B14302, Forwards Response to NRC 921120 Request for Addl Info on Performing Criticality Analysis of Millstone Unit 2 Spent Fuel Pool,Per Util 920416 Application
| ML20127N183 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 11/24/1992 |
| From: | Opeka J NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20127N188 | List: |
| References | |
| CON-#193-13468 B14302, OLA, NUDOCS 9212010051 | |
| Download: ML20127N183 (9) | |
Text
-.
NORTHEAST UTILITIES o.ner i cec... som.n sir..i. sernn conn.ci cut l
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bhbfb!bbb (nrpgn0 CONNECTICUT 06141-0270 eo 27 L
<Ta 500lll.70?%:
tem) ess-som November 24, 1992 Docket No. 50-336 B14302 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Gentlemen:
Millstone Nuclear Power Station, Unit No. 2 Spent Fuel Pool Criticality License Amendment Response to Reauest for Additional Information in a letter dated April 16, 1992,W Northeast Nuclear Energy Company proposed to amend Operating License DPR-65 for Millstone Unit No.
2, pursuant to 10CFR50.90. Subsequently, during their technical review, the NRC Staff requested additional information as described in a letter dated November 20, 1992.* of this letter provides the detailed technical information as l
requested, including gap size, frequency, and distribution characteristics.
l We appreciate the opportunity to respond to the Staff's information request in this efficient manner.
If you have additional questions, please contact my
- staff, Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY b (5d J. F.'Opeka U
Executive Vice President cc:
T. T. Martin, Region I Administrator G. S. Vissing, NRC Project Manager, Millstone Unit No. 2 P. D. Swetland, Senior Resident Inspector, Millstone Unit Nos. 1, 2, and 3 (1)
J.
F. Opeka letter to U.S. Nuclear Regulatory Commission, " Millstone Nuclear Power Station, Unit No.
2, Proposed Revision to Technical Specifications Spent Fuel Pool Reactivity," dated Aprii 16, 1992.
(2)
G.
S.
Vissing letter to J.
F.
Opeka, " Request for Information for Performing the Criticality Analysis of the Millstone 2 Spent Fuel Pool,"
dated November 20, 1992.
9., \\ '] s.
e s gU 9212o10032,2,32, DR ADOCK 05000336 PDR 1
j
4 Docket No. 50-336 B14302 Millstone Nuclear Power Station, Unit No. 2 Spent Fuel Pool Criticality License Amendment Response to Request for Additional Information Technical Information for Independent Analysis l
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November 1992 l
c.
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Millstone Nuclear Power Station, Unit No. 2 4
l Spent Fuel Pool Criticality License Amendment Response to Request for Additional Information Technical Information for Indeoendent Analysis i'
The information listed below, as well as the attached figure 1, provide the 3
information requested related to the performance of independent criticality calculations for the Millstone Unit No. 2 Spent fuel Pool.
j (1) This informatirn applies to ILeaion B only of the Millstone Unit No. 2 spent fuel pr.,1.
1 i
(2) All Keff values presented in the April 16, 1992, license amendment request
]
for Region B include a bias of +0.0101 and a combined manufacturing l
tolerance and uncertainty allowance of 0.0115.
2 (3) The nominal B-10 areal density used is 0,033 gm/cm,
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(4) The cross-section library used is the 27-group SCALE library with a NITAWL-KENO Va three-dimensional model.
(5) The soluble boron concentration in the spent fuel pool is typically greater than 1720 ppm boron, (6) The fuel cladding and guide tube material is Zircaloy-4.
(7) The necinal cold stack height of the fuel is 136.7 inches.
(8) The fuel pin enrichment used in the calculation is 4.5 w/o U 235.
(9) The Millstone Unit No. 2 fuel assembly is a standard Combustion Engineering 14 x 14 lattice design.
(10) The water density used in the calculation is
- 4. hat which corresponds to a temperature of 4'C.
i (11) On Figure 1, cross section of Region 1 cells, a common outside can wali is l
shared between adjacent cells.
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12.2746 cm I
- p-12.0150 cm
'g*- -- 11.5037 cm ---*-
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,e 9.60"
- 0.g9" PITCH q'
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L CELL i 1.0.
l 8.710" 4 0.050" f
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.135" SS ls I
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' FUEL OD 0.370' I
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! CLAD ID 0.378" j'
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l CLAD 00 0.440"
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' Pi1CH 0.580" I
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l ARRAY 14 X 14 9
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- CT 1.035"1D 1.115"0D iE ti *
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I 11.0617 cm i
h-11.2827 cm
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WATER CAP BORAFLEX i+-
11.7595 cm
- I 1/2 L = 8.6652 cm 1/2 L = 10.3188 cm I
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1/2 Thick = 0.2552 cm 1/2 ThlCK 0.1397 cm Center of 11.7595 cm Center of 11.2827 cm I
'i FIG. 1 CROSS-SECTION OF REGION 1 CELLS 4
~ _.. _ _.... _. _. _ _ _
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24 22 20 l
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a 24
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D 12 -
10 s
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0.5
-1.0 1.5 2.0 2.5 2.8 GAP WIDTH, INCHES O FIRST CAMPAIGN E SECOND CAMPAIGN Frequency of occurrence of gap sizes l
i Millstone Unit 2 Status "
1346 Total Sterage Ceils in Pool,384 Contain Boraflex
~
i Test Celis Panels Gaps Date Irradsated No. Tested % Tested - Defects % Defects irrad#ated No. Tested % Tested *" Defects % Defects No. Ave Siz Max Size Aug-90 384
~105 27%
32 30 %
1536 420 27 %
46 11 %
49
.76*
1.7*
+
i Oct-91 384 141 37 %
53 38 %
1536 564 37%
89 16 %
93
.83" 2.8-
- 4 3
sotal 384 176 46 %
53 30 %
1536 704 46 %
89 13 %
93 NA 2.8*
- i
)
i T/S f
Analysis 384-100 % '
Random axial distribution 100 %
5.65-5.65*
f Assumes i
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- The two cells with >2" gaps had poison boxes replaced l
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" Work is underesy to recapture use of all blocked cells by positioning old fuel under cell blockers.
This will require a Technical Specification change.
. Additional blackness testing is planned for next cycle Eoc f1 j-
"The second campaign tested 32 cells with gaos and 38 cells without gaps from the first campaign Y
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10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 DISTANC' J'.
JELL, INCHES i
O FIRST CAMPAIGN E SECOND CAMPAIGN Axial distribution of gap locations
__