ML11325A193
| ML11325A193 | |
| Person / Time | |
|---|---|
| Site: | Millstone  (NPF-049) |
| Issue date: | 11/10/2011 |
| From: | Price J Dominion Nuclear Connecticut |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 11-610 | |
| Download: ML11325A193 (8) | |
Text
'z7Dkm in ioni Dominion Nuclear Connecticut, Inc.
5000 Dominion Boulevard, Glen Allen, Virginia 23060 Web Address: www.dom.com November 10, 2011 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Serial No.
NLOS/MAE Docket No.
License No.11-610 RO 50-423 NPF-49 DOMINION NUCLEAR CONNECTICUT, INC.
MILLSTONE POWER STATION UNIT 3 10 CFR 50.55A RELIEF REQUEST IR-3-16: TEMPORARY NON-CODE REPAIR, CLASS 3 REACTOR PLANT COMPONENT COOLING WATER SYSTEM PUMPS M33CCP*P1A, M33CCP*PIB, AND M33CCP*PIC Dominion Nuclear Connecticut, Inc. (DNC) requests relief from the Section Xl requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, pursuant to 10 CFR 50.55a(g)(5)(iii). This request is based upon the impracticality of performing required ASME code repair/replacement activities to the Millstone Power Station Unit 3 (MPS3) Reactor Plant Component Cooling Water System Pumps M33CCP*P1A, M33CCP*P1B, and M33CCP*P1C mechanical seal plates due to the long lead time required to procure replacement parts. Attachment 1 to this letter describes the temporary compensatory actions taken by DNC and the basis for the proposed request.
A permanent code replacement for the identified mechanical seals eliminating the discrepancy will be completed no later than December 15, 2012.
If you have any questions regarding this submittal, please contact Ms. Wanda Craft at (804) 273-4687.
Sincerely, J.
an rice Vic V3sident
- Nuclear Engineering :
Relief Request IR-3-16, Temporary Non-Code Repair Class 3 Reactor Plant Component Cooling Water System Pumps, M33CCP*P1A, M33CCP*P1B, AND M33CCP*P1C Commitments made in this letter: None
/Q 1z L
Serial No.11-610 Relief Request IR-3-16 Page 2 of 2 cc:
U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406-1415 C. J. Sanders Project Manager - Millstone Power Station U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop O-8B3 Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station
Serial No.11-610 Docket No. 50-423 ATTACHMENT 1 RELIEF REQUEST IR-3-16. TEMPORARY NON-CODE REPAIR CLASS 3 REACTOR PLANT COMPONENT COOLING WATER SYSTEM PUMPS M33CCP*PIA. M33CCP*PIB. AND M33CCP*P1C MILLSTONE POWER STATION UNIT 3 DOMINION NUCLEAR CONNECTICUT, INC
Serial No.11-610 Docket No. 50-423, Relief Request IR-3-16 Page 1 of 5 ATTACHMENT 1 RELIEF REQUEST IR-3-16, TEMPORARY NON-CODE REPAIR CLASS 3 REACTOR PLANT COMPONENT COOLING WATER SYSTEM PUMPS M33CCP*PIA, M33CCP*PIB, AND M33CCP*PIC CONTENTS C O N T E N T S.....................................................................................................................
1 A C R O N Y M S....................................................................................................................
2 1.0 ASME CODE COMPONENT(S) AFFECTED....................................................
3 2.0 APPLICABLE CODE EDITION AND ADDENDA.............................................
3 3.0 APPLICABLE CODE REQUIREMENT.............................................................
3 4.0 REASON FOR THE REQUEST........................................................................
3 5.0 BURDEN CAUSED BY COMPLIANCE.............................................................
5 6.0 PROPOSED ALTERNATIVE AND BASIS FOR USE.......................................
5 7.0 DURATION OF PROPOSED ALTERNATIVE..................................................
5 8.0 R E F E R E N C E S................................................................................................
.. 5
Serial No.11-610 Docket No. 50-423, Relief Request IR-3-16 Page 2 of 5 ACRONYMS
- 1. ASME - American Society of Mechanical Engineers
- 2. ASTM - American Society for Testing and Materials
- 3. CCP -Reactor Plant Component Cooling Water System Pump
- 4. CFR - Code of Federal Regulations
- 5. CR - Condition Report
- 6. DNC - Dominion Nuclear Connecticut, Inc.
- 8. ERC - Engineering Record of Correspondence
- 9. GL - Generic Letter
- 10. ISI - Inservice Inspection
- 11. LCO - Limiting Condition for Operation
- 12. MPS3 - Millstone Power Station Unit 3
- 14. NRC - U.S. Nuclear Regulatory Commission
- 15. P&ID - Piping and Instrumentation Diagram
- 16. psig - pounds per square inch gauge
- 17. RPCCW - Reactor Plant Component Cooling Water System
- 18. RT - Radiographic Test
- 19. SW - Service Water
- 20. TE - Technical Evaluation
- 21. TRM - Technical Requirements Manual
- 22. UT - Ultrasonic Test
- 23. WO - Work Order
Serial No.11-610 Docket No. 50-423, Relief Request IR-3-16 Page 3 of 5 RELIEF REQUEST IR-3-16, TEMPORARY NON-CODE REPAIR CLASS 3 REACTOR PLANT COMPONENT COOLING WATER SYSTEM PUMPS M33CCP*PIA. M33CCP*PIB. AND M33CCP*P1C Relief Request In Accordance with 10 CFR 50.55a(g)(5)(iii)
- Code Repair/Replacement Impracticality -
1.0 ASME CODE COMPONENT(S) AFFECTED ASME Code Class:
Code Class 3
Reference:
ASME Section XI, IWA-4000 Description Repair/Replacement Component:
Reactor Plant Component Cooling System Pumps M33CCP*P1B, M33CCP*P1A, and M33CCP*P1C Material:
Stainless Steel 2.0 APPLICABLE CODE EDITION AND ADDENDA MPS3 is currently in the third 10-year inservice inspection (ISI) interval, which began on April 23, 2009. American Society of Mechanical Engineers (ASME) Section Xl, 2004 Edition, No Addenda (Reference 8.1) applies to the ISI program and is used as the primary ASME code edition for Section Xl repair/replacement activities. This Temporary Non-Code Repair of the seal plate is not in compliance with ASME Section XI, 2004 Edition, IWA-4000 (Reference 8.1).
3.0 APPLICABLE CODE REQUIREMENT ASME Code Section Xl, 2004 Edition, No Addenda, Article IWA-4000, Repair/Replacement Activities 4.0 REASON FOR THE REQUEST On September 13, 2011, Dominion personnel identified that mechanical seal cartridges (stock code M331740R) which did not meet quality assurance program requirements (i.e., Non-QA) were ordered and installed on the ASME Class 3 Reactor Plant Component Cooling Water (RPCCW) System Pump (CCP)
M33CCP*P1 B at Millstone Power Station Unit 3 (MPS3). It was later determined that the inboard and outboard mechanical seal plates on M33CCP*P1A and M33CCP*P1C had no visible ASME stamps. The mechanical seal cartridge
Serial No.11-610 Docket No. 50-423, Relief Request IR-3-16 Page 4 of 5 includes the seal plate and is replaced as a unit. The RPCCW system provides an intermediate barrier between radioactive or potentially radioactive heat sources and the Service Water (SW) System. It is designed to remove heat from various plant safety related and non-safety related components in a manner which precludes direct leakage of radioactive fluids to the environment. The system has two 100%
capacity loops with three 100% capacity pumps. The pumps are designed in accordance with ASME Section III Safety Class 3. Each CCP pump has a design pressure of 250 psig with a design temperature of 160 degrees F. The suction piping for each pump has a design pressure of 185 psig with a design temperature of 150 degrees F. The CCP pump mechanical seal plate is part of the pump casing pressure boundary and is subjected to the pump suction pressure.
Following discovery, the seal plates recently removed from the 'B' CCP pump and the two plates currently installed in the 'B' CCP pump were analyzed using an X-ray Fluorescence Analyzer. This analysis determined that the two installed plates were made with 316 stainless steel (304 stainless steel is required by design, John Crane HSP-1037403). The CCP system is an ASME III Class 3 system which requires that the pressure boundary material be certified ASME materials. The ASME stamp gives assurance that the material properties are within specified guidelines and typically come with Certified Material Test Report (CMTR) documentation. CMTRs comply with Code requirements for material chemical composition verification/documentation.
Certificate of Compliances (C of Cs) do not meet the Code requirements but do provide a high level of confidence that the material's chemical composition is correct.
The materials analyzer used to analyze the 'B' CCP pump seal plates is very accurate in determining material type and is used by Dominion Materials Engineering to issue C of Cs. Dominion Materials Engineering has issued a C of C for the seal plates presently installed on the 'B' CCP pump and has designated the material as 316 SS.
The installed seal plates in the 'A' and 'C' CCP pumps were also analyzed using an X-ray Fluorescence Analyzer. The material of the seal plates on the 'A' CCP pump was determined to be 304 stainless steel. The inboard seal plate material on the 'C' CCP pump was determined to be 316 stainless steel and the outboard seal plate was determined to be 304 stainless steel. Type 304 and type 316 stainless steel have the same mechanical properties. The primary difference between the two alloys is the 2% molybdenum in type 316 which provides better corrosion resistance in some environments. The RPCCW system water is de-ionized water and is not corrosive. Therefore, this difference is not detrimental in any way to the performance of the component. Dominion Materials Engineering has issued a C of C for the seal plates presently installed on the 'A' and 'C' CCP pumps based on the material analysis performed.
Serial No.11-610 Docket No. 50-423, Relief Request IR-3-16 Page 5 of 5 5.0 BURDEN CAUSED BY COMPLIANCE A Code repair would require replacement of the seal plates with code stamped components. Work orders have been generated to replace the mechanical seal plates on each of the three RPCCW pumps. An order has been placed to procure six mechanical seal plates with two seal plates reserved for each pump.
Preliminary discussions with the seal plate manufacturer indicate the lead time for the required number of replacement seal plates is approximately six months for each set of seal plates. Based on this information, replacing the seal plates on the three RPCCW pumps is scheduled to be completed by December 15, 2012.
6.0 PROPOSED ALTERNATIVE AND BASIS FOR USE The installed seal plate is a robust design. It is approximately 2 inches thick and 9 inches in diameter. The CCP pump mechanical seal plate is part of the pump casing pressure boundary and is subjected to the pump suction pressure (approximately 32 psig). Since the design pressure for the CCP suction piping is 185 psig and the seal plate is only subjected to approximately 32 psig (RPCCW Surge Tank head), it has been concluded that the seal plate has significant design margin. Dominion Materials Engineering has issued a C of C for the seal plates presently installed on the 'A', 'B', and 'C' CCP pumps and has designated the material as either 316 SS or 304 SS based on a very accurate materials analyzer. Although 304 stainless steel is required by design, type 316 stainless steel has been determined to be acceptable in the RPCCW system.
7.0 DURATION OF PROPOSED ALTERNATIVE Preliminary discussions with the seal plate vendor indicated a lead time for each set of replacement seal plates is approximately six months. Based on these preliminary discussions with the seal plate vendor and review of internal scheduling and manpower availability, replacement of the identified seal plates to re-establish full qualification is scheduled to be completed by December 15, 2012.
8.0 REFERENCES
8.1 ASME Code Section Xl, Division 1, 2004 Edition with No Addenda