NRC-15-0029, Response to NRC Request for Additional Information for the Review of License Renewal Application - Set 11 Question B.1.22-1

Response to NRC Request for Additional Information for the Review of License Renewal Application - Set 11 Question B.1.22-1

ML15050A602
Person / Time
Site:	Fermi
Issue date:	02/19/2015
From:	Kaminskas V DTE Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NRC-15-0029
Download: ML15050A602 (6)

Text

Vito A. Kaminskas Site Vice President DTE Energy Company 6400 N. Dixie Hi'ghway, Newport, MI 48166 Tel: 734.586.6515 Fax: 734.586.4172 Email: kaminskasv@dteenergy.com DYE Ensergy 10 CFR 54 February 19, 2015 NRC-15-0029 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington D C 20555-0001

References:

1) Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43

2) DTE Electric Company Letter to NRC, "Fermi 2 License Renewal Application," NRC-14-0028, dated April 24, 2014 (ML14121A554)

3) NRC Letter, "Requests for Additional Information for the Review of the Fermi 2 License Renewal Application - Set 11 (TAC No.

MF4222)," dated December 19, 2014 (ML14342A938)

4) DTE Electric Company Letter to NRC, "Response to NRC Request for Additional Information for the Review of the Fermi 2 License Renewal Application - Set 11," NRC-15-0006, dated January 20, 2015 (ML15021A433)

Subject:

Response to NRC Request for Additional Information for the Review of the Fermi 2 License Renewal Application -

Set 11 Question B.1.22-1 In Reference 2, DTE Electric Company (DTE) submitted the License Renewal Application (LRA) for Fermi 2. In Reference 3, NRC staff requested additional information regarding the Fermi 2 LRA. The DTE responses to the requests for additional information (RAIs) in Set 11 except for RAI B.1.22-1 were provided in Reference 4. The Enclosure to this letter provides the DTE response to RAI B.1.22-1.

No new commitments are being made in this submittal.

Should you have any questions or require additional information, please contact Lynne Goodman at 734-586-1205.

USNRC NRC-15-0029 Page 2 I declare under penalty of perjury that the foregoing is true and correct.

Executed on ebruary

, 2015 Vito A. Kaminskas Site Vice President Nuclear Generation

Enclosure:

DTE Response to NRC Request for Additional Information for the Review of the Fermi 2 License Renewal Application -

Set 11 Question B.1.22-1 cc: NRC Project Manager NRC License Renewal Project Manager NRC Resident Office Reactor Projects Chief, Branch 5, Region III Regional Administrator, Region III Michigan Public Service Commission, Regulated Energy Division (kindschl@ michigan.gov)

Enclosure to NRC-15-0029 Fermi 2 NRC Docket No. 50-341 Operating License No. NPF-43 DTE Response to NRC Request for Additional Information for the Review of the Fermi 2 License Renewal Application -

Set 11 Question B.1.22-1

Enclosure to NRC-15-0029 Page 1 RAI B.1.22-1

Background

The LRA states that the Inservice Inspection - IWF Program, with enhancements, is consistent with GALL Report AMP XI. S3, "ASME Section XI, Subsection IWF." The "detection of aging effects" program element in GALL Report AMP XI. S3 recommends that, for high-strength structural bolting (actual measured yield strength greater than or equal to 150 ksi) in sizes greater than 1 inch nominal diameter, volumetric examinations should be performed in addition to VT-3 to detect cracking. The GALL Report AMP XLS3 has the following recommendations for aging management of high-strength structural bolting:

The "scope of program" program element states that the scope of the program includes high-strength structural bolting.

o The "preventive actions" program element recommends using bolting material that has an actual measured yield strength that is less than 150 ksi.

The "parameters monitored or inspected" program element recommends that high-strength structural bolting susceptible to SCC be monitored for cracking.

o The "detection of aging effects" program element states that the volumetric examination may be waived with adequate plant-specific justification.

Issue LRA Section B.1.22, "Inservice Inspection - IW, " includes enhancements to revise plant procedures to identify unacceptable conditions such as "cracked or sheared bolts, including high-strength bolts." However it is not clear whether there are high-strength structural bolts (actual measured yield strength greater than or equal to 150 ksi) in sizes greater than 1 inch nominal diameter within the scope of the Inservice Inspection - IWF Program. In addition, it is not clear how the applicant plans to manage aging for these components consistent with GALL Report AMP XLS3 recommendations in the "preventive actions" and "parameters monitored or inspected" program elements described above.

The LRA also states that "[p]lant procedures prohibit the use of lubricants containing molybdenum disulfide. Since the use of this type of lubricant is prohibited in plant procedures and plant procedures provide the technical guidance for installation requirements [...], the potential for [SCC] for high-strength structural bolting material, i.e., ASTMA325 and A490, is not plausible." Given that the use of molybdenum disulfide is not the only contributor to SCC of high-strength bolts; the staff has not determined that there is sufficient basis to conclude that SCC is not a credible aging effect for high-strength structural bolting (actual measured yield strength greater than or equal to 150 ksi) in sizes greater than 1 inch diameter. If there are high-strength structural bolts (actual measured yield strength greater than or equal to 150 ksi) in sizes greater than 1 inch diameter within the scope of license renewal, the staff needs additional information regarding the environments to which these bolts are exposed to evaluate the applicant's claim that there is no potential for SCC.

Enclosure to NRC-15-0029 Page 2 Request (1) State whether or not there are high-strength structural bolts (actual measured yield strength greater than or equal to 150 ksi) in sizes greater than 1 inch diameter within the scope of the Inservice Inspection - IWF Program.

(2) If high strength structural bolts (actual measured yield strength greater than or equal to 150 ksi) in sizes greater than 1 inch diameter are within the scope of the Inservice Inspection -

IWF Program, state how the recommendations will be implemented for the Inservice Inspection - IWF Program:

(a) Provide additional information regarding the environments to which bolts are exposed.

(b) State whether the recommendations for managing degradation of high-strength bolts described in the "preventive actions" and "parameters monitored or inspected" of the GALL Report AMP XI.S3 will be implemented for the Inservice Inspection - IWF Program.

Response

(1) DTE has identified one instance of high-strength structural bolting with actual measured yield strength greater than or equal to 150 ksi in sizes greater than 1 inch diameter within the scope of the Inservice Inspection - IWF Program: the RPV skirt to ring girder bolted joint, which contains sixty 2-1/2" x 9-7/8" ASTM A490 bolts. These bolts are covered in the Inservice Inspection - IWF Program for visual inspection.

There are no other high-strength structural bolts with actual measured yield strength greater than or equal to 150 ksi in sizes greater than 1 inch diameter within the scope of the Inservice Inspection - IWF Program. This conclusion is based on the following:

1. The Fermi 2 pipe erection specification does not specify use of high-strength material.

2. The Fermi 2 concrete anchor specification and drawing do not specify the use of high-strength bolts.

3. A 100% review of all hanger sketch bill of materials for the representative sample of ASME Section XI Class 1, 2, and 3 component supports inspected each Inservice Inspection 10-year interval did not find any high-strength bolts greater than 1 inch diameter identified.

(2) (a) These bolts are installed in the lower area of the bioshield annulus which is a dry and relatively cool area of the drywell. During operation, the drywell is inerted with nitrogen.

The thread lubricant used is Never-Seez #NS-160 which is a copper, aluminum, graphite based thread lubricant not containing molybdenum disulfide. Because this is a non-corrosive and low temperature environment, stress corrosion initiation in these bolts is

Enclosure to NRC-15-0029 Page 3 not credible. In addition, NUREG-1801 indicates (for item TP-300) that ASTM A490 bolts used in structural applications have not been shown to be prone to stress corrosion cracking and that stress corrosion cracking potential need not be evaluated for these bolts.

(b) The recommendations in the "preventive actions" program element of NUREG-1801 AMP XI.S3 will be implemented for the high-strength bolts in the Fermi 2 Inservice Inspection - IWF Program. LRA Section B.1.22 includes enhancements to the preventive actions program element in order to implement the Inservice Inspection - IWF Program consistent with NUREG-1801 AMP XI.S3.

NUREG-1801 AMP XI.S3 "detection of aging effects" program element states that volumetric examination may be waived with adequate plant-specific justification. Part 2 (a) of this response provides the plant-specific justification for waiving volumetric examination of Fermi 2 high-strength bolting identified in Part 1 of this response.

Volumetric examination of high-strength bolts will not be implemented for the Inservice Inspection - IWF Program. The volumetric examination of high-strength bolting susceptible to stress corrosion cracking discussed in program elements 3 and 4 of NUREG-1801 AMP XI.S3 does not apply to Fermi 2 because there are no Fermi 2 high-strength bolts susceptible to stress corrosion cracking.

LRA Revisions:

None.