ML060540510

Submitter'S Additional Comments on DPO Panel Report

ML060540510
Person / Time
Site:	Oconee
Issue date:	07/27/2005
From:	Shannon M NRC/RGN-II
To:	Pedersen R NRC/OE
Pedersen R OE 415-2742
Shared Package
ML060600478	List: ML050550052 ML052240171 ML052430259 ML060540435 ML060540472 ML060540498 ML060540504 ML060540510 ML060540533 ML060540542 ML060580027 ML060590651 ML060590653 ML060620037 ML060760325
References
DPO-2005-003
Download: ML060540510 (2)

Text

From: Mel Shannon To: Renee Pedersen Date: 7/27/05 8:14AM

Subject:

Re: ACTION: DPO-2005-003 Panel Report Renee, can you have the panel provide the initial calculation that determined the amount of stress in the restraint rod. This should be the first calculation that needs to be completed to solve the problem. If the panel performed the calculation the same way the licensee did, then there is a likely error. In addition, can you have the panel provide the values they used for the ultimate strength for the feedwater pipe and the total calculated stress in the feedwater pipe at the whip restraint attachment. Based on statements in the report, the stress in the piping did not exceed the ultimate strength, I am curious as to how close it came.

>>> Renee Pedersen 07/25/05 4:53 PM >>>

Mel, I'm glad that you believe that your concerns have been heard. I will pass your comments along to the Panel for their consideration and provide a copy to Bill Travers for his information. If Bill has comments, I will likewise pass those along to you for your general information. The Panel may choose to follow up with you on your comments. Other than that, we'll wait and see what the RA's Decision is.

If you have any questions, please feel free to give me a call.

Renee

>>> Mel Shannon 07/25/05 11:46 AM >>>

Renee, I can say that my concerns have been heard. I would like to stress that I think the licensee needs to perform the piping inspections (UT NDE for thickness and NDE for cracks) as recommended in the report. I would like to point out that the whip restraint temperatures were measured at 210 degrees and the feedwater was at 465 degrees (with the insulation package installed) so the use of 200 degrees and 450 degrees in the calculation was not overly conservative as stated in the report. In fact the licensee operated at least one cycle without the insulation installed which would cause the restraints to be at an even lower temperature. This is just for comment, no other actions are necessary on this part of the issue.

For Concern 1, Part C, the report stated that "there is no validity to this concern." Could you have the team provide a basis for this conclusion?

I can understand the answer if the pipe is allowed to bend and absorb the stress. However in this case, with the piping restrained, and for example equal stress applied to both sides, the stresses should be cummulative. I think that is one of the reasons that licensees are cautioned about welding the restraints directly to the piping. I thought of the problem like this, 1) the lower thermal expansion of the whip restraint vs the pipe is like tightening up the nut of the whip restraint. 2) If I tighten up the nut on opposite whip restraints, the pipe does not bend and the stresses from each tightened bolt add to the total stress on the pipe. 3) This would be what would happen to a bolt that was attached at both ends, tightening up the nut on one end 1/2 half turn would apply a certain stress, tightening the nut on the other end 1/2 turn would cause the stress to double. Am I missing something? If I am wrong you have my appology.

Do I need to do anything else?

Thanks for listening to my concern.

>>> Renee Pedersen 07/20/05 11:20 AM >>>

Senior moment. I forgot to attach the report. Here it is.

Renee

>>> Mel Shannon 07/20/05 10:10 AM >>>

Sounds OK, when do I get the report?

>>> Renee Pedersen 07/20/05 9:54 AM >>>

Good morning Mel, I am forwarding a copy of the DPO Panel's report that has been provided to Bill Travers for his review and comment. As part of the revised DPO Program, you also have an opportunity to provide a written statement to me identifying any areas of the report that you believe are not factually correct or complete with regard to your expressed safety concerns that are the subject of this DPO. The purpose of this review is to ensure that your concerns have been accurately and completely "heard." This is not a request for you to comment on the conclusions and recommendations in the report. Therefore, please limit your comments within the stated scope.

Keep in mind that you if you have issues with the report, you can consider pursuing them through the DPO Appeal process.

I will forward your written statement to the DPO Panel for its consideration. The DPO Panel will review your comments as well as any comments that Mr. Travers may have with regard to the completeness and accuracy of the staff position discussion included in the report. The DPO Panel will issue a revision to the report only if they believe that it is warranted from a completeness and accuracy standpoint. I will also forward your written statement to Bill Travers.

If you choose to provide a written statement, in the interest of timeliness, I ask that you send it to me (email is O.K.) by July 27, 2005. Please contact me ASAP if you want to submit a written statement, but do not believe you can meet the due date.

If you have any questions, please feel free to contact me at 415-2742.

Renee Pedersen, Acting DPOPM