ML15349A808

Email from W.Craft to R.Guzman Millstone Unit 3 Information Regarding LAR to Adopt Dominion Core Design and Safety Analysis Methods

ML15349A808
Person / Time
Site:	Millstone
Issue date:	06/30/2015
From:	Craft W Dominion Resources Services
To:	Richard Guzman Plant Licensing Branch 1
Guzman R
References
TAC MF6251
Download: ML15349A808 (1)

Text

Guzman, Richard From: Wanda D Craft (Generation - 6) <wanda.d.craft@dom.com>

Sent: Tuesday, June 30, 2015 10:23 AM To: Guzman, Richard Cc: John Harrell (Generation - 6)

Subject:

[External_Sender] Information related to MPS3 LAR to Adopt Dominion Core Design and Safety Analysis Methods Categories: Followup

Rich, The NAF group discovered a discrepancy between the MPS3 RETRAN Base Model Pressurizer Shell Heat Conductor and the Dominion RETRAN Topical Report this past weekend (June 27/28). The MPS3 RETRAN base input deck models the pressurizer shell as a heat conductor, which differs from Topical Report VEPFRD41. VEPFRD41 states, Dominion continues to model the nonequilibrium wall as an adiabatic surface.

This model is not used in any analyses of record, so this discrepancy has no impact on plant licensing or operations. However, the RETRAN base model was used to benchmark/replicate Westinghouse analyses of record in support of the subject LAR submitted on May 8, 2015 for generic NRCapproval of application of Dominion reload design analysis methods to MPS3. Each of the five benchmarking cases supporting the May 8, 2015 LAR were rerun with the needed correction. This resulted in either essentially no difference or improved replication of the Westinghouse analysis of record results (i.e. in the case of the of the predicted pressurizer water volume for the loss of normal feedwater benchmark).

This information was not known at the time of our June 25 clarification call. We anticipate that modified graphs and text for the affected Loss of Normal Feedwater benchmark case in the LAR may be needed by the NRC tech reviewer to complete his review of the LAR, and that he may wish for us to provide this additional information in conjunction with responses to forthcoming RAIs.

A CR is being written to document this issue. I will be happy to send you a copy after it has been submitted. If you have any questions, please let me know. We are available to discuss this at any time. Thanks.

Wanda D. Craft Nuclear Licensing and Operations Support Dominion Resources Services, Inc (804) 273-4687 tie-line 730-4687 CONFIDENTIALITY NOTICE: This electronic message contains information which may be legally confidential and or privileged and does not in any case represent a firm ENERGY COMMODITY bid or offer relating thereto which binds the sender without an additional express written confirmation to that effect. The information is intended solely for the individual or entity named above and access by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution, or use of the contents of this information is prohibited and may be unlawful. If you have received this electronic transmission in error, please reply immediately to the sender that you have received the message in error, and delete it. Thank you.

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