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| number = ML063390665 | | number = ML063390665 | ||
| issue date = 11/30/2006 | | issue date = 11/30/2006 | ||
| title = | | title = Additional Supplement to Technical Specification Change 05-09 - Application for Technical Specification Improvement Regarding Steam Generator Tube Integrity and Deletion of License Condition | ||
| author name = Morris G | | author name = Morris G | ||
| author affiliation = Tennessee Valley Authority | | author affiliation = Tennessee Valley Authority | ||
| addressee name = | | addressee name = | ||
Line 13: | Line 13: | ||
| document type = Letter | | document type = Letter | ||
| page count = 60 | | page count = 60 | ||
| project = | |||
| stage = Supplement | |||
}} | }} | ||
=Text= | =Text= | ||
{{#Wiki_filter:Tennessee Valley Authority, Post Office Box 2000, Soddy-Daisy, Tennessee 37384-2000 November 30, 2006 TVA-SQN-TS-05--09 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Gentlemen: | {{#Wiki_filter:Tennessee Valley Authority, Post Office Box 2000, Soddy-Daisy, Tennessee 37384-2000 November 30, 2006 TVA-SQN-TS-05--09 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Gentlemen: | ||
In the Matter of | In the Matter of ) Docket No. 50-328 Tennessee Valley Authority SEQUOYAH NUCLEAR PLANT (SQN) - UNIT 2 - ADDITIONAL SUPPLEMENT TO TECHNICAL SPECIFICATION (TS) CHANGE 05 APPLICATION FOR TECHNICAL SPECIFICATION IMPROVEMENT REGARDING STEAM GENERATOR TUBE INTEGRITY AND DELETION OF LICENSE CONDITION | ||
==Reference:== | ==Reference:== | ||
NRC letter to TVA dated November 7, 2006, "Sequoyah Nuclear Plant, Unit 2 - Request for Additional Information Regarding Steam Generator Tube Integrity Technical Specification Amendment (TAC NO. MD0145)" | |||
By the reference letter, NRC staff requested additional information to support staff review of SQN TS Change 05-09. In response to the reference letter, TVA is providing the requested information. | |||
The enclosed information provides TVA responses to NRC questions and includes new TS and TS Bases markups. The new TS and Bases markups reflect discussion with your staff during an October 31, 2006 telephone call. The enclosed markups supersede those previously provided by TVA's August 30, 2006, submittal and February 15, 2006, submittal. | |||
Printed on recycled paper | |||
U.S. Nuclear Regulatory Commission Page 2 November 30, 2006 provides TVA responses. Enclosure 2 provides a new set of TS page markups. Enclosure 3 provides a new set of TS Bases page markups. | |||
TVA's schedule for implementing TS Change 05-09 will be during the Unit 2 Cycle 15 refueling outage (outage scheduled to begin in April 2008). Accordingly, TVA requests NRC approval by January 2008 to allow for TS implementation during the Unit 2 Cycle 15 refueling outage. | |||
TVA has determined that the enclosed changes do not affect the original evaluation of proposed changes and TVA's review for the no significant hazards considerations provided in TVA's original February 15, 2006, submittal. | |||
Enclosure 2 provides a new set of TS page markups. Enclosure 3 provides a new set of TS Bases page markups.TVA's schedule for implementing TS Change 05-09 will be during the Unit 2 Cycle 15 refueling outage (outage scheduled to begin in April 2008). Accordingly, TVA requests NRC approval by January 2008 to allow for TS implementation during the Unit 2 Cycle 15 refueling outage.TVA has determined that the enclosed changes do not affect the original evaluation of proposed changes and TVA's review for the no significant hazards considerations provided in TVA's original February 15, 2006, submittal. | Additionally, in accordance with 10 CFR 50.91(b) (1), TVA is sending a copy of this letter and enclosures to the Tennessee State Department of Public Health. | ||
Additionally, in accordance with 10 CFR 50.91(b) (1), TVA is sending a copy of this letter and enclosures to the Tennessee State Department of Public Health.There are no commitments contained in this submittal. | There are no commitments contained in this submittal. | ||
If you have any questions about this change, please contact me at 843-7170.I declare under penalty of perjury that the foregoing is true and correct. Executed on this 30th day of November, 2006.Sincerely, Glenn W. Morris Manager, Site Licensing and Industry Affairs | If you have any questions about this change, please contact me at 843-7170. | ||
I declare under penalty of perjury that the foregoing is true and correct. Executed on this 30th day of November, 2006. | |||
Sincerely, Glenn W. Morris Manager, Site Licensing and Industry Affairs | |||
==Enclosures:== | ==Enclosures:== | ||
: 1. TVA Responses to NRC Questions 2. New Technical Specification Page Markups 3. New Technical Specification Bases Page Markups cc: See page 3 U.S. Nuclear Regulatory Commission Page 3 November 30, 2006 Enclosures cc (Enclosures): | : 1. TVA Responses to NRC Questions | ||
Mr. Lawrence E. Nanney, Director Division of Radiological Health Third Floor L&C Annex 401 Church Street Nashville, Tennessee 37243-1532 Mr. Douglas V. Pickett, Senior Project Manager U.S. Nuclear Regulatory Commission Mail Stop 08G-9a One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2739 ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQk)UNIT 2 TVA Responses to NRC Request for Additional Information Regarding SQN TS Change 05-09 NRC Question 1 In definition 1.16 for IDENTIFIED LEAKAGE on page E2-3 of the TS proposed August 30, 2006, the third part of the definition is as follows: c. Reactor coolant system leakage through a steam generator to the secondary system.The proposal indicates the phrase ""(primary to secondary)" will be added to the end of the definition (i.e., "to the secondary system (primary to secondary)." In the TS originally proposed (February 15, 2006), the term "'(primary to secondary leakage)", which is consistent with TSTF-449, was to be added to this definition. | : 2. New Technical Specification Page Markups | ||
Please discuss why the word "leakage" was deleted from the proposal, or discuss your plans for making the proposal consistent with the TSTF-449.TVA Response The word "leakage" is hidden from view in the comment box and does not appear in the printed text for the submittal. | : 3. New Technical Specification Bases Page Markups cc: See page 3 | ||
The comment box size was altered during TVA's submittal preparation and caused the word"leakage" to be hidden from view. TVA has expanded the comment box to restore the word "leakage" and has provided a corrected page in | |||
("comment box"). In some cases, it is unclear whether the entire comment is printed in the comment box. Two examples follow: For proposed TS 3.4.6.2, Reactor Coolant System, ACTION b, page E2-17, the comment to be inserted is,"or primary-to-secondary. " The corresponding statement in TSTF-449 is, "or primary-to-secondary leakage." Your original proposal included the word"leakage," and it appears that it may still be in the comment box but mostly out of view.Following proposed TS Surveillance Requirement 4.4.6.2.1, there is a comment that, "The above surveillance requirement is not applicable." The original proposal, which is consistent with TSTF-449, was, "The above surveillance El-I requirement is not applicable to primary to secondary leakage." The final part of this sentence is clearly necessary. | U.S. Nuclear Regulatory Commission Page 3 November 30, 2006 Enclosures cc (Enclosures): | ||
TVA Response The missing text is hidden from view in the comment box and does not appear in the printed text for the submittal. | Mr. Lawrence E. Nanney, Director Division of Radiological Health Third Floor L&C Annex 401 Church Street Nashville, Tennessee 37243-1532 Mr. Douglas V. Pickett, Senior Project Manager U.S. Nuclear Regulatory Commission Mail Stop 08G-9a One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2739 | ||
The comment box size was altered during TVA's submittal preparation and caused the missing text to be hidden from view. TVA has expanded the comment box to restore the text and has provided a corrected page in Enclosure 2.NRC Question 3 For the structural integrity performance criterion defined in proposed TS 6.8.4.k.b.1 (page E2-19), in the sentence on safety factors, you are proposing to insert the phrase, "except as permitted through application of the alternative repair criteria discussed in TS 6.8.4.k.c.i." The staff notes that the proposed statement could be misinterpreted to mean that TS 6.8.4.k.c.1 contains guidance concerning when an exception to the safety-factor requirement is permitted. | |||
Please discuss you plans to revise this proposed insert, for example, "except for flaws addressed through application of the alternate repair criteria discussed in TS 6.8.4.k.c.I." TVA Response TVA has revised page E2-19 as suggested and has included the revised page with the TS markups in Enclosure 2.NRC Question 4 The insert regarding the required probability of burst, proposed at the end of TS 6.8.4.k.b.l (page E2-19), uses the abbreviations,"ODSCC" and "TSP." Please discuss your plans to define these abbreviations within the insert. For example, "outside diameter stress corrosion cracking (ODSCC) ." TVA Response TVA has revised page E2-19 to define the abbreviations as suggested, and has included the revised page with the TS markups in Enclosure 2.NRC Question 5 For the accident induced leakage performance criterion defined in proposed TS 6.8.4.k.b.2 (page E2-19), the first sentence of the criteria states that leakage is "not to exceed 1.0 gpm for the faulted SG." Since the corresponding statement in TSTF-449 is, "not to exceed 1.0 gpm per SG," and the proposal for Sequoyah Nuclear Plant, Unit 2 (SQN2), does not address the non-faulted steam generators, please discuss your plans to revise the proposal to make it consistent with the TSTF-449.E1-2 TVA Response TVA has revised page E2-19 to address the leakage criteria for the non-faulted SGs and include clarification of the leakage criteria for SQN's SGs. The revised page is provided with the TS markups in | ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQk) | ||
Since this is not the intent of the repair criteria, please discuss your plans to revise this statement. | UNIT 2 TVA Responses to NRC Request for Additional Information Regarding SQN TS Change 05-09 NRC Question 1 In definition 1.16 for IDENTIFIED LEAKAGE on page E2-3 of the TS proposed August 30, 2006, the third part of the definition is as follows: | ||
For example: "At TSP intersections, the plugging (repair) limit is described below:" TVA Response TVA has revised page E2-20 as suggested and has included the revised page with the TS markups in Enclosure 2.NRC Question 7 Paragraph (c) of proposed TS 6.8.4.k.c.1 (page E2-20) refers to "Note 2." Since this is now the only note following deletion of the original Note 1, changing the name of the original Note 2 to Note 1 may avoid potential confusion. | : c. Reactor coolant system leakage through a steam generator to the secondary system. | ||
In addition, since there is no flow distribution baffle at SQN2, Note 2 could be shortened to one sentence. | The proposal indicates the phrase ""(primary to secondary)" will be added to the end of the definition (i.e., "to the secondary system (primary to secondary)." In the TS originally proposed (February 15, 2006), the term "'(primary to secondary leakage)", which is consistent with TSTF-449, was to be added to this definition. Please discuss why the word "leakage" was deleted from the proposal, or discuss your plans for making the proposal consistent with the TSTF-449. | ||
/The staff notes that it may improve readability to eliminate Note 2 as a separate item and instead include the relevant information within parentheses in TS 6.8.4.k.c.l.c. | TVA Response The word "leakage" is hidden from view in the comment box and does not appear in the printed text for the submittal. The comment box size was altered during TVA's submittal preparation and caused the word "leakage" to be hidden from view. TVA has expanded the comment box to restore the word "leakage" and has provided a corrected page in . | ||
For example: "SG tubes, with indications of potential flaws attributed to ODSCC within the bounds of the TSP with a bobbin voltage greater than 2.0 volts but less than or equal to the upper voltage repair limit (calculated according to the methodology in GL 95-05 as supplemented) may remain .....TVA Response TVA has revised page E2-20 to eliminate Note 2 and add the text from Note 2 into the SG program requirements as suggested and has included the revised page with the TS markups in Enclosure 2.NRC Question 8 In order to be consistent with the TSTF-449 wording used elsewhere in your proposal, please discuss your plans to replace the term"degradation" with "flaws" in your proposed TS in 6.8.4.k.c.2 (W*Methodology). | NRC Question 2 The staff's review depends in part on the revisions in your proposal that are enclosed by a bold rectangle ("comment box"). In some cases, it is unclear whether the entire comment is printed in the comment box. Two examples follow: | ||
E1-3 TVA Response TVA has revised TS 6.8.4.k.c.2 to replace the term "degradation" with"flaws" as suggested and has included the revised page with the TS markups in Enclosure 2.NRC Question 9 Paragraph (c) of proposed TS 6.8.4.k.c.1 (page E2-20) addresses two different conditions of bobbin coil voltage for ODSCC flaw indications. | For proposed TS 3.4.6.2, Reactor Coolant System, ACTION b, page E2-17, the comment to be inserted is, "or primary-to-secondary. " The corresponding statement in TSTF-449 is, "or primary-to-secondary leakage." Your original proposal included the word "leakage," and it appears that it may still be in the comment box but mostly out of view. | ||
The staff notes that it may improve the clarity of the repair criteria to start a new paragraph (i.e., 6.8.4.k.c.l.d) for the case where bobbin indication voltage is greater than the upper voltage limit, since the second sentence of this paragraph is not an exception as discussed in Item b. For example: d) SG tubes with indications of ODSCC flaws with a bobbin coil voltage greater than the upper voltage repair limit (calculated according to the methodology in GL 95-05 as supplemented) will be plugged.e) If an unscheduled mid-cycle inspection is performed, the following repair limits apply instead of the limits-identified in Items 6.8.k.c.l.a), .b), .c), and .d).As a result of this change, references to these specifications on page E2-20 and E2-21 will also need to be modified. | Following proposed TS Surveillance Requirement 4.4.6.2.1, there is a comment that, "The above surveillance requirement is not applicable." The original proposal, which is consistent with TSTF-449, was, "The above surveillance El-I | ||
For example, Implementation of these mid-,cycle repair limits should follow the same approach as in TS items 6.8.k.c.l.a), .b), .c), and.d).TVA Response TVA has revised page E2-20 and E2-21 to include a new item d as suggested, and has included the revised page with the TS markups in | |||
Please discuss your plans to move the inspection discussion to TS 6.8.4.k.d (Provisions for SG Tube Inspections.) | requirement is not applicable to primary to secondary leakage." The final part of this sentence is clearly necessary. | ||
For example, consider adding a TS 6.8.4.k.d.5: | TVA Response The missing text is hidden from view in the comment box and does not appear in the printed text for the submittal. The comment box size was altered during TVA's submittal preparation and caused the missing text to be hidden from view. TVA has expanded the comment box to restore the text and has provided a corrected page in Enclosure 2. | ||
NRC Question 3 For the structural integrity performance criterion defined in proposed TS 6.8.4.k.b.1 (page E2-19), in the sentence on safety factors, you are proposing to insert the phrase, "except as permitted through application of the alternative repair criteria discussed in TS 6.8.4.k.c.i." The staff notes that the proposed statement could be misinterpreted to mean that TS 6.8.4.k.c.1 contains guidance concerning when an exception to the safety-factor requirement is permitted. Please discuss you plans to revise this proposed insert, for example, "except for flaws addressed through application of the alternate repair criteria discussed in TS 6.8.4.k.c.I." | |||
TVA Response TVA has revised page E2-19 as suggested and has included the revised page with the TS markups in Enclosure 2. | |||
NRC Question 4 The insert regarding the required probability of burst, proposed at the end of TS 6.8.4.k.b.l (page E2-19), uses the abbreviations, "ODSCC" and "TSP." Please discuss your plans to define these abbreviations within the insert. For example, "outside diameter stress corrosion cracking (ODSCC) ." | |||
TVA Response TVA has revised page E2-19 to define the abbreviations as suggested, and has included the revised page with the TS markups in Enclosure 2. | |||
NRC Question 5 For the accident induced leakage performance criterion defined in proposed TS 6.8.4.k.b.2 (page E2-19), the first sentence of the criteria states that leakage is "not to exceed 1.0 gpm for the faulted SG." Since the corresponding statement in TSTF-449 is, "not to exceed 1.0 gpm per SG," and the proposal for Sequoyah Nuclear Plant, Unit 2 (SQN2), does not address the non-faulted steam generators, please discuss your plans to revise the proposal to make it consistent with the TSTF-449. | |||
E1-2 | |||
TVA Response TVA has revised page E2-19 to address the leakage criteria for the non-faulted SGs and include clarification of the leakage criteria for SQN's SGs. The revised page is provided with the TS markups in . | |||
NRC Question 6 The first paragraph of proposed TS 6.8.4.k.c.l (page E2-20), the GL 95-05 voltage-based alternate repair criteria, states, "the plugging (repair) limit is based on maintaining SG tube integrity as described below:" The staff notes this statement may.imply that this repair criteria prescribes methods to ensure tube integrity. Since this is not the intent of the repair criteria, please discuss your plans to revise this statement. For example: "At TSP intersections, the plugging (repair) limit is described below:" | |||
TVA Response TVA has revised page E2-20 as suggested and has included the revised page with the TS markups in Enclosure 2. | |||
NRC Question 7 Paragraph (c) of proposed TS 6.8.4.k.c.1 (page E2-20) refers to "Note 2." Since this is now the only note following deletion of the original Note 1, changing the name of the original Note 2 to Note 1 may avoid potential confusion. In addition, since there is no flow distribution baffle at SQN2, Note 2 could be shortened to one sentence. /The staff notes that it may improve readability to eliminate Note 2 as a separate item and instead include the relevant information within parentheses in TS 6.8.4.k.c.l.c. For example: | |||
"SG tubes, with indications of potential flaws attributed to ODSCC within the bounds of the TSP with a bobbin voltage greater than 2.0 volts but less than or equal to the upper voltage repair limit (calculated according to the methodology in GL 95-05 as supplemented) may remain ..... | |||
TVA Response TVA has revised page E2-20 to eliminate Note 2 and add the text from Note 2 into the SG program requirements as suggested and has included the revised page with the TS markups in Enclosure 2. | |||
NRC Question 8 In order to be consistent with the TSTF-449 wording used elsewhere in your proposal, please discuss your plans to replace the term "degradation" with "flaws" in your proposed TS in 6.8.4.k.c.2 (W* | |||
Methodology). | |||
E1-3 | |||
TVA Response TVA has revised TS 6.8.4.k.c.2 to replace the term "degradation" with "flaws" as suggested and has included the revised page with the TS markups in Enclosure 2. | |||
NRC Question 9 Paragraph (c) of proposed TS 6.8.4.k.c.1 (page E2-20) addresses two different conditions of bobbin coil voltage for ODSCC flaw indications. The staff notes that it may improve the clarity of the repair criteria to start a new paragraph (i.e., 6.8.4.k.c.l.d) for the case where bobbin indication voltage is greater than the upper voltage limit, since the second sentence of this paragraph is not an exception as discussed in Item b. For example: | |||
d) SG tubes with indications of ODSCC flaws with a bobbin coil voltage greater than the upper voltage repair limit (calculated according to the methodology in GL 95-05 as supplemented) will be plugged. | |||
e) If an unscheduled mid-cycle inspection is performed, the following repair limits apply instead of the limits | |||
-identified in Items 6.8.k.c.l.a), .b), .c), and .d). | |||
As a result of this change, references to these specifications on page E2-20 and E2-21 will also need to be modified. For example, Implementation of these mid-,cycle repair limits should follow the same approach as in TS items 6.8.k.c.l.a), .b), .c), and | |||
.d). | |||
TVA Response TVA has revised page E2-20 and E2-21 to include a new item d as suggested, and has included the revised page with the TS markups in . | |||
NRC Question 10 In proposed TS 6.8.4.k.c.2, the W* methodology, the staff notes that the initial statement about inspecting 100 percent of the tubes is an inspection criteria rather than a repair criteria. Please discuss your plans to move the inspection discussion to TS 6.8.4.k.d (Provisions for SG Tube Inspections.) For example, consider adding a TS 6.8.4.k.d.5: | |||
: 5. When the W* methodology has been implemented, inspect 100 percent of the inservice tubes in the hot-leg tubesheet region with the objective of detecting flaws that may satisfy the applicable tube repair criteria of TS 6.8.4.k.c.2. | : 5. When the W* methodology has been implemented, inspect 100 percent of the inservice tubes in the hot-leg tubesheet region with the objective of detecting flaws that may satisfy the applicable tube repair criteria of TS 6.8.4.k.c.2. | ||
In addition, since this section of the TS is a repair criteria, and since TS 6.8.4.d) defines the part of the tube requiring inspection (from the tube-to-tubesheet weld at the tube inlet to the tube-to-E1-4 tubesheet weld at the tube outlet, and that may. satisfy the applicable tube repair criteria), the proposed insert on page E2-21 is unnecessary | In addition, since this section of the TS is a repair criteria, and since TS 6.8.4.d) defines the part of the tube requiring inspection (from the tube-to-tubesheet weld at the tube inlet to the tube-to-E1-4 | ||
("The inspection of SG tubes isfrom the point of entry Finally, TS 6.8.4.k.c.2 should have a statement that, "Flaws located below the W* distance may remain in service regardless of size." TVA Response TVA has revised TS 6.8.4.k.c.2, 6.8.4.k.d, and added TS 6.8.4.k.d.5 as suggested and has included the revised page with the TS markups in | |||
Indications left in service as a result of application of the TSP voltage-based repair criteria shall be inspected by bobbin coil probe during all future refueling outages.The staff notes that a requirement of every 24 effective full-power months or one refueling outage, whichever is less, would provide the intended minimum inspection frequency, without requiring an additional inspection in the event that SG tubes are inspected during an outage other than a refueling outage. Please discuss any plans you have to change the wording in this requirement and reference the TS section for the repair criteria, for example: Indications left in service as a result of application of the TSP voltage-based repair criteria (6.8.4.k.c.1) shall be inspected by bobbin coil probe every 24 effective full-power months or one refueling outage, whichever is less.E1-5 TVA Response TVA has revised page E2-22 to include "every 24 effective full-power months or one refueling outage, whichever is less," as suggested, and has included the revised page with the TS markups in Enclosure 2.NRC Question 13 In the proposed reporting requirement TS 6.9.1.16 .2, the wording of the first sentence is somewhat awkward and the second sentence contains a typographical error ("'shil"). | tubesheet weld at the tube outlet, and that may. satisfy the applicable tube repair criteria), the proposed insert on page E2-21 is unnecessary ("The inspection of SG tubes isfrom the point of entry Finally, TS 6.8.4.k.c.2 should have a statement that, "Flaws located below the W* distance may remain in service regardless of size." | ||
A suggestion for alternative wording is provided below.A report shall be submitted within 90 days ... performed in accordance with the steam generator program (6.8.4.k) amad when voltage based alternate repair criteria "e have bbeen applied. The report shall include..Please discuss your plans to modify this paragraph using the wording suggested above or comparable wording.TVA Response*TVA has revised TS 6.9.1.16.2 to include the alternative wording as suggested, and has included the revised page with the TS markups in Enclosure 2.NRC Question 14 Proposed TS 6.9.1..16 has been revised, with a separate section for each of the required reports. The content of these sections is generally acceptable; however, the wording about returning the steam generators to service following a tube inspection is different for each of the sections. | TVA Response TVA has revised TS 6.8.4.k.c.2, 6.8.4.k.d, and added TS 6.8.4.k.d.5 as suggested and has included the revised page with the TS markups in . | ||
For example, in 6.9.1.16.3 and 6.9.1.16.4, the phrase, "following completion of an inspection performed in accordance with the steam generator program (6.8.4 .k)" (or a comparable phrase), was not included. | NRC Question 11 Proposed TS 6.8.4.c.2 on page E2-21 uses the term "W* distance" before defining it. Please discuss your plans to move the terms/definitions to the beginning of the W* methodology section. In addition, since the W* length is not part of the specifications, please discuss the reason for including it in the TS definitions, or discuss your plans for removing it from the TS. | ||
Please discuss your plans to make this wording consistent throughout the reporting requirements section and consistent with the TSTF-449 wording, such as the wording used in proposed TS 6.9.1.16.1 below.....after the initial entry into MODE 4 following completion of an inspection performed in accordance with Specification 6.8.4.k, ""Steam Generator (SG) Program.". | TVA Response TVA has revised page E2-21 to remove the W* length and relocate the terms/definitions to the beginning as suggested, and has included the revised page with the TS markups in Enclosure 2. | ||
TVA Response TVA has revised TS 6.9.1.16 to include consistent wording throughout the reporting requirement section as suggested, and has included the revised page with the TS markups in Enclosure 2., E1-6 NRC Question 15 On page E3-6 of the proposed bases, there is a statement that "this limit is approved for use for alternate repair criteria (ARC) and W*leakage calculations." This statement appears incomplete. | NRC Question 12 Proposed TS 6.8.4.d.4, the SG tube inspection provision related to the GL 95-05 alternate repair criteria (page E2-22) states the following in the first paragraph: | ||
The leakage from all sources must be limited to 3.7 gpm in the faulted SG with no more than 1.0 gpm coming from non-alternate repair criteria.A similar comment applies to the statements on page E3-8.TVA Response TVA has revised page E3-6 and E3-8 to address leakage from non-alternate repair criteria as suggested, and has included the revised page with the TS markups in Enclosure 3.NRC Question 16 ,The staff notes that on proposed bases page B 3/4 4-3c, page E3-8 in the submittal, the current wording ("0.1 gpm for the non-faulted SGs")could be misinterpreted to mean 0.1 gpm total in the three non-faulted SGs. Please discuss your plans to clarify the wording to indicate"0.1 gpm for each of the non-faulted SGs." TVA Response TVA has revised page E3-8 to include "each of" as suggested, and has included the revised page with the TS markups in Enclosure 3.NRC Question 17 On page E3-9 you indicate that "If at any time, evaluation determines SG tube integrity is not being maintained, ..." The reason for adding the underlined text is not clear. Please discuss your plans for removing this text-(and making your submittal consistent with TSTF-449).TVA Response The phrase "if at any time, evaluation determines SG tube integrity is not being maintained," was added to SQN's TS Bases to provide clarification of TVA's proposed action requirement (a) which states: "With one more SG tubes satisfying the tube repair criteria and not plugged in accordance with the Steam Generator Program, within 7 days verify tube integrity of the affected tube(s) is maintained until the next refueling outage or SG tube inspection, or be in Hot STANDBY within 6 hours and in COLD SHUTDOWN within the next 30 hours." This phrase was in response to RAI question 2 from your June 6, 2006 RAI. The RAI expressed concern that.Condition B of TSTF-449 would not be met in TVA's proposed TS action (a), (i.e., specifically that unit shutdown may not occur if it is determined that SG tube integrity is not maintained). | Indications left in service as a result of application of the TSP voltage-based repair criteria shall be inspected by bobbin coil probe during all future refueling outages. | ||
E1-7 TVA's response to RAI question 2 dated August 7, 2006, stated that TVA was processing a revision to the Bases to ensure consistent application of this action when SG tube integrity cannot be maintained. | The staff notes that a requirement of every 24 effective full-power months or one refueling outage, whichever is less, would provide the intended minimum inspection frequency, without requiring an additional inspection in the event that SG tubes are inspected during an outage other than a refueling outage. Please discuss any plans you have to change the wording in this requirement and reference the TS section for the repair criteria, for example: | ||
Indications left in service as a result of application of the TSP voltage-based repair criteria (6.8.4.k.c.1) shall be inspected by bobbin coil probe every 24 effective full-power months or one refueling outage, whichever is less. | |||
E1-5 | |||
TVA Response TVA has revised page E2-22 to include "every 24 effective full-power months or one refueling outage, whichever is less," as suggested, and has included the revised page with the TS markups in Enclosure 2. | |||
NRC Question 13 In the proposed reporting requirement TS 6.9.1.16 .2, the wording of the first sentence is somewhat awkward and the second sentence contains a typographical error ("'shil"). A suggestion for alternative wording is provided below. | |||
A report shall be submitted within 90 days ...performed in accordance with the steam generator program (6.8.4.k) amad when voltage based alternate repair criteria "e have bbeen applied. The report shall include.. | |||
Please discuss your plans to modify this paragraph using the wording suggested above or comparable wording. | |||
TVA Response | |||
*TVA has revised TS 6.9.1.16.2 to include the alternative wording as suggested, and has included the revised page with the TS markups in Enclosure 2. | |||
NRC Question 14 Proposed TS 6.9.1..16 has been revised, with a separate section for each of the required reports. The content of these sections is generally acceptable; however, the wording about returning the steam generators to service following a tube inspection is different for each of the sections. For example, in 6.9.1.16.3 and 6.9.1.16.4, the phrase, "following completion of an inspection performed in accordance with the steam generator program (6.8.4 .k)" (or a comparable phrase), | |||
was not included. Please discuss your plans to make this wording consistent throughout the reporting requirements section and consistent with the TSTF-449 wording, such as the wording used in proposed TS 6.9.1.16.1 below. | |||
.... after the initial entry into MODE 4 following completion of an inspection performed in accordance with Specification 6.8.4.k, ""Steam Generator (SG) Program.". | |||
TVA Response TVA has revised TS 6.9.1.16 to include consistent wording throughout the reporting requirement section as suggested, and has included the revised page with the TS markups in Enclosure 2., | |||
E1-6 | |||
NRC Question 15 On page E3-6 of the proposed bases, there is a statement that "this limit is approved for use for alternate repair criteria (ARC) and W* | |||
leakage calculations." This statement appears incomplete. The leakage from all sources must be limited to 3.7 gpm in the faulted SG with no more than 1.0 gpm coming from non-alternate repair criteria. | |||
A similar comment applies to the statements on page E3-8. | |||
TVA Response TVA has revised page E3-6 and E3-8 to address leakage from non-alternate repair criteria as suggested, and has included the revised page with the TS markups in Enclosure 3. | |||
NRC Question 16 | |||
,The staff notes that on proposed bases page B 3/4 4-3c, page E3-8 in the submittal, the current wording ("0.1 gpm for the non-faulted SGs") | |||
could be misinterpreted to mean 0.1 gpm total in the three non-faulted SGs. Please discuss your plans to clarify the wording to indicate "0.1 gpm for each of the non-faulted SGs." | |||
TVA Response TVA has revised page E3-8 to include "each of" as suggested, and has included the revised page with the TS markups in Enclosure 3. | |||
NRC Question 17 On page E3-9 you indicate that "If at any time, evaluation determines SG tube integrity is not being maintained, ... " The reason for adding the underlined text is not clear. Please discuss your plans for removing this text-(and making your submittal consistent with TSTF-449). | |||
TVA Response The phrase "if at any time, evaluation determines SG tube integrity is not being maintained," was added to SQN's TS Bases to provide clarification of TVA's proposed action requirement (a) which states: | |||
"With one more SG tubes satisfying the tube repair criteria and not plugged in accordance with the Steam Generator Program, within 7 days verify tube integrity of the affected tube(s) is maintained until the next refueling outage or SG tube inspection, or be in Hot STANDBY within 6 hours and in COLD SHUTDOWN within the next 30 hours." | |||
This phrase was in response to RAI question 2 from your June 6, 2006 RAI. The RAI expressed concern that.Condition B of TSTF-449 would not be met in TVA's proposed TS action (a), (i.e., specifically that unit shutdown may not occur if it is determined that SG tube integrity is not maintained). | |||
E1-7 | |||
TVA's response to RAI question 2 dated August 7, 2006, stated that TVA was processing a revision to the Bases to ensure consistent application of this action when SG tube integrity cannot be maintained. | |||
Accordingly, TVA's proposed revision to the Bases to include the underlined phrase "if at any time, evaluation determines SG tube integrity is not being maintained," ensures that unit shutdown occurs immediately upon determining SG tube integrity is not maintained. | Accordingly, TVA's proposed revision to the Bases to include the underlined phrase "if at any time, evaluation determines SG tube integrity is not being maintained," ensures that unit shutdown occurs immediately upon determining SG tube integrity is not maintained. | ||
This is a conservative measure with respect to requiring unit shutdown"at any time" during the 7 day period in action (a) that provides for verification of SG tube integrity. | This is a conservative measure with respect to requiring unit shutdown "at any time" during the 7 day period in action (a) that provides for verification of SG tube integrity. | ||
It should be noted that during a telephone conference between NRC and TVA on October, 31, 2006, NRC requested that TVA clarify the intent of the Bases to ensure any evaluation of SG tube integrity for unit shutdown would apply to all SG tubes (those SG tubes that are plugged and those not plugged). | It should be noted that during a telephone conference between NRC and TVA on October, 31, 2006, NRC requested that TVA clarify the intent of the Bases to ensure any evaluation of SG tube integrity for unit shutdown would apply to all SG tubes (those SG tubes that are plugged and those not plugged). TVA has included a proposed revision to Bases page E3-9 in Enclosure 3 to clarify this intent. | ||
TVA has included a proposed revision to Bases page E3-9 in Enclosure 3 to clarify this intent.NRC Question 18 The proposed Insert E for the Bases (page E3-12) refers to the "mid-cycle equation of TS 6.8.4.k.c.I.c." The staff notes this equation is currently in 6.8.4.k.c.1.d in the proposed TS (page E2-20). As indicated in #9 above, it may be appropriate to make it 6.8.4.k.c.l.e. | NRC Question 18 The proposed Insert E for the Bases (page E3-12) refers to the "mid-cycle equation of TS 6.8.4.k.c.I.c." The staff notes this equation is currently in 6.8.4.k.c.1.d in the proposed TS (page E2-20). As indicated in #9 above, it may be appropriate to make it 6.8.4.k.c.l.e. | ||
TVA Response The reference to the mid-cycle equation of TS 6.8.4.k.c.1.c is an improper reference. | TVA Response The reference to the mid-cycle equation of TS 6.8.4.k.c.1.c is an improper reference. TVA has included a corrected page E3-12 in that revises the TS reference from TS "6.8.4.k.c.1.c" to TS "6.8.4.k.c.l.e" NRC Question 19 The paragraph that starts near the bottom of page E3-12 and begins with, "Wastage-type defects ... " was essentially replaced with TSTF-449. Please discuss your plans to remove this paragraph. | ||
TVA has included a corrected page E3-12 in | TVA Response TVA has revised page E3-12 to remove the sentence addressing wastage-type defects as suggested, and has included the revised page with the TS markups in Enclosure 3. | ||
TVA Response TVA has revised page E3-12 to remove the sentence addressing wastage-type defects as suggested, and has included the revised page with the TS markups in Enclosure 3.NRC Question 20 On page E3-13 there is an equation for calculating postulated steam line break leakage. It appears that this equation is incomplete, since it does not include the leakage from non-alternate repair criteria sources. Please discuss your plans to modify this equation to add "leakage from other sources" or to indicate that this equation only includes leakage from the alternate repair criteria.E1-8 TVA Response TVA has revised page E3-13 to clarify application of the equation to accident induced alternate repair criteria leakage. TVA has included the revised page with the TS markups in Enclosure 3.NRC Question 21 Please discuss your plans to remove the first sentence in the last paragraph on page E3-14, since reporting the aggregate calculated steam line break leakage is no longer a requirement. | NRC Question 20 On page E3-13 there is an equation for calculating postulated steam line break leakage. It appears that this equation is incomplete, since it does not include the leakage from non-alternate repair criteria sources. Please discuss your plans to modify this equation to add "leakage from other sources" or to indicate that this equation only includes leakage from the alternate repair criteria. | ||
E1-8 | |||
TVA Response TVA has revised page E3-13 to clarify application of the equation to accident induced alternate repair criteria leakage. TVA has included the revised page with the TS markups in Enclosure 3. | |||
NRC Question 21 Please discuss your plans to remove the first sentence in the last paragraph on page E3-14, since reporting the aggregate calculated steam line break leakage is no longer a requirement. | |||
TVA Response SQN TS includes W* reporting requirements as an aggregate calculation. | TVA Response SQN TS includes W* reporting requirements as an aggregate calculation. | ||
Accordingly, TVA is retaining the bases description for aggregate reporting on E3-13.NRC Question 22 On page E3-16, you indicated that the safety analysis for events resulting in steam discharge to the atmosphere accounts for a maximum normal operational leakage of 0.4 gpm. This wording is not consistent with TSTF-449.- | Accordingly, TVA is retaining the bases description for aggregate reporting on E3-13. | ||
Please clarify whether the safety analysis actually accounts for 0.4 gpm normal operating leakage (i.e., the safety analysis accounts for the equivalent accident-induced leakage from a 0.4 gpm normal operating leak which would be something greater than 0.4 gpm) or whether the analysis simply assumes that there is 0.4 gpm or increases to 0.4 gpm as a result of accident-induced conditions. | NRC Question 22 On page E3-16, you indicated that the safety analysis for events resulting in steam discharge to the atmosphere accounts for a maximum normal operational leakage of 0.4 gpm. This wording is not consistent with TSTF-449.- Please clarify whether the safety analysis actually accounts for 0.4 gpm normal operating leakage (i.e., the safety analysis accounts for the equivalent accident-induced leakage from a 0.4 gpm normal operating leak which would be something greater than 0.4 gpm) or whether the analysis simply assumes that there is 0.4 gpm or increases to 0.4 gpm as a result of accident-induced conditions. | ||
If the analysis accounts for 0.4 gpm operating leakage, please discuss the technical basis for determining the equivalent accident induced leak rate from the normal operating leak rate. In addition, please clarify whether your accident analysis assumes 1 gpm leakage from all steam generators or 0.4 gpm.TVA Response TVA has revised page E3-16 to clarify the accident analysis assumption as suggested and has included the revised page with the TS markups in | If the analysis accounts for 0.4 gpm operating leakage, please discuss the technical basis for determining the equivalent accident induced leak rate from the normal operating leak rate. In addition, please clarify whether your accident analysis assumes 1 gpm leakage from all steam generators or 0.4 gpm. | ||
(7) Low Temperature Overpressure Protection (Section 5.2.2)Prior to startup after the first refueling, TVA shall install an overpressure mitigation system which meets NRC requirements. | TVA Response TVA has revised page E3-16 to clarify the accident analysis assumption as suggested and has included the revised page with the TS markups in . | ||
(8) Steam Generator Inspection (Section 5.3.1)(a) Prior to start-up after the first refueling, TVA shall install inspection ports in each steam generator or have an alternative for inspection that is acceptable to the NRC.(b) By May , Ashall establish a steam genlerat onprogram that is in accordance wi it in Enclosure 2 to the TVA letter to the Commi | NRC Question 23 Please discuss your plans to indicate in the Applicable Safety Analyses for B3/4.4.6.2 (Operational Leakage), on page E3-17, that the "primary to secondary leakage safety analysis assumption is relatively inconsequential." The staff notes that this is consistent with TSTF-449. | ||
* s subject a 12, 1997, as modified by W ~e March 17, 1997.(9) Containment Isolation Systems (Section 6.2.4)Prior to startup after the first refueling, TVA shall modify to the satisfaction of the NRC the one-inch chemical feed lines to the main and auxiliary feedwater lines for compliance with GDC 57.(10) Environmental Qualification (Section 7.2.2)a. No later than June 30, 1982, TVA shall be in compliance with the requirements of NUREG-0588, "Interim Staff Position on Environmental Qualification of Safety-Related Electrical Equipment," for safety-related equipment exposed to a harsh environment. | TVA Response . | ||
April 9, 1997 Amendment No. 2, 213 E2-2 DEFINITIONS IDENTIFIED LEAKAGE 1.16 IDENTIFIED LEAKAGE shall be: a. Leakage, such as that from pump seals or valve packing (except reactor coolant pump seal injection or leakoff) that is captured and conducted to collection systems or a sump or collecting tank, or b. Leakage into the containment atmosphere from sources that are both specifically located and known either not to interfere with the operation of leakage detection systems or not to be PRESSURE BOUNDARY LEAKAGE, or c. Reactor coolant system leakage through a steam generator to the secondary system. | TVA has revised page E3-17 to add "safety analysis assumption" as suggested and has included the revised page with the TS markups in . | ||
OF THE PUBLIC /" | EI-9 | ||
OF THE PUBLIC.. ..(primary to secondary leakage)1.17 DELETED I OFFSITE DOSE CALCULATION MANUAL 1.18 The OFFSITE DOSE CALCULATION MANUAL (ODCM) shall contain the methodology and parameters used in the calculation of offsite doses resulting from radioactive gaseous and liquid effluents, in the calculation of gaseous and liquid effluent monitoring alarm/trip setpoints, and in the conduct of the Radiological Environmental Monitoring Program. The ODCM shall also contain (1) the Radioactive Effluent Controls and Radiological Environmental Monitoring Programs required by Section 6.8.4 and (2)descriptions of the information that should be included in the Annual Radiological Environmental Operating and Annual Radioactive Effluent Release Reports required by Specifications 6.9.1.6 and 6.9.1.8.OPERABLE -OPERABILITY 1.19 A system, subsystem, train, or component or device shall be OPERABLE or have OPERABILITY when it is capable of performing its specified function(s), and when all necessary attendant instrumentation, controls, a normal and an emergency electrical power source, cooling or seal water, lubrication or other auxiliary equipment that are required for the system, subsystem, train, component or device to perform its function(s) are also capable of performing their related support function(s). | |||
SEQUOYAH -UNIT 2 1-4 | ENCLOSURE 2 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN) | ||
__pimaysteseondary PRESSURE BOUNDARY LEAKAGE 1.22 PRESSURE BOUNDARY LEAKAGE shall be leakage (except ti..m age.... n | UNIT 2 New TS Page Markups for TS Change 05-09 E2-1 | ||
QUADRANT POWER TILT RATIO 1.26 QUADRANT POWER TILT RATIO shall be the ratio of the maximum upper excore detector calibrated output to the average of the upper excore detector calibrated outputs, or the ratio of the maximum lower excore detector calibrated output to the average'of the lower excore detector calibrated outputs, which-ever is greater.September 15, 2004 SEQUOYAH -UNIT 2 1-5 Amendment No. 63, 134, 146, 191, 223, 284 E2-4 Remove Pages 3/4 4-10 through -16 and replace with INSERT A.REACTOR COOLANT SYSTEM 3 4.5 STEAM GENERATORS LIMII CONDITION FOR OPERATION 3.4.5 Each ar generator shall be OPERABLE.APPLICABILI | : d. Failure to complete any tests included in thd described program (planned or scheduled) for power levels up to the authorized power level. | ||
.MODES 1, 2, 3 and 4.ACTION: With one or more steam enerators inoperable, restore the inoperable generator(s) t OPERABLE status prior to increasing Ta.g abo e 200°F.SURVEILLANCE REQUIREME S 4.4.5.0 Each steam generator shall demonstrated OPERABLE by ormance of the following augmented inservice inspection progra and the requirements of Spe fication 4.0.5.4.4.5.1 Steam Generator Sample Selectio and Inspection | (4) Monitoring Settlement Markers (SER/SSER Section 2.6.3) | ||
-Eac team generator shall be determined OPERABLE during shutdown by selecting an inspecting at lea the minimum number of steam generators specified in Table 4.4-1.4.4.5.2 Steam Generator Tube Sample Selection d Ins ction -The steam generator tube minimum sample size, inspection result classification, and the spnding action required shall be as specified in Table 4.4-2. The inservice inspection of steam gener r tubes shall be performed at the frequencies specified in Specification 4.4.5.3 and the inspected s hall be verified acceptable per the acceptance criteria of Specification 4.4.5.4. The tubes selecte for ac inservice inspection shall include at least 3%of the total number of tubes in all steam generat r; the tube lected for these inspections shall be selected on a random basis except: a. Where experience in similar ants with similar water emistry indicates critical areas to be inspected, then at least 50 0 of the tubes inspected sha be from these critical areas.b. The first sample of tu selected for each inservice inspec -tn (subsequent to the preservice inspectio of each steam generator shall include: QUOYAH -UNIT 2 3/4 4-10 E2-5 | TVA shall continue to monitor the settlement markers along the ERCW conduit for the new ERCW intake structure for a period not less than three years from the date of this license. Any settlement greater than 0.5 inches that occurs during this period will be evaluated by TVA and a report on this matter will be submitted to the NRC. | ||
,IILNC EUIEET (Continued)- | (5) Tornado Missiles (Section 3.5) | ||
I 1.AIll nonplugged tubes that previously had detectable wall penetrations (greater than 20%)2. ubes in those areas where experience has indicated potential problems.3. | Prior to startup after the first refueling of the facility, TVA shall reconfirm to the satisfaction of the NRC that adequate tornado protection is provided for the 480 V transformer ventilation systems. | ||
: 4. Indications | (6) Design of Seismic Cate-ory Structures (Section 3.8) | ||
The determination of the lowest cold-leg tu support p1 intersections having ODSCC indications shall be based on the performance of at ast a 20 percen andom sampling of tubes inspected over their full length.e Implementation of the steam gener tor WEXTEX expanded regi inspection methodology (W*)requires a 100 percent rotating probe inspection of the hot leg besheet W* distance.The results of each sample in ction shall be classified into one of the follo three categories: | Prior to startup following the first refueling, TVA shall evaluate all seismic Category I masonry walls to final NRC criteria and implement NRC required modifications that are indicated by that evaluation. | ||
Category Insoection Results C-1 Less than 5% of the total tubes inspected are degr ed tubes and none of the inspected tubes are defective. | (7) Low Temperature Overpressure Protection (Section 5.2.2) | ||
Prior to startup after the first refueling, TVA shall install an overpressure mitigation system which meets NRC requirements. | |||
* 3/44-11 Amendment No. 181, 211, 213, 243, E2-6 RECO OLANT SYSTEM S RVELLANC REQUIREMENTS (Continued) | (8) Steam Generator Inspection (Section 5.3.1) | ||
C-2 One or more tubes, but not more than I% of the total tubes ins e are d&fetive, or between 5% and 106/ of the total tubes ins e are degraded tubes.More than 10% of the total tubes inspected are degrad ubes or more than 1% of the inspected tubes are defective. | (a) Prior to start-up after the first refueling, TVA shall install inspection ports in each steam generator or have an alternative for inspection that is acceptable to the NRC. | ||
N In all inspections, previously degraded tubes must exhibi ignificant (greater than 10%) further wall penetrations to be included in th above percentage calculations. | (b) By May , Ashall establish a steam genlerat onprogram that is in accordance wi it in Enclosure 2 to the TVA letter to the Commi | ||
April 3, 1996 3/4 4-11a Amendment No. 181, 11 E2-7 | * s subject a 12, 1997, as modified by W ~e March 17, 1997. | ||
\REACTOR COOLANT SYSTEM /SUVILLANCE REQUIREMENTS (Continued) 4.4.5.3 | (9) Containment Isolation Systems (Section 6.2.4) | ||
-The above required inservice inspections of steam generator ttuu shall be performS at the following frequencies:/ | Prior to startup after the first refueling, TVA shall modify to the satisfaction of the NRC the one-inch chemical feed lines to the main and auxiliary feedwater lines for compliance with GDC 57. | ||
(10) Environmental Qualification (Section 7.2.2) | |||
Subsequent inservice inspections shall rformed at intervals o not less than 12 nor more than 24 calendar months after the previo inspection. | : a. No later than June 30, 1982, TVA shall be in compliance with the requirements of NUREG-0588, "Interim Staff Position on Environmental Qualification of Safety-Related Electrical Equipment," for safety-related equipment exposed to a harsh environment. | ||
April 9, 1997 Amendment No. 2, 213 E2-2 | |||
: 3. A loss-of-coolant accident req ng actuation the engineered safeguards. | |||
: 4. A main steam line or feed ter line break. | DEFINITIONS IDENTIFIED LEAKAGE 1.16 IDENTIFIED LEAKAGE shall be: | ||
: 1. Im rfection means an exception to the dimensions, finish or contour a tube from that uired by fabrication drawings or specifications. | : a. Leakage, such as that from pump seals or valve packing (except reactor coolant pump seal injection or leakoff) that is captured and conducted to collection systems or a sump or collecting tank, or | ||
Eddy-current testi g indications below 2 6 of the nominal tube wall thickness, if detectable, may be con ered as im ections.2. 0 rad ion means a service-induced cracking, wastage, we r or general corrosion occurring n either inside or outside of a tube.3. Dfraded Tu means a tube containing imperfections reater than or equal to 20% of the nominal wall thi ness caused by degradation. | : b. Leakage into the containment atmosphere from sources that are both specifically located and known either not to interfere with the operation of leakage detection systems or not to be PRESSURE BOUNDARY LEAKAGE, or | ||
: 4. % Deqradation me s the percentage of the tube al thickness affected or removed by degradation. | : c. Reactor coolant system leakage through a steam generator to the secondary system. | ||
: 5. Defect means an imperfe tion of such sever that it exceeds the plugging limit. A tube containing a defect is defe ve.6. Pluaaina Umit means the im ectio epth at or beyond which the tube shall be removed from service and is eq Iut 0% of the nominal tube wall thickness. | MEMBER(S*I OF THE PUBLIC /" | ||
Plugging limit does not apply to that portion the tube that is not within the pressure boundary of the reactor coolant system (tube n pto the strt of the tube-to-tubesheet weld). This definition does not apply to tu sup plate intersections if the voltage-based repair criteria are being applied. R er to 4.4. .a.10 for the repair limit applicable to these intersections. | OF THE PUBLIC.. .. | ||
This definiti does not app to service induced degradation identified in the W* distance. | (primary to secondary leakage) 1.17 DELETED I OFFSITE DOSE CALCULATION MANUAL 1.18 The OFFSITE DOSE CALCULATION MANUAL (ODCM) shall contain the methodology and parameters used in the calculation of offsite doses resulting from radioactive gaseous and liquid effluents, in the calculation of gaseous and liquid effluent monitoring alarm/trip setpoints, and in the conduct of the Radiological Environmental Monitoring Program. The ODCM shall also contain (1) the Radioactive Effluent Controls and Radiological Environmental Monitoring Programs required by Section 6.8.4 and (2) descriptions of the information that should be included in the Annual Radiological Environmental Operating and Annual Radioactive Effluent Release Reports required by Specifications 6.9.1.6 and 6.9.1.8. | ||
Servi nduced degradati n identified in the W* distance below the top-of-tube sheet (TTS), s I be plugged on deteo 7. Unserviceable des ies the condition of a tube i leaks or contains a defect large enough to affect i structural integrity in the event an Operating Basis Earthquake, a loss-of-coolant ccident, or a steam line or feedwater* | OPERABLE - OPERABILITY 1.19 A system, subsystem, train, or component or device shall be OPERABLE or have OPERABILITY when it is capable of performing its specified function(s), and when all necessary attendant instrumentation, controls, a normal and an emergency electrical power source, cooling or seal water, lubrication or other auxiliary equipment that are required for the system, subsystem, train, component or device to perform its function(s) are also capable of performing their related support function(s). | ||
e break as specified in 4.4.5.3.c, above.8. Tube Ins ction means an inspection of the steam generat tube from the point of entry (hot leg ide) completely around the U-bend to the top suppo of the cold leg exclu ing the portion of the tube within the tubesheet below th WN distance, the tube to tu eet weld and the tube end extension. | February 11, 2003 SEQUOYAH - UNIT 2 1-4 Amendment Nos. 63, 134, 146, 159, 165, 169, 250, 272 E2-3 | ||
: 9. reservice Inspection means an inspection of the full length of each be in each steam/generator performed by eddy current techniques prior to service to est lish a baseline condition of the tubing.. This inspection shall be performed prior to initial OWER OPERATION using the equipment and techniques expected to be used d ung subsequent i inservice inspections. | |||
May 3,2 5 EQUOYAH -UNIT 2 3/4 4-13 Amendment No. 181, 211, 213, 243,r 266, 2 E2-9 | DEFINITIONS OPERATIONAL MODE - MODE 1.20 An OPERATIONAL MODE (i.e., MODE) shall cdrrespond to any one inclusive combination of core reactivity condition, power level and average reactor coolant temperature specified in Table 1.1. | ||
\REACTOR COOLANT. SYTEM// | PHYSICS TESTS 1.21 PHYSICS TESTS shall be those tests performed to measure the fundamental nuclear characteristics of the reactor core and related instrumentation and 1) described in Chapter 14.0 of the FSAR, 2) authorized under the provisions of 10 CFR 50.59, or 3) otherwise approved by the Commission. | ||
: 10. Tube Support Plate Pluqqgingq Limit is used for the disposition of an alloy 600 steam generator tube for continued service that is experiencing predominately axially on ted outside diameter stress corrosion cracking confined within the thickness of the t support plates. At tube support plate intersections, the plugging (repair) limit is basedn aintaining steam generator tube serviceability as described below: a. Steam generator tubes, whose degradation is attributed to outsid iameter stress rrosion cracking within the bounds of the tube support plate ' bobbin voltages iSs than or equal to the lower voltage repair limit (Note 1), wil allowed to remain inrvIqce.b. Steam enerator tubes, whose degradation is attributed outside diameter stress corrosio cracking within the bounds of the tube sup plate with a bobbin voltage greater th the lower voltage repair limit (Note 1), be repaired or plugged, except as n ed in 4.4.5.4.a.10.c below.c. Steam generat tubes, with indications of pote ial degradation attributed to outside diameter stress rosion-cracking within the ounds of the tube support plate with a bobbin voltage gre er than the lower volta repair limit (Note 1), but less than or equal to upper voltag repair limit (Note 2Y, may remain in service | __pimaysteseondary PRESSURE BOUNDARY LEAKAGE 1.22 PRESSURE BOUNDARY LEAKAGE shall be leakage (except ti..m age.... n tub, leakage) | ||
Steam generator tubes, with indications of outside dia eter stress rrosion-cracking degradation with a bobbin coil voltage greater than th upper v tage repair limit (Note 2) will be plugged or repaired.d. Not applicable to SQN.e. If an unscheduled mid-cy inspecti n is performed, the following mid-cycle repair limits apply instead of th imits identi i d in 4.4.5.4.a.10.a, 4.4.5.4.a.10.b, and 4.4.5.4.a.10.c. | -rator through a non-isolable fault in a Reactor Coolant System component body, pipe wall or vessel wall. | ||
The mid-cycle repair limits are determi from the following eq tions: VSL VUL1.0 + NDE + Gr (CL -At)= V~-(v~-v~)(CL -At)April 9, 997 QUOYAH -UNIT 2 3/4 4-14 Amendment No. 28, 211, 3 E2-10 VURL upper voltage repair limit VLRL -lower voltage repair limit VMURL mid-cycle upper voltage repair limit based on time into cycle VMLRL = mid-cycle lower voltage repair limit based on VMURL and ti into cycle At = ngth of time since last scheduled inspection during ich VURL and VLRL were ilemented CL = cycle ngth (the time between two scheduled st m generator inspections) | PRESSURE AND TEMPERATURE LIMITS REPORT (PTLR) 1.23 The PTLR is the unit specific document that provides the reactor vessel pressure and temperature limits, including heatup and cooldown rates and the LTOP arming temperature, for the current reactor vessel fluence period. These pressure and temperature limits shall be determined for each fluence period in accordance with Specification 6.9.1.15. | ||
VSL = structura mitvoltage Gr = average g rate per cycle length NDE = 95-percent cumu tive probability all ance for nondestructive examination uncertainty (i.e., a lue of 20-per t has been approved by NRC)Implementation of these mid-cycle repair limits s uld foil the same approach as in TS 4.4.5.4.a.10.a, 4.4.5.4.a.10.b, and 4.4.5.4.a.10.c. | PROCESS CONTROL PROGRAM (PCP) 1.24 DELETED PURGE - PURGING 1.25 PURGE or PURGING is the controlled process of discharging air or gas from a confinement to maintain temperature, pressure, humidity, concentration or other operating condition, in such a manner that replacement air or gas is required to purify the confinement. | ||
Note 1: The lower voltage repair limit is 1.0 vol 3/4-inch diameter tubing or 2.0 volts for 7/8-inch diameter tubing.Note 2: The upper voltage repair limit is Iculated a rding to the methodology in GL 95-05 as supplemented. | QUADRANT POWER TILT RATIO 1.26 QUADRANT POWER TILT RATIO shall be the ratio of the maximum upper excore detector calibrated output to the average of the upper excore detector calibrated outputs, or the ratio of the maximum lower excore detector calibrated output to the average'of the lower excore detector calibrated outputs, which-ever is greater. | ||
VURL may differ t the TSPs and ow distribution baffle.11. a) Bottom of WEXTEX ransition (BWT) is the h hest point of contact between the tube and tubesh at, or below the top-of-tube eet, as determined by eddy current testing.b) The W* dist ce is the larger of the following two dis nces as measured from the top-of-the-sheet (TTS): (a) 8 inches below the TT or (b) 7 inches below the bottom he WEXTEX transition plus the uncertainty as iated with determining the dis nce below the bottom of the WEXTEX transition a defined by WC -14797, Revision 2.c) Length is the length of tubing below the bottom of the W transition WT), which must be demonstrated to be non-degraded in order r the tube to maintain structural and leakage integrity. | September 15, 2004 SEQUOYAH - UNIT 2 1-5 Amendment No. 63, 134, 146, 191, 223, 284 E2-4 | ||
For the hot leg, the W* len th is 7.0 inches which represents the most conservative hot-leg length defined in WC -14797, Revision 2.b. The steam generator shall be determined OPERABLE after completing the corres nding actions (plug all tubes exceeding the plugging limit and all tubes containing through- ll cracks) required by Table 4.4-2.May 3,2 5 QUOYAH -UNIT 2 3/4 4-14a Amendment No. 28, 211, 213, 243, 2 E2-11 | |||
\R EACTOR COOLANT SYSTEM S EILNEREQUIREMENTS (Continued) 4.45.5 Rep.orts a. Following each inservice inspection of steam generator tubes, the number of tub pluged each steam generator shall be reported to the Commission within 15 days.b. Th mplete results of the steam generator tube inservice inspection shall e submitted to the mmission in a Special Report pursuant to Specification | Remove Pages 3/4 4-10 through -16 and replace with INSERT A. | ||
REACTOR COOLANT SYSTEM 3 4.5 STEAM GENERATORS LIMII CONDITION FOR OPERATION 3.4.5 Each ar generator shall be OPERABLE. | |||
APPLICABILI . MODES 1, 2, 3 and 4. | |||
ACTION: | |||
With one or more steam enerators inoperable, restore the inoperable generator(s) t OPERABLE status prior to increasing Ta.g abo e 200°F. | |||
SURVEILLANCE REQUIREME S 4.4.5.0 Each steam generator shall demonstrated OPERABLE by ormance of the following augmented inservice inspection progra and the requirements of Spe fication 4.0.5. | |||
4.4.5.1 Steam Generator Sample Selectio and Inspection - Eac team generator shall be determined OPERABLE during shutdown by selecting an inspecting at lea the minimum number of steam generators specified in Table 4.4-1. | |||
4.4.5.2 Steam Generator Tube Sample Selection d Ins ction - The steam generator tube minimum sample size, inspection result classification, and the spnding action required shall be as specified in Table 4.4-2. The inservice inspection of steam gener r tubes shall be performed at the frequencies specified in Specification 4.4.5.3 and the inspected s hall be verified acceptable per the acceptance criteria of Specification 4.4.5.4. The tubes selecte for ac inservice inspection shall include at least 3% | |||
of the total number of tubes in all steam generat r; the tube lected for these inspections shall be selected on a random basis except: | |||
: a. Where experience in similar ants with similar water emistry indicates critical areas to be inspected, then at least 50 0 of the tubes inspected sha be from these critical areas. | |||
: b. The first sample of tu selected for each inservice inspec -tn (subsequent to the preservice inspectio of each steam generator shall include: | |||
QUOYAH - UNIT 2 3/4 4-10 E2-5 | |||
,IILNC EUIEET (Continued)- | |||
I 1.AIll nonplugged tubes that previously had detectable wall penetrations (greater than 20%) | |||
: 2. ubes in those areas where experience has indicated potential problems. | |||
: 3. At inspection (pursuant to Specification 4.4.5.4.a.8) shall be performed on eac elected tube. any selected tube does not permit the passage of the eddy current probe r a tube inspecti , this shall be recorded and an adjacent tube shall be selected and s jected to a tube inspection. | |||
: 4. Indications service as a result of application of the tube support pla voltage-based repair olen criteria shall be spected by bobbin coil probe during all future refuelin outages. | |||
: c. The tubes selected as the econd and third samples (if required by Table .4-2) during each inservice inspection may be subject o a partial tube inspection provided: | |||
: 1. The tubes selected for the samples include the tubes from ose areas of the tube sheet array where tubes with imperfecti s were previously found./ | |||
: 2. The inspections include those ions of the tubes wh e imperfections were previously found. | |||
Note: Tube degradation identified in t portion of th ube that is not a reactor coolant pressure boundary (tube end up to.the starf the tu to-tubesheet weld) is excluded from the Result and Action Required in Table 4.4-d Implementation of the steam generator tube/tube port plate repair criteria requires a 100 percent bobbin coil inspection for hot-leg and cold-leg t s port plate intersections down to the lowest cold-leg tube support plate with known outside di eter str s corrosion cracking (ODSCC) indications. | |||
The determination of the lowest cold-leg tu support p1 intersections having ODSCC indications shall be based on the performance of at ast a 20 percen andom sampling of tubes inspected over their full length. | |||
e Implementation of the steam gener tor WEXTEX expanded regi inspection methodology (W*) | |||
requires a 100 percent rotating probe inspection of the hot leg besheet W* distance. | |||
The results of each sample in ction shall be classified into one of the follo three categories: | |||
Category Insoection Results C-1 Less than 5% of the total tubes inspected are degr ed tubes and none of the inspected tubes are defective. | |||
A - UiMay 3, 209 | |||
/ EEQUOYAH Unit 2 | |||
* 3/44-11 Amendment No. 181, 211, 213, 243, 291* | |||
E2-6 | |||
RECO OLANT SYSTEM | |||
* S RVELLANC REQUIREMENTS (Continued) | |||
C-2 One or more tubes, but not more than I% of the total tubes ins e are d&fetive, or between 5% and 106/ of the total tubes ins e are degraded tubes. | |||
More than 10% of the total tubes inspected are degrad ubes or more than 1% of the inspected tubes are defective. | |||
N In all inspections, previously degraded tubes must exhibi ignificant (greater than 10%) further wall penetrations to be included in th above percentage calculations. | |||
April 3, 1996 3/4 4-11a Amendment No. 181, 11 E2-7 | |||
\REACTOR COOLANT SYSTEM / | |||
SUVILLANCE REQUIREMENTS (Continued) 4.4.5.3 Inaction Freuencies - The above required inservice inspections of steam generator ttuu shall be performS at the following frequencies:/ | |||
: a. The fi inservice inspection shall be performed after 6 Effective Full Power Month/ ut within 24 calen ar months of initial criticality. Subsequent inservice inspections shall rformed at intervals o not less than 12 nor otu, more than 24 calendar months after the previo inspection. | |||
;nerato If sthe a two consec 've inspections following service under AVT conditions, not inclu ng the preservice inspection, re It in all inspection results falling into the C-1 category or if consecutive inspections de nstrate that previously observed degradation has not co inued and no additional degrad ion has occurred, the inspection interval may be ext ded to a maximum of once per 40 months. | |||
g ~ ne s~ e ~mgenerator | |||
~aasteam c r t o cndoted in accordance with | |||
: b. in~ns cp~ c~i nofof If the results of the inse ice iinspection Table 4.4-2 at 40 month i ervals fall in Category C-3, the inspe ion frequency shall be increased to at least once r 20 months. The increase in ins ction frequency shall apply until the subsequent inspections s isfy the criteria of Speciflcati 4.4.5.3.a; the interval may then be extended to a maximum of on r 40 months. | |||
: c. Additional, unscheduled inservice i pections shall be rformed on each steam generator in accordance with the first sample inse tion specified Table 4.4-2 during the shutdown subsequent to any of the following con tions: | |||
: 1. Primary-to-secondary tubes leaks ( t i uding leaks originating from tube-to-tube sheet welds) in excess of the limits of Spe tion 3.4.6.2. | |||
: 2. A seismic occurrence greater than e Op rating Basis Earthquake. | |||
: 3. A loss-of-coolant accident req ng actuation the engineered safeguards. | |||
: 4. A main steam line or feed ter line break. | |||
SUOYAH - UNIT 2 3/4 4-12 E2-8 | |||
CTOR COOLANT SYSTEM SU ýEILLANCE REQUIREMENTS (Continued) 4.4.5.4 oce tance Criteria | |||
: a. Aused in this Specification: | |||
: 1. Im rfection means an exception to the dimensions, finish or contour a tube from that uired by fabrication drawings or specifications. Eddy-current testi g indications below 2 6 of the nominal tube wall thickness, if detectable, may be con ered as im ections. | |||
: 2. 0 rad ion means a service-induced cracking, wastage, we r or general corrosion occurring n either inside or outside of a tube. | |||
: 3. Dfraded Tu means a tube containing imperfections reater than or equal to 20% of the nominal wall thi ness caused by degradation. | |||
: 4. % Deqradation me s the percentage of the tube al thickness affected or removed by degradation. | |||
: 5. Defect means an imperfe tion of such sever that it exceeds the plugging limit. A tube containing a defect is defe ve. | |||
: 6. Pluaaina Umit means the im ectio epth at or beyond which the tube shall be removed from service and is eq Iut 0% of the nominal tube wall thickness. Plugging limit does not apply to that portion the tube that is not within the pressure boundary of the reactor coolant system (tube n pto the strt of the tube-to-tubesheet weld). This definition does not apply to tu sup plate intersections if the voltage-based repair criteria are being applied. R er to 4.4. .a.10 for the repair limit applicable to these intersections. This definiti does not app to service induced degradation identified in the W* distance. Servi nduced degradati n identified in the W* distance below the top-of-tube sheet (TTS), s I be plugged on deteo | |||
: 7. Unserviceable des ies the condition of a tube i leaks or contains a defect large enough to affect i structural integrity in the event an Operating Basis Earthquake, a loss-of-coolant ccident, or a steam line or feedwater* e break as specified in 4.4.5.3.c, above. | |||
: 8. Tube Ins ction means an inspection of the steam generat tube from the point of entry (hot leg ide) completely around the U-bend to the top suppo of the cold leg exclu ing the portion of the tube within the tubesheet below th WN distance, the tube to tu eet weld and the tube end extension. | |||
: 9. reservice Inspection means an inspection of the full length of each be in each steam | |||
/generator performed by eddy current techniques prior to service to est lish a baseline condition of the tubing.. This inspection shall be performed prior to initial OWER OPERATION using the equipment and techniques expected to be used d ung subsequent i inservice inspections. | |||
May 3,2 5 EQUOYAH - UNIT 2 3/4 4-13 Amendment No. 181, 211, 213, 243,r 266, 2 E2-9 | |||
\REACTOR COOLANT. | |||
SRVEILLANCE SYTEM// (Continued) | |||
REQUIREMENTS | |||
: 10. Tube Support Plate Pluqqgingq Limit is used for the disposition of an alloy 600 steam generator tube for continued service that is experiencing predominately axially on ted outside diameter stress corrosion cracking confined within the thickness of the t support plates. At tube support plate intersections, the plugging (repair) limit is basedn aintaining steam generator tube serviceability as described below: | |||
: a. Steam generator tubes, whose degradation is attributed to outsid iameter stress rrosion cracking within the bounds of the tube support plate ' bobbin voltages iSs than or equal to the lower voltage repair limit (Note 1), wil allowed to remain inrvIqce. | |||
: b. Steam enerator tubes, whose degradation is attributed outside diameter stress corrosio cracking within the bounds of the tube sup plate with a bobbin voltage greater th the lower voltage repair limit (Note 1), be repaired or plugged, except as n ed in 4.4.5.4.a.10.c below. | |||
: c. Steam generat tubes, with indications of pote ial degradation attributed to outside diameter stress rosion-cracking within the ounds of the tube support plate with a bobbin voltage gre er than the lower volta repair limit (Note 1), but less than or equal to upper voltag repair limit (Note 2Y, may remain in service ifa rotating pancake coil inspection oes not detect egradation. Steam generator tubes, with indications of outside dia eter stress rrosion-cracking degradation with a bobbin coil voltage greater than th upper v tage repair limit (Note 2) will be plugged or repaired. | |||
: d. Not applicable to SQN. | |||
: e. If an unscheduled mid-cy inspecti n is performed, the following mid-cycle repair limits apply instead of th imits identi i d in 4.4.5.4.a.10.a, 4.4.5.4.a.10.b, and 4.4.5.4.a.10.c. | |||
The mid-cycle repair limits are determi from the following eq tions: | |||
VSL VUL1.0 + NDE + Gr(CL -At) | |||
= V~-(v~-v~)(CL -At) | |||
April 9, 997 QUOYAH - UNIT 2 3/4 4-14 Amendment No. 28, 211, 3 E2-10 | |||
VURL upper voltage repair limit VLRL - lower voltage repair limit VMURL mid-cycle upper voltage repair limit based on time into cycle VMLRL = mid-cycle lower voltage repair limit based on VMURL and ti into cycle At = ngth of time since last scheduled inspection during ich VURL and VLRL were ilemented CL = cycle ngth (the time between two scheduled st m generator inspections) | |||
VSL = structura mitvoltage Gr = average g rate per cycle length NDE = 95-percent cumu tive probability all ance for nondestructive examination uncertainty (i.e., a lue of 20-per t has been approved by NRC) | |||
Implementation of these mid-cycle repair limits s uld foil the same approach as in TS 4.4.5.4.a.10.a, 4.4.5.4.a.10.b, and 4.4.5.4.a.10.c. | |||
Note 1: The lower voltage repair limit is 1.0 vol 3/4-inch diameter tubing or 2.0 volts for 7/8-inch diameter tubing. | |||
Note 2: The upper voltage repair limit is Iculated a rding to the methodology in GL 95-05 as supplemented. VURL may differ t the TSPs and ow distribution baffle. | |||
: 11. a) Bottom of WEXTEX ransition (BWT) is the h hest point of contact between the tube and tubesh at, or below the top-of-tube eet, as determined by eddy current testing. | |||
b) The W* dist ce is the larger of the following two dis nces as measured from the top-of-the- sheet (TTS): (a) 8 inches below the TT or (b) 7 inches below the bottom he WEXTEX transition plus the uncertainty as iated with determining the dis nce below the bottom of the WEXTEX transition a defined by WC -14797, Revision 2. | |||
c) Length is the length of tubing below the bottom of the W transition WT), which must be demonstrated to be non-degraded in order r the tube to maintain structural and leakage integrity. For the hot leg, the W* len th is 7.0 inches which represents the most conservative hot-leg length defined in WC -14797, Revision 2. | |||
: b. The steam generator shall be determined OPERABLE after completing the corres nding actions (plug all tubes exceeding the plugging limit and all tubes containing through- ll cracks) required by Table 4.4-2. | |||
May 3,2 5 QUOYAH - UNIT 2 3/4 4-14a Amendment No. 28, 211, 213, 243, 2 E2-11 | |||
\R EACTOR COOLANT SYSTEM S EILNEREQUIREMENTS (Continued) 4.45.5 Rep.orts | |||
: a. Following each inservice inspection of steam generator tubes, the number of tub pluged each steam generator shall be reported to the Commission within 15 days. | |||
: b. Th mplete results of the steam generator tube inservice inspection shall e submitted to the mmission in a Special Report pursuant to Specification 6.9.2 within 2 months followi the completion of the inspection. This Special Report shall in de: | |||
: 1. Num r and extent of tubes inspected. | |||
: 2. imperfectior d percent of wall-thickness penetration for eac Location ndication of an | |||
: 3. Identification o bes plugged. | |||
: c. Results of steam gene r tube inspections which fal nto Category C-3 shall be reported as a degraded condition pursint to 10 CFR 50.73 pri t resumption of plant operation. The written followup of this reporshall provide a descr tion of investigations conducted to determine cause of the tube radation and co ective measures taken to prevent recurrence. | |||
: d. For implementation of the voltage-b ed r air criteria to tube support plate intersections, notify the staff prior to returning the st generators to service should any of the following conditions arise: | |||
: 1. Leakage is estimated based the pr 'ected end-of-cycle (or if not practical using the actual measured end-of-cy e) voltage tribution. This leakage shall be combined with the postulated leakage r Lulting from the i plementation of the W* criteria to tubesheet inspection depth. If th otal projected end -cycle accident Induced leakage from all sources exceeds the akage limit (determin from the licensing basis dose calculation for the postulated in steam line break) for th ext operating cycle, the staff shall be notified./ | |||
: 2. If circumfere al crack-like indications are detected a e tube support plate intersecti. | |||
: 3. If ndi ons are identified that extend beyond the confines the tube support plate. | |||
: 4. If i ications are identified at the tube support plate elevations at are attributable to p ary water stress corrosion cracking. | |||
: 5. Ifthe calculated conditional burst probability based on the projected d-of-cycle (or if not practical, using the actual measured end-of-cycle) voltage distributi n exceeds 1 X 102, notify the NRC and provide an assessment of the safety significan of the occurrence. | |||
SEQUOYAH - UNIT 2 3/4 4-14b Amendment No. 28, 211, 213, 267, 2 E2-12 | |||
\RATR OLN SYSTEM./ | |||
e.T calculated steam line break ibakage from the applicatio n"Of tube support plate altent rep i criteria and W* inspection methodology shall be submitted in a Special Report accor nce with 10 CFR 50.4 within 90 days following return of the steam generato toservice (MOD'): The report will include the number of indications within the tubesheet r ion, the location the indications (relative to the bottom of the WEXTEX transition (BWT and TTS), | |||
the orienta in (axial, circumferential, skewed, volumetric), the severity of each Idication (e.g., | |||
near throug *all or not through-wall), the side of the tube from which the in i tion initiated (inside or outsi e diameter), and an assessment of whether the results wer consistent with expectations wit respect to the number of flaws and flaw severity (and if ot consistent, a description of the posed corrective action). | |||
May 3, 005 QUOYAH - UNIT 2 3/4 4-14c Amendment No. 243, 1 E2-13 | |||
TABLE 4.4-1 MINIMUM NUMBER OF STEAM GENERATORS TO BE INSPECTED DURING INSERVICE INSPECTION II I I | |||
.L Table Notation: | |||
: 1. The inservice Ins ction may be limited to one steam ge rator on a rotating schedule encompassing 3 of the tubes (where N is the num r of steam generators in the plant) if the results of the fir or previous inspections indica that all steam generators are performing in a like ma er. Note that under some ' cumstances, the operating conditions in one or more steam ge rators may be found to more severe than those in other steam generators. Under such ci umstances the samr e sequence shall be modified to inspect the most severe conditions. | |||
: 2. The other steam generator not i cted ring the first inservice inspection shall be inspected. The third and subseque tins ctions should follow the instructions described in I above. | |||
: 3. Each of the other two steam gener ors ot inspected during the first inservice inspections shall be inspected during the se d and ird inspections. The fourth and subsequent inspections shall follow the inst ctions des 'bed in I above. | |||
S QUOYAH -UNIT 2 3/44-15 | |||
.E2-14 | |||
TABLE 4.4-2 STEAM GENERATOR TUBE INSPECTION SAMPLE INSPECTION 2ND SAMPLE INSPECTION 3 RD SAMP E INSPEC ON Sample esult Action Required Result Action Required Result Action Size ___ Required A minimum C-i None N/A N/A NA N/A of S Tubes _ _ | |||
per S.G. | |||
C-2 PI defective tubes C-1 None N/A N/A and | |||
* pect additional Plug defective tubes C-1 None 2S tu in this S.G. C-2 and inspect additional 4S tubes in this S.G _ | |||
C-2 Plug defective tubes C-3 Perform action for C-3 result of first sample Performf ction for C-3 C-3 resutf first sample N/A N/A C-3 Inspect all tubes in All her this S.G. plug S.G None N/A N/A defective tubes and C-1 inspect,2S. _/_ | |||
tubes in each other Some Perform action for C-2 S.G. S/G 2 sult of second sample N/A N/A bu o ditional | |||
.G.are Additional Inspect all) bes in each S/G is C-3 S.G. and plu defective N/A N/A | |||
____ __________________ ______ tubes. ___,_ | |||
S = 3-% Where N isth umber of steam generators in the unit, and n i henumber of steam n | |||
generators spected during an inspection. | |||
May24,2 2 SEQUOYAH - UNIT 2 3/4 4-16 Amendment No. 28,26 E2-15 | |||
INSERT A REACTOR COOLANT SYSTEM 3/4.4.5 STEAM GENERATOR (SG) TUBE INTEGRITY LIMITING CONDITION FOR OPERATION 3.4.5 SG tube integrity shall be maintained. | |||
AND All SG tubes satisfying the tube repair criteria shall be plugged in accordance with the Steam Generator Program. | |||
APPLICABILITY: MODES 1,2,3, and 4. | |||
ACTIONS*: | |||
: 3. | : a. With one or more SG tubes satisfying the tube repair criteria and not plugged in accordance with the Steam Generator Program, within 7 days verify tube integrity of the affected tube(s) is maintained until the next refueling outage or SG tube inspection, or be in HOT STANDBY within 6 hours and in COLD SHUTDOWN within the next 30 hours. | ||
AND | |||
: b. Plug the affected tube(s) in accordance with the Steam Generator Program prior to startup following the next refueling outage or SG tube inspection. | |||
SURVEILLANCE REQUIREMENTS 4.4.5.0 Verify steam generator tube integrity in accordance with the Steam Generator Program. | |||
4.4.5.1 Verify that each inspected SG tube that satisfies the tube repair criteria is plugged in accordance with the Steam Generator Program prior to startup following a SG tube inspection. | |||
* Separate Action entry Is allowed for each SG tube. | |||
SEQUOYAH - UNIT 2 3/4 4-10 E2-16 | |||
REACTOR COOLANT SYSTEM OPERATIONAL LEAKAGE LIMITING CONDITION FOR OPERATION 3.4.6.2 Reactor Coolant System leakage shall be limited to: | |||
: a. No PRESSURE BOUNDARY LEAKAGE, | |||
: b. 1 GPM UNIDENTIFIED LEAKAGE, C. 150 gallons per day of primary-to-secondary leakage through any one steam generator, and | |||
The | : d. 10 GPM IDENTIFIED LEAKAGE from the Reactor Coolant System. | ||
APPLICABILITY: MODES 1, 2, 3 and 4 or with primary-to-secondary leakage not within limits, ACTION: n PbS | |||
: a. With any PRESSURE BOUNDARY LEAKAGý be in at least HOT STANDBY within 6 hours and in COLD SHUTDOWN within the following 30 hours. | |||
: b. With any Reactor Coolant System leakage greater than any one of the above limits, excluding PRESSURE BOUNDARY LEAKAGE reduce the leakage rate to within limits I Verify within 4 hours or be in at least HOT STANDBY ithin the next 6 hours and in COLD SHUTDOWN within the following 30 hours. | |||
or primary-to-secondary leakage SU*RýILLANCE REQUIREMENTS 4.4.6.24 Reactor Coolant System leakages ha!l be vorifi:d to be .ithin each of the above limits b performance of a Reactor Coolant System water inventory balance at least once per 72 hours.* | |||
The provision of Specification 4.0.4 are not applicable for entry into MODE 3 or 4. | |||
4.4.6.2.2 Yrf'; steam gene-rator tubhe ntgisyi inaccordance with th oiemotS of Technia | |||
-4 R 344 4 9, S+aam kv9ReFatGF6. | |||
[verify primary-to-secondary leakage is <150 gallons per day through any one steam Igenerator at least once per 72 hours.*. 1 above surveillance requirement is not applicable to rhe primary-to-secondary leakage. | |||
* Not required to be performed until 12 hours after establishment of steady state operation. | |||
August 4, 2000 SEQUOYAH - UNIT 2 3/4 4-18 Amendment No. 211, 213, 250 E2-17 | |||
ADMINISTRATIVE CONTROLS | |||
: b. Air lock testing acceptance criteria are: | |||
In addition, the Steam Generator Program shall include the following provisions: | : 1) Overall air lock leakage rate is < 0.05 L, when tested at >_ Pa. | ||
: 2) For each door, leakage rate is < 0.01 La when pressurized to Ž_6 psig for at least two minutes.) | |||
The provisions of SR 4.0.2 do not apply to the test frequencies specified in the Containment Leakage Rate Testing Program. | |||
The provisions of SR 4.0.3 are applicable to the Containment Leakage Rate Testing Program. | |||
: i. Configuration Risk Management Program (DELETED) | |||
: j. Technical Specification (TS) Bases Control Program This program provides a means for processing changes to the Bases of these TSs. | |||
: a. Changes to the Bases of the TS shall be made under appropriate administrative controls and reviews. | |||
: b. Licensees may make changes to Bases without prior NRC approval provided the changes do not require either of the following: | |||
: 1. A change in the TS incorporated in the license or | |||
: 2. A change to the updated FSAR or Bases that requires NRC approval pursuant to 10 CFR 50.59. | |||
: c. The Bases Control Program shall contain provisions to ensure that the Bases are maintained consistent with the FSAR. | |||
: d. Proposed changes that meet the criteria of Specification 6.8.4.j.b above shall be reviewed and approved by the NRC prior to implementation. Changes to the Bases implemented without prior NRC approval shall be provided to the NRC on a frequency consistent with 10 CFR 50.71(e). "' | |||
6.9 REPORTING REQUIREMENTS ROUTINE REPORTS 6.9.1 In addition to the applicable reporting requirements of Title 10, Code of Federal Regulations, the following reports shall be submitted in accordance with 10 CFR 50.4. | |||
STARTUP REPORT 6.9.1.1 DELETED 6.9.1.2 DELETED 6.9.1.3 DELETED February 11, 2003 SEQUOYAH - UNIT 2 6-10 Amendment No. 28, 50, 64, 66, 134, 207,223, 231,271,272 E2-18 | |||
INSERT B from all sources, excluding the leakage attributed to the | |||
: k. Steam Generator (SG) Program degradation described in 6.8.4.k.c.1 and .2, A Steam Generator Program shall be established and implemented to ensure that SG tube integrity is maintained. In addition, the Steam Generator Program shall include the following provisions: | |||
: a. Provisions for Condition Monitoring Assessments. | : a. Provisions for Condition Monitoring Assessments. | ||
Condition monitoring assessment means an evaluation of the "as found" condition of the tubing with respect to the performance criteria for structural integrity and accident induced leakage. The "as found" condition refers to the condition of the tubing during an SG inspection outage, as determined from the inservice inspection results or by other means, prior to the plugging of tubes. Condition monitoring assessments shall be conducted during each outage during which the SG tubes are inspected and/or plugged, to confirm that the performance criteria are being met. --b. Provisions for Performance Criteria for SG Tube Integrity. | Condition monitoring assessment means an evaluation of the "as found" condition of the tubing with respect to the performance criteria for structural integrity and accident induced leakage. The "as found" condition refers to the condition of the tubing during an SG inspection outage, as determined from the inservice inspection results or by other means, prior to the plugging of tubes. Condition monitoring assessments shall be conducted during each outage during which the SG tubes are inspected and/or plugged, to confirm that the performance criteria are being met. -- | ||
application of the alterate repair | : b. Provisions for Performance Criteria for SG Tube Integrity. application of the alterate repair in TS 6.8.4.k.c.1, criteria discussed SG tiube integrity shall be maintained by meeting the performance criteria for tube struc:tural integrity, accident induced leakage, and operational leakage. | ||
All in-service SG tubes shall retain structural integrity over the full range of normal operating conditions (includi startup, operation in the power range, hot standby, cooldown, and all antici ated transients included in the design specification) and design basis accidents | Structural integrity performance criterion: All in-service SG tubes shall retain For predominantly structural integrity over the full range of normal operating conditions (includi axially oriented startup, operation in the power range, hot standby, cooldown, and all antici ated transients included in the design specification) and design basis accidents /(DBAs). | ||
/(DBAs).This includes retaining a safety factor of 3.0 against burst under normal s eady state full power operation primary-to-secondary pressure differential an safety factor of 1.4 against burst applied to the DBA primary-to-secondary pressure differentials. | This includes retaining a safety factor of 3.0 against burst under normal s eady state full power operation primary-to-secondary pressure differential an safety factor of 1.4 against burst applied to the DBA primary-to-secondary pressure elevations; (refer to differentials. Apart from the above requirements, additional loading conditions 6.8.4.k.c.1) the associated with the DBAs, or combination of accidents in accordance with the probability of burst design and licensing basis, shall also be evaluated to determine if the associated (POB) of one or loads contribute significantly to burst or collapse. In the assessment of tube more indications integrity, those loads that do significantly affect burst or collapse shall be given a steam line determined and assessed in combination with the loads due to pressure with a break shall be less safety factor of 1.2 on the combined primary loads and 1.0 on axial secondary than 1 x 10.2. loads. OW. | ||
Apart from the above requirements, additional loading conditions | 9.I I | ||
In the assessment of tube integrity, those loads that do significantly affect burst or collapse shall be determined and assessed in combination with the loads due to pressure with a safety factor of 1.2 on the combined primary loads and 1.0 on axial secondary | : 2. Accident induced leakage performance crites."The accident induced leakage,* | ||
not to exceed 1.0 gpm for the faulted SQ=xcopt for o.tcido di,,otor ctocs aerrociomncracký (ODSCC) and W* I lr-icationc that have an approved limit of | |||
VSL | * g,.,.., . P .. , . The primary-to-secondary accident induced leakage rate for any DBA, other than a SG tube rupture, shall not exceed the leakage rate assumed in the accident analysis in terms of total leakage rate for all SGs and leakage rate for an individual SG. | ||
: 3. The operational leakage performance criterion is specified in Limiting Condition of Operation (LCO) 3.4.6.2, "Reactor Coolant System, Operational Leakage." | |||
: c. Provisions for SG Tube Repair Criteria. | |||
Tubes found by inservice inspection to contain flaws with a depth equal to or exceeding 40% of the nominal tube wall thickness shall be plugged. | |||
The | E2-19 | ||
The | |||
INSERT B The following alternate tube repair criteria (ARC) may be applied as an alternative to the 40% depth based criteria: | |||
GL 95-05 Voltage-Based ARC (Tube Support Plate [TSP]) | |||
A voltage-based TSP plugging limit is used for the disposition of an alloy 600 SG tube for continued service that is experiencing predominately axially oriented ODSCC confined within the thickness of the tube support plates (TSPs). At TSP intersections, the plugging (repair) limit is described below: below: .2.0 volts a) SG tubes, whose degradation is attributed to DSCC within the bounds of the TSP with bobbin voltages less thjan or equ t F l (Note1-)-,.will be allowed to remain in servi e. | |||
b) SG tubes, whose degradation is attribu d to ODS within the bounds of the TSP with a bobbin voltage greater than"yoweM--(No.... | |||
will be repaiFed- plugged, except as noted in Item elow. | |||
1 6.8. | |||
c) SG tubes, with indications of potential degradation attrib ted to ODSCC wi in the bounds of the TSP with a bobbin voltage greater than rop,.rremain limit (N-o 1), but less than or equal pper voltage repair Iin may re ani.in service s riei if a rottn a cke coil inspectio does n detect d d t "V .5.i !le For comparable ais e) f on pe-re, unceule mi-cy letechnology isetfloig th I[lMi-yl e) If an unscheduled mid-cycle inspection is performed, the following mid-cycle repair limits apply instead of the limits identified in Items ba~d-G The mid-cycle repair limits are determined from the followin equations: | |||
VSL 6.8.4.k.c.l.a), b), c), I i-- | |||
I 1.O+NDE+Gr (CL-At) | |||
CL Wv "(CL-At) | |||
: | =v - (vU- V L" where: | ||
VURL upper voltage repair limit VLRL lower voltage repair limit VMURL mid-cycle upper voltage repair limit based on time into cycle VMLRL mid-cycle lower voltage repair limit based on V*uRL and time into cycle E2-20 | |||
INSERT B At length of time since last scheduled inspection during which VURL and Vu*_ were implemented CL cycle length (the time between two scheduled SG inspections) | |||
VSL structural limit voltage Gr average growth rate per cycle length NDE 95 percent cumulative probability allowance for nondestructive examination uncertainty (i.e., a value I6.8.4kc.l.a), .b),.c) of 20 percent has been approved by KIM:nt Implemen/ation of these mid-cycle repair limits should follow the same approach as in TS items W Thne 1owor: veonage rcpair limit is 1.t volt for W4 iRen diameter tubing or | |||
_w.uW_ 19911it *OF4!b menR oiamoter tu-mno Theo accnident leakage limit aopr-ovod fo-r 0-DSRC-C ARC_ andc- for W* calculated loakaao it n -7 4- 1- IL9__ ;-..I A C% | |||
MI- - gt2mlidw Eb P"'I W0111MEG If I ty EZV W* Methodology J191 The implementation of WV does not aply to service induced de@adati R identified in the W* distance. Service induced dgradatioR identified in the W*. | |||
distance below the top-of-tubesheet (TTS) shall be plugged on detection. The | |||
- w.. ~ ,%J-r, .I5~.. r''' I~ Itt 3 ~* ~ *%~ JISA'~/ wrfl 1 JI'., .~.J TUvrt-.J~n~'Ir.. | |||
Ul bendrto thel te~n runnert ef the *.. Goldl lean ryr4,dinn the~ nnrtign | |||
. . *o" of~ theWh waithiR the~ | |||
tu_ P_S.H.eM. UPI9W L[IeU U 1SIILGe, tH e IULU LU)t S.U '.40i 4UU MUU tH e U 19R_ A exteRsieiR. | |||
The following terms/definitions apply to the W*. | |||
a) Bottom of WEXTEX Transition (BWT) is the highest point of contact between the tube and tubesheet at, or below the U-S, as determined by eddy current testing. | |||
b) W* Distance is the larger of the following two distances as measured from the TTS: (a) 8 inches below the U-S or (b) 7 inches below the bottom of the WEXTEX transition plus the uncertainty associated with determining the distance below the bottom of the WEXTEX transition as defined by WCAP-14797, Revision 2. | |||
E2-21 | |||
INSERT B | |||
: d. Provisions for SG Tube Inspections and d.4 Periodic SG tube inspections shall be perfor The number and portions of the tubes inspected and methods of inspection shall be/erformed with the objective of detecting | |||
______flaws of any type (e.g., volumetric flaws, axi l and circumferential cracks) that may be | |||
** present a long the length of the tube, from tfe tube-~to-tubesheet weld at the tube inlet to the tube-to-tubesheet weld at the tube o let, and that may satisfy the applicable tube repair criteria. The tube-to-tubesheet is not part of the tube. In addition to meeting I/ed the requirements of d.1, d.2, and d.3, 1elow, the inspection scope, inspection methods, and inspection intervals shall be such as to ensure that SG tube integrity is mainained until the next SG inspection. An assessment of degradation shall be performed to determine the type and location of flaws t t hhthe tubes may be susceptible and, based on this assessment, to determine which inspection methods need to be employed and at what locations. | |||
: 1. Inspect 100% of the tubes in each SG during the first refueling outage following SG replacement. | |||
: 2. Inspect 100% of the tubes at sequential peods of 60 effective full power months. The first sequential period shall be considered to begin than after the first inservice inspection of the SGs. No SGs shall operate for more 24 effective full power months or one refueling outage (whichever is less) without | |||
: 3. If crackinspected. | |||
being indications are found in any SG tube, then the next inspection for each SG for the degradation mechanism that caused the crack indication shall not and exeed 24 effective full power months or one refueling outage (whichever is less). Ifdefinitive information, such as from examination of a pulled tube, diagnostic non-destructive testing, or engineering evaluabtion indicates that a Scrack-like indication is not associated with a crack(s), then the indication need not be treated as a crack. | |||
. IGL 95-05 Voltage-Based ARC for TSP Indications left in service as a result of application of the TSP voltage-based repair crtera shall be inspected by bobbin coil probed n aftere rst eutages*. | |||
Implementation of the SG tube/TSP repair citera requires a 100 percent bobbin coil inspection for hot-leg and cold-leg TSP intersections down to the lowest cold-leg TSP with known ODSCC indications. The determination of the lowest cold-leg TSP intersections having ODSCC indications shall be based on lthe performance of at least a 20 perent random sampling of tubes inspected diKoover their full length. | |||
p E2-22 | |||
INSERT B W* METHODOLOGY IS MOVED TO Methoolog REPAIR CRITERIA SECTION (c) ABOVE Imp etatonof the SG WEXTEX expanded regionofinspection methodolI ug:e l'etW N(*) | |||
hot-le tu | |||
,*, ercet rtating coil probe inspection the | |||
* 100 distance. Te implementation of W* does not apply to service induce degradation identified in W* distance. Service induced degradation identff* in the W* | |||
distance below t-top-of-tubesheet (TTS) shall be pluggedlon etection. The inspection of S tu s is from the point of entry (hot-leg sid completely around the U-bend to the top sup of the cold leg excluding the p ion of the tube within the tubesheet below the W* tance, the tube-to-tubeshe weld and the tube outlet end extension. | |||
The following terms/definitions ap to the d) Bottom of WEXTEX Transiti WT) is the highest point of contact between the tube and tub eet or below the TTS, as determined by eddy current testing. | |||
e) W* Distance is t larger of the following distances as measured from the TTS: (a) 8 ches below the U-S or (b) 7 1 es below the bottom of the WEXTEX t sition plus the uncertainty associa with determining the distance elow the bottom of the WEXTEX transitio as defined by WCA -14797, Revision 2. | |||
f) Length is the length of tubing below the bottom of the B which must be demonstrated to be non-degraded in order for the tube to mi tain structural and leakage integrity. For the hot leg, the W* length is . inches which represents the most conservative hot leg length defined in WCAP-14797, Revision 2. | |||
: e. Provisions for Monitoring Operational Primary-to-Secondary Leakage. | |||
E2-23 | |||
ADMINISTRATIVE CONTROLS CORE OPERATING LIMITS REPORT (continued) | |||
: 6. WCAP-1 0054-P-A, Westinghouse Small Break ECCS Evaluation Model Using the NOTRUMP Code, August 1985, &W_ Proprietary) | |||
(Methodology for Specification 3/4.2.2 - Heat Flux Hot Channel Factor) | |||
: 7. WCAP-1 0266-P-A, Rev. 2, "THE 1981 REVISION OF WESTINGHOUSE EVALUATION MODEL USING BASH CODE", March 1987, PN Proprietary). | |||
(Methodology for Specification 3.2.2 - Heat Flux Hot Channel Factor). | |||
: 8. BAW-10227P-A, "Evaluation of Advance Cladding and Structural Material (M5) in PWR Reactor Fuel," February 2000, (FCF Proprietary) | |||
(Methodology for Specification 3/4.2.2 - Heat Flux Hot Channel Factor) 6.9.1.14.b The core operating limits shall be determined so that all applicable limits (e.g., fuel thermal-mechanical limits, core thermal-hydraulic limits, ECCS limits, nuclear limits such as shutdown margin, and transient and accident analysis limits) of the safety analysis are met. | |||
6.9.1.14.c THE CORE OPERATING LIMITS REPORT shall be provided within 30 days after cycle start-up (Mode 2) for each reload cycle or within 30 days of issuance of any midcycle revision of the NRC Document Control Desk with copies to the Regional Administrator and Resident Inspector. | |||
REACTOR COOLANT SYSTEM (RCS) PRESSURE AND TEMPERATURE LIMITS (PTLR) | |||
REPORT 6.9.1.15 RCS pressure and temperature limits for heatup, cooldown, low temperature operation, criticality, and hydrostatic testing, LTOP arming, and PORV lift settings as well as heatup and cooldown rates shall be established and documented in the PTLR for the following: | |||
Specification 3.4.9.1, "RCS Pressure and Temperature (PIT) Limits" Specification 3.4.12, "Low Temperature Over Pressure Protection (LTOP) System" 6.9.1.15.a The analytical methods used to determine the RCS pressure and temperature limits shall be those previously reviewed and approved by the NRC, specifically those described in the following documents: | Specification 3.4.9.1, "RCS Pressure and Temperature (PIT) Limits" Specification 3.4.12, "Low Temperature Over Pressure Protection (LTOP) System" 6.9.1.15.a The analytical methods used to determine the RCS pressure and temperature limits shall be those previously reviewed and approved by the NRC, specifically those described in the following documents: | ||
: 1. Westinghouse Topical Report WCAP-1 4040-NP-A, "Methodology used to Develop Cold Overpressure Mitigating System Setpoints and RCS Heatup and Cooldown Limit Curves." 2. Westinghouse Topical Report WCAP-1 5321, "Sequoyah Unit 2 Heatup and Cooldown Limit Curves for Normal Operation and PTLR Support Documentation." 3. Westinghouse Topical Report WCAP-1 5984, "Reactor Vessel Closure Head/Vessel Flange Requirements Evaluation for Sequoyah Units I and 2." 6.9.1.15.b The PTLR shall be provided to the NRC within 30 days of issuance of any revision or supplement thereto.SPECIAL REPORTS 6.9.2.1 Special reports shall be submitted within the time period specified for each report, in accordance with 10 CFR 50.4.6.9.2.2 This specification has been deleted.September 15,2004 SEQUOYAH -UNIT 2 6-14 Amendment Nos. 44, 50, 64, 66, 107,134,146,206,214,231,249,284 E2-24 INSERT C STEAM GENERATOR (SG) TUBE INSPECTION REPORT 6.9.1.16.1 A report shall be submitted within 180 days after the initial entry into MODE 4 following completion of an inspection performed in accordance with Specification 6.8.4.k, "Steam Generator (SG) Program." The report shall include: a. The scope of inspections performed on each SG, b. Active degradation mechanisms found, c. Nondestructive examination techniques utilized for each degradation mechanism, d. Location, orientation (if linear), and measured sizes (if available) of service induced indications, e. Number of tubes plugged during the inspection outage for each active degradation mechanism, f. Total number and percentage of tubes plugged to date, g. The results of condition monitoring, including the results of tube pulls and in-situ testing, and -. | : 1. Westinghouse Topical Report WCAP-1 4040-NP-A, "Methodology used to Develop Cold Overpressure Mitigating System Setpoints and RCS Heatup and Cooldown Limit Curves." | ||
This leakage shall be combinod with the postulated leakage rcsulting from the projecated end Of cGycle accident induced leakagc from all. Sources exceeds the leakage limit (determined from the licensing basis dose calculation for the postulated main steamn line break) for the next operating cycle, the staff shall | : 2. Westinghouse Topical Report WCAP-1 5321, "Sequoyah Unit 2 Heatup and Cooldown Limit Curves for Normal Operation and PTLR Support Documentation." | ||
E2-25 INSERT | : 3. Westinghouse Topical Report WCAP-1 5984, "Reactor Vessel Closure Head/Vessel Flange Requirements Evaluation for Sequoyah Units I and 2." | ||
6.9.1.15.b The PTLR shall be provided to the NRC within 30 days of issuance of any revision or supplement thereto. | |||
based on the proj-eted end Of cyc.e (or if not practica, using. the actual measured end of cycle) v.ltag.distribution exceeds 1 X 10-2 netif' the NRC and proevide an assessment of the safety' signifcance of the occurrence. | SPECIAL REPORTS 6.9.2.1 Special reports shall be submitted within the time period specified for each report, in accordance with 10 CFR 50.4. | ||
".j--For implementation of W*, the calculated steam line break leakage from the application of TSP alternate repair criteria and W* inspection methodology shall be submitted | 6.9.2.2 This specification has been deleted. | ||
* | September 15,2004 SEQUOYAH - UNIT 2 6-14 Amendment Nos. 44, 50, 64, 66, 107,134,146,206,214,231,249,284 E2-24 | ||
[BWT] and TTS), the orientation (axial, circumferential, skewed, volumetric), the severity of each indication (e.g., near through-wall or not through-wall), the side of the tube from which the indication initiated (inside or outside diameter), and an assessment of whether the results were consistent with expectations with respect to the number of flaws and flaw severity (and if not consistent, a description of the proposed corrective action).E2-26 ENCLOSURE 3 TENNESSEE VALLEY AUTHOR~ITY SEQUOYAH NUCLEAR PLANT (SQN)UNIT 2 New TS Bases Page Markups for TS Change 05-0 9 E3-1 INSERT D REACTOR COOLANT SYSTEM BASES 3/4.4.5 STEAM GENERATORS The Surveillance Requirements for inspection of the steam generator tubes ensure that the s ctural integrity of this portion of the RCS will be maintained. | |||
The program for inservice inspe ion of s am generator tubes is based on a modification of Regulatory Guide 1.83, Revision 1. In rvice inspecd in of steam generator tubing is essential In order to maintain surveillance of the co itions of the tube the event that there is evidence of mechanical damage or progressive degra tion due to design, nufacturing errors, or inservice conditions that lead to corrosion. | INSERT C STEAM GENERATOR (SG) TUBE INSPECTION REPORT 6.9.1.16.1 A report shall be submitted within 180 days after the initial entry into MODE 4 following completion of an inspection performed in accordance with Specification 6.8.4.k, "Steam Generator (SG) Program." The report shall include: | ||
Inservic inspection of steam genera r tubing also provides a means of characterizing the nature and caus of any tube degradation so at corrective measures can be taken.The plant is e ected to be operated in a manner such that the secon ry coolant will be maintained within thos emistry limits found to result in negligible corrosi of the steam generator tubes. If the secondary lant chemistry is not maintained within these I its, localized corrosion may likely result in stress co osion cracking. | : a. The scope of inspections performed on each SG, | ||
The extent of cracking d ing plant operation would be limited by the limitation of stea generator tube leakage beteen th primary coolant system and the secondary coolant system (prim -to-secondary leakage = 150 g ons per day per steam generator). | : b. Active degradation mechanisms found, | ||
Cracks having a prima -to-secondary leakage less tan this limit during operation will have an adequate margin of safety to ithstand the loads im sed during normal operation and by postulated accidents. | : c. Nondestructive examination techniques utilized for each degradation mechanism, | ||
Sequoyah has de onstrated that pri ary-to-secondary leakage of 150 gallons per day per steam generator can readily detected by r diation monitors of steam generator blowdown or condenser off-gas. Leakage in cess of is limit will require plant shutdown and an unscheduled inspection, during which the leaki tu s will be located and plugged.The voltage-based repair limits of SR 4.. lement the guidance in GL 95-05 and are applicable only to Westinghouse-designed st m gen tors (S/Gs) with outside diameter stress corrosion cracking (ODSCC) located at the be-to-tube pport plate intersections. | : d. Location, orientation (if linear), and measured sizes (if available) of service induced indications, | ||
The voltage-based repair limits are not applicable to er formsf S/G be degradation nor are they applicable to ODSCC that occurs at other locatio within the S/G. Add, nally, the repair criteria apply only to indications where the degradation nchanism is dominantly axi ODSCC with no significant cracks extending outside the thickness oe support plate. Refer to GL -05 for additional description of the degradation morphology. | : e. Number of tubes plugged during the inspection outage for each active degradation mechanism, | ||
Implementation of 4.4.5 requires a derivation of the voltage st ctural limit from the burst versus voltage empirical rrelation and then the subsequent derivation of voltage repair limit from the structural limi which is then implemented by this surveillance). | : f. Total number and percentage of tubes plugged to date, | ||
The volta structural limit is the voltage from the burst pressure/bobbin vo ge correlation, at the 95 percent ediction interval curve reduced to account for the lower 95/95 perce tolerance bound for tu g material properties at 650°F (i.e., the 95 percent LTL curve). The volta structural limit must adjusted downward to account for potential flaw growth during an operating i erval and to acco for NDE uncertainty. | : g. The results of condition monitoring, including the results of tube pulls and in-situ testing, and / - . | ||
The upper voltage repair limit; VuRL, is determined from the ctural volta limit by applying the following equation: VUnRL -VSL VGR- VNDE April 9, 1997 SEQUOYAH -UNIT 2 B 3/4 4-3 Amendment No. 181, 211, 213 E3-2 REACTOR COOLANT SYSTEM BASES ere VGR represents the allowance for flaw growth between inspections andrVNDE represents the allowance for otential sources of error in the measurement of the bobbin coil voltage. Further discussion of the assu tions necessary to determine the voltage repair limit are discussed in GL 95-05.mid-cycle equation of SR 4.4.5.4.a.10.e should only be used during unplanned inspection i wich eddy curren data is acquired for indications at the tube support plates.SR 4.4. 5implements several reporting requirements recommended by GL 95-05 for si ations which NRC wants to be tified prior to returning the SIGs to service. For SR 4.4.5.5.d., Items 3 and , indications are applicable only ere alternate plugging criteria is being applied. For the purposes of th reporting requirement, leakage d conditional burst probability can be calculated based on the as--f nd voltage distribution rather than t projected end-of-cycle voltage distribution (refer to GL 95-05 r more information) when it is not practical to plete these calculations using the projected EOC voltag distributions prior to returning the S/Gs to serv ce. ote that if leakage and conditional burst probability ere calculated using the measured EQC voltage disstribW | : h. The effective plu ng percentage for all plugg'g in each SG. | ||
Plugging will be required for tubeswithime rfect s exceeding the repair limit defined in Surveillance Requirement 4.4.54.a. | 6.9.1.16.2 A report shall be bmitted within 90 days after the inj{ial entry into MODE 4 following completion otfn inspection performed in accordancq with the steam generator program (6.8.4.k) -voltage based alternate repair criteria @ applied. The report sh[ll include information described in Section 6.b of Attachment I to NRC Generic Letter 95-05, "Voltage-Based Repair Criteria for Westinghouse Steam Generator Tubes Affected by Outside Diameter Stress Corrosion Cracking." | ||
The porti ofthe be thatt plugging limit does not apply to is the portion of the tube that is not within the RCS pre roiunda ube end up to the start of the tubesto-tubesheet weld). The tube end to tube-to-tubeshee eld po n of the tube does not affect structural integrity of the steam generator tubes and therefore indication ou in this portion of the tube will be excluded from the Result and Acton Required for tube inspections. | I | ||
It is cted that any indications that extend from this region will be detected during the scheduled tube inspections, am generator tube inspections of operating plants have demonstrated the capability to reliably detect d radati that has penetrated 20% of the original tube wall thickness. | : 1. For implementation of the voltage-based repair criteria for tube support plate (TSP) intersections, notify the staff prior to ' should any of the following conditions arise: | ||
Tubes experiencing outside diameter ress rrosion crac ng within the thickness of the tube support plate are plugged or repaired by the criteria 4.4.5.4.a. | : 1) Leakage is estimiatted based on the projected end of-cycle (or9F not practical ng t-he ant-u-al measured end of cycle) v.'oltage dist,-buton. This leakage shall be combinod with the postulated leakage rcsulting from the projecated end Of cGycle accident induced leakagc from all. Sources exceeds the leakage limit (determined from the licensing basis dose calculation for the postulated main steamn line break) for the next operating cycle, the staff shall be])4*neie LIf circumferential crack-like indications are detected at the TSP intersections. | ||
10.The W* criteria | E2-25 | ||
W* length is the length of tubing into the tubesheet low the bottom of the WEXTEX transitio BWT) that precludes tube pullout in the event of a complet | |||
Indications dete ed within the W* distance below the top-of-tube sheet (nS), wi be plugged upon detection. | INSERT C Eih* a3)If indications are identified that extend beyond the confines of the TSP. | ||
Tubes to ich WCAP-14797 is applied can experience through-wall degradatio up to the limits defined in Revision, without Increasing the probability of a tube rupture or large leakage eve Tub 'e degradation of a type or 6xtent below W*, distance, including a complete circumferential sepa tion of the tube, is accept le. As applied at Sequoyah Nuclear Plant Unit 2, the W* methodology is used to efine the required tu nspection depth into the hot-leg tubesheet, and isý not used to permit degradation in th W*distance to emain in service. Thus while primary to secondary leakage in the W* distance need not postulat , primary to secondary leakage from potential degradation below the W* distance will be assu for every ' service tube in the bounding steam generator. | ZJ-* 4)- If indications are identified at the TSP elevations that are attributable to primary water stress corrosion cracking. | ||
May 3, 2005 QUOYAH -UNIT 2 B 3/4 4-3a Amendment No. 181, 211, 213, 243, 291 E3-3 REACTOR COOLANT SYSTEM BASES he postulated leakage during a steam line break shall be equal to the following equation: Postulated SLB Leakage = ARC GL 95-05 + Assumed Leakage o-*-w<Trs | 6.9.1.16.4 5) if the cGalu*ated conditional burst pobabilit,; based on the proj-eted end Of cyc.e (or if not practica, using. the actual measured end of cycle) v.ltag. | ||
+ Assumed Leakag -.12"<us + Asmed Leakage >.12"<TstS Where: | distribution exceeds 1 X 10-2 netif' the NRC and proevide an assessment of the safety'signifcance of the occurrence. | ||
Assumed Leakag --rs is the postulated leakage for undetected i ications in steam generator tubes left in servic etween 0 and 8 inches below the top of t tubesheet. | ".j--For implementation of W*, the calculated steam line break leakage from the application of TSP alternate repair criteria and W* inspection methodology shall be submitted *Aa Special Reot in accordance vWth 10 CFR 50.1 within V 90 day W The report will inci e the number of indications within the tubesheet region, the location of e indications (relative to the bottom of the WEXTEX transition [BWT] and TTS), the orientation (axial, circumferential, skewed, volumetric), the severity of each indication (e.g., near through-wall or not through-wall), the side of the tube from which the indication initiated (inside or outside diameter), and an assessment of whether the results were consistent with expectations with respect to the number of flaws and flaw severity (and if not consistent, a description of the proposed corrective action). | ||
AssumedLeakage | E2-26 | ||
Th is 0.0045 gpm Itiplied by the number of indications. | |||
Postulated unidentified indications will be con rvatively sumed to be in one steam generator. | ENCLOSURE 3 TENNESSEE VALLEY AUTHOR~ITY SEQUOYAH NUCLEAR PLANT (SQN) | ||
The highest number of identified indications left in se e etween 8 and 12 inches below TTS in any one steam generator will be included in this term.Assumed Leakage >12. <u-s is the co ervatively ass ed leakage for the bounding steam generator tubes left in service below 12 1 es below the top oe tubesheet. | UNIT 2 New TS Bases Page Markups for TS Change 05-0 9 E3-1 | ||
This is 0.00009 gpm multiplied by the number of tubes Iei service in the least plugg steam generator. | |||
The aggregate calcula SLB leakage from the application of al temate repair criteria and the above assumed leaka shall be reported to the NRC in accordance wi pplicable Technical Specifications. | INSERT D REACTOR COOLANT SYSTEM BASES 3/4.4.5 STEAM GENERATORS The Surveillance Requirements for inspection of the steam generator tubes ensure that the s ctural integrity of this portion of the RCS will be maintained. The program for inservice inspe ion of s am generator tubes is based on a modification of Regulatory Guide 1.83, Revision 1. In rvice inspecd in of steam generator tubing is essential In order to maintain surveillance of the co itions of the tube the event that there is evidence of mechanical damage or progressive degra tion due to design, nufacturing errors, or inservice conditions that lead to corrosion. Inservic inspection of steam genera r tubing also provides a means of characterizing the nature and caus of any tube degradation so at corrective measures can be taken. | ||
The co r ned calculated leak rate from all alternate repair crite *must be less than the maximum allow e steam line break leak rate limit in any one steam generato order to maintain doses !in 10 CFR 100 guideline values and within GDC-19 values during stulated steam line b event.May 3, 2005 SEQUOYAH -UNIT 2 B 3/4 4-3b Amendment No. 213,243,267, 291 E3-4 B 3.4 REACTOR COOLANT SYSTEM B 3/4.4.5 Steam Generator (SG) Tube Integrity BASES BACKGROUND Steam generator (SG) tubes are small diameter, thin walled tubes that carry primary coolant through the primary to secondary heat exchangers. | The plant is e ected to be operated in a manner such that the secon ry coolant will be maintained within thos emistry limits found to result in negligible corrosi of the steam generator tubes. If the secondary lant chemistry is not maintained within these I its, localized corrosion may likely result in stress co osion cracking. The extent of cracking d ing plant operation would be limited by the limitation of stea generator tube leakage beteen th primary coolant system and the secondary coolant system (prim -to-secondary leakage = 150 g ons per day per steam generator). Cracks having a prima -to-secondary leakage less tan this limit during operation will have an adequate margin of safety to ithstand the loads im sed during normal operation and by postulated accidents. Sequoyah has de onstrated that pri ary-to-secondary leakage of 150 gallons per day per steam generator can readily detected by r diation monitors of steam generator blowdown or condenser off-gas. Leakage in cess of is limit will require plant shutdown and an unscheduled inspection, during which the leaki tu s will be located and plugged. | ||
The SG tubes have a number of important safety functions. | The voltage-based repair limits of SR 4.. lement the guidance in GL 95-05 and are applicable only to Westinghouse-designed st m gen tors (S/Gs) with outside diameter stress corrosion cracking (ODSCC) located at the be-to-tube pport plate intersections. The voltage-based repair limits are not applicable to er formsf S/G be degradation nor are they applicable to ODSCC that occurs at other locatio within the S/G. Add, nally, the repair criteria apply only to indications where the degradation nchanism is dominantly axi ODSCC with no significant cracks extending outside the thickness oe support plate. Refer to GL -05 for additional description of the degradation morphology. | ||
Steam generator tubes are an integral part of the reactor coolant pressure boundary (RCPB) and, as such, are relied on to maintain the primary system's pressure and inventory. | Implementation of 4.4.5 requires a derivation of the voltage st ctural limit from the burst versus voltage empirical rrelation and then the subsequent derivation of voltage repair limit from the structural limi which is then implemented by this surveillance). | ||
The SG tubes isolate the radioactive fission products in the primary coolant from the secondary system. In addition, as part of the RCPB, the SG tubes are unique in that they act as the heat transfer surface between the primary and secondary systems to remove heat from the primary system. This specification addresses only the RCPB integrity function of the SG. The SG heat removal function is addressed by Limiting Condition of Operation (LCO) 3.4.1.1, "Startup and Power Operation," LCO 3.4.1.2,"Hot Standby," LCO 3.4.1.3, "Shutdown," and LCO 3.4.1.4, "Cold Shutdown." SG tube integrity means that the tubes are capable of performing their intended RCPB safety function consistent with the licensing basis, including applicable regulatory requirements. | The volta structural limit is the voltage from the burst pressure/bobbin vo ge correlation, at the 95 percent ediction interval curve reduced to account for the lower 95/95 perce tolerance bound for tu g material properties at 650°F (i.e., the 95 percent LTL curve). The volta structural limit must adjusted downward to account for potential flaw growth during an operating i erval and to acco for NDE uncertainty. The upper voltage repair limit; VuRL, is determined from the ctural volta limit by applying the following equation: | ||
Steam generator tubing is subject to a variety of degradation mechanisms. | VUnRL - VSL VGR- VNDE April 9, 1997 SEQUOYAH - UNIT 2 B 3/4 4-3 Amendment No. 181, 211, 213 E3-2 | ||
Steam generator tubes may experience tube degradation related to corrosion phenomena, such as wastage, pitting, intergranular attack, and stress corrosion cracking, along with other mechanically induced phenomena such as denting and wear. These degradation mechanisms can impair tube integrity if they are not managed effectively. | |||
The SG performance criteria are used to manage SG tube degradation. | REACTOR COOLANT SYSTEM BASES ere VGR represents the allowance for flaw growth between inspections andrVNDE represents the allowance for otential sources of error in the measurement of the bobbin coil voltage. Further discussion of the assu tions necessary to determine the voltage repair limit are discussed in GL 95-05. | ||
mid-cycle equation of SR 4.4.5.4.a.10.e should only be used during unplanned inspection i wich eddy curren data is acquired for indications at the tube support plates. | |||
SR 4.4. 5implements several reporting requirements recommended by GL 95-05 for si ations which NRC wants to be tified prior to returning the SIGs to service. For SR 4.4.5.5.d., Items 3 and , indications are applicable only ere alternate plugging criteria is being applied. For the purposes of th reporting requirement, leakage d conditional burst probability can be calculated based on the as--f nd voltage distribution rather than t projected end-of-cycle voltage distribution (refer to GL 95-05 r more information) when it is not practical to plete these calculations using the projected EOC voltag distributions prior to returning the S/Gs to serv ce. ote that if leakage and conditional burst probability ere calculated using the measured EQC voltage disstribW nfor the purposes of addressing GL Sections 61 .1and 6.a.3 reporting criteria, then the results of the pro cted EOC voltage distribution should be p ed per GIL Section 6.b(c) criteria. | |||
Wastage-type defects are unlike with proper chemistry treatme of the secondary coolant. However, even if a defect should develop in service, will be found during sch ed inservice steam generator tube examinations. Plugging will be required for tubeswithime rfect s exceeding the repair limit defined in Surveillance Requirement 4.4.54.a. The porti ofthe be thatt plugging limit does not apply to is the portion of the tube that is not within the RCS pre roiunda ube end up to the start of the tubesto-tubesheet weld). The tube end to tube-to-tubeshee eld po n of the tube does not affect structural integrity of the steam generator tubes and therefore indication ou in this portion of the tube will be excluded from the Result and Acton Required for tube inspections. It is cted that any indications that extend from this region will be detected during the scheduled tube inspections, am generator tube inspections of operating plants have demonstrated the capability to reliably detect d radati that has penetrated 20% of the original tube wall thickness. | |||
Tubes experiencing outside diameter ress rrosion crac ng within the thickness of the tube support plate are plugged or repaired by the criteria 4.4.5.4.a. 10. | |||
The W* criteria incorprate the idance provided inWCAP-147 Revision 2, "Generic W* Tube Plugging Criteria for 51 Series Steam-enerator Tubesheet Region W Expansions.* W* length is the length of tubing into the tubesheet low the bottom of the WEXTEX transitio BWT) that precludes tube pullout in the event of a complet separation of the tube below t W*length. W* distance is crcumferential the distance from the top of th ubesheet to the bottom of the W* length including e distance from the top of the tubesheet to the BWT a measurement uncertainties. | |||
Indications dete ed within the W* distance below the top-of-tube sheet (nS), wi be plugged upon detection. Tubes to ich WCAP-14797 is applied can experience through-wall degradatio up to the limits defined in Revision, without Increasing the probability of a tube rupture or large leakage eve Tub'e degradation of a type or 6xtent below W*, distance, including a complete circumferential sepa tion of the tube, is accept le. As applied at Sequoyah Nuclear Plant Unit 2, the W* methodology is used to efine the required tu nspection depth into the hot-leg tubesheet, and isý not used to permit degradation in th W* | |||
distance to emain in service. Thus while primary to secondary leakage in the W* distance need not postulat , primary to secondary leakage from potential degradation below the W* distance will be assu for every ' service tube in the bounding steam generator. | |||
May 3, 2005 QUOYAH - UNIT 2 B 3/4 4-3a Amendment No. 181, 211, 213, 243, 291 E3-3 | |||
REACTOR COOLANT SYSTEM BASES he postulated leakage during a steam line break shall be equal to the following equation: | |||
Postulated SLB Leakage = ARC GL 95-05 + Assumed Leakage o-*-w<Trs + Assumed Leakag -.12" | |||
<us + Asmed Leakage >.12"<TstS Where: CGL 95-05 is the normal SLB leakage derived from alternate repair crit a methods and the steam gen ator tube inspections. | |||
Assumed Leakag - -rs is the postulated leakage for undetected i ications in steam generator tubes left in servic etween 0 and 8 inches below the top of t tubesheet. | |||
AssumedLeakage 12. <,-rs the conservatively assumed ,kage from the total of identified andpostulated unidentified indication steam generator tub in service between 8 and 12 inches below the top of the tubesheet. Th is 0.0045 gpm Itiplied by the number of indications. | |||
Postulated unidentified indications will be con rvatively sumed to be in one steam generator. The highest number of identified indications left in se e etween 8 and 12 inches below TTS in any one steam generator will be included in this term. | |||
Assumed Leakage >12. <u-s is the co ervatively ass ed leakage for the bounding steam generator tubes left in service below 12 1 es below the top oe tubesheet. This is 0.00009 gpm multiplied by the number of tubes Iei service in the least plugg steam generator. | |||
The aggregate calcula SLB leakage from the application of al temate repair criteria and the above assumed leaka shall be reported to the NRC in accordance wi pplicable Technical Specifications. The co r ned calculated leak rate from all alternate repair crite *must be less than the maximum allow e steam line break leak rate limit in any one steam generato order to maintain doses !in 10 CFR 100 guideline values and within GDC-19 values during stulated steam line b event. | |||
May 3, 2005 SEQUOYAH - UNIT 2 B 3/4 4-3b Amendment No. 213,243,267, 291 E3-4 | |||
B 3.4 REACTOR COOLANT SYSTEM B 3/4.4.5 Steam Generator (SG) Tube Integrity BASES BACKGROUND Steam generator (SG) tubes are small diameter, thin walled tubes that carry primary coolant through the primary to secondary heat exchangers. The SG tubes have a number of important safety functions. Steam generator tubes are an integral part of the reactor coolant pressure boundary (RCPB) and, as such, are relied on to maintain the primary system's pressure and inventory. The SG tubes isolate the radioactive fission products in the primary coolant from the secondary system. In addition, as part of the RCPB, the SG tubes are unique in that they act as the heat transfer surface between the primary and secondary systems to remove heat from the primary system. This specification addresses only the RCPB integrity function of the SG. The SG heat removal function is addressed by Limiting Condition of Operation (LCO) 3.4.1.1, "Startup and Power Operation," LCO 3.4.1.2, "Hot Standby," LCO 3.4.1.3, "Shutdown," and LCO 3.4.1.4, "Cold Shutdown." | |||
SG tube integrity means that the tubes are capable of performing their intended RCPB safety function consistent with the licensing basis, including applicable regulatory requirements. | |||
Steam generator tubing is subject to a variety of degradation mechanisms. Steam generator tubes may experience tube degradation related to corrosion phenomena, such as wastage, pitting, intergranular attack, and stress corrosion cracking, along with other mechanically induced phenomena such as denting and wear. These degradation mechanisms can impair tube integrity if they are not managed effectively. The SG performance criteria are used to manage SG tube degradation. | |||
Specification 6.8.4.k, "Steam Generator (SG) Program," requires that a program be established and implemented to ensure that SG tube integrity is maintained. | Specification 6.8.4.k, "Steam Generator (SG) Program," requires that a program be established and implemented to ensure that SG tube integrity is maintained. | ||
Pursuant to Specification 6.8.4.k, tube integrity is maintained when the SG performance criteria are met. There are three SG performance criteria: | Pursuant to Specification 6.8.4.k, tube integrity is maintained when the SG performance criteria are met. There are three SG performance criteria: structural integrity, accident induced leakage, and operational leakage. The SG performance criteria are described in Specification 6.8.4.k. Meeting the SG performance criteria provides reasonable assurance of maintaining tube integrity at normal and accident conditions. | ||
structural integrity, accident induced leakage, and operational leakage. The SG performance criteria are described in Specification 6.8.4.k. Meeting the SG performance criteria provides reasonable assurance of maintaining tube integrity at normal and accident conditions. | The processes used to meet the SG performance criteria are defined by the Steam Generator Program Guidelines (Ref. 1). | ||
The processes used to meet the SG performance criteria are defined by the Steam Generator Program Guidelines (Ref. 1).SEQUOYAH -UNIT 2 B 3/4 4-3 I ,or the NRC approved licensing basis.BASES APPLICABLE The steam generator tube rupture (SGTR) accident is the limiting design SAFETY basis event for SG tubes and avoiding an SGTR is the basis for this ANALYSES specification. | SEQUOYAH - UNIT 2 B 3/4 4-3 | ||
The analysis of an SGTR event assumes a bounding primary to secondary leakage rate equal to the operational leakage rate limits in LCO 3.4.6.2"Operational Leakage," plus the leakage rate associated with a double-ended rupture of a single tube. The accident analysis for a SGTR assumes the contaminated secondary fluid is released to the atmosphere via safety valves. The main condenser isolates based on an assumed concurrent loss of off-site power.The analysis for design basis accidents and transients other than a SGTR assume the SG tubes retain their structural integrity (i.e., they are assumed not to rupture).In these analyses, the steam discharge to the atmosphere is based on a primary to secondary leakage of 0.1 gallons per minute (gpm) for the non-faulted SGs and 3.7 gpm for the faulted Sq. This limit is approved for use for alternate repair criteria (ARC) and W* le ge calculations. | |||
For non-ARC applications, the accident Pinduced leak in the faulted SG is limited to 1.0 gpm, which is | I ,or the NRC approved licensing basis. | ||
For | BASES APPLICABLE The steam generator tube rupture (SGTR) accident is the limiting design SAFETY basis event for SG tubes and avoiding an SGTR is the basis for this ANALYSES specification. The analysis of an SGTR event assumes a bounding primary to secondary leakage rate equal to the operational leakage rate limits in LCO 3.4.6.2 "Operational Leakage," plus the leakage rate associated with a double-ended rupture of a single tube. The accident analysis for a SGTR assumes the contaminated secondary fluid is released to the atmosphere via safety valves. The main condenser isolates based on an assumed concurrent loss of off-site power. | ||
The analysis for design basis accidents and transients other than a SGTR assume the SG tubes retain their structural integrity (i.e., they are assumed not to rupture). | |||
if a tube was determined to satisfy the repair criteria but was not plugged, the tube may still have tube integrity. | In these analyses, the steam discharge to the atmosphere is based on a primary to secondary leakage of 0.1 gallons per minute (gpm) for the non-faulted SGs and 3.7 gpm for the faulted Sq. This limit is approved for use for alternate repair criteria (ARC) and W* le ge calculations. For non-ARC applications, the accident Pinduced leak in the faulted SG is limited safety bounded by the to 1.0 gpm, which is accidents maximum, aekage established by the plant analysis. For that do not iny ,e fuel damage, the primary coolant activity level of DOSE EQUIVALENT I-1 is assumed to be equal to the LCO 3.4.8, "Specific Activity," limits. For ccldents amount of that assume activity released damage, fuel from the primary the damaged coolant fuel. activity The dose consequences of the is a function of these events are within the limits of GDC 19 (Ref. 2), 10 CFR 100 (Ref. 3), " | ||
s In the context of this specification,ta SG tube is defined as the entire length of the tube, including the tube wall, between the tube-to-tubesheet weld at the tube inlet and the tube-to-tubesheet weld at the tube outlet.The tube-to-tubesheet weld is not considered part of the tube.SEQUOYAH -UNIT 2 B 3/4 4-3a E3-6 BASES LCO (continued) | Steam o generator tube integrity satisfies Criterion 2 of 10 CFR | ||
A SG tube has tube integrity when it satisfies th6 SG performance cdteria. The SG performance criteria are defined in Specification 6.8.4.k, "Steam Generator Program," and describe acceptable SG tube performance. | "*,*0.36(c)(2)(ii). | ||
The Steam Generator Program also provides the evaluation .process for determining conformance with the SG performance criteria.There are three SG performance criteria: | LCO The LCO requires that SG tube integrty be maintained. The LCO also requires that all SG tubes that satisfy the repair citera be plugged in accordance with the Steam Generator Program. | ||
structural integrity, accident induced leakage, and operational leakage. Failure to meet any one of these criteria is considered failure to meet the LCO.The structural integrity performance criterion provides a margin of safety against tube burst or collapse under normal and accident conditions, and ensures structural integrity of the SG tubes under all anticipated transients included in the design specification. | During an SG inspection, any inspected tube that satisfies the Steam Generator Program repair cteria is removed from service by plugging. if a tube was determined to satisfy the repair criteria but was not plugged, the tube may still have tube integrity. s In the context of this specification,ta SG tube is defined as the entire length of the tube, including the tube wall, between the tube-to-tubesheet weld at the tube inlet and the tube-to-tubesheet weld at the tube outlet. | ||
Tube burst is defined as, "The gross structural failure of the tube wall. The condition typically corresponds to an unstable opening displacement (e.g., opening area increased in response to constant pressure) accompanied by ductile (plastic) tearing of the tube material at the ends of the degradation." Tube collapse is defined as, "For the load displacement curve for a given structure, collapse occurs at the top of the load versus displacement curve where the slope of the curve becomes zero." The structural integrity performance criterion provides guidance on assessing loads that have a significant effect on burst or collapse. | The tube-to-tubesheet weld is not considered part of the tube. | ||
In that context, the term "significant" is defined as "An accident loading condition other than differential pressure is considered significant when the addition of such loads in the assessment of the structural integrity performance criterion could cause a lower structural limit or limiting burst/collapse condition to be established." For tube integrity evaluations, except for circumferential degradation, axial thermal loads are classified as secondary loads. For circumferential degradation, the classification of axial thermal loads as primary or secondary loads will be evaluated on a case-by-case basis. The division between primary and secondary classifications will be based on detailed analysis and/or testing.Structural integrity requires that the primary membrane stress intensity in a tube not exceed the yield strength for all American Society of Mechanical Engineers (ASME)Code, Section III, Service Level A (normal operating conditions), and Service Level B (upset or abnormal conditions) transients included in the design specification. | SEQUOYAH - UNIT 2 B 3/4 4-3a E3-6 | ||
This includes safety factors and applicable design basis loads based on ASME Code, Section III, Subsection NB (Ref. 4) and Draft Regulatory Guide 1.121 (Ref.5).SEQUOYAH -UNIT 2 B 3/4 4-3b E3-7 BASES LCO (continued) | |||
The accident induced leakage performance criterion ensures that the primary to secondary leakage caused by a design basis accident, other than a SGTR, is within the accident analysis assumptions. | BASES LCO (continued) | ||
In the main steam line break (MSLB) analysis for ARC, SG leakage is assumed to be 3.7 gpm for the faulted SG and 0.1 gpm for the non-faulted S .Limiting the allowable leakage in the faulted SG to 1.0 gpm for non-ARC ap cations ensures that the MSLB analysis remains conservative and boundin e accident induced leakage rate includes any primary to W " secondary akage existing prior to the accident in addition to primary to secondary leakage' duced during the accident. | A SG tube has tube integrity when it satisfies th6 SG performance cdteria. The SG performance criteria are defined in Specification 6.8.4.k, "Steam Generator Program," and describe acceptable SG tube performance. The Steam Generator Program also provides the evaluation .process for determining conformance with the SG performance criteria. | ||
The 3.7 gpm is approved for use in ARC appli tions where the cracks are limited to locations within the tubesheet or within a lied tube support plate._The operational leakage performance criterion provides an observable indication of SG tube conditions during plant operation. | There are three SG performance criteria: structural integrity, accident induced leakage, and operational leakage. Failure to meet any one of these criteria is considered failure to meet the LCO. | ||
The limit on operational leakage is contained in LCO 3.4.6.2, "Operational Leakage," and limits primary to secondary leakage through any one SG to 150 gallons per day. This limit is based on the assumption that a single crack leaking this amount would not propagate to a SGTR under the stress conditions of a loss-of-coolant accident (LOCA) or a MSLB. If this amount of leakage is due to more than one crack, the cracks are very small, and the above assumption is conservative. | The structural integrity performance criterion provides a margin of safety against tube burst or collapse under normal and accident conditions, and ensures structural integrity of the SG tubes under all anticipated transients included in the design specification. Tube burst is defined as, "The gross structural failure of the tube wall. The condition typically corresponds to an unstable opening displacement (e.g., opening area increased in response to constant pressure) accompanied by ductile (plastic) tearing of the tube material at the ends of the degradation." Tube collapse is defined as, "For the load displacement curve for a given structure, collapse occurs at the top of the load versus displacement curve where the slope of the curve becomes zero." The structural integrity performance criterion provides guidance on assessing loads that have a significant effect on burst or collapse. In that context, the term "significant" is defined as "An accident loading condition other than differential pressure is considered significant when the addition of such loads in the assessment of the structural integrity performance criterion could cause a lower structural limit or limiting burst/collapse condition to be established." For tube integrity evaluations, except for circumferential degradation, axial thermal loads are classified as secondary loads. For circumferential degradation, the classification of axial thermal loads as primary or secondary loads will be evaluated on a case-by-case basis. The division between primary and secondary classifications will be based on detailed analysis and/or testing. | ||
APPLICABILITY Steam generator tube integrity is challenged when the pressure differential across the tubes is large. Large differential pressures across SG tubes can only be experienced in MODES 1,2, 3, or 4.Reactor coolant system (RCS) conditions are far less challenging in MODES 5 and 6 than during MODES 1, 2, 3, and 4. In MODES 5 and 6, primary to secondary differential pressure is low, resulting in lower stresses and reduced potential for leakage.ACTIONS The ACTIONs are modified by a clarifying footnote that Action (a) may be entered independently for each SG tube. This is acceptable because the actions provide appropriate compensatory measures for each affected SG tube. Complying with the actions may allow for continued operation, and subsequent affected SG tubes are governed by subsequent action entry, and application of associated actions.SEQUOYAH -UNIT 2 B 3/4 4-3c E3-8 BASES ACTIONS (continued) | Structural integrity requires that the primary membrane stress intensity in a tube not exceed the yield strength for all American Society of Mechanical Engineers (ASME) | ||
Actions (a) and (b) | Code, Section III, Service Level A (normal operating conditions), and Service Level B (upset or abnormal conditions) transients included in the design specification. | ||
This includes safety factors and applicable design basis loads based on ASME Code, Section III, Subsection NB (Ref. 4) and Draft Regulatory Guide 1.121 (Ref. | |||
The tube integrity determination is based on the estimated condition of the tube at the the situation Is discovered and the estimated growth of the degradation prior to the ne inspection. | 5). | ||
If it is determined that tube integrity is not being G | SEQUOYAH - UNIT 2 B 3/4 4-3b E3-7 | ||
If the evaluation determines that the affected tube(s) have tube integrity, Action (a)allows plant operation to continue until the next refueling outage or SG inspection provided the inspection interval continues to be supported by an operational assessment that reflects the affected tubes.+This allowed time is acceptable since operation until the next inspection is supported by the operational assessment. | |||
I G tube integrity is not being maintained he reactor-must be brought to HOT ,STANDBY within 6 hours and COLD SHUT DWN within the next 30 hours and the affected tube(s) plugged prior to | BASES LCO (continued) | ||
During SG inspections a condition monitoring assessment of the SG tubes is performed. | The accident induced leakage performance criterion ensures that the primary to secondary leakage caused by a design basis accident, other than a SGTR, is within the accident analysis assumptions. In the main steam line break (MSLB) analysis for ARC, SG leakage is assumed to be 3.7 gpm for the faulted SG and 0.1 gpm for the non-faulted S . Limiting the allowable leakage in the faulted SG to 1.0 gpm for non-ARC ap cations ensures that the MSLB analysis remains conservative and boundin e accident induced leakage rate includes any primary to W " secondary akage existing prior to the accident in addition to primary to secondary leakage' duced during the accident. The 3.7 gpm is approved for use in ARC appli tions where the cracks are limited to locations within the tubesheet or within a lied tube support plate. | ||
The condition monitoring assessment determines the "as found" condition of the SG tubes. The purpose of the condition monitoring assessment is to ensure that the SG performance criteria have been met for the previous operating period.The Steam Generator Program determines the scope of the inspection and the methods used to determine whether the tubes contain flaws satisfying the tube repair criteria. | _The operational leakage performance criterion provides an observable indication of SG tube conditions during plant operation. The limit on operational leakage is contained in LCO 3.4.6.2, "Operational Leakage," and limits primary to secondary leakage through any one SG to 150 gallons per day. This limit is based on the assumption that a single crack leaking this amount would not propagate to a SGTR under the stress conditions of a loss-of-coolant accident (LOCA) or a MSLB. If this amount of leakage is due to more than one crack, the cracks are very small, and the above assumption is conservative. | ||
Inspection scope (i.e., which tubes or areas of tubing within the SG are to be inspected) is a function of existing and potential degradation locations. | APPLICABILITY Steam generator tube integrity is challenged when the pressure differential across the tubes is large. Large differential pressures across SG tubes can only be experienced in MODES 1,2, 3, or 4. | ||
The Steam Generator Program also specifies the inspection methods to be used to find potential degradation. | Reactor coolant system (RCS) conditions are far less challenging in MODES 5 and 6 than during MODES 1, 2, 3, and 4. In MODES 5 and 6, primary to secondary differential pressure is low, resulting in lower stresses and reduced potential for leakage. | ||
Inspection methods are a function of degradation morphology, nondestructive examination (NDE) technique capabilities, and inspection locations. | ACTIONS The ACTIONs are modified by a clarifying footnote that Action (a) may be entered independently for each SG tube. This is acceptable because the actions provide appropriate compensatory measures for each affected SG tube. Complying with the actions may allow for continued operation, and subsequent affected SG tubes are governed by subsequent action entry, and application of associated actions. | ||
The Steam Generator Program defines the frequency of SR 4.4.5.0. The frequency is determined by the operational assessment and other limits in the SG examination guidelines (Ref. 6). The Steam Generator Program uses information on existing degradations and growth rates to determine an inspection frequency that provides reasonable assurance that the tubing will meet the SG performance criteria at the next scheduled inspection. | SEQUOYAH - UNIT 2 B 3/4 4-3c E3-8 | ||
In addition, Specification 6.8.4.k contains prescriptive requirements concerning inspection intervals to provide added assurance that the SG performance criteria will be met between scheduled inspections. | |||
SEQUOYAH -UNIT 2 B 3/4 4-4 E3-10 BASES SURVEILLANCE REQUIREMENTS (continued) | BASES ACTIONS (continued) | ||
SR 4.4.5.1 During an SG inspection, any inspected tube that satisfies the Steam Generator Program repair criteria is removed from service by plugging. | Actions (a) and (b) | ||
The tube repair criteria delineated in Specification 6.8.4.k are intended to ensure thattubes accepted for continued service satisfy the SG performance criteria with allowance for error in the flaw size measurement and for future flaw growth. In addition, the tube repair criteria, in conjunction with other elements of the Steam Generator Program, ensure that the SG performance criteria will continue to be met until the next inspection of the subject tube(s). Reference I provides guidance for performing operational assessments to verify that the tubes remaining in service will continue to meet the SG performance criteria.The frequency of this surveillance ensures that the surveillance has been completed and all tubes meeting the repair criteria are plugged prior to subjecting the SG tubes to significant primary to secondary pressure differential I (i.e., prior to HOT SHUTDOWN following a SG tube inspection) | Action (a) applies if it is discovered that one or more SG tubes examined in an inservice inspection satisfy the tube repair criteria but were not plugged in accordance with the Steam Generator Program as required by SR 4.4.5.1. An evaluation of SG tube integrity of the affected tube(s) must be made. Steam generator tube integrity is based on meeting the SG performance criteria described in the Steam Generator Program. The SG repair criteria define limits on SG tube degradation that allow for flaw growth between inspections while still providing assurance that the SG performance criteria will continue to be met. In order to determine if a SG tube that should have been plugged has tube integrity, an evaluation must be completed that demonstrates that the SG performance criteria will continue to be met until the next refueling outage or SG tube inspection. The tube integrity determination is based on the estimated condition of the tube at the refueling outage or the situation Is discovered and the estimated growth of the degradation prior to the ne inspection. If it is determined that tube integrity is not being mantaine G inspection, Action (a) requires unit shutdown and However, the Action (b) requires the affected tube(s) be plugged. | ||
I REFERENCES | affected tube(s) An allowed time of 7 days is sufficient to complete the evaluation while minimizing must be plugged the risk of plant operation with a SG tube that may not have tube integrity. | ||
prior to startup following the next If the evaluation determines that the affected tube(s) have tube integrity, Action (a) refueling outage or allows plant operation to continue until the next refueling outage or SG inspection SG inspection. provided the inspection interval continues to be supported by an operational assessment that reflects the affected tubes.+This allowed time is acceptable since operation until the next inspection is supported by the operational assessment. | |||
I G tube integrity is not being maintained he reactor-must be brought to HOT at any time, ,STANDBY within 6 hours and COLD SHUT DWN within the next 30 hours and the evaluation determinE affected tube(s) plugged prior to restart,,. ."fue!!ng -t, or SG I (Mode 4). | |||
The action times are reasonable, based on operatin xperience, to reach the desired plant condition from full power in an orderly ma ner and without challenging plant systems. | |||
I CZ~fl.~,flfl,~flA6~F SEQUOYAH - UNIT 2 B 3/4 4-3d E3-9 | |||
BASES SURVEILLANCE SR 4.4.5.0 REQUIREMENTS Dudng shutdown periods the SGs are inspected as required by this SR and the Steam Generator Program. NEI 97-06, Steam Generator Program Guidelines (Ref. | |||
1), and its referenced EPRI Guidelines, establish the content of the Steam Generator Program. Use of the Steam Generator Program ensures that the inspection is appropriate and consistent with accepted industry practices. | |||
During SG inspections a condition monitoring assessment of the SG tubes is performed. The condition monitoring assessment determines the "as found" condition of the SG tubes. The purpose of the condition monitoring assessment is to ensure that the SG performance criteria have been met for the previous operating period. | |||
The Steam Generator Program determines the scope of the inspection and the methods used to determine whether the tubes contain flaws satisfying the tube repair criteria. Inspection scope (i.e., which tubes or areas of tubing within the SG are to be inspected) is a function of existing and potential degradation locations. | |||
The Steam Generator Program also specifies the inspection methods to be used to find potential degradation. Inspection methods are a function of degradation morphology, nondestructive examination (NDE) technique capabilities, and inspection locations. | |||
The Steam Generator Program defines the frequency of SR 4.4.5.0. The frequency is determined by the operational assessment and other limits in the SG examination guidelines (Ref. 6). The Steam Generator Program uses information on existing degradations and growth rates to determine an inspection frequency that provides reasonable assurance that the tubing will meet the SG performance criteria at the next scheduled inspection. In addition, Specification 6.8.4.k contains prescriptive requirements concerning inspection intervals to provide added assurance that the SG performance criteria will be met between scheduled inspections. | |||
SEQUOYAH - UNIT 2 B 3/4 4-4 E3-10 | |||
BASES SURVEILLANCE REQUIREMENTS (continued) | |||
SR 4.4.5.1 During an SG inspection, any inspected tube that satisfies the Steam Generator Program repair criteria is removed from service by plugging. The tube repair criteria delineated in Specification 6.8.4.k are intended to ensure thattubes accepted for continued service satisfy the SG performance criteria with allowance for error in the flaw size measurement and for future flaw growth. In addition, the tube repair criteria, in conjunction with other elements of the Steam Generator Program, ensure that the SG performance criteria will continue to be met until the next inspection of the subject tube(s). Reference I provides guidance for performing operational assessments to verify that the tubes remaining in service will continue to meet the SG performance criteria. | |||
The frequency of this surveillance ensures that the surveillance has been completed and all tubes meeting the repair criteria are plugged prior to subjecting the SG tubes to significant primary to secondary pressure differential I (i.e., prior to HOT SHUTDOWN following a SG tube inspection) I REFERENCES 1. NEI 97-06, "Steam Generator Program Guidelines." | |||
: 2. 10 CFR 50 Appendix A, GDC 19. | |||
: 3. 10 CFR 100. | |||
: 4. ASME Boiler and Pressure Vessel Code, Section III, Subsection NB. | |||
: 5. Draft Regulatory Guide 1.121, "Basis for Plugging Degraded Steam Generator Tubes," August 1976. | |||
: 6. EPRI, "Pressurized Water Reactor Steam Generator Examination Guidelines." | |||
SEQUOYAH - UNIT 2 B 3/4 4-4a E3-11 | |||
INSERT E Voltage-Based Alternate Repair Criteria (ARC) and W* Methodoloqy a) Voltage-Based ARC The voltage-based repair limits implement the guidance in Generic Letter (GL) 95-05 and are applicable only to Westinghouse-designed steam generators (SGs) with outside diameter stress corrosion cracking (ODSCC) located at the tube-to-tube support plate intersections. | |||
The voltage-based repair limits are not applicable to other forms of SG tube degradation nor are they applicable to ODSCC that occurs at other locations within the SG. Additionally, the repair criteria apply only to indications where the degradation mechanism is dominantly axial ODSCC with no significant cracks extending outside the thickness of the support plate. Refer to GL 95-05 for additional description of the degradation morphology. | The voltage-based repair limits are not applicable to other forms of SG tube degradation nor are they applicable to ODSCC that occurs at other locations within the SG. Additionally, the repair criteria apply only to indications where the degradation mechanism is dominantly axial ODSCC with no significant cracks extending outside the thickness of the support plate. Refer to GL 95-05 for additional description of the degradation morphology. | ||
Implementation of voltage-based repair limits require a derivation of the voltage structural limit from the burst versus voltage empirical correlation and then the subsequent derivation of the voltage repair limit from the structural limit (which is then implemented by this surveillance). | Implementation of voltage-based repair limits require a derivation of the voltage structural limit from the burst versus voltage empirical correlation and then the subsequent derivation of the voltage repair limit from the structural limit (which is then implemented by this surveillance). | ||
The voltage structural limit is the voltage from the burst pressure/bobbin voltage correlation, at the 95 percent prediction interval curve reduced to account for the lower 95/95 percent tolerance bound for tubing material properties at 650°F (i.e., the 95 percent lower tolerance limit curve). The voltage structural limit must be adjusted downward to account for potential flaw growth during an operating interval and to account for NDE uncertainty. | The voltage structural limit is the voltage from the burst pressure/bobbin voltage correlation, at the 95 percent prediction interval curve reduced to account for the lower 95/95 percent tolerance bound for tubing material properties at 650°F (i.e., the 95 percent lower tolerance limit curve). The voltage structural limit must be adjusted downward to account for potential flaw growth during an operating interval and to account for NDE uncertainty. The upper voltage repair limit; VURL, is determined from the structural voltage limit by applying the following equation: | ||
The upper voltage repair limit; VURL, is determined from the structural voltage limit by applying the following equation: VURL = VSL -VGR -VNDE where VGR represents the allowance for flaw growth between inspections and VNDE represents the allowance for potential sources of error in the measurement of the bobbin coil voltage.Further discussion of the assumptions necessary to determine the voltage repair limit are discussed in GL 95-05.The mid-cycle equation of TS 6.8.4.k.c.1 | VURL = VSL - VGR - VNDE where VGR represents the allowance for flaw growth between inspections and VNDE represents the allowance for potential sources of error in the measurement of the bobbin coil voltage. | ||
.- should only be used durng unplanned inspection in;.9.1.16.3 which eddy current data is acquired for indications at the tube support plates.Specification 69.16 implements several reporting requirements recommended by GL 95-05 for situations which NRC wants to be notified prior to returning the SGs to service. | Further discussion of the assumptions necessary to determine the voltage repair limit are discussed in GL 95-05. | ||
The portion of the tube that the plugging limit does not apply to is the portion of the tube that is not within the RCS pressure boundary (tube end up to the start of the tube-to-tubesheet weld). The tube end tube-to-tubesheet weld portion of the tube does not affect structural integrity of the SG tubes and therefore indications found in this portion of the tube will be excluded from the "Result and Action Required" for tube inspections. | The mid-cycle equation of TS 6.8.4.k.c.1 .- should only be used durng unplanned inspection in | ||
It is expected that any indications that extend from this region will be detected during the scheduled tube inspections. | ;.9.1.16.3 which eddy current data is acquired for indications at the tube support plates. | ||
SG tube inspections of operating plants have demonstrated the capability to reliably detect degradation that has penetrated 20% of the original tube wall thickness. | Specification 69.16 implements several reporting requirements recommended by GL 95-05 for situations which NRC wants to be notified prior to returning the SGs to service. For 6._9*464, Item , indications are applicable only where alternate plugging criteria is being applii. For the purposes of this reporting requirement, leakage and conditional burst probaO" can be calculated based on the as-found voltage distribution rather than the ected end-of-cycle (EOC) voltage distribution (refer to GL 95-05 for more information) 2 and 3 when it is not practical to complete these calculations using the projected EOC voltage distdrbutions prior to returning the SGs to service. Note that if leakage and conditional burst probability were calculated using the measured EOC voltage distribution for the purposes of addressing GL Sections 6.a.1 and 6.a.3 reporting criteria, then the results of the projected EOC voltage distribution should be provided per GL Section 6.b(c) criteria. | ||
E3-12 | |||
INSERT E (Continued) repair limit defined in Specification 6.8.4.k.c. The portion of the tube that the plugging limit does not apply to is the portion of the tube that is not within the RCS pressure boundary (tube end up to the start of the tube-to-tubesheet weld). The tube end tube-to-tubesheet weld portion of the tube does not affect structural integrity of the SG tubes and therefore indications found in this portion of the tube will be excluded from the "Result and Action Required" for tube inspections. It is expected that any indications that extend from this region will be detected during the scheduled tube inspections. SG tube inspections of operating plants have demonstrated the capability to reliably detect degradation that has penetrated 20% of the original tube wall thickness. | |||
Tubes experiencing ODSCC within the thickness of the tube support plate are plugged or repaired by the criteria of 6.8.4.k.c.1. | Tubes experiencing ODSCC within the thickness of the tube support plate are plugged or repaired by the criteria of 6.8.4.k.c.1. | ||
b) W* Methodology The W* criteria incorporates the guidance provided in WCAP-14797, Revision 2, "Generic W*Tube Plugging Criteria for 51 Series Steam Generator Tubesheet Region WEXTEX Expansions." W* length is the length of tubing into the tubesheet below the bottom of the WEXTEX transition (BWT) that precludes tube pullout in the event of a complete circumferential separation of the tube below the W* length. W* distance is the distance from the top-of-tube sheet (TTS) to the bottom of the W* length including the distance from the TTS to the BWT and measurement uncertainties. | b) W* Methodology The W* criteria incorporates the guidance provided in WCAP-14797, Revision 2, "Generic W* | ||
Tube Plugging Criteria for 51 Series Steam Generator Tubesheet Region WEXTEX Expansions." W* length is the length of tubing into the tubesheet below the bottom of the WEXTEX transition (BWT) that precludes tube pullout in the event of a complete circumferential separation of the tube below the W* length. W* distance is the distance from the top-of-tube sheet (TTS) to the bottom of the W* length including the distance from the TTS to the BWT and measurement uncertainties. | |||
Indications detected within the W* distance below the TTS, will be plugged upon detection. | Indications detected within the W* distance below the TTS, will be plugged upon detection. | ||
Tubes to which WCAP-14797 is applied can experience through-wall degradation up to the limits defined in Revision 2 without increasing the probability of a tube rupture or large leakage event. Tube degradation of any type or extent below W* distance, including a complete circumferential separation of the tube, is acceptable. | Tubes to which WCAP-14797 is applied can experience through-wall degradation up to the limits defined in Revision 2 without increasing the probability of a tube rupture or large leakage event. Tube degradation of any type or extent below W* distance, including a complete circumferential separation of the tube, is acceptable. As applied at Sequoyah Nuclear Plant Unit 2, the W* methodology is used to define the required tube inspection depth into the hot-leg tubesheet, and is not used to permit degradation in the W* distance to remain in service. | ||
As applied at Sequoyah Nuclear Plant Unit 2, the W* methodology is used to define the required tube inspection depth into the hot-leg tubesheet, and is not used to permit degradation in the W* distance to remain in service.Thus while primary to secondary leakage in the W* distance need not be postulated, primary to secondary leakage from potential degradation below the W* distance will be assumed for every inservice tube in the bounding SG.c) Calculation of Accident Leakage The postulated leakage during a steam line break (SLB) shall be equal to the following equation: Postulated SLB Leakage = ARC GL 95-05 + Assumed Leakage 0--erTrs + Assumed Leakage 8--2<rs + Assumed Leakage >12. Trs Where: ARC GL 95-05 is the normal SLB leakage derived from ARC methods and the SG tube inspections. | Thus while primary to secondary leakage in the W* distance need not be postulated, primary to secondary leakage from potential degradation below the W* distance will be assumed for every inservice tube in the bounding SG. | ||
Assumed Leakage 0--r<rs is the postulated leakage for undetected indications in SG tubes left in service between 0 and 8 inches below the TTS.Assumed Leakage 12-.<rs is the conservatively assumed leakage from the total of identified and postulated unidentified indications in SG tubes left in service between 8 and 12 inches E3-13 INSERT E (Continued) below the TTS. This is 0.0045 gpm multiplied by the number of indications. | c) Calculation of Accident Leakage The postulated leakage during a steam line break (SLB) shall be equal to the following equation: | ||
Postulated unidentified indications will be conservatively assumed to be in one SG. The highest number of identified indications left in service between 8 and 12 inches below TTS in any one SG will be included in this term.Assumed Leakage >IT-,TTT s the conservatively assumed leakage for the bounding SG tubes left in service below 12 ches below the UTS. This is 0.00009 gpm multiplied by the number of tubes left in service n the least plugged SG.The aggregate cumulated SLB leakage from the application of all ARC and the above assumed leaka shall be reported to the NRC in accordance with technical specifications The combined calculated leak rate from all ARC must be less than the maximum allowable SLB leak rate limit in any one SG in order to maintain doses within 10 CFR 100 guideline values and within GDC-19 values during a postulated SLB event.E3-14 INSERT F 7. NRC Generic Letter 95-05, Voltage Based Repair Criteria for Westinghouse Steam Generator Tubes Affected by Outside Diameter Stress Corrosion Cracking 8. NRC letter to TVA dated April 9, 1997, Issuance of Technical Specification Amendments for the Sequoyah Nuclear Plant, Units I and 2 (TAC Nos. M96998 and M96999) (TS 96-05)9. NRC letter to TVA dated May 3, 2005, Sequoyah Nuclear Plant, Unit 2 -Issuance of Amendment Regarding Changes to the Inspection Scope for the Steam Generator Tubes (TAC No. MC5212) (TS-03-06) | Postulated SLB Leakage = ARC GL 95-05 + Assumed Leakage 0--erTrs + Assumed Leakage 8--2 | ||
E3-15 REACTOR COOLANT SYSTEM BASES 3/4.4.6.2 OPERATIONAL LEAKAGE BACKGROUND Components that contain or transport the coolant to or from the reactor core make up the reactor coolant system (RCS). Component joints are made by welding, bolting, rolling, or pressure loading, and valves isolate connecting systems from the RCS.During plant life, the joint and valve interfaces can produce varying amounts of reactor coolant leakage, through either normal operational wear or mechanical deterioration. | <rs + Assumed Leakage >12. Trs Where: ARC GL 95-05 is the normal SLB leakage derived from ARC methods and the SG tube inspections. | ||
The purpose of the RCS Operational leakage LCO is to limit system operation in the presence of leakage from these sources to amounts that do not compromise safety. This LCO specifies the types and amounts of leakage.10 CFR 50, Appendix A, GDC 30 (Ref. 1), requires means for detecting and, to the extent practical, identifying the source of reactor coolant leakage. Regulatory Guide 1.45 (Ref. 2) describes acceptable methods for selecting leakage detection systems.The safety significance of RCS LEAKAGE varies widely depending on its source, rate, and duration. | Assumed Leakage 0--r<rs is the postulated leakage for undetected indications in SG tubes left in service between 0 and 8 inches below the TTS. | ||
Therefore, detecting and monitoring reactor coolant leakage into the containment area is necessary. | Assumed Leakage 12-.<rs is the conservatively assumed leakage from the total of identified and postulated unidentified indications in SG tubes left in service between 8 and 12 inches E3-13 | ||
Quickly separating the identified LEAKAGE from the unidentified leakage is necessary to provide quantitative information to the operators, allowing them to take corrective action should a leak occur that is detrimental to the safety of the facility and the public.A limited amount of leakage inside containment is expected from auxiliary systems that cannot be made 100% leaktight. | |||
Leakage from these systems should be detected, located, and isolated from the containment atmosphere, if possible, to not interfere with RCS leakage detection. | INSERT E (Continued) below the TTS. This is 0.0045 gpm multiplied by the number of indications. Postulated unidentified indications will be conservatively assumed to be in one SG. The highest number of identified indications left in service between 8 and 12 inches below TTS in any one SG will be included in this term. | ||
This LCO deals with protection of the reactor coolant pressure boundary (RCPB)from degradation and the core from inadequate cooling, in addition to preventing the accident analyses radiation release assumptions from being exceeded. | Assumed Leakage >IT-,TTT s the conservatively assumed leakage for the bounding SG tubes left in service below 12 ches below the UTS. This is 0.00009 gpm multiplied by the number of tubes left in service n the least plugged SG. | ||
The consequences of violating this LCO include the possibility of a loss of coolant accident (LOCA).APPLICABLE | The aggregate cumulated SLB leakage from the application of all ARC and the above assumed leaka shall be reported to the NRC in accordance with technical specifications The combined calculated leak rate from all ARC must be less than the maximum allowable SLB leak rate limit in any one SG in order to maintain doses within 10 CFR 100 guideline values and within GDC-19 values during a postulated SLB event. | ||
August 4, 2000 | E3-14 | ||
To a lesser extent, other accidents or transientsivolve secondary steam release to the atmosphere , ,.h as a steam ....... | |||
INSERT F | |||
The | : 7. NRC Generic Letter 95-05, Voltage Based Repair Criteria for Westinghouse Steam Generator Tubes Affected by Outside Diameter Stress Corrosion Cracking | ||
The dose consequences resulting from the SLB accident are well within the limits defined in 10 CFR 100 or the staff approved licensing basis (i.e., a small fraction of these limits). Based on the NDE uncertainties, bobbin coil voltage distribution and crack growth rate from the previous inspection, the expected leak rate following a steam line rupture is limited to belov#82 gpm at atmospheric conditions and 70°F in the faulted loop, which will limit the Zat+/-Iated-ofite doses to within 10 percent of the 10 CFR 100 guidelines. | : 8. NRC letter to TVA dated April 9, 1997, Issuance of Technical Specification Amendments for the Sequoyah Nuclear Plant, Units I and 2 (TAC Nos. M96998 and M96999) (TS 96-05) | ||
If the projected and Ey tion of crack indications results in primary-to-secondary leakage greater than & gpm in the faulted loop during a postulated steam line break event, additional tubes must be removed from service in order to reduce the postulated primary-to-secondary steam line break leakage to below 98-1. gpm. I and 0.3 gpm through the non-affected generators 1 | : 9. NRC letter to TVA dated May 3, 2005, Sequoyah Nuclear Plant, Unit 2 - Issuance of Amendment Regarding Changes to the Inspection Scope for the Steam Generator Tubes (TAC No. MC5212) (TS-03-06) | ||
LCO RCS operational leakage shall be limited to: a. PRESSURE BOUNDARY LEAKAGE No PRESSURE BOUNDARY LEAKAGE is allowed, being indicative of material deterioration. | E3-15 | ||
Leakage of this type is unacceptable as the leak itself could cause further deterioration, resulting in higher leakage. Violation of this LCO could result in continued degradation of the RCPB. Leakage past seals and gaskets is not PRESSURE BOUNDARY LEAKAGE.b. UNIDENTIFIED LEAKAGE One gpm of UNIDENTIFIED LEAKAGE is allowed as a reasonable minimum detectable amount that the containment air monitoring and containment pocket September 11,2003 | |||
In MODES 5 and 6, leakage limits are not required because the reactor coolant pressure is far lower, resulting in lower stresses and reduced potentials for leakage.May 17, 2002 | REACTOR COOLANT SYSTEM BASES 3/4.4.6.2 OPERATIONAL LEAKAGE BACKGROUND Components that contain or transport the coolant to or from the reactor core make up the reactor coolant system (RCS). Component joints are made by welding, bolting, rolling, or pressure loading, and valves isolate connecting systems from the RCS. | ||
It should be noted that leakage past seals and gaskets is not PRESSURE BOUNDARY LEAKAGE. The reactor must be brought to MODE 3 within 6 hours and MODE 5 within the following 30 hours. This action reduces the leakage and also reduces the factors that tend to degrade the pressure boundary.The allowed completion times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. In MODE 5, the pressure stresses acting on the RCPB are much lower,and further deterioration is much less likely.Action b: UNIDENTIFIED LEAKAG 7 IDENTI D LEAKAGE, or pima;y to-Gcwonday leakage in excess of the LCO limits mus e reduced to within limits within 4 hours. This completion time allows time to leakage rates and either identify UNIDENTIFIED LEAKAGE or reduce le e to within limits before the reactor must be shut down. This action is necessa prevent further deterioration of the RCPB. If UNIDENTIFIED LEAKAG,, IDENTIFIED LEAKAGE;-r p.imry to second.a; leakage cannot be reduced to within limits within 4 hours, the reactor must be brought to lower pressure conditions to reduce the severity of the leakage and its potential consequences. | During plant life, the joint and valve interfaces can produce varying amounts of reactor coolant leakage, through either normal operational wear or mechanical deterioration. The purpose of the RCS Operational leakage LCO is to limit system operation in the presence of leakage from these sources to amounts that do not compromise safety. This LCO specifies the types and amounts of leakage. | ||
The reactor must be brought to MODE 3 within 6 hours and MODE 5 within the following 30 hours. This action reduces the leakage and also reduces the factors that tend to degrade the pressure boundary.The allowed completion times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. In MODE 5, the pressure stresses acting on the RCPB are much lower, and further deterioration is much less likely.August 4, 2000 SEQUOYAH -UNIT 2 B 3/4 4-4h Amendment No. 211,213, 227, 250 E3-19 REACTOR COOLANT SYSTEM BASES SURVEILLANCE Surveillance 4.4,6.2.1 REQUIREMENTS Verifying RCS leakage to be within the LCO limits ensures the integrity of the RCPB is maintained. | 10 CFR 50, Appendix A, GDC 30 (Ref. 1), requires means for detecting and, to the extent practical, identifying the source of reactor coolant leakage. Regulatory Guide 1.45 (Ref. 2) describes acceptable methods for selecting leakage detection systems. | ||
PRESSURE BOUNDARY LEAKAGE would at first appear as UNIDENTIFIED LEAKAGE and can only be positively identified by inspection. | The safety significance of RCS LEAKAGE varies widely depending on its source, rate, and duration. Therefore, detecting and monitoring reactor coolant leakage into the containment area is necessary. Quickly separating the identified LEAKAGE from the unidentified leakage is necessary to provide quantitative information to the operators, allowing them to take corrective action should a leak occur that is detrimental to the safety of the facility and the public. | ||
It should be noted that leakage past seals and gaskets is not PRESSURE BOUNDARY LEAKAGE. UNIDENTIFIED LEAKAGE and IDENTIFIED LEAKAGE are determined by performance of an RCS water inventory balance.'the P.m-.r,' to cnr',' loa.ago ,i.,a , | A limited amount of leakage inside containment is expected from auxiliary systems that cannot be made 100% leaktight. Leakage from these systems should be detected, located, and isolated from the containment atmosphere, if possible, to not interfere with RCS leakage detection. | ||
sy-stoms.The surveillance is Th CS water inventory balance must be met with the reactor at steady state Imodified by a opera g conditions (stable pressure, temperature, power level, pressurizer and footnote .I makeup nk levels, makeup, letdown, and RCP seal injection and return flows).L .J we &ootnote -s add-ed- alewfn. that this SR is not required to be performed until 12 ho after establishing steady state operation. | This LCO deals with protection of the reactor coolant pressure boundary (RCPB) from degradation and the core from inadequate cooling, in addition to preventing the accident analyses radiation release assumptions from being exceeded. The consequences of violating this LCO include the possibility of a loss of coolant accident (LOCA). | ||
The 12-hour allowance provides suffi ent time to collect and process all necessary data after stable plant conditions are stablished. | safety analyses events APPLICABLE Except for primary-to-secondary leakage, the SAFETY ANALYSES do not address operational leakage. However, other o a leakage is related to the safety analyses for LOCA; the amount o ge can affect the probability of such an event. The safety analysis for. resulting in steam discharge to the atmosphereassumeo a . gpm prima.y to. Onday . leakage as the .. itial co.ndition. | ||
Performance of this surveillance within the 12-hour allowance is re ired to maintain compliance with the provisions of Specification | "maximum normal operational leakage of 0.4 gpm (0.1 gpm per steam generator or the equivalent of 150 gallons per day per steam generator). | ||
August 4, 2000 SEQUOYAH - UNIT 2 B 3/4 4-4e Amendment No. 211,213, 227,250 E3-16 | |||
REACTOR COOLANT SYSTEM steam generator tube rupture or a BASES Primary to secondary leakag) is a fator in the dose releases outside containment resulting from a team Ih e break (SLB) accident. To a lesser extent, other accidents or transientsivolve secondary steam release to the atmosphere , ,.h as a steam,., ,, | |||
. ...... , .p -Tr' . The leakage j ontaminates the secondary fluid. '0.4 gpm operational he FSAR (Ref. 3) analysis fcr SGTR assumes the contaminated s ondary RC fluid is released via safety valjres for up to 30 minutes. Operator acti is taken to isolate the affected steam Cenerator within this time period. The m | |||
[ | |||
with ARC applied leakage, I seondary leakagiAs relatively inconsequential. tthrough thefc the affectedl ri The SLB is more limiting for site radiation releases. The safetyanalysis for the L c n s pm primary to secondary leakage agenerator s a maximu an initial condition. The dose consequences resulting from the SLB accident are well within the limits defined in 10 CFR 100 or the staff approved licensing basis (i.e., a small fraction of these limits). Based on the NDE uncertainties, bobbin coil voltage distribution and crack growth rate from the previous inspection, the expected leak rate following a steam line rupture is limited to belov#82 gpm at atmospheric conditions and 70°F in the faulted loop, which will limit the Zat+/-Iated-ofite doses to within 10 percent of the 10 CFR 100 guidelines. If the projected and Ey tion of crack indications results in primary-to-secondary leakage greater than & gpm in the faulted loop during a postulated steam line break event, additional tubes must be removed from service in order to reduce the postulated primary-to-secondary steam line break leakage to below 98-1. gpm. I and 0.3 gpm through the non-affected generators 1 The RCS operational leakage satisfies I Criterion 22 of the NRC Policy Statement. | |||
LCO RCS operational leakage shall be limited to: | |||
: a. PRESSURE BOUNDARY LEAKAGE No PRESSURE BOUNDARY LEAKAGE is allowed, being indicative of material deterioration. Leakage of this type is unacceptable as the leak itself could cause further deterioration, resulting in higher leakage. Violation of this LCO could result in continued degradation of the RCPB. Leakage past seals and gaskets is not PRESSURE BOUNDARY LEAKAGE. | |||
: b. UNIDENTIFIED LEAKAGE One gpm of UNIDENTIFIED LEAKAGE is allowed as a reasonable minimum detectable amount that the containment air monitoring and containment pocket September 11,2003 SEQUOYAH - UNIT 2 B 3/4 4-4f Amendment No. 211, 213, 227,250 E3-17 | |||
REACTOR COOLANT SYSTEM BASES sump level monitoring equipment can collectively detect within a I reasonable time period. Violation of this LCO could result in continued degradation of the RCPB, if the leakage is from the pressure boundary. | |||
C. Primary to Secondary Leakage through Any One Steam Generator (SGI 150 gallons per day limit on one SG is based on the assumption th single c king this amount would not propagate to a SGTR u r the stress con s of a LOCA or a main steam line rupture. If I ed through many cracks, the cks are very small, and the above mption is conservative. **.. | |||
The 150-gallons per day limit in ra into Surveillance 4.4.6.2.1 is more restrictive than the standard leakage limit and is intended to provide an additional ma'gi accommoda crack which might grow at a greater than expected or unexpectedly exten tside the thickness of the tube support e. Hence, the reduced leakage li hen combined with an effe leak rate monitoring program, provides addii al assu that, should a significant leak be experienced, it will be cted, e plant shut down in a timely manner. | |||
: d. IDENTIFIED LEAKAGE Up to 10 gpm of IDENTIFIED LEAKAGE is considered allowable because leakage is from known sources that do not interfere with detection of UNIDENTIFIED LEAKAGE and is well within the capability of the RCS Makeup System. IDENTIFIED LEAKAGE includes leakage to the containment from specifically known and located sources, but does not include PRESSURE BOUNDARY LEAKAGE or controlled reactor coolant pump (RCP) seal leakoff (a normal function not considered leakage). | |||
Violation of this LCO could result in continued degradation of a component or system.' | |||
APPLICABILITY In MODES 1, 2, 3, and 4, the potential for reactor coolant PRESSURE BOUNDARY LEAKAGE is greatest when the RCS is pressurized. | |||
In MODES 5 and 6, leakage limits are not required because the reactor coolant pressure is far lower, resulting in lower stresses and reduced potentials for leakage. | |||
May 17, 2002 SEQUOYAH - UNIT 2 B 3/4 4-4g Amendment No. 211,213,227,250 E3-18 | |||
REACTOR COOLANT SYSTEM BASES LCO 3/4.4.6.3, "RCS Pressure Isolation Valve (PIV) Leakage," measures leakage through each individual PIV and can impact this LCO. Of the two PIVs in series in each isolated line, leakage measured through one PIV does not result in RCS leakage when the other is leak tight. If both valves leak and result in a loss of mass from the RCS, the loss must be included in the allowable IDENTIFIED LEAKAGE. | |||
ACTIONS Action a: A or with primary to secondary leakage not within limits, If any PRESSURE BOUNDARY LEAKAGE existsthe reactor must be brought to lower pressure conditions to reduce the severity of the leakage and its potential consequences. It should be noted that leakage past seals and gaskets is not PRESSURE BOUNDARY LEAKAGE. The reactor must be brought to MODE 3 within 6 hours and MODE 5 within the following 30 hours. This action reduces the leakage and also reduces the factors that tend to degrade the pressure boundary. | |||
The allowed completion times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. In MODE 5, the pressure stresses acting on the RCPB are much lower,and further deterioration is much less likely. | |||
Action b: | |||
UNIDENTIFIED LEAKAG 7 IDENTI D LEAKAGE, or pima;y to-Gcwonday leakage in excess of the LCO limits mus e reduced to within limits within 4 hours. This completion time allows time to leakage rates and either identify UNIDENTIFIED LEAKAGE or reduce le e to within limits before the reactor must be shut down. This action is necessa prevent further deterioration of the RCPB. If UNIDENTIFIED LEAKAG,, IDENTIFIED LEAKAGE; | |||
-r p.imry to second.a; leakage cannot be reduced to within limits within 4 hours, the reactor must be brought to lower pressure conditions to reduce the severity of the leakage and its potential consequences. The reactor must be brought to MODE 3 within 6 hours and MODE 5 within the following 30 hours. This action reduces the leakage and also reduces the factors that tend to degrade the pressure boundary. | |||
The allowed completion times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. In MODE 5, the pressure stresses acting on the RCPB are much lower, and further deterioration is much less likely. | |||
August 4, 2000 SEQUOYAH - UNIT 2 B 3/4 4-4h Amendment No. 211,213, 227, 250 E3-19 | |||
REACTOR COOLANT SYSTEM BASES SURVEILLANCE Surveillance 4.4,6.2.1 REQUIREMENTS Verifying RCS leakage to be within the LCO limits ensures the integrity of the RCPB is maintained. PRESSURE BOUNDARY LEAKAGE would at first appear as UNIDENTIFIED LEAKAGE and can only be positively identified by inspection. It should be noted that leakage past seals and gaskets is not PRESSURE BOUNDARY LEAKAGE. UNIDENTIFIED LEAKAGE and IDENTIFIED LEAKAGE are determined by performance of an RCS water inventory balance. | |||
'the P.m-.r,'to cnr',' loa.ago ,i.,a,kemau*red by pe*rfFmance o-f an RC--S-Z ,,ater | |||
*nven;toiy ballnc in conjunction With offluont moni~toring within the seoodar,' | |||
steam and feedwate: sy-stoms. | |||
The surveillance is Th CS water inventory balance must be met with the reactor at steady state Imodified by a opera g conditions (stable pressure, temperature, power level, pressurizer and footnote . I makeup nk levels, makeup, letdown, and RCP seal injection and return flows). | |||
L . J we &ootnote -s add-ed-alewfn. that this SR is not required to be performed until 12 ho after establishing steady state operation. The 12-hour allowance provides suffi ent time to collect and process all necessary data after stable plant conditions are stablished. Performance of this surveillance within the 12-hour allowance is re ired to maintain compliance with the provisions of Specification 4.0.3. states Steady state operation is required to perform a proper inventory balance since calculations during maneuvering are not useful. For RCS operational leakage determination by water inventory balance, steady state is defined as stable RCS pressure, temperature, power level, pressurizer and makeup tank levels, makeup and letdown, and RCP seal injection and return flows. | |||
An early warning of PRESSURE BOUNDARY LEAKAGE or UNIDENTIFIED LEAKAGE is provided by the automatic systems that monitor the containment atmosphere radioactivity and the containment pocket sump level. It should be noted that leakage past seals and gaskets is not PRESSURE BOUNDARY LEAKAGE. These leakage detection systems are specified in LCO 3/4.4.6.1, "Leakage Detection Instrumentation." | |||
The 72 hour frequency is a reasonable interval to trend leakage and recognizes the importance of early leakage detection in the prevention of accidents. | |||
Surveillance 4.4.6.2.2 | |||
-rrs_~lace provides the means necessary to determine SG 0 in*-' | |||
IINSERTI I an operationadrMG9E5-.]Deeeeerequirement to denmonsta negrity in at normal 0 " dtos August 4, 2000 SEQUOYAH - UNIT 2 B 3/4 4-4i Amendment No. 211,213, 227, 250 E3-20 | |||
REACTOR COOLANT SYSTEM BASES REFERENCES 1. 10 CFR 50, Appendix A, GDC 30. | |||
: 2. Regulatory Guide 1.45, May 1973. | |||
: 3. FSAR, Section 15.4.3. | |||
/ 4. NEI 97-06, "Steam Generator Program Guidelines." | |||
: 5. EPRI, "Pressurized Water Reactor Primary-to-Secondary Leak Guidelines." | |||
I August 4, 2000 SEQUOYAH - UNIT 2 B 3/4 4-4j Amendment No. 211,213, 227,250 E3-21 | |||
INSERT G The limit of 150 gallons per day per SG is based on theoperational leakage performance criterion in NEI 97-06, Steam Generator Program Guidelines (Ref. 4). The Steam Generator Program operational leakage performance criterion in NEI 97-06 states, "The RCS operational primary to secondary leakage through any one SG shall be limited to 150 gallons per day." | |||
The limit is based on operating experience with SG tube degradation mechanisms that result in tube leakage. The operational leakage rate criterion, in conjunction with the implementation of the Steam Generator Program, is an effective measure for minimizing the frequency of SG tube ruptures. | |||
INSERT H Notation associated with this SR states that this SR is not applicable to primary to secondary leakage because leakage of 150 gallons per day cannot be measured accurately by an RCS water inventory balance. | |||
The 150 gallons per day limit is measured at 70 degrees Fahrenheit (Reference 5). The operational leakage rate limit applies to leakage through any one SG. If it is not practical to assign the leakage to an individual SG, all the primary-to-secondary leakage should be conservatively assumed to be from one SG.The surveillance is modified by a note which states that the surveillance is not required to be performed until 12 hours after establishment of steady state operation. | INSERT I This SR verifies that primary to secondary leakage is less than or equal to 150 gallons per day through any one SG. Satisfying the primary to secondary leakage limit ensures that the operational leakage performance criterion in the Steam Generator Program is met. If this SR is not met, compliance with LCO 3.4.5, "Steam Generator Tube Integrity," should be evaluated. | ||
For RCS primary-to-secondary leakage determination, steady state is defined as stable RCS pressure, temperature, power level, pressurizer and makeup tank levels, makeup and letdown, and RCP seal injection and return flows.The surveillance frequency of 72 hours is a reasonable interval to trend primary-to-secondary leakage and recognizes the importance of early leakage detection in the prevention of accidents. | The 150 gallons per day limit is measured at 70 degrees Fahrenheit (Reference 5). The operational leakage rate limit applies to leakage through any one SG. If it is not practical to assign the leakage to an individual SG, all the primary-to-secondary leakage should be conservatively assumed to be from one SG. | ||
The primary-to-secondary leakage is determined using continuous process radiation monitors or radiochemical grab sampling in accordance with the EPRI guidelines (Ref. 5).E3-22}} | The surveillance is modified by a note which states that the surveillance is not required to be performed until 12 hours after establishment of steady state operation. For RCS primary-to-secondary leakage determination, steady state is defined as stable RCS pressure, temperature, power level, pressurizer and makeup tank levels, makeup and letdown, and RCP seal injection and return flows. | ||
The surveillance frequency of 72 hours is a reasonable interval to trend primary-to-secondary leakage and recognizes the importance of early leakage detection in the prevention of accidents. The primary-to-secondary leakage is determined using continuous process radiation monitors or radiochemical grab sampling in accordance with the EPRI guidelines (Ref. 5). | |||
E3-22}} |
Latest revision as of 21:48, 13 March 2020
ML063390665 | |
Person / Time | |
---|---|
Site: | Sequoyah |
Issue date: | 11/30/2006 |
From: | Morris G Tennessee Valley Authority |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
TVA-SQN-TS-05-09 | |
Download: ML063390665 (60) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Soddy-Daisy, Tennessee 37384-2000 November 30, 2006 TVA-SQN-TS-05--09 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Gentlemen:
In the Matter of ) Docket No. 50-328 Tennessee Valley Authority SEQUOYAH NUCLEAR PLANT (SQN) - UNIT 2 - ADDITIONAL SUPPLEMENT TO TECHNICAL SPECIFICATION (TS) CHANGE 05 APPLICATION FOR TECHNICAL SPECIFICATION IMPROVEMENT REGARDING STEAM GENERATOR TUBE INTEGRITY AND DELETION OF LICENSE CONDITION
Reference:
NRC letter to TVA dated November 7, 2006, "Sequoyah Nuclear Plant, Unit 2 - Request for Additional Information Regarding Steam Generator Tube Integrity Technical Specification Amendment (TAC NO. MD0145)"
By the reference letter, NRC staff requested additional information to support staff review of SQN TS Change 05-09. In response to the reference letter, TVA is providing the requested information.
The enclosed information provides TVA responses to NRC questions and includes new TS and TS Bases markups. The new TS and Bases markups reflect discussion with your staff during an October 31, 2006 telephone call. The enclosed markups supersede those previously provided by TVA's August 30, 2006, submittal and February 15, 2006, submittal.
Printed on recycled paper
U.S. Nuclear Regulatory Commission Page 2 November 30, 2006 provides TVA responses. Enclosure 2 provides a new set of TS page markups. Enclosure 3 provides a new set of TS Bases page markups.
TVA's schedule for implementing TS Change 05-09 will be during the Unit 2 Cycle 15 refueling outage (outage scheduled to begin in April 2008). Accordingly, TVA requests NRC approval by January 2008 to allow for TS implementation during the Unit 2 Cycle 15 refueling outage.
TVA has determined that the enclosed changes do not affect the original evaluation of proposed changes and TVA's review for the no significant hazards considerations provided in TVA's original February 15, 2006, submittal.
Additionally, in accordance with 10 CFR 50.91(b) (1), TVA is sending a copy of this letter and enclosures to the Tennessee State Department of Public Health.
There are no commitments contained in this submittal.
If you have any questions about this change, please contact me at 843-7170.
I declare under penalty of perjury that the foregoing is true and correct. Executed on this 30th day of November, 2006.
Sincerely, Glenn W. Morris Manager, Site Licensing and Industry Affairs
Enclosures:
- 1. TVA Responses to NRC Questions
- 2. New Technical Specification Page Markups
- 3. New Technical Specification Bases Page Markups cc: See page 3
U.S. Nuclear Regulatory Commission Page 3 November 30, 2006 Enclosures cc (Enclosures):
Mr. Lawrence E. Nanney, Director Division of Radiological Health Third Floor L&C Annex 401 Church Street Nashville, Tennessee 37243-1532 Mr. Douglas V. Pickett, Senior Project Manager U.S. Nuclear Regulatory Commission Mail Stop 08G-9a One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2739
ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQk)
UNIT 2 TVA Responses to NRC Request for Additional Information Regarding SQN TS Change 05-09 NRC Question 1 In definition 1.16 for IDENTIFIED LEAKAGE on page E2-3 of the TS proposed August 30, 2006, the third part of the definition is as follows:
- c. Reactor coolant system leakage through a steam generator to the secondary system.
The proposal indicates the phrase ""(primary to secondary)" will be added to the end of the definition (i.e., "to the secondary system (primary to secondary)." In the TS originally proposed (February 15, 2006), the term "'(primary to secondary leakage)", which is consistent with TSTF-449, was to be added to this definition. Please discuss why the word "leakage" was deleted from the proposal, or discuss your plans for making the proposal consistent with the TSTF-449.
TVA Response The word "leakage" is hidden from view in the comment box and does not appear in the printed text for the submittal. The comment box size was altered during TVA's submittal preparation and caused the word "leakage" to be hidden from view. TVA has expanded the comment box to restore the word "leakage" and has provided a corrected page in .
NRC Question 2 The staff's review depends in part on the revisions in your proposal that are enclosed by a bold rectangle ("comment box"). In some cases, it is unclear whether the entire comment is printed in the comment box. Two examples follow:
For proposed TS 3.4.6.2, Reactor Coolant System, ACTION b, page E2-17, the comment to be inserted is, "or primary-to-secondary. " The corresponding statement in TSTF-449 is, "or primary-to-secondary leakage." Your original proposal included the word "leakage," and it appears that it may still be in the comment box but mostly out of view.
Following proposed TS Surveillance Requirement 4.4.6.2.1, there is a comment that, "The above surveillance requirement is not applicable." The original proposal, which is consistent with TSTF-449, was, "The above surveillance El-I
requirement is not applicable to primary to secondary leakage." The final part of this sentence is clearly necessary.
TVA Response The missing text is hidden from view in the comment box and does not appear in the printed text for the submittal. The comment box size was altered during TVA's submittal preparation and caused the missing text to be hidden from view. TVA has expanded the comment box to restore the text and has provided a corrected page in Enclosure 2.
NRC Question 3 For the structural integrity performance criterion defined in proposed TS 6.8.4.k.b.1 (page E2-19), in the sentence on safety factors, you are proposing to insert the phrase, "except as permitted through application of the alternative repair criteria discussed in TS 6.8.4.k.c.i." The staff notes that the proposed statement could be misinterpreted to mean that TS 6.8.4.k.c.1 contains guidance concerning when an exception to the safety-factor requirement is permitted. Please discuss you plans to revise this proposed insert, for example, "except for flaws addressed through application of the alternate repair criteria discussed in TS 6.8.4.k.c.I."
TVA Response TVA has revised page E2-19 as suggested and has included the revised page with the TS markups in Enclosure 2.
NRC Question 4 The insert regarding the required probability of burst, proposed at the end of TS 6.8.4.k.b.l (page E2-19), uses the abbreviations, "ODSCC" and "TSP." Please discuss your plans to define these abbreviations within the insert. For example, "outside diameter stress corrosion cracking (ODSCC) ."
TVA Response TVA has revised page E2-19 to define the abbreviations as suggested, and has included the revised page with the TS markups in Enclosure 2.
NRC Question 5 For the accident induced leakage performance criterion defined in proposed TS 6.8.4.k.b.2 (page E2-19), the first sentence of the criteria states that leakage is "not to exceed 1.0 gpm for the faulted SG." Since the corresponding statement in TSTF-449 is, "not to exceed 1.0 gpm per SG," and the proposal for Sequoyah Nuclear Plant, Unit 2 (SQN2), does not address the non-faulted steam generators, please discuss your plans to revise the proposal to make it consistent with the TSTF-449.
E1-2
TVA Response TVA has revised page E2-19 to address the leakage criteria for the non-faulted SGs and include clarification of the leakage criteria for SQN's SGs. The revised page is provided with the TS markups in .
NRC Question 6 The first paragraph of proposed TS 6.8.4.k.c.l (page E2-20), the GL 95-05 voltage-based alternate repair criteria, states, "the plugging (repair) limit is based on maintaining SG tube integrity as described below:" The staff notes this statement may.imply that this repair criteria prescribes methods to ensure tube integrity. Since this is not the intent of the repair criteria, please discuss your plans to revise this statement. For example: "At TSP intersections, the plugging (repair) limit is described below:"
TVA Response TVA has revised page E2-20 as suggested and has included the revised page with the TS markups in Enclosure 2.
NRC Question 7 Paragraph (c) of proposed TS 6.8.4.k.c.1 (page E2-20) refers to "Note 2." Since this is now the only note following deletion of the original Note 1, changing the name of the original Note 2 to Note 1 may avoid potential confusion. In addition, since there is no flow distribution baffle at SQN2, Note 2 could be shortened to one sentence. /The staff notes that it may improve readability to eliminate Note 2 as a separate item and instead include the relevant information within parentheses in TS 6.8.4.k.c.l.c. For example:
"SG tubes, with indications of potential flaws attributed to ODSCC within the bounds of the TSP with a bobbin voltage greater than 2.0 volts but less than or equal to the upper voltage repair limit (calculated according to the methodology in GL 95-05 as supplemented) may remain .....
TVA Response TVA has revised page E2-20 to eliminate Note 2 and add the text from Note 2 into the SG program requirements as suggested and has included the revised page with the TS markups in Enclosure 2.
NRC Question 8 In order to be consistent with the TSTF-449 wording used elsewhere in your proposal, please discuss your plans to replace the term "degradation" with "flaws" in your proposed TS in 6.8.4.k.c.2 (W*
Methodology).
E1-3
TVA Response TVA has revised TS 6.8.4.k.c.2 to replace the term "degradation" with "flaws" as suggested and has included the revised page with the TS markups in Enclosure 2.
NRC Question 9 Paragraph (c) of proposed TS 6.8.4.k.c.1 (page E2-20) addresses two different conditions of bobbin coil voltage for ODSCC flaw indications. The staff notes that it may improve the clarity of the repair criteria to start a new paragraph (i.e., 6.8.4.k.c.l.d) for the case where bobbin indication voltage is greater than the upper voltage limit, since the second sentence of this paragraph is not an exception as discussed in Item b. For example:
d) SG tubes with indications of ODSCC flaws with a bobbin coil voltage greater than the upper voltage repair limit (calculated according to the methodology in GL 95-05 as supplemented) will be plugged.
e) If an unscheduled mid-cycle inspection is performed, the following repair limits apply instead of the limits
-identified in Items 6.8.k.c.l.a), .b), .c), and .d).
As a result of this change, references to these specifications on page E2-20 and E2-21 will also need to be modified. For example, Implementation of these mid-,cycle repair limits should follow the same approach as in TS items 6.8.k.c.l.a), .b), .c), and
.d).
TVA Response TVA has revised page E2-20 and E2-21 to include a new item d as suggested, and has included the revised page with the TS markups in .
NRC Question 10 In proposed TS 6.8.4.k.c.2, the W* methodology, the staff notes that the initial statement about inspecting 100 percent of the tubes is an inspection criteria rather than a repair criteria. Please discuss your plans to move the inspection discussion to TS 6.8.4.k.d (Provisions for SG Tube Inspections.) For example, consider adding a TS 6.8.4.k.d.5:
- 5. When the W* methodology has been implemented, inspect 100 percent of the inservice tubes in the hot-leg tubesheet region with the objective of detecting flaws that may satisfy the applicable tube repair criteria of TS 6.8.4.k.c.2.
In addition, since this section of the TS is a repair criteria, and since TS 6.8.4.d) defines the part of the tube requiring inspection (from the tube-to-tubesheet weld at the tube inlet to the tube-to-E1-4
tubesheet weld at the tube outlet, and that may. satisfy the applicable tube repair criteria), the proposed insert on page E2-21 is unnecessary ("The inspection of SG tubes isfrom the point of entry Finally, TS 6.8.4.k.c.2 should have a statement that, "Flaws located below the W* distance may remain in service regardless of size."
TVA Response TVA has revised TS 6.8.4.k.c.2, 6.8.4.k.d, and added TS 6.8.4.k.d.5 as suggested and has included the revised page with the TS markups in .
NRC Question 11 Proposed TS 6.8.4.c.2 on page E2-21 uses the term "W* distance" before defining it. Please discuss your plans to move the terms/definitions to the beginning of the W* methodology section. In addition, since the W* length is not part of the specifications, please discuss the reason for including it in the TS definitions, or discuss your plans for removing it from the TS.
TVA Response TVA has revised page E2-21 to remove the W* length and relocate the terms/definitions to the beginning as suggested, and has included the revised page with the TS markups in Enclosure 2.
NRC Question 12 Proposed TS 6.8.4.d.4, the SG tube inspection provision related to the GL 95-05 alternate repair criteria (page E2-22) states the following in the first paragraph:
Indications left in service as a result of application of the TSP voltage-based repair criteria shall be inspected by bobbin coil probe during all future refueling outages.
The staff notes that a requirement of every 24 effective full-power months or one refueling outage, whichever is less, would provide the intended minimum inspection frequency, without requiring an additional inspection in the event that SG tubes are inspected during an outage other than a refueling outage. Please discuss any plans you have to change the wording in this requirement and reference the TS section for the repair criteria, for example:
Indications left in service as a result of application of the TSP voltage-based repair criteria (6.8.4.k.c.1) shall be inspected by bobbin coil probe every 24 effective full-power months or one refueling outage, whichever is less.
E1-5
TVA Response TVA has revised page E2-22 to include "every 24 effective full-power months or one refueling outage, whichever is less," as suggested, and has included the revised page with the TS markups in Enclosure 2.
NRC Question 13 In the proposed reporting requirement TS 6.9.1.16 .2, the wording of the first sentence is somewhat awkward and the second sentence contains a typographical error ("'shil"). A suggestion for alternative wording is provided below.
A report shall be submitted within 90 days ...performed in accordance with the steam generator program (6.8.4.k) amad when voltage based alternate repair criteria "e have bbeen applied. The report shall include..
Please discuss your plans to modify this paragraph using the wording suggested above or comparable wording.
TVA Response
- TVA has revised TS 6.9.1.16.2 to include the alternative wording as suggested, and has included the revised page with the TS markups in Enclosure 2.
NRC Question 14 Proposed TS 6.9.1..16 has been revised, with a separate section for each of the required reports. The content of these sections is generally acceptable; however, the wording about returning the steam generators to service following a tube inspection is different for each of the sections. For example, in 6.9.1.16.3 and 6.9.1.16.4, the phrase, "following completion of an inspection performed in accordance with the steam generator program (6.8.4 .k)" (or a comparable phrase),
was not included. Please discuss your plans to make this wording consistent throughout the reporting requirements section and consistent with the TSTF-449 wording, such as the wording used in proposed TS 6.9.1.16.1 below.
.... after the initial entry into MODE 4 following completion of an inspection performed in accordance with Specification 6.8.4.k, ""Steam Generator (SG) Program.".
TVA Response TVA has revised TS 6.9.1.16 to include consistent wording throughout the reporting requirement section as suggested, and has included the revised page with the TS markups in Enclosure 2.,
E1-6
NRC Question 15 On page E3-6 of the proposed bases, there is a statement that "this limit is approved for use for alternate repair criteria (ARC) and W*
leakage calculations." This statement appears incomplete. The leakage from all sources must be limited to 3.7 gpm in the faulted SG with no more than 1.0 gpm coming from non-alternate repair criteria.
A similar comment applies to the statements on page E3-8.
TVA Response TVA has revised page E3-6 and E3-8 to address leakage from non-alternate repair criteria as suggested, and has included the revised page with the TS markups in Enclosure 3.
NRC Question 16
,The staff notes that on proposed bases page B 3/4 4-3c, page E3-8 in the submittal, the current wording ("0.1 gpm for the non-faulted SGs")
could be misinterpreted to mean 0.1 gpm total in the three non-faulted SGs. Please discuss your plans to clarify the wording to indicate "0.1 gpm for each of the non-faulted SGs."
TVA Response TVA has revised page E3-8 to include "each of" as suggested, and has included the revised page with the TS markups in Enclosure 3.
NRC Question 17 On page E3-9 you indicate that "If at any time, evaluation determines SG tube integrity is not being maintained, ... " The reason for adding the underlined text is not clear. Please discuss your plans for removing this text-(and making your submittal consistent with TSTF-449).
TVA Response The phrase "if at any time, evaluation determines SG tube integrity is not being maintained," was added to SQN's TS Bases to provide clarification of TVA's proposed action requirement (a) which states:
"With one more SG tubes satisfying the tube repair criteria and not plugged in accordance with the Steam Generator Program, within 7 days verify tube integrity of the affected tube(s) is maintained until the next refueling outage or SG tube inspection, or be in Hot STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />."
This phrase was in response to RAI question 2 from your June 6, 2006 RAI. The RAI expressed concern that.Condition B of TSTF-449 would not be met in TVA's proposed TS action (a), (i.e., specifically that unit shutdown may not occur if it is determined that SG tube integrity is not maintained).
E1-7
TVA's response to RAI question 2 dated August 7, 2006, stated that TVA was processing a revision to the Bases to ensure consistent application of this action when SG tube integrity cannot be maintained.
Accordingly, TVA's proposed revision to the Bases to include the underlined phrase "if at any time, evaluation determines SG tube integrity is not being maintained," ensures that unit shutdown occurs immediately upon determining SG tube integrity is not maintained.
This is a conservative measure with respect to requiring unit shutdown "at any time" during the 7 day period in action (a) that provides for verification of SG tube integrity.
It should be noted that during a telephone conference between NRC and TVA on October, 31, 2006, NRC requested that TVA clarify the intent of the Bases to ensure any evaluation of SG tube integrity for unit shutdown would apply to all SG tubes (those SG tubes that are plugged and those not plugged). TVA has included a proposed revision to Bases page E3-9 in Enclosure 3 to clarify this intent.
NRC Question 18 The proposed Insert E for the Bases (page E3-12) refers to the "mid-cycle equation of TS 6.8.4.k.c.I.c." The staff notes this equation is currently in 6.8.4.k.c.1.d in the proposed TS (page E2-20). As indicated in #9 above, it may be appropriate to make it 6.8.4.k.c.l.e.
TVA Response The reference to the mid-cycle equation of TS 6.8.4.k.c.1.c is an improper reference. TVA has included a corrected page E3-12 in that revises the TS reference from TS "6.8.4.k.c.1.c" to TS "6.8.4.k.c.l.e" NRC Question 19 The paragraph that starts near the bottom of page E3-12 and begins with, "Wastage-type defects ... " was essentially replaced with TSTF-449. Please discuss your plans to remove this paragraph.
TVA Response TVA has revised page E3-12 to remove the sentence addressing wastage-type defects as suggested, and has included the revised page with the TS markups in Enclosure 3.
NRC Question 20 On page E3-13 there is an equation for calculating postulated steam line break leakage. It appears that this equation is incomplete, since it does not include the leakage from non-alternate repair criteria sources. Please discuss your plans to modify this equation to add "leakage from other sources" or to indicate that this equation only includes leakage from the alternate repair criteria.
E1-8
TVA Response TVA has revised page E3-13 to clarify application of the equation to accident induced alternate repair criteria leakage. TVA has included the revised page with the TS markups in Enclosure 3.
NRC Question 21 Please discuss your plans to remove the first sentence in the last paragraph on page E3-14, since reporting the aggregate calculated steam line break leakage is no longer a requirement.
TVA Response SQN TS includes W* reporting requirements as an aggregate calculation.
Accordingly, TVA is retaining the bases description for aggregate reporting on E3-13.
NRC Question 22 On page E3-16, you indicated that the safety analysis for events resulting in steam discharge to the atmosphere accounts for a maximum normal operational leakage of 0.4 gpm. This wording is not consistent with TSTF-449.- Please clarify whether the safety analysis actually accounts for 0.4 gpm normal operating leakage (i.e., the safety analysis accounts for the equivalent accident-induced leakage from a 0.4 gpm normal operating leak which would be something greater than 0.4 gpm) or whether the analysis simply assumes that there is 0.4 gpm or increases to 0.4 gpm as a result of accident-induced conditions.
If the analysis accounts for 0.4 gpm operating leakage, please discuss the technical basis for determining the equivalent accident induced leak rate from the normal operating leak rate. In addition, please clarify whether your accident analysis assumes 1 gpm leakage from all steam generators or 0.4 gpm.
TVA Response TVA has revised page E3-16 to clarify the accident analysis assumption as suggested and has included the revised page with the TS markups in .
NRC Question 23 Please discuss your plans to indicate in the Applicable Safety Analyses for B3/4.4.6.2 (Operational Leakage), on page E3-17, that the "primary to secondary leakage safety analysis assumption is relatively inconsequential." The staff notes that this is consistent with TSTF-449.
TVA Response .
TVA has revised page E3-17 to add "safety analysis assumption" as suggested and has included the revised page with the TS markups in .
EI-9
ENCLOSURE 2 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
UNIT 2 New TS Page Markups for TS Change 05-09 E2-1
- d. Failure to complete any tests included in thd described program (planned or scheduled) for power levels up to the authorized power level.
(4) Monitoring Settlement Markers (SER/SSER Section 2.6.3)
TVA shall continue to monitor the settlement markers along the ERCW conduit for the new ERCW intake structure for a period not less than three years from the date of this license. Any settlement greater than 0.5 inches that occurs during this period will be evaluated by TVA and a report on this matter will be submitted to the NRC.
(5) Tornado Missiles (Section 3.5)
Prior to startup after the first refueling of the facility, TVA shall reconfirm to the satisfaction of the NRC that adequate tornado protection is provided for the 480 V transformer ventilation systems.
(6) Design of Seismic Cate-ory Structures (Section 3.8)
Prior to startup following the first refueling, TVA shall evaluate all seismic Category I masonry walls to final NRC criteria and implement NRC required modifications that are indicated by that evaluation.
(7) Low Temperature Overpressure Protection (Section 5.2.2)
Prior to startup after the first refueling, TVA shall install an overpressure mitigation system which meets NRC requirements.
(8) Steam Generator Inspection (Section 5.3.1)
(a) Prior to start-up after the first refueling, TVA shall install inspection ports in each steam generator or have an alternative for inspection that is acceptable to the NRC.
(b) By May , Ashall establish a steam genlerat onprogram that is in accordance wi it in Enclosure 2 to the TVA letter to the Commi
- s subject a 12, 1997, as modified by W ~e March 17, 1997.
(9) Containment Isolation Systems (Section 6.2.4)
Prior to startup after the first refueling, TVA shall modify to the satisfaction of the NRC the one-inch chemical feed lines to the main and auxiliary feedwater lines for compliance with GDC 57.
(10) Environmental Qualification (Section 7.2.2)
- a. No later than June 30, 1982, TVA shall be in compliance with the requirements of NUREG-0588, "Interim Staff Position on Environmental Qualification of Safety-Related Electrical Equipment," for safety-related equipment exposed to a harsh environment.
April 9, 1997 Amendment No. 2, 213 E2-2
DEFINITIONS IDENTIFIED LEAKAGE 1.16 IDENTIFIED LEAKAGE shall be:
- a. Leakage, such as that from pump seals or valve packing (except reactor coolant pump seal injection or leakoff) that is captured and conducted to collection systems or a sump or collecting tank, or
- b. Leakage into the containment atmosphere from sources that are both specifically located and known either not to interfere with the operation of leakage detection systems or not to be PRESSURE BOUNDARY LEAKAGE, or
- c. Reactor coolant system leakage through a steam generator to the secondary system.
MEMBER(S*I OF THE PUBLIC /"
OF THE PUBLIC.. ..
(primary to secondary leakage) 1.17 DELETED I OFFSITE DOSE CALCULATION MANUAL 1.18 The OFFSITE DOSE CALCULATION MANUAL (ODCM) shall contain the methodology and parameters used in the calculation of offsite doses resulting from radioactive gaseous and liquid effluents, in the calculation of gaseous and liquid effluent monitoring alarm/trip setpoints, and in the conduct of the Radiological Environmental Monitoring Program. The ODCM shall also contain (1) the Radioactive Effluent Controls and Radiological Environmental Monitoring Programs required by Section 6.8.4 and (2) descriptions of the information that should be included in the Annual Radiological Environmental Operating and Annual Radioactive Effluent Release Reports required by Specifications 6.9.1.6 and 6.9.1.8.
OPERABLE - OPERABILITY 1.19 A system, subsystem, train, or component or device shall be OPERABLE or have OPERABILITY when it is capable of performing its specified function(s), and when all necessary attendant instrumentation, controls, a normal and an emergency electrical power source, cooling or seal water, lubrication or other auxiliary equipment that are required for the system, subsystem, train, component or device to perform its function(s) are also capable of performing their related support function(s).
February 11, 2003 SEQUOYAH - UNIT 2 1-4 Amendment Nos. 63, 134, 146, 159, 165, 169, 250, 272 E2-3
DEFINITIONS OPERATIONAL MODE - MODE 1.20 An OPERATIONAL MODE (i.e., MODE) shall cdrrespond to any one inclusive combination of core reactivity condition, power level and average reactor coolant temperature specified in Table 1.1.
PHYSICS TESTS 1.21 PHYSICS TESTS shall be those tests performed to measure the fundamental nuclear characteristics of the reactor core and related instrumentation and 1) described in Chapter 14.0 of the FSAR, 2) authorized under the provisions of 10 CFR 50.59, or 3) otherwise approved by the Commission.
__pimaysteseondary PRESSURE BOUNDARY LEAKAGE 1.22 PRESSURE BOUNDARY LEAKAGE shall be leakage (except ti..m age.... n tub, leakage)
-rator through a non-isolable fault in a Reactor Coolant System component body, pipe wall or vessel wall.
PRESSURE AND TEMPERATURE LIMITS REPORT (PTLR) 1.23 The PTLR is the unit specific document that provides the reactor vessel pressure and temperature limits, including heatup and cooldown rates and the LTOP arming temperature, for the current reactor vessel fluence period. These pressure and temperature limits shall be determined for each fluence period in accordance with Specification 6.9.1.15.
PROCESS CONTROL PROGRAM (PCP) 1.24 DELETED PURGE - PURGING 1.25 PURGE or PURGING is the controlled process of discharging air or gas from a confinement to maintain temperature, pressure, humidity, concentration or other operating condition, in such a manner that replacement air or gas is required to purify the confinement.
QUADRANT POWER TILT RATIO 1.26 QUADRANT POWER TILT RATIO shall be the ratio of the maximum upper excore detector calibrated output to the average of the upper excore detector calibrated outputs, or the ratio of the maximum lower excore detector calibrated output to the average'of the lower excore detector calibrated outputs, which-ever is greater.
September 15, 2004 SEQUOYAH - UNIT 2 1-5 Amendment No. 63, 134, 146, 191, 223, 284 E2-4
Remove Pages 3/4 4-10 through -16 and replace with INSERT A.
REACTOR COOLANT SYSTEM 3 4.5 STEAM GENERATORS LIMII CONDITION FOR OPERATION 3.4.5 Each ar generator shall be OPERABLE.
APPLICABILI . MODES 1, 2, 3 and 4.
ACTION:
With one or more steam enerators inoperable, restore the inoperable generator(s) t OPERABLE status prior to increasing Ta.g abo e 200°F.
SURVEILLANCE REQUIREME S 4.4.5.0 Each steam generator shall demonstrated OPERABLE by ormance of the following augmented inservice inspection progra and the requirements of Spe fication 4.0.5.
4.4.5.1 Steam Generator Sample Selectio and Inspection - Eac team generator shall be determined OPERABLE during shutdown by selecting an inspecting at lea the minimum number of steam generators specified in Table 4.4-1.
4.4.5.2 Steam Generator Tube Sample Selection d Ins ction - The steam generator tube minimum sample size, inspection result classification, and the spnding action required shall be as specified in Table 4.4-2. The inservice inspection of steam gener r tubes shall be performed at the frequencies specified in Specification 4.4.5.3 and the inspected s hall be verified acceptable per the acceptance criteria of Specification 4.4.5.4. The tubes selecte for ac inservice inspection shall include at least 3%
of the total number of tubes in all steam generat r; the tube lected for these inspections shall be selected on a random basis except:
- a. Where experience in similar ants with similar water emistry indicates critical areas to be inspected, then at least 50 0 of the tubes inspected sha be from these critical areas.
- b. The first sample of tu selected for each inservice inspec -tn (subsequent to the preservice inspectio of each steam generator shall include:
QUOYAH - UNIT 2 3/4 4-10 E2-5
,IILNC EUIEET (Continued)-
I 1.AIll nonplugged tubes that previously had detectable wall penetrations (greater than 20%)
- 2. ubes in those areas where experience has indicated potential problems.
- 3. At inspection (pursuant to Specification 4.4.5.4.a.8) shall be performed on eac elected tube. any selected tube does not permit the passage of the eddy current probe r a tube inspecti , this shall be recorded and an adjacent tube shall be selected and s jected to a tube inspection.
- 4. Indications service as a result of application of the tube support pla voltage-based repair olen criteria shall be spected by bobbin coil probe during all future refuelin outages.
- c. The tubes selected as the econd and third samples (if required by Table .4-2) during each inservice inspection may be subject o a partial tube inspection provided:
- 1. The tubes selected for the samples include the tubes from ose areas of the tube sheet array where tubes with imperfecti s were previously found./
- 2. The inspections include those ions of the tubes wh e imperfections were previously found.
Note: Tube degradation identified in t portion of th ube that is not a reactor coolant pressure boundary (tube end up to.the starf the tu to-tubesheet weld) is excluded from the Result and Action Required in Table 4.4-d Implementation of the steam generator tube/tube port plate repair criteria requires a 100 percent bobbin coil inspection for hot-leg and cold-leg t s port plate intersections down to the lowest cold-leg tube support plate with known outside di eter str s corrosion cracking (ODSCC) indications.
The determination of the lowest cold-leg tu support p1 intersections having ODSCC indications shall be based on the performance of at ast a 20 percen andom sampling of tubes inspected over their full length.
e Implementation of the steam gener tor WEXTEX expanded regi inspection methodology (W*)
requires a 100 percent rotating probe inspection of the hot leg besheet W* distance.
The results of each sample in ction shall be classified into one of the follo three categories:
Category Insoection Results C-1 Less than 5% of the total tubes inspected are degr ed tubes and none of the inspected tubes are defective.
A - UiMay 3, 209
/ EEQUOYAH Unit 2
- 3/44-11 Amendment No. 181, 211, 213, 243, 291*
E2-6
RECO OLANT SYSTEM
- S RVELLANC REQUIREMENTS (Continued)
C-2 One or more tubes, but not more than I% of the total tubes ins e are d&fetive, or between 5% and 106/ of the total tubes ins e are degraded tubes.
More than 10% of the total tubes inspected are degrad ubes or more than 1% of the inspected tubes are defective.
N In all inspections, previously degraded tubes must exhibi ignificant (greater than 10%) further wall penetrations to be included in th above percentage calculations.
April 3, 1996 3/4 4-11a Amendment No. 181, 11 E2-7
\REACTOR COOLANT SYSTEM /
SUVILLANCE REQUIREMENTS (Continued) 4.4.5.3 Inaction Freuencies - The above required inservice inspections of steam generator ttuu shall be performS at the following frequencies:/
- a. The fi inservice inspection shall be performed after 6 Effective Full Power Month/ ut within 24 calen ar months of initial criticality. Subsequent inservice inspections shall rformed at intervals o not less than 12 nor otu, more than 24 calendar months after the previo inspection.
- nerato If sthe a two consec 've inspections following service under AVT conditions, not inclu ng the preservice inspection, re It in all inspection results falling into the C-1 category or if consecutive inspections de nstrate that previously observed degradation has not co inued and no additional degrad ion has occurred, the inspection interval may be ext ded to a maximum of once per 40 months.
g ~ ne s~ e ~mgenerator
~aasteam c r t o cndoted in accordance with
- b. in~ns cp~ c~i nofof If the results of the inse ice iinspection Table 4.4-2 at 40 month i ervals fall in Category C-3, the inspe ion frequency shall be increased to at least once r 20 months. The increase in ins ction frequency shall apply until the subsequent inspections s isfy the criteria of Speciflcati 4.4.5.3.a; the interval may then be extended to a maximum of on r 40 months.
- c. Additional, unscheduled inservice i pections shall be rformed on each steam generator in accordance with the first sample inse tion specified Table 4.4-2 during the shutdown subsequent to any of the following con tions:
- 1. Primary-to-secondary tubes leaks ( t i uding leaks originating from tube-to-tube sheet welds) in excess of the limits of Spe tion 3.4.6.2.
- 2. A seismic occurrence greater than e Op rating Basis Earthquake.
- 3. A loss-of-coolant accident req ng actuation the engineered safeguards.
- 4. A main steam line or feed ter line break.
SUOYAH - UNIT 2 3/4 4-12 E2-8
CTOR COOLANT SYSTEM SU ýEILLANCE REQUIREMENTS (Continued) 4.4.5.4 oce tance Criteria
- a. Aused in this Specification:
- 1. Im rfection means an exception to the dimensions, finish or contour a tube from that uired by fabrication drawings or specifications. Eddy-current testi g indications below 2 6 of the nominal tube wall thickness, if detectable, may be con ered as im ections.
- 2. 0 rad ion means a service-induced cracking, wastage, we r or general corrosion occurring n either inside or outside of a tube.
- 3. Dfraded Tu means a tube containing imperfections reater than or equal to 20% of the nominal wall thi ness caused by degradation.
- 4. % Deqradation me s the percentage of the tube al thickness affected or removed by degradation.
- 5. Defect means an imperfe tion of such sever that it exceeds the plugging limit. A tube containing a defect is defe ve.
- 6. Pluaaina Umit means the im ectio epth at or beyond which the tube shall be removed from service and is eq Iut 0% of the nominal tube wall thickness. Plugging limit does not apply to that portion the tube that is not within the pressure boundary of the reactor coolant system (tube n pto the strt of the tube-to-tubesheet weld). This definition does not apply to tu sup plate intersections if the voltage-based repair criteria are being applied. R er to 4.4. .a.10 for the repair limit applicable to these intersections. This definiti does not app to service induced degradation identified in the W* distance. Servi nduced degradati n identified in the W* distance below the top-of-tube sheet (TTS), s I be plugged on deteo
- 7. Unserviceable des ies the condition of a tube i leaks or contains a defect large enough to affect i structural integrity in the event an Operating Basis Earthquake, a loss-of-coolant ccident, or a steam line or feedwater* e break as specified in 4.4.5.3.c, above.
- 8. Tube Ins ction means an inspection of the steam generat tube from the point of entry (hot leg ide) completely around the U-bend to the top suppo of the cold leg exclu ing the portion of the tube within the tubesheet below th WN distance, the tube to tu eet weld and the tube end extension.
- 9. reservice Inspection means an inspection of the full length of each be in each steam
/generator performed by eddy current techniques prior to service to est lish a baseline condition of the tubing.. This inspection shall be performed prior to initial OWER OPERATION using the equipment and techniques expected to be used d ung subsequent i inservice inspections.
May 3,2 5 EQUOYAH - UNIT 2 3/4 4-13 Amendment No. 181, 211, 213, 243,r 266, 2 E2-9
\REACTOR COOLANT.
SRVEILLANCE SYTEM// (Continued)
REQUIREMENTS
- 10. Tube Support Plate Pluqqgingq Limit is used for the disposition of an alloy 600 steam generator tube for continued service that is experiencing predominately axially on ted outside diameter stress corrosion cracking confined within the thickness of the t support plates. At tube support plate intersections, the plugging (repair) limit is basedn aintaining steam generator tube serviceability as described below:
- a. Steam generator tubes, whose degradation is attributed to outsid iameter stress rrosion cracking within the bounds of the tube support plate ' bobbin voltages iSs than or equal to the lower voltage repair limit (Note 1), wil allowed to remain inrvIqce.
- b. Steam enerator tubes, whose degradation is attributed outside diameter stress corrosio cracking within the bounds of the tube sup plate with a bobbin voltage greater th the lower voltage repair limit (Note 1), be repaired or plugged, except as n ed in 4.4.5.4.a.10.c below.
- c. Steam generat tubes, with indications of pote ial degradation attributed to outside diameter stress rosion-cracking within the ounds of the tube support plate with a bobbin voltage gre er than the lower volta repair limit (Note 1), but less than or equal to upper voltag repair limit (Note 2Y, may remain in service ifa rotating pancake coil inspection oes not detect egradation. Steam generator tubes, with indications of outside dia eter stress rrosion-cracking degradation with a bobbin coil voltage greater than th upper v tage repair limit (Note 2) will be plugged or repaired.
- d. Not applicable to SQN.
- e. If an unscheduled mid-cy inspecti n is performed, the following mid-cycle repair limits apply instead of th imits identi i d in 4.4.5.4.a.10.a, 4.4.5.4.a.10.b, and 4.4.5.4.a.10.c.
The mid-cycle repair limits are determi from the following eq tions:
VSL VUL1.0 + NDE + Gr(CL -At)
= V~-(v~-v~)(CL -At)
April 9, 997 QUOYAH - UNIT 2 3/4 4-14 Amendment No. 28, 211, 3 E2-10
VURL upper voltage repair limit VLRL - lower voltage repair limit VMURL mid-cycle upper voltage repair limit based on time into cycle VMLRL = mid-cycle lower voltage repair limit based on VMURL and ti into cycle At = ngth of time since last scheduled inspection during ich VURL and VLRL were ilemented CL = cycle ngth (the time between two scheduled st m generator inspections)
VSL = structura mitvoltage Gr = average g rate per cycle length NDE = 95-percent cumu tive probability all ance for nondestructive examination uncertainty (i.e., a lue of 20-per t has been approved by NRC)
Implementation of these mid-cycle repair limits s uld foil the same approach as in TS 4.4.5.4.a.10.a, 4.4.5.4.a.10.b, and 4.4.5.4.a.10.c.
Note 1: The lower voltage repair limit is 1.0 vol 3/4-inch diameter tubing or 2.0 volts for 7/8-inch diameter tubing.
Note 2: The upper voltage repair limit is Iculated a rding to the methodology in GL 95-05 as supplemented. VURL may differ t the TSPs and ow distribution baffle.
- 11. a) Bottom of WEXTEX ransition (BWT) is the h hest point of contact between the tube and tubesh at, or below the top-of-tube eet, as determined by eddy current testing.
b) The W* dist ce is the larger of the following two dis nces as measured from the top-of-the- sheet (TTS): (a) 8 inches below the TT or (b) 7 inches below the bottom he WEXTEX transition plus the uncertainty as iated with determining the dis nce below the bottom of the WEXTEX transition a defined by WC -14797, Revision 2.
c) Length is the length of tubing below the bottom of the W transition WT), which must be demonstrated to be non-degraded in order r the tube to maintain structural and leakage integrity. For the hot leg, the W* len th is 7.0 inches which represents the most conservative hot-leg length defined in WC -14797, Revision 2.
- b. The steam generator shall be determined OPERABLE after completing the corres nding actions (plug all tubes exceeding the plugging limit and all tubes containing through- ll cracks) required by Table 4.4-2.
May 3,2 5 QUOYAH - UNIT 2 3/4 4-14a Amendment No. 28, 211, 213, 243, 2 E2-11
\R EACTOR COOLANT SYSTEM S EILNEREQUIREMENTS (Continued) 4.45.5 Rep.orts
- a. Following each inservice inspection of steam generator tubes, the number of tub pluged each steam generator shall be reported to the Commission within 15 days.
- b. Th mplete results of the steam generator tube inservice inspection shall e submitted to the mmission in a Special Report pursuant to Specification 6.9.2 within 2 months followi the completion of the inspection. This Special Report shall in de:
- 1. Num r and extent of tubes inspected.
- 2. imperfectior d percent of wall-thickness penetration for eac Location ndication of an
- 3. Identification o bes plugged.
- c. Results of steam gene r tube inspections which fal nto Category C-3 shall be reported as a degraded condition pursint to 10 CFR 50.73 pri t resumption of plant operation. The written followup of this reporshall provide a descr tion of investigations conducted to determine cause of the tube radation and co ective measures taken to prevent recurrence.
- d. For implementation of the voltage-b ed r air criteria to tube support plate intersections, notify the staff prior to returning the st generators to service should any of the following conditions arise:
- 1. Leakage is estimated based the pr 'ected end-of-cycle (or if not practical using the actual measured end-of-cy e) voltage tribution. This leakage shall be combined with the postulated leakage r Lulting from the i plementation of the W* criteria to tubesheet inspection depth. If th otal projected end -cycle accident Induced leakage from all sources exceeds the akage limit (determin from the licensing basis dose calculation for the postulated in steam line break) for th ext operating cycle, the staff shall be notified./
- 2. If circumfere al crack-like indications are detected a e tube support plate intersecti.
- 3. If ndi ons are identified that extend beyond the confines the tube support plate.
- 4. If i ications are identified at the tube support plate elevations at are attributable to p ary water stress corrosion cracking.
- 5. Ifthe calculated conditional burst probability based on the projected d-of-cycle (or if not practical, using the actual measured end-of-cycle) voltage distributi n exceeds 1 X 102, notify the NRC and provide an assessment of the safety significan of the occurrence.
SEQUOYAH - UNIT 2 3/4 4-14b Amendment No. 28, 211, 213, 267, 2 E2-12
\RATR OLN SYSTEM./
e.T calculated steam line break ibakage from the applicatio n"Of tube support plate altent rep i criteria and W* inspection methodology shall be submitted in a Special Report accor nce with 10 CFR 50.4 within 90 days following return of the steam generato toservice (MOD'): The report will include the number of indications within the tubesheet r ion, the location the indications (relative to the bottom of the WEXTEX transition (BWT and TTS),
the orienta in (axial, circumferential, skewed, volumetric), the severity of each Idication (e.g.,
near throug *all or not through-wall), the side of the tube from which the in i tion initiated (inside or outsi e diameter), and an assessment of whether the results wer consistent with expectations wit respect to the number of flaws and flaw severity (and if ot consistent, a description of the posed corrective action).
May 3, 005 QUOYAH - UNIT 2 3/4 4-14c Amendment No. 243, 1 E2-13
TABLE 4.4-1 MINIMUM NUMBER OF STEAM GENERATORS TO BE INSPECTED DURING INSERVICE INSPECTION II I I
.L Table Notation:
- 1. The inservice Ins ction may be limited to one steam ge rator on a rotating schedule encompassing 3 of the tubes (where N is the num r of steam generators in the plant) if the results of the fir or previous inspections indica that all steam generators are performing in a like ma er. Note that under some ' cumstances, the operating conditions in one or more steam ge rators may be found to more severe than those in other steam generators. Under such ci umstances the samr e sequence shall be modified to inspect the most severe conditions.
- 2. The other steam generator not i cted ring the first inservice inspection shall be inspected. The third and subseque tins ctions should follow the instructions described in I above.
- 3. Each of the other two steam gener ors ot inspected during the first inservice inspections shall be inspected during the se d and ird inspections. The fourth and subsequent inspections shall follow the inst ctions des 'bed in I above.
S QUOYAH -UNIT 2 3/44-15
.E2-14
TABLE 4.4-2 STEAM GENERATOR TUBE INSPECTION SAMPLE INSPECTION 2ND SAMPLE INSPECTION 3 RD SAMP E INSPEC ON Sample esult Action Required Result Action Required Result Action Size ___ Required A minimum C-i None N/A N/A NA N/A of S Tubes _ _
per S.G.
C-2 PI defective tubes C-1 None N/A N/A and
- pect additional Plug defective tubes C-1 None 2S tu in this S.G. C-2 and inspect additional 4S tubes in this S.G _
C-2 Plug defective tubes C-3 Perform action for C-3 result of first sample Performf ction for C-3 C-3 resutf first sample N/A N/A C-3 Inspect all tubes in All her this S.G. plug S.G None N/A N/A defective tubes and C-1 inspect,2S. _/_
tubes in each other Some Perform action for C-2 S.G. S/G 2 sult of second sample N/A N/A bu o ditional
.G.are Additional Inspect all) bes in each S/G is C-3 S.G. and plu defective N/A N/A
____ __________________ ______ tubes. ___,_
S = 3-% Where N isth umber of steam generators in the unit, and n i henumber of steam n
generators spected during an inspection.
May24,2 2 SEQUOYAH - UNIT 2 3/4 4-16 Amendment No. 28,26 E2-15
INSERT A REACTOR COOLANT SYSTEM 3/4.4.5 STEAM GENERATOR (SG) TUBE INTEGRITY LIMITING CONDITION FOR OPERATION 3.4.5 SG tube integrity shall be maintained.
AND All SG tubes satisfying the tube repair criteria shall be plugged in accordance with the Steam Generator Program.
APPLICABILITY: MODES 1,2,3, and 4.
ACTIONS*:
- a. With one or more SG tubes satisfying the tube repair criteria and not plugged in accordance with the Steam Generator Program, within 7 days verify tube integrity of the affected tube(s) is maintained until the next refueling outage or SG tube inspection, or be in HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
AND
- b. Plug the affected tube(s) in accordance with the Steam Generator Program prior to startup following the next refueling outage or SG tube inspection.
SURVEILLANCE REQUIREMENTS 4.4.5.0 Verify steam generator tube integrity in accordance with the Steam Generator Program.
4.4.5.1 Verify that each inspected SG tube that satisfies the tube repair criteria is plugged in accordance with the Steam Generator Program prior to startup following a SG tube inspection.
- Separate Action entry Is allowed for each SG tube.
SEQUOYAH - UNIT 2 3/4 4-10 E2-16
REACTOR COOLANT SYSTEM OPERATIONAL LEAKAGE LIMITING CONDITION FOR OPERATION 3.4.6.2 Reactor Coolant System leakage shall be limited to:
- a. No PRESSURE BOUNDARY LEAKAGE,
- b. 1 GPM UNIDENTIFIED LEAKAGE, C. 150 gallons per day of primary-to-secondary leakage through any one steam generator, and
- d. 10 GPM IDENTIFIED LEAKAGE from the Reactor Coolant System.
APPLICABILITY: MODES 1, 2, 3 and 4 or with primary-to-secondary leakage not within limits, ACTION: n PbS
- a. With any PRESSURE BOUNDARY LEAKAGý be in at least HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
- b. With any Reactor Coolant System leakage greater than any one of the above limits, excluding PRESSURE BOUNDARY LEAKAGE reduce the leakage rate to within limits I Verify within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or be in at least HOT STANDBY ithin the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
or primary-to-secondary leakage SU*RýILLANCE REQUIREMENTS 4.4.6.24 Reactor Coolant System leakages ha!l be vorifi:d to be .ithin each of the above limits b performance of a Reactor Coolant System water inventory balance at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.*
The provision of Specification 4.0.4 are not applicable for entry into MODE 3 or 4.
4.4.6.2.2 Yrf'; steam gene-rator tubhe ntgisyi inaccordance with th oiemotS of Technia
-4 R 344 4 9, S+aam kv9ReFatGF6.
[verify primary-to-secondary leakage is <150 gallons per day through any one steam Igenerator at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.*. 1 above surveillance requirement is not applicable to rhe primary-to-secondary leakage.
- Not required to be performed until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after establishment of steady state operation.
August 4, 2000 SEQUOYAH - UNIT 2 3/4 4-18 Amendment No. 211, 213, 250 E2-17
ADMINISTRATIVE CONTROLS
- b. Air lock testing acceptance criteria are:
- 1) Overall air lock leakage rate is < 0.05 L, when tested at >_ Pa.
- 2) For each door, leakage rate is < 0.01 La when pressurized to Ž_6 psig for at least two minutes.)
The provisions of SR 4.0.2 do not apply to the test frequencies specified in the Containment Leakage Rate Testing Program.
The provisions of SR 4.0.3 are applicable to the Containment Leakage Rate Testing Program.
- i. Configuration Risk Management Program (DELETED)
- j. Technical Specification (TS) Bases Control Program This program provides a means for processing changes to the Bases of these TSs.
- a. Changes to the Bases of the TS shall be made under appropriate administrative controls and reviews.
- b. Licensees may make changes to Bases without prior NRC approval provided the changes do not require either of the following:
- 1. A change in the TS incorporated in the license or
- 2. A change to the updated FSAR or Bases that requires NRC approval pursuant to 10 CFR 50.59.
- c. The Bases Control Program shall contain provisions to ensure that the Bases are maintained consistent with the FSAR.
- d. Proposed changes that meet the criteria of Specification 6.8.4.j.b above shall be reviewed and approved by the NRC prior to implementation. Changes to the Bases implemented without prior NRC approval shall be provided to the NRC on a frequency consistent with 10 CFR 50.71(e). "'
6.9 REPORTING REQUIREMENTS ROUTINE REPORTS 6.9.1 In addition to the applicable reporting requirements of Title 10, Code of Federal Regulations, the following reports shall be submitted in accordance with 10 CFR 50.4.
STARTUP REPORT 6.9.1.1 DELETED 6.9.1.2 DELETED 6.9.1.3 DELETED February 11, 2003 SEQUOYAH - UNIT 2 6-10 Amendment No. 28, 50, 64, 66, 134, 207,223, 231,271,272 E2-18
INSERT B from all sources, excluding the leakage attributed to the
- k. Steam Generator (SG) Program degradation described in 6.8.4.k.c.1 and .2, A Steam Generator Program shall be established and implemented to ensure that SG tube integrity is maintained. In addition, the Steam Generator Program shall include the following provisions:
- a. Provisions for Condition Monitoring Assessments.
Condition monitoring assessment means an evaluation of the "as found" condition of the tubing with respect to the performance criteria for structural integrity and accident induced leakage. The "as found" condition refers to the condition of the tubing during an SG inspection outage, as determined from the inservice inspection results or by other means, prior to the plugging of tubes. Condition monitoring assessments shall be conducted during each outage during which the SG tubes are inspected and/or plugged, to confirm that the performance criteria are being met. --
- b. Provisions for Performance Criteria for SG Tube Integrity. application of the alterate repair in TS 6.8.4.k.c.1, criteria discussed SG tiube integrity shall be maintained by meeting the performance criteria for tube struc:tural integrity, accident induced leakage, and operational leakage.
Structural integrity performance criterion: All in-service SG tubes shall retain For predominantly structural integrity over the full range of normal operating conditions (includi axially oriented startup, operation in the power range, hot standby, cooldown, and all antici ated transients included in the design specification) and design basis accidents /(DBAs).
This includes retaining a safety factor of 3.0 against burst under normal s eady state full power operation primary-to-secondary pressure differential an safety factor of 1.4 against burst applied to the DBA primary-to-secondary pressure elevations; (refer to differentials. Apart from the above requirements, additional loading conditions 6.8.4.k.c.1) the associated with the DBAs, or combination of accidents in accordance with the probability of burst design and licensing basis, shall also be evaluated to determine if the associated (POB) of one or loads contribute significantly to burst or collapse. In the assessment of tube more indications integrity, those loads that do significantly affect burst or collapse shall be given a steam line determined and assessed in combination with the loads due to pressure with a break shall be less safety factor of 1.2 on the combined primary loads and 1.0 on axial secondary than 1 x 10.2. loads. OW.
9.I I
- 2. Accident induced leakage performance crites."The accident induced leakage,*
not to exceed 1.0 gpm for the faulted SQ=xcopt for o.tcido di,,otor ctocs aerrociomncracký (ODSCC) and W* I lr-icationc that have an approved limit of
- g,.,.., . P .. , . The primary-to-secondary accident induced leakage rate for any DBA, other than a SG tube rupture, shall not exceed the leakage rate assumed in the accident analysis in terms of total leakage rate for all SGs and leakage rate for an individual SG.
- 3. The operational leakage performance criterion is specified in Limiting Condition of Operation (LCO) 3.4.6.2, "Reactor Coolant System, Operational Leakage."
- c. Provisions for SG Tube Repair Criteria.
Tubes found by inservice inspection to contain flaws with a depth equal to or exceeding 40% of the nominal tube wall thickness shall be plugged.
E2-19
INSERT B The following alternate tube repair criteria (ARC) may be applied as an alternative to the 40% depth based criteria:
GL 95-05 Voltage-Based ARC (Tube Support Plate [TSP])
A voltage-based TSP plugging limit is used for the disposition of an alloy 600 SG tube for continued service that is experiencing predominately axially oriented ODSCC confined within the thickness of the tube support plates (TSPs). At TSP intersections, the plugging (repair) limit is described below: below: .2.0 volts a) SG tubes, whose degradation is attributed to DSCC within the bounds of the TSP with bobbin voltages less thjan or equ t F l (Note1-)-,.will be allowed to remain in servi e.
b) SG tubes, whose degradation is attribu d to ODS within the bounds of the TSP with a bobbin voltage greater than"yoweM--(No....
will be repaiFed- plugged, except as noted in Item elow.
1 6.8.
c) SG tubes, with indications of potential degradation attrib ted to ODSCC wi in the bounds of the TSP with a bobbin voltage greater than rop,.rremain limit (N-o 1), but less than or equal pper voltage repair Iin may re ani.in service s riei if a rottn a cke coil inspectio does n detect d d t "V .5.i !le For comparable ais e) f on pe-re, unceule mi-cy letechnology isetfloig th I[lMi-yl e) If an unscheduled mid-cycle inspection is performed, the following mid-cycle repair limits apply instead of the limits identified in Items ba~d-G The mid-cycle repair limits are determined from the followin equations:
VSL 6.8.4.k.c.l.a), b), c), I i--
I 1.O+NDE+Gr (CL-At)
CL Wv "(CL-At)
=v - (vU- V L" where:
VURL upper voltage repair limit VLRL lower voltage repair limit VMURL mid-cycle upper voltage repair limit based on time into cycle VMLRL mid-cycle lower voltage repair limit based on V*uRL and time into cycle E2-20
INSERT B At length of time since last scheduled inspection during which VURL and Vu*_ were implemented CL cycle length (the time between two scheduled SG inspections)
VSL structural limit voltage Gr average growth rate per cycle length NDE 95 percent cumulative probability allowance for nondestructive examination uncertainty (i.e., a value I6.8.4kc.l.a), .b),.c) of 20 percent has been approved by KIM:nt Implemen/ation of these mid-cycle repair limits should follow the same approach as in TS items W Thne 1owor: veonage rcpair limit is 1.t volt for W4 iRen diameter tubing or
_w.uW_ 19911it *OF4!b menR oiamoter tu-mno Theo accnident leakage limit aopr-ovod fo-r 0-DSRC-C ARC_ andc- for W* calculated loakaao it n -7 4- 1- IL9__ ;-..I A C%
MI- - gt2mlidw Eb P"'I W0111MEG If I ty EZV W* Methodology J191 The implementation of WV does not aply to service induced de@adati R identified in the W* distance. Service induced dgradatioR identified in the W*.
distance below the top-of-tubesheet (TTS) shall be plugged on detection. The
- w.. ~ ,%J-r, .I5~.. r I~ Itt 3 ~* ~ *%~ JISA'~/ wrfl 1 JI'., .~.J TUvrt-.J~n~'Ir..
Ul bendrto thel te~n runnert ef the *.. Goldl lean ryr4,dinn the~ nnrtign
. . *o" of~ theWh waithiR the~
tu_ P_S.H.eM. UPI9W L[IeU U 1SIILGe, tH e IULU LU)t S.U '.40i 4UU MUU tH e U 19R_ A exteRsieiR.
The following terms/definitions apply to the W*.
a) Bottom of WEXTEX Transition (BWT) is the highest point of contact between the tube and tubesheet at, or below the U-S, as determined by eddy current testing.
b) W* Distance is the larger of the following two distances as measured from the TTS: (a) 8 inches below the U-S or (b) 7 inches below the bottom of the WEXTEX transition plus the uncertainty associated with determining the distance below the bottom of the WEXTEX transition as defined by WCAP-14797, Revision 2.
E2-21
INSERT B
- d. Provisions for SG Tube Inspections and d.4 Periodic SG tube inspections shall be perfor The number and portions of the tubes inspected and methods of inspection shall be/erformed with the objective of detecting
______flaws of any type (e.g., volumetric flaws, axi l and circumferential cracks) that may be
- present a long the length of the tube, from tfe tube-~to-tubesheet weld at the tube inlet to the tube-to-tubesheet weld at the tube o let, and that may satisfy the applicable tube repair criteria. The tube-to-tubesheet is not part of the tube. In addition to meeting I/ed the requirements of d.1, d.2, and d.3, 1elow, the inspection scope, inspection methods, and inspection intervals shall be such as to ensure that SG tube integrity is mainained until the next SG inspection. An assessment of degradation shall be performed to determine the type and location of flaws t t hhthe tubes may be susceptible and, based on this assessment, to determine which inspection methods need to be employed and at what locations.
- 2. Inspect 100% of the tubes at sequential peods of 60 effective full power months. The first sequential period shall be considered to begin than after the first inservice inspection of the SGs. No SGs shall operate for more 24 effective full power months or one refueling outage (whichever is less) without
- 3. If crackinspected.
being indications are found in any SG tube, then the next inspection for each SG for the degradation mechanism that caused the crack indication shall not and exeed 24 effective full power months or one refueling outage (whichever is less). Ifdefinitive information, such as from examination of a pulled tube, diagnostic non-destructive testing, or engineering evaluabtion indicates that a Scrack-like indication is not associated with a crack(s), then the indication need not be treated as a crack.
. IGL 95-05 Voltage-Based ARC for TSP Indications left in service as a result of application of the TSP voltage-based repair crtera shall be inspected by bobbin coil probed n aftere rst eutages*.
Implementation of the SG tube/TSP repair citera requires a 100 percent bobbin coil inspection for hot-leg and cold-leg TSP intersections down to the lowest cold-leg TSP with known ODSCC indications. The determination of the lowest cold-leg TSP intersections having ODSCC indications shall be based on lthe performance of at least a 20 perent random sampling of tubes inspected diKoover their full length.
p E2-22
INSERT B W* METHODOLOGY IS MOVED TO Methoolog REPAIR CRITERIA SECTION (c) ABOVE Imp etatonof the SG WEXTEX expanded regionofinspection methodolI ug:e l'etW N(*)
hot-le tu
,*, ercet rtating coil probe inspection the
- 100 distance. Te implementation of W* does not apply to service induce degradation identified in W* distance. Service induced degradation identff* in the W*
distance below t-top-of-tubesheet (TTS) shall be pluggedlon etection. The inspection of S tu s is from the point of entry (hot-leg sid completely around the U-bend to the top sup of the cold leg excluding the p ion of the tube within the tubesheet below the W* tance, the tube-to-tubeshe weld and the tube outlet end extension.
The following terms/definitions ap to the d) Bottom of WEXTEX Transiti WT) is the highest point of contact between the tube and tub eet or below the TTS, as determined by eddy current testing.
e) W* Distance is t larger of the following distances as measured from the TTS: (a) 8 ches below the U-S or (b) 7 1 es below the bottom of the WEXTEX t sition plus the uncertainty associa with determining the distance elow the bottom of the WEXTEX transitio as defined by WCA -14797, Revision 2.
f) Length is the length of tubing below the bottom of the B which must be demonstrated to be non-degraded in order for the tube to mi tain structural and leakage integrity. For the hot leg, the W* length is . inches which represents the most conservative hot leg length defined in WCAP-14797, Revision 2.
- e. Provisions for Monitoring Operational Primary-to-Secondary Leakage.
E2-23
ADMINISTRATIVE CONTROLS CORE OPERATING LIMITS REPORT (continued)
- 6. WCAP-1 0054-P-A, Westinghouse Small Break ECCS Evaluation Model Using the NOTRUMP Code, August 1985, &W_ Proprietary)
(Methodology for Specification 3/4.2.2 - Heat Flux Hot Channel Factor)
- 7. WCAP-1 0266-P-A, Rev. 2, "THE 1981 REVISION OF WESTINGHOUSE EVALUATION MODEL USING BASH CODE", March 1987, PN Proprietary).
(Methodology for Specification 3.2.2 - Heat Flux Hot Channel Factor).
- 8. BAW-10227P-A, "Evaluation of Advance Cladding and Structural Material (M5) in PWR Reactor Fuel," February 2000, (FCF Proprietary)
(Methodology for Specification 3/4.2.2 - Heat Flux Hot Channel Factor) 6.9.1.14.b The core operating limits shall be determined so that all applicable limits (e.g., fuel thermal-mechanical limits, core thermal-hydraulic limits, ECCS limits, nuclear limits such as shutdown margin, and transient and accident analysis limits) of the safety analysis are met.
6.9.1.14.c THE CORE OPERATING LIMITS REPORT shall be provided within 30 days after cycle start-up (Mode 2) for each reload cycle or within 30 days of issuance of any midcycle revision of the NRC Document Control Desk with copies to the Regional Administrator and Resident Inspector.
REACTOR COOLANT SYSTEM (RCS) PRESSURE AND TEMPERATURE LIMITS (PTLR)
REPORT 6.9.1.15 RCS pressure and temperature limits for heatup, cooldown, low temperature operation, criticality, and hydrostatic testing, LTOP arming, and PORV lift settings as well as heatup and cooldown rates shall be established and documented in the PTLR for the following:
Specification 3.4.9.1, "RCS Pressure and Temperature (PIT) Limits" Specification 3.4.12, "Low Temperature Over Pressure Protection (LTOP) System" 6.9.1.15.a The analytical methods used to determine the RCS pressure and temperature limits shall be those previously reviewed and approved by the NRC, specifically those described in the following documents:
- 1. Westinghouse Topical Report WCAP-1 4040-NP-A, "Methodology used to Develop Cold Overpressure Mitigating System Setpoints and RCS Heatup and Cooldown Limit Curves."
- 2. Westinghouse Topical Report WCAP-1 5321, "Sequoyah Unit 2 Heatup and Cooldown Limit Curves for Normal Operation and PTLR Support Documentation."
- 3. Westinghouse Topical Report WCAP-1 5984, "Reactor Vessel Closure Head/Vessel Flange Requirements Evaluation for Sequoyah Units I and 2."
6.9.1.15.b The PTLR shall be provided to the NRC within 30 days of issuance of any revision or supplement thereto.
SPECIAL REPORTS 6.9.2.1 Special reports shall be submitted within the time period specified for each report, in accordance with 10 CFR 50.4.
6.9.2.2 This specification has been deleted.
September 15,2004 SEQUOYAH - UNIT 2 6-14 Amendment Nos. 44, 50, 64, 66, 107,134,146,206,214,231,249,284 E2-24
INSERT C STEAM GENERATOR (SG) TUBE INSPECTION REPORT 6.9.1.16.1 A report shall be submitted within 180 days after the initial entry into MODE 4 following completion of an inspection performed in accordance with Specification 6.8.4.k, "Steam Generator (SG) Program." The report shall include:
- a. The scope of inspections performed on each SG,
- b. Active degradation mechanisms found,
- c. Nondestructive examination techniques utilized for each degradation mechanism,
- d. Location, orientation (if linear), and measured sizes (if available) of service induced indications,
- e. Number of tubes plugged during the inspection outage for each active degradation mechanism,
- f. Total number and percentage of tubes plugged to date,
- g. The results of condition monitoring, including the results of tube pulls and in-situ testing, and / - .
- h. The effective plu ng percentage for all plugg'g in each SG.
6.9.1.16.2 A report shall be bmitted within 90 days after the inj{ial entry into MODE 4 following completion otfn inspection performed in accordancq with the steam generator program (6.8.4.k) -voltage based alternate repair criteria @ applied. The report sh[ll include information described in Section 6.b of Attachment I to NRC Generic Letter 95-05, "Voltage-Based Repair Criteria for Westinghouse Steam Generator Tubes Affected by Outside Diameter Stress Corrosion Cracking."
I
- 1. For implementation of the voltage-based repair criteria for tube support plate (TSP) intersections, notify the staff prior to ' should any of the following conditions arise:
- 1) Leakage is estimiatted based on the projected end of-cycle (or9F not practical ng t-he ant-u-al measured end of cycle) v.'oltage dist,-buton. This leakage shall be combinod with the postulated leakage rcsulting from the projecated end Of cGycle accident induced leakagc from all. Sources exceeds the leakage limit (determined from the licensing basis dose calculation for the postulated main steamn line break) for the next operating cycle, the staff shall be])4*neie LIf circumferential crack-like indications are detected at the TSP intersections.
E2-25
INSERT C Eih* a3)If indications are identified that extend beyond the confines of the TSP.
ZJ-* 4)- If indications are identified at the TSP elevations that are attributable to primary water stress corrosion cracking.
6.9.1.16.4 5) if the cGalu*ated conditional burst pobabilit,; based on the proj-eted end Of cyc.e (or if not practica, using. the actual measured end of cycle) v.ltag.
distribution exceeds 1 X 10-2 netif' the NRC and proevide an assessment of the safety'signifcance of the occurrence.
".j--For implementation of W*, the calculated steam line break leakage from the application of TSP alternate repair criteria and W* inspection methodology shall be submitted *Aa Special Reot in accordance vWth 10 CFR 50.1 within V 90 day W The report will inci e the number of indications within the tubesheet region, the location of e indications (relative to the bottom of the WEXTEX transition [BWT] and TTS), the orientation (axial, circumferential, skewed, volumetric), the severity of each indication (e.g., near through-wall or not through-wall), the side of the tube from which the indication initiated (inside or outside diameter), and an assessment of whether the results were consistent with expectations with respect to the number of flaws and flaw severity (and if not consistent, a description of the proposed corrective action).
E2-26
ENCLOSURE 3 TENNESSEE VALLEY AUTHOR~ITY SEQUOYAH NUCLEAR PLANT (SQN)
UNIT 2 New TS Bases Page Markups for TS Change 05-0 9 E3-1
INSERT D REACTOR COOLANT SYSTEM BASES 3/4.4.5 STEAM GENERATORS The Surveillance Requirements for inspection of the steam generator tubes ensure that the s ctural integrity of this portion of the RCS will be maintained. The program for inservice inspe ion of s am generator tubes is based on a modification of Regulatory Guide 1.83, Revision 1. In rvice inspecd in of steam generator tubing is essential In order to maintain surveillance of the co itions of the tube the event that there is evidence of mechanical damage or progressive degra tion due to design, nufacturing errors, or inservice conditions that lead to corrosion. Inservic inspection of steam genera r tubing also provides a means of characterizing the nature and caus of any tube degradation so at corrective measures can be taken.
The plant is e ected to be operated in a manner such that the secon ry coolant will be maintained within thos emistry limits found to result in negligible corrosi of the steam generator tubes. If the secondary lant chemistry is not maintained within these I its, localized corrosion may likely result in stress co osion cracking. The extent of cracking d ing plant operation would be limited by the limitation of stea generator tube leakage beteen th primary coolant system and the secondary coolant system (prim -to-secondary leakage = 150 g ons per day per steam generator). Cracks having a prima -to-secondary leakage less tan this limit during operation will have an adequate margin of safety to ithstand the loads im sed during normal operation and by postulated accidents. Sequoyah has de onstrated that pri ary-to-secondary leakage of 150 gallons per day per steam generator can readily detected by r diation monitors of steam generator blowdown or condenser off-gas. Leakage in cess of is limit will require plant shutdown and an unscheduled inspection, during which the leaki tu s will be located and plugged.
The voltage-based repair limits of SR 4.. lement the guidance in GL 95-05 and are applicable only to Westinghouse-designed st m gen tors (S/Gs) with outside diameter stress corrosion cracking (ODSCC) located at the be-to-tube pport plate intersections. The voltage-based repair limits are not applicable to er formsf S/G be degradation nor are they applicable to ODSCC that occurs at other locatio within the S/G. Add, nally, the repair criteria apply only to indications where the degradation nchanism is dominantly axi ODSCC with no significant cracks extending outside the thickness oe support plate. Refer to GL -05 for additional description of the degradation morphology.
Implementation of 4.4.5 requires a derivation of the voltage st ctural limit from the burst versus voltage empirical rrelation and then the subsequent derivation of voltage repair limit from the structural limi which is then implemented by this surveillance).
The volta structural limit is the voltage from the burst pressure/bobbin vo ge correlation, at the 95 percent ediction interval curve reduced to account for the lower 95/95 perce tolerance bound for tu g material properties at 650°F (i.e., the 95 percent LTL curve). The volta structural limit must adjusted downward to account for potential flaw growth during an operating i erval and to acco for NDE uncertainty. The upper voltage repair limit; VuRL, is determined from the ctural volta limit by applying the following equation:
VUnRL - VSL VGR- VNDE April 9, 1997 SEQUOYAH - UNIT 2 B 3/4 4-3 Amendment No. 181, 211, 213 E3-2
REACTOR COOLANT SYSTEM BASES ere VGR represents the allowance for flaw growth between inspections andrVNDE represents the allowance for otential sources of error in the measurement of the bobbin coil voltage. Further discussion of the assu tions necessary to determine the voltage repair limit are discussed in GL 95-05.
mid-cycle equation of SR 4.4.5.4.a.10.e should only be used during unplanned inspection i wich eddy curren data is acquired for indications at the tube support plates.
SR 4.4. 5implements several reporting requirements recommended by GL 95-05 for si ations which NRC wants to be tified prior to returning the SIGs to service. For SR 4.4.5.5.d., Items 3 and , indications are applicable only ere alternate plugging criteria is being applied. For the purposes of th reporting requirement, leakage d conditional burst probability can be calculated based on the as--f nd voltage distribution rather than t projected end-of-cycle voltage distribution (refer to GL 95-05 r more information) when it is not practical to plete these calculations using the projected EOC voltag distributions prior to returning the S/Gs to serv ce. ote that if leakage and conditional burst probability ere calculated using the measured EQC voltage disstribW nfor the purposes of addressing GL Sections 61 .1and 6.a.3 reporting criteria, then the results of the pro cted EOC voltage distribution should be p ed per GIL Section 6.b(c) criteria.
Wastage-type defects are unlike with proper chemistry treatme of the secondary coolant. However, even if a defect should develop in service, will be found during sch ed inservice steam generator tube examinations. Plugging will be required for tubeswithime rfect s exceeding the repair limit defined in Surveillance Requirement 4.4.54.a. The porti ofthe be thatt plugging limit does not apply to is the portion of the tube that is not within the RCS pre roiunda ube end up to the start of the tubesto-tubesheet weld). The tube end to tube-to-tubeshee eld po n of the tube does not affect structural integrity of the steam generator tubes and therefore indication ou in this portion of the tube will be excluded from the Result and Acton Required for tube inspections. It is cted that any indications that extend from this region will be detected during the scheduled tube inspections, am generator tube inspections of operating plants have demonstrated the capability to reliably detect d radati that has penetrated 20% of the original tube wall thickness.
Tubes experiencing outside diameter ress rrosion crac ng within the thickness of the tube support plate are plugged or repaired by the criteria 4.4.5.4.a. 10.
The W* criteria incorprate the idance provided inWCAP-147 Revision 2, "Generic W* Tube Plugging Criteria for 51 Series Steam-enerator Tubesheet Region W Expansions.* W* length is the length of tubing into the tubesheet low the bottom of the WEXTEX transitio BWT) that precludes tube pullout in the event of a complet separation of the tube below t W*length. W* distance is crcumferential the distance from the top of th ubesheet to the bottom of the W* length including e distance from the top of the tubesheet to the BWT a measurement uncertainties.
Indications dete ed within the W* distance below the top-of-tube sheet (nS), wi be plugged upon detection. Tubes to ich WCAP-14797 is applied can experience through-wall degradatio up to the limits defined in Revision, without Increasing the probability of a tube rupture or large leakage eve Tub'e degradation of a type or 6xtent below W*, distance, including a complete circumferential sepa tion of the tube, is accept le. As applied at Sequoyah Nuclear Plant Unit 2, the W* methodology is used to efine the required tu nspection depth into the hot-leg tubesheet, and isý not used to permit degradation in th W*
distance to emain in service. Thus while primary to secondary leakage in the W* distance need not postulat , primary to secondary leakage from potential degradation below the W* distance will be assu for every ' service tube in the bounding steam generator.
May 3, 2005 QUOYAH - UNIT 2 B 3/4 4-3a Amendment No. 181, 211, 213, 243, 291 E3-3
REACTOR COOLANT SYSTEM BASES he postulated leakage during a steam line break shall be equal to the following equation:
Postulated SLB Leakage = ARC GL 95-05 + Assumed Leakage o-*-w<Trs + Assumed Leakag -.12"
<us + Asmed Leakage >.12"<TstS Where: CGL 95-05 is the normal SLB leakage derived from alternate repair crit a methods and the steam gen ator tube inspections.
Assumed Leakag - -rs is the postulated leakage for undetected i ications in steam generator tubes left in servic etween 0 and 8 inches below the top of t tubesheet.
AssumedLeakage 12. <,-rs the conservatively assumed ,kage from the total of identified andpostulated unidentified indication steam generator tub in service between 8 and 12 inches below the top of the tubesheet. Th is 0.0045 gpm Itiplied by the number of indications.
Postulated unidentified indications will be con rvatively sumed to be in one steam generator. The highest number of identified indications left in se e etween 8 and 12 inches below TTS in any one steam generator will be included in this term.
Assumed Leakage >12. <u-s is the co ervatively ass ed leakage for the bounding steam generator tubes left in service below 12 1 es below the top oe tubesheet. This is 0.00009 gpm multiplied by the number of tubes Iei service in the least plugg steam generator.
The aggregate calcula SLB leakage from the application of al temate repair criteria and the above assumed leaka shall be reported to the NRC in accordance wi pplicable Technical Specifications. The co r ned calculated leak rate from all alternate repair crite *must be less than the maximum allow e steam line break leak rate limit in any one steam generato order to maintain doses !in 10 CFR 100 guideline values and within GDC-19 values during stulated steam line b event.
May 3, 2005 SEQUOYAH - UNIT 2 B 3/4 4-3b Amendment No. 213,243,267, 291 E3-4
B 3.4 REACTOR COOLANT SYSTEM B 3/4.4.5 Steam Generator (SG) Tube Integrity BASES BACKGROUND Steam generator (SG) tubes are small diameter, thin walled tubes that carry primary coolant through the primary to secondary heat exchangers. The SG tubes have a number of important safety functions. Steam generator tubes are an integral part of the reactor coolant pressure boundary (RCPB) and, as such, are relied on to maintain the primary system's pressure and inventory. The SG tubes isolate the radioactive fission products in the primary coolant from the secondary system. In addition, as part of the RCPB, the SG tubes are unique in that they act as the heat transfer surface between the primary and secondary systems to remove heat from the primary system. This specification addresses only the RCPB integrity function of the SG. The SG heat removal function is addressed by Limiting Condition of Operation (LCO) 3.4.1.1, "Startup and Power Operation," LCO 3.4.1.2, "Hot Standby," LCO 3.4.1.3, "Shutdown," and LCO 3.4.1.4, "Cold Shutdown."
SG tube integrity means that the tubes are capable of performing their intended RCPB safety function consistent with the licensing basis, including applicable regulatory requirements.
Steam generator tubing is subject to a variety of degradation mechanisms. Steam generator tubes may experience tube degradation related to corrosion phenomena, such as wastage, pitting, intergranular attack, and stress corrosion cracking, along with other mechanically induced phenomena such as denting and wear. These degradation mechanisms can impair tube integrity if they are not managed effectively. The SG performance criteria are used to manage SG tube degradation.
Specification 6.8.4.k, "Steam Generator (SG) Program," requires that a program be established and implemented to ensure that SG tube integrity is maintained.
Pursuant to Specification 6.8.4.k, tube integrity is maintained when the SG performance criteria are met. There are three SG performance criteria: structural integrity, accident induced leakage, and operational leakage. The SG performance criteria are described in Specification 6.8.4.k. Meeting the SG performance criteria provides reasonable assurance of maintaining tube integrity at normal and accident conditions.
The processes used to meet the SG performance criteria are defined by the Steam Generator Program Guidelines (Ref. 1).
SEQUOYAH - UNIT 2 B 3/4 4-3
I ,or the NRC approved licensing basis.
BASES APPLICABLE The steam generator tube rupture (SGTR) accident is the limiting design SAFETY basis event for SG tubes and avoiding an SGTR is the basis for this ANALYSES specification. The analysis of an SGTR event assumes a bounding primary to secondary leakage rate equal to the operational leakage rate limits in LCO 3.4.6.2 "Operational Leakage," plus the leakage rate associated with a double-ended rupture of a single tube. The accident analysis for a SGTR assumes the contaminated secondary fluid is released to the atmosphere via safety valves. The main condenser isolates based on an assumed concurrent loss of off-site power.
The analysis for design basis accidents and transients other than a SGTR assume the SG tubes retain their structural integrity (i.e., they are assumed not to rupture).
In these analyses, the steam discharge to the atmosphere is based on a primary to secondary leakage of 0.1 gallons per minute (gpm) for the non-faulted SGs and 3.7 gpm for the faulted Sq. This limit is approved for use for alternate repair criteria (ARC) and W* le ge calculations. For non-ARC applications, the accident Pinduced leak in the faulted SG is limited safety bounded by the to 1.0 gpm, which is accidents maximum, aekage established by the plant analysis. For that do not iny ,e fuel damage, the primary coolant activity level of DOSE EQUIVALENT I-1 is assumed to be equal to the LCO 3.4.8, "Specific Activity," limits. For ccldents amount of that assume activity released damage, fuel from the primary the damaged coolant fuel. activity The dose consequences of the is a function of these events are within the limits of GDC 19 (Ref. 2), 10 CFR 100 (Ref. 3), "
Steam o generator tube integrity satisfies Criterion 2 of 10 CFR
"*,*0.36(c)(2)(ii).
LCO The LCO requires that SG tube integrty be maintained. The LCO also requires that all SG tubes that satisfy the repair citera be plugged in accordance with the Steam Generator Program.
During an SG inspection, any inspected tube that satisfies the Steam Generator Program repair cteria is removed from service by plugging. if a tube was determined to satisfy the repair criteria but was not plugged, the tube may still have tube integrity. s In the context of this specification,ta SG tube is defined as the entire length of the tube, including the tube wall, between the tube-to-tubesheet weld at the tube inlet and the tube-to-tubesheet weld at the tube outlet.
The tube-to-tubesheet weld is not considered part of the tube.
SEQUOYAH - UNIT 2 B 3/4 4-3a E3-6
BASES LCO (continued)
A SG tube has tube integrity when it satisfies th6 SG performance cdteria. The SG performance criteria are defined in Specification 6.8.4.k, "Steam Generator Program," and describe acceptable SG tube performance. The Steam Generator Program also provides the evaluation .process for determining conformance with the SG performance criteria.
There are three SG performance criteria: structural integrity, accident induced leakage, and operational leakage. Failure to meet any one of these criteria is considered failure to meet the LCO.
The structural integrity performance criterion provides a margin of safety against tube burst or collapse under normal and accident conditions, and ensures structural integrity of the SG tubes under all anticipated transients included in the design specification. Tube burst is defined as, "The gross structural failure of the tube wall. The condition typically corresponds to an unstable opening displacement (e.g., opening area increased in response to constant pressure) accompanied by ductile (plastic) tearing of the tube material at the ends of the degradation." Tube collapse is defined as, "For the load displacement curve for a given structure, collapse occurs at the top of the load versus displacement curve where the slope of the curve becomes zero." The structural integrity performance criterion provides guidance on assessing loads that have a significant effect on burst or collapse. In that context, the term "significant" is defined as "An accident loading condition other than differential pressure is considered significant when the addition of such loads in the assessment of the structural integrity performance criterion could cause a lower structural limit or limiting burst/collapse condition to be established." For tube integrity evaluations, except for circumferential degradation, axial thermal loads are classified as secondary loads. For circumferential degradation, the classification of axial thermal loads as primary or secondary loads will be evaluated on a case-by-case basis. The division between primary and secondary classifications will be based on detailed analysis and/or testing.
Structural integrity requires that the primary membrane stress intensity in a tube not exceed the yield strength for all American Society of Mechanical Engineers (ASME)
Code,Section III, Service Level A (normal operating conditions), and Service Level B (upset or abnormal conditions) transients included in the design specification.
This includes safety factors and applicable design basis loads based on ASME Code,Section III, Subsection NB (Ref. 4) and Draft Regulatory Guide 1.121 (Ref.
5).
SEQUOYAH - UNIT 2 B 3/4 4-3b E3-7
BASES LCO (continued)
The accident induced leakage performance criterion ensures that the primary to secondary leakage caused by a design basis accident, other than a SGTR, is within the accident analysis assumptions. In the main steam line break (MSLB) analysis for ARC, SG leakage is assumed to be 3.7 gpm for the faulted SG and 0.1 gpm for the non-faulted S . Limiting the allowable leakage in the faulted SG to 1.0 gpm for non-ARC ap cations ensures that the MSLB analysis remains conservative and boundin e accident induced leakage rate includes any primary to W " secondary akage existing prior to the accident in addition to primary to secondary leakage' duced during the accident. The 3.7 gpm is approved for use in ARC appli tions where the cracks are limited to locations within the tubesheet or within a lied tube support plate.
_The operational leakage performance criterion provides an observable indication of SG tube conditions during plant operation. The limit on operational leakage is contained in LCO 3.4.6.2, "Operational Leakage," and limits primary to secondary leakage through any one SG to 150 gallons per day. This limit is based on the assumption that a single crack leaking this amount would not propagate to a SGTR under the stress conditions of a loss-of-coolant accident (LOCA) or a MSLB. If this amount of leakage is due to more than one crack, the cracks are very small, and the above assumption is conservative.
APPLICABILITY Steam generator tube integrity is challenged when the pressure differential across the tubes is large. Large differential pressures across SG tubes can only be experienced in MODES 1,2, 3, or 4.
Reactor coolant system (RCS) conditions are far less challenging in MODES 5 and 6 than during MODES 1, 2, 3, and 4. In MODES 5 and 6, primary to secondary differential pressure is low, resulting in lower stresses and reduced potential for leakage.
ACTIONS The ACTIONs are modified by a clarifying footnote that Action (a) may be entered independently for each SG tube. This is acceptable because the actions provide appropriate compensatory measures for each affected SG tube. Complying with the actions may allow for continued operation, and subsequent affected SG tubes are governed by subsequent action entry, and application of associated actions.
SEQUOYAH - UNIT 2 B 3/4 4-3c E3-8
BASES ACTIONS (continued)
Actions (a) and (b)
Action (a) applies if it is discovered that one or more SG tubes examined in an inservice inspection satisfy the tube repair criteria but were not plugged in accordance with the Steam Generator Program as required by SR 4.4.5.1. An evaluation of SG tube integrity of the affected tube(s) must be made. Steam generator tube integrity is based on meeting the SG performance criteria described in the Steam Generator Program. The SG repair criteria define limits on SG tube degradation that allow for flaw growth between inspections while still providing assurance that the SG performance criteria will continue to be met. In order to determine if a SG tube that should have been plugged has tube integrity, an evaluation must be completed that demonstrates that the SG performance criteria will continue to be met until the next refueling outage or SG tube inspection. The tube integrity determination is based on the estimated condition of the tube at the refueling outage or the situation Is discovered and the estimated growth of the degradation prior to the ne inspection. If it is determined that tube integrity is not being mantaine G inspection, Action (a) requires unit shutdown and However, the Action (b) requires the affected tube(s) be plugged.
affected tube(s) An allowed time of 7 days is sufficient to complete the evaluation while minimizing must be plugged the risk of plant operation with a SG tube that may not have tube integrity.
prior to startup following the next If the evaluation determines that the affected tube(s) have tube integrity, Action (a) refueling outage or allows plant operation to continue until the next refueling outage or SG inspection SG inspection. provided the inspection interval continues to be supported by an operational assessment that reflects the affected tubes.+This allowed time is acceptable since operation until the next inspection is supported by the operational assessment.
I G tube integrity is not being maintained he reactor-must be brought to HOT at any time, ,STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD SHUT DWN within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> and the evaluation determinE affected tube(s) plugged prior to restart,,. ."fue!!ng -t, or SG I (Mode 4).
The action times are reasonable, based on operatin xperience, to reach the desired plant condition from full power in an orderly ma ner and without challenging plant systems.
I CZ~fl.~,flfl,~flA6~F SEQUOYAH - UNIT 2 B 3/4 4-3d E3-9
BASES SURVEILLANCE SR 4.4.5.0 REQUIREMENTS Dudng shutdown periods the SGs are inspected as required by this SR and the Steam Generator Program. NEI 97-06, Steam Generator Program Guidelines (Ref.
1), and its referenced EPRI Guidelines, establish the content of the Steam Generator Program. Use of the Steam Generator Program ensures that the inspection is appropriate and consistent with accepted industry practices.
During SG inspections a condition monitoring assessment of the SG tubes is performed. The condition monitoring assessment determines the "as found" condition of the SG tubes. The purpose of the condition monitoring assessment is to ensure that the SG performance criteria have been met for the previous operating period.
The Steam Generator Program determines the scope of the inspection and the methods used to determine whether the tubes contain flaws satisfying the tube repair criteria. Inspection scope (i.e., which tubes or areas of tubing within the SG are to be inspected) is a function of existing and potential degradation locations.
The Steam Generator Program also specifies the inspection methods to be used to find potential degradation. Inspection methods are a function of degradation morphology, nondestructive examination (NDE) technique capabilities, and inspection locations.
The Steam Generator Program defines the frequency of SR 4.4.5.0. The frequency is determined by the operational assessment and other limits in the SG examination guidelines (Ref. 6). The Steam Generator Program uses information on existing degradations and growth rates to determine an inspection frequency that provides reasonable assurance that the tubing will meet the SG performance criteria at the next scheduled inspection. In addition, Specification 6.8.4.k contains prescriptive requirements concerning inspection intervals to provide added assurance that the SG performance criteria will be met between scheduled inspections.
SEQUOYAH - UNIT 2 B 3/4 4-4 E3-10
BASES SURVEILLANCE REQUIREMENTS (continued)
SR 4.4.5.1 During an SG inspection, any inspected tube that satisfies the Steam Generator Program repair criteria is removed from service by plugging. The tube repair criteria delineated in Specification 6.8.4.k are intended to ensure thattubes accepted for continued service satisfy the SG performance criteria with allowance for error in the flaw size measurement and for future flaw growth. In addition, the tube repair criteria, in conjunction with other elements of the Steam Generator Program, ensure that the SG performance criteria will continue to be met until the next inspection of the subject tube(s). Reference I provides guidance for performing operational assessments to verify that the tubes remaining in service will continue to meet the SG performance criteria.
The frequency of this surveillance ensures that the surveillance has been completed and all tubes meeting the repair criteria are plugged prior to subjecting the SG tubes to significant primary to secondary pressure differential I (i.e., prior to HOT SHUTDOWN following a SG tube inspection) I REFERENCES 1. NEI 97-06, "Steam Generator Program Guidelines."
- 3. 10 CFR 100.
- 4. ASME Boiler and Pressure Vessel Code,Section III, Subsection NB.
- 5. Draft Regulatory Guide 1.121, "Basis for Plugging Degraded Steam Generator Tubes," August 1976.
- 6. EPRI, "Pressurized Water Reactor Steam Generator Examination Guidelines."
SEQUOYAH - UNIT 2 B 3/4 4-4a E3-11
INSERT E Voltage-Based Alternate Repair Criteria (ARC) and W* Methodoloqy a) Voltage-Based ARC The voltage-based repair limits implement the guidance in Generic Letter (GL) 95-05 and are applicable only to Westinghouse-designed steam generators (SGs) with outside diameter stress corrosion cracking (ODSCC) located at the tube-to-tube support plate intersections.
The voltage-based repair limits are not applicable to other forms of SG tube degradation nor are they applicable to ODSCC that occurs at other locations within the SG. Additionally, the repair criteria apply only to indications where the degradation mechanism is dominantly axial ODSCC with no significant cracks extending outside the thickness of the support plate. Refer to GL 95-05 for additional description of the degradation morphology.
Implementation of voltage-based repair limits require a derivation of the voltage structural limit from the burst versus voltage empirical correlation and then the subsequent derivation of the voltage repair limit from the structural limit (which is then implemented by this surveillance).
The voltage structural limit is the voltage from the burst pressure/bobbin voltage correlation, at the 95 percent prediction interval curve reduced to account for the lower 95/95 percent tolerance bound for tubing material properties at 650°F (i.e., the 95 percent lower tolerance limit curve). The voltage structural limit must be adjusted downward to account for potential flaw growth during an operating interval and to account for NDE uncertainty. The upper voltage repair limit; VURL, is determined from the structural voltage limit by applying the following equation:
VURL = VSL - VGR - VNDE where VGR represents the allowance for flaw growth between inspections and VNDE represents the allowance for potential sources of error in the measurement of the bobbin coil voltage.
Further discussion of the assumptions necessary to determine the voltage repair limit are discussed in GL 95-05.
The mid-cycle equation of TS 6.8.4.k.c.1 .- should only be used durng unplanned inspection in
- .9.1.16.3 which eddy current data is acquired for indications at the tube support plates.
Specification 69.16 implements several reporting requirements recommended by GL 95-05 for situations which NRC wants to be notified prior to returning the SGs to service. For 6._9*464, Item , indications are applicable only where alternate plugging criteria is being applii. For the purposes of this reporting requirement, leakage and conditional burst probaO" can be calculated based on the as-found voltage distribution rather than the ected end-of-cycle (EOC) voltage distribution (refer to GL 95-05 for more information) 2 and 3 when it is not practical to complete these calculations using the projected EOC voltage distdrbutions prior to returning the SGs to service. Note that if leakage and conditional burst probability were calculated using the measured EOC voltage distribution for the purposes of addressing GL Sections 6.a.1 and 6.a.3 reporting criteria, then the results of the projected EOC voltage distribution should be provided per GL Section 6.b(c) criteria.
E3-12
INSERT E (Continued) repair limit defined in Specification 6.8.4.k.c. The portion of the tube that the plugging limit does not apply to is the portion of the tube that is not within the RCS pressure boundary (tube end up to the start of the tube-to-tubesheet weld). The tube end tube-to-tubesheet weld portion of the tube does not affect structural integrity of the SG tubes and therefore indications found in this portion of the tube will be excluded from the "Result and Action Required" for tube inspections. It is expected that any indications that extend from this region will be detected during the scheduled tube inspections. SG tube inspections of operating plants have demonstrated the capability to reliably detect degradation that has penetrated 20% of the original tube wall thickness.
Tubes experiencing ODSCC within the thickness of the tube support plate are plugged or repaired by the criteria of 6.8.4.k.c.1.
b) W* Methodology The W* criteria incorporates the guidance provided in WCAP-14797, Revision 2, "Generic W*
Tube Plugging Criteria for 51 Series Steam Generator Tubesheet Region WEXTEX Expansions." W* length is the length of tubing into the tubesheet below the bottom of the WEXTEX transition (BWT) that precludes tube pullout in the event of a complete circumferential separation of the tube below the W* length. W* distance is the distance from the top-of-tube sheet (TTS) to the bottom of the W* length including the distance from the TTS to the BWT and measurement uncertainties.
Indications detected within the W* distance below the TTS, will be plugged upon detection.
Tubes to which WCAP-14797 is applied can experience through-wall degradation up to the limits defined in Revision 2 without increasing the probability of a tube rupture or large leakage event. Tube degradation of any type or extent below W* distance, including a complete circumferential separation of the tube, is acceptable. As applied at Sequoyah Nuclear Plant Unit 2, the W* methodology is used to define the required tube inspection depth into the hot-leg tubesheet, and is not used to permit degradation in the W* distance to remain in service.
Thus while primary to secondary leakage in the W* distance need not be postulated, primary to secondary leakage from potential degradation below the W* distance will be assumed for every inservice tube in the bounding SG.
c) Calculation of Accident Leakage The postulated leakage during a steam line break (SLB) shall be equal to the following equation:
Postulated SLB Leakage = ARC GL 95-05 + Assumed Leakage 0--erTrs + Assumed Leakage 8--2
<rs + Assumed Leakage >12. Trs Where: ARC GL 95-05 is the normal SLB leakage derived from ARC methods and the SG tube inspections.
Assumed Leakage 0--r<rs is the postulated leakage for undetected indications in SG tubes left in service between 0 and 8 inches below the TTS.
Assumed Leakage 12-.<rs is the conservatively assumed leakage from the total of identified and postulated unidentified indications in SG tubes left in service between 8 and 12 inches E3-13
INSERT E (Continued) below the TTS. This is 0.0045 gpm multiplied by the number of indications. Postulated unidentified indications will be conservatively assumed to be in one SG. The highest number of identified indications left in service between 8 and 12 inches below TTS in any one SG will be included in this term.
Assumed Leakage >IT-,TTT s the conservatively assumed leakage for the bounding SG tubes left in service below 12 ches below the UTS. This is 0.00009 gpm multiplied by the number of tubes left in service n the least plugged SG.
The aggregate cumulated SLB leakage from the application of all ARC and the above assumed leaka shall be reported to the NRC in accordance with technical specifications The combined calculated leak rate from all ARC must be less than the maximum allowable SLB leak rate limit in any one SG in order to maintain doses within 10 CFR 100 guideline values and within GDC-19 values during a postulated SLB event.
E3-14
INSERT F
- 7. NRC Generic Letter 95-05, Voltage Based Repair Criteria for Westinghouse Steam Generator Tubes Affected by Outside Diameter Stress Corrosion Cracking
- 8. NRC letter to TVA dated April 9, 1997, Issuance of Technical Specification Amendments for the Sequoyah Nuclear Plant, Units I and 2 (TAC Nos. M96998 and M96999) (TS 96-05)
- 9. NRC letter to TVA dated May 3, 2005, Sequoyah Nuclear Plant, Unit 2 - Issuance of Amendment Regarding Changes to the Inspection Scope for the Steam Generator Tubes (TAC No. MC5212) (TS-03-06)
E3-15
REACTOR COOLANT SYSTEM BASES 3/4.4.6.2 OPERATIONAL LEAKAGE BACKGROUND Components that contain or transport the coolant to or from the reactor core make up the reactor coolant system (RCS). Component joints are made by welding, bolting, rolling, or pressure loading, and valves isolate connecting systems from the RCS.
During plant life, the joint and valve interfaces can produce varying amounts of reactor coolant leakage, through either normal operational wear or mechanical deterioration. The purpose of the RCS Operational leakage LCO is to limit system operation in the presence of leakage from these sources to amounts that do not compromise safety. This LCO specifies the types and amounts of leakage.
10 CFR 50, Appendix A, GDC 30 (Ref. 1), requires means for detecting and, to the extent practical, identifying the source of reactor coolant leakage. Regulatory Guide 1.45 (Ref. 2) describes acceptable methods for selecting leakage detection systems.
The safety significance of RCS LEAKAGE varies widely depending on its source, rate, and duration. Therefore, detecting and monitoring reactor coolant leakage into the containment area is necessary. Quickly separating the identified LEAKAGE from the unidentified leakage is necessary to provide quantitative information to the operators, allowing them to take corrective action should a leak occur that is detrimental to the safety of the facility and the public.
A limited amount of leakage inside containment is expected from auxiliary systems that cannot be made 100% leaktight. Leakage from these systems should be detected, located, and isolated from the containment atmosphere, if possible, to not interfere with RCS leakage detection.
This LCO deals with protection of the reactor coolant pressure boundary (RCPB) from degradation and the core from inadequate cooling, in addition to preventing the accident analyses radiation release assumptions from being exceeded. The consequences of violating this LCO include the possibility of a loss of coolant accident (LOCA).
safety analyses events APPLICABLE Except for primary-to-secondary leakage, the SAFETY ANALYSES do not address operational leakage. However, other o a leakage is related to the safety analyses for LOCA; the amount o ge can affect the probability of such an event. The safety analysis for. resulting in steam discharge to the atmosphereassumeo a . gpm prima.y to. Onday . leakage as the .. itial co.ndition.
"maximum normal operational leakage of 0.4 gpm (0.1 gpm per steam generator or the equivalent of 150 gallons per day per steam generator).
August 4, 2000 SEQUOYAH - UNIT 2 B 3/4 4-4e Amendment No. 211,213, 227,250 E3-16
REACTOR COOLANT SYSTEM steam generator tube rupture or a BASES Primary to secondary leakag) is a fator in the dose releases outside containment resulting from a team Ih e break (SLB) accident. To a lesser extent, other accidents or transientsivolve secondary steam release to the atmosphere , ,.h as a steam,., ,,
. ...... , .p -Tr' . The leakage j ontaminates the secondary fluid. '0.4 gpm operational he FSAR (Ref. 3) analysis fcr SGTR assumes the contaminated s ondary RC fluid is released via safety valjres for up to 30 minutes. Operator acti is taken to isolate the affected steam Cenerator within this time period. The m
[
with ARC applied leakage, I seondary leakagiAs relatively inconsequential. tthrough thefc the affectedl ri The SLB is more limiting for site radiation releases. The safetyanalysis for the L c n s pm primary to secondary leakage agenerator s a maximu an initial condition. The dose consequences resulting from the SLB accident are well within the limits defined in 10 CFR 100 or the staff approved licensing basis (i.e., a small fraction of these limits). Based on the NDE uncertainties, bobbin coil voltage distribution and crack growth rate from the previous inspection, the expected leak rate following a steam line rupture is limited to belov#82 gpm at atmospheric conditions and 70°F in the faulted loop, which will limit the Zat+/-Iated-ofite doses to within 10 percent of the 10 CFR 100 guidelines. If the projected and Ey tion of crack indications results in primary-to-secondary leakage greater than & gpm in the faulted loop during a postulated steam line break event, additional tubes must be removed from service in order to reduce the postulated primary-to-secondary steam line break leakage to below 98-1. gpm. I and 0.3 gpm through the non-affected generators 1 The RCS operational leakage satisfies I Criterion 22 of the NRC Policy Statement.
LCO RCS operational leakage shall be limited to:
- a. PRESSURE BOUNDARY LEAKAGE No PRESSURE BOUNDARY LEAKAGE is allowed, being indicative of material deterioration. Leakage of this type is unacceptable as the leak itself could cause further deterioration, resulting in higher leakage. Violation of this LCO could result in continued degradation of the RCPB. Leakage past seals and gaskets is not PRESSURE BOUNDARY LEAKAGE.
- b. UNIDENTIFIED LEAKAGE One gpm of UNIDENTIFIED LEAKAGE is allowed as a reasonable minimum detectable amount that the containment air monitoring and containment pocket September 11,2003 SEQUOYAH - UNIT 2 B 3/4 4-4f Amendment No. 211, 213, 227,250 E3-17
REACTOR COOLANT SYSTEM BASES sump level monitoring equipment can collectively detect within a I reasonable time period. Violation of this LCO could result in continued degradation of the RCPB, if the leakage is from the pressure boundary.
C. Primary to Secondary Leakage through Any One Steam Generator (SGI 150 gallons per day limit on one SG is based on the assumption th single c king this amount would not propagate to a SGTR u r the stress con s of a LOCA or a main steam line rupture. If I ed through many cracks, the cks are very small, and the above mption is conservative. **..
The 150-gallons per day limit in ra into Surveillance 4.4.6.2.1 is more restrictive than the standard leakage limit and is intended to provide an additional ma'gi accommoda crack which might grow at a greater than expected or unexpectedly exten tside the thickness of the tube support e. Hence, the reduced leakage li hen combined with an effe leak rate monitoring program, provides addii al assu that, should a significant leak be experienced, it will be cted, e plant shut down in a timely manner.
- d. IDENTIFIED LEAKAGE Up to 10 gpm of IDENTIFIED LEAKAGE is considered allowable because leakage is from known sources that do not interfere with detection of UNIDENTIFIED LEAKAGE and is well within the capability of the RCS Makeup System. IDENTIFIED LEAKAGE includes leakage to the containment from specifically known and located sources, but does not include PRESSURE BOUNDARY LEAKAGE or controlled reactor coolant pump (RCP) seal leakoff (a normal function not considered leakage).
Violation of this LCO could result in continued degradation of a component or system.'
APPLICABILITY In MODES 1, 2, 3, and 4, the potential for reactor coolant PRESSURE BOUNDARY LEAKAGE is greatest when the RCS is pressurized.
In MODES 5 and 6, leakage limits are not required because the reactor coolant pressure is far lower, resulting in lower stresses and reduced potentials for leakage.
May 17, 2002 SEQUOYAH - UNIT 2 B 3/4 4-4g Amendment No. 211,213,227,250 E3-18
REACTOR COOLANT SYSTEM BASES LCO 3/4.4.6.3, "RCS Pressure Isolation Valve (PIV) Leakage," measures leakage through each individual PIV and can impact this LCO. Of the two PIVs in series in each isolated line, leakage measured through one PIV does not result in RCS leakage when the other is leak tight. If both valves leak and result in a loss of mass from the RCS, the loss must be included in the allowable IDENTIFIED LEAKAGE.
ACTIONS Action a: A or with primary to secondary leakage not within limits, If any PRESSURE BOUNDARY LEAKAGE existsthe reactor must be brought to lower pressure conditions to reduce the severity of the leakage and its potential consequences. It should be noted that leakage past seals and gaskets is not PRESSURE BOUNDARY LEAKAGE. The reactor must be brought to MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and MODE 5 within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. This action reduces the leakage and also reduces the factors that tend to degrade the pressure boundary.
The allowed completion times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. In MODE 5, the pressure stresses acting on the RCPB are much lower,and further deterioration is much less likely.
Action b:
UNIDENTIFIED LEAKAG 7 IDENTI D LEAKAGE, or pima;y to-Gcwonday leakage in excess of the LCO limits mus e reduced to within limits within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. This completion time allows time to leakage rates and either identify UNIDENTIFIED LEAKAGE or reduce le e to within limits before the reactor must be shut down. This action is necessa prevent further deterioration of the RCPB. If UNIDENTIFIED LEAKAG,, IDENTIFIED LEAKAGE;
-r p.imry to second.a; leakage cannot be reduced to within limits within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, the reactor must be brought to lower pressure conditions to reduce the severity of the leakage and its potential consequences. The reactor must be brought to MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and MODE 5 within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. This action reduces the leakage and also reduces the factors that tend to degrade the pressure boundary.
The allowed completion times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems. In MODE 5, the pressure stresses acting on the RCPB are much lower, and further deterioration is much less likely.
August 4, 2000 SEQUOYAH - UNIT 2 B 3/4 4-4h Amendment No. 211,213, 227, 250 E3-19
REACTOR COOLANT SYSTEM BASES SURVEILLANCE Surveillance 4.4,6.2.1 REQUIREMENTS Verifying RCS leakage to be within the LCO limits ensures the integrity of the RCPB is maintained. PRESSURE BOUNDARY LEAKAGE would at first appear as UNIDENTIFIED LEAKAGE and can only be positively identified by inspection. It should be noted that leakage past seals and gaskets is not PRESSURE BOUNDARY LEAKAGE. UNIDENTIFIED LEAKAGE and IDENTIFIED LEAKAGE are determined by performance of an RCS water inventory balance.
'the P.m-.r,'to cnr',' loa.ago ,i.,a,kemau*red by pe*rfFmance o-f an RC--S-Z ,,ater
- nven;toiy ballnc in conjunction With offluont moni~toring within the seoodar,'
steam and feedwate: sy-stoms.
The surveillance is Th CS water inventory balance must be met with the reactor at steady state Imodified by a opera g conditions (stable pressure, temperature, power level, pressurizer and footnote . I makeup nk levels, makeup, letdown, and RCP seal injection and return flows).
L . J we &ootnote -s add-ed-alewfn. that this SR is not required to be performed until 12 ho after establishing steady state operation. The 12-hour allowance provides suffi ent time to collect and process all necessary data after stable plant conditions are stablished. Performance of this surveillance within the 12-hour allowance is re ired to maintain compliance with the provisions of Specification 4.0.3. states Steady state operation is required to perform a proper inventory balance since calculations during maneuvering are not useful. For RCS operational leakage determination by water inventory balance, steady state is defined as stable RCS pressure, temperature, power level, pressurizer and makeup tank levels, makeup and letdown, and RCP seal injection and return flows.
An early warning of PRESSURE BOUNDARY LEAKAGE or UNIDENTIFIED LEAKAGE is provided by the automatic systems that monitor the containment atmosphere radioactivity and the containment pocket sump level. It should be noted that leakage past seals and gaskets is not PRESSURE BOUNDARY LEAKAGE. These leakage detection systems are specified in LCO 3/4.4.6.1, "Leakage Detection Instrumentation."
The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> frequency is a reasonable interval to trend leakage and recognizes the importance of early leakage detection in the prevention of accidents.
Surveillance 4.4.6.2.2
-rrs_~lace provides the means necessary to determine SG 0 in*-'
IINSERTI I an operationadrMG9E5-.]Deeeeerequirement to denmonsta negrity in at normal 0 " dtos August 4, 2000 SEQUOYAH - UNIT 2 B 3/4 4-4i Amendment No. 211,213, 227, 250 E3-20
REACTOR COOLANT SYSTEM BASES REFERENCES 1. 10 CFR 50, Appendix A, GDC 30.
- 2. Regulatory Guide 1.45, May 1973.
- 3. FSAR, Section 15.4.3.
/ 4. NEI 97-06, "Steam Generator Program Guidelines."
- 5. EPRI, "Pressurized Water Reactor Primary-to-Secondary Leak Guidelines."
I August 4, 2000 SEQUOYAH - UNIT 2 B 3/4 4-4j Amendment No. 211,213, 227,250 E3-21
INSERT G The limit of 150 gallons per day per SG is based on theoperational leakage performance criterion in NEI 97-06, Steam Generator Program Guidelines (Ref. 4). The Steam Generator Program operational leakage performance criterion in NEI 97-06 states, "The RCS operational primary to secondary leakage through any one SG shall be limited to 150 gallons per day."
The limit is based on operating experience with SG tube degradation mechanisms that result in tube leakage. The operational leakage rate criterion, in conjunction with the implementation of the Steam Generator Program, is an effective measure for minimizing the frequency of SG tube ruptures.
INSERT H Notation associated with this SR states that this SR is not applicable to primary to secondary leakage because leakage of 150 gallons per day cannot be measured accurately by an RCS water inventory balance.
INSERT I This SR verifies that primary to secondary leakage is less than or equal to 150 gallons per day through any one SG. Satisfying the primary to secondary leakage limit ensures that the operational leakage performance criterion in the Steam Generator Program is met. If this SR is not met, compliance with LCO 3.4.5, "Steam Generator Tube Integrity," should be evaluated.
The 150 gallons per day limit is measured at 70 degrees Fahrenheit (Reference 5). The operational leakage rate limit applies to leakage through any one SG. If it is not practical to assign the leakage to an individual SG, all the primary-to-secondary leakage should be conservatively assumed to be from one SG.
The surveillance is modified by a note which states that the surveillance is not required to be performed until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after establishment of steady state operation. For RCS primary-to-secondary leakage determination, steady state is defined as stable RCS pressure, temperature, power level, pressurizer and makeup tank levels, makeup and letdown, and RCP seal injection and return flows.
The surveillance frequency of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is a reasonable interval to trend primary-to-secondary leakage and recognizes the importance of early leakage detection in the prevention of accidents. The primary-to-secondary leakage is determined using continuous process radiation monitors or radiochemical grab sampling in accordance with the EPRI guidelines (Ref. 5).
E3-22