ML11363A074

10 CFR 50.55a Request ISI-05: Proposed Alternative Bottom Mounted Instrument Examinations

ML11363A074
Person / Time
Site:	Ginna
Issue date:	12/16/2011
From:	Mogren T Constellation Energy Group, EDF Group, Ginna
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML11363A074 (9)

Text

Thomas G. Mogren Manager - Engineering Services CENG R.E. Ginna Nuclear Power Plant, LLC 1503 Lake Road Ontario, New York 14519-9364

a joint venture of 585.771.5208 585.771.3392 Fax oc F-nerw010 til =eDF Thomas.Mogqren(,cenQllc.corn December 16, 2011 U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTENTION: Document Control Desk

SUBJECT:

R.E. Ginna Nuclear Power Plant Docket No. 50-244 10 CFR 50.55a Request ISI-05: Proposed Alternative Bottom Mounted Instrument Examinations

References:

(1) Letter from N. Salgado, NRC, to John Carlin, R.E. Ginna Nuclear Power Plant LLC, dated March 8, 2010,

Subject:

Relief Request Number 24-Fourth Interval Inservice Inspection Program Proposed Alternative for Bottom Mounted Instrument Examinations - R.E. Ginna Nuclear Power Plant (TAC NO. ME1364) (ADAMS Accession No. ML100290926)

Pursuant to 10 CFR 50.55a (a)(3)(i), R.E. Ginna Nuclear Power Plant (R.E. Ginna) hereby requests NRC approval of the enclosed request for the Fifth Interval Inservice Inspection (ISI)

Program. In Reference 1, the NRC granted the requested alternative to the requirements of ASME Section XI Code Case N-722 for performing a bare metal visual exam every other RFO.

This alternative was effective during the fourth 10-year ISI interval.

During the 2011 RFO, Ultrasonic Examination of all Bottom Mounted Instrument (BMI) Nozzles was performed. This examination did not identify Inside Diameter (ID) or Outside Diameter (OD) initiated cracking. Continued Ultrasonic examination of all BMI Nozzles is not warranted since no service induced cracking was identified. Additional information is being presented in Enclosures 2 and 3 which shows that the painted coating on the BMI annuli will not prevent the timely visual identification of leakage.

Relief Request Number ISI-05 (Enclosure 1) is being submitted for the fifth 10-year ISI interval to identify the continued plan with R.E. Ginna's BMI nozzles in accordance with Code Case N-722-1, with applicable conditions specified within 10CFR50.55a. The proposed alternative provides an acceptable level of quality and safety. Approval is requested by June 22, 2012 to support planning for the 2012 refueling outage.

U)PI 100,q494

Document Control Desk December 16, 2011 Page 2 There are no new commitments identified in this correspondence. Should you have questions regarding this matter, please contact Thomas Harding at (585) 771-5219, or Thomas. Hard i nqJ RCcenq IIc.com.

Very truly yours, e> i N.Pp kAn F^LS V'a 0 Thomas Mogren

Enclosures:

1. R.E. Ginna Nuclear Power Plant - Fifth Interval Inservice Inspection Program Proposed Alternative in Accordance with 10 CFR 50.55a (a)(3)(i) Bottom Mounted Instrument Examinations

2. Ginna Reactor Vessel Bottom Mounted Instrumentation Paint Cracking Analysis, October 5, 2011

3. Evaluation of Leakage and Deposit Formation In Painted Full-Scale BMI Mockups, SwRI Project No. 18.16196, Rev. 2., August 2011 cc: W. M. Dean, NRC D. V. Pickett, NRC Resident Inspector, NRC (Ginna LLC)

Document Control Desk December 16, 2011 Page 3 bcc: C. W. Fleming, Esquire J. C. Wells E. J. Groh T. Harding T. G. Mogren B. Rudell COMMITMENTS IDENTIFIED IN THIS CORRESPONDENCE:

0 None

ENCLOSURE 1 R.E. Ginna Nuclear Power Plant - Fifth Interval Inservice Inspection Program Proposed Alternative in Accordance with 10 CFR 50.55a (a)(3)(i)

Bottom Mounted Instrument Examinations

Relief Request Number ISI-05 R.E. Ginna Nuclear Power Plant - Fifth Interval Inservice Inspection Program Proposed Alternative in Accordance with 10 CFR 50.55a (a)(3)(i)

Bottom Mounted Instrumentation Examinations

- Alternative Provides Acceptable Level of Quality and Safety -

1. ASME Code Component(s) Affected The Class 1 Reactor Vessel includes the sub components of 36 Inconel 600 Bottom Mounted Instrumentation (BMI) Penetrations. The specific nozzle component numbers are:

A65 A68-2 A71 A75 A80 A86 A66-1 A69 A72 A76 A81 A87 A66-2 A70-1 A73-1 A77 A82 A88-1 A67-1 A70-2 A73-2 A78-1 A83 A88-2 A67-2 A70-3 A74-1 A78-2 A84 A89-1 A68-1 A70-4 A74-2 A79 A85 A89-2

2. Applicable Code Edition and Addenda The R.E. Ginna Nuclear Power Plant Fifth Interval Inservice Inspection (ISI) Program Plan complies with American Society of Mechanical Engineers (ASME)Section XI Code, 2004 Edition, No Addenda.

3. Applicable Code Requirement 10CFR50.55a incorporates additional requirements, one of which is ASME Code Case N-722-1 "Additional examinations for (PWR) Pressure Retaining Welds in Class 1 Components Fabricated with Alloy 600/82/182 Materials" with conditions, Section Xl, Division 1. Table 1, Examination Category Item Number B15.80, RPV Bottom Mounted Instrument Penetration requires a bare metal visual examination every other refueling outage.

4. Reason for Request

10CFR50.55a(g)(6)(ii)(E)(1) requires pressurized water reactors to augment the inservice inspection program by implementing Code Case N-722-1 with conditions in 10CFR50.55a (g)(6)(ii)(E)(2) through (4).

Code Case N-722-1 requires a bare metal visual examination during every other refueling outage starting with the first refueling outage after January 1, 2009. Code Case N-722-1 Table 1 referenced notes 3, 4, 5 that provide specific examination requirements.

R.E. Ginna Nuclear Power Plant is not able to perform a complete bare metal visual examination as defined in ASME Code Case N-722-1 due to paint in and around the nozzle annulus. The extent of paint-occlusion has been documented and ranges from 12.5% to 100%, with 10 nozzles being 100% occluded with paint in the annuli.

Page 1 of 5

Relief Request Number ISI-05 R.E. Ginna Nuclear Power Plant - Fifth Interval Inservice Inspection Program Proposed Alternative in Accordance with 10 CFR 50.55a (a)(3)(i)

Bottom Mounted Instrumentation Examinations

- Alternative Provides Acceptable Level of Quality and Safety -

While the paint could be potentially minimized in the area of interest, replication has shown that the paint has wicked up into the annuli. As a result, the ability to remove paint to meet the 100% bare metal visual inspection will not be met.

The Fourth Interval Inservice Inspection Program, Relief Request Number 24, dealt with this subject and was submitted and approved by the Nuclear Regulatory Commission (NRC). Relief Request Number 24 identified the historical visual examination performed every refueling outage (RFO) since the 2003 RFO with no detection of leakage during the as-found inspections of the Bottom Mounted Instruments (BMIs). Relief Request Number 24 also identified R.E. Ginna Nuclear Power Plant's commitment to perform a detailed visual examination during the 2009 and 2011 Refueling Outages (RFOs) and a volumetric examination of the 36 BMI nozzles including the volume of the tube and the weld interface to the intent of ASME Section XI Appendix VIII during the 2011 RFO.

Relief Request Number ISI-05 is being submitted to identify the continued plan for R.E Ginna Nuclear Power Plant's 36 BMI nozzles. Work Ginna has performed demonstrates this proposed alternative provides equal if not better detection capability and therefore satisfies the criteria of 10CFR50.55a(a)(3)(i).

5. Proposed Alternative and Basis for Use R.E. Ginna Nuclear Power Plant will perform an as-found visual examination of the BMI surfaces during every refueling outage to the visual examination requirement (VE, enhanced visual) of Code Case N-722-

1. Since detailed visual examinations were performed in the as-found condition since 2003 with no detection of reactor coolant leakage, the visual examination shall be performed during the 2012 RFO and every refueling outage after the 2012 RFO.

The Reactor Pressure Vessel (RPV) was designed and constructed to ASME Section III, 1965 Edition. This code did not contain requirements to ensure that items be accessible for future examination. The construction code did not contain requirements to prevent the application of paint to the BMI nozzle annuli which now prevents a bare metal visual examination. Removal of the paint by chemical, mechanical, or thermal process will expose workers to unneeded dose, spread contamination, and risk damaging the pressure boundary. In addition, due to paint being wicked in the annulus area, there is no guarantee of successful accomplishment of adequate paint removal.

During the 2009 RFO, samples of paint from the R. E. Ginna Nuclear Power Plant's Reactor Vessel Bottom head were removed for analysis [6]. The paint samples taken were from the machined nozzle OD surface and from the lower head. Cracks in the paint were identified in the nozzle annulus. During Page 2 of 5

Relief Request Number IS1-05 R.E. Ginna Nuclear Power Plant - Fifth Interval Inservice Inspection Program Proposed Alternative in Accordance with 10 CFR 50.55a (a)(3)(i)

Bottom Mounted Instrumentation Examinations

- Alternative Provides Acceptable Level of Quality and Safety -

the 2011 RFO, metallurgical replicas were taken of the nozzle-to-head annulus at three locations [6].

Cracks in the paint were identified.

R.E. Ginna Nuclear Power Plant, with the assistance of Southwest Research Institute [7], performed an evaluation of leakage and deposit formation in painted full-scale BMI mockups. The objective of this testing program was to determine the effect of a paint layer applied to the bottom of the low alloy steel ring and covering the annulus gap on leakage out of the annulus and deposit formation around the leaking annulus. A secondary objective was to obtain information about the effect of the paint layer on pressures within the leaking annulus.

The results of the Southwest Research Institute investigation are as follows:

1. Paint applied over the annulus exit on the bottom of the mockup was not an effective barrier for either liquid water or steam exiting the annulus. Leakage through the paint started quickly when pressure was applied, even under ambient temperature conditions. Low annulus pressures, 149 psi maximum, were sufficient to create the leak paths through the paint.

2. Thermal cycling produced cracking of the paint over the annulus similar to those observed on the Ginna RPV in 2009. These cracks serve as effective leak paths for effluent trying to leave the annulus.

3. Even in the absence of prior degradation, the paint does not provide an effective barrier to prevent or delay steam from exiting the annulus at elevated temperatures.

4. Once leaks form, the paint does not appear to alter either the location or the volume of the boric acid deposits that form from the steam escaping from the annulus.

5. If the presence of a stress corrosion crack provides a path for primary coolant to enter the annulus surrounding a BMI nozzle, the presence of paint on the bottom of the reactor around the nozzle should not provide any significant impediment to the steam exiting the bottom of the annulus nor to leak detection by visual inspection for the presence of deposits around the nozzle.

6. The small annulus pressure and time required to produce leakage through the paint indicates that the presence of the paint should not alter the boric acid wastage processes or rates within the annulus from those that would occur in an unpainted annulus.

During the 2011 RFO, Ultrasonic Examination of all Bottom Mounted Instrument (BMI) Nozzles was performed. This examination did not identify ID or OD initiated cracking. One original manufacturing defect on BMI nozzle "A86" was identified. In accordance with ASME Section XI Code, 2004 Edition, No Addenda, paragraph IWB-3144 (b), an Analytical Evaluation of the embedded (non-wetted) indication on BMI nozzle "A86" caused from original manufacturing will be provided under a separate submittal.

Continued Ultrasonic examination of all BMI Nozzles is not warranted since no service induced cracking Page 3 of 5

Relief Request Number IS1-05 R.E. Ginna Nuclear Power Plant- Fifth Interval Inservice Inspection Program Proposed Alternative in Accordance with 10 CFR 50.55a (a)(3)(i)

Bottom Mounted Instrumentation Examinations

- Alternative Provides Acceptable Level of Quality and Safety -

was identified. Additional information is being presented (Reference 6 and 7) which shows that the painted coating on the BMI annuli will not prevent the timely visual identification of leakage.

Based on these results, R.E. Ginna Nuclear Power Plant proposes to perform an as-found visual examination of the BMI surfaces during every refueling outage as an alternative to the 100% bare metal visual examination required by Code Case N-722-1. This is considered to be an alternative that is better than Code Case N-722-1 requirements because any minor impediments that the paint contributes to the timely identification of external leakage is more than compensated by the inspections every RFO (instead of every other RFO). The visual examination (VE examination of Code Case N-722-1) shall be performed again during the 2012 RFO and every refueling outage after the 2012 RFO.

6. Duration of Proposed Alternative The performance of an as-found visual examination of the BMI surfaces shall be performed every refueling outage starting at the 2012 RFO until the end of R.E. Ginna Nuclear Power Plant 5'h Interval ISI Program (12/31/2019).

7. Precedents None

8. References

1. 10 CFR 50.55a, Codes and Standards

2. American Society of Mechanical Engineers (ASME) Code Case N-722-1; "Additional Examinations for PWR Pressure Retaining Welds in Class 1 Components Fabricated with Alloy 600/82/182 Materials".

3. ASME Boiler and Pressure Vessel Code, Section Xl, 2004 Edition, No Addenda; "Rules for Inservice Inspection of Nuclear Power Plant Components".

4. Pacific Northwest National Laboratory, NUREG/CR-6943, PNNL-16472, A Study of Remote Visual Methods to Detect Cracking in Reactor Components, October 2007, Prepared for Division of Fuel, Engineering and Radiological Research Office of Nuclear Regulatory Research.

5. R. E. Ginna BMI drawing 117828E Rev. 6 (Westinghouse Proprietary)

Page 4 of 5

Relief Request Number ISI-05 R.E. Ginna Nuclear Power Plant - Fifth Interval Inservice Inspection Program Proposed Alternative in Accordance with 10 CFR 50.55a (a)(3)(i)

Bottom Mounted Instrumentation Examinations

- Alternative Provides Acceptable Level of Quality and Safety -

6. R. E. Ginna Materials Laboratory Report, Ginna Reactor Vessel Bottom Mounted Instrumentation Paint Cracking Analysis, October 5, 2011.

7. Southwest Research Institute, SwRI Project No. 18.16196, Evaluation of Leakage and Deposit Formation in Painted Full-Scale BMI Mockups, Revision 2, April 2011.

8. Letter from N. Salgado, NRC, to John Carlin, R.E. Ginna Nuclear Power Plant LLC, dated March 8, 2010,

Subject:

Relief Request Number 24 - Fourth Interval Inservice Inspection Program Proposed Alternative for Bottom Mounted Instrument Examinations - R.E. Ginna Nuclear Power Plant Page S of 5