L-MT-10-062, Response to Request for Additional Information Regarding 10 CFR 50.55a Request No. 19 (RR-19): Relief from Impractical Examination Coverage, Requirements Pursuant to 10 CFR 50.55a(g)(5)(iii) for the Fourth Ten-Year Inservice Inspection I

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Response to Request for Additional Information Regarding 10 CFR 50.55a Request No. 19 (RR-19): Relief from Impractical Examination Coverage, Requirements Pursuant to 10 CFR 50.55a(g)(5)(iii) for the Fourth Ten-Year Inservice Inspection Inte
ML102720729
Person / Time
Site: Monticello 
Issue date: 09/29/2010
From: O'Connor T
Northern States Power Co, Xcel Energy
To:
Office of Nuclear Reactor Regulation, Document Control Desk
References
L-MT-10-062, TAC ME3937
Download: ML102720729 (9)
v • d • e


Text

@ Xcel Energy.

September 29, 201 0 Monticello Nuclear Generating Plant 2807 W County Road 75 Monticello, MN 55362 L-MT-10-062 10 CFR 50,55a(g)(5)(iii)

U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Monticello Nuclear Generating Plant Docket 50-263 Renewed Facility Operating License No. DPR-22

Subject:

Response to Request for Additional Information Regarding 10 CFR 50.55a Request No. 19 (RR-19): Relief from lmpractical Examination Coverage Requirements Pursuant to 10 CFR 50.55a(g)(5)(iii) for the Fourth Ten-Year lnservice lnspection Interval (TAC No. ME3937)

References:

1) Letter from Northern States Power - Minnesota (NSPM) to the U.S. Nuclear Regulatory Commission (NRC), "10 CFR 50.55a Request No. 19: Relief from lmpractical Examination Coverage Requirements Pursuant to 10 CFR 50.55a(g)(5)(iii) for the Fourth Ten-Year lnservice lnspection Interval,"

dated May 6,201 0 (ADAMS Accession No. ML072710119)

2) Electronic mail from P. Tam (NRC) to NSPM, "Monticello - Draft RAI re. Relief Request 19 dated 51611 0" (TAC No. ME3937), dated July 27, 201 0 (ADAMS Accession No. MLI 02080492)
3) Electronic mail from P. Tam (NRC) to NSPM, "Monticello - Revised draft RAI re. Relief Request 19 dated 5/6/10 (TAC No. ME3937)", dated August 9, 201 0 (ADAMS Accession No. ML102210157)

By letter dated May 6, 2010 (Reference I), and pursuant to 10 CFR 50.55a(g)(5)(iii),

Northern States Power - Minnesota (NSPM) requested U.S. Nuclear Regulatory Commission (NRC) review and approval of 10 CFR 50.55a Request No. 19 (RR-19).

NSPM submitted this request for the Fourth Ten-Year lnservice Inspection Interval scheduled to end on May 31,2012.

Document Control Desk L-MT-10-062 Page 2 of 2 RR-19 requests relief for the Monticello Nuclear Generating Plant (MNGP) from certain examination coverage requirements imposed by the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components." Request RR-19 is for weld examinations performed during the 2009 refueling outage where the required coverage of "essentially 100 percent" could not be obtained when examined to the extent practical. The basis for the 10 CFR 50.55a request is that compliance with the specified requirements is impractical due to plant design.

On July 27, 2010, the NRC staff notified NSPM by electronic mail (Reference 2) that additional information was necessary for the staff to complete the review. A conference call between NSPM and NRC staff was held on August 9, 2010, to clarify the requests for additional information (RAI). Following the conference call, the NRC staff sent a revised RAI to NSPM by electronic mail (Reference 3). The NSPM response to the NRC RAI is included in Enclosure 1.

If you have further questions regarding this request, please contact Mr. Randy Rippy at 61 2-330-691 1.

commitments and does not revise any existing ello Nuclear Generating Plant pany - Minnesota Enclosure cc:

Administrator, Region Ill, USNRC Project Manager, Monticello, USNRC Resident Inspector, Monticello, USNRC Minnesota Department of Commerce

L-MT-10-062 Page 1 of 7 ENCLOSURE I Response to Request for Additional Information Regarding 10 CFR 50.55a Request No. 19 (RR-19)

By letter dated May 6, 2010, and pursuant to 10 CFR 50.55a(g)(5)(iii), Northern States Power Company - Minnesota (NSPM) requested U.S. Nuclear Regulatory Commission (NRC) review and approval of 10 CFR 50.55a Request RR-19 (Reference 1).

Under RR-19, NSPM requested relief for the Monticello Nuclear Generating Plant (MNGP) from certain examination coverage requirements imposed by the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (BPV) Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components." As indicated in RR-19, seven nozzle-to-vessel (NV) welds were examined to the extent practical during the 2009 refueling outage (RFO). Enclosure 4 of RR-19 provided the prior examination history for all of the subject welds which were examined during the 2009 RFO.

On July 27, 2010, the NRC staff notified NSPM by electronic mail (Reference 2) that additional information was necessary for the staff to complete the review. A conference call between NSPM and NRC staff was held on August 9, 2010, to clarify the requests for additional information (RAI). Following the conference call, the NRC staff sent a revised RAI to NSPM by electronic mail (Reference 3). The NRC RAI is repeated below with the NSPM response following the RAI.

NRC Request:

1.

A number of the welds for which relief was requested are not unique in the Monticello plant (i.e., relief was requested for a subset of multiple, similar welds). Please indicate how many additional welds of the same type (recirculation inlet nozzle, feedwater inlet, etc.) exist and have been inspected during this or the prior interval. For those similar welds that have been inspected during this or the prior interval, please provide the percentage of the required weld volume that was inspected, whether any indications were identified, and how those indications were dispositioned.

L-MT-10-062 Page 2 of 7 ENCLOSURE I Response to Request for Additional Information Regarding 10 CFR 50.55a Request No. 19 (RR-19)

NSPM Response:

In Table A, which follows, the subject nozzle-to-vessel welds of RR-19 are listed (Welds Examined in 2009). For each of the subject welds, Table A also includes:

a description of the Reactor Pressure Vessel (RPV) nozzle type associated with the weld (RPV Nozzle Type),

the total quantity of that type installed on the Monticello RPV, e.g.

recirculation inlet nozzle, feedwater inlet, etc. (Total Qty on RPV),

the number of additional exams of the same type performed to date during the 4th lnterval (this lnterval), excluding the 2009 exams (Add1 4th Int Exams), and the number of additional exams of the same type performed during the 3rd lnterval (prior Interval), excluding the historical exams of the subject welds provided in RR-I 9 submittal (Add'l3rd Int Exams).

Table A

~ d d ' l 3'

Ink Exam:

9 3

3 1

NIA 1

NIA Examined in 2009 N-2A NV N-3C NV N-4B NV N-6B NV N-7 NV N-8B NV N-10 NV Total Qty on RPV I 0 4

4 2

1 2

1 RPV Recirculation Inlet (N2)

Main Steam Outlet (N3)

Feedwater l nlet (N4)

Reactor Head Spare (N6)

Reactor Head Vent (N7)

Jet Pump Instrumentation (N8)

Standby Liquid Control Inlet I Core Differential Pressure (Nl 0)

Add'l 4th Int Exams 5

1 2

1 NIA 1

NIA

L-MT-10-062 Page 3 of 7 ENCLOSURE 1 Response to Request for Additional Information Regarding 10 CFR 50.55a Request No. 19 (RR-19)

NSPM Response (continued):

Table B of this Enclosure provides the examination history applicable to this and/or the prior lnterval for the same weld types as the subject welds of RR-19.

Table B also includes the percentage of examination coverage obtained for all of these welds.

Each of the subject welds were examined during the current or previous lnterval shown in the Table. Review of historical examination results for these similar welds found that no indications were identified, therefore no disposition of indications has been necessary.

The N7 and N10 nozzles listed in RR-19 are each a set of one. Therefore, since they have no similar welds, there are no additional N7 or N10 entries in Table B.

Also, as noted previously, Enclosure 4 of RR-19 provided the examination history for all of the specified welds examined in 2009, therefore, they are not included in Table B.

' N-5 nozzle type exams are not applicable to the RR-19 subject population. Therefore, examination history information for N-5A and similar type weld N-5B are not included in Table B of this RAI response.

  • N-10 and its examination history was included in the RR-19 submittal and is therefore not included in Table B of this RAI response.

Table B: Historical Nozzle-to-Vessel Weld Examination for This lnterval (4th lnterval) or the Prior lnterval (3rd Interval)

Notes:

Note 1 Code Coverage was not determined for limited exams prior to 1997 (Reference 1)

Note 2 Relief was not requested for limited exams prior to 1997 (Reference ;l)

Note 3 Limited nozzle-to-vessel weld exams for N-2C, N-2F, N-3D, N-5A, N-6B, and N-10' were errantly omitted from 3rd lnterval IS1 10CFR50.55a Request 11 which was submitted for the 2000 refueling outage and approved by the NRC on October 25, 2000. (References 1,4, 5, 6, and 7)

Weld N-2B N-2C Exam Results no indications no indications no indications IS1 Interval 3rd 4'h 3rd 1 OCFR50.55a Request RR-16 (Ref. 8)

RR-15 (Ref. 9)

Note 3 NRC Approval Date May 19, 2003 (Ref. 10)

May 19, 2008 (Ref. 11)

Note 3 Exam Year 2001 2007 2000 Exam Coverage 62%

78%

61 %

L-MT-10-062 Page 4 of 7 ENCLOSURE I Response to Request for Additional Information Regarding 10 CFR 50.55a Request No. 19 (RR-19)

Table B: Historical Nozzle-to-Vessel Weld Examination for This lnterval (4th lnterval) or the Prior lnterval (3rd lnterval)

Notes:

Note 1 Code Coverage was not determined for limited exams prior to 1997 (Reference 1)

Note 2 Relief was not requested for limited exams prior to 1997 (Reference ;l)

Note 3 Limited nozzle-to-vessel weld exams for N-2C, N-2F, N-3D, N-5A, N-6B, and N-lo2 were Weld N-2D N-2 E N-2F N-2G N-2H N-2 J N-2 K N-3A N-3B N-3D N-4A Request 11 which was 25, 2000. (References 10CFR50.55a Request Note 2 RR-13 (Ref. 12)

Note 2 RR-I3 (Ref. 12)

Note 3 RR-10 (Ref. 14)

RR-15 (Ref.9)

RR-10 (Ref.14)

Note 2 RR-13 (Ref.12)

RR-16 (Ref. 8)

Note 2 RR-13 (Ref. 12)

RR-11 (Ref. 4)

Note 3 Note 2 RR-15 (Ref. 9) submitted for the 2000 1, 4, 5, 6, and 7)

NRC Approval Date Note 2 July 18, 2006 (Ref. 13)

Note 2 July 18, 2006 (Ref. 13)

Note 3 August 4, 1999 (Ref. 15)

May 19, 2008 (Ref. I I )

August 4, 1999 (Ref. 15)

Note 2 July 18, 2006 (Ref. 13)

May 19, 2003 (Ref. 10)

Note 2 July 18, 2006 (Ref. 13)

October 25, 2000 (Ref. 7)

Note 3 Note 2 May 19, 2008 (Ref. 11) errantly refueling IS1 Interval 3rd 4th 3rd 4th 3rd 3rd 4th 3rd 3rd 4th 3rd 3rd 4th 3rd 3rd 3rd 4th omitted from outage and Exam Year 1994 2005 1994 2005 2000 1998 2007 1998 1994 2005 2001 1994 2005 2000 2000 1996 2007 3rd Interval IS1 approved by Exam Coverage Note 1 82%

Note 1 78%

61 %

51 %

78%

47%

Note 1 78%

62%

Note 1 83%

61 %

61 %

Note 1 79%

1 OCFR50.55a the NRC on October Exam Results no indications no indications no indications no indications no indications no indications no indications no indications no indications no indications no indications no indications no indications no indications no indications no indications No indications

L-MT-10-062 Page 5 of 7 ENCLOSURE I Response to Request for Additional Information Regarding 10 CFR 50.55a Request No. 19 (RR-19)

Table B: Historical Nozzle-to-Vessel Weld Examination for This Interval (dh Interval) or the Prior Interval (3rd Interval)

Notes:

Note 1 Code Coverage was not determined for limited exams prior to 1997 (Reference 1)

Note 2 Relief was not requested for limited exams prior to 1997 (Reference 1)

Note 3 Limited nozzle-to-vessel weld exams for N-2C, N-2F, N-3D, N-5~', N-6B, and N-lo2 were errantly omitted from 3rd Interval IS1 10CFR50.55a Request 11 which was submitted for the 2000 refueling outage and approved by the NRC on October 25, 2000. (References 1, 4, 5, 6, and 7)

Weld N-4C N-4D N-6A N-8A 1 OCFR50.55a Request Note 2 RR-13 (Ref. 12)

RR-11 (Ref. 4)

Note 2 RR-15 (Ref. 9)

Note 2 RR-13 (Ref. 12)

NRC Approval Date Note 2 July 18, 2006 (Ref. 13)

October 25, 2000 (Ref. 7)

Note 2 May 19, 2008 (Ref. 11)

Note 2 July 18, 2006 (Ref. 13)

IS1 Interval 3rd 4th 3rd 3rd 4'h 3rd 4th Exam Year 1994 2005 2000 1996 2007 1994 2005 Exam Coverage Note 1 79%

61 %

Note I 86%

Note 1 83%

Exam Results no indications no indications no indications no indications no indications no indications no indications

L-MT-10-062 Page 6 of 7 ENCLOSURE 1 Response to Request for Additional lnformation Regarding 10 CFR 50.55a Request No. 19 (RR-19)

REFERENCES

1.

NSPM letter to NRC, "10 CFR 50.55a Request No. 19: Relief from Impractical Examination Coverage Requirements Pursuant to 10 CFR 50,55a(g)(5)(iii) for the Fourth Ten-Year lnservice lnspection Interval," dated May 6, 2010 (ADAMS Accession No. ML072710119)

2.

Electronic mail from P. Tam (NRC) to NSPM, "Monticello - Draft RAI re. Relief Request 19 dated 51611 0" (TAC No. ME3937), dated July 27, 2010 (ADAMS Accession No. ML102080492)

3.

Electronic mail from P. Tam (NRC) to NSPM, "Monticello - Revised draft RAI re.

Relief Request 19 dated 5/6/10 (TAC No. ME3937)," dated August 9, 201 0 (ADAMS Accession No. ML102210157)

4.

MNGP letter to NRC, "Request for Relief No. 11 for the 3rd 10-Year lnterval lnservice lnspection Program," dated May 25, 2000 (ADAMS Accession No. ML003720899)

5.

MNGP letter to NRC, "Supplemental lnformation Request for Relief No. 11 for the 3rd 10-Year lnterval lnservice lnspection Program," dated July 11, 2000 (ADAMS Accession No. ML003734843)

6.

MNGP Corrective Action Program Action Request (CAP AIR) 01013875, "6 limited IS1 exams not included in Cycle 19 Relief Request," origination date February 7, 2006

7.

NRC letter to NMC, "Monticello Nuclear Generating Plant - Evaluation of Relief Request Number 11 for the Third 10-Year lnterval lnservice lnspection Program Plan (TAC No. MA91 14)," dated October 25, 2000 (ADAMS Accession No. ML003763033)

8.

MNGP letter to NRC, "Request for Review and Approval of Relief Request Nos.

15 and 16 for the Monticello 3rd 1 O-Year lnterval lnservice lnspection Examination Plan," dated May 30,2002 (ADAMS Accession No. ML021680035)

9.

MNGP letter to NRC, "10 CFR 50.55a Request No. 15: Relief from Impractical Examination Coverage Requirements Pursuant to 10 CFR 50.55a(g)(5)(iii) for the Fourth Ten-Year lnservice lnspection Interval," dated September 26, 2007 (ADAMS Accession No. ML072710119)

L-MT-10-062 Page 7 of 7 ENCLOSURE 1 Response to Request for Additional Information Regarding 10 CFR 50.55a Request No. 19 (RR-19)

10.

NRC letter to MNGP, "Monticello Nuclear Generating Plant (MNGP) - Third 10-Year Interval lnservice lnspection Relief Request No. 16 (TAC No. MB5487),"

dated May 19,2003 (ADAMS Accession No. ML03140019)

11.

NRC letter to MNGP, "Monticello Nuclear Generating Plant (MNGP) - Granting of Relief Regarding Limited Ultrasonic Examination Coverage of Five Welds (TAC No. MD6854)," dated May 19,2008 (ADAMS Accession No. ML081050678) 12 MNGP letter to NRC, "1 0 CFR 50.55a Request No. 13: Relief from Impractical Examination Coverage Requirements Pursuant to 10 CFR 50.55a(g)(5)(iii) for the Fourth Ten-Year lnservice lnspection Interval," dated September 27, 2005 (ADAMS Accession No. ML052760169)

13.

NRC letter to MNGP, "Monticello Nuclear Generating Plant (MNGP) - Fourth 10-Year Interval lnservice lnspection (ISI) Program Plan Relief Request No. 13 (TAC No. MC8882)," dated July 18,2006 (ADAMS Accession No. ML061780172)

14.

NSP letter to NRC, "Request for Relief for the 3rd 10-Year Interval lnservice lnspection Program," dated July 24 1998

15.

NRC letter to NSPM, "Monticello Nuclear Generating Plant - Evaluation of Relief Request Number 10 for the Third 1 0-Year Interval Inservice lnspection Program Plan (TAC No. MA3397)," dated August 4, 1999

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