ML071360100

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Response to NRC Requests for Additional Information Related to Wolf Creek Generating Station License Renewal Application
ML071360100
Person / Time
Site: Wolf Creek Wolf Creek Nuclear Operating Corporation icon.png
Issue date: 05/09/2007
From: Garrett T
Wolf Creek
To:
Document Control Desk, NRC/NRR/ADRO
References
ET 07-0014
Download: ML071360100 (24)
v • d • e


Text

W.LF CREEK NUCLEAR OPERATING CORPORATION May 9, 2007 Terry J. Garrett Vice President, Engineering ET 07-0014 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

Reference:

1) Letter ET 06-0038, dated September 27, 2006, from T.J. Garrett, WCNOC, to USNRC 2) Letter dated April 9, 2007, from V. Rodriguez, USNRC, to T.J. Garrett, WCNOC (ML070930695)
3) Letter dated April 10, 2007, from V. Rodriguez, USNRC, to T.J. Garrett, WCNOC (ML070930685)
4) Letter dated April 12, 2007, from V. Rodriguez, USNRC, to T.J. Garrett, WCNOC (ML070800176)

Subject:

Docket No. 50-482: Response to NRC Requests for Additional Information Related to Wolf Creek Generating Station License Renewal Application Gentlemen:

Reference 1 provided Wolf Creek Nuclear Operating Corporation's (WCNOC) License Renewal Application for the Wolf Creek Generating Station (WCGS). References 2 through 4 requested additional information regarding the License Renewal Application.

Attachments I, II, and III provide the WCNOC response to each NRC request.This letter contains no commitments.

If you have any questions concerning this matter, please contact me at (620) 364-4084, or Mr. Kevin Moles at (620) 364-4126.Sincerely, Terry J. Garrett TJG/rlt A)-2-1 P.O. Box 411 / Burlington, KS 66839 / Phone: (620) 364-8831 An Equal Opportunity Employer M/FIHCNET ET 07-0014 Page 2 of 3 Attachments I -WCNOC Response to NRC Requests for Additional Information (ML070930695)

Dated April 9, 2007 II -WCNOC Response to NRC Requests for Additional Information (ML070930685)

Dated April 10, 2007 III -WCNOC Response to NRC Requests for Additional Information (ML070800176)

Dated April 12, 2007 Enclosure 1 -Tables for RAI 4.2.1-1 and RAI 4.2.2-1 Enclosure 2 -Figure for RAI 4.5-4 cc: J. N. Donohew (NRC), w/a, w/e V. G. Gaddy (NRC), w/a, wie B. S. Mallett (NRC), w/a, wie V. M. Rodriguez (NRC), w/a, w/e Senior Resident Inspector (NRC), w/a, w/e ET 07-0014 Page 3 of 3 STATE OF KANSAS 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.By_~-$Terry .Garrett Vice liresident Engineering SUBSCRIBED and sworn to before me this 9 day of MaO, 2007.Notary Public SV. 2 7 AkyLLAf)I Expiration Date otrXmflJa I N 1 D/)

Attachment I to ET 07-0014 Page 1 of 3 Attachment I WCNOC Response to NRC Requests for Additional Information (ML070930695)

Dated April 9, 2007 RAI 3.1.2.2.3-1 RAI 4.2.1-1 RAI 4.2.2-1 Attachment i to ET 07-0014 Page 2 of 3 WCNOC Response to NRC Requests for Additional Information (ML070930695)

Dated April 9, 2007 AGING MANAGEMENT REVIEW Aging Management of Reactor Vessel, Internals, and Reactor Coolant System RAI 3.1.2.2.3-1 LRA Section 3.1.2.2.3-1 states that since beltline materials remain limiting, nozzles were not evaluated separately.

In accordance with 10 CFR Part 50, Appendix H, Section III, if the end of life (EOL) peak neutron fluence exceeds 1017 n/cm 2 (E > 1 MeV) the material must be monitored through a surveillance program. The staff requests that the applicant confirm that the increase in peak 60-year EOL fluence for the nozzles will not exceed this value. The staff requests that the applicant provide appropriate data for the inclusion of nozzle materials in the surveillance program, or explain how the nozzle materials are adequately monitored by the proposed aging management program.RAI 3.1.2.2.3-1 Response In accordance with 10 CFR 50 Appendix G paragraph II.F, reactor vessel beltline materials are those "...predicted to experience sufficient neutron radiation damage to be considered in the selection of the most limiting material with regard to radiation damage." 10 CFR 50 Appendix H Section III, and ASTM E185-82 paragraphs 1.1 and 5.1 provide the 1017 n/cm 2 lifetime neutron fluence criterion for"sufficient neutron damage." These appendices and ASTM E185 then further require that coupons prepared from the most limiting material identified by this process be irradiated and tested per the surveillance program.The original selection of the limiting beltline material was made for an expected 32 effective full power years (EFPY) peak beltline clad-base metal fluence of 3.14 x 1019 neutrons/cm 2 (E > 1 MeV), before the change to low-leakage cores. With low-leakage cores, the expected 54 EFPY peak beltline clad-base metal fluence is now only 3.51 x 1019 neutrons/cm 2 (E > 1 MeV), an increase of only 12 percent. This change is smaller than the 20% tolerance of Regulatory Guide 1.190,"Calculational and Dosimetry Methods for Determining Pressure Vessel Neutron Fluence".Wolf Creek Generating Station (WCGS) projected the fluence at the nozzles based on a fluence model consistent with Regulatory Guide 1.190 and projected the clad-base metal interface upper shelf energy (USE) and nil-ductility transition reference temperature (RTNDT), of the nozzles using methods consistent with Regulatory Guide 1.99, "Radiation Embrittlement of Reactor Vessel Materials." This evaluation determined that the nozzles will not become the limiting components for the extended licensed operating period. Since the nozzle materials will not become limiting, the existing program will adequately monitor them.

Attachment I to ET 07-0014 Page 3 of 3 WCNOC Response to NRC Requests for Additional Information (ML070930695)

Dated April 9, 2007 TIME-LIMITED AGING ANALYSIS Neutron Fluence, Upper Shelf Energy and Adjusted Reference Temperature RAI 4.2.1-1 The staff requests that the applicant submit a table of the 60-year EOL upper shelf energy (USE) values for each beltline material.

The heat numbers, material ID, copper content (weight-percent), initial USE, EOL 1/4 T fluence and the EOL 1/4 T USE should be included.

In addition, the staff requests that the applicant discuss how surveillance results were evaluated in the determination of the USE values.RAI 4.2.1-1 Response The requested table is provided in Enclosure 1.The X-coupon surveillance examination occurred at a coupon exposure within the Regulatory Guide 1.190 tolerance of the fluence expected at the peak clad-base metal interface at 54 EFPY. These coupon examinations demonstrated that USE of the limiting material will be acceptable even at the fluence expected at the peak clad-base metal interface at 54 EFPY. WCGS therefore did not calculate 1/4 T fluence and USE.Surveillance capsule results were applied to the determination of the EOL USE values as described in the notes to the table. The surveillance coupon examination incorporated as-tested surveillance coupon chemistry in the determination of best-estimate chemistry.

Pressurized Thermal Shock RAI 4.2.2-1 The staff requests that the applicant submit a table of the 60-year EOL reference temperature for pressurized thermal shock (RTpTs) values for each beltline material.

The heat numbers, material ID, copper and nickel content (weight-percent), chemistry factor, initial RTNDT, margin, EOL peak fluence, fluence factor, ARTPTS, and EOL RTPTS values should be included.

In addition, the staff requests that the applicant discuss how surveillance capsule results were applied in the determination of the RTPTS values.RAI 4.2.2-1 Response The requested table is provided in Enclosure 1.Surveillance capsule results were applied to the determination of the RT,,, values as described in the notes to the table. The surveillance coupon examination incorporated as-tested surveillance coupon chemistry in the determination of best-estimate chemistry.

Attachment II to ET 07-0014 Page 1 of 7 Attachment II WCNOC Response to NRC Requests for Additional Information (ML070930685)

Dated April 10, 2007 RAI 2.4-1 RAI 2.4-2 RAI 2.4-3 RAI B.3.3-1 RAI B.3.3-2 RAI 4.5-1 RAI 4.5-2 RAI 4.5-3 RAI 4.5-4 2~' 2 K **l Attachment II to ET 07-0014 Page 2 of 7 WCNOC Response to NRC Requests for Additional Information (ML070930685)

Dated April 10, 2007 SCOPING AND SCREENING RESULTS Scoping and Screening Results: Structures RAI 2.4-1 LRA Section 2.4.9 states that structural features are provided to protect safety-related components from flooding.

The staff requests that the applicant identify these structural features, which are used to protect safety-related components from flooding, and discuss whether they should be within the scope of license renewal.RAI 2.4-1 Response Updated Safety Analysis Report (USAR) Section 3B.4.3.1 (last paragraph on page 3B-14): Floodwater could enter the control building through the communications corridor.Also, floodwater could indirectly enter the auxiliary building basement via the control building. "As discussed in Section 3.B.4.3.3 these potential paths utilize curbs to preclude water from entering the safety-related areas." USAR Section 3B.4.3.3 (last paragraph on page 36-15): "The curbs along the west side of the condenser pit and around the T-1 stairwell are provided to prevent water from spilling over into the safety-related spaces." License Renewal Application (LRA) Tables 2.4-9 and 3.5.2-9 include "Direct Flow" as one of the intended functions of the component type "Concrete Elements".

In Table 2.4-9, "Concrete Elements" includes curbing, which is within the scope of license renewal.RAI 2.4-2 LRA Section 2.4.10 states that there is a wooden H-frame structure within each of the two transmission power lines. However, LRA Table 2.4-10 does not list the wooden H-frame as a structure within the scope of license renewal. The staff requests that the applicant justify its exclusion from the scope of license renewal.RAI 2.4-2 Response LRA Table 2.4-10 includes the wooden H-frame structure within the component type "Transmission Tower". LRA Table 3.5.2-10 includes a line item for"Transmission Tower" with carbon steel identified as the material and a line item for "Transmission Tower" with treated wood identified as the material.

Attachment II to ET 07-0014 Page 3 of 7 WCNOC Response to NRC Requests for Additional Information (ML070930685)

Dated April 10, 2007 RAI 2.4-3 The staff requests that the applicant clarify if the ocomponent type structural steel described in LRA Table 2.4-13 include the trash rack and stop log slots, guideways for the traveling water screens, and walls. If not, the staff requests that the applicant explain and justify its response.RAI 2.4-3 Response USAR Section 3.8.4.1.8 describes the Essential Service Water System (ESWS)pumphouse as a conventionally reinforced concrete structure of heavy shear wall construction.

LRA Table 2.4-13 includes these walls in component type Concrete Elements.LRA Section 2.4-13 states, "Structural steel commodities are provided for trash rack and stop log slots, guideways for the traveling water screens and walls." The term 'walls' in this context refers to the structural steel components that are part of the walls, such as platform attachments and ladders.AGING MANAGEMENT PROGRAMS Concrete Containment Tendon Prestress RAI B.3.3-1 LRA Section B.3.3 states that procedures which list surveillance tendons will be extended to include random samples for the 40, 45, 50, and 55 year surveillances.

The staff requests that the applicant discuss the differences between these enhanced procedures and the current procedures.

RAI B.3.3-1 Response Current procedures contain a list of specific tendons for each surveillance up to and including year 35. Tendons for surveillance have been selected in a random manner and are representative of the various types of tendons and conditions of exposure existing in containment.

This enhancement only adds lists of additional randomly selected surveillance tendons for the 40, 45, 50, and 55 year surveillances.

These additional surveillance tendons will be selected on the same basis as the surveillance tendons currently listed in the procedures for the intervals through year 35.RAI B.3.3-2 LRA Section B.3.3 states that "Procedures will be enhanced to explicitly require a regression analysis for each tendon group after every surveillance; and to invoke and describe regression analysis methods used to construct the lift-off trend lines, including Attachment II to ET 07-0014 Page 4 of 7 WCNOC Response to NRC Requests for Additional Information (ML070930685)

Dated April 10, 2007 the use of individual tendon data in accordance with Information Notice (IN) 99-10,"Degradation of Prestressing Tendon Systems in Prestressed Concrete Containments." The staff requests that the applicant address the following:

(1) Describe the enhanced procedures and requirements of the regression analysis for each tendon group after every surveillance (2) Discuss the difference between the current procedures and requirements and the enhanced procedures and requirements to be used during the period of extended operation (3) Describe the analysis methods used to construct the lift-off trend lines, and the difference between the current methods and the enhanced ones RAI B.3.3-2 Response (1) WCGS currently employs a qualified contractor to perform the tendon examinations, and these regression analyses are included in the examination report supplied for each examination interval.

The contractor's qualified procedures produce lifetime regression analyses for both the hoop and inverted-U tendon groups. These are standard methods consistent with NRC Information Notice 99-10, "Degradation of Prestressing Tendon Systems in Prestressed Concrete Containments".

These regressions are extended to 60 years.This enhancement will revise WCGS procedures to explicitly describe the current practice performed by a qualified contractor for regression analysis.(2) There is no difference between the current practice and that proposed for the period of extended operation.

(3) The lift-off trend lines for each of the hoop and inverted-U tendon groups are constructed by a regression analysis of all individual tendon lift-off data for that group to date, consistent with requirements of NRC Information Notice 99-10. As stated in the responses to (1) and (2) there are no differences between the current methods and those proposed for the period of extended operation.

TIME-LIMITED AGING ANALYSIS Concrete Containment Tendon Prestress Analysis RAI 4.5-1 LRA Table 4.5-2 indicates that two tendon types, dome hoop and cylinder hoop, are combined into one horizontal hoop group. The total number of examined tendons for these two types was seven for the first, third, and fifth year surveillance, and three for the tenth, fifteenth, and twentieth year surveillance.

Two dome hoop tendons were inspected at the first and third year surveillance; however, no dome hoop tendon was inspected after the third year surveillance.

ASME Code Section XI, Subsection IWL-Attachment II to ET 07-0014 Page 5 of 7 WCNOC Response to NRC Requests for Additional Information (ML070930685)

Dated April 10, 2007 2520, "Examination of Unbonded Post-Tensioning Systems", states that tendons on dome and cylinder shall be characterized into two different tendon types because of their geometry and position in the containment.

In addition, Subsection IWL-2520 states that the minimum number of surveillance tendons is four for each type of tendons for the first, third, and fifth year surveillance, and three for the tenth, fifteenth, and twentieth year surveillance.

The staff requests that the applicant justify this deviation from the ASME Code requirements.

RAI 4.5-1 Response The use of a single horizontal hoop tendon surveillance group is part of the original licensing basis for this surveillance program. The Wolf Creek program was originally developed using Regulatory Guide 1.35, 1979, Proposed Revision 3.It was modified to conform to the Technical Specification Amendment 152,"Containment Tendon Surveillance Program and Containment Leakage Rate Testing Program", Section 5.5.6 commitment to ASME Section XI, Subsection IWL (1998, as specified by 10 CFR 50.55a; see USAR Appendix 3A). A review of the program plan and specification confirms that the present program is consistent with IWL (1998) and with the 1990 Revision 3 of Reg Guide 1.35.IWL-2520 (1998) does not state that horizontal

"...tendons on dome and cylinder shall be characterized into two different tendon types ....." It does state: (a) Tendons to be examined during an inspection shall be selected on a random basis except as noted in IWL 2521(b) and (c). The populations from which the random sample is drawn shall consist of all tendons of a particular type (as defined in Table IWC-2521-1) not examined during earlier inspections.

The number of tendons to be examined during an inspection shall be as specified in Table IWL-2521-1.

Table IWC-2521-1 does not exist, and is a typographical error. The only definition of "particular type" in Table IWL-2521-1 is in Note 3: (3) A tendon type is defined by its geometry and position in the containment:

e.g., hoop, vertical, dome, helical, and inverted U.First, note that "hoop, vertical, dome, helical, and inverted U" are examples, not prescribed definitions.

Second, note that "hoop" is an example of a type, and that both of the dome and cylinder horizontal tendon subgroups of Bechtel BC-TOP-5A containments are specifically described, in virtually all documents, as "hoop" tendons.Third, the use of only two tendon surveillance groups occurs in similar programs for other Bechtel BC-TOP-5A containments of this period.

Attachment II to ET 07-0014 Page 6 of 7 WCNOC Response to NRC Requests for Additional Information (ML070930685)

Dated April 10, 2007 Since, for these reasons, a single hoop tendon group is correct, the first, third, and fifth year hoop sample sizes meet the minimum limits specified by Table IWL-2521-1.RAI 4.5-2 LRA Table 3.5-2 states that the seven horizontal tendons forces at the first year surveillance were 1358.0 kips, 1359.0 kips, 1381.0 kips, 1409.0 kips, 1348.0 kips, 1422.0 kips, and 1387.0 kips. The average value of these seven tendons force is 1380.6 kips, which is different from the value of 1416.0 kips shown on LRA Figure 4.5-1.The staff requests~that the applicant explain this discrepancy.

RAI 4.5-2 Response The upper line of LRA Figure 4.5-1 for horizontal tendons is the result of the lifetime log-linear regression analysis of all lift-off data to date. It reliably predicts the mean future lift-off values but may differ from the early-life data mean.The "first year surveillance" values to which the RAI refers are at 1 year following the structural integrity test (SIT), but were under tension for about 2.5 years longer, and when shown on this plot therefore appear at about 3.5 to 4 years. See the "Time Under Stress" values in Tables 4.5-1 and 4.5-2. At 3 years the trend line value is 1384 kips, in good agreement with the first-year post-SIT horizontal tendon data. Note that this value and the log-linear regression line are well above the IWL predicted force line, indicating that tendon performance has been, and is expected to remain, much better than the design basis prediction.

WGCS has reconfirmed the log-linear regression analysis of lift-off data (the trend line) and has prepared revised plots that include scattergraphs of the lift-off data.The revised plots are provided in Enclosure 2.RAI 4.5-3 LRA Figure 4.5-1, Note 4, states that "The surveillance program predicted force lines were calculated per wire. The values plotted here assume 170 wires per tendon. Some tendons have fewer due to failure to meet acceptance criteria at installation, or due to removal for surveillance testing." If the numbers of wires in a tendon is less than 170 due to failure to meet acceptance criteria at installation, or due to removal for surveillance testing, the predicted magnitude of force of that tendon based on the assumption of 170 wires would be higher than it should have been. Therefore, the staff requests that the applicant provide its basis for using the assumed 170 wires per tendon instead of using the actual numbers of wires per tendon to calculate the tendon force.RAI 4.5-3 Response LRA Figure 4.5-1 Note 4 applies only to the IWL predicted force lines. For that purpose a "per wire" value is appropriate, since it is used to generate a predicted Attachment II to ET 07-0014 Page 7 of 7 WCNOC Response to NRC Requests for Additional Information (ML070930685)

Dated April 10, 2007 force per tendon based on the number of wires in order to compare predicted force to the actual surveillance lift-off.

The trend lines of LRA Figure 4.5-1 were calculated from the actual tendon lift-off forces, regardless of the number of effective wires per tendon.RAI 4.5-4 Based on the discussion of RAIs 4.5-2 and 4.5-3, the staff requests that the applicant establish a new trend line in LRA Figure 4.5-1 with actual prestressed tendon force. The trend line points should be calculated based on the actual number of wires multiplied by the lift-off-wire force.RAI 4.5-4 Response See the response to RAIs 4.5-2 and 4.5-3. The trend lines of LRA Figure 4.5-1 (but not the IWL predicted force lines) were calculated from the actual tendon lift-off forces, regardless of (and therefore with) the actual number of effective wires per tendon.WCGS has reconfirmed the log-linear regression analysis of lift-off data (the trend line) and has prepared revised plots that include scattergraphs of the lift-off data.The revised plots are provided in Enclosure

2.

Attachment III to ET 07-0014 Page 1 of 6 Attachment III WCNOC Response to NRC Requests for Additional Information (ML070800176)

Dated April 12, 2007 RAI 2.5-1 RAI 2.5-2 RAI 2.5-3 I Attachment Ill to ET 07-0014 Page 2 of 6 WCNOC Response to NRC Requests for Additional Information (ML070800176)

Dated April 12, 2007 Electrical and Instrumentation and Control Systems RAI 2.5-1 LRA Section 2.5 does not explicitly describe the offsite recovery paths (from the switchyard to the onsite distribution system) for a station blackout (SBO).The General Design Criterion 17 described in Title 10 Code of Federal Regulations Part 50 (10 CFR Part 50), Appendix A, requires that electric power from the transmission network to the onsite electric distribution system be supplied by two physically independent circuits to minimize the likelihood of their simultaneous failure.In addition, the guidance provided by letter dated April 1, 2002, "Staff Guidance on Scoping of Equipment Relied on to Meet the Requirements of the Station Blackout Rule (10 CFR 50.63) for License Renewal (10 CFR 54.4(a)(3))," states: For purposes of the license renewal rule, the staff has determined that the plant system portion of the offsite power system that is used to connect the plant to the offsite power source should be included within the scope of the rule. This path typically includes switchyard circuit breakers that connect to the offsite system power transformers (startup transformers), the transformers themselves, the intervening overhead or underground circuits between circuit breaker and transformer and transformer and onsite electrical system, and the associated control circuits and structures.

Ensuring that the appropriate offsite power system long-lived passive structures and components that are part of this circuit path are subject to an aging management review will assure that the bases underlying the SBO requirements are maintained over the period of extended license.According to the above, both paths that are used to control the offsite circuits to the plant should be age managed. According to LRA drawing LR-WCGS-ELEC-KD-7496, the high voltage switchyard circuit breakers, underground cables, and its associated components and structures are not presently included within the scope of license renewal. The staff requests that the applicant justify why these components are not within the scope of license renewal. In addition the staff requests that the applicant explain in detail which high voltage breakers and other components in the switchyard will be connected to startup transformer XMR01 and ESF No. 1 transformer XNBO1 for the purpose of SBO recovery.RAI 2.5-1 Response The entire WCGS plant system portion of the SBO restoration power system is within the scope of license renewal. This is consistent with ISG-2 Staff Position which states, "Consistent with the requirements specified in 10 CFR 54.4(a)(3) and 10 CFR 50.63(a)(1), the plant system portion of the offsite power system should be included within the scope of license renewal."

Attachment Ill to ET 07-0014 Page 3 of 6 WCNOC Response to NRC Requests for Additional Information (ML070800176)

Dated April 12, 2007 The WCGS is connected to the switchyard using disconnects not circuit breakers.The 345-kV switchyard system equipment beyond disconnect 345-163 and the 13.8-kV switchyard system equipment beyond disconnects 13-21 and 13-23 are not within the scope of license renewal because they are part of the transmission system grid and not part of the plant system.This arrangement is similar to other applicants where the boundary from the station power system and the switchyard is the last active component that connects the plant to the transmission system grid. The following two recent SERs provide examples of where the Staff accepted disconnects as boundary from the station to the switchyard.

The Palisades SER (ML062710074) states, "Upstream of the motor operating disconnects are the 345kV buses, switchyard components, and the incoming lines, all parts of the transmission (grid) system, not the plant system. As part of the staff's scoping methodology review, the Electrical Engineering Branch (EEEB)evaluated the switchyard components and the license renewal boundaries established by the applicant.

EEEB concluded that the switchyard configuration provides a reliable source of power to the preferred and alternate offsite circuits.In addition, EEEB concluded that the established boundaries are adequate for switchyard equipment within the scope of license renewal." The Oyster Creek SER (ML070890637) states, "In accordance with ISG-02, the applicant identified SSCs required to recover from the SBO event and included within the scope of the license renewal. For OCGS, this portion of the plant electrical system connects safety-related buses to onsite emergency power and offsite power to recover from SBO events. Disconnection switches on the supply side of switch yard circuit breakers connecting the 34.5 kV OCGS substation to the plant and continuing through the startup transformers to the switchgear breakers of the plant 4160 alternating current (AC) breakers were included within the scope of license renewal." The Kansas Gas and Electric (KG&E) and Kansas City Power and Light (KCPL)transmission systems serve as the main source of offsite power for 345-kV switchyard.

Primary offsite power feeds the WCGS startup transformer No I XMR01 through disconnect 345-163 which is connected to the switchyard West 345-kV bus. The West switchyard bus can receive power from three transmission lines. The Benton 345-kV transmission line is connected to the West bus through switchyard circuit breaker 345-70, the LaCygne 345-kV transmission line is connected to the West bus through switchyard circuit breaker 345-110 and the Rose Hill 345-kV transmission line is connected to the West bus through switchyard circuit breaker 345-40.A second offsite power feeds the WCGS transformer ESF No 01 XNB01 through disconnects 13-21 or 13-23. Disconnect 13-23 is connected to the secondary side Attachment III to ET 07-0014 Page 4 of 6 WCNOC Response to NRC Requests for Additional Information (ML070800176)

Dated April 12, 2007 of switchyard transformer No 7 through switchyard circuit breaker 13-48. The primary side of switchyard transformer No 7 connects to the switchyard East 345-kV bus through disconnect 345-167. Disconnect 13-21 is connected to switchyard 13.8-kV switchgear No I through switchyard circuit breaker 13-8. Switchyard 13.8-kV switchgear No 1 is connected to the secondary sides of switchyard transformer No 4 and No 5 through switchyard disconnects 13-9, 13-11, 13-13 and 13-15. The primary side of switchyard transformers No 4 and No 5 connects to the secondary side of switchyard transformer No 6 through switchyard breaker 69-16.The primary side of switchyard transformer No 6 connects to the East bus through switchyard disconnect 345-165. The East bus can receive power from the same three transmission lines as the West bus. The Benton 345-kV transmission line is connected to the East bus through switchyard circuit breakers 345-80 and 345-90, the LaCygne 345-kV transmission line is connected to the East bus through switchyard circuit breaker 345-120 and the Rose Hill 345-kV transmission line is connected to the East bus through switchyard circuit breaker 345-50 and 345-60.The primary path of SBO restoration power is from disconnect 345-163 via overhead transmission lines to the primary side of station start-up transformer No 1 XMR01, then from the secondary side (x-winding) of station start-up transformer No 1 XMR01 via above ground cable to circuit breaker PA00201. The second path of SBO restoration power is from disconnects 13-21 or 13-23 via underground cable to secondary side of station transformer ESF No 01 XNBO1, then from the secondary side of station transformer ESF No 01 XNB01 via above ground cable to circuit breakers NB00212 and NB00112. This configuration conforms to the requirement of Criterion 17 that states, "the onsite electrical distribution system shall be supplied by two physically independent circuits designed and located so as to minimize to the extent practical the likelihood of their simultaneous failure under operating and postulated accident and environmental conditions." RAI 2.5-2 Regulatory Guide 1.188, "Standard Format and Content for Application to Renew Nuclear Power Plant Operating Licenses," endorses Nuclear Energy Institute (NEI) 95-10, revision 6, "Industry Guideline for Implementing the Requirements of 10 CFR Part 54-The License Renewal Rule," issued in June 2005. NEI 95-10, Appendix B, indicates that elements, resistance temperature detectors, sensors, thermocouples and transducers should be included in the list of components and/or commodity groups subject to an aging management review (AMR) if a pressure boundary is applicable.

The staff requests that the applicant explain why these components are not included in LPA Section 2.5 as components within the scope of license renewal.RAI 2.5-2 Response The pressure boundary associated with RTDs, sensors, thermocouples and transducers are evaluated in the mechanical systems as thermowells, flow indicators and flow elements.

The following mechanical systems have

~'¶ ~Attachment III to ET 07-0014 Page 5 of 6 WCNOC Response to NRC Requests for Additional Information (ML070800176)

Dated April 12, 2007 thermowells, flow indicators and flow elements within the scope of license renewal that are subject to an aging management review.2.3.1.2 Reactor Coolant System 2.3.2.1 Nuclear Sampling System 2.3.2.2 Containment Spray System 2.3.2.5 Liquid Radwaste System 2.3.2.10 High Pressure Coolant Injection System 2.3.2.11 Residual Heat Removal System 2.3.3.2 Fuel Pool Cooling and Cleanup System 2.3.3.3 Essential Service Water 2.3.3.4 Component Cooling Water System 2.3.3.5 Containment Cooling System 2.3.3.7 Chemical and Volume Control System 2.3.3.16 Emergency Diesel Engine System 2.3.3.21 Miscellaneous Auxiliary Systems in-scope Only for Criterion 1 OCFR54.4(a)(2) 2.3.4.3 Feedwater System RAI 2.5-3 There has been operating experience regarding the failure of cable tie-wraps caused by the brittleness of the plastic material.

The cable tie-wraps are long-lived passive components.

Its intended functions include to maintain spacing for power cable ampacity, maintain stiffness in unsupported lengths of wire bundles to ensure minimum bending radius, and maintain cables within vertical raceways, among others. Most recently, at Point Beach, the regional inspectors identified an unresolved item after noticing that the current configuration of the plant may not be consistent with plant design documents due to the age related breakage of a large number of plastic tie-wraps used to fasten wires and cables. At Point Beach, cable tie-wraps are part of the cable design in order to maintain cable ampacity or are credited in the licensee's Seismic Qualifications Utility Group to seismically qualify the cable tray system. The staff requests that the applicant explain how WCGS manages the aging of cable tie-wraps.

In addition, the staff requests that the applicant justify why the cable tie-wraps are not included within the scope of license renewal in accordance with the requirements of 10 CFR 54.4.RAI 2.5-3 Response Cable tie wraps at the WCGS are not within the scope of license renewal and therefore aging management is not required.

Cable tie wraps perform no license renewal intended functions.

The functions stated by the Staff "maintain spacing for power cable ampacity, maintain stiffness in unsupported lengths of wire bundles to ensure minimum bending radius, and maintain cables within vertical raceways, among others" are not intended function at the WCGS as defined by 10 CFR 54.4. WCGS has no current licensing basis (CLB) requirements that cable tie wraps remain functional during and following design-basis events. Cable tie Attachment III to ET 07-0014 Page 6 of 6 WCNOC Response to NRC Requests for Additional Information (ML070800176)

Dated April 12, 2007 wraps provide no license renewal intended functions and do not meet any criteria found in 10 CFR 54.4(a)(1), 10 CFR 54.4(a)(2) or 10 CFR 54.4(a)(3).

Tie wraps are used as an aid during cable installation to establish power cable spacing in cable trays. WGCS design drawing "Installation, Inspection and Testing Details for Electrical Equipment and Cable" directs the use of tie wraps when maintained spacing is required per the construction documents.

Once the cables have been installed and in place, the cables own weight in the tray and the inherent rigidity of the Class B copper stranding will continue to maintain the spacing. This spacing provides a path for natural circulation of air through the cables in the tray. The power cables are sized to carry currents well in excess of load requirements with margin considering worst case routing. Where cable ties are used during installation care is exercised to prevent excessive tightening of the tie wrap, which could result in the deformation of the cable jacket material.

Tie wraps are not credited in WCGS seismic qualification of the cable tray support system.

Enclosure 1 to 'ET 07-0014 Enclosure 1 Tables for RAI 4.2.1-1 and RAI 4.2.2-1 Wolf Creek Reactor Vessel Material USE Projected at 60 Years (54 EFPY) or Tested at -59.7 Years (-53.7 EFPY)(Note 1)[RAI 4.2.1-1]Material Description(2)

Expected X Capsule Predicted 4 EFPY Tested EOL USE Unirrad- 64 EFPY fluence USE USE(4) at eptancE Cu1)Projected Acceptance Cu lated USE 1 2 1 Fluence (-53.7 EFPY) Decrease E X-Capsule Reactor Vessel Wt%1 2'3 19) USE sue Criterion Beltline Region Heat Number Type ft-lbf 101 n/cm 2 1019 n/cm2 ft-lbf ft-lbf Fluence ft-lbf Location (E>I.OMeV) (E>I.OMeV)

[RG 1.99 %] ft-lbf Intermediate Shell NR61 836-1 A533B, 0.04 127 3.51 :33 94 50 Plate R2005-1 Cl. 1 .. .. ... _[261 Intermediate Shell NR61 783-1 A533B, 0.04 127 3.51 33 94 ?50 Plate R2005-2 Cl. 1 [26]Intermediate Shell NR61 799-1 A533B, 0.05 135 3.51 36 99 >50 PlateR2005-3 Cl. 1 ____ _ ___[261 Lower Shell Plate B87592 A533B, 0.09 87 3.51 23 64 a50 R2508-1 Cl. 1 [261 Lower Shell Plate C48402 A533B, 0.05 100 3.51 26 50 R2508-2 Cl. 1 [261 Lower Shell Plate C4935-2 A533B, 0.08 94 3.51 3.49 25 69 95 ?50 R2508-3 Cl. 1 0.070 Transverse Transverse Intermediate and 90146 Type B4 Wire, Lower Plate Linde 0091 Flux, SAW 0.04 100 3.08 6, 3.49 28(7) 72 Longitudinal Weld Lot 0842(1)Seams G2.06 93 >50 Intermediate to Lower 90146 Type 64 Wire, Shell Plate Linde 124 Flux, SAW 0.04 100 3.51 3.49 28(7) 72 Circumferential Weld Lot 1061"'E3.16 HAZ Coupons from Lower Shell Plate -161 3.51 3.49 135 50 R2508-3 I I I I 1 1 1'Information in this table is from WCAP-16028, except as noted. EOL USE for the first five materials in this table (through Lower Shell Plate R2508-2) is from the initial unirradiated USE and RG 1.99 Figure 2 reduction (without interpolation).

2 Boldface heat numbers and types, chemistry, and unirradiated USE are from the RVID.1 Cu values are from WCAP-16030 except as noted, and match those in the RVID except as noted.' The X-Coupon surveillance examination occurred at a coupon exposure within the Reg Guide 1.190 tolerance of the fluence expected at the peak clad-base metal interface at 54 EFPY. These coupon examinations demonstrated that USE of the limiting material will be acceptable even at the fluence expected at the I1eak clad-base metal interface at 54 EFPY. WCGS therefore did not calculate

% T fluence and USE.Flux "Lot 0842" is from WCAP-16030 Table 1 Note (b).6 WCAP-16028 Table 6-2. These welds are at the 0, 120, and 2400 azimuths (0 and 30' quadrant azimuths), and therefore have a reduced peak beltline fluence.7 WCAP-1 6028 Table 5-10 for mean tested Cu (<0.05%, as indicated by WCAP-16028 Table 4-3). Figure 2 of Regulatory Guide 1.99 Rev. 2 indicates that the USE reduction should be 25 to 26 percent at this Cu analysis and worst-case fluence (3.49 to 3.51 x 1019 neutrons/cm2

). The 28 percent is therefore conservative.

8 "1081" in the RVID, a typographical error for 1061. "1061" in WCAP-10015 page A-1, WCAP-16028 Table 4-1 Note (b), and in WCAP-16030 Table 4-1 Note (b).

Wolf Creek Reactor Vessel Limiting RTPTs at 60 Years (54 EFPY)(Note 9)[RAI 4,2.2-1]M e 1 0) Chemical Chemistry Factors Composition(2) OF(2) Initial 54 EFPY 54 EFPY 54 EFPY 54 EFPY Screening Fluence Mri Reactor Vessel RG 1.99 RG 1.99 RTNDT 19 n/cM2 Fluence ARTPTs argin RTPTS Criteria Reator Vessel Heat Type Cu Ni Rev. 2 Rev. 2 IF (E>1.0MeV)

Factor OF IF IF Beltline Region Number Wt% Wt% Position Position Location 1.1 CF 2.1 CF Intermediate Shell A533B, Pla te Shell NR61 836-1 Cl. 0.04 0.66 26 --20 3.51 1.33 34.58 34.00 49 5270 Plate R2005-1 Cl. I Intermediate Shell A533B, Pla te Shell NR61 783-1 Cl. 1' 0.04 0.64 26 --20 3.51 1.33 34.58 34.00 49 5270 Plate R2005-2 CI. I Intermediate Shell NR61 799-1 A533B, 0.05 0.63 31 --20 3.51 1.33 41.23 34.00 55 5270 PlateR2005-3 Cl. I Lower Shell Plate B8759-2 A5331, 0.09 0.67 58 -0 3.51 1.33 77.14 34.00 111 5270 R2508-1 Cl. I Lower Shell Plate C4840-2 A533B, 0.06 0.64 37 -10 3.51 1.33 49.21 34.00 93 -5270 R2508-2 Cl. 1 Lower Shell Plate 51 -67.83 34.00 142 R2508-3 A533B, 0.08 0.58 51 3 67.8 3.0 1 C4935-2 40 3513 270-Using Surveillance Cl. 1 0.070 0.620 39.1 52.00 17.00 109 Data 35.93 Intermediate and 90146 Type Lower Plate B4 Wire, 32.6 -43.36 43.36 37 Longitudinal Weld Linde 0091 SAW 0.04 -50 3.08(121 1.33112) 5270 Seams G2.06 lind 0.08 Flux,-Using Surveillance Lot 0842(11) 29.7 39.50 28 18 Data 28.36 Intermediate to 90146 Type Lower Shell Plate B4 Wire, 0.09 32.6 -43.36 43.36 37 Circumferential Linde 124 SAW 0.04 -50 3,51 1.33 :5300 Weld E3.16 lind 124 0.08 -50 3-Using Surveillance Lo2069.70 281-UgLot 106113) 239.50 28 18 Data ______ 28.36 1________________________________

' This table is from information in WCAP-16030.

RVID chemistry values and chemistry factors are in boldface, if different.

WCAP-16030 Table 1 Note (c) says these values were "Updated from previous PTS Report (WCAP-15080) based on new chemical analysis presented in WCAP-16028." 10 Boldface heat numbers and types, chemistry, and chemistry factors are from the RVID.11 Flux "Lot 0842" is from WCAP-16030 Table 1 Note (b).12 These welds are at the 0, 120, and 2400 azimuths (0 and 30° quadrant azimuths), and therefore have a reduced peak beltline fluence. For conservatism the 3eak fluence, which occurs at the 450 azimuth, was used for the PTS calculation, hence the fluence factor is the same.'"1081" in the RVID, a typographical error for 1061. "1061" in WCAP-10015 page A-1, WCAP-16028 Table 4-1 Note (b), and in WCAP-16030 Table 4-1 Note (b).

Enclosure 2 to WET 07-0014 Enclosure 2 Figure for RAI 4.5-4 Vertical Tendons Forecast Value = -44.90972 log t + 1430.23305 1450 1400 1350 .. .i ,* ..0 1300 C 1250 _I--1200 1150 ..... .0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Log (Years)1 10 40 60 100 Years Horizontal Tendons Forecast Value = -69.43 log t + 1417.1 1450 1400 U)CD 1350

  • 0 1300 1250 1200 ...1.. ._0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Log (Years)1 10 40 60 100 Years Surveillance Data Regression Surveillance Program-Forecast Value (Trend Line)Lift-off Data---- Predicted Force ("Predicted Losses")Ave. Min. Design Prestress (MRV)
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