ML19344F207
| ML19344F207 | |
| Person / Time | |
|---|---|
| Site: | 07000258 |
| Issue date: | 06/03/1980 |
| From: | Mandel H ILLINOIS, UNIV. OF, URBANA, IL |
| To: | |
| Shared Package | |
| ML19344F208 | List: |
| References | |
| 03387, 16629, 3387, AMBA-800603, NUDOCS 8009120611 | |
| Download: ML19344F207 (8) | |
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\\' 3.Bgp o,.,, p .......,,s... s.,.,, @f, = =... s gKGB a m=tr "" h juR0 9 $80 * .6 une 3, 1980 v.s.g" James G. Keppler, Dire. f/ U.S.N.R.C., Region III' g g7 /8 - O gg[ 799 Roosevelt Road G/ Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
The University of Illinois hereby requests an amendment to Special Nuclear Materials License Number SNM-236 to allow it to possess up to 300 grams of Uranium-235 in the fonn of 23bUF6 powder to be used in experiments attheAdvancedTRIGAReactor(facilitylicenseR-ll5). The University Health Physics Office will supervise and control the radiation hazards that might be involved in the use of such material. The matarial will be used in experiments performed at the Nuclear Reactor Lab. Irradiation of the material will take place in an experimental facility of the Illinois Advanced Triga Reactor within the provisions of facility license R-ll5. Approval for the irradiation will be obtained from the Nuclear Reactor Committee as indicated in the Technical Specifications for the Reactor. Enclosed, for your information, is a complete and detailed description of the proposed use of the material and an analysis of the concomitant hazards. It is hoped that this information will be sufficient to allow timely approval of this amendment application. If you should have any questions, please contact me. Very truly yours, M m bW h l .7 Dh5 ector Mandel, Head Health Physics Section 9 8 0, -\\Q ] 30p 1 HM:bw V-ggss nr. "/-{ 0 h II cc: John Hunnel r G. Miley q, , ~f ~ l 16e2s 1 1 g 80 09120 hl JUN 9 1980 hjja DOCUMENT CONTAINS M..k [,k, mfbi P00R QtjAUTY PAGES.4 control ac.0. T
I ~ Nucleor Engineering Program P i,L,,"l'.'E',""l,7o','~' '***'" May 30,1980 , m,,,, .Mr. Hector Handel Dept. of Environment.cf Health and Safety l University of Illinois Urbana, Illinois 61801
Dear Mr. Hardel:
This is a request to purchase a small quantity (300 grams) of 98% enriched UF for use in nuclear pumped laser experiments. We have enclosed 6 a copy of the anticipated hazards analysis of the proposed experiment. I cir the faculty adviser and principal investigator on this research. Graduate research students involved include Sam Nacalingan, Fred Doody, Mark Zediker, and Tim Dooling. The nuclear pumped laser group have been utilizing the niversity of Illinois TRIGA reactor for their experiments for the last few years. Some of the many experiments conducted here intc1ved the use of L, 35 (937. enriched coated tubes where the fission f ragments werc employed to pump a laser i medium. In the proposed experiments we plan to utilize gaseous UF6 for this purpose. These experiments are part of a series of studies performed under a three year contract with NASA. The initial two phases which include the development and construction of a UF handling system and the use of natural UF6 are well 6 I ~ we hope to collaborate underway. For the final phase involving enriched UF6 with personnel from NASA. The tentative date for these experiments which would be conducted a,t the University of Illinois TRIGA reactor is August 15th. Consequently, we would appreciate if you would kindly expedite the review of this request to the extent possible. Thanking you, ..i.]ff.o( , George H. Miley, Chairp4rson Nuclear Engineering Program GHM:rm G cc: -Sam Nagalingam G. Beck ,,n-. - - -., -,m- .,,n. n,.,
e ,- T, Hazards Analysis For An Enriched UF6 Experiment Objectives: The nuclear pumped laser group (NPL group) has a three year contract with NASA, to investigate the feasibility of developing a U235 fission fragment excited nuclear pumped laser. XeF* laser seemed to be the most compatible of all lasers 7 The initial experiments IO coated surface source and the University with this system using a B of Illinois TRIGA reactor was conducted in 1977-1978. Encouraging results prompted us to put forward the three year proposal to NASA. The phase I of the project which includes the development and construction of a UF6 handling system (Appendix A) and a hybrid laser cell is being completed. Phase II is to perform experiments at the University of Illinois TRIGA reactor using natural UF. Planned initial experiments 6 are investigation of quenching eff 3 cts of UF6 on rare gas halide flourescence and photo absorption effects of UF. The bench studies 6 which preceed the reactor experiments have just begun. By the end of summer we hope to successfully concl'ude this phase of the project. Besides the goals mentioned abovc, we hope to successfully transport UF6 from one part of the vacuum system (supply cylinder) to the laser cell and at the end of the reactor pulse return it from the laser cell to mentioned in the premier goals mentioned earlier, the successful completion of this aspect is extremely necessary to the achievement of l the return cylinder. Though this is not mentioned in the premier goals I mentioned earlier, the successful completion of this aspect is extremely necessary to the achievement of them. A discussion of the UF6 handling system and the procedures are explained in detail in Appendix A. The phase III which includes the addition of enriched UF6 would merely constitute the extension and continuation of the set of experiments j 232.39 conducted in phase II. l
2 1 Description of Experimental Apparatus The laser cell to be employed and the UF6 handling system is described in detail in Appendix A. An activated charcoal trap (innersed in liquid N ) which is depicted in Figure 1, is inserted between the 2 - dry ice trap and the vacuum system. The sole purpose of this trap is to contain the fissio4 products formed in the cell when the reactor is operated. gperimental Procedure As a preliminary step the laser cell will be positioned adjacent to the core at the thruport of the reactor which will be run at low power (at i.e.15 watts) to check the possible effect of extra reactivity due to the presence of uranium in the tube. Reactor pulses of reactivity insertion from $1.10 to $3.50 will be utilized. The filling and evacuation of the laser cell will be carefully monitored with the aid of a check list. (i) The filling of the laser cell would be accomplished with valves V i and V2 closed. (ii) Immediately after the laser cell is filled, V3 would be closed and the system would be evacuated. (iii) After the reactor pulse, Vi and Y2 would be opened. (Making is closed). Thus the laser cell is evacuated completely sure that V3 through the charcoal trap. (iv) The cell will be evacuated up to e pressure of 10-3 torr. Then the valves VI and V2 will be closed and V3 will be opened. From similar experiments performed previously the charcoal trap has been observed to outgas below a presse.re of 10-3 torr. (v) Shielding is provided by steel pl.ugs in the throughport and the ( blockhouse will be monitored at all times. -.m v.,..,.,_-,_y w .,-r-.__y-., _
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4 Anticipated Hazards _ A. Hazards to Reactor Operation. The presence of uraniu'm in the throughport next to the core of the reactor might introduce a slight positive reac'f.ivity. The reactivity effect is measure to be less than one cent. Furthermore, the cell is removed only if the reactt,r is shut down. Since the beam port is isolated from the core any accident in the experiment would not affect normal operation of the reactor. B. Hazards from Induced Radioactivity a. Hazards from UF6 The UF6 will be retained within the system. The necessary precautions and steps to achieve this has been described in detail in Appendix A. b. Hazards from fission product activity. ) The activated charcoal trap immersed in liquid N2 is primarily for the purpose of trapping fission products in particular the iodine isotopes. Lead bricks will shield the trap. Such a trap has been found to perform very efficiently in experiments conducted previously by Guyot and later by Russ DeYoung. In evacuating the laser cell, the procedure detailed in the experimental procedure will be strictly adhered to. After a 53.00 pulse, if the cell is evacuated the iodine activity estimated to be present in the charcoal trap is 3.71 m Ci ( App B). At the end of a run of 20 pulses (53.00) at intervals of 1/2 hour, it is estimated that the accumulated activity in the trap will be of the order of 265 m Ci corresponding to a dose rate of 264 mR/hr at 1 foot (App B). i l-l
p. 5 In Guyot's experiments after 20 pulses ($3.00) the maximum dose rate was 100 mR/hr at one foot from the charcoal trap where estimates under similar assumptions as in App B had indicated a dose rate of about 3R/hr at 1 foot. Thus no major radiation problems are expected from the charcoal trap. The dose rate from the trap can be monitored after each l' pul se. At any moment the trap can be isolated from the system by two valves (Fig 1) or disconnected from the system. Finally, it is estimated that the total release of iodine isotopes in case of an accident after two days of pulsing (about 20, 53.00 pulses) would be at most 20 mci (a limit of 1.5 Ci is specified in the Tech. 90 would be 0.2 x 10-3 mci (a limit of 0.5 Specs) and that of Sr mci is specified in the Tech Specs). If a rupture occurs,and all of the iodine is exhausted to the stacks, the amount,of iodine evacuated would be the equivalent of iodine activity allowed by the 10 CFR 20 over a i period ranging from 20 to 100 days precaution to be taken against a rupture are the following. 1. The trap will be made of metal (probably brass). 2. The trap will be isolated from both the cell and vacuum system by two metal valves, except for filling and evacuating operations. 3. The trap shall not be disconnected from the vacuum line without the health physicist's approval. 4. The trap will be immersed in liquid N2 during the i experiments. An air sample will be taken near the apparatus after the initial pulse and after about 10 pulses to check on any airborne activity. 8
6 c. Hazards from laser cell. From previous experiments, the activity in the structural material causes a dose rat,e of the order of 500 mR/hr at 30 cm.16 hrs after the last pulse. Af ter 20 pulses ($3.00) over a period of two days and ~ allcwing 1/2 day cooling time, the estimated dose rate due to the l' presence of fissioE fragments in the cell walls is estimated to be 46 mR/hr. ( App B). After the laser cell is removed from the thruport, it would be placed in the blockhouse with proper shielding and posted signs.- The laser cell will be removed when the exposure is not more than 20 mR/hr 0 30 cm. The carriage will then be taken to 104 NEL. Label s indicating the radiation hazard and exposure rate will be posted on the carriage after its removal from the thruport. Dose rates and dates will be recorded for the following. 1. The rate at the beam port after the shielding is removed to insert i the laser. 2. The rate at 1 foot from the laser carriage when it is removed from the beam port. 3. The rate at 1 foot from the laser carriage when it is removed from . the blockhouse. 9 h I i l . _ _,. _. _. _ __ _ _,__.-_ __ __..,_.}}