ML20080Q453

Nonproprietary Suppl 1 to Hb Robinson Unit 2,Cycle 10 Sar

ML20080Q453
Person / Time
Site:	Robinson
Issue date:	09/14/1983
From:	Adams F, Lambert W, Stone I SIEMENS POWER CORP. (FORMERLY SIEMENS NUCLEAR POWER
To:
Shared Package
ML14184A504	List: ML20080Q453
References
REF-GTECI-A-49, REF-GTECI-RV, TASK-A-49, TASK-OR XN-NF-83-72-S01, XN-NF-83-72-S1, NUDOCS 8310120422
Download: ML20080Q453 (28)

Text

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XN NF 83-72 SUPPLEMENT 1 E ISSUE DATE

9/14/83 L

H.B. ROBINSON UNIT 2, CYCLE 10 r

l SAFETY ANALYSIS REPORT i

SEPTEMBER 1983

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ERON NUCLEAR COMPANY,Inc.

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1 XN-NF-83-72 Supplement 1

~ Issue Date: 9/14/83 r

L H.B. ROBINSON UNIT 2, CYCLE 10

( SAFETY ANALYSIS REPORT ps I nf 3 Written by: 8:49/#5

[ I.'Z.' Stone / F. f. Adams / W. L. Lambert t Engineers Reviewed by: / // PR _

l'J. PGdr83, F.B.Skogen,Managd]

PWR Neutronics Prepared by: h .f .. x f/] %.3 H. E. Williamson, Manager

{ Neutronics and Fuel Management

( Prepared by: IR. B.[.Stout, eb Manager

9. n -n Licensing and Safety Engineering P

Approvedby:h /JMf/ M 9ds/6G " '

1l/J/Bifsse'lman, Manager

( FW Design Approved by:

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/

G. A. Sofer,' Manager Fuel Engineering and' Technical Services Concurred by: , da 7//J)P:7 f J. gMorgan, Manage'r '

Proposals and Customer Services Engineering csk

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l ERON NUCLEAR COMPANY,Inc.

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O IMPORTANT NOTICE REGARDING CONTENTS AND USE OF THIS DOCUMENT )

PLEASE READ CAREFULLY This technical report was derived through research and development programs sponsored by Exxon Nuclea'r Company, Inc. Ii. is being submitted by Exxon Nuclear to the USNRC as part of a technical contribution to facilitate safety analyses by licensees of the USNRC which utilize Exxon Nuclear-fabricated reload fuel or other technical services provided by Exxon Nuclear for light water power reactors and it is true and correct to the best of Exxon Nuclear's knowledge, information, and belief. The

.information contained herein may be used by the USNRC in its review of this report, and by licensees or applicants before the USNRC which are customers of Exxon Nuclear in their demonstration of compliance with the USNRC's regulations.

• Without derogating from the foregoing, neither Exxon Nuclear nor any person acting on its behalf-A. Makes any warranty, express or implied, with respect )

to the accuracy, completeness, or usefulness of the

'information contained in this document, or that the i use of any information, apparatus, method, or process i disclosed in this document will not infringe privately l

owned rights; or 1

B. Assumes any liabilities with rer.pect to t he u .e of , or i

for damages resulting from the use of, any information apparatus, method, or process disclosed in this document. ,

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k i XN-NF-83-72 Supplement 1 L

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TABLE OF CONTENTS Section Page 1.0 1N1a0DUCTIOu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 . 0 S UMMAR Y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3.0 OPERATING HISTORY OF THE REFERENCE CYCLE . . . . . . . . . . . . . . . 4

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4.0 GENERAL DESCRIPTION. . . . . . . . . . . . . . . . . . . . . . . . . . 5 k- 5.0 MECHANICAL DESIGN. . . . . . . . . . . . . . . . . . . . . . . . . . 11 6.0 NUCLEAR CORE DES IGN. . . . . . . . . . . . . . . . . . . . . . . . . 12 l 6.1 PHYSICS CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . 13 6.1.1 Power Distribution Considerations. . . . . . . . . . . . 14

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6.1.2 Control Rod Reactivity Requirements. . . . . . . . . . . 15

( 6.1.3 Moderator Temperature Coefficient Considerations . . . . 15 6.2 POWER DISTRIBUTION CONTROL PROCEDURES . . . . . . . . . . . . . 15 6.3 ANALYTICAL METHODOLOGY. . . . . . . . . . . . . . . . . . . . . 15 7.0 THERMAL-HYDRAULIC DESIGN . . . . . . . . . . . . . . . . . . . . . . 19

- 8.0 ACCIDENT AND TRANSIENT ANALYSIS. . . . . . . . . . . . . . . . . . . 20 8.1 PLANT TRANSIENT AND ECCS ANALYSES FOR H.B. ROBINSON . . . . . . 20

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8.2 R00 EJECTION ANALYSIS FOR H.B. ROBIRSON CYCLE 10. . . . . . . . 20 8.3 LOCA ANALYSES FOR H.B. ROBINSON . . . . . . . . . . . . . . . . 20 8.4 END-0F-LIFE FUEL R00 INTERNAL PRESSURE. . . . . . . . . . . . . 21

9.0 REFERENCES

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I LIST OF TABLES Table Page 4.1 H.B. Robinson Unit 2, Cycle 10, Fuel Assembly Design Parameters. . . . 8 i LIST OF FIGURES

( Figure Page 4.1 H.B. Robinson Unit 2 Cycle 10, Reference Loading Pattern for an E0C9 Exposure of 10,100 MWD /MT. . . . . . . . . . . . . . . . . . . 9

'4.2 H.B. Robinson Unit 2, 80C10 and E0C10, Quarter Core Exposure Distribution and Region ID for E0C9=10,100 MWD /MT. . . . . . . . . . 10 6.1 H.B. Robinson Unit 2, Cycle 10 Relative Assembly Power Distribution Comparison Between 36" and 42" PLSA Assembly Designs

at 100 MWD /MT for 1,840 MWt, 3-D XTGPWR Analysis . . . . . . . . . . 16 6.2 H.B. Robinson Unit 2, Cycle 10 Relative Assembly Power Distribution Comparison Between 36" and 42" PLSA Assembly Designs

{ at 5,000 MWD /MT for 1,840 MWt, 3-D XTGPWR Analysis . . . . . . . . . 17

( 6.3 H.B. Robinson Unit 2, Cycle 10 Relative Assembly Power i Distribution Comparison Between 36" and 42" PLSA Assembly Designs at 12,390 MWD /MT, 0 ppm, for 1,840 MWt, 3-D XTGPWR Analysis. . . . . 18 l

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s 1 XN-NF-83-72

' Supplement 1 H.B. ROBINSON UNIT 2, CYCLE 10 SAFETY ANALYSIS REPORT SUPPLEMENT 1

1.0 INTRODUCTION

The results of the safety analysis for Cycle 10 of the H.B. Robinson Unit 2 nuclear plant were presented in XN-NF-83-72 II) . This supplement to the preceding Safety Analysis document addresses the impacts resulting from a slight modification to the design of the Part Length Shield Assemblies (PLSAs). The revised PLSA design replaces forty-two (42) inches of the fuel pellet column with stainless steel rather than thirty-six (36) inches as reported in the original Safety Analysis. The topics addressed in this supplement include effects on power distributions, control rod reactivity requirements, and temperature coefficients.

The Cycle 10 design reflects the loading of sixty-five (65) fresh Exxon Nuclear Company (ENC) supplied fuel assemblies based on an E0C9 exposure of 10,100 MWD /MT. The core design is the first reload of axially blanketed fuel for H.B. Robinson Unit 2. The design includes twelve (12) special fuel assemblies which will reduce the fast neutron fluence reaching the pressure vessel wall denoted as PLSAs. This core design is the second reload fuel design for H.B. Robinson which contains 4 w/o gadolinia. Thirty-six (36) of the forty-four (44) fresh Region 13 (XN-7) fuel assemblies will contain gadolinia-bearing fuel pins. Also, one (1) of the nine (9) Region 12 (XN-6) assemblies will contain gadolinia.

N 2 XN-NF-83-72 Supplement 1 J .

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2.0

SUMMARY

f The H.B. Robinson Unit 2 nuclear plant will continue to operate in Cycle 10 at reduced core average temperature beginning late in December

'1983. The characteristics of the fuel and of the reload core, including considerations resulting from the utilization of an additional six inches

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of stainless steel in the PLSA, result in conformance with required shutdown margins and thermal limits. This document provides the supple-mentary neutronic analysis for the plant during Cycle 10 operation reflecting revision to the PLSA fuel assembly design.

The Cycle 10 fuel design differs from the Cycle 9 design in

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enrichment, utilization of axially blanketed fuel, and the inclusion of Part Length Shield Assemblies (PLSAs).

The ENC fuel design is presented in Reference 2. The thermal-hydraulic analyses are provided in Reference 11. Plant Transient ,

Analyses (6) and ECCS Analyses (6) have been re-evaluated at the revised operating conditions for up to 30% average steam generator tube plugging.

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The re-evaluated analyses are applicable to the Cycle 10 revised operating conditions, as is the Control Rod Ejection Analysis (7). The results and validity of these analyses for Cycle 10 remain applicable with the modified PLSA design.

The neutronics characteristics of Cycle 10 are insignificantly impacted by the revision in the PLSA design. The total core fuel mass is reduced by 0.32% (216 Kgs of U), the core excess reactivity is reduced by

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3 XN-NF-83-72 Supplement 1

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about 10 pcm, the power distribution changes by about 1% (except the PLSAs), and the total control rod worth differs by less than 10 pcm.

The Cycle 10 safety evaluations based on a shielding material length of thirty-six (36) inches remain applicable for shielding material length

'of forty-two (42) inches.

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4 XN-NF-83-72 Supplement 1 3.0 OPERATING HISTORY OF THE REFERENCE CYCLE

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A detailed ' description of the operating history of the Reference Cycle 9 can be found in Reference 1.

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6 5 XN-NF-83-72

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4.0 GENERAL DESCRIPTION The H.B. Robinson reactor consists of 157 assemblies, each having a 15x15 fuel rod array. Each assembly contains 204 fuel rods, twenty RCC

( guide tubes, and one instrumentation tube. The RCC guide tubes and the instrumentation tube are made of zircaloy. Each ENC assembly contains neven zircaloy spacers with Inconel springs; six of the spacers are located within the active fuel region. The fuel rods consist of slightly

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enriched U02 pellets inserted into zircaloy tubes. In the Part length

( Shield Assemblies (PLSAs), the bottom 42 inches of fuel is replaced by 304 stainless steel.

The projected Cycle 10 loading pat. tern is shown in Figure 4.1 and remains unchanged from Reference 1. BOC10 and E0C10 exposures, based on an E0C9 exposure of 10,100 MWD /MT, along with Region ID's are shown in Figure 4.2. The initial enrichments of the various regions are listed in

, Table 4.1. Also included in Table 4.1 are the peak assembly exposures by region and fuel type.

The Cycle 10 design reflects the loading of sixty-five (65) fresh ENC supplied fuel assemblies. This core design contains the first reload of axially blanketed fuel in H.B. Robinson Unit 2, XN-7, and twelve (12) special fuel assemblies which will reduce the fast neutron fluence reaching the pressure vessel wall. With the introduction of the additional six inches of stainless steel into the shielding assemblies, the fast flux reaching the pressure vessel wall will be reduced even e+

6 XN-NF-83-72 Supplement 1 further. These fluence reducing assemblies are denoted as Part length Shielding Assemblies (PLSAs). This core design is the second H.B.

Robinson reload fuel design containing 4 w/o gadolinia. Thirty-six (36) of the forty-four (44) fresh Region 13 (XN-7) fuel assemblies and one of the nine (9) Region 12 (XN-6) assemblies contain gadolinia-bearing pins.

The design for Batch XN-7, Region 13, includes natural uranium axial l

blankets in the top and bottom six (6) inches of the active fuel region. .]

The batch average enrichment for the blanketed assemblies is 3.08 w/o U-235. This average enrichment is achieved by using a central axial zone enrichment of 3.34 w/o in fuel pins which contain no gadolinia and 2.37 w/o in those which do. In twelve (12) Region 13 assemblies, twelve (12) fuel pins will contain 4 w/o gadolinia. In another twenty-four (24) assemblies, eight~(8) pins of 4 w/o gadolinia per assembly will be utilized. In the remaining eight (8) Region 13 fuel assemblies no gadolinia pins will be used. In addition to the forty-four (44) blanketed assemblies loaded, nine (9) fresh XN-6 assemblies containing 2.85 w/o f

enrichment will be used in Cycle 10. One (1) XN-6 assembly will contain twelve (12) pins of 4 w/o gadolinia and will be loaded in the center core location. Thus, the total number of gadolinia pins required for Cycle 10 is 348.

The enrichment of the gadolinia-bearing rods is selected to assure that the temperature in those rods never reaches the temperature of the limiting fuel pins. An enrichment of 2.20 w/o U-235 in XN-6 gadolinia-bearing fuel and 2.37 w/o U-235 in XN-7 gadolinia-bearing fuel provides ample margin.

5 7 XN-NF-83-72 l Supplement 1 The twelve (12) PLSAs are being loaded on the core periphery (the

" flats") as part of the program to reduce the fast neutron fluence to the

. pressure: vessel wall. In the active fuel region, the top six (6) inches contain natural uranium, the next ninety-six (96) inches contain uranium enriched to 1.24 w/o, and the bottom forty-two (42) inches contain 304 stainless steel.

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t Table 4.1 H.B. Robinson Unit 2, Cycle 10 Fuel Assembly Design Parameters .

I Region PLSA 11 12 12 12* 12** 12*** 12*** 13 13** 13***

XN Number XN-7 PLSA 5 6 6 6 6 6 6 7 7 7 Number of Assemblies 12 48 16 8 12 8 8 1 8 24 12 ,

Pellet Density, %TD 94.0 94.0 94.0 94.0 94.0 94.0 94.0 94.0 94.0 94.0' 94.0 )

Pellet to Clad Diametral Gap, Mil 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 Initial Enrichment (w/o U-235)

Upper 6 inches U02 .71 2.90 2.85 2.85 2.85 2.85 2.85 2.85 .71 .71 .71

'2.20 UO2-Gd 023 2.20 2.20 2.20 ------ ------ ------

4 Central 132 inches UO2 1.24+ 2.90 2.85 2.85 2.85 2.85 2.85 2.85 3.34 3.34 3.34 UO2-Gd 023 2.20 2.20 2.20 2.20 ------

2.37 2.37 ,

lower 6 inches UO2 304SSTL 2.90 2.85 2.85 2.85 2.85 2.85 2.85 .71 .71 .71 UO2-Gd 023 ------ ------ ------ ------

2.20 2.20 2.20 2.20 ------ ------ ------

Average 0.86 2.90 2.85 2.85 2.84 2.82 2.81 2.81 3.12 3.09 3.02 Initial Gd23 0 , w/o ------ ------ ------ ------ 4 4 4 4 ------ 4 4 Batch Average Burnup at 80C10, MWD /MT 0 20,939 7,920 0 10,304 10,406 11,968 0 0 0 0 Peak Assembly Burnup at E0C10, MWD /MT 5,775 35,640 22,488 11,861 25,399 24,086 26,492 16.127 9,039 13,854 15,949 ,U E M.

• Fuel with 4 pins of 4 w/o gadolinia per assembly g& i

• • Fuel with 8 pins of 4 w/o 9adolinea per assembly 3 5,d

• • • Fuel with 12 pins of 4 w/o gadolinia per assembly "M

+ Lower 36 inches of central 132 inches contains 304SSTL PLSA Part Length Shield Assembly

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9 XN-NF-83-72 Supplement 1

, R P N M L K J H G F E D C B A PLSA PLSA PLSA 1 N45 N49 N53 13 12 ** ** ** 12 13 2 N01 M18 N21 N25 N29 M19 N02 K3 ** L3 D13 H7 M13 ** F3

[ E3 3

L01 N41 L10 M07 LO2 M08 L13 N42 LO3 N6 ** E14 J4 F14 H14 K14 G4 L14 ** C6

[ 4 L L22 N37 M03 LO4 M43 M49 M44 LO9 M04 N38 L25

( 13 ** Bil K7 *** L4 ***- E4 *** F7 P11 ** 13 5 t N05 N33 MIS L20 N09 LO6 N17 LO7 N10 L21 M16 N34 N06 12 N5 M7 *** G10 G14 K5 J14 J10 *** D7 C5 12 6

( M22 L14 L16 N13 L48 M36 L42 M35 L45 N14 L19 L15 M23 PLSA ** C12 B10 M5 B9 012 H11 M12 P9 D5 P10 N12 ** PLSA 7 N56 N32 Mll M52 L23 M40 M32 M28 M31 M38 L24 M45 M12 N22 N46

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PLSA ** J8 88 *** L6 E8 *** L8 E10 *** P8 G8 ** PLSA 8 N52 N28 L26 M48 N20 L36 M27 MS3 M26 L17 N18 M50 L27 N26 N50 PLSA .** C4 86 M11 87 D4 H5 M4 P7 D11 P6 N4 ** PLSA 9 N48 N24 M10 M51 L29 M39 M30 M17 M29 M37 L30 M46 M09 N30 N54 12 N11 M9 *** G6 G2 Fil J2 J6 *** 09 C11 12 10 M25 L38 L34 N16 LO8 M34 L11 M33 LOS N15 L37 L39 M24 i

f 13 B5 K9 L12 E12 F9 P5 13 11 N08 N36 M14 L32 N12 L46 N19 L47 N11 L33 M13 N35 N07 N10 ** E2 J12 F2 G12 L2 ** C10 H2 K2' 12 L28 N40 M02 L44 M42 M47 M41 L49 M01 N39 L31

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K13 ** L13 D3 H9 M3 E13 ** F13 l 13

[ L50 N44 L40 M06 L51 MOS L43 N43 L52 13 12 ** ** ** 12 13 14 N04 M21 N31 N27 N23 M20 NO3 PLSA PLSA PLSA 15 N55 N51 N47

• • 8 Pins of 4 w/o Gadolinia per Assembly in Region 13 Fuel

• • • 12 Pins of 4 w/o Gado; inia per Assembly in Region 13 Fuel l

l PLSA Part Length Shield Assembly

+ 12 Pins of 4 w/o Gadolinia per Assembly in Region 12 Fuel JNumberofgadoliniapinsperassembly (Cycle 8 core location or region number

+ Assembly Fabrication ID Figure 4.1 HB Robinson Unit 2 Cycle 10 Reference Loading Pattern for an EOC9 Exposure of 10,100 MWD /MT l .

10 XN-NF-83-72 Supplement 1 H G F E D C B A

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0 12,491 23,490 0 11,058 20,511 0 0 8 16,127 26,492 '35,365 15,945 25,399 33,009 13,848 5,775 )

12*** 12 11 13*** 12 11 13** PLSA 12,459 11,462 10,435 23,479 9,960 8,340 0 0 ]

9 26,467 25,456 24,086 35,640 24,084 22,488 13,422 4,865 12 12 12 11 12 12 13** PLSA

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23,486 10,378 22,037 0 19,822 18,976 0 10 35,364 24,031 34,365 15,851 32,268 30,922 11,858 11 12 11 13*** 11 11 12 0 23,477 0 22,059 7,505 0 0 11 15,949 35,634 15,828 34,678 21,831 13,658 9,038 13*** 11 13*** 11 12 13** 13 10,976 9,935 19,781 7,497 0 19,352 12 25,343 24,069 32,229 21,815 13,541 25,723 12 12 11 12 13** 11 20,494 8,339 18,959 0 19,330 33,004 22,494 30,910 13,658 25,703 11 12 11 13** 11 0 0 0 0 80C10 Exposure MWD /MT I 13,854 13,427 11,861 9,039 EOC10 Exposure MWD /MT 13** 13** 12 13 0 0 15 5,777 4,867 PLSA PLSA

• • Fuel with 8 pins of 4 w/o gadolinia per assembly

• • • Fuel with 12 pins of 4 w/o gadolinia per assembly PLSA Part Length Shield Assembly (with 42 inches of 304 Stainless Steel)

Figure 4.2 H.B. Robinson Unit 2, B0C10 and E0C10, Quarter Core Exposure Distribution and Region ID for E0C9=10,100 MWD /MT

1 11 XN-NF-83-72 Supplement 1 f

L 5.0 MECHANICAL DESIGN

(- A description of the basic Exxon Nuclear supplied fuel design and design methods is contained in Reference 2. In addition, a mechanical design analysis of the Reload XN-7 fuel and the resident XN-5 and XN-6 fuel with current methodology is contained in Reference 9.

f A supplemental mechanical design analysis for the PLSA's will be provided in Reference 10 and will reflect a shield length of forty-two (42) inches.

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s 12 XN-NF-83-72 Supplement 1 f

L 6.0 NUCLEAR CORE DESIGN The H.B. Robinson Unit 2, Cycle 10, Region 13 reload design has been developed in accordance with the following requirements:

1. The Cycle 10 reload shall contain sixty-five (65) new fuel assemblies; nine (9) XN-6 assemblies, forty-four (44) XN-7

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assemblies, and twelve (12) Part length Shield Assemblies.

f 2. The length of Cycle 10 shall be maximized.

3. The rated power for Cycle 10 shall be 1,955 MWt.

( 4. The length of the Cycle 10 exposure is determined on the basis of an assumed E0C9 equal to 10,100 MWD /MT.

5. The Cycle 10 reload shall be designed for the anticipated base loaded operation. The design shouid accommodate a load fol-lowing operation between 50% and 100% rated power while not precluding the current ramp and step change bases as set forth in

/ the FSAR.

6. In accordance with plant Technical Specifications, the control rod worth requirements shall be met.

7. The loading pattern shall be designed to produce a desirable T

power distribution. The design F g, including uncertainties, shall be less than 2.32 at 1,955. MWt. The integrated peak to average pin power, FAH, including measurement uncertainties, shall be less than 1.60 at 1,955 MWt.

f 13 XN-NF-83-72 Supplement 1 )

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8. The. loading pattern shall be designed to accommodate forty-two

~ (42). inches of stainless steel shielding material in the PLSA assemblies.

The neutronic design methods utilized in this analysis are consistent (

with those described in Reference 1.

6.1 PHYSICS CHARACTERISTICS.

The neutronic characteristics of the Cycle 10 core are given in )

Table 2.1 of Reference 1, and the comparisons to the Cycle 9 data still remain valid with the addition of an extra six (6) inches of stainless l-steel shield material in the PLSA. The reactivity coefficients used in

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the Cycle 10 safet) analys.is remain appl _icable in light of the PLSA design change. The < Safety Analyses as presented in Reference 1 are also applicable _to-those core physics characteristics expected for operation over Cycle 9 endurance limits of +500 MWD /MT about a nominal value for Cycle 9 of 10,100 MWO/MT. _

Increasing the shielding material in the PLSAs has a negligible

. effect on the boron letdown curve as presented in Reference 1. The Cycle 10 length -is projected to be 12,390+300 MWD /MT (446+11 EFPDs) with no boron at E0C. The actual XTGPWR depletion indicated a reduction in the HFP

, critical boron on the order of 1 ppm, however, the 2 EFPDs lost from that 4

given in Reference 1 is due to the total core fuel-inventory being reduced by the replacement of the six (6) inches of fuel by six (6) inches of stainless steel.

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6.1.1 Power Distribution Considerations Representative power distribution comparisons have been

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made between the core design using the thirty-six (36) inches of stainless f steel with the core design utilizing the forty-two (42) inches of stainless steel. The power distribution comparison for B0C, MOC and E0C are shown in Figures 6.1, 6.2, and 6.3, respectively. The power distributions were obtained from a three-dimensional XTG code incorp-orating twenty-four (24) axial nodes with moderator density and Doppler feedback effects included. With utilization of the extended shielding

( N region the expected peak F 3H is projected to increase by 0.5% from the 1.52

( given in Reference 1. The peak is still anticipated to occur at a Cycle N

10 exposure of 5,000 MWD /MT. Similarly, the F g is projected to increase by about 0.5% above the 1.78 as given in Reference 1. This Fq is expected to occur at BOC10,100 MWD /MT. The maximum planar peak to average power, Fx ,, evaluated in the central eight feet of the c;re is expected to increase by less than 1% above the Reference 1 value of 1.61. This F xy peak is also. expected to occur at about 7,000 MWD /MT into the cycle. The N N peak pin to average power, FAH, and the total peak, F g, are therefore expected to remain below the Technical Specification limits (with uncertainties backed out) of 1.54 and 2.06, respectively. An F above i

1.435 implies that the Axial Power Distribution Monitoring System (APDMS) will be required.

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15 XN-NF-83-72 Supplement 1 f 6.1.2 Control Rod Reactivity Requirements The control rod reactivity requirements were evaluated at BOC and E0C and negligible changes in the total worth occurred. The 80C total rod worth decreased by a -3.0 pcm, whereas, the E0C total rod worth '

increased by +4.0 pcm. Therefore, the shutdown requirements as presented in Reference 1 remain applicable.

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! 6.1.3 Moderator Temperature Coefficient Considerations j

! The moderator temperature coefficient remains unchanged ,

! from the calculated Reference value for both HFP and HZP conditions.

6.2 POWER DISTRIBUTION CONTROL PROCEDURES The applicability of the Power Distribution Control Procedure (PDC) remains for this core fuel design modification. ,

6.3 ANALYTICAL METHODOLOGY The calculational methods used in this supplement analysis are identical to that presented in the Reference 1 methodology, i

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16 XN-NF-83-72 Supplement 1 Y

G F E D C 8 A H

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1.284 1.269 1.036 1.239 1.270 1.073 1.022 .2 83 8 1.278 1.2 64 1.032 1.236 1.268 1.075 1.031 .275

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+.5 +.4 +.4 +.2 +.2 .2 .9 -5.5 PLSA 1.270 1.285 1.210 1.014 1.249 1.243 1 019 .217

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9 1.265 1.279 1.205 1.011 1.247 1.245 1.026 .229

+.4 +.5 +.4 +.3 +.2 .2 .7 -5.2 PLSA

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1.037 1.210 1.022 1.184 1.048 1.015 1.009 10 1.206 1.018 1.180 1.046 1.014 1.011 1.033

+.4 +.3 +.4 +.3 +.2 +.1 .2

• • • *** ** +

1.240 1.014 1.182 1.020 1.202 1.062 .753

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11 1.237 1.011 1.178 1.017 1.199 1.061 .753

+.2 +.3 +.3 +.3 +.3 +.1 0

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1.273 1.251 1.048 1.202 1.027 .475 12 1.272 1.249 1.046 1.199 1.024 .474

{ +.2 +.3 +.3 +.2

+.1 +.2 1.075 1.245 1.016 1363 .476 PLSA with 42" SS304 13 1.078 1.246 1.016 1.061 .474 PLSA with 36" SS304

.3 .1 0 +.2 +.4  % Difference

• • ** +

1.023 1.020 1.010 .753 14 Relative Assembly Power 1.033 1.028 1.012 .753

-1.0 .8 .2 0 36" SS304 42" SS304

.260 .217 Peak Assembly = 1.28 (G9) 1.29 (G9)

.275 .230 1.55 (G9)

Peak F = 1.54 (G9)

-5.5 PLSA -5.7 PLSA U N

Peak F g = 1.78 (H11) 1.79 (H11)

N Peak F3H = 1.43 (H8) 1.44 (H8)

• • 8 gadolinia pins per assembly

• • • 12 gadolinia pins per assembly

+ Region 12 fuel PLSA Part Length Shield Assembly Figure 6.1 H.B. Robinsot, Unit 2, Cycle 10 Relative Assembly Power Distribution Comparison Between 36" and 42" PLSA Assembly Designs at 100 MWD /MT for 1,840 MWt, 3-D XTGPWR Analysis I. . .

17 XN-NF-83-72 Supplement 1 H. G F E D C 8 A

• • • + *** **

1.374 1.147 .973 1.341 1.176 1.024 1.147 .326 8

1.370 -1.140 .968 1.338 1.172 1.025 1.162 .344

+.3 +.6 +.5 +.2 +.3 .1 -1.3 -5.2 PISA 1.147 1.141 1.118 1.005 1.158 1.161 1.109 .266 9

1.141 1.134 1.112 1.001 1.154 1.160 1.120 .280

+.5 +.6 +.5 +.4 +.3 +.1 -1.0 -5.0 PLSA

• • • +

.973 1.118 1.020 1.338 1.027 .981 .976 10 .968 1.112 1.016 1.337 1.024 .979 .977

+.5 +.5 +.4 +.1 +.3 +.2 .1 1.341 1.004 .1.336 1.050 1.187 1.131 .744 11 1.339 1.001 1.334 1.047 1.183 1.130 .743

+.1 +.3 +.1 +.3 +.3 +.1 +.1 1.178 1.159 1.027 1.186 1.123 .622 12 1.174 1.155 1.024 1.182 1.121 .521

+.3 +.3 +.3 +.3 +.2 +.2 1.025 1.161 .981 1.131 .522 PLSA with 42" SS304 13 1.026 1.160 .979 1.130 .521 PLSA with 36" S5304

.1 +.1 +.2 +.1 +.2  % Difference ,

• • ** +

1.148 1.110 .976 .744 14 1.162 1.120 .977 .743 Relative Assembly Power

-1.2 .9 .1 +.1 , ,

.327 .266 Peak Assembly = 1.34 (Hil) 1.34 (H11)

.344 .280

= 1.61 (Hil) 1.62 (H8)

-4.9 PLSA -5.0 PLSA PeakF(Y Peak F = 1.78 (H14) 1.77 (H14) q Peak F3g = 1.52 (H8) 1.52 (H8) .

• • 8 gadolinia pins per assembly

• • • 12 gadolinia pins per assembly

+ Region 12 fuel PLSA Part length Shield Assembly Figure 6.2 H.B. Robinson Unit 2, Cycle 10 Relative Assembly Power Distribution Comparison Between the 36" and 42" PLSA Assembly Designs at 5,000 MWD /MT .

for 1,840 MWt, 3-D XTGPWR Analysis

s 18 XN-NF-83-72 Supplement 1 F E D C B A H G

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• • • +

1.312 1.110 .967 1.320 1.139 1.020 1.219 .393 8 1.108 .966 1.317 1.136 1.018 1.222 .417 1.310

( +.2 +.1 +.2 +.3 +.2 .2 -5.8 PLSA

+.2 1.111 1.107 1.096 .999 1.123 1.127 1.168 .320

{ 9 .340 1.109 1.105 1.094 .997 1.120 1.125 1.169

+.2 +.2 +.2 +.2 +.3 +.2 .1 -5.9 PLSA

• • • +

.968 1.096 1.013 1.325 1.011 .977 .967 10 .966 1.094 1.012 1.322 1.009 .975 .966

+.2 +.2 +.1 +.2 +.2 +.2 +.1

1.320 .999 1.324 1.034 1.145 1.151 .749 11 1.031 1.143 1.149 .747 1.317 .997 1.321

+.2 +.2 +.2 +.3 +.? +.2 +.3 1.141 1.123 1.012 1.145 1.151 .569 12 1.138 1.120 1.009 1.142 1.149 .568

+.3 +.3 +.3 +.3 +.2 +.2 1.020 1.127 .977 1.151 .569 PLSA with 42" SS304 f 13 1.019 1.120 .975 1.149 .568 PLSA with 36" SS304

+.1 +.6 +.2 +.2 +.2  % Difference

• • ** +

1.219 1.168 .967 .749 14 1.222 1.169 .966 .747 Relative Assembly Power

.2 .1 +.1 +.3 36" S5304 42" SS304

.393 .320 Peak Assembly = 1.32 (E10) 1.33 (E10) 15

.417 .340 = 1.57 (E10) 1.57 (E10)

Peak F*Y

-5.8 PLSA -5.9 PLSA N Peak F g = 1.66 (E10) 1.66(E10)

Peak F H

= 1.42 (88) 1.42 (E10)

• • 8 gadolinia pins per assembly

• • • 12 gadolinia pins per assembly

+ Region 12 fuel PLSA Part length Shield Assembly Figure 6.3 H.B. Robinson Unit 2, Cycle 10 Relative Assembly Power Distribution Comparison Between 36" and 42" PLSA Assembly Designs at 12,390 MWD /MT, 0 ppm, for 1,840 MWt, 3-D XTGPWR Analysis

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7.0 THERMAL-HYDRAULIC DESIGN Thermal margins for Cycle 10 at Technical Specification peaking limits under the reduced temperature operating schedule are significantly greater than those reported in Reference 11. This is largely due to the 15% reduction in power associated with low temperature operation.

{

The replacement of an additional six (6) inches of the fuel column

( with stainless steel in the PLSA assemblies results in an active fuel zone length of 102 inches (including natural U02 ). The impact of this minor

( design change on core thermal margin is nil.

The PLSA assemblies will not approach limiting assembly conditions in l their lifetime due to their low operating power and being restricted to peripheral positions in the core. The hydraulic impact of these twelve (12) assemblies on the limiting assembly is negligible.

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-8.0 ACCIDENT AND TRANSIENT ANALYSIS r

{ 8.1 PLANT TRANSIENT AND ECCS ANALYSES FOR H.B. ROBINSON The results of the Plant Transient Simulation for H.B. Robinson Unit 2 for operation at 2,300 MWt are documented in XN-75-14(P)

(Reference 3) and XN-NF-79-42 (Reference 4). Similarly, the LOCA/ECCS

{

analysis for H.B. Robinson Unit 2 at 2,300 MWt are presented in the f document XN-NF-81-54 (Reference 5). Plant transient and ECCS analyses supporting Cycle 10 operation up to 1,955 MWt with reduced primary coolant temperature are documented in XN-NF-82-18(6) ,

The replacement of an additional six (6) inches of the fuel column with stainless steel in the PLSA assemblies results in an active fuel zone length of 102 inches (including natural U02 ). The impact of this minor design change in plant thermal margins is negligible. The safety analyses cited below are valid for the H.B. Robinson plant operating within current Technical Specification limits with 12 modified PLSA's.

8.2 R0D EJECTION ANALYSIS FOR H.B. ROBINSON CYCLE 10 The Control Rod Ejection analysis as given in Reference 1 remains applicable to this shielding assembly design change.

8.3 LOCA ANALYSES FOR H.B. ROBINSON 1

The results of the LOCA/ECCS analysis for H.B. Robinson Unit 2 at 2,300 MWt are presented in XN-NF-81-54(5) . Analyses for operation at 1,955 MWt with reduced primary coolant temperature are documented in XN-1

~

21 XN-NF-83-72 Supplement 1

]

NF-82-18 I6) . The results of these analyses bound Cycle 10 operation and are in conformance with 10 CFR 50.46 criteria. This result rer.iains valid for a core containing 12 PLSA's modified as noted in Section 8.1.

8.4 END-0F-LIFE FUEL ROD INTERNAL PRESSURE A RODEX2 analysis was performed for H.B. Robinson Unit 2 Cycle 10 fuel to evaluate the end-of-life (EOL) internal fuel rod pressure.

The internal rod pressure does not exceed system pressure (2,250 psia)

for assembly burnups less than 44,000 MWD /MT. The Cycle 10 fuel a'ssemblies will, therefore, remain stable throughout their expected power history. This result is unaffected by the incorporation into the core of 12 PLSA's modified as noted in Section 8.1.

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22 XN-NF-83-72 Supplement 1

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9.0 REFERENCES

1. XN-NF-83-72, "H.B. Robinson Unit 2, Cycle 10, Safety Analysis Report", September 1983.

k. 2. XN-75-39, " Generic Fuel Design for 15x15 Reload Assemblies for Westinghouse Plants", September 1975.

3. XN-75-14, " Plant Transient Analysis of the H.B. Robinson Unit 2 PWR

[ for 2,300 MWt", July 1975.

4. XN-79-42, " Review of Plant Tr6nsient Analysis for Positive Moderator Temperature Reactivity Feedback for the H.B. Robinson Unit 2 Nuclear Power Plant", June 1979.

f 5. XN-NF-81-54, "LOCA/ECCS Analysis for H.B. Robinson Unit 2 Reactor for Revised Safety injection Location", August 1981.

6. XN-NF-82-18, "ECCS and PTS Analysis for H.B. Robinson Unit 2 Reactor

{ Operating at Reduced Primary Temperature", and Supplements 1(P) and 2(P), March 1982.

7. XN-75-44, " Control Rod Ejection Accidents for H.B. Robinson Unit 2 Based on Exxon Nuclear Reload Fuel", July 1975.

~

8. XN-CC-28, Revision 5, "XTG - A Two Group Three-Dimensional Reactor r Simulator utilizing Coarse Mesh Spacing (PWR Versioni", Exxon Nuclear L , ,., '< Company, July is/9.

- 9. XN-NF-83-55, " Mechanical Design Report Supplement for H.B. Robinson Extended Burnup Fuel Assemblies", August 1983.

10. XN-NF-83-71, " Mechanical Design Report Supplement for H.B. Robinson Part Length Shielding Assemblies", to be issued in September 1983.

11. XN-75-38, "HB Robinson Unit 2, Cycle 4 Reload Fuel Licensing Data Submittal", August 1975.

I _- -- - - - - -

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XN-NF-83-72

( Supplement 1 issue Date: 9/14/83

[

H.B. ROBINSON UNIT 2, CYCLE 10 SAFETY ANALYSIS REPORT

( DISTRIBUTION '

FT ADAMS WL LAMBERT GJ BUSSELMAN CE LEACH

( JC CHANDLER JN MORGAN LJ FEDERICO FB SK0 GEN RL FEVERBACHER GA SOFER TJ HELBLING RB ST0UT JS HOLM TT TAHVILI WV KAYSER HE WILLIAMSON

(

MR KILLGORE DOCUMENT CONTROL (5) f II STONE CP&L (5)/TJ HELBLING

(-

1