ML022100043

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Facsimile Transmission, Issues to Be Discussed in an Upcoming Conference Call
ML022100043
Person / Time
Site: Millstone Dominion icon.png
Issue date: 07/30/2002
From: Richard Ennis
NRC/NRR/DLPM/LPD1
To: Jacob Zimmerman
NRC/NRR/DLPM/LPD1
Ennis R, NRR/DLPM, 415-1420
References
TAC MB3386
Download: ML022100043 (4)


Text

July 30, 2002 MEMORANDUM TO: Jacob I. Zimmerman, Acting Chief, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation FROM: Richard B. Ennis, Sr. Project Manager, Section 2 /RA/

Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation

SUBJECT:

MILLSTONE NUCLEAR POWER STATION, UNIT NO. 2, FACSIMILE TRANSMISSION, ISSUES TO BE DISCUSSED IN AN UPCOMING CONFERENCE CALL (TAC NO. MB3386)

The attached information was transmitted by facsimile on July 25, 2002, to Mr. Ravi Joshi of Dominion Nuclear Connecticut, Inc. (the licensee). This information was transmitted to facilitate a upcoming conference call in order to clarify the licensees submittal dated November 6, 2001, as supplemented December 27, 2001, and July 15, 2002. In the submittal, the licensee requested a revision to the Millstone Nuclear Power Station, Unit No. 2 Technical Specifications associated with the spent fuel pool. This memorandum and the attachment do not convey a formal request for information or represent an NRC staff position.

Docket No. 50-336

Attachment:

Issues for Discussion in Upcoming Telephone Conference

July 30, 2002 MEMORANDUM TO: Jacob I. Zimmerman, Acting Chief, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation FROM: Richard B. Ennis, Sr. Project Manager, Section 2 /RA/

Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation

SUBJECT:

MILLSTONE NUCLEAR POWER STATION, UNIT NO. 2, FACSIMILE TRANSMISSION, ISSUES TO BE DISCUSSED IN AN UPCOMING CONFERENCE CALL (TAC NO. MB3386)

The attached information was transmitted by facsimile on July 25, 2002, to Mr. Ravi Joshi of Dominion Nuclear Connecticut, Inc. (the licensee). This information was transmitted to facilitate a upcoming conference call in order to clarify the licensees submittal dated November 6, 2001, as supplemented December 27, 2001, and July 15, 2002. In the submittal, the licensee requested a revision to the Millstone Nuclear Power Station, Unit No. 2 Technical Specifications associated with the spent fuel pool. This memorandum and the attachment do not convey a formal request for information or represent an NRC staff position.

Docket No. 50-336

Attachment:

Issues for Discussion in Upcoming Telephone Conference DISTRIBUTION PUBLIC CLauron RGiardina PDI-2 Reading ASmith TAttard JZimmerman REnnis YDiaz ACCESSION NO.: ML022100043 OFFICE PDI-2/PM NAME REnnis DATE 7/29/02 OFFICIAL RECORD COPY

ISSUES FOR DISCUSSION IN UPCOMING TELEPHONE CONFERENCE REGARDING PROPOSED AMENDMENT TO TECHNICAL SPECIFICATIONS SPENT FUEL POOL REQUIREMENTS MILLSTONE NUCLEAR POWER STATION, UNIT NO. 2 DOCKET NO 50-336 By application dated November 6, 2001, as supplemented December 27, 2001, and July 15, 2002, Dominion Nuclear Connecticut, Inc. (the licensee) submitted a proposed amendment to the Technical Specifications (TSs) associated with the spent fuel pool (SFP) for Millstone Nuclear Power Station, Unit No. 2 (MP2). Specifically, the licensee has proposed changes that would increase the nominal average fuel assembly enrichment for all regions of the SFP, the new fuel storage racks (dry), and the reactor core; allow fuel to be stored in previously blocked fuel cells; credit SFP soluble boron for reactivity control during normal conditions, and reduce the boraflex reactivity credit in Regions A and B of the SFP. The Nuclear Regulatory Commission (NRC) staff has reviewed your submittals and would like to discuss the following issues:

1. How long have RACKLIFE and destructive examinations of poison panels been conducted? At what frequency are each completed?
2. What were the initial assumptions (including the escape coefficient) in RACKLIFE used to support the selection for the first poison panel subjected to destructive examination?
3. What assumptions in RACKLIFE have been modified to ensure that the predictions reflect the changes in the SFP parameters (e.g., chemistry) and actual Boraflex degradation?
4. The SFP racks in Regions A and B contain Boraflex in a flux trap design. However, Region B has 40 storage locations which are empty and blocked for reactivity control.

How are the differences in these two regions modeled in the RACKLIFE code?

5. Are RODLETS used only in Region C of the SFP and not in Regions A and B?
6. RACKLIFE is used to predict the remaining B-10 in the panels. In addition, the Boraflex panel with the highest predicted gamma dose and predicted Boraflex degradation value is destructively tested to determine the amount of B-10 remaining in the panel.
a. How do the results of the destructive tests compare with the RACKLIFE predictions? How are these results tracked?
b. How are the results of the destructive tests factored into future RACKLIFE projections?
7. After determining the Boraflex panel to be removed and destructively tested, the licensee does not discuss its replacement.
a. Is the destructively tested Boraflex panel that is removed replaced? If so, with what material?
b. How is the removal of the Boraflex panel destructively tested factored into RACKLIFE?
c. How does the removal of this Boraflex panel affect the future placement of fuel in this storage rack?
8. With respect to your submittal dated July 15, 2002, the response to question 1d states that 4 sections of near full Boraflex width were removed for B-10 density measurements.

In addition, the submittal states: 4 sections were chosen to avoid the top and bottom 2 feet of the boraflex... Also sections of Boraflex were chosen if they showed thinned areas... testing was performed by selecting 32 random locations, and 1 specific location for a section that showed some minor thinning.

a. What were the constraints that formed the basis for the 32 random locations tested on the 4 Boraflex panels?
b. What was the tested area length for each of the 33 locations tested?
9. With respect to your submittal dated July 15, 2002, the response to question 2 states:

Cell blockers serve no function other than to provide a visible cue to the fuel handler that the fuel should not be inserted in that location.

a. What is the purpose of the cell blocker if fuel will be stored beneath it?
b. Will all fuel storage cells be blocked if fuel is stored beneath them?
10. Placing spent fuel underneath the cell blockers is something that hasn't been done before at MP2. The cell blockers weight about 20 pounds and are made of stainless steel. Has the licensee evaluated the possibility and subsequent consequences of cell blockers falling on the spent fuel?
11. The staff would also like to discuss the following:

a) criticality analysis for the new fuel storage vault and transfer machine as described on pages 11 and 12 of Attachment 1 in your submittal dated November 6, 2001; and b) responses to questions 6 and 8 in your submittal dated July 15, 2002.