ML050670340
| ML050670340 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 02/28/2005 |
| From: | Jones T Florida Power & Light Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-2005-53 IR-04-005 | |
| Download: ML050670340 (12) | |
Text
- - S FPLL2053FPL lo CFR §50.55a February 28, 2005 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Re: Turkey Point Units 3 and 4 Docket Nos. 50-250 and 50-251 NRC Integrated Inspection Report 2004-005 Denial of Non-Cited Violation Concerning the Unit 3 Containment Moisture Barrier The NRC issued Integrated Inspection Report 2004-005 on January 28, 2005 for the Turkey Point Nuclear Plant. The report identified a Non-Cited Violation (NCV) of 10 CFR Part 50.55a(b)(2)(ix) related to the Unit 3 containment moisture barrier. The asserted basis for the NCV is that Florida Power and Light Company (FPL) did not meet the requirements of ASME Section XI, Subsection IWE in four areas.
In addition, the inspection report identifies two apparent crosscutting aspects relating to the moisture barrier activities: 1)missing a problem identification opportunity during the review of NRC Information Notice 2004-009, "Corrosion of Steel Containment Liner," and 2) failing to promptly identify and resolve Unit 3 moisture barrier deficiencies during the 2004 refueling outage.
FPL denies that a violation of 10 CFR Part 50.55a(b)(2)(ix) occurred. FPL believes that the NRC staff's positions on ASME Section XI, Subsection IWE relative to the Turkey Point containment moisture barrier design, as documented in the inspection report, are incorrect. FPL also disagrees with the identified crosscutting aspects. FPL's response to the NCV and crosscutting aspects is attached.
Based on the information provided in the attachment, FPL respectfully requests that the NRC withdraw the NCV and the identified crosscutting aspects in their entirety.
If there are any questions regarding the information contained in this submission, please contact Mr.
Walter Parker at 305-246-6632.
Very truly yours, Terry 0. Jones Vice President Turkey Point Nuclear Plant Attachments: 1) FPL Response to Moisture Barrier NCV and Related Crosscutting Aspects
- 2) Sketches (2) cc: Regional Administrator, Region II, USNRC Director, Office of Enforcement, USNRC Senior Resident Inspector, USNRC, Turkey Point Nuclear Plant an FPL Group company
4 Attachment 1 FPL Letter L-2005-53 Response to Moisture Barrier NCV and Related Crosscutting Aspects NRC Integrated Inspection Report 05000250/251-2004-005 Page 1 of 8 NRC Integrated Inspection Report 05000250/251-2004-005 contains a non-cited violation (NCV) concerning the Turkey Point Unit 3 moisture barrier and discusses two crosscutting aspects relating to FPL problem identification and resolution of moisture barrier deficiencies.
The NCV is discussed in Section A of the Summary of Findings and Section 1R08.2.b (pages 5 through 9) of the inspection report. The crosscutting aspects are also discussed in Section 1R08.2.b.
FPL denies the violation and disagrees that FPL's activities to address moisture barrier deficiencies were not responsive or effective in protecting the barrier integrity of the containment liner. FPL's response to each of the four examples given in the inspection report as a non-cited violation of 10 CFR Part 50.55a(b)(2)(ix), as well as the two crosscutting aspects of problem identification and resolution, follows.
Non-Cited Violation of 10 CFR Part 50.55a(b)(2)(ix)
NRC Example 1 (Section IR08.b.2. Page 8)
"Contrary to ASME Section XI, Subsection IWE, Paragraph IWE-3513.1, on November 2, 2004, it was determined that the licensee failed to repair defects identified in the moisture barrier in March, 2000, or replace the moisture barrier until March 2003. Additionally defects identified in 2004 were not repaired or replaced."
FPL Response FPL disagrees that the ASME Code requires the immediate repair of the specific conditions identified in the moisture barrier in March 2000 or in 2004.
The Turkey Point moisture barrier consists of a sealant (caulking) and a mastic cover (see Turkey Point moisture barrier detail sketch in Attachment 2). The sealant is applied as a 1/2 inch deep layer at the top portion of the concrete/steel joint but it is not in direct contact with the liner.
Directly below the sealant is a 1/4 inch thick layer of mastic material that is applied to the liner.
The mastic material provides direct protection to the liner and the sealant material keeps excess moisture or water from reaching the mastic material. The degraded condition originally identified in 2000 affected the sealing compound only. The sealing compound showed signs of separation from either the surrounding steel or concrete surfaces. After a number of inspections, there has been no evidence of degradation indicating that the mastic material or the liner plate are degrading such that immediate repairs would be required.
FPL Letter L-2005-53 Response to Moisture Barrier NCV and Related Crosscutting Aspects NRC Integrated Inspection Report 05000250/251-2004-005 Page 2 of 8 The process utilized by FPL to characterize the reported moisture barrier sealant deficiencies follows the typical process used to review conditions deviating from the ASME Code. The Code allows the condition to be evaluated in accordance with acceptance standards, and then mandates repair if the condition fails to meet the acceptance standards. In accordance with ASME Section XI, Subsection IWE, Article IWE-3122.4 Acceptance by Evaluation:
"a) Components whose examination results reveal flaws or areas of degradation that do not meet the acceptance standards listed in Table IWE-3410-1 shall be acceptable for service without the removal or repair of the flaw or area of degradation or replacement if an engineering evaluation indicates that the flaw or area of degradation is nonstructural in nature or has no effect on the structural integrity of the containment."
Table IWE-3410-1 lists IWE-3513 as the acceptance standard for seals, gaskets, and moisture barriers. IWE-3513.1 states that wear, damage, erosion, tears, surface cracks or other defects that may violate the leak-tight integrity of the moisture barrier shall be repaired or replaced.
The engineering evaluation provided in Condition Report (CR) 00-0491, Interim Disposition #1, as allowed by IWE-3122.4, concluded that the degraded sealant will have no adverse effect on the liner plate corrosion protection system. The condition posed by the degraded sealing compound did not affect the structural integrity of the liner plate. The sealing compound in question is only one part of the moisture barrier system and the degradation of this sealing compound, as identified in the 2000 inspections, would not cause a loss of containment liner leak tight integrity. This material is the first (or top) layer of the moisture barrier and it fills the void between the concrete floor and the air test system structure. A layer of mastic is installed (1/4 inch minimum thickness) between the concrete and the containment liner plate to provide the actual protection for the liner. Based on this evaluation, the conditions specified in IWE-3513.1 were not met, thereby eliminating the need for immediate repair since there was no evidence that the degraded sealant posed a structural concern for the containment liner.
NRC Example 2 (Section IR08.b.2. Page 8)
"Contrary to ASME Section XI, Subsection IWE, Paragraph, IWE-1241, as of November 2, 2004, augmented inspections were not performed to examine the moisture barrier and areas at the junction of the liner plate and Elevation 14.0 concrete floor although these areas were known to be exposed to standing water, repeated wetting and drying, persistent leakage, and had geometries that permit water accumulation."
FPL Letter L-2005-53 Response to Moisture Barrier NCV and Related Crosscutting Aspects NRC Integrated Inspection Report 05000250/251-2004-005 Page 3 of 8 FPL Response FPL disagrees that the Code requires augmented inspections in the cited case.
Paragraph IWE-1241 states that areas requiring augmented inspection include areas such as:
"a) interior and exterior containment surface areas that are subject to accelerated corrosion with no or minimum corrosion allowance or areas where absence or repeated loss of protective coatings has resulted in substantial corrosion and pitting."
The moisture barrier configuration at Turkey Point (see moisture barrier detail sketch in ) is different from typical moisture barriers at other facilities (see Figure IWE-2500-2 in Attachment 2). At Turkey Point, the containment concrete floor does not extend laterally to the liner plate. Therefore, there is no junction of the liner plate with the concrete floor at the 14 foot elevation. Instead, the concrete floor extends to the air test system angle at the 14 foot elevation. The Turkey Point moisture barrier consists of a sealant (caulking) and a mastic cover. The sealant is applied as a 11/2 inch deep layer at the top portion of the concrete/steel joint but not in direct contact with the liner. Directly below the sealant is a 1/4 inch thick layer of mastic material that is applied to the liner. The mastic material provides direct protection to the liner and the sealant material keeps excess moisture or water from reaching the mastic material.
The liner plate thickness at the moisture barrier location is 1/2 inch. The typical thickness of liner plate at other containment locations is 1/41 inch. The increase in liner thickness provides additional corrosion allowance discussed in IWE-1241.a.
The areas in question are exposed to standing water on a limited basis during outages due to condensation; however, the coatings in these areas are robust, there is an increase in liner thickness and no evidence of substantial corrosion or pitting nor concrete spalling that would indicate corrosion of the liner in inaccessible areas near the moisture barrier. Therefore, the Code does not require augmented inspections for these areas.
FPL Letter L-2005-53 Response to Moisture Barrier NCV and Related Crosscutting Aspects NRC Integrated Inspection Report 05000250/251-2004-005 Page 4 of 8 NRC Example 3 (Section IR08.b.2. Page 9)
"Contrary to ASME Section XI, Subsection IWE, Paragraph IWE-2430, additional inspections were not performed to examine additional areas (expand sample size) when defects were identified during the March 2000 IWE inspection."
FPL Response FPL disagrees that additional inspections were required by the findings of the 2000 and 2003 IWE inspections.
This example is addressed as follows:
"IWE-2430 ADDITIONAL EXAMINATIONS (a) Examinations performed during any one inspection that reveal flaws or areas of degradation exceeding the acceptance standards of Table IWE-3410-1 shall be extended to include an additional number of examinations within the same category approximately equal to the initial number of examinations during the inspection."
Based on the engineering evaluation of the conditions noted (CR 00-0491), the areas of degradation did not exceed the acceptance standards of IWE-3513.1, as required by Table IWE-3410-1. The 1/4 inch mastic layer provides the primary protection of the liner with the sealing material in question providing a secondary barrier. The 2000 evaluation, and the examinations performed in 2003 with the sealing material removed, concluded that the condition posed by the degraded sealant does not affect liner plate integrity and no observable degradation of the mastic material was noted. Therefore, sealant repair was determined to be a maintenance activity and not a Section XI non-conforming condition subject to repair/replacement or sample expansion.
NRC Example 4 (Section IR08.b.2. Page 9)
"Contrary to ASME Section XI, Subsection IWE, Paragraph IWE-2420, areas that were identified during the March 2000 IWE inspection as being degraded were not re-examined in subsequent outages."
FPL Letter L-2005-53 Response to Moisture Barrier NCV and Related Crosscutting Aspects NRC Integrated Inspection Report 05000250/251-2004-005 Page 5 of 8 FPL Response FPL believes that the cited requirement was met by FPL's inspections in 2003 of the degraded conditions discovered in 2000.
Examinations were conducted during the 2003 outage in accordance with the requirements of IWE-2420, which states:
"(b) When component examination results require evaluation of flaws, areas of degradation, or repair in accordance with IWE-3000, and the component is found to be acceptable for continued service, the areas containing such flaws, degradation, or repairs shall be reexamined during the next inspection period,"
The degraded area was identified in 2000 during the first inspection period. The March 2003 outage was within the next inspection period following the findings in 2000. Inspecting this area in 2003, which is in the second period, meets the requirements of IWE-2420. In addition, a minimum of two more inspections will be conducted on this area, one in each of the next two consecutive inspection periods (extending into the next 10-year interval), in accordance with IWE-2420(c).
NRC Crosscutting!Aspects Crosscutting Aspect #1 (Section IR08.b.2. Page 7. Paraoraph 3)
The inspection report asserts that FPL's review of Information Notice (IN) 2004-009, Corrosion of Steel Containment and Containment Liner, missed the opportunity to identify deficiencies with the (liner plate) moisture barrier. The report claims that FPL missed a problem identification opportunity when it was determined that the containment inspection program was adequate based on (moisture barrier) issues identified previously.
FPL Response The background section of the IN states that "recent experience has shown that the integrity of the moisture barrier seal at the floor-to-liner or floor-to-containment junction is important in avoiding conditions favorable to corrosion and thinning of the containment liner plate material."
Attachment 1 FPL Letter L-2005-53 Response to Moisture Barrier NCV and Related Crosscutting Aspects NRC Integrated Inspection Report 05000250/251-2004-005 Page 6 of 8 IN 2004-009 was reviewed by FPL in 2004, as documented by CR 2004-2478. The CR evaluation takes credit for the results of previous IWE inspections and moisture barrier restoration efforts that allowed FPL to conclude that no evidence of liner plate corrosion existed.
Programmatically, FPL is committed to comply with the provisions of IWE starting in year 2000.
The IWE inspection plan requires inspecting the entire length of the moisture barrier in 1/3 segments over an interval of 10 years. The first period inspection started in 2000, followed by second period inspection in 2003 and last period inspection set for 2006. The IWE inspection has provided positive results in addressing deficiencies with the moisture barrier in that deficiencies were first identified with the moisture barrier in 2000 when the first IWE inspection was conducted. Restoration efforts of the degraded moisture barrier identified in 2000 were completed in 2003 when liner plate integrity was verified. The second segment IWE inspection conducted in 2003 did not yield any negative results for the moisture barrier or liner plate.
Therefore, there is no history or evidence that the liner plate is degraded in any manner, and in particular, in the area of the moisture barrier. This was the key consideration in response to the contents of the IN. The evidence at the time of FPL's review of the IN did not provide indications of containment integrity degradation and supports FPL's conclusion that the Code inspection program has been effective in ensuring the integrity of the containment liner.
Conclusion FPL's consideration of IN 2004-009 was based on historical performance of the containment liner plate where no adverse trends had been identified to date. The moisture barrier sealant and adjacent air test system angle degradation identified originally in 2000, and corrected in 2003, reinforce the evaluation provided in response to the IN. The scope of the IWE program is providing intended results where moisture barrier sealant degradation will be recognized in a periodic manner before the condition leads to corrosion of the liner. FPL disagrees that a problem identification opportunity was missed since IN 2004-009 was considered in the context of the Turkey Point moisture barrier inspection and repair program.
NRC Crosscutting Asnect #2 (Section 1R08.b.2. Page 7. Paragraphs 2 and 4)
During the October 2004 Unit 3 refueling outage, FPL identified areas with a degraded moisture barrier prior to the inspectors' walkdown, but did not initiate a CR to document the degraded moisture barrier until questioned by the inspector nor were repairs planned for that outage. This is considered a crosscutting aspect of problem identification and resolution.
FPL Letter L-2005-53 Response to Moisture Barrier NCV and Related Crosscutting Aspects NRC Integrated Inspection Report 05000250/251-2004-005 Page 7 of 8 FPL Response FPL began implementation of a formal inspection program of the containment liner plate and moisture barrier located at the floor-to-liner plate interface under the scope of ASME Section XI, Subsection IWE in 2000. This program was instituted in response to the final IWE/IWL rule issued by the NRC in the summer of 1996 where NRC indicated that the primary concern for implementation of the rule was corrosion degradation of containment steel liners.
The FPL moisture barrier and liner inspections performed in 2000 and in 2003 provided an in-depth inspection of critical features. These inspections concluded that there is neither presence nor indication of liner plate corrosion in either Turkey Point containment building. A third inspection of the moisture barrier is scheduled for 2006 to complete the 10-year inspection interval committed by FPL under the IWE inspection plan.
In the fall 2004 refueling outage, there was no scheduled IWE inspection for the moisture barrier. As the NRC inspection report indicates, FPL was aware of the moisture barrier deficiencies that had been identified during coatings walkdowns, performed according to FPL Specification SPEC-C-034, but not immediately entered into the Turkey Point problem identification program. The documented process for these types of material condition issues (e.g., coatings, caulking, etc.) in the containment buildings specifies that these items are to be inspected through the course of the refueling outages. Those items determined to require repair during the outage are immediately addressed, and those items that can be deferred are documented prior to restart in a "containment coatings roll-up" CR.
This deferral of identifying the condition to the containment coatings roll-up CR was based on the knowledge of historical results of previous moisture barrier inspections and repairs, coupled with knowledge of the design of the moisture barrier at the floor-to-expansion joint. This provided FPL assurance that there was no imminent concern with the containment liner plate as a result of the degraded moisture barrier sealant identified during the containment coatings walkdowns. In addition, the containment coatings roll-up CR contains a Mode 4 hold that ensured a documented evaluation of any degradation prior to unit restart.
While Turkey Point Engineering was in the process of preparing the standard containment coating assessment CR, the NRC inspector raised the degraded moisture barrier condition to Engineering. At Turkey Point, it is usual practice to record NRC inspector's concerns in a CR (CR 2004-12917) to ensure that issues identified by the NRC are tracked and addressed individually. Even with the knowledge of historical moisture barrier results and knowledge of the design of the floor-to-liner expansion joint, FPL decided, under the corrective actions of CR 2004-12917, to excavate the moisture barrier at one of the degraded locations to verify liner plate FPL Letter L-2005-53 Response to Moisture Barrier NCV and Related Crosscutting Aspects NRC Integrated Inspection Report 05000250/251-2004-005 Page 8 of 8 integrity. The results documented in the CR indicate that the liner plate did not exhibit any significant evidence of degradation confirming that no immediate repairs were necessary.
The evaluation in CR 2004-12917 stated that moisture barrier sealant degradation is an age-related condition for a sealant that has been in service for over 30 years. The corrective actions of the CR proposed to inspect the entire length of the sealant on a more aggressive schedule than required by the IWE program and complete repairs, as appropriate, in the upcoming refueling outages for both units.
Conclusion Based on past evaluations performed for moisture barrier deficiencies as a result of IWE inspections, the degraded joint was not considered as an emergent condition in need of immediate repair. Reporting of moisture barrier sealant deficiencies in the coating CR for the 2004 Unit 3 outage is an appropriate measure under the Turkey Point corrective action program.
FPL's actions regarding the condition of the containment moisture barrier and liner plate complied in all respects with ASME Section XI, Subsection IWE assuring containment barrier integrity.
FPL submits that adequate attention has been and will be provided to the moisture barrier and liner plate and there is no crosscutting aspect of problem identification and resolution associated with moisture barrier inspection and repair activities.
Attachment 2 FPL Letter L-2005-53 Denial of Moisture Barrier NCV Sketches Figure IWE-2500-2 Turkey Point Moisture Baffler Detail
Fig.. IWE-2500-2 1992 SECTION XI- DIVISION I
/
Examination area A-B . Pressure retaining metal containment shell or liner External concrete-to-metal interface moisture barrier A Examination are C-D.
.- EI A S BRInterfacS Embedded shell or liner FIG. IWE-2500-2 EXAMINATION AREAS FORP*OISTURE BARRIERS 220
CONTAINMENT WALL LINER PLATE L2 x 2 x Al JOINT SEALANT CONTAINMENT dd ~*.~ FLOOR
- S, . g . - - ' . 44'--*
MASTIC i' MIN.
THICKNESS i' THICK PLATE . v S- *:
TURKEY POINT MOISTURE BARRIER