ML20077D048
| ML20077D048 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Byron, Braidwood  |
| Issue date: | 12/02/1994 |
| From: | Saccomando D COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19311B542 | List: |
| References | |
| NUDOCS 9412070213 | |
| Download: ML20077D048 (20) | |
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) 1400 Opus Place Downers Grove. Illinois 60515 December 2 ,1994 Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attn: Document Control Desk
Subject:
Response to Request for Additional Information Regarding Application to Facility Operating Licenses:
Byron Station Units 1 and 2 NPF-37/66: 50-454 and 50-415 Braidwood Station Units 1 and 2 NPF-72/77: 50-456 and 50-457 "F* Technical Specification Amendment Request"
References:
- 1. J. Bauer letter to T. Murley dated March 20,1994, transmitting Application for Amendment to Facility Operating Licenses for Byron and Braidwood Stations pertaining to an Alternative Repair Criteria Defined as F*
- 2. G. Dick letter to D. Farrar dated November 3,1994, transmitting Requesting for Additional Information Petaining to the F* methodology In Reference 1, Commonwealth Edison Company (Comed) requested approval of a license amendment to pemlit the use of an alternate tube repair criteria, F*, for the steam generators at Byron and Braidwood Stations. In Reference 2, the Nuclear Regulatory Commission (NRC) transmitted to Commonwealth Edison Company (Comed) a request for additional information (RAI) regarding this amendment request. Attached is Comed's response, specifically, Attachment A contains the Staff's questions and Comed's response, some of which refer to Attachment B, BAW-10196 " Response to NRC Questions on Byron F* Report dated November 29,1994, and Exhibit A.1 BWNT Document 51-12061780 " Boric Acid Corrosion of Oconee 1 Upper Tubesheet," dated August 1991, proprietary version. Also, included is Attachment C, the nonproprietary versions of these documents.
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Document Control Desk December 2,1994 )
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Please note that BAW-10196 " Response to NRC Questions on Byron F* Repon dated l
November 29,1994, and Exhibit A.1 BWNT Document 51-12061780 " Boric Acid Corrosion i of Oconee 1 Upper Tubesheet," dated August 1991, contains information proprietary to l B&W Nuclear Technologies, are supported by an affidavit signed by B&W Nuclear l Technologies the owner of the information. The affidavit sets fonh the basis on which the !
information may be withheld from public disclosure by the Commisision and addresses with I specificity the considerations listed in paragraph (b)(4) of Section 2.790 of the Commission's !
regulation. Accordingly, it is respectfully requested that the information which is proprietray to B&W be withheld from public disclosure. The affidavit regarding this matter is provided in ;
Exhibit B. j Correspondence with respect to the proprietary aspects of the items listed above should refer l to Mr. Frank Levandoski, B&W Nuclear Technologies,155 Mill Ridge Road, Lychburg, i Virginia, 24502-4341, phone 804-832-3700.
Please address any further comments or questions regarding this matter to this office.
1 Sipqerely, ,
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Denise Saje Nuclea6 Licensing Administrator .
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cc: R. Assa, Braidwood Project Manager, NRR !
G. Dick, Byron Project Manager, NRR S. Dupont, Senior Resident Inspector, Braidwood Station l
- 11. Peterson, Senior Resident Inspector, Byron Station J. Martin, Regional Administrator, Ill l Office of Nuclear Safety, IDNS l l
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I Exhibit B !
B &W Nuclear Technologies Affidavit I
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f 4 AFFIDAVIT OF JAMES H. TAYLOR A. My name is James'H. Taylor. I am Manager of Licensing Services for B&W Nuclear Technologies (BWNT), and as such I am authorized to execute this Affidavit.
B. I am familiar with the criteria applied by BWNT to determine whether certain information of BWNT is proprietary and I am familiar with the procedures established within BWNT to ensure the proper application of these criteria.
C. In determining whether a BWNT document is to be classified as proprietary information, an initial determination is made by the l Unit Manager, who is responsible for originating the document, as to whether it falls within the criteria set forth in Paragraph D hereof. If the information falls within any one of these criteria, it is classified as proprietary by the originating Un;' Manager. This initial determination is reviewed by the cognizant Section Manager. If the document is designated as proprietary, it is reviewed again by Licensing personnel and other management within BWNT as designated by the Manager of Licensing Services to assure that the regulatory requirements of 2 0 CFR Section 2.790 are met.
D. The following information is provided to demonstrate that the provisions of 10 CFR Section 2.790 of the Commission's regulations have been considered:
1 (i) The information has been held in confidence by BWNT.
l Copies of the document are clearly identified as !
proprietary. In addition, whenever BWNT transmits the l
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AFFIDAVIT OF JAMES H. TAYLOR (Cont'd.)
t information to a customer, customer's agent, potential l l
custcmer or regulatory agency, the transmittal requests !
the recipient to hold the information as proprietary.
Also, in order to strictly limit any potential or actual customer's use of proprietary information, the following I
provision is included in all proposals submitted by BWNT, and an applicable version of the proprietary provision is included in all of BWNT's contracts:
" Purchaser may retain Company's proposal for use in i connection with any contract resulting therefrom, and, for that purpose, make such copies thereof as may be necessary. Any proprietary information .
t concerning Company's or its Supplier's products or ,
I manufacturing processes which is so designated by j Company or its Suppliers and disclosed to Purchaser I incident to the performance of such contract shall remain the property of Company or its Suppliers and is disclosed in confidence, and Purchaser shall not publish or otherwise disclose it to others without the written approval of Company, and no rights,
- implied or otherwise, are granted to produce or have produced any products or to practice or cause to be I, L
practiced any manufacturing processes covered thereby. n h
Notwithstanding the above, Purchaser may provide the NRC or any other regulatory agency with any GU4h
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proprietary information as the NRC or such other h
agency may require; provided, however, that Purchaser shall first give Company written notica of su h proposed disclosure and company shall have the j rigit to amend such proprietaty information so as to O make it non-proprietary. In the event that Company cannot amend such proprietary information, Purchaser r
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AFFIDAVIT OF JAMES H. TAYLOR (Cont'd.)
shall, prior to disclosing such information, use its best efforts to obtain a commitment from NRC or such other agency to have such information withheld from public inspection.
Company shall be given the right to participate in pursuit of such confidential trec.tment."
(ii) The following criteria are customarily applied by BWNT in t a rational decision process to determine whether the information should be classified as proprietary.
Information may be classified as proprietary if one or more of the following criteria are met:
,a. Information reveals cost or price information, ;
commercial strategies, production capabilities, or budget levels of BWNT, its customers or suppliers.
- b. The information reveals data or material concerning BWNT research or development plans or programs of .
l present or potential competitive advantage to BUNT.
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- c. The use of the information by a competitor would decrease his expenditures, in time or resources, in designing, producing or marketing a similar product.
- d. The information consists of test data or other similar data concerning a process, method or component, the application of which results in a competitive advantage to BWNT.
- e. The information reveals special aspects of a process, methotl, component or the like, the exclusive use of which results in a competitive advantage to BWNT.
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AFFIDAVIT OF JAMES H. TAYLOR (Cont'd.)
- f. The information contains ideas for which patent protection may be nought.
The document (s) listed on Exhibit "A", which is attached hereto and made a part hereof, has been evaluated in accccdance with normal BWNT procedures with respect to classification and has been found to contain information which falls within one or more of the criteria enumerated above. Exhibit "B", which is attached hereto and made a part hereof, specifically identifies the criteria applicable to the document (s) listed in Exhibit "A".
(iii) The document (s) listed in Exhibit "A", which has been made available to the United States Nuclear Regulatory Commission was made available in confidence with a request that the document (s) and the information contained therein be withheld from public disclosure.
(iv) The information is not available in the open literature and to the best of our knowledge is not known by Combustion Engineering, EXXON, General Electric, Westinghouse or other current or potential domestic or foreign competitors of BWNT.
(v) Specific information with regard to whether public disclosure of the information is likely to cause harm to the competitive position of BWNT, taking into account the value of the information to BWNT; the amount of effort or money expended by BWNT developing the information; and the ease or difficulty with which the information could be properly duplicated by others is given in Exhibit "B".
E. I have personally reviewed the document (s) listed on Exhibit "A" and have found that it is considered proprietary by BWNT because it contains information which falls within one or more of the 4
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AFFIDAVIT OF JAMES H. TAYLOR (Cont'd.)
criteria enumerated in Paragraph D, and it is information which l is customarily held in confidence and protected as proprietary information by BWNT. This report comprises information utilized by BWNT in its business which afford BWNT an opportunity to obtain a competitive advantage over those who may wish to know or use the information contained in the document (s).
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( & nth m ex JAMES H. TAYL State of Virginia)
) SS. Lynchburg City of Lynchburg)
James H. Taylor, being duly sworn, on his oath deposes and says that he is the person who subscribed his name to the foregoing statement, and that the matters and facts set forth in the statement are true.
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//f?t111 /E JAMES I. TAYL Subscribed and sworn before me this 89* day of Thac mlus 1994. i u u <C~ ,
<Oe ftas Notary Public in and for the City of Lynchburg, State of Virginia.
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ATTACHMENT A
- 1. "A s described in Section 5.1.4, "F* Determination and Correction," of BA W-10196 P. F* is calculated using the following equation, 1 F*, ,= F* o x (F ,/Fo) x (c o/c,.)
l The test in BA W-10/96 P states that this technique was developed in "F* Calculation for W-D RSG's" (BWNT Document 32-1228356). Please supply this document orprovide written justification describing how the above equation is acceptable for calculating an at temperature F* length."
RESPONSE
See Attachment 11, BAW-10196 P, page 1 of 7. l I
- 2. "Several tests subjected tubes to both an internal pressure and an asialload. For the RG 1.121 load tests, l the pressure cycling tests, and the ultimate load tests, the licensee should describe the order in which these l two loads were applied. If both the pressure and direct axial loading were increased simultaneously l provide details describing the internal ressure vs time and axial volume vs time loading sequence." i
RESPONSE
See Attachment B, IJAW-10196 P, page 2 of 7
- 3. "A n evaluation of the effects of boric acid corrosion is detailed in " Boric Acid Corrosion of Oconee i Upper Tubesheet"(BWNT Document 51-12061780). Please supply this document to clarify the conclusions of BA W 10196 P."
RESPONSE
See Exhibit A.1 of Attachment 11 I
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- 4. "The tests described in liA W-10/96 P attempted to determine whether several variables. not directly included in the equation to determine F* (Question 1), would have an impact on the results. These variables included effects from surface roughness of the tubesheet bore, the ;ield strength of the tubing ,
and a larger tubesheet bore diameter. The report concluded that these variables had no effect on the -
calculated F* length. Ilowever, the test matrix does not appear to . support the possibility that these variables may interact during testing. If the test matrix did not adequately separate each of the variables then the conclusion in the report may be erroneous. Describe how the test matrix isolated the effects of yield strength and tubesheet bore surface noughness during the testing."
RESPONSE
See Attachment B, BAW-10196 P. page 3 of 7.
i 5 "flased on suff calculations performedfor a similar test series, the tubesheet surface roughness may affect the proposed F* length. The pullout shear stress between the tube and tubesheet varies around a mean value as the surface roughness increases. Ilowev er, the scatter around this mean appears to increase as the roughness increases (see A ttachment A, Figure 1). Since all data (high and low roughness) were used, the resultant F* length nay be non conservative if the actual tubesheet roughness is relatively high compared to ;
the test conditions. In !ight of the apparent increase in data scatter as surface roughness increases, please provide a response justifying the pn> posed F* length."
RESPONSE
See Attachment B, BAW-10196 P, page 4 of 7.
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- 6. "The licensee should show that the marimum postulated accident leakagefrom cracks that are allowable to remain in service by use of the F* criterion and by the use of other criteria, for example the interim repair l criteriafor ODSCC at tube suppon plates, will continue to be within the allowed leakage limits under l accident conditions. Such considerations should be discussed in the Bases Section of the plant techt.ical specifications. " ,
RESPONSE
Comed will include in a supplement to the original Technical Specificatia Change Request for F* a i change to the Bases of Technical Specification 3/4.4.5. to include a diswssion of the maximum postulated [
accident leakage relationships between F* and other criteria. The revised bases will explain that the MSLB l leakage limit includes the accident leakage from IPC. the accident leakage ' rom F* on the faulted steam generator, and the operational leakage limit of Specification 3.4.6.2.c. The operational leakage limit of _ .
Specification 3.4.6.2.c in each of the three remaining intact steam generators shall include the operational leakage from F*. .,
l This supplemental change request shall be submitted to the NRC by February 3,1995.
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- 7. " IIA W:10196 P states that the F* criteria will establish an undegraded expanded region within the tubesheet which satisfies all of the necessary stntctaral und leakage requirements of Regulatory Guide 1.121 and the ' )
plant Technical Specifications. The licensee's proposed Technical Specifications states that a F* sube "contains sound expanded tubing within the F* distarice," however, this expression is not defined. I The licensee should define this expression or indicate that the F* region has "no indications of degradation" ;
or that it is '"f.ee from indications of cracking." ^;
RESPONSE: !
Insert "C" of Attachment the original submittal dated May 20,1994, defines the F* distance and a F* i tube. The F* tube definition shall be changed to read: .
I "F* Tube is a Unit i SG tube with degradation below the F* distance and has no indications of .
degradation (i.e., no indication of cracking) within the F* distance. Defects contained in an F* tube are not dependant on flaw geometry." ,
This supplemental change request shall be submitted to the NRC by February 3,1995.
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Attachment C B&W Nuclear Technologies Non-Proprietary Information Document 51-12061780
" Boric Acid Corrosion of Oconee 1 Upper Tubesheet" i
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Responses to NRC Questions on Byron FC Report BAW-10196 P 11/29/94
- 1. Question:
As described in Section 5.1.4, "F* Determination and Correction," of BAW-10196 P, F* is calculated using the following equation,
[ ]
The text in BAW-10196 P states that this technique was developed in "F* Calculation for W-D RSG's" (BWNT Document 32-1228356). Please supply this document or provide written justification describing how the above equation is acceptable for calculating an at temperature F*
length.
Response
Because all the F* qualification testing was done at room temperature, the results of the testing had to be equated to actual steam generator (SG) temperature and pressure conditions. The above equation was derived to relate the results of room temperature testing to the (SG) operating conditions based on standard stress equations.
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3 BWNT NON-PROPRIETARY Page 1 of 7
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- Responses to NRC' Questions on Byron F* Report BAW-10196 P 11/29/94 )
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- 2. Question:
Several tests subjected . tubes to both an internal pressure and an axial load. For'the RG 1.121 load tests, the pressure cycling tests, and the ultimate load tests, the licensee should describe the order in which these two loads were applied. If both the pressure and axial loads were increased simultaneously provide details describing the -,
internal pressure vs' time and axial volume vs time loading sequence. >
Response
As described in BAW-10196 P, section 5.2.3 " Tensile Tests", the RG 1.121 load tests used a combination of pressure loading (2750 psig) i and direct axial loading ( ) to conservatively reach the total ,
axial load of ( ). [
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The final ultimate load testing utilized the same procedure as above, but the axial load was increased until the sample met the failure criteria (see BAW-10196 P, section 5.2.3, page 5-11). !
The pressure cycling tests used only pressure loading.
- 3. Question: !
An evaluation of the effects of boric acid corrosion is detailed in r
" Boric Acid Corrosion of Oconee 1 Upper Tubesheet" (BWNT Document 51-12061780). Please supply this document to clarify the conclusions of BAW-10196 P. i
Response
The document requested is enclosed.
BWNT NON-PROPRIETARY Page 2 of 7
Responses to NRC Questions on Byron F* Report BAW-10196 P 11/29/94
- 4. Question:
The tests described in BAW-10196 P attempted to determine whether i several variables, not directly included in the equation to determine F* (Question 1), would have an impact on the results. These variables included effects from surface roughnesa of the tubesheet bore, the yield strength of the tubing, and a larger tubesheet bore diameter.
The report concluded that these variables had no effect on the calculated F* length. However, the test matrix doec not appear to support the possibility that these variables may interact during testing. If the test matrix did not adequately separate each of the variables then the conclusion in the report may be erroneous.
Describe how the test matrix isolated the effects of yield strength and tubesheet bore surface roughness during the testing.
Response
The effects of tubesheet surface roughness, tube yield strength and tubesheet bore diameter were tested over the range of conditions expected in the steam generator. Within this range, the testing performed (as reported in BAW-10196 P) showed that these variables had little to no effect on the results.
The effects of yield strength on the radial stress due to springback were considered during the springback testing (BWNT Document 51-1228675-01). These tests utilized both high and low yield tubing installed into nominally sized tubesheet bores with nominal surface roughnesses. [
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The effects of surface roughness on the tube pull-out strength were considered by having a range of surf ace roughnesses for each bore size tested, as shown in Figure 1. [
] Therefore, it was concluded that surface roughness (within the range expected) has a negligible ef fect on the results. Also, see the response to Question 5.
Figure 1 also shows that a large range of tubesheet bore diameters were tested. Because [ ] of the bore diameters tested had the same high yield strength tubing, the effect of diameter was sufficiently separated.
In conclusion the effects of tube yield strength, tubesheet bore diameter and surface roughness were separated in such a way that possible interactions were considered. These variables were found to have no significant effect and were thus encompassed in the final calculated F* length.
BWNT NON-PROPRIETARY Page 3 of 7
1 Responses to NRC Questions on Byron FC Report BAW-10196 P 11/29/94
- 5. Question: l Based on staff calculations performed for a similar test series, the.
tubesheet surface ror;hness may affect the proposed F* length. The- !
pullout shear stress between the tube and tubesheet. varies around a mean value as the surface roughness increases. However, the scatter ;
around this mean appears'to increase as the roughness increases (see :
Attachment A, Figure 1). Since all-data (high and low roughness) were used, the resultant F* length may be non-conservativo if the actual ,
tubesheet roughness is relatively high compared' to the test i conditions. In light 'of the apparent increase in data scatter ~as surface roughness increases, please provide a response. justifying' the proposed F* length.
Response
As shown in BAW-10196 P, Table 5.2.1, the majority of the test' specimens envelope the surface finish range of ( ]. Based on '
our industry experience, the [ ] range is a conservative representation of the manufactured drilled bore finishes found in RSG l tubesheets. The roughness range is conservative because when rolling )
a tube into a tubesheet, the tube metal can fill the irregularities !
present in the tube-hole finish before full metal-to-metal contact l occurs. In this manner t he resistance to sliding tends to increase l as the roughness increases. However, a surface roughness as high as '
[ ] was still found to fall within the stress range of the other samples. Thus, no clearly defined relationship between shear stress and surface roughness was found.
In order to better understand the NRC staff calculations and their relation to our data, Figure 2 was created. Figure 2 utilizes the Byron 1 F* data from BAW-10196 P to see if there is a relationship between increasing surface roughness and pull-out. stress variation.
The graph was created by using the average tubesheet bore surface roughness for each M/U location and the pullout stress was calculated using the equation given in Attachment 2 of the NRC transmittal.
Pullout Stress = Ultimate Load /(Tube to TS Contact Area) i Inspection of Figure 2 shows no correlation to the trend stated in the question. Although the tube properties and installation torques may be different, the Byron and NRC data sets were combined in Figure 3.
Again, no correlation is evident. Because no correlation was seen, !
all the data was used to determine the F* length. As stated in the I response to question 4, the lower mean value (of a 95% confidence interval) of the springback testing data was used to determine the !
radial preload stress. l BWNT NON-PROPRIETARY Page 4 of 7
R.sponses to NRC Questions on Byron F0 Report BAW-10196 P 11/29/94 FIGURE 1
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Note: The above graph depicts the range of surface roughnesses that were test ed for each bore diameter. This information is from BAW-10196 P, Table 5.2.1.
BWNT NON-PROPRIETARY Page 5 of 7 l
Responses to NRC Questions on Byron F0 Report BAW-10196 P 11/29/94 FIGURE 2 l
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P Note: This graph uses the average tubesheet bore surface roughness for each M/U location. This information is from BAW-10196 P, Table 5.2.1. The pullout load information is f rom BAW-10196 P, Table 5. 2. 3.
BWNT NON-PROPRIETARY Page 6 of 7 l l
e a Responses to NRC Questions on Byron Fo Report BAW-10196 P 11/29/94 l FIGURE 3
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Note: This graph uses the average tubesheet bore surface roughness for each M/U location. This information is from BAW-10196 P, Table 5.2.1.
The pullout load information is from BAW-10196 P, Table 5.2.3. The NRC data is from Attachment 2 of the NRC questions faxed from Commonwealth Edison Company (referred to as Attachment A, Figure 1 in the question).
The individual data point values were approximated by visual inspection.
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