already installed spare power the normal charging power to the NCP in cases circuit breaker, pump from an existing of station blackout or loss implementation requires spare breaker from the of service water power and control AEPS. cables.
188 Install a permanent, Another source of backup AEPS was installed with dedicated generator for the power to the NCP, DC a spare breaker and NCP, and a motor-driven power (pump/valve control expansion capability that AFW pump and battery and SG level could be used to supply charger to address SBO instrumentation), and various equipment.
events in which the TD power to an AFW pump in AFW pump is unavailable. cases of station blackout or loss of service water
ULNRC-05919 October 17, 2012 Page 30 of 34 Table 11-1. Callaway Plant Release Category Frequency Results Obtained From SAMA Cases RELEASE CATEGORY BASE NOATWS INSTAIR NOLOSP NOSLOCA CCW01 FW01 NOSGTR NOSLB CHG01 LERF-IS 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 LERF-CI 1.658E-10 1.411E-10 1.658E-10 1.422E-10 6.210E-11 1.567E-10 1.658E-10 1.658E-10 1.610E-10 1.658E-10 LERF-CF 1.125E-08 1.103E-08 1.124E-08 7.372E-09 5.378E-09 1.071E-08 1.115E-08 1.135E-08 1.116E-08 1.123E-08 LERF-SG 2.331E-06 2.306E-06 2.330E-06 2.331E-06 2.331E-06 2.331E-06 2.331E-06 0.000E+00 2.331E-06 2.331E-06 LERF-ITR 2.170E-07 1.845E-07 2.167E-07 1.309E-07 2.072E-07 2.170E-07 2.052E-07 0.000E+00 1.936E-07 2.169E-07 LATE-BMT 2.551E-06 2.268E-06 2.547E-06 1.254E-07 2.022E-06 2.507E-06 2.448E-06 2.626E-06 2.515E-06 2.467E-06 LATE-COP 3.185E-06 3.185E-06 3.185E-06 1.796E-08 3.170E-06 3.185E-06 3.185E-06 2.234E-06 3.185E-06 3.185E-06 SERF 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 INTACT 8.080E-06 8.075E-06 8.080E-06 7.065E-06 2.540E-06 7.573E-06 7.983E-06 8.119E-06 7.773E-06 8.137E-06 TOTAL 1.655E-05 1.620E-05 1.654E-05 9.851E-06 1.045E-05 1.600E-05 1.634E-05 1.316E-05 1.618E-05 1.652E-05 Table 11-1. Callaway Plant Release Category Frequency Results Obtained From SAMA Cases (Cont.)
RELEASE CATEGORY SW01 NOSBO LOCA05 H2BURN RCPLOCA LOCA 12 CONT02 LOCA04 LOCA03 CONT01 LERF-IS 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 LERF-CI 1.658E-10 1.658E-10 6.210E-11 1.658E-10 1.567E-10 1.658E-10 0.000E+00 1.658E-10 1.658E-10 1.658E-10 LERF-CF 1.124E-08 1.030E-08 5.018E-09 4.102E-12 1.048E-08 1.099E-08 1.125E-08 1.114E-08 1.089E-08 1.125E-08 LERF-SG 2.331E-06 2.329E-06 2.331E-06 2.331E-06 2.331E-06 2.331E-06 2.331E-06 2.331E-06 2.298E-06 2.331E-06 LERF-ITR 2.170E-07 1.443E-07 2.072E-07 2.170E-07 2.170E-07 2.165E-07 2.170E-07 2.170E-07 2.169E-07 2.170E-07 LATE-BMT 2.553E-06 1.611E-06 2.009E-06 2.551E-06 2.475E-06 1.893E-06 2.551E-06 2.441E-06 2.007E-06 2.551E-06 LATE-COP 3.181E-06 2.426E-06 3.170E-06 3.170E-06 3.173E-06 3.182E-06 3.185E-06 3.185E-06 3.185E-06 0.000E+00 SERF 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 INTACT 8.080E-06 7.883E-06 2.170E-06 8.080E-06 7.301E-06 8.329E-06 8.080E-06 8.080E-06 8.180E-06 8.080E-06 TOTAL 1.655E-05 1.458E-05 1.007E-05 1.652E-05 1.568E-05 1.614E-05 1.655E-05 1.644E-05 1.607E-05 1.336E-05
ULNRC-05919 October 17, 2012 Page 31 of 34 Table 11-1. Callaway Plant Release Category Frequency Results Obtained From SAMA Cases RELEASE CATEGORY BREAKER DC01 SW02 CCW02 CST01 ISLOCA LOSP1 DEPRESS LOCA06 HVAC LERF-IS 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 0.000E+00 1.730E-07 1.730E-07 1.730E-07 1.730E-07 LERF-CI 1.666E-10 1.658E-10 1.514E-10 1.422E-10 1.650E-10 1.658E-10 1.666E-10 1.658E-10 1.658E-10 1.658E-10 LERF-CF 1.129E-08 1.124E-08 9.088E-09 8.906E-09 1.112E-08 1.125E-08 1.113E-08 1.122E-08 1.109E-08 1.099E-08 LERF-SG 2.328E-06 2.331E-06 2.331E-06 2.331E-06 2.331E-06 2.331E-06 2.331E-06 2.331E-06 2.331E-06 2.329E-06 LERF-ITR 2.093E-07 2.170E-07 2.013E-07 2.108E-07 2.169E-07 2.170E-07 1.814E-07 2.160E-07 2.169E-07 1.944E-07 LATE-BMT 2.047E-06 2.551E-06 2.213E-06 1.864E-06 2.022E-06 2.551E-06 2.039E-06 2.508E-06 2.020E-06 1.657E-06 LATE-COP 3.210E-06 3.185E-06 8.964E-07 1.455E-06 3.185E-06 3.185E-06 2.991E-06 3.166E-06 3.185E-06 2.917E-06 SERF 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 INTACT 8.180E-06 8.080E-06 7.898E-06 7.836E-06 8.471E-06 8.080E-06 8.431E-06 8.069E-06 8.431E-06 8.312E-06 TOTAL 1.616E-05 1.655E-05 1.372E-05 1.388E-05 1.641E-05 1.638E-05 1.616E-05 1.647E-05 1.637E-05 1.559E-05
ULNRC-05919 October 17, 2012 Page 32 of 34 Table 11-1. Callaway Plant Release Category Frequency Results Obtained From SAMA Cases RELEASE CATEGORY FB01 PORV EDGFUEL FW02 SW03 HVAC02 RAI7a SLIS HEP FWCCW2 LERF-IS 1.730E-07 1.730E-07 1.730E-10 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 1.730E-07 LERF-CI 1.658E-10 1.658E-10 1.658E-10 1.658E-10 1.514E-10 1.658E-10 1.658E-10 1.658E-10 1.658E-10 1.567E-10 LERF-CF 1.094E-08 1.112E-08 1.124E-08 1.047E-08 1.031E-08 1.096E-08 1.135E-08 1.123E-08 1.080E-08 1.048E-10 LERF-SG 2.326E-06 2.331E-06 2.331E-06 2.324E-06 2.331E-06 2.331E-06 2.331E-06 2.290E-06 2.329E-06 2.317E-06 LERF-ITR 1.796E-07 2.169E-07 2.169E-07 1.659E-07 2.141E-07 2.169E-07 7.508E-08 2.138E-07 2.170E-07 2.170E-07 LATE-BMT 2.006E-06 2.022E-06 2.544E-06 1.983E-06 2.428E-06 1.990E-06 2.631E-06 2.545E-06 2.523E-06 2.467E-06 LATE-COP 3.185E-06 3.185E-06 3.182E-06 3.185E-06 2.557E-06 2.823E-06 3.235E-06 3.185E-06 3.185E-06 3.174E-06 SERF 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 0.000E+00 INTACT 8.146E-06 8.471E-06 8.078E-06 7.796E-06 7.907E-06 8.461E-06 8.119E-06 8.036E-06 7.529E-06 7.311E-06 TOTAL 1.603E-05 1.641E-05 1.636E-05 1.564E-05 1.562E-05 1.601E-05 1.658E-05 1.645E-05 1.597E-05 1.566E-05
ULNRC-05919 October 17, 2012 Page 33 of 34 Table 11-1. Callaway Plant Release Category Frequency Results Obtained From SAMA Cases RELEASE CATEGORY SBOMOD SBOmod2 4kv2 FWCCW LERF-IS 1.730E-07 1.730E-07 1.730E-07 1.730E-07 LERF-CI 1.658E-10 1.658E-10 1.658E-10 1.658E-10 LERF-CF 1.102E-08 1.102E-08 1.124E-10 1.124E-08 LERF-SG 2.331E-06 2.331E-06 2.331E-06 2.331E-06 LERF-ITR 1.628E-07 1.603E-07 2.170E-07 2.170E-07 LATE-BMT 2.485E-06 2.482E-06 2.551E-06 2.551E-06 LATE-COP 2.668E-06 2.642E-06 3.156E-06 3.184E-06 SERF 0.000E+00 0.000E+00 0.000E+00 0.000E+00 INTACT 8.046E-06 8.044E-06 8.080E-06 8.078E-06 TOTAL 1.588E-05 1.584E-05 1.651E-05 1.655E-05
ULNRC-05919 October 17, 2012 Page 34 of 34 RAI 7.b:
SAMA 64 (implement procedure and hardware modifications to allow manual alignment of the fire water system to the component cooling water system, or install a component cooling water header cross-tie) is evaluated by eliminating CCW pump failures. Consider a similar SAMA that provides fire water to the ESW system.
Callaway Response SAMA 64 was revised to evaluate the benefit of a temporary hookup of fire water as backup on loss of CCW cooling to the RHR heat exchangers. This determined the benefit to be $104K with a 95% CDF benefit of $220K. This SAMA is considered potentially cost beneficial and has been added to the list of potentially cost beneficial SAMAs.
SAMA 186 was added to evaluate procedures to provide fire water to the ESW system. This SAMA was considered potentially cost beneficial based on the 95% CDF benefit.
Implementation of this SAMA will cost significantly more than a procedure change since it would require replacement of the existing fire pumps with larger pumps.
FWCCW The CCW fault trees were modified to add fire water as a backup source of cooling to the CCW heat exchangers. The fire water pumps and system do not appear in the PRA. To simulate the use of the fire water pumps and operator actions to perform the temporary hookup, a single basic event with failure probability of 0.1 was placed in the fault trees.
This case is used to evaluate the benefit of providing a temporary hookup of fire water to the CCW heat exchangers.
Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.