0CAN021504, Reply to Notice of Violation; EA-14-088

Reply to Notice of Violation; EA-14-088

ML15054A607
Person / Time
Site:	Arkansas Nuclear
Issue date:	02/23/2015
From:	Jeremy G. Browning Entergy Operations
To:	Document Control Desk, NRC Region 4
References
0CAN021504, EA-14-088
Download: ML15054A607 (11)

Text

Entergy Operations, Inc.

1448 S.R. 333 Russellville, AR 72802 Tel 479-858-3110 Jeremy G. Browning Site Vice President Arkansas Nuclear One 0CAN021504 February 23, 2015 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

Subject:

Reply to Notice of Violation; EA-14-088 Arkansas Nuclear One - Units 1 and 2 Docket Nos. 50-313 and 50-368 License Nos. DPR-51 and NPF-6

Dear Sir or Madam:

In Reference 5, the Nuclear Regulatory Commission (NRC) transmitted a Yellow Finding and a Notice of Violation to Entergy Operations, Inc. (Entergy). The Yellow Finding was associated with the failure to design, construct, and maintain the Arkansas Nuclear One Units 1 and 2 auxiliary building and emergency diesel fuel storage building flood barriers so that they could protect safety-related equipment from the design flood level.

Entergy performed root cause analyses to determine the causes of this finding and developed and implemented associated corrective actions.

Pursuant to 10 CFR 2.201, Entergys response to the Notice of Violation is provided in the attachment to this letter.

Entergy recognizes the significance of this finding and, upon discovery of these deficiencies, took aggressive action to ensure the identified discrepancies have been corrected or have compensatory measures implemented.

This submittal contains no regulatory commitments.

Should you have questions or comments, please contact Stephenie Pyle at 479-858-4704.

Sincerely, ORIGINAL SIGNED BY JEREMY G. BROWNING JGB/jas

0CAN021504 Page 2 Attachments: 1. Response to Notice of Violation EA-14-088

2. Notice of Violation EA-14-088 Exception

References:

1. NRC letter dated June 7, 2013, NRC Augmented Inspection Team Report 05000313/2013011 and 05000368/2013011 (ML13158A242)

2. NRC letter dated March 24, 2014, AIT Follow-up, Inspection Report 05000313/2013012 and 05000368/2013012 (ML14083A409)

3. Entergy Licensee Event Report dated May 5, 2014 (LER 50-313/2014-001-01) (0CAN051401)

4. NRC letter dated September 9, 2014, NRC Inspection Report 05000313/2014009 and 05000368/2014009; Preliminary Yellow Findings (ML14253A122)

5. NRC letter dated January 22, 2015, Final Significance Determination of Yellow Finding and Notice of Violation; NRC Inspection Report 05000313/2014010 and 05000368/2014010 (ML15023A076) cc: Mr. Marc L. Dapas Regional Administrator U. S. Nuclear Regulatory Commission Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 NRC Senior Resident Inspector Arkansas Nuclear One P. O. Box 310 London, AR 72847

Attachment 1 to 0CAN021504 Response to Notice of Violation EA-14-088 to 0CAN021504 Page 1 of 5 NOTICE OF VIOLATION Entergy Operations, Inc. Dockets: 05-313;05-368 Arkansas Nuclear One, Units 1 and 2 Licenses: DRP-51, NPF-6 EA-14-088 During a Nuclear Regulatory Commission (NRC) inspection conducted on February 10 through August 1, 2014, a violation of NRC requirements was identified. In accordance with the NRC Enforcement Policy, the violation is listed below:

A. 10 CFR Part 50, Appendix B, Criterion Ill, "Design Control," states, in part, that measures shall be established to assure that applicable regulatory requirements and the design basis, as defined in § 50.2 and as specified in the license application, for those structures, systems, and components to which this appendix applies, are correctly translated into specifications, drawings, procedures, and instructions. Design changes shall be subject to design control measures commensurate with those applied to the original design.

Unit 1, Safety Analysis Report (SAR), Amendment 26, Section 5.1.6, Flooding, defined the design basis and stated, in part, that seismic class 1 structures are designed for the maximum probable flood level at elevation 361 feet above Mean Sea Level (MSL). The Unit 1 SAR further stated that all seismic class 1 systems and equipment are either located on floors above elevation 361 feet or protected. Sections 5.3.2 and 5.3.5.2 of the SAR indicated that the auxiliary building and emergency diesel fuel storage vault, both quality-related, are seismic class 1 structures.

Unit 2, Safety Analysis Report, Amendment 25, Section 3.4.4, Flood Protection, defined the design basis and stated, in part, that seismic category 1 structures were designed for the probable maximum flood. The Unit 2 SAR further stated that all category 1 systems and equipment are either located on floors above elevation 369 feet, or protected. Table 3.2-2, Seismic Categories of Systems, Components, and Structures, of the Unit 2 SAR indicated that the auxiliary building and emergency diesel fuel storage vault, both quality-related, are seismic class 1 structures.

Unit 1, Safety Analysis Report, Amendment 26, Section 5.3.2, Auxiliary Building stated, in part, that the floor area at elevation 317 feet containing engineered safeguards equipment was partitioned into separate rooms to provide protection in the event of flooding due to a pipe rupture.

Contrary to the above, as of March 31, 2013, the licensee failed to assure that applicable regulatory requirements and the design basis were correctly translated into specifications, drawings, procedures, and instructions and that design changes were subject to design control measures commensurate with those applied to the original design. Specifically, the licensee failed to assure that safety-related equipment below the design flood level was protected in the following examples:

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a. The licensee failed to include a procedural step to install a blind flange in a ventilation duct that penetrated the Unit 1 auxiliary building below the design flood level.

b. The licensee failed to design the floor drain system with isolation capability so that the drain piping from the turbine building and radwaste storage building, which are non-flood protected structures, would not allow water to drain into the Unit 1 auxiliary building in the event of a flood.

c. The licensee failed to design the Unit 1 Hatch 522 and Unit 2 Door 253, which allow access to the area between the auxiliary buildings and containment buildings, to prevent water intrusion during a design basis flood event.

d. The licensee failed to seal open penetrations into the Unit 1 auxiliary building below the design flood level that were created when the licensee abandoned portions of the waste solidification system.

e. The licensee failed to assure that the Unit 1 decay heat vault drain valves were specified as safety-related, as required to maintain the vaults watertight.

B. 10 CFR Part 50, Appendix B, Criterion V, "Instructions, Procedures, and Drawings,"

states, in part, that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings.

Unit 1 Quality Drawing A-304, Sheet 1, Wall and Floor Penetrations Key Plan, Revision 1, and Unit 2, Quality Drawings A-2002, Architectural Schematic, Fire and Flood Protection Plans and Sections, Revision 10, prescribed walls, ceilings, and floors as flood barriers that required seals.

Unit 1, Quality Drawing A-337, Wall and Floor Penetrations Enclosure Details, Revision 9, and Unit 2 Quality Drawing Series E-2073, Electrical Penetration Sealing Details, Revision 3, prescribed conduit seal installation details that would act as a barrier to flood water. Unit 2 Quality Drawing Series A-2600, Fire Barrier Penetration Seal Details, Revision 5, prescribed pipe penetration seal details that would act as a barrier to flood water.

Contrary to the above, as of March 31, 2013, the licensee did not accomplish activities affecting quality in accordance with documented instructions, procedures, or drawings.

Specifically, the licensee failed to assure that safety-related equipment below the design flood level was protected in the following examples:

a. The licensee failed to install seals in conduits that penetrated flood barriers for the Unit 1 and Unit 2 auxiliary and emergency diesel fuel storage buildings.

b. The licensee failed to install seals in piping that penetrated flood barriers for the Unit 2 auxiliary building extension.

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c. For the Unit 1 and Unit 2 auxiliary building hatches and building expansion joints between the building and containment, the licensee failed to provide appropriate seal inspection criteria, establish a replacement frequency for the seals, and develop post-maintenance test procedures to verify the effectiveness of the seals after they were reinstalled.

These violations are associated with a Yellow Significance Determination Process finding for Units 1 and 2.

to 0CAN021504 Page 4 of 5 Reply to a Notice of Violation; EA-14-088 Entergy Operations, Inc. (Entergy) concurs with the violation as cited with the exception of Section A.e of the Notice of Violation regarding the safety-related classification of the Arkansas Nuclear One (ANO) Unit 1 decay heat vault drain valves. Supporting information for this exception is discussed in Attachment 2.

Entergy performed a root cause investigation into the initial failure of the external flood barriers that were self-revealed by the March 31, 2013, stator drop event. As a result of the Near-Term Task Force (NTTF) Recommendation 2.3, Flooding Walk Down of the NTTF Review Insights from the Fukushima Dai-ichi Accident, walk downs and extent of condition reviews, additional deficiencies in the ANO flood boundary were identified. Based on these results, a subsequent root cause investigation was completed. The majority of the deficiencies were determined to be legacy issues that had existed since original plant construction. The remaining deficiencies were a result of inadequate preventative maintenance (PM) strategies or equipment that had been abandoned in place. The identified deficiencies have been evaluated, corrected to restore the flood related function or have had compensatory measures implemented. Activities are ongoing to replace the compensated measures with robust engineered design features.

(1) The reason for the violation Root cause evaluations identified the following causes:

Insufficient configuration control of external flood barriers was identified. This included controlled design drawings that do not properly display or define flood barriers (penetration seals, conduits, etc.). Additionally, operating procedures were identified that did not contain the detail necessary to ensure manual actions would be sufficiently implemented, resulting in the potential for ineffective response to external flooding.

The design of some external flood protection barriers was found to be inadequate. Some instances were identified where a floor drain system was cross-connected between non-flood protected areas and flood protected areas with no method of isolation. Additionally, several unscheduled embedded conduits that penetrate flood barriers were not properly sealed.

In several cases, the PM strategy in place to maintain flood hatches and doors in accordance with plant design basis was inadequate, with respect to both frequency and content.

Additionally, the instructions in the PM activities in place were found to be inconsistent and inadequate for maintaining hatch seals.

Contributing factors were also identified related to inadequate flood penetration barrier walk downs, breakdown in the Operating Experience (OE) process, and the lack of understanding with regard to risk significant flood barriers.

to 0CAN021504 Page 5 of 5 (2) The corrective steps that have been taken and the results achieved The cited examples, with the exception of the safety-classification of the decay heat drain valves, along with other identified flooding deficiencies have been evaluated, corrected, or have had compensatory measures implemented. Examples of other deficiencies include those associated with ductwork, ceiling/floor areas, and embedded features such as floor drain connectivity and embedded conduit routing which could potentially allow water intrusion past the barrier and result in inadequate flood protection. Corrective actions included reestablishment of qualified flood barriers and revisions to the flood-related procedures, restoring the site to the original design basis for an external flooding event.

Other completed corrective actions include:

Identified deficiencies associated with the NTTF flooding walk down reports have been addressed Expectations regarding effective use of internal and external OE was reinforced with Engineering personnel Revisions to, or establishment of, PM frequencies and instructions for flood hatches and doors Training that included risk significance and importance of maintaining flood barriers (3) The corrective steps that will be taken Activities are ongoing to replace the compensatory measures with robust engineered design features.

Design basis documentation clearly delineating the external flood protection features and boundaries is being developed. This documentation will include identification of equipment required for flood protection, basis for safety classification, and flood mitigation features.

As part of the extent of condition review the design basis for internal flood protection is to be reconstituted. Following design basis reconstitution, a walk down of internal flood protection features to ensure conformance will be conducted.

The Maintenance Rule scoping and performance criteria will be revised to ensure identified flood protection features are monitored under the maintenance rule program.

Flood protection boundaries and features, including penetrations, are being clearly labeled to aid in controlling the physical configuration of flood protection features along with facilitating identification of such features by plant personnel.

(4) The date when full compliance will be achieved The evaluation, correction, or compensation of identified flooding deficiencies has restored the site to full compliance with regard to the protection of safety-related equipment for the external design flood level.

Attachment 2 to 0CAN021504 Notice of Violation EA-14-088 Exception to 0CAN021504 Page 1 of 2 Entergy Operations Inc. (Entergy) takes exception to Section A.e of the Notice of Violation regarding the safety-related classification of the Unit 1 Decay Heat (DH) vault drain valves, ABS-13 and ABS-14, in that the non-safety related classification for these valves is consistent with the Arkansas Nuclear One (ANO) licensing basis.

Design and Testing ABS-13 and ABS-14 are McCannaflo, flanged, 4 in, Class 150, non-Q ball valves. The valves are located on ANO Unit 1 Elevation 317 in the Tendon Gallery Access area. The valves are classified as non-safety related and have no safety related function. These manual valves are maintained closed and are verified closed prior to initiating post-accident Reactor Building Sump recirculation to limit the spread of contaminated liquid outside the decay heat vaults (non-safety function). The closure of these valves also isolates the vaults from the auxiliary building general area. The valves are opened as needed to drain from various areas within the DH vaults to the Auxiliary Building Sump (non-safety function).

The valves have a PM classification of Non-Critical - Essential. ABS-13 and ABS-14 PM activities include a periodic flush and leak rate test. The PM activity (flush / leak rate test) provides high confidence that the valves can prevent the backflow of water through the drain system. The Non-Critical - Essential PM classification ensures that engineering evaluates and concurs with any proposed changes in the PM program associated with these valves.

In addition, the DH vault drain valves are included in the augmented inspection program to manage aging effects such as loss of material and cracking for components that are beyond the scope of ASME Code,Section XI, as discussed in the License Renewal Safety Evaluation for Unit 1 (April 2001) (ML011030091).

Section 9.3.3 of the Safety Evaluation (SE) indicates that the DH Removal (DHR) system provides adequate protection from the effects of a single active or a single passive failure during post-accident long term cooling. The single active and passive failures discussed in the SE were failures of components within the DHR system, and not associated with other systems such as the Auxiliary Building Drain System.

Further, ULD-0-TOP-18 provides Single Failure Criterion for Unit 1. Section 3.1.3 of the Upper Level Document (ULD), ECCS Final Acceptance Criteria / 10 CFR 50, Appendix K, indicates that Unit 1 is committed to the single failure requirements of 10 CFR 50, Appendix K, and only active failures were considered in the evaluation of the Final Acceptance Criteria. Section 3.1.3 specifically addresses the SE statements regarding passive component failures in the DHR system. The Unit 1 Safety Analysis Report (SAR) is silent regarding these drain valves relative to passive component failures.

Safety Classification ULD-0-TOP-22, Design Configuration documentation Project, ANO Component Classification Topical, describes the classification criteria that were in place when these valves were installed.

ULD-0-TOP-22 provides a detailed discussion regarding the historical evolution of design criteria dating from the issuance of the General Design Criteria (GDC) by the Atomic Energy Commission (AEC) in 1967; 10 CFR 50, Appendix B, in 1970; Revised GDC and incorporation into 10 CFR 50, Appendix A, in 1971; 10 CFR 100, Appendix A, in 1973; Regulatory Guide 1.29 to 0CAN021504 Page 2 of 2 in 1973; ANSI/ANS N18.2 and N51.8 in 1973; 10 CFR 50.49 in 1983; ANSI/ANS 51.1 in 1983; 1983 NRC Correspondence; Generic Letter (GL) 83-28; and EPRI Safety Classification Guidelines published in 1990.

Unit 1 was designed to meet the intent of the original GDC, which provided the basis for equipment classification. A significant portion of the Unit 1 construction was completed before additional classification guidance began to appear in 1972 and 1973. The classification of structures, systems and components was documented in the Final Safety Analysis Report (FSAR) as the Q-List. The Q-List was a summary level document which classified systems and selected major components rather than each individual component. The NRC AEC accepted this approach to the classification of Unit 1 equipment. The Safety Evaluation Report (SER) for the Operating License restated the Unit 1 FSAR definition of Class I. The SER concluded that this method of classification meets our requirements for the seismic and quality classification of safety-related structures, components and systems.

In the mid-1980s, in response to GL 83-28, Required Actions Based on Generic Implications of Salem ATWS Events, ANO implemented a Component Level Q-list (CLQL) which detailed classification at the component level. During this timeframe, Safety Related (Q) was defined in governing procedure OP-6010.002, QACat and ENVQ Component Classification, as those systems, structures or components that are relied upon to remain functional during or following design basis events to ensure (1) the integrity of the reactor coolant pressure boundary, (2) the capability to shutdown the reactor and maintain it in a safe shutdown condition, or (3) the capability to prevent or mitigate the consequences of accidents which could result in potential offsite exposures comparable to the guideline exposures of 10 CFR 100. This definition is consistent with the definition of safety-related identified in GL 83-28 and 10 CFR 50.2. As documented in the NRC minutes of an October 13, 1988 meeting between the NRC staff and ANO, the definition for a safety-related component was presented at the meeting and found acceptable to the staff.

The decay heat drain valves, ABS-13 and ABS-14, were reviewed against this criterion and as a result, these valves were classified as non-safety-related. As stated above, these manual valves are maintained closed and are verified closed prior to initiating post-accident Reactor Building Sump recirculation to limit the spread of contaminated liquid outside the decay heat vaults. Additionally, there are no Unit 1 licensing commitments related to DH vault drain system valves that classify these valves as safety or augmented quality related.

The non-safety related classification for ABS-13 and ABS-14 is consistent with the classification of other drain system valves. Assignment of a safety / augmented quality classification to these valves would not impact the maintenance practice related to the valves. As such, the non-safety related component classification is considered correct for the drain isolation valves.

These valves are maintained closed. Since the valves are in the PM program which provides inspection on a periodic frequency, component reliability, consistent with their risk significance, is sufficiently maintained. As such, the non-safety related component classification is considered correct for the DH vault drain isolation valves.