NL-15-1997, Revision to Relief Request P-5 and P-9
| ML15299A464 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 10/26/2015 |
| From: | Pierce C Southern Co, Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-15-1997 | |
| Download: ML15299A464 (7) | |
Text
Charles R. Pierce Southern Nuclear Regulatory Affairs Director Operating Company, Inc.
40 Inverness Center Parkway A
Post Office Box 1295 Birmingham, AL 35201 Tel 205.992.7872 Fax 205.992 .7601 SOUTHERN COMPANY OCT 2 6 2015 Docket Nos.: 50-321 NL-15-1997 50-366 U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Revision to Relief Request P-5 and P-9 Ladies and Gentlemen:
By letter dated May 4, 2015, Southern Nuclear Operating Company (SNC) requested Nuclear Regulatory Commission (NRC) approval of changes to the Edwin I. Hatch Nuclear Plant Units 1 and 2 Fifth Ten-Year Interval In-service Testing Program. By letter dated September 15, 2015, SNC resubmitted those changes, for which approval was still being requested, in their entirety. The changes to the 1ST program involve several relief requests (RR), all of which were included in Enclosure 3 of the September letter.
During subsequent phone conversations between SNC and NRC staff, it was agreed to revise RR-P-5 and P-9 to remove a reference to positive displacement pumps. Accordingly, the Enclosure to this letter provides the revised versions of RR-P-5 and RR-P-9.
Neither RR-P-5 nor RR-P-9 involve positive displacement pumps.
This letter contains no new NRC commitments. If you have any questions, please contact Mr. G.K. McElroy at 205-992-7369.
RZ"ftf!;"d, C. R. Pierce Regulatory Affairs Director CRP/OCV/
Enclosure:
Revision to Relief Requests P-5 and P-9
U.S. Nuclear Regulatory Commission NL-15-1997 Page 2 cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bast, Executive Vice President & Chief Nuclear Officer Mr. D. R. Vineyard, Vice President- Hatch Mr. M. D. Meier, Vice President- Regulatory Affairs Mr. D. R. Madison, Vice President- Fleet Operations Mr. B. J. Adams, Vice President- Engineering Mr. G. L. Johnson, Regulatory Affairs Manager- Hatch RTYPE: CHA02.004 U.S. Nuclear Regulatory Commission Mr. L. D. Wert, Regional Administrator (Acting)
Mr. R. E. Martin, NRR Senior Project Manager- Hatch Mr. D. H. Hardage, Senior Resident Inspector- Hatch
Edwin I. Hatch Nuclear Plant Units 1 and 2 Enclosure Revision to Relief Requests P-5 and P-9
SOUTHERN NUCLEAR OPERATING COMPANY ISTPROGRAM PROPOSED ALTERNATIVE IN ACCORDANCE WITH 10 CFR 50.55a(z)(2)
RR-P-5 PLANT/UNIT: Edwin I Hatch Nuclear Plant/Unit I and 2.
INTERVAL: 5th Interval beginning January I, 2016 and ending December 31, 2025.
COMPONENTS 1E11-C001A,B,C,D (RHRSW Vertical Line Shaft Pumps)- Group A AFFECTED: 2E11-C001A,B,C,D (RHRSW Vertical Line Shaft Pumps)- Group A 1P41-C001A,B,C,D (PSW Vertical Line Shaft Pumps)- Group A 2P41-C001A,B,C,D (PSW Vertical Line Shaft Pumps) - Group A CODE EDITION ASME OM Code-2004 Edition with Addenda through OMb-2006 AND ADDENDA:
REQUIREMENTS: ISTB-3540(b) requires that vibration measurements on vertical line shaft pumps be taken on the upper motor-bearing housing in three approximately orthogonal directions, one of which is the axial direction.
REASON FOR This alternative is are-submittal of NRC approved 4th Interval relief request RR-REQUEST: P-5 that was based on the ASME OM Code-2001 Edition. This 5th Interval request for relief, RR-P-5, is based on the ASME OM Code-2004 Edition with Addenda through OMb-2006. There have been no substantive changes to this alternative, to the OM Code requirements or to the basis for use, which would alter the previous NRC Safety Evaluation conclusions. (See References for SER date and TAC numbers associated with RR-P-5).
The Code required vibration measurements on the upper motor bearing housing on these vertical line shaft pumps are impractical because of the following reasons.
- 1. Plant design did not include permanent scaffolding or ladders which provide access to the top of the motors for the subject pumps.
- 2. Physical layout of the pumps and interference with adjacent components does not allow for the installation of temporary scaffolding or ladders which are adequate and safe for routine use.
- 3. There is a thin cover plate bolted to the top-center of each motor which prevents measurements in line with the motor bearing. Measurement on the edge of the motor housing would be influenced by eccentricity and may not be representative of actual axial vibration. *
- 4. Special tools (extension rod) for placing the vibration transducers are not practical because placement would not be sufficiently accurate for trending purposes.
I of2
RR-P-5 (Cont.)
- 5. Research within the industry has indicated that vibration monitoring of vertical line shaft pumps has been of limited benefit for detecting mechanical degradation due to problems inherent with pump design. The OM Code imposes more stringent hydraulic acceptance criteria on these pumps than for centrifugal pumps. These more stringent hydraulic acceptance criteria place more emphasis on detection of degradation through hydraulic test data than through mechanical test data.
PROPOSED Vibration measurements will be taken in three orthogonal directions, one of which is ALTERNATIVE in the axial direction in the area of the pump to motor mounting flange when AND BASIS: conducting Group A, Comprehensive Pump and Preservice Testing. This is the closest accessible location to a pump bearing housing and this location is easily and safely accessible for test personnel which should ensure repeatable vibration data and should provide readings which are at least as representative of pump mechanical condition as those required by the Code.
The above proposed alternative provides reasonable assurance of operational readiness since vibration measurements will be taken in three orthogonal directions at the pump to motor mounting flange which will provide information as to the mechanical integrity of the pump. Based on the determination that compliance with the Code requirement results in a hardship without a compensating increase in the level of quality and safety, this proposed alternative should be granted pursuant to I 0 CFR50.55a(z)(2).
DURATION: 5th Interval beginning January I, 2016 and ending December 31, 2025.
PRECEDENTS: This Relief Request was approved as RR-P-5 for the Fourth 10 Year 1ST Interval
REFERENCES:
NRC Safety Evaluation dated February 14, 2006- TAC Nos. MC6837, MC6838, MC7626 and MC7627 2 of2
SOUTHERN NUCLEAR OPERATING COMPANY ISTPROGRAM PROPOSED ALTERNATIVE IN ACCORDANCE WITH 10 CFR 50.55a(z)(2)
RR-P-9 PLANT/UNIT: Edwin I Hatch Nuclear Plant/Unit 2.
INTERVAL: 5th Interval beginning January I, 2016 and ending December 31, 2025.
COMPONENTS 2P41-C002 (Vertical Line Shaft Pump)- Group B AFFECTED:
CODE EDITION ASME OM Code-2004 Edition with Addenda through OMb-2006 AND ADDENDA:
REQUIREMENTS: ISTB-3540(b) requires that vibration measurements on vertical line shaft pumps be taken on the upper motor-bearing housing in three approximately orthogonal directions, one of which is the axial direction.
REASON FOR This alternative is are-submittal of NRC approved 4th Interval relief request RR-P-9 REQUEST: that was based on the ASME OM Code-2001 Edition. This 5th Interval request for relief, RR-P-9, is based on the ASME OM Code-2004 Edition with Addenda through OMb-2006. There have been no substantive changes to this alternative, to the OM Code requirements or to the basis for use, which would alter the previous NRC Safety Evaluation conclusions. (See References for SER date and TAC numbers associated with RR-P-9).
The Code required vibration measurements on the upper motor-bearing housing on this Unit 2 Standby Diesel Generator Service Water vertical line shaft pump are impractical because of the following reasons.
I. The motor has a cooling fan mounted at the top which is attached to the rotating shaft. The fan is protected by a relatively thin cover plate which prevents access to the motor housing for vibration measurements. Removing the cover does not provide for transducer placement since the rotating fan would still be in the way.
- 2. Research within the industry has indicated that vibration monitoring of vertical line shaft pumps has been of limited benefit for detecting mechanical degradation due to problems inherent with pump design. The OM Code imposes more stringent hydraulic acceptance criteria on these pumps than for centrifugal pumps. These more stringent hydraulic acceptance criteria place more emphasis on detection of degradation through hydraulic test data than through mechanical test data.
I of2
RR-P-9 (Cont.)
PROPOSED Vibration measurements will be taken in three orthogonal directions, one of which is ALTERNATIVE in the axial direction in the area of the pump to motor mounting flange. This is the AND BASIS: closest accessible location to a pump bearing housing and this location is easily accessible for test personnel which should ensure repeatable vibration data and should provide readings which are at least as representative of pump mechanical condition as those required by the Code.
Therefore, application of the OM Code hydraulic testing criteria along with radial and axial vibration monitoring in the area of the pump to motor mounting flange should provide adequate data for assessing the condition of the subject pumps and for monitoring degradation. This request is only applicable to Comprehensive Pump and Preservice Testing. The above proposed alternative provides reasonable assurance of operational readiness since vibration measurements will be taken in three orthogonal directions at the pump to motor mounting flange which will provide information as to the mechanical integrity of the pump. Based on the determination that compliance with the Code requirements results in a hardship without a compensating increase in the level of quality and safety, this proposed alternative should be granted pursuant to 10 CFR50.55a(z)(2).
DURATION: 5th Interval beginning January 1, 2016 and ending December 31, 2025.
PRECEDENTS: This Relief Request was approved as RR-P-9 for the Fourth 10 Year 1ST Interval
REFERENCES:
NRC Safety Evaluation dated February 14, 2006- TAC Nos. MC6837, MC6838, MC7626 and MC7627 2 of2
Charles R. Pierce Southern Nuclear Regulatory Affairs Director Operating Company, Inc.
40 Inverness Center Parkway A
Post Office Box 1295 Birmingham, AL 35201 Tel 205.992.7872 Fax 205.992 .7601 SOUTHERN COMPANY OCT 2 6 2015 Docket Nos.: 50-321 NL-15-1997 50-366 U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Revision to Relief Request P-5 and P-9 Ladies and Gentlemen:
By letter dated May 4, 2015, Southern Nuclear Operating Company (SNC) requested Nuclear Regulatory Commission (NRC) approval of changes to the Edwin I. Hatch Nuclear Plant Units 1 and 2 Fifth Ten-Year Interval In-service Testing Program. By letter dated September 15, 2015, SNC resubmitted those changes, for which approval was still being requested, in their entirety. The changes to the 1ST program involve several relief requests (RR), all of which were included in Enclosure 3 of the September letter.
During subsequent phone conversations between SNC and NRC staff, it was agreed to revise RR-P-5 and P-9 to remove a reference to positive displacement pumps. Accordingly, the Enclosure to this letter provides the revised versions of RR-P-5 and RR-P-9.
Neither RR-P-5 nor RR-P-9 involve positive displacement pumps.
This letter contains no new NRC commitments. If you have any questions, please contact Mr. G.K. McElroy at 205-992-7369.
RZ"ftf!;"d, C. R. Pierce Regulatory Affairs Director CRP/OCV/
Enclosure:
Revision to Relief Requests P-5 and P-9
U.S. Nuclear Regulatory Commission NL-15-1997 Page 2 cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bast, Executive Vice President & Chief Nuclear Officer Mr. D. R. Vineyard, Vice President- Hatch Mr. M. D. Meier, Vice President- Regulatory Affairs Mr. D. R. Madison, Vice President- Fleet Operations Mr. B. J. Adams, Vice President- Engineering Mr. G. L. Johnson, Regulatory Affairs Manager- Hatch RTYPE: CHA02.004 U.S. Nuclear Regulatory Commission Mr. L. D. Wert, Regional Administrator (Acting)
Mr. R. E. Martin, NRR Senior Project Manager- Hatch Mr. D. H. Hardage, Senior Resident Inspector- Hatch
Edwin I. Hatch Nuclear Plant Units 1 and 2 Enclosure Revision to Relief Requests P-5 and P-9
SOUTHERN NUCLEAR OPERATING COMPANY ISTPROGRAM PROPOSED ALTERNATIVE IN ACCORDANCE WITH 10 CFR 50.55a(z)(2)
RR-P-5 PLANT/UNIT: Edwin I Hatch Nuclear Plant/Unit I and 2.
INTERVAL: 5th Interval beginning January I, 2016 and ending December 31, 2025.
COMPONENTS 1E11-C001A,B,C,D (RHRSW Vertical Line Shaft Pumps)- Group A AFFECTED: 2E11-C001A,B,C,D (RHRSW Vertical Line Shaft Pumps)- Group A 1P41-C001A,B,C,D (PSW Vertical Line Shaft Pumps)- Group A 2P41-C001A,B,C,D (PSW Vertical Line Shaft Pumps) - Group A CODE EDITION ASME OM Code-2004 Edition with Addenda through OMb-2006 AND ADDENDA:
REQUIREMENTS: ISTB-3540(b) requires that vibration measurements on vertical line shaft pumps be taken on the upper motor-bearing housing in three approximately orthogonal directions, one of which is the axial direction.
REASON FOR This alternative is are-submittal of NRC approved 4th Interval relief request RR-REQUEST: P-5 that was based on the ASME OM Code-2001 Edition. This 5th Interval request for relief, RR-P-5, is based on the ASME OM Code-2004 Edition with Addenda through OMb-2006. There have been no substantive changes to this alternative, to the OM Code requirements or to the basis for use, which would alter the previous NRC Safety Evaluation conclusions. (See References for SER date and TAC numbers associated with RR-P-5).
The Code required vibration measurements on the upper motor bearing housing on these vertical line shaft pumps are impractical because of the following reasons.
- 1. Plant design did not include permanent scaffolding or ladders which provide access to the top of the motors for the subject pumps.
- 2. Physical layout of the pumps and interference with adjacent components does not allow for the installation of temporary scaffolding or ladders which are adequate and safe for routine use.
- 3. There is a thin cover plate bolted to the top-center of each motor which prevents measurements in line with the motor bearing. Measurement on the edge of the motor housing would be influenced by eccentricity and may not be representative of actual axial vibration. *
- 4. Special tools (extension rod) for placing the vibration transducers are not practical because placement would not be sufficiently accurate for trending purposes.
I of2
RR-P-5 (Cont.)
- 5. Research within the industry has indicated that vibration monitoring of vertical line shaft pumps has been of limited benefit for detecting mechanical degradation due to problems inherent with pump design. The OM Code imposes more stringent hydraulic acceptance criteria on these pumps than for centrifugal pumps. These more stringent hydraulic acceptance criteria place more emphasis on detection of degradation through hydraulic test data than through mechanical test data.
PROPOSED Vibration measurements will be taken in three orthogonal directions, one of which is ALTERNATIVE in the axial direction in the area of the pump to motor mounting flange when AND BASIS: conducting Group A, Comprehensive Pump and Preservice Testing. This is the closest accessible location to a pump bearing housing and this location is easily and safely accessible for test personnel which should ensure repeatable vibration data and should provide readings which are at least as representative of pump mechanical condition as those required by the Code.
The above proposed alternative provides reasonable assurance of operational readiness since vibration measurements will be taken in three orthogonal directions at the pump to motor mounting flange which will provide information as to the mechanical integrity of the pump. Based on the determination that compliance with the Code requirement results in a hardship without a compensating increase in the level of quality and safety, this proposed alternative should be granted pursuant to I 0 CFR50.55a(z)(2).
DURATION: 5th Interval beginning January I, 2016 and ending December 31, 2025.
PRECEDENTS: This Relief Request was approved as RR-P-5 for the Fourth 10 Year 1ST Interval
REFERENCES:
NRC Safety Evaluation dated February 14, 2006- TAC Nos. MC6837, MC6838, MC7626 and MC7627 2 of2
SOUTHERN NUCLEAR OPERATING COMPANY ISTPROGRAM PROPOSED ALTERNATIVE IN ACCORDANCE WITH 10 CFR 50.55a(z)(2)
RR-P-9 PLANT/UNIT: Edwin I Hatch Nuclear Plant/Unit 2.
INTERVAL: 5th Interval beginning January I, 2016 and ending December 31, 2025.
COMPONENTS 2P41-C002 (Vertical Line Shaft Pump)- Group B AFFECTED:
CODE EDITION ASME OM Code-2004 Edition with Addenda through OMb-2006 AND ADDENDA:
REQUIREMENTS: ISTB-3540(b) requires that vibration measurements on vertical line shaft pumps be taken on the upper motor-bearing housing in three approximately orthogonal directions, one of which is the axial direction.
REASON FOR This alternative is are-submittal of NRC approved 4th Interval relief request RR-P-9 REQUEST: that was based on the ASME OM Code-2001 Edition. This 5th Interval request for relief, RR-P-9, is based on the ASME OM Code-2004 Edition with Addenda through OMb-2006. There have been no substantive changes to this alternative, to the OM Code requirements or to the basis for use, which would alter the previous NRC Safety Evaluation conclusions. (See References for SER date and TAC numbers associated with RR-P-9).
The Code required vibration measurements on the upper motor-bearing housing on this Unit 2 Standby Diesel Generator Service Water vertical line shaft pump are impractical because of the following reasons.
I. The motor has a cooling fan mounted at the top which is attached to the rotating shaft. The fan is protected by a relatively thin cover plate which prevents access to the motor housing for vibration measurements. Removing the cover does not provide for transducer placement since the rotating fan would still be in the way.
- 2. Research within the industry has indicated that vibration monitoring of vertical line shaft pumps has been of limited benefit for detecting mechanical degradation due to problems inherent with pump design. The OM Code imposes more stringent hydraulic acceptance criteria on these pumps than for centrifugal pumps. These more stringent hydraulic acceptance criteria place more emphasis on detection of degradation through hydraulic test data than through mechanical test data.
I of2
RR-P-9 (Cont.)
PROPOSED Vibration measurements will be taken in three orthogonal directions, one of which is ALTERNATIVE in the axial direction in the area of the pump to motor mounting flange. This is the AND BASIS: closest accessible location to a pump bearing housing and this location is easily accessible for test personnel which should ensure repeatable vibration data and should provide readings which are at least as representative of pump mechanical condition as those required by the Code.
Therefore, application of the OM Code hydraulic testing criteria along with radial and axial vibration monitoring in the area of the pump to motor mounting flange should provide adequate data for assessing the condition of the subject pumps and for monitoring degradation. This request is only applicable to Comprehensive Pump and Preservice Testing. The above proposed alternative provides reasonable assurance of operational readiness since vibration measurements will be taken in three orthogonal directions at the pump to motor mounting flange which will provide information as to the mechanical integrity of the pump. Based on the determination that compliance with the Code requirements results in a hardship without a compensating increase in the level of quality and safety, this proposed alternative should be granted pursuant to 10 CFR50.55a(z)(2).
DURATION: 5th Interval beginning January 1, 2016 and ending December 31, 2025.
PRECEDENTS: This Relief Request was approved as RR-P-9 for the Fourth 10 Year 1ST Interval
REFERENCES:
NRC Safety Evaluation dated February 14, 2006- TAC Nos. MC6837, MC6838, MC7626 and MC7627 2 of2