W3F1-2009-0058, Request for Alternative W3-ISI-016, Inspection of Reactor Pressure Vessel Head Control Element Drive Mechanism Nozzles During Third Ten-Year Inservice Inspection Interval

Request for Alternative W3-ISI-016, Inspection of Reactor Pressure Vessel Head Control Element Drive Mechanism Nozzles During Third Ten-Year Inservice Inspection Interval

ML092940243
Person / Time
Site:	Waterford
Issue date:	10/19/2009
From:	Murillo R Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
W3F1-2009-0058
Download: ML092940243 (11)

Text

Enteigy Entergy Operations, Inc.

17265 River Road Killona, LA 70057-3093 Tel 504-739-6715 Fax 504-739-6698 rmuricl@entergy.com Robert J. Murillo Licensing Manager Waterford 3 W3F1-2009-0058 October 19, 2009 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

REFERENCES:

Request for Alternative W3-ISI-01 6, Inspection of Reactor Pressure Vessel Head Control Element Drive Mechanism Nozzles during Third Ten-Year Inservice Inspection Interval Waterford Steam Electric Station, Unit 3

,Docket No. 50-382 License No. NPF-38 1.

Entergy Letter to the NRC dated April 15, 2004, Waterford 3 Relaxation Request #4 to NRC Order EA-03-009 for the Control Element Drive Mechanism Nozzles (CNRO-2004-0020) (ML041120367)

2. Entergy Letter to the NRC dated August 13, 2004, Response to NRC Request for Additional Information Pertaining to Waterford 3 Relaxation Request #4 to NRC Order EA-03-009 for the Control Element Drive Mechanism Nozzles (CNRO-2004-0039) [ML042320558]

3. NRC Letter to Entergy dated March 22, 2005, Waterford Steam Electric Station, Unit 3 (Waterford 3) -Relaxation Request from U.S. Nuclear Regulatory Commission (NRC) First Revised Order EA-03-009 for Control Element Drive Mechanism (CEDM) Nozzles (TAC No. MC2643)

[ML050820683]

Dear Sir or Madam; Pursuant to 10CFR50.55a(a)(3)(ii), Entergy Operations, Inc (Entergy) requests relief from the inspection requirements of American Society of Mechanical Engineers (ASME) Code Case N-729-1, as conditioned by 10CFR50.55a(g)(6)(ii)(D), for Waterford 3 Steam Electric Station, Unit 3 (Waterford 3) for the fall 2009 (RFl 6) refueling outage.

Effective October 10, 2008, the Nuclear Regulatory Commission (NRC) amended 10CFR50.55a to include ASME Code Case N-729-1, "Alternative Examination Requirements for Pressurized Water Reactor (PWR) Reactor Vessel Upper Heads With Nozzles Having Pressure-Retaining Partial-Penetration Welds, Section Xl Division 1," with conditions. Once a licensee implements the code case, the First Revised NRC Order EA-03-009 (the Order) is no longer applicable and shall be deemed to be withdrawn.

04o-T

W3F1-2009-0058 Page 2 Waterford Steam Electric Station, Unit 3 (Waterford 3) was categorized as having a high susceptibility to primary water stress corrosion cracking (PWSCC) in accordance with the Order. As such, Sections IV.C.(5)(a) and (b) of the Order required certain inspections to be performed. Under the requirements of Code Case N-729-1, Waterford 3 is still highly susceptible to PWSCC and is required to perform inspections that are similar to those required under the Order. In References 1 and 2 above, Entergy requested relaxation from Section IV.C.(5)(b) of the Order for Waterford 3. Specifically, the bottom of the Waterford 3 control element drive mechanism (CEDM) nozzles contains threads that could not be effectively examined in accordance with the Order. In Reference 3, the NRC granted relaxation to the Order based on.the conclusion that performance of inspection below the J-groove weld according to the Order requirements would result in hardship without a compensating increase in the level of quality and safety.

The conditions that required Entergy to submit a relaxation request to the Order remain with Code Case N-729-1 as conditioned by 10CFR50.55a. Therefore, pursuant to 10CFR50.55a(a)(3)(ii), Entergy requests approval of the proposed alternative to the requirements of the Code Case N-729-1 for the upcoming fall 2009 Waterford 3 refueling outage. The request is provided in Attachment 1 to this letter. It should be noted that the request is a summary of that made in References 1 and 2.

The recent performance demonstration qualification performed by Electric Power Research Institute (EPRI) added limitations to the CEDM examinations. In particular, the qualification process imposed a limitation on use of circumferentially oriented Time of Flight Diffraction (TOFD) ultrasonic transducers for detection of circumferential flaws. During previous examination, the circumferential oriented TOFD transducers were credited for detection of planar flaws in all orientations. The requirement to include axially oriented TOFD hardware for circumferential flaw detection has resulted in additional coverage limitation for Waterford 3's CEDM examination processes. However, this does not affect the technical justification for the requested alternative.

This relief request includes one new commitment as provided in Attachment 2.

Entergy requests approval of the proposed alternative. by November 6, 2009 because the RPV head inspections are scheduled to be completed by then. This request is also to support the return to service of Waterford 3 from the fall 2009 refueling outage.

If you have any questions or require additional information, please contact me at 504-739-6715.

S*Kcerely, RJM/RJP Attachments:

1.

Request for Alternative W3-1SI-01 6, Inspection of RPV Head Control Element Drive Mechanism Nozzles during Third Ten-Year Inservice Inspection Interval

2.

List of Regulatory Commitments

W3F11-2009-0058 Page 3 cc:

Mr. Elmo E. Collins, Jr.

Regional Administrator U. S. Nuclear Regulatory Commission Region IV 612 E. Lamar Blvd., Suite 400 Arlington, TX 76011-4125 NRC Senior Resident Inspector Waterford Steam Electric Station Unit 3 P.O. Box 822 Killona, LA 70066-0751 U. S. Nuclear Regulatory Commission Attn: Mr. N. Kalyanam Mail Stop O-07D1 Washington, DC 20555-0001 Wise, Carter, Child & Caraway ATTN: J. Smith P.O. Box 651 Jackson, MS 39205 Winston & Strawn ATTN: N.S. Reynolds 1700 K Street, NW Washington, DC 20006-3817 Morgan, Lewis & Bockius LLP ATTN: T.C. Poindexter 1111 Pennsylvania Avenue, NW Washington, DC 20004 Louisiana Department of Environmental Quality Office of Environmental Compliance Surveillance Division P. O. Box 4312 Baton Rouge, LA 70821-4312 American Nuclear Insurers Attn: Library 95 Glastonbury Blvd.

Suite 300 Glastonbury, CT 06033-4443 I

to W3F1-2009-0058 Request for Alternative W3-1SI-01 6, Inspection of RPV Head Control Element Drive Mechanism Nozzles During Third Ten-Year Inservice Inspection Interval to W3F17-2009-0058 Page 1 of 5 Entergy Operations, Inc.

Waterford Steam Electric Station, Unit 3 Request for Alternative W3-SI-O016, Inspection of RPV Head Control Element Drive Mechanism Nozzles During Third Ten-Year Inservice Inspection Interval

1.

ASME CODE COMPONENT AFFECTED Waterford Steam Electric Station, Unit 3 (Waterford 3) has one hundred-two (102) ASME Class 1 reactor pressure vessel (RPV) head penetration nozzles comprised of ninety-one (91) Control Element Drive Mechanism (CEDM) nozzles, ten (10) In-Core Instrument (ICI) nozzles, and one (1) vent line nozzle. This request pertains to the CEDMs nozzles only.

Component Numbers:

Ninety one (91) RPV head CEDM Nozzles [02-T-01 through 02-T-91]

Code

References:

Examination Category:

Item Number:

==

Description:==

Unit/Inspection Interval Applicability:

(1) ASME Section XI 2001 Edition through 2003 Addenda (2) ASME Code Case N-729-1, as conditioned by 1 OCFR50.55a(g)(6)(ii)(D)

Code Case N-729-1 in lieu of Table IWB-2500-1 Exam Category B-P B4.20 Proposed Alternative to Table 1 of ASME Code Case N-729-1 as conditioned by 10CFR50.55a(g)(6)(ii)(D)

Waterford 3 / Third (3 rd) 10-year inspection interval May 31, 2008 thru July 2017 II. 'APPLICABLE CODE REQUIREMENT The Code of Federal Regulations (Rule) 10CFR50.55a(g)(6)(ii)(D)(3) requires:

Instead of the specified 'examination method' requirements for volumetric and surface examinations in Note 6 of Table I of Code Case N-729-1, the licensee shall perform volumetric and/or surface examination of essentially 100 percent of the required volume or equivalent surfaces of the nozzle tube, as identified by Figure 2 of ASME Code Case N-729-1. A demonstrated volumetric or surface leak path assessment through all J-groove welds shall be performed. If a surface examination is being substituted for a volumetric examination on a portion of a penetration nozzle that is below the toe of the J-groove weld [Point E on Figure 2 of ASME Code Case N-729-1], the surface examination shall be of the inside and outside wetted surface of the penetration nozzle not examined volumetrically.

Code Case N-729-1 (Reference 1) requires that components shall be examined as specified in Table 1 of the code case.

to W3F1-2009-0058 Page 2 of 5 Ill. REASON FOR REQUEST Pursuant to 10CFR50.55a(a)(3)(ii), Entergy Operations, Inc. (Entergy) requests an alternative to the requirements of Code Case N-729-1 as conditioned by 1 OCFR50.55a(g)(6)(ii)(D) for the fall 2009 refueling outage 16 (RF1 6). Entergy plans to inspect the RPV head CEDM penetration nozzles at Waterford 3 using the ultrasonic testing (UT) method to the extent possible. Under the First Revised NRC Order EA 009 (Reference 4) and associated relaxation request, a UT inspection from the inside diameter (ID) of the CEDM nozzles at Waterford 3 has been previously performed from 2 inches above the root of the J-groove weld down to a point approximately 1.544 inches above the bottom of the nozzle. This 1.544 inch "blind zone" is due to limitations resulting from CEDM nozzle configuration (1.344 inches) and inspection probe design (0.200 inches). These limitations are discussed below. The hardships asso6iated with these limitations are discussed in Reference 2.

Nozzle Configuration Limitation - Guide cones are attached to the bottoms of the Waterford 3 CEDM nozzles via threaded connections. Specifically, thel guide cone screws into the end of the CEDM nozzle with a welded set screw and two tack welds at the cone-nozzle interface to secure the guide cone to the nozzle. The length ofthe threaded connection region is 1.25 inches. Additionally, a 450 chamfer exists immediately above the threaded connection region. The length of the chamfer region is 0.094 inches.

Due to the threaded connection and chamfer region at the bottom of each CEDM nozzle, a meaningful UT examination in that area cannot be performed. Specifically, the chamfer region geometry causes sporadic signals while, once the guide cone is reached, sound cannot pass into the CEDM nozzle base material because of the gap that exists between

-the guide cone and the nozzle at the threaded connection. Therefore, UT of the bottom 1.344 inches (1.25 + 0.094) of the CEDM nozzles is not possible.

Inspection Probe Design Limitation - The inspection probe to be used to inspect the Waterford 3 CEDM nozzles typically consists of multiple individual transducers. Various probe configurations may be utilized to perform the inspections.

The inspection probe is designed so that the ultrasonic transducers are slightly recessed into the transducer holder. This recess must be filled with water to provide an acoustic coupling between the transducer and the nozzle wall. Because of this design, the complete diameter of the transducer must fully contact the inspection surface before ultrasonic information can be collected. Because UT probes have a diameter of 0.250 inch, these transducers, in theory, are able to collect meaningful UT data down to a point approximately 0.125 inch (1/2 diameter) above the chamfer. However, when the lower edge of the transducer recess drops below the chamfer, the water between the transducer and the nozzle cannot be maintained, and the acoustic coupling is lost. Based on prior UT inspection experience and a review of UT data from previous inspections, meaningful data down to a point 0.200 inches above the chamfer can be collected.

to W3F1-2009-0058 Page 3 of 5 IV. PROPOSED ALTERNATIVE AND BASIS FOR USE Proposed Alternative UT Examination - The ID of each CEDM nozzle (i.e., nozzle base material) will be ultrasonically examined from the applicable point above the root of the J-groove weld (per Code Case N-729-1, 1.5 inches for nozzles with an incidence angle less than or equal to 300, and 1.0 inch for nozzles with an incidence angle greater than 300); down to 1.544 inches above the bottom of the nozzle.

The data acquisition techniques used are similar, but improved over those used in previous examination activities. The UT examination procedures, equipment, and personnel being applied have been qualified by EPRI in accordance with 10CFR50.55a(g)(6)(ii)(D). In addition, a demonstrated UT leak path assessment will be performed for all of the CEDM nozzle penetrations. Entergy will also perform a bare metal visual (BMV) inspection of the RPV head surface in accordance with Code Case N-729-1 during the fall 2009 refueling outage.

Analysis - The extent of the proposed alternative is established by an engineering evaluation that includes a finite element stress analysis and fracture mechanics evaluations. The intent of the engineering evaluation is to determine whether sufficient crack propagation length exists between the tip of a postulated crack and the toe of the J-groove weld to facilitate one cycle of crack growth without the crack reaching the weld.

Augmented Inspections - Based on the analytical results discussed in Reference 2 and as described in the response to NRC Question 5 of Reference 3, no augmented examinations are necessary for Waterford 3.

Basis for Use The background and basis for the proposed alternative is provided in References 2 and 3, with regard to the requirements of the Order. There are some differences between the requirements of the Order and the requirements of Code Case N-729-1 as conditioned by 10CFR50.55a.

Differences in the Required Examination Volume The examination volume required by the Order specified ultrasonic testing of the RPV head penetration nozzle (i.e., nozzle base material) from 2 inches above the highest point of the root of the J-groove weld (on a horizontal plane perpendicular to the nozzle axis) to 2 inches below the lowest point at the toe of the J-groove weld on a horizontal plane perpendicular to the nozzle axis (or the bottom of the nozzle if less than 2 inches); OR from 2 inches above the highest point of the root of the J-groove weld (on a horizontal plane perpendicular to the nozzle axis) to 1.0 inch below the lowest point at the toe of the J-groove weld (on a horizontal plane perpendicular to the nozzle axis) and including all RPV head penetration nozzle surfaces below the J-groove weld that have an operating stress level (including all residual and normal operating stresses) of 20 ksi tension and greater.

to W3F1-2009-0058 Page 4 of 5 The examination volume required by Code Case N-729-1 specifies volumetric or surface testing of the RPV head penetration nozzle (i.e., nozzle base material) from 1.5 inches above the highest point of the root of the J-groove weld (on a horizontal plane perpendicular to the nozzle axis) to 1.5 inches below the lowest point at the toe of the J-groove weld on a horizontal plane perpendicular to the nozzle axis (or the bottom of the nozzle if less than 1.5 inches) for nozzles with an incidence angle less than or equal to 300; and from 1.0 inches above the highest point of the root of the J-groove weld (on a horizontal plane perpendicular to the nozzle axis) to 1.0 inches below the lowest point at the toe of the J-groove weld on a horizontal plane perpendicular to the nozzle axis (or the bottom of the nozzle if less than 1.0 inches) for nozzles with an incidence angle greater than 300.

Differences in the specified examination frequency between the Order and Code Case N-729-1 are not relevant because this relief request is a one time request due to the Waterford reactor closure head being replaced in the next refueling outage in the spring 2011.

The proposed alternative provides a combination of UT examinations to the extent possible, to ensure that a postulated flaw in the lower portion of the nozzle that cannot be volumetrically (UT) examined will not propagate into the weld during one cycle of operation. The basis for the proposed alternative does not require that the specified UT examination volume be met; therefore, the.basis for the proposed alternative remains valid with regard to the differences between the examination volumes specified in the Order and in Code Case N-729-1.

10CFR50.55a(a)(3) states:

"Proposed alternatives to the requirements of paragraphs (c), (d), (e), (f), (g) and (h) of this section or portions thereof may be used when authorized by the Director of the Office of Nuclear Reactor Regulation. The applicant shall demonstrate that:

(i) The proposed alternatives would provide an acceptable level of quality and safety, or (ii) Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety."

Entergy believes the proposed alternative provides an acceptable level of quality and safety by utilizing a combination of examination and supplemental analysis to ensure the pressure boundary integrity of the Waterford-3 CEDM nozzles for the one remaining operating cycle prior to head replacement. Other possible examination options, such as manual surface examinations, would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. This request is the same as the request for relaxation documented in Reference 2 and approved by the NRC in Reference 5.

V.

DURATION OF PROPOSED ALTERNATIVE The proposed alternative will apply to the existing RPV head for the fall 2009 (RF16)

Waterford 3 refueling outage CEDM examinations. Entergy will replace the Waterford 3 RPV head during the spring 2011 refueling outage.

to W3F17-2009-0058 Page 5 of 5 VI. PRECEDENT A similar alternative was requested by Entergy for Arkansas Nuclear One, Unit 2 (ANO-2) on February 9, 2009 (Reference 6) and approved by the NRC on August 27, 2009 (Reference 7).

VII. REFERENCES

1. ASME Code Case N-729-1, "Alternative Examination Requirements for PWR Reactor Vessel Upper Heads With Nozzles Having Pressure-Retaining Partial-Penetration Welds, Section Xl, Division 1", Approved March 28, 2006.

2. Entergy Letter to the NRC dated April 15, 2004, Waterford 3 Relaxation Request #4 to NRC Order EA-03-009 for the Control Element Drive Mechanism Nozzles (CNRO-2004-0020) (ML041120367).

3. Entergy Letter to the, NRC dated August 13, 2004, Response to NRC Request for Additional Information Pertaining to Waterford 3 Relaxation Request #4 to NRC Order EA-03-009 for the Control Element Drive Mechanism Nozzles (CNRO-2004-0039)

[ML042320558].

4. First Revised NRC Order (EA-03-009) Establishing Interim Inspection Requirements for Reactor Pressure Vessel Heads at Pressurized Water Reactors, issued on February 20, 2004 [ML040220181].

5. NRC Letter to Entergy dated March 22, 2005, Waterford Steam Electric Station, Unit 3 (Waterford 3) - Relaxation Request from U.S. Nuclear Regulatory Commission (NRC)

First Revised Order EA-03-009 for Control Element Drive Mechanism (CEDM)

Nozzles (TAC NO. MC2643) [ML050820683].

6. Entergy Letter to the NRC dated February 9, 2009, "Request for Alternative to 10 CFR 50.55a(g)(6)(ii)(D) Examination Requirements" [ML090400962].

7. NRC letter to Entergy dated August 27, 2009, Arkansas Nuclear One, Unit 2 -Request for Alternative AN02-1SI-002 for The Remainder of the Current (Third) 10-Year ISI Interval and the Fourth ISI Interval until the Reactor Vessel Head Is Replaced (TAC NO. ME0629) [ML092300551].

TO W3F1-2009-0058 List of Regulatory Commitments to W3F1-2009-0058 Page 1 of 1 List of Regulatory Commitments The following table identifies those actions committed to by Entergy in this document. Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments.

TYPE SCHEDULED COMPLETION DATE COMMITMENT (Check one)

(If Required)

ONE-TIME CONTINUING ACTION COMPLIANCE The alternative examination proposed by X

Fall 2009 Refueling the Relief Request W3-ISI-01 6 will be Outage performed for Waterford 3.