Text

Reactor Core Shroud Repair Relief Request
	ML050820278
Person / Time
Site:	Clinton
Issue date:	03/15/2005
From:	Simpson P; AmerGen Energy Co
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	RS-05-019
	Download: ML050820278 (18)
	v • d • e

AmerGenrS AmerGen Energy Company. LLC www.exeloncorp.com An Exeron 4300 Winfield Road Warrenville, IL 60555 10 CFR 50.55a RS-05-019 March 15, 2005 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461

Subject:

Reactor Core Shroud Repair Relief Request

References:

1. Boiling Water Reactor Vessel Internal Project BWRVIP-02, "Core Shroud Repair Design Criteria," Revision 2, March 1999

2.

EPRI Technical Report EPRI-TR-1 006600, "BWRVIP-04-A: BWR Vessel and Internals Project, Guide for Format and Content of Core Shroud Repair Design Submittals," April 2002 In accordance with 10 CFR 50.55a, 'Codes and standards," paragraph (a)(3)(i), AmerGen Energy Company, LLC (AmerGen) is requesting relief from the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section Xl, 'Rules for Inservice Inspection of Nuclear Power Plant Components," on the basis that the proposed alternative provides an acceptable level of quality and safety.

Specifically, this proposed alternative would allow Clinton Power Station (CPS) to use Reference 1 to structurally replace core shroud horizontal welds H1 through H7. This alternative approach will be performed in lieu of the defined ASME Code, Section Xl, 1989 Edition weld repair or replacement methods. The proposed alternative does not invoke any modifications or exceptions to the design requirements described in Reference 1. The details of the proposed alternative are presented in Attachment 2 and consistent with the format and content requirements of Reference 2.

In accordance with 10 CFR 50.59, 'Changes, tests, and experiments," an evaluation of these changes to CPS, as currently described in the Updated Safety Analysis Report, has been completed. This evaluation determined that the core shroud repair modification does not result in a change requiring a license amendment per 10 CFR 50.90, 'Application for amendment of license or construction permit."

March 15, 2005 U. S. Nuclear Regulatory Commission Page 2 This submittal is subdivided as follows:

1. Attachment 1 contains CPS Relief Request 4211

2. Attachment 2 contains the CPS specific design details prepared by General Electric Company (GENE) in accordance with Reference 2. Portions of the information in are proprietary to GENE, and we request that this attachment be withheld from public disclosure in accordance with 10 CFR 2.390, "Public inspections, exemptions, requests for withholding," paragraph (a)(4).

3. Attachment 3 provides affidavits supporting the request for withholding and a non-proprietary version of Attachment 2.

CPS intends to perform the proposed core shroud repair during the refuel outage presently scheduled for February 2006. Therefore, AmerGen requests approval for this relief request prior to January 8, 2006.

If you have any questions concerning this letter, please contact Mr. David Gullott at (630) 657-2819.

Respectfully, Patrick R. Simpson Manager - Licensing Attachments:

1. Relief Request 4211

2. CPS Core Shroud Repair Design (GENE Proprietary)

3. Affidavits and CPS Core Shroud Repair Design (GENE Non-Proprietary) cc:

Regional Administrator - NRC Region IlIl NRC Senior Resident Inspector - Clinton Power Station

ATTACHMENT I Relief Request 4211 dI

Clinton Power Station Relief Request Number 4211 10 CFR 50.55a Request Proposed Alternative In Accordance with 10 CFR 50.55a(a)(3)(i)

Alternative Provides Acceptable Level of Quality and Safety

1. ASME Code Component(s) Affected Core Shroud, Equipment Number 1 B13-D070, ASME Code Class CS Eight (8) Core Shroud Horizontal Welds - HI1, H2, H3, H4, H5, H6A, H6B, H7

2. Applicable Code Edition and Addenda

American Society of Mechanical Engineers (ASME) Boiler & Pressure Vessel Code, Section Xl, 1989 Edition with no Addenda

3. Applicable Code Requirement

ASME Code Section Xl, Article IWA-4000, "Repair Procedure" and Article IWA-7000, "Replacement"

4. Reason for Request

Industry experience has shown that boiling water reactor (BWR) core shroud welds are subject to intergranular stress corrosion cracking (IGSCC). As a result, the NRC issued Generic Letter 94-03, "Intergranular Stress Corrosion Cracking of Core Shrouds at Boiling Water Reactors," which led Clinton Power Station (CPS) to perform detailed inspections and analyses of the CPS core shroud to determine susceptibility to this phenomenon. Significant cracking was identified in the H4 weld of the core shroud during the 2002 refueling outage. CPS had evaluated this cracking and justified operation until the refueling outage C1 RIO presently scheduled for February 2006.

CPS is planning to install a pre-emptive repair/replacement during the C1 RI0 refueling outage.

The General Electric Company designed repair/replacement is not addressed in ASME Section Xl, 1989 Edition, Articles IWA-4000 and IWA-7000. This repair/replacement will mitigate the effects of IGSCC on the affected core shroud circumferential horizontal welds H1 through H7. Once installed, this alternative repair will perform the structural functions of the specified core shroud welds.

' Weld H1 is classified as an internal structure.

5. Proposed Alternative and Basis for Use

The proposed alternative involves installing radially acting stabilizers, mounted on four vertical preloaded tie rods. This installation will maintain the alignment of the core shroud to the reactor pressure vessel (RPV) and the originally designed reactor flow partitions. Upon installation, this alternative repair will replace the structural functions of the core shroud horizontal welds (H1 through H7), which currently contain cracks and have been postulated to propagate. Each stabilizer assembly consists of a tie rod, an upper and lower stabilizer, an upper support, and other connecting members. The tie rod and upper support provide the vertical load restraint capability from the top of the shroud to the RPV shroud support plate, as well as positioning the new radial stabilizers. The tie rod preload acts downward on the top surface of the shroud flange at four equally spaced azimuths. It is reacted by its toggle attachment at the bottom that is attached to the shroud support plate. This alternative repair design is based on Reference 1.

The specific details of this alternative are delineated in Reference 2. Reference 2 is prepared in accordance with Reference 3.

6. Duration of Proposed Alternative

This proposed alternative is considered a permanent repair of all horizontal circumferential core shroud welds. The repair hardware is designed for an effective design life of 60 years, inclusive of a 20-year license renewal period.

7. References

1. Boiling Water Reactor Vessel Internal Project BWRVIP-02, "Core Shroud Repair Design Criteria," Revision 2, March 1999

2. General Electric Company (GENE) GENE-0000-0023-6259-05, "AmerGen Energy Co, LLC Clinton Power Station BWRVIP-04A Core Shroud Repair Submittal to the Nuclear Regulatory Commission (NRC)," Revision 1, March 2005

3. EPRI Technical Report EPRI-TR-1 006600, "BWRVIP-04-A: BWR Vessel and Internals Project, Guide for Format and Content of Core Shroud Repair Design Submittals," April 2002

ATTACHMENT 3 Affidavits and CPS Core Shroud Repair Design (GENE Non-Proprietary)

)

General Electric Company AFFIDAVIT I, George B. Stramback, state as follows:

(1) I am Manager, Regulatory Services, General Electric Company ("GE") and have been delegated the function of reviewing the information described in paragraph (2) which is sought to be withheld, and have been authorized to apply for its withholding.

(2) The information sought to be withheld is contained in the GE proprietary report GENE-0000-0023-6259-05P, AmerGen Energy Co., LLC, Clinton Power Station, BWIRVIP-04A, Core Shroud Repair Design Submittal to the Nuclear Regulatory Commission (NRC), Revision 1, Class III (GE Proprietary Information), dated March 2005. The proprietary information is delineated by a double underline inside double square brackets.

Figures and large equation objects are identified with double sguare brackets before and after the object. In each case, the superscript notation(9) refers to Paragraph (3) of this affidavit, which provides the basis for the proprietary determination.

(3) In making this application for withholding of proprietary information of which it is the owner, GE relies upon the exemption from disclosure set forth in the Freedom of Information Act ("FOIA"), 5 USC Sec. 552(b)(4), and the Trade Secrets Act, 18 USC Sec. 1905, and NRC regulations 10 CFR 9.17(a)(4), and 2.790(a)(4) for "trade secrets" (Exemption 4). The material for which exemption from disclosure is here sought also qualify under the narrower definition of "trade secret", within the meanings assigned to those terms for purposes of FOIA Exemption 4 in, respectively, Critical Mass Energy Project v. Nuclear Regulatory Commission.

975F2d871 (DC Cir. 1992), and Public Citizen Health Research Group v. FDA, 704F2d1280 (DC Cir. 1983).

(4) Some examples of categories of information which fit into the definition of proprietary information are:

a.

Information that discloses a process, method, or apparatus, including supporting data and analyses, where prevention of its use by General Electric's competitors without license from General Electric constitutes a competitive economic advantage over other companies;

b.

Information which, if used by a competitor, would reduce his expenditure of resources or improve his competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product; GBS-05-1-af Clinton Core Shroud BWRVIP-04 Repair Design Submit GENE 23-6259-05P Rev L.doc Affidavit Page I

c.

Information which reveals aspects of past, present, or future General Electric customer-funded development plans and programs, resulting in potential products to General Electric;

d.

Information which discloses patentable subject matter for which it may be desirable to obtain patent protection.

The information sought to be withheld is considered to be proprietary for the reasons set forth in paragraphs (4)a., and (4)b, above.

(5) To address 10 CFR 2.790 (b) (4), the information sought to be withheld is being submitted to NRC in confidence. The information is of a sort customarily held in confidence by GE, and is in fact so held. The information sought to be withheld has, to the best of my knowledge and belief, consistently been held in confidence by GE, no public disclosure has been made, and it is not available in public sources. All disclosures to third parties including any required transmittals to NRC, have been made, or must be made, pursuant to regulatory provisions or proprietary agreements which provide for maintenance of the information in confidence.

Its initial designation as proprietary information, and the subsequent steps taken to prevent its unauthorized disclosure, are as set forth in paragraphs (6) and (7) following.

(6) Initial approval of proprietary treatment of a document is made by the manager of the originating component, the person most likely to be acquainted with the value and sensitivity of the information in relation to industry knowledge. Access to such documents within GE is limited on a "need to know" basis.

(7) The procedure for approval of external release of such a document typically requires review by the staff manager, project manager, principal scientist or other equivalent authority, by the manager of the cognizant marketing function (or his delegate), and by the Legal Operation, for technical content, competitive effect, and determination of the accuracy of the proprietary designation. Disclosures outside GE are limited to regulatory bodies, customers, and potential customers, and their agents, suppliers, and licensees, and others with a legitimate need for the information, and then only in accordance with appropriate regulatory provisions or proprietary agreements.

(8) The information identified in paragraph (2), above, is classified as proprietary because it contains detailed results of analytical models, methods and processes, including computer codes, which GE has developed and applied to perform evaluations of indications in the core shroud for the BWR. The development and approval of the BWR Shroud Repair Program was achieved at a significant cost, on the order of one million dollars, to GE.

The development of the evaluation process along with the interpretation and application of the analytical results is derived from the extensive experience database that constitutes a major GE asset.

GBS-05-I-af Clinton Core Shroud BWRVIP-04 Repair Design Submit GENE 23-6259-05P Rev L.doc Affidavit Page 2

(9) Public disclosure of the information sought to be withheld is likely to cause substantial harm to GE's competitive position and foreclose or reduce the availability of profit-making opportunities.

The information is part of GE's comprehensive BWR safety and technology base, and its commercial value extends beyond the original development cost. The value of the technology base goes beyond the extensive physical database and analytical methodology and includes development of the expertise to determine and apply the appropriate evaluation process. In addition, the technology base includes the value derived from providing analyses done with NRC-approved methods.

The research, development, engineering, analytical and NRC review costs comprise a substantial investment of time and money by GE.

The precise value of the expertise to devise an evaluation process and apply the correct analytical methodology is difficult to quantify, but it clearly is substantial.

GE's competitive advantage will be lost if its competitors are able to use the results of the GE experience to normalize or verify their own process or if they are able to claim an equivalent understanding by demonstrating that they can arrive at the same or similar conclusions.

The value of this information to GE would be lost if the information were disclosed to the public.

Making such information available to competitors without their having been required to undertake a similar expenditure of resources would unfairly provide competitors with a windfall, and deprive GE of the opportunity to exercise its competitive advantage to seek an adequate return on its large investment in developing these very valuable analytical tools.

I declare under penalty of perjury that the foregoing affidavit and the matters stated therein are true and correct to the best of my knowledge, information, and belief.

Executed on this.I day of A

/44c..

2005.

Geoge B. Stramback General Electric Company GBS 1 -af Clinton Core Shroud BWRVIP-04 Repair Design Submit GENE 23-6259-05P Rev L.doc Affidavit Page 3

General Electric Company AFFIDAVIT I, George B. Stramback, state as follows:

(1) I am Manager, Regulatory Services, General Electric Company ("GE") and have been delegated the function of reviewing the information described in paragraph (2) which is sought to be withheld, and have been authorized to apply for its withholding.

(2) The information sought to be withheld is contained in the GE proprietary report GENE-0000-0023-6259-O1P, AmerGen Energy Co., LLC, Reactor Core Shroud Repair, Clinton Power Station, Seismic and Dynamic Analysis, Revision 1, Class III (GE Proprietary Information), dated February 2005. The proprietary information is delineated by a double underline inside double square brackets. Figures and large equation objects are identified with double square brackets before and after the object.

In each case, the superscript notation 3 ) refers to Paragraph (3) of this affidavit, which provides the basis for the proprietary determination.

(3) In making this application for withholding of proprietary information of which it is the owner, GE relies upon the exemption from disclosure set forth in the Freedom of Information Act ("FOIA"), 5 USC Sec. 552(b)(4), and the Trade Secrets Act, 18 USC Sec. 1905, and NRC regulations 10 CFR 9.17(a)(4), and 2.790(a)(4) for "trade secrets" (Exemption 4). The material for which exemption from disclosure is here sought also qualify under the narrower definition of "trade secret", within the meanings assigned to those terms for purposes of FOIA Exemption 4 in, respectively, Critical Mass Energy Project v. Nuclear Regulatory Commission.

975F2d871 (DC Cir. 1992), and Public Citizen Health Research Group v. FDA, 704F2dl280 (DC Cir. 1983).

(4) Some examples of categories of information which fit into the definition of proprietary information are:

a.

Information that discloses a process, method, or apparatus, including supporting data and analyses, where prevention of its use by General Electric's competitors without license from General Electric constitutes a competitive economic advantage over other companies;

b.

Information which, if used by a competitor, would reduce his expenditure of resources or improve his competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product;

c.

Information which reveals aspects of past, present, or future General Electric customer-funded development plans and programs, resulting in potential products to General Electric; GBS-05-1-af Clinton Core Shroud Repair Seismic & Dynamic Analysis GENE 23-6259-OIP Rev L.doc Affidavit Page I