ML14052A052
| ML14052A052 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 02/10/2014 |
| From: | Korsnick M Constellation Energy Nuclear Group, EDF Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML14052A052 (18) | |
Text
CENG.
a joint venture of 0 Comenation February 10, 2014 U.S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852 ATTENTION: Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant, Units 1 and 2 Renewed Facility Operating License Nos. DPR-53 and DPR-69 Docket Nos. 50-317 and 50-318 Response to NRC 10 CFR 50.54(0 Request for Information Regarding Near-Term Task Force Recommendation 2.1, Flooding - Flood Hazard Reevaluation
REFERENCES:
(a) Email from M. Thadani (NRC) to E. Tyler (CENG), "Calvert Cliffs R2.1 flooding reevaluations: RAls," dated January 9, 2014 (ML14010A015)
(b) Letter from J. A. Spina (CENG) to Document Control Desk (NRC), Calvert Cliffs Nuclear Power Plant, Units 1 and 2, Flood Hazard Reevaluation Report, dated March 12, 2013 (ML13078A010)
(c) Letter from E. J. Leeds (NRC) and M. R. Johnson (NRC) to All Power Reactor Licensees and Holders of Construction Permits in Active or Deferred Status, Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident, dated March 12, 2012 (ML12053A340)
On January 9, 2014 (Reference a), the Nuclear Regulatory Commission (NRC) issued a Request for Additional Information (RAI) to Constellation Energy Nuclear Group, LLC (CENG) regarding the Calvert Cliffs Nuclear Power Plant, LLC (CCNPP) Flood Hazard Reevaluation Report submitted on March 12, 2013 (Reference b). Reference (b) was submitted in response to Enclosure 2 of the Fukushima Lessons-Learned 50.54(f) letter dated March 12, 2012 (Reference c) regarding Near-Term Task Force (NTTF) Recommendation 2.1: Flooding.
Attachment (1) provides the CENG response to the NRC's RAI with the exception of RAI 3. Due to the time it will take to obtain the requested calculation information from the responsible vendor, CENG will provide the requested information by March 7, 2014. This change in schedule was discussed with the NRC staff on January 30, 2014.
Constellation Energy Nuclear Group, LLC 100 Constellation Way, Suite 200C, Baltimore, MD 21202
Document Control Desk February 10, 2014 Page 2 Attachment (2) lists the regulatory commitment included within this correspondence.
If there are any questions regarding this submittal, please contact Bruce Montgomery, Manager-Nuclear Safety and Security, at 443-532-6533.
I declare under penalty of perjury that the foregoing is true and correct. Executed on February 10, 2014.
Sincerely, /A 1
- 6MýW-cy' MGK/STD/EMT Attachments: (1) Calvert Cliffs Nuclear Power Plant Response to Request for Additional Information (2) Regulatory Commitments Contained in this Correspondence
Enclosure:
(1) Compact Disk - Data Files cc: (Without Enclosure 1)
NRC Project Manager, Calvert Cliffs Resident Inspector, Calvert Cliffs NRC Project Manager, Ginna Resident Inspector, Ginna NRC Project Manager, Nine Mile Point Resident Inspector, Nine Mile Point Regional Administrator, NRC Region I S. Gray, DNR
ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION Constellation Energy Nuclear Group, LLC February 10, 2014
ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION NRC RAI 1 - Local Intense Precipitation Flooding The licensee is requested to provide electronic versions of the input files used for HEC-HMS analysis in the [Flood Hazard Reevaluation Report] FHRR related to local intense precipitation analyses.
CCNPP Response Electronic versions of the HEC-HMS input files used in the local intense precipitation flooding analysis are provided in the enclosed Compact Disc (CD) in the folder named "LIP Flooding Input Files\HEC-HMS\CCNPP 1 2\".
NRC RAI 2 - Local Intense Precipitation Flooding The licensee is requested to provide electronic versions of the input files used for HEC-RAS analysis in the FHRR related to local intense precipitation analyses.
CCNPP Response Electronic versions of the HEC-RAS input files used in the local intense precipitation flooding analysis are provided in the enclosed CD in the folder named "LIP Flooding Input Files\HEC-RAS\".
The HEC-RAS project (*.PRJ) includes two 'Plan' files corresponding to two different steady flow datasets, and consequently two model run files. The first steady flow dataset includes the probable maximum precipitation steady state flow data from the HEC-HMS model. The second dataset includes several steady flow profiles to help develop rating relationships at model cross-section locations.
NRC RAI 3 - Local Intense Precipitation Flooding The licensee is requested to provide a description of the methods used to incorporate elevation measurements in the flood analysis and the likely magnitude of the errors associated with these elevations. Elevation measurement and conversion is crucial in defining flow parameters such as slope and flowpaths. Staff [is] also requesting a discussion of the methods used to incorporate elevation measurements in the flood analyses performed using HEC-RAS and HEC-HMS.
CCNPP Response Due to the time it will take to obtain the requested calculation information related to measurement uncertainties from the responsible vendor, CENG will provide the requested information by March 7, 2014. This change in schedule was discussed with the NRC staff on January 30, 2014.
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ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION NRC RAI 4 - Local Intense Precipitation Flooding The licensee is requested to clarify the consistent use of the vertical elevation datum in the FHRR_ More specifically, please provide a consistent description of the vertical datums [Mean Sea Level] MSL, NGVD29, and their relationship as used in the FHRR analysis. Estimation of water surface elevations and comparison with established levels flood hazards rely on the consistency of a [well-defined] vertical datum and clear descriptions of correlations between datums if the multiple datums used.
CCNPP Response This question was addressed during our independent third party review. The resolution of the issue resulted in the following:
From Page 1-1 of the FHRR:
Calvert Cliffs Nuclear Power Plant (CCNPP) Units 1 & 2 adopts the mean sea level (MSL) datum as the plant's reference vertical datum. The MSL datum is also referred to as the National Geodetic Vertical Datum of 1929 (NGVD 29). In this report, the NGVD 29 datum is referenced primarily; however, the two definitions could be used interchangeably. Tidal data are referenced as they appear in the source.
Directions are described relative to true north in this report, unless specified otherwise. English units are used consistently throughout this report except for instances where the base information is developed in SI units. In such a case, the corresponding English unit is provided in parentheses.
In section 4 of the FHRR, paragraph 2.4.1.1 describes the adjustment to the tidal datum for the PMSS analysis. Specifically the (Updated Final Safety Analysis Report] UFSAR uses MLW (Mean Low Water) versus NGVD. To rectify this, a comparison was made and a correction factor of 0.12 ft. is added to MLW values to convert to NGVD.
As described above, the remainder of the report treats MSL data and NGVD data as equivalent.
NRC RAI 5 - River and Stream Flooding Provide a more detailed discussion of the [Probable Maximum Flood] PMF for the Haul Road and Branch 1 and 2 drainage areas. Since the Haul Road drainage area is adjacent to the site and since Branch 1 and 2 drainage areas are near the site, the staff requests a detailed discussion of the potential for flooding the site from local intense precipitation event (and resulting PMF) in these adjacent areas, CCNPP Response Scenario 1 - Existing Conditions - No Haul Road The "Proposed Haul Road" pictured in Figure 2.1-3, Sub-Basin Drainage Area Map, is not a part of the CCNPP Units 1 and 2 site characteristics; however, based on topography shown in Figure 2.1-3 and given 2 of 13
ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION that the "Proposed Haul Road" does not exist, the area shows a high point elevation of I Ift. The Probable Maximum Precipitation (PMP) impacts to CCNPP Units 1 and 2 would potentially be:
- Water would flow in the N-NW direction towards the plant (Sally Port Road with low point elevations of 46-51ft.) and flow into Sub-basin 5 and ultimately discharge into the Chesapeake Bay as evaluated.
- Water would flow in the N-NW direction towards the plant (Sally Port Road with low point elevations of 46-51fi.), follow Barge Rd east (with low points of 17-25ft.), and ultimately discharge into the Chesapeake Bay.
- Water would flow in the S-SE direction away from CCNPP Units 1 and 2 towards Branches I and 2 and discharge directly into Chesapeake Bay and not impact CCNPP Units 1 and 2.
Scenario 2 - Future Conditions if Unit 3 Construction Commences The "Proposed Haul Road" does not currently exist, and its future existence is dependent on the construction of CCNPP Unit 3. If the "Proposed Haul Road" pictured in Figure 2.1-3, Sub-Basin Drainage Area Map, were to exist, so would CCNPP Unit 3. As a result, the engineering and conclusions reached in Chapter 2 of the CCNPP Unit 3 FSAR regarding the "Proposed Haul Road" and flooding impacts on branch lines 1 and 2 would be valid.
Per Section 2.4.2.3.2 of the CCNPP Unit 3 FSAR, the -Proposed Haul Road" will be designed to drain into two swales which eventually discharge to the Chesapeake Bay. Also, Figures 2.4.8 through 2.4.11 show the location of the "Proposed Haul Road" in conjunction with a "Proposed Flood Wall," as well as the "proposed swales" that will exist to help mitigate flooding.
Per Section 2.4.2.3.1 of the CCNPP Unit 3 FSAR, CCNPP Unit 3 is located adjacent to the existing CCNPP Units 1 and 2. The site layout and drainage system are shown in Figure 2.4-7. The site grade completely fills in the upper reaches of the two unnamed branches (Branch 1 and Branch 2) shown on Figure 2.4-1 such that the streams will now begin just east of the CCNPP Unit 3 plant boundary area.
Additionally, the drainage area for these streams, at the headwater., consists of only the CCNPP Unit 3 power block area. Since the power block area is at a much higher elevation than the existing streams, flood flows in these streams will not affect the CCNPP Unit 3 power block area. Thus, local PMP analysis on these two streams was not performed.
With the existence of CCNPP Unit 3, flooding of Branch lines 1 and 2 will have a minimal impact on CCNPP Units I and 2. Also, flooding of the "Proposed Haul Road" (as depicted in Figure 2.1-3, Sub-Basin Drainage Area Map) will not affect CCNPP Units land 2. Therefore, statements and conclusions in Section 2.2.1 of the CCNPP Unitsl and 2 FHRR are correct and consistent with the conclusions reached in the CCNPP Unit 3 FSAR.
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ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION NRC RAI 6 - Storm Surge Flooding The licensee's walkdown report submitted as part of Enclosure 4 of the March 12, 2012 50.54(f) letter states the design basis flooding elevation is 27.5 ft. MSL (although the walkdown report also notes that both 27.1 ft. MSL and 27.5 ft. MSL appears in the [Updated Final Safety Analysis Report] UFSAR). The FHRR states the design basis is 27.1 ft. NGVD 29, however FHRR Table 2.4.3 states the [Probable Maximum Storm Surge] PMSS + Wave [Run-up] is 28.14 ft. NGVD. Please describe the apparent contradiction of the site's design basis storm surge height.
CCNPP Response This question of 27.5 ft. MSL versus 27.1 ft. MSL was addressed during our independent third party review of the FHRR. The resolution of the issue resulted in the following comment and resolution:
Comment Section 1.2 - review the flooding walkdown report and incorporate relevant details e.g., page 5 -
discrepancy in the storm surge wave run-up elevation 27.1 ft. vs. 27.5 ft.
Resolution The UFSAR provides a run-up elevation of 27.5 ft. MSL (Section 2.8.3.5) as a calculated value, which is confirmed as 27.1 ft. MSL (Section 2.8.3.6) through a physical model test. The model test required use of an adverse slope for the intake deck to reduce wave run-up. The adverse slope is an as-built design feature for this plant. Section 2.8.3.6 concludes that the maximum run-up for the intake structure would be 27.1 ft. MSL with a margin of 1.4 ft. to the intake structure roof. The FHRR uses 27.1 ft. MSL run-up.
FHRR Table 2.4.3 FHRR Table 2.4.3 identifies a value of 28.14 NGVD as the PMSS + Wave Run-up. This is a calculated value using the PMSS level (including the antecedent level 2.7 ft. MLW) and Wave run-up height of 11.9 ft. The 11.9 ft. value is a new calculated value. The original supporting vendor Storm Surge Report, Table 3-2 used values directly taken from Sections 3.8.3.5 and 3.8.5.6. The final submitted report edited some of the values to show the makeup of the PMSS value by including the antecedent water level, and the newly calculated wave run up (11.9 ft.) which yields the 28.14 ft. value. The purpose of the edited values was to provide a better comparison to CCNPP Unit 3 Combined Operating License Application (COLA) data. It would have been more appropriate to leave the previous value of 27.1 ft. as the existing design value.
However, Table 3.0.1, Section 3 of the FHRR, compares new hazard values to existing design values. As can be seen on this table, the value for wave run-up including storni surge used for comparison is 27.1 ft.
NGVD, which is consistent with the UFSAR value. (See Table 3.0-1 below).
2.3 Walkdown Report The walkdown report did use 27.5 ft. as the design value. As stated, both 27.5 ft. and 27.1 ft. are contained in the UFSAR. Section 2.8.3.6 of the UFSAR explains the model verification that was performed as a method to validate the calculated value, taking into account the physical attributes of the 4 of 13
ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION Intake Structure. This section was added to the UFSAR in response to questions from the NRC in 1971, related to the calculated value of 27.5 ft. The use of 27.5 ft. in this report is conservative for penetrations in the Intake structure as it relates to Available Physical Margin determination.
Conclusion The use of different values in the two reports did not adversely affect the results of the reports. The 0.4 ft.
delta between 27.5 ft. and 27.1 ft. does not change the results in either report. The design basis storm surge value is 27.5 ft. MSL.
Table 3.0-1 Current Design Basis Flood Elevations for Safety-Related and Important-to-Safety SSCs Current Flood Current Reevaluated Flood Critical Protection Design Basis Flood Level Flooding Mechanism Structure Elevation Flood Level ft NGVD 29 ft NGVD 29 ft NGVD 29 Containment Buildings, Auxiliary Building, EDG11 4 Local Intense Precipitation Building, SBO 450, 455(4), 44.8(4) 45-1i4 -47.0 Building, Turbine Building(3)
No Flooding No Flooding No Flooding No Flooding Expected Expected Expected Expected Upstream Dam Failures No Flooding No Flooding No Flooding Expected Expected Not Evaluated Expected Storm Surge (including wave Intake Structure 28.5 27.1 31.3 runup)
Seiche No Flooding No Flooding Not Evaluated No Flooding Expected Expected Expected 11.5 Tsunami (including runup) Intake Structure 28.5 No Flooding (No Flooding Expected Expected)
Ice Induced Flooding No Flooding No Flooding Not Evaluated No Flooding Expected Expected Expected Channel Migration or No Flooding No Flooding No Flooding No Flooding Diversion(5) Expected Expected Expected Expected Notes:
(1) Emergency Diesel Generator Building (2) Station Blackout Building is augmented safety-related (3) Turbine Building is Seismic Category II; see Chapter 4 for further discussions (4) At the Emergency Diesel Generator and SBO Buildings (5) Shoreline protection measures exist and no erosion expected 5 of 13
ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION NRC RAI 7 - Integrated Assessment The March 12, 2012, 50.54(f) letter, Enclosure 2, requests the licensee to perform an integrated assessment of the plant's response to the reevaluated hazard if the reevaluated flood hazard is not bounded by the current design basis. The licensee is requested to provide the applicable flood event duration parameters (see definition and Figure 6 of the Guidance for Performing an Integrated Assessment, JLD-ISG-2012-05) associated with mechanisms that trigger an Integrated Assessment. This includes (as applicable) the warning time the site will have to prepare for the event, the period of time the site is inundated, and the period of time necessary for water to recede off the site for the mechanisms that are not bounded by the current design basis. The licensee is also requested to provide a basis for the flood event duration parameters. The basis for warning time may include information from relevant forecasting methods (e.g., products from local, regional, or national weather forecasting centers).
CCNPP Response PMP Event As shown in the attached pictogram (provided on the next page) the warning time for the PMP event is in excess of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The PMP event requires a 40% PMP followed by 2 to 3 day dry period to allow for ground saturation. The ensuing stormn was analyzed as a six hour duration rainstorm, resulting in an anticipated flood level of 47 ft. or 2 ft. above grade. The flooding above grade occurs at approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> into the event, rapidly reaches a peak at three hours and begins to recede. The total duration of flooding at the site is 90 minutes (See Figures 5, 6 and 7 below). The warning time for the site is in excess of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. A precursor stormn must occur and be followed by the actual 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> rainfall in the following days. A trigger point for site preparation, contained in ERPIP-3.0, requires deployment of the flood barriers when the following conditions are met:
- 1. The site has experienced greater than 11.2 inches of rain in a 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> period AND
- 2. A dry period of 2-3 days has occurred AND
- 3. Rainfall is predicted at the site in excess of 18" in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> OR rainfall rate is predicted to be greater than 3 inches/hour.
Prior to the onset of the rainfall, the site will deploy the flood barriers, interim measure from the FHRR.
CCNPP has a contract in place with "Code Red" that automatically sends an alert message to specific Operations staff for all weather watches and warnings that affect St. Mary's, Calvert and Anne Arundel Counties in Maryland. This alert will trigger monitoring of the event by the station staff.
Additionally, weather information is obtained from WEATHERTAP.com and the National Weather Service as defined by ERPIP 3-0, Attachment 20, Severe Weather.
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ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION Timeline based on Figure 6 of the Guidance for Performing an Integrated Assessment, (JLD-ISG-2012-05)
I PMP Flood Duration Pictogram I Flood Event Duration 47 ft Dry Period Ground Saturates Flood Bamers deployed 2-34FHR ft- 120 90 Minutes 45 ft Mins 40% PMP Ram Prediction of :3 inches per - o FkxROQ WSW P5 Occurs at hour OR P.R.
P., F -ood Cvl
- B Site 18* six period wp.o
>11 2 inches of rain in a 6 Reference Bechtel Calculation hour periou 25794-000-KOC-OO00-00001 (on eportal) figures 5, 6
&7. pages 21 and 22 Tngger Points as defined in ERPIP-3.0 Immediate Actions and EP-1-108 Severe Weather 1oi, __ _
F11odig 1.5 Hours 0000 0200 0410o 0600 0800 1000 1200 Time (hr) 0olo0CM1
-lMPpWs fitoomill0 *011111
- -- Rln PMP Slohi.o SUfB-4*es0ult O.*tO. Fb
PW St s Kl n" ONERS0N R.UONA Oi Flo Figure 7. Hydrograph at Junction J-3 on Downstream-2 7 of 13
ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION CCPMP-U12 PWL CCPMP-U12-plian 12/2W02012 River OnSrearn 2 Reach CCPMP- DN2 RS =1509 K.02,02 02 75: 2 EGPM 702 ws PwP aO 7WGround BankSte I¢ w
"evatiorI of 45.0 ft at E~tra*ico 400 Figure 5. Predicted Maximum Water Level at Cross Section 1509 465
~4n5 0
2 40 .- t 455" j 45.0o 43.5-I'I 43.05 ...- .... T- - r -
160$ 2W 400 600 800 Q TotW (cs)
Figure 6. Rating Curve at Cross Section 1509 on Downstream-2 8 of 13
ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION PMSS Event As shown in the attached pictogram (provided below) the warning time for the PMSS event is in excess of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The initiating event is prediction of a hurricane that may affect the CCNPP site. Hurricane watches are issued when the storm is within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> from, and approaching, the United States. The site will start monitoring the hurricane once a hurricane watch has been issued. Hurricane warnings are issued when the storm is within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> from landfall. Site initial preparations as outlined in EP-1-108 begin as soon as the watch is issued. Additionally, once the warning has been received with a potential for landfall and a path of approach to the CCNPP site, additional actions are implemented. These actions include the recall of additional personnel, execution of various preparation checklists, and a unit shutdown 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> prior to an anticipated site impact. All of these actions are contained in ERPIP-3.0 Immediate Actions and EP- 1-108 Severe Weather preparation.
These procedures also contain guidelines for implementation of interim flood protection measures, including the covering of the intake structure ventilation louvers, as described in the FHRR section 4.
These interim measures will be in place prior to the arrival of the PMH on site.
Weather information can be obtained as described under PMP above as well as www.fema.gov/fema/trop.htm, as described in EP-1-108 Severe Weather.
PMSS Flood Duration Pictogram Flood Event Duration This event impacts the Intake Structure Only. Other critical structures located above PMSS water level Duration Undefined - Hurricane 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br /> 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> strength, track and forward I I I ý speed dependent FHRRintern weasuos NoteI T-48 T-36 T-8 T- 4 T-0 Fl-d Hurricane Watch Hurricane warning issued Unit Louver covers Storm HumaneF issued at 48 additional preparations as Shutdown deployed to Surge and mes rooved hours Site outlined in Severe Weather to Mode 3 protect Salt Water Wave Run past site monitoring and procedure Hot pumps located in Up cause and strm initial reparations It track and landfatl predicted to shutdown Intake structure overtopping surge begin impact CCNPP Eelotod Tier B-.d -, of Intake recedes un erwyintoMode3 structure roof Note I- Loeose ECP wiea--.i operoso U tu 24 ho-t o,5,o, w55. ewuct. vifavosastbre Trigger Points as defined in ERPIP-3-0 Immediate Actions and EP-1-108 Severe Weather j All Activities are governed by ERPIP-3-0 & EP-1-108 Severe Weather 9 of 13
ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION No specific duration has been defined for the PMSS event. This is difficult to predict as it is dependent on hurricane strength, track and speed. The only structure affected by the PMSS is the intake structure.
Other structures containing critical equipment are well above the PMSS elevation of 31.3 ft. (See Table 8 below)
PMP Affected Structures and Flood Duration Length - Structures are not affected by PMSS (Reference Bechtel Calculation -25794-000-KOC-0000-0000 1-000 Local PMP Drainage Study)
South Service Building 45.0 489 Downstream-1 4e.8 - 1.8 1.5 Turbine Building 45.0 382 Downstream-1 45.9 - 0.9 0.8 Auxiliary Building 45.0 1722 Downstream-2 47.0 -2.0 1.5 Auxiliary Building 45.0 1509 Downstream-2 46.9 - 1.9 1.5 Auxiliary Building 45.0 1412 Downstrean-2 46.9 - 1.9 1.3 Auxiliary Building 45.0 1336 Downstream-2 46.9 - 1.9 1.0 Turbine Building 45.0 1075 Downstream-2 45.1 -0.1 0.3 Diesel Generator Bulldinv 45.5 1075 Downstream-2 45.1 0.4 0.0 Elevations for safety relatea racilmes are based on Reference 1u Table 8. Comparison of Maximum PMP Water Level and Floor Elevation at Openings/Entrances of Critical Structures NRC RAI 8 - Integrated Assessment The March 12, 2012, 50.54(f) letter, Enclosure 2, requests the licensee to perform an integrated assessment of the plant's response to the reevaluated hazard if the reevaluated flood hazard is not bounded by the current design basis. The licensee is requested to provide the flood height and associated effects (as defined in Section 9 of JLD-ISG-2012-05) that are not described in the flood hazard reevaluation report for mechanisms that trigger an Integrated Assessment. This includes the following quantified information for each mechanism (as applicable):
0 Hydrodynamic loading, including debris, 0 Effects caused by sediment deposition and erosion (e.g., flow velocities, scour),
0 Concurrent site conditions, including adverse weather 0 Groundwater ingress, and 0 Other pertinent factors (e.g., waterborne projectiles)
CCNPP Response The following tables describe the inputs to be used for the Integrated Assessment as defined in Section 9 of JLD-ISG-2012-05.
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ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION PMP Event - Probable Maximum Precipitation Parameter FHRR Evaluated Reference Section or Integrated Supporting Calculation Assessment Input PMP Flood Height New PMP Water Level 47 ft. Section 2.1.6 Yes Hydrodynamic Not Evaluated N/A No loading Debris loading Determined to be minimal Section 2.1.5 Effect of Yes based on site conditions. Also Local PMP procedure changes to EP- 1-108 Severe Weather identify the need to remove potential flotsam from area of concern i.e., staged materials Concurrent site No specific concurrent N/A No conditions, condition evaluated. Interim including adverse actions to be performed prior weather to the expected PMP event.
Groundwater Interim actions to prevent on Section 4 of FHRR Yes ingress Auxiliary Building to preclude ingress See Table 8 in the response to RAI 7 for Intake Structure and 1A Diesel Critical Structures Generator not susceptible elevations.
Turbine Building evaluated for Bechtel Calculation -
Ingress during PMP with all 25794-000-KOC-0000-ingress paths open and it was 0005-000, Evaluation of determined that no safety TB flooding due to Local significant SSCs affected PMP Other pertinent None noted N/A No factors Effects caused by Sediment and erosion and Section 2.1.5 Effect of Yes sediment deposition scour determined to be Local PMP and erosion (e.g., minimal based on site flow velocities, conditions and impermeable scour), surfaces.
Bechtel Calculation-Flow velocities contained in 25794-000-KOC-0000-calculation 00001-000 Local PMP Drainage Study 11 of 13
ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION PMSS Event - Probable Maximum Storm Surge Parameter FHRR Evaluated Reference Section or Integrated Supporting Calculation Assessment Input PMSS Water Level New PMSS Water Level 31.3 Section 2.4 Storm Surge Yes ft.
Hydrodynamic Evaluated for new hazard and Rizzo Calculation Yes loading new loads on intake structure 4832-F-3 roof due to overtopping See Figure 4, hydrodynamic load pictogram provided on next page.
Section 2.8.3.6 Structural Analysis of the Intake Structure and Conclusions Debris loading No specific debris load Section 3 -Comparison Yes identified of Current and Reevaluated Flood-Existing UFSAR states intake Causing Mechanisms structure can withstand impact of baffle wall plate without damage to the intake structure (UFSAR 2.8.3.6)
Concurrent site No specific concurrent N/A No conditions, condition evaluated. Interim including adverse actions to be performed prior weather to expected PMSS storm.
Groundwater N/A for this event N/A No ingress Intake Structure Wind and hydrodynamic ECP-13-000549 Yes Roof Ventilation loading and wind driven Louvers missiles evaluated during ECP generation for interim actions No specific debris loading identified Effects caused by Scour is not expected as stated N/A No sediment deposition in UFSAR 2.8.3.6 and erosion (e.g.,
flow velocities, scour),
Note: All supporting calculations were previously uploaded to the ePortal site.
As stated in Section 2.6.8, the Probable Maximum Tsunami (PMT) is not a controlling flood mechanism and is bounded by the PMSS so it will not be reevaluated as part of the integrated assessment.
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ATTACHMENT (1)
CALVERT CLIFFS NUCLEAR POWER PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION Intake Structure Hydrodynamic load pictogram - Reference Calculation, Rizzo, 12-4832-F-3 Sandbags 2
P2 = 1.08 kN/m EL. +31.3 ft NGVD P. = 4.64#m k EL. +28.5 ft NGVD nMeaWeSurface EL +17.5 ft NGVD
=ý h. -
=k ] =.6 . depIntake Structure Wall hb= h,= d = depth = 43.5 ft =1 3.26mm 13 of 13
ATTACHMENT (2)
REGULATORY COMMITMENTS CONTAINED IN THIS CORRESPONDENCE Constellation Energy Nuclear Group, LLC February 10, 2014
ATTACHMENT (2)
REGULATORY COMMITMENTS CONTAINED IN THIS CORRESPONDENCE The following table defines the Calvert Cliffs Nuclear Power Plant, LLC Units 1 and 2 (CCNPP),
regulatory commitments contained in this correspondence.
Regulatory Commitment Due Date CCNPP will provide the information requested by the NRC on January 9, 2014, in March 7, 2014 RAI 3 by March 7,2014.
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