ML20196K794
| ML20196K794 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 03/25/1999 |
| From: | Jain S DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20196K797 | List: |
| References | |
| L-99-029, L-99-29, NUDOCS 9904060297 | |
| Download: ML20196K794 (4) | |
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o Beav Valley Power Station Shippingport. PA 15077M4 Ser or V President Fan / 643 8 9 U*Nei'$viwon L-99-029 March 25, 1999
- U. S. Nuclear Regulatery Commission Attentio1. Document Control Desk
[lVashingon, DC 20555-0001
Subject:
Beaver Velley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 Cycle 8 Reload and Core Operating Limits Report Beaver Valley Power Station, Unit No. 2 completed the seventh cycle of operation on February 26, Im>9, with a burnup of 16952 MWD /MTU. This letter describes the Cycle 8 reload design, documents our review in accordance with 10 CFR 50.59 including our determination that no unreviewed safety question is involved, and provides a copy of the Core Operating Limits Report (COLR) in accordance with Technical Specification 6.9.1.12.
The new ure configuration is arrang:d in a low low leakage loading pattern and involves replacing 1 Region 5B, 28 Region 7A and 7B, and 36 Region 8A fuel i
assemblies with 44 fresh Region 10A ZIRLO fuel assemblies enriched to 3.8 weight percent and 20 fresh Region 10B ZIRLO fuel assemblies enriched to 4.2 weight percent. The center fuel assembly from Region 5B was replaced with a fuel assembly from Region 8B.
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/i The mechanical design of the new Region 10A and 10B fuel assemblies is similar to the previous reload fuel except for the following features:
1.
The natural uranium axial blankets for Regions 10A and 10B will have annular pellets in the integral fuel bumable absorber (IF 9A) rods only. Annular pellets in the axial blankets provide additional void volume to provide increased rod internal pressure margin.
2 2.
The Region 10 fuel assemblics contain the cast composite bottom nozzle. This change represents a manufacturing process change. The composite bottom nozzle DEllVERING 9904060297 990325 ~
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n Beaver Valley Power Station, Unit No. 2 Cycle 8 Reload and Core Operating Limits Report Page 2 is a two-piece design incorporating a highly machined stainless steel adapter plate welded to a low cobalt investment casting. This casting replaces the previous eight-piece weldment' comprised of four cast legs and four rolled skirt plates. Also a pitch change was introduced to provide for cold alignment of the thimble tube and thimble screw hole to improve part fit-up during nozzle removal / replacement. The composite bottom nozzle design is functionally interchangeable with the previous design. All bottom nozzle design criteria continue to be met.
The fuel assemblies resident in the core contain debrir filter bottom nozzles manufactured by one of Westinghouse's qualified vendors, Jedinstvo.
Recently performed flow testing has indicated a variance in pressure drop across the nozzle between those made by Westinghouse and those made by Jedinstvo due to minor mariufacturing differences. However, evaluations have shown that flow effects from these differences cre quickly recovered, and there is no significant effect an the overall perfonnance of the assembly with respect to acceptance limits. The entire Cycle 8 core consists of Jedinstvo bottom nozzles.
Four Region 8A and eight Region 8B fuel assemblies will utilize damper rods (vibration suppression assemblies).
The purpose of the damper rod assembly is to provide additional assurence that any flow induced vibration of the VANTAGE 5H fuel assemblics be maintained at acceptable levels when the fuel assemblies are located at the core perig,hery. Each damper assembly consists of twenty-four solid Zircaloy-4 damper rodlets attached to a holddown assembly. The damper rods are inserted into the fuel assembly guide thimbles and the damping devices are designed to be used in fuel assemblies placed in the baffle region of the core. The pertinent thermal-hydraulic and boiling criteria were evaluated and found to be acceptable. The use of vibration damping assemblies does not compromise the performance of any safety-related system nor result in any adverse effect on any analysis, since this change does not affect the normal plant operating parameters, the safeguards systems actuation, or the assumptions and input parameters used in these analyses.
These modifications meet fuel assembly and fuel rod desi n criteria and will not 6
adversely affect the core safety considerations. Fuel rod design evaluations for the new fuel were performed using NRC approved methodology to demonstrate that the fuel rod design bases are satisfied.
Duquesne Light Company has performed a review of this reload core design including a c
i review of the core characteristics to determine those parameters affecting the postulated accidents described in the Updated Final Safety Analysis Report (UFSAR).
The consequences of those accidents described in the UFSAR which could potentially be affected by the reload core characteristics were evaluated in accordance with the NRC L
Beaver Valley Pcwer Station, Unit No. 2 Cycle 8 Reload and Core Operating Limits Report
. Page 3 approved methodology. described in WCAP-9272-P-A " Westinghouse Reload Safety Evaluation Methodology." The effect of the reload design was either accommodated within the conservatisms of the assumptions used in the current analysis design basis, or it was demonstrated through evaluatinn that the reload parameters would not change the conclusions in the UFSAR.
No technical specification changes are required as a result of this reload design.
The NRC approved dropped rod methodolcgy (WCAP-10298-A [non-proprietary), June 1983) was used for this design evaluation and confirmed that the peaking factors did not.
- exceed the safety analyses limits.
i The reload core design will be verified by performing the standard Westinghouse reload core physics startup tests. The results of the following startup tests will be submitted in accordance with Technical Specification 6.9.1.3:
1.
Control rod drive tests and rod drop time measurements.
2.
Critical boron concentration measurements.
3.
Control rod bank worth measurements.
4.
Moderator temperature coefficient measurements.
5.
Startup power distribution measurements using the incore flux mapping system.
The COLR (enclosed) has been updated for this c,-
by changing the figure numbers referenced on pages 4.1-1 and 4.1-2 and including new radial peaking factor at rated thermal power [Fxy (RTP)] limits for unrodded core planes on page 4.1-2. Figure 4 has been replaced with a new figure to address these new limits.
The Beaver Valley Onsite Safety Committee and the Duquesne Light Company Nuclear Safety Review Board have reviewed the Reload Safety EvalusLon and Core Operating Limits Report and detennined that this reload de.cign will not adversely affect the safety of the plant and does not involve an unreviewed safety question.
Sincerely, L _>
Sushil C. Jain l
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B: aver Valley Power Station, Unit No. 2 l
Cycle 8 Reload and Core Operating Limits Report i
Page 4 l
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Mr. D. S. Collins, Project Manager Mr. D. M. Kern, Sr. Resident Inspector Mr. H. I Miller, NRC Region I Administrator l
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