ET 09-0025, Revision to Technical Specification (TS) 5.5.9, Steam Generator (SG) Program, and TS 5.6.10, Steam Generator Tube Inspection Report

Revision to Technical Specification (TS) 5.5.9, Steam Generator (SG) Program, and TS 5.6.10, Steam Generator Tube Inspection Report

ML092730340
Person / Time
Site:	Wolf Creek
Issue date:	09/15/2009
From:	Garrett T Wolf Creek
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
ET 09-0025
Download: ML092730340 (15)

Text

WSLF CREEK WNUCLEAR OPERATING CORPORATION Terry J. Garrett September 15, 2009 Vice President Engineering ET 09-0025 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

Reference:

1) Letter ET 09-0016, dated June 2, 2009, from T. J. Garrett, WCNOC,'to USNRC

2) Letter dated August 11, 2009, from B. K. Singal, USNRC, to R. A. Muench, WCNOC, "Wolf Creek Generating Station -

Request for Additional Information Regarding the Permanent Alternate Repair Criteria License Amendment Request (TAC NO. ME1393)"

3) Letter ET 09-0021, dated August 25, 2009, from T. J.

Garrett, WCNOC, to USNRC

4) Letter ET 09-0023, dated September 3, 2009, from T. J.

Garrett, WCNOC, to USNRC

Subject:

Docket No. 50-482: Revision to Technical Specification (TS). 5.5.9, "Steam Generator (SG) Program," and TS 5.6.10, "Steam Generator Tube Inspection Report" Gentlemen:

Reference 1 provided Wolf Creek Nuclear Operating Corporation's (WCNOC's) application to revise Technical Specification (TS) 5.5.9, "Steam Generator (SG) Program," and TS 5.6.10, "Steam Generator Tube Inspection Report," for a permanent alternate repair criterion to exclude portions of the tube below the top of the steam generator tube sheet from periodic steam generator tube inspections. Westinghouse WCAP-17071-P, Revision 0, "H*: Alternate Repair Criteria for the Tubesheet Expansion Region in Steam Generators with Hydraulically Expanded Tubes (Model F)," was submitted with Reference 1 and provided the basis for the proposed change. WCNOC requested approval of the permanent alternate repair criterion by October 1, 2009, to support Refueling Outage 17, which is scheduled to start in October, 2009.

P.O. Box 411 / Burlington, KS 66839 / Phone: (620) 364-8831 AJ(21A An Equal Opportunity Employer M/F/HC/VET

ET 09-0025 Page 2 of 4 Reference 2 provided a request for additional information (RAI) related to the application for a permanent alternate repair criterion. Reference 3 provided the responses to the RAI with the exception of Question 4 in Reference 2. Reference 4 provided the response to Question 4 in Reference 2.

On September 2, 2009, in a teleconference between NRC Staff and industry personnel, the NRC Staff indicated that Staff concerns with eccentricity of the tubesheet tube bore in normal and accident conditions (response to Question 4 of Reference 2) have not been completely resolved to the satisfaction of the Staff. The Staff further indicated that there was insufficient time to resolve these remaining questions to support approval of the permanent amendment request to support the fall 2009 refueling outage. As such, WCNOC is' proposing to revise the requested changes to the technical specification in Reference 1 to be a one-time change to TS 5.5.9 and TS 5.6.10 for Refueling Outage 17 and the subsequent operating cycle. WCNOC requests that the Staff provide the specific questions remaining to be resolved and that the review of the amendment request for a permanent alternate repair criteria continue.

Attachment I provides additional information to support a one-time change for Refueling Outage 17 and the subsequent operating cycle. Attachment II provides revised TS markups for TS 5.5.9 and TS 5.6.10. Attachment III provides proposed changes to the TS Bases (for information only). Final TS Bases changes will be implemented pursuant to TS 5.5.14, "Technical Specification (TS) Bases Control Program," at the time the amendment is implemented. Attachment IV provides a List of Regulatory Commitments. The commitments are based on References 1 and 3 and are applicable for Refueling Outage 17 and the subsequent operating cycle.

WCNOC requests approval of the one-time change by October 1, 2009 to support Refueling Outage 17, which is scheduled to start in October 2009. Once approved, the amendment will be implemented prior to MODE 4 entry during startup from Refueling Outage 17.

The requested changes do not expand the scope of the application as originally noticed, and does not impact the conclusions of the NRC staff's original proposed no significant hazards consideration determination as published in the Federal Register (74 FR 35892). The proposed changes to TS 5.5.9 and TS 5.6.10 have been reviewed by the Plant Safety Review Committee.

In accordance with 10 CFR 50.91, a copy of this submittal is being provided to the designated Kansas State official.

ET 09-0025 Page 3 of 4 If you have any questions concerning this matter, please contact me at (620) 364-4084, or Mr.

Richard D. Flannigan at (620) 364-4117.

Sincerely, Terry J. Garrett TJG/rlt Attachments: I - Additional Information for One-Time Alternate Repair Criterion II - Revised Markup of Technical Specification pages III - Revised Markup of Technical Specification Bases pages (for information only)

IV - List of Regulatory Commitments cc: E. E. Collins (NRC), w/a T. A. Conley (KDHE), w/a V. G. Gaddy (NRC), w/a B. K. Singal (NRC), w/a Senior Resident Inspector (NRC), w/a

ET 09-0025 Page 4 of 4 STATE OF KANSAS )

SS COUNTY OF COFFEY )

Terry J. Garrett, of lawful age, being first duly sworn upon oath says that he is Vice President Engineering of Wolf Creek Nuclear Operating Corporation; that he has read the foregoing document and knows the contents thereof; that he has executed the same for and on behalf of said Corporation with full power and authority to do so; and that the facts therein stated are true and correct to the best of his knowledge, information and belief.

Terry arrett Vice esident Engineering SUBSCRIBED and sworn to before me this J5"'day of Sep& embe- , 2009.

eOFFJauay% 1, 010:1 L. TIEMEYER~

RHONDA Notary Public I EAL.. MY COMMISSION EXPIRES"N t Expiration DateQ4/2 /, ,l'. 11 3

-, -*r ....

i! ., - " 1,

, ' ,, ,I¢ Attachment I to ET 09-0025 Page 1 of 2 Additional Information for One-Time Alternate Repair Criterion Reference 1 provided Wolf Creek Nuclear Operating Corporation's (WCNOC's) application to revise Technical Specification (TS) 5.5.9, "Steam- Generator (SG) Program," and TS 5.6.10, "Steam Generator Tube Inspection Report," for a permanent alternate repair criterion to exclude portions of the tube below the top of the steam generator tube sheet from periodic steam generator tube inspections. Westinghouse WCAP-17071-P, Revision 0, "H*: Alternate Repair Criteria for the Tubesheet Expansion Region in Steam Generators with Hydraulically Expanded Tubes (Model F)," was submitted with Reference 1 and provided the basis for the proposed change. Reference 2 provided a request for additional information (RAI) related to the application for a permanent alternate repair criterion. Reference 3 provided the responses to the RAI with the exception of Question 4 in Reference 2. Reference 4 provided the response to Question 4 in Reference 2.

On September 2, 2009, in a teleconference between NRC Staff and industry personnel, the NRC Staff indicated that Staff concerns with eccentricity of the tubesheet tube bore in normal and accident conditions (response to Question 4 of Reference 2) have not been completely resolved to the satisfaction of the Staff. The Staff further indicated that there was insufficient time to resolve these remaining questions to support approval of the permanent amendment request to support the fall 2009 refueling outage. As such, WCNOC is proposing to revise the requested changes to the technical specification in Reference 1 to be a one-time change to TS 5.5.9 and TS 5.6.10 for Refueling Outage 17 and the subsequent operating cycle. WCNOC requests that the Staff provide the specific questions remaining to be resolved and that the review of the amendment request for a permanent alternate repair criteria continue.

The permanent H* alternate repair criterion amendment request (Reference 1) is based on maintaining structural and leakage integrity in the event of an accident.

From a structural perspective, the 13.1 inch value of H* ensures that tube rupture or tube pull out from the tube sheet will not occur in the event of an accident during the life of the plant.

Even in the event that all tubes in the steam generator have a 360-degree sever at 13.1 inches, structural integrity of the steam generator tube bundle will be maintained. This assumption bounds the current status of the Wolf Creek Generating Station (WCGS) steam generators with significant margin.

At WCGS, tube flaw indications within the tube sheet have only been found at the hot leg tube ends. Approximately 18,414 tube ends were inspected at WCGS during Refueling Outage 16.

Seventy-six flaw indications have been found in the inspections within 1 inch of the tube end.

Of these seventy-six flaw indications, only eight met the tube repair criteria in the technical specifications.

Based on these inspections, a limited number of tube flaws existed in the tubesheet area of the WCGS steam generators. The flaws that have been found are associated with residual stress conditions at the tube ends. No indications of a 360 degree sever has been detected in any steam generator at WCGS. Consequently, the level of degradation in the WCGS steam generators is very limited compared to the assumption of "all tubes severed" that was utilized in the development of the permanent H* alternate repair criterion. Consequently, structural integrity will be assured for the operating period between inspections allowed by TS 5.5.9, "Steam Generator (SG) Program."

Attachment I to ET 09-0025 Page 2 of 2 From a leakage perspective, projections of accident induced steam generator tube leakage are based on leakage rate factors applied to leakage detected during normal operation. The multiplication factor used for.. WCGS bounds the expected increased leakage in the event of an accident at WCGS. The projected accident induced leakage remains the same for both the one-time and permanent H* amendments. No primary-to-secondary steam generator tube leakage has been detected during the current operating cycle.

For WCGS, the number of tubes identified with flaws within the tubesheet is small in comparison to the input assumptions used in the development of the permanent H* alternate repair criterion. Consequently, significant margin exists between the current state of the WCGS steam generators and the conservative assumptions used as the basis for the permanent H*

alternate repair criterion. Structural and leakage integrity will continue to be assured for the operating period between inspections allowed by TS 5.5.9, "Steam Generator (SG) Program,"

with the implementation of the proposed one-time H* repair criterion.

References:

1. Letter ET 09-0016 dated June 2, 2009, from T. J. Garrett, WCNOC, to USNRC, "Revision to Technical Specifications 5.5.9, "Steam Generator (SG) Program," and TS 5.6.10, "Steam Generator Tube Inspection Report," for a Permanent Alternate Repair Criterion."

2. Letter dated August 11, 2009, from B. K. Singal, USNRC, to R. A. Muench, WCNOC, "Wolf Creek Generating Station - Request for Additional Information Regarding the Permanent Alternate Repair Criteria License Amendment Request (TAC NO. ME1393)."

3. Letter ET 09-0021 dated August 25, 2009, from T. J. Garrett, WCNOC, to USNRC, "Response to Request for Additional Information Related to License Amendment Request for a Permanent Alternate Repair Criterion to Technical Specification 5.5.9, "Steam Generator ,(SG) Program"."

4. Letter ET 09-0023 dated September 3, 2009, from T. J. Garrett, WCNOC, to USNRC, "Response to Request for Additional Information Related to License Amendment Request for a Permanent Alternate Repair Criterion to Technical Specification 5.5.9, "Steam Generator (SG) Program"."

Attachment Page 1 of II to ET 09-0025 5

Revised Markup of Technical Specification pages

V! J4 Attachment II to ET 09-0025 Page 2 of 5 Programs and Manuals 5.5 5.5 Programs and Manuals 5.5.9 Steam Generator (SG) Program (continued)

3. The operational LEAKAGE performance criterion is specified in LCO 3.4.13, "RCS 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 following alternate tube repair criteria shall be applied as an alternative to the 40% depth-based criteria:

1.

7 For R ueling Ou ge 16 and e subsequ nt operatin cycle, F i -Ld*L7tub with flaw aving a ci umferenti componen ess than or

-k's .n o-'- iwi e alto 203 grees fou in the po *on of the t e below 17 caitb w xvit ches fro *nAhe top of t tubeshee and above inch from e x.ýS oCA~e4L I*,.e6&

,4% 3

• l.* e +OF[ o bottom having ohe tubesh t do nt reentuire pluggi . Tubes h flaws d

circumfe tial comp ent greate han 203 d rees han P-e +ubes~ieet 4o t-ot r1,tr- foun in the porti n of the tu below 17' ches from e top of the Fbx.Aiv,.T- u b,, , "

w'vtu.-nv- A tu sheet andibovei r om of the besheet sh

• . aIv.,.

" 4" - o f-I- removed om servic icF . lWTubes *ih service-i uced flaw located wi in the regio rom ISA~

-1b a -~~ -t the

~~~~~~~~~ to h o/fte of the tub ue*ettheet to 17' 7Jopches belo the top oft 0l stub heet shall e removed rom servic . Tubes witl service-

.,in uced axial racks foun in the port n of the tub below 17 ches fro he top ofte tubeshe o not requ/e plugging.

When ore than o e flaw with ircumferent' componen is foun in the port n of the tu e below 17 ' ches from t top of the tu sheet and bove 1 in from the b om of the tu esheet wit

. e total oft circumfe ntial comp ents greate han 203 degrees a I an axial eparation d -anceof les han 1 inch en the tub hall be re oved from rvice. Whe the circum rential comp nents of e h of the fla s are adde it is accept le to co the over pped portio s only once* the total o C" umferen I compone s.

When o e or more fl s with circ ferential mponents e foun :n the portio of the tube ithin 1 inc rom the bo m of the ttub sheet, and e total of th circumfer tial compo nts found tmhe tube e eds 94 de ees, then e tube shal e removed rom servic . When on r more fla s with circ ferential (continued)

Wolf Creek - Unit 1 5.0-12 Amendment No. 1-23,'*153, "72,178

Atahm n...o...T0902 * . ,*  :*** . ':*

Attachment 11to ET 09-0025 Page 3 of 5 Programs and Manuals 5.5 5.5 Programs and Manuals 5.5.9 Steam Generator (SG) Program (continued) ande total of t circumfe ntial compenents foun in the tube eeeeds 9 de re the he tue srII e removfrom se e.

hen the ci umferenti compons of each the flaws a a ded, it acceptab to count t e overlapp portions o y once

.in the t al of circu ferential c oplonents.

d. Provisions for SG tube inspections. Periodic SG tube inspections shall be performed. The number and portions of the tubes inspected and methods of inspection shall be performed with the objective of detecting flaws of any type (e.g., volumetric flaws, axial and circumferential cracks) that may Reul-7. be present along the length of the tube, from the tube-to-tubesheet weld Ri*r -l I*&4_ II O.LJA,,.. " at the tube inlet to the tube-to-tubesheet weld at the tube outlet, and that SVAO~t~bLAt odG,*j '_Y,-~-I, may satisfy the applicable tube repair criteria The tube-to-tubesheet

-t4. *-porti -4 4k,- +ulo,- 6__low G, Iweld is not part of the tube. In addition to meeting the requirements of c,

• ~cAes -,-~-o-. -,_ 4-,

• d.1, d.2, and d.3 below, the inspection scope, inspection methods, and uloesVme. Ls =Kr,-1uzkeA-"-, v--,,%-,inspection intervals shall be such as to ensure that SG tube integrity is

• rie,,,

,i.,, %,,,,*e,,*,. maintained shall be performed until thetonext SG inspection.

determine the type An andassessment of degradation location of flaws to which the 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 periods of 120, 90, and, thereafter, 60 effective full power months. The first sequential period shall be considered to begin after the first inservice inspection of the SGs. In addition, inspect 50% of the tubes by the refueling outage nearest the midpoint of the period and the remaining 50% by the refueling outage nearest the end of the period. No SG shall operate for more than 48 effective full power months or two refueling outages (whichever is less) without being inspected. . ,. ( _.L JeAar--

3. If crack 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 exceed 24 effective full power months or one refueling outage (whichever is less). If definitive information, such as from examination of a pulled tube, diagnostic non-destructive testing, or engineering evaluation indicates that a crack-like indication is not associated with a crack(s), then the indication need not be treated as a crack.

e. Provisions for monitoring operational primary to secondary LEAKAGE.

(continued)

Wolf Creek - Unit 1 5.0-13 Amendment No. 123, 153, 172, 178

Attachment II to ET 09-0025 Page 4 of 5 Reporting Requirements 5.6 5.6 Reporting Requirements 5.6.10 Steam Generator"Tube Inspection Report "

A report shall be submitted within 180 days after the initial entry into MODE 4 following completion of an inspection performed in accordance with the Specification 5.5.9, 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;49

g. The results of condition monitoring, including the results of tube pulls and in-situ testing

h. Foio ng completion of inspection perform in Refueling Ou ge 1 and any inspection performed in the su equent operati cycle),

he number of indic ons and location, si,, orientation, whher initiated on prim or secondary side f each service-in ced flaw within the thi ness of the tubeshee , and the total of e circumferential compone and any circumfereWa overlap below inches from the top ofhe tubesheet as deterrnKed in accordanc with TS 5.5.9c.1; Wolf Creek - Unit 1 5.0-28 Amendment No. 123, 12,158, 164, 4-7-8, 179

I Attachment II to ET 09-0025 Page 5 of 5 INSERT 5.0-28

h. Following completion of an inspection performed in Refueling Outage 17 (and any inspections performed in the subsequent operating cycle) the primary to secondary LEAKAGE rate observed in each SG (if it is not practical to assign the LEAKAGE to an individual SG, the entire primary to secondgry LEAKAGE should be conservatively assumed to be from one SG) during the cycle preceding the inspection which is the subject of the report; Following completion of an inspection performed in Refueling Outage 17 (and any inspections performed in the subsequent operating cycle) the calculated accident induced leakage rate from the portion of the tubes below 13.1 inches from the top of the tubesheet for the most limiting accident in the most limiting SG. In addition, if the calculated accident induced leakage rate from the most limiting accident is less than 2.50 times the maximum operational primary to secondary leak rate, the report should describe how it was determined; and

j. Following completion of an inspection performed in Refueling Outage 17 (and any inspections performed in the subsequent operating cycle) the results of monitoring for the tube axial displacement (slippage). If slippage is discovered, the implications of discovery and corrective action shall be provided.

Attachment III to ET 09-0025 Page 1 of 3 Revised Markup of Technical Specification Bases pages (for information only)

,~ .1.

Attachment III to ET 09-0025'"`.-

Page 2 of 3 SG Tube Integrity B 3.4.17 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 LEAKAGErate equal to the operational LEAKAGE rate limits in LCO 3.4.13, "RCS Operational LEAKAGE," plus the leakage rate associated with a double-ended rupture of a single tube. The accident analysis for an SGTR assumes the contaminated secondary fluid is released to the atmosphere via SG atmospheric relief valves and safety valves.

The analysis for design basis accidents and transients other than an 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 the total primary to secondary LEAKAGE from all SGs of 1 gallon per minute or is assumed to increase to 1 gallon per minute as a result of accident induced conditions. For accidents that do not involve fuel damage, the primary coolant activity level of DOSE EQUIVALENT 1-131 is assumed to be equal to the LCO 3.4.16, "RCS Specific Activity," limits. For accidents that assume fuel damage, the primary coolant activity is a function of the amount of activity released from the damaged fuel. The dose consequences of these events are within the limits of GDC 19 (Ref. 2), 10 CFR 100 (Ref. 3) or the NRC approved licensing basis (e.g., a small fraction of these limits).

Steam generator tube integrity satisfies Criterion 2 of 10 CFR 50.36(c)(2)(ii).

LCO The LCO requires that SG tube integrity be maintained. The LCO also requires that all SG tubes that satisfy the repair criteria be plugged in accordance with the Steam Generator Program.

During a SG inspection, any inspected tube that satisfies the Steam Generator Program repair criteria 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.

In the context of this Specification, a 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.

For Refueling Outage--and the subsequent operating c cle, alternate repair criterion for the portion of the tube below nches from the top of the tubesheet is specified in TS 5.5.9c. 1. (Ref. 7 e tube-to-tubesheet weld is not considered part of the tube.

Wolf Creek - Unit 1 B 3.4.17-2 Revision 37

Attachment III to ET 09-0025 Page 3 of 3 SG Tube Integrity B 3.4.17 BASES 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."

7. License Amendment No.

• Wolf Creek - Unit 1 B 3.4.17-7 Revision 37

Attachment IV to ET 09-0025 Page 1 of 1 List of Regulatory Commitments The following table identifies those actions committed to by WCNOC in this document. Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments. Please direct questions regarding these commitments to Mr.

364-4117.

Richard Flannigan at (620)

Regulatory Commitments Due Date / Event In addition the NRC staff has requested that licensees determine Prior to MODE 4 entry if there are any significant deviations in the location of the bottom during startup from of the expansion transition (BET) relative to the top of tubesheet Refueling Outage 17 that would invalidate assumptions in Reference 4. Therefore, WCNOC commits to perform a one-time verification of tube expansion locations to determine if any significant deviations exist from the top of tubesheet to the BET. If any deviations are found, the condition will be entered into the plants corrective action program. Additionally, WCNOC commits to notify the NRC of any significant deviations.

WCNOC commits to monitor for tube slippage as part of the Each inspection of the steam generator tube inspection program. Slippage monitoring WCGS steam generators will occur for each inspection of the WCGS steam generators.

For the condition monitoring (CM) assessment, the component of During each inspection operational leakage from the prior cycle from below the H* required by TS 5.5.9, distance will be multiplied by, a factor of 2.50 and added to the "Steam Generator (SG) total accident leakage from any other source and compared to the Program" allowable accident induced leakage limit. For the operational assessment (OA), the difference in the leakage between the allowable accident induced leakage and the accident induced leakage from sources other than the tubesheet expansion region will be divided by 2.50 and compared to the observed operational leakage. An administrative limit will be established to not exceed the calculated value.

Once approved, the amendment will be implemented prior to Prior to MODE 4 entry MODE 4 entry during startup from Refueling Outage 17. Final TS during startup from Bases changes will be implemented pursuant to TS 5.5.14, Refueling Outage 17 "Technical Specification (TS) Bases Control Program," at the time the amendment is implemented.