ML11336A371
| ML11336A371 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 12/01/2011 |
| From: | Markey E US Congress, US HR (House of Representatives) |
| To: | Jaczko G NRC/Chairman |
| Rihm R | |
| Shared Package | |
| ML11354A287 | List: |
| References | |
| G20110839, LTR-11-0638, SECY-2011-0638, CORR-11-0142, SECY-017 | |
| Download: ML11336A371 (7) | |
Text
EDO Principal Correspondence Control FROM: DUE: 12/20/11 EDO CONTROL: G20110839 DOC DT: 12/01/11 FINAL REPLY:
Representative Edward J. Markey TO:
Chairman Jaczko FOR SIGNATURE OF : ** PRI ** CRC NO: 11-0638 Chairman Jaczko DESC: ROUTING:
Recent Results of Nuclear Regulatory Commission Borchardt Investigation of Palisades Shutdown Weber (Due to Congress: 1/6/12) (EDATS: SECY-2011-0639) Virgilio Ash Mamish OGC/GC DATE: 12/02/11 Leeds, NRR Pederson, RIII ASSIGNED TO: CONTACT: Burns, OGC Schmidt, OCA EDO Rihm SPECIAL INSTRUCTIONS OR REMARKS:
Please prepare response in accordance with OEDO Notice 2009-0441-02 (ML093290179). NRR and Region III to provide input to Roger Rihm, OEDO, if required. Roger Rihm to coordinate response with OGC and OCA.
L4 JI6JC~ ~§&KOVU .S5ICY I0
EDATS Number: SECY-2011-0639 Source: SECY General Inorato Assigned To: OEDO OEDO Due Date: 12/20/2011 11:00 PM Other Assignees: SECY Due Date: 12/22/2011 11:00 PM
Subject:
Recent Results of Nuclear Regulatory Commission hwestigation of Palisades Shutdown
Description:
CC Routing: NRR; Regionl~l; OGC; OCA ADAMS Accession Numbers - Incoming: NONE Response/Package: NONE I.OteInomto Cross Reference Number: G20110839, LTR-l 1-0638 Staff Initiated: NO Related Task: Recurring Item: NO File Routing: EDATS Agency Lesson Learned: NO OEDO Monthly Report Item: NO Proes Inoraion Action Type: Letter Priority: Medium Sensitivity: None Signature Level: Chairman Jaczko Urgency: NO )
Approval Level: No Approval Required OEDO Concurrence: YES OCM Concurrence: NO OCA Concurrence: NO Special Instructions: Please prepare response in accordance with OEDO Notice 2009-0441-02 (ML093290179). NRR and Region III to provide input to Roger Rihm, OEDO, if required. Roger Rihm will coordinate response with OGC and OCA.
I Dcuen Infomaion Originator Name: Representative Edward J. Markey Date of Incoming: 12/1/2011 Originating Organization: Congress Document Received by SECY Date: 12/2/201 I Addressee: Chairman Jaczko Date Response Requested by Originator: 1/6/2012 Incoming Task Received: Letter Page 1 of l
OFFICE OF THE SECRETARY CORRESPONDENCE CONTROL TICKET Date Printed: Dec 01, 2011 11:35 PAPER NUMBER: LTR-1 1-0638 LOGGING DATE: 12/01/2011 ACTION OFFICE: EDO AUTHOR: REP Edward Markey AFFILIATION: CONG ADDRESSEE: Gregory Jaczko
SUBJECT:
Response to the recent release of the results of a NRC investigation of an August 9, 2011 shutdown of the Palisades Nuclear Power Plant ACTION: Signature of Chairman DISTRIBUTION: RF, OCA to Ack LETTER DATE: 12/01/2011 ACKNOWLEDGED No SPECIAL HANDLING: Commission Correspondence NOTES: Response requested by COB, January 6, 2012 FILE LOCATION: ADAMS DATE DUE: 12/22/2011 DATE SIGNED:
EDO -- G20110839
COMMrTTEES EDWARD J. MARKEY 2108 RAYBURN HOUSE OFFICE BIJILDING WASHINGTON, DC 20515-2107 NATURAL RESOURCES 7T1 DIST2RT, MASSAC2.ISETrs (2021 225-2836 RANKING DEMOCRAT DISTRICT OFFICES.
ENERGY AND COMMERCE tit ThtGt tatt 55+,H HI STREET, SUITE 101 of CiongJr!,te Jb bMEDFORD, MA 02155 7" (7811 391-2900 188 CONCORD STREET, SUITE 102 la~lj ington, *C 20515-2107 FRAMINGHAM,. MA 01702 (5r8) 875-2900 December 1, 2011 http://markey.house.gov The Honorable Greg Jaczko Chairman Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852
Dear Chairman Jaczko:
I am writing to you in response to the recent release of the results of a Nuclear Regulatory Commission (NRC) investigation of an August 9, 2011 shutdown of the Palisades Nuclear Power Plant'. The circumstances surrounding this shutdown, which was due to a service water (SW) pump failure, led the NRC to issue a preliminary White enforcement finding yesterday. I am concerned that this failure is the latest in a string of similar incidents at Palisades and other nuclear power plants over the last two decades, and may be related to the continued use of types 410 and 416 martensitic stainless steel (41OSS and 416SS), which are used in components of SW pumps at nuclear power plants.
As you know, 410SS and 416SS steels have been employed in the coupling mechanism for joining pump shafts in SW systems in a number of nuclear power plants for decades. SW systems include vertical deep draft pumps that provide cooling water to safety related equipment such as component cooling water, containment air coolers, diesel generators, and control room coolers. The pumps are critical to reactor safety, and I am concerned that despite a well-known history of problems related to the vulnerability of these metals to intergranular stress corrosion cracking (IGSCC), they continue to be used and continue to cause failures in U.S. nuclear power plants.
As the NRC has noted 2 , there is a collection of scientific literature and industry operating experience describing the vulnerability of 4 1OSS and 416SS steels to IGSCC degradation, in which cracks form, propagate as stress opens cracks that are subject to corrosion, which are then corroded further, weakening the metal through further cracking.
Three simultaneous conditions must be present for such corrosion and cracking to occur:
susceptible material, tensile stress, and a harsh environment. 41OSS and 416SS steels are inherently susceptible to IGSCC due to embrittlement from the tempering and hardening process in its manufacture. In SW pump couplings, the nature of the coupling function ensures tensile stress. However, it was assumed that these stainless steel grades could safely be used in SW
' Palisades Nuclear Plant, NRC Inspection Report 05000255/2011016; Preliminary White Finding 2 Palisades Nuclear Plant - NRC Special Inspection Team (SIT) Report 05000255/2011012 PF'IINIEDON TIECYCLEDP4PER
pumps because they are rated to operate without corrosion in fresh water. Nonetheless, a number of pump failures from this type of corrosion have been reported to the NRC since at least 1991.
In the following documented pump failure events, the failure mechanism was IGSCC in 41OSS or 416SS components:
3
" June 20, 1991 Beaver Valley Power Station 2
- September 22, 1993 Indian Point Energy Center 4
" May 2001 VC Summer Nuclear Station 5
- September 1, 2003 Perry Nuclear Power Plant 6
- May 21, 2004 Perry Nuclear Power Plant 7
" June 14, 2005 Columbia Generating Station 8
- September 29, 2009 Palisades Nuclear Power Plant 2
" July 2010 Prairie Island Nuclear Generating Plant 2
- August 9, 2011 Palisades Nuclear Power Plant NRC's licensees have also been alerted to these problems by the NRC and others on several occasions:
- On September 1, 1993, the NRC issued an Information Notice 3 informing licensees of problems stemming from temper embrittlement of 41OSS supplied by Byron-Jackson, referring to the 1991 Beaver Valley pump coupling failure.
- In 2006, the Institute of Nuclear Power Operations released a communication 9 that discussed SW pump shaft, coupling and impeller failures occurring in the industry. The report noted that 12 failures occurred between 1998 and 2006, with the most frequent including corrosion causing coupling separation.
" On February 9, 2007, the NRC issued a second Information Notice 7 referencing the 4 1OSS pump coupling failures due to IGSCC that occurred at the Columbia Generating Station. The operating experience review identified at least 23 essential SW pump shaft and coupling failures since 1983 involving more than six different manufacturers. Many of these pump failures involved IGSCC as a primary cause.
The purpose of such communications is ostensibly to alert licensees to these potential safety problems, presumably so that they can take measures to prevent their recurrence.
However, these failures evidently have continued, and I believe that is at least in part because licensees have not been required to take any action or even report back to the NRC regarding what they are doing to identify, mitigate or prevent this corrosion cracking.
3 Information Notice 93-68: Failure of Pump Shaft Coupling Caused by Temper Embrittlement During Manufacture 4 NRC Inspection Report No. 50-395/02-06 5 Final Significance Determination for a White Finding (NRC Inspection Report 50-440/2004-005) 6 Perry Nuclear Power Plant NRC Special Inspection Report 05000440/2004011 7 NRC Information Notice 2007-05: Vertical Deep Draft Pump Shaft and Coupling Failures 8 Licensee Event Report 2010-001, Potential Loss of Safety Function Due to a Service Water Pump Shaft Coupling Failure Palisades Nuclear Plant, Docket 50-255, License No. DPR-20 9 Operating Experience Digest 2006-02, Institute of Nuclear Power Operations
In the most recent pump failure due to IGSCC in a 416SS coupling, which resulted in the November 30, 2011 NRC preliminary White enforcement finding, the pump in question had also failed two years prior. The NRC found that "...the licensee failed to take into consideration significant operating experience from as early as 1993 and as late as 2010 that linked IGSCC susceptibility of 410 and 416 stainless steels to temper embrittlement."'1 This demonstrates that merely making available information about the problem to licensees is not enough to assure that the appropriate steps will be taken.
This lack of a requirement for action is particularly alarming considering how the NRC's 2007 Information Notice characterizes the IGSCC problems in pumps: "These failures might not be detected by commonly employed condition monitoring, during routine operations, or from surveillance test or IST results. Pump shaft and coupling failures can challenge operability even though performance degradation over time may appear consistent with normal wear. Operating experience also shows that pump shaft failures and coupling failures can result in sudden total loss of flow before standard performance monitoring techniques alert plant staff to the impending failure."
The NRC General Design Criterion 1 requires that all components, such as pumps and valves, that are necessary for safe operation be tested to demonstrate that they will perform satisfactorily in service. The failures outlined above clearly show that pump components made with 41OSS and 416SS do not rise to the standard of performing satisfactorily in service, and I believe that further mandatory NRC action is in order. Therefore, I ask that you address the following:
- 1. Please provide copies of of any licensee voluntary responses to the NRC's 1993 and 2007 Information Notices.
- 2. Please provide a list of all U.S. nuclear power plants currently using 41OSS and 416SS components.
- 3. Please provide a list of all the known uses of 41OSS and 416SS steels in nuclear power plants.
- 4. In April 2005, NRC published a review of the performance of steel Alloy 600 in nuclear power plants across the fleet'°. The impetus for collecting information on Alloy 600 cracking was in part the discovery in March 2002 of vessel head penetration flaws, leaks, and pressure boundary corrosion at the Davis-Besse plant. This review found that Alloy 600 and its associated welds are susceptible to crack nucleation and growth in a wide range of applications. NRC staff concluded that additional inspections beyond one-time inspections were warranted, and industry developed inspection and evaluation guidelines to manage degradation. Will you initiate a similar review for the 410SS and 416SS steels used in pump components? If not, why not?
- 5. What regulatory actions will the Commission undertake in order to assess, require licensee reporting and inspection of, and address the IGSCC problems involved in 41OSS and 416SS pump components? If no such actions are planned, why not?
1o "U.S. Plant Experience With Alloy 600 Cracking and Boric Acid Corrosion of Light-Water Reactor Pressure Vessel Materials", NRC Office of Nuclear Regulatory Research
Thank you very much for your consideration of this important matter. Please provide your response no later than close of business Friday, January 6, 2012. If you have any questions or concerns, please have your staff contact Dr. Makenzie Lystrup or Dr. Michal Freedhoff of my staff at 202-225-2836.
Sincerely, Edward J. Markey