ML13095A006

University of Maryland - License Renewal for the Maryland University Training Reactor (Mutr), TAC ME1592

ML13095A006
Person / Time
Site:	University of Maryland
Issue date:	03/21/2013
From:	Al-Sheikhly M Univ of Maryland
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC ME1592
Download: ML13095A006 (40)

Text

U N IVERSITY OF Building 090 College Park, Maryland 20742-2115 301.405.5207 TEL 301.314.2029 FAX MARYLAND vwww.nmse.umd.edu GLENN L. MARTIN INSTITUTE OF TECHNOLOGY A. JAMES CLARK SCHOOL OF ENGINEERING Department of Materials Science and Engineering March 21, 2013 Document Control Desk United States Nuclear Regulatory Commission Washington, D.C. 20555-0001

Reference:

UNIVERSITY OF MARYLAND, LICENSE RENEWAL FOR THE MARYLAND UNIVERSITY TRAINING REACTOR ("MUTR") (TAC NO. ME1592), Docket No. 50-166, License No. R-70 The University of Maryland hereby submits the following documents for the Maryland University Training Reactor in connection with the renexval application identified above:

1. Ar-41 Occupational and Public Dose Assessment Report at the MUTR; and

2. Accident Analysis MHA Report (updated).

If there are questions about the information submitted, please write to me at: Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742-2115 or email me at mohamad@umd.edu.

Please copy Prof. Robert Briber on any such correspondence:

Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742-2115; rbriber@umd.edu.

I declare under penalty of perjury that the foregoing and the enclosed documents are true and correct.

Sincerely, Mohamad Al-Sheikhly Professor and Director Maryland University Training Reactor Enclosures (2) cc:

Robert Briber (By E-mail).

Ar-41 Occupational and Public Dose Assessment at the MUTR This section deals with the assessment of radiation dose contributions due to Argon-41 gas generated from operation of the Maryland University Training Reactor (MUTR). The MUTR is housed at the Chemical and Nuclear Engineering Building on the University of Maryland College Park Campus. The MUTR is used for the training of Nuclear Engineering students and for research purposes.

Radiation Protection Federal guidelines demand that "A sustained effort should be made to ensure that collective doses, as well as annual, committed, and cumulative lifetime individual doses, are maintained ALARA (As Low As Reasonably Achievable)." In working toward this goal, several conditions needed to be taken into account. Firstly, the dose levels of Argon-41 achievable in areas immediately adjacent to the MUTR accessible by the general public were to be kept below limits as outlined in Federal regulation 10 CFR 20.

Secondly, total dose contribution of Argon-41 for radiation workers in the MUTR facility must not only be kept below the limits specified in 10 CFR 20, but also ALARA. Thirdly, actions taken to comply with the first two tenets must not cause excess wear or damage to operation controls or components of the MUTR or induce excessively adverse working conditions for radiation workers at the MUTR.

To ensure safe and productive use of the MUTR, all activities taken there are conducted in strict accordance with federal and state safety regulations. Operation at the MUTR shall be carried out in ways designed to minimize unnecessary radiation dose to radiation workers and to members of the general public. These doses shall be maintained ALARA.

Sources of Argon-41 Argon-41 is generated during use of the MUTR. Most stems from the activation of dissolved air in the reactor water, though some trace contributions may come from neutron beam activation of air trapped in the thermal column or beam ports. As the reactor water warms, it loses its ability to hold air and it percolates through the reactor pool surface. Assays of Argon-41 levels within the MUTR have been performed to determine concentration and public dose due to normal reactor operations.

Occupational Dose to Argon-41 from Normal Reactor Operations The dose risk for those occupationally exposed to Argon-41 is determined by calculating its concentration in air in terms of activity per unit volume. This is compared to the Derived Air Concentration (DAC),

which is the threshold whereupon a radiation worker over the course of a standard "work-year" would receive a dose equivalent to their annual limit of 5 rem per year for whole body dose. The DAC for Argon-41 is 3.0 x 10-6 uCi/ml.

An accurate measure of Argon-41 levels at the MUTR was necessary to evaluate actions to mitigate potential doses. Two techniques were chosen to obtain this data. The first involved using an unshielded radiation measuring probe, a High Purity Germanium (HPGe) detector, to directly measure gamma emissions from Argon-41 and track its increase in concentration until equilibrium was obtained. This data provided the time required to reach maximum Argon-41 concentration, as shown in Figure 1.

2 Figure 1 Argon-41 levels at maximum power from time zero to 300 minutes MUTR Control Room Spectra 60000 50000 Post Shutdown. + 2 Minutes M)S kW. 799 Minutes 250kW. 276 Minutes 40000

)S0 kW + IS) Minutes 25OkW 4228 Minutes 250 kW s 204 Minutes AO kW 1$D Minutel, IXX) i---2501kW 15SMinutes

-250 kW 1 136 Minutes 250 kW

• 114 Wutes

-250 kW + 92 MInutes (XXX)

-250kW

+ G9 Minutes

--*-250kW 1 47 Minutes 250kW + 25 Minutes 250 kW + 0 Minutes 10"0 0

1WS0 1160 WOll IMt 1.,W) 13W0 1311) 13A11 1:130 1:40 3IW)

Channe The results indicated a time of between 3 V2 and 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to reach equilibrium of Argon-41 within the MUTR facility. These results were projected in a graph versus time, as shown in Figure 2. The sample counts taken from 180 minutes to shutdown were averaged to determine an equilibrium value. From this projection, Argon-41 increased approximately 0.56% of the averaged equilibrium rate per minute from Time Zero.

Figure 2 Argon-41 levels versus time 45000 40000 35000 30000 25000 20000 15000 10000 5000 0

R' = 09876 7-0 50 100 150 200 250 300 350

3 The second technique took air samples from various locations within the MUTR facility and measured activities of Argon-41.

Concentrations in various zones within the MUTR and in areas adjacent to it could then be determined.

All measurements in these assays were taken with the MUTR at its maximum power (250 kW) and air samples were taken with Argon-41 levels at equilibrium. In actuality, the MUTR could not be operated at maximum power for the duration of one "work-year" (2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br />) in the course of a calendar year. These conditions were chosen for the evaluation, however, to provide a safety margin as it represented "worst-case" conditions.

Air samples were taken from four zones within the MUTR facility as indicated in Figure 3.

All the samples were taken at breathing level, defined as I meter above the floor for sitting position, and 1.5 meters for standing positions. Position A took samples at the reactor pool edge at a height of 1.5 meters.

Position B took samples 1 meter back from the reactor control console at a height of I meter. Position C took samples at 2 meters back from thermal column at a height of 1.5 meters. Position D took samples at 1 meter from balcony edge at a height of 1.5 meters.

I liter Marinelli beakers evacuated under vacuum were used to take the air samples. Measurements of the Marinelli beakers after evacuation indicated a pressure of approximately 150 Torr, a level comparable to the rating of the vacuum pump used (Little Giant model 13154). This translates to approximately 20% of the original volume of air held within the beaker. To account for the difference from ideal vacuum, the Marinelli beakers were evacuated in the sample zone within the MUTR. Each Marinelli beaker was then evacuated three times (opening on-site in between each evacuation) to reduce the amount of original ambient air within the beaker to less than 1% of the sample volume. Three samples were taken at each location and the sample closest to the median was used for activity calculations. This would eliminate the effect of outliers possibly caused by loss of vacuum of the Marinelli beakers or anomalous plumes of Argon-41.

Figure 3 Argon-41 sampling locations 22308E B

A 1308A D

2308D

4 To account for deviations from Normal Temperature and Pressure (NTP - 200 C and 760 Torr),

measurements of ambient temperatures and pressures were taken with each sample. With this data, an Effective Volume of air contained within the Marinelli beaker was calculated. Effective volume was determined from the Ideal Gas Law. With PV=nRT as our sample of gas and P'V'=nRT' as a sample of gas at NTP, we can calculate the following:

nRT V =P nRT V

p V'

nRT' p/

nRT' P/

nRT nR P T' v n--R-r Pf As V' = 1 liter nRT V-P nRT' P

1 T

VT TP' PT' Efficiency calibration carried out using an air equivalent standard (Eckhart and Ziegler Standard 81144A-577), as shown in Figure 4. The efficiency for Argon-41(which has a gamma emission energy of 1293 keV) was determined by calculating the slope between Co-60 energies (1173 keV and 1332 keV). For the measurements taken in this assay, the fractional efficiency for Argon-41 was calculated to be 6.61 x 10'.

Figure 4 - Efficiencies of radionuclides contained in Eckhart and Ziegler Standard 81144A-577 i.OOE-o2 Lioo_0E-o 3 t " "

0 500 1000 1500 Energy (kcV) l0 Activity was determined by first decay correcting the total counts back to the time of sampling. The decay-corrected counts were then divided by the detector efficiency to get the total counts over the counting period.

5 The counts were divided by the total time in seconds to determine decays per second (Bq) and then converted to jtCi. The equation is as follows:

Activity = (Counts/1200 )/(37000dps/(j+/-CO)

The final concentration is a ratio of the Activity to the Effective Volume in milliliters.

The results of the assays of the MUTR at maximum power and Argon-41 levels at equilibrium are shown in Tables 1 and 2.

Table 1 Argon-41 count levels with relevant sample data at time of acquisition with calculation values highlighted.

Location Time of Transit Time of Air Humidity Pressure Water Counts Sample time (s)

Acquisition Temp

(%)

(in)

Temp Console I

MR-Room 2

12:51 159 12:

75 24 30.16 39.1 1330 3

13:13 152 13:15 75 25 30.15 38 1150 Bridge I

4-2 13:59 138 14:02 78 25 30.11 36.3 1132 3

14:21 158 14:24 78 25 30.10 35.6 1205 Experiment 1

14:45 120 14:47 69 28 30.09 35.1 2643 Floor 2 *5 U-*0 3

15:31 125 15:33 65 33 30.08 34.3 3794 BalconyT 1

15:52 129 15:54 75 30 30.07 33.8 961 2

16:14 250 16:18 75 30 30.07 33.8 964 1 As only two samples could be obtained prior to reactor shutdown, their results were averaged for the sake of calculation.

6 Table 2 Argon-41 concentrations at equilibrium expressed as activity/volume and in percentage of DAC in the occupationally exposed area of the MUTR at maximum power Sample Location Air Temp (C)

Air Press (TORR)

Effective Volume (I)

Console 23.3 766.1 1.16 Bridge 25.6 765.3 1.27 Exp. Floor 18.9 764 0.94 Balcony2 23.9 763.8 1.19 Sample Time Acquisition Time Counts Decay Corrected 12:30 12:32 1296 1312.5 13:36 13:38 1134 1148.4 15:08 15:10 2848 2884.2 15:52 15:54 963 975.3 Activity (gCi)

Concentration (ftCi/ml)

% of DAC 0.0045 3.87E-06 129.0 0.0039 3.08E-06 102.6 0.0098 1.05E-05 348.5 0.0033 2.79E-06 93.2 Since the MUTR takes between 3 /2 and 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for Argon-41 to reach equilibrium values, the calculated concentrations of Argon41 do not represent a proper way to compare to the DAC. To account for lower concentration of Argon-41 over the time interval between Time Zero and equilibrium, an Effective Concentration was determined by 1) assuming a linear increase in concentration until equilibrium; 2) obtaining the equilibrium level from an average of counts taken between 180 to 299 minutes; and 3) using 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> as the time to reach average equilibrium. With a linear concentration increase inArgon-41 concentration, the effective concentration would be 0.75 of the average equilibrium, assuming 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> operation of the MUTR. The results are shown in Table 3.

Table 3 Effective Concentration of Argon-41 levels over 8-hour operation of the MUTR at maximum power Sample Location Activity (jtCi)

Concentration Effective

% of DAC

_(Ci/ml)

Concentration

• Console 0.0045 3.87E-06 2.90E-06 96.7 Bridge 0.0039 3.08E-06 2.31E-06 77.0 Exp. Floor 0.0098 1.05E-05 7.84E-06 261.4 Balcony 0.0033 2.79E-06 2.10E-06 69.9

7 Even adjusted as Effective Concentration, the assays of Argon-41 still yield two zones near or above the DAC. One possible action to minimize levels of Argon-41 would be to run the ventilation fans within the MUTR during all hours of operation. While this would definitely minimize public and radiation worker dose contributions from Argon-41, it would have several negative effects on the MUTR facility and its operation. During the winter months, outside air would cause a severe drop in temperature, as the air is not conditioned, and this would likely affect safe operator and worker performance. High humidity, especially in the summer months, would eventually corrode and degrade control components such as relays. For this reason, constant operation of the fans was not considered a viable action. Instead, intermittent use of the fans during MUTR operation was chosen as the technique best suited to meet the required conditions. At 50% of the maximum concentration of Argon-41, the fans were operated for ten and fifteen minutes intervals (allowing for a complete change of the volume of air in the MUTR). In this way Argon-4 l's dose contributions would be mitigated, as dictated by the ALARA principle, while not affecting the safe operation of the MUTR through excess wear. This was tested in the experiment shown below.

The first trials tested 10 minute runs of the ventilation fans approximately every two hours. Assays were conducted using both an open HPGe probe at the Console and evacuated Marinelli beaker samples at the Experiment Floor. The HPGe probe logged data every 20 minutes and the Marinelli samples were taken at points prior to and after fan operation. These tests indicated the technique would result in an effective concentration of 50 to 55% of the average equilibrium, assuming an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> operation of the MUTR at full power (See Figure 5).

Figure 5 Chart of effects of 10 minute ventilation fan operation on Argon 41 concentration, expressed as percentage of the DAC 120%

Fan Effects on Argon 41 Concentration in Control Room. Normalized to U 0:00 E 0:23 100%

N 0:43 0 1:07 0 1:30 80%

0 1:52 a 2:24 60%

2:46 3:10

%~IN 3:32 40%

3:57 0 4:28 E 4:50 20%

065:11 N 5:44 0%

Aq,6:06 Time (HH:MM)

8 Considering the concentration of Argon-41 found on the Experiment Floor, the next trial increased the length of fan operation to 15 minutes. Evacuated Marinelli beakers were used to assay Argon-41 concentration at the Console. Two samples were taken for each fan run, one prior and one after, to calculate the drop in Argon-41 concentration. For these tests, movement to and from the MUTR was restricted as much as possible and the door from the Console to the Bridge was shut. This resulted in higher concentrations of Argon-41 than would be found under normal conditions, but would give the clearest indication of the ventilation fan performance. The results of the tests are shown in Table 4.

Table 4 Argon-41 reductions in concentration with ventilation fan operation expressed as activity/volume and in percentage of DAC in the occupationally exposed area of the MUTR at maximum power Sample Location Air Temp (C)

Air Press (TORR)

Adjusted Volume (I)

Console pre 1 22.2 771.9 1.09 Console post 1 18.8 771.9 0.93 Console pre 2 20 771.9 0.98 Console post 2 20 771.4 0.99 Console pre 3 21.7 769.9 1.07 Console post 3 20 769.9 0.99 Sample Time Acquisition Time Counts Decay Correced 10:45 10:48 1093 1106.91 11:16 11:17 339 343.31 1:04 1:06 1575 1595.04 1:34 1:36 395 400.03 3:22 3:23 1793 1815.81 3:49 3:51 315 319.01 Decay Corrected Concentration Activity (pCi)

(RCi/mi)

%of DAC

% rebd i ticr 1106.91 0.0035 3.16E-06 105.32 343.31 0.0011 1.16E-06 38.57 0.69 1595.04 0.005 5.05E-06 168.45 400.03 0.0012 1.27E-06 42.22 0.75 1815.81 0.0057 5.29E-06 176.29 319.01 0.0001 1.01E-06 33.6 0.82 Argon-41 concentrations averaged drops of 75% after ventilation fan runs of 15 minutes. We can project this pattern of reduction onto the equilibrium levels of Argon-41 obtained under normal conditions at maximum power. Conducting 15 minute fan runs every two hours results in the reductions in Argon-41 concentrations in the following tables and graphs.

9 Table 6 Reduction in Argon-41 concentration at MUTR Bridge expressed as percentage of DAC with reactor power at 250kW 0

0 2

52.5 2.42 16.3 4.42 68.8 4.84 17.2 6.84 69.7 7.26 12.3

%of DAC 80o 60 40 -

U %of DAC 20 04 0

2 2.42 4.42 4.84 6.84 7.26 Average % of DAC 33.8 Table 7 Reduction in Argon-41 concentration at MUTR Console expressed as percentage of DAC with reactor power at 250kW U

U 2

65 2.42 20.2 4.42 85.2 4.84 21.3 6.84 86.3 7.26 15.2

%of DAC 100 90 70 50 -m

%of DAC 40 30 20 10 0

2 2.42 4.42 4.84 6.84 7.26 Average % of DAC 41.9 Table 8 Reduction in Argon-41 concentration at MUTR Balcony expressed as percentage of DAC with reactor power at 250kW

%of DAC 0

0 2

46.6 2.42 14.4 4.42 61.0 4.84 15.3 6.84 61.9 7.26 10.9 70 60 50 40 30 m %of DAC 20 10 0

Average % of DAC 30.0 0

2 2.42 4.42 4.84 6.84 7.26

10 Table 9 Reduction in Argon-41 concentration at MUTR Experiment Floor expressed as percentage of DAC with reactor power at 250kW

%of DAC 0

0 2

175 2.42 54.3 4.42 229.3 4.84 57.3 6.84 232.3 7.26 40.9 250 200 150 -

100 -

U %of DAC 50 -

0 -

I A)

Ah A)~

AQA rQA 71r Average % of DAC 112.7 1..

Using ventilation fan runs at two hour intervals result in overall Argon-41 concentrations well below the DAC except in the case of the Experiment Floor, which remains at an estimated 112.7% of the DAC.

Estimated Annual Dose to Uncontrolled Areas due to Argon-41 Production from the MUTR The dose risk for members of the general public in uncontrolled areas due to Argon-41 is conducted using two modeling software packages: the Environmental Protection Agency program COMPLY, and HotSpot (Version 2.07.1). To model the dose to the general public outside the Chemical and Nuclear Engineering Building, which houses the MUTR, both programs are used.

Both models take into consideration factors such as release height and wind speed. HotSpot uses a more detailed model to calculate the Total Effective Dose Equivalent (TEDE) to a receptor. For the total activity, the average concentration of Argon-41 generated by the MUTR at maximum power at equilibrium, 5.82 xl0-6 ý.Ci/ml, was multiplied by the total volume of the facility. This figure was determined by averaging the three highest concentrations of Argon-41 in the MUTR as listed on Table 2.

The balcony was excluded due to insufficient data, and, since the balcony measurements were the lowest of the four locations, discounting it results in a more conservative value. With ventilation fans running every 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> during operation, 4 "flushes" of 75% of the total Argon-41 activity would occur each operating day. Projected over 250 operating days per year, this calculates to 1.7 Curies per Year released.

The HotSpot program projection can be found in Attachment A. According to HotSpot, the maximum possible dose received by a member of the general public would be 1.81 mrem.

The factors were then entered into the COMPLY program as a confirmation model. The report can be found in Attachment B. The maximum potential dose according to the COMPLY model projects to 5.1 mrem per year.

To account for seepage of Argon-41 at ground level, HotSpot was used to model leakage. A leakage rate of 5% of the previously calculated total activity at the surface was used to calculate potential dose. As a point of comparison the leakage model was calculated manually. The calculation assumed no ventilation fans run during the operation, the most conservative model. One calculates the Deep Dose Equivalent (DDE) to members of the public at a given distance downwind from the facility by the following equation:

11 DDE thy or DDEwb = [i [(X/Q) DCFCXt Ai X, [exp{-iti)-exp{-Ait 2}])/()

Where:

Parameters used to calculated Dose Room Ventilation exhaust rate Room Leakage rate Reactor Room Volume 2.83 0.00236 1700 m 3/S m 3/S m 3 Variables in the Dose X/Q DCFext Ai ti t2 Atmospheric dispersion coefficient in s/m 3 External Dose Conversion Factors mrem M3 uCi' s1 Released Activity per isotope I in uCi Ventilation Constant (leakage rate/reactor volume) 1/s time plume arrives at receptor point s 5 s time plume has passed receptor point s 28800 s radioactive decay constant in 1/s Note: only one set of t1 and t 2 values are used as the change in arrival and passage does not change the TEDE values with any significance between 100 and 300 m.

The results of this calculation are shown in Table 10.

Table 10 Argon-41 Leakage Dose rate per day in mrem/day DDE Public Ground Level Release (Leakage Case)

Isotope X/Q (10)

X/Q X/Q X/Q (300)

BR DCFu Ai [uCil

.1 (100)

(200)

Ar-41 6.OOE-02 2.41E-02 6.63E-2.61E-03 3.30E-2.41 E-3.95E+03 1.052E-1 03 04 04 04 ti exp{-

A&tI t2 exp{-

Xt 2)

DDE(,Om)

DDE DDE (100m)

(200m)

DDE (300m) 0 1.OOE+00 2.88E+04 4.83E-02 1.74E-02 2.86E-7.86E-3.09E-04 03 04 Total dose to public over 50 weeks/yr at 8hr/d =

Ai is 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> activity tI is 0 time t2 is 8hrs

12 Figure 6 Forecasted Exponential Trend Line Analysis of the X/Q Values for 100 to 300 meters Leakage forecast of 10 meter x/Q [s/m3]

0.08 0.07 0.06 0.05 0.04 XIQ [s/m3]

0.03 -

Expon. (x/Q [s/m3])

yy -= 0.069e&o-11x 0.02

= 0.9914 0.01 0

0 50 100 150 200 250 300 350 distance along centerline Ground Level Release (H =0) Centerline XIQ [S/M3i = [1/p OEI!I

[

___]

A C

E_

100 4.02E_04 9.5E0 1.59E-03 1.75E02 2.41E-0 2 200 1.18E-04 2.5E0 4.72E-04 4.25-03 663E-03 300 4.14E-05 1OJ.14E-04 2.02E-04 1.88-03 2.61E-03]

X(xO) [M] XIO. [s/rn3]

300 2.61E-03 200 6.63E-03 100 2.41E-02 10 6.00E-02 These hand calculations were carried out as a verification of the HotSpot and COMPLY models. The HotSpot leakage model projection, used as the official calculation in this publication, can be found in Attachment C. As such, the maximum potential dose to a member of the general public according to the HotSpot model is 4.39 mrem, which is below 10 CFR Part 20 limits.

Conclusion In uncontrolled areas, the potential public dose due to Argon-41 is well within the limits specified in 10 CFR 20. The potential occupational dose contribution due to Argon-41 is also well within regulatory limits when the ventilation fans are operated at 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> intervals for a minimum of 15 minutes at all locations within the MUTR except the Experiment Floor. In order to maintain the occupational dose of all workers around the MUTR, the following additional precautions will be taken.

13 EXPERIMENT FLOOR KILOWATT HOUR RESTRICTION The DAC of 3.0 x 10-6 ýiCi per ml is based on a work year of 2000 hours0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br />. Access to the Experiment Floor of the MUTR shall have an annual cap of the equivalent of 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> at full power. After reaching this threshold, personnel shall be restricted from accessing the Experiment Floor during reactor operation.

Logs of total kilowatt hours of operation are maintained at the MUTR. With such a cap in place, all of the zones within the MUTR will have effective Argon-41 concentrations below the DAC (projected over the course of the calendar year).

ALARA PROGRAM All radiation workers at the MUTR are issued dosimetry sensitive to beta, gamma and neutron radiation on a bimonthly basis. The ALARA program triggers an investigation whenever a radiation worker receives a dose of 10% of the bimonthly limit (approximately 80 mrem). The investigation will take into account worker technique and evaluate possible changes in potential dose. This assures workers at the MUTR that not only will their occupational dose be within regulatory limits, but will be maintained ALARA.

The MUTR will continue to evaluate performance on an ongoing basis and strive to optimize all techniques to reduce the level of exposure due to Argon-41.

In this way, we can assure that both workers within the MUTR and the general public that safety is a top concern at the University of Maryland.

14 Attachment A - Annual Release of Ar-41 from MUTR Effluent Assessment From HotSpot

15 Annual Release of Ar-41 from MUTR HotSpot Version 2.07.1 General Plume Feb 03, 2012 03:33 PM Source Material Ar-41 1.0961 E+02 m Material-at-Risk (MAR) :7.4200E+00 Ci Damage Ratio (DR) :1.000 Airborne Fraction (ARF) :1.000 Respirable Fraction (RF) 1.000 Leakpath Factor (LPF) :1.000 Respirable Source Term

7.42E+00 Ci Non-respirable Source Term : 0.OOE+00 Ci Effective Release Height : 7.25 m Wind Speed (h=10 m)

2.00 m/s Distance Coordinates

All distances are on the Plume Centerline Wind Speed (h=H-eff)

1.68 m/s Stability Class

F Respirable Dep. Vel.

0.00 cm/s Non-respirable Dep. Vel. : 8.00 cm/s Receptor Height

1.5 m Inversion Layer Height

None Sample Time

10.000 min Breathing Rate

3.33E-04 m3/sec Maximum Dose Distance

0.32 km MAXIMUM TEDE

1.81E-03 rem Inner Contour Dose

1.0 rem Middle Contour Dose

0.500 rem Outer Contour Dose

0.100 rem

16 Exceeds Inner Dose Out To : Not Exceeded Exceeds Middle Dose Out To : Not Exceeded Exceeds Outer Dose Out To : Not Exceeded FGR-1 I Dose Conversion Data -Total Effective Dose Equivalent (TEDE)

Include Plume Passage Inhalation and Submersion Include Resuspension (Resuspension Factor : Constant Value) 1.00E-05 1/meter Exposure Window:(Start: 0.00 years; Duration: 1.00 years) [100% stay time].

Initial Deposition and Dose Rate shown Ground Roughness Correction Factor: 1.000 RESPIRABLE DISTANCE T E D E TIME-INTEGRATED ARRIVAL TIME AIR CONCENTRATION km (rem)

(Ci-sec)/m3 (hour:min) 0.010 0.100 0.200 0.300 0.400 0.500 0.0E+00 2.9E-05 1.2E-03 1.8E-03 1.7E-03 I.4E-03 0.OE+00 1.2E-04 5.2E-03 7.5E-03 7.OE-03 5.9E-03

<00:01

<00:01 00:01 00:02 00:03 00:04

17 Attachment B - Annual Release of Ar-41 from MUTR Effluent Assessment From COMPLY

'.1 18 40 CFR Part 61 National Emission Standards for Hazardous Air Pollutants REPORT ON COMPLIANCE WITH THE CLEAN AIR ACT LIMITS FOR RADIONUCLIDE EMISSIONS FROM THE COMPLY CODE, VERSION 1.4 Prepared by:

University of Maryland MUTR Building 090 Mary Dorman 301-314-8336 Prepared for:

U.S. Environmental Protection Agency Office of Radiation Programs Washington, D.C. 20460 Ar-41 release from MUTR SCREENING LEVEL 2 DATA ENTERED:

RELEASE RATES FOR STACK 1.

Release Rate Nuclide (curies/YEAR)

AR-41 3.710E+00 RELEASE RATES FOR STACK 2.

19 Release Rate Nuclide (curies/YEAR)

AR-41 3.710E+00 SITE DATA FOR STACK 1.

Release height 7 meters.

Building height 11 meters.

The source and receptor are not on the same building.

Distance from the source to the receptor is 10 meters.

Building width 14 meters.

SITE DATA FOR STACK 2.

Release height 7 meters.

Building height 11 meters.

The source and receptor are not on the same building.

Distance from the source to the receptor is 10 meters.

Building width 14 meters.

Default mean wind speed used (2.0 m/sec).

NOTES:

Input parameters outside the "normal" range:

None.

RESULTS:

Effective dose equivalent:

5.1 mrem/yr.

• • • Comply at level 2.

This facility is in COMPLIANCE.

It may or may not be EXEMPT from reporting to the EPA.

You may contact your regional EPA office for more information.

• END OF COMPLIANCE REPORT

• 20 Attachment C - Leakage Dose from MUTR for Argon-41 Effluent Assessment From HotSpot

21 Annual Leakage Dose from MUTR for Ar-41 HotSpot Version 2.07.1 General Plume Feb 03, 2012 03:31 PM Source Material

Ar-41 1.0961E+02 m Material-at-Risk (MAR) :3.7100E-01 Ci Damage Ratio (DR) :1.000 Airborne Fraction (ARF) :1.000 Respirable Fraction (RF) : 1.000 Leakpath Factor (LPF) :1.000 Respirable Source Term

3.71E-01 Ci Non-respirable Source Term : 0.OOE+00 Ci Effective Release Height : 0.00 m Wind Speed (h=10 m)

2.00 mrs Distance Coordinates

All distances are on the Plume Centerline Wind Speed (h=H-eff)

0.83 m/s Stability Class

F Respirable Dep. Vel.

0.00 cm/s Non-respirable Dep. Vel. : 8.00 cm/s Receptor Height

1.5 m Inversion Layer Height

None Sample Time

10.000 min Breathing Rate

3.33E-04 m3/sec Maximum Dose Distance

0.067 km MAXIMUM TEDE

4.39E-03 rem Inner Contour Dose

1.0 rem Middle Contour Dose

0.500 rem Outer Contour Dose

0.100 rem Exceeds Inner Dose Out To : Not Exceeded Exceeds Middle Dose Out To : Not Exceeded Exceeds Outer Dose Out To : Not Exceeded FGR-I I Dose Conversion Data - Total Effective Dose Equivalent (TEDE)

Include Plume Passage Inhalation and Submersion Include Resuspension (Resuspension Factor: Constant Value) 1.OOE-05 1/meter Exposure Window:(Start: 0.00 years; Duration: 1.00 years) [100% stay time].

Initial Deposition and Dose Rate shown Ground Roughness Correction Factor: 1.000 RESPIRABLE DISTANCE T E D E TIME-INTEGRATED ARRIVAL TIME AIR CONCENTRATION km (rem)

(Ci-sec)/m3 (hour:min) 0.010 0.OE+00 1.4E-19

<00:01 0.100 3.4E-03 1.4E-02 00:02 0.200 1.2E-03 5.2E-03 00:04 0.300 6.OE-04 2.5E-03 00:06 0.400 3.5E-04 1.5E-03 00:08 0.500 2.3E-04 9.7E-04 00:10

Accident Analysis MHA Accident Analysis Introduction The NRC licenses research and test reactors consistent with the NRC mission to ensure adequate protection of the public health and safety and to promote and protect the environment.

NUREG 1537 Part 1 and 2 guidance describes acceptable format and content of the safety analysis report (SAR) to be submitted to the U.S. Nuclear Regulatory Commission (NRC) by an applicant or licensee of a non-power reactor for a license renewal.

Chapter 13 lists the bases, scenarios, and analyses of accidents at the reactor facility, and describes a Maximum Hypothetical Accident, MHA, which may include a fission product release, and radiological consequences to the operational staff reactor users and the public. For research reactors licensed before January 1, 1994, the doses that the NRC has generally found acceptable for accident analysis result in less than 5 rem whole body and less than 30 rem thyroid for occupational exposure, and less than 0.5 rem whole body and less than 3 rem thyroid for members of the public.

The, MHA, which assumes an incredible failure that can lead to fuel cladding or to a fueled experiment containment breach, is used to bound credible accidents in the accident analysis. The MHA for TRIGA reactors is a cladding failure of a single irradiated fuel element in air with release of fission product inventories to the reactor confines and the public. In general, the escape of fission products from fuel 'or fueled 'experiments and their release to the unrestricted environment would be the most hazardous radiological accident conceivable at a non-power reactor. However, non-power reactors are designed and operated so that a fission product release is not credible for most.

Therefore, this release under accident conditions can reasonably be selected as the MHA, which bounds all credible accidents and can be used in the analysis of events and consequences during the accidental release of radioactive material. Instantaneous release of noble gases and halogen fission products follow from the cladding failure of this one element. The gases and fission products instantly and uniformly mix with the reactor room air. This concentration may be exhausted out of the building through elevated vents 'elevated release', at a rate of 2.83 m3 per s. Leakage out of the building through a window crack or doorway leak 'ground release', is assumed to occur at a rate of 5%/hour, at a rate of 2.42 x 10-2 m3 per s.

Fuel element failure can occur at any time during normal operations or when the reactor is at rest and shutdown. In this worst case scenario a single element has been removed from the reactor and dropped to the floor of the reactor building outside of the biological shield. Fission products are released in air from the gap and the cladding and instantaneously and uniformly mix in the volume of the reactor building.

In NUREG CR-2387 Credible Accident Analysis for TRIGA and TRIGA Fueled Reactors, the only potential for offsite exposures and doses is indicated as a fuel handling accident that based on highly conservative assumptions would result in dose equivalents of < 1 mrem TEDE from noble gases and < 1.2 rem to the thyroid from radioiodines.

The analysis and accident scenario given in NUREG 2387 gives the following analysis for a 1MW TRIGA after 1 year of continuous operation at full power, 365MWd. The Maryland University Training Reactor, MUTR is a 250 kW TRIGA reactor and therefore not capable of this level of 1

Accident Analysis MHA operation. The analysis and subsequent inventories and released activities from the damaged fuel elements are thus highly conservative for this facility.

The analysis assumes 50 elements were present in the core and the central element experiences the greater than average burn up. At 1/50 or 2% or the total the element would contain 4% of the total activity in the core. The noble gas and radioiodine activities in this element are 3828.8 Ci or Krypton, 9431 Ci of Iodine, and 3933 Ci of Xenon. A one year operation of the MUTR at 250 kW for 365 days is 91.25 MWd and the equivalent activities would be 25% of these values or 957.2 Ci or Krypton, 2357.8 Ci of Iodine and 983.3 Ci of Xenon.

All the activity would not be released from the element as the fuel matrix acts strongly to retain the fission products. According to NUREG 2387 the gap activity fraction is approximately 1.5xl0 5. GA developed a conservative correlation for fission product release to be:

e = 1.5E-5 + 3.6x10 3 e {-1.34x10/ (T+273)}, at T = 300 for the MUTR this yields 1.5E-5 For the MUTR the total release activity based on this release fraction would be 14.4 mCi Krypton, 35.4 mCi of Iodine and 14.7 mCi of Xenon. Activities and released values are as follows:

Noble Gases Iodine products Cesium and Strontium Released Released Released Activity Activities Activity Activities Activity Activities Isotope (Ci)

(mCi)

Isotope (Ci)

(mCi)

Isotope (Ci)

(mCi)

Kr-83m 30.9 0.463 1-131 270.0 4.05 Sr-89 16.7 0.25 Kr-85m 71.7 1.076 1-132 415.3 6.23 Sr-90 0.5 0.008 Kr-85 1.2 0.018 1-133 483.3 7.25 Sr-91 21.5 0.323 Kr-87 138.0 2.07 1-134 636.0 9.54 Sr-92 24.4 0.366 Kr-88 197.3 2.959 1-135 553.3 8.3 Cs-134m 0.1 0.001 Xe-133m 9.7 0.146 Cs-134 0.1 0.001 Xe-133 566.7 8.5 Cs-136 0.5 0.007 Xe-135m 149.5 2.243 Cs-137 8.3 0.124 Xe-135 256.3 3.844 Cs-138 34.3 0.515 Dose determination for these released activities was calculated using Federal Guidance Report 11 and 12 Dose Conversion Factors (DCF) for internal and external values. For atmospheric stability a ground level release was assumed for the case of leakage out of the reactor building and an elevated release for exhaust through the MUTR ventilation system. Horizontal and vertical diffusion coefficients were utilized from CEMBER, Introduction to Health Physics third edition as referenced from D.H. Slade, Meteorology and Atomic Energy Tech Inform 1968 and are also readily available through other references. A Pasquill category F, moderately stable condition, was chosen for all releases as a conservative category. Values below 100 m are not available in any reference therefore dose determination at minimum distances to the unrestricted areas such as at I Om were determined using HOTSPOT software.

2

Accident Analysis MHA Atmospheric Dispersion Values for Pasquill F category:

[l/lY__,__[]

e"[1/2 (H/G)A2]

X(x,O)

[m]

A B

C E

F A

B C

E F

100 4.02E-04 9.95E-04 1.59E-03 1.72E-02 2.41E-02 9.21E-01 7.65E-01 6.58E-01 5.07E-02 5.25E-05 200 1.18E-04 2.65E-04 4.72E-04 4.25E-03 6.63E-03 9.71E-01 9.35E-01 8.88E-01 4.12E-01 5.07E-02 300 4.14E-05 1.14E-04 2.02E-04 1.88E-03 2.61E-03 9.91E-01 9.71E-01 9.48E-01 6.90E-01 2.97E-01 Elevated Release ( Effective Height H, centerline) x/Q [s/m 3]=[ 1/I=[1 y zat] x e-[1/2 (H/G)A2]

x(x,O)

[m]

A B

C E

F 100 3.70E-04 7.61E-04 1.05E-03 8.74E-04 1.27E-06 200 1.14E-04 2.48E-04 4.19E-04 1.75E-03 3.37E-04 300 4.10E-05 1.11E-04 1.92E-04 1.30E-03 7.74E-04 Ground Level Release (H = 0) Centerline x/Q [s/m 31 = [1/gwaazir_]

x(x,O)

[im]

A B

C E

F 100 4.02E-04 9.95E-04 1.59E-03 1.75E-02 2.41E-02 200 1.18E-04 2.65E-04 4.72E-04 4.25E-03 6.63E-03 300 4.14E-05 1.14E-04 2.02E-04 1.88E-03 2.61E-03 Moderately Stable conditions selected Pasquill Category F 3

Accident Analysis M HA Ground Level Release Leakage (ventilation OFF) Public Dose Committed Dose Equivalent (CDE) to the thyroid and CEDE for members of the public at a given distance downwind from the facility for all isotopes of concern can be calculated by the following equation:

CDE or CEDE = 1i

[(X/Q) BR DCFint Aj Xv [exp{Xit 11-exp{Xit 2}]

)

Parameters used to calculated Dose Room Ventilation exhaust 2.83 m3/S rate Room Leakage rate 0.00236 m3/s Reactor Room Volume 1700 m 3 Breathing Rate 3.30E-04 m3/s Variables in the Dose Equation X/Q Atmospheric dispersion coefficient in s M3 BR Breathing rate 3.3e-4 m3 s1 DCF1nt Internal Dose Conversion Factors mrem uCi' Ai Released Activity per isotope uCi XV Ventilation Constant (leakage rate/reactor volume) s-tj time plume arrives at receptor point s 50 s t2 time plume has passed receptor point s 72050 s Note - the tj and t2 values were not changed for 200 and 300, there should be little change in the values based on these changes 4

Accident Analysis M HA CEDE Public Ground Level Release (Leakage Case)

Isotope Kr-83m Kr-85m Kr-85 Kr-87 Kr-88 Xe-133m Xe-133 Xe-135m Xe-135 1-131 1-132 1-133 1-134 1-135 Sr-89 Sr-90 Sr-91 Sr-92 Cs-134m Cs-134 Cs-136 Cs-137 Cs-138 X/Q (W0)

X/Q (200) /Q (300)

BR 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6,63E-03 6.63E-03 6.63E-03 6.63E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.3E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 DCFjr O.EOOE0 O.OOE40O O.OOE40O O.00E400 OX.EOOE0 4.63E+02 1.08E+03 1.80E+01 2,07E+03 2.96E+03 1.46E+02 O.OOE+O0 8.50E+03 O.OOE+00 3.29E+01 3.81E-01 5.85E+00 2.24E+03 3.84E+03 4.05E+03 6.23E+03 7.25E+03 1.05E-04 4.30E-05 2.05E-09 1.51E-04 4.07E-03 3.67E-06 1.53E-06 7.55E-04 2.12E-05 1.OOE-06 8.37E-05 9.25E-06 2.20E-04 2.91E-05 1.59E-07 7.58E-10 2.03E-05 7.10E-05 6.64E-05 1.07E-08 6.12E-07 7.32E-10 3.56E-04 exp{-k.Q 9.95E-01 9.98E-01 9.92E-01 8.16E-01 1.OOE+0O 1.00E400 9.63E-01 9.99E-01 9.96E-01 1.OJE+00 9.89E-01 9.99E-01 1.00E400 1A.EOOE0 9.99E-01 9.96E-01 9.97E-01 7.20E+04 5.14E-04 7.20E+04 7.20E+04 7.20E-+04 7.20E+04 7.20E+04 7.20E+04 7.20E+04 7.20E+04 7.20E+04 7.20E+04 7.20E+04 7.20E+04 7.20E+04 7.20E+04 7.20E+04 7.20E+04 7.20E+04 7.20E+04 4.53E-02 1.85E-05 6.78E-128 7.68E-01 8.96E-01 2.40E-24 2.18E-01 9.30E-01 2.41E-03 5.14E-01 1.36E-07 1.23E-01 9.89E-01 1.OOE+0O 2.32E-01 6.02E-03 8.40E-03 O.OOE+00 O.OOE40O O.OOE40O O.O3E+OO O.OOE40O O.OOE40O 1.02E+00 3.10E-03 2.45E-01 6.20E-04 3.37E-02 1.28E-02 1.51E-02 1.25E-03 3.53E-04 7.14E-08 3.65E-04 3.97E-04 3.13E-02 1.5S-os O.OOE+00 O.OOE40O O.OOE44J O.OOE+00 O.00E400 O.,EOOE0 O.AOE+iJ O.OOE40O 2.79E-01 8.51E-04 6.72E-02 1.71E-04 9.26E-03 3.52E-03 4.16E-03 3,44E-04 9.70E-05 1.96E-08 1.01E-04 1.09E-04 8.61E-03 4.35E406 O.OOE+00 O.OOE+00 O.COE+0O O.OOE40O O.OOE+00 O.OOE4OO O.OOE40O O.EOOE0 1.OE-O1 3.34E-04 2.64E-02 6.70E-05 3.64E-03 1.38E-03 1.64E-03 1.35E-04 3.81E-05 7.71E-09 3.95E-05 4.28E-05 3.38E-03 IIiir ti t2 expf-At2} CEDE (10m) CEDE (200m) CEDE (30Om) aMOE+M O.WE4OO O.WE4O 3.30E-04 1.31E-01 9.54E+03 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.3E-04 3.30E-04 1.23E4WJ 6.51E+00 2.39E+02 9.32E-01 6.29E-01 4.37E-02 4.63E+01 7.33E+00 3.19E+01 1.01E-01 8.30E+03 2.50E+02 8.OOE40O 3.23E+02 3.66E+02 1.OOE+00 1.OOE+0O 7.OOE40O 1.24E+02 5.15E+02 1.OOE40O 7.20E+04 9.99E-01 1.00E400 1.OOE40O 9.82E-01 7.20E+04 7.20E+04 7.20E+04 9.57E-01 1.OOE40O 7.13F-12 5

Accident Analysis MHA Ground Level Release (Leakage Case) ventilation OFF Deep Dose Equivalent (DDE) to the thyroid and CEDE for members of the public at a given distance downwind from the facility for all isotopes of concern can be calculated by the following equation:

DDE thy or D DEwb = Ii

[(X/Q) DCFext Ai X* [exp{-Xjiti-exp{-Xit 2}])

X(i) ]

Parameters used to calculated Dose Room Ventilation exhaust rate Room Leakage rate Reactor Room Volume 2.83 0.00236 1700 m 3/S m 3/

Variables in the Dose Equation X/Q DCFext Ai Xv ti t 2 Xi Atmospheric dispersion coefficient in s/m 3 External Dose Conversion Factors mrem m3 uCi-s1 Released Activity per isotope I in uCi Ventilation Constant (leakage rate/reactor volume) 1/s time plume arrives at receptor point s 50 s time plume has passed receptor point s 72050 s radioactive decay constant in 1/s Note: only one set of t1 and t 2 values are used as the change in arrival and passage does not change the TEDE values with any significance between 100 and 300 m 6

Accident Analysis MHA DDE Public Ground Level Release (Leakage Case)

Isotope X/Q(100)

X/Q(200) X/Q(300)

Kr-83m Kr-85m Kr-85 Kr-87 Kr-88 Xe-133m Xe-133 Xe-135m Xe-135 1-131 1-132 1-133 1-134 1-135 Sr-89 Sr-90 Sr-91 Sr-92 Cs-134m Cs-134 Cs-136 Cs-137 Cs-138 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E 2.41E-02 2,41E-02 2.41E-02 2.41E-02 2.41E-02 2,41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2.41E-02 2,41E-02 2.41E-02 2.41E-02 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 6.63E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 2.61E-03 BR 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04

.3.30E-04 3.30E-04 3.30E-04 3,30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 DCFext 5.55E-09 2,74E-05 4.40E-07 1,52E-04 3.77E-04 5.07E-06 5.77E-06 7.55E-05 4.40E-05 6.73E-05 4.14E-04 1.09E-04 4.81E-04 2.95E-04 2.86E-07 2.79E-08 1.28E-04 2.51E-04 3,35E-06 2,80E-04 3.92E-04 2.86E-08 4.48E-04 A,

i 4.63E+02 1.052E-04 1.08E+03 4.297E-05 1.80E+01 2.050E-09 2.07E+03 1.514E-04 2.96E+03 4.067E-03 1.46E+02 3.666E-06 8.50E+03 1.529E-06 2.24E+03 7.554E-04 3.84E+03 2.118E-05 4.05E+03 1.003E-06 6.23E+03 8.370E-05 7.25E+03 9.255E-06 9.54E+03 2.196E-04 8.30E+03 2.912E-05 2.50E+02 1.588E-07 8.OOE+00 7.580E-10 3.23E+02 2.026E-05 3.66E+02 7.100E-05 1.00E+00 6.638E-05 1.OOE+00 1.066E-08 7.OOE+00 6.123E-07 1.24E+02 7.325E-10 5.15E+02 3.565E-04 exp{--.tj}

t2 exp{-?*t4} DDE (100m) DDE (200m) DDE (300m) 9.95E-01 9.98E-01 1.00E+00 9,92E-01 8.16E-01 1.00E+00 1.00E+00 9.63E-01 9.99E-01 1,00E+00 9.96E-01 1.OOE+00 9.89E-01 9.99E-01 1.00E+00 1.00E+00 9.99E-01 9.96E-01 9.97E-01 1,00E+00 1.00E+00 1.00E+00 9.82E-01 7.20E+04 5.14E-04 7,20E-*04 4,53E-02 7.20E+04 1.OOE+00 7.20E+04 1.85E-05, 7.20E+04 6.78E-128 7.20E+04 7.68E-01 7.20E+04 8.96E-01 7.20E+04 2.40E-24 7.20E+04 2.18E-01 7.20E+04 9.30E-01 7.20E+04 2.41E-03' 7.20E+04 5.14E-01 7.20E+04 1.36E-07 7.20E+04 1.23E-01 7.20E+04 9.89E-01 7.20E+04 1.OOE+00 7.20E+04 2.32E-01 7.20E+04 6.02E-03 7.20E+04 8.40E-03 7.20E+04 9.99E-01 7.20E+04 9.57E-01 7.20E+04 1.OOE+00 7.20E+04 7.13E-12 Total DDE mrem 8.09E-09 2,17E-04 1.90E-07 6.89E-04 7,46E-05 1.56E-05 1.11E-03 7.19E-05 2.08E-03 6.30E-03 1.02E-02' 1,38E-02 6.88E-03 2.45E-02 1.70E-06 5.34E-09 5.19E-04 4.27E-04, 1.66E-08 6.71E-06, 6.43E-05 8,51E-08 2.12E-04, 0.067 2.22E-09!

5,98E-05 5.22E-08 1.89E-04i 2.05E-05 4.28E-06 3.06E-04,_

1.-98E-05.,

5.72E-04 1.73E-03:

2.81E-03 3.79E-01 1.89E-03 6.75E-03' 4.68E-07 1.47E-09 1.43E-04, 1.17E-04 4.56E-09 1.84E-06' 1.77E-05 2.34E-08, 5.82E-05:

0.018 8.74E-10ý 2,35E-05 2.05E-08

-7.44E-05.

8,06E-06' 1.68E-06 1.20E-04" 7.76E-06 2.25E-04

-6.81-E-04, 1.10E-03 1.49E-03, 7.43E-04 2.65E-031 1.84E-07 5.77E-10 5.61E-05, 4.61E-05 1.79E-09.

-7.25E-07:

6.95E-06 9.19E-09 2.29E-05!

0.007 7

Accident Analysis MHA Elevated Release (ventilation ON) Public Dose Committed Dose Equivalent (CDE) to the thyroid and CEDE for members of the public at a given distance downwind from the facility for all isotopes of concern can be calculated by the following equation:

CDE or CEDE = 1i [(X/Q) BR DCFint Ai Xv [exp{Xitji-exp{Ait 2 }] )/(WAi)]

Parameters used to calculated Dose Room Ventilation exhaust 2.83 m3/S rate Room Leakage rate 0.00236 m3/s Reactor Room Volume 1700 m3 Breathing Rate 3.30E-04 m3/s Variables in the Dose Equation X/Q Atmospheric dispersion coefficient in s m3 BR Breathing rate 3.3e-4 m3 S1 DCFint Internal Dose Conversion Factors mrem uCi' Ai Released Activity per isotope uCi Xv Ventilation Constant (ventilation rate/reactor volume) s' ti time plume arrives at receptor point s 50 s t2 time plume has passed receptor point s 650 s 8

Accident Analysis MHA CEDE Public Elevated Release (Ventilation Case)

Isotope X/Q (100) X/Q (200) X/Q (300)

BR DCFj A1

-A t1 exp{-kt1}

t2 exp{-ktz] CEDE (100m) CEDE (200m) CEDE(300m)

Kr-83m 1.27E-06 3.37E-04 7.74E-04 3.30E-04 0.O0E+00 4.63E+02 LOSE-04 SO 9.95E-01 650 9.34E-01 0.00E+001 0.OOE+0 2.94E-06 Kr-&Sm 1.27E-06 3.37E-04 7.74E-04 3.30E-04 0.OOE+00 1.08E+03 4.30E-05 50 9.98E-01 650 9.72E-01 0.00E+00 0.00E+00 2.89E-06 Kr-85 1.27E-06 3.37E-04 7.74E-04 3.30E-04 O.OOE+00 1.80E+01 2.OSE-OS 50 1.OOE+00 650 1.OE00E+ O.OOE+O0 O.OOE+O0 2.37E-12 Kr-V 1.27E-06 3.37E-04 7.74E-04 3.30E-04 O.OOE+00 2.07E+03 1.51E-04 SO 9.92E-01 650 9.06E-01 O.OOE+00 O.OOE+O0 1.84E-05 Kr-88 1.27E-06 3.37E-04 7.74E-04 3.30E-04 O.OOE+O0 2.96E+03 4.07E-03 50 8.16E-01 650 7.11E-02 O.OOE+00 OOOE+O0 6.74E-05 Xe-133m 1.27E-06 3.37E-04 7.74E-04 3.30E-04 O.OOE+O0 1.46E+02 3.67E-06 50 1.O0E+O0 650 9.98E-01 O.OOE+00 O.OOE+O0 3.43E-08 Xe-133 1.27E-06 3.37E-04 7.74E-04 3.30E-04 O.OOE+O0 8.5OE+03 1.53E-06 50 1.OCE+O0 650 9.99E-01 O.OOE+00 O.OOE+00 8.34E-07 Xe-135m 1.27E-06 3.37E-04 7.74E-04 3.30E-04 O.OOE+00 2.24E+03 7.55E-04 50 9.63E-01 650 6.12E-01 O.OOE+00 O.OOE+OO 6.92E-05 Xe-135 1.27E-06 3.37E-04 7.74E-04 3.30E-04 O.OOE+O0 3.84E+03 2.12E-05 50 9.99E-01 650 9.86E-01 O.OOE+O0 O.OOE+OO 5.16E-O6 1-131 1.27E-06 3.37E-04 7.74E-04 3.30E-04 3.29E+01 4.05E+03 1.OOE-06 50 1.O0E+O0 650 9.99E-01 5.56E-05 9.71E-07 2.61E-07 1-132 1.27E-06 3.37E-04 7.74E-04 3.30E-04 3.81E-01 6.23E+03 8.37E-05 50 9.96E-01 650 9.47E-01 9.63E-07 1.45E-06 3.19E-05 1-133 1.27E-06 3.37E-04 7.74E-04 3.30E-04 5.85E+00 7.25E+03 9.25E-06 50 1.00E+OO 650 9.94E-01 1.76E-05 2.85E-06 4.29E-06 1-134 1.27E-06 3.37E-04 7.74E-04 3.30E-04 1.31E-01 9.54E+03 2.20E-04 SO 9.89E-01 650 8.67E-01 4.5E-07 2.O0E-OE 1.18E-04 1-135 1.27E-06 3.37E-04 7.74E-04 3.30E-04 1.23E+00 8.30E+03 2.91E-05 50 9.99E-01 650 9.81E-01 4.21E-06 2.16E-06 1.53E-05 Sr-89 1.27E-06 3.37E-04 7.74E-04 3.30E-04 6.51E+00 2.5OE+02 1.59E-07 50 i.O0E+O0 650 1.O0E+OG 6.80E-07 1.88E-OS 2.55E-OS Sr-90 1.27E-06 3.37E-04 7.74E-04 3.30E-04 2.39E+02 8.OOE+0O 7.58E-1O 50 1.O0E+O0 650 1.O0E+(O 7.99E-07 1.06E-11 3.90E-13 Sr-91 1.27E-06 3.37E-04 7.74E-04 3.30E-04 9.32E-01 3.23E+02 2.03E-05 50 9.99E-01 650 9.87E-01 1.25E-07 4.44E-08 4.15E-07 Sr-92 1.27E-06 3.37E-04 7.74E-04 3.30E-04 6.29E-01 3.66E+02 7.lIE-05 50 9.96E-01 650 9.5SE-01 9.37E-08 1.19E-07 1.60E-06 Cs-134m 1.27E-06 3.37E-04 7.74E-04 3.30E-04 4.37E-02 1.OOE+O0 6.64E-05 50 9.97E-01 650 9.S8E-01 1.78E-11 2.11E-11 4.10E-09 Cs-134 1.27E-06 3.37E-04 7.74E-04 3.30E-04 4.63E+01 1.00E+O0 1.07E-O 50 1.O0E+O0 650 1.00E+O0 1.93E-08 3.58E-12 6.85E-13 Cs-36 1.27E-06 3.37E-04 7.74E-04 3.30E-04 7.33E+0C 7.OOE+00 6.12E-07 50 1.O0E+O0 650 1.OOE+O0 2.14E-08 2.28E-10 2.75E-10 Cs-137 1.27E-06 3.37E-04 7.74E-04 3.30E-04 3.19E+01 1.24E+02 7.32E-10 SO 1.O0E+O0 650 l.O0E+O0 1.65E-06 2.11E-1 5.84E-12 Cs-138 1.27E-06 3.37E-04 7.74E-04 3.30E-04 1.01E-01 5.15E+02 3.56E-04 50 9.82E-01 650 7.93E-0 1.93E-08 1.35E-07 9.52E-06 Total CEDE mrem 8.23E-05 9.73E-06 3.48E-04 9

Accident Analysis MHA Elevated Release (ventilation ON) Public Dose Deep Dose Equivalent (DDE) to the thyroid and CEDE for members of the public at a given distance downwind from the facility for all isotopes of concern can be calculated by the following equation:

DDE thy or DDEwb = Ii

[ (X/Q) DCFext Ai Av [exp{-Xitj}-exp{-Xit 2}]) W/(hI)]

Parameters used to calculated Dose Room Ventilation exhaust rate Room Leakage rate Reactor Room Volume 2.83 0.00236 1700 m3/s m3/s m 3 Variables in the Dose Equation X/Q Atmospheric dispersion coefficient in s/m 3 DCFet External Dose Conversion Factors mrem m3 uCi1 s1 Ai Released Activity per isotope I in uCi X,,

Ventilation Constant (leakage rate/reactor volume) 1/s tj time plume arrives at receptor point s t2 time plume has passed receptor point s Xi radioactive decay constant in 1/s 10

Accident Analysis MHA DDE Public Elevated Release (Ventilation Case)

Isotope X/Q (100)

X/Q (200) X/Q (300)

Ai k~

ti exp{-Akt1 t2 exP{-t 21 DDE (100M1) ýE(00)

D BR DCFet Kr-83m 1.27E-06 3.37E-04 7.74E-04 3.30E-04 5.55E-09 4.63E+02 1.0SE-04 50 9.95E-01 650 9.34E-01 3.13E-12 8.31E-10 1.91E-09 Kr-85m 1.27E-06 3.37E-04 7.74E-04 3.30E-04 2.74E-05 1.08E+03 4.30E-05 50 9.98E-01 650 9.72E-01 3.67E-08 9.74E-06 2.24E-05 Kr-85 1.27E-06 3.37E-04 7.74E-04 3.30E-04 4.40E-07 1.80E+01 2.05E-09 50 1.00E+00 650 1.00E+00 1.OOE-11 2.66E-09 6.11E-09 Kr-87 1.27E-06 3.37E-04 7.74E-04 3.30E-04 1.52E-04 2.07E+03 1.51E-04 50 9.92E-01 650 9.06E-01 3.79E-07 1.00E-04 2.31E-04 Kr-88 1.27E-06 3.37E-04 7.74E-04 3.30E-04 3.77E-04 2.96E+03 4.07E-03 50 8.16E-01 650 7.11E-02 4.31E-07 1.14E-04 2.63E-04 Xe-133m 1.27E-06 3.37E-04 7.74E-04 3.30E-04 5.07E-06 1.46E+02 3.67E-06 50 1.00E+00 650 9.98E-01 9.35E-10 2.48E-07 5.70E-07 Xe-133 1.27E-06 3.37E-04 7.74E-04 3.30E-04 5.77E-06 8.SOE+03 1.53E-06 50 1.O0E+00 650 9.99E-01 6.20E-08 1.65E-05 3.78E-05 Xe-135m 1.27E-06 3.37E-04 7.74E-04 3.30E-04 7.55E-05 2.24E+03 7.55E-04 50 9.63E-01 650 6.12E-01 1.66E-07 4.40E-05 1.01E-04 Xe-135 1.27E-06 3.37E-04 7.74E-04 3.30E-04 4.40E-05 3.84E+03 2.12E-05 50 9.99E-01 650 9.86E-01 2.13E-07 5.64E-05 1.30E-04 1-131 1.27E-06 3.37E-04 7.74E-04 3.30E-04 6.73E-05 4.05E+03 1.00E-06 50 1.00E+00 650 9.99E-01 3.45E-07 9.15E-05 2.10E-04 1-132 1.27E-06 3.37E-04 7.74E-04 3.30E-04 4.14E-04 6.23E+03 8.37E-05 50 9.96E-01 650 9.47E-01 3.17E-06 8.42E-04 1.93E-03 1-133 1.27E-06 3.37E-04 7.74E-04 3.30E-04 1.09E-04 7.25E+03 9.25E-06 50 1.00E+00 650 9.94E-01 9.94E-07 2.64E-04 6.06E-04 1-134 1.27E-06 3.37E-04 7.74E-04 3.30E-04 4.81E-04 9.54E+03 2.20E-04 50 9.89E-01 650 8.67E-01 5.38E-06 1.43E-03 3.28E-03 1-135 1.27E-06 3.37E-04 7.74E-04 3.30E-04 2.95E-04 8.30E+03 2.91E-05 50 9.99E-01 650 9.81E-01 3.07E-06 8.14E-04 1.87E-03 Sr-89 1.27E-06 3.37E-04 7.74E-04 3.30E-04 2.86E-07 2.50E+02 1.59E-07 50 1.00E+00 650 1.00E+00 9.04E-11 2.40E-08 S.S1E-08 Sr-90 1.27E-06 3.37E-04 7.74E-04 3.30E-04 2.79E-08 8.OOE+00 7.58E-10 50 1.OOE+00 650 1.OOE+00 2.82E-13 7.48E-11 1.72E-10 Sr-91 1.27E-06 3.37E-04 7.74E-04 3.30E-04 1.28E-04 3.23E+02 2.03E-05 50 9.99E-01 650 9.87E-01 5.18E-08 1.37E-05 3.16E-05 Sr-92 1.27E-06 3.37E-04 7.74E-04 3.30E-04 2.51E-04 3.66E+02 7.10E-05 50 9.96E-01 650 9.55E-01 1.13E-07 3.01E-05 6.92E-05 Cs-134m 1.27E-06 3.37E-04 7.74E-04 3.30E-04 3.35E-06 1.OOE+00 6.64E-05 50 9.97E-01 650 9.5SE-01 4.14E-12 1.10E-09 2.52E-09 Cs-134 1.27E-06 3.37E-04 7.74E-04 3.30E-04 2.80E-04 1.OOE+00 1.07E-08 50 1.OOE+00 650 1.OOE+00 3.54E-10 9.40E-08 2.16E-07 Cs-136 1.27E-06 3.37E-04 7.74E-04 3.30E-04 3.92E-04 7.OOE+00 6.12E-07 50 1.OOE+00 650 1.00E+00 3.47E-09 9.21E-07 2.12E-06 Cs-137 1.27E-06 3.37E-04 7.74E-04 3.30E-04 2.86E-08 1.24E+02 7.32E-10 50 1.OOE+00 650 1.OOE+00 4.49E-12 1.19E-09 2.74E-09 Cs-138 1.27E-06 3.37E-04 7.74E-04 3.30E-04 4.48E-04 5.15E+02 3.56E-04 50 9.82E-01 650 7.93E-01 2.I8E-07 6.84E-05 1.57E-04 Total DDE 1.47E-05 3.89E-03 8.94E-03 mrem 11

Accident Analysis MHA Internal Dose to Occupational Reactor Staff Ventilation ON and Ventilation OFF (leakage)

Committed Dose Equivalent (CDE) to the thyroid and CEDE for reactor occupational workers in the facility for all isotopes of concern can be calculated by the following equation:

CDE or CEDE = X [ BR DCFIt Ai [1-exp{-Xefftst}] )/(XeffV)]

Parameters used to calculated Dose Room Ventilation exhaust rate 2.83 m3/s Room Leakage rate 0.00236 m3/s Reactor Room Volume V 1700 m3 Breathing Rate 3.30E-04 m3/s Variables in the Dose Equation BR Breathing rate 3.3e-4 m 3 s-1 DCFint Internal Dose Conversion Factors mrem uCi-1 Ai Released Activity per isotope uCi Ventilation Constant (ventilation rate/reactor volume) 1.66E-3 s-Xv 1

Xl Leakage Constant (leakage rate/reactor volume) 1.388E-5 s' tst reactor worker stay time of 5 minutes (evac time) 300 s V

room volume m 3 Xj radioactive decay constant Xeff vent Xi + Xv Xeff leak X*i + X1, 12

Accident Analysis M HA CEDE Occupational Workers in Reactor from MHA Fans ON vent and Fans OFF leak On Off CEDE (vent) CEDE (leak)

Isotope Kr-83m Kr-85m Kr-85 Kr-87 Kr-88 Xe-133m Xe-133 Xe-135m Xe-135 1-131 1-132 1-133 1-134 1-135 Sr-89 Sr-90 Sr-91 Sr-92 Cs-134m Cs-134 Cs-136 Cs-137 Cs-138 BR 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 3.30E-04 DCFint 0.00E+00 0.00E+0O 0.OOE+O0 0.00E+O0 0.00E+00 0.00E+00 0.00E+0O O.00E+00 O.OOE+00 3.29E+01 3.81E-01 5.85E+00 1.31E-01

.1.23E+00 6.51E+00 2.39E+02 9.32E-01 6.29E-01 4.37E-02 4.63E+01 7.33E+00

3. 19E+01 1.01 E-01 4.63E+02 1.08E+03 1.80E+01 2.07E+03 2.96E+03 1.46E+02 8.50E+03 2.24E+03 3.84E+03 4.05E+03 6.23E+03 7.25E+03 9.54E+03 8.30E+03 2.50E+02 N

effvent kffleak 1.052E-04 1.765E-03 1.191E-04 4.297E-05 1.703E-03 5.685E-05 2.050E-09 1.660E-03 1.388E-05 1.514E-04 1.811E-03 1.653E-04 4.067E-03 5.727E-03 4.081E-03 3.666E-06 1.664E-03 1.755E-05 1.529E-06 1.662E-03 1.541E-05 7.554E-04 2.415E-03 7.693E-04 2.118E-05 1.681E-03 3.506E-05 1.003E-06 1.661E-03 1.488E-05 8.370E-05 1.744E-03 9.758E-05 9.255E-06 1.669E-03 2.313E-05 2.196E-04 1.880E-03 2.335E-04 2.912E-05 1.689E-03 4.300E-05 1.588E-07 1.660E-03 1.404E-05 tst 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 1-exp{4-ffventtst}

4.11E-01 4.00E-01 3.92E-01 4.19E-01 8.21E-01 3.93E-01 3.93E-01 5.15E-01 3.96E-01 3.92E-01 4.07E-01 3.94E-01 4.31E-01 3.98E-01 3.92E-01 3.92E-01 3.96E-01 4.05E-01 4.04E-01 3.92E-01 3.92E-01 3.92E-01 4.54E-01 1-exp{-Xeffleaktst) 3.51E-02 1.69E-02 4.16E-03 4.84E-02 7.06E-01 5.25E-03 4.61E-03 2.06E-01 1.05E-02 4.45E-03 2.88E-02 6.92E-03 6.76E-02 1.28E-02 4.20E-03 4.16E-03 1.02E-02 2.51E-02 2.38E-02 4.16E-03 4.34E-03 4.16E-03 1.05E-01 Total CEDE mrem 0.00E+00 0.00E+00 0.00E+0O 0.00E+0O_

0.00E+O0 0.00E+O0 0.00E+O0 0.00E+O0 0.00E+OO

6. 11E+00 1.08E-01 1.94E+00-'

5.58E-02 4.66E-01 7.47E-02 8.78E-02

-1.38E 1.05E-02 1.98E-06 2.12E-03 2.35E-03 1.82E-0 1 2.28E-03 0.00E+O0 0.00E+O0 0.00E+O0 0.00E+OO 0.00E+O0 0.00E+OO 0.00E+O0 0.00E+O0 0.00E+O00 7.74E+00 1.3611-01 2.46E+00_

7.05E-02 5.90-E-01.

9.46E-02 1.11iE-01 1.74E-02 1.32E-02 2.51E-06 2.69E-03 2.98-E-0.3 2.30E-01 2.88E-03 8.00E+O0 7.580E-10 1.660E-03 1.388E-05 3.23E+02 2.026E-05 1.680E-03 3.414E-05 3.66E+02 7.100E-05 1.731E-03 8.488E-05 1.00E+00 6.638E-05 1.726E-03 8.026E-05 1.00E+O0 1.066E-08 1.660E-03 1.389E-05 7.00E+O0 6.123E-07 1.661E-03 1.449E-05 1.24E+02 7.325E-10 1.660E-03 1.388E-05 5.15E+02 3.565E-04 2.016E-03 3.704E-04 9.056 11.472 13

Accident Analysis MHA External Dose to Occupational Reactor Staff Ventilation ON and OFF (leakage)

Deep Dose Equivalent (DDE) to reactor occupational workers in the facility for all isotopes of concern can be calculated by the following equation:

DDE thy or DDEvcb=

=i

[ DCFCt Ai [l-exp{-Xefftst}]/,effV]

Parameters used to calculated Dose Room Ventilation exhaust rate 2.83 m3/s Room Leakage rate 0.00236 1ml3/s Reactor Room Volume 1700 m3 Variables in the Dose Equation DCFext External Dose Conversion Factors mrem m3 uCi' S-1 Ai Released Activity per isotope uCi Ventilation Constant (ventilation rate/reactor volume) 1.66E-3 s-Leakage Constant (leakage rate/reactor volume) 1.388E-5 s'

~t*

reactor worker stay time of 5 minutes (evac time) 300 s V

room volume m3 kradioactive decay constant keff vent k + ?1, 14

Accident Analysis MHA External Dose DDE to Occupational Reactor Staff Ventilation ON and OFF (leakage)

On Off Isotope Kr-83m Kr-85m Kr-85 Kr-87 Kr-88 Xe-133m Xe-133 Xe-135m Xe-135 1-131 1-132 1-133 1-134 1-135 Sr-89 Sr-90 Sr-91 Sr-92 Cs-134m Cs-134 Cs-136 Cs-137 Cs-138 5.55E-09 2.74E-05 4.40E-07 1.52E-04 3.77E-04 5.07E-06 5.77E-06 7.55E-05 4.40E-05 6.73E-05 4.14E-04 1.09E-04 4.81E-04 2.95E-04 2.86E-07 2.79E-08 1.28E-04 2.51E-04 3.35E-06 2.80E-04 3.92E-04 2.86E-08 4.48E-04 4.63E+02 1.08E+03 1.80E+01, 2.07E+03 2.96E+03 1.46E+02 8.50E+03 2.24E+03 3.84E+03 4.05E+03 6.23E+03 7.25E+03 9.54E+03 8.30E+03 2.50E+02 8.OOE+I00 3.23E+02 3.66E+02 1.OOE+0O 1.00E+00 7.00E+00

1. 24E+02

5. 15E+02 N

kffvent 1.05E-04 1.77E-03 4.30E-05 2.05E-09 1.51E-04 4.07E-03 3.67E-06 1.53E-06 7.55E-04 2.12E-05 1.00E-06 8.37E-05 9.25E-06 2.20E-04 2.91E-05 1.59E-07 7.58E-10 2.03E-05 7.10E-05 6.64E-05 1.07E-08 6.12E-07 7.32E-10 3.56E-04 1.70E-03 1.66E-03 1.81E-03 5.73E-03 1.66E-03 1.66E-03 2.42E-03 1.68E-03 1.66E-03 1.74E-03 1.67E-03 1.88E-03 1.69E-03 1.66E-03 1.66E-03 1.68E-03 1.73E-03 1.73E-03 1.66E-03 1.66E-03 1.66E-03 2.02E-03 Xeffleak 1.19E-04 5.68E-05 1.39E-05 1.65E-04 4.08E-03 1.75E-05 1.54E-05 7.69E-04 3.51E-05 1.49E-05 9.76E-05 2.31E-05 2.33E-04 4.30E-05 1.40E-05 1.39E-05 3.41E-05 8.49E-05 8.03E-05 1.39E-05 1.45E-05 1.39E-05 3.70E-04 tst 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 1-exp{-kffventtst}

4.11E-01 4.OOE-01 3.92E-01 4.19E-01 8.21E-01 3.93E-01 3.93E-01 5.15E-01 3.96E-01 3.92E-01 4.07E-01 3.94E-01 4.31E-01 3.98E-01 3.92E-01 3.92E-01 3.96E-01 4.05E-01 4.04E-01 3.92E-01 3.92E-01 3.92E-01 4.54E-01 1-exp{-kffleaktstl 3.51E-02 1.69E-02 4.16E-03 4.84E-02 7.06E-01 5.25E-03 4.61E-03 2.06E-01 1.05E-o02...

4.45E-03 2.88E-02 6.92E-03 6.76E-02 1.28E-02 4.20E-03 4.16E-03 1.02E-02 2.51E-02 2.38E-02 4.16E-03 4.34E-03 4.16E-03 1.05E-01 Total DDE mrem DDE (vent) 3.52E-07 4.07E-03 1.10E-06 4.30E-02 9.41E-02 1.03E-04 6.82E-03 2.13E-02 2.35E-02 3.79E-02 3.55E-01 1.09E-01 6.19E-01 3.39E-01 9.94E-06 3.10E-08 5.72E-03 1.27E-02 4.61E.07 3.89E-05 3.82E-04 4.94E-07 3.05E-02 1.702 DDE (leak) 4.45E-07 5.15E-03 1.40E-06 5.43E-02 1.14E-01 1.30E-04 8.64E-03 2.67E-02 2.97E-02.-

4.80E-02 J 4.49E-01 1.39E-01 7.82E-01 4.30E-01 1.26E-05 3.93E-08 7.24E-03 1.60E-02 5.84E-07 4.93E-05 4.83E-04 6.25E-07 3.85E-02 2.148 15

Accident Analysis MHA HOTSPOT Total Effective Dose Results for MHA Elevated Release Hotspot Version 2.07.2 General Plume Elevated Release Ventilation ON Jan 25, 2012 09:56 PM Source Term: MUTR.mix (Mixture Scale Factor = 1.0000E+00) Noble gas Effective Release Height : 7.25 m Wind Speed (h=10 m)

2.32 m/s Wind Speed (h=H-eff)

1.94 m/s Stability Class

F Receptor Height

1.5 m Inversion Layer Height

None Sample Time

10.000 min Breathing Rate

4.17E-04 m3/sec Distance Coordinates

All distances are on the Plume Centerline Maximum Dose Distance

0.31 km MAXIMUM TED

1.86E-04 rem Inner Contour Dose

0.500 rem Middle Contour Dose

0.100 rem Outer Contour Dose

0.010 rem Exceeds Inner Dose Out To: Not Exceeded Exceeds Middle Dose Out To: Not Exceeded Exceeds Outer Dose Out To: Not Exceeded Include Plume Passage Inhalation and Submersion Include Resuspension (Resuspension Factor: Maxwell-Anspaugh)

Exposure Window:( Start: 0.00 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />; Duration: 0.34 hours3.935185e-4 days <br />0.00944 hours <br />5.621693e-5 weeks <br />1.2937e-5 months <br />) [100% stay time].

Initial Deposition and Dose Rate shown Ground Roughness Correction Factor: 1.000 Respirable Time-Integrated Ground Surface Ground Shine Arrival Distance TED Air Concentration Deposition Dose Rate Time (km)

(Rem)

(Ci-sec)/m3 (uCi/m2)

(rem/hr)

(hour:min) 0.010 0.OE+00 O.OE+00 O.OE+00 O.OE+00

<00:01 0.025 O.OE+00 O.OE+00 0.OE+00 O.OE+00

<00:01 0.050 3.1E-14 8.9E-15 4.9E-18 O.OE+00

<00:01 0.100 3.OE-06 8.6E-07 5.5E-05 1.1E-09

<00:01 0.200 1.3E-04 3.7E-05 4.2E-02 8.7E-07 00:01 0.300 1.9E-04 5.3E-05 8.9E-02 1.8E-06 00:02 0.400 1.7E-04 4.9E-05 8.8E-02 1.8E-06 00:03 0.500 1.4E-04 4.OE-05 7.4E-02 1.5E-06 00:04 16

Accident Analysis MHA HOTSPOT Total Effective Dose Results for MHA Ground Release Hotspot Version 2.07.2 General Plume Ground Release Ventilation OFF'(leakage)

Jan 25, 2012 09:54 PM Source Term: MUTR.mix (Mixture Scale Factor = 1.OOOOE+00)

Effective Release Height : 0.00 m Wind Speed (h=10 m)

2.32 m/s Wind Speed (h=H-eff)

0.96 m/s Stability Class

F Receptor Height

1.5 m Inversion Layer Height

None Sample Time

10.000 min Breathing Rate

4.17E-04 m3/sec Distance Coordinates

All distances are on the Plume Centerline Maximum Dose Distance,

0.065 km MAXIMUM TED

6.74E-03 rem Inner Contour Dose

0.500 rem Middle Contour Dose

0.100 rem Outer Contour Dose

0.010 rem Exceeds Inner Dose Out To: Not Exceeded Exceeds Middle Dose Out To: Not Exceeded Exceeds Outer Dose Out To: Not Exceeded Include Plume Passage Inhalation and Submersion Include Resuspension (Resuspension Factor: Maxwell-Anspaugh)

Exposure Window :( Start: 0.00 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />; Duration: 20.00 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />) [100% stay time].

Initial Deposition and Dose Rate shown Ground Roughness Correction Factor: 1.000 Respirable Time Integrated - Ground Surface GROUND SHINE ARRIVAL Distance TED Air concentration Deposition DOSE RATE TIME km (rem)

(Ci-sec)/m3 (uCi/m2)

(rem/hr.)

(Hour: min) 0.010 1.8E-03 1.6E-04 5.8E+02 1.2E-02

<00:01 0.025 3.8E-04 6.OE-05 8.1E+01 1.7E-03

<00:01 0.050 5.7E-03 1.8E-03 1.8E+01 3.8E-04

<00:01 0.100 5.OE-03 1.7E-03 4.1E+00 8.6E-05 00:01 0.200 1.6E-03 5.6E-04 9.5E-01 2.OE-05 00:03 0.300 7.5E-04 2.6E-04 4.1E-01 8.3E-06 00:05 0.400 4.2E-04 1.5E-04 2.2E-01 4.5E-06 00:06 0.500 2.7E-04 9.5E-05 1.4E-01 2.8E-06 00:08 17

Accident Analysis MHA The results of all calculations for the MHA scenario are given in the Summation and Public Dose Summary Table following. In all cases the doses to the general public and to reactor staff occupational workers are well below the annual dose limits as specified by 10 CFR 20 as well as any guidance on doses expected from an MHA type scenario accident.

Summation of Doses for the MHA and Summary Table MHA Condition Fans Off/Leakage Public Dose at 100 m 200 m 300 m CEDE mrem 1.361 0.374 0.147 DDE mrem 0.067 0.019 0.007 TEDE mrem 1.428 0.393 0.154 MHA Condition Fans On/Ventilation Public Dose at 100 m 200 m 300 m CEDE mrem 8.23E-05 9.73E-06 3.84E-04 DDE mrem 1.47E-05 3.89E-03 8.94E-03 TEDE mrem 9.70E-05 3.90E-03 9.32E-03 MHA Condition Fans Off Fans On Occupational Dose 5 min 5 min CEDE mrem 11.472 9.056 DDE mrem 2.148 1.702 TEDE mrem 13.620 10.758 Summary Table MHA MHA Condition Fans On/Ventilation mrem Condition Fans Off/Leakage mrem Public Dose at 100 m 200 m 300 m Public Dose at 100 m 200m 300hm CEDE mrem 8.23E-05 9.73E-06 3.48E-04 CEDE mrem 1.361 0.374 0.147 DDE mrem 1.47E-05 3.89E-03 8.94E-03 DDE mrem 0.067 0.019 0.007 TEDE mrem 9.70E-05 3.90E-03 9.29E-03 TEDE mrem 1.428 0.393 0.154 HOTSPOT ANALYSIS RESULTS MHA MHA Condition Fans Off/leakage

-Condition Fans ON/Ventilation HOTSPOT at lom 100m 200m HOTSPOT at 10m 100m 200m TEDE mrem 1.83 5.00 1.00 TEDE mrem

< 1.00

< 1.00

< 1.00 18