IR 05000317/2013003
| ML13213A062 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 07/31/2013 |
| From: | Daniel Schroeder Reactor Projects Branch 1 |
| To: | George Gellrich Constellation Energy Nuclear Group |
| Schroeder D | |
| References | |
| IR-13-003 | |
| Download: ML13213A062 (44) | |
Text
{{#Wiki_filter:UNITED STATES NUCLEAR REGULATORY COMMISSION uly 31, 2013
SUBJECT:
CALVERT CLIFFS NUCLEAR POWER PLANT - NRC INTEGRATED INSPECTION REPORT 05000317/2013003 AND 05000318/2013003
Dear Mr. Gellrich:
On June 30, 2013, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Calvert Cliffs Nuclear Power Plant (CCNPP), Units 1 and 2. The enclosed inspection report documents the inspection results, which were discussed on July 11, 2013, 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.
The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel.
This report documents two NRC-identified findings of very low safety significance (Green).
These findings were determined to involve violations of NRC requirements. Additionally, a licensee-identified violation, which was determined to be of very low safety significance, is listed in this report. However, because of the very low safety significance, and because they are entered into your corrective action program, the NRC is treating these findings as non-cited violations (NCVs) consistent with Section 2.3.2 of the NRC Enforcement Policy. If you contest any NCVs in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the Nuclear Regulatory Commission, ATTN.: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region I; the Director, Office of Enforcement, United States Nuclear Regulatory Commission, Washington, DC 20555-0001; and the NRC Resident Inspectors at CCNPP. In addition, if you disagree with the cross-cutting aspect assigned to any finding in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the Regional Administrator, Region I, and the NRC Resident Inspectors at CCNPP. In accordance with 10 CFR 2.390 of the NRCs 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 component of NRCs Agencywide Documents Access Management System (ADAMS). ADAMS is accessible from the NRC website at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely, /RA/ Daniel L. Schroeder, Chief Reactor Projects Branch 1 Division of Reactor Projects Docket Nos: 50-317 and 50-318 License Nos: DPR-53 and DPR-69
Enclosure:
Inspection Report 05000317/2013003 and 05000318/2013003 w/Attachment: Supplemental Information
REGION I== Docket Nos: 50-317 and 50-318 License Nos: DPR-53 and DPR-69 Report No: 05000317/2013003 and 05000318/2013003 Licensee: Constellation Energy Nuclear Group, LLC (CENG) Facility: Calvert Cliffs Nuclear Power Plant, Units 1 and 2 Location: Lusby, MD Dates: April 1, 2013 through June 30, 2013 Inspectors: S. Kennedy, Senior Resident Inspector E. Torres, Resident Inspector E. Burket, Emergency Preparedness Inspector J. Furia, Senior Health Physicist J. Laughlin, Emergency Preparedness Inspector, Office of Nuclear Security and Incident Response S. Pindale, Senior Reactor Inspector R. Rolph, Health Physicist Approved by: Daniel L. Schroeder, Chief Reactor Projects Branch 1 Division of Reactor Projects Enclosure
SUMMARY
IR 05000317/2013003, 05000318/2013003; 04/01/2013 - 06/30/2013; Calvert Cliffs Nuclear
Power Plant (CCNPP), Units 1 and 2; Equipment Alignment.
This report covered a three-month period of inspection by resident inspectors and announced inspections performed by regional inspectors. Inspectors identified two findings of very low safety significance (Green), which were non-cited violations (NCVs). The significance of most findings is indicated by their color (i.e., greater than Green, or Green, White, Yellow, Red) and determined using Inspection Manual Chapter (IMC) 0609, Significance Determination Process, dated June 2, 2011. Cross-cutting aspects are determined using IMC 0310, Components Within the Cross-Cutting Areas, dated October 28, 2011. All violations of NRC requirements are dispositioned in accordance with the NRCs Enforcement Policy, dated January 28, 2013.
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.
Cornerstone: Mitigating Systems
Green: The inspectors identified an NCV of Title 10 of the Code of Federal Regulations (10 CFR) 50, Appendix B, Criterion XI, Test Control, because CENG failed to establish a test program to ensure that diesel fuel oil (DFO) transfer system header check valves, DFO-146 and DFO-148, would perform their safety function. Specifically, on November 1, 2012, the inspectors identified that DFO-146 and DFO-148 had never been tested in the reverse flow direction or inspected. DFO-146 and DFO-148 have a design function to close in reverse flow conditions to ensure that the Tornado/Missile protected No. 21 fuel oil storage tank (FOST) will not drain if the non-Tornado/Missile protected No. 11 FOST fails during a tornado/missile event. CENGs immediate corrective actions included entering this issue into their corrective action program (CAP) and performing a reasonable expectation of continued operability. Planned corrective actions include performing an evaluation which includes a probabilistic risk assessment to credit a non-tornado/missile protected manual valve located in the DFO unloading station and a tornado/missile protected manual valve in the No. 21 FOST building to perform the function of the DFO tornado/missile protected check valves.
This finding is more than minor because it is associated with the protection against external factors attribute of the Mitigating Systems cornerstone and affects the cornerstone objective of ensuring the capability of systems that respond to initiating events to prevent undesirable consequences (i.e., core damage). Specifically, a reasonable doubt of operability existed because the capability of the check valves to perform their design function had never been demonstrated. The failure of check valves during a tornado/missile event causing the loss of the No. 11 FOST would result in the draining of the safety-related No. 21 FOST and consequential loss of all Fairbanks Morse emergency diesel generators (EDGs). Also, this issue is similar to IMC 0612, Appendix E, Example 3.i, in that, if credit is taken for manual valves in lieu of testing the check valves, additional analysis would be required to be performed to assure licensing basis requirements are met. The inspectors evaluated the significance of this finding using IMC 0609 Appendix A, The Significance Determination Process for Findings at Power, Exhibit 2, Mitigating Systems Screening Questions. The inspectors determined that this finding was of very low safety significance (Green) because the finding did not involve the loss or degradation of equipment or function specifically designed to mitigate a seismic, flooding, or severe weather event. The inspectors determined that the finding has a cross-cutting aspect in the area of Problem Identification and Resolution, CAP, because CENG failed to ensure that issues potentially impacting nuclear safety are promptly identified and fully evaluated and that actions are taken to address safety issues in a timely manner, commensurate with their significance. Specifically, CENG did not take appropriate corrective actions to address safety issues and adverse trends in a timely manner associated with inadequate testing programs of risk significant equipment. [P.1(d)] (Section 1R04)
Cornerstone: Barrier Integrity
Green: The inspectors identified an NCV of Technical Specification 5.4.1.b, Procedures, because CENG failed to maintain guidance in Emergency Operating Procedure (EOP)-6, Steam Generator Tube Rupture (SGTR). Specifically, EOP-6 guidance does not provide an alternative action to cool down the reactor coolant system (RCS) for a SGTR event with a loss of offsite power (LOOP) and the single failure of the unaffected steam generator (SG) atmospheric dump valve (ADV). This could result in the inability to terminate the primary to secondary leak into the affected SG and the cycling of the affected SG ADV to control the SG level resulting in additional dose to the public. Immediate corrective actions included entering this issue into their CAP.
Corrective actions planned include revising EOP-6 to address the identified deficiency.
In addition, CENG established interim administrative controls of the ADVs to ensure that appropriate remedial actions are taken if the ADVs are out of service and is evaluating adding the ADVs to their technical specifications.
This finding is more than minor because it is associated with the procedure quality attribute of the Barrier Integrity cornerstone and affects the cornerstone objective to provide reasonable assurance that physical design barriers (fuel cladding, RCS, and containment) protect the public from radionuclide releases caused by accidents or events. Specifically, the performance deficiency could result in the operation of the affected SG ADV and, consequently, the release of radioactivity to the environment until an adequate method to cool down the RCS is established. The inspectors evaluated the significance of this finding using IMC 0609, Appendix A, The Significance Determination Process for Findings at Power, Exhibit 3, Barrier Integrity Screening Questions. The inspectors determined that this finding was of very low safety significance (Green)because the finding does not represent an actual open pathway in the physical integrity of reactor containment. Also, the finding did not involve an actual reduction of hydrogen igniters in the reactor containment. The inspectors determined that the finding has a cross-cutting aspect in the area of Human Performance, Resources, because CENG did not ensure that personnel, equipment, procedures, and other resources were available and adequate to assure nuclear safety. Specifically, CENG did not ensure that EOP-6 was complete, accurate, and up-to-date through required periodic reviews. [H.2(c)]
(Section 1R04)
Other Findings
A violation of very low safety significance that was identified by CENG was reviewed by the inspectors. Corrective actions taken or planned by CENG have been entered into CENGs CAP. This violation and corrective action tracking number are listed in Section 4OA7 of this report.
REPORT DETAILS
Summary of Plant Status
Unit 1 began the inspection period at 100 percent power. The unit remained at or near 100 percent power throughout the inspection period.
Unit 2 began the inspection period at 100 percent power. On May 8, 2013, the unit automatically tripped due to high pressurizer pressure caused by a malfunction in the main turbine controls system. On May 11, operators commenced a reactor start up.
The unit reached 100 percent power on May 13. On May 21, operators manually tripped the unit due to the loss of the No. 22 SG feed pump. On May 23, operators commenced a reactor start up. On May 30, the unit reached 100 percent power. The unit remained at or near 100 percent power for the remainder of the inspection period.
REACTOR SAFETY
Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity
1R01 Adverse Weather Protection
.1 Readiness for Seasonal Extreme Weather Conditions
a. Inspection Scope
The inspectors performed a review of CENGs readiness for the onset of seasonal high temperatures. The review focused on EDGs. The inspectors reviewed the Updated Final Safety Analysis report (UFSAR), technical specifications, control room logs, and the CAP to determine what temperatures or other seasonal weather could challenge these systems, and to ensure CENG personnel had adequately prepared for these challenges. The inspectors reviewed station procedures, including CENGs seasonal weather preparation procedure and applicable operating procedures. The inspectors performed walkdowns of the selected systems to ensure station personnel identified issues that could challenge the operability of the systems during hot weather conditions.
Documents reviewed for each section of this inspection report are listed in the .
b. Findings
No findings were identified.
.2 Summer Readiness of Offsite and Alternate Alternating Current (AC) Power Systems
a. Inspection Scope
The inspectors performed a review of plant features and procedures for the operation and continued availability of the offsite and alternate AC power system to evaluate readiness of the systems prior to seasonal high grid loading. The inspectors reviewed CENGs procedures affecting these areas and the communications protocols between the transmission system operator and CENG. This review focused on changes to the established program and material condition of the offsite and alternate AC power equipment. The inspectors assessed whether CENG established and implemented appropriate procedures and protocols to monitor and maintain availability and reliability of both the offsite AC power system and the onsite alternate AC power system. The inspectors evaluated the material condition of the associated equipment by reviewing condition reports (CRs) and open work orders, and walking down portions of the offsite and AC power systems including the 500 kilovolt (kV) switchyard.
b. Findings
No findings were identified.
.3 Readiness for Impending Adverse Weather Conditions
a. Inspection Scope
The inspectors reviewed CENGs preparations for a severe weather tornado watch on April 19, 2013. The inspectors reviewed the implementation of adverse weather preparation procedures before the onset of and during this adverse weather condition.
The inspectors walked down the EDGs and the intake structure. The inspectors verified that operator actions defined in CENGs adverse weather procedure maintained the readiness of essential systems. The inspectors discussed readiness and staff availability for adverse weather response with operations and work control personnel.
b. Findings
No findings were identified. ==1R04 Equipment Alignment
.1 Partial System Walkdowns
==
a. Inspection Scope
The inspectors performed partial walkdowns of the following systems: No. 13 saltwater pump during maintenance on No. 12 saltwater pump on April 13, 2013 No. 13 and No. 14 containment air coolers during maintenance on No. 11 and No.
12 containment air coolers on April 22, 2013 2A EDG during maintenance on 2B EDG on May 10, 2013 1B EDG during maintenance on 1A EDG on May 21, 2013 No. 12 auxiliary feedwater (AFW) pump during maintenance on No. 11 AFW pump on June 17, 2013 The inspectors selected these systems based on their risk-significance relative to the reactor safety cornerstones at the time they were inspected. The inspectors reviewed applicable procedures, system diagrams, the UFSAR, technical specifications, CRs, and the impact of ongoing work activities on redundant trains of equipment in order to identify conditions that could have impacted system performance of their intended safety functions. The inspectors also performed field walkdowns of accessible portions of the systems to verify system components and support equipment were aligned correctly and were operable. The inspectors examined the material condition of the components and observed operating parameters of equipment to verify that there were no deficiencies.
The inspectors also reviewed whether CENG staff had properly identified equipment issues and entered them into the CAP for resolution with the appropriate significance characterization.
b. Findings
Introduction:
The inspectors identified a Green NCV of 10 CFR 50, Appendix B, Criterion XI, Test Control, because CENG failed to establish a test program to ensure that DFO transfer system header check valves, DFO-146 and DFO-148, would perform their safety function.
Description:
Calvert Cliffs DFO system for the three Fairbanks Morse EDGs consists of two above ground diesel FOSTs, three fuel oil transfer pumps, three fuel oil day tanks, and the piping between the FOSTs to the fuel oil day tanks. Two headers interconnect the FOSTs and the EDGs. The No. 21 FOST is enclosed in a concrete structure that protects the tank from tornado/missile events. The No. 11 FOST is not tornado/missile protected. The DFO unloading station is in front of the No. 11 FOST which contains above ground portions of both DFO header piping and manual valves that are not tornado/missile protected. DFO-146 and DFO-148 are located in an underground vault in front of the DFO unloading station and separate the tornado/missile protected FOST from the non-missile protected FOST. Calvert Cliffs normally maintains 2A EDG aligned to No. 11 FOST on header one and the 1B and 2B EDGs aligned to No. 21 FOST on header two, maintaining both tanks separate. In this configuration DFO-146 and DFO-148 will assure that the No. 21 FOST will not drain as a result of a tornado/missile that would cause the loss of No. 11 FOST.
On November 1, 2012, the inspectors identified that DFO-146 and DFO-148 had never been tested in the reverse flow direction or disassembled and inspected. Calvert Cliffs UFSAR states, in part, A check valve in each supply header ensures a failure of No. 11 FOST will not drain No. 21 FOST. This statement refers to the reverse flow design function of DFO-146 and DFO-148 in a tornado/missile event.
DFO-146 and DFO-148 are swing check valves. Industry operating experience has shown that check valves are susceptible to failures and commensurate with their safety function, they must be tested and inspected. The NRC issued Bulletin No. 83-03, Check Valve Failures in Raw Water Cooling Systems of Diesel Generators, focused on the failure mode of disassembly or partial disassembly of check valve internals. The bulletin states that forward flow testing to verify the open position are inadequate for detecting internal disassembly. On October 22, 1992, Morning Report (MR 4-92-0085), Inoperability Caused by EDG Fuel Oil System Check Valve Failure, South Texas Project Nuclear Power Plant reported that a 3/4 inch fuel line check valve disc separated from its hinge and lodged in the fuel line. South Texas Project Nuclear Power Plant disassembled the valve and determined that the check valve disc hold-down nut had not been staked to its threaded fastener. This resulted in the disc hold-down nut backing off the threaded fastener, causing the disc to become disconnected from the hinge.
The inspectors determined that CENG had a reasonable recent opportunity to identify this issue. In May 2012, following the inspectors identification of testing issues associated with the AFW system emergency air accumulators and the EDG shutdown sequencers, CENG initiated CR-2012-005253 to identify any additional inadequate test programs. In support of this review, CENG selected the top ten risk significant systems, which included the EDGs, and formed a multi-discipline team of Operations, Maintenance, System Engineering, and Design Engineering personnel to review each selected system. CENG completed the review without identifying any additional testing issues. This review did not identify the lack of testing of the DFO transfer system header check valves.
CENG entered this issue into their CAP (CR-2012-009976). Immediate corrective actions included a reasonable expectation of continued operability that was based on the favorable service conditions of the DFO and experience with similar check valves at CCNNP. Planned corrective actions include performing an evaluation which includes a probabilistic risk assessment to credit a non-tornado/missile protected manual valve located in the DFO unloading station and a tornado/missile protected manual valve in the No. 21 FOST building to perform the function of the DFO tornado/missile protected check valves.
Analysis:
CENGs failure to establish a testing program in accordance with 10 CFR 50, Appendix B, Criterion XI, Test Control, to demonstrate that the DFO check valves will satisfactorily perform their safety function described in the UFSAR is a performance deficiency that was within the CENGs ability to foresee and correct and should have been prevented. This finding is more than minor because it is associated with the protection against external factors attribute of the Mitigating Systems cornerstone and affects the cornerstone objective of ensuring the capability of systems that respond to initiating events to prevent undesirable consequences (i.e., core damage). Specifically, a reasonable doubt of operability existed because the capability of the check valves to perform their design function had never been demonstrated. The failure of check valves during a tornado/missile event causing the loss of the No. 11 FOST would result in the draining of the safety related No. 21 FOST and consequential loss of all Fairbanks Morse EDGs. Also, this issue is similar to IMC 0612, Appendix E, Example 3.i, in that, if credit is taken for manual valves in lieu of testing the check valves, additional analysis would be required to be performed to assure licensing basis requirements are met. The inspectors evaluated the significance of this finding using IMC 0609 Appendix A, The Significance Determination Process for Findings at Power, Exhibit 2, Mitigating Systems Screening Questions. The inspectors determined that this finding was of very low safety significance (Green) because the finding did not involve the loss of degradation of equipment or function specifically designed to mitigate a seismic, flooding, or severe weather event.
The inspectors determined that the finding has a cross-cutting aspect in the area of Problem Identification and Resolution, CAP, because CENG failed to ensure that issues potentially impacting nuclear safety are promptly identified, fully evaluated and that actions are taken to address safety issues in a timely manner, commensurate with their significance. Specifically, CENG did not take appropriate corrective actions to address safety issues and adverse trends in a timely manner associated with inadequate testing programs of risk significant equipment [P.1(d)].
Enforcement:
10 CFR 50, Appendix B, Criterion XI, Test Control, requires, in part, that a test program shall be established to assure that all testing required to demonstrate that structures, systems, and components (SSCs) will perform satisfactorily in service. The test program shall include an operational test during power plant operation. Contrary to the above, prior to March 31, 2013, CENG failed to establish a test program for DFO-146 and DFO-148 to demonstrate that the valves would perform satisfactorily in service.
Specifically, the reverse flow design function of these valves had not been incorporated into a testing program. Immediate corrective actions included a reasonable expectation of continued operability. Planned corrective actions include performing an evaluation, including a probabilistic risk assessment, to credit manual valves (missile-protected and non-missile protected) to perform the function of the check valves. Because this violation was of very low safety significance (Green) and has been entered into CENGs CAP (CR-2012-009976), this violation is being treated as an NCV, consistent with Section 2.3.2.a of the NRC Enforcement Policy. (NCV-05000317/318/2013003-01: Failure to Establish a Test Program for DFO Check Valves)
.2 Full System Walkdown
a. Inspection Scope
On June 4, 2013, the inspectors performed a complete system walkdown of accessible portions of the main steam system, to verify the existing equipment lineup was correct.
The inspectors reviewed operating procedures, EOPs, surveillance tests, drawings, equipment line-up check-off lists, and the UFSAR to verify the system was aligned to perform its required safety functions. The inspectors also reviewed valves and actuators design and construction for the main steam isolation valves (MSIVs) and ADVs, MSIV actuator refurbish testing, and ADVs weak link and thrust calculations. The inspectors performed field walkdowns of accessible portions of the systems to verify system components and support equipment were aligned correctly and operable. The inspectors examined the material condition of the components and observed operating parameters of equipment to verify that there were no deficiencies. Additionally, the inspectors reviewed a sample of related CRs and work orders to ensure CENG appropriately evaluated and resolved any deficiencies.
b. Findings
Introduction:
The inspectors identified a Green NCV of Technical Specification 5.4.1.b, Procedures, because CENG failed to maintain adequate guidance in EOP-6, Steam Generator Tube Rupture, to prevent excessive radiological releases.
Description:
EOP-6 mitigates a SGTR event by directing plant operators to: Monitor RCS depressurization Cooldown the RCS by steaming from both SGs ADVs to prevent lifting a SG safety relief valve and feeding with AFW flow Identify and Isolate the most effected SG Cool down the RCS by steaming the unaffected SG and feeding with AFW Maintain SG pressure and level in the affected SG Transition to shutdown cooling and cooldown affected SG The EOP is written for both non-LOOP and LOOP conditions. Preferred method of RCS cooldown is steaming to the condenser via the turbine bypass valve with the alternate method steaming through the ADVs. When a LOOP occurs, condenser vacuum will be lost and MSIV will go shut thus the only methods to draw steam from the SG is via the ADVs and the SG Safety Relief valves. During RCS depressurization, high pressure safety injection (HPSI) will be initiated to control RCS subcooling and RCS inventory.
Cooldown will be established by steaming both SG with ADVs and feeding with AFW until the RCS temperature reaches 515°F. When RCS temperature reaches 515°F, the most affected SG will be isolated and RCS cooldown will continue with the unaffected SG ADV until shutdown cooling system conditions are established for decay heat removal.
On June 7, 2013, the inspectors identified a concern that EOP-6 guidance was inadequate for the design basis analysis SGTR event with a LOOP and the failure of the ADV to operate on the unaffected (or least affected) SG. Following identification and isolation of the affected SG, if the ADV on the unaffected SG is not available, the EOP guidance does not provide an alternative action to cool down the RCS and there is no means to exit the EOP in order to implement alternate means of core cooling. In this condition the affected SG level and pressure could remain elevated and be required to be relieved via ADV operation per the procedure. Therefore, the affected SG ADV will be operated longer and more frequently to control the affected SG level or pressure.
The more frequent operation of the affected SG ADV would lead to increased release of radioactivity to the environment.
The inspectors observed this postulated design bases SGTR event in the CCNPP simulator and noted that without a controlled method to cool down the RCS, RCS pressure could not be reduced to nearly equal the affected SG pressure to terminate the leak of RCS into the SG. Operation of the affected SG ADV was required to control the SG level by steaming. During the postulated event, the inspectors further noted that RCS temperature slowly decreased due to some cooling being provided by HPSI system flow; however, this was not a controllable method of cooling. The inspectors observed all safety function status checks were met during the event, including RCS cold leg temperature. Based on the simulator response, the inspectors concluded that the inability to perform a controlled cool down of the RCS could result in continuous steaming of the affected steam generator to the atmosphere with no exit criterion from EOP-6 if all safety function status checks are met. The operation of the affected SG ADV would result in release of radioactivity to the environment until an adequate method to cool down the RCS is established.
In addition, the inspectors noted that although the CCNPP ADVs are relied upon in the EOP as a primary success path for mitigating a design basis event, the ADVs operability or functionality is not controlled in the technical specifications or the technical requirements manual. The ADVs are monitored via the Calvert Cliffs Maintenance Rule Program for reliability and unavailability. CENG initiated CR-2013-005020 to review this issue.
After the Three Mile Island accident in 1979, the NRC issued NUREG-0737, Clarification of Three Mile Island Action Plan Requirements, concerning the upgrade of EOPs. Section I.C.1, Guidance for the Evaluation and Development of Procedures for Transient and Accidents, stated that EOPs contained insufficient information to assess the extent of multiple failures. NUREG-0737 further stated that the single failure criterion was not considered appropriate for the development of EOPs and concluded that EOPs should consider the occurrences of multiple and consequential failures. Contrary to this guidance, CENG did not consider the consequential failure of the ADVs for a design basis SGTR event with a LOOP and did not provide alternative actions to cool down the RCS following identification and isolation of the affected SG. An alternative action could consist of additional methods within EOP-6 for cool down or an exit criterion to a procedure (e.g. EOP-8, Functional Recovery) which has additional methods to cool down the RCS if the ADVs are not available.
The inspectors determined that CENG had reasonable opportunities to identify the issue associated with EOP-6. Calvert Cliffs procedure PR-1-100, Preparation and Control of Calvert Cliffs Procedures, Section 5.3, Procedure Periodic Review, Step 1, states that EOP reviews shall be performed no less than every two years. The periodic review ensures that the procedure remains technically and functionally accurate. The inspectors noted that CENG biennial reviews did not identify this issue.
Immediate corrective actions included entering this issue into their CAP (CR-2013-004965). Corrective actions planned include revising EOP-6 to address the identified deficiency. In addition, CENG established interim administrative controls of the ADVs to ensure that appropriate remedial actions are taken if the ADVs are out of service and is evaluating adding the ADVs to their technical specifications (CR-2013-005020).
Analysis:
Constellations failure to consider the occurrences of multiple and consequential failures of the ADVs in EOP-6 contrary to the requirements of TS 5.4.1.b was a performance deficiency that was within Constellations ability to foresee and correct and should have been prevented. This finding is more than minor because it is associated with the procedure quality attribute of the Barrier Integrity cornerstone and affects the cornerstone objective to provide reasonable assurance that physical design barriers (fuel cladding, reactor coolant system, and containment) protect the public from radionuclide releases caused by accidents or events. Specifically, during a SGTR event with a LOOP and the failure of the unaffected SG ADV, EOP-6 guidance does not provide an alternative action to cool down the RCS which could result in the inability to terminate the primary to secondary leak and the cycling of the affected SG ADV to control the SG level. The operation of the ADV would result in release of radioactivity to the environment until an adequate method to cool down the RCS has been established.
The inspectors evaluated the significance of this finding using IMC 0609, Appendix A, The Significance Determination Process for Findings at Power, Exhibit 3, Barrier Integrity Screening Questions. The inspectors determined that this finding was of very low safety significance (Green) because the finding does not represent an actual open pathway in the physical integrity of reactor containment. Also, the finding did not involve an actual reduction of hydrogen igniters in the reactor containment.
The inspectors determined that the finding has a cross cutting aspect in the area of Human Performance, Resources, because CENG did not ensure that personnel, equipment, procedures, and other resources are available and adequate to assure nuclear safety. Specifically, CENG did not ensure that EOP-6 was complete, accurate, and up-to-date through required periodic reviews. [H.2(c)]
Enforcement:
Technical Specification 5.4.1.b, states in part, Written procedures shall be established, implemented and maintained covering the following activities: Emergency operating procedures required to implement the requirements of NUREG-0737 and to NUREG-0737, Supplement 1, as stated in Generic Letter 82-33. NUREG-0737 states, in part, that EOPs should consider the occurrences of multiple and consequential failures and should address alternative actions that should be performed to mitigate the event should these systems fail. Contrary to the above, prior to June 7, 2013, CENG did not consider the consequential failure of the ADVs for a design basis SGTR event with a LOOP and, as a result, did not provide alternative actions in EOP-6 to cool down the RCS following identification and isolation of the affected SG. Without an alternative action to cool down the plant, this could result in the inability to terminate the primary to secondary leak and the cycling of the affected SG ADV to control the SG level. The operation of the ADV would result in release of radioactivity to the environment until an adequate method to cool down the RCS is established. Immediate corrective actions included entering this issue into their CAP (CR-2013-004965).
Corrective actions planned include revising EOP-6 to address the identified deficiency.
In addition, CENG established interim administrative controls of the ADVs to ensure that appropriate remedial action is taken if the ADVs are out of service and is evaluating adding the ADVs to their technical specifications. Because this violation was of very low safety significance (Green) and has been entered into CENGs CAP, this violation is being treated as an NCV, consistent with Section 2.3.2a of the NRC Enforcement Policy (NCV 05000317/318/2013003-02: Inadequate Steam Generator Tube Rupture Emergency Operating Procedure)
==1R05 Fire Protection