ML20203H212
| ML20203H212 | |
| Person / Time | |
|---|---|
| Site: | 07000036 |
| Issue date: | 12/08/1997 |
| From: | Sharkey R ABB COMBUSTION ENGINEERING NUCLEAR FUEL (FORMERLY, ASEA BROWN BOVERI, INC. |
| To: | Soong S NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| TAC-L30995, NUDOCS 9712180347 | |
| Download: ML20203H212 (19) | |
Text
,
96- %
Docl!et No. 70 36 1.ieense No. SNM 33 Dr. Sean Soong 1.icensing Ilranch Division of Fuel Cycle Safety and Safeguards, NMSS U.S. Nuclear llegulatory Commission Washington, DC 20555 0001
Subject:
Addi:lonalluformation: Amendment itequest for Unrestricted Itclease of Ilydrofluoric Acid (TAC NO,( 0995) linclosures: 1) llesponses to 1.etter from NitC, Sean Soong, to Cll, Itobert Sharkey, dated November 6,1997.
2)llevised l'athway Analysis for liF Scrubber 1.lquid
Dear Dr. Soong:
Enclosed are responses to questions posed in your letter dated November 6,1997. In addition, a reviset lose assessment for the proposed release ofIIF is attached. This revised dose assessment supersedes the assessment transmitted to the NRC on August 12, 1997.
If there are questions regarding this matter, please feel free to contact Dr. Earl Salto of my staff at (314) 937-4691 Ext. 461 or myself at (314) 937-4691 Ext. 399.
I Sincerely, N
COMllUSTION ENGINEERING,INC.
I'b li gG wb m/
/9-%-9 7 Robert W. Sharkey Date:
Director, Regulatory /.iairs ec: Patrick lilland Region 111 IW'/6$$
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c ABB Combustion Engineering Nuclear Fuel M*" rVeerg Pc Pm e
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ikclostre I ta 11A97/655 1
llespbnse to letter from Sean Soong, NRC, to Itobert Sharkey, CE, dated November 6, 1997.
Questiren 1: Is there a possibility that the uranium released in the hydrofluoric acid (liF) may be reconcentrated (for example, in a waste treatment or metal recovery operation after use of the llF)? Frovide a conservative dose assessment for this possibility.
Considering not only the original buyer but possible end uses of the material, ltesponse: Afler use in metals processing, the metals in the liF likely will be precipitated using a base producing fluoride and metal salts. These salts are then either directly disposed ofin a RCRA land fill or stabilized and disposed in a land fill. A detailed dose assessment has been added for imth the waste water treatment personnel and land fill personnel.
Since the material will be free released, oft specification or excess material may be sent from the metals processor to be used fbr water fluoridation. This potential pathway is also considered in the revised dose estimate.
Question 2: Commit to representative sampling of the hold tank before release of each batch ofIIF.
llesponse: The uranium concentrations in the hold tank will be veritied by taking and analyzing a representative sample of the tank. A representative sample of the hold tank will be collected prior to transfer to a tanker truck by circulating the solution to mix the hold tank. The llF solution being produced will not be transferred frcm qualification tanks to the hold tank during the period of sampling and transfer.
Question 3: You indicated in your August 12,1997 submittal that a diked pad will be constructed for the llF holding tank. What volume ofIIF will the diked area be capable oftontaining in the event of a leak?. lust!fy why this volume is sullicient.
1 lletponse: The volume of the dike is 38,000 liters and the volume of the tank is 35,000 liten. Additionally, the storage tank is double walled. Since the dike will hold more than the entire contents of the storage tank the volume of the dike is s'iflicient.
Question 4: Indicate the total volume ofIlF per year which is expected to be transferred from the site for unrestricted use.
Ilesponse: Less than 1 million liters.
Question 5: Correct the dose unit in the third column of Table 2 of your August 12, 1997 submittal, llesponse: Corrected page is enclosed.
E ciostre I to RA97/655 Question 6: Provide the basis for the internal dose estimates used to calculate the total efTective dose equivalent presented on page 9 of your August 12,1997 submittal. The internal doses cited are inconsistent with the calculations presented on pages 6 and 7 of
~
your submittal.
Response: The paragraph titled Total EITective Dose Equivalent was erroneously added from a previous version of the report. The corrected version is enclosed.
Revised Pcthway AnClysis for HF Scrubber Liquid
Purpose:
This document has been prepared to support the request for authorization for unrestricted release of hydrofluoric acid (HF) from Combustion Engineering's (CE) facility in Hematite, Missouri. In order to support such a release, HF production rates and process, proposed license release guidelines, potential
~
usage, and pathway analysis are included in this report.
Process
Description:
UFe is converted to UO using a multi stage
- dry" conversion process. The UFa is 2
converted to UO F using superheated steam. The UO F is further processed 22 22 using disassociated ammonia (hydrogen) and superheated steam. The off gas is passed through two sets of sintered metal filters to remove particulate.
Therefore, only gaseous effluents from this process are passed out to the scrubbing system. The we' scrubbing system captures the HF which then will be used as an industrial feed stock. A more detailed description of the conversion process may be found in Part ll of SNM 33.
The advar' age of using a wet scrubbing process, as opposed to the present use of a dry (calcium carbonate) scrubbing system, is two fold. First a usable Industrial feed stock is produced. Second the emission of HF gas to the environment is reduced due to the increased efficiency of the wet scrubbing process.
Operational Details (Current):
Approximately 300,000 kg(U)/ year of UO are produced by CE. This produces 2
approximately 100,000 kg(HF)/ year with ~10,000 kg(HF)/ year in stack emissions and a production of ~180,000 kg(CaF )/ year.
2 Wet Scrubber Operations:
Currently, trace amounts of uranium that could pass through the metal filters is captured by the scrubber rock. The rock is routinely checked and found to have less than 30 pCl(U)/g%. At this level a design basis for the wet scrubber was es'ablished to ensure lets than 3E-6 pCl(U)/mi during routine production.
The HF scrubbers will be placed plant south-west of the current dry scrubbers (Figure 1) and will remain a clear area as defined in SNM 33 3.2.6.2. The HF solution will be created by a wet scrubbing process which removes HF vapors from the effluent and places them into a liquid form. The liquid is collected in a favorable geometry configuration (Figure 2). This configuration is set up such that different cells may be isolated, mixed, and sampled. When mixing and I
I:nclosure 11 RA97/655
Revis:d Pcthway An lycia fer HF Scrubb:r Liquid Figure 1 I
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3 ILnclosure 11 RA97/655
Revised Pathway Analysis for HF Scrubber Liquid
. sampling are in progress, the " day tanks" will receive HF produced while the
- qualification tanks" are undergoing testing. After sampling the liquid HF is passed from the qualification tanks to a hold tank which will have a volume of up to 35,000 liters. In the unlikely event of a process upset which would raise the uranium concentration in the hold tank above the release limits, then prior to release from the qualification tanks to the hold tank the liquid will either be diverted for later introduction into the system or placed into a container and neutralized. If neutralized, the neutralization may create a solid phase that contains uranium. This solid phase will either be recovered or disposed of as low level radioactive waste. The neutralized liquid effluent will be sent to a waste water treatment plant, released to the site creek, or if sufficient amounts of uranium cannot be removed from the liquid it will be solidified for disposal as radioactive waste.
Planned Acid Handling The HF solution will be collected in a set of favorable geometry cells, known as day tanks and qualification tanks. The qualification tanks will be sampled prior to transfer to the hold tank to assure that in the case of a severe process upset that criticality safety is maintained. The HF solution being produced will not be transferred from the day tanks to the qualification tanks during the period of sampling and transfer. The uranium concentrations in the hold tank will be verified by taking and analyzing a representative sample of the tank. A representative sample of the hold tank will be collected prior to transfer to a tanker truck by circulating the solution to mix the hold tank. The HF solution being produced will not be transferred from qualification tanks to the hold tank during the period of samplirg and transfer. The hold tank will contain a maximum of 35,000 liters with a maximum of 20,000 liters leaving the site in any one shipment.
Proposed Release Guidelines:
CE will market the HF solution for use as a industrial feed material with uranium concentration less than 3 E-6 pCl/ml, which is equal to the sewer release limit in 10 CFR 20 Appendix B. Each shipment will contain a maximum of 20,000 liters.
Many types of analyses may be used to determine uranium concentration some of these methods either measure uranium by mass (chemical methods) or specific uranium isotopes (gamma spectroscopy). Conversion of these measurements for comparison to release limits requires knowledge of the uranium isotopic ratios. For this pathway analysis the uranium will be assumed to be at the ASTM limits, in actual production, isotopic analysis of every cylinder which enters the conversion process will be known and may be used to calculate specific activities for the uranium in the HF.
i 4 1 RA97/655
Revised P thway Analy;is for HF Scrubber Liquid i
l Table 1 provides the specific activities of the uranium isotopes of interest as well as their contribution to the total activity in the HF assunning isotopic ratios at the ASTM limit. The ASTM C990 90 specifications are:
232 235 s 0.002 pg U per g U
23s s 10,000 pg zuU per g u
s 5,000 pg "U per g 23sU 2
The total uranium concentration, ppm U, for different enrichments has been adjusted to represent the maximum release concentration at 3 E 6 pCl/ml. The density of the liquid was assumed to be 1.15 g/ml.
Table 1 Uranium in HF at Maximum ASTM C996 90 Concentrations U
isotope isotope %
Specific Activity by A ntivity Total U
% risu concentration by mass Activity mass (pCl) of activity per Enrichment (ppm)
(pCVg)
(pCl/gU) isotope per ml HF ml of HF solution solution
( Cl/ml)
"U 1.00E-08 2.14E407 2.14E 03 1.80E-09
'" U 5.00E-02 6.23E+03 3.11 E+00 2.62E-06 5
0.73
'"U 5.00E+00 2.16E+00 1.08E-01 9.07E-08 2.99E-06
'"U 2.50E 02 6A 7E+01 1.62E 02 1.36E-09
'"U 9 49E+01 3.36E 01 3.19E-01 2.68E-07
'"U 1.40E-08 2.14E+07 3.04E-03 1.83E-09 8"U 7.00E-02 6.23E+03 4.36E+00 2.66E-06 7
0.53
'"U 7.00E+00 2.16E+00 1.51 E-01 9.22E-00 2.96E-06
U 3.50E-02 647E+01 2.26E+00 1.38E-08
'"U 9.29E+01 3.36E-01 3.12E-01 1.90E 07 Pathway Analyses:
Pathway analyses were performed to bound the potential exposure due to free released material for workers at non-licensed facilities handling HF, treating waste generated by the subsequent use of HF, and reuse as a drinking water additive. Conservative potential exposures were used for these analyses.
Scenario 1 Occupational Worker using HF:
This dose estimate assumes that the HF is used for metal processing and personnelinhale vapors and are immersed in HF produced by CE. The assumptions used for Inhalation and immersion are conservative because
$ 1 RA97/655
Revised P thway Analy;is for HF Scrubber Liquid injuries resulting from the chemical hazards of the HF would preclude HF
' use in the manner described.
~
Dose estimates have been assessed using conserve 4m at winotions.
The calcu!ated dose has conservatively estimated to k ' u a: ers of magnitude below the dose limit to the public of 100 n.e m i equired by 10 CFR 20, which in turn is well below the average baL9 o.w dose of 300 mrem / year from all sources that tne average person iiving in the USA receives.
Internal Dose:
Inhalation Conservative Assumptions: The concentration of HF in the solution provided as feed stock by CE is 35% HF by weight. The average HF concentration in workin0 areas of the plant is 30 ppm, concentration of HF which is immediately dangerous to life or health (Note: In the August 12 submittal a conservative ppm by mass instead of ppm by volume. This submittal uses the actual ppm by volume listed by NIOSH.). The majority of uranium which passes into the scrubber will be UO F from the conversion of fugitive UFe 22 gas with the scrubber solution. However, some UF may be 4
present so it is conservatively assumed that 50% of the uranium is i
in the form of UO F, Class D, and 50% is UF Class W. Density of 22 4
HF is 1.15 g/ml. Uranium activity in HF solution is 3E-6 pCl/ml.
I U wne. = Air Density x HF concentration in work place x g HF per mol x mass of U per mass (HF).oi x mass (HF). i per mass HF x Specific Activity of uranium @ 5% enrichment
, 4 E - 5 g - rnol(air) 30 g - rn al(llF) y rni 1 E 6 g - rn ol(air) 20g(IIF) 0.73 x U 100g(/IF),,,,
3.6 Cl
, g - inol(llF) l E 6 g( HF),,,
35g(11F) g(U )
Uconc# l.8 E - 13 p CI / rni,,,
8 A worker inhales 2,400 m /y (2.4 E9 mily, year in this case is a 2,000 hour0 days <br />0 hours <br />0 weeks <br />0 months <br /> work year) and uranium has an All of 2 pCl for Class D 232 (stochastic) and 0.7 pCi for Class W (Note:
U has a slightly 6 1 RA97/655
Rovised Pathway AnClysis for HF Scrubber Liquid
)
232 lower All, but the U concentration is orders of magnitude lower than that of the other uranium isotopes).
Dosc(CEDC) = l ^"
- x " ~ ' E# x0.5x^" +
Jr ml 2pCl 2.4 E9ml 1.8 E - 13pCl 0.7pCi] x 0.5x ALI yr ml Dose (internal) = 2 mrem / year Ingestion:
Due to the corrosivity of HF, ingestion is not considered a credible pathway. However, referring to Scenario 3 the assumption is made that the HF is somehow diluted and used at some future time as a drinking water source. This leads to a dose of 0.001 mrem / year.
External Dose:
For external doses the alpha and beta components will be absorbed by the aqueous matrix or the protective clothing needed for immersion in the ccrrosive liquid. Therefore only the gamma components of uranium and progeny will be considered in this discussion. The gamma rays from uranium progeny were considered up to a half life less than 100 years. For instance #3dTh 138 and 23'"'Pa were considered to be in secular equilibrium with U.
The external dose (in mrem) was conservatively calculated assuming:totalimmersion in a liquid solution using the following equt.. ton Dose = 5.100 P
Nhere:Uconc.= Uranium (isotope) concentration l't
= the stopping power of tissue relative to water (unity in this case) t
= time immersed in days (250 days)
W
= average gamma energy in MeV p
= density in g/ml (conservatively set to 1) 7 1 RA97/655
r
' Revloed Pathway Analy:lo for t!F Scrubber Liquid l
Table 2 Scenario 1 j
Esternaioooo lootope lootope Average Gamma mromtyear for Concentration Ray Energy 5%
pCl/ml (MeV) per Enrichment disintegration f
"U 1.8E 09 -
1.43! *+ 00 3E-02
- U 2.6E 1.12e 04 4E-03 8"U 9.1E 08 1.42E-01 2E 01 I
8"U 1,4E 08 0
0 8"U 2.7E 1.52E-02
$E-02
{
TotalU 3.0E 6 3E-01 l
The external dose is extremely overestimated because of the assumed cor%rativo uranium concentration and geometry. A person would not be immersed in HF, because of the extreme j
r.orrosiveness of HF.
Total Effective Dose Equivalent Summing the intemal dose resulting from the inhalalon dose of 2 mrom/y
)
and external dose 0.3 mrom/y provides a TEDE of 2 mrem /y. A dose of I mrom/y is 2 orders of magnitude less than the 10 CFR 20 limit to the general public of 100 mrom a year. Therefore, the release of umnium at 3E-6 pCl/ml does not pose an undue risk to the public or the environment.
i One should note that this la an extremely conservative estimate for the following reasons; 1) it assurnes all exposure to HF is due to HF provided by CE,2)it assumes that all releases are at the release limit of 3E 6 7
pCl/mi, 3) it assumes that the person works every day performing this task, i
- 4) it assumes that the person is continually working in an IDLH environment, and 5) it assumes that a person becomes engulfed in a HF
(
solution.
i Scenario 2 Occupational Worker Conecting Waste from HF Processing:
After HF is used in metals processing, the material is then a RCRA regulated hazardous waste. Therefore, the materialis generally disposed of by neutralization which precipitates fluoride and metal salts. The -
scenario described below is conservative in that it assumes that a moist material becomes airborne at a level that is equal to the permissit.ie exposure limit of NaF.
L 8-1 RA97/655 t
Revised P thway Analysis f;r HF Scrubber Liquid This scenario assumes that after the HF is used for solidification of metals it is then neutralized using sodium hydroxide. This neutralization pret:lpitates sodium fluoride and metal salts. The salt is then pressed to a moisture level of approximately 60%. This materialis then buried at a RCRA landfill. The worker exposure at a land disposal facility is conservatively bound by this analysis because the same OSHA standards for NaF exposure would limit the dose to tne worker. Because this analysis assumes that the sodium fluoride is concentrated by pressing out excess water, this ana! sis bounds the case where a slurry is made then
/
stabilized and solidified using cement.
Dose estimates have been assessed using conservative assumptions.
The calculated dose is approximately two orders of magnitude below the exposure limit to the public of 100 mrem / year required by 10 CFR 20, which in turn is well below the average background dose of 300 mrem / year from all sources that the average person living in the USA receives.
Internal Dose:
Inhalation Conservative Assumptions: The concentration of HF in the solution provided as feed stock by CE is 35% HF by weight with a uranium activity of 3E-6 pCl/ml. The solution is neutralized using sodium hydroxide producing sodium fluoride and other metal salts.
U wne = HF density x weight fraction of liquid to F x conversation of g HF to g F x conversation g fluoride to g NaF x concentration of U in HF solution
'4
~ 'E Ucorr = "I"9) x x
x x
1.15Mlig) 35g(1/F) 19g(F) 42g(NaF) ml(lig)
Ucorr = 3.5/i-6 Ci/g(NaF)
Note: NaF has a density of 2.5 g/ml. Therefore, the uranium in a dry NaF salt will be concentrated to 8.7 E-6 pCi/ml from 3 E-6 pCl/miin the original 35% HF solution.
The NaF then becomes airborne at the OSHA PEL of 2.5 mg/m (2.5E 9 g/ml).
9 Enclomre 11 RA97/655
R vi:ed P:thw y An:ly:13 for HF Scrubber Liquid 2.5E-9p(Nd0 3.5E-6p0 ni g(Nd9 Uconc = 8.8E-15 Ci/ml A worker inhales 2,400 m /y (2.4 E9 mily, year is a 2,000 hour0 days <br />0 hours <br />0 weeks <br />0 months <br /> work year). It is conservatively assumed that during neutralization all 232 uranium becomes class Y with an ALI of 0.04 pCi(Note:
U has a 232 slightly lower All, but the U concentration is orders of magnitude lower than that of the other uranium isotopes).
Dose (CEDE) =
NE x x
x y
ml 0.04pCI ALI Dose (CEDE) = 3mremly Ingestion:
Due to 1:ra toxicity of sodium fluoride the ingestion pathway considered is scenario 3, drinking water. This leads to an ingestion dose of 0.001 rnrem/ year.
External Dose:
This dose assessment assumes that a person becomes covered with the NaF filter cake for 250 working days a year. For external doses the alpha and beta components will be absorbed by the matrix (60% water) or the protective clothing used in processing.
Therefore only the gamma components of uranium and progeny will be considered in this discusalon. The gamma rays from uranium progeny were considered up to a half life less than 100 years. For instance, zuTh and ur"Pa were considered to be in secular 2
equilibrium with 23sU. The extemal dose, in mrem, was conservatively calculated assuming total immersion in a solution, assuming a density of 1 since it is 60% water (however the U concentration neglects the water), using the fc! lowing equation':
Dose = 5,100 (Equation 1)
P 10 i
l 1 RA97/655
R;vi:ed P:thway Analy;is f:r HF Scrubber Liquid Where:Uconc = Uranium (isotope) concentration Pt
= the stopping power of tissue relative to water (unity in this case)
I
= time immersed in days (250 days)
Ty'
= average gamma energy in MeV p
= censity in g/ml (conservatively set to 1) 4 1 ble 3 scenario 2 External Dose Yotope isotope Average Gamma i mrem / year for Concentration Ray Encrgy (MeV) 5%
pCL/mi per disintegration Enrichment
'"U 3.8E-09 1.43E+00 7E-02 8"U 5.5E-00 1.12E-04 8E-03 2"U 1.9E-07 1.42E-01 3E-01
- U 2.8E 08 0
0
'"U 5.6E 07 1.52E-02 1E-01 Total U 6.3E-6 SE-01 The external dose is extremely overestimated because of the assumed conservative uranium concentration and geometry. A person would not be immersed in NaF. Because of the nature of the process it is very unlikely that a person would become immersed in this filter cake.
Total Effective Dose Equivalent Summing the internal dose resulting from inhalation dose of 3 mrem /y and external dose of 0.5 mrem /y provides a TEDE of 4 mrem /y. A dose of 1 mrem / year is 2 orders of magnitude less than the 10 CFR 20 limit to the general public of 100 mrem a year. Therefore, the release of uranium at 3E-6 Ci/mi does not pose an undue risk to the public or the environment.
One should note that this is an extremely conservative estimate for the f00 wing reasons; 1) it assumes all exposure to HF would be due to HF from CE,2) it is assumed that all HF released from CE is at the release limit of 3E-6 Ci/ml 3)it assumes that the person works every day performing this task,4) it assumes that a filter cake that is 60% liquid becomes airborne, and 5) it assumes that a person becomes engulfed in a slurry of this cake.
1I 1 RA97/655
)
R:vi:ed Pathw:y Analy:Is f:r HF Scrubber Liquid I
Scenario 3 HF Used as Source for Water Fluoridation:
This scenario assumes that the HF is rejected by the metal processor and is then used to make sodium fluoride that is used to fluoridate drinking water, The use of the sodium fluoride by the operators of the drinking water treatment plant is bounded by Scenario 2.
U cone. = HF density x weight fraction of liquid to F x conversation of g HF to g F x conversation g fluoride to g NaF x concentration of U in HF solution Uconc = ml(liq) x 100g(liq) x 20g(HF) x 19x(F) 3E -6 Ci(U) x 1.15g(liq) 35g(HF) 19g(F) 42g(NaF) ml(lig)
Uconc = 3.5E-6pci/ g(NaF)
The sodium fluoride is then placed irl a water at a fluoride concentration of 1 ppm.
U cene. = c fluoride per g water x conversion from g NaF to fluoride x concentration of U in NaF solution 2g(NaF) 3.5E - 6 Ci Uconc =
x IE6ml(#,0) g(NaF)
Uconc = 7.0E-12pCi/ml Dose estimates have been assessed using conservative assumptions.
The calculated dose is less than two orders of magnitude below the exposure limit to the public of 100 mrem / year required by 10 CFR 20, which in turn is well below the average background dose of 300 mrem / year from all sources that the average person livir,g in the USA receives.
12 1 RA97/655
R;vic:d Pcthway An2iycl3 f:r HF Scrubber Liquid Internal Dose:
Inhalation Conservative Assumptions: Combustion Engineering provides HF which produces a yeara supply of NaF for t. water tmatment plant. A person inhales suspended class Y uranium in air vapor.
The air is at 100% relative humidity and 30 Celsius results in an air density of 0.024 g(H O)/g(air) 2
= Fraction of H O to air x density of air x uranium U cone.
2 concentration in water 2g(NaF) 3.5E - 6pci Uame=
x IE6mI(H O) g(NaF) 2 Uamc = 2.2E-16 C/ /ml A person inhales 11,000 m /y (1.1 E10 ml/y) and uranium has an 32 ALI of 0.02 Ci for Class Y (Note:
U has a slightly lower All, but as2 the U concentration is orders of magnitude lower than that of the other uranium isotopes).
. E - 6pCi AU 5,000 mum Dosc(CEDE) =
x yr ml 0.02pCl All Dose (inhalation) = 0.6 mrem / year Ingestion:
The ingestion assessment assumes a person drinking the uranium bearing water at the rate of 2 liters a day 365 days a year.
365 days 7.2E -12pci All 5,000 mrem Dose (CEDE) =
x day yen-ml 20pCl ALi Dose (ingestion) = 0.001 mrem / year i
13 1 RA97/655
Revised Pathway. Analy:Is for HF Scrubber Liquid
, External Dose:
To calculate external dose it is assumed that a person is immersed in a bath of water that has been fluoridated using NaF that contains uranium, External doses the alpha and beta components will be absorbed by the aqueous matrix Therefore only the gamma components of uranium and progeny will be considered in this discussion. The gamma rays from uranium progeny were considered up to a half life less than 100 years. For instance,2xTh 288 and ***Pa were considered to be in secular equilibrium with U.
The external dose was conservatively calculated assuming: total immersion in a liquid solution using the following equation Dose = 5,100 (Equation 1)
P Where: Uconc = Uranium (isotope) concentration Pt
= the stopping power of tissue relative to water (unity in this case) t
= time immersed in days (365 days)
Ef
= average gamma energy in MeV p
= density in g/ml(1 g/ml)
Table 4 Scenario 3 External Dose isotope isotope Average Gamma Ray mrem / year for Concentration Energy (MeV) per 5%
pClimi disintegration Enrichment "U
4.3E-15 1.43E+00 1 E-07
- U 6.2E-12 1.12E-04 1 E-08 8"U 2.2E-13 142E-01 3E-07 8"U 3.3E 14 0
0 2xu 6.4E-13 1.52E-02 2E-07 Total U 7.1 E-12 9E-07 The external dose is extremely overestimated because it assumes a person in a extremely hot and humid environment every day of the year.
14 1 RA97/655
Revised Pathway An:ly:Is for HF Scrubber Liquid
. Total Effective Dose Equivalent Summ'ng the internal dose resulting from inhalation dose of 0.6 mrem /y, an ingestion dose of 0.001 mremly and external dose of 0.0000009 mremly provides a TEDE of 0.6 mremly. A dose of 1 mrem / year is 2 orders of magnitude less than the 10 CFR 20 limit to the general public of 100 mrem a year. Therefore, the release of uranium at 3E-6 pCi/ml does not pose an undue risk to the public or the environment. One should note that this is an extremely conservative estimate for the following reasons; 1) it assumes all exposure would be due to water fluoridated using NaF derived from HF supplied by CE,2)it assumes al! HF released by CE is at the release limit of 3E-6 pCl/mi,3) it assumes that the person breaths hot humid air all day long every day of the year, and 4) it assumes a person takes a continuous bath in the water derived from this HF.
End Product Usage:
CE expects to sell the HF to a chemical manufacture or distributor, for example, Chemtech Products of St. Louis, MO. Conversations with this distributor have identified everal potential users for the HF.
The most likely use would be for metal pickling which is used in the aerospace and automotive industries. The spent acid in these industries is typically collected, neutralized, and possibly clarified for metals recovery prior to disposal.
CE's industrial grade HF would not be used in any industry directly contacting the food chain. The Food and Drug Administration currently prohibits the usage of any hydrofluoric acid in food processing, allowing its usage only as a bonding agent for adhesives in food packaging.
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References:
1
_ Radiation Hygiene Handbook. Blatz, Hanson, McGraw-Hill Book Company, a
Inc., New York,1959.
e 4
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