ML110810760

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Requests Licensee to Docket Certain Information Regarding the Replacement Steam Dryer, and Identifies Issues to Be Audited During April 7 - 8
ML110810760
Person / Time
Site: Monticello Xcel Energy icon.png
Issue date: 03/21/2011
From: Tam P
Plant Licensing Branch III
To: Fields J, Gunderson L
Northern States Power Co
Tam P
References
TAC MD9990
Download: ML110810760 (2)


Text

Accession No. ML110810760 From: Tam, Peter Sent: Monday, March 21, 2011 1:21 PM To: Lynne Gunderson (Lynne.Gunderson@xenuclear.com);

John.Fields@xenuclear.com Cc: Khanna, Meena; Basavaraju, Chakrapani

Subject:

Monticello EPU - Supplemental information needed for the docket, and items needed for the steam dryer audit of 4/7 - 4/8 Lynne, John:

Below please find the description of 6 types of information that the staff would like to have docketed. We suggest that the first 5 items be submitted as a supplement to the power ascension test program, and the 6th item submitted as a supplement to the steam dryer stress analysis document.

1) Instrumented replacement steam dryer (RSD) will be installed in the March 2011 (current) outage. Instrumented dryer data will be collected up to CLTP level during power ascension to CLTP from this March 2011 outage.
2) Power ascension to EPU will be in another outage in Fall 2011.
3) The two plans :Primary Plan A : Dryer instruments functioning up to CLTB; Backup or secondary Plan B: Dryer instruments not functioning & relying only on indirect MSL measurements. These were only described in the conference call.
4) Will the dryer instruments remain and functional in the Fall 2011 outage during power ascension from CLTP to EPU?
5) During power ascension from March 2011 outage to CLTP, if the dryer instruments function only up to 80% CLTP not up to 100% CLTP, then the minimum dryer stress ratio needs to be 2.0.

Is there any chance that dryer instruments placed in the March 2011 outage function in the next cycle (that is in power ascension to EPU coming out of the Fall 2011 outage)?

6) If the dryer instruments functioned up to 100% CLTP coming out of the March 2011 outage, and non-functional in the power ascension to EPU from the Fall 2011 outage, then can we allow stress ratio of 1.0 for projected EPU conditions. How are the factors to project stresses from CLTP to EPU established? Are they based on scale model tests (SMTs)? Based on the submittals thus far, are there any resonances noted between CLTP and EPU in SMTs. ?

In addition, below please find the documentation that the staff would like to audit in the 4/7 - 4/8 audit in the Westinghouse office in Rockville:

Dryer Instrumentation plan, Types of dryer instruments, locations, and basis for the selection of location.

Comparison of Nordic dryer with Monticello dryer: Geometrical dimensions, power levels, MSL size, standpipe details Nordic dryer operating experience, any fatigue cracking issues and root cause analysis.

Peter S. Tam, Senior Project Manager (for D.C. Cook and Monticello)

Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Tel. 301-415-1451