ML14037A126
| ML14037A126 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 02/14/2014 |
| From: | Satorius M NRC/EDO |
| To: | Shaheen J US SEN (Senate) |
| Rihm, Roger 415-1717 | |
| Shared Package | |
| ML14007A714 | List: |
| References | |
| G20140030, LTR-14-0009 | |
| Download: ML14037A126 (3) | |
Text
February 14, 2014 The Honorable Jeanne Shaheen United States Senate Washington, DC 20510
Dear Senator Shaheen:
On behalf of the U.S. Nuclear Regulatory Commission (NRC), I am responding to a January 7, 2014, email from Sarah Holmes of your staff forwarding an email from your constituent, Michael Mulligan. Mr. Mulligan provided a detailed account of his concerns associated with the service water piping system at the Seabrook Station nuclear power plant. The NRC is well aware of Mr.
Mulligans concerns and has discussed them with him in the past. Please be assured that the Seabrook Station service water system currently meets NRC regulatory requirements and is capable of performing its safety function.
Because the service water system cools important plant equipment that is continuously operating, much of the system is always in service. Therefore, the licensee regularly monitors the condition of the system via flow tests, as well as periodic examinations of portions of the interior of the piping and measurements of its wall thickness. The NRC has conducted several of its own inspections of the condition of this system over the years, and has taken enforcement action when the system was not in compliance with our requirements.
Due to the design of a majority of the piping system (carbon steel lined with cement for corrosion protection), NextEra Energy Seabrook, LLC (NextEra or the licensee) has experienced degradation of the lining of the piping and subsequent corrosion of the pipe wall in some areas, principally downstream of pumps and valves where the water flow is turbulent.
Where lining erosion was experienced, NextEra removed the cement lining and installed alternate materials. In select areas, the licensee has experienced some problems with these alternate materials that have resulted in pieces of the lining breaking free and/or corrosion of the underlying carbon steel piping. The NRC inspected these issues under the agencys Reactor Oversight Process, dispositioned the individual performance issues in accordance with the NRC Enforcement Policy, as applicable, and documented these inspections in NRC Inspection Reports. In the long-term, NextEra is in the process of replacing critical sections of the piping with an unlined stainless steel alloy that is corrosion resistant, which will ensure the service water system continues to perform its safety function.
Regarding the particular incident in late August 2013, referenced by Mr. Mulligan, where a small (less than 1/2 inch diameter) through-wall hole developed in the service water system, NextEra made a temporary repair to the pipe using a technique that was reviewed and accepted by the NRC. Specifically, the licensee submitted a request to the NRC to be relieved of compliance with the applicable American Society of Mechanical Engineers (ASME) developed code and provided the information to justify why this temporary repair method was technically acceptable as an alternative to the method prescribed by the applicable ASME code. The NRC concluded that the licensees relief request was acceptable and that the system with the temporary repair was capable of performing its safety function. This spring, NextEra will either make a permanent ASME code-compliant repair to this portion of the service water system or replace the affected section of piping. The NRC did have concerns with the technical adequacy of the evaluation performed by NextEra when the leak first developed regarding the ability of the system to perform its design functions (i.e., an operability determination), and took appropriate enforcement action. However, at no time was there an indication of falsification regarding this operability determination by the licensee.
The NRC will continue to monitor the condition of the service water system to ensure that proper maintenance, testing, and repairs are performed and that the system remains fully capable of performing its safety function. If you need any additional information, please contact me or the Office of Congressional Affairs, at (301) 415-1776.
Sincerely,
/RA/
Mark A. Satorius Executive Director for Operations
ML14037A126 OFFICE OEDO/CPM RGNI OGC OCA EDO NAME RRihm DTifft CHair GDacus MSatorius DATE 2/06/14 2/04/14 2/04/14 2/04/14 2/14/14