ML19296A043
| ML19296A043 | |
| Person / Time | |
|---|---|
| Site: | 07106698 |
| Issue date: | 09/25/1978 |
| From: | Clark J NUCLEAR FUEL SERVICES, INC. |
| To: | Macdonald C NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| JDR-78-16-ETS, NUDOCS 7810300381 | |
| Download: ML19296A043 (9) | |
Text
r Nuclear Assurance Corporation 24 Executwe Park West.
Atlanta. Georgia 30329 (404) 325-4200 Telex 549%7 Weinbergstrasse 9 8001 Zunch. SMtzenand (01)470844 Telex 57275
\\\\ 47 3 C[,1. '<
M September 25, 1978 01'
'7,,
JDR/78/16/ETS
-M9 Mr.
C.
E. MacDonald, Chief Transportation Branch Division of Fuel Cycle & Material Safety Nuclear Regulatory Commission Washington, D.
C.
20555 RE:
Letter from J.
D.
Rollins to C.
E.
MacDonald, July 13, 1978,
.n"1/7 8/09/ETS
Dear Mr. MacDonald:
In accordance with Mr. Odegaarden's request in our telephone conversation of August 18, 1978, we hereby resubmit our referenced request for amendment to USNRC Certi*ficate of Compliance No. 6 6 9 fi,
Revision 7.
The requested amendment will change references to NFS Drawing No. 10080, Sheets 1 throuch 4, Revision 14 to NFS Drawing No. 10080, Sheets 1 through 4, Revision 16.
In addition pages 3-99.1 and 3-99.2, attached hereto, will be added to the Safety Analysis Report For Nuclear Fuel Sarvices, Inc. Soent Fuel Shipping Cask, Model No. NFS-4 (SAR).
This change to the SAR wj 11 be indicated as Revision 2 dated September 25, 1978.
In summary, the requested revision will permit limited local vdriittions in ef fective lead thickness which will improve manu-facturing case for NFS-4 (NAC-1) type casks.
Specifically the requested amendment permits effective local lead thickness r e duc --
tions of up to 13.5 percent.
The local region of lead thickness reduction is limited by an accentance criteria specified in Note 14 on NFS Drawing No. 10080, Sheet 4, Revision 16.
This criteria specifies that the maximum total cylindrical shield area which may be affected by an underlying reduction in effective lead thickness shall be no more than 2.4 percent of the total cylindrical surface.
This change will result in a decrease in packaaina weight of no more than 75 lbs.
This veicht change is not significant to the thermal or structural performance of the packaginq in an accident or other conditions prescribed by the regulations.
Also, this change has no significant eifect on the post accident ionizing radiation dose rate measured 1 meter from the cask surface.
A shield void which may occur due to lead slump would increase from 0.315 inches, as calce]a ted in the SAh, page 3-97, to 0.88 inches at the cask end.
The additional.565 inch slump results 7810300 Ml C 11
-1
'Mr. C.
E. MacDonald Page 2
[
September 25, 1978 l
from the assumption that a reduced effective lead thickness regic compresses to nominal effective thickness under high doccieration forces.
The lead region referred to is that which would have an effective reduction of lead thickness of 3/4 inch over 2.4% of the shield area.
The total lead slump calculated is within the 1 inch allowable specified in the SAR.
For nuclear criticality safety evaluation purposes, neutron interaction be-tween like packaaings will not be significantly affected by this change.
In our judgement, this change in design has no significant affect on the design normal or accident conditions performance of the packaging.
Notwithstanding this judgement, the as-built packagings shall be subject to acceptance tests and inspections and evaluated against acceptance criteria specified in the Safety Analysis Report and in the USNRC Certification of Compliance No.
6698.
In accordance with the schedule of fees published on page 7223 cf the Federal Register, Volume 4, Number 35, dated February 21, 1978, a check for the amount of $2,800.00 was includad with the referenced letter.
If you have any questions, please call Mr.
C.
C. Hoffman or Mr.
R.
E.
Best.
Sincerely, NUCLEAR ASSURANCE CORPORATION whsa8cfb'4 n)
Jack D.
Rollins Vice President & General Manager Engineering and Transport Services JDR:saf nclosur NUCLEAP, FUEL SERVICES, INC.
=-
James R.
'la rk Manager, Quality Assurance and Licensing
ATTACHMENT REVISION 2-ADDITIONAL PAGES (dated 9/1/78) FOR THE SAFETY ANALYSIS REPORT FOR NUCLEAR FUEL SERVICES INC.
SPENT FUEL SHIPPING CASK MODEL NO. NFS-4 (dated 12/30/71, updated 9/29/72)
REVISION 2 3-99.1 9/1/78 12.5
=
w 25" g
-f Reduced Effective Thickness Region Surface Overlying Affected i
}-~-[-'-
Lead Region 145" Engineered Void i
I y
l
- -A y
l b
't 5"
l I
~
7.06" y
,_12.5" 13.75" y
In addition to the engineered lead void provided at the base of the cask, there may be small regions of reduced effective radial thickness within the lead shield.
This reduced effective thick-ness will not impair the structural or thermal performance of the packaging in an accident or other conditions prescribed by the regulations.
Assumption:
Reduced effective thickness lead compresses under high deceleration loads.
2 2
Total lead volume of the cask = n/4 (25 - 14.12
) x 25 +
n/4 (27. 5
- 14.12 2) x 145 + n/4 (25
- 14.12 2) x5 2
2 8
or Total lead volume V
= 73447 inch In section 3.1.6.1.4.4.1 the end lead void resulting from deceler-ation forces was computed to be 0.315 inches.
The maximum permitted length of end void is 1.0 inches.
To assure conservatism this ana-lysis uses 0.88 inch as the permitted length of lead void at the cask ends.
3-99.2 Therfore, the additional end void length which may result from compression of the reduced effective thickness region =.565 inches 2
2 V
= volume of the region = n/4 (27.5
- 14.12 ) x.565 247.11 inch' or V
=
D Lead pour experience has shown that reduced effective thickness regions in free-poured lead are localized and easily detectable by non-destructive examination techniques.
Accordingly, it is assumed here that the surface area of the heavy metal shield under which such regions may exist is no more than two and four tenths (2.4) percent of the cylindrical surface area of the lk inch steel shell.
The volume of the lead under this localized area is approximately:
V
= 0.024 x 76540 inch (n/4 x (27.5
-14.12 2) x 175) 8 2
local 3
= 1837 inch The allowable average percent reduced effective thickness in the lead shield in the localized region = V
= 247.1 x 100 1837 ylead
= 13.5%
Hence total lead slump in the cask
= 0.315 +.565 = 0.88<"1.0" which is less than the one inch allowable specified in section 3.1.6.1.4.4.1.
O M
m l
1 M
N M
O.% -
k NO. OF PAGES REASON-O PAGE ILLEGIBLE:
C HARD COPY FILED AT.
PDR OTHER O BETTER COPv' REQUESTED ON
/_
1 D#KGE 100 LARGE TO FILM.
O HARD COPY FILED AT:
PDR CF OTHER O FILMED ON APERTURE CARD NO. ? ff/C
- %yL -.o 5