NL-08-030, Response to Request for Additional Information Regarding the 2007 Steam Generator Tube Inspections
| ML080440264 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 02/05/2008 |
| From: | Joseph E Pollock Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-08-030, TAC MD6216 | |
| Download: ML080440264 (9) | |
Text
Indian Point Energy Center Indian Point Energy Center 450 Broadway, GSB P.O. Box 249 Buchanan, NY 10511-0249 Tel 914 734 6700 J.E. Pollock Site Vice President Indian Point Energy Center February 5, 2008 Re:
Indian Point Unit 3 Docket Nos. 50-286 NL-08-030 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
SUBJECT:
Response to Request for Additional Information Regarding The 2007 Steam Generator Tube Inspections (TAC MD 6216)
REFERENCES:
- 1)
Entergy letter NL-07-083 dated July 19, 2007 regarding 3R14 Steam Generator Tube Inspection Report per TS 5.6.8
- 2)
NRC Letter dated December 7, 2007 Request for Additional Information Regarding Steam Generator Tube Inspections (TAC No. MD6216)
Dear Sir or Madam:
Entergy Nuclear Operations, Inc (Entergy) submitted a report on the 3R14 Steam Generator Tube Inspection in accordance with Technical Specification 5.6.8 (Reference 1). The NRC indicated that additional information was needed to complete the NRC review (Reference 2). The purpose of this letter is to provide that information. Attachment 1 contains the requests for additional information and the Entergy response.
There are no new regulatory commitments made in this submittal. If you should have any questions regarding this submittal, please contact Mr. Robert W. Walpole, Manager, Licensing at (914) 734-6710.
,J"m
NL-08-030 Docket No. 50-286 Page 2 of 2 I declare under penalty of perjury that the foregoing is true and correct. Executed on
$ O, 2008.
Sincerely, J. E. Pollock Site Vice President Indian Point Energy Center Attachments: 1. Response to Request for Additional Information Regarding the 2007 Steam Generator Tube Inspections (TAC MD 6216) cc:
Mr. John P. Boska, Senior Project Manager, NRC NRR DORL Mr. Samuel J. Collins, Regional Administrator, NRC Region 1 NRC Resident Inspector, IP3 Mr. Paul D. Tonko, President, NYSERDA Mr. Paul Eddy, New York State Public Service Commission
ATTACHMENT 1 TO NL-08-030 Response to Request for Additional Information Regarding the 2007 Steam Generator Tube Inspections (TAC MD 6216)
ENTERGY NUCLEAR OPERATIONS, INC.
INDIAN POINT NUCLEAR GENERATING UNIT NO. 3 DOCKET NO. 50-286 NL-08-030 Docket No. 50-286 Page 1 of 6 Response to Request for Additional Information Regarding the 2007 Steam Generator Tube Inspections (TAC MD 6216)
In a letter dated July 19, 2007, Entergy Nuclear Operations, Inc. (Entergy), submitted information pertaining to their 2007 steam generator (SG) tube inspections at the Indian Point Nuclear Generating Unit No. 3. These inspections were performed during the Unit 3 refueling outage fourteen (RFO14). The Nuclear Regulatory Commission staff reviewed the information Entergy provided and requested, in a letter'dated December 7, 2007, that additional information be provided in order to complete the NRC evaluation. Requests and responses with additional information are as follows:
- 1.
In Section 6.0, you indicated that a loose part was detected during a secondary side visual exam. Please provide the scope and results of any other secondary side inspections (including foreign object search and retrieval) performed during the 2007 outage.
Response
The tubesheets of all 4 steam generators were visually inspected following sludge lancing in the following areas: annulus, peripheral tubes up to 3 in from the annulus, tube lane and approximately every fifth column in-bundle from the annulus to the tube lane of both hot and cold legs. In addition, the steam drum areas of 31 and 32 steam generators were visually inspected focusing on general condition, primary separators, secondary separators, J-nozzles and the feed ring. A list of both the foreign objects retrieved and those remaining is provided in Tables 1 and 2. Those objects remaining are considered to have no potential impact on tube integrity, except for the irretrievable object in SG 31 wedged between tube Row 29 Column 79 and Row 29 Column 80. Those two tubes were administratively plugged to preclude any possible leakage that might occur should the part wear into either tube.
- 2.
+PointTM inspections were performed at the top of the tubesheet (TTS) in both the hot leg and cold leg to detect possible loose parts (PLPs). Please discuss whether there were any PLPs found by rotating probe that were not detected by the bobbin probe. In addition, discuss whether these PLPs were confirmed as loose parts via visual inspection. Please discuss whether PLPs were detected at any other locations (i.e.,
other than the TTS) and discuss how these were dispositioned.
Response
During the SG eddy current inspections performed in 3R14, there were a total of 25 PLP indications. Twenty-four were made with the +PointTM probes and one with a bobbin probe.
The PLP indication called with the bobbin probe was in the same location as a call made with a
+PointTM probe. Eight PLP indications found with the +PointTM probes were in tubes that were not inspected with a bobbin probe. This leaves 16 PLP indications made with the +PointTM probe that were not identified with the bobbin inspection. Of those 16 PLP indications, only 2 indications in adjacent tubes were confirmed visually to be the result of a significant foreign object. This object appeared to be a piece of a washer which could not be retrieved so the two NL-08-030 Docket No. 50-286 Page 2 of 6 tubes were preventatively plugged although no tube wear was detected. It should also be noted that this object was first discovered by visual examination and not with eddy current. The majority of the PLP indications were in SG 31 in areas where small piles of sludge mixed with very small pieces of wire (0.010" diameter by about 1/22" long) from the demister pads of the moisture separator reheaters that were replaced during RFO13. This material was not removed by sludge lancing, impractical to retrieve, and evaluated as having no impact on tube integrity.
This material could explain why the bobbin probe inspections did not result in PLP indications made by the +PointTM probe. All PLP indications except 4 were located at or just above the TTS. Three indications (two at the same location reported with different probes) were approximately 2 inches above the hot leg TTS in two adjacent tubes that were reported in prior inspections and showed not signs of wear. This information was used to disposition the PLP indications in the absence of direct visual inspection. The fourth indication was approximately one inch above the cold leg TTS where a visual inspection in the area identified no foreign objects.
- 3.
During the 2003 outage, the U-bend region of three tubes in SG 3 could not be inspected with a 0.700-inch diameter bobbin probe. Please discuss whether these three tubes were inspected this outage. In addition, please discuss whether any other tubes were found that would not pass the nominal sized probe, and whether the "restrictions" are becoming more severe with time.
Response
The three tubes inspected in 2003 that could not pass a 0.700-inch diameter bobbin probe were all in row 3 columns 49, 50 and 57 in SG 34. None of those tubes were inspected again during RFO14 in 2007. Of the tubes inspected during RFO14, none were found that could not pass the nominal sized probe so there are no indications that any "restrictions" are developing or becoming more severe with time.
- 4.
During the 1997 outage, possible indications of erosion-corrosion were identified in two J-tube welds in SG 4. If the steam generator internals in SG 4 were inspected in the 2007 outage, please discuss the inspection results including the results, if any, from the inspection of the two J-tube welds that had possible indications of erosion-corrosion in 1997.
Response
The steam generator internals in SG 34 were not inspected during the RFO14 refueling outage in 2007. This inspection is currently scheduled for RFO17 in 2013. However, during the RFO14 in 2007 the upper internals of SGs 31 and 32 were inspected including selected J-nozzles. No anomalies or evidence of erosion corrosion was seen in either SG.
- 5.
During the 2003 outage, inspections revealed one tube that was classified by the licensee as having a '"rackable anomaly." This tube was not considered to be flaw-like, but was added to the sample population for the next inspection of that SG. In addition to the trackable anomaly, a free span bobbin indication was identified in one tube in 1997 in SG 4 (Row 8 Column 21). During the 1997 outage, a rotating probe inspection of this location revealed the presence of a small ding. No inspections were required to be performed on this tube and the licensee did not consider it necessary to inspect this tube as part of the sample inspection performed during RFO 12 in 2003 (i.e., the licensee did NL-08-030 Docket No. 50-286 Page 3 of 6 not consider it necessary to inspect this tube until its regularly scheduled inspection during RFO 14). Please discuss whether these indications (i.e., the trackable anomaly and the freespan indication) were inspected in the 2007 outage, and if so, include the inspection results.
Response
The tube identified with a "trackable anomaly" in 2003 was in Row 5 Column 37 in SG 32 and was not inspected during RFO14 in 2007. The tube in SG 34 at Row 8 Column 21 identified with a small ding during the 1997 outage was also not inspected during RFO14 in 2007. There was no reason to suspect that any degradation existed at those locations and they were not part of the base inspection scope of 50% of the tubes.
- 6.
Since the 2003 inspection, there was at least one chemical excursion that exceeded Action Level 1 of the Electric Power Research Institute's Secondary Buffer Chemistry Guidelines. Please discuss whether any deleterious affects were discovered as a result of this chemical excursion (or other chemical excursions) including any abnormal deposit buildup.
Response
No anomalies were discovered in any of the four SGs during SG inspections performed in RFO14. Based on both eddy current results and visual inspections, deposit buildup appeared consistent with previous inspection results. In addition, preliminary [no final report completed]
deposit analysis results of samples taken during sludge lancing operations were also consistent with prior results. It can be concluded that any chemistry excursions that may have occurred since the 2003 inspection did not have any deleterious effects on the steam generators.
- 7.
For future reference, please provide the cumulative effective full power months of operation for each refueling outage, or SG tube inspection outage, since the steam generators were installed.
Response
Indian Point Unit 3 Refueling Outage Information since Steam Generator Replacement is as follows:
Replacement 1 st Inspection RFO Year Cycle Cycle SG Period No.
EFPD EFPM Cumulative Cumulative Notes EFPM EFPM 6
1989 436 14.33 0.00 n/a SG Replacement 7
1990 394 12.96 12.96 0.00 1st ISI, all 4 SGs 8
1992 414 13.61 26.57 13.61 Inspect all 4 SGs 9
1997 565 18.57 45.14 32.18 Inspect 33/34 SGs 10 1999 654 21.51 66.65 53.69 Inspect 31/32 SGs 11 2001 541 17.79 84.44 71.48 No SG inspections 12 2003 661 21.74 106.18 93.22 Inspect all 4 SGs 13 2005 669 21.98 128.16 115.20 No SG inspections NL-08-030 Docket No. 50-286 Page 4 of 6 Replacement 1st Inspection RFO Year Cycle Cycle SG Period Notes No.
EFPD EFPM Cumulative Cumulative EFPM EFPM Last SG inspection 14 2007 686 22.55 150.72 137.75 irst period in first period
- 8.
Please confirm that the straight sections of 100 percent of the row one and row two tubes have been inspected since the first in-service inspection of your SGs.
Response
Entergy has performed eddy current inspections of the straight section of 100 percent of the row one and row two tubes since the first in-service inspection of the replacement SGs. As of the completion of the steam generator inspections performed in RFO14 in 2007 all in-service tubes have been eddy current inspected over their full length at least once since the first in-service inspection performed in RFO7 in 1990.
NL-08-030 Docket No. 50-286 Page 5 of 6 Table 1 Foreign Objects Retrieved from the Steam Generators during 3R14 PART SG ROW COL DESCRIPTION 34 39 66 weld slag 34 21 87 weld slag 34 35 21 gasket 34 40 60 machine remnant 34 30 79 machine remnant 34 27 80 machine remnant 34 2
49 gasket 34 8
45 wire 34 39 60 wire 32 34 21 gasket 32 44 37 gasket 32 43 55 wire 32 40 52 gasket and wire machining 32 43 57 remnant 32 33 74 spherical object 32 43 50 weld slag 32 3
50 scale 31 36 20 gasket 31 41 67 rod 31 31 13 metal object 31 30 14 gasket 31 33 15 MSR wire pile 31 35 18 wire 2 wires & MSR 31 37 20 wire / rock pile 31 37 21 gasket 31 39 24 machine remnant 31 39 24 gasket 31 39 25 gasket 31 38 26 metal object 31 40 26 gasket 31 42 31 machine remnant 31 42 32 wire 31 43 33 MSR wire 31 42 31 machine remnant 31 42 31 machine remnant 31 42 32 wire 31 43 33 MSR wire 31 43 61 weld slag 31 35 80 flat metal object 31 29 15 gasket 31 30 15 gasket 31 5
70 gasket 31 27 80 gasket AXIAL DEPTH WIDTH LEN LOC LEG inches TTS COLD 0.25 TTS HOT 0.36 TTS HOT 0.125 TTS HOT 0.2 TTS HOT 0.35 TTS HOT 0.25 TTS HOT 0.25 TTS HOT 0.06 TTS COLD 0.06 TTS HOT 0.25 TTS HOT 0.25 TTS HOT 0.06 TTS HOT 0.25 TTS HOT 0.25 TTS HOT 0.33 TTS COLD 0.125 TTS COLD 0.125 TTS HOT 0.125 TTS HOT 0.062 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.25 TTS COLD 0.05 TTS COLD 0.016 TTS COLD 0.25 TTS COLD 0.25 TTS COLD 0.05 TTS COLD 0.016 TTS COLD 0.25 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS HOT 0.125 TTS COLD 0.125 inches inches QTY 0.25 0.36 1
0.36 0.36 1
0.125 1
1 0.2 0.3 1
0.35 0.35 1
0.25 0.25 1
0.125 3
1 0.06 4
1 0.06 0.6 1
0.125 1
1 0.125
'1 1
0.06 0.75 1
0.125 0.75 1
0.06 0.55 0.33 0.33 0.4 0.4 0.3 0.75 0.062 0.5 0.062 0.312 0.125 0.5 0.125 2
0.125 2
0.125 1
0.125 3
0.125 0.25 0.375 0.5 0.125 0.375 0.125 0.375 0.125 0.36 0.125 0.5 0.25 0.36 0.05 2.5 0.016 2
0.25 0.36 0.25 0.36 0.05 2.5 0.016 2
0.25 0.36 0.125 0.75 0.125 0.359 0.125 1
0.125 0.359 0.125 0.6 NL-08-030 Docket No. 50-286 Page 6 of 6 Table 2 Foreign Objects Remaining in the Steam Generators following 3R14 PART SG ROW COL DESCRIPTION scale and MSR wire 32 44 40 pile 32 42 55 MSR wire pile 31 27 12 MSR wire 31 28 11 weld slag 31 34 17 scale pile 31 36 19 scale pile scale pile & MSR 31 37 20 wire 31 36 21 sludge rock pile 31 38 22 sludge rock pile 31 38 23 sludge & scale pile 31 39 24 sludge & scale pile 31 40 25 sludge & scale pile 31 40 26 sludge & scale pile 31 40 28 sludge rock 31 42 30 sludge rock 31 42 67 MSR wire 31 38 70 sludge rock 31 38 22 gasket 31 38 23 metal object 31 39 27 slag 31 40 27 slag 31 44 53 sludge rock 31 27 15 gasket 31 36 20 MSR wire pile 34 13 15 sludge rock 31 29 79 metal washer AXIAL DEPTH WIDTH LEN LOC LEG inches TTS COLD 0.33 TTS HOT 0.2 TTS HOT 0.016 TTS HOT 0.125 TTS HOT 0.125 TTS HOT 0.125 TTS HOT 0.125 TTS HOT 0.125 TTS HOT 0.125 TTS HOT 0.125 TTS HOT 0.125 TTS HOT 0.125 TTS HOT 0.125 TTS HOT 0.125 TTS HOT 0.125 TTS HOT 0.016 TTS HOT 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS COLD 0.125 TTS HOT 0.125 TTS HOT 0.015 TTS HOT 0.3 TTS HOT 0.125 inches inches QTY 0.33 0.2 0.016 0.125 0.312 0.312 0.312 0.312 0.36 0.36 0.36 0.36 0.36 0.36 0.125 0.016 0.125 0.125 0.125 0.125 0.125 0.125 0.06 0.015 0.3 0.125 0.33 0.2 0.25 0.25 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 0.36 1
0.36 0.25 0.25 0.125 0.375 0.25 0.25 0.12 0.3 0.5 1
61 1
6 6
12 6
4 12 12 12 12 1
1 1
1 1
1 1
1 1
1 2
1 1