IR 05000461/2016007

NRC Temporary Instruction 2515/191, Mitigation Strategies, Spent Fuel Pool Instrumentation and Emergency Preparedness Report 05000461/2016007

ML16266A301
Person / Time
Site:	Clinton
Issue date:	09/22/2016
From:	Ann Marie Stone NRC/RGN-III
To:	Bryan Hanson Exelon Generation Co, Exelon Nuclear
References
IR 2016007
Download: ML16266A301 (16)

Text

September 22, 2016

SUBJECT:

CLINTON POWER STATION, NRC TEMPORARY INSTRUCTION 2515/191, MITIGATION STRATEGIES, SPENT FUEL POOL INSTRUMENTATION AND EMERGENCY PREPAREDNESS REPORT 05000461/2016007

Dear Mr. Hanson:

On August 9, 2016, the U.S. Nuclear Regulatory Commission (NRC) completed Temporary Instruction (TI) 2515/191, Inspection of the Implementation of Mitigation Strategies and Spent Fuel Pool Instrumentation Orders and Emergency Preparedness Communication/Staffing/Multi-Unit Dose Assessment Plans inspection at your Clinton Power Station. The NRC inspection team discussed the results of this inspection with you and other members of your staff. The inspection team documented the results of this inspection in the enclosed inspection report.

The inspection examined activities conducted under your license as they relate to the implementation of mitigation strategies and spent fuel pool instrumentation orders (EA-12-049 and EA-12-051) and Emergency Preparedness Communication/Staffing/Multi-Unit Dose Assessment Plans, your compliance with the Commissions rules and regulations, and with the conditions of your operating license. Within these areas, the inspection involved examination of selected procedures and records, observation of activities, and interviews with station personnel.

Based on the results of this inspection, one NRC-identified finding of very low safety significance was identified. The finding did not involve any violation of NRC requirements.

If you contest the subject or severity of this finding, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001, with a copy to the Regional Administrator, U.S. Nuclear Regulatory Commission-Region III, 2443 Warrenville Road, Suite 210, Lisle, IL 60532-4352; the Director, Office of Enforcement, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001; and the Resident Inspectors Office at the Clinton Power Station. In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 2.390, Public Inspections, Exemptions, Requests for Withholding, 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 NRC's 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/

Ann Marie Stone, Team Leader Technical Support Staff

Docket No. 50-461 License No. NPF-62

Enclosure:

Inspection Report 05000461/2016007

REGION III==

Docket No:

50-461 License No:

NPF-62 Report No:

05000461/2016007 Licensee:

Exelon Generation Company, LLC Facility:

Clinton Power Station Location:

Clinton, IL Dates:

June 20 through August 09, 2016 Inspectors:

B. Bartlett, Project Engineer, (Team Lead)

E. Sanchez-Santiago, Resident Inspector, Clinton

T. Bilik, Senior Reactor Inspector,

D. McNeil, Senior Operations Engineer

Approved by:

A. Stone, Team Leader Technical Support Staff

SUMMARY

Inspection Report (IR) 05000461/2016007; 06/20/2016 - 08/09/2016; Clinton Power Station:

Temporary Instruction 2515/191 Implementation of Mitigation Strategies and Spent Fuel Pool Instrumentation Orders and Emergency Preparedness Communication/Staffing/Multi-Unit Dose Assessment Plans.

This inspection was performed by three NRC regional inspectors and one resident inspector.

One Green finding was identified by the NRC. The finding was not considered a violation of NRC regulations. The significance of inspection 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 April 29, 2015. Cross-cutting aspects are determined using IMC 0310, Aspects Within the Cross-Cutting Areas effective date December 4, 2014. All violations of NRC requirements are dispositioned in accordance with the NRCs Enforcement Policy dated February 4, 2015. The NRC's program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, dated July 201

Cornerstone: Mitigating Systems

Green.

Two examples of a finding of very low safety significance was identified by the inspectors for the licensees failure to have hose configurations that were verified to be able to ensure a timely and successful implementation of a flexible response (FLEX) strategy.

Specifically, the licensee did not ensure through evaluations, calculations, analyses or any other means that the strategy for maintaining core cooling, containment heat removal and Spent Fuel Pool (SFP) cooling during a Beyond-Design-Basis External Event (BDBEE) flooding scenario would be capable of fulfilling its function. No violation of NRC requirements were identified.

The performance deficiency is more than minor because it was associated with the mitigating systems cornerstone objective attribute of protection against external factors, specifically the BDBEE flood hazard, and it adversely affected the cornerstone attribute of ensuring the availability, reliability and capability of systems that respond to initiating events to prevent undesirable consequences. Issues identified through TI-191 are evaluated through a cross-regional panel using IMC 0609, Appendix M, Significance Determination Process Using Qualitative Criteria, as informed by draft Appendix O, Post Fukushima Mitigation Strategies Significance Determination Process. The finding was determined to be of very low safety significance (Green). The inspectors concluded that the cause of the finding involved a cross-cutting component in the Human Performance area of Design Margins because the organization did not ensure the selected strategy contained the required verification that it could be successfully implemented. [H.6] (Section 4OA5.1)

Licensee-Identified Violations

None

REPORT DETAILS

4OA5 Other Activities (TI 2515/191)

The objective of Temporary Instruction (TI) 2515/191, Inspection of the Implementation of Mitigation Strategies and Spent Fuel Pool Instrumentation Orders and Emergency Preparedness Communication/Staffing/Multi-Unit Dose Assessment Plans, is to verify the licensees have adequately implemented the mitigation strategies as described in the licensees Revised Final Integrated Plan (ADAMS Accession No. ML15349A911) and the NRCs plant safety evaluation (ADAMS Accession No. ML15324A238) and to verify the licensees installed reliable water-level measurement instrumentation in their spent fuel pools. The purpose of this TI was also to verify the licensees had implemented Emergency Preparedness (EP) enhancements as described in their site-specific submittals and NRC safety assessments, including multi-unit dose assessment capability and enhancements to ensure staffing is sufficient and communications can be maintained during such an event.

The inspection also verifies plans for complying with NRC Orders EA-12-049, Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (ADAMS Accession No. ML12229A174) and EA-12-051, Order Modifying Licenses With Regard to Reliable Spent Fuel Pool Instrumentation (ADAMS Accession No. ML12056A044) are in place and are being implemented by the licensee. Additionally, the inspection verifies implementation of staffing and communications information provided in response to the March 12, 2012, request for information letter and multiunit dose assessment information provided per COMSECY-13-0010, Schedule and Plans for Tier 2 Order on Emergency Preparedness for Japan Lessons Learned, dated March 27, 2013, (ADAMS Accession No. ML12339A262).

The team discussed the plans and strategies with plant staff, reviewed documentation, and where appropriate, performed plant walk downs to verify that the strategies could be implemented as stated in the licensees submittals and the NRC staff prepared safety evaluation. For most strategies, this included verification that the strategy was feasible, procedures and/or guidance had been developed, training had been provided to plant staff, and required equipment had been identified and staged. Specific details of the teams inspection activities are described in the following sections.

1. Mitigation Strategies for Beyond-Design Basis External Events

a. Inspection Scope

The team examined the licensees established guidelines and implementing procedures for the beyond-design basis mitigation strategies. The team assessed how the licensee coordinated and documented the interface/transition between existing off-normal and emergency operating procedures with the newly developed mitigation strategies. The team selected a number of mitigation strategies and conducted plant walk downs with licensed operators and responsible plant staff to assess: the adequacy and completeness of the procedures; familiarity of operators with the procedure objectives and specific guidance; staging and compatibility of equipment; and the practicality of the operator actions prescribed by the procedures, consistent with the postulated scenarios.

The team verified the licensee established a preventive maintenance program for the Diverse and Flexible Coping Strategies (FLEX) portable equipment and that periodic equipment inventories were in place and being conducted. Additionally, the team examined the introductory and planned periodic/refresher training provided to the Operations staff most likely to be tasked with implementation of the FLEX mitigation strategies. The team also reviewed the introductory and planned periodic training provided to the Emergency Response Organization personnel. Documents reviewed are listed in the attachment.

b. Assessment

Based on samples selected for review, the inspectors verified that the licensee satisfactorily implemented appropriate elements of the FLEX strategy as described in the plant specific submittal(s) and the associated safety evaluation and determined that the licensee is generally in compliance with NRC Order EA-12-049. The inspectors verified that the licensee satisfactorily:

• developed and issued FLEX Support Guidelines (FSG) to implement the FLEX strategies for postulated external events;

• integrated their FSGs into their existing plant procedures such that entry into and departure from the FSGs were clear when using existing plant procedures;

• protected FLEX equipment from site-specific hazards;

• developed and implemented adequate testing and maintenance of FLEX equipment to ensure their availability and capability;

• trained their staff to assure personnel proficiency in the mitigation of beyond-design basis events; and

• developed the means to ensure that the necessary off-site FLEX equipment would be available from off-site locations.

The inspectors verified that non-compliances with current licensing requirements, and other issues identified during the inspection were entered into the licensee's corrective action program as appropriate.

c. Findings

Introduction:

Two examples of a finding of very low safety significance (Green) was identified by the inspectors involving hose configurations that would have challenged the timely and successful implementation of a FLEX strategy.

Description:

The licensee implemented order EA-12-049 through a number of procedures and Engineering Changes. With respect to the strategy for a Clinton cooling lake Beyond Design Basis External Event (BDBEE) flooding scenario, EC 392339, addressed the design of the hose connection from the portable ultimate heat sink (UHS)pumps to a pipe header (DG building manifold) that had been installed in the safety related structure. This design required a 12-inch hose to be connected to the DG building manifold, traverse through an area in an S-curve configuration, through a penetration on the side the building and suspended 28 feet down the side of the Unit 2 diesel generator structure to the connection on the portable pumps. The hose and water from the UHS would be required to support the Phase 2 core coolant, containment heat removal and spent fuel pool (SFP) cooling strategies.

On June 21, 2016, the inspectors performed a walk down of selected FLEX strategies, including the BDBEE flooding scenario and identified two concerns. The first involved the path that a 12-inch diameter hose would take and whether the path was so tight as to introduce an excessive bend which could reduce flow. The second involved the stresses imposed on the coupling used to connect the same 12-inch hose coming from pumps near the lake to the manifold located inside the Diesel Generator (DG) building.

• Path for temporary hoses: For this strategy, the licensee would lay hose from the DG building manifold through an area which required the hose to be placed in a tight S-curve configuration. The inspectors determined the licensee had not considered the manufacturers minimum bend radius of 15 feet when establishing the path for this strategy and did not test/analyze whether a tighter bend radius would be acceptable. In addressing the inspectors questions, the licensee determined the maximum bend radius achievable through this S-curve area would be 7 feet. The inspectors verified this value but questioned whether the hose would crimp during use, inhibiting flow to below acceptable values. The initial calculations by the licensee showed significant flow reductions caused by hose crimping at this reduced bend radius. The manufacturer was requested by the licensee to test a similar configuration at their facility. The manufacturers test demonstrated that there would be minimal kinking of the hose initially and that as pressure was increased to the expected operating pressure of 150 psig there were no signs of kinking.

• Stresses on hose coupling: The hose coupling stress issue had initially been identified by the licensee and involved the forces imposed on the hose and coupling at the top of a 28 foot tall wall. Specifically, the licensee raised a question on whether the coupling connection, where the outer hose connects to the inner hose, would be able to withstand the stresses imposed by the hose when it is full of water.

The licensee documented this issue in their Corrective Action Program as AR 02675017, 12 inch FLEX Hose Coupling Concern. Procedure CPS 4306.01P002, FLEX UHS Water Supply, which addressed the set up and operation of the hose stated in Step 4.5.5.1 that personnel should use a 12 inch Storz saddle that was stored nearby to prevent a hose kink where the hose exited the building. EC 392339 specified the hose be connected to a pipe section (commonly called a pup piece) to reduce the amount of stress that the hose would be subjected to during operation. The licensee contacted the vendor who had designed and built the hose and the vendor stated that they did not recommend hanging the hose from such a height as it could damage the hose. The vendor also state that under these conditions that the hose coupling would probably fail.

After further review, the licensee concluded the piping section would not be suspended as described in AR 02675017, and that the actual configuration, as documented in an engineering change (EC) document, would not impose such a large amount of stress on the coupling connection. The licensee closed this issue without taking any corrective action, stating the problem was in the way the procedure was written.

During the walkdowns and through other interviews with various operators, the inspectors determined the licensee misinterpreted the configuration described in the EC. The licensee believed an additional piece called a hose bun would be used and with the use of the hose bun, the coupling would not be suspended. Using the pup piece alone, the coupling would be suspended and the original concern about the stresses on the coupling remained. In addition some operators indicated they would use only the pup piece as designated in the EC. The inspectors determined the configuration evaluated in AR 02675017, was not the configuration that would have been installed and that the licensee inappropriately closed the AR.

Based on the inspectors questions, the licensee initiated further review of the issue.

Following a more detailed Finite Element Analysis by a contractor, the licensee was able to demonstrate the stresses were acceptable assuming the expected connection condition.

Both issues involve concerns about whether the method for providing water to the DG manifold during a flooding event would be able to function. At the time of inspection, the inspectors had reasonable doubt with the success of this strategy because the licensee was initially unable to demonstrate the intended actions would be successful. After significant analysis including a field demonstration, the licensee was able to demonstrate the planned strategy could be successful.

The licensees corrective actions included performing the analysis and tests described above to demonstrate the equipment would perform as expected, revising the EC to reflect the needed changes and clarification, as well as performing an assessment to determine if an alternate strategy would be more efficient.

Analysis:

The inspectors determined that the licensees failure to ensure that the strategy for cooling the reactor core, performing containment heat removal and cooling the SFP during a BDBEE flooding event would be successful was within the licensees ability to foresee and correct and should have been prevented, and therefore constituted a performance deficiency.

The performance deficiency is more than minor because it was associated with the mitigating systems cornerstone objective attribute of protection against external factors, specifically the BDBEE flood hazard, and it adversely affected the cornerstone attribute of ensuring the availability, reliability and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the licensee did not ensure through evaluations, calculations, analyses or any other means that the strategy for maintaining core cooling, containment heat removal and SFP cooling during a BDBEE flooding scenario would be capable of fulfilling its function.

Issues identified through TI-191 are evaluated through a cross-regional panel using IMC 0609, Appendix M, Significance Determination Process Using Qualitative Criteria, as informed by draft Appendix O, Post Fukushima Mitigation Strategies Significance Determination Process. (ML16055A351). The finding was determined to be of very low safety significance (Green) because the inspector answered no to the 5 questions in the draft Appendix O. Specifically, this condition was not associated with Spent Fuel Pool Level instrumentation required by order A-12-051 and did not result in a complete loss of function to maintain or restore core cooling, containment pressure control/heat removal and/or spent fuel pooling cooling capabilities.

The inspectors concluded that the cause of the finding involved a cross-cutting component in the Human Performance area of Design Margins because the organization did not conduct adequate verification of design to ensure the strategy could be successfully implemented. [H.6]

Enforcement:

Because the finding did not result in a loss of function, there are no applicable regulatory requirements. Consequently, the inspectors determined the issue constituted a finding of very low safety significance without a corresponding violation of any NRC requirements. (FIN 05000461/2016007-01)

2. Spent Fuel Pool Instrumentation

a. Inspection Scope

The team examined the licensees newly installed spent fuel pool instrumentation.

Specifically, the inspectors verified the sensors were installed as described in the plant specific submittals and the associated safety evaluation and that the cabling for the power supplies and the indications for each channel are physically and electrically separated. Additionally, environmental conditions and accessibility of the instruments were evaluated. Documents reviewed are listed in the attachment.

b. Assessment

Based on samples selected for review, the inspectors determined the licensee satisfactorily installed and established control of the spent fuel pool (SFP)instrumentation as described in the plant specific submittal(s) and the associated safety evaluation and determined the licensee is generally in compliance with NRC Order EA-12-051. The inspectors verified the licensee satisfactorily:

• installed the SFP instrumentation sensors, cabling and power supplies to provide physical and electrical separation as described in the plant specific submittal(s) and safety evaluation;

• installed the SFP instrumentation display in the location, environmental conditions and accessibility as described in the plant specific submittal(s); and

• trained their staff to assure personnel proficiency with the maintenance, testing, and use of the SFP instrumentation.

The inspectors verified non-compliances with current licensing requirements, and other issues identified during the inspection were entered into the licensee's corrective action program.

c. Findings

No findings were identified.

3. Staffing and Communication Request for Information

a. Inspection Scope

Through discussions with plant staff, review of documentation and plant walk downs, the team verified the licensee has implemented required changes to staffing, communications equipment and facilities to support a multi-unit extended loss of offsite power (ELAP) scenario as described in the licensees staffing assessment and the NRC safety assessment. The team also verified the licensee has implemented multi-unit dose assessment (including releases from spent fuel pools) capability using the licensees site-specific dose assessment software and approach as described in the licensees multi-unit dose assessment submittal. Documents reviewed are listed in the attachment.

b. Assessment

The inspectors reviewed information provided in the licensees multi-unit dose submittal and in response to the NRCs March 12, 2012, request for information letter and verified the licensee satisfactorily implemented enhancements pertaining to Near-Term Task Force Recommendation 9.3 response to a large scale natural emergency event that results in an extended loss of all AC power to all site units and impedes access to the site. The inspectors verified the following:

• licensee satisfactorily implemented required staffing change(s) to support a multi-unit ELAP scenario;

• EP communications equipment and facilities are sufficient for dealing with a multi-unit ELAP scenario; and

• implemented multi-unit dose assessment capabilities (including releases from spent fuel pools) using the licensees site-specific dose assessment software and approach.

The inspectors verified non-compliances with current licensing requirements, and other issues identified during the inspection were entered into the licensee's corrective action program.

4OA6 Management Meeting

Exit Meeting Summary

On August 9, 2016, the inspectors presented the inspection results to Mr. T. Stoner of the licensees staff. The licensee acknowledged the issues presented. The inspectors confirmed that none of the potential report input discussed was considered proprietary.

ATTACHMENT:

SUPPLEMENTAL INFORMATION

KEY POINTS OF CONTACT

Licensee

D. Avery, Regulatory Assurance

D. Shelton, Regulatory Assurance Manager

T. Stoner, Site Vice-President

B. Kapellas, Plant Manager

S. Gackstetter, Engineering Director

T. Dean, Training Director

J. Cunningham, Maintenance Director

R. Champley, Shift Operations Superintendent

J. Forman, Work Control

K. Blankenship, Site Security

J. Lyter, Corporate Exelon

D. Distel, Corporate Exelon

S. Pierson, Corporate Exelon

U.S. Nuclear Regulatory Commission

W. Schaup, Senior Resident Inspector

J. Quinones-Navarro, Japan Lessons Learned Division

LIST OF ITEMS OPENED, CLOSED, AND DISCUSSED

Opened and Closed

05000461/2016007-01 FIN Failure to have Hose Configurations that were Verified to be able to Ensure a Timely and Successful Implementation of a FLEX Strategy (Section 4OA5.1)

Discussed

None.