ML16208A598

E-mail from R.Guzman to K.Greene - NRC Staff Feedback Calvert Cliffs Nuclear Power Plant Unit Nos. 1 and 2, Supplemental Response to GL 2004-02

ML16208A598
Person / Time
Site:	Calvert Cliffs
Issue date:	07/26/2016
From:	Richard Guzman Plant Licensing Branch 1
To:	Greene K Exelon Nuclear Generation Corp
Guzman R
References
GL-2004-02
Download: ML16208A598 (2)

Text

From: Guzman, Richard To: "Greene, Ken:(GenCo-Nuc)"

Subject:

Calvert Cliffs Supplemental Response to Generic Letter 2004-02 (June 8, 2016) - NRC staff feedback Date: Tuesday, July 26, 2016 6:13:00 AM

Ken, Calvert Cliffs submitted a supplemental response (ADAMS accession no. ML16165A490) dated June 8, 2016, regarding closure of Generic Letter 2004-02. During the related public meeting held on July 18, 2016, the licensee requested that the NRC staff provide feedback regarding the acceptability of the information contained in the supplemental response. The staff understands that the licensee desires feedback on the supplemental response prior to continuing their risk-informed evaluation for Generic Letter 2004-02. Below is a summary of the staff evaluation of the information provided by Calvert Cliffs.

• The NRC staff reviewed the debris characteristics assigned for Nukon and Thermal Wrap insulation using a centroid methodology to define the average distance from the jet source to the insulation that could become a target for the jet. The NRC had previously discussed this methodology with Enercon during an audit of their risk-informed methodology. The NRC staff expressed concern during the audit that the centroid method might not appropriately characterize insulation when it had been determined to be closer to the break than assumed using the previously approved sub-zone methodology. During the Calvert Cliffs public meeting, an Enercon representative stated that they did not change the methodology, but believed that they had developed sufficient justification to use the methodology as previously developed. The NRC staff would need to evaluate this justification before a decision regarding its acceptability can be made.

• The NRC reviewed the CCNPP ZOI and debris characteristics for mineral wool insulation encapsulated in metal cassettes. The ZOI and debris characteristics proposed by Calvert Cliffs are the same as those proposed by other licensees and approved by the NRC staff as acceptable. Therefore, the information regarding mineral wool destruction zones and characteristics would be considered acceptable by the staff.

• The NRC reviewed the CCNPP ZOI and debris characteristics for generic fiberglass. The ZOI and debris characteristics proposed by Calvert Cliffs are the same as those proposed by Indian Point and accepted by the staff during an audit.

Therefore, the information regarding mineral wool destruction zones and characteristics would be considered acceptable by the staff.

• The NRC reviewed the CCNPP ZOI, debris characteristics, and transport metrics for lead blanket shielding. The ZOI and debris characteristics proposed by Calvert Cliffs are the same as those proposed by other licensees and approved by the NRC staff as acceptable. Therefore, the information regarding mineral wool destruction zones and characteristics would be considered acceptable by the staff.

Please let me know if you have any questions/concerns on this matter.

Thanks,

Rich

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Rich Guzman Sr. PM, Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Office: O-8E10 l Phone: 301-415-1030