ML18054B516
| ML18054B516 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 03/29/1990 |
| From: | Frisch R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML18054B517 | List: |
| References | |
| TAC-72622, NUDOCS 9004030147 | |
| Download: ML18054B516 (10) | |
Text
consumers Power POW ERIN&
M.ICHl&ANYS PRO&RESS General Offices: 1945 West Parnall Road, Jackson,' Ml 49201 * (517) 788-0550 March 29, 1990 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT -
RESPONSE TO PALISADES SECOND TEN-YEAR INTERVAL INSERVICE INSPECTION PROGRAM REQUEST FOR ADDITIONAL INFORMATION (TAC NO 72622)
Consumers Power Company was informed by letter from the NRC dated January 12, 1990 that additional information was required to enable the NRC staff to complete their review and evaluation of the Palisades Plant Second Ten-Year Interval Inservice Inspection Program which was submitted to the NRC on December 19, 1988.
Consumers Power Company's response to each concern is detailed in Attachment 1.
Consumers Power Company agrees certain components in Class 2 systems should not be exempted per IWC-1220 1974S75 Section XI of the ASME Code.
Therefore, it was necessary to make changes to Section 3 "Basis Statement" and Section 6 "Verification of Section XI Compliance" of the Palisades Second Ten-Year Interval Inservice Inspection Program.
The attached two volumes contain the changes made to Section 3, pages 18 thru 50, (Tab 1) and Section 6, pages 143 thru 193, (Tab 2) of the Inservice Inspection Program, December 19, 1988 submittal, which pertain to Class 2 components.
Also included in the volumes, as requested, are copies of the Palisades 40 Year (long-term) Inservice Inspection Master Plan for Class 1 (Tab 5) and Class 2 (Tab 6) welds, components and component supports and isometric drawings for Class 1 (Tab 4) and Class 2 (Tab 5) welds, components and component supports.
As requested by the NRC staff, a copy of this information is being forwarded to Boyd W Brown, Idaho National Engineering Laboratory, P 0 Box 1625, Idaho Falls, Idaho 83415-2209, in order to expedite the review.
~~~~Mot_~
Staff Licensing Engineer CC Administrator, Region III, USNRC NRC Resident Inspector - Palisades OC0390-0004-NL02
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I A CMS' ElVERGY COMPANY f/()'f7
OC0390-0004-NL02 ATTACHMENT Consumers Power Company Palisades Plap.t Docket 50-255 RESPONSE TO NRC QUESTIONS ON SECOND TEN-YEAR INTERVAL INSERVICE INSPECTION PROGRAM March 29, 1990 8 Pages
1 NRC CONCERN 2.A.
Please provide the staff with an itemized listing of the welds/components subject to examination during the second ten-year interval.
2.B.
Please provide isometric and/or component drawings showing the welds, components and supports which Section XI of the ASME Code requires to be examined during the second ten-year interval.
2.C.
The Second Ten-Year Interval ISI Program submitted, makes reference to long-term inspection plans for Class 1, Class 2, and Class 3 components.
If these documents contain the information requested in Items 2A and 2B, please provide the long-term plans for Class 1 and Class 2 components in lieu of the above.
RESPONSE
As requested, Consumers Power Company has included the 40-Year (long-term)
Inservice Inspection Master Plan Exam Tables and Isometrics for Class 1 and Class 2 items examined or to be examined during the second ten-year interval at the Palisades Plant, (Volume 2, Tab 5 and 6).
OC0390-0004-NL02
2 NRC CONCERN 2.D.
Table Al (page 21 of the ISI Program) "Pressure Temperature Exemptions IWC-1220(a)," states that "IWC-1220(a), 74S75 has been applied to all Class 2 piping." Verify that the pressure/temperature exclusion will not be used for RHR, ECC and CHR systems and that the ISI Program includes volumetric examinations of a representative sampling of welds in these systems.
The staff points out that later editions and addenda of the Code do not permit the pressure/temperature exclusion for these systems.
RESPONSE
As identified in 10CFR50.55a(b)(2)(iv)(A), "Appropriate Code Class 2 pipe welds in Residual Heat Removal systems, Emergency Core Cooling systems and Containment Heat Removal systems, shall be examined." Also, stated is that "when applying editions and addenda up to the 1983 edition through the summer 1983 addenda of Section XI of the ASME Code, the extent of examination for these systems shall be determined by the requirements of paragraph IWC-1220, Table IWC-2520 Cate-gories C-F and G-G, and paragraph IWC-2411 in the 1974 edition and addenda through the summer 1975 addenda."
As permitted by 10CFR50.55a(b)(2)(iv)(B), Consumers Power Company has elected to determine the extent of examination (ie, selection of welds for examination) for all Class 2 piping by the requirements of paragraph IWC-1220, Table IWC-2520 Categories C-F and C-G and paragraph IWC-2411 from the 1974 edition of Section XI with addenda through summer 1975.
Based on the requirements as identified above, the 1974 edition of Section XI with addenda through summer 1975 paragraph IWC-1220 [IWC-1220(a)] states in part, "The following components may be exempted from the examination require-ments of Table IWC-2520."
Also, IWC-1220(A) states that "Components in systems where both the design pressure and temperature are equal to or less than 275 psig and 200°F respectively" may be exempted.
Consumers Power Company has reviewed Table Al (page 21 of the "Second Interval Inservice Inspection" program), "Pressure Temperature Exemptions IWC-1220(a)."
Based on this review, certain components have been removed and are scheduled for examination in accordance with Table IWC-2520 and paragraph IWC-2411 of the 1974 edition with addenda through summer 1975 of the ASME Section XI Code.
The pressure temperature exclusion is being applied to three subsystems attached to the SIRW Tank which is part of the emergency core cooling system.
Consumers Power Company does not intend to update the later editions and addenda of the code at this time.
OC0390-0004-NL02
3 NRC CONCERN 2.E.
Table A2 (page 22 of the ISI Program), "Class 2 Operational Exemptions IWC-1220(b)" shows that the Containment Spray system has been exempted from ISI examinations based on the fact that the Containment Spray system does not perform an emergency core cooling function.
This exemption includes eight inch and ten inch lines containing stagnated borated water.
As stated, 10CFR50.55a(b)(2)(iv) requires that pipe welds in CHR systems (ie, Containment Spray) be examined.
Confirm that the ISI Program will be revised to include a representative sample of welds in the Containment Spray system.
RESPONSE
As identified in 10CFR50.55a(b)(2)(iv)(A), "Appropriate Code Class 2 pipe welds in Residual Heat Removal systems, Emergency Core Cooling systems and Containment Heat Removal systems, shall be examined."
Also identified is "The extent of examination for these systems shall be determined by the requirements of para-graph IWC-1220, Table IWC-2520 Categories C-F and C-G and paragraph IWC-2411 in the 1974 edition and addenda through summer 1975 addenda."
The containment spray lines identified on Table A2 (page 22 of the "Second Interval Inservice Inspection" Program) do not perform an emergency core cooling function, and do not function during normal reactor operation.
There-fore, are exempted from the examination requirements based on IWC-1220(b) which states "Components in systems or portions.of systems, other than Emergency Core Cooling systems, which do not function during normal reactor operation."
Consumers Power Company has determined that a revision to the Palisades Plant's Second Interval Inservice Inspection Program is not required based on the requirements identified above.
OC0390-0004-NL02
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NRC CONCERN.
2.F.
Table A3 (page 23 of the ISI Program), "Class 2 Controlled Chemistry Exemptions (IWC-1220(c)" describes the use of the chemistry control exemption at Palisades Nuclear Plant.
The licensee should not be using 4
the control of water chemistry exemption of IWC-1220(c).
The control of water chemistry to minimize stress corrosion is not an acceptable basis for exempting components from examination because practical evaluation, review and acceptance standards cannot be defined.
Operating data indi-cate that "chemistry control" has not supported the exclusion and later editions and addenda of the Code have deleted the chemistry control exclusion.
Therefore examinations should be included for any components for which exemption is selected by the licensee under paragraph IWC-1220(c) of the 1974 edition and addenda through summer 1975 of the ASME Code.
Verify that the chemistry control exclusion will not be used and that the ISI Program will be revised to include examinations for these components.
RESPONSE
Consumers Power Company has reviewed the control of chemistry exemptions.
Although the requirements as identified in 10CFR50.55a(b)(2)(iv) and the 1974 edition of ASME XI with addenda through summer 1975 paragraph IWC-1220(c) allow this exemption, we agree that good engineering judgement does not support the use of the control of chemistry exemption.
Therefore, the components identified on Table A3 (page 23 of the "Second Interval Inservice Inspection" Program) have been removed and are now scheduled for examination in accordance with Table IWC-2520 and paragraph IWC-/.411 of the 1974 edition with addenda through summer 1975 of the ASME Section XI Code.
OC0390-0004-NL02
5 NRC CONCERN 2.G.
The staff notes that the "Examination Catgory C-F Table (page 145 of the ISI program) shows a total of 942 Engineered Safeguards System (ESS) welds which have not been exempted based on the exclusion criteria of IWC-1220.
This table also indicates that an additional 489 ESS welds have been exempted based on the exclusion criteria of IWC-1220.
Of the*
942 welds which have not been exempted, 78 are scheduled to receive surface only examinations and only 5 are scheduled to receive volumetric examination.
Volumetric examination of 5 ESS system welds is not con-sidered a representative sample and, therefore, does not meet the intent of the Code and the regulations.
Please clarify or explain how a volu-metric examination of 5 welds in the ESS system over the ten year ISI interval would be statistically representative and would provide a level of confidence that a generic problem would be identified.
RESPONSE
Consumers Power Company has made changes to the examination tables for Class 2 systems which were previously exempted per IWC-1220, 1974S75 Section XI of the ASME Code.
Based on the changes that were made it was necessary to make changes to Section 3, pages 18 th*ru 50, "Basis Statement" Volume 1, Tab 1 and Section 6, pages 143 thru 193 "Verification of Section XI Compliance" Volume 1, Tab 2 of the Palisades Second Ten-Year Interval Inservice Inspection Program which are attached for reference.
It should be noted that based on Section XI Item/Category C5.21 C-F Engineered Safeguards System (ESS) welds (ie, circumferential piping welds greater than 0.5 inch nominal wall thickness), Consumers Power Company has a total of 98 welds which require surface and volumetric examinations.
Over the next interval 12 welds are scheduled for volumetric examination which represents a 12 percent sample.
OC0390-0004-NL02
6 NRC CONCERN 2.H.
Plans for inservice examination of the reactor pressure vessel welds should address the degree of compliance with NRC Regulatory Guide 1.150, "Ultrasonic Testing of Reactor Vessel Welds During Preservice and Inser-vice Examinations." Discuss the near-surface examination and resolution with regard to finding service induced flaws and the use of electronic gating as related to the volume of material near the surface that is not being examined.
RESPONSE
Consumers Power Company has adopted the position on USNRC Regulatory Guide 1.150 that has been developed by Westinghouse Electric Corporation.
This position is incorporated in the Westinghouse procedure, CPAL-ISI-154, Revision 2, used for the performance of this testing.
The procedure is included in the attached Volume 1, Tab 3.
Westinghouse will be performing our reactor vessel examination during this ten-year interval.
OC0390-0004-NL02
7 NRC CONCERN 2.I.
Relief Request RR-2:
Relief is requested from the ASME Code required surface examination of piping weJ.ds adjacent to the reactor pressure vessel.
These welds are buried in cement and are inaccessible for 0 D surface examinations.
The licensee has proposed the use of ultrasonic techniques from the I D surface to examine the outside surf ace of the subject welds in lieu of the code required surface examination.
The licensee reports that the welds will be 100% examined in lieu of the bottom one-third as required by the code for volumetric examination.
This proposal could be considered acceptable provided the licensee meets the following conditions.
- 1.
The remote volumetric examination includes the entire weld volume and heat affected zone instead of only the inner one-third of the weld as required by the Code,
- 2.
The ultrasonic testing instrumentation and procedures are demonstrated to be capable of detecting 0 D surface connected defects in the circumferential orientation in a laboratory test block.
The defects should be cracks and not machined notches.
Provide a discussion of the above conditions and verify that they will be met.
RESPONSE
- 1.
Consumers Power Company will perform volumetric (mechanized ultrasonic) examination of the entire weld volume and heat affected zone instead of the inner one-third of the weld as required by Figure IWB-2500-8 of the 1983 edition summer 1983 addenda ASME B&PV Section XI Code.
- 2.
Consumers Power Company utilizes Westinghouse Electric Corporation to perform the mechanized ultrasonic examinations as identified in Relief Request RR-2.
Westinghouse Electric Corporation Ultrasonic Procedure CPAL-ISI-154 Revision 2, which is used for the performance of these examinations is included in attached Volume 1, Tab 3.
With regards to the instrumentation and procedure ability to detect 0 D surface connected defects in the circumferential orientation, Consumers Power Company supplies ultrasonic calibration blocks (30-ID-CSCL-3.0-19-PAL and 42-ID-CSCL-X-4,0-20-PAL) which meet the ASME 1983 edition summer 1983 addenda Section XI Code, mandatory Appendix III Section III-3400, The above identified ultrasonic calibration blocks which contain I D and 0 D machined notches are representative of both I D and 0 D defects as demonstrated during the pre-examination calibration, verifications performed during the examinations when required and post examination calibration verifications.
We are not aware of any requirements for inducing cracking in ultrasonic calibration blocks.
Also, we do not feel that inducing cracks would add any significant examination results.
OC0390-0004-NL02
NRC CONCERN 2.J. Verify that there are no additional relief requests applicable for the second ten-year interval, other than RR-1 through RR-4 in Section 5 of the ISI Program for the second ten-year interval as submitted 8
December 19, 1988.
Because requests for relief are not automatically granted for subsequent inspection intervals, the licensee must make a complete submittal of all requests for relief for each ten-year inspection interval.
This enables the staff to review the requests for relief against the updated Code requirements and the licensee's use of new and improved examination techniques as they become available.
If relief requests other than RR-1 through RR-4 are required, the licensee should submit them for staff review.
RESPONSE
Consumers Power Company has determined that the requests for relief, RR-1 through RR-4 of the December 19, 1988 submittal are the only relief requests necessary for the Palisades Plant during the second ten-year interval.
OC0390-0004-NL02