ML20059D468
| ML20059D468 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 08/16/1990 |
| From: | ALABAMA POWER CO. |
| To: | |
| Shared Package | |
| ML19307A549 | List: |
| References | |
| NUDOCS 9009070052 | |
| Download: ML20059D468 (10) | |
Text
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Attachment 1 Proposed' Technical Specification Page Changes Unit 1 Revision Page 3/4 4-12 Replace Page B3/4'4-3 Replace Page B3/4 4-3a- Replace .
Unit 2 Revision Pag' 3/4 4-12 Replace l Page B3/4 4-3 ?.eplace Page B3/4 4-3a Replace 1
f phj9070052900816 P ADOCK 05000348 PDC l
n REACTOR COOLANT SYSTEM SURVEILLANCEREQUIREMENTS{Continugd},,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
4.4.6.4. Acceptance Criteria
- a. As used in this Specification:
- 1. Imperfection means an exception to the dimensions, finish or contour of a tube or sleeve from that required by fabrication drawings or specifications. Eddy-current testing indications belov 20% of the nominal vall thickness, if detectable, may be considered as imperfections.
- 2. Degradation eans a service-induced cracking, vastage, vear or general corrosion occurring on ti'.her inside or outside of a tube or sleeve.
- 3. Degraded Tube means a tube, inclu3ing the sleeve if the tube has been repaired, that contains imperfections greater than or equal to 20% of the nominal vall thickness caused by degradation.
- 4. % Degradation means the percentage of the tube or sleeve vall thickness affected or removed by degradation.
- 5. Defect means an imperfection of such severity that it exceeds the plugging or repair limit. A tube or sleeve containing a defect is defective.
- 6. Plugging or Repair Limit means the imperfection depth at or beyond which t1e tube shall be repaired (i.e., sleeved) or removed from service by plugging and is greater than or equal to-40% of the nominal tube vall thickness. For a tube that has been sleeved with a mechanical joint sleeve, through vall penetration of greater than or equal to 31% of sleeve nominal vall thickness in the sleeve requires-the tube to be removed from service by plugging. For a tube that has been sleeved with a velded joint sleeve, through wall penetration greater than or equal to 37% of sleeve nominal vall thickness in the sleeve.
between the veld joints requires the tube to bc removed from service br plugging.
- 7. Unserviceable describes the condition of a tube or sleeve if it leaks or contains a defect large enough to affect its structural integrity in the event of an Operating Basis Earthquake, a loss-of-coolant accident, or a stean line or feedvater line break as specified in 4.4.6.3.c, above.
- 8. Tube Inspection means an inspection of the steam generator tube from the point of entry (hot leg side) completely around the U-bend to the top support of the cold leg. For a tube that has.
been repaired by sleeving, the tube inspection should include the sleeved portion of the tube.
- 9. Tube Repair refers to mechanical sleeving, as described by Westinghouse report VCAP-11178 Rev. 1, or laser velded sleeving, as described by Vestinghouse report VCAP-12672, which is used to main-tain a tube in service or return a tube to service. This includes the removal of plugs that were installed as a corrective or preventive measure.
FARLEY-UNIT 1 3/4 4-12 AMENDMENT NO.
' REACTOR COOLANT SYSTEM N!!!.....................................................................
3/4.4.6 STEAM GENERATORS The Surveillance Requirements for inspection of the steam generator tubes ,
ensure that the structural integrity of this' portion of the RCS vill be j maintained. The program for inservice inspection of steam generator tubec is based on a modification of Regulatory Guide 1.83, Revision 1. Inservice inspection of steam generator tubing is essential in order to maintain surveillance of the conditions of the tubes in the event that there is ovidence of mechanical damage or progressive degradation due to design, manufacturing errors, or inservice conditions that lead to corrosion.
Inservice inspection of steam generator tubing also provides a means of characterizing the nature and cause of any tube degradation so that corrective measures can be taken.
l The plant is expected to be operated in a manner such that the secondary i coolant vill be maintained within those chemistry limits found to result in !
negligible corrosion of the steam generator tubes. If the secondary l coolant chemistry is not maintained within these limits, localized I corrosion may likely result in stress corrosion cracking. The' extent of cracking during plant operation vould be limited by the limitation of steam generator tube leakage between the primary coolant system and the secondary coolant system (primary-to-secondary leakage . 500 gallons per day per l steam generator). Cracks having a primary-to-secondary leakage less than .
this limit during operation will have an adequate margin of safety to l withstand the loads imposed during normal operation and by postulated accidents. Operating plants have demonstrated that primary-to-secondary leakage of 500 gallons per day per steam generator can readily be detected
- by radiation monitors of steam generator blevdown. Leakage in excess of this limit vill require plant shutdown and an unscheduled inspection, ;
during which the leaking tubes vill be located and plugged or repaired.
Vastage-type defects are unlikely with proper chemistry treatment of th'e secondary coolant. However, even if a defect should develop in service, it vill be found during scheduled inservice steam generator tube examinations.
Plugging or repair vill be required for all tubes with imperfections exceeding 40% of the tube nominal vall thickness. If a sleeved' tube is found to have through vall penetration of greater than or equal to 31%
for the mechanical sleeve and 37% for the laser velded sleeve of sleeve nomint'l vall thickness in the sleeve, it must be plugged. The 31% and 37%
limits are derived from R.G. 1.121 calculations-with 20% added for<conserva-
, tism. The portion of the tube and the sleeve for which indications of vall degradation must be evaluated can be summarized as follovs:
- a. Mechanical l i
- 1. Indications of degradation in the entire length of the sleeve must be evaluated against the sleeve plugging limit.
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- 2. Indication of tube degradation of any type including a complete 1- guillotine break in the tube between the bottom of the upper joint
[ and the top of the lover roll expansion does not require that the l-tube be removed from service.
l FARLEY-UNIT 1 B3/4 4-3 AMENDMENT NO.
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1 1 1 3. The tube plugging limit continues to apply to the portion'of the tube in the entire upper joint region and in the lover roll ex- I pansion. As noted above the sleeve plugging limit applies to these areas also.
- 4. The tube plugging limit continues to apply to that portion of the tube above the top of the upper joint.
l b. Laser Velded ;
- 1. Indications of degradation in the length of the. sleeve between the l veld joints must be evaluated against the sleeve plugging limit.
2.' Indication of tube degradation of any type including a complete 1 break in the tube between the upper veld joint and the lower veld- !
joint does not require that the tube be removed from service.
- 3. At the veld joint, degradation must be evaluated in both the sleeve and tube.
- 4. In a joint with more than one veld, the veld closest to the end of-the sleeve represents the joint to be inspected and the limit of the sleeve inspection.
- 5. The tube plugging limit continues to apply to the portion of the tube above the upper veld joint and below the lower veld joint.
Steam generator tube inspections of operating plants have demonstrated the {
capability to reliably detect degradation that has penetrated 20% of the original tube vall thickness.
Whenever the results of any steam generator tubing inservice inspection fall into Category C-3, these results will be reported to the Commission pursuant i to 10CFR50.73 prior to resumption of plant operation. Such cases vill be considered by the Commission on a case-by-case basis and may result in a ,
requirement for analysis, laboratory examinations, tests, additional eddy- !
L current inspection, and revision of the Technical Specifications, if I necessary, s l
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FARLEY-UNIT 1 B3/4 4-3a AMENDMENT NO. ,
1 1
REACTOR COOLANT SYSTEM Eh5%51Eh6Ngg,g{gUgggggg{g,{ggn3{gggd},,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
4.4.6.4. Acceptance Criteria l
- a. As used in this Specification:
- 1. Imperfection means an exception to the dimensions, finish or
{
contour of a tube or sleeve from that required by fabrication drawings or specifications. Eddy-current testing indications below 20% of the nominal vall thickness, if detectable, may be '
considered as imperfections. 1 i
- 2. Degradation means a service-induced cracking, vastage, wear or general corrosion occurring on either inside or outside of a tube or sleeve.
- 3. Degraded Tube means a tube, including.the sleeve if the' tube has been repaired, that contains imperfections greater than or equal to 20% of the nominal vall thickness caused by degradation.
- 4. % Degradation means the percentage of the tube or sleeve-vall thickness affected or removed by degradation.
- 5. Defect means an imperfection of such severity that it exceeds the plugging or repair limit. A tube or sleeve containing a defect is defective.
- 6. Plugging or Repair Limit means the imperfection depth at or beyond which the tube shall be repaired (i.e., sleeved) or removed from service by plugging and-is greater than or equal'to 40% of the nominal tube vall thickness. This definition does not apply to the area of the tubesheet region below the F*
distance in F* tubes. For a tube that has been sleeved with i a mechanical joint sleeve, through vall penetration of greater than or equal to 31% of sleeve nominal vall' thickness in the sleeve requires the tube to be removed from service by plugging. For a tube that has been sleeved with a velded~ joint sleeve, through vall j penetration greater than or equal to 37% of sleeve nominal vall '
thickness in the sleeve between the veld joints' requires the tube 1 to be removed from service by plugging.
- 7. i Unserviceable describes the condition of a tube or sleeve if it '
leaks or contains a defect large_enough to affect-its structural integrity in the event of an Operating Basis Earthquake, a loss-of-coolant accident, or a steam line or feedvater line break as specified in 4.4.6.3.c, above. i
- 8. Tube Inspection means an inspection of the steam generator tube from the point of entry (hot leg. side) completely around the U-bend to the top support of the cold leg. For a tube that has been repaired by sleeving, the tube inspection should include the sleeved portion of the tube.
- 9. t Tube Repair refers to mechanical sleeving, as described by Westinghouse report VCAP-11178 Rev. 1, or laser velded sleeving, as described by Vestinghouse Teport WCAP-12672, which is used to maintain a tube in service or return a tube to service. This includes the removal of plugs that were installed as a corrective or preventive measure.
FARLEY-UNIT 2 3/4 4-12 AMENDHENT NO.
n
REACTOR C00LAln SYSTEM
!6!!!...............,.....................................................
3/4.4.6 STEAM GENERATORS j The Surveillance Requirements for inspection of the steam generator tubes snsure-that the structural integrity of this portion of the RCS will be ,
maintained.. The program for inservice inspection of steam generator tubes ]
is based on a modification of Regulatory Guide 1.83, Revision 1. Inservice 1 inspection of steam Fenerator tubing is essential in order.to maintain {
surveillance of the conditions of the tubes in the event that there is !
svidence of mechanical damage or progressive degradation due to design, l 2anufacturing errors, or inservice conditions that lead to corrosion. l Inservice inspection of steam generator tubing also provides a means of ;
characterizing the nature and cause of any tube degradation so that I corrective measures can be taken. I The plant is expected to be operated in a manner such that the secondary coolant vill be maintained within those chemistry limits found to result in i negligible corrosion of the steam generator-tubes. If the secondary coolant chemistry is not maintained within these limits, localized corrosion may likely result in stress corrosion cracking. The extent of I
cracking during plant operation vould be limited by the limitation of steam-generator tube leakage between the primary coolant system and the secondary coolant system (primary-to-secondary leakage - 500 gallons per day per steam generator). Cracks having a primary-to-secondary leakage less than this limit during operation vill have an adequate margin of safety to withstand the loads imposed during normal operation an4 by postulated cecidents. Operating plants 1: ave demonstrated that primary-to-secondary i leakage of 500 gallons per day per steam generator can readily be detected '
by radiation monitors of steam generator blovdown. Leakage in excess of this limit vill require plant sisutdown and an' unscheduled inspection, l during which the leaking tubes v111 be located and plugged or repaired. I Vastage-type defects are unlikely with proper chemistry treatment of the secondary coolant. However, even if a defect should develop in' service, it vill be found during scheduled inservice steam generator tube examinations. I Plugging or repair vill be required for all tubes with imperfections ;
exceeding 40% of the tube nominal vall thickness. If a sleeved tube is found to have through vall penetration of greater than or equal to 31% l for the mechanical sleeve and 37% for the laser velded sleeve of sleeve .l nominal vall thickness in the sleeve, it must be plugged. The 31% and 37% ;
limits are derived frcm R.G.1.121 calculations with 20% added for conserva-tism. The portion of the tube and the sleeve for which indications of vall degradation must be evaluated can be summarized as follows:
- a. Mechanical l
- 1. Indications of degradation in the entire length of the sleeve must be evaluated-against the sleeve plugging limit.
- 2. Indication of tube degradation of any type including a complete guillotine break in the tube between the bottom of the upper joint and the top of the lover roll expansion does not require that the tube be removed from service.
FARLEY-UNIT 2 B3/4 4 -3 AMENDMENT NO. ,
i L !6s!!.....................................................................
- 3. The tube plugging limit continues to apply to the portion of the tube in the entire upper joint region and in the lover roll ex-pansion. As noted above the sleeve plugging limit applies to these areas also.
- 4. The tube plugging limit continues to apply to that portion of the tube above the top of the upper joint,
- b. Laser Velded-
- 1. Indications of degradation in the length of the sleeve between the veld joints must be evaluated aFainst. the sleeve plugging limit.
- 2. Indication of tube degradation of any type including a complete -
break in the tube between the upper veld joint and the lover veld joint does not require that the tube be removed from service.
- 3. At the veld joint, degradation must be evaluated in both the sleeve and tube.
1
- 4. In a joint with more than one veld, the veld closest to the end of the sleeve represents the joint to be inspected and the limit of the sleeve inspection.
- 5. The tube plugging limit continues to apply'to the portion of the tube above the upper veld joint and below the lover veld joint.-
F* tubes do not have to be plugged or repaired provided the remainder of the tube within the tubesheet that is above the F* distance is not degraded. The F* distance is equal to 1.79 inches and is measured down from the top of the tubesheet or the bottom of the roll transition, whichever is lower in-elevation.
Included in this distance is an allowance of 0.25 inch for eddy current elevation measurement uncertainty.
Steam generator tube inspections of operating plants have demonstrated the capability to reliably detect vastage type degradation that has penetrated 20% of the original tube vall thickness.
Whenever the results of any steam generator tubing inservice inspection fall into Category C-3, these results vill be reported to the Commission pursuant to 10CFR50.73 prior to resumption of plant operation. Such cases vill be considered by the Commission su a case-by-case basis and may result in a raquirement for analysis, laboratory examinations, tests, additional eddy-current inspection, and revision of the Technical Specifications, if necessary.
FARLEY-UNIT 2 B3/4 4-3a AMENDHENT NO.
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Attachment 2 VCAP-12672 VCAP-12673
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Proprietary Information Notice .
Transmitted herewith are proprietary and/or non proprietary versions of documents furnished to the NRC in connection with requests for generic and/or plant-specific review and approval.
In order to conform to the requirements of 10 CFR 2.790 of the Commission's regulations concerning the protection of proprietary information- so submitted
- to the NRC, the information which is proprietary in the proprietary versions is contained within brackets and where the proprietary information'has been deleted in the non-proprietary versions on the brackets _ remain, the information that was contained within brackets and where the proprietary information has been deleted 'in the non-proprietary versions only the brackets remain, the information that was contained within the brackets in-the proprietary versions having been deleted. The justification for claiming the_information so designated as proprietary is indicated in both versions by means of lower case letters (a) through (g) contained within parentheses located as a superscript immediately following the brackets enclosing each item of information being l identified as proprietary or in the margin opposite such information. These l
lower case letters refer to the types of information Westinghouse customarily holds in confidence identified in Sections (4)(ii)(a) through (4)(ii)(g) of the I
affidavit accompanying this transmittal pursuant to 10 CFR 2.790(b)(1).
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Copyright Notice I l
The reports transmitted herewith each bear a_ Westinghouse copyright notice. ,
The NRC is permitted to make the number of copies of the information contained in these reports which are necessey for its internal use in connection with generic and plant-specific reviews and approvals as well as the issuance, denial, amendment, transfer, renewal, modit .ation, suspension, revocation, or violation of a license, permit, order, or regulation subject to the requirements of 10 CFR 2.190 regarding restrictions on public disclosure to the extent such information has been identified as proprietary by Westinghouse, copyright protection not withstanding. With respect to the non-proprietary versions of these reports, the NRC is permitted to make the number of copies beyond those necessary for its internal use which are necessary in order to have one copy available for public viewing in the appropriate docket-files in' i the public document room in Washington, DC and in local public document rooms as may be required by NRC regulations if the number of copies subm' ,ted is insufficient for this purpose. The NRC is not authorized to make copies for
- the personal use of members of the public who make use of the NRC public l document rooms. Copies made by the NRC must include the copyright notice in l all instances and the proprietary notice if the original was identified as l proprietary.
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i Westinghouse Energy Systems an 355 Electric Corporation Pmsburgh Pennsylvania 15230-0355 August 14,-1990 !
CAW-90-063 l Document Control Desk I US Nuclear Regulatory Commission Washington, DC 20555 Attention: Dr. Thomas Murley, Director APPLICATION FOR WITHHOLDING PROPRIETARY INFORMATION FROM PUBLIC DISCLOSURE
Subject:
" Steam Generator Sleeving Report - Laser Welded Sleeves - J. M.- j Farley Units 1 and 2" (WCAP-12672) '
Dear Dr. Murley:
The proprietary information for which withholding is being-requested in the above-referenced letter is further identified in Affidavit CAW-90-063 signed by ,
the owner of the proprietary information, Westinghouse Electric Corporation.
The affidavit, which accompanies this letter, sets forth the basis on which the information may be withheld from public disclosure by the Commission and i addresses with specificity the considerations listed in paragraph (b)(4) of 10 CFR Section 2.790 of the Commission's regulations.
Accordingly, this letter authorizes the utilization'of the accompanying !
Affidavit by Alabama Power Company. '
Correspondence with respect to the proprietary aspects of the application for !
withholding or the Westinghouse affidavit should reference this letter, CAW-90-063, and should be addressed to the undersigned.
Very truly yours, lo el Robert A. Wiesemann,-Manager Enclosures Regulatory & Legislative Affairs cc: C. M. Holzle, Esq. '
Office of the General Counsel, NRC 1
V. Wilson, NRR 9009070057 DR 999g34 ADOCK Osooof4g PDC
CAW-90-063 AFFIDAVIT COMMONWEALTH OF PENNSYLVANIA:
ss COUNTY OF ALLEGHENY:
Before me, the undersigned authority, personally appeared Robert A. Wiesemann, who, being by me duly sworn according.to law, deposes and says that he is authorized to execute this Affidavit on behalf of Westinghouse Electric Corporation (" Westinghouse") and that the averments of fact set forth in this Affidavit are true and correct to the best of his knowledge, information, and belief:
Robert A. Wiesemann, Manager.
Regulatory and Legislative Affairs Sworn to and subscribed before me this /[ day of/2N#n# d , 1990.
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J l l b d & fjvidl4 J
! Notary Public pou,,xo e nfa Pttk MyC e el 0 ,
l Mentw,PwwwpsiaAesoduond he
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CAW-90-063 I
1 (1) I am Manager, Regulatory and legislative Affairs, -in the Nuclear and Advanced Technology Division, of the Westinghouse Electric Corporation -
and as such, I have been specifically delegated the function of reviewing i the proprietary information sought to be withheld from public disclosure in j connection with nuclear power plant licensing and rulemaking proceedings, and am authorized to apply for its withholding on behalf of the Westinghouse Energy Systems Business Unit.
(2) I am making this Affidavit in conformance with the provisions of 10CFR Section 2.790 of the . Commission's regulations and in conjunction with the Westinghouse application for withholding accompanying this Affidavit.
i (3) I have personal knowledge of the criteria and procedures utilized by the Westinghouse Energy Systems Business Unit in designating information'as a trade secret, privileged or as co' dential commercial or financial information.
(4) Pursuant to the provisions of paragraph (b)(4) of section 2.790 of the Commission's regulations, the following is furnished for consideration by the Commission in determining whether the information sought to be withheld from public disclosure should be withheld.
(i) The information sought to be withheld from public disclosure is owned and has been held in confidence by Westinghouse.
-3 CAW-90-063 (ii) The infor.n: ion is of a type customarily held in confidence by Westingho, a ar.d not customarily disclosed to the public. !
Westinghouse has a rational bacis for determining the types of !
information customarily held in confidence by it and, in that -j connection, utilizes a system to determine when and whether to hold certain types of information in confidence. The ;
application d that system and the substance of that system }
constitJtes Westinghouse policy and provides the rational basis' required. j Under that system, information is held-it :onfidence if it falls 3 in ono or more of several types, the release of which might .i result in the loss' of an existing or potential competitive ;
advantage, as follows: I (a) The information reveals the distinguishing aspects of a process (or component, structure, tool, method, etc.) where i prevention of its use by any of Westinghouse's competitors ,
without license from Westinghouse constitutes a competitive '
economic advantage over other companies.
g (b') It consists of supporting data, including test data, relative to a process (or component,- structure, tool, method, etc.), the application of which data secures a
, 4 competitive economic advantage, e.g., by optimization or '
improved marketability. I
CAW 90 06? j l
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J (c) Its use 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 a similar product. J (d) It reveals cost or price information, production capacities, budget levels, or commercial strategies of l
, Westinghouse, its customers or suppliers, l
j (e) It reveals aspects of past, present, or future Westinghouse or customer funded development plans and programs of i
( 1 i potential commercial value to Westinghouse. '
(f) It contains patentable ideas, for which patent protection may be desirable.
I (g) It is not 1he property of Westinghouse, but must be treated as proprietary by Westinghouse according to agreements with i l the owner.
There are sound policy reasons behind the Westinghouse system l which include the following: -
l (a) The use of such information by Westinghouse gives Westinghouse a competitive advantage over its competitors.
It is, therefore, withheld frca disclosure to protect the Westinghouse competitive position.
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l (b) It is information which is marketable in many ways. The i extent to which such information is available to competitors diminishes the Westinghouse ability to sell products and services involving the use of the information.
(c) Use by our competitor would put Westinghouse at a competitive disadvantage by reducing his expenditure of resources at our expense.
(d) Each component of proprietary information pertinent to a
, particular competitive advantage is potentially as valuable as the total competitive advantage. If competitors acquire components of proprietary information, any one component may be the key to the entire puzzle, thereby depriving i
Westinghouse of a competitive advantage.
(e) Unrestricted disclosure would jeopardize the position of
^
l prominence of Westinghouse in the world market, and thereby give a market advantage to the competition of those countries.
(f) The Westinghouse capacity to invest corporate assets.in research and development depends upon the success in l obtaining and maintaining a competitive advantagq, l
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CAW 90-063 i .
(iii) The information is being transmitted to the Commission in I confidence and, under the provisions of 10CFR Section 2.790, it is to be received in et4fidence by the Commission. l l
l (iv) The information sought to be protected is not available in l public sources or available information has not been previously employed in the same original manner or m#.od to the best of our knowledge and belief.
(v) The proprietary information sought to be withheld in th u submittal is that which is appropriately markeit in " Steam Generator Sleeving Report - Laser Welded Sleeves" for Joseph M. Farley Units 1 and 2, WCAP 12672, (Proprietary) being transmitted by the Alabama Power Company (APCo) ;
letter and Application for Withholding Proprietary ,
Information from Pubile Disclosure, Mr. W. G. Hairston III, APCo, to Document Control Desk,-attention Dr. Thomas Murley, August,1990. The proprietary information as submitted for use by Alabama Power Company for Joseph M.
Farley Units 1 a:v is expected to be applicable in other [
licensee submitta:s in response to certain NRC requirements l for justification of use of laser welded sleeving in steam generator tubes.
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j, l CAW-90-063 This infermation is part or that which will enable ;
Westinghouse to:
l (a) Provide documentation of the methods for laser welded sleeving of steam generator tubes. ,
(b) Establish applicable testing methods.
(c) Establish the use of fiber optics in laser welded sleeving applications.
i (d) Establish applicable codes and standards which are to be applied to the process.
l (e) Assist the customer to obtain NRC approval.
Further this information has substantial commercial value as follows:
l (a) Westinghouse plans to sell the use of similar information to its customers for purposes of meeting i NRC requirements for licensing documentation.
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l (b) Westinghouse can sell support and defense of the technology to its customers in the licensing process.
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8- CAW 90 063 Public disclosure of this proprietary information is likely to cause substantial harm to the competitive position of Westinghouse because it would enhance the ability of competitors to provide similar sleeving services and I
licensing defense services for commercial power reactors without commensurate expenses. A1:o, public disclosure of the information would enable others to use the information to meet NRC requirements for licensing documentation without purchasing the right to use the information.
l The development of the technology described in part by the information is the result of applying the results of many years of experience in an intensive Westinghouse effort and the expenditure of a considerable sum of money, j In order for competitors of Westinghouse to duplicate this information, similar technical programs would have to be performed and a significant manpower effort, having the requisite talent and experience, would have to be expended !
for developing testing and analytical methods and !
performing tests. i Further the deponent sayeth not.
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, Attachment 3 !
10CFR50.92 Significant Hazards Consideration 6-e e
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NS.PL.RCSCL.90 255, Rev. 1 PAGE 2 0F 7 ,
i REPAIR OF STEAM GENERATOR TUBES USING LASER WELDED SLEEVES ,
J. M. FARLEY NUCLEAR PLANT UNITS 1 AND 2 51GNIFICANT HAZARDS CONSIDERATION ANALYS!$
INTRODUCTION -
As required by 10 CFR 50.91 (a)(1) this analysis is provided to demonstrate that a proposed license amendment to impleinent repair of tubes using tube sleeves for the Farley Nuclear Plant Units 1 and 2 steam generators represents no significant hazards consideration. In accordance with the '
three factor test of 10 CFR 50.92(c), implementation of the proposed license amenument was at.alyzed using the following standards and found not to: 1) involve a significant increase in the probability or consequences for an dCCident previously evaluatedi 2) create the possibility of a new or different kind of accident from any accident previously evaluated; or 3) involve a significant reduction in a margin of safety.
Due to the importance of the barrier provided by the steam generator tubes, maintenance of tube bundle integrity has been provided for by regular inspection of the tubes and removal from service of tubes which have indication of degradation in excess of specified criteria. A repair method i using sleeves placed inside the tubes at the location of the degradation has been developed. The sleeves are short lengths of tubing with an outside diameter less than the inside diameter of the degraded tube. The sleeve is placed inside the tube and is joined at the top and bottom by a laser welding process to sound portions of the tube. The installed sleeve in a degraded or defective tube restores the integrity of the barrier provided by the tubes between the primary and secondary fluids Using Technical Specification tube plugging criteria without provision for sleeving, tubes with indications of degradation in excess of the plugging-l criteria would have to be removed from service. R ooval of a tube from service results in a reduc' tion of reactor coolant flow through the steam generator. This small reduction in flow has an impact on the margin in the
NS PL RCSCL 90 259. Rey, 1
- PAGE 3 0F 7 l reactor coolant flow through the steam generator in LOCA analyses and on the j heat transfer efficiency of the steam generator. Repair of a tube with I
- sleeving maintains the tube in s6rvice and results in a much smaller flow reduction. Therefore the use of sleeving in lieu of plugging would minimize loss of margin in reactor coolant system flow and assist in assuring that minimum flow rates are maintained in excess of that required for operation at full power. Also, minimizing the reduction in flow has operational benefits and minimizes the increase in heat flux across the tubes remaining irt ,
service. Increased heat fluxes have been associated with an increased l potential for tube corrosion.
The proposed amendment would modify a portion of the Technical Specifications ,
to specify the requirements for the repair of a steam generator tube by installation of sleeves with laser welded joints. Currently, Farley Units 1 and 2 Technical Specifications include requirements for repair using sleeves cith mechanical joints for those steam generator tubes with eddy current int'ications showing greater than 40% through wall degradation. The current Technical Specification language was esulished before the proposed sleeving
- repair method using laser welded joints to repair tubes and maintain the tubes in service was developed for Farley Units 1 and 2. The proposed Technical Specification change would specify the requirements for repairing degraded or defective tubes utilizing sleeves with laser welded joints in the Farley Units 1 and 2 steam generators. The proposed amendment also includes criteria for allowable wall degradation in the sleeve and in the tube in the region of the sleeve to tube joint.
ANALYSIS Conformance of the proposed amendments to the standards for a determination of no significant hazard as defined in 10 CFR 50.92 (three factor test) is shown in the following:
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! NS PL RCSCL 90 259, Rev. I l par 4 4 0F 7 '
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- 8) Operation of the Farley Units 1 and ? in accordance with the proposed license amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated.
. The supporting technical and safe n evaluations of the subject amendment (Westinghouse WCAP 12672, *Farley Unus 1 and 2. Steam Generator Sleeving Report, (Laser Welded Sleeves)" (Proprietary) and WCAP 12673, 'Farley i Units 1 and 2. Steam Generator Sleeving Report, (Laser Welded Sleeves)"
(Non Proprietary)) demonstrate that repair of degraded tubes using sleeves will result in tube bundle integrity censistent with the original design basis.
The sleeve configuration has been designed and analyted in accordance l with the rules of the ASME Boiler and Pressure Vessel Code. Fatigue and stress analyses of the sleeved tube assemblies produced acceptable results. Mechanical testing has shown that the structural strength of the sleeves under normal, faulted and upset conditions is within acceptable limits. Leak rate testing has demonstrated that the leak rates of the joints between the sleeve and the existing tube under normal, faulted and upset conditions are well below acceptable rates.
The existing Technical Specification leakage rate requirements and accident analysis assumptions remain unchanged in the event signific;nt leakage from the sleeve would occur. Any leakage through the sleeved region of the tube due to hypothetical localized tube degradation is fully bounded by leak before break considerations and ultimately the existing steam generator tube rupture analysis included in the Farley Units 1 and 2 Final Safety Analysis Report Update. The proposed Technical Specification change to support the installation of laser welded joint sleeves does not adversely impact any other previously evaluated design basis accident or the results of LOCA and Non LOCA accident analyses. The results of the qualificaticn testing, analyses, and plant operating experience demonstrate that the sleeve assembly is an acceptable means of maintaining tubes in service. Furthennore, per
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' NS.PL RCSCL 90 259 Rev. 1 PAGE 5 0F 7 r
Regc itory Guide 1.83 recommendations, the sleeved tube can be monitored through periodic inspections with present eddy current techniques.
Plugging limit criteria are established in the ter.hnical specifications for the tube in the region of the sleeve and the sleeve. These measures demonstrate that installation of sleeves which span degraded areas of the I
tube will restore the tube to its original design basis.
- 2) The propoked license amendment does not create the possibility oi a new or different kind of accident from any accident previously evaluated.
i Implementation of the proposed tube degradation repair method does not introduce significant changes to the plant design casis. . Repair of tubes does not provide a mechanism to result in an accident outside of the sleeved area. Any hypothetical accident as a result of potential tube or sleeve degradation in the repaired portion of the tube would be bounded by the existing tube rupture accident analyeis.
J) The proposed license amendment does not involve a significant reduction in a margin of safety.
The sleeve repair of deghdod staan generators tubes as identified in i
sleeving report has been demonstrated to restore the integrity of the tube bundle under normal and postulated accident conditions. The safety factors used in the design of sleeves for the repair of degraded tubes are consistent with the safety factors in the ASME Boiler and Pressure l Vessel Code used in steam generator design. The plugging limit criteria for the sleeve has been established using the method of Regulatory Guide 1.121. The design of the sleeve joints has been verified by testing to preclude significant leakage during normal and postulated accident l conditions. Use of the ASME Code and Regulatory Guide 1.121 criteria and methods assures that the margin to safety with respect to structural integrity is the same for the sleeves as for the original steam guerat;r tubes.
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l The effect of sleeving on the design transients and accident safety analyses has been reviewed based on the installation up to the level of the licensed plugging level. The installation of sleeves can be evaluated as the equivalent of some level of steam generator tube plugging. The Farley Units 1 and 2 steam generators are currently j licensed to 10 percent steam generator tube plugging (SGTP). An evaluation is being completed to support an increase of the licensed plugging level to an average of 15 per cent with up to 20 percent in the most plugged steam generator. Evaluation of the installation of sleeves is based on the determination that LOCA evaluations for the licensed tube plugging level bound the effect of a combination of tube plugging and sleeving up to an equivalent of the licensed !3TP. For the purpose of assessing the impact on the non LOCA safety analyses and the design transients, it has been determined that the analyses and evaluations for the licensed plugging level bound the effect of up to the equivalent SGTP' due to a combination of sleeving and plugging, therefore, the non LOCA safety anbyses and design transients are not adversely impacted by steam ,
generator sleeving.
The safety margins in the analysis of postulated accident conditions and design transients are provided in the assumptions and conservatism in the calculations and computer codes used and in the requirements and recommendations of the NRC. Accordingly, based on the information I outlined above, there is no decrease in the safety margins defined in the bases of the plant Technical Specifications.
l Implementation of tube repair by sleeving will decrease the number of tubes which must be taken out of service with tube plugs. Installation of tube plugs reduces the RCS flow margin, thus implementation of tube repair by sleeving will maintain the margin of flow that would otherwise be reduced in the event of increased plugging. Based on the above, it is concluded that the proposed change does not result in a significant reduction in a loss of margin with respect to plant safety as defined in the Up:tated Final Safety Analysis Report or the bases of the plant technical specifications.
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PAGE 7 0F 7 CONCLUSION Based on the preceding analysis it is concluded that operation of J. M.
Fctley Nuclear Plant Units 1 and 2 in accordance with the proposed atendment -
does not result in the creation of an unreviewed safety question, an increase in the probability of an accident previously evaluated, create the possibility of a new or different kind of accident from any t:cident previously evaluated, nor reduce any margins to plant safety. Therefore, the license amendment does not involve a Significant Hazards Cons,deration as defined in 10 CFR 50.92.
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