ML17286A609

Suppls 900413 & 0928 Responses to NRC Bulletin 90-002, Loss of Thermal Margin Caused by Channel Box Bow, Per NRC 901224 Request

ML17286A609
Person / Time
Site:	Columbia
Issue date:	02/25/1991
From:	Sorensen G WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
IEB-90-002, IEB-90-2, TAC-76354, NUDOCS 9103040382
Download: ML17286A609 (23)

Text

ACCELERATED EQTRIBUTION DEMONSATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9103040382 DOC.DATE: 91/02/25 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION SORENSEN,G.C. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk) -

R

SUBJECT:

Suppls 900413 & 0928 responses to NRC Bulletin 90-002, "Loss I of Thermal Margin Caused by Channel Box Bow," per NRC 901224 request. D DISTRIBUTION CODE: IE38D COPIES'RECEIVED:LTR + ENCL SIZE: /~ S y

NOTES: /

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 0 PD5 PD 1 1 D INTERNAL: AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 D NRR FIENO,D 1 1 NRR LONG,W PD31 1 1 NRR/DET/EMEB 7E 1 1 NRR/DOEA/OEAB11 1 1 NRR/DOEA/OGCB11 1 1 NRR/DREP/PEPB9D 1 1 NRR/DST/ 8E2 1 1 N S B12 1 1 PM 1 1 G 02 1 1 RES/DSIR/EIB 1 1 RGN5 FILE 01 1 1 EXTERNAL: NRC PDR NSIC 1' D

NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 18 ENCL 17

WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George Washington Way ~ Richland, Washington 99352 February 25, 1991 G02-91-037 Docket No. 50-397 U.S. Nuclear Regulatory Commission Attn: Document Control Desk

.Washington, D.C. 20555 Gentlemen:

Subject:

NUCLEAR PLANT NO. 2, OPERATING LICENSE NPF-21 REQUEST FOR ADDITIONAL INFORMATION REGARDING NRC BULLETIN 90-02, "LOSS OF THERMAL MARGIN CAUSED BY CHANNEL BOX BOW" {TAC NO. 76354)

Reference:

1. G02-90-075, April 13, 1990, GC Sor'ensen (Supply System) to USNRC, "Nuclear Plant No. 2, Operating License NPF-21, Modification to the WNP-2 Cycle 6 Reload Submittal and Response to NRC Bulletin No. 90-02: Loss of Thermal Margin Caused by Channel Box Bow"

2. G02-90-. 162, September 28, 1990, GC Sorenson (Supply System) to USNRC, "Nuclear Plant No. 2, Operating License NPF-21, Final Response to NRC Bulletin No. 90-02: Loss of Thermal Margin Caused by Channel Box Bow"

3. Letter and Attachments, December 24, 1990, P.L. Eng .(NRC) to G.C. Sorensen {Supply System), same subject Attached is the Supply System response to the request (Reference 3) for additional information, on channel box bow in WNP-2.

Very truly yours, G. C. Sorensen, Manager Regulatory Programs WCW:bw

Attachment:

Response

cc: JB Martin - NRC RV NS Reynolds - Winston 8 Strawn PL Eng - NRC DL Williams - BPA/399 NRC Site Inspector - 901A 9103040382 910220 PDR ADOCK 05000397 9 PDR

REQUESTED INFORMATION REGARDING KNP-2 CYCLE 7 OPERATION KITH REUSED CHANNELS

1. The number of channels scheduled to be reused in Cycle 7.

The number of reused channels scheduled for" Cycle 7 is 349. Of the 352 reused channels in Cycle 6, three will be discharged at EOC6.

2. Please provide the following for each channel scheduled for reuse in Cycle 7~

a. Planned location coordinates for Cycle 7 for each channel.

The planned location coordinates for Cycle 7 for each reused channel are given in Table 1 attached. The location of each reused channel is also indicated on the attached Cycle 7 core map {Figure 1) by assembly number.

The appropriate channel number for each assembly number can be determined from Table l.

b. Mhether any of the channels scheduled to be reused in Cycle 7 will be located adjacent to new fuel assemblies.

One-hundred-sixty-four of the reused channels will -

be located face adjacent to new fuel assemblies.

c.'hether any of the reused channels will be adjacent to a limiting bundle during Cycle 7.

Given the number will of reused channels, it is likely that a reused channel to a limiting assembly during Cycle 7. The precise be adjacent location of limiting assemblies during Cycle 7 will be dependent upon the actual operating experience of (and control rod patterns used for) Cycle 7 operation. However, experience has shown that limiting assemblies are almost always once burned assemblies and, potentially at the end of a long cycle, fresh assemblies can become limiting. There are many instances of reused channels being adjacent to once burned and fresh assemblies in the Cycle 7 core. As an example, at the beginning of Cycle 7 assembly UD5104 in location 22,22 is the limiting assembly. This assembly is face adjacent to reused channel 73227 (location 21,22), reused channel 63947 (location 22,21), and reused channel 63940 (location 22,23). At the end of Cycle 7, limiting assembly UD6074 (location 17,19) is face adjacent to channel 71990 { l ocati on 17, 18), channel 73405 (=1 ocati on 16,'19), and channel 70106 (location 18,19). It is therefore likely that a reused channel could be adjacent to a limiting assembly at some time during Cycle

7. This probability is recognized and taken into account in calculation of the Safety Limit Minimum Critical Power Ratio, SLMCPR, as discussed in the response to 3.b given below.

Page Two ATTACHMENT

d. Discuss the estimated exposure and maximum calculated channel bow for each channel reused in Cycle 7 (using the Supply System Analytical Model).

Channel distortion (bow + bulge) magnitude and direction is directly dependent upon the location history of the channels. The channel that will have the largest estimated maximum exposure at EOC 7 is channel 71927. This channel will -reside in core location 2,15 (xy coordinates from the upper left corner as shown in Figure 1) in WNP-2 during Cycle 7.

The operational history of this channel is:

CYCLE EXPOSURE ACCUMULATED EXPOSURE CYCLE NO. LOCATION (x, ) (MWD/MTU) (MWD/NTU) 23,6 9169 9169 16,10 5860 15029 17,5 5644 20673 Spent Fuel Pool 0 20673 ll,ll 3,10 8590 8400*

29263 37663 2,15 7800* 45463

• Estimated The Supply System analytical model predicts a maximum calculated channel bow for this channel to be equal to or less than 58 mils. The model predicts a maximum calculated channel bulge to be less than or equal to 45 mils for- this channel. The total predicted distortion is less than or equal to 103 mils. Exposures for the other reused channels in WNP-2 are shown ,in Table 1. The calculated total distortion of these channels can generally be expected to be less than this value.

We would like to reaffirm that the Supply System model is used to re-qualify channels. It is not used to estimate SLNCPR effects. This process is described in 3.b below, and is, based on a measured channel distortion data base. The Supply System has measured channels out to .

exposures of 30,655 MWD/NTU. Their measured maximum distortion was compared, on a selected basis, to the Supply System model. Calculated values were found to be conservative relative to measurements, except at very low exposures. (

Reference:

EANF-90-0434, November 13, 1990, WC Wolkenhauer to DL'hitcomb, "Comparison of Supply System Channel Distortions Model to Experimental Data).

Page Three ATTACHMENT

3. Discuss how the anticipated maximum channel bow will affect the following parameters during Cycle 7:

a. MCPR Operating Limit The anticipated effect of maximum channel bow is accounted for in the MCPR operating limit by modification to the SLNCPR which is a part of the NCPR operating limit. A discussion of the method for inclusion of channel bow affects in the SLNCPR is given below in 3.b.

b. MCPR Safety Limit The WNP-2 NCPR safety limit, SLMCPR, is established through statistical consideration of measurement and calculational uncertainties associated with the thermal hydraulic state of the reactor using design basis radial, axial and local power distributions and considering fuel channel bow.

Topical Report XN-NF-524(P)(A), Revision 2 and Supplements, "Advanced Nuclear Fuels Critical Power Methodology for Boiling Water Reactors",

discusses ANF MCPR safety limit methodology and describes in detail how channel bow effects are incorporated into the NCPR safety limit. The effects of channel bow are included in the WNP-2 Cycle 7 safety limit.

Without channel bow the WNP-2 Cycle 7 NCPR safety limit would be reduced by about 0.03.

CYCLE 7 LOAD PATTERN SHOWING ASSEMBLIES WITH REINSERTEO CHANKELS 2 3 ~

4 5 7 8 9 10 11 12 13 14 15 I XH2013 LJT197* LJT273* LJT393* LJT342* LJT171* LJT202*

2 LJT277* AM3092>> UDS)25 UD4045 UD5066* UD4054 UD5122 UD4146 3 XN2124 XH2132 U04018 UD4051- AN3074* AN3043* XH2025 UD6001 U04034* AM3064*

4 XN2121 WA6003 U06700 U05069* UD6003 AN3035* XN2087" XN2115 UD6004 AN3068*

5 XN1060 U04052 U06007 XH2006 U05064* UD4112 U05062 AN3070* UD5124 UD4046 U05132 6 XH2027* XH)065 U04118 XN2018 . UD5070* UD6009 XH2127 UD601D UD4115* UD6011 UD4048 UD6012 XH1039 7 XH2026* UD5111 UD6017 U05135 AH3032* AN3051* UD5131 UD4100 AH3100* XN2046" UD5072* UD4053 XH2091*

8 LJT)88* UD4111 UD6702 XN2130 UD6019 AH3099* XN2120 UD4114 U06020 AH3040* XH2106* XH2045 UD6021 XH2129 9 XH)160>> AN3104* UD4088 UD5087 LYV153 XH2004 U05123 UD4017 U05058 AH3075* U05057 UO4099 U05093 UD4107 UD5128 10 LJT339>> U05065* AH3053* U06025 UD406) UD6026 UD4043 UD6027 AH3076* UD6028 XH)150 UD6029 XHZ)14 UD6030 XH2134 ll LJT311>> UD4128 AH3031* AH3041* UD5055 UD4024* AN3042* AH3038* UD5056 XH1154 AH3052* AN3039* U05071* UD4082 XN1074 12 LJT325>> UD5127 XH2024 XN2084* AH3079* UD6037 XN1135 XH2085* UD4104 UD6038 AN3069* AH3067>> UD4108 UD6039 X HZ)25 13 LJT187>> UD4032* UD6043 XN2047* UD5121 U04047 U05061 XN2023>> UD5054 XH2007 U05129 U04117 UD5126 AH3054* UO4025*

14 LJT328" U05030* U04122 U06045 UD4044 UD6046 UD4 103 UD6047 UD4113 UD6048 UD4062 UD6049 AN3066* UD6050 AN3036*

15 LJT282>> AM3133* AH3046 AH3034>> UD5063* XN1100 XN2086* XN1146 UD5130 XH2126 XH2003 'N2022* UD4121 AN3080* AH3033*

16 LJT240" AH3102* AN3037* AN3011* UD5084 XN)066 XH2056* XH2123* UD5040* XH2102* XH1137 XN2040* UD4072 AN3002* AN3132*

17 LJT235>> UD5042 UD4071 UD6057 UD4098 UD6058 UD4040* U06059 U04144* UD6060 U04016* U06061 AH3114* U06062 AH3014*

18 LJT270* U04006* UD6069 XHZ)18 U05085 UD4005* UD5008* XH2116 UD5075 XN2105* UD5078 UD4033>> UD5094 AH3058* UD4087 19 LJT272>> UD508D XH2D71 XH2066* AN3128* UD6071 XH2048* XH2055* U04012* UD6072 AN3010 AH3072* UD4026* UD6073 XH2050*

20 LJT271>> UD4131 AH3044* AN3020* UD5039>> U04076 AN3127* AH3009 UD5036* XN2058* AH3019* AN3055* U05020* U04028* XH2075" 21 LJT193" UD5095 AN3057* UD6077 UD4143" UD6078 U04101 UD6079 AN3073* UD6080 XH200S* U06081 XH2110* U06082 XH2111>>

ZZ XH2037* AN3050* UO4021* UD5134 LYV)56 XN2062* UDS010* UD4077 UD5009* AN3D71>> UD5016* UD4039* UD5120 UD4027* U05077 23 LJT308* UD4042* UD6704 XN2104* UD6089 AN3101* XN2113 U04137* UD6090 AH3118 XH2098* XN2072* UD6091 XH2028*

24 XH2061* UDS086 U06095 UD5102 AN3123* AH3013* UD5004* UD4041* AN3086* XN2119 U05011* UD4095 XN2081*

25 XN2041* XN2122* UD4116" XN2012 U05017* U06097 XHZ089* U06098 UD4011* UD6099 UD4015* UD6100 XN1124 26 XN)117 UD409) UD6105 XH1153 UD5076 UD4138* UD5014* AH3131* U05081 UD4102 U05103 27 XN2112 WA6001 UD6706 U05028* UD 6107 AH3056* XN2065* XN2088* U06108 AN3113*

28 XH2049* 'XN2103* U04078 U04092 AN3087* AH3012* XN2073* UD6111 UD4094 AN3018" 29 LJT3)Z* AN3088* UD5079 U04038* UD5082 UD4097 UD5018* UD4145 30 XH2131 LJT)60* LJT340* LJT384* LJT231* LJT387* LJT250*

16 17 19 20 21 22 23 24 25 26 27 28 29 30

" 1 LJT205* LJT)84>> LJT331* LJT)76* LJT286* LJT213* XN1159 2 U04147 UD5116 U04069 UDS))5 UD4020 U05108 AN3089* LJT341*

3 AN3028* UD4059 UD6002 XN2108* AN3083* AH3090* UD4065 UD4058 XN1140 XH2034 4 AN3096* UD6005 XN1110 XN2095* AN3007* UD6006 UD5112 U06701 WA6004 XN1092 5 UD5119 U04057 UD5052 AN3027" U05045 UD4109 UD5073 XK2031 U06008 U040Z9* XIN)06) 6 XN1037 UD6013 UD4010 UD60)4 UD4105 UD6015 XN 1144 UD6016 UD5D50 XN1156 UD4126 XN2032 XH2010 7 XN2D99* UD4070 U05091 XN2009 AN3049* U04001 UD5117 AH 3119* AH3030>> UD5046 U06018 U05133 XH2035 8 XH1106 UD6022 XN2097* XH2080* AN3126* UD6023 UD4127 XN)093 AN3045* UD6024 XN1162 UD6703 UD4110 LJT288*

9 U05068 U04129 UD5083 UD4120 UD5041 AH3107* UDS)09 UD4066 U05051 XK20Z) 'LYV155 UD5013* U04125 AH3085* XN2033 10 XN)143 UD6031 XN)161 UD6032 XN2015 UD6033 AN3097* UD6034 UD4064 UD6035 UD4009 UD6036 AN3103* UD5067 LJT)62*

ll XN2016 UD4093 UD5043 AH3125* AH3120* XH2044 UD 5074 AH3130* AH3025* UD4022* UD5053 AN3026* AN3029* UD4130 LJT323*

12 XH2020 UD6040 UD4124 AH3098* AN3081* UD6041 U04106 XH 2101* XN 2017 UD6042 AH3084* XH2067" XH1090 UD5113 LJT369*

13 UD4073 AN3082* U05118 UD4123 U05048 XN2117 U05110 X HZ)09* U05044 U04019 U05047 XH)158 UD6044 UO4055 LJT241*

14 AH3008* UD6051 AH3095* UD6052 UD4056 UD6053 UD4050 UD6054 UD4119 UD6055 UD4063 UD6056 UD4096 UD5035* LJT337*

15 AN3021>> AH3001* UD4031* XN2096* XH2030 XN1138 U05114 XN1155 XH2094* XH1101 UD5049 AH3022* AH3124* AH3134* LJT214*

16 AN3024* AN3122" UD4075 XN2136 XN1151 XN 2038" U05101 XN 2054* XN2068* XN1081 U05001 AN3061* AN3129* AH3065* LJT179*

17 AH3015* UD6063 AH3106* U06064 UD4139* U06065 UD4142* UO6066 U04035* UOBO67 UO4OBO UD6068 UD4089 UD5060 LJT237*

18 U04090 AN3112" UD5033* UD4023* UD5029* XH2039* UD5026* XM2008 UD5096 UD4014* UD5023* XH)020 UD6070 U04002 LJT216*

19 XH2076* UD6074 UD4037* AH3110* AH3023* U06075 U04134* XH2051* XN 1152 UD6076 AN3016* XH2100* XN1141 UD5105 LJT247*

20 XN2057* U04049 UD5098 AN3077* AH3063* XN2074* U05022* AH3006* AN3062* UD4060 UD5031* AN3060* AH3047* U04133 LJT295" 21 XN2093* UD6083 XN2042* U06084 XN2135 U06085 AN3116* UD6086 U04079 U06087 UD4140* UD6088 AH3)ll>> UD5021* LJT376*

22 UD5038* UO4OOS UD5059 UD4007* UD5037* AH3115* U05104 UD4086 UD5024* XH2063* LYV)54 UD5136 UD4003* AH3093* XH2083*

23 XH2036* UD6092 XN2059* XH2090* AH3017* U06093 U04141* XH)103 AH3108* UD6094 XH2092* UD6705 UD4135>> LJT218*

24 XH2078* UD4068 UD5089 XN2011 AN3091* UD4036* UD5106 AN3005* AM3048* UD5088 UD6096 U05092 XH2064>>

25 XN1125 UD 6101 UD4013* UD6102 U04132* U06103 XN2069* UO6104 U05099 XN1070 U04 004* XH2082* XN2)33 ,

26 UD5090 UD4084 UD5032* AN3121* UD5100 UD4136" UDSD97 XN 1142 UD6106 UD4081 XH1111 27 AH3109* UD6109 XHZ)07* XH2052* AH3078* UD6110 UD5025* UD6707 WA6002 XH1157 28 AN3117 U04074 UD6112 XN2060* AN3059* AN3105* UD4030* UD4085 XN2043* XH2001*

29 UD4148 UD5002 UD4067 UD5034* U04083* U05107 AH3094* LJT227*

30 LJT335* LJT)65* LJT226* LJT)80* LJT253* LJT)67* XN)102

• ASSEMBLY WITH REINSERTED CHANNEL

TABLE 1 REINSERTED CHANNELS~ ASSEMBLIES'ND PROJECTED EOC 7 EXPOSURE CURRENT PROJ ~ EOC 7 ASSEMBLY CHANNEL ID EXPOSURE 1 10 LJT197 73437 37291 ~

1 11 LJT273 70171 42181 1 12 LJT393 71815 37859 1 13 LJT342 73418 ~

'7410 1 14 LJT17 1 73169 37681 ~

1 15 LJT2 02 60835 42389.

1 16 LJT2 05 71832 42047 1 17 LJT184 71996 '7674 1 18 LJT33 1 71462 41790 ~

1 19 LJT176 73113 37838 ~

1 20 LJT286 71329 41624 1 21 LJT2 13 73363 '7034 2 8 LJT277 60903 '1318.

2 9 AN3092 635,72 42000 2 12 UD5066 7 1780 '6087 2 22 AN3089 62513 42087 2 23 LJT341 60827 ~

'1996 3 10 AN3074 73425 43942.

3 11 AN3043 6450D 36086 3 14 UD4034 72009 '6550 3 15 AN3064 72035 40944.

3 16 AN3028 72474 40760 3 19 XN2 108 73379 '0520 3 20 AN3083 71809 '4760 3 21 AN3090 73390 '4018 9 UD5069 63492 37599 11 AN3035 71986 '0193 4 12 XN2087 71965 '7611.

15 AN3068 70287 41846 16 AN3096 70257 ~

'1548 19 XN2095 70104 37735 20 AN3007 5960D ~

'1472 5 9 UD5064 71198 37048 5 12 AN3070 5881D '1839 5 19 AN3027 71437 ~

'0198 5 25 UD4029 73090 44725 6 3 XN2027 73412 '7572 6 7 UD5070 71945 '7374 6 11 UD4 115 71785 '2967 7 3 XN2026 73375 43416 7 7 AN3032 71942 ~

'1281 7 8 AN3051 63949 44000 7' 11 AN3100 73120 '3638 12 XN2046 71370 ~

'4071 7 13 UD5072 70238 37375 '

TABLE 1 (CONT )

CURRENT PROJ EOC 7 ASSEMBLY CHANNEL ID EXPOSURE 7 '5 XN2091 71387 32832 7 16 XN2099 61638 '9340 7 20 AN3049 72024 '3636 7 23 AN3119 63442 '4045 7 24 AN3030 71443 '1420 8 2. LJT188 73225 ~'8183 8 7 AN3099 71956 44006 8 11 AN3040 73367 '2178 8 12 XN210 6 73168 '3080 8 18 XN2097 62446 '1169 8 19 XN2080 72003 '3058 8 20 AN3126 71933 '4604 8 24 AN3045 71914 ~

'4501 8 29 LJT288 72019 41459+

9 1 XN1 160 72475 42631 ~

9 2 AN3 104 72039 44759 9 10 AN3075 73079 '4723 9 21 AN3107 71808 ~

'1961 9 27 UD5013 70110 37045 9 29 AN3085 73394 '4054 10 1 'LJT339 71889 '7565 10 2 UD5065 61550 '4444'5484 10 3 AN3053 5898D 10 9 AN3076 5809D '6217 10 22 AN3097 71400 '4878 10 28 AN3103 73154 '5474 10 30 LJT162 70262 '7290 11 1 LJT311 71480 '8181 11 3 AN30 3 1 71389

'l

'5069 11 AN30 4 1 ~ 73108 '9430 11 6 'D4024 62926 '3058 7 AN3042 71970 ~

'4217 11 8 AN3038 71756 44389 11 11 AN3052 71958 ~

'3211 11 12 AN3039 71789 39495.

11 13 UD5071 71938 30622 11 19 AN3125 71755 '9350 11 20 AN3120 73226 '3678 11 23 AN3 130 6012D '2858 11 24 AN3025 63257 ~'4119 73386 ll 11 11 25 27 28 UD4022 AN3026 AN3029 72001 72439 31704 39889

~

'4530 11 30 LJT323 72000 ~

'1422 12 1 LJT325 73443 37900 12 XN2084 71936 '7690 12 5 AN3079 63445 '

'0382

TABLE 1 (CONT ~ )

CURRENT PROJ ~ EOC 7 ASSEMBLY CHANNEL ID EXPOSURE 12 8 XN2085 71762 32634 12 11 AN3069 73116 ~

'0169 12 12 AN3067 61769 43971.

12 19 AN3098 5900D 35207 12 20 AN3081 73111 ~

'1215 12 23 XN210 1 73438 32193 12 26 AN3084 71391 '0621 12 27 XN2067 73582 '8280 12 30 LJT369 71364 '7854 13 1 LJT187 73136 '7900 13 2 UD4032 ~ 72010 '5037 13 4 XN2047 73584 '3813 13 8 XN2023 73401 34739 13 14 AN3054 63427 '4417 13 15 UD4025 70279 '6086 13 17 AN3082 71447 '2846 13 23 XN2109 73424 '1991.

13 30 LZT241 71441 38180 ~

14 1 LZT328 70161 37360 14 2 UD5030 71848 '7270 14 13 AN3066 73366 '2317 14 15 AN3036 63602 41983 ~

14 16 AN3008 71758 41921 ~

14 18 AN3095 5938D 35801 14 29'0 UD5035 71983 '6876 14 LZT337 73119 ~

'7291 15 1 LJT282 71378 37417 ~

15 -2 AN3133 71927 45463 15 AN3034 71757 ~'1747 15 5 UD5063 71817 37160 15 7 XN2086 71300 '3124 15 12 XN2022 71461 '3800 15 14 AN3080 5866D '3684 15 15 AN3033 73130 '4189 15 16 AN3021 71458 '4185 15 17 AN3001 71790 '2628 15 18 UD4031 72038 '6872 15 19 XN2096 71472 '3764 15 24 XN2094 71761 '2563 15 27 AN3022 72027 '3751 15 28 AN3124 71376 73384

'0867'4677 15 29 AN3134 15 30 LJT2 14 72028 ~'1313 16 1 LZT24 0 70105 37418 16 2 AN3 102 71753 ~

'6410 16 3 AN3037 72037 40774 16 AN30 11 60890 '4585.

TABLE 1 (CONT ~ )

CURRENT PROJ EOC 7 Y ASSEMBLY CHANNEL ID EXPOSURE 16 7 XN2056 72023 38801 ~

16 8 XN2123 . 71465 36181 ~

16 9 UD5040 62522 37057 16 10 XN2 102 62711 '2634 16 12 XN2040 71302 '3801 16 14 AN3002 62283 '3766.-

16 15 AN3 132 71981 44327 16 16 AN3024 71445 '4481 16 17 AN3122 71928 39683 16 21 XN2038 71371 '6167 16 23 XN2054 71767 '5906 16 24 XN2068 61682 ~

'9391 16 27 AN3061 73399 44383 16 28 AN312 9 71442 '0558.

16 29 AN3065 71976 39162 16 30 LJT17 9 63945 '2075 17 1 LJT235 70244 ~

'7322 17 7 UD4040 71786 26545 17 9 UD4144 62335 '4127 17 11 UD4016 71904 '6333 17 13 M3114 5805D '3100 17 15 M3014 71985 '2042 17 16 AN3015 72014 ~

'2136 17 18 M3106 5932D 35929 17 20 UD4 139 61794

'4507 17 22 UD4142 6028D '9027 17 24 UD4035 71957 42133 17 18 30 1

LJT237 LJT270 72011 71920 37294 38181 18 2 UD4006 71954 '7007 18 6 UD4005 73089 '6904 18 7 UD5008 71377 '7647 18 10 XN2 105 61650 '5058 18 12 UD4033 72007 '5129 18 14 AN3058 73388 '4300 18 17 M3112 71990 43978 18 18'9 UD5033 70158 '7376 18 UD4023 73614 '3368 18 20 UD5029 61773 '7363 18 21 XN2039 71194 '5509 18 22 UD5026 61750 '7563 18 25 UD4014 71853 '4757 18 26 UD5023 73069 '7161 18 30 LJT2 16 73404 '7058 19 1 LJT272 70080 ~

'7961 19 XN2066 61972 31487 19 5 AN3 128 72021 ~

'0571

(CONT+)

TABLE 1 CURRENT PROJo EOC 7 Y X ASSEMBLY CHANNEL ZD EXPOSURE 19 7 XN2048 5924D 31187 ~

19 8 XN2055 71134 32886 19 9 UD4012 71950 '6433 19 12 AN3072 71788 ~'3811 19 13 UD4026 71467 44365 19 15 XN2050 71934 '3144 19 16 XN2076 73405 '3354.

19 18 UD4037 70106 42801 19 19 AN3 1 10 7 1773 '3660 19 20 AN3023 5850D ~

'1198 19 22 UD4134 71903 44412 ~,

19 23 XN2051 70280 39107 19 26 AN3016 71448 '0081 19 27 XN2100 71959 ~'1566 19 30 MT247 71931 37681 20 LJT271 73585 37903 20 3 AN3044 73422 '5064 20 AN3020 63956 '0297 20 5 UD5039 70011 ~

'7160 20 .7 AN3127 70102 44118 20 9 'D5036 73238 '6967 20 10 XN2058 73076 '2570 20 11 AN3019 71852 44051 ~

20 12 AN3055 73171 39853 20 13 UD5020 71791 ~'7031 20 14 UD4028 73110 44990.

20 15 XN2075 71886 43287 20- 16 XN2057 71909 '5093 20 19 AN3077 71812 '9435 20 20 AN3063 62937 '3842 20 21 XN2074 71949 '6174 20 22 UD5022 70252 '7107 20 23 AN3006 71912 '4509 20 24 AN3062 71890 ~

'4111 20 26 UD5031 73415 37268 20 27 AN3060 71268 ~

'0133 20 28 AN3047 73133 42421 ~

20 30 LJT295 70236 37193 21 1 LJT193 62609 '7320 21 3 AN3057 5802D '5475 21 5 UD4143 72042 '6505 21 9 AN3073 72036 '4878 21 -

11 XN2005 71495 '6326 21 13 , XN2110 73588 '4720 21 15 XN2111 63951 '2650 21 16 XN2093 72040 '5965 21 18 XN2042 61727 '

'4468

TABLE 1 (CONT ~ )

CURRENT PROJ EOC 7 Y X ASSEMBLY CHANNEL ZD EXPOSURE AN3 116 63947 44849 21 21 22 26 UD4 140 AN3111 73083 73135 44031

' '4370 21 28 21 29 UD5021 71799 ~

'6971 21 30 Za7T37 6 71362 37194 22 1 XN2037 71170 '7435 22 2 AN3050 71449 '3271 22 3 UD4021 73232. '2137 22 6 XN2062 71410 '6317 22 7 UD5010 72034 '7193 22 9 UD5009 71913 '7653 22 10 AN307 1 73131 '3018 22 11 UD5016 71356 '7100 22 12 UD4039 71835 '5931 22 14 UD4027 70233 ~

'3941 22 16 UD5038 71960 37562 ~

22 17 UD4008 73148 44235 22 19 UD4007 62647 '2447 22 20 UD5037 71830 '7272 22 21 AN3115 73227 44622 22 24 UD5024 61529 '6968 22 25 XN2063 71897 '6809 22 28 UD4003 63953 ~

'2136 22 29 AN3093 73420 44750 22 30 XN2083 71843 '7284 23 2" MT308 71955 '2622 23 3 UD4042 71943 '4834 23 5 XN2 104 71146 '3851 23 7 AN3 10 1 61523 '4334 23 9 UD4137 70221 '4973 23 12 XN2098 73364 '

'9960 73440 33577

'3 23 13 15 XN2072 XN2028 73383 61541

'1860 23 16 XN2036 '2581 23 18 XN2059 71765 ~

'1291 23 19 XN2090 62699 33788 23 20 AN30 17 73139 ~

'4616 23 22 UD414 1 63940 44898 23 24 AN3108 71994 '4200 23 26 XN2092 71810 '7028 71975 23 23 '9 28 UD4135 Za7T2 18 XN2061 71398 71456 36990

'2323

~

'7199 24 3 24 7 AN3 123 71991 '3382 24 8 AN3013 71838 '3973 24 9 UD5004 71908 '7836 24 10 UD4041 71923 ~

'6129

TABLE 1 (CONT o )

CURRENT PROJ ~ EOC ASSEMBLY CHANNEL ZD EXPOSURE 24 11 AN3086 70047 41188 ~

24 13 UD5011 71930 37098 24 15 XN2081 71390 '2833 24 16 XN2078 61673 39034 24 20 AN3091 73112 '3635 24 21 UD4036- 73441 ~

'6631 24 23 AN3005 73153 43908 24 24 AN3048 70272 ~

'1281 24 28 XN2064 73239 37011 ~

25 3 XN2041 73392 44465 25 4 XN2122 71280 '8537 25 5 UD4 116 71764 '4882 25 7 UD5017 63943 '7359 25 9 XN2089 73376 35736 25 11 UD4011 71792 ~

'4391 25 13 UD4 015 5912D 27317 ~

25 18 UD4013 71289 45234 25 20 UD4132 73167 '2969 25 22 XN2069 71905 '6627 25 26 UD4004 73444 '3932 25 27 XN2082 71893 '7812 26 10 UD4 138 71485 45221 ~

26 11 UD5014 71759 37587 26 12 AN3 13 1 72041 '0537 26 18 UD5032 70243'1444

'7268 26 19 AN3 12 1 '0793 26 21" UD4136 62412 '5092 27 9 UD5028 71962 '6967 27 11 AN3056 61741 '0347 27 12 XN2065 71921 '1248 27 13 XN2088 72476 '6455 27 15 AN3113 HA5422 '3584 27 16 AN310 9 73121 '4005 27 18 XN2107 73224 '2796 27 19 XN2052 61526 ~'1227 27 20 AN3078 71967 40534 27 22 UD5025 71141 '7646 28 6 XN2049 71857 '7407 28 7 XN2103 71331 ~

'7571 28 10 AN3087 61578 43699 AN3012 5999D '6057 28 12 XN2073 71964 '0520 28 15 AN3018 71431 '0535 28 19 XN2060 73416 ~

'3571 28 20 AN3059 5868D 33397 28 21 AN3 105 70206 '3474.

22 UD4030 71308 42105 ~

TABLE 1 (CONT )

CURRENT PROJ ~ EOC 7 Y 'X. ASSEMBLY CHANNEL XD EXPOSURE 28 24 XN2043, 71910 36813 ~

28 25 XN2001 72012 37379 29 8 LJT3 12 70293 41433 29 9 AN3088 5905D '3246.

29 11 UD4038 73403 26010 29 14 UD5018 61538 '7028 29 19 UD5034 71771 '7032 29 20 UD4083 72017 '4038 29 22 AN3094 5852D '5967 29 23 MT227 73067 '1079 30 10 MT160 62542 '7680 30 11 MT340 71211 '2466 30 12 MT384 71499 ~

'7100

30. 13 MT231 70216 42075 ~

30 14 MT387 73609 37318 30 15 LJT250 71997 41424 30 16 LJT335 70291 '7234.

30 17 LTT165 71457 37027.

30 18 ZaTT22 6 70060 "

37234 30 19 LJT180 71438 '7035.

30 20 LTT253 63636 37233 30 21 LJT167 71911 ~

'7677

April 22, 1991 Docket No. 50-397 Mr. G. C. Sorensen, Manager Regulatory Programs Washington Public Power Supply System 3000 George Washington Way P.O. Box 968 Richland, Washington 99352

SUBJECT:

EVALUATION OF RESPONSE TO NRC BULLETIN NO. 90-02, "LOSS OF THERMAL MARGIN CAUSED BY CHANNEL BOX BOW" (TAC NO. 76354)

On March 20, 1990, the NRC issued Bulletin No. 90-02, "Loss of Thermal Margin Caused By Channel Box Bow." The bulletin contained reporting requirements applicable to boiling water reactor facilities using fuel channel boxes for a second bundle lifetime. You responded to the bu lletin in letters dated April 13, 1990 (G02-90-075) and September 28, 1990 (G02-90-162). You provided additional information by letter dated February 25, 1991 (G02-91-037) in response to the staff 's request.

In each letter, you indicated that 349 channel boxes were to be reused in the upcoming cycle ( cycle 7). Your responses described the number and disposition of the affected channel boxes and the actions taken to assure compliance with the technical specification for thermal limits.

We have completed our review of your responses and find that it satisfactorily resolves the issues discussed in NRC Bulletin 90-02 for cycle 7 and that its application to any future channel reuse must be evaluated on a cycle specific basis. A copy of our safety evaluation is enclosed.

This completes our efforts under TAC No. 76354. If you have any questions regarding this issue, please contact me.

Sincerely, Original signed by Patricia L. Eng, Project Manager Project Directorate V Division of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation cc w/enclosure:

See next page DISTRIBUTION NRC I LP R P /f g NVi gill OF PEng OGC EJordan PD5 p/f ACRS (10) RZimmerman, RV INC KE Cal'TER ggpj 0 C:LA PD5 DRPI :PM P RPW:D PD DRPW NAME: DFos ter :PEn .s DATE: / /91 91 /g 1 ocumen arne:

f v i

Mr. G. C. Sorensen WPPSS Nuclear Project No. 2

'Washington Public Power Supply System (WNP-2)

CC:

Mr. J. W. Baker Regional Administrator, Region V WNP-2 Plant Manager U.S. Nuclear Regulatory Corenission Washington Public Power Supply System 1450 Maria Lane, Suite 2lO P.O. Box 968, MD 927M Walnut Creek, California 94596 Richland, Washington 99352 G. E. C. Doupe, Esq. Chairman Washington Public Power Supply System Benton County Board of Commissioners 3000 George Washington Way P. 0. Box 190 P. 0. Box 968 Prosser, Washington 99350-0190 Richland, Washington 99532 Mr. R. G. Waldo, Chairman Mr. R. C. Sorensen Energy Facility Site Evaluation Council U. S. Nuclear Regulatory Commission Mail Stop PY-ll P. 0. Box 69 Olympia, Washington 98504 Richland, Washington 99352 Mr. Alan G. Hosier, Licensing Manager Nicholas'S. Reynolds, Esq.

Washington Public Power Supply System Winston 8 Strawn P. 0. Box 968, MD 956B 1400 L Street, N.W.

Richland, Washington 99352 Washington, D.C. 20005-3502 Mr. A. Lee Oxsen, Acting Managing Director for Operations Washington Public Power Supply System P. 0. Box 968, MD 1023 Richland, Washington 99352 Mr. Gary D. Bouchey, Director Licensing and Assurance Washington Public Power Supply System P. 0. Box 968, MD 280 Richland, Washington 99352

~p,S REoy, dp 0 UNITED STATES Op 0 NUCLEAR REGULATORY COMMISSION C O WASHINGTON, D. C. 20555 Vg

+**++

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO EVALUATION RESPONSE TO NRC BULLETIN NO. 90-02 WASHINGTON PUBLIC POWER SUPPLY SYSTEM WASHINGTON NUCLEAR POWER UNIT 2 DOCKET NO. 50-397 1.0 .BACKGROUND WNP-2 is a C-lattice BWR and, as such, is less susceptible than a D-Lattice core to the phenomena of and effects from channel box bow. Washington Public Power Supply System (WPPSS) is aware of the potential problems associated with channel box bow, and for that reason WPPSS had embarked on a channel management program since initial operation. This channel management program consists of data collection on channel operating history and actual measurement of channel distortion as a function of channel operation. The licensee s ultimate goal is to make the transition away from channel box reuse.

Beginning with the upcoming cycle, cycle 7, the effects of channel box bow wi 11 be addressed in WNP-2 reload design using the approved ANF methodology for determining the Safety Limit Critical Power Ratio (SLCPR). The ANF data incorporated in the ANF methodology has been reviewed previously by the NRC and included WNP-2 measured data (Reactor D in this data base). Analysis of the data indicated that WNP-2 is observing less channel box bow because WNP-2 is a C-lattice. This data extends to an exposure of 50 GWD/MTU.

This safety evaluation covers the staff review of the Washington Public Power Supply System strategy for reuse of channel boxes in the upcoming cycle.

2.0 EVALUATION 2.1 Channel Box Characterization Channel boxes are selected for reuse by WNP-2 by establishing an accept/reject criteria based on "Distortion Allowance." Discharged channel boxes are .

measured in the WNP-2 channel box measuring machine and the total maximum distortion (bow plus bulge) due to reactor operation is determined. The licensee showed that total channel box distortion will vary along the channel with the maximum distortion value usually located near the middle of the channel.

The Distortion Allowance was developed based on the following relation:

Distortion Allowance = Nominal Design Clearance - Calculated Future Distortion.

Used channel boxes are qualified for reuse if their measured distortion (from nominal) is less than the Distortion Allowance as developed from the above rel ati onship.

The licensee defines the Nominal Design Clearance as the nominal clearance between the channel box and the potential interference (in this case the control blade and/or Local Power Range Monitor (LPRM) as defined by the design drawings of the reactor core.

The Calculated Future Distortion is defined as the total distortion (bow plus bulge) as determined by the WNP-2 channel box model. The model is based upon the expected future irradiation path of the fuel assembly upon which the channel box will be placed. The licensee pointed out that typically, the future irradiation path is assumed to be five cycles at the interior of the core and one cycle on the periphery. The amount of channel box bulge for the interior and the periphery is determined from the channel box bow model, assuming operation at 1005 power. The model sums the results of the five cycles at the interior and one at the periphery to obtain a total expected bulge.

Similarly, channel box bow data is obtained from figures/plots generated by the channel box model for both the interior and periphery locations and again at assumed 100% power. The total expected channel box bow and bulge are then summed to obtain the total expected channel box distortion.

With the Nominal Design Clearance known from design drawings and Calculated Future Distortion determined from the WNP-2 channel box bow model, the licensee is able to determine a Distortion Allowance value(s) for clearance of both the control blade and the LPRM for any given cycle. Channel boxes with measured total distortion less than the control blade and the LPRM Distortion Allowances are qualified for reuse.

2.2 Estimated Ex osure and Maximum Calculated Channel Box Bow In their February 25 submittal, the licensee pointed out that the magnitude and direction of channel box distortion (bow plus bulge), is directly dependent upon the location history of the channel boxes. The channel box that will have the largest estimated maximum at the end of cycle 7 is channel box designated 71927. During cycle 7, this channel box is expected to be exposed to approximately 7.8 GWD/MTU with a total accumulated exposure at the end of cycle? of approximately 45 GWD/MTU.

The Supply System analytical model predicts a maximum calculated channel box bow for this channel to be equal to or less than 58 mils. The model also predicts a maximum calculated channel bulge of 45 mils or less. Consequently, the total predicted channel box distortion for this channel is less than or equal to 103 mils. The exposures and channel box distortion for the remaining reused channels in WNP-2 are less (in some cases much less) than the values stated above.

2.3 Channel Box Measurement The Supply System has measured bow data on channel boxes out to exposures of approximately 31 GWD/MTU. Their measured (maximum) data was compared to calculated data generated by the channel box distortion model. The calculated values were found to be conservative relative to measured data (Reference 4).

2.4 Channel Box Bow Effects on the MCPR Limits The licensee indicated that it will take into account the channel box bow effects on the MCPR operating limit by modifying (recalculating) the SLMCPR, maintaining the same delta CPR. The WNP-2 SLMCPR was established through statistical considerations of measurement and calculations uncertainties, associated with the thermal hydraulics state of the reactor using design basis radial, axial and local power distributions and considering fuel channel box bow (Reference 5). The effects of the channel box bow are included in the WNP-2 cycle 7 safety limit adjustment.

3.0 CONCLUSION

Based on the above evaluation, the NRC staff has concluded that the licensee's cycle 7 reload design with reused channel boxes and the methods used to account for the channel box impact on the core operating limits is acceptable. The data and methodology used provide reasonable assurance that the thermal margin to the MCPR safety limit is maintained.

If in future cycles channel box reuse is continued, further review and prior approval by the NRC staff will be required.

Principal Contributor: A. Attard Date: April 22, 199$

4

4.0 REFERENCES

1. G02-90-162, September 28, 1990, G.C. Sorensen (Supply System) to USNRC, "Nuclear Plant No. 2, Operating License NPF-21, Final Response to NRC Bulletin No. 90-02: Loss of Thermal Margin Caused by Channel Box Bow".

2. Supply System Interoffice Memorandum, from W.C. Wolkenhauer, Principal Engineer, to D.L. Whitcomb, Manager, Nuclear Fuel, November 13, 1990.

3. G02-91-037, February 25, 1991, G.C. Sorensen to USNRC, "Nuclear Plant No. 2, Operating License NPF-21, Request for additional information regarding NRC Bulletin No. 90-02, "Loss of Thermal Margin Caused by Channel Box Bow".

4. EANF-90-0434, November 13, 1990.

5. Letter, 'August 8, 1990, A.C. Thadani, NRC to R.A. Copeland, ANF, "Acceptance for Referencing'. of Topical Report ANF-524 (p), Revision 2, ANF Critical Power Methodology for Boiling Water Reactor'.

'f