ML100750388
ML100750388 | |
Person / Time | |
---|---|
Site: | Crystal River ![]() |
Issue date: | 10/09/2009 |
From: | Farzam F NRC/NRR/DE/EMCB |
To: | Jason Paige Plant Licensing Branch II |
References | |
FOIA/PA-2010-0010 | |
Download: ML100750388 (3) | |
Text
,'Sykes, Marvin From: Farzam, Farhad Sent: Friday, October 09, 2009 10:41 AM To: Paige, Jason Cc: Khanna, Meena; Boyce, Tom (NRR); Sykes, Marvin; Thomas, George
Subject:
RE: Outcome from Crystal River Teleconference RE Containment Crack Jason, In the phone call yesterday, the licensee discussed 10 vertical and 17 horizontal tendons that were detensioned before concrete removal. I did question them about this statement because the number of detensioned tendons seemed low based on my experience. However, I do not believe they had the right people to answer the question. I try to explain the issue:
For SG replacement, when a temporary construction opening is required in a post-tensioned containment, there are two different sets of tendons that will require detensioning:
- 1. tendons that are traversing the opening which must be detensioned and removed. (in CR3 case - 10 vertical and 17 horizontal tendons)
- 2. tendons adjacent to the opening which must be detensioned only (not removed) to reduce/balance the stress distribution when the concrete is removed (in CR3 case - 20 vertical and 18 horizontal tendons).
Based on CR3 relief request 08-001-MX which was submitted for our review via Dec. 10, 2009 letter (ML083590224), The licensee discussed the plan for tendon detensioning. The excerpt from this relief request is as follows:
"A total of thirty vertical tendons and thirty five horizontal tendons will be affected by the containment access opening repair/replacement activity. Ten vertical tendons and seventeen horizontal tendons fall within the construction opening and will be completely removed and replaced with tendons of the same design and construction. In addition, twenty vertical tendons and eighteen horizontal tendons immediately adjacent to the access opening will be temporarily detensioned and subsequently retensioned."
Therefore, the statement in your summary (although that is what the licensee said), "The licensee detensioned 10 vertical tendons (of -144) and 17 horizontal tendons (of -282) in preparation for the hydro-demolition." is not consistent with the plan communicated to us in the relief request. A total of 30 vertical tendons and 35 horizontal tendons should have been detensioned before the concrete removal. This should be an action item for the licensee to confirm.
Regards, Farhad From: Paige, Jason Sent: Thursday, October 08, 2009 6:36 PM To: Skeen, David; Dennig, Robert; Sullivan, Ted,. Boyce, Tom (NRR); Ruland, William; Ashar, Hansraj; Brown, Eva; Mendiola, Anthony; Taylor, Robert; Khanna, MeEna; Manoly, Kamal; Sheikh, Abdul; Thomas, George; Auluck, Rajender; Kuntz, Robert; Farzam, Farhad; Saba, Farideh; GUtter, Joseph; Howe, Allen; Nelson, Robert; Burnell, Scott; Bernardo, Robert; Hiland, Patrick; Parillo, John; Holian, Brian; Lee, Samson; Mozafari, Brenda; Sykes, Marvin; Munday, Joel; Reyes, Rogerio; Morrissey, Thomas
Subject:
Outcome from Crystal River Teleconference RE Containment Crack "3 1
Below is a summary of the call from NRR's perspective, and are providing it for NRR management awareness only. Region II has the lead for this issue and will provide additional information as appropriate. We will forward talking points on this issue to you when received from Region II.
On Friday, October 2, 2009, Crystal River was performing hydro-demolition to support steam generator removal and replacement activities (the equipment hatch is too small to remove the SGs). While performing the demolition, the licensee noticed that water was leaking out of containment from a crack about 2.5 feet long.
The crack runs vertically up containment and is located in between the vertical and horizontal tendons. It has been categorized as delamination of concrete. The licensee has not yet been able to determine how far around the containment the crack has propagated.
Current plant status: Crystal River is in Mode 6 and they have completed the hydro-demolition on containment for a removed section of 25' by 26'. They are currently offloading fuel from the reactor vessel. They had completed an analysis that shows that the containment will be able to withstand temperatures generated from any decay heat. Tomorrow (10/9), the licensee will have completed an analysis on the polar crane to ensure that it will be able to withstand the weight of the SGs.
NRC call with licensee: On Thursday afternoon, October 8, 2009, NRC Region II led a teleconference with Crystal River for them to discuss their actions to date, their strategy for addressing the identified crack in containment, and ongoing analyses being performed by Crystal River and vendors. Representatives from Research, OPA and NRR DE, DLR, and DORL also tied into the call. The following items were discussed:
- In the near future, the licensee will complete a failure analysis and root cause analysis, although no specific date has been set for completing this. The analyses mentioned above have all been entered in their corrective action program for tracking. The licensee plans to determine how far the crack has propagated using non-destructive techniques. To assist in their analyses, the licensee has requested support from various vendors (MPR, Sargent & Lundy, and Bechtel). They have also outreached to NEI and INPO for assistance. Until the licensee has completed its failure and root cause analyses, they will not know their path forward with regards to licensing action(s) needed (i.e., license amendment request). The licensee will need to declare the containment operable before they transition to Mode 4, which is tentatively scheduled for early December 2009. The licensee stated that once they obtain additional or any new information, they will notify the NRC immediately.
- The licensee detensioned 10 vertical tendons (of -144) and 17 horizontal tendons (of -282) in preparation for the hydro-demolition.
- No patterns of relaxed tendons had be seen from a review of the data from surveillances of containment tendons.
- In preparation for the hydro-demolition, the licensee had performed an operating experience search of issues that resulted from replacing SGs through a removed section from containment. The licensee only identified voiding issues in the containment and set forth contingency plans to address potential voiding issues.
- There have been no media reports on the crack issue to date. There were two phone calls related to the hydro-demolition activity.
- The region will be conducting a special inspection starting on Tuesday, October 13, 2009, that is expected to last for approximately three months. They may hold a public meeting sometime after Thanksgiving to discuss the progress of the inspection as well as to maintain openness with the public. The region will complete a press release by COB today (10/8) to announce the special inspection and purpose. The region (special inspection team) will be the lead on this issue as well as serve as the NRC point of contact for the licensee.
NRR will support the inspection by sending an experienced structural engineer to Crystal River.
Jason Paige, Turkey Point Project Manager 2
Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation US Nuclear Regulatory Commission Phone:, (301) 415-5888 3