ML20058G699
| ML20058G699 | |
| Person / Time | |
|---|---|
| Site: | 07106678 |
| Issue date: | 11/08/1990 |
| From: | Read J ENERGY, DEPT. OF |
| To: | Macdonald C NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| NUDOCS 9011130362 | |
| Download: ML20058G699 (3) | |
Text
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8.,
Department oi uorgy '
i r Washington, DC 20585-e NOV 8.51000 T%
Mr. Charles MacDonald Chief, Transportation Branch Division of Safeguards.and Transportation,-NMSS-U.S. Nuclear Regulatory Commission' Washington, DC 20555-
Dear Mr. MacDonald:
This is in response to you request for' additional information concerning our application for an amerJment:to NRC Certificate of Compliance 6678:to allow a one-time shipment of ten-LP-50 containers from the UK to DOE.
o Please' note that we are hereby amending our request toLstate that shipment-of the ten containers will take place.no later than February'28, 1991c-not-November-30, 1990, as'previously stated.
Theinformationyourequestedis.asLfollows:
1.
Tritium, a diatomic t s', dec'ays by beta. emission to He-3,' a-monatomic gas. Thus,,theidecay-.of one mole of tritium. gas in a-sealed container will result in two moles ofLHe-3fandia' corresponding increase in the internalJpressureb according to.the l
ideal gas law. - Tritium has a-half-life of 12.3 years, and the y
pressure buildup in'a container follows the equation:
1 t
- Pd Po xL[Ad + 2(Ao"- Ad));
il where:
Pd = pressure at date
]
Po - fill pressure Ad - assay decayed to date-Ao = assay at-fill date 4
If we assume that Ao - 1.0; then after one year: >
l Ad-Aoxexp((-in2)t/12.3),t=decaytimeinGears.
= 0.95 Pd - 1.05(Po) i i
i Thus,.the pressure in sealed LP;50 cont'ainers increases; approxim;tely 5% per year, depending or, the11nitialiassay.
2.
The contents of the containers are' tritium g'as;; impurities are -
isotopes of helium-and other:.isotopesiof, hydrogen.
Initial" purities-are given in Table la Both:the smalloimp'urity levels. and 1
the lack of oxygen present no; concern due' to hydrogen:.ombustion.
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i 9011130362 901108 PDR ADOCK 07106678 i
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o 2-3.
The fill dates, fill pressures, initial assays (purities), and' calculated pressures of the ten containers are presented in-Table l El. Note that at the' proposed shipment date of February 28, 1991, the calculated' pressures will be significantly less than the maximum permitted fill' pressure of 1200 Torr.
Because the containers hef: M en so underfilled, the operating pressures will-
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be -significantly less than the. maximum operating pressure,for normal transport conditions of 1507 Torr. (29.14 psia) specified in Section 2.- 4.4 of the SARP.
e 4.
Both the. rate of decay of tritium and the ideal gas law are well established and obviate the need for direct pressure measurement' y
of the containers prior to shipment.
5.
No components of the packaging system need replacement prior to shipment.
6.
An interspace check (a check of the space between the LP 50 inner ~
container and the aluminum-shell) will be performed prior to shipment to shcw that:the valve: leak rate is below'the specified limit and that no permeation is taking place through the container.
7.
The proposed shipment will take place.by air and!will not add-u significantly to.the tritium storage. time -
M you have any further questiota, please do not hesit'ateft'o contact Steve Primeau at 353-4210.
Sincerely,-
.b60fSh Q y
l Jacques-B."J. Read Acting Director Division of Quality Verification and Transportation Safety Enclosure a
fcc w/ encl'-
B. Wilson, SR.
R. L. Chandler, SR R. C. Yates, DP-143 n.
4 file:
90-42-6678 i
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' TABLE 1:
LP-50 CONTAINER DATA
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I' ID No.
Fill Date Po, Torr.
Purity (Ao), w/o Pd,--Torr (2/28/911-976 5/26/89 639' 98.46 707
.y 6
6/4/89 644
. 99.23
,08 a
1016 6/12/89 649-
. 98.91 715 1035 6/21/89 649' 3 99.43 710 t
t 1004 6/26/89
'656 i
299.28 719-1 989 7/7/89
-631-999.19:
691-1, t
a i
909 7/15/89 f 647 99.33
'707 1
+,
P 1048 7/24/89 J653 7 '"99.32 712
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l 933 8/6/89
643 99.04
' 7 03-s
>3 994 8/16/89
'637
'99:37l
, /, 1;694-m 4
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