ML102460552

NSP000006-Revised Testimony of Steven Skoyen-2006 AES Letter

ML102460552
Person / Time
Site:	Prairie Island
Issue date:	09/03/2010
From:	Setlur A Automated Engineering Services Corp
To:	Mccall S Atomic Safety and Licensing Board Panel, Nuclear Management Co
SECY RAS
Shared Package
ML102460550	List: IR 05000282/2009009 IR 05000282/2009011 IR 05000282/2009015 Information Notice 2009-11, NSP000059-Revised Prefiled Testimony of Northard/Petersen/Peterson-NRC Information Notice 2009-11 L-PI-10-027, NSP000046-Revised Testimony of Northard/Petersen/Peterson-NSPM Response to NRC Annual Assessment Letter for Calendar Year 2009 ML102460551 ML102460552 ML102460553 ML102460554 ML102460555 ML102460556 ML102460557 ML102460558 ML102460559 ML102460560 ML102460562 ML102460563 ML102460564 ML102460565 ML102460566 ML102460568 ML102460569 ML102460615 ML102460616 ML102460617 ML102460618 ML102460619 ML102460620 ML102460621 ML102460624 ML102460625 ML102460626 ML102460627 ML102460628 ML102460629 ML102460630 ML102460631 ML102460633 ML102460634 ML102460635 ML102460636 ML102460637 ML102460638 ML102460639 ML102460715 ML102460716 ML102460718 ML102460719 ML102460720 ML102460722 ... further results
References
50-282-LR, 50-306-LR, ASLBP 08-871-01-LR-BD01, RAS 18550
Download: ML102460552 (3)

Text

NSP000006 AUTOMATED 387 Shuman Blvd., Suite 230W ENGINEERING Naperville, IL 60563 SERVICES CORP. (630) 357-8880, Ext. 11 Fax: (630) 357-4445 E-mail: avsetlur@aesengineering.com December 4, 2006 Mr. Scott McCall Nuclear Management Company, LLC Prairie Island Nuclear Generating Plant 1717 Wakonade Drive East Welch, MN 55089

Subject:

Review of 2R24 Observed Leakage through Concrete Adjacent to the Containment Shell in Sump B Automated Engineering Services Corp. (AES) was requested to review the observed leakage in Sump B area on both sides of the RHR suction lines relative to an evaluation of a similar leakage performed by AES dated December 16, 1998 titled Report on the Effect of Borated Water Leaks on Containment Concrete, Reinforcing Steel and Containment Steel Plate (Ref. 1).

AES has reviewed the following documents emailed by you on December 2, 2006.

1. Summary of Refuel Cavity Leakage in 2R24 dated 12/2/06, (Ref. 2)

2. Unit 1 - Sump B In-Leakage History, undated, (Ref. 3)

3. Unit 2 - Sump B In-Leakage History, undated, (Ref. 4)

4. Support/Refute Matrix describing the source and path (Ref. 5)

5. Picture of leakage into Sump B (Ref. 6)

6. Picture of the most likely flow path traveling from the Refueling Pool to Sump B (Ref. 7)

The following observations are made relative to the Reference 1 report:

1. The current observed leakage in the Sump B area is very similar to that observed and reviewed in the Reference 1 report. In that report it was stated that the source of the borated water leaking into the Sump B area was most likely from the flooded Refueling Pool. The current observations with regards to the water chemistry also strongly points to the same source and the leakage path (Ref. 7). It is evident that the Refueling Pool stainless steel liner is not completely watertight. This issue should be attended to at the earliest and I recommend that a formal procedure to inspect and caulk suspected areas be implemented at the end of and before each Refueling Pool flooding.

The basis and conclusions developed in the Reference 1 report are still valid and in my opinion the integrity of the structural components (concrete, rebar and containment shell) are not compromised.

Letter: Mr. Scott McCall Page 2 Review of 2R24 Observed Leakage through Concrete Adjacent to the Containment Shell in Sump B December 4, 2006

2. From Reference 2, leakage into other most likely areas based on past experience, such as the Regen HX room, seem to be arrested. This is a positive development. This points to requiring a closer review of the flow paths to understand the reasons why Sump B is still experiencing leakage whereas the other area leakage seem to have been stopped.

3. The Refuel Cavity should be inspected and vulnerable or potentially vulnerable leakage paths should be made watertight prior to the pool flooding.

4. I have reviewed the Support / Refute matrix (Reference 4), which confirms that the leakage source is from the Refueling Pool. I support this matrix evaluation.

The notations in this matrix and those in References 2 and 3 (Leakage Histories) need to be more descriptive for proper understanding.

My review of the 2R24 leakage is that the conclusions regarding the safety and capability of the vulnerable structural components are not compromised and that more effort should be given to detect and correct the leakage source in the Refueling Pool.

If you have any questions or comments concerning the information contained herein, please contact the undersigned at Ext.11.

Sincerely, A.V. Setlur, MN PE #21678 President

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