ULNRC-05947, License Renewal Application, Clarification of Responses to SAMA RAIs to the License Renewal Application

License Renewal Application, Clarification of Responses to SAMA RAIs to the License Renewal Application

ML13016A171
Person / Time
Site:	Callaway
Issue date:	01/15/2013
From:	Ameren Missouri
To:	Office of Nuclear Reactor Regulation
Shared Package
ML130160235	List: ML13016A170 ULNRC-05947, License Renewal Application, Clarification of Responses to SAMA RAIs to the License Renewal Application
References
ULNRC-05947
Download: ML13016A171 (86)

Text

ULNRC-05947 January 15, 2013 Page 1 of 86 CALLAWAY PLANT UNIT 1 LICENSE RENEWAL APPLICATION CLARIFICATION OF RESPONSES TO SAMA RAIs TO THE CALLAWAY LRA

ULNRC-05947 January 15, 2013 Page 2 of 86

1. RAI 1.a The response states that for the new model, consequential loss of offsite power (LOSPs) account for 28 percent of the station blackout (SBO) frequency and only 2.5 percent of the core damage frequency (CDF). This indicates that the benefit from an SBO or LOSP mitigating SAMA should be increased to account for the omission of consequential LOSPs. Also, the impact on other SAMAs of increase in total CDF should be considered. If it is assumed that the likelihood of an SBO is the same for the consequential LOSP as it is for the LOSP initiator, the above indicates that the total SBO frequency (and therefore total LOSP frequency) is approximately 39 percent higher than the frequency due solely to the LOSP initiator alone.

Incorporating this in the Rev. 4B probabilistic risk assessment (PRA) results yields an increase in CDF of 2.17E-06 (39 percent of 5.58E-06) or 13 percent of the SAMA baseline CDF of 1.66E-05. The NRC staff plans to discuss this in the safety evaluation report (SER) and consider these factors in determining the cost-beneficial SAMAs. Based on current information, while several SAMAs are marginally cost-beneficial at the 95th percentile, considering the conservatisms in the assessment, the staff would not consider them to be cost-beneficial. This conclusion could change due to the responses to other requests for clarifications. Clarify this information.

Callaway Response This request was clarified during the call, no further response is necessary. See Reference 4.

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 3 of 86

2. RAI 2.d The response does not provide a response to the last portion of the RAI which states:

"Also, if the source terms for each release category are not bounding, then provide justification of how the impact of higher source term sequences are accounted for in determining the benefit of potential SAMAs, or provide a sensitivity analysis using bounding case source terms."

While the response indicates that both likelihood and potential offsite effects were considered for large early release frequency (LERF) categories, no details are provided, and further, for other release categories, the most likely sequence was chosen. Provide further justification that the source terms selected provide an adequate analysis of the benefit of each SAMA.

Callaway Response The representative sequences for each LERF release category considered both the likelihood and consequences, while each non-LERF release category utilized the most likely contributors.

For all release categories, the dominant Level 1 and Level 2 sequences were identified and considered down to at least a 10% contribution, sometimes less. Based on engineering judgment, none of these dominant sequences were expected to increase the consequences more than the chosen representative sequence. More severe (bounding) scenarios could have been considered, but would have a much lower frequency (at most a 10% contribution).

Therefore, for all release categories, sequences that could have had higher consequences would have much lower frequencies, and therefore not be expected to have a great effect on the SAMA results. There are no specific sensitivity runs that use truly bounding consequences for every release category.

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 4 of 86

3. RAI 5.a The response provides a description of NFPA 805 FPRA results in terms of important fire areas, scenarios and modifications identified in the 805 transition LAR. The 805 LAR modifications were included as SAMAs and considered cost-beneficial. No other fire related SAMAs were considered. It is not clear if the 805 FPRA results were reviewed to determine if there would be any further modifications that might be cost-beneficial. Provide the core damage frequency of the important fire scenarios from the NFPA FPRA. Also provide a discussion of the potential for cost-beneficial mitigation of the risk of the important fire areas and/or fire scenarios considering their contribution to the total Callaway CDF.

Callaway Response There was no formal review for SAMAs beyond the identified modifications. The NFPA-805 fire PRA was not completed at the time the SAMA analysis was performed. The fire PRA team position was that no other items should be considered under the NFPA-805 transition process, although this was not performed as a formal SAMA assessment. The Level 2 and Level 3 PRA models used to determine the benefits of SAMA items are based on PRA Update 4b. They cannot interface with the new Fire PRA without extensive modification and analysis. In addition, the NFPA-805 fire PRA is still undergoing changes due to additional plant modifications being installed.

The current Callaway fire PRA results show 14 fire scenarios that are individually greater than 1% of Fire CDF. These scenarios are listed in Enclosure 2, Table 1.

These 14 scenarios make up approximately 56% of the total fire CDF and 7 of the 14 scenarios are dominated by RCP seal LOCA with additional contributions from seal LOCA in several other scenarios. Callaway is scheduled to install the SHIELDTM (no-leakage) RCP seals (SAMA 58) in Refueling Outage 19 (RF19), Spring 2013, which will address a large percentage of the fire risk significant scenarios. In addition, the risk profile will be so significantly changed that it is not warranted to evaluate any further changes until the PRA modeling for the SHIELDTM seals is completed following RF19.

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 5 of 86

4. RAI 5.b While the response states:

"The 1999 internal flooding analysis used as a basis for the SAMA identified only one flood that was below the screening value used. After implementation of the internal flooding task force recommendations, this flood was considered an acceptable risk and no further actions were needed."

it does not discuss if the results of current internal flooding analysis were reviewed to identify potential cost-beneficial SAMAs. The Update 5 internal flooding analysis CDF of 6.21E-06 is sufficiently large that cost-beneficial SAMAs for important flood sequences are possible.

Mitigating an internal flood scenario that has a CDF of approximately 1.1E-06, or 18% of the new internal flood total CDF, would be cost-beneficial at the 95th percentile at the minimum hardware cost of $100,000. A flood scenario with a CDF of 1.8E-07, or 2.8% of the new internal flood CDF, would be cost-beneficial at the minimum procedure cost of $15,000. Provide the CDF of the important internal flooding scenarios or sequences from the Update 5 internal flooding analysis and a discussion of the potential for their cost-beneficial mitigation considering their contribution to the total Callaway CDF.

Callaway Response The Update 5 Internal Flooding analysis was not reviewed in detail to identify potential cost-beneficial SAMAs. This flooding analysis was not available at the time the SAMA analysis was performed. The Update 5 Internal Flooding analysis is based on a significantly different PRA model than the model used to calculate the SAMA benefits. In order to determine benefits from the Update 5 PRA, the full Level 2 PRA model and Level 3 PRA models would require extensive modification.

The current Callaway Internal Flooding analysis results show 17 flooding scenarios that are greater than 1% of Flooding CDF. These scenarios are listed in Enclosure 2, Table 2.

These 17 scenarios make up approximately 70% of the total internal flooding CDF, some of which are primarily seal LOCA events with additional seal LOCA impact in other scenarios.

Although no formal SAMA exists specifically for seal LOCA flood zones, original SAMA 58 is applicable. Callaway is scheduled to install the SHIELDTM (no-leakage) RCP seals in Refueling Outage 19 (RF19), Spring 2013, which will address associated internal flooding scenarios. The risk profile will be changed to the extent that it is not warranted to evaluate any further changes until the PRA modeling for the SHIELDTM seals is completed following RF19.

SAMA 160, modification to change the impact of flooding through the Control Building dumbwaiter, was added while the internal flooding analysis was still being performed.

Personnel participating in the internal flooding analysis had identified this flood path as potentially risk significant and having a low cost of implementation. These personnel also participated in the SAMA Expert Panel Review and added this item to the list of SAMAs.

Analysis is currently underway to determine a more realistic flood height capability for certain plant doors affecting internal flooding. It would limit flood propagation if the evaluation shows the doors are currently capable of higher flood heights or if these doors could be modified to increase their capability to a certain critical flood height. The results of the analysis will be

ULNRC-05947 January 15, 2013 Page 6 of 86 considered for implementation as potentially cost-beneficial. This analysis has been added as SAMA 189. This SAMA is considered potentially cost-beneficial due to management having directed that the analysis proceed. Tables 5-1, 6-1, 7-1, 8-1, and 9-1 have been updated to include SAMA 189. These updated tables are included at the end of this enclosure.

In addition to these specific flooding SAMA items, numerous SAMA items generically address loss of equipment impacted by floods in the flood zones listed in Enclosure 2, Table 2.

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 7 of 86

5. RAI 6.c A new SBO value of 7.85E-07 compared to the earlier (and repeated value in the response to 1.a) of 4.71E-06 is given. Neither is consistent with that inferred from SAMA 2 Case NOSBO of 2.0E-06 (12% of 1.66E-05). The elimination of SBO sequences from the SAMA model resulting from Case NOSBO should have the same percent reduction in CDF as the SBO contribution to the total SAMA model CDF. If the SBO of 7.85E-07 is correct this is 4.73 % compared to the Case 2 result of 12.1%. Provide an explanation of why the Case NOSBO reduction in CDF is different from the correct SBO contribution to the total CDF.

Callaway Response The original case NOSBO (2.0E-06/yr) considered only failures of the diesel generators. The case did not consider failure of the diesel generators due to support systems. This caused Case NOSBO to underestimate the potential benefit of elimination of all EDG failures. However, this case also did not consider recovery of AC power from the Alternate Emergency Power System (AEPS) given failure of the onsite diesel generators. Thus, this case represented failures of the EDGs and sequences initially recovered by power from AEPS. In a large percentage of the cases loss of onsite AC power is recovered through the AEPS, and so this had an appreciable impact on the results. The SBO related CDF of 7.85E-07/yr represents failure of the EDGs, including those from EDG support systems, without sequences where power is recovered from AEPS.

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 8 of 86

6. RAI 7.b The revised response indicated that the evaluation of SAMA 186, to evaluate procedures to provide fire water to the ESW system, was changed from SW02 (no failure of ESW pumps) to FWCCW (add fire water as a backup source of cooling to the CCW heat exchangers) and resulted in a decrease in benefit from $635K to $1K). It would appear that SW02 better represents the benefit of this SAMA. Justify the selection of Case FWCCW.

Callaway Response Case SW02 applies to all loads supplied by ESW, including the EDGs, not just the CCW heat exchangers. Emergency procedures are already in place to provide backup cooling to the EDGs using onsite fire trucks in the event that ESW cooling is lost. Case FWCCW evaluates the specific benefit of providing fire water for cooling only the CCW system heat exchangers.

This is because SAMA 186 was intended to evaluate providing backup cooling to only the CCW heat exchanger loads.

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 9 of 86

7. RAI 1.a

i. The SBO value given of 4.71E-6 is different from that given in the response to 6.c of 7.85E-07, which states that the earlier value in incorrect. Provide the correct value for the frequency of total loss of AC power to the station. (See also the question concerning RAI 6.c above.)

ii. In the last sentence of the response, clarify whether or not the internal flood induced ATWS and SBO sequences are included in the ATWS (3.14E-7) and SBO (4.71 E-6) values quoted earlier in the response.

Callaway Response

i. The 4.71E-6/yr value included in the response to 1.a included sequences where AC power was recovered from the Alternate Emergency Power System (AEPS). The correct CDF value for total loss of AC power is 7.85E-07/yr.

ii. The frequencies of the internal flood induced ATWS and SBO sequences are included in the total internal flood CDF but are not included in the ATWS (3.14E-7) and SBO (7.85E-

07) values.

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 10 of 86

8. RAI 6.d Case FW02 eliminates failure of all feedwater (FW) check valves and had a CDF reduction of 5.5 percent. Common cause (CC) failure of the 4 main feedwater (MFW) check valves (AEV 120 -123) is listed along with failures of individual valves. Not listed is CC failure of 4 check valves (AEV 124 -127) from motor-driven auxiliary feedwater (MDAFW). Results of the importance analysis appear to indicate that this later failure was included in this case since it gives the 5.5 percent results. Clarify this information.

Callaway Response Case FW02 included the individual and common cause failures of valves AEV 124-127 in addition to AEV 120-123.

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 11 of 86

9. RAI 6.g The response states that:

"For SAMAs 1, 2, and 5 in addition to the TDAFW pump dependency, loss of DC impacts the availability of instrumentation. Emergency Coordinator Supplemental Guidelines exist for the use of portable generators to provide backup power on extended SBO events. This backup portable power is not credited in the PRA."

It is not clear that the availability of this backup source of power and these guidelines would reduce the benefit of SAMA 5, DC bus cross-ties, revised to include the impact on instrumentation, to such an extent that this SAMA would not be cost-beneficial. Provide a discussion of the impact on the benefit for SAMA 5 of including the mitigation of the loss of DC instrumentation and a further justification for the evaluation of SAMA 5.

Callaway Response The instrumentation powered by DC power is not directly modeled in the PRA. The procedural guidance in the Emergency Coordinator supplemental guidelines provides for installation of a portable generator to provide power to the battery charges. This provides a greater benefit than a cross-tie to another battery. A battery cross-tie only extends the availability of the DC bus until the second battery depletes. Use of a portable generator provides DC power availability as long as fuel is available for the generator. Callaway is currently developing additional guidance on the prolonged use of portable generators as part of the post Fukushima response. Use of the generator provides a greater benefit in prolonged SBO conditions that would deplete both the primary and the cross-tied battery.

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 12 of 86

10. RAI 6.q Relative to RCP seal modeling and a SAMA to use improved seals, Case RCPLOCA gives a 5.5% reduction in CDF for SAMAs 55, 56 and 58. This seems low compared to that for other plants and it should be different for both SAMAs 55 which includes a dedicated diesel and therefore mitigates RCP seal LOCAs for an SBO and SAMA 58 which is for new improved seals which should also be beneficial for SBOs then for SAMA 56 which doesn't mitigate against an SBO. The response to RAI 6.q says this case eliminates all RCP seal LOCA events that are caused by failure of seal cooling and injection except those which occur as a result of a support system initiating event such as loss of CCW. The Loss of CCW and Loss of SW add up to 1.4%

of the CDF. Is mitigation of RCP seal failure due loss of AC power (SBO) considered in the case? If not, justify this approach and assess the impact on the benefit of these SAMAs.

Callaway Response The existence of the AEPS and the non-safety auxiliary feedwater pump reduced the risk associated with RCP seal failures. The additional AC power source and cooling ability provided by these modifications already reduce the probability of RCP seal failure and thus the relative reduction in overall risk due to elimination of seal LOCAs is not as significant as it is for plants that do not have these modifications installed.

In addition, the modeling of case RCPLOCA was examined in more detail. It was determined that this case did not include those RCP seal LOCA events that were hard coded in the event tree logic. The original case included RCP seal failures due to LOSP and SBO, but did not include seal failures due to loss of CCW or loss of all service water initiating events. No re-evaluation of this case was performed since Callaway is scheduled to install the SHIELDTM (no-leakage) RCP seals in RF19, Spring 2013, which will address a large percentage of the risk due to failure of RCP seals. In addition, the risk profile will be so significantly changed that it is not warranted to evaluate any further changes until the PRA modeling for the SHIELDTM seals is completed following RF19.

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 13 of 86

11. RAI Table 7-1 A number of the percent reductions in offsite dose risk in Table 7-1 are given as 0.00%. Does this mean that there is no reduction (i.e. zero) or that it is less than 0.005%? For several cases where 0.00% is given we believe that 0.00% is in error. Please provide the necessary corrections.

Callaway Response All values for offsite dose reduction that are shown in the Table 7-1 as 0.00% are actually less than 0.005%; the rounding to two decimal places causes them to be displayed as 0.00%

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 14 of 86

12. RAI 5.d The Oct. 18 revised response to this RAI indicated that automating the initiation of CCW flow to the RHR heat exchangers was now considered cost-beneficial with a 95th percentile benefit of

$132K and a cost of $200K. Explain.

Callaway Response During the expert panel discussion of this item, it was noted that Wolf Creek had implemented this modification and felt it to be beneficial. Even though the estimated cost was greater than the calculated benefit, Callaway management believes it to be beneficial in areas outside the SAMA and thus close enough to be considered potentially cost beneficial.

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 15 of 86

13. RAI 6.j The response provides a description of SAMA Case LOCA 12 used to evaluate SAMAs 25, 26, and 39 which include passive or independently powered injection systems. The calculated benefit does not include that associated with loss of AC power. This would appear to be non-conservative for at least those SAMAs which do not rely on AC power. Discuss the impact of this non-conservatism.

Callaway Response The original LOCA12 case considered only the failures of the HPI and charging pumps and did not consider the loss of AC power which would be mitigated by SAMA items which provided independent AC power. This case was revised to modify the fault trees for the HPI pumps and charging pumps to remove the dependencies on AC power, room cooling, and cooling water from those pumps. The revised case results in a 22.61% reduction in Offsite Economic Cost Risk (OECR). With a benefit of $616K and a 95% CDF benefit of $1.3M, SAMAs 25, 26, and 39 are still considered not cost-beneficial.

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 16 of 86

14. RAI 7.a

i. The discussion of Wolf Creek SAMAs 1 and 14 indicate that the AEPS has a spare breaker that could be used to supply the loads in these SAMAs. Our understanding is that credit for the AEPS to supply plant loads is already included in the Callaway PRA and thus what is included in new Callaway SAMAs 187 and 188 and the resulting benefit is not clear. The analysis cases used to evaluate these SAMAs (SBOMOD and SBOMOD2) both reduce the SBO frequency due to the benefit of the added availability of AC power to certain equipment. Depending on the function of the AEPS and the definition of SBO, it is possible that if credit for the AEPS is already given it must have failed in order for there to be an SBO. Explain the credit for AEPS, the description of these SAMAs and the benefit calculation.

ii. In the discussion of Wolf Creek SAMA 3, Case 4KV, used to evaluate the benefit of revised SAMA 11 (to prepare procedures for using existing equipment to cross-tie 4kV busses), is described as resolving SBO sequences assuming a 0.05 failure rate for the cross-tie then removing this failure event from cutsets involving failure of both emergency diesel generators. Exactly what this accomplished is not clear since all SBO sequences must involve failure of both emergency diesel generators (EDGs). Clarify this information.

Callaway Response

i. The PRA contains modeling for AEPS to supply those plant loads that are capable of obtaining power from AEPS. Not all plant equipment is able to obtain power from AEPS.

Implementing these SAMAs by the installation of an additional diesel generator were shown to not be cost beneficial. Plant personnel proposed using the spare AEPS supply circuit breaker as a lower cost alternative of accomplishing a similar function. The use of the spare AEPS supply circuit breaker is considered to be potentially cost beneficial.

ii. This SAMA case was revised. This case first generated a fault tree reflecting loss of offsite power conditions along with the major component failure combinations that would fail both EDGs or both ESW trains. This fault tree was quantified and the resultant cutsets were removed from the total internal events core damage, LERF, and Late release cutset equations. The resulting files included those core damage cutsets where consideration of an AC bus cross-tie might reasonably provide some benefit.

The total internal events core damage frequency is 1.655E-05/yr. Removal of loss of offsite power cutsets where both EDGs or both ESW trains fail results in a core damage frequency of 1.264E-05/yr.

It was assumed that an AC bus cross-tie would have a failure probability on the order of 5.0E-02. This factor was applied to all remaining cutsets which included failure of an EDG. This resulted in a final core damage frequency of 1.225E-05/yr.

The benefit due to addition on an AC bus cross-tie would therefore be approximately 3.9E-07/yr (1.264E 1.225E-05). This equates to a benefit of $75K with a 95%

ULNRC-05947 January 15, 2013 Page 17 of 86 uncertainty benefit of $159K. Based on Wolf Creeks estimated implementation cost of

$330K, installation of an AC power cross-tie would not be cost beneficial.

Corresponding Amendment Changes No changes to the License Renewal Application (LRA) are needed as a result of this response.

ULNRC-05947 January 15, 2013 Page 18 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Extended DC power availability during an SBO station 1 Provide additional DC battery capacity. AC/DC 1 blackout (SBO).

2 Replace lead-acid batteries with fuel cells. Extended DC power availability during an SBO. AC/DC 1 Add additional battery charger or portable, diesel-driven battery 3 Improved availability of DC power system. AC/DC 1 charger to existing DC system.

4 Improve DC bus load shedding. Extended DC power availability during an SBO. AC/DC 1 5 Provide DC bus cross-ties. Improved availability of DC power system. AC/DC 1 6 Provide additional DC power to the 120/240V vital AC system. Increased availability of the 120 V vital AC bus. AC/DC 1 Add an automatic feature to transfer the 120V vital AC bus from 7 Increased availability of the 120 V vital AC bus. AC/DC 1 normal to standby power.

Increase training on response to loss of two 120V AC buses which Improved chances of successful response to loss of two 8 AC/DC 1 causes inadvertent actuation signals. 120V AC buses.

9 Provide an additional diesel generator. Increased availability of on-site emergency AC power. AC/DC 1 10 Revise procedure to allow bypass of diesel generator trips. Extended diesel generator operation. AC/DC 1 11 Improve 4.16-kV bus cross-tie ability. Increased availability of on-site AC power. AC/DC 1 12 Create AC power cross-tie capability with other unit (multi-unit site) Increased availability of on-site AC power. AC/DC 1 13 Install an additional, buried off-site power source. Reduced probability of loss of off-site power. AC/DC 1 14 Install a gas turbine generator. Increased availability of on-site AC power. AC/DC 1 15 Install tornado protection on gas turbine generator. Increased availability of on-site AC power. AC/DC 1 Increased availability of power supplies supporting front-16 Improve uninterruptible power supplies. AC/DC 1 line equipment.

17 Create a cross-tie for diesel fuel oil (multi-unit site). Increased diesel generator availability. AC/DC 1 18 Develop procedures for replenishing diesel fuel oil. Increased diesel generator availability. AC/DC 1 19 Use fire water system as a backup source for diesel cooling. Increased diesel generator availability. AC/DC 1 Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 19 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number 20 Add a new backup source of diesel cooling. Increased diesel generator availability. AC/DC 1 Increased probability of recovery from failure of breakers 21 Develop procedures to repair or replace failed 4 KV breakers. that transfer 4.16 kV non-emergency buses from unit AC/DC 1 station service transformers.

In training, emphasize steps in recovery of off-site power after an Reduced human error probability during off-site power 22 AC/DC 1 SBO. recovery.

Improved off-site power recovery following external 23 Develop a severe weather conditions procedure. AC/DC 1 weather-related events.

Improved off-site power reliability during severe 24 Bury off-site power lines. AC/DC 1 weather.

Install an independent active or passive high pressure injection Core 25 Improved prevention of core melt sequences. 1 system. Cooling Provide an additional high pressure injection pump with independent Reduced frequency of core melt from small LOCA and Core 26 1 diesel. SBO sequences. Cooling Revise procedure to allow operators to inhibit automatic vessel Core 27 Extended HPCI and RCIC operation. 1 depressurization in non-ATWS scenarios. Cooling Core 28 Add a diverse low pressure injection system. Improved injection capability. 1 Cooling Core 29 Provide capability for alternate injection via diesel-driven fire pump. Improved injection capability. 1 Cooling Core 30 Improve ECCS suction strainers. Enhanced reliability of ECCS suction. 1 Cooling Add the ability to manually align emergency core cooling system Core 31 Enhanced reliability of ECCS suction. 1 recirculation. Cooling Add the ability to automatically align emergency core cooling system Core 32 Enhanced reliability of ECCS suction. 1 to recirculation mode upon refueling water storage tank depletion. Cooling Extended reactor water storage tank capacity in the Provide hardware and procedure to refill the reactor water storage Core 33 event of a steam generator tube rupture (or other 1 tank once it reaches a specified low level. Cooling LOCAs challenging RWST capacity).

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 20 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Continuous source of water to the safety injection pumps during a LOCA event, since water released from a breach of the primary system collects in the in- Core 34 Provide an in-containment reactor water storage tank. 1 containment reactor water storage tank, and thereby Cooling eliminates the need to realign the safety injection pumps for long-term post-LOCA recirculation.

Throttle low pressure injection pumps earlier in medium or large- Core 35 Extended reactor water storage tank capacity. 1 break LOCAs to maintain reactor water storage tank inventory. Cooling Reduced human error probability associated with Core 36 Emphasize timely recirculation alignment in operator training. 1 recirculation failure. Cooling For a plant like the Westinghouse AP600, where the Upgrade the chemical and volume control system to mitigate small chemical and volume control system cannot mitigate a Core 37 1 LOCAs. small LOCA, an upgrade would decrease the frequency Cooling of core damage.

Change the in-containment reactor water storage tank suction from Core 38 Reduced common mode failure of injection paths. 1 four check valves to two check and two air-operated valves. Cooling Reduced common cause failure of the safety injection system. This SAMA was originally intended for the Replace two of the four electric safety injection pumps with diesel- Core 39 Westinghouse-CE System 80+, which has four trains of 1 powered pumps. Cooling safety injection. However, the intent of this SAMA is to provide diversity within the high- and l Improved chance of successful operation during station Provide capability for remote, manual operation of secondary side Core 40 blackout events in which high area temperatures may be 1 pilot-operated relief valves in a station blackout. Cooling encountered (no ventilation to main steam areas).

Allows low pressure emergency core cooling system Core 41 Create a reactor coolant depressurization system. injection in the event of small LOCA and high-pressure 1 Cooling safety injection failure.

Allows low pressure emergency core cooling system Make procedure changes for reactor coolant system Core 42 injection in the event of small LOCA and high-pressure 1 depressurization. Cooling safety injection failure.

Cooling 43 Add redundant DC control power for SW pumps. Increased availability of SW. 1 Water Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 21 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Elimination of ECCS dependency on component cooling Cooling 44 Replace ECCS pump motors with air-cooled motors. 1 system. Water Enhance procedural guidance for use of cross-tied component Reduced frequency of loss of component cooling water Cooling 45 1 cooling or service water pumps. and service water. Water Cooling 46 Add a service water pump. Increased availability of cooling water. 1 Water Reduced potential for loss of SW due to clogging of Cooling 47 Enhance the screen wash system. 1 screens. Water Reduced frequency of loss of component cooling water Cap downstream piping of normally closed component cooling water initiating events, some of which can be attributed to Cooling 48 1 drain and vent valves. catastrophic failure of one of the many single isolation Water valves.

Enhance loss of component cooling water (or loss of service water) Reduced potential for reactor coolant pump seal Cooling 49 1 procedures to facilitate stopping the reactor coolant pumps. damage due to pump bearing failure. Water Enhance loss of component cooling water procedure to underscore Cooling 50 the desirability of cooling down the reactor coolant system prior to Reduced probability of reactor coolant pump seal failure. 1 Water seal LOCA.

Improved success of operator actions after a loss of Cooling 51 Additional training on loss of component cooling water. 1 component cooling water. Water Reduced effect of loss of component cooling water by Provide hardware connections to allow another essential raw cooling Cooling 52 providing a means to maintain the charging pump seal 1 water system to cool charging pump seals. Water injection following a loss of normal cooling water.

On loss of essential raw cooling water, proceduralize shedding Increased time before loss of component cooling water Cooling 53 component cooling water loads to extend the component cooling (and reactor coolant pump seal failure) during loss of 1 Water water heat-up time. essential raw cooling water sequences.

Increased time before charging pump failure due to lube Cooling 54 Increase charging pump lube oil capacity. 1 oil overheating in loss of cooling water sequences. Water Reduced frequency of core damage from loss of Install an independent reactor coolant pump seal injection system, Cooling 55 component cooling water, service water, or station 1 with dedicated diesel. Water blackout.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 22 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Reduced frequency of core damage from loss of Install an independent reactor coolant pump seal injection system, Cooling 56 component cooling water or service water, but not a 1 without dedicated diesel. Water station blackout.

Reduced frequency of core damage from loss of component cooling water or service water, but not a Cooling 57 Use existing hydro test pump for reactor coolant pump seal injection. 1 station blackout, unless an alternate power source is Water used.

Cooling 58 Install improved reactor coolant pump seals. Reduced likelihood of reactor coolant pump seal LOCA. 1 Water Reduced likelihood of loss of component cooling water Cooling 59 Install an additional component cooling water pump. 1 leading to a reactor coolant pump seal LOCA. Water Reduced frequency of loss of reactor coolant pump seal cooling if spurious high pressure injection relief valve Cooling 60 Prevent makeup pump flow diversion through the relief valves. 1 opening creates a flow diversion large enough to Water prevent reactor coolant pump seal injection.

Change procedures to isolate reactor coolant pump seal return flow Reduced frequency of core damage due to loss of seal Cooling 61 on loss of component cooling water, and provide (or enhance) 1 cooling. Water guidance on loss of injection during seal LOCA.

Implement procedures to stagger high pressure safety injection Extended high pressure injection prior to overheating Cooling 62 1 pump use after a loss of service water. following a loss of service water. Water Use fire prevention system pumps as a backup seal injection and Cooling fa63 Reduced frequency of reactor coolant pump seal LOCA. 1 high pressure makeup source. Water Implement procedure and hardware modifications to allow manual Improved ability to cool residual heat removal heat Cooling 64 alignment of the fire water system to the component cooling water 1 exchangers. Water system, or install a component cooling water header cross-tie.

Reduced chance of loss of main feed water following a Feedwater/C 65 Install a digital feed water upgrade. 1 plant trip. ondensate Create ability for emergency connection of existing or new water Feedwater/C 66 Increased availability of feedwater. 1 sources to feedwater and condensate systems. ondensate Install an independent diesel for the condensate storage tank Feedwater/C 67 Extended inventory in CST during an SBO. 1 makeup pumps. ondensate Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 23 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Feedwater/C 68 Add a motor-driven feedwater pump. Increased availability of feedwater. 1 ondensate Install manual isolation valves around auxiliary feedwater turbine- Reduced dual turbine-driven pump maintenance Feedwater/C 69 1 driven steam admission valves. unavailability. ondensate Eliminates the need for local manual action to align Install accumulators for turbine-driven auxiliary feedwater pump flow Feedwater/C 70 nitrogen bottles for control air following a loss of off-site 1 control valves. ondensate power.

Install a new condensate storage tank (auxiliary feedwater storage Feedwater/C 71 Increased availability of the auxiliary feedwater system. 1 tank). ondensate Feedwater/C 72 Modify the turbine-driven auxiliary feedwater pump to be self-cooled. Improved success probability during a station blackout. 1 ondensate Extended auxiliary feedwater availability during a station Proceduralize local manual operation of auxiliary feedwater system blackout. Also provides a success path should auxiliary Feedwater/C 73 1 when control power is lost. feedwater control power be lost in non-station blackout ondensate sequences.

Provide hookup for portable generators to power the turbine-driven Feedwater/C 74 Extended auxiliary feedwater availability. 1 auxiliary feedwater pump after station batteries are depleted. ondensate Feedwater/C 75 Use fire water system as a backup for steam generator inventory. Increased availability of steam generator water supply. 1 ondensate Allows greater inventory for the auxiliary feedwater Change failure position of condenser makeup valve if the condenser Feedwater/C 76 pumps by preventing condensate storage tank flow 1 makeup valve fails open on loss of air or power. ondensate diversion to the condenser.

Provide a passive, secondary-side heat-rejection loop consisting of a Reduced potential for core damage due to loss-of- Feedwater/C 77 1 condenser and heat sink. feedwater events. ondensate Modify the startup feedwater pump so that it can be used as a Feedwater/C 78 backup to the emergency feedwater system, including during a Increased reliability of decay heat removal. 1 ondensate station blackout scenario.

Replace existing pilot-operated relief valves with larger ones, such Feedwater/C 79 Increased probability of successful feed and bleed. 1 that only one is required for successful feed and bleed. ondensate Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 24 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Increased availability of components dependent on 80 Provide a redundant train or means of ventilation. HVAC 1 room cooling.

Add a diesel building high temperature alarm or redundant louver 81 Improved diagnosis of a loss of diesel building HVAC. HVAC 1 and thermostat.

Increased availability of ventilation in the event of a loss 82 Stage backup fans in switchgear rooms. HVAC 1 of switchgear ventilation.

83 Add a switchgear room high temperature alarm. Improved diagnosis of a loss of switchgear HVAC. HVAC 1 Create ability to switch emergency feedwater room fan power supply 84 Continued fan operation in a station blackout. HVAC 1 to station batteries in a station blackout.

Provide cross-unit connection of uninterruptible compressed air Increased ability to vent containment using the 85 IA/Nitrogen 1 supply. hardened vent.

Modify procedure to provide ability to align diesel power to more air 86 Increased availability of instrument air after a LOOP. IA/Nitrogen 1 compressors.

Replace service and instrument air compressors with more reliable Elimination of instrument air system dependence on 87 compressors which have self-contained air cooling by shaft driven IA/Nitrogen 1 service water cooling.

fans.

88 Install nitrogen bottles as backup gas supply for safety relief valves. Extended SRV operation time. IA/Nitrogen 1 89 Improve SRV and MSIV pneumatic components. Improved availability of SRVs and MSIVs. IA/Nitrogen 1 Enhanced debris cool ability, reduced core concrete Containment 90 Create a reactor cavity flooding system. 1 interaction, and increased fission product scrubbing. Phenomena Containment 91 Install a passive containment spray system. Improved containment spray capability. 1 Phenomena Use the fire water system as a backup source for the containment Containment 92 Improved containment spray capability. 1 spray system. Phenomena Increased decay heat removal capability for non-ATWS Containment 93 Install an unfiltered, hardened containment vent. 1 events, without scrubbing released fission products. Phenomena Install a filtered containment vent to remove decay heat. Option 1: Increased decay heat removal capability for non-ATWS Containment 94 1 Gravel Bed Filter; Option 2: Multiple Venturi Scrubber events, with scrubbing of released fission products. Phenomena Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 25 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Enhance fire protection system and standby gas treatment system Containment 95 Improved fission product scrubbing in severe accidents. 1 hardware and procedures. Phenomena Reduced likelihood of hydrogen and carbon monoxide Containment 96 Provide post-accident containment inerting capability. 1 gas combustion. Phenomena Increased cooling and containment of molten core debris. Molten core debris escaping from the vessel is Create a large concrete crucible with heat removal potential to Containment 97 contained within the crucible and a water cooling 1 contain molten core debris. Phenomena mechanism cools the molten core in the crucible, preventing melt-through of the base mat.

Increased cooling and containment of molten core debris. Refractory material would be placed underneath the reactor vessel such that a molten core falling on the Containment 98 Create a core melt source reduction system. material would melt and combine with the material. 1 Phenomena Subsequent spreading and heat removal from the vitrified compound would be facilitated, and concrete attack would not occur.

Strengthen primary/secondary containment (e.g., add ribbing to Containment 99 Reduced probability of containment over-pressurization. 1 containment shell). Phenomena Increase depth of the concrete base mat or use an alternate Containment 100 Reduced probability of base mat melt-through. 1 concrete material to ensure melt-through does not occur. Phenomena Increased potential to cool a molten core before it Containment 101 Provide a reactor vessel exterior cooling system. causes vessel failure, by submerging the lower head in 1 Phenomena water.

Construct a building to be connected to primary/secondary Containment 102 Reduced probability of containment over-pressurization. 1 containment and maintained at a vacuum. Phenomena Improved arrest of core melt progress and prevention of Containment 103 Institute simulator training for severe accident scenarios. 1 containment failure. Phenomena Increased piping surveillance to identify leaks prior to Containment 104 Improve leak detection procedures. complete failure. Improved leak detection would reduce 1 Phenomena LOCA frequency.

Containment 105 Delay containment spray actuation after a large LOCA. Extended reactor water storage tank availability. 1 Phenomena Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 26 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Extended time over which water remains in the reactor Containment 106 Install automatic containment spray pump header throttle valves. water storage tank, when full containment spray flow is 1 Phenomena not needed.

Containment 107 Install a redundant containment spray system. Increased containment heat removal ability. 1 Phenomena Install an independent power supply to the hydrogen control system using either new batteries, a non-safety grade portable generator, Containment 108 Reduced hydrogen detonation potential. 1 existing station batteries, or existing AC/DC independent power Phenomena supplies, such as the security system diesel.

Containment 109 Install a passive hydrogen control system. Reduced hydrogen detonation potential. 1 Phenomena Erect a barrier that would provide enhanced protection of the Containment 110 containment walls (shell) from ejected core debris following a core Reduced probability of containment failure. 1 Phenomena melt scenario at high pressure.

Install additional pressure or leak monitoring instruments for Containment 111 Reduced ISLOCA frequency. 1 detection of ISLOCAs. Bypass Add redundant and diverse limit switches to each containment Reduced frequency of containment isolation failure and Containment 112 1 isolation valve. ISLOCAs. Bypass Containment 113 Increase leak testing of valves in ISLOCA paths. Reduced ISLOCA frequency. 1 Bypass Containment 114 Install self-actuating containment isolation valves. Reduced frequency of isolation failure. 1 Bypass Containment 115 Locate residual heat removal (RHR) inside containment Reduced frequency of ISLOCA outside containment. 1 Bypass Ensure ISLOCA releases are scrubbed. One method is to plug Containment 116 drains in potential break areas so that break point will be covered Scrubbed ISLOCA releases. 1 Bypass with water.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 27 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Increased likelihood that LOCAs outside containment are identified as such. A plant had a scenario in which Containment 117 Revise EOPs to improve ISLOCA identification. an RHR ISLOCA could direct initial leakage back to the 1 Bypass pressurizer relief tank, giving indication that the LOCA was inside containment.

Containment 118 Improve operator training on ISLOCA coping. Decreased ISLOCA consequences. 1 Bypass Institute a maintenance practice to perform a 100% inspection of Containment 119 Reduced frequency of steam generator tube ruptures. 1 steam generator tubes during each refueling outage. Bypass Containment 120 Replace steam generators with a new design. Reduced frequency of steam generator tube ruptures. 1 Bypass Increase the pressure capacity of the secondary side so that a steam Eliminates release pathway to the environment following Containment 121 1 generator tube rupture would not cause the relief valves to lift. a steam generator tube rupture. Bypass Install a redundant spray system to depressurize the primary system Enhanced depressurization capabilities during steam Containment 122 1 during a steam generator tube rupture generator tube rupture. Bypass Backup method to using pressurizer sprays to reduce Proceduralize use of pressurizer vent valves during steam generator Containment 123 primary system pressure following a steam generator 1 tube rupture sequences. Bypass tube rupture.

Provide improved instrumentation to detect steam generator tube Containment 124 Improved mitigation of steam generator tube ruptures. 1 ruptures, such as Nitrogen-16 monitors). Bypass Route the discharge from the main steam safety valves through a Reduced consequences of a steam generator tube Containment 125 structure where a water spray would condense the steam and 1 rupture. Bypass remove most of the fission products.

Install a highly reliable (closed loop) steam generator shell-side heat Reduced consequences of a steam generator tube Containment 126 removal system that relies on natural circulation and stored water 1 rupture. Bypass sources Revise emergency operating procedures to direct isolation of a Reduced consequences of a steam generator tube Containment 127 1 faulted steam generator. rupture. Bypass Direct steam generator flooding after a steam generator tube Improved scrubbing of steam generator tube rupture Containment 128 1 rupture, prior to core damage. releases. Bypass Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 28 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Reduced consequences of a steam generator tube Containment 129 Vent main steam safety valves in containment. 1 rupture. Bypass 130 Add an independent boron injection system. Improved availability of boron injection during ATWS. ATWS 1 Add a system of relief valves to prevent equipment damage from 131 Improved equipment availability after an ATWS. ATWS 1 pressure spikes during an ATWS.

132 Provide an additional control system for rod insertion (e.g., AMSAC). Improved redundancy and reduced ATWS frequency. ATWS 1 Install an ATWS sized filtered containment vent to remove decay Increased ability to remove reactor heat from ATWS 133 ATWS 1 heat. events.

Affords operators more time to perform actions.

Discharge of a substantial fraction of steam to the main condenser (i.e., as opposed to into the primary Revise procedure to bypass MSIV isolation in turbine trip ATWS 134 containment) affords the operator more time to perform ATWS 1 scenarios.

actions (e.g., SLC injection, lower water level, depressurize RPV) than if the main condenser was unavailable, resulting in lower human error probabilities.

Allows immediate control of low pressure core injection.

On failure of high pressure core injection and Revise procedure to allow override of low pressure core injection 135 condensate, some plants direct reactor depressurization ATWS 1 during an ATWS event.

followed by five minutes of automatic low pressure core injection.

136 Install motor generator set trip breakers in control room. Reduced frequency of core damage due to an ATWS. ATWS 1 Decreased time required to insert control rods if the Provide capability to remove power from the bus powering the 137 reactor trip breakers fail (during a loss of feedwater ATWS 1 control rods.

ATWS which has rapid pressure excursion).

Reduced frequency of internal flooding due to failure of Internal 138 Improve inspection of rubber expansion joints on main condenser. 1 circulating water system expansion joints. Flooding Modify swing direction of doors separating turbine building basement Internal 139 Prevents flood propagation. 1 from areas containing safeguards equipment. Flooding Increased availability of necessary plant equipment 140 Increase seismic ruggedness of plant components. Seismic Risk 1 during and after seismic events.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 29 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Increased availability of fire protection given a seismic 141 Provide additional restraints for CO2 tanks. Seismic Risk 1 event.

Decreased probability of spurious fire suppression 142 Replace mercury switches in fire protection system. Fire Risk 1 system actuation.

143 Upgrade fire compartment barriers. Decreased consequences of a fire. Fire Risk 1 144 Install additional transfer and isolation switches. Reduced number of spurious actuations during a fire. Fire Risk 1 145 Enhance fire brigade awareness. Decreased consequences of a fire. Fire Risk 1 146 Enhance control of combustibles and ignition sources. Decreased fire frequency and consequences. Fire Risk 1 Reduced probability of a large break LOCA (a leak 147 Install digital large break LOCA protection system. Other 1 before break).

148 Enhance procedures to mitigate large break LOCA. Reduced consequences of a large break LOCA. Other 1 Install computer aided instrumentation system to assist the operator Improved prevention of core melt sequences by making 149 Other 1 in assessing post-accident plant status. operator actions more reliable.

Improved prevention of core melt sequences by 150 Improve maintenance procedures. Other 1 increasing reliability of important equipment.

Increase training and operating experience feedback to improve Improved likelihood of success of operator actions taken 151 Other 1 operator response. in response to abnormal conditions.

Reduced consequences of transportation and nearby 152 Develop procedures for transportation and nearby facility accidents. Other 1 facility accidents.

Prevents secondary side depressurization should a steam line break occur upstream of the main steam Install secondary side guard pipes up to the main steam isolation 153 isolation valves. Also guards against or prevents Other 1 valves.

consequential multiple steam generator tube ruptures following a main steam line break event.

Reduces failure probability of MCCs during an IPEEE -

154 Mount or anchor the MCCs to the respective building walls. B earthquake Seismic Takes up the shear load on the pump and/or driver IPEEE -

155 Install shear pins (or strength bolts) in the AFW pumps. B during an earthquake. Seismic Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 30 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Mount all fire extinguishers within their UL Standard required drop Reduces the potential for the fire extinguishers to fall IPEEE -

156 height and remove hand-held fire extinguishers from Containment during an earthquake and potentially fracturing upon B Seismic during normal operation. impact with the floor or another object.

Ensures direct access to areas such as Load Shedding and Emergency Load Sequencing (LSELS) and Identify and remove unsecured equipment near areas that contain Engineered Safety Feature Actuation IPEEE -

157 B relays that actuate, so area is kept clear. System (ESFAS) cabinets. Unsecured equipment (e.g., Seismic carts, filing cabinets, and test equipment) in these areas could result Improper positioning of hoists reduces the availability Properly position chain hoists that facilitate maintenance on pumps due to moving during an earthquake and having IPEEE -

158 within pump rooms and institute a training program to ensure that the B chainfalls impacting pump oil bubblers or other soft Seismic hoists are properly positioned when not in use.

targets resulting in failure of the pumps.

Secure floor grating to prevent damage to sensing lines due to Prevent sensing lines that pass through the grating from IPEEE -

159 B differential building motion. being damaged. Seismic Modifications to lessen impact of internal flooding path through Lower impact of flood that propagates through the Internal 160 D Control Building dumbwaiter. dumbwaiter Flooding Improvements to PORV performance that will lower the probability of Core 161 Decrease in risk due to PORV failing to open. E failure to open. Cooling Install a large volume EDG fuel oil tank at an elevation greater than Allows transfer of EDF fuel oil to the EDG day tanks on 162 AC/DC C the EDG fuel oil day tanks. failure of the fuel oil transfer pumps.

Lower risk due to failures in which feedwater check Improve feedwater check valve reliability to reduce probability of Cooling 163 valves fail to open and allow feeding of the steam E failure to open. Water generators.

Provide the capability to power the normal service water pumps from Provide backup to ESW in conditions with power only Cooling 164 D AEPS. available from AEPS. Water Purchase or manufacture a "gagging device" that could be used to Reduce the amount of radioactive material release to 165 close a stuck open steam generator relief valve for a SGTR event SGTR C the atmosphere in a SGTR event with core damage.

prior to core damage.

RCP Seal 166 Installation of high temperature qualified RCP seal O-rings. Lower potential for RCP seal leakage. A LOCA Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 31 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Addition of procedural guidance to re-establish normal service water Cooling 167 Provide back-up pumps for UHS cooling. A should essential service water fail. Water Addition of procedural guidance for running charging and safety Allow use of pumps following loss of component cooling Cooling 168 A injection pumps without component cooling water water. Water Addition of procedural guidance to verify RHR pump room cooling at Verifying that support system for RHR pumps is in 169 HVAC A switchover to ECCS recirculation phase. service to allow continued operation of RHR pumps.

Modifications to add controls in the main control room to allow Faster ability to provide power to the plant electrical 170 remote operation of nearby diesel generator farm and AC Power C busses from the offsite diesel generator farm.

alignment/connection to the plant vital electrical busses.

Increase the size of the RWST or otherwise improve the availability Ensure a supply of makeup water is available from the Core 171 E of the RWST RWST. Cooling Addition of procedural guidance and the required hardware to enable 172 the operators to feed one or more steam generators with a diesel Provide a backup to turbine driven auxiliary feedwater. Feedwater A driven firewater pump.

A redundant source of AC Power that could be used in 173 Addition of a black start combustion turbine generator. AC Power A station blackout events.

Ability to power a 125VDC battery charger and a charging pump. Powering the battery charger would Addition of a black-start engine-generator to provide AC Power permit operation of the TDAFP without recovering AC 174 AC Power A during a station blackout power. Powering a charging pump could provide RCP seal injection and preclude a RCP seal LOCA during a station blackout.

Replacement of the positive displacement charging pump with a third Provide another source for RCP seal cooling, RCS Cooling 175 A centrifugal charging pump. makeup, and pumped flow for feed and bleed. Water Allow faster and more reliable bypass of the main Provide control modifications to bypass feedwater isolation in order feedwater isolation signal in order to restore main 176 Feedwater A to restore main feedwater. feedwater to the steam generators should auxiliary feedwater fail.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 32 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number The IPE identified a need to form a task force to identify and evaluate potential procedural and hardware Procedural and hardware modifications to reduce core damage risk modifications aimed at reducing the risk due to internal 177 Flooding A due to internal flooding. flooding.

178 Improvements to UHS cooling tower electrical room HVAC. Improve availability or mitigate loss of HVAC. HVAC E Modify procedures such that the water loop seals in the RCS cold Prevents possible thermally induced steam generator Containment 179 C legs are not cleared following core damage. tube rupture following core damage. Bypass Install lower amperage fuses for various 14 AWG control circuits in 180 the MCR. The majority of the modification centers around the trip Reduced fire risk. Fire Risk F circuit fuses on NB, NG, PA, PB, and PG system breakers.

Install redundant fuses and isolation switches for MCR evacuation 181 Reduced fire risk. Fire Risk F procedure OTO-ZZ-00001.

To protect against multiple spurious operation scenarios, cable runs will be changed to run a single wire in a protected metal jacket such 182 that spurious valve opening due to a hot short affecting the valve Reduced fire risk. Fire Risk F control circuit is eliminated for the fire area. This modification will be implemented in multiple fire areas.

Quick response sprinkler heads in cable chases A-11, C-30, and C-183 31 will be modified to be in accordance with the applicable Reduced fire risk. Fire Risk F requirements of NFPA 13-1976 edition.

Improvements in the reliability of the Steam Line Isolation automatic Containment 184 More reliable main steam line isolation. E signal. Isolation Cooling 185 Automate initiation of CCW flow to the RHR heat exchangers. More reliable than manual initiation of flow to RRHR HX. E Water Develop a procedure and obtain equipment to provide a temporary Backup cooling water if ESW/SW is lost Cooling 186 D hookup of fire water as a replacement for ESW Water Install modification to power the normal charging pump from an Another source of backup power to the NCP in cases of Cooling 187 C existing spare breaker from the AEPS. station blackout or loss of service water Water Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 33 of 86 Table 5-1. List of SAMA Candidates.

Callaway Focus of SAMA Potential Improvement Discussion Source SAMA Number Another source of backup power to the NCP, DC power Install a permanent, dedicated generator for the NCP, and a motor-(pump/valve control and SG level instrumentation), and Cooling 188 driven AFW pump and battery charger to address SBO events in C power to an AFW pump in cases of station blackout or Water which the TD AFW pump is unavailable.

loss of service water Perform analysis to determine if it is possible to modify current plant doors to withstand higher flood heights. Either perform modifications Internal 189 to install improved doors or revise flooding analysis to incorporate Reduction in risk due to internal flooding. D Flooding results that doors will withstand higher flooding heights without propagating the flood.

Note 1: The source references are:

1 NEI 05-01 (Reference 19)

A IPE (Reference 28)

B IPEEE (Reference 29)

C Recent industry SAMA submittals (Wolf Creek, South Texas, Diablo Canyon, Seabrook)

D Expert panel convened to review SAMA analysis or other plant personnel E PRA importance list review F Callaway NFPA 805 License Amendment Request Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 34 of 86 6.0 PHASE I ANALYSIS A preliminary screening of the complete list of SAMA candidates was performed to limit the number of SAMAs for which detailed analysis in Phase II was necessary. The screening criteria used in the Phase I analysis are described below.

Screening Criterion A - Not Applicable: If a SAMA candidate did not apply to the Callaway Unit 1 plant design, it was not retained.

Screening Criterion B - Already Implemented or Intent Met: If a SAMA candidate had already been implemented at the Callaway Plant or its intended benefit already achieved by other means, it was not retained.

Screening Criterion C - Combined: If a SAMA candidate was similar in nature and could be combined with another SAMA candidate to develop a more comprehensive or plant-specific SAMA candidate, only the combined SAMA candidate was retained.

Screening Criterion D - Excessive Implementation Cost: If a SAMA required extensive changes that will obviously exceed the maximum benefit (Section 4.5), even without an implementation cost estimate, it was not retained.

Screening Criterion E - Very Low Benefit: If a SAMA from an industry document was related to a non-risk significant system for which change in reliability is known to have negligible impact on the risk profile, it was not retained. (No SAMAs were screened using this criterion.)

Table 6-1 presents the list of Phase I SAMA candidates and provides the disposition of each candidate along with the applicable screening criterion associated with each candidate. Those candidates that have not been screened by application of these criteria are evaluated further in the Phase II analysis (Section 7).

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 35 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Create AC power cross-tie 12 capability with other unit (multi-unit Increased availability of on-site AC power. Yes A - Not Applicable Callaway is a single unit site.

site)

Create a cross-tie for diesel fuel oil 17 Increased diesel generator availability. Yes A - Not Applicable Callaway is a single unit site.

(multi-unit site).

Revise procedure to allow operators to inhibit automatic 27 Extended HPCI and RCIC operation. Yes A - Not Applicable BWR item.

vessel depressurization in non-ATWS scenarios.

Continuous source of water to the safety injection pumps during a LOCA event, since water released from a breach of the primary Not applicable for existing Provide an in-containment reactor 34 system collects in the in-containment reactor Yes A - Not Applicable designs. Insufficient room water storage tank.

water storage tank, and thereby eliminates inside primary containment.

the need to realign the safety injection pumps for long-term post-LOCA recirculation.

Per the Callaway safety analysis, this is an Throttle low pressure injection undesirable action. The pumps earlier in medium or large- Extended reactor water storage tank Callaway safety analysis and 35 Yes A - Not Applicable break LOCAs to maintain reactor capacity. design calls for injection of the water storage tank inventory. RWST to inside the containment as soon as possible.

Change the in-containment reactor Callaway does not have an in-water storage tank suction from Reduced common mode failure of injection 38 Yes A - Not Applicable containment RWST with this four check valves to two check and paths.

valve arrangement.

two air-operated valves.

Plant uses Ultimate Heat Sink pond for cooling. UHS sized Reduced potential for loss of SW due to 47 Enhance the screen wash system. Yes A - Not Applicable for 30 days without make-up.

clogging of screens.

River intake is only used for make-up to the UHS.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 36 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Provide hardware connections to Reduced effect of loss of component cooling Charging pump seals do not allow another essential raw cooling water by providing a means to maintain the require external cooling, they 52 Yes A - Not Applicable water system to cool charging charging pump seal injection following a loss are cooled by the process pump seals. of normal cooling water. fluid.

Callaway does not have a Reduced frequency of core damage from permanently installed hydro Use existing hydro test pump for loss of component cooling water or service test pump. Timing 57 Yes A - Not Applicable reactor coolant pump seal injection. water, but not a station blackout, unless an considerations prevent credit alternate power source is used. for hookup of temporary pump.

Existing fire protection system Use fire prevention system pumps Reduced frequency of reactor coolant pump pumps do not have sufficient 63 as a backup seal injection and high Yes A - Not Applicable seal LOCA. discharge head to use as high pressure makeup source.

pressure makeup source.

Install manual isolation valves Reduced dual turbine-driven pump Callaway does not have dual 69 around auxiliary feedwater turbine- Yes A - Not Applicable maintenance unavailability. turbine AFW pump.

driven steam admission valves.

Provide cross-unit connection of Increased ability to vent containment using 85 uninterruptible compressed air Yes A - Not Applicable N/A, single unit.

the hardened vent.

supply.

Enhance fire protection system and Improved fission product scrubbing in severe Standby gas treatment system 95 standby gas treatment system Yes A - Not Applicable accidents. is BWR item.

hardware and procedures.

Per the Callaway safety analysis, this is an undesirable action. The Delay containment spray actuation Extended reactor water storage tank Callaway safety analysis and 105 Yes A - Not Applicable after a large LOCA. availability. design calls for injection of the RWST to inside the containment as soon as possible.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 37 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Per the Callaway safety analysis, this is an undesirable action. The Extended time over which water remains in Install automatic containment spray Callaway safety analysis and 106 the reactor water storage tank, when full Yes A - Not Applicable pump header throttle valves. design calls for injection of the containment spray flow is not needed.

RWST to inside the containment as soon as possible.

Affords operators more time to perform actions. Discharge of a substantial fraction of steam to the main condenser (i.e., as Revise procedure to bypass MSIV opposed to into the primary containment) 134 isolation in turbine trip ATWS affords the operator more time to perform Yes A - Not Applicable Specific to BWRs.

scenarios. actions (e.g., SLC injection, lower water level, depressurize RPV) than if the main condenser was unavailable, resulting in lower human error probabilities.

Allows immediate control of low pressure core injection. On failure of high pressure Revise procedure to allow override core injection and condensate, some plants Based on description, this is a 135 of low pressure core injection Yes A - Not Applicable direct reactor depressurization followed by BWR item.

during an ATWS event.

five minutes of automatic low pressure core injection.

Improve inspection of rubber Reduced frequency of internal flooding due to No risk significant flooding 138 expansion joints on main failure of circulating water system expansion Yes A - Not Applicable sources identified in the condenser. joints. turbine building.

Modify swing direction of doors Flooding analysis did not separating turbine building indicate any flooding issues 139 Prevents flood propagation. Yes A - Not Applicable basement from areas containing related to the direction of door safeguards equipment. swing.

Replace mercury switches in fire Decreased probability of spurious fire No mercury switches in the 142 Yes A - Not Applicable protection system. suppression system actuation. fire protection system.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 38 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Fire analysis did not identify any issues related to fire barriers. NFPA 805 Fire 143 Upgrade fire compartment barriers. Decreased consequences of a fire. Yes A - Not Applicable Protection Program is in progress, any issues identified by that project will be handled by the NFPA 805 program.

IPEEE determined that there Develop procedures for Reduced consequences of transportation and are no transportation routes or 152 transportation and nearby facility Yes A - Not Applicable nearby facility accidents. nearby facilities that could accidents.

cause concern.

Callaway does not have the ability to isolate the steam Purchase or manufacture a generator from the RCS loop.

"gagging device" that could be Reduce the amount of radioactive material The amount of force required 165 used to close a stuck open steam release to the atmosphere in a SGTR event Yes A - Not Applicable to close a stuck open generator relief valve for a SGTR with core damage. atmospheric steam dump event prior to core damage. valve would likely not be successful and would result in further damage to the valve.

Current configuration is two spare battery chargers for the instrument buses. The spare can carry one bus. One feeds Add additional battery charger or A/B, the other feeds C/D 3 portable, diesel-driven battery Improved availability of DC power system. Yes B - Intent Met trains. Also Emergency charger to existing DC system.

Coordinator Supplemental Guidelines, Attachment N, "Temporary Power to NK Swing Charger Extended DC power availability during an DC load shedding is 4 Improve DC bus load shedding. Yes B - Intent Met SBO. conducted.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 39 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Procedures in place to provide Provide additional DC power to the Increased availability of the 120 V vital AC temporary power to DC 6 Yes B - Intent Met 120/240V vital AC system. bus. Chargers which can power vital AC system.

On loss of DC or inverter, the UPS static switch automatically transfers to AC Add an automatic feature to Increased availability of the 120 V vital AC power through a constant 7 transfer the 120V vital AC bus from Yes B - Intent Met bus. voltage transformer. An normal to standby power.

additional backup AC source is available, but must be closed manually.

Increase training on response to loss of two 120V AC buses which Improved chances of successful response to Typical response training in 8 Yes B - Intent Met causes inadvertent actuation loss of two 120V AC buses. place.

signals.

Provide an additional diesel Increased availability of on-site emergency Alternate Emergency Power 9 Yes B - Intent Met generator. AC power. System installed.

Bypass of non-vital diesel Revise procedure to allow bypass 10 Extended diesel generator operation. Yes B - Intent Met generator trips were in original of diesel generator trips.

design for Callaway.

Install an additional, buried off-site AEPS installed with buried 13 Reduced probability of loss of off-site power. Yes B - Intent Met power source. power lines.

Alternate Emergency Power 14 Install a gas turbine generator. Increased availability of on-site AC power. Yes B - Intent Met System installed.

Improve uninterruptible power Increased availability of power supplies Replaced to add static switch 16 Yes B - Intent Met supplies. supporting front-line equipment. and upgrade to newer design.

Develop procedures for EOP Addenda direct ordering 18 Increased diesel generator availability. Yes B - Intent Met replenishing diesel fuel oil. fuel oil.

Use fire water system as a backup Procedures exist for cooling 19 Increased diesel generator availability. Yes B - Intent Met source for diesel cooling. EDG with fire water.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 40 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Add a new backup source of diesel Procedure exists for backup 20 Increased diesel generator availability. Yes B - Intent Met cooling. diesel cooling.

Increased probability of recovery from failure Develop procedures to repair or of breakers that transfer 4.16 kV non- Spares exist and procedures 21 Yes B - Intent Met replace failed 4 KV breakers. emergency buses from unit station service exist.

transformers.

In training, emphasize steps in Reduced human error probability during off-22 recovery of off-site power after an Yes B - Intent Met Recovery stressed in training.

site power recovery.

SBO.

Develop a severe weather Improved off-site power recovery following Severe weather condition 23 Yes B - Intent Met conditions procedure. external weather-related events. procedure in place.

Callaway has implemented a containment sump modification that now uses state-of-the-art strainers to 30 Improve ECCS suction strainers. Enhanced reliability of ECCS suction. Yes B - Intent Met address the industrys concerns on blockage from debris. This modification occurred over two outages in 2007 and 2008.

Add the ability to manually align Current alignment capabilities 31 emergency core cooling system Enhanced reliability of ECCS suction. Yes B - Intent Met are half and half recirculation. (manual/automatic).

Add the ability to automatically align emergency core cooling Current alignment capabilities 32 system to recirculation mode upon Enhanced reliability of ECCS suction. Yes B - Intent Met are half and half refueling water storage tank (manual/automatic).

depletion.

Provide hardware and procedure to Extended reactor water storage tank capacity refill the reactor water storage tank in the event of a steam generator tube Addressed in SAMGs and the 33 Yes B - Intent Met once it reaches a specified low rupture (or other LOCAs challenging RWST EC Supplemental Guideline.

level. capacity).

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 41 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Current alignment capabilities are half and half Emphasize timely recirculation Reduced human error probability associated 36 Yes B - Intent Met (manual/automatic). Swap to alignment in operator training. with recirculation failure.

recirculation is stressed in operator training.

For a plant like the Westinghouse AP600, Upgrade the chemical and volume where the chemical and volume control CVCS system is capable of 37 control system to mitigate small system cannot mitigate a small LOCA, an Yes B - Intent Met mitigating small LOCA.

LOCAs. upgrade would decrease the frequency of core damage.

Remote Operation of Provide capability for remote, Improved chance of successful operation Atmospheric Steam Dumps manual operation of secondary side during station blackout events in which high 40 Yes B - Intent Met (ASDs) is possible.

pilot-operated relief valves in a area temperatures may be encountered (no Equipment Operators trained station blackout. ventilation to main stream areas).

and Operator Aid posted.

Make procedure changes for Allows low pressure emergency core cooling Multiple depressurization 42 reactor coolant system system injection in the event of small LOCA Yes B - Intent Met methods are in place.

depressurization. and high-pressure safety injection failure.

Current ECCS pump motors are air-cooled. Additionally Replace ECCS pump motors with Elimination of ECCS dependency on 44 Yes B - Intent Met the plant OTN procedures air-cooled motors. component cooling system.

allow for alternate trains to supply cooling.

Enhance procedural guidance for Reduced frequency of loss of component Can use service water as 45 use of cross-tied component Yes B - Intent Met cooling water and service water. backup to ESW.

cooling or service water pumps.

Reduced frequency of loss of component Cap downstream piping of normally cooling water initiating events, some of which 48 closed component cooling water Yes B - Intent Met Vents & drains capped.

can be attributed to catastrophic failure of drain and vent valves.

one of the many single isolation valves.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 42 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Enhance loss of component cooling CCW is cooled by ESW.

water (or loss of service water) Reduced potential for reactor coolant pump 49 Yes B - Intent Met Currently authorized to run 10 procedures to facilitate stopping the seal damage due to pump bearing failure.

minutes.

reactor coolant pumps.

Enhance loss of component cooling water procedure to underscore the Procedures include direction Reduced probability of reactor coolant pump 50 desirability of cooling down the Yes B - Intent Met to cool down to minimize seal failure.

reactor coolant system prior to seal impact of RCP seal LOCA.

LOCA.

Additional training on loss of Improved success of operator actions after a Training is conducted for Loss 51 Yes B - Intent Met component cooling water. loss of component cooling water. of CCW.

On loss of essential raw cooling Most non-safety loads have Increased time before loss of component water, proceduralize shedding been removed from the cooling water (and reactor coolant pump seal 53 component cooling water loads to Yes B - Intent Met system. Non-safety loop is failure) during loss of essential raw cooling extend the component cooling automatically isolated on water sequences.

water heat-up time. safety injection signal.

Reduced frequency of loss of reactor coolant pump seal cooling if spurious high pressure Prevent makeup pump flow Current configuration does not 60 injection relief valve opening creates a flow Yes B - Intent Met diversion through the relief valves. have a relief valve.

diversion large enough to prevent reactor coolant pump seal injection.

Change procedures to isolate reactor coolant pump seal return flow on loss of component cooling Reduced frequency of core damage due to 61 Yes B - Intent Met Procedure exist water, and provide (or enhance) loss of seal cooling.

guidance on loss of injection during seal LOCA.

Implement procedures to stagger Extended high pressure injection prior to Procedure currently in place 62 high pressure safety injection pump Yes B - Intent Met overheating following a loss of service water. to stagger use of HPSI.

use after a loss of service water.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 43 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Create ability for emergency connection of existing or new water 66 Increased availability of feedwater. Yes B - Intent Met Procedures exist.

sources to feedwater and condensate systems.

Procedures do exist for make-Install an independent diesel for the up to CST from fire water and 67 condensate storage tank makeup Extended inventory in CST during an SBO. Yes B - Intent Met for supplying fire water directly pumps.

to the TDAFW pump.

Add a motor-driven feedwater Non-Safety Auxiliary 68 Increased availability of feedwater. Yes B - Intent Met pump. Feedwater Pump installed.

Install accumulators for turbine- Eliminates the need for local manual action to Currently have nitrogen 70 driven auxiliary feedwater pump align nitrogen bottles for control air following Yes B - Intent Met accumulators.

flow control valves. a loss of off-site power.

Turbine-driven auxiliary Modify the turbine-driven auxiliary Improved success probability during a station 72 Yes B - Intent Met feedwater pump is self-feedwater pump to be self-cooled. blackout.

cooled.

Extended auxiliary feedwater availability Proceduralize local manual during a station blackout. Also provides a 73 operation of auxiliary feedwater success path should auxiliary feedwater Yes B - Intent Met Procedures exist.

system when control power is lost. control power be lost in non-station blackout sequences.

Provide hookup for portable generators to power the turbine- Procedures exist, hardware 74 Extended auxiliary feedwater availability. Yes B - Intent Met driven auxiliary feedwater pump on site.

after station batteries are depleted.

Equipment staged at CST for Use fire water system as a backup Increased availability of steam generator makeup.

75 Yes B - Intent Met for steam generator inventory. water supply. See operator aids.

Procedural guidance exists.

Change failure position of Allows greater inventory for the auxiliary condenser makeup valve if the 76 feedwater pumps by preventing condensate Yes B - Intent Met Valve currently fails closed.

condenser makeup valve fails open storage tank flow diversion to the condenser.

on loss of air or power.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 44 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Modify the startup feedwater pump Non-Safety Auxiliary so that it can be used as a backup Feedwater Pump gets power 78 to the emergency feedwater Increased reliability of decay heat removal. Yes B - Intent Met from Alternate Emergency system, including during a station Power System.

blackout scenario.

Add a diesel building high Computer points for Improved diagnosis of a loss of diesel 81 temperature alarm or redundant Yes B - Intent Met monitoring diesel room building HVAC.

louver and thermostat. temperatures.

Procedures include Stage backup fans in switchgear Increased availability of ventilation in the instructions for opening doors 82 Yes B - Intent Met rooms. event of a loss of switchgear ventilation. to provide alternate cooling capability.

Plant Process Computer has Add a switchgear room high Improved diagnosis of a loss of switchgear 83 Yes B - Intent Met alarming computer points for temperature alarm. HVAC.

switchgear room temperature.

Create ability to switch emergency feedwater room fan power supply Procedure currently in place 84 Continued fan operation in a station blackout. Yes B - Intent Met to station batteries in a station to switch fan power supply.

blackout.

Currently have 3 air compressors (service air).

A/B compressors are powered off the emergency buses Modify procedure to provide ability Increased availability of instrument air after a (cooled from essential service 86 to align diesel power to more air Yes B - Intent Met LOOP. lines). Compressors are compressors.

initially load shed, but procedure direct operators to override and place compressor in service.

Current configuration includes Install nitrogen bottles as backup 88 Extended SRV operation time. Yes B - Intent Met nitrogen bottles as backup gas supply for safety relief valves.

gas supply.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 45 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number MSIV actuators changed to process fluid actuated.

Improve SRV and MSIV pneumatic 89 Improved availability of SRVs and MSIVs. Yes B - Intent Met Modification installed to components.

relocate Atmospheric Steam Dump valve controllers.

Enhanced debris cool ability, reduced core Create a reactor cavity flooding 90 concrete interaction, and increased fission Yes B - Intent Met Procedures exist system.

product scrubbing.

Use the fire water system as a 92 backup source for the containment Improved containment spray capability. Yes B - Intent Met Procedures exist spray system.

Increased potential to cool a molten core Provide a reactor vessel exterior 101 before it causes vessel failure, by Yes B - Intent Met Procedures exist.

cooling system.

submerging the lower head in water.

Operators are trained on the Institute simulator training for Improved arrest of core melt progress and 103 Yes B - Intent Met SAMG that the operators must severe accident scenarios. prevention of containment failure.

implement.

Increased likelihood that LOCAs outside containment are identified as such. A plant Revise EOPs to improve ISLOCA had a scenario in which an RHR ISLOCA Current EOPs address 117 Yes B - Intent Met identification. could direct initial leakage back to the ISLOCA identification.

pressurizer relief tank, giving indication that the LOCA was inside containment.

Current procedure training Improve operator training on 118 Decreased ISLOCA consequences. Yes B - Intent Met addresses ISLOCA ISLOCA coping.

identification.

Replaced during the fall of Replace steam generators with a Reduced frequency of steam generator tube 2005 (newer design) which 120 Yes B - Intent Met new design. ruptures. consist of 72,000 sq. ft. per generator.

Proceduralize use of pressurizer Backup method to using pressurizer sprays 123 vent valves during steam generator to reduce primary system pressure following Yes B - Intent Met Procedure currently in place.

tube rupture sequences. a steam generator tube rupture.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 46 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Provide improved instrumentation Modification installed to to detect steam generator tube Improved mitigation of steam generator tube 124 Yes B - Intent Met improve operation of N16 ruptures, such as Nitrogen-16 ruptures.

detectors.

monitors).

Revise emergency operating Reduced consequences of a steam 127 procedures to direct isolation of a Yes B - Intent Met EOP currently in place.

generator tube rupture.

faulted steam generator.

Direct steam generator flooding Procedures direct that steam Improved scrubbing of steam generator tube 128 after a steam generator tube Yes B - Intent Met generator level be maintained rupture releases.

rupture, prior to core damage. above the tubes.

Provide an additional control Improved redundancy and reduced ATWS 132 system for rod insertion (e.g., Yes B - Intent Met Currently have AMSAC.

frequency.

AMSAC).

Decreased time required to insert control Provide capability to remove power rods if the reactor trip breakers fail (during a 137 from the bus powering the control Yes B - Intent Met Response procedure in place.

loss of feedwater ATWS which has rapid rods.

pressure excursion).

Items are identified and are being implemented as part of the 805 process.

Install additional transfer and Reduced number of spurious actuations 144 Yes B - Intent Met Examples include fuse and isolation switches. during a fire.

alternate feed line modifications to prevent the loss of the 4160 V buses.

Most recent inspections and 145 Enhance fire brigade awareness. Decreased consequences of a fire. Yes B - Intent Met evaluations did not identify any weaknesses in this area.

Procedure in place. NFPA-Enhance control of combustibles 805 project will evaluate the 146 Decreased fire frequency and consequences. Yes B - Intent Met and ignition sources. needs for any additional controls.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 47 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Existing procedures meet Enhance procedures to mitigate Reduced consequences of a large break 148 Yes B - Intent Met current guidelines issued by large break LOCA. LOCA.

the Owner's Group.

Install computer aided instrumentation system to assist Improved prevention of core melt sequences 149 Yes B - Intent Met Currently have SPDS in place.

the operator in assessing post- by making operator actions more reliable.

accident plant status.

Improved prevention of core melt sequences Current procedures are in line 150 Improve maintenance procedures. by increasing reliability of important Yes B - Intent Met with industry guidelines and equipment. practices.

Increase training and operating Improved likelihood of success of operator Current training program 151 experience feedback to improve actions taken in response to abnormal Yes B - Intent Met meets industry standards and operator response. conditions. practices.

Mount or anchor the MCCs to the Reduces failure probability of MCCs during Identified in the IPEEE and 154 Yes B - Intent Met respective building walls. an earthquake successfully implemented.

Install shear pins (or strength bolts) Takes up the shear load on the pump and/or Identified in the IPEEE and 155 Yes B - Intent Met in the AFW pumps. driver during an earthquake. successfully implemented.

Mount all fire extinguishers within Reduces the potential for the fire their UL Standard required drop extinguishers to fall during an earthquake Identified in the IPEEE and 156 height and remove hand-held fire Yes B - Intent Met and potentially fracturing upon impact with successfully implemented.

extinguishers from Containment the floor or another object.

during normal operation.

Ensures direct access to areas such as Load Shedding and Emergency Load Sequencing Identify and remove unsecured (LSELS) and Engineered Safety Feature equipment near areas that contain Identified in the IPEEE and 157 Actuation Yes B - Intent Met relays that actuate, so area is kept successfully implemented.

System (ESFAS) cabinets. Unsecured clear.

equipment (e.g., carts, filing cabinets, and test equipment) in these areas could result Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 48 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Properly position chain hoists that Improper positioning of hoists reduces the facilitate maintenance on pumps availability due to moving during an within pump rooms and institute a Identified in the IPEEE and 158 earthquake and having chainfalls impacting Yes B - Intent Met training program to ensure that the successfully implemented.

pump oil bubblers or other soft targets hoists are properly positioned when resulting in failure of the pumps.

not in use.

Secure floor grating to prevent Prevent sensing lines that pass through the Identified in the IPEEE and 159 damage to sensing lines due to Yes B - Intent Met grating from being damaged. successfully implemented.

differential building motion.

Installation of high temperature High temperature O-Rings 166 Lower potential for RCP seal leakage. Yes B - Intent Met qualified RCP seal O-rings. installed.

Addition of procedural guidance to 167 re-establish normal service water Provide back-up pumps for UHS cooling. Yes B - Intent Met Procedures in place.

should essential service water fail.

Addition of procedural guidance for running charging and safety Allow use of pumps following loss of 168 Yes B - Intent Met Procedures in place.

injection pumps without component component cooling water.

cooling water Addition of procedural guidance to Verifying that support system for RHR pumps verify RHR pump room cooling at 169 is in service to allow continued operation of Yes B - Intent Met Procedures in place.

switchover to ECCS recirculation RHR pumps.

phase.

AEPS diesel generators Modifications to add controls in the automatically start upon loss main control room to allow remote of offsite power to the local Faster ability to provide power to the plant operation of nearby diesel electrical co-op distribution 170 electrical busses from the offsite diesel Yes B - Intent Met generator farm and system. The controls for the generator farm.

alignment/connection to the plant breakers to connect to the vital electrical busses. Callaway distribution system are in the main control room.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 49 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Addition of procedural guidance and the required hardware to Provide a backup to turbine driven auxiliary Procedure and hardware 172 enable the operators to feed one or Yes B - Intent Met feedwater. changes complete more steam generators with a diesel driven firewater pump.

The original evaluation of this proposed modification concluded that the cost for this modification was prohibitively high. However, this was subsequently Addition of a black start combustion A redundant source of AC Power that could 173 Yes B - Intent Met changed and the offsite turbine generator. be used in station blackout events.

Alternate Emergency Power System (AEPS) system was installed. The AEPS system consists of diesel generators and a connection to the offsite electrical Co-op.

The original evaluation of this proposed modification concluded that the cost for this modification was Ability to power a 125VDC battery charger prohibitively high. However, and a charging pump. Powering the battery later implementation of the Addition of a black-start engine- charger would permit operation of the TDAFP AEPS system provides the 174 generator to provide AC Power without recovering AC power. Powering a Yes B - Intent Met backup power source during a station blackout charging pump could provide RCP seal represented by this item. Also injection and preclude a RCP seal LOCA the EC Coordinator during a station blackout.

Supplemental Guidelines provide procedures and equipment for hookup of a portable generator.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 50 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number The positive displacement charging pump has been Replacement of the positive Provide another source for RCP seal cooling, replaced by a centrifugal 175 displacement charging pump with a RCS makeup, and pumped flow for feed and Yes B - Intent Met pump that does not require third centrifugal charging pump. bleed. component cooling water. It is powered from a non-safety 4160 VAC power supply.

Allow faster and more reliable bypass of the Provide control modifications to Feedwater Isolation bypass main feedwater isolation signal in order to 176 bypass feedwater isolation in order Yes B - Intent Met switches installed and EOP in restore main feedwater to the steam to restore main feedwater. place with directions for use.

generators should auxiliary feedwater fail.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 51 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number The flooding task force identified 3 generic recommendations; 1) evaluate the impact of the normal charging pump (NCP), 2) evaluate the impact of increased inspections or changes in pipe class on pipe failure probability, and 3) re-analyze pipe break flowrates for actual flow, rather than assuming pump runout The IPE identified a need to form a task force flowrates. All three Procedural and hardware to identify and evaluate potential procedural recommendations have been modifications to reduce core and hardware modifications aimed at implemented. The flooding 177 Yes B - Intent Met damage risk due to internal reducing the risk due to internal flooding. analysis credited the NCP and flooding. reduced one flood zone below the screening value. A leakage detection program was implemented which uses security personnel and operators to visually inspect specific piping in the major flood zones. The implementation of the leakage detection program reduced flooding risk sufficiently to not require the installation of some watertight doors and piping encapsulation.

Individual seismic issues Increase seismic ruggedness of Increased availability of necessary plant identified in the IPEEE are 140 Yes C - Combined plant components. equipment during and after seismic events. included as SAMA items 154, 155, 156, 157, 158, and 159.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 52 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Individual seismic issues Provide additional restraints for Increased availability of fire protection given identified in the IPEEE are 141 Yes C - Combined CO2 tanks. a seismic event. included as SAMA items 154, 155, 156, 157, 158, and 159.

Original battery capacity is 4 Provide additional DC battery Extended DC power availability during an hrs. No additional battery 1 No capacity. SBO. capacity has been added.

Evaluate in Phase II.

Plant currently uses batteries Replace lead-acid batteries with Extended DC power availability during an 2 No rather than fuel cells.

fuel cells. SBO.

Evaluate in Phase II.

No existing capability for DC 5 Provide DC bus cross-ties. Improved availability of DC power system. No bus cross-ties. Evaluate in Phase II.

Improve 4.16-kV bus cross-tie 11 Increased availability of on-site AC power. No Evaluate during Phase II ability.

No gas turbine currently installed. No tornado Install tornado protection on gas protection for Alternate 15 Increased availability of on-site AC power. No turbine generator. Emergency Power System diesel generators. Evaluate in Phase II.

Improved off-site power reliability during 24 Bury off-site power lines. No Evaluate during Phase II severe weather.

Install an independent active or 25 passive high pressure injection Improved prevention of core melt sequences. No Evaluate during Phase II system.

Provide an additional high pressure Reduced frequency of core melt from small 26 injection pump with independent No Evaluate during Phase II LOCA and SBO sequences.

diesel.

Add a diverse low pressure 28 Improved injection capability. No Evaluate during Phase II injection system.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 53 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Currently being evaluated by plant improvement program.

Would use unborated water and portable pump (fire truck).

Provide capability for alternate Calculation of specific benefit 29 injection via diesel-driven fire Improved injection capability. No of this SAMA was not pump. performed since it is judged to be potentially low cost.

Evaluation will consider impacts of injection of non-borated water.

Reduced common cause failure of the safety injection system. This SAMA was originally Replace two of the four electric intended for the Westinghouse-CE System 39 safety injection pumps with diesel- No Evaluate during Phase II 80+, which has four trains of safety injection.

powered pumps.

However, the intent of this SAMA is to provide diversity within the high- and l Allows low pressure emergency core cooling Create a reactor coolant 41 system injection in the event of small LOCA No Evaluate during Phase II depressurization system.

and high-pressure safety injection failure.

Add redundant DC control power 43 Increased availability of SW. No Evaluate during Phase II for SW pumps.

46 Add a service water pump. Increased availability of cooling water. No Evaluate during Phase II Increased time before charging pump failure Increase charging pump lube oil 54 due to lube oil overheating in loss of cooling No Evaluate during Phase II capacity.

water sequences.

Install an independent reactor Reduced frequency of core damage from 55 coolant pump seal injection system, loss of component cooling water, service No Evaluate during Phase II with dedicated diesel. water, or station blackout.

Install an independent reactor Reduced frequency of core damage from 56 coolant pump seal injection system, loss of component cooling water or service No Evaluate during Phase II without dedicated diesel. water, but not a station blackout.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 54 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway Screened SAMA Potential Improvement Discussion Screening Criterion Phase I Disposition Out Ph 1?

Number Install improved reactor coolant Reduced likelihood of reactor coolant pump 58 No Evaluate during Phase II pump seals. seal LOCA.

Reduced likelihood of loss of component Install an additional component 59 cooling water leading to a reactor coolant No Evaluate during Phase II cooling water pump.

pump seal LOCA.

Implement procedure and hardware modifications to allow manual alignment of the fire water system Improved ability to cool residual heat removal 64 No Evaluate during Phase II to the component cooling water heat exchangers.

system, or install a component cooling water header cross-tie.

Reduced chance of loss of main feed water 65 Install a digital feed water upgrade. No Evaluate during Phase II following a plant trip.

Install a new condensate storage Increased availability of the auxiliary 71 tank (auxiliary feedwater storage No Evaluate during Phase II feedwater system.

tank).

Provide a passive, secondary-side Reduced potential for core damage due to 77 heat-rejection loop consisting of a No Evaluate during Phase II loss-of-feedwater events.

condenser and heat sink.

Replace existing pilot-operated relief valves with larger ones, such Increased probability of successful feed and 79 No Evaluate during Phase II that only one is required for bleed.

successful feed and bleed.

Provide a redundant train or means Increased availability of components 80 No Evaluate during Phase II of ventilation. dependent on room cooling.

Replace service and instrument air compressors with more reliable Air compressors currently Elimination of instrument air system 87 compressors which have self- No cooled by ESW. Evaluate dependence on service water cooling.

contained air cooling by shaft during Phase II driven fans.

Install a passive containment spray 91 Improved containment spray capability. No Evaluate during Phase II system.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 55 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway SAMA Screened Number Potential Improvement Discussion Out Ph 1? Screening Criterion Phase I Disposition 93 Install an unfiltered, hardened Increased decay heat removal capability for No Evaluate during Phase II containment vent. non-ATWS events, without scrubbing released fission products.

94 Install a filtered containment vent to Increased decay heat removal capability for No Evaluate during Phase II remove decay heat. Option 1: non-ATWS events, with scrubbing of Gravel Bed Filter; Option 2: released fission products.

Multiple Venturi Scrubber 96 Provide post-accident containment Reduced likelihood of hydrogen and carbon No Evaluate during Phase II inerting capability. monoxide gas combustion.

97 Create a large concrete crucible Increased cooling and containment of molten No Evaluate during Phase II with heat removal potential to core debris. Molten core debris escaping contain molten core debris. 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 containment of molten No Evaluate during Phase II reduction system. core 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 containment over- No Evaluate during Phase II containment (e.g., add ribbing to pressurization.

containment shell).

100 Increase depth of the concrete Reduced probability of base mat melt- No Evaluate during Phase II base mat or use an alternate through.

concrete material to ensure melt-through does not occur.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 56 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway SAMA Screened Number Potential Improvement Discussion Out Ph 1? Screening Criterion Phase I Disposition 102 Construct a building to be Reduced probability of containment over- No Evaluate during Phase II connected to primary/secondary pressurization.

containment and maintained at a vacuum.

104 Improve leak detection procedures. Increased piping surveillance to identify leaks No Evaluate during Phase II prior to complete failure. Improved leak detection would reduce LOCA frequency.

107 Install a redundant containment Increased containment heat removal ability. No Evaluate during Phase II spray system.

108 Install an independent power Reduced hydrogen detonation potential. No Evaluate during Phase II supply to the hydrogen 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 control Reduced hydrogen detonation potential. No Evaluate during Phase II system.

110 Erect a barrier that would provide Reduced probability of containment failure. No Evaluate during Phase II enhanced protection of the containment walls (shell) from ejected core debris following a core melt scenario at high pressure.

111 Install additional pressure or leak Reduced ISLOCA frequency. No Evaluate during Phase II monitoring instruments for detection of ISLOCAs.

112 Add redundant and diverse limit Reduced frequency of containment isolation No Evaluate during Phase II switches to each containment failure and ISLOCAs.

isolation valve.

113 Increase leak testing of valves in Reduced ISLOCA frequency. No Evaluate during Phase II ISLOCA paths.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 57 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway SAMA Screened Number Potential Improvement Discussion Out Ph 1? Screening Criterion Phase I Disposition 114 Install self-actuating containment Reduced frequency of isolation failure. No Evaluate during Phase II isolation valves.

115 Locate residual heat removal Reduced frequency of ISLOCA outside No Evaluate during Phase II (RHR) inside containment containment.

116 Ensure ISLOCA releases are Scrubbed ISLOCA releases. No Evaluate during Phase II scrubbed. One method is to plug drains in potential break areas so that break point will be covered with water.

119 Institute a maintenance practice to Reduced frequency of steam generator tube No Current frequency of perform a 100% inspection of ruptures. inspection of SG tubes is steam generator tubes during each 100% inspection every third refueling outage. outage.

Evaluate during Phase II 121 Increase the pressure capacity of Eliminates release pathway to the No Evaluate during Phase II the secondary side so that a steam environment following a steam generator generator tube rupture would not tube rupture.

cause the relief valves to lift.

122 Install a redundant spray system to Enhanced depressurization capabilities No Evaluate during Phase II depressurize the primary system during steam generator tube rupture.

during a steam generator tube rupture 125 Route the discharge from the main Reduced consequences of a steam No Evaluate during Phase II steam safety valves through a generator tube rupture.

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 steam No Evaluate during Phase II steam generator shell-side heat generator tube rupture.

removal system that relies on natural circulation and stored water sources Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 58 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway SAMA Screened Number Potential Improvement Discussion Out Ph 1? Screening Criterion Phase I Disposition 129 Vent main steam safety valves in Reduced consequences of a steam No Evaluate during Phase II containment. generator tube rupture.

130 Add an independent boron injection Improved availability of boron injection during No Evaluate during Phase II system. ATWS.

131 Add a system of relief valves to Improved equipment availability after an No Evaluate during Phase II prevent equipment damage from ATWS.

pressure spikes during an ATWS.

133 Install an ATWS sized filtered Increased ability to remove reactor heat from No Evaluate during Phase II containment vent to remove decay ATWS events.

heat.

136 Install motor generator set trip Reduced frequency of core damage due to No Evaluate during Phase II breakers in control room. an ATWS.

147 Install digital large break LOCA Reduced probability of a large break LOCA No Evaluate during Phase II protection system. (a leak before break).

153 Install secondary side guard pipes Prevents secondary side depressurization No Evaluate during Phase II up to the main steam isolation should a steam line break occur upstream of valves. 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 propagates No Evaluate during Phase II internal flooding path through through the dumbwaiter Control Building dumbwaiter.

161 Improvements to PORV Decrease in risk due to PORV failing to open. No Evaluate during Phase II performance that will lower the probability of failure to open.

162 Install a large volume EDG fuel oil Allows transfer of EDF fuel oil to the EDG No Evaluate during Phase II tank at an elevation greater than day tanks on failure of the fuel oil transfer the EDG fuel oil day tanks. pumps.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 59 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway SAMA Screened Number Potential Improvement Discussion Out Ph 1? Screening Criterion Phase I Disposition 163 Improve feedwater check valve Lower risk due to failures in which feedwater No Valves replaced with new reliability to reduce probability of check valves fail to open and allow feeding of type, but are still significant failure to open. the steam generators. risk contributor. Evaluate in Phase II.

164 Provide the capability to power the Provide backup to ESW in conditions with No Evaluate during Phase II normal service water pumps from power only available from AEPS.

AEPS.

171 Increase the size of the RWST or Ensure a supply of makeup water is available No Evaluate during Phase II otherwise improve the availability of from the RWST.

the RWST 178 Improvements to UHS cooling Improve availability or mitigate loss of HVAC. No Evaluate during Phase II tower electrical room HVAC.

179 Modify procedures such that the Prevents possible thermally induced steam No Evaluate during Phase II water loop seals in the RCS cold generator tube rupture following core legs are not cleared following core damage.

damage.

180 Install lower amperage fuses for Reduced fire risk. No Evaluate during Phase II various 14 AWG control circuits in the MCR. The majority of the modification centers around the trip circuit fuses on NB, NG, PA, PB, and PG system breakers.

181 Install redundant fuses and Reduced fire risk. No Evaluate during Phase II isolation switches for MCR evacuation procedure OTO-ZZ-00001.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 60 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway SAMA Screened Number Potential Improvement Discussion Out Ph 1? Screening Criterion Phase I Disposition 182 To protect against multiple spurious Reduced fire risk. No Evaluate during Phase II operation scenarios, cable runs will be changed to run a single wire in a protected metal jacket such that spurious valve opening due to a hot short affecting the valve control circuit is eliminated for the fire area.

This modification will be implemented in multiple fire areas.

183 Quick response sprinkler heads in Reduced fire risk. No Evaluate during Phase II cable chases A-11, C-30, and C-31 will be modified to be in accordance with the applicable requirements of NFPA 13-1976 edition.

184 Improvements in the reliability of More reliable main steam line isolation. No Evaluate during Phase II the Steam Line Isolation automatic signal.

185 Automate initiation of CCW flow to More reliable than manual initiation of flow to No Evaluate during Phase II the RHR heat exchangers. RRHR HX.

186 Develop a procedure and obtain Backup cooling water if ESW/SW is lost No Evaluate during Phase II equipment to provide a temporary hookup of fire water as a replacement for ESW 187 Install modification to power the Another source of backup power to the NCP No Evaluate during Phase II normal charging pump from an in cases of station blackout or loss of service existing spare breaker from the water AEPS.

188 Install a permanent, dedicated Another source of backup power to the NCP, No Evaluate during Phase II generator for the NCP, and a DC power (pump/valve control and SG level motor-driven AFW pump and instrumentation), and power to an AFW pump battery charger to address SBO in cases of station blackout or loss of service events in which the TD AFW pump water is unavailable.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 61 of 86 Table 6-1. Callaway Plant Phase I SAMA Analysis Callaway SAMA Screened Number Potential Improvement Discussion Out Ph 1? Screening Criterion Phase I Disposition 189 Perform analysis to determine if it is Reduction in risk due to internal flooding. No Evaluate during Phase II possible to modify current plant doors to withstand higher flood heights. Either perform modifications to install improved doors or revise flooding analysis to incorporate results that doors will withstand higher flooding heights without propagating the flood.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 62 of 86 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway  % Red.

% Red. SAMA SAMA Case SAMA Potential Improvement Discussion In OS Benefit Cost  % Red Cost Basis Evaluation Basis for Evaluation In CDF Case Description Number Dose IN OECR Provide additional DC battery Extended DC power No Station Blackout Not Cost-1 12.17% 10.87% NOSBO $360K >$1M 10.49% Expert Panel Cost will exceed benefit.

capacity. availability during an SBO. Events Beneficial Replace lead-acid batteries Extended DC power No Station Blackout Not Cost-2 12.17% 10.87% NOSBO $360K >$1M 10.49% Expert Panel Cost will exceed benefit.

with fuel cells. availability during an SBO. Events Beneficial Improved availability of DC TDAFW no DC Not Cost-5 Provide DC bus cross-ties. 0.30% 0.00% DC01 $1K >$199K 0.03% Expert Panel Cost will exceed benefit.

power system. Dependency Beneficial Physical cross-tie exists, but there is no analysis or procedures to allow its use except in specific outage conditions. Cost is to Add 4KV cross-tie Potentially Improve 4.16-kV bus cross- Increased availability of on- develop procedures and 11 0.26% 0.58% 4kv2 capability for SBO $13K <$100K 0.58% Expert Panel Cost-tie ability. site AC power. analysis to allow use of the sequences Beneficial cross-tie. Benefit calculated is under-estimated since it was evaluated for only SBO sequences.

Install tornado protection on Increased availability of on- No tornado related Not Cost-15 2.65% 4.35% LOSP1 $91K >$500K 3.38% Expert Panel Cost will exceed benefit.

gas turbine generator. site AC power. LOSP Beneficial Cost will exceed benefit.

Improved off-site power Previous SAMA submittals Eliminate all Loss of Not Cost-24 Bury off-site power lines. reliability during severe 40.66% 41.30% NOLOSP $1.2M >$3M 35.28% Expert Panel have estimated Offsite Power Events Beneficial weather. approximately $1M per mile.

Install an independent active Improved prevention of No failures of the Not Cost-25 or passive high pressure 16.46% 0.00% LOCA12 $616K >$1.5M 22.61% Expert Panel Cost will exceed benefit.

core melt sequences. charging or SI pumps Beneficial injection system.

Provide an additional high Reduced frequency of core No failures of the Not Cost-26 pressure injection pump with melt from small LOCA and 16.46% 0.00% LOCA12 $616K >$1.5M 22.61% Expert Panel Cost will exceed benefit.

charging or SI pumps Beneficial independent diesel. SBO sequences.

Add a diverse low pressure Improved injection No failure of low Not Cost-28 3.19% 2.17% LOCA03 $65K >$1M 1.01% Expert Panel Cost will exceed benefit.

injection system. capability. pressure injection Beneficial Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 63 of 86 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway  % Red.

% Red. SAMA SAMA Case SAMA Potential Improvement Discussion In OS Benefit Cost  % Red Cost Basis Evaluation Basis for Evaluation In CDF Case Description Number Dose IN OECR SAMA is judged to be low cost, but analysis is needed to determine impacts of injection of non-Provide capability for Potentially borated water to RCS.

Improved injection 29 alternate injection via diesel- Cost-capability. Expert Panel judged this driven fire pump. Beneficial SAMA to be potentially cost-beneficial without determining an actual benefit or cost.

Reduced common cause failure of the safety injection system. This SAMA was originally Replace two of the four intended for the electric safety injection Westinghouse-CE System No failures of the Not Cost-39 16.46% 0.00% LOCA12 $616K >$1.5M 22.61% Expert Panel Cost will exceed benefit.

pumps with diesel-powered 80+, which has four trains charging or SI pumps Beneficial pumps. of safety injection.

However, the intent of this SAMA is to provide diversity within the high-and l Allows low pressure emergency core cooling Create a reactor coolant system injection in the No failures of Not Cost-41 0.78% 0.00% DEPRESS $12K >$500K 0.27% Expert Panel Cost will exceed benefit.

depressurization system. event of small LOCA and depressurization Beneficial high-pressure safety injection failure.

Service Water Pumps Add redundant DC control Increased availability of Not Cost-43 0.30% 0.00% SW01 not dependent on DC $1K >$100K 0.06% Expert Panel Cost will exceed benefit.

power for SW pumps. SW. Beneficial Power Increased availability of No failures of ESW Not Cost-46 Add a service water pump. 17.60% 27.72% SW02 $636K >$5M 23.26% Expert Panel Cost will exceed benefit.

cooling water. pumps Beneficial Increased time before charging pump failure due Charging pumps not Increase charging pump lube Not Cost-54 to lube oil overheating in 0.48% 0.00% CHG01 dependent on cooling $4K >$100K 0.06% Expert Panel Cost will exceed benefit.

oil capacity. Beneficial loss of cooling water water.

sequences.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 64 of 86 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway  % Red.

% Red. SAMA SAMA Case SAMA Potential Improvement Discussion In OS Benefit Cost  % Red Cost Basis Evaluation Basis for Evaluation In CDF Case Description Number Dose IN OECR Cost will exceed benefit.

Previous investigation into Reduced frequency of core Install an independent installing such a system damage from loss of reactor coolant pump seal RCPLOC Not Cost- concluded that operators 55 component cooling water, 5.54% 0.00% No RCP Seal LOCAs $94K >$1M 0.21% Expert Panel injection system, with A Beneficial did not have sufficient time service water, or station dedicated diesel. to place the system in blackout.

service prior to seal damage.

Reduced frequency of core Install an independent damage from loss of reactor coolant pump seal RCPLOC Not Cost-56 component cooling water 5.54% 0.00% No RCP Seal LOCAs $94K >$500K 0.21% Expert Panel Cost will exceed benefit.

injection system, without A Beneficial or service water, but not a dedicated diesel.

station blackout.

Reduced likelihood of Install improved reactor RCPLOC Not Cost-58 reactor coolant pump seal 5.54% 0.00% No RCP Seal LOCAs $94K >$3M 0.21% Expert Panel Cost will exceed benefit.

coolant pump seals. A Beneficial LOCA.

Reduced likelihood of loss Install an additional of component cooling water No failures of the CCW Not Cost-59 component cooling water 3.61% 0.00% CCW01 $59K >$1M 0.07% Expert Panel Cost will exceed benefit.

leading to a reactor coolant Pumps Beneficial pump.

pump seal LOCA.

Implement procedure and The cost estimate is for hardware modifications to development of a allow manual alignment of Improved ability to cool Potentially procedure and use of the fire water system to the Evaluate fire water 64 residual heat removal heat 5.39% 0.76% FWCCW2 $104K <$150K 0.77%% Expert Panel Cost temporary connections.

component cooling water hookup to RHR HX exchangers. Beneficial Cost of permanent system, or install a modification would be component cooling water significantly higher.

header cross-tie.

Reduced chance of loss of Callaway Install a digital feed water No loss of Feedwater Not Cost-65 main feed water following a 1.57% 0.00% FW01 $29K $19M 0.49% Modification Cost will exceed benefit.

upgrade. Events Beneficial plant trip. Costs Install a new condensate Increased availability of the Not Cost-71 storage tank (auxiliary 1.14% 0.00% CST01 CST does not deplete $18K >$2.5M 0.24% Expert Panel Cost will exceed benefit.

auxiliary feedwater system. Beneficial feedwater storage tank).

Provide a passive, Reduced potential for core secondary-side heat- No loss of Feedwater Not Cost-77 damage due to loss-of- 1.57% 0.00% FW01 $29K $>1M 0.49% Expert Panel Cost will exceed benefit.

rejection loop consisting of a Events Beneficial feedwater events.

condenser and heat sink.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 65 of 86 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway  % Red.

% Red. SAMA SAMA Case SAMA Potential Improvement Discussion In OS Benefit Cost  % Red Cost Basis Evaluation Basis for Evaluation In CDF Case Description Number Dose IN OECR Replace existing pilot-operated relief valves with Only one PORV Increased probability of Not Cost-79 larger ones, such that only 3.43% 2.17% FB01 required for Feed & $79K >$500K 1.68% Expert Panel Cost will exceed benefit.

successful feed and bleed. Beneficial one is required for successful Bleed feed and bleed.

Procedures to open doors or provide temporary ventilation may be cost Increased availability of Potentially beneficial for the EDGs, Provide a redundant train or No dependencies on 80 components dependent on 6.08% 4.35% HVAC $156K <$100K 3.87% Expert Panel Cost MDAFW pumps, and means of ventilation. HVAC room cooling. Beneficial charging pumps.

Procedures for opening doors to the DC switchgear rooms exist.

Replace service and instrument air compressors Elimination of instrument with more reliable Eliminate all Not Cost-87 air system dependence on 0.36% 0.00% INSTAIR $2K >$500K 0.06% Expert Panel Cost will exceed benefit.

compressors which have instrument air failures Beneficial service water cooling.

self-contained air cooling by shaft driven fans.

No failures due to Install a passive containment Improved containment Not Cost-91 19.52% 36.96% CONT01 containment $793K >$10M 31.32% Expert Panel Cost will exceed benefit.

spray system. spray capability. Beneficial overpressure Increased decay heat removal capability for non- No failures due to Install an unfiltered, Not Cost-93 ATWS events, without 19.52% 36.96% CONT01 containment $793K >$2M 31.32% Expert Panel Cost will exceed benefit.

hardened containment vent. Beneficial scrubbing released fission overpressure products.

Install a filtered containment Increased decay heat vent to remove decay heat. removal capability for non- No failures due to Not Cost-94 Option 1: Gravel Bed Filter; ATWS events, with 19.52% 36.96% CONT01 containment $793K >$2M 31.32% Expert Panel Cost will exceed benefit.

Beneficial Option 2: Multiple Venturi scrubbing of released overpressure Scrubber fission products.

Provide post-accident Reduced likelihood of No hydrogen Not Cost-96 containment inerting hydrogen and carbon 0.48% 0.00% H2BURN $10K >$100K 0.44% Expert Panel Cost will exceed benefit.

burns/explosions Beneficial capability. monoxide gas combustion.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 66 of 86 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway  % Red.

% Red. SAMA SAMA Case  % Red SAMA Potential Improvement Discussion In OS Benefit Cost Cost Basis Evaluation Basis for Evaluation In CDF Case Description IN Number Dose OECR Increased cooling and containment of molten core debris. Molten core debris Create a large concrete escaping from the vessel is crucible with heat removal contained within the Not Cost-97 MAB >$10M Note 1 Expert Panel Cost will exceed benefit.

potential to contain molten crucible and a water Beneficial core debris. cooling mechanism cools the molten core in the crucible, preventing melt-through of the base mat.

Increased cooling and containment of molten core debris. Refractory material would be placed underneath the reactor vessel such that a molten Create a core melt source core falling on the material Not Cost-98 MAB >$10M Note 1 Expert Panel Cost will exceed benefit.

reduction system. would melt and combine Beneficial with the material.

Subsequent spreading and heat removal from the vitrified compound would be facilitated, and concrete attack would not occur.

Strengthen Reduced probability of No failures due to primary/secondary Not Cost-99 containment over- 19.52% 36.96% CONT01 containment $1.2M >$10M 31.32% Expert Panel Cost will exceed benefit.

containment (e.g., add Beneficial pressurization. overpressure ribbing to containment shell).

Increase depth of the concrete base mat or use an Reduced probability of Not Cost-100 alternate concrete material to MAB >$10M Note 1 Expert Panel Cost will exceed benefit.

base mat melt-through. Beneficial ensure melt-through does not occur.

Construct a building to be connected to Reduced probability of No failures due to Not Cost-102 primary/secondary containment over- 19.52% 36.96% CONT01 containment $1.2M >$10M 31.32% Expert Panel Cost will exceed benefit.

Beneficial containment and maintained pressurization. overpressure at a vacuum.

Increased piping surveillance to identify Improve leak detection leaks prior to complete No piping system Not Cost-104 39.34% 2.17% LOCA05 $689K >$2M 1.03% Expert Panel Cost will exceed benefit.

procedures. failure. Improved leak LOCAs Beneficial detection would reduce LOCA frequency.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 67 of 86 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway  % Red.

% Red. SAMA SAMA Case  % Red SAMA Potential Improvement Discussion In OS Benefit Cost Cost Basis Evaluation Basis for Evaluation In CDF Case Description IN Number Dose OECR No failures due to Install a redundant Increased containment Not Cost-107 19.52% 36.96% CONT01 containment $1.2M >$2M 31.32% Expert Panel Cost will exceed benefit.

containment spray system. heat removal ability. Beneficial overpressure Install an independent power supply to the hydrogen control system using either new batteries, a non-safety Reduced hydrogen No hydrogen Not Cost-108 grade portable generator, 0.48% 0.00% H2BURN $10K >$100K 0.44% Expert Panel detonation potential. burns/explosions Beneficial existing station batteries, or existing AC/DC independent power supplies, such as the security system diesel.

Install a passive hydrogen Reduced hydrogen No hydrogen Not Cost-109 0.48% 0.00% H2BURN $10K >$100M 0.44% Expert Panel Cost will exceed benefit.

control system. detonation potential. burns/explosions Beneficial Erect a barrier that would provide enhanced protection of the containment walls Reduced probability of Not Cost-110 MAB >$10M Note 1 Expert Panel Cost will exceed benefit.

(shell) from ejected core containment failure. Beneficial debris following a core melt scenario at high pressure.

Install additional pressure or Reduced ISLOCA Not Cost-111 leak monitoring instruments 1.33% 8.70% ISLOCA No ISLOCA events $123K >$500K 7.08% Expert Panel Cost will exceed benefit.

frequency. Beneficial for detection of ISLOCAs.

Add redundant and diverse Reduced frequency of No failures of Not Cost-112 limit switches to each containment isolation 0.30% 0.00% CONT02 $1K >$1M Expert Panel Cost will exceed benefit.

containment isolation Beneficial containment isolation valve. failure and ISLOCAs.

Increase leak testing of Reduced ISLOCA Not Cost-113 1.33% 8.70% ISLOCA No ISLOCA events $123K >$1M 7.08% Expert Panel Cost will exceed benefit.

valves in ISLOCA paths. frequency. Beneficial Install self-actuating Reduced frequency of No failures of Not Cost-114 0.30% 0.00% CONT02 $1K >$500K 0.03% Expert Panel Cost will exceed benefit.

containment isolation valves. isolation failure. containment isolation Beneficial Reduced frequency of Locate residual heat removal Not Cost-115 ISLOCA outside 1.33% 8.70% ISLOCA No ISLOCA events $123K >$1M 7.08% Expert Panel Cost will exceed benefit.

(RHR) inside containment Beneficial containment.

Cost would exceed benefit.

Ensure ISLOCA releases are Current plant design scrubbed. One method is to requires drains to be open.

Scrubbed ISLOCA Not Cost-116 plug drains in potential break 1.33% 8.70% ISLOCA No ISLOCA events $123K >$1M 7.08% Expert Panel Analysis and license releases. Beneficial areas so that break point will changes required to be covered with water. implement are included in the cost estimate.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 68 of 86 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway  % Red.

% Red. SAMA SAMA Case  % Red SAMA Potential Improvement Discussion In OS Benefit Cost Cost Basis Evaluation Basis for Evaluation In CDF Case Description IN Number Dose OECR Institute a maintenance practice to perform a 100% Reduced frequency of 20.47% 69.43% Not Cost-119 inspection of steam steam generator tube 63.28% NOSGTR No SGTR Events $1.4M >$3M Expert Panel Cost will exceed benefit.

Beneficial generator tubes during each ruptures.

refueling outage.

Increase the pressure capacity of the secondary Eliminates release pathway side so that a steam to the environment 20.47% >$10M 69.43% Not Cost-121 63.28% NOSGTR No SGTR Events $1.4M Expert Panel Cost will exceed benefit.

generator tube rupture would following a steam Beneficial not cause the relief valves to generator tube rupture.

lift.

Install a redundant spray Enhanced depressurization 20.47% >$10M 69.43%

system to depressurize the Not Cost-122 capabilities during steam 63.28% NOSGTR No SGTR Events $1.4M Expert Panel Cost will exceed benefit.

primary system during a Beneficial generator tube rupture.

steam generator tube rupture Route the discharge from the main steam safety valves Reduced consequences of 20.47% >$10M 69.43%

through a structure where a Not Cost-125 a steam generator tube 63.28% NOSGTR No SGTR Events $1.4M Expert Panel Cost will exceed benefit.

water spray would condense Beneficial rupture.

the steam and remove most of the fission products.

Install a highly reliable (closed loop) steam Reduced consequences of 20.47% >$10M 69.43%

generator shell-side heat Not Cost-126 a steam generator tube 63.28% NOSGTR No SGTR Events $1.4M Expert Panel Cost will exceed benefit.

removal system that relies on Beneficial rupture.

natural circulation and stored water sources Cost will exceed benefit.

Current containment design does not support this Reduced consequences of 20.47% >$10M 69.43%

Vent main steam safety Not Cost- modification. Modifications 129 a steam generator tube 63.28% NOSGTR No SGTR Events $1.4M Expert Panel valves in containment. Beneficial to containment and rupture.

associated analysis are included in the cost estimate.

Improved availability of Add an independent boron Not Cost-130 boron injection during 2.41% 2.17% NOATWS Eliminate all ATWS $63K >$1M 1.85% Expert Panel Cost will exceed benefit.

injection system. Beneficial ATWS.

Add a system of relief valves to prevent equipment Improved equipment Not Cost-131 2.41% 2.17% NOATWS Eliminate all ATWS $63K >$2M 1.85% Expert Panel Cost will exceed benefit.

damage from pressure availability after an ATWS. Beneficial spikes during an ATWS.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 69 of 86 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway  % Red.

% Red. SAMA SAMA Case  % Red SAMA Potential Improvement Discussion In OS Benefit Cost Cost Basis Evaluation Basis for Evaluation In CDF Case Description IN Number Dose OECR Install an ATWS sized filtered Increased ability to remove Not Cost-133 containment vent to remove reactor heat from ATWS 2.41% 2.17% NOATWS Eliminate all ATWS $63K >$1M 1.85% Expert Panel Cost will exceed benefit Beneficial decay heat. events.

Install motor generator set Reduced frequency of core Not Cost-136 2.41% 2.17% NOATWS Eliminate all ATWS $63K >$500K 1.85% Expert Panel Cost will exceed benefit.

trip breakers in control room. damage due to an ATWS. Beneficial Reduced probability of a Install digital large break No piping system Not Cost-147 large break LOCA (a leak 39.34% 2.17% LOCA05 $689K >$5M 1.03% Expert Panel Cost will exceed benefit.

LOCA protection system. LOCAs Beneficial before break).

Prevents secondary side depressurization should a steam line break occur upstream of the main Install secondary side guard steam isolation valves.

No Steam Line Not Cost-153 pipes up to the main steam Also guards against or 2.53% 0.00% NOSLB $51K >$1M 0.87% Expert Panel Cost will exceed benefit.

Breaks Beneficial isolation valves. prevents consequential multiple steam generator tube ruptures following a main steam line break event.

Relatively minor modifications to door opening could result in Modifications to lessen lower flow to the Lower impact of flood that Potentially impact of internal flooding dumbwaiter. Specific 160 propagates through the <$50K Expert Panel Cost-path through Control Building benefit could not be dumbwaiter Beneficial dumbwaiter. calculated but SAMA item is judged to be low cost and therefore potentially cost beneficial.

Improvements to PORV performance that will lower Decrease in risk due to 0.46% PORVs do not fail to Not Cost-161 0.85% PORV $18K >$100K 0.24% Expert Panel Cost will exceed benefit.

the probability of failure to PORV failing to open. open Beneficial open.

Install a large volume EDG Allows transfer of EDF fuel Potentially Wolf Creek estimated cost fuel oil tank at an elevation oil to the EDG day tanks on No EDG fuel pump 162 1.14% 7.60% EDGFUEL $124K $150K 7.11% Wolf Creek Cost- of $150K is less than the greater than the EDG fuel oil failure of the fuel oil failures Beneficial potential benefit.

day tanks. transfer pumps.

Lower risk due to failures in Improve feedwater check which feedwater check Feedwater Check Not Cost-163 valve reliability to reduce valves fail to open and 5.52% 2.05% FW02 Valves do not fail to $127K >$500K 2.23% Expert Panel Cost will exceed benefit.

Beneficial probability of failure to open. allow feeding of the steam open generators.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 70 of 86 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway  % Red.

% Red. SAMA SAMA Case  % Red SAMA Potential Improvement Discussion In OS Benefit Cost Cost Basis Evaluation Basis for Evaluation In CDF Case Description IN Number Dose OECR Provide the capability to Provide backup to ESW in 5.62% AEPS power to SW Not Cost-164 power the normal service conditions with power only 7.64% SW03 $191K >$500K 6.37% Expert Panel Cost will exceed benefit.

pumps Beneficial water pumps from AEPS. available from AEPS.

Increase the size of the Ensure a supply of makeup RWST does not Not Cost-171 RWST or otherwise improve water is available from the 0.68% 0.13% LOCA04 $13K >$100K 0.07% Expert Panel Cost will exceed benefit.

deplete Beneficial the availability of the RWST RWST.

Implementation of Improvements to UHS UHS cooling tower Potentially temporary ventilation or Improve availability or 4.75%

178 cooling tower electrical room 3.29% HVAC02 electrical room HVAC $113K <$100K 3.82% Expert Panel Cost opening of doors will be a mitigate loss of HVAC.  %

HVAC. does not fail. Beneficial lower cost than the calculated benefit.

Modify procedures such that Implementation of Prevents possible thermally Reduced probability the water loop seals in the Potentially procedure change will be induced steam generator of thermally induced 179 RCS cold legs are not 0.15% 3.18% RAI7a $63K <$100K 4.46% Expert Panel Cost lower cost than benefit, tube rupture following core steam generator tube cleared following core Beneficial especially if 95% CDF damage. failure damage. benefit is considered.

SAMA considered Install lower amperage fuses potentially cost beneficial for various 14 AWG control without benefit or cost circuits in the MCR. The Potentially determination since the 180 majority of the modification Reduced fire risk. Cost NFPA 805 license centers around the trip circuit Beneficial amendment request fuses on NB, NG, PA, PB, committed to performing and PG system breakers. the modification.

SAMA considered potentially cost beneficial without benefit or cost Install redundant fuses and determination since the Potentially isolation switches for MCR NFPA 805 license 181 Reduced fire risk. Cost evacuation procedure OTO- amendment request Beneficial ZZ-00001. committed to performing the modification.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 71 of 86 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway  % Red.

% Red. SAMA SAMA Case  % Red SAMA Potential Improvement Discussion In OS Benefit Cost Cost Basis Evaluation Basis for Evaluation In CDF Case Description IN Number Dose OECR To protect against multiple spurious operation scenarios, SAMA considered cable runs will be changed to potentially cost beneficial run a single wire in a without benefit or cost protected metal jacket such determination since the Potentially that spurious valve opening NFPA 805 license 182 Reduced fire risk. Cost due to a hot short affecting amendment request Beneficial the valve control circuit is committed to performing eliminated for the fire area. the modification.

This modification will be implemented in multiple fire areas.

SAMA considered Quick response sprinkler potentially cost beneficial heads in cable chases A-11, without benefit or cost C-30, and C-31 will be Potentially determination since the 183 modified to be in accordance Reduced fire risk. Cost NFPA 805 license with the applicable Beneficial amendment request requirements of NFPA 13- committed to performing 1976 edition. the modification.

Cost is for installation of redundant instrumentation system and would likely be Improvements in the More reliable main steam Steam Line Isolation Not Cost- much higher. Procedure 184 reliability of the Steam Line 0.59% 0.95% SLIS $28K >$500K 1.06% Expert Panel line isolation. System does not fail Beneficial and training already direct Isolation automatic signal.

operators to manually back up failed automatic actuations.

Automate initiation of CCW More reliable than manual Evaluate automating Potentially 185 flow to the RHR heat initiation of flow to RHR 3.53% 0.14% HEP CCW flow to RHR $62K $200K 0.11% Expert Panel Cost exchangers. HX. HXs Beneficial Develop a procedure and obtain equipment to provide Backup cooling water if ESW/SW is lost Fire water available Not Cost- Ability to do this will require 186 a temporary hookup of fire 0.04% 0.05% FWCCW $1K >$1M 0.04% Expert Panel to cool CCW HX Beneficial larger fire pumps.

water as a replacement for ESW Install modification to power Another source of backup Already installed spare Reduce the Potentially the normal charging pump power to the NCP in cases circuit breaker, 187 4.07% 7.63% SBOMOD frequency of SBO $174K $350K 7.03% Expert Panel Cost from an existing spare of station blackout or loss implementation requires sequences. Beneficial breaker from the AEPS. of service water power and control cables.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 72 of 86 Table 7-1. Callaway Plant 1 Phase II SAMA Analysis Callaway  % Red.

% Red. SAMA SAMA Case  % Red SAMA Potential Improvement Discussion In OS Benefit Cost Cost Basis Evaluation Basis for Evaluation In CDF Case Description IN Number Dose OECR Another source of backup Install a permanent, power to the NCP, DC dedicated generator for the AEPS was installed with a power (pump/valve control NCP, and a motor-driven Reduce the Potentially spare breaker and and SG level 188 AFW pump and battery 4.28% 7.63% SBOMOD2 frequency of SBO $182K $400K 7.38% Expert Panel Cost expansion capability that instrumentation), and charger to address SBO sequences. Beneficial could be used to supply power to an AFW pump in events in which the TD AFW various equipment.

cases of station blackout or pump is unavailable.

loss of service water Perform analysis to determine if it is possible to modify current plant doors to withstand higher flood Installation of modified heights. Either perform doors or modification of Callaway Potentially modifications to install Reduction in risk due to flooding analysis will result 189 Plant Cost improved doors or revise internal flooding. in lower flooding risk.

Management Beneficial flooding analysis to Analysis is currently in incorporate results that doors progress.

will withstand higher flooding heights without propagating the flood.

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.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 73 of 86 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA Benefit SAMA Potential Improvement Discussion Benefit 3% Disc Realistic at 95% Cost Cost Basis Evaluation Basis for Evaluation Case at 33yrs Number Rate Disc Rate CDF Provide additional DC battery Extended DC power availability Not Cost- Cost will exceed 1 NOSBO $360K $588K $325K $512K $761K >$1M Expert Panel capacity. during an SBO. Beneficial benefit.

Replace lead-acid batteries with fuel Extended DC power availability Not Cost- Cost will exceed 2 NOSBO $360K $588K $325K $512K $761K >$1M Expert Panel cells. during an SBO. Beneficial benefit.

Improved availability of DC power Not Cost- Cost will exceed 5 Provide DC bus cross-ties. DC01 $1K $1K $1K $1K $1K >$199K Expert Panel system. Beneficial benefit.

Physical cross-tie exists, but there is no analysis or procedures to allow its use except in specific outage Potentially conditions. Cost is to Increased availability of on-site 11 Improve 4.16-kV bus cross-tie ability. 4kv2 $13K $20K $12K $17K $27K <$100K Expert Panel Cost- develop procedures AC power.

Beneficial and analysis to allow use of the cross-tie.

Benefit calculated is under-estimated since it was evaluated for only SBO sequences.

Install tornado protection on gas Increased availability of on-site Not Cost- Cost will exceed 15 LOSP1 $91K $144K $82K $125K $192K >$500K Expert Panel turbine generator. AC power. Beneficial benefit.

Cost will exceed benefit. Previous Improved off-site power reliability Not Cost- SAMA submittals 24 Bury off-site power lines. NOLOSP $1.2M $2.0M $1.1M $1.7M $2.6M >$3M Expert Panel during severe weather. Beneficial have estimated approximately $1M per mile.

Install an independent active or Improved prevention of core melt Not Cost- Cost will exceed 25 passive high pressure injection LOCA12 $616K $979K $557K $850 $1.3M >$1.5M Expert Panel sequences. Beneficial benefit.

system.

Provide an additional high pressure Reduced frequency of core melt Not Cost- Cost will exceed 26 injection pump with independent from small LOCA and SBO LOCA12 $616K $979K $557K $850 $1.3M >$1.5M Expert Panel Beneficial benefit.

diesel. sequences.

Add a diverse low pressure injection Not Cost- Cost will exceed 28 Improved injection capability. LOCA03 $65K $111K $58K $97K $137K >$1M Expert Panel system. Beneficial benefit.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 74 of 86 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA Benefit SAMA Potential Improvement Discussion Benefit 3% Disc Realistic at 95% Cost Cost Basis Evaluation Basis for Evaluation Case at 33yrs Number Rate Disc Rate CDF SAMA is judged to be low cost, but analysis is needed to determine impacts of injection of non-Potentially borated water to Provide capability for alternate RCS.

29 Improved injection capability. Cost-injection via diesel-driven fire pump.

Beneficial Expert Panel judged this SAMA to be potentially cost-beneficial without determining an actual benefit or cost.

Reduced common cause failure of the safety injection system. This SAMA was originally intended for Replace two of the four electric safety the Westinghouse-CE System Not Cost- Cost will exceed 39 injection pumps with diesel-powered LOCA12 $616K $979K $557K $850K $1.3M >$1.5M Expert Panel 80+, which has four trains of Beneficial benefit.

pumps.

safety injection. However, the intent of this SAMA is to provide diversity within the high- and l Allows low pressure emergency core cooling system injection in Create a reactor coolant DEPRES Not Cost- Cost will exceed 41 the event of small LOCA and $12K $20K $11K $17K $25K >$500K Expert Panel depressurization system. S Beneficial benefit.

high-pressure safety injection failure.

Add redundant DC control power for Not Cost- Cost will exceed 43 Increased availability of SW. SW01 $1K $2K $1K $2K $3K >$100K Expert Panel SW pumps. Beneficial benefit.

Increased availability of cooling Not Cost- Cost will exceed 46 Add a service water pump. SW02 $636K $1M $575K $879K $1.3M >$5M Expert Panel water. Beneficial benefit.

Increased time before charging Increase charging pump lube oil pump failure due to lube oil Not Cost- Cost will exceed 54 CHG01 $4K $7K $4K $6K $9K >$100K Expert Panel capacity. overheating in loss of cooling Beneficial benefit.

water sequences.

Cost will exceed benefit. Previous investigation into Reduced frequency of core installing such a Install an independent reactor coolant damage from loss of component Not Cost- system concluded 55 pump seal injection system, with RCPLOCA $94K $168K $85K $148K $198K >$1M Expert Panel cooling water, service water, or Beneficial that operators did not dedicated diesel.

station blackout. have sufficient time to place the system in service prior to seal damage.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 75 of 86 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA Benefit SAMA Potential Improvement Discussion Benefit 3% Disc Realistic at 95% Cost Cost Basis Evaluation Basis for Evaluation Case at 33yrs Number Rate Disc Rate CDF Reduced frequency of core Install an independent reactor coolant damage from loss of component Not Cost- Cost will exceed 56 pump seal injection system, without RCPLOCA $94K $168K $85K $148K $198K >$500K Expert Panel cooling water or service water, but Beneficial benefit.

dedicated diesel.

not a station blackout.

Install improved reactor coolant pump Reduced likelihood of reactor Not Cost- Cost will exceed 58 RCPLOCA $94K $168K $85K $148K $198K >$3M seals. coolant pump seal LOCA. Beneficial benefit.

Reduced likelihood of loss of Cost will Install an additional component component cooling water leading Not Cost- Cost will exceed 59 CCW01 $59K $106K $53K $93K $124K >$1M exceed cooling water pump. to a reactor coolant pump seal Beneficial benefit.

benefit LOCA.

The cost estimate is Implement procedure and hardware for development of a modifications to allow manual procedure and use of Potentially alignment of the fire water system to Improved ability to cool residual temporary 64 FWCCW2 $104K $184K $94K $161K $220K <$150K Expert Panel Cost the component cooling water system, heat removal heat exchangers. connections. Cost of Beneficial or install a component cooling water permanent header cross-tie. modification would be significantly higher.

Callaway Reduced chance of loss of main Not Cost- Cost will exceed 65 Install a digital feed water upgrade. FW01 $29K $50K $27K $44K $62K $19M Modification feed water following a plant trip. Beneficial benefit.

Costs Install a new condensate storage Increased availability of the Not Cost- Cost will exceed 71 tank (auxiliary feedwater storage CST01 $18K $32K $16K $28K $39K >$2.5M Expert Panel auxiliary feedwater system. Beneficial benefit.

tank).

Provide a passive, secondary-side Reduced potential for core Not Cost- Cost will exceed 77 heat-rejection loop consisting of a damage due to loss-of-feedwater FW01 $29K $50K $27K $44K $62K $>1M Expert Panel Beneficial benefit.

condenser and heat sink. events.

Replace existing pilot-operated relief valves with larger ones, such that Increased probability of Not Cost- Cost will exceed 79 FB01 $79K $133K $72K $117K $168K >$500K Expert Panel only one is required for successful successful feed and bleed. Beneficial benefit.

feed and bleed.

Procedures to open doors or provide temporary ventilation may be cost Increased availability of Potentially beneficial for the Provide a redundant train or means 80 components dependent on room HVAC $156K $259K $141K $227K $331K <$100K Expert Panel Cost EDGs, MDAFW of ventilation.

cooling. Beneficial pumps, and charging pumps. Procedures for opening doors to the DC switchgear rooms exist.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 76 of 86 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA Benefit SAMA Potential Improvement Discussion Benefit 3% Disc Realistic at 95% Cost Cost Basis Evaluation Basis for Evaluation Case at 33yrs Number Rate Disc Rate CDF Replace service and instrument air compressors with more reliable Elimination of instrument air Not Cost- Cost will exceed 87 compressors which have self- system dependence on service INSTAIR $2K $3K $2K $$2K $4K >$500K Expert Panel Beneficial benefit.

contained air cooling by shaft driven water cooling.

fans.

Install a passive containment spray Improved containment spray Not Cost- Cost will exceed 91 CONT01 $793K $1.2M $717K $1.1M $1.7M >$10M Expert Panel system. capability. Beneficial benefit.

Increased decay heat removal Install an unfiltered, hardened capability for non-ATWS events, Not Cost- Cost will exceed 93 CONT01 $793K $1.2M $717K $1.1M $1.7M >$2M Expert Panel containment vent. without scrubbing released fission Beneficial benefit.

products.

Install a filtered containment vent to Increased decay heat removal remove decay heat. Option 1: Gravel capability for non-ATWS events, Not Cost- Cost will exceed 94 CONT01 $793K $1.2M $717K $1.1M $1.7M >$2M Expert Panel Bed Filter; Option 2: Multiple Venturi with scrubbing of released fission Beneficial benefit.

Scrubber products.

Reduced likelihood of hydrogen Provide post-accident containment Not Cost- Cost will exceed 96 and carbon monoxide gas H2BURN $10K $15K $9K $13K $20K >$100K Expert Panel inerting capability. Beneficial benefit.

combustion.

Increased cooling and containment of molten core debris. Molten core debris Create a large concrete crucible with escaping from the vessel is Not Cost- Cost will exceed 97 heat removal potential to contain contained within the crucible and MAB >$10M Expert Panel Beneficial benefit.

molten core debris. a water cooling mechanism cools the molten core in the crucible, preventing melt-through of the base mat.

Increased cooling and containment of molten core debris. Refractory material would be placed underneath the reactor vessel such that a molten core Create a core melt source reduction falling on the material would melt Not Cost- Cost will exceed 98 MAB >$10M Expert Panel system. and combine with the material. Beneficial benefit.

Subsequent spreading and heat removal from the vitrified compound would be facilitated, and concrete attack would not occur.

Strengthen primary/secondary Reduced probability of Not Cost- Cost will exceed 99 containment (e.g., add ribbing to CONT01 $1.2M $1.2M $717K $1.1M $1.7M >$10M Expert Panel containment over-pressurization. Beneficial benefit.

containment shell).

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 77 of 86 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA Benefit SAMA Potential Improvement Discussion Benefit 3% Disc Realistic at 95% Cost Cost Basis Evaluation Basis for Evaluation Case at 33yrs Number Rate Disc Rate CDF Increase depth of the concrete base mat or use an alternate concrete Reduced probability of base mat Not Cost- Cost will exceed 100 MAB >$10M Expert Panel material to ensure melt-through does melt-through. Beneficial benefit.

not occur.

Construct a building to be connected Reduced probability of Not Cost- Cost will exceed 102 to primary/secondary containment CONT01 $1.2M $1.2M $717K $1.1M $1.7M >$10M Expert Panel containment over-pressurization. Beneficial benefit.

and maintained at a vacuum.

Increased piping surveillance to identify leaks prior to complete Not Cost- Cost will exceed 104 Improve leak detection procedures. LOCA05 $685K $1.2M $620K $1.1M $1.5M >$2M Expert Panel failure. Improved leak detection Beneficial benefit.

would reduce LOCA frequency.

Install a redundant containment spray Increased containment heat Not Cost- Cost will exceed 107 CONT01 $1.2M $1.2M $717K $1.1M $1.7M >$2M Expert Panel system. removal ability. Beneficial benefit.

Install an independent power supply to the hydrogen control system using either new batteries, a non-safety Reduced hydrogen detonation Not Cost-108 grade portable generator, existing H2BURN $10K $15K $9K $13K $20K >$100K Expert Panel potential. Beneficial station batteries, or existing AC/DC independent power supplies, such as the security system diesel.

Install a passive hydrogen control Reduced hydrogen detonation Not Cost- Cost will exceed 109 H2BURN $10K $15K $9K $13K $20K >$100M Expert Panel system. potential. Beneficial benefit.

Erect a barrier that would provide enhanced protection of the Reduced probability of Not Cost- Cost will exceed 110 containment walls (shell) from ejected MAB >$10M Expert Panel containment failure. Beneficial benefit.

core debris following a core melt scenario at high pressure.

Install additional pressure or leak Not Cost- Cost will exceed 111 monitoring instruments for detection Reduced ISLOCA frequency. ISLOCA $123K $179K $111K $154K $259K >$500K Expert Panel Beneficial benefit.

of ISLOCAs.

Add redundant and diverse limit Reduced frequency of Not Cost- Cost will exceed 112 switches to each containment containment isolation failure and CONT02 $1K $1K $1K $1K $2K >$1M Expert Panel Beneficial benefit.

isolation valve. ISLOCAs.

Increase leak testing of valves in Not Cost- Cost will exceed 113 Reduced ISLOCA frequency. ISLOCA $123K $179K $111K $154K $259K >$1M Expert Panel ISLOCA paths. Beneficial benefit.

Install self-actuating containment Reduced frequency of isolation Not Cost- Cost will exceed 114 CONT02 $1K $1K $1K $1K $2K >$500K Expert Panel isolation valves. failure. Beneficial benefit.

Locate residual heat removal (RHR) Reduced frequency of ISLOCA Not Cost- Cost will exceed 115 ISLOCA $123K $179K $111K $154K $259K >$1M Expert Panel inside containment outside containment. Beneficial benefit.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 78 of 86 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA Benefit SAMA Potential Improvement Discussion Benefit 3% Disc Realistic at 95% Cost Cost Basis Evaluation Basis for Evaluation Case at 33yrs Number Rate Disc Rate CDF Cost would exceed benefit. Current plant Ensure ISLOCA releases are design requires scrubbed. One method is to plug drains to be open.

Not Cost-116 drains in potential break areas so that Scrubbed ISLOCA releases. ISLOCA $123K $179K $111K $154K $259K >$1M Expert Panel Analysis and license Beneficial break point will be covered with changes required to water. implement are included in the cost estimate.

Institute a maintenance practice to perform a 100% inspection of steam Reduced frequency of steam Not Cost- Cost will exceed 119 NOSGTR $1.4M $2.1M $1.2M $1.8M $2.9M >$3M Expert Panel generator tubes during each refueling generator tube ruptures. Beneficial benefit.

outage.

Increase the pressure capacity of the Eliminates release pathway to the secondary side so that a steam Not Cost- Cost will exceed 121 environment following a steam NOSGTR $1.4M $2.1M $1.2M $1.8M $2.9M >$10M Expert Panel generator tube rupture would not Beneficial benefit.

generator tube rupture.

cause the relief valves to lift.

Install a redundant spray system to Enhanced depressurization depressurize the primary system Not Cost- Cost will exceed 122 capabilities during steam NOSGTR $1.4M $2.1M $1.2M $1.8M $2.9M >$10M Expert Panel during a steam generator tube Beneficial benefit.

generator tube rupture.

rupture Route the discharge from the main steam safety valves through a Reduced consequences of a Not Cost- Cost will exceed 125 structure where a water spray would NOSGTR $1.4M $2.1M $1.2M $1.8M $2.9M >$10M Expert Panel steam generator tube rupture. Beneficial benefit.

condense the steam and remove most of the fission products.

Install a highly reliable (closed loop) steam generator shell-side heat Reduced consequences of a Not Cost- Cost will exceed 126 NOSGTR $1.4M $2.1M $1.2M $1.8M $2.9M >$10M Expert Panel removal system that relies on natural steam generator tube rupture. Beneficial benefit.

circulation and stored water sources Cost will exceed benefit. Current containment design does not support this Vent main steam safety valves in Reduced consequences of a Not Cost- modification.

129 NOSGTR $1.4M $2.1M $1.2M $1.8M $2.9M >$10M Expert Panel containment. steam generator tube rupture. Beneficial Modifications to containment and associated analysis are included in the cost estimate.

Add an independent boron injection Improved availability of boron Not Cost- Cost will exceed 130 NOATWS $63K $104K $57K $90K $134K >$1M Expert Panel system. injection during ATWS. Beneficial benefit.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 79 of 86 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA Benefit SAMA Potential Improvement Discussion Benefit 3% Disc Realistic at 95% Cost Cost Basis Evaluation Basis for Evaluation Case at 33yrs Number Rate Disc Rate CDF Add a system of relief valves to Improved equipment availability Not Cost- Cost will exceed 131 prevent equipment damage from NOATWS $63K $104K $57K $90K $134K >$2M Expert Panel after an ATWS. Beneficial benefit.

pressure spikes during an ATWS.

Install an ATWS sized filtered Increased ability to remove Not Cost- Cost will exceed 133 containment vent to remove decay NOATWS $63K $104K $57K $90K $134K >$1M Expert Panel reactor heat from ATWS events. Beneficial benefit heat.

Install motor generator set trip Reduced frequency of core Not Cost- Cost will exceed 136 NOATWS $63K $104K $57K $90K $134K >$500K Expert Panel breakers in control room. damage due to an ATWS. Beneficial benefit.

Reduced probability of a large Install digital large break LOCA Not Cost- Cost will exceed 147 break LOCA (a leak before LOCA05 $689K $1.2M $620K $1.1M $1.5M >$5M Expert Panel protection system. Beneficial benefit.

break).

Prevents secondary side depressurization should a steam line break occur upstream of the Install secondary side guard pipes up main steam isolation valves. Also Not Cost- Cost will exceed 153 NOSLB $51K $87K $46K $77K $108K >$1M Expert Panel to the main steam isolation valves. guards against or prevents Beneficial benefit.

consequential multiple steam generator tube ruptures following a main steam line break event.

Relatively minor modifications to door opening could result in lower flow to the Modifications to lessen impact of Lower impact of flood that Potentially dumbwaiter. Specific 160 internal flooding path through Control propagates through the <$50K Expert Panel Cost- benefit could not be Building dumbwaiter. dumbwaiter Beneficial calculated but SAMA item is judged to be low cost and therefore potentially cost beneficial.

Improvements to PORV performance Decrease in risk due to PORV Not Cost- Cost will exceed 161 that will lower the probability of failure PORV $18K $32K $16K $28K $39K >$100K Expert Panel failing to open. Beneficial benefit.

to open.

Wolf Creek estimated Install a large volume EDG fuel oil Allows transfer of EDF fuel oil to Potentially cost of $150K is less 162 tank at an elevation greater than the the EDG day tanks on failure of EDGFUEL $124K $131K $113K $156K $263K $150K Wolf Creek Cost-than the potential EDG fuel oil day tanks. the fuel oil transfer pumps. Beneficial benefit.

Lower risk due to failures in which Improve feedwater check valve feedwater check valves fail to Not Cost- Cost will exceed 163 reliability to reduce probability of FW02 $127K $218K $115K $191K $270K >$500K Expert Panel open and allow feeding of the Beneficial benefit.

failure to open.

steam generators.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 80 of 86 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA Benefit SAMA Potential Improvement Discussion Benefit 3% Disc Realistic at 95% Cost Cost Basis Evaluation Basis for Evaluation Case at 33yrs Number Rate Disc Rate CDF Provide the capability to power the Provide backup to ESW in

$1191 Not Cost- Cost will exceed 164 normal service water pumps from conditions with power only SW03 $307K $172K $267K $403K >$500K Expert Panel K Beneficial benefit.

AEPS. available from AEPS.

Increase the size of the RWST or Ensure a supply of makeup water Not Cost- Cost will exceed 171 otherwise improve the availability of LOCA04 $13K $23K $12K $20K $27K >$100K Expert Panel is available from the RWST. Beneficial benefit.

the RWST Implementation of temporary ventilation Potentially Improvements to UHS cooling tower Improve availability or mitigate or opening of doors 178 HVAC02 $113K $181K $102K $158K $239K <$100K Expert Panel Cost electrical room HVAC. loss of HVAC. will be a lower cost Beneficial than the calculated benefit.

Implementation of procedure change Modify procedures such that the Prevents possible thermally Potentially will be lower cost water loop seals in the RCS cold legs 179 induced steam generator tube RAI7a $63K $87K $57K $75K $134K <$100K Expert Panel Cost than benefit, are not cleared following core rupture following core damage. Beneficial especially if 95%

damage.

CDF benefit is considered.

SAMA considered potentially cost Install lower amperage fuses for beneficial without various 14 AWG control circuits in the benefit or cost Potentially MCR. The majority of the determination since 180 Reduced fire risk. Cost modification centers around the trip the NFPA 805 license Beneficial circuit fuses on NB, NG, PA, PB, and amendment request PG system breakers. committed to performing the modification.

SAMA considered potentially cost beneficial without benefit or cost Install redundant fuses and isolation Potentially determination since 181 switches for MCR evacuation Reduced fire risk. Cost the NFPA 805 license procedure OTO-ZZ-00001. Beneficial amendment request committed to performing the modification.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 81 of 86 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA Benefit SAMA Potential Improvement Discussion Benefit 3% Disc Realistic at 95% Cost Cost Basis Evaluation Basis for Evaluation Case at 33yrs Number Rate Disc Rate CDF SAMA considered To protect against multiple spurious potentially cost operation scenarios, cable runs will beneficial without be changed to run a single wire in a benefit or cost protected metal jacket such that Potentially determination since 182 spurious valve opening due to a hot Reduced fire risk. Cost the NFPA 805 license short affecting the valve control circuit Beneficial amendment request is eliminated for the fire area. This committed to modification will be implemented in performing the multiple fire areas.

modification.

SAMA considered potentially cost beneficial without Quick response sprinkler heads in benefit or cost cable chases A-11, C-30, and C-31 Potentially determination since 183 will be modified to be in accordance Reduced fire risk. Cost the NFPA 805 license with the applicable requirements of Beneficial amendment request NFPA 13-1976 edition.

committed to performing the modification.

Cost is for installation of redundant instrumentation system and would Improvements in the reliability of the More reliable main steam line Not Cost- likely be much higher.

184 Steam Line Isolation automatic SLIS $28K $40K $23K $35K $55K >$500K Expert Panel isolation. Beneficial Procedure and signal.

training already direct operators to manually back up failed automatic actuations.

Potentially Automate initiation of CCW flow to More reliable than manual 185 HEP $62K $112K $56K $99K $132K >$200K Expert Panel Cost the RHR heat exchangers. initiation of flow to RHR HX.

Beneficial Develop a procedure and obtain equipment to provide a temporary Ability to do this will Backup method of removing Not Cost 186 hookup of fire water to the RHR heat FWCCW $1K $2K $1K $2K $2K >$1M Expert Panel require larger fire decay heat if CCW is lost. Beneficial exchangers to use as a backup to pumps CCW for removing decay heat.

Already installed Install modification to power the Another source of backup power Potentially spare circuit breaker, normal charging pump from an 187 to the NCP in cases of station SBOMOD $174K $272K $157K $236K $367K $350K Expert Panel Cost implementation existing spare breaker from the blackout or loss of service water Beneficial requires power and AEPS.

control cables.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Enclosure 1 Page 82 of 86 Table 8-1. Callaway Plant Sensitivity Evaluation Callaway Benefit at Benefit at Benefit SAMA Benefit SAMA Potential Improvement Discussion Benefit 3% Disc Realistic at 95% Cost Cost Basis Evaluation Basis for Evaluation Case at 33yrs Number Rate Disc Rate CDF Install a permanent, dedicated Another source of backup power AEPS was installed generator for the NCP, and a motor- to the NCP, DC power with a spare breaker Potentially driven AFW pump and battery (pump/valve control and SG level SBOMOD and expansion 188 $182K $285K $165K $247K $385K $400K Expert Panel Cost charger to address SBO events in instrumentation), and power to an 2 capability that could Beneficial which the TD AFW pump is AFW pump in cases of station be used to supply unavailable. blackout or loss of service water various equipment.

Perform analysis to determine if it is Installation of 189 possible to modify current plant doors modified doors or to withstand higher flood heights. modification of Callaway Potentially Either perform modifications to install Reduction in risk due to internal flooding analysis will Plant Cost improved doors or revise flooding flooding. result in lower Management Beneficial analysis to incorporate results that flooding risk.

doors will withstand higher flooding Analysis is currently heights without propagating the flood. in progress.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 83 of 86 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.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 84 of 86 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.

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.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 85 of 86 Table 9-1. Callaway Plant Potentially Cost Beneficial SAMAs Callaway SAMA Number Potential Improvement Discussion Additional Discussion 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.

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.

Callaway Plant Unit 1 Environmental Report for License Renewal

ULNRC-05947 January 15, 2013 Page 86 of 86 Table 9-1. Callaway Plant Potentially Cost Beneficial SAMAs Callaway SAMA Number Potential Improvement Discussion Additional Discussion 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 189 Perform analysis to Reduction in risk due to Installation of modified determine if it is possible to internal flooding. doors or modification of modify current plant doors flooding analysis will to withstand higher flood result in lower flooding heights. Either perform risk. Analysis is modifications to install currently in progress.

improved doors or revise flooding analysis to incorporate results that doors will withstand higher flooding heights without propagating the flood.

Callaway Plant Unit 1 Environmental Report for License Renewal