Navy Response to NRC Comments on the Draft Technical ...information on the subject document in a letter to the Navy dated November 19, 2018. The Navy is providing the requested additional

Mr. Richard Chang Nuclear Regulatory Commission 11545 Rockville Pike M.S. T5Al0 Rockville, MD 20852

Dear Mr. Chang:

DEPARTMENT OF THE NAVY BASE REALIGNMENT AND CLOSURE

PROGRAM MANAGEMENT OFFICE WEST

33000 NIXIE WAY, BLDG 50 Suite 207 SAN DIEGO, CA 92147

5000-33C Ser BPMOW.cy/108 April 12, 2019

SUBJECT: RESPONSE TO COMMENTS AND REQUEST FOR ADDITIONAL INFORATION, DRAFT TECHNICAL MEMORANDUM, REQUEST FOR UNRESTRICTED RADIOLOGICAL RELEASE OF SELECT OPEN SPACES INSTALLATION RESTORATION SITE 12, FORMER NAVAL STATION

TREASURE ISLAND, SAN FRANCISCO, CALIFORNIA

The U.S. Nuclear Regulatory Commission provided comments and a request for additional information on the subject document in a letter to the Navy dated November 19, 2018. The Navy is providing the requested additional information in Enclosure 1. Enclosure 2 is a Dose Run Summary which supports the Navy response in Enclosure 1.

Thank you for your continued support and monitoring of the radiological program at Treasure Island. Should you have any questions or need additional information, please contact Mr. David Clark, Lead Project Manager, at (619) 524-6870.

Sincerely,

~d~OO'\-(_

SARAH ANN MOORE Base Closure Manager By direction of the Director

Enclosure: 1. Response to comments, Draft Technical Memorandum, Request for unrestricted Radiological Release of Select Open Spaces Installation Restoration Site 12, Former Naval Station Treasure Island

2. Dose Run Summary (MicroShield case files)

Copy to: Mr. Richard Chang, U.S. Nuclear Regulatory Commission

Blind copy to: D. Silva, Site File Z. Edwards (email copy) C. Yantos (email copy) D. Clark (email copy) XFile Read File Serial File

Writer: C. Y antos Typist: J. Perez,

2

5000-33C Ser BPMOW.cy/108 April 12, 2019

Page 1 of 5

Response to Comments on the redline Draft Technical Memorandum, Request for Unrestricted Radiological Release of Select Open Spaces,

Installation Restoration Site 12, Former Naval Station Treasure Island, San Francisco, California, October 2018, DCN: APTM-2005-0014-

0058 Comments by: Richard Chang, U.S. Nuclear Regulatory Commission Project Manager, comments dated November 19, 2018

General Comments Response

1. Provide additional discussion associated with your previous site

characterization efforts on survey design, decision points, decision

confidence levels, information on the process used to classify the site,

information used to determine survey coverage, and the sample

population used to support release of the site; or provide an alternative

method for demonstrating compliance with NRC’s 25 millirem per year

dose criterion.

Description: A FSS demonstrates that a facility meets NRC criteria for

release (i.e., the 25 millirem per year dose criterion). Attributes of a FSS for

this purpose have been described in Section 15.4.3 of NUREG-1757, Vol. 1.

In the TM, the U.S. Navy treats these previous characterization surveys like

a FSS.

Consistent with a FSS, please provide the following information: 1) a

discussion of systematic planning methods that are designed for site-specific

conditions, and FSS decision points and confidence levels; 2) additional

detail on the data quality inputs that were used to generate the sample

population size and locations; 3) additional information as to how these

sample results and the resulting average concentrations demonstrate that

release criteria are satisfied; 4) additional information on the systematic

process that was used to plan and collect data, the statistical or other

appropriate methods applied to data assessments, and whether the site

satisfies the requirements for release without radiological restrictions; and 5)

additional information and illustrations of Site 12 classification and decision

unit boundaries and methods used to demonstrate either a non-impacted

determination, or that each decision unit demonstrates compliance with the

unrestricted release criteria at a specified level of confidence.

As described in Section 15.4.3 of NUREG-1757, there are four methods,

including Multi-Agency Radiation Survey and Site Investigation Manual

(MARSSIM) methodology or an alternative methodology, acceptable to

NRC as the basis for facility radiation surveys associated with a FSS. One

such alternative would be dose assessments that would bound reasonable

foreseeable future uses.

As discussed in the Technical Memorandum, characterization efforts

support the conceptual site model that radioactive material in open spaces

of Site 12 was in the form of discarded objects, not distributed

concentrations of 226Ra.

Characterization of the site was realized over several phases of

investigation to ultimately develop the conceptual site model. Work

included historical research; trenching; surface and subsurface surveys;

and, soil sampling.

The design of the radiological remediation efforts at Installation

Restoration Site 12, Treasure Island, followed the Comprehensive

Environmental Response, Compensation, and Liability Act (CERCLA)

process.

California does not have a dose or risk-based residual material standard for

remedial sites and the acceptance of radiological end-points is the

responsibility of California Department of Health Services (CDPH)

Radiologic Health Branch (RHB) or the Environmental Management

Branch (EMB). Per California Code of Regulations, Title 17, Section

30256(k), the acceptable end-point for CDPH-RHB/EMB is reasonable

effort as discussed in Governor Gray Davis’ 2002 resolution regarding

decommissioning activities.

In an effort to quantify reasonable effort, a sitewide background was

established in 2011. Actual background concentrations in non-

radiologically impacted areas of Treasure Island were as high as 1.3 pCi/g

of soil from naturally occurring 226Ra. Additionally, within Site 12, sand

used for construction base material has been identified which exhibit

higher levels of radioisotopes than the standard fill in the non-

radiologically impacted areas. The naturally occurring 226Ra

concentrations of the sand ranged from approximately 2 to 4 pCi/g and

thorium-232 concentrations ranged from approximately 5 to 11 pCi.g.

Naturally occurring sands high in thorium and radium were not enhanced

by Navy operations but were placed as part of housing construction

projects. Sands with these characteristics are common and have been

Page 2 of 5




Basis: 10 Code of Federal Regulations (CFR) 20.1402 dose criterion of 25

millirem per year

RAI: As discussed above, in order to be consistent with a FSS, please

provide additional discussion associated with your previous site

characterization efforts on survey design, decision points, decision

confidence levels, information on the process used to classify the site,

determine survey coverage, and the sample population to support release of

the site.

Otherwise, please provide the alternative method for demonstrating

compliance with 10 CFR Part 20.1402. Section 15.4.3 of NUREG-1757,

Vol. 1 provides four methods, including alternative methodology, acceptable

to NRC as the basis for facility radiation surveys associated with a FSS. One

such alternative would be dose assessments that would bound reasonable

foreseeable future uses. If the dose assessment methodology approach is

chosen, please conservatively define the source terms used and the scenarios

chosen.

documented in other areas of California such as Half Moon Bay and

Richmond Point.

An action limit (or preliminary remediation guideline) of 1 picocurie per

gram (pCi/g) radium 226 (226Ra) plus average background, which was

determined to be 0.69 pCi/g 226Ra, was established for any project where

soil samples were evaluated for radioisotopes. When objects were located

and remediated as part of historical investigations, the remaining soil

concentration was confirmed to be at the background levels of naturally

occurring radioactive materials. In many cases, soils from the vicinity of

discovered objects were collected, analyzed, and discarded as low-level

radioactive waste as appropriate. These recovery actions demonstrate the

low mobility of radium from objects found at the site. This provides an

additional line of evidence supporting the CSM and demonstrates

reasonable effort.

Sitewide background concentration is discussed in Section 3.3 of the

technical memorandum. The action limit of 1.69 pCi/g 226Ra resulted in a

dose-based remediation goal of approximately 12.5 millirem per year

(mrem/yr) using methodology of that time frame (worst-case year), below

the U.S. Nuclear Regulatory Commission’s 25 mrem/yr dose criterion

shown in Code of Federal Regulations, Title 10, Section 20.1402.

Future use of the site is a combination of open space and multi-unit

residential which is taken into account when requesting free-release.

Future construction workers are also recognized due to future subsurface

construction efforts. Given the reasonable effort to scan and remove all

identified objects in the open spaces, along with characterization of the

fill/construction materials left in place, the Navy recommends that the

select open space of Site 12 is suitable for unrestricted release.

2. Provide additional information that clarifies that survey coverage

satisfies the potential for contamination (e.g., percent coverage).

Description: Section 2.5.1 describes the 2013/2014 radiological scoping

survey, the intent of which was “to determine if residual radioactivity

requiring remediation was present” and, as noted in the introductory review

summary, was “to provide design input for either characterization or final

Survey coverage is a combination of several investigations. The compiled

survey coverage is shown on Figure 2 and consisted of 100 percent high

density scans. All accessible land areas, including common spaces, private

fenced backyards, and paved roadways, were surveyed. Areas not

surveyed include the solid waste disposal areas (SWDAs), which are

excluded from this Technical Memorandum’s request for unrestricted

Page 3 of 5




status surveys.” Section 2.5.2 of the TM presents the results of the 2017

Scoping Survey Follow-up Investigation, where 196 potential anomalies that

were judgmentally selected for further survey following review and

assessment of the 2013/2014 radiological scoping gamma survey files.

Section 2.5.3 summarizes the 2017 Open Space Surveys. These surveys

were not described as final status surveys.

Basis: Scoping and characterization surveys performed during the

radiological survey and site investigation process may also support FSS

decisions, provided the methods, field and laboratory instrumentation type

and sensitivity, and the resulting data quality also can be demonstrated to

have satisfied FSS requirements.

The Section 3 descriptions and discussions for the gamma radiation scanning

equipment sensitivities and applicability to MARSSIM-based requirements

achieve the desired FSS objective for use and detection sensitivity.

However, the adequacy of the survey coverage when using the described

detectors cannot be assessed. MARSSIM and NUREG-1757 FSS planning

and FSSR content includes scanning requirements as a function of

contamination potential by applying a graded approach based on area

classification. As noted previously, area classification is not clearly

defined. Furthermore, the TM does not specify scanning coverage. Figures 2

through 5 of the TM Appendix A give the appearance of high-density

coverage during the 2013/2014 scoping survey of the four housing series

areas. However, the coverage or plotting methods are not specifically

described in the text.

The 2017 follow-up scoping survey was limited to gamma scanning and

measurements within 3 meter × 3 meter blocks and soil sampling. The

scanning data were not mapped, graphically plotted or otherwise statistically

summarized for review and assessment. Instead, the data were simply

included by housing series in over 1000 pages of individual count rates

without the coordinate reference data.

RAI: Provide additional information on survey scan coverage and area

classification for review to determine if FSS requirements for these data

were satisfied.

release. The SWDA boundaries have been delineated through historical

document review and several site investigations including:

Time-critical removal action (TCRA) of lead-contaminated soil

near Building 1133 (1999)

TCRA of lead-contaminated soil near Buildings 1207 and 1209

(IT Corp 1999)

Site 12 trenching (2003)

Non-time Critical Removal Action for SWDAs Westside Drive,

Bayside Drive, and North Point Drive (performed in phases from

2007-2017)

Potholing to confirm SWDA boundaries (2017)

As stated in Section 5.0, the Navy excluded four distinct IR Site 12 open

space areas and Building 1229 from the Technical Memorandum’s request

for unrestricted release. The four distinct areas include the area outside of

SWDA Westside and adjacent to Building 1131, area adjacent to Building

1204, area adjacent to Building 1306, and park area south of Building

1301.

To bound the worst-case scenario of leaving a low-level radiological

object (LLRO) in place, eight different dose models were run (see

Enclosure 2-Dose Run Summary). The models were based on the

following LLROs:

3 microcuries (µCi), the geometric average of LLROs discovered

at TI,

90 µCi, the arithmetic average of LLROs discovered at TI, and

2.1 millicuries (mCi), the highest activity LLRO included on the

LLRO log discovered outside of the Deep Debris Area (subarea of

SWDA Westside that contained a concentrated quantity of

LLROs)

The doses ranged from 0.05 to 32,000 mrem/year.

The worst case scenario is a 2.1 mCi LLRO located at 1 foot below ground

surface and assuming 24/7 exposure. The dose was calculated at 32,000

mrem/year for the total body. If the same LLRO was on the surface, the

Page 4 of 5




Should an alternative method, such as conservative dose assessments, serve

as the response basis to Comment 1 and is provided for NRC staff’s review,

please incorporate information that addresses how scanning coverage and the

measurement system sensitivity were integrated into the final status site

investigation and decision process. If the scanning data and coverage serve

as inputs to conservative scenarios or are otherwise used to demonstrate

confidence in LLRO discovery, provide information that demonstrates that

coverage and sensitivity were adequate and provide information that bounds

decision error probabilities. Most notably, false negative decision errors and

dose consequence to a future site receptor encountering undiscovered

LLROs is of interest.

exposure is 857 mrem/hour. However, exposure scenarios based on a

2.1 mCi LLRO are highly unlikely. An LLRO of this activity would have

been identified in the surveys performed. Calculational models included

in the Technical Memorandum have demonstrated that LLROs in the

3 µCi range can be detected when buried in the soil. Excavation and

spreading of soils increased detection capability. In any case, detection

capability, in counts per minute equivalent to dose rate readings, in the

single µR per hour range were successfully discovered. Dose rates in the

mrem per hour range, and certainly in the tens or hundreds of mrem per

hour range, are easily detected due to the sensitivity of the instruments and

the impact on general area radiological conditions.

3. Provide confirmation of historical site grading to ensure the depth of

contamination would not exceed historic grading records and remain

within the detectability depth of instruments.

Description: The lines of evidence summary is discussed in Section 2.8 of

the TM. The statements are made that “the Site 12 open areas have been

characterized and in some cases fully investigated…the Navy has taken

reasonable efforts to investigate the majority of open spaces and discover

LLROs.” As part of the argument for release of Site 12, the NRC staff

understands that the records of historical site grading (for areas where fill is

less than a depth of 3 feet) is used in conjunction with survey instruments

that are likely able to detect radium at similar depths.

NRC staff also understands that there has been a lot of subsurface

investigations at Site 12 dating back many years. NRC staff is seeking

information on what efforts have been made to validate historical records on

site grading with previous subsurface investigations at Site 12.

Basis: Section 15.4.3 of NUREG-1757, Vol. 1 provides four methods,

including MARSSIM methodology, acceptable to NRC as the basis for

facility radiation surveys associated with FSS. Requirements for the FSS and

information to be included in the FSSR are stated in NUREG- 1757, Vol. 2

Sections 4.4 and 4.5, and special circumstances and alternative methods are

addressed in the appendices.

During document review for preparation of the Final Historical

Radiological Assessment—Supplemental Technical Memorandum, Naval

Station Treasure Island, San Francisco, California (HRA STM; TriEco-

Tt, a Joint Venture of TriEco LLC and Tetra Tech EM Inc), historical

Navy grading plans were reviewed. Both the pre- and post-construction

survey maps were available. The maps were compared and the difference

between the pre- and post-construction grades was calculated to establish

the maximum depth of graded material placed over the open space areas.

The grading plans were summarized in Figure 18 of the HRA STM, which

is also shown on Figure 3 of this Technical Memorandum. Several

investigations, including trenching throughout Site 12, 1400 Series

Housing Area sampling, and the 2014 Rubbish Area Investigation

Trenches, have been performed a Treasure Island. The trenches and

sample locations are shown on Figure 2. These investigations have

validated the grading plan.

Page 5 of 5




RAI: Please provide additional information on the systematic radiological

survey process that was used for subsurface investigations, and how that

information has confirmed historical site grading records.

Dose Run Summary

Dose Run

LLRO LLRO Position

Exposure Basis Dose (total body)

1 3 µCi 3 ft bgs 24/7 exposure (8766 hr/yr), standing on surface over the LLRO

0.052 mrem/yr

2 90 µCi 3 ft bgs 24/7 exposure (8766 hr/yr), standing on surface over the LLRO

1.6 mrem/yr

3 90 µCi 3 ft bgs 24/7 exposure (8766 hr/yr), on contact (sitting on surface)

3.4 mrem/yr

4 90 µCi 3 ft bgs 24/7 exposure (8766 hr/yr), 6 inches above surface

2.8 mrem/yr

5 2.1 mCi 0 ft bgs (surface)

Hourly exposure, sitting on surface over the LLRO Hourly exposure, standing on surface over the LLRO Assuming 50% of day is spent outdoors, 10% of outdoor time (438 hr/yr), standing on surface over the LLRO

857 mrem/hr* 8.6 mrem/hr* 3,767 mrem/yr

6 2.1 mCi 1 ft bgs 24/7 exposure (8766 hr/yr), on contact (sitting on surface) 24/7 exposure (8766 hr/yr), standing on surface over the LLRO Assuming 50% of day is spent outdoors, 10% of outdoor time (438 hr/yr), standing on surface over the LLRO

32,000 mrem/yr 6,100 mrem/yr 307 mrem/yr


1,290 mrem/yr 450 mrem/yr 22.4 mrem/yr


84 mrem/yr 38 mrem/yr 1.9 mrem/yr

Dose Run

LLRO LLRO Position

Exposure Basis Dose (total body)


7 mrem/yr 3.6 mrem/yr 0.18 mrem/yr

* Annual doses not calculated per notes on MicroShield output pdf. 3 µCi is geometric average of LLROs discovered at TI. 90 µCi is arithmetic average of LLROs discovered at TI. 2.1 mCi is the highest activity LLRO we have on the LLRO log found outside the Westside deep debris area. Total body exposure is modeled as leg above the knee.

MicroShield 9.07CB&I Federal Services-Mark O. Somerville (9.07-0000)

Date By Checked

Filename Run Date Run Time DurationCase1 February 15, 2019 11:49:13 AM 00:00:00

Project InfoCase Title Case 1

Description Case 1 Geometry 3 - Disk

Source DimensionsRadius 0.787 cm (0.3 in)

Dose PointsA X Y Z#1 142.24 cm (4 ft 8.0 in) 0.0 cm (0 in) 0.0 cm (0 in)

ShieldsShield N Dimension Material DensityShield 1 36.0 in Compact Soil 1.6Air Gap Air 0.00122

Source Input: Grouping Method - Standard IndicesNumber of Groups: 25

Lower Energy Cutoff: 0.015Photons < 0.015: Included

Library: GroveNuclide Ci Bq µCi/cm² Bq/cm²Bi-210 1.8057e-006 6.6810e+004 9.2704e-001 3.4300e+004Bi-214 2.9607e-006 1.0955e+005 1.5200e+000 5.6241e+004Pb-210 1.8064e-006 6.6836e+004 9.2740e-001 3.4314e+004Pb-214 2.9607e-006 1.0955e+005 1.5200e+000 5.6241e+004Po-210 1.7857e-006 6.6070e+004 9.1677e-001 3.3920e+004Po-214 2.9601e-006 1.0952e+005 1.5197e+000 5.6229e+004Po-218 2.9613e-006 1.0957e+005 1.5203e+000 5.6252e+004Ra-226 2.9613e-006 1.0957e+005 1.5203e+000 5.6252e+004Rn-222 2.9613e-006 1.0957e+005 1.5203e+000 5.6252e+004

Buildup: The material reference is Shield 1Integration ParametersRadial 20

Circumferential 20

Results

Energy (MeV)

Activity (Photons/sec)

Fluence Rate

MeV/cm²/secNo Buildup

Fluence Rate

MeV/cm²/secWith

Buildup

Exposure Rate

mR/hrNo

Buildup

ExposureRate

mR/hrWith

Buildup

Absorbed Dose Rate

mrad/hrNo

Buildup

Absorbed Dose Rate

mrad/hrWith

Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith

Buildup0.015 3.250e+04 0.000e+00 1.801e-29 0.000e+00 1.545e-30 0.000e+00 1.349e-30 0.000e+00 1.349e-320.05 3.918e+03 9.037e-32 1.361e-28 2.407e-34 3.625e-31 2.102e-34 3.165e-31 2.102e-36 3.165e-33

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lisa.bercik

Highlight

0.08 2.526e+04 1.314e-16 1.397e-14 2.080e-19 2.211e-17 1.816e-19 1.931e-17 1.816e-21 1.931e-190.1 1.487e+02 2.907e-16 5.147e-14 4.447e-19 7.874e-17 3.883e-19 6.874e-17 3.883e-21 6.874e-190.2 1.180e+04 1.124e-10 2.392e-08 1.984e-13 4.222e-11 1.732e-13 3.686e-11 1.732e-15 3.686e-130.3 2.261e+04 4.666e-09 6.254e-07 8.851e-12 1.186e-09 7.727e-12 1.036e-09 7.727e-14 1.036e-110.4 4.192e+04 6.282e-08 5.419e-06 1.224e-10 1.056e-08 1.069e-10 9.217e-09 1.069e-12 9.217e-110.5 1.957e+03 1.255e-08 7.479e-07 2.462e-11 1.468e-09 2.150e-11 1.282e-09 2.150e-13 1.282e-110.6 5.282e+04 1.058e-06 4.617e-05 2.064e-09 9.012e-08 1.802e-09 7.867e-08 1.802e-11 7.867e-100.8 1.035e+04 1.153e-06 3.136e-05 2.193e-09 5.966e-08 1.914e-09 5.208e-08 1.914e-11 5.208e-101.0 3.430e+04 1.349e-05 2.567e-04 2.486e-08 4.732e-07 2.170e-08 4.131e-07 2.170e-10 4.131e-091.5 2.086e+04 6.783e-05 7.156e-04 1.141e-07 1.204e-06 9.963e-08 1.051e-06 9.963e-10 1.051e-082.0 2.932e+04 3.556e-04 2.650e-03 5.499e-07 4.098e-06 4.801e-07 3.577e-06 4.801e-09 3.577e-08

Totals 2.877e+05 4.392e-04 3.707e-03 6.933e-07 5.938e-06 6.052e-07 5.184e-06 6.052e-09 5.184e-08



5.938e-6 mrem/hour * 8766 hours/year = 0.05205 mrem/year

lisa.bercik

Highlight


Date By Checked









Library: GroveNuclide Ci Bq µCi/cm² Bq/cm²Bi-210 5.4170e-005 2.0043e+006 2.9696e+001 1.0988e+006Bi-214 8.8821e-005 3.2864e+006 4.8692e+001 1.8016e+006Pb-210 5.4191e-005 2.0051e+006 2.9708e+001 1.0992e+006Pb-214 8.8821e-005 3.2864e+006 4.8692e+001 1.8016e+006Po-210 5.3570e-005 1.9821e+006 2.9367e+001 1.0866e+006Po-214 8.8802e-005 3.2857e+006 4.8681e+001 1.8012e+006Po-218 8.8838e-005 3.2870e+006 4.8701e+001 1.8020e+006Ra-226 8.8838e-005 3.2870e+006 4.8701e+001 1.8019e+006Rn-222 8.8838e-005 3.2870e+006 4.8701e+001 1.8020e+006


Circumferential 20

Results

Energy (MeV)


Fluence Rate


Fluence Rate

MeV/cm²/secWith

Buildup

Exposure Rate

mR/hrNo

Buildup

ExposureRate

mR/hrWith

Buildup

Absorbed Dose Rate

mrad/hrNo

Buildup

Absorbed Dose Rate

mrad/hrWith

Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith




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90 uCi source under 3 feet of soil - dose to leg above the knee





0.00018 mrem/hour * 8766 h/y = 1.6 mrem/year


Date By Checked











Circumferential 20

Results

Energy (MeV)


Fluence Rate


Fluence Rate

MeV/cm²/secWith

Buildup

Exposure Rate

mR/hrNo

Buildup

ExposureRate

mR/hrWith

Buildup

Absorbed Dose Rate

mrad/hrNo

Buildup

Absorbed Dose Rate

mrad/hrWith

Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith




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90 uCi of Ra-226 under 3 feet of soil - Receptor sitting above object







Date By Checked

Filename Run Date Run Time DurationCase1 February 19, 2019 11:24:01 AM -01:59:6










Circumferential 20

Results

Energy (MeV)


Fluence Rate


Fluence Rate

MeV/cm²/secWith

Buildup

Exposure Rate

mR/hrNo

Buildup

ExposureRate

mR/hrWith

Buildup

Absorbed Dose Rate

mrad/hrNo

Buildup

Absorbed Dose Rate

mrad/hrWith

Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith




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90 uCi Ra-226 at a depth of 3 feet - 6 inch detector offset





mark.somerville

Typewritten Text



Date By Checked

Filename Run Date Run Time DurationCase1 April 2, 2019 1:29:19 PM 00:00:00

Project InfoCase Title 2.2119 mCi

Description Ra226-surface and WB Geometry 3 - Disk


Dose PointsA X Y Z#1 5.08 cm (2.0 in) 0.0 cm (0 in) 0.0 cm (0 in)#2 50.8 cm (1 ft 8.0 in) 0.0 cm (0 in) 0.0 cm (0 in)

ShieldsShield N Dimension Material DensityAir Gap Air 0.00122




Buildup: The material reference is Air GapIntegration ParametersRadial 20

Circumferential 20

Results - Dose Point # 1 - (2,0,0) in

Energy (MeV)


Fluence Rate


Fluence Rate

MeV/cm²/secWith

Buildup

Exposure Rate

mR/hrNo

Buildup

Exposure Rate

mR/hrWith

Buildup

Absorbed Dose Rate

mrad/hrNo

Buildup

Absorbed Dose Rate

mrad/hrWith

Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith

Buildup0.015 2.396e+07 1.086e+03 1.088e+03 9.313e+01 9.333e+01 8.130e+01 8.148e+01 8.130e-01 8.148e-010.05 2.889e+06 4.399e+02 4.409e+02 1.172e+00 1.174e+00 1.023e+00 1.025e+00 1.023e-02 1.025e-020.08 1.862e+07 4.538e+03 4.547e+03 7.181e+00 7.195e+00 6.269e+00 6.281e+00 6.269e-02 6.281e-02

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April 2, 2019 mos

Surface, contact

0.1 1.096e+05 3.340e+01 3.346e+01 5.110e-02 5.118e-02 4.461e-02 4.468e-02 4.461e-04 4.468e-040.2 8.700e+06 5.302e+03 5.307e+03 9.358e+00 9.367e+00 8.170e+00 8.178e+00 8.170e-02 8.178e-020.3 1.667e+07 1.524e+04 1.525e+04 2.891e+01 2.893e+01 2.523e+01 2.525e+01 2.523e-01 2.525e-010.4 3.091e+07 3.768e+04 3.770e+04 7.341e+01 7.346e+01 6.409e+01 6.413e+01 6.409e-01 6.413e-010.5 1.443e+06 2.199e+03 2.200e+03 4.316e+00 4.318e+00 3.768e+00 3.770e+00 3.768e-02 3.770e-020.6 3.894e+07 7.122e+04 7.125e+04 1.390e+02 1.391e+02 1.214e+02 1.214e+02 1.214e+00 1.214e+000.8 7.633e+06 1.861e+04 1.862e+04 3.540e+01 3.541e+01 3.091e+01 3.092e+01 3.091e-01 3.092e-011.0 2.529e+07 7.709e+04 7.711e+04 1.421e+02 1.421e+02 1.240e+02 1.241e+02 1.240e+00 1.241e+001.5 1.538e+07 7.031e+04 7.033e+04 1.183e+02 1.183e+02 1.033e+02 1.033e+02 1.033e+00 1.033e+002.0 2.161e+07 1.318e+05 1.318e+05 2.038e+02 2.038e+02 1.779e+02 1.779e+02 1.779e+00 1.779e+00

Totals 2.122e+08 4.355e+05 4.357e+05 8.561e+02 8.566e+02 7.474e+02 7.478e+02 7.474e+00 7.478e+00


Energy (MeV)


Fluence Rate


Fluence Rate

MeV/cm²/secWith

Buildup

Exposure Rate

mR/hrNo

Buildup

Exposure Rate

mR/hrWith

Buildup

Absorbed Dose Ratemrad/hr

No Buildup

Absorbed Dose Ratemrad/hr

With Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith

Buildup0.015 2.396e+07 1.008e+01 1.030e+01 8.649e-01 8.836e-01 7.550e-01 7.714e-01 7.550e-03 7.714e-030.05 2.889e+06 4.399e+00 4.498e+00 1.172e-02 1.198e-02 1.023e-02 1.046e-02 1.023e-04 1.046e-040.08 1.862e+07 4.547e+01 4.632e+01 7.196e-02 7.330e-02 6.282e-02 6.399e-02 6.282e-04 6.399e-040.1 1.096e+05 3.349e-01 3.403e-01 5.124e-04 5.206e-04 4.473e-04 4.545e-04 4.473e-06 4.545e-060.2 8.700e+06 5.325e+01 5.377e+01 9.397e-02 9.490e-02 8.204e-02 8.284e-02 8.204e-04 8.284e-040.3 1.667e+07 1.532e+02 1.543e+02 2.905e-01 2.927e-01 2.536e-01 2.555e-01 2.536e-03 2.555e-030.4 3.091e+07 3.789e+02 3.812e+02 7.383e-01 7.428e-01 6.446e-01 6.484e-01 6.446e-03 6.484e-030.5 1.443e+06 2.212e+01 2.224e+01 4.343e-02 4.365e-02 3.791e-02 3.810e-02 3.791e-04 3.810e-040.6 3.894e+07 7.168e+02 7.200e+02 1.399e+00 1.405e+00 1.221e+00 1.227e+00 1.221e-02 1.227e-020.8 7.633e+06 1.874e+02 1.881e+02 3.565e-01 3.578e-01 3.113e-01 3.124e-01 3.113e-03 3.124e-031.0 2.529e+07 7.767e+02 7.790e+02 1.432e+00 1.436e+00 1.250e+00 1.254e+00 1.250e-02 1.254e-021.5 1.538e+07 7.089e+02 7.105e+02 1.193e+00 1.195e+00 1.041e+00 1.044e+00 1.041e-02 1.044e-022.0 2.161e+07 1.329e+03 1.332e+03 2.056e+00 2.059e+00 1.794e+00 1.798e+00 1.794e-02 1.798e-02

Totals 2.122e+08 4.387e+03 4.402e+03 8.551e+00 8.597e+00 7.465e+00 7.505e+00 7.465e-02 7.505e-02



leg above knee

LLRO activity is 2.2119 mCi, Ra-226 There are 2 dose points and no soil shielding. 1) The 2 inch dose point is a "contact" location and shows dose rate

of 857 mrem/hour.2) The 20 inch location is to the leg above the knee. The 20' change

in distance drops the dose rate to about 8.6 mrem per hour.I did not include annualized doses. Though they are included in the other depth-shielded calculations, they are intended to show doses under very unreasonable assumptions; that is, not moving from a single spot for an entire year. A "recreator" spending 438 hours at this source location would recieve an estimated 3,767 mrem/year.Also, with all the calculations, only a portion of the whole body is actually irradiated. As shown above, there is a steep distance/dose gradient. One further note: The calculations include equilibrium daughters and those daughters drive the photon dose. An weathered object in free air would not likely be in equilibrium and doses would be lower.


Date By Checked



Description Ra226-1 foot-surface and WB Geometry 3 - Disk


Dose PointsA X Y Z#1 35.56 cm (1 ft 2.0 in) 0.0 cm (0 in) 0.0 cm (0 in)#2 81.28 cm (2 ft 8.0 in) 0.0 cm (0 in) 0.0 cm (0 in)






Circumferential 20


Energy (MeV)


Fluence Rate


Fluence Rate

MeV/cm²/secWith

Buildup

ExposureRate

mR/hrNo

Buildup

Exposure Rate

mR/hrWith

Buildup

Absorbed Dose Rate

mrad/hrNo

Buildup

Absorbed Dose Rate

mrad/hrWith

Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith

Buildup0.015 2.396e+07 1.775e-221 2.124e-25 1.523e- 1.822e-26 1.329e- 1.591e-26 1.329e- 1.591e-28



April 2, 2019 mos

Ground surface

222 222 2240.05 2.889e+06 4.451e-09 4.420e-08 1.186e-11 1.177e-10 1.035e-11 1.028e-10 1.035e-13 1.028e-120.08 1.862e+07 2.391e-03 5.763e-02 3.783e-06 9.120e-05 3.303e-06 7.962e-05 3.303e-08 7.962e-070.1 1.096e+05 1.179e-04 3.445e-03 1.803e-07 5.271e-06 1.574e-07 4.601e-06 1.574e-09 4.601e-080.2 8.700e+06 2.517e-01 6.240e+00 4.442e-04 1.101e-02 3.878e-04 9.615e-03 3.878e-06 9.615e-050.3 1.667e+07 1.761e+00 3.047e+01 3.341e-03 5.780e-02 2.917e-03 5.046e-02 2.917e-05 5.046e-040.4 3.091e+07 7.660e+00 9.821e+01 1.492e-02 1.914e-01 1.303e-02 1.671e-01 1.303e-04 1.671e-030.5 1.443e+06 6.735e-01 6.781e+00 1.322e-03 1.331e-02 1.154e-03 1.162e-02 1.154e-05 1.162e-040.6 3.894e+07 3.001e+01 2.480e+02 5.857e-02 4.841e-01 5.113e-02 4.227e-01 5.113e-04 4.227e-030.8 7.633e+06 1.262e+01 7.744e+01 2.401e-02 1.473e-01 2.096e-02 1.286e-01 2.096e-04 1.286e-031.0 2.529e+07 7.389e+01 3.646e+02 1.362e-01 6.721e-01 1.189e-01 5.867e-01 1.189e-03 5.867e-031.5 1.538e+07 1.190e+02 4.117e+02 2.003e-01 6.927e-01 1.749e-01 6.047e-01 1.749e-03 6.047e-032.0 2.161e+07 3.144e+02 8.866e+02 4.861e-01 1.371e+00 4.244e-01 1.197e+00 4.244e-03 1.197e-02

Totals 2.122e+08 5.603e+02 2.130e+03 9.252e-01 3.641e+00 8.077e-01 3.178e+00 8.077e-03 3.178e-02


Energy (MeV)


Fluence Rate


Fluence Rate

MeV/cm²/secWith

Buildup

Exposure Rate

mR/hrNo

Buildup

ExposureRate

mR/hrWith

Buildup

Absorbed Dose Rate

mrad/hrNo

Buildup

Absorbed Dose Rate

mrad/hrWith

Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith

Buildup

0.015 2.396e+07 3.272e-222 4.066e-26 2.806e-223 3.488e-27 2.450e-

223 3.045e-27 2.450e-225 3.045e-29

0.05 2.889e+06 8.444e-10 8.389e-09 2.249e-12 2.235e-11 1.964e-12 1.951e-11 1.964e-14 1.951e-130.08 1.862e+07 4.540e-04 1.095e-02 7.185e-07 1.734e-05 6.273e-07 1.513e-05 6.273e-09 1.513e-070.1 1.096e+05 2.239e-05 6.553e-04 3.426e-08 1.003e-06 2.991e-08 8.753e-07 2.991e-10 8.753e-090.2 8.700e+06 4.788e-02 1.189e+00 8.451e-05 2.099e-03 7.378e-05 1.832e-03 7.378e-07 1.832e-050.3 1.667e+07 3.353e-01 5.812e+00 6.361e-04 1.102e-02 5.553e-04 9.624e-03 5.553e-06 9.624e-050.4 3.091e+07 1.459e+00 1.874e+01 2.843e-03 3.651e-02 2.482e-03 3.188e-02 2.482e-05 3.188e-040.5 1.443e+06 1.284e-01 1.294e+00 2.520e-04 2.540e-03 2.200e-04 2.218e-03 2.200e-06 2.218e-050.6 3.894e+07 5.721e+00 4.735e+01 1.117e-02 9.243e-02 9.749e-03 8.069e-02 9.749e-05 8.069e-040.8 7.633e+06 2.408e+00 1.479e+01 4.579e-03 2.813e-02 3.998e-03 2.456e-02 3.998e-05 2.456e-041.0 2.529e+07 1.410e+01 6.965e+01 2.599e-02 1.284e-01 2.269e-02 1.121e-01 2.269e-04 1.121e-031.5 1.538e+07 2.273e+01 7.868e+01 3.824e-02 1.324e-01 3.339e-02 1.156e-01 3.339e-04 1.156e-032.0 2.161e+07 6.004e+01 1.695e+02 9.285e-02 2.621e-01 8.106e-02 2.288e-01 8.106e-04 2.288e-03

Totals 2.122e+08 1.070e+02 4.070e+02 1.766e-01 6.956e-01 1.542e-01 6.072e-01 1.542e-03 6.072e-03



Leg above knee

LLRO activity is 2.2119 mCi, Ra-226. There are 2 dose points listed. 1) 14 inch dose point is ground surface and has a calculated dose rate

of 3.641 mrem/hour. If there for an entire year, this would yield a dose of about 32 rem (32,000 mrem).

2) The 32 inch dose point is to the leg above the knee and has a calculated dose rate of 0.696 mrem which if there for an entire year would yield a dose of 6.1 rem (6,100 mrem).

3) For an outdoor "recreator" who spends 438 hours per year outdoorsover this object, the dose to the leg above the knee would be 307mrem per year.


Date By Checked



Description Ra226-2 feet-surface and WB Geometry 3 - Disk








Circumferential 20


Energy (MeV)


Fluence Rate


Fluence Rate

MeV/cm²/secWith

Buildup

Exposure Rate

mR/hrNo

Buildup

ExposureRate

mR/hrWith

Buildup

Absorbed Dose Rate

mrad/hrNo

Buildup

Absorbed Dose Rate

mrad/hrWith

Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith

Buildup0.015 2.396e+07 0.000e+00 6.160e-26 0.000e+00 5.283e-27 0.000e+00 4.612e-27 0.000e+00 4.612e-29



April 2, 2019 mos

ground surface

0.05 2.889e+06 6.351e-19 1.069e-17 1.692e-21 2.848e-20 1.477e-21 2.486e-20 1.477e-23 2.486e-220.08 1.862e+07 1.773e-08 1.052e-06 2.806e-11 1.664e-09 2.450e-11 1.453e-09 2.450e-13 1.453e-110.1 1.096e+05 5.854e-09 5.047e-07 8.957e-12 7.722e-10 7.819e-12 6.741e-10 7.819e-14 6.741e-120.2 8.700e+06 1.681e-04 1.492e-02 2.967e-07 2.633e-05 2.590e-07 2.299e-05 2.590e-09 2.299e-070.3 1.667e+07 2.863e-03 1.675e-01 5.432e-06 3.178e-04 4.742e-06 2.774e-04 4.742e-08 2.774e-060.4 3.091e+07 2.190e-02 8.763e-01 4.268e-05 1.707e-03 3.726e-05 1.491e-03 3.726e-07 1.491e-050.5 1.443e+06 2.902e-03 8.431e-02 5.696e-06 1.655e-04 4.973e-06 1.445e-04 4.973e-08 1.445e-060.6 3.894e+07 1.778e-01 3.967e+00 3.471e-04 7.744e-03 3.030e-04 6.760e-03 3.030e-06 6.760e-050.8 7.633e+06 1.204e-01 1.794e+00 2.290e-04 3.413e-03 1.999e-04 2.979e-03 1.999e-06 2.979e-051.0 2.529e+07 9.958e-01 1.097e+01 1.836e-03 2.022e-02 1.603e-03 1.765e-02 1.603e-05 1.765e-041.5 1.538e+07 2.834e+00 1.901e+01 4.768e-03 3.198e-02 4.163e-03 2.792e-02 4.163e-05 2.792e-042.0 2.161e+07 1.054e+01 5.274e+01 1.630e-02 8.155e-02 1.423e-02 7.119e-02 1.423e-04 7.119e-04



Energy (MeV)


Fluence Rate


Fluence Rate

MeV/cm²/secWith

Buildup

Exposure Rate

mR/hrNo

Buildup

ExposureRate

mR/hrWith

Buildup

Absorbed Dose Rate

mrad/hrNo

Buildup

Absorbed Dose Rate

mrad/hrWith

Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith

Buildup0.015 2.396e+07 0.000e+00 2.151e-26 0.000e+00 1.845e-27 0.000e+00 1.611e-27 0.000e+00 1.611e-290.05 2.889e+06 2.196e-19 3.696e-18 5.849e-22 9.847e-21 5.106e-22 8.596e-21 5.106e-24 8.596e-230.08 1.862e+07 6.139e-09 3.644e-07 9.716e-12 5.766e-10 8.482e-12 5.034e-10 8.482e-14 5.034e-120.1 1.096e+05 2.028e-09 1.750e-07 3.103e-12 2.677e-10 2.708e-12 2.337e-10 2.708e-14 2.337e-120.2 8.700e+06 5.831e-05 5.181e-03 1.029e-07 9.144e-06 8.985e-08 7.982e-06 8.985e-10 7.982e-080.3 1.667e+07 9.942e-04 5.823e-02 1.886e-06 1.105e-04 1.646e-06 9.642e-05 1.646e-08 9.642e-070.4 3.091e+07 7.610e-03 3.047e-01 1.483e-05 5.938e-04 1.294e-05 5.184e-04 1.294e-07 5.184e-060.5 1.443e+06 1.009e-03 2.933e-02 1.980e-06 5.757e-05 1.728e-06 5.026e-05 1.728e-08 5.026e-070.6 3.894e+07 6.182e-02 1.381e+00 1.207e-04 2.695e-03 1.053e-04 2.353e-03 1.053e-06 2.353e-050.8 7.633e+06 4.187e-02 6.246e-01 7.965e-05 1.188e-03 6.953e-05 1.037e-03 6.953e-07 1.037e-051.0 2.529e+07 3.466e-01 3.820e+00 6.388e-04 7.042e-03 5.577e-04 6.147e-03 5.577e-06 6.147e-051.5 1.538e+07 9.869e-01 6.623e+00 1.660e-03 1.114e-02 1.450e-03 9.727e-03 1.450e-05 9.727e-052.0 2.161e+07 3.673e+00 1.838e+01 5.679e-03 2.842e-02 4.958e-03 2.481e-02 4.958e-05 2.481e-04




leg above the knee

LLRO activity is 2.2119 mCi, Ra-226. There are 2 dose points listed. 1) The 26 inch dose point is ground surface and calculates to

0.147 mrem/hour. Annualized without any movement calculates to 1,290 mrem.

2) The 44 inch dose point is to the leg above the knee and calculates to 0.0513 mrem/hour. Standing there for one year calculates toabout 450 mrem for that year.

3) For an outdoor "recreator" who spends 438 hours per year outdoors over this object, the dose to the leg above the knee would be 22.4 mrem per year.


Date By Checked











Circumferential 20


Energy (MeV)


Fluence Rate


Fluence Rate

MeV/cm²/secWith

Buildup

Exposure Rate

mR/hrNo

Buildup

ExposureRate

mR/hrWith

Buildup

Absorbed Dose Rate

mrad/hrNo

Buildup

Absorbed Dose Rate

mrad/hrWith

Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith




April 2, 2019 mos

Ground Contact

0.05 2.889e+06 1.462e-28 2.179e-25 3.895e-31 5.805e-28 3.401e-31 5.068e-28 3.401e-33 5.068e-300.08 1.862e+07 2.123e-13 2.256e-11 3.359e-16 3.571e-14 2.933e-16 3.117e-14 2.933e-18 3.117e-160.1 1.096e+05 4.693e-13 8.304e-11 7.180e-16 1.270e-13 6.268e-16 1.109e-13 6.268e-18 1.109e-150.2 8.700e+06 1.812e-07 3.853e-05 3.198e-10 6.801e-08 2.792e-10 5.937e-08 2.792e-12 5.937e-100.3 1.667e+07 7.515e-06 1.006e-03 1.425e-08 1.909e-06 1.244e-08 1.667e-06 1.244e-10 1.667e-080.4 3.091e+07 1.011e-04 8.715e-03 1.970e-07 1.698e-05 1.720e-07 1.482e-05 1.720e-09 1.482e-070.5 1.443e+06 2.018e-05 1.202e-03 3.962e-08 2.360e-06 3.459e-08 2.060e-06 3.459e-10 2.060e-080.6 3.894e+07 1.701e-03 7.420e-02 3.320e-06 1.448e-04 2.898e-06 1.264e-04 2.898e-08 1.264e-060.8 7.633e+06 1.853e-03 5.039e-02 3.525e-06 9.584e-05 3.077e-06 8.367e-05 3.077e-08 8.367e-071.0 2.529e+07 2.167e-02 4.123e-01 3.994e-05 7.600e-04 3.487e-05 6.635e-04 3.487e-07 6.635e-061.5 1.538e+07 1.089e-01 1.149e+00 1.833e-04 1.932e-03 1.600e-04 1.687e-03 1.600e-06 1.687e-052.0 2.161e+07 5.708e-01 4.252e+00 8.826e-04 6.575e-03 7.705e-04 5.740e-03 7.705e-06 5.740e-05

Totals 2.122e+08 7.050e-01 5.948e+00 1.113e-03 9.529e-03 9.716e-04 8.319e-03 9.716e-06 8.319e-05


Energy (MeV)


Fluence Rate


Fluence Rate

MeV/cm²/secWith

Buildup

Exposure Rate

mR/hrNo

Buildup

ExposureRate

mR/hrWith

Buildup

Absorbed Dose Rate

mrad/hrNo

Buildup

Absorbed Dose Rate

mrad/hrWith

Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith

Buildup0.015 2.396e+07 0.000e+00 1.328e-26 0.000e+00 1.139e-27 0.000e+00 9.943e-28 0.000e+00 9.943e-300.05 2.889e+06 6.663e-29 1.003e-25 1.775e-31 2.673e-28 1.550e-31 2.334e-28 1.550e-33 2.334e-300.08 1.862e+07 9.690e-14 1.030e-11 1.533e-16 1.630e-14 1.339e-16 1.423e-14 1.339e-18 1.423e-160.1 1.096e+05 2.143e-13 3.795e-11 3.279e-16 5.806e-14 2.863e-16 5.068e-14 2.863e-18 5.068e-160.2 8.700e+06 8.289e-08 1.764e-05 1.463e-10 3.113e-08 1.277e-10 2.718e-08 1.277e-12 2.718e-100.3 1.667e+07 3.440e-06 4.611e-04 6.526e-09 8.747e-07 5.697e-09 7.636e-07 5.697e-11 7.636e-090.4 3.091e+07 4.631e-05 3.995e-03 9.024e-08 7.785e-06 7.878e-08 6.796e-06 7.878e-10 6.796e-080.5 1.443e+06 9.250e-06 5.514e-04 1.816e-08 1.082e-06 1.585e-08 9.449e-07 1.585e-10 9.449e-090.6 3.894e+07 7.798e-04 3.404e-02 1.522e-06 6.644e-05 1.329e-06 5.801e-05 1.329e-08 5.801e-070.8 7.633e+06 8.500e-04 2.313e-02 1.617e-06 4.399e-05 1.411e-06 3.840e-05 1.411e-08 3.840e-071.0 2.529e+07 9.943e-03 1.893e-01 1.833e-05 3.489e-04 1.600e-05 3.046e-04 1.600e-07 3.046e-061.5 1.538e+07 5.001e-02 5.276e-01 8.414e-05 8.877e-04 7.346e-05 7.749e-04 7.346e-07 7.749e-062.0 2.161e+07 2.622e-01 1.954e+00 4.054e-04 3.021e-03 3.539e-04 2.638e-03 3.539e-06 2.638e-05

Totals 2.122e+08 3.238e-01 2.733e+00 5.112e-04 4.378e-03 4.462e-04 3.822e-03 4.462e-06 3.822e-05



Leg above knee

LLRO activity is 2.2119 mCi. Ra-226 There are 2 dose points listed. 1) The 38 inch dose point is ground surface. Dose rate is 0.00953 mrem/hour.

Annualized without moving, this is about 84 mrem.2) the 56 inch point is to the leg above the knee and has a dose rate of 0.0044

mrem/hour. Annualized, this is about 38 mrem.3) For an outdoor "recreator" who spends 438 hours per year outdoors over

this object, the dose to the leg above the knee would be 1.9 mrem/year.


Date By Checked











Circumferential 20


Energy (MeV)


Fluence Rate


Fluence Rate

MeV/cm²/secWith

Buildup

Exposure Rate

mR/hrNo

Buildup

ExposureRate

mR/hrWith

Buildup

Absorbed Dose Rate

mrad/hrNo

Buildup

Absorbed Dose Rate

mrad/hrWith

Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith




April 2, 2019 mos

This is surface Contact

0.05 2.889e+06 4.153e-38 1.259e-25 1.106e-40 3.353e-28 9.658e-41 2.927e-28 9.658e-43 2.927e-300.08 1.862e+07 3.135e-18 5.262e-16 4.961e-21 8.327e-19 4.331e-21 7.270e-19 4.331e-23 7.270e-210.1 1.096e+05 4.641e-17 1.413e-14 7.101e-20 2.161e-17 6.199e-20 1.887e-17 6.199e-22 1.887e-190.2 8.700e+06 2.410e-10 1.007e-07 4.254e-13 1.777e-10 3.713e-13 1.551e-10 3.713e-15 1.551e-120.3 1.667e+07 2.433e-08 6.174e-06 4.615e-11 1.171e-08 4.029e-11 1.022e-08 4.029e-13 1.022e-100.4 3.091e+07 5.758e-07 8.906e-05 1.122e-09 1.735e-07 9.794e-10 1.515e-07 9.794e-12 1.515e-090.5 1.443e+06 1.732e-07 1.774e-05 3.399e-10 3.482e-08 2.968e-10 3.040e-08 2.968e-12 3.040e-100.6 3.894e+07 2.007e-05 1.448e-03 3.918e-08 2.826e-06 3.421e-08 2.467e-06 3.421e-10 2.467e-080.8 7.633e+06 3.520e-05 1.502e-03 6.695e-08 2.856e-06 5.844e-08 2.494e-06 5.844e-10 2.494e-081.0 2.529e+07 5.816e-04 1.671e-02 1.072e-06 3.080e-05 9.360e-07 2.689e-05 9.360e-09 2.689e-071.5 1.538e+07 5.164e-03 7.660e-02 8.689e-06 1.289e-04 7.585e-06 1.125e-04 7.585e-08 1.125e-062.0 2.161e+07 3.812e-02 3.854e-01 5.895e-05 5.960e-04 5.147e-05 5.203e-04 5.147e-07 5.203e-06



Energy (MeV)


Fluence Rate


Fluence Rate

MeV/cm²/secWith

Buildup

Exposure Rate

mR/hrNo

Buildup

ExposureRate

mR/hrWith

Buildup

Absorbed Dose Rate

mrad/hrNo

Buildup

Absorbed Dose Rate

mrad/hrWith

Buildup

Absorbed Dose Rate

mGy/hrNo

Buildup

Absorbed Dose Rate

mGy/hrWith

Buildup0.015 2.396e+07 0.000e+00 9.005e-27 0.000e+00 7.724e-28 0.000e+00 6.743e-28 0.000e+00 6.743e-300.05 2.889e+06 2.222e-38 6.805e-26 5.918e-41 1.813e-28 5.167e-41 1.583e-28 5.167e-43 1.583e-300.08 1.862e+07 1.680e-18 2.821e-16 2.659e-21 4.464e-19 2.321e-21 3.897e-19 2.321e-23 3.897e-210.1 1.096e+05 2.489e-17 7.578e-15 3.808e-20 1.159e-17 3.324e-20 1.012e-17 3.324e-22 1.012e-190.2 8.700e+06 1.294e-10 5.411e-08 2.284e-13 9.550e-11 1.994e-13 8.337e-11 1.994e-15 8.337e-130.3 1.667e+07 1.308e-08 3.321e-06 2.481e-11 6.299e-09 2.166e-11 5.499e-09 2.166e-13 5.499e-110.4 3.091e+07 3.097e-07 4.793e-05 6.034e-10 9.339e-08 5.268e-10 8.153e-08 5.268e-12 8.153e-100.5 1.443e+06 9.319e-08 9.550e-06 1.829e-10 1.875e-08 1.597e-10 1.637e-08 1.597e-12 1.637e-100.6 3.894e+07 1.081e-05 7.797e-04 2.109e-08 1.522e-06 1.841e-08 1.329e-06 1.841e-10 1.329e-080.8 7.633e+06 1.896e-05 8.091e-04 3.605e-08 1.539e-06 3.148e-08 1.344e-06 3.148e-10 1.344e-081.0 2.529e+07 3.134e-04 9.005e-03 5.776e-07 1.660e-05 5.043e-07 1.449e-05 5.043e-09 1.449e-071.5 1.538e+07 2.784e-03 4.131e-02 4.684e-06 6.950e-05 4.089e-06 6.068e-05 4.089e-08 6.068e-072.0 2.161e+07 2.056e-02 2.079e-01 3.180e-05 3.216e-04 2.776e-05 2.807e-04 2.776e-07 2.807e-06




At Leg above knee

LLRO activity is 2.2119 mCi, Ra-226. There are 2 dose points listed. 1) The 50 inch dose point is ground surface. It is 0.00076 mrem/hour.

If one is in contact with the ground over this spot for 8.766 hours, the external dose would be close to 7 mrem for that year.

2) The 68 inch dose point is to the leg above the knee as if standing on the ground above the object. That dose rate is 0.00041 mrem/hour. For the 1 year exposure, this equals 3.6 mrem.

3) A realistic time and motion estimate for proximity to the source would be similar to a "recreator". This would be someone who spent 0.5 of their time out of doors. Of that out of doors time, 10% would be spent in an activity above the source. 8,766 h/y * 0.5 * 0.1 * 4.1E-4mrem/h = 0.18 mrem/year. This is to leg above the knee.

Documents

Navy Response to NRC Comments on the Draft Technical ...information on the subject document in a letter to the Navy dated November 19, 2018. The Navy is providing the requested additional