ML051940291
| ML051940291 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 06/29/2005 |
| From: | Crouch W Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TAC MC1704, TAC MC1705, TAC MC1706 | |
| Download: ML051940291 (16) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Decatur, Alabama 35609-2000 June 29, 2005 10 CFR 54 U.S. Nuclear Regulatory Commission ATTN:
Document Control Desk Mail Stop:
OWFN P1-35 Washington, D.C. 20555-0001 Gentlemen:
In the Matter of
)
Docket Nos. 50-259 Tennessee Valley Authority
)
50-260 50-296 BROWNS FERRY NUCLEAR PLANT (BFN) -
UNITS 1, 2, AND 3 LICENSE RENEWAL APPLICATION (LRA)
RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION (RAI)
CONCERNING FOLLOW UP TO SECTION 4.7.7 TIME LIMITED AGING ANALYSIS RAIs (TAC NOS.
By letter dated December 31, 2003, TVA submitted, for NRC review, an application pursuant to 10 CFR 54, to renew the operating licenses for the Browns Ferry Nuclear Plant, Units 1, 2, and 3. As part of its review of TVA's LRA, the NRC staff, through a letter dated June 22, 2005, identified additional RAIs for LRA Section 4.7.7, Time Limited Aging Analysis (TLAA) for Stress Relaxation of the Core Plate Hold-Down Bolts.
U.S. Nuclear Regulatory Commission Page 2 June 29, 2005 to this letter contains the specific NRC requests for additional information and the corresponding TVA responses.
Some of the information in Enclosure 1 is proprietary to General Electric (GE).
GE requests that the proprietary information in the enclosure be withheld from public disclosure in accordance with 10 CFR 9.17(a)(4),
10 CFR 2.390(a)(4), and 10 CFR 2.390(b)(1).
An affidavit supporting this request is included in Enclosure 1. A non-proprietary version of this response is contained in.
If you have any questions regarding this information, please contact Ken Brune, Browns Ferry License Renewal Project Manager, at (423) 751-8421.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on this 29th day of June, 2005.
Sincerely, UVt William D. Crouch Manager of Licensing and Industry Affairs
Enclosure:
cc: See page 3
U.S. Nuclear Regulatory Commission Page 3 June 29, 2005 Enclosure cc (Enclosure):
State Health Officer Alabama Department of Public Health RSA Tower -
Administration Suite 1552 P.O. Box 303017 Montgomery, Alabama 36130-3017 Chairman Limestone County Commission 310 West Washington Street Athens, Alabama 35611 (Via NRC Electronic Distribution)
Enclosure cc (Enclosure):
U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 Mr. Stephen J. Cahill, Branch Chief U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 NRC Senior Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611-6970 NRC Unit 1 Restart Senior Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611-6970 cc: continued page 4
U.S. Nuclear Regulatory Commission Page 4 June 29, 2005 cc:
(Enclosure)
Margaret Chernoff, Project Manager U.S. Nuclear Regulatory Commission (MS 08G9)
One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 Eva A. Brown, Project Manager U.S. Nuclear Regulatory Commission (MS 08G9)
One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 Yoira K. Diaz-Sanabria, Project Manager U.S. Nuclear Regulatory Commission (MS 01iF1)
One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739 Ramachandran Subbaratnam, Project Manager U.S. Nuclear Regulatory Commission (MS 011F1)
One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852-2739
6b Contains GE Proprietary Information Per 10 CFR 2.390 ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)
UNITS 1, 2, AND 3 LICENSE RENEWAL APPLICATION (LRA)
RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION (RAI)
CONCERNING NRC FOLLOW UP QUESTIONS RELATED TO TLAA 4.7.7, STRESS RELAXATION OF THE CORE PLATE HOLD-DOWN BOLTS (Proprietary Version)
SEE ATTACHED:
- Response to NRC Request for Additional Information (RAI)
Concerning NRC Follow Up Questions Related to TLAA 4.7.7, Stress Relaxation of The Core Plate Hold-Down Bolts (Proprietary Version)
This enclosure contains proprietary information of the General Electric Company (GE) and is furnished in confidence solely for the purpose(s) stated in the transmittal letter.
No other use, direct or indirect, of the document or the information it contains is authorized.
Furnishing this enclosure does not convey any license, express or implied, to use any patented invention or, except as specified above, any proprietary information of GE disclosed herein or any right to publish or make copies of the enclosure without prior written permission of GE.
The header of each page in this enclosure carries the notation "GE Proprietary Information."
GE proprietary information is identified by a double underline inside double square brackets.
In each case, the superscript notation "3" refers to Paragraph (3) of the affidavit provided in this enclosure, which documents the basis for the proprietary determination.
((This sentence is an example.(3 ))1 Specific information that is not so marked is not GE proprietary.
- L General Electric Company AFFIDAVIT 1, Louis M. Quintana, state as follows:
(1) I am Manager, Licensing, 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 Attachment 2 to GE letter GENE 0000-0015-9859-016, Larry King (GE) to Ken Brune (TVA), Responses to NRC Follow Up Questions To Section 4.7.7 Time Limited Aging Analysis. The proprietary information in Attachment 2, GE Responses to NRC License Renewal RAlIs 4.7.7-3 through 4.7.7-7, is identified by a double underline inside double square brackets. In each case, the superscript notation 3 ) refers to Paragraph (3) of the enclosed 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 2.390(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 Regulatorv 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; Affidavit Page I
- 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 2.390 (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 GE analytical models, methods and processes, and design data, which GE has developed, and applied to perform evaluations of the behavior of aging materials used in the GE Boiling Water Reactor ("BWR"). The development of these methods, processes, and data was achieved at a significant cost to GE, on the order of a million dollars.
The development of the evaluation process along with the interpretation and application of the results is derived from the extensive experience database that constitutes a major GE asset.
(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 Affidavit Page 2
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 the 28th day of June 2005.
Louis M. Quintana General Electric Company Affidavit Page 3
ENCLOSURE 2 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)
UNITS 1, 2, AND 3 LICENSE RENEWAL APPLICATION (LRA)
RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION (RAI)
CONCERNING NRC FOLLOW UP QUESTIONS RELATED TO TLAA 4.7.7, STRESS RELAXATION OF THE CORE PLATE HOLD-DOWN BOLTS (Non-Proprietary Version)
(See Attached.)
((I
)) shows where proprietary information has been redacted.
TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)
UNITS 1,' 2, AND 3 LICENSE RENEWAL APPLICATION (LRA),
RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION (RAI)
CONCERNING NRC FOLLOW UP QUESTIONS RELATED TO TLAA 4.7.7, STRESS RELAXATION OF THE CORE PLATE HOLD-DOWN BOLTS (Non-Proprietary Version)
By letter dated December 31, 2003, TVA submitted, for NRC review, an application pursuant to 10-CFR 54, to renew the operating licenses for the Browns'Ferry Nuclear Plant, Units 1, 2, and 3. As part of its review of TVA's LRA, the NRC staff, through a letter dated June 22, 2005, identified additional RAIs for LRA Section 4.7.7, Time Limited Aging Analysis (TLAA) for Stress Relaxation Of The Core Plate Hold-Down Bolts.
Section 4.7.7 of the LRA evaluated loss of preload of the core plate hold-down bolts due to thermal and irradiation effects in accordance with the requirements of 10' CFR 54.21(c)(1)(ii).
For the 40-year lifetime, the Boiling Water Reactor Vessel and Internals Project-25 (BWRVIP-25) concluded that all core plate hold-down bolts will maintain some preload throughout the life of the plant.
For the'period of extended operation, the expected loss-of preload was assumed to be 20%, which bounds the original BWRVIP analysis.
With a loss of 20% in preload, the core plate will maintain sufficient preload to prevent sliding under both normal and accident conditions. Based on this assumption, TVA concludes that the loss of preload is acceptable for the period of extended operation.
The NRC staff previously sent RAIs 4.7.7-1 and 4.7.7-2 by letter dated March 3, 2005.
TVA answered those RAIs by letter dated:May 31, 2005.
The NRC's follow up questions (RAIs 4.7.7-3 through 4.7.7-7) and TVA's response to each follow.
Non-Proprietary Version NRC RAI 4.7.7-3 (a) In response to RAI-4.7.7-2(b) the applicant referenced stress relaxation curves that were developed by General Electric Nuclear Energy (GENE).
Provide the data that was used to develop the curves and explain how this data was utilized to establish the curves.
(b) The applicant's response referenced a paper by J. P. Foster, "Analysis of In-reactor Stress Relaxation Using Irradiation Creep Models," which provides data regarding the relationship between the irradiation creep stress/strain vs. displacements per atom (dpa) by using a "McVetty" equation.
Did General Electric Company (GE) use this equation to calculate the maximum stress relaxation curve for the type 304 stainless steel bolts at the end-of-life fluence (54 EFPY) for the BFN units?
TVA Response to RAI 4.7.7-3 (a) Stress-relaxation properties of irradiated austenitic steels and nickel alloys were studied extensively at GE in the late 1970s and early 1980s, and mean and 95-95 limit curves for use in design were developed and issued in the GE BWR Materials Handbook.
The data used to develop these design curves were stress relaxation measurements on irradiated austenitic steels and nickel alloys in laboratory and in-core specimens.
The specimen types for these measurements were springs and bent-beam specimens.
Figure 1 shows the GE mean design curve along with the data used for its derivation.
H 1]
The data presented as closed symbols is from measurements made on springs, and the data shown as open symbols is measurements made using bent-beam specimens.
(b) A McVetty equation was not used; the type of equation used to calculate the curves is described in the response to RAI 4.7.7-3(a), and is the basis of the calculation of the maximum stress relaxation curve for the Type 304 stainless steel bolts at the end-of-life fluence (54 EFPY) for the BFN units.
Comparison of the GE design curve to the data from J. P. Foster is shown in the response to RAI 4.7.7-4.
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Non-Proprietary Version Figure 1 NRC RAI 4.7.7-4 To justify the GENE analysis, the applicant referenced Figure 7-13 of the BWRVIP-99 report, "Crack Growth Rates in Irradiated Stainless Steels in BWR Internal Components,"
which shows data and modeling projections for stress relaxation versus fluence values measured in displacements per atom (dpa), for 20% cold worked type 316 stainless steel material.
Provide an explanation as to why the type 316 stainless steel data is applicable to the type 304 stainless steel core plate hold-down bolts at the BFN units.
TVA Response to RAI 4.7.7-4 The Type 316 stainless steel data presented was used for comparison purposes to show that the BFN result was consistent with previous results.
This data was not used to develop the GE curves and was not used in the BFN-specific calculation.
However, based on the following discussion, the use of data from other austenitic material is considered appropriate, as shown in Figure 1.
High energy radiation produces a number of simultaneous effects in materials, mostly originating with the displacement of atoms from their original lattice position to relatively distant locations, usually as an interstitial.
The interstitial atoms and the associated vacancies group into interstitial and vacancy clusters (hardening), migrate to grain boundaries, and relax constant displacement stresses with interaction with and displacement by dislocations.
These effects in austenitic stainless steels are most strongly influenced by the face-centered cubic (FCC) structure of the materials.
Relaxation of irradiated, structural materials from radiation creep is much less sensitive to "normal material variations" (e.g., in austenitic stainless steels) than other radiation properties. Radiation segregation and hardening characteristics are similar for all austenitic stainless steels, although some experience presegregation (from annealing).
Also, neutron relaxation is among the most E2-3
Non-Proprietary Version consistent and reproducible phenomenon, and little variation is observed in 304SS, 316SS, 321SS, 347/8SS, L-grade and nuclear grade.
The relaxation behavior of these stainless steels is often used for many different austenitic alloys such as Nitronic 50, Alloy X-750, and Alloy 718.
To further support this observation, see Figure 7-17 in the BWRVIP-99 report, "Crack Growth Rates in Irradiated Stainless Steels in BWR Internal Components" (repeated here as Figure 2).
This figure shows stress relaxation data from wedge loaded DCB specimens in 2880C water at Halden that are exposed to neutron fluences of approximately 4.4 to 6 x 1020 n/cm2 (>1 MeV) (i.e., - 0.6 to 0.9 dpa).
This data shows stress relaxation levels clustered between 28% and 36% for DCB specimens fabricated from 304/316/348 stainless steels.
It should be noted that this data is for fluence levels nearly 10 times higher than that predicted for the BFN bolts, but the effects at lower fluences would be no more pronounced.
To further demonstrate the applicability of the GE design curve, Figure 3 shows the relaxation data from J. P. Foster and Halden with the curve.
It is seen that the GE design curve predicts higher relaxation levels (i.e., lower fraction of load remaining) than observed from the Foster and Halden data, and is thus conservative compared to this data.
Figure 2:
Stress Relaxation Data from Halden (Reference 1)
\\ [Shown as Figure 7-17 in BWRVIP-99 (Reference 2)]
Figure 3 E2-4
Non-Proprietary Version NRC RAI 4.7.7-5 The paper by J. P. Foster uses a "Half-Nelson" model to calculate displacement damage (measured as dpa) due to radiation. 'Provide the dpa values for type 304 core plate hold-down bolts that correspond toSend-of-life fluence (54 EFPY) using the "Half-Nelson" model or its'equivalent for the BFN units.
TVA Response to RAI 4.7.7-5 The "Half-Nelson" model was not used.' -The dpa value for the core plate bolts'that corresponds' tothe 54-EFPY fast neutron fluence (E >1 MeV) of 5'x 1019 n/cm2 is 0.07.
This dpa value is calculated based on the calculated'fast fluence and an effective dpa cross section (E >1MeV) of approximately 1380 barns for steel.
The effective dpa'"cross section was obtained-from another'BWR/4-plant with a similar neutron flux spectra, and was based on the average of calculated.
spectral-average dpa cross sections (E >1 MeV) from 54 samples, each calculated with 100-group dpa cross sections contained in-SPECTER (Reference-3)Vand neutron-flux spectra
'computed with the MCNP code (Reference'"4).'
NRC RAI 4.7.7-6 Provide justification for the application of relaxation curves obtained in torsion to axial r'elaxation in'bolts.
-TVA'Response to'RAI 4.7.7-6 As discussed in'the response to RAI 4;.7.7-4, the GE design curve is based on data-from different'austenitic materials.
and specimen types.
Relaxation data-from.springs (torsion)
,and bent-beam.specimens (tension)'make up the database used
'to derive the GE design curve, and is:'shown in.Figure 1-Data reported later by Halden (in-core DCBs/tension) and Foster (springs/shear) and shown in Figure 3 exhibit the same behavior with-increasing fluence as the GE design curve, but at a lower value of relaxation'(i.e;, higher fraction of.
remaining load).The data'-in both Figures 1 and 3 does not exhibit any'apparent effect of specimen or loading type.
Therefore, the data used to derive the GE design curve is-applicable to the BFN loading configuration.
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Non-Proprietary Version NRC RAI 4.7.7-7 BWRVIP-25, Appendix B refers to a letter dated January 15, 1997, from V. L. McCarthy to B. A. McAllister, GENE, "Core Plate Bolt Relaxation Calculations for Extended Period of Operation."
The staff requests that the applicant provide these calculations so that it can evaluate the stress relaxation of the core plate hold-down bolts for the end-of-life fluence (54 EFPY) for the BFN units.
The applicant may like to make appropriate proprietary determination as necessary to make original vendor evaluation available for staff review.
TVA Response to RAI 4.7.7-7 The original 20% assumption used in the licensing submittal was intended to bound the relaxation values provided in Appendix B of BWRVIP-25.
In place of the BWRVIP calculation, a BFN-specific calculation was performed to determine if the relaxation was bounded by the original 20% assumption.
A BFN-specific fluence of 5 x 1019 n/cm2 (E >1 MeV) was calculated at the peak fluence location.
Given that the fluence on the core plate bolts varies depending on the radial location, this provides a conservative relaxation value.
The BFN-specific fluence of 5 x 1019 n/cm2 (E >1 MeV) was then compared to the original GE design curves to determine a value of 15% relaxation.
Figure 1 contains a replotted version of the GE design curve used for the BFN-specific calculation.
The conservative value of 15%
relaxation reported is based on a reading of the original hand-drawn curve; a calculation using the statistical curve fit shown in Figure 1 would result in slightly less relaxation at a fluence of 5 x 1019 n/cm2 (E >1 MeV).
See response to RAI 4.7.7-3(a) for how the curves were developed.
References
- 1. "Final Report On IFA-586, 605; Water Chemistry and Crack Behavior," Proprietary Final Report HWR-473, Halden, April 1996 (Halden Proprietary)
- 2. "Crack Growth Rates in Irradiated Stainless Steels in BWR Internal Components," EPRI report TR-1003018, December 2001 (BWRVIP-99)
- 3. L. R. Greenwood and R. K. Smither, "SPECTER:
Neutron Damage Calculations for Materials Irradiations," Argonne National Laboratory, ANL/FPP/TM-197 (1985)
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Non-Proprietary Version
- 4. J. F. Briesmeister, Ed., "MCNP - A Monte Carlo N-Particle Transport Code, Version 4A," Los Alamos National Laboratory report LA-12625 (1993)
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