ML19281A259
| ML19281A259 | |
| Person / Time | |
|---|---|
| Site: | 07106639 |
| Issue date: | 01/31/1979 |
| From: | Genser J EGGERS, RIDIHALGH PARTNERS, INC. |
| To: | Marotta C NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| NUDOCS 7903090096 | |
| Download: ML19281A259 (4) | |
Text
-
7Hoss9
- 4 RIOlHALGH, EDGERS & AssocsATEs aucts.=.a o man. s a s s e, eversue co nsu67.=re e........o-.......
(614)299-2995 January 31, 1979 Mr. Charles R. Marotta U.S. fluclear Regulatory Conmission Transportation Branch Mail Stop 396-55 Washington, D.C. 20555
Dear Charlie:
In accordance with our telephone conversation yesterday, I have enclosed eight copies of each of the three revised pages to the January 2,1979, " Amendment to Safety Analysis Report for Packaging TRIGA Fuel in MH-l A Spent Fuel Shipping Cask".
If yoi' should have any further questions, please do not hestitate to call me.
Sincerely, J
W J
' hn Robert Genser enior Research Engineer Enc.
JRG/cls cc: Mr. Jerry Luckow 79030900N
17 3.4 Calculations The KEN 0 program was run with specular albedo reflection on the inner quadrant boundaries to simulate the entire cask.
The effective neutron multiplication factor was calculated as keff = 0.572 wi th a single standard deviation of 0.0058.
The 99 percent confidence level is keff + 3a = 0.589.
Therefore, the cask is more than adequately criticality safe.
Additional calculations were performed to simulate structural failure of the fuel element tubes.
The fuel element tubes were assumed to collapse down around the fuel elements in a tight concentric configuration Two geometry models were considered: (1) a closely packed square array of 12 elements per quadrant positioned in the central corner of the basket and (2) a square array of 12 elements per quadrant with the fuel elements spread uniformily to fill the basket cavity.
The results are summarized in Table 2.
An additional calculation was performed with the boral poison cruciform removed and all other geometrical constraints retained.
This result is also reported in Table 2.
3.5 Summary These findings indicate the criticality safety of the cask even ur. der extreme accident conditions.
From the results of the above analysis, it is obvious that the proposed basket modifications in the MH-1A cask is a non-critical item.
18 TABLE 1.
MATERIAL ATOMIC DENSITIES Material Nuclide N (b r cm)
No.
Name No.
Name 4.2257(-2)(a) 1 Zirconium 4000000 Zr 2
ZrH2+U
-92?.31 U235 2.7688(-4) 922381 0238 1.0936(-3) 10001 H
8.0256(-2) 400000 Zr 4.0128(-2) 3 SS-304 240003 Cr 1.7397(-2) 260001 Fe 6.0521(-2) 280003 Ni 8.1045(-3) 4 H0 10001 H
6.6863(-2) 2 80003 0xy 3.3431(-2) 5 Graphite 60001 C
8.5326(-2) 6 Boral 50000 B
1.4329(-2) ihtural 60001 C
8.4628(-3) 130000 Al 4.1858(-2) 7 Lead 820000 Pb 3.2964(-2)
(a) 4.2257(-2) 4.2257x10-2
19 TABLE 2.
CRITICALITY SAFETY ANALYSIS k
N o..
Gff
_ la eff + 3a Geometry I
0.572 0.0058 0.589 Figure 2 2
0.579 0.0050 0.594 Closely packed square array in basket central corner.
3 0.555 0.0053 0.571 Square array spread to fill basket.
4 0.612 0.0048 0.626 Figure 2 with boral cruciform removed, but other dimensional con-straints retained.