IR 05000317/2014007
| ML14321A259 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 11/17/2014 |
| From: | Paul Krohn Engineering Region 1 Branch 2 |
| To: | George Gellrich Exelon Generation Co |
| References | |
| IR 2014007 | |
| Download: ML14321A259 (23) | |
Text
November 17, 2014
SUBJECT:
CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 & 2 - NRC EVALUATION OF CHANGES, TESTS, OR EXPERIMENTS AND PERMANENT PLANT MODIFICATIONS TEAM INSPECTION REPORT 05000317/2014007 AND 05000318/2014007
Dear Mr. Gellrich:
October 9, 2014
SUBJECT:
CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 & 2 - NRC EVALUATION OF CHANGES, TESTS, OR EXPERIMENTS AND PERMANENT PLANT MODIFICATIONS TEAM INSPECTION REPORT 05000317/2014007 AND 05000318/2014007
Dear Mr. Gellrich:
On October 9, 2014, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at the Calvert Cliffs Nuclear Power Plant (CCNPP), Units 1 and 2. The enclosed inspection report documents the inspection results, which were discussed on October 9, 2014, with you and other members of your staff.
The inspection examined activities conducted under your license as they relate to safety and compliance with the Commissions rules and regulations and with the conditions of your license.
In conducting the inspection, the team reviewed selected procedures, calculations and records, observed activities, and interviewed station personnel.
Based on the results of this inspection, no findings were identified.
In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of the NRC's document system, Agencywide Documents Access and Management System (ADAMS).
ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
Paul G. Krohn, Chief Engineering Branch 2 Division of Reactor Safety
Docket Nos. 50-317, 50-318 License Nos. DPR-53, DPR-69
Distribution: See Next Page DOCUMENT NAME: G:\\DRS\\Engineering Branch 2\\Mangan\\CC mods 2014\\Calvert Cliffs MODS 2014007.docx ADAMS ACCESSION NUMBER: ML14321A259
Enclosure:
Inspection Report 05000317/2014007 and 05000318/2014007 w/Attachment: Supplemental Information
REGION I==
Docket Nos.:
50-317, 50-318
License Nos.:
Report No.:
05000317/2014007 and 05000318/2014007
Licensee:
Exelon Generation Company, LLC Facility:
Calvert Cliffs Nuclear Power Plant, Units 1 and 2 Location:
Lusby, MD
Inspection Period:
September 22 through October 9, 2014
Inspectors:
K. Mangan, Senior Reactor Inspector, Division of Reactor Safety (DRS),
Team Leader J. Schoppy, Senior Reactor Inspector, DRS S. Galbreath, Reactor Inspector, DRS
Approved By:
Paul G. Krohn, Chief Engineering Branch 2 Division of Reactor Safety
ii Enclosure
SUMMARY OF FINDINGS
IR 05000317/2014007 and 05000318/2014007; 9/22/2014 - 10/9/2014; Calvert Cliffs Nuclear
Power Plant, Units 1 and 2; Permanent Plant Modifications Engineering Team Inspection.
This report covers a 2-week on-site inspection of the evaluations of changes, tests, or experiments and permanent plant modifications. The inspection was conducted by three region based engineering inspectors. No findings were identified. The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision 4, dated December 2006.
No findings were identified.
REPORT DETAILS
REACTOR SAFETY
Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity
==1R17 Evaluations of Changes, Tests, or Experiments and Permanent Plant Modifications
==
.1 Evaluations of Changes, Tests, or Experiments (31 samples)
a. Inspection Scope
The team reviewed eight safety evaluations to evaluate whether the changes to the facility or procedures, as described in the Updated Final Safety Analysis Report (UFSAR), had been reviewed and documented in accordance Title 10 of the Code of Federal Regulations (10 CFR) 50.59 requirements. In addition, the team evaluated whether Exelon had been required to obtain U.S. Nuclear Regulatory Commission (NRC) approval prior to implementing the changes. The team interviewed plant staff and reviewed supporting information including calculations, analyses, design change documentation, procedures, the UFSAR, Technical Specifications (TS), and plant drawings to assess the adequacy of the safety evaluations. The team compared the safety evaluations and supporting documents to the guidance and methods provided in Nuclear Energy Institute (NEI) 96-07, Guidelines for 10 CFR 50.59 Evaluations, Revision 1, as endorsed by NRC Regulatory Guide 1.187, Guidance for Implementation of 10 CFR 50.59, Changes, Tests, and Experiments, to determine the adequacy of the safety evaluations.
The team also reviewed a sample of twenty-three 10 CFR 50.59 screenings for which Exelon had concluded that a safety evaluation was not required. These reviews were performed to assess whether Exelon's threshold for performing safety evaluations was consistent with 10 CFR 50.59. The sample included design changes, calculations, and procedure changes.
The team reviewed the safety evaluations and screenings that Exelon had performed and approved during the time period covered by this inspection not previously reviewed by NRC inspectors. All 50.59 safety evaluations completed since the last modifications inspection were reviewed, and the screenings and applicability determinations selected were based on the safety significance, risk significance, and complexity of the change to the facility.
In addition, the team compared Exelons administrative procedures used to control the screening, preparation, review, and approval of safety evaluations to the guidance in NEI 96-07 to evaluate whether the procedures adequately implemented the requirements of 10 CFR 50.59. The reviewed safety evaluations and screenings are listed in the Attachment.
b. Findings
No findings were identified.
.2 Permanent Plant Modifications (10 samples)
.2.1 Unit 1 - Swap Location of CC HX Isolation Valves 1CV5206 and 1HVSW-254
a. Inspection Scope
The team reviewed modification engineering change package (ECP)-11-000702 which was performed to remove, switch location, and reinstall valves 1HVSW-254 and 1CV5206. The orientation of 1HVSW-254 was also changed by the modification. The valves are a manual operated valve and air-operated throttle valve in the salt water system which provides a flow path for cooling water through the salt water heat exchanger. Additionally, CV5206 controls flow though the heat exchanger to maintain adequate closed-loop cooling water temperature to safety-related components. The modification was performed to address valve packing leakage issues which affected the performance of CV5206. Exelon placed the valve in the new location in order to provided sufficient space to rotate the orientation of valve CV5206. The valve orientation was changed to prevent packing leakage from impacting valve performance.
The team reviewed the modification to determine if the design basis, licensing basis, and performance capability of the heat exchanger or valves had been degraded by the modification. The team reviewed the completed work order instructions and documentation to verify that the modification was installed as designed and the team reviewed the associated post modification testing (PMT) results to ensure that Exelon specified appropriate tests and acceptance criteria, and that the test results confirmed satisfactory performance. Additionally, the team interviewed design engineers and reviewed condition reports (CR) to determine if the modification effectively corrected the performance issues associated with the control valve and to determine if there were reliability or performance issues created from the modification. The team also reviewed affected drawings and operating procedures to ensure that they were properly updated and walked down the salt water system, including the location of the valve and air operator, to assess the material condition and configuration of the valve. The documents reviewed are listed in the
.
b. Findings
No findings were identified.
.2.2 Replace the Masoneilan Series 8005 Transducers with Conoflow Model GT25CD1826
a. Inspection Scope
The team reviewed modification ECP-11-000878 which replaced the transducer for air-operated valve (CV 5206) in the salt water system. The transducer is used to convert electrical control signals to an air signal in order to position control valves. As part of the modification Exelon updated calculations to verify that adequate air supply from both safety-related air accumulators and air compressors would be available to supplied components during design basis accidents. The CV 5206 valve provides a flow path for cooling water to the salt water heat exchanger and throttles flow to the heat exchanger as needed to maintain adequate heat exchanger outlet temperature. The electrical input signal to the transducer is an output signal from the associated closed-loop cooling water system heat exchanger outlet temperature. Exelon performed the modification to reduce maintenance requirements for the valve transducers and has performed this modification on several safety-related valves in the auxiliary feedwater (AFW), salt water, and component cooling (CC) water systems.
The team reviewed the modification to determine if the design basis, licensing basis, or performance capability of the valve, air system or associated electrical control system had been degraded by the modifications. The team interviewed design engineers and reviewed design drawings and calculations to determine if the transducer met the design and licensing requirements of the system. Additionally, the team reviewed PMT results, associated maintenance work orders and calibration procedures to determine if the changes were appropriately implemented. Finally, the team performed a walkdown of the transducer to determine if the modification was installed in accordance with the design, and to assess the overall material conditions of the systems following the modification work. The 10 CFR 50.59 screening determination performed for this modification, which address modifications on the AFW, salt water, and CC water systems was also reviewed as described in Section 1R17.1 of this report. Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.3 Unit 2 - Provide a New Cross Connection between SWAC Air and AFW Back-up Air
a. Inspection Scope
The team reviewed modification ECP-12-000082 which installed tubing and isolation valves in order to connect the AFW and salt water safety-related air systems. The modification was performed to allowed the AFW air system to be supplied by the safety-related salt water air compressors (SWAC) and the salt water air system to be supplied by non-safety related plant air, if needed, during a design basis event. In addition to the physical modifications to the plant, the team verified that the air compressors in either system had adequate capacity to supply all safety-related components in both systems. The modification was performed to add redundancy to both systems in order to reduce overall plant risk to Unit 2.
The team reviewed the modification to determine if the design basis, licensing basis, or performance capability of the air systems had been degraded by the modifications. The team interviewed design engineers and reviewed design drawings and calculations to determine if the new piping and valves met design and licensing requirements.
Additionally, the team reviewed PMT results and associated maintenance work orders to determine if the modification was appropriately implemented. The team also performed a walkdown of the piping and valves to determine if the modification was installed in accordance with the design and to assess the overall material conditions of the systems following the modification work. Finally, the team reviewed the implementing procedures to determine if adequate procedure guidance was provided and to ensure implementation of the procedure would not introduce new failure mechanisms to either system. The 10 CFR 50.59 screening determination associated with this modification was also reviewed as described in Section 1R17.1 of this report. Documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.4 Unit 2, Separate the 125 Volts, Direct Current Control Power to the Main Generator Coast
Down Relays and P-1300 Protective Relay Circuits
a. Inspection Scope
The team reviewed modification ECP-11-000188, which separated the 125 Volts, Direct Current (Vdc) control power to the main generator and P-13000 transformer protective relay circuits. The modification consisted of moving a sub-part of the 2DISC2D1502 circuit to the 2DISC2D1724 circuit. The function of the 2DISC2D1502 circuit is to provide generator protection and coast down protection circuits for the main generator and P-13000-2 transformer. Exelon performed the modification to separate the main generator and P-13000 transformer protective relay circuits in order to lower plant trip risk during online preventive maintenance work on the P-13000 lockout relays.
The team reviewed the modification to determine if the design basis, licensing basis, or performance capability of the protective relay circuit had been degraded by the modification.
The team interviewed plant engineers and reviewed the design and configuration to determine if the changes met design requirements. Design assumptions were reviewed to evaluate whether they were technically appropriate and consistent with the UFSAR.
Additionally, the team reviewed selected calculation changes and drawings to evaluate whether Exelon had properly updated these documents to reflect modification specifications. The 10 CFR 50.59 screening determination associated with this modification was also reviewed as described in Section 1R17.1 of this report. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.5 Units 1 and 2, Changes to Service Water Heat Exchanger Flow Control Instrumentation
a. Inspection Scope
The team reviewed modification ECP-13-000353 which installed a local flow indicator for each service water (SRW) heat exchanger to provide alternative shutdown capability for safe shutdown fire scenarios. The local flow indicators, not normally connected to the saltwater system, are used to provide alternative monitoring of saltwater flow in the event of a safe shutdown fire event. Exelon performed this modification in order to enable operators to have flow indication so that mitigating actions could be taken for a fire in the cable spreading rooms, switchgear rooms, or fan exhaust room.
The team reviewed the modification to determine if the design basis, licensing basis, or performance capability of the SRW system or fire protection plan had been degraded by the modification. The team interviewed plant engineers and reviewed the installed configuration to determine if the changes met design requirements. Design assumptions were reviewed to evaluate whether they were technically appropriate and consistent with the UFSAR.
Additionally, the team performed a walkdown of the related areas to determine if the modification was in accordance with the design and to assess the material condition of the equipment. Finally, the team evaluated whether the modification would provide adequate flow indication during a fire event. The 10 CFR 50.59 screening determination associated with this modification was also reviewed as described in Section 1R17.1 of this report. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.6 Unit 1, Replace Main Steam Line Radiation Monitors and N-16 Detection/Indication
a. Inspection Scope
The team reviewed modification ECP-13-000646 which replaced the Unit 1 main steam line (MSL) effluent and N-16 radiation monitoring system (RMS) with new equipment. Exelon performed the modification because the original equipment had become obsolete and difficult to maintain. This modification encompassed both the demolition and installation of the equipment and was performed to improve plant reliability and maintainability by replacing the installed equipment with equivalent equipment such that system functionality was maintained.
The team reviewed the modification to determine if the design basis, licensing basis, or performance capability of the main steam line effluent and N-16 radiation monitoring system had been degraded by the modification. The team reviewed the technical evaluations and verified that the design specifications of the MSL effluent and N-16 RMS were equivalent or improved when compared to the installed equipment. The team interviewed plant engineers and reviewed calculations, vendor manuals, and drawings to verify that the modification was adequately implemented. Additionally, design assumptions were reviewed to evaluate whether they were technically appropriate and consistent with the UFSAR. Finally, the team performed a walkdown of the related areas to determine if the modification was in accordance with the design and to assess the material condition of the equipment. The 10 CFR 50.59 screening determination associated with this modification was also reviewed as described in Section 1R17.1 of this report. The documents reviewed are listed in the
.
b. Findings
No findings were identified
.2.7 Unit 2, Install Main Steam Line Radiation Monitoring System
a. Inspection Scope
The team reviewed modification ECP-12-000790 which replaced the obsolete existing MSL effluent monitors. Exelon performed this modification because the original equipment was obsolete and difficult to maintain. This modification encompassed both the demolition and installation of new equipment and was performed to improve plant reliability and maintainability by replacing the installed equipment with equivalent equipment such that system functionality was maintained.
The team reviewed the modification to determine if the design basis, licensing basis, or performance capability of the MSL radiation monitors had been degraded by the modification. The team reviewed the technical evaluations and verified that the design specifications of the MSL radiation monitors were equivalent or an improvement over the installed equipment. Additionally, the team interviewed plant engineers and reviewed calculations, vendor manuals, procedures, and drawings to determine if the modification was adequately implemented. Design assumptions were also reviewed to evaluate whether they were technically appropriate and consistent with the UFSAR. The team also performed a walkdown of the related areas to determine if the modification was in accordance with the design and to assess material condition. Finally, the team reviewed an associated finding (05000318/2014003-02) related to inaccurate radiation monitor setpoint calculations which was dispositioned in NRC inspection report 05000318/2014010. The 10 CFR 50.59 screening determination associated with this modification was also reviewed as described in Section 1R17.1 of this report. The documents reviewed are listed in the
.
b. Findings
No findings were identified.
.2.8 Unit 1, Installation of Thermo-Wells in the Containment Sump Suction Headers
a. Inspection Scope
The team reviewed modification ECP-11-000429 which installed thermo-wells in the Unit 1 containment sump suction headers to support the availability of control room temperature indication during post-accident containment sump recirculation. Exelon installed two sockolets and two thermo-wells in both Unit 1 emergency core cooling system (ECCS)headers downstream of the containment sump suction motor-operated valves. The sockolets are used to house resistive thermal devices (RTD) which will provide control room temperature indication.
The team reviewed the modification to determine if the design bases, licensing bases, and performance capability of the ECCS had been degraded by the modification. The team reviewed the associated work order instructions, post-modification test results, and work order documentation to verify that the maintenance implemented the modification as designed. The team performed a walkdown of the accessible portions of the Unit 1 ECCS piping, temperature instrumentation conduit routing, and control room instrumentation to verify that Exelon had adequately implemented the modification, maintained configuration control, and had not impacted the function of other safety-related structures, systems, and components (SSC) located in the vicinity. The team also reviewed CRs to determine if there were reliability or performance issues that may have resulted from the modification.
Additionally, the team reviewed the 10 CFR 50.59 screening and engineering evaluation associated with this modification which was also reviewed as described in Section 1R17.1 of this report. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.9 Resolution of Component Design Bases Inspection Issues Related to the Auxiliary
Feedwater System
a. Inspection Scope
The team reviewed modification ECP-12-000396 associated with Exelons resolution of issues previous identified during an NRC component design bases inspection (CDBI)related to AFW system design basis calculations. The AFW system is designed to maintain the steam generator water inventory, when the normal feedwater system is not available, in order to provide a secondary heat sink for residual heat removal following a reactor trip.
Exelon implemented the design change to evaluate and resolve previously identified issues with AFW system design basis calculations. Specifically, the evaluation addressed the maximum allowable flow in the suction line before pump cavitation occurs for all combinations of AFW pumps (CA03414); calculation of the worst case air-operated valve (AOV) operating conditions for the AFW pump control valves (CA03548); calculation of the required thrust and actuator capability for the AFW pump control valves (CA03548, CA03550, and CA05666), and evaluation of the vortexing potential with offsite power available by including the heat transfer from the reactor coolant pumps to the boil-off rates of the steam generators (SG) (CA04978).
The team reviewed the calculations to evaluate whether Exelons results and conclusions were adequate to maintain the design bases, licensing bases, and design margins of the AFW system. The team verified that Exelon properly and consistently translated design inputs into the associated AFW calculations, maintenance procedures, and system operating procedures. The team also performed several walkdowns of accessible portions of the AFW system for both units, including control room instrumentation, to assess if Exelon used appropriate inputs and assumptions in the associated calculations and adequately maintained configuration control. Additionally, the team reviewed associated CRs to assess Exelon's ability to evaluate and correct problems associated with the calculations. The team reviewed the 10 CFR 50.59 screening and engineering evaluation associated with this design change. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
.2.10 Installation of Vent Valves in the Component Cooling System
a. Inspection Scope
The team reviewed modification ECP-12-000825 which installed high point vent valves in the Unit 2 CC system. The CC system maintains certain reactor plant and auxiliary system components at their required normal operating temperatures by removing heat and transferring it to the saltwater system. Additionally, during a loss-of-coolant accident (LOCA), the CC system removes heat from the containment spray system and certain reactor plant components. Exelon installed four high point vent valve assemblies in the CC supply and return piping to/from the reactor coolant waste evaporators and miscellaneous waste evaporator. The vent valve assemblies were installed to provide venting capability (of trapped gasses) for the CC supply and return piping to/from the waste evaporators.
Exelon installed these vent valve assemblies in order to ensure that gas accumulation did not challenge the operability of the CC system components and to ensure the CC pressure boundary was maintained.
The team reviewed the modification to determine if the design bases, licensing bases, and performance capability of the CC system had been degraded by the vent valve installation.
The team reviewed calculations, isometric drawings, and the CC operating procedure to verify that the vent valves would function and be controlled in accordance with design assumptions. The team reviewed the associated work order instructions, PMT results, and work order documentation to verify that the modification had been implemented as designed. The team also performed walkdowns of accessible portions of the Unit 2 CC piping and vent valves to verify that Exelon had adequately implemented the modification, maintained configuration control, and had not impacted the function of other safety-related SSCs located in the vicinity. Additionally, the team reviewed corrective action reports to determine if there were reliability or performance issues that may have resulted from the modification. Finally, the team reviewed the 10 CFR 50.59 screening and engineering evaluation associated with this modification, which was also reviewed as described in Section 1R17.1 of this report. The documents reviewed are listed in the Attachment.
b. Findings
No findings were identified.
OTHER ACTIVITIES
4OA2 Identification and Resolution of Problems (IP 71152)
a. Inspection Scope
The team reviewed a sample of CRs associated with 10 CFR 50.59 and plant modification issues to evaluate whether Exelon was appropriately identifying, characterizing, and correcting problems associated with these areas, and whether the planned or completed corrective actions were appropriate. In addition, the team reviewed CRs written on issues identified during the inspection to verify Exelon adequately described the problem and incorporated the issue into their corrective action system. The CRs reviewed are listed in the Attachment.
b. Findings
No findings were identified.
4OA6 Meetings, including Exit
The team presented the inspection results to Mr. George Gellrich, Site Vice President, and other members of Exelon's staff at an exit meeting on October 9, 2014. The team returned the proprietary information reviewed during the inspection and verified that this report does not contain proprietary information.
ATTACHMENT
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
Licensee Personnel
- G. Gellrich, Site Vice President
- M. Flaherty, Plant Manager
- K. Robinson, Director Site Engineering
- B. Scott, Senior Engineering Manager
- S. Reichard, Regulatory Specialist
- A. Lederer, Engineering
- J. Gaffey, Engineering
- M. Herron, Engineering Manager
- K. Robinson, Engineering
- A. Drake, Senior Mechanical Design Engineer
- D. Dvorak, Design Engineer
- R. Haley, Fire Marshal
- W. Lang, System Engineer
Open and Closed
None
Discussed
Inaccurate EAL Threshold Valves Incorporated
into Site EAL Scheme Change (IR17.2.7)