BYRON 2008-0045, Response to Notice of Violation EA-08-046

Response to Notice of Violation EA-08-046

ML081230070
Person / Time
Site:	Byron
Issue date:	05/01/2008
From:	Hoots D Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BYRON 2008-0045, EA-08-046, IR-07-009
Download: ML081230070 (7)

Text

Nuclear May 1,2008 LTR: BYRON 2008-0045 File: 1.I0.0101 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-001 Byron Station, Units 1 and 2 Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455

Subject:

Response to Notice of Violation EA-08-046

Reference:

Letter from J.L. Caldweii (NRC) to C.G. Pardee (Exeion Generation Company, LLC), "Byron Station - Final Significance Determination for a White Finding and Notice of Violation; NRC Inspection Report No.

05000454/2007009 (DRS) and 05000455/2007009 (DRS)" dated April 1, 2008 In the referenced letter, the NRC provided Exelon Generation Company, LLC (EGC) with the final significance determination for a White finding and two associated Notices of Violation (NOV) of 10CFR 50, Appendix B Criterion XVI, "Corrective Actions," and Criterion Ill, "Design Control," for the EGC Byron Station, Units 1 and 2. In accordance with 10CFR 2.201, "Notice of Violation," this letter provides EGC's written statement or explanation for the NOVs. This reply is required to be submitted within 30 days of the date of the referenced letter transmitting the NOVs. to this letter provides for each NOV: (1) the reason for the violation; (2) the corrective steps that have been taken and the results achieved; (3) the corrective steps that will be taken to avoid further violations; and (4) the date when full compliance will be achieved. Attachment 2 contains a listing of regulatory commitments.

If you have any questions concerning this ietter, please contact Mr. William Grundmann at (815)406-2800,

~ a G M.d fioots Site Vice President Byron Station

U.S. Nuclear Regulatory Commission Byron Letter 2008-0045 May 1,2008 Attachments: 1. Reply to Notice of Violation: EA-08-046

2. Regulatory Commitments cc: NRC Regional Administrator, Region 111 NRC Senior Resident Inspector, Byron Nuclear Generating Station

Attachment 1 Byron Letter 2008-0045 Reply to Notice of Violation: EA-08-046 NOTICE OF VIOLATION EA-08-046

1. 10CFR Part 50, Appendix B, Criterion XVI "Corrective Actions," requires in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and non-conformances are promptly identified and corrected.

Contrary to the above:

a. From May 17, 2007 to October 20, 2007, the licensee failed to assure that a condition adverse to quality was promptly corrected. Specifically, on May 17, 2007, the licensee identified in Action Request (AR) 00630679 that there was significant corrosion of the OA essential service water riser pipe. However, as of October 20, 2007, no corrective actions had been taken to correct this condition.

b. From November 30 2006, to October 20, 2007, the licensee failed to assure that a condition adverse to quality was promptly corrected. Specifically, on November 30,2006, the licensee identified in ARs 00563914 and 00563907 that there was significant corrosion of the OB essential service water riser pipe. However, as of October 20, 2007, no corrective actions had been taken to correct this condition.

c. From March 5, 2007 to October 20, 2007, the licensee failed to assure that a condition adverse to quality was promptly corrected. Specifically, on March 5, 2007, the licensee identified in AR 00599643 that there was significant corrosion of the OC essential service water riser pipe and the corroded condition had degraded from a May 2006 inspection. However, as of October 20, 2007, no corrective actions had been taken to correct this condition.

d. From October 16, 2006 to October 20, 2007, the licensee failed to assure that a condition adverse to quality was promptly corrected. Specifically, on October 16, 2006, the licensee identified in AR 00544803 that there was significant corrosion of the OD essential service water riser pipe. However, as of October 20, 2007, no corrective actions had been taken to correct this condition.

e. From June 14, 2007 to October 20, 2007, the licensee failed to assure that a condition adverse to quality was promptly corrected. Specifically, on June 14, 2007, the licensee identified in ultrasonic test report 2007-005 and AR 00640363 that there was significant corrosion of the OE essential service water riser pipe. However, as of October 20, 2007, no corrective actions had been taken to correct this condition,

f. From May 17, 2007 to October 20, 2007, the licensee failed to assure that a condition adverse to quality was promptly corrected. Specifically, on May 17, 2007, the licensee identified in AR 00630679 and again on June 5, 2007, in AR 00637335, that there was significant corrosion on all essential service water riser pipes (including the OF and OG essential service water riser pipes). However, as of October 20, 2007, no corrective actions had been taken to correct this condition.

g. From June 4, 2007, to October 20, 2007, the licensee failed to assure that a condition adverse to quality was promptly corrected. Specifically, on June 4, 2007, the licensee identified in AR 00636745 that there was significant corrosion of the OH essential service water riser pipe. However, as of October 20, 2007, no corrective actions had been taken to correct this condition.

RESPONSE

1. Reason for the violation A root cause evaluation was performed for the through wall leak on the OC essential service water (SX) riser piping. The evaluation identified that the programmatic root cause for the piping failure was inadequate procedural guidance related to trending, tracking, identification threshold, and follow-up action for safety related external pipe corrosion. A contributing cause was a weakness in procedural guidance related to Issue Report and work request prioritization related to corrosion on safety related piping.

2. Corrective steps taken and results achieved All eight of the SX riser piping sections have been replaced with new carbon steel pipe pieces. To initially address the trending, tracking, threshold, prioritization and follow-up of corrosion on safety related piping various actions have been taken. An issue report (IR) template has been implemented that provides for consistent identification of corrosion related issues. The template also provides for an assessment of the level of corrosion present on the piping. Additionally, a Byron Station specific procedure (WC-BY-106) covering the prioritization of work activities has been implemented that increases the priorities placed on corrosion related issues. These initial actions have raised the awareness and monitoring of corrosion related issues.

3. Corrective steps to be taken to avoid further violation The corrective action to prevent recurrence (CAPR) associated with the programmatic root cause is the development and implementation of procedural guidance pertaining to trending, tracking, identification threshold, and follow-up action related to external pipe corrosion. This has been accomplished through a revision to the Conduct of Plant Engineering (COPE) Manual (procedure ER-AA-2030) and the Buried Piping Raw Water Corrosion Program procedure ER-AA-5400 and implementing Training and Reference Material documents (T&RM ER-AA-5400-1001 and 1002).

Additionally, an EGC fleet-wide procedure (WC-AA-106) will be devefoped that addresses the prioritization of corrosion related work activities.

4. Date when full compliance will be achieved Full compliance will be achieved by May 30, 2008. All actions described above are complete with the exception of EGC fleet-wide implementation of WC-AA-106; which will be complete by June 27, 2008.

NOTICE OF VIOLATION EA-08-046

2. 10 CFR Part 50, Appendix B, Criterion Ill, "Design Control,"requires, in part, that design control measures provide for verifying or checking the adequacy of design, such as by the performance of design reviews, by the use of alternate or simplified calculational methods, or by the performance of a suitable testing program.

Contrary to the above:

a. On July 11, 2007, the licensee's design control measures failed to verify the adequacy of the design of the degraded OE essential service water riser pipe, in that the methodology and design inputs used did not include significant factors (e.g. thermal stress, compressive loads (buckling) and functional capability) which affected the structural integrity of this degraded riser pipe. Specifically, as documented in Engineering Change 366395 "Nonconformance Evaluation for Line OSX97AE-24 Near Valve OSX163E," the licensee failed to: (1) check the thermal stress in accordance with Equations 10 and 11 from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (the Code) 1977 Edition, Section Ill, Division 1 Subsection ND-3600; (2) evaluate the compressive (buckling) loads present within the thinned essential service water riser pipe wall; and (3) check the functional capability in accordance with site procedures that implemented Updated Final Safety Analysis Report Section 3.9.3.1.3 requirements for Class 2 and 3 piping. Consequently, the licensee incorrectly concluded that the minimum pipe wall thickness was sufficient to meet the Code allowable stress levels. As a result, the degraded OE essential service water riser was left in service until October 20, 2007.

b. On October 12, 2007, and October 17, 2007, the licensee's design control measures failed to verify the adequacy of the design of the degraded OH and OB essential service water riser pipes, in that, the methodology and design inputs used did not apply an appropriate allowable stress value, and did not account for compressive stresses. Specifically, as documented in Engineering Change 367754 "OP EVAL 07-009, SXCT Riser Piping Below Minimum Wall Thickness" and AR 00685955, the licensee failed to apply the lower allowable stress (Sh) values applicable to Class 3 piping and failed to evaluate the compressive (buckling) loads present within the thinned essential service water riser pipe wall.

Consequently, the licensee incorrectly concluded that the pipe wall thicknesses were sufficient to meet Code allowable stress levels. The degraded OH andOB essential service water risers were left in service until October 20, 2007

RESPONSE

1. Reason for the violation A root cause evaluation was performed for the through wall leak on the OC essential service water (SX) riser piping. The evaluation identified that individuals failed to accurately characterize the level of degradation due to a lack of sensitivity to allowable design margins on the piping. Another contributing cause was inadequate use of, and adherence to engineering standards. This aspect was further evaluated in an apparent cause evaluation (ACE). The ACE identified that that engineering procedures and administrative controls were inadequate to provide the necessary details needed to perform the evaluations.

2. Corrective steps taken and results achieved To address the sensitivity to margin management, a series of communications and training sessions were provided to plant personnel. The training was initially provided to Byron Station leadership and supervision and will be cascaded to all other designated personnel. These actions, to date have increased the awareness and sensitivity to available margins during various station activities.

3. Corrective steps to be taken to avoid further violation To address the inadequate procedural and administrative controls, EGC engineering standard NES-MS-03.2 will be revised to provide guidance on ASME code usage for the type of evaluations noted in the NOV.

4. Date when full compliance will be achieved Full compliance will be achieved by June 27, 2008. This is the date the above mentioned engineering standard will be implemented at Byron. The training described above will be completed with all designated personnel by May 9, 2008.

Attachment 2 Byron Letter 2008-0045 Regulatory Commitments The following table identifies commitments made in this document. Any other actions discussed in this submittal represent intended or planned actions. They are described to the NRC for the NRC's information and are regulatory commitments Commitment Revise the Conduct of Plant Engineering (COPE)

Manual (procedure ER-AA-2030) and the Buried Piping Raw Water Corrosion Program procedure ER-AA-5400 and implementing Training and Reference Material documents (T&RM ER-AA-5400-1001 and provide guidance on ASME code usage for the type of evaluations noted in the T June 27,2008 One Time NOV.

T Develop an EGC fleet-wide One Time procedure that addresses the prioritization of corrosion related work sensitivity on margin management to designated Byron Station personnel I May 30,2008 One Time