ML11356A035
| ML11356A035 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  |
| Issue date: | 12/22/2011 |
| From: | Entergy Nuclear Operations |
| To: | Atomic Safety and Licensing Board Panel |
| SECY RAS | |
| Shared Package | |
| ML11356A026 | List: |
| References | |
| RAS 21601, 50-247-LR, 50-286-LR, ASLBP 07-858-03-LR-BD01 | |
| Download: ML11356A035 (12) | |
Text
Entergy CONDITION REPORT CR-IP2-2001-10525 Originator: MALONE, HAZEL Originator Site Group: IP2 ENG P&C-Code, Programs Staff Originator Phone: 0 Operability Required: Y Reportability Required: N Supervisor Name: SCHWARTZ, GEOFFREY Discovered Date: I 0/31/2001 00:00 Initiated Date: 10/31/200 I 00:00 Condition
Description:
CR Date: 10/31/2001 12:33 CR Entered Date: 10/3112001 14:21 UT inspections were performed on sections of Crossunder piping as the result of a pinhole leak found on the MSR21A inlet piping during the cycle (see CR# 200103681). Areas on the expansion joints and piping upstream ofMSR21A show measured thickness below or close to allowable minimum wall (0.247") based on UT results taken during the mid-cycle outage. The cause of these thinned areas is believed to be Flow Accelerated Corrosion (FA C). It is recommended that these areas be repaired at this time. Design Engineering has been notified and temporary repair of thinned areas are being performed. See drawings attached for location of thinned area and the mearsured thickness readings of these areas.
Immediate Action
Description:
Evaluated thinned areas and worked with Design Engineering to develop temporary repair for degraded areas.
Suggested Action
Description:
EQUIPMENT:
Tag Name 21AMSR REFERENCE ITEMS:
Type Code CR CR CR CR DETECTION LOCATION WON WON WON WON Tag Suffix Name Component Code Process System Code MS Item Desc 200103681 200103681 200110521 200110526 Sl Turbine 01-23886 01-23886 y 01-24370 01-24370 y TRENDING (For Reference Purposes Only):
Trend Type PR OR EQ KA IPEC00092616 Trend Code PR-CORROSION & EROSION (ALL WALL-THINNING PROCESSE OR-DESIGN ENGINEERING EQ-AH KA-IN RIV000028 Submitted: December 22, 2011
Entergy I CORRECTIVE ACTION I CR-IP2-2001-10525 CANumber:
Site Group Name Assigned By:
IP2 CA&AStaff Assigned To:
IP2 Subassigned To :
IP2 ENG P&C-Code Programs Mgmt ENG P&C-Code Programs Staff E-CAPTAIN, CRS Azevedo,Nelson F MALONE, HAZEL Originated By: E-CAPTAIN, CRS Performed By: Azevedo,Nelson F Subperformed By: MALONE, HAZEL Approved By:
Closed By: E-CAPT AIN, CRS Current Due Date: 12/01/2001 CA Type: DISP - CORR ACTION Plant Constraint: NONE CA
Description:
11/1/2001 00:00:00 11129/2001 00:00:00 11126/2001 00:00:00 11129/2001 00:00:00 Initial Due Date: 12/01/2001 Please evaluate to determine apparent cause and recommend corrective actions. (cbh)
CA REFERENCE ITEMS:
Type Code CRSID
Response
IPEC00092617 Description 254719
Entergy l CORRECTIVE ACTION I
CR-IP2-2001-10525 Subresponse :
11/09/2001 Assigned to: MALONE, HAZEL Status: Closed+ Approved Action Requsted: Hazel, please evaluate this SL2 and provide corrective actions \\\\5 required. Nelson Assignee Response: See SL Report Reviewer Comment:
Although this CR was classified as an SL2, the wall thinning detected during the mid-cycle inspection was a result of Flow Accelerated Corrosion (FA C) which is a well understood degradation mechanism and it is well modeled in industry and in IP2 F AC analysis. No causal factors or any other evaluation was perfformed on this CR because it was considered provide no additional value to this already, well understood phenomena. Based on this, it is requested that this CR be downgraded to an SL3 and closed as such.
Nelson Azevedo 11/29/01 Significance Level 3 Report UT inspections were performed on the 26.5" ID vertical*riser section of crossunder piping leading to MSR21A as the result of a pinhole leak which occurred in this section during the cycle (See CR# 200103681). Results of the UT inspections performed found an additional thinned area on the same expansion joint containing the pinhole leak and a thinned area on a pup piece adjacent to that expansion joint (See attachment for locations of thinned areas). The thinned areas found measured below or close to allowable minimum wall thickness (See wear rate/structural evaluation for each component inspected for details).
Cause of wear is believed to be the result of Flow Accelerated Corrosion (F AC). F AC is the process whereby the protective oxide layer on carbon steel piping is dissolved by flowing water or wet steam which results in the wearing away of the underlying metal. Main Steam exhausted from the High Pressure Turbine enters the Crossunder piping as a wet steam, that can contain as much as 20% moisture. This wet steam mixture combined with the high fluid velocity and high temperature of this piping system can result in extremely high wear rates and establishes Crossunder piping as one of the most susceptible systems to F AC. Though the IP2 FAC program history shows that all crossunder piping was completely weld overlaid with Stainless Steel to prevent wear, certain areas near expansion joints were not weld overlaid due to restrictions on welding near the expansion joints links (dogbones). Certain areas near these expansion joint dogbones may have been consequently left as Carbon Steel due to these restrictions and are still vulnerable to the effects ofF AC. The leak that occurred during the cycle 15, as well as the thinned areas found during the mid-cycle outage were all located in the vicinity of the expansion joints.
Thinned areas located during the mid cycle inspection will be temporarily repaired externally per WO# 01-23886 until they can be visually inspected internally during the 2002 refueling outage and permanently repaired. Internal inspections are recommended to determine the location of the expansion dogbones and also to locate areas not weld overlayed that may need repair. Internal inspections of crossunder piping will be added to the scope of the 2002 refueling outage as part of the F AC outage inspection scope (see F AC Master Inspection List for details) and may include inspection of parallel trains or similar expansion joint areas.
Permanent repair of thinned areas will be performed under work order 01-24370. Methods of permanent repair as well as expansion joint replacement options should be researched and planned for accordingly prior to the outage to ensure proper scheduling.
Thinned areas located during the mid cycle inspection will be temporarily repaired externally per WO# 01-23886 until they can be visually inspected internally during the 2002 refueling outage and permanently repaired. Internal inspections are recommended to determine the location of the --- see attachment for rest ---
Closure Comments:
reject per CAG quality review Attachments:
Subresp Description 11109/2001 Assigned to: MA IPEC00092618
Entergy j
CORRECTIVE ACTION I
CR-IP2-2001-10525 CANumber:
2 Site Group Name Assigned By:
IP2 CA&A Staff Assigned To:
IP2 ENG P&C-Code Programs Mgmt E-CAPT AIN, CRS Azevedo,Nelson F Subassigned To :
Originated By: E-CAPTAJN, CRS Performed By: Azevedo,Nelson F Subperformed By:
Approved By:
Closed By: Azevedo,Nelson F Current Due Date: 12/06/2001 CA Type: DISP - CORR ACTION Plant Constraint: NONE CA
Description:
reject per CAG quality review 12/4/2001 00:00:00 12/4/2001 00:00:00 12/4/2001 00:00:00 Initial Due Date: 12/06/2001 Downgraded from SL2 to SL3 per Joe Barlok. Due date changed to 12/6/01...12/4/01 MK CA REFERENCE ITEMS:
Type Code CRSID IPEC00092619 Description 260983
Entergy I CORRECTIVE ACTION I CR-IP2-2001-10525
Response
Significance Level3 Report UT inspections were performed on the 26.5" ID vertical riser section of crossunder piping leading to MSR21A as the result of a pinhole leak which occurred in this section during the cycle (See CR# 200 l 03681 ). Results of the UT inspections performed found an additional thinned area on the same expansion joint containing the pinhole leak and a thinned area on a pup piece adjacent to that expansion joint (See attachment for locations of thinned areas). The thinned areas found measured below or close to allowable minimum wall thickness (See wear rate/structural evaluation for each component inspected for details).
Cause of wear is believed to be the result of Flow Accelerated Corrosion (FA C). F AC is the process whereby the protective oxide layer on carbon steel piping is dissolved by flowing water or wet steam which results in the wearing away of the underlying metal. Main Steam exhausted from the High Pressure Turbine enters the Crossunder piping as a wet steam, that can contain as much as 20% moisture. This wet steam mixture combined with the high fluid velocity and high temperature of this piping system can result in extremely high wear rates and establishes Crossunder piping as one of the most susceptible systems to F AC. Though the IP2 F AC program history shows that all crossunder piping was completely weld overlaid with Stainless Steel to prevent wear, certain areas near expansion joints were not weld overlaid due to restrictions on welding near the expansion joints links (dog bones). Certain areas near these expansion joint dog bones may have been consequently left as Carbon Steel due to these restrictions and are still vulnerable to the effects ofF AC. The leak that occurred during the cycle 15, as well as the thinned areas found during the mid-cycle outage were all located in the vicinity of the expansion joints.
Thinned areas located during the mid cycle inspection will be temporarily repaired externally per WO# 01-23886 until they can be visually inspected internally during the 2002 refueling outage and permanently repaired. Internal inspections are recommended to determine the 'location of the expansion dogbanes and also to locate areas not weld overlayed that may need repair. Internal inspections of crossunder piping will be added to the scope of the 2002 refueling outage as part of the F AC outage inspection scope (see F AC Master Inspection List for details) and may include inspection of parallel trains or similar expansion joint areas.
Permanent repair of thinned areas will be performed under work order 01-24370. Methods of permanent repair as well as expansion joint replacement options should be researched and planned for accordingly prior to the outage to ensure proper scheduling.
Thinned areas located during the mid cycle inspection will be temporarily repaired externally per WO# 01-23886 until they can be visually inspected internally during the 2002 refueling outage and permanently repaired. Internal inspections are recommended to determine the location of the expansion dogbones and also to locate areas not weld overlayed that may need repair. Internal inspections of crossunder piping will be added to the scope of the 2002 refueling outage as part of the F AC outage inspection scope (see F AC Master Inspection List for details) and may include inspection of parallel trains or similar expansion joint areas.
Permanent repair of thinned areas will be performed under work order 01-24370. Methods of permanent repair as well as expansion joint replacement options should be researched and planned for accordingly prior to the outage to ensure proper scheduling.
Subresponse :
Closure Comments:
N/A IPEC00092620
Entergy I CORRECTIVE ACTION
-~ CR-IP2-2001-10525 CANumber:
3
--~Si~te~ ---------------G~ro~u~p~------------~1 ----~N~a~m~e----~'
Assigned By:
IP2 CA&AStaff Assigned To:
IP2 ENG SYS-Balance of Plant Staff Subassigned To :
Originated By: E-CAPTAIN, CRS Performed By: Ray,Bryan J Subperformed By:
Approved By:
Closed By: Ray,Bryan J E-CAPTAIN, CRS Ray,BryanJ 111112001 00:00:00 1113/200 l 00:00:00 11/3/2001 00:00:00 Current Due Date: 11/08/2001 CA Type: CRS - FYI Initial Due Date: 11108/2001 Plant Constraint: NONE CA
Description:
For your infonnation on equipment with your system.
CA REFERENCE ITEMS:
Type Code CRSID
Response
Subresponse :
Closure Comments:
NIA IPEC00092621 Description 254720
Entergy I CORRECTIVE ACTION I
CR-IP2-2001-10525 CA Number:
4 Site Group Assigned By:
CA&AStaff Assigned To:
IP2 IP2 ENG P&C-Code Programs Mgmt Subassigned To:
Originated By: E-CAPTAIN, CRS Performed By: Azevedo,Nelson F Subperformed By:
Approved By:
Closed By: Azevedo,Nelson F Name E-CAPTAIN, CRS Azevedo,Nelson F 12/4/2001 00:00:00 2/1/2002 00:00:00 2/1/2002 00:00:00 Current Due Date: 02/17/2002 Initial Due Date: 02/ 17/2002 CA Type: CR CLOSURE REVIEW Plant Constraint: NONE CA
Description:
Follow up on corrective action assignments CA REFERENCE ITEMS:
Type Code CRSID
Response
Description
. 261193 Since the corresponding I CAs have been adequately implemented, this CR is ready for closure.
Subresponse :
Closure Comments:
N/A IPEC00092622
Entergy I CORRECTIVE ACTION I CR-IP2-2001-10525 CANumber:
5 Site Group Name Assigned By:
IP2 Assigned To:
IP2 ENG P&C-Code Programs Mgmt ENG P&C-Code Programs Staff Azevedo,Nelson F MALONE, HAZEL Subassigned To :
Originated By: Azevedo,Nelson F Performed By: MALONE, HAZEL Subperformed By:
Approved By:
Closed By: Azevedo,Nelson F Current Due Date: 01/18/2002 CA Type: PERFORM CA Plant Constraint: NONE CA
Description:
12/4/2001 00:00:00 1118/2002 00:00:00 l/18/2002 00:00:00 Initial Due Date: 01118/2002 Add internal inspection of MSR vertical risers to F AC Master Inspection List (MIL) for 2002 refueling outage.
CA REFERENCE ITEMS:
Response
Description 261191 Internal inspection of 21A&B, 22A&B and 23A&B MSR vertical risers will be added to F AC Master Inspection List (MIL) for 2002 refueling outage. Final MIL is due for release 113112002 Subresponse :
Closure Comments:
Please reflect the fact that the inspection locations have been added to the inspection list even though the final list will not be issued until l/31i02.
IPEC00092623
Entergy I CORRECTIVE ACTION I CR-IP2-2001-10525 CANumber:
6 Site Group Name Assigned By:
IP2 Assigned To:
IP2 E"NG P&C-Code Programs Mgmt ENG P&C-Code Programs Staff Azevedo,Nelson F MALONE, HAZEL Subassigned To:
Originated By: Azevedo,Nelson F Performed By: MALONE, HAZEL Subperformed By:
Approved By:
Closed By: Azevedo,Nelson F Current Due Date: 01/18/2002 CA Type: PERFORM CA Plant Constraint: NONE CA
Description:
12/4/2001 00:00:00 1/18/2002 00:00:00 1118/2002 00:00:00 Initial Due Date: 01118/2002 Research methods of permanent repairs tor previously temporary repaired areas of crossunder piping. Also, research the cost
.and resource information for the replacement of crossunder expansion joints to determine if this option is practicable.
CA REFERENCE ITEMS:
Type Code CRSCLASS CRSID IPEC00092624 Description 261192
Entergy CORRECTIVE ACTION I CR-lP2-2001-10525
Response
There have been many different methods used to permanently repair these areas of crossunder piping. The following are descriptions of these methods:
- 1. Welding under expansion dog bones One option of repair that has been performed at plants such as Surry is to remove the expansion dogbones, perform Stainless steel cladding to expose piping underneath and replace dogbones. Advantages to this repair method are that the entire area would be protected (including area under dogbones) and thinned areas of piping can be brought back up to nominal thickness by the overlay. Disadvantages to this repair is that it is not a recommended repair method of Westinghouse because it may jeopardize the flexibility of the expansion joint and that extra time will be needed to perform the engineering to analyze this concern.
- 2. Stainless Steel Tubing Repair This repair option was used at St. Lucie Unit 1 & 2 to repair eroded area under dog bones. A stainless steel piece of tubing was placed next to the dogbones and welded in place. The tubing was then deformed to ensure a secure fit up to the dogbone (see attachment for details). Advantages to this repair are that there is no welding to the dogbone and no arc strikes on the dogbone as recommended by Westinghouse. Disadvantage to this repair is that if there is not a consistent bond between the tubing and the dog bone, steam can still get into that area and erode the piping underneath.
- 3. Stainless Steel Covering over dogbones During the lastCHECWORKs Users Group (CHUG) meeting (January 14&15, 2002), it was mentioned the Point Beach has welded stainless steel covers over the dogbones in their crossunder piping. At this time, Point Beach F AC engineer has provided no additional information.
- 4. Welding on Outside of crossunder piping A 199 5 letter to Westinghouse on the subject of repairing eroded areas of crossunder piping from the outside yield the following response:
These eroded areas beneath the expansion joint link (dog bones) can be repaired from the outside of the pipe. The eroded area beneath the link should be ground out and weld repaired using 309 stainless as per PS 600374 for the first few passes to provide an erosion resistant inner surface. The remaining cavity should be built-up with carbon steel weld material as per PS 600945 Part 1-1-l-B. Post weld heat treatment should not be performed for any of the above welding processes.
The expansion joint link should not be subjected to any arc strikes during the welding process. It is recommended that a copper backing plate be placed between the link and the area of repair to protect the link during welding.
- A carbon steel backing plate can be welded over the repaired area on the outside diameter of the pipe, if desired. This welding should be performed toPS 600945 1-1-1-B. No PWHT is to be performed.
Advantages of this repair are that it is a recommended repair from the expansion joint vendor (Westinghouse) and that it would restore original pipe thickness. Would need to obtain welding procedure from Westinghouse if similar procedure is not available.
Replacement of Expansion Joint sections (21A & 218 Vertical Risers) was also investigated for this RES. At the time of this response, Westinghouse (Siemens) had not replied with an estimate for replacing both 21A and 218 vertical risers. The following information was provided from proposals ofiP3 1997 Crossunder replacement of their 31A and 31B vertical risers and IP2 1995 Crossunder replacement of 32"expansionjoints under the HP turbine.
IP2 32" Expansion Joints under HP Turbine (1995) o Material cost- $24,160 (8, 32" Plates of l-l/4 Chrome) o Heat Treatment of32" Expansion Joints- $17,086.76 (15 days to perform)
IP3 31A & 318 Vertical Riser Replacement (1997) o Lump sum quote for design/engineering of all MSR vertical risers and--- see attachment for rest---
Sub response :
Closure Comments:
N/A I PEC00092625
Entergy I CORRECTIVE ACTION I CR-IP2-2001-10525 Attachments:
Resp Description There have been many different IPEC00092626
Entergy I CORRECTIVE ACTION I CR-IP2-2001-10525 CA Number:
7 Site Group Name Assigned By:
IP2 Assigned To:
IP2 ENG P&C-Code Programs Mgmt ENG P&C-Code Programs Statl Azevedo,Nelson F MALONE, HAZEL Subassigned To:
Originated By: Azevedo,Nelson F Performed* By: MALONE, HAZEL Subperforme.d By:
Approved By:
Closed By: Azevedo,Nelson F Current Due Date: 01118/2002 CA Type: PERFORM CA Plant Constraint: NONE CA
Description:
1/18/2002 00:00:00 1118/2002 00:00:00 1/18/2002 00:00:00 Initial Due Date: 01/18/2002 Please reflect the fact that the inspection locations have been added to the inspection list even though the final list will not be issued until 1131102.
CA REFERENCE ITEMS:
Response
Description 1
270378 Internal inspections of 21A&B, 22A&B and 23A&B MSR vertical risers have been added to FAC Master Inspection List (MIL) for the 2002 refueling outage. The final MIL is due for release 1131/2002 Subresponse :
Closure Comments:
N/A IPEC00092627