ML031140208

NMP1 P-T Limits Curve Amendment - Issues for Discussion

ML031140208
Person / Time
Site:	Nine Mile Point
Issue date:	04/24/2003
From:	Tam P NRC/NRR/DLPM/LPD1
To:	Mackaman C Nine Mile Point
Tam P NRR/415-1451
References
TAC MB6687, TAC MB6703
Download: ML031140208 (3)

Text

From: Peter Tam To: INTERNET:Clyde.Mackaman@nmp.cn.com; INTernet:Denise.Wolniak@nmp.cn.com; internet:steven.leonard@nmp.cn.com Date: 4/24/03 8:44AM

Subject:

NMP1 P-T Limits Curve Amendment - Issues for Discussion Clyde:

Our Reactor Systems Branch has completed its review of your 11/15/02 application for amendment. Based on this review, we plan to approve your proposed use of the curves for 23.38 (in lieu of 28) EFPYs. If you agree, we would request that you revise all the curves with a label to limit their usefulness to 23.38 EFPYs, similar to what Pilgrim and Susquehanna did for similar amendments. If you disagree with this assessment and would like to pursue 28 EFPYs, we would be glad to discuss with you the following issues in a conference call:

Benchmarking - The licensee used the computer program DORT to calculate two-dimensional (r,z) and (r, ) flux distributions, and were combined to produce a three-dimensional flux (fluence) distribution. The cross sections were obtained from BUGLE-96. The BUGLE-96 values are derived from the ENDF/B-VI file, the recommended cross section set in RG 1.190. The licensee derived the neutron sources using the power distribution and the ORIGEN 2.1 code. It is not clear to the NRC staff why this code was used since fuel composition as a function of burnup should be available from reload reports or the licensee.

Poolside Critical Assembly (PCA) Benchmark - The arrangement analyzed has a 12-cm gap between the core and the thermal shield and a 13-cm gap between the thermal shield and the vessel. However, the core-to-shroud distances in Unit 1 range from 10 to about 40 cm and the shroud-to-vessel distance is about 40 cm. The arrangement chosen is not representative of a BWR geometry. In addition, the test excluded the Rh-103 and U-238 detectors. The licensees justification was that the Rh-103 detector is not commonly used due to its short half-life; therefore, the cross sections are not well known. Based on NUREG/CR-6115 (ORNL/TM-13205), the NRC staff disagrees with the justification provided. The licensees basis for rejecting the U-238 dosimeter was due to cross section difficulties. The purpose of benchmarking is to demonstrate the ability of the methodology as an integrated tool to calculate the dosimeter activation. Based on this review, the benchmarking appears not successful because it analyzed the wrong geometry and rejected dosimeters without a reasonable justification.

NMP1 Surveillance Capsule at 210-Degree Azimuthal - The NRC staff reviewed the NMP1 210-degree surveillance capsule report (the capsule was removed at the end of cycle 12 at 16.81 EFPYs). This report does not include any information on the methodology of neutronic calculations and in addition indicates substantial discrepancies between the Cu, Fe and Ni dosimeters. The report recommends the fluence value based on the Cu results, yet Cu activation represents a small part of the spectrum compared to Fe and Ni. Fe and Ni results are also available. Because the neutronic methodology was not presented and because of very large discrepancies in the dosimeter response, the NRC staff finds that the NMP1 210-degree surveillance capsule results do not support the benchmarking of the fluence calculational methodology.

Surveillance Capsules Used in the Proposed Benchmarking - The licensee removed, tested, and analyzed a total of 5 surveillance capsules from both Nine Mile Point units. However, only

two were proposed in the submitted benchmarking analysis. As stated in RG 1.190, one of the objectives of benchmarking is to determine potential bias in the calculation of the best estimate which requires that all of the existing data be used. This licensee ignored the existence of 3 Nine Mile Point capsules and made no effort to determine the existence of a bias. The benchmarking effort appears incomplete.

This e-mail aims solely to prepare you for a conference call. It does not formally state an NRC staff position, nor does it formally request for additional information.

Peter S. Tam, Senior Project Manager Project Directorate I-1 Division of Licensing Project Management Office of Nuclear Reactor Regulation e-mail: pst@nrc.gov Tel.: 301-415-1451 CC: Brian Fuller; Christopher Sydnor; Ed Knutson; Gordon Hunegs; Lambros Lois Mail Envelope Properties (3EA7DC12.638 : 10 : 20510)

Subject:

NMP1 P-T Limits Curve Amendment - Issues for Discussion Creation Date: 4/24/03 8:44AM From: Peter Tam Created By: PST@nrc.gov Recipients Action Date & Time Clyde Transferred 04/24/03 08:44AM Mackaman (INTERNET:Clyde.Mackaman@nmp.cn.

Denise Transferred 04/24/03 08:44AM Wolniak (INTernet:Denise.Wolniak@nmp.cn.c steven Transferred 04/24/03 08:44AM leonard (internet:steven.leonard@nmp.cn.c kp1_po.KP_DO Delivered 04/24/03 08:44AM BJF CC (Brian Fuller)

ECK CC (Ed Knutson)

GKH CC (Gordon Hunegs) owf2_po.OWFN_DO Delivered 04/24/03 08:44AM LXL1 CC (Lambros Lois) Opened 04/24/03 08:52AM nrc.gov

owf2_po.OWFN_DO Delivered 04/24/03 08:44AM CRS CC (Christopher Sydnor) Opened 04/24/03 09:08AM Post Office Delivered Route Clyde INTERNET:nmp.cn.c om Denise INTernet:nmp.cn.com steven internet:nmp.cn.com kp1_po.KP_DO 04/24/03 08:44AM owf2_po.OWFN_DO 04/24/03 08:44AM owf2_po.OWFN_DO 04/24/03 08:44AM nrc.gov Files Size Date & Time MESSAGE 5588 04/24/03 08:44AM Options Auto Delete: No Expiration Date: None Notify Recipients: Yes Priority: Standard Reply Requested: No Return Notification: None Concealed

Subject:

No Security: Standard To Be Delivered: Immediate Status Tracking: Delivered & Opened