RS-12-170, Day Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Flooding Aspects of Recommendation 2.3 of the Near-Term Task Force Review of Insights from Fukushima Dai-ichi Accident
ML12332A307 | |
Person / Time | |
---|---|
Site: | Quad Cities |
Issue date: | 11/27/2012 |
From: | Kaegi G Exelon Generation Co |
To: | Office of Nuclear Reactor Regulation, Document Control Desk |
References | |
RS-12-170 | |
Download: ML12332A307 (43) | |
Text
RS-12-170 November 27, 2012 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852 Quad Cities Nuclear Power Station, Units 1 and 2 Renewed Facility Operating License Nos. DPR-29 and DPR-30 NRC Docket Nos. 50-254 and 50-265
Subject:
Exelon Generation Company, LLCs 180-day Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding the Flooding Aspects of Recommendation 2.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident
References:
- 1. NRC Letter, 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
- 2. NRC Letter, Endorsement of Nuclear Energy Institute (NEI) 12-07, Guidelines For Performing Verification Walkdowns of Plant Flood Protection Features, dated May 31, 2012
- 3. Exelon Generation Company, LLCs 90-day Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendations 2.1 and 2.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident (Flooding), dated June 11, 2012 On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued Reference 1 to all power reactor licensees. Enclosure 4 of Reference 1 contains specific Requested Actions, Requested Information, and Required Responses associated with Recommendation 2.3 for Flooding. On June 11, 2012, Exelon Generation Company, LLC (EGC) submitted the 90-day response requested in Enclosure 4 of Reference 1, confirming that EGC would use the NRC-endorsed flooding walkdown procedure (Reference 3).
u.s.
U.S. Nuclear Regulatory Commission Commission 180-Day Response 180-Day Response to to 50.54(f) 50.54(f) Letter Letter NTTF Recommendation 2.3: Flooding NTIF Flooding November27,2012 November 27, 2012 Page Page 2 2 Forflooding For floodingRecommendation Recommendation 2.3 2.3 (walkdowns),
(walkdowns), Enclosure 4 of Reference Reference11states statesthat thatwithin within 180 days 180 days of of the the NRC's NRC's endorsement endorsement of of the the walkdown walkdownprocess process (Reference (Reference 2),
2), each each addressee addressee willsubmit will submitaafinalfinalresponse, response, including includingaalist listofofany anyareas areasthat thatareareunable unabletotobebeinspected inspected due to inaccessibility and inaccessibility and aa schedule schedule for when the walkdownwalkdown willwillbebecompleted.
completed. This letter provides the letter provides the Quad Cities Quad Cities Nuclear Nuclear Power Power Station, Station, Units Units 11 andand 22 180-day 180 -day response response to Reference 11 for Flooding Recommendation Flooding Recommendation 2.3. 2.3.
There were There were no no deficiencies deficiencies identified identified during during the the walkdowns walkdowns requiring requiring follow follow-up
- up in in the the corrective action program.
action Enclosure 1 to this letter provides the requested Enclosure requestedinformation information forfor Quad Cities Nuclear Nuclear Power Power Station Units Station Units 11 andand 2.
contains no new regulatory This letter contains regulatory commitments.
Should Should you you have any questions questions concerning concerning the the content content of of this letter, letter, please please contact Ron Ron Gaston at (630)
(630) 657-3359.
II declare declare under penalty penalty of of perjury perjurythat thatthe theforegOing foregoingisistrue trueandandcorrect.
correct. Executed Executed on the 27th day of November 2012.
Respectfully,
'~iLL¥ Glen T. Kaegi Director - Licensing Licensing & Regulatory Regulatory Affairs Affairs Exelon Generation Generation Company, LLC LLC
Enclosures:
Enclosures:
1.
- 1. Flooding Flooding Walkdown Walkdown Report In In Response Response To ToTheThe50.54(f) 50.54(f)Information Information Request RequestRegarding Regarding Near-Near-Term Term Task ForceForce Recommendation Recommendation2.3: 2.3:Flooding Floodingforfor the the Quad Quad Cities CitiesNuclear NuclearPower Power Station, Station, Units Units 11 and and 22 cc:
cc: Director, Director, Office Office of of Nuclear NuclearReactor ReactorRegulation Regulation Regional Regional Administrator Administrator -- NRC NRCRegion RegionIIIIII NRC NRC Senior Senior Resident ResidentInspector Inspector -- Quad QuadCities CitiesNuclear NuclearPowerPowerUnits Units 11and and22 NRC NRC Project Project Manager, Manager, NRR NRR - Quad QuadCitiesCitiesNuclear NuclearPower PowerUnits Units11and and22 Illinois Illinois Emergency Management ManagementAgency Agency--Division Division of of Nuclear Nuclear Safety Safety
U.S. Nuclear Regulatory Commission 180-Day Response to 50.54(f) Letter NTTF Recommendation 2.3: Flooding November 27, 2012 Page 3 Enclosure 1 Flooding Walkdown Report In Response To The 50.54(f) Information Request Regarding Near-Term Task Force Recommendation 2.3: Flooding for the Quad Cities Nuclear Power Station, Units 1 and 2 (40 pages)
FLOODING WALKDOWN REPORT IN RESPONSE TO THE 50.54(f) INFORMATION REQUEST REGARDING NEAR-TERM TASK FORCE RECOMMENDATION 2.3: FLOODING for the QUAD CITIES NUCLEAR POWER STATION (Unit 1 & Unit 2) 22710 206th Avenue, Cordova, IL 61242 Renewed Facility Operating License Nos. DPR-29 & DPR-30 NRC Docket Nos. 50-254 & 50-265 l
Exelon Generation Company, LLC 300 Exelon Way, Kennett Square, PA 19348 Prepared by:
AMEC Environment & Infrastructure, Inc.
502 West Germantown Pike, Suite 850, Plymouth Meeting, PA 19462 October 31, 2012 Printed Name Affiliation Signature Preparer: PETR MASOPUST AMEC MATIHEW LEHRER AMEC JEFFREY WRIGHT
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0
- 1. EXECUTIVE
SUMMARY
2
- 2. PURPOSE 3
- a. Background 3
- b. Site Description 4
- c. Requested Actions 6
- d. Requested Information 6
- 3. METHODOLOGY 7
- a. Overview of NEI 12-07 (Walkdown Guidance) 7
- b. Application of NEI12~07 8
- c. Reasonable Simulations 9
- d. Walkdown Inspection Guidance .......................................................................................................... 11
- 4. RESULTS .......................................................................... 12
- a. Requested Information Item 2(a) Design Basis Flood Hazards ......................................................... 12
- b. Requested Information Item 2(b) - Protection and Mitigation Features ............................................ 13
- c. Requested Information Item 2(c) - Flood Warning Systems ............................................................... 14
- d. Requested Information Item 2(d) - Flood Protection System/Barrier Effectiveness .......................... 14
- e. Requested Information Item 2(e) Implementation of Walkdown Process ....................................... 30
- f. Requested Information Item 2(f) Findings and Corrective Actions Taken/Planned 31
- g. Requested Information Item 2(g) Cliff -Edge Effects and Available Physical Margin 32
- h. Requested Information Item 2(h) Planned/Newly-Installed Flood Protection Enhancements ........ 33 CONCLUSIONS 33 REFERENCES 1
NTTF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 2012 Revision 0 Per NRC's request} a flooding protection walkdown was conducted at Quad Cities Nuclear Power Station (Quad Cities Station) to identify and address plant-specific degraded, nonconforming} or unanalyzed conditions of the planfs flood features, including flood protection mitigation procedures. The flooding walkdown was conducted between September 10 and September 14, 2012 and included visual inspections and reasonable simulations.
The scope of the flooding walkdown was developed following a detailed review of all relevant licensing documents. Since the site is inundated during the design-basis Probable Maximum Flood (PMF) event}
Quad Cities Station is licensed to mitigate the affects of a flood by implementing procedures to prevent damage to the reactor core. The main flood emergency procedure (QCOA 0010-16) invokes a concurrent shutdown of both units using the standard operating procedure for reactor shutdown and removal of decay heat. In addition} reactor disassembly is initiated to allow for natural circulation of cooling water between the reactors, reactor cavities, and storage pools. Additional procedural steps are initiated to provide for make-up of water during the flooding emergency. Since the flood emergency procedure is the critical component of the plant's flood mitigation strategy} the main focus of the flooding walkdown was the review of the flood emergency procedure and the associated standard operating procedures.
Quad Cities Station does not have incorporated/exterior or temporary features that are credited in the Updated Final Safety AnalysiS Report (UFSAR) documents with providing flood protection. Exterior below-grade walls are not explicitly mentioned as protecting space credited as dry and providing flood protection against extreme groundwater conditions. However, following industry-wide guidance, below-grade structures (i.e., basement walls and basement slabs) of Unit 1 and Unit 2 Reactor and Turbine Buildings were included in the walkdown scope. The exterior walls and slabs were visually inspected for degraded and non-conforming conditions.
The methodology and acceptance criteria for the evaluation of flood protection features was developed based on NEI report 12-07 (Rev O-A), Guidelines for Performing Verification Wolkdowns of Plont Protection Features. The verification process for all implementing procedures included a reasonable simulation (Le., a detailed procedure walk-through with the staff responsible for implementation of the procedure). For procedures or procedural that have not been performed in the past, a drill or exercise was performed of the reasonable simulation to that the procedure can be performed as of the of the flood and documented a areas with below-grade walls and slabs, which were visually inspected during the walkdown. The majority of walls and slabs were seven were considered inaccessible. Since the are not credited individual flood features in the review of available drawings and judgment were used to assess whether they could potentially impact the ability 2
NTTF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 2012 Revision 0 of below-grade walls to function as flood barriers. There was no evidence of ,,,.,,,->,,,'" below these inaccessible penetrations.
Electrical conduits entering the turbine and reactor buildings were evaluated to determine whether they can provide a pathway for groundwater into safety-related buildings. There are several locations on the west side of the turbine building where electrical conduits, connected to electrical manholes or hand holes, penetrate the Turbine Buildings below grade. Conduits that were not visible during the walkdown were considered due to junction boxes or other obstructions preventing access to the penetrations.
Reasonable assurance that inaccessible penetrations and seals are present and will perform the external flood protection function was demonstrated if, during visible inspection, there was no evidence of past or current groundwater seepage observed on below-grade walls below these penetrations. In addition, all safety-related below-grade SSCs in the Turbine Buildings are located in watertight vaults providing protection from flooding. The penetrations through the watertight vaults are periodically tested per procedure, any small conduits which are not tested per procedure have been evaluated by engineering and have been determined not to affect the functionality of the safety related equipment and, therefore, the walkdown team determined that visual inspection of electrical manholes/handholes was unnecessary. The flood emergency procedure and the associated procedures (including standard shutdown procedures) were reasonably simulated to ensure that they can be performed as specified and protect the reactor from core damage during flooding conditions. Overall, twelve (12) reasonable simulations related to the implementation ofthe flood emergency procedure were performed. Based on the results ofthe evaluation and the review of operator and outage logs, the critical path items of the flood emergency procedure can be implemented as written. The concurrent disassembly of both reactors is, however, not clearly described in the flood emergency procedure. Interviews were conducted with the appropriate personnel in order to determine an appropriate and accurate time line for the implementation of the associated procedural steps.
- a. Background In response to the nuclear fuel damage at the Fukushima Daiichi power plant due to the March 11, 2011 earthquake and subsequent tsunami, the United States Nuclear Regulatory Commission (NRC) established the Near Term Task Force (NTTF) to conduct a systematic review of NRC processes and regulations, and to make recommendations to the Commission for its policy direction. The NTTF reported a set of recommendations that were intended to clarify and the framework for natural the NRC issued an information Title 10 of the Code of Federal CFR included
- Recommendation Seismic
- [NTTF} Recommendation 2.3: Flooding Recommendation EP
- Licensees and Holders of Construction Permits 3
NTTF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 In Enclosure 4 of Reference 3, the NRC requested that licensees "perform flood protection walkdowns to identify and address plant-specific degraded, nonconforming, or unanalyzed conditions and cliff-edge effects (through the corrective action program) and verify the adequacy of monitoring and maintenance procedures. note below regarding cliff-edge effects.)
Structures, systems, and components (SSCs) important to safety at nuclear power plants must be designed to withstand the effects of natural phenomena, including floods, without loss of capability to perform their intended safety functions. For flooding walkdowns, identifying/addressing plant-specific degraded, nonconforming, or unanalyzed conditions (through the corrective action program) and verifying the adequacy of monitoring and maintenance procedures is associated with flood protection and mitigation features credited in the current design/licensing basis. New flood hazard information will be considered in response to Enclosure 2 of Reference 3.
On behalf of Exelon Generation Company, LLC (Exelon), this report provides the information requested in the March 12, 2012 50.54(f} letter; specifically, the information listed under the "Requested Information" section of Enclosure 4, paragraph 2 ("a" through "h"). The "Requested Information" section of Enclosure 4, paragraph 1 ("a" through an, regarding flooding walkdown procedures, was addressed via Exelon's June 11, 2012, acceptance (Reference 1) of the industry walkdown guidance (Reference 2).
Note Regarding Cliff-Edge Effects Cliff-edge effects were defined by the NTTF Report (Reference 5), which noted that 'the safety consequences of a flooding event may increase sharply with a small increase in the flooding level'. While the NRC used the same term as the NTTF Report in the March 12 50.54(t) information request (Reference 3), the information the NRC expects utilities to obtain during the Recommendation 2.3: Flooding Walkdowns is different. To clarify, the NRC has now differentiated between cliff-edge effects (which are dealt with under Enclosure 2 of Reference 3) and a new term, Available Physical Margin (APM). APM information is required to be collected during the walkdowns. Refer to section 4G for further details regarding APM information.
- b. Site Description Quad Cities Station is located approximately 3.2 miles north of the Town of Cordova, Illinois. The plant is located on the Mississippi River at its confluence with Wapsipinicon River at Mile Mark 506.8 and at an elevation of 594.5 ft Mean Sea Level (MSL). There are no structural flood protection exterior active or flood in for Cities Station.
4
NTIF Recommendation 2.3 (Walkdowns) : Flooding Exelon Corporation October 31,2012 Revision 0 0- .
- r
'.n j;-
~' - ,
Figure 1: Site Location Quad Cities Station's external flood response efforts are designed with the intent to mitigate the damage resulting from the occurrence of the PMF of the Mississippi River. According to Section 3.4 of the Quad Cities Updated Final Safety Analysis Report (UFSARL there would be adequate time for a safe shutdown of both reactors prior to the flood reaching the plant grade and the plant can be maintained in a safe condition up to a flood of 603 ft MSL. If a flood ever exceeded the plant's grade, independently powered portable pumping equipment would be deployed above the projected flood elevation to supply the make-up water required in the storage pools and reactor vessels due to the evaporative cooling losses. It is also estimated that a flood producing an elevation of 603 ft MSL would be expected to recede down to grade level in about eight (8) days. The original design-basis flood, described in Section 2.4.3 of the Quad Cities UFSAR, was based on a 200-year flood with a peak discharge of 385,000 cfs and a peak flood stage of 589 ft MSL was considered to be the PMF at the time of the plant design . However, the UFSAR also states that floods exceeding the 200-yea r flood are plausible and would result in significantly greater flood elevations than the original PMF. To estimate flood stages associated w ith floods exceeding those of the original PMF, a stage-discharge curve was developed to estimate flows corresponding to a flood stage at plant grade of 594.5 ft MSL. Furthermore, the approximate PMF was estimated to be 1,200,000 cfs and reaching a flood Page 5
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 of 601 ft MSL The UFSAR does not discuss the effect of wind-generated waves. Local Intense Precipitation (LIP) evaluation is not included in the UFSAR and is, therefore, considered a beyond design-basis event.
- c. Requested Actions Per Enclosure 4 of Reference 3, the NRC requested that each licensee confirm use of the industry-developed, NRC-endorsed, flood walkdown procedures or provide a description of plant-specific walkdown procedures. In a letter dated June 11, 2012 (Reference 1), Exelon confirmed that the flooding walkdown procedure {Reference endorsed by the NRC on May 2012, will be used as the basis for the flooding walkdowns.
Other NRC-requested actions include:
(1) Perform flood protection walkdowns using an NRC-endorsed walkdown methodology; (2) Identify and address plant-specific degraded, nonconforming, or unanalyzed conditions, as well as cliff-edge effects, through the corrective action program, and consider these findings in the Recommendation 2.1 hazard evaluations, as appropriate; (3) Identify any other actions taken or planned to further enhance the site flood protection; (4) Verify the adequacy of programs, monitoring and maintenance for protection features; and (5) Report to the NRC the results of the wa!kdowns and corrective actions taken or planned. of Reference 3 also states, "If any condition identified during the walkdown activities represents a degraded, nonconforming, or unanalyzed condition (i.e. noncompliance with the current licensing basis) for an SSC, describe actions that were taken or are planned to address the condition using the guidance in Reference 6, including entering the condition in the corrective action program. Reporting requirements pursuant to 10 CFR 50.72 should also be considered."
- d. Requested Information Per Enclosure 4 of Reference 3,
- 1. The NRC requests that each licensee confirm that it will use the industry-developed, NRC endorsed, walkdown or provide a description of walkdown confirmed that the will be used walkdowns.
hazard for all
- b. Describe protection and mitigation features that are considered in the basis evaluation to external of water into SSCs to
- c. Describe any warning <,\I<..t"",,,, to detect the presence of water in rooms to 6
NTTF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0
- d. Discuss the effectiveness of flood protection systems and exterior, incorporated, and temporary flood barriers. Discuss how these systems and barriers were evaluated using the acceptance criteria developed as part of Requested Information item l.h.
- e. Present information related to the implementation of the walkdown process details of selection of the walkdown team and procedures) using the documentation template discussed in Requested Information item including actions taken in response to the peer review.
- f. Document results of the walkdown including key findings and identified degraded}
nonconforming, or unanalyzed conditions. Include a detailed description ofthe actions taken or planned to address these conditions using the guidance in Regulatory Issues Summary 2005-20}
Revision 1, Revision to NRC Inspection Manual Part 9900 Technical Guidance} "Operability Conditions Adverse to Quality or Safety," including entering the condition in the corrective action program.
- g. Document any cliff-edge effects identified and the associated basis. Indicate those that were entered into the corrective action program. Also include a detailed description of the actions taken or planned to address these effects. See note in Section 1a regarding the NRC's change in position on cliff-edge effects.
- h. Describe any other planned or newly installed flood protection systems or flood mitigation measures including flood barriers that further enhance the flood protection. Identify results and any subsequent actions taken in response to the peer review.
- a. Overview ofNEI 12-07 (Walkdown Guidance)
In a collaborative effort with NRC staff, NEI developed and issued report 12-07 (Rev O-A), Guidelines for Performing Verification Walkdowns of Plant Protection Features, dated May 2012 (Reference 2). The NRC endorsed NEI 12-07 on May 31, 2012 with amendments. NEI 12-07 was updated to incorporate the amendments and re-issued on June 18, 2012. On June 11, 2012, Exelon issued a letter to the NRC (Reference 1) stating that the endorsed flooding walkdown procedure (Reference 2) will be used as the basis for the flooding walkdowns. NE112~07 provides guidance on the following items:
- Definitions Flood Protection Features Reasonable Simulation 7
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 Available Physical Margin Variety of Site Conditions Flood Duration Basis for Establishing Walkdown Scope Identify Flood Protection Features (Walkdown List)
- Methodology Develop Walkdown Walkdown Packages Walkdown Team Selection and Training Perform Pre-Job Briefs Inspection of Flood Protection And Mitigation Features
- General
- Incorporated or Exterior Passive Flood Protection Features
- Incorporated or Exterior Active Flood Protection Features
- Temporary Passive Flood Protection Features
- Temporary Active Flood Protection Features
- Procedure Walk-through and Reasonable Simulation o Review ofthe Maintenance and Monitoring of Flood Protection Features o Review of Operating Procedures o Documentation of Available Physical Margins Documenting Possible Deficiencies Restricted Access, or Inaccessible
- Acceptance Criteria
- Evaluation and Reporting Results of the Walkdown
- Related Information Sources
- Examples
- Walkdown Record Form
- Sample Training Content
- Walkdown Application ofNE112-07 the walkdowns included three Data and The purpose of Phase 1 was to obtain a clear of the flood scope, methodology, and criteria for the walkdowns; and logistical planning. The following activities were Phase 1:
- Data and O&M and 8
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31} 2012 Revision 0
- Site visit to nrc>\J""u/ features and plant conditions;
- Desktop review of CLB documents to identify and describe flood protection/mitigation ctr::>t"'o\j
- Development of Walkdown List;
- Development of Walkdown methodology and "orr'''''o
- and strategy planning; and
- of Walkdown The purpose of Phase 2 was to execute the Flooding Walkdown, which included:
- Visual Inspection;
- Reasonable Simulation;
- Evaluation of maintenance/monitoring procedures; and
- Documentation of observations and possible deficiencies.
The purpose of Phase 3 was to develop the Walkdown Report to document the methodology and findings of the Flooding Walkdown and provide a response to "Requested Information" section of the "Recommendation 2.3: Floodinglf enclosure from the 10CFRS0.54 (f) letter. The Walkdown Report was developed per the template provided in NEI 12-07 [Rev. O-AL Appendix D.
- c. Reasonable Simulations A procedure walk-through} or "Reasonable Simulation", was conducted for temporary and/or active features that require manual/operator actions to perform their intended flood protection function. The purpose of the reasonable simulations was to verify the procedure or activity can be executed as specified/written. Per NEI 12-07 (Reference 2), reasonable simulation included the following:
- Verify that any credited time-dependent activities can be completed in the time required. Time-dependent activities include detection that the event will occur! has
- in
- to or For movement of across be impeded by soft soil conditions created by excessive water.
- Review the reliance on the station staff to execute If the review several activities are identified to 9
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 2012 Revision 0 evaluation of the effect on the station staff to demonstrate all actions can be completed as required.
- Verify that all resources needed to complete the actions will be available. (Note that staffing must be consistent with site access assumptions in emergency planning procedures.)
- Show that the execution of the activity will not be impeded by other adverse conditions that could reasonably be to simultaneously occur (for winds, lightning, and extreme air temperatures).
- Personnel/departments that have responsibility for supporting or implementing the procedure should participate in the simulation effort.
- The simulation should demonstrate that the personnel assigned to the procedure do not have other duties that could keep them from completing their flood protection activities during an actual event. Actions that would be performed in parallel during an event should be simulated in parallel; not checked individually and the results combined.
- Reasonable simulation need not require the actual performance of the necessary activities jf the activities have been previously performed and documented, or it has been periodically demonstrated and documented that the activities can be completed in the credited time.
The Flooding Walkdown activities for Quad Cities Station predominantly involved reasonable simulations since the flood mitigation strategy is to execute the flood emergency procedure, which prepares the plant for safe shutdown prior to the advent of the UFSAR flood event. The following categories of reasonable simulations were performed:
- Simple Simulations - simulations/walk-throughs with short performance times that have been previously performed, and records for which are available to document the successful implementation of the procedure in the credited time.
- Complex Simulations - simulations/walk-throughs with long performance times that have been previously performed, and records for which are available to document the successful implementation of the procedure in the credited time.
- Drills or Exercises activities that have not been performed before and that, therefore, require the actual performance of the activity to demonstrate that they can be completed in the credited time.
to execute the were in and accessible per the requirements of the procedures. The Walkdown Record Form provided in NEI 12-07 (Rev. O-A), Appendix Bf and Reasonable Simulation Worksheets were used to document the results of the Walkdown and 10
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 2012 Revision 0 Overall, twelve (12) reasonable simulations of procedural or standard shutdown procedures were performed to evaluate the effectiveness of the flood emergency procedure. Table 1 provides a summary of reasonable simulations performed during the walkdown. A detailed description of each reasonable simulation is provided in Section 4 d of this report.
Table 1: list of Reasonable Simulations Simulation # Simulation Name 1 Flood and Flood Watch 2 Mobile Makeup Demineralizer 3 Moving and Staging of Darley Model HE20V Portable Pump 4 De-energize Station Loads 5 Add Water to Tori/Drywells through the RHR System Test Lines 6 Filling the Reactor Cavities and Dryer-Separator Pools 7 Filling Radwaste Tanks using Fire System 8 Place Drywell Loads in PTL 9 al Diesel Oil Storage Tank Vents 10 n Plant Doors 11 Reactor Disassembly 12 Normal Unit Shutdown
- d. Walkdown Inspection Guidance A "Walkdown Inspection Guidance N was developed by Exelon to supplement NEI 12-07 (Reference 2),
based largely on A of NEI 12-07 (Examples). The was intended to not NEI for listed below.
It Exterior Passive Features:
Elevations and Passive Flood Barriers or Water Diversion Structures Drains and Catch Basins and Manhole Covers 11
NTTF Recommendation 23 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision a Floor Hatches Flap Gate/Backwater Valve/Duckbill Valve Flood Wall
- Incorporated or Exterior Active Features:
o Credited Watertight Doors Credited Non~Watertight Doors Pumps o Water Level Indication Gate Valves
- Temporary Passive Features:
Portable Flood Barriers and Inflatable Rubber Seals Flood Gate
- Temporary Active Feature o Pumps The information requested in Reference 3, Enclosure 4, under paragraph 2 of the "Requested Information" section, is provided below. The contents of each item were developed in accordance with Reference 2, Appendix D.
- a. Requested Information Item 2(a) - Design Basis Flood Hazards Describe the design basis flood hazard level(s) for all flood-causing mechanisms, including groundwater ingress.
The original flood design basis flood, described in Section 2.4.3 of the Quad Cities UFSAR, was based on a 200-year flood with a peak discharge of 385,000 cfs and a peak flood stage of 589 ft MSL The 200-year flood was considered to be the PMF at the time of the plant design. However, the UFSAR also states that floods exceeding the 200-year flood are plausible and would result in significantly greater flood elevations than the original PMF. To estimate flood stages associated with floods exceeding those of the original PMF, curve was developed by plotting river for the following floods: cfs (1951 cfs and maintained in a safe condition. The UFSAR does not discuss the affect (UP) evaluation is not included in the UFSAR and therefore, considered a beyond There are no incorporated/exterior or temporary flood ,,""'lOy.an to the site a flood than 594.5 ft MSL The site is allowed to flood the PMF and external flood 12
NITF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 control efforts are directed toward mitigation and prevention of damage to the reactor core during flooding conditions, No additional flood-causing events local intense precipitation, lock and dam failure, ice jams, and groundwater ingress) were considered in the UFSAR documents as a plausible flood hazard, Groundwater ingress was included in this report as a potential flooding source even if not explicitly described in the UFSAR and any exterior walls (above or below grade) protecting space credited as dry in the UFSAR were inspected, The inspection of the walls also noted any degrading or nonconforming conditions for associated
- b. Requested Information Item 2(b) - Protection and Mitigation Features Describe protection and mitigation features that are considered in the licensing basis evaluation to protect against external ingress of water into SSCs important to safety.
The Quad Cities Station is inundated during the PMF event and external flood mitigation efforts are directed toward safe shutdown of the reactor and prevention of damage to the reactor core during flooding conditions. The flood emergency procedure (QCOA 0010-16, rev. 16) describes the steps to be taken by the plant operators in the event of an upcoming flood and during the flooding conditions. During the flood, plant doors are opened to allow water to freely enter the plant and equalize pressure once river rises to elevation 594 ft MSL. The reactor is maintained in a safe state by implementing actions described in the procedure. These actions are initiated by flood stages reaching certain elevations or by flood warnings.
According to the UFSAR, U.S. Army Corps of Engineers (USACE) predicts that a flood of this magnitude (PMF) would recede to below-grade level in approximately eight (8) days.
The flood emergency procedure goes into effect either when (1) the actual river level exceeds 586 ft MSL, as monitored by the gauge at the plant intake bay, or (2) water level is predicted to be above 594 ft MSL in less than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. These symptoms initiate several actions, including staging of the gasoline-driven pump used for providing make-up cooling water to the storage pools and reactor vessels. The pump, along with necessary hosing, scaffolding (as needed) and fuel is initially set up at the access hole MHl-5A with the discharge routed to the fuel storage pool. As the flood waters rise, the pump must be moved to alternative locations inside the reactor building.
The shutdown is followed by the removal of decay heat (by normal procedures) and disassembly of both reactors according to MA-AB-7S6-600. The disassembly includes removal shield plugs, drywell heads and reactor process, the the necessary well as the tori and the radwaste tanks the core spray the reactor flooding are the two 350,000 gallon tanks, the 100,000 gallon clean demineralized water tank, the Mobile Makeup Demineralizer and once those are empty, the river water.
Radwaste tanks also filled with water the fire and vents to fuel oil tanks are sealed. Once the reactor vessels are filled with the are removed to 13
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 2012 Revision 0 promote natural circulation cooling between the reactor cavities and pools. Finally, all station loads are de-energized and all plant doors are opened in preparation for the flood to ensure of water pressure on both sides of the walls.
The portable gasoline-driven pump is used to provide make-up water evaporated from the reactors and the pools throughout the course of the flood.
The UFSAR does not address plant configurations during various modes of operation with to flooding. No adverse weather conditions were explicitly stated in the UFSAR and assumed to occur concurrently with the implementation of the flood emergency procedure.
- c. Requested Information Item 2(c) - Flood Warning Systems The site is allowed to be flooded during the PMF and, therefore, no room water level warning are credited in the plant's external flooding licensing basis.
- d. Requested Information Item 2(d) - Flood Protection System/Barrier Effectiveness Discuss the effectiveness of flood protection systems and exterior, incorporated, and temporary flood barriers. Discuss how these systems and barriers were evaluated using the acceptance criteria developed as part of Requested Information Item l.h [in Enclosure 4 of the March 12, 2012, S0.54(f) letter]
Section 6 of NE112-07 defines "acceptance" as:
"Flood protection features are considered acceptable if no conditions adverse to quality were identified during walkdowns, verification activities, or program reviews as determined by the licensee's Corrective Action Program. Conditions adverse to quality are those that prevent the flood protection feature from performing its credited function during a design basis external flooding event and are must be reported to the NRC in the response to the 50.54(f) letter."
As indicated in Section 3 d, guidance was developed, supplementing NEI to provide more criteria for judging All observations that were not immediately judged as acceptable were entered into the site1s Corrective Action where an evaluation of the observation can be made.
to the execution of the walkdown. Due to the of the flood emergency the evaluation of its effectiveness was performed by first evaluating all procedural actions and associated procedures individually. This was followed by identification of critical path items and evaluation of the as a whole. The individual procedural and associated were drilled or simulated the walkdown to verify that the actions can be completed in the credited time and to estimate the manpower resources to each task or nrr,ro,"!.
14
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 The desktop evaluation of the flood emergency procedure included evaluation of available resources based on past staffing logs and estimates of staff available to respond to emergency. AI! of these resources and times were obtained from appropriate site personnel that were involved in the simulations/evaluations/
drills. This section is summarized into the fOl/owing sub-sections:
- 1. Field evaluation of Flood Emergency Procedure - an evaluation of effectiveness of procedural steps, and associated procedures based on reasonable simulations/drills. Times stated for performing each procedure or procedural were based on the actual performance of the drill/exercise or, in case of simulations that were performed in the past, on past records. For routine tasks that do not require performance times to be recorded (e.g., scaffold erection) the estimates were provided by the staff responsible for execution of the task/procedure.
- 2. Desktop evaluation of Flood Emergency Procedure an identification of critical path items and an evaluation of overall effectiveness of the entire flood emergency procedure.
- 3. Evaluation of Incorporated Passive Barriers an evaluation of below-grade walls and slabs against ground water ingress.
- 4. Site Topography evaluation of site topography (Le., contours, slopes, grades, imperviousness, structures, fences, etc.) against that assumed in the UFSAR site drainage evaluation.
FIELD EVALUATION OF FLOOD EMERGENCY PROCEDURE (QCOA 0010-16)
Flood Forecast/Flood Warning
- Flood forecast and the ability to provide a sufficient flood warning are two critical components of the flood emergency procedure. The flood emergency procedure requires that the Shift Operations Supervisor monitor the weather and flood forecast using available sources such as the National Weather Service (NWSj - Chicago Office, US Army Corps of Engineers, and Exelon's internal weather monitoring system. The flood emergency procedure goes into effect when the actual river level exceeds elevation 586 ft MSl, as monitored by the gauge at the plant intake bay, or is predicted to exceed elevation 594 ft MSl in less than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Monitoring of river levels at the plant intake bay is performed during the day shift by an Environmental Chemist or other assigned staff. Once a flood emergency is declared, a flood watch is established and river levels are monitored every two (2) hours to determine the rate of rise. In addition, the NWS website provides continuous monitoring of actual river stages at lO-minute increments for a river gauge located 5 miles upstream at Camanche, Iowa.
- 2) Shift 1 Continuous monitoring of flood &
Supervisor weather forecast 15
NTTF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0
- The AMEC Team interviewed the Shift Operations to evaluate whether the plant staff are knowledgeable of procedural steps related to flood warning and flood watch and whether the plant will have the ability to receive sufficient flood warning to allow for successful implementation the flood emergency Based on AMEC's evaluation, the site has resources and ability to monitor actual and predicted river levels as described in the flood emergency procedure. The site would mostly rely on the NWS website and the flood predicting gauge at Camanche, which provides a reasonable prediction of flooding conditions at the site.
It The procedural steps related to flood forecast and flood warning can be implemented successfully by the plant staff. The Shift Operations Supervisor interviewed during the walkdown was knowledgeable of the procedure and was able to perform the required actions as written.
Mobile Make-up Demineralizer System (QCOP 4300-08)
- Section D.4 requires placing the Mobile Makeup Demineralizer System in operation per QCOP 4300-08 to fill Contaminated Condensate Storage Tanks (CCSTs) and provide additional water as required. This step will be initiated immediately when actual river level exceeds elevation 586 ft MSL or water level is predicted to be greater than elevation 594 ft MSL within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This is a standard operating procedure that is executed on a regular basis.
- Manpower resources required for implementation of this task are as follows:
Type of Resources Required Quantity of Duration of Resources Resources Required to Perform Task
- 1) Unit Supervisor 1 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> 40 minutes
- 2) Equipment Operator 1 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> 40 minutes
- 3) I Chemistry Personnel 1 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> 40 minutes
- The Operations staff was able to successfully simulate the procedural step as written with no conflicts/issues.
- Based on the reasonable simulation, the evaluated procedural step can be performed per Section D.4. The Operations staff showed sufficient knowledge and ability to perform this step in the rwr,rCl,rl, Moving and of Portable Pump It disabled. The pump and the suction hoses are located in the Protected Area Warehouse. The fire which are used to convey river water into the pools, are stored in the C-Van west of the Fire Training Building. The pump is initially set up at plant elevation near a storm drain manhole located 25 ft southeast of the outer door. The states that water would be first drawn from the storm drain manhole as river levels increase and river water backflows the storm drain Once the flood waters rise above 16
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 elevation, the pump is moved inside the reactor building and set up on the trackway stairwell or at a location that would remain within the limitations of the pumping criteria (Le.,
maximum 5-ft suction and available head). A scaffold would also be erected to provide an alternate location for the pump.
- Manpower resources required for implementation of this task are as following:
of Resources Required Duration of Resources I I
Quantity of Required to Perform Task Resources
- 1) Equipment Operators 4 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />
- 2) Operations Supervisor 1 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />
- 3) Mechanical Maintenance 4 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 20 minutes
- The AMEC Team observed a drill of this procedural step, which included connecting two suction hoses and one fire hose to the portable pump in the Protected Area Warehouse to verify that the hoses can be connected as written. The hoses were disconnected before the portable make-up pump was transported inside the reactor building. The Operation staff indicated where the make-up pump would be staged and showed the path through which the hoses would be routed to the storage pools. The AMEC team did not observe any obstructions that would prevent the hoses from being routed as specified. The Mechanical Maintenance staff was interviewed to estimate the time to erect the scaffolding, as specified in the procedure.
The site has a sufficient supply of gasoline for the operation of the make-up pump. Dedicated fuel for the operation of the make-up pump is stored in five (5) 5-gallon containers in the Storeroom.
The plant has significant reserves of gasoline, which are stored in an on-site storage tank outside the protected area. In case of a flood emergency, the plant staff would ensure that additional gasoline supplies are available for the operation of the pump.
During the visual inspection, it was observed that the fuel line leading to the fuel tank was damaged and could not be connected to the tank. However, the Operations staff was able to replace the damaged hose within 30 minutes. All other components, including hoses and fittings, were in good condition.
- Based on the observed ''OFt'."",,, and reasonable simulations, the Portable the of '[;HWlI 17
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 Normal Unit Shutdown (QCGP 2-1)
- QCGP Normal Unit Shutdown, is a procedure that is initiated when the river level is predicted to reach elevation 594 ft MSL within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This is a standard operating procedure that is performed on a regular basis and, therefore, only a desktop review of the procedure was performed to evaluate the timing and resources needed for its execution.
- Manpower resources required for implementation of this task are as follows:
Type of Resources Required Quantity of Duration of Resources I Resources Required to Perform Task I
- 1) Senior Reactor Operator 2 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> 5 minutes
- 2) Reactor Operator 2 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> 5 minutes
- 3) Equipment Operator 4 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> 5 minutes
- The Operation staff presented operator logs, outage schedules and refuel logs to support the determination whether Normal Unit Shutdown (QCGP 2-1) can be performed in the credited time.
Operator and outage logs from the last four refueling outages (Q1R20, Q2R20, Q1R21, and Q2R21) were reviewed and the slowest performance time was used from Q2R21 for the evaluation of the flood emergency procedure. The procedure will not be challenged by flooding conditions since it is performed from the control room before flood waters inundate the site.
- Based on the provided operator logs, outage schedules, and refuel logs, Normal Unit Shutdown can be performed in the credited time.
Reactor Disassembly (MA-AB-756-600)
- MA-AB-756-600, Rector Disassembly, is a standard operating procedure performed during every refueling outage. According to the flood emergency procedure (rev. 16), reactor disassembly would be initiated following a load decrease of Units 1 and 2 to subcritical during shutdown when the predicted flood crest exceeds elevation 594 ft MSL in less than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or when the actual river levels are above elevation 594 ft MSL 1 The review of the procedure included a desktop evaluation and a reasonable simulation/interview conducted with the Reactor Services Manager to evaluate the timing, lay down areas, and resources needed for the execution of the procedure, and to verify that a concurrent disassembly of both reactor units can be accomplished. The flood emergency calls for removal of shield from the reactor and heads of Unit 1 and 18
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31/2012 Revision 0 2
- Manpower resources required for implementation of this task :
Type of Resources Required Quantity Duration of of Resources Resources Required to Perform Task
- 1) Senior Reactor Operator 1 58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br />
- 2) Reactor Operator I1 58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br />
- 3) Equipment Operator I 2 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />
- 4) Instrument Maintenance 2 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />
- 5) Mechanical Maintenance Staff 30 58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br /> (interchangeable with Boiler Makers)
- 6) Mechanical Maintenance Supervisor 4 58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br />
- 7) Laborers 8 58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br />
- 8) Vendor Representative (PAR) 2 58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br />
- 9) Vendor Representative (Simmers 2 58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br /> Crane)
- 10) Vendor Representative (BIACH) 2 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />
- 11) Boiler Makers 32 58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br /> (interchangeable with Mechanical Maintenance Staff)
- 12) Reactor Services (Floor Manager) 2 63 hours7.291667e-4 days <br />0.0175 hours <br />1.041667e-4 weeks <br />2.39715e-5 months <br />
- 13) Reactor Services (Tech Director) 4 63 hours7.291667e-4 days <br />0.0175 hours <br />1.041667e-4 weeks <br />2.39715e-5 months <br />
- 14) Reactor Services (Project Manager) 2 63 hours7.291667e-4 days <br />0.0175 hours <br />1.041667e-4 weeks <br />2.39715e-5 months <br />
- ) Reactor Services (Fu !I Handlers) ,3 (if needed) 58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br /> Reactor """'lIr,o" The schedule included a sequence of individual tasks and a time duration estimated based the would be available 19
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 2012 Revision 0 available for disassembled reactor components. The time duration and the sequence of individual including the preceding and subsequent tasks, are provided in Table 2 below.
Table 2: Reactor Disassembly Duration Duration (Hours) Action 9 Load Decrease per QCGP 2-1 8 Remove Cavity Shield Blocks (U1 & U2) 5 I Dryer Separator Pit Blocks (U1 & U2) 5 Fuel Pool Slot Blocks (Ul & U2) 1.5 Stairs (U1) 1.5 Cavity Ladder Cage (U2l 3 Drywell Head Bolts (U1 & U2) 3 Drywell Head Removal (Ul & U2) 3 Loosen Head Vent Piping (U1 & U2) 3 Remove Piping (U1 & U2) 4 Remove Insulation (U1 & U2) usel (U1) 3 -tension Head (U1) 3 emove Nuts (U1) 15 Carousel Off (U1) Unload Nuts 1.5 Carousel (U2) 1.5 Rx Head Strongback (U1)
In Parallel 2 Remove RX Head (U1)
(critical path 3 De-tension Head (U2) 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />) 3 Remove Nuts (U2) 1 Carousel Off {U2l 15 Rx Head Strongback 2 Remove RX Head (U2l 1.5 Flood Cavity & Dryer Separator Pools 3 Remove Fuel Pool Gates (U1 & U2) 71.5 Total After the dimensions of the disassembled parts and lay down areas on the reactor refuel AMEC confirmed that lay down areas are sufficient for of disassembled parts of both reactor the of all and tools used are located on 20
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 the refuel floor and stored in the dryer/steam separator pits. Furthermore, there is an adequate supply of tools for a dual Unit disassembly. This allows for easy access and short preparation time.
- Based on the reviewed information, including outage and operator drawings, and reasonable simulation/procedure walk-through with the Reactor Services Manager, the reactor disassembly can be performed in the credited time before flood levels reach elevation 594 ft MSL. Since the lay down areas are located above the design-basis flood elevation, they would not be impacted or reduced by flooding. However, the Reactor Disassembly procedure does not provide specific guidance and sequence for concurrent disassembly of both reactor units during the flood emergency. Given the time duration required for reactor disassembly and a 72-hour advanced flood warning, as specified in the flood emergency procedure, it is critical that the Reactor Disassembly procedure be implemented as efficiently as possible.
Seal the Emergency Diesel Generator (EDG) Fuel Oil Storage Tank Vent
- Section D.11.a states when flood levels are predicted to remain greater than elevation 594 ft MSL, the site will seal EDG fuel oil storage tank vents with Permagum and plastic bags with tie-wraps.
- Manpower resources required for implementation of this task are as follows:
Type of Resources Required Quantity of Duration of Resources Resources Required to Perform Task
- 1) Equipment Operator 1 30 minutes
- The Operations staff was able to successfully simulate the procedural step as written with no conflicts/issues.
- Based on the reasonable simulation, the evaluated procedural step can performed successfully per Section D.ll.a. The Operations staff showed sufficient knowledge ofthe action being performed.
Place Dryweilloads in Pull-Io-lock
- Section D.ll.b requires that the drywell coolers, drywell equipment and the floor drain sump pumps loads be placed in Pull-To-Lock (PTL). This means that the loads will be which scheduled to occur if the river level flood crest remains than elevation 594 ft MSL This of the is in the Control Room.
- The Shift Operations Supervisor demonstrated the knowledge of the procedural and the ability to the as written. As a no were found.
21
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31, 2012 Revision 0
- Based on the reasonable simulation, the evaluated procedural step can be performed successfully per Section O.11.b. The Shift Operations Supervisor showed sufficient knowledge of the action needed to be performed.
Add Water to Tori/Drywells through the Residual Heat Removal (RHR) System Test Lines
- Section O.l1.c & d requires water to be added to the tori through the RHR test lines per 4100-11. The water will be added until the tori are filled completely and then the drywells will be filled to a level attained when the tori are full. This step will be initiated if the predicted flood crest remains greater than elevation 594 ft MSL A reasonable simulation of the procedure was performed to evaluate whether the Operations staff can perform the procedure, as written.
- Manpower resources required for implementation of this task are as follows:
- The Shift Operations Supervisor was able to successfully demonstrate via detailed discussion that the procedural steps can be performed as written and no conflicts/issues were found. The process of filling the tori is specified in procedure QCOP 4100-11 section F.3. The task will be performed in parallel with Reactor Disassembly. The estimated time to perform the task is the time duration for all necessary preparations, Fire Water Supply System (FWSS) connection to the RHR system, filling the tori and filling the drywells. Since this is an abnormal procedure, Calculation No: QDC-1000-M-0847 Rev. 1 was used as a reference for the time duration of the task. Based on the volume of the tori and drywells and injection rate of 2,000 gpm, as presented in the calculation, it would take 9.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> to completely fill the tori and drywelfs. The calculation did not take into account the necessary preparations and connecting the FWSS to the RHR system, which were estimated to be 0.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />. The Operations staff also identified the valves that need to be closed/opened as part of the execution of the procedure and hoses and fittings used to connect to the fire header.
- Based on the reasonable simulation, the evaluated procedural can be "ArTnrrn per Section O.l1.c & d. The staff showed sufficient of the action needed to the Reactor Cavities and flood crest remains than elevation 594 ft MSL A reasonable simulation of the procedure was performed to evaluate the and resources needed for the execution of the procedure.
22
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0
- Manpower resources required for implementation of this task are as follows:
Type of Resources Required Quantity of Duration of Resources i Resources Required to Perform Task I
- 1) Equipment Operator 1 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 15 minutes
- 2) Reactor Operator 1 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 15 minutes
- 3) Instrument Maintenance 2 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> 15 minutes
- The Shift Supervisor was able to successfully demonstrate via detailed discussion and procedure walk-through that the procedural steps can be performed as written. As a result, no conflicts/issues were found. The process will be done in parallel with Reactor Disassembly. The estimated time to perform the task is the time duration for all necessary preparations, filling the reactor cavities and the dryer-separator pools using suction from the CCSTs and then if/when the CCSTs have been emptied, using the fire suppression system, as needed. The task can be initiated before the reactor heads are removed, reducing the duration of this task on the reactor disassembly critical path to 1.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />. It should be noted that this is not a typical process for filling the reactor cavities and dryer-separator pools and, therefore, it has not been performed in the past. However, Calculation No: QDC-1000-M-0847 Rev. 1 demonstrated that the actual filling of reactor cavities and dryeHeparator pools would take approximately 1.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.
- Based on the reasonable simulation, the evaluated procedural step can be performed successfully per Section D.ll.e & f. The Shift Operation Supervisor showed sufficient knowledge of the action needed to be performed.
Filling Radwaste Tanks Using the Fire System
- Section D.11.g requires that all radwaste tanks be filled using river water from the fire suppression system to prevent uplift and possible damage that could result in the spread of contaminated water. This will occur when the river level predicted flood crest remains greater than elevation 594 ft MSL
- Manpower resources required for implementation of this task are as follows:
of Resources Required Quantity of Duration of Resources Required to Perform ours 20 minutes hours 20 minutes Station. While flood emergency calls for of all radwaste the radwaste are located at or below the PMF elevation of 603 ft MSL There are 5 additional tanks that are located at an approximate elevation of 620 ft MSl and would not need to be filled. The volume of the radwaste tanks ranges from 1,000 to Based on the reasonable simulation, which included a the time duration to fill the tanks will vary between 5 minutes to 12 23
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 perform the task is the time duration for all necessary preparations and the filling of all tanks starting with the largest one. The Equipment Operator identified each tank and described how the tanks would be filled by opening the inspection hatches on the tanks and using the local fire hose stations. Several radwaste tanks would be filled using the domestic water in shower drains located directly above one of the tanks and using the condensate transfer system,
- Based on the reasonable simulation, the evaluated procedural step can be performed successfully per Section The Operations staff showed sufficient knowledge and the ability to successfully execute the task, De~energizing Station loads for a Flood Emergency
- Attachment E (QCOA 0010 Flood Emergency Procedure) requires that all station loads be de-energized for a flood emergency when the river level is predicted to be greater than elevation 594 ft MSl and following the completion of all remaining procedural steps, before the plant doors are opened. The execution of the procedure requires a Control Room action, as well actions performed in the field.
- Manpower resources required for implementation of this task are as follows:
Type of Resources Required Quantity of Duration of Resources Resources Required to Perform Task
- 1) Reactor Operator 1 30 minutes
- 2) Equipment Operator 2 30 minutes
- The Shift Operations Supervisor demonstrated the knowledge of the procedural step and the ability to successfully perform the procedural step as written. As a result, no conflicts/issues were found.
- Based on the reasonable simulation, the evaluated procedural step can be performed successfully per Attachment E (QCOA 0010 Flood Emergency Procedure) and the Shift Operations Supervisor showed sufficient knowledge of the action needed to be performed.
Open Plant Doors
- of interior and exterior doors to the free flow of when the water within one foot of the elevation.
allow for the floodwaters to fill the the on 24
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0
- A reasonable simulation of the opening the plant interior and exterior doors involved a visual inspection of a representative sample of interior and exterior doors led by Operations staff. The time duration to open and secure all doors was based on previous performance.
The inspected doors were in good condition and did not show that they would malfunction during a flood event. The procedure does not specify how the doors would be secured to remain opened; however, the Operator demonstrated how the doors would be secured.
- Based on the reasonable all plant doors can be opened and secured a flooding event, as <:n~'rltl"'r!
DESKTOP EVALUA TlON OF FLOOD EMERGENCY PROCEDURE {QCOA 0010-16}
Following the completion of reasonable simulations and evaluation of individual procedural and actions, AMEC performed a desktop evaluation of the flood emergency procedure. During the desktop evaluation, timing and resource data obtained during the walkdown were analyzed and compiled together.
The major emphasis of the desktop evaluation focused on answering the following questions:
- 1. Are required resources available during overlapping tasks?
- 2. Is there a sufficient flood warning available to allow for safe reactor shutdown and staging of the diesel-driven emergency make-up pump and the associated components and consumables?
- 3. Are consumables available for the entire durations of the design basis flood?
- 4. Can the flood emergency procedure be performed under adverse weather conditions or if there is a loss of off-site power?
Availability of Resources Actual staffing logs, Emergency Preparedness (EP) Dialogics Database, and interviews with Operations staff were used to determine whether sufficient resources are available to implement the entire flood emergency procedure. The staffing at Quad Cities Station is at its minimum levels during weekend shifts, when only eighteen (18) Operations staff would be available to immediately respond to emergency. The remaining staff would report to the plant, based on their Emergency Classification Level, and following the procedure for emergency response. Initially, the Emergency Response Organization (ERO) would be staffed based on the ERO The ERO would initiate calls to all available staff to The times for staff other than the use a conservative that the staff needed for within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> after the emergency has been declared.
- 3. Unable to to an emergency due to adverse weather conditions or due to other reasons 20% of all available personnel.
A summary of available based on the above-mentioned and the is presented in Table 3 below. The lowest i.e. weekend shifts, were used to determine the 25
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 actual number of staff available to immediately respond to a flood emergency. As indicated in the evaluation of the Reactor Disassembly Reactor Services and outside vendors are typically involved in reactor disassembly during refueling Response time requirements for Reactor Services staff are not available; based on the reasonable evaluation with Reactor Services Manager it was determined that at minimum eight (8) Reactor Services staff would be available to report to duty within one hour. The remaining twelve (12) staff would be able to respond to duty within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. Response time for outside vendors will likely be than for helon but the 9-hour lag between the initiation of unit shutdown and reactor would provide sufficient time to arrange for transport of outside vendors to site.
Table 3: Personnel Available to Respond to Emergency Source - EP Dialoglcs Database Response lime Unable to Group Number Total <1 hr <4 hrs Respond Mechanical Maintenance (craft) 64 7 45 12 Mechanical Maintenance (supervisors) 9 1 7 1 Electrical Maintenance (craft) 34 4 24 6 Electrical Maintenance (supervisors) 7 1 5 1 184 Instrument Maintenance (craft) 33 4 24 5 Instrument Maintenance (supervisors) 6 1 5 0 Radiation Protection (craft) 26 3 19 4 Radiation Protection (supervisors) 5 1 4 0 Source - EP Dialogics Database Response lime Normal on-shift staffing Number Total <1 hr I <4 hrs IUnable to Respond Senior Reactor Operators 5 Reactor Operators 4 18 Always on site Equipment Operators 9 Off-shift personnel available for short notice call-out (estimate based on general work-hour rules and normal department staffing Response lime Unable to Off-shift personnel Number Total <1 hr <4 hrs Respond Senior Reactor Operators 20 2 14 4 Reactor Operators 25 3 18 4 Equipment Operators 30 3 21 6 tasks are initiated at later The evaluation of resources the procedure was performed a Gantt chart and is not provided as part of this report.
26
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 Table 4: Resource Utilization based on Availability (Early Procedural Tasks)
The flood emergency procedure would be initiated by the Shift Manager, who would coordinate with Unit Supervisors and determine the actions needed to be performed immediately. The Shift Manager would also determine whether conditions of an Emergency Action Level are met and declare Emergency Classification Level, as appropriate. Depending on the Emergency Classification Level, the Emergency Response Organization would be activated to coordinate emergency activities on site.
Flood Warning As described previously, successful implementation and execution of the flood emergency procedure is dependent on early flood warning. Accurate flood predictions for the Mississippi River are provided by the NWS and are available online. The closest flood predicting gauge is located approximately five (5) miles upstream at Camanche, Iowa. The gauge forecasts river levels for up to six (6) days in advance and takes into account past precipitation and the precipitation amounts expected approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> into the future from the forecast issuance time. Additional gauges with river forecasting capabilities are located in Clinton and LeClaire, Iowa. These gauges would allow the site to predict the applicable flood hazard, as written in the flood emergency procedure. Furthermore, it is expected that additional advanced river forecasts would be provided by the USACE during a flood of this magnitude.
Availability of Consumabies of the pump flood stored in the Evaluation of Effectiveness of the Flood I"m,or"u:.r",." Procedure The effectiveness of flood emergency on a 72~hour flood when river levels are predicted to exceed plant grade elevation of 594 ft MSL Based on the evaluation of the flood emergency the critical path items for successful execution of the procedure are the shutdown and the of both reactors. The reactor a number of staff and can, at the be initiated 72 minutes after the reactor has entered subcritical mode 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> after load decrease at 150 MW/hr the unit 27
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 2012 Revision 0 shutdown). Disassembly of both reactors, including flooding of reactor cavities and dryer pools, would be completed 71.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> after the shutdown of both reactors has been initiated. The procedure would be fully implemented before flood waters reach plant to ensure that both reactors can be maintained in a safe condition when safety-related equipment is inoperable. Since both reactors would be shut down and cooled for three days prior to flooding of the plant, decay heat would be reduced to a level that can be removed by natural circulation cooling between the reactor and the reactor cavities and pools. AdditionallYl it is anticipated that a flood plant grade elevation would be predicted well in advance, and the site would have a longer than the 72-hour flood warning stated in the flood emergency procedure. For the purpose of the evaluation, the more conservative assumption of 72-hour flood warning was used.
The remaining procedural steps can be accomplished efficiently (as described earlier in this section) and in parallel with reactor disassembly. The sequence of the procedural steps allows for proper staffing with available resources. The reactor disassembly requires the largest number of staff and vendors. While exact emergency response times for vendors could not be verified, based upon the staffing evaluation above, it was determined that the 9-hour lag between the unit shutdown and the initiation of reactor disassembly would provide sufficient time to ensure that vendors or alternate staff are on site and available to perform their duties.
Adverse weather conditions (e.g., high winds, localized flooding, and freezing temperatures) can be expected during the execution of the flood emergency procedure. However, the majority of the procedural steps would likely not be affected by these conditions, since they are performed from the control room or inside. For procedural steps performed outside, site conditions were evaluated to determine whether adverse weather conditions could delay the completion of the task. The task most likely to be affected by adverse weather conditions is the initial staging of the make-up pump outside the reactor building and the transport of hoses from the C-Van to the protected area. These tasks are initiated early enough in the execution of the procedure to provide an additional margin of safety, with respect to adverse weather conditions. In case of loss of off-site power, Emergency Diesel Generators would be used to power the equipment and systems required for the execution of the flood emergency procedure.
The flood emergency procedure does not specifically state modes of operation for which the procedure is applicable. For evaluation of the PMF, full power mode operation was considered the most critical plant failure mode. This mode would require the highest number of resources and the longest duration. During other modes of operation, e.g. refueling outage, additional manpower resources would be available to assist with implementation of the The implementation of the procedure during other modes of nn.Oy",Tlnn would not additional to the effects of an external flood and the
'.r~ITln,n would be able EVALUATION OF INCORPORATED PASSIVE BARRIERS soe~ctE!d as of the walls and basement slabs. The penetrations and the associated seals were, however, not treated as features and were recorded as observations associated with the Walkdown Record Form for the wall or slab feature.
28
NTTF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31 1 2012 Revision 0 The following acceptance criteria were used for visual of walls and seals:
Below-Grade Walls I Basement Floor Slabs
- No of degradation of structural members.
- No significant surface cracks.
- No of significant degradation.
- No significant spalling, scaling, or cracking of concrete surfaces Penetrations I Seals:
- No indication of degradation that would allow flood waters to penetrate into the flood protected area. Conditions that should be recorded include (but are not limited to) damage, undocumented openings or holes (such as those due to abandoned equipment), etc.
- Visible penetrations are sealed with no visible gaps.
- Penetration sleeves, link seals, piping, and conduit should have an absence of corrosion on the exposed steel surface.
- Conduit seal material should have an absence of water stains below the penetrations.
- Material should appear to be as indicated in plant documents and in generally good condition.
Based on the visual inspection, the condition of below-grade walls and floor slabs of Unit 1 and Unit 2 Reactor Buildings and Unit 1 and Unit 2 Turbine Buildings, including penetrations/seals, were considered acceptable. The features would be able to withstand hydrostatic loads associated with potential extreme groundwater conditions and keep the below-grade areas dry.
The majority of the below-grade walls were inspected by the walkdown team and determined to be in acceptable condition. A relatively small portion of torus walls were designated by the walkdown team to be inaccessible and were not inspected during the walkdown. Reasonable assurance that the walls can provide their intended flood protection function was based on a visual inspection of the remainder of torus walls and the absence of non-conforming or degraded conditions of the representative sample.
As part of the evaluation of incorporated passive barriers, electrical drawings were reviewed to determine whether electrical conduits the building below could become pathway for groundwater There are several locations the western side of the turbine where electrical conduits connected to electrical manholes handholes through the exterior Turbine walls. The the walkdown and were considered due to SSCs in the Turbine Buildings are located in nr(',r"',"'1"('ln from flooding. The penetrations through the watertight vaults are any small conduits which are not tested per procedure have been evaluated by "'nn~'1'1 and have been determined not to affect the functionality of the related 29
NTTF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 equipment and, the walkdown team determined that visual of electrical manholes/hand holes was unnecessary.
SITE TOPOGRAPHY Evaluation of site topography was not included in the scope of the walkdown, since an LIP analysis was not considered part of the UFSAR. The site is allowed to be flooded during the flood and any potential changes to topography since the completion of the construction would not have a effect on flood
- e. Requested Information Item 2(e) -Implementation of Walk down Process the walkdown team and procedures) using the documentation template discussed in Requested Information Item Lj [in Enclosure 4 of the March 12, 2012, SO.S4(f) letter], including actions taken in The members of the walkdown team were carefully selected to ensure that the team includes individuals who are experienced in conducting visual inspections of plant structures, systems and components and flood protection features. The team for Quad Cities Station included two Water Resources Engineers, an Electrical Engineer, and a Structural Engineer. Both water resources engineers are flooding specialists and have significant experience with inspections and evaluations of flood protection features. The remaining two engineers are employees of AMEC's Nuclear Services division and are experienced in conducting visual inspection of plant SSCs.
Each member of the team completed Exelon's Walkdown Training, Nuclear Generation Employee Training (NGET), and NANTeL's generic verification walkdowns of plant flood protection features course, including passing the NANTeL exam based on NEI 12-07. In preparation for the walkdown, the team members became knowledgeable of the site's current licensing basis and operating procedures by thoroughly reviewing them during the first phase of the project. Where specific knowledge was necessary to inspect a flood protection feature/procedure, at least one member of the walkdown team had the ability to determine if the condition of the needed to be entered into the Corrective Action IJrrHl'F;un (CAP).
walkdown process to break down the evaluation of the based on staff's individual and of the reasonable simulations were divided among individuals with cn~.rITlr of the evaluated task/action~
at the were not limited to field documentation 30
NTTF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 walkdown lessons learned. A high-radiation pre-job brief was performed with the walkdown team and radiation protection personnel, as necessary. Subjects discussed in high-radiation pre-job briefs included but were not limited to tasks required to complete the job, time required to complete the dose rate surveys, maximum dose rates and total allowable dose.
A "camera on a stick" was used to perform visual inspection of flood protection features that were not accessible from the plant floor.
Observations captured during the walkdowns were documented using the Filed Observation Report.
Walkdown Record Forms provided in Appendix B of NEI 12-07 (Rev O-A) were completed based on the observations made during the visual inspection. Degraded or non-conforming conditions were documented using a camera, when possible.
A daily project report was generated at the end of each workday documenting the following:
- Industrial Safety/First Aid
- Radiological Information
- ALARA Information
- Production Performance
- Deficiencies Identified
- Operability Issues Identified
- General Problems
- IRs
- Items Requiring Further Review
- Lessons Learned Observations not immediately judged as acceptable were reported to Exelon personnel immediately and entered in the CAP, as necessary.
- f. Requested Information Item 2(f) Findings and Corrective Actions Taken/Planned Observations Designated through CAP as Deficient None Observations Awaiting Final Disposition in CAP 31
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 None Features in Restricted Access Areas None Features in Inaccessible Areas Higher areas of torus below-grade walls were inaccessible for visual inspection during the walkdown.
Reasonable assurance for these areas was based on a visual inspection of a representative sample of the walls and the absence of any non-conforming or degraded conditions for the representative sample.
Seven (7) penetrations/seals were not visually inspected during the walkdown and are considered inaccessible. Reasonable assurance that these penetrations will provide their intended flood protection function was determined by review of available drawings and absence of evidence of past or current groundwater seepage below the penetration/seal. Based on the visual inspection and review of available drawings, it is reasonable to conclude that the condition of all inaccessible penetrations/seals is acceptable and would not compromise the below-grade walls' and slabs' ability to function as a flood protection barrier. Table 10 in Section 5 provides a list of all inaccessible features.
Actions Taken or Planned to Address Deficiencies None
- g. Requested Information Item 2 (g) - Cliff -Edge Effects and Available Physical Margin Document any cliff-edge effects identified and the associated basis. Indicate those that were entered into the corrective action program. Also include a detailed description of the actions taken or planned to address these effects.
Cliff-edge effects were defined in the NTIF Report (Reference 5) as "the safety consequences of a flooding event may increase sharply with a small increase in the flooding leveL" As indicated in Sections 3.12 of NEI 12-07 (Reference 2), the NRC is no longer expecting the Recommendation 2.3: Flooding Walkdowns to include an evaluation of cliff-edge effects. The NRC is now differentiating between cliff-edge effects, which are addressed in Enclosure 2 of Reference 3, and Available Physical Margin (APM).
As indicated in Sections 3.13 of NEI 12-07 {Reference APM describes the flood available for flood all flood nr(',l'",,'TI(',n The APM flood feature and the flood water could affect an the pump, are allowed to be pump can be at different elevations.
UP evaluation not included the UFSAR the Station not flood features nu,r""'r,,,,O' LIP flooding.
32
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 2012 Revision a 3~ Extreme groundwater conditions were not considered in the UFSAR and were assumed to be at plant
- h. Requested Information Item 2(h) - Planned/Newly-Installed Flood Protection Enhancements Quad Cities Station is currently investigating multiple flood protection enhancements concurrent reactor disassembly). Upon completion of this study, the station will incorporate flood protection enhancements as determined to be necessary.
The flooding walkdown at Quad Cities Station was conducted between September 10 and September 14, 2012, and included a visual inspection of below-grade walls and the associated penetrations, a visual inspection of basement slabs, and reasonable simulations of the flood emergency procedure and the associated tasks and procedures.
A summary of the flooding walkdown results is provided in Table 5 through Table 10 below. The below grade-walls and slabs were inspected and arranged by areas or rooms for a total of twenty-five (25) features. Associated penetrations/seals were visually inspected during the walkdown; however, they were not considered individual flood protection features and only penetrations/seals not readily judged as acceptable or inaccessible penetrations/seals were listed in Table 8 and Table la, respectively. The below-grade wall and slab features were immediately judged as acceptable and no further actions were required.
For penetrations/seals considered inaccessible, reasonable assurance that these components will provide their intended flood protection function was provided by visual inspection of the walls features and review of relevant drawings. There was no evidence of past or current groundwater seepage through the penetrations/seals.
Twelve reasonable simulations of the flood emergency procedure and the associated procedures (including standard shutdown procedures) were performed to ensure that they can be performed as and the reactor from core The reasonable simulations included review of and Based be
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 Table 5: Summary Features Included in the Walkdown Scope Feature Type Total Number Passive - Incorporated 25 Passive - Temporary 0 Active -Incorporated 0 Active Temporary 0 Table 6: Reasonable Simulations
- I Description Purpose Provide sufficient flood warning to safely shut 1 Flood Warning and Flood Watch down both reactors and implement dependent flood emergency actions.
Provide additional water to the CCSTs for filling 2 Mobile Makeup Demineralizer System of reactor cavities/dryer separator pools Provide make-up water to the fuel pool for Moving and Staging of Darley Model 3 cooling when the remaining SCCs are HE20V Portable Pump inoperable.
Disconnect all electrical equipment prior to 4 De-energize Station Loads flood water reaching plant grade elevation.
Abnormal activity to use fire water supply Add Water to Tori/Drywells through system to fill tori/drywells prior to filling reactor 5
the RHR System Test Lines cavities and dryer separator pools to maintain cooling temperatures.
Provides a method(s) to fill reactor cavities and dryer-separator pools to the level of fuel Filling the Reactor Cavities and 6 pools to allow for natural circulation Pools between the and the Disconnect all electrical Place Loads in PTL filling Prevent introduction of river water 34
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0
- Description Purpose Allow free flow of water through plant to 10 Open Plant Doors hydrostatic pressure and prevent collapse of exterior walls.
Procedure to allow the flooding of reactor cavities/dryer separator pools and natural 11 Reactor Disassembly circulation between the reactor/cavities and fuel pools.
Procedure to shut down the reactor ;ing 12 Normal Unit Shutdown control rods and subsequently allow initiation of reactor disassembly.
Table 7: List of Features Immediately Judged as Acceptable
- Feature ID ## Description Passive!Active Incorporated/Temporary Exterior below-grade walls of 1A RHR 1 1-RB-WOlO Incorporated Passive Room 1-TB-W001 Exterior below-grade walls of 1A Vault 2 Incorporated Passive 1-TB-W004-001 (Service Water Pump [SWPj1A) Room 1-RB-WOOl Exterior below-grade walls of 1B Core 3 Incorporated Passive 1-RB-W002 Spray Pump Room 1-RB-W012 Exterior below-grade walls of 1B RHR 4 Incorporated Passive 1-RB-W013 Room Exterior below-grade walls of 1B-C Vault 5 1-TB-W004-002 Incorporated Passive
{SWP 8
1"1A/_""'O>1'110 walls of 2A Vault 9
35
NTTF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 1# Feature 101# Description Passive/Active Incorporated/Temporary Exterior below-grade walls of 2B RHR 10 2-RB-W009 Incorporated Passive Room Exterior below-grade walls of 2B-C Vault 11 2-TB-WOOl-2 Incorporated Passive (SWP 2B-C) Room Exterior below-grade walls of 2D Vault 12 2-TB-WOO1-3 Incorporated Passive (SWP 2D) Room 2-RB-HPCI-S Exterior below-grade walls of High 13 Pressure Coolant Injection (HPCI) Access Incorporated Passive 1-RB-HPCI-N Tunnel 1-TB-WOO9 Exterior below-grade walls of U1 14 1-TB-WOlO Incorporated Passive Condensate Booster Pump Area 1-TB-WOll 1-RB-W015 Exterior below-grade walls of Ul HPCI 15 Incorporated Passive 1-RB-W016 Room 1-RB-TO-E Exterior below-grade walls of Ul Torus 16 l-RB-TO-S Incorporated Passive Basement 1-RB-TO-W Exterior below-grade walls of Ul Turbine 17 I-TB-MEZW Incorporated Passive Bldg Mezzanine Level 2-TB-WOO4 Exterior below-grade walls of U2 18 2-TB-WOO6 Incorporated Passive Condensate Booster Pump Area 2-TB-WOll 19 2-RB-W016 I Exterior bduw-15 1 <I' walls of U2 HPCI IILV !JVI ClLt:U Passive 2-RB-W015 Room l-RB-TO-N Exterior h -:1:." -g. adt:: U2
!Jurated beluw-I:}I ad!::: walls of Irbine Passive 122 l-RB-SOOl Floor slabs of U1 Reactor Building Incorporated Passive 23 l-TB-SOOl Floor slabs of Ul Turbine Building I' Irated Passive 36
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0
- Feature 10 # Description Passive/Active Incorporated/Temporary 24 2-RB-SOO1 Floor slabs of U2 Reactor Building Incorporated Passive 2S 2-TB-S002 Floor slabs of U2 Turbine Building Incorporated Passive Table 8: list of Features Not Immediately Judged as Acceptable
- Feature 10 # Description Observation Component Resolution Operability
~I N/A N/A N/A N/A N/A Table 9: list of Features in Restricted Access Areas Table 10: list of Features in Inaccessible Areas
- Feature 10 # Description Reason Resolution Reasonable assurance that 24-in diameter Pipe shielding the component can provide opening/sleeve prevented the its intended function was 1 7-PEN (penetration (typical seal per access to and visual provided by absence of past
- 1, drawing FL-12) drawing B-61O/B- inspection of the or current evidence of 611) penetration. groundwater seepage below the penetration.
The penetration Reasonable assurance that 20-in diameter was located high in the component can provide the wall above the intended function was by absence of 12-PEN 3 (penetration #1; 37
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0 I area. the :io
- Feature 10# Description Reason Resolution The penetration 4
14-PEN (penetration 12-1n diameter I N/A no further action was not identified drawing FL-43) ' needed.
in the field.
Reasonable assurance that I I-Pen-UI-003 (B-8-in diameter pipe Visual inspection of the seal would the component can provide its intended function was 102, Section 5 sleeve 3-in by require breaking provided by absence of Ul Mezzanine Level in seal the plane of the or current evidence of South Wall) wall. groundwater seepage below the penetration.
Reasonable assurance that Visual inspection of the component can provide I-Pen-UI-004 (B-8-in diameter pipe the seal would its intended function was 102, Section G-G; 6 sleeve w/3-in by };l- require breaking provided by absence of past Ul Mezzanine Level in seal ring the plane of the or current evidence of South Wall) wall. groundwater seepage below the penetration.
Reasonable assurance that Visual inspection of the component can provide I-Pen-UI-OOS (B-6-in diameter pipe the seal would its intended function was 102, Section G-G; 7 sleeve w/3-in by };l- require breaking provided by absence of past Ul Mezzanine Level in seal ring the plane of the or current evidence of South Wall) wall. groundwater seepage below the penetration.
1,
- 3. U.S. Nuclear Regulatory Commission. Letter to Licensees. Information Pursuant to Title HP,rlrly'{71nlrl Recommendations and 9.3 the 2012, 38
NTIF Recommendation 2.3 (Walkdowns): Flooding Exelon Corporation October 31,2012 Revision 0
- 4. U.s. Nuclear Regulatory Commission. Demonstrating the and "e'H1l.JJIlJ Manual Actions in to Fire. NUREG-1852. October 2007.
- 5. U.s. Nuclear Regulatory Commission. Recommendations for Enhancing Reactor in the 21st The Near Term Task Force Review of Insights fram the Fukushima Dai-ichi Accident. July 2011.
- 6. US Nuclear Regulatory Commission. Operability Determinations & Functionality Assessments Resolution of Degraded or Nonconforming Conditions Adverse to Quality or Safety. NRC Inspection Manual. Part 9900: Technical Guidance. Regulatory Issues Summary Revisions l.
September 2005.
- 7. U.s. Nuclear Regulatory Commission. Inspection of Structures, Passive Components, and Civil Engineering Features at Nuclear Power Plants. Inspection Manual. Inspection Procedure 62002.
Section 03.01(h), Dams, Embankments and Canals.
- 8. Updated Final Safety Analysis Report for Quad Cities Generating Station, Rev. 9, October Sections and 3.4.
- 9. U.S. Nuclear Regulatory Commission. Safety Evaluation Report of Individual Plant Examination of External Events (/PEEE) on Quad Cities Nuclear Power Station. February 07, 1997.
- 10. QCOA 0010-16, Flood Emergency Procedure, Rev. 15, Rev. 16 and Rev. 17
- 11. QCGP Normal Unit Shutdown
- 12. MA-AB-756-600, Reactor Disassembly
- 13. QCOP 0201-06, Filling the Reactor Vessel/Reactor Cavity using the Core Spray System
- 14. QCOP 4100-11, Using Diesel Fire Pumps via Safe Shutdown Hose Line for Reactor Vessel Level Control or Flood Emergency Injection Source
- 15. QCOP 4300-08, Makeup Demineralizer System Mobile Demineralizer
- 16. ER-AA-4S0, Structures Monitoring, Rev. 1
- 17. Calculation No: QDC-100-M-0847 Rev. 1, Station/Unit: Quad Cities/1 and 2,
Title:
Use of Fire Water System for External Flood Protection Measures
- 18. Flood Barrier (FL-l through FL-S2)
- 19. Floor and Wall 1
Cable Turbine and Reactor Bldg Ground Floor 39