ML19347B258
| ML19347B258 | |
| Person / Time | |
|---|---|
| Issue date: | 09/12/1980 |
| From: | Martin J NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Hannon G HOUSING & URBAN DEVELOPMENT, DEPT. OF |
| References | |
| REF-WM-40 NUDOCS 8010140146 | |
| Download: ML19347B258 (8) | |
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[(fg#o}3 NUCLEAR REGULATORY COitMISSION g) M Q UNITED STATES l
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- E WAT tlNGTON D. C. 20555 O
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\\.... 8 SEP 121980 l
Mr. Gerald Hannon Deputy Regional Administrator Department of Housing and Urban Development 1405 Curtis Street Denver, Colorado 80202
Dear Mr. Hannon:
This letter requests your concurrence in the enclosed Edgemont Cleanup i
Action Program. As Mr. Gregory Eadie of my staff indicated during the meeting with your staff in Denver on September 5,1980, this supplemental program embodies all of the essential criteria as contained in your August 5,1980, protocol; however, greater emphasis will be placed in thorough gama radiation grid surveys, soil sample analysis for radium-226 content, and bore hole logging in order to fully evaluate all areas containing residual radioactivity. The State of South Dakota is in complete agreement with the enclosed program; and Mr. Eadie has discussed the specific details of this program with representatives of the U. S.
l Environmental Protection Agency and has. received their preliminary j
concurrence in it.
l As you are aware, the mobile laboratory and personnel from the Battelle Pacific Northwest Laboratories (BPNL) will arrive in Edgemont about September 15, 1980, and the radiological surveys should be initiated later that week. As we are all anxious to evaluate any potential radiological problem areas and to complete all required cleanup actions in the Edgemont area as soon as possible, your concurrence in the enclosed supplemental program is urgently needed so that the actual work will not be delayed and that we may be asswed that all of the results of the Edgemont Cleanup Action Program will be fully acceptable to you.
The ultimate goal of the Edgemont Cleanup Action Program is to locate, and, if possible, to cleanup all areas of residual radioactivity.
However, at this time, the NRC is not authorized to conduct any type of remedial action at any location identified as having a radiation anomaly due to natural terrestrial radioactivity. Since natural terrestrial radioactivity exists in every comunity of the United States, the HUD requirement that the weighted grab-Working Level (WWL) be less than 0.02WWL regardless of the identifiable source of the radiation anomaly l
seems to unjustifiably single out and burden the hnmaowners of Edgemont, i
and imposes a precedent setting standard. The NRC staff agrees with and i
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Mr. Gerald Hannon SEP 121980 supports your concern for the helth and safety of Edgemont homeowners; however, it should be recognizeo that, similar to the Edgemont sitJation, the entire U. S. populat'^n is being continually exposed to low-levels of radiation due sole'
.., natural terrestrial radioactivity.
Therefore, it is recomended that HUD reconsider its requirement for Edgemont, and to specifically exclude any existing structure having elevated radiation levels due solely to natural terrestrial radioactivity from having to meet the HUD indoor grab-Working Level value of 0.02WWL.
Additionally, upon the owner's request, the Edgemont Cleanup Action Program will complete extensive radiological surveys at any structure or open land area; and for those areas identified as natural terrestrial radioactivity, possible remedial actions for the affected structure will be recomended for the homeowner's consideration and implementation.
Thereby, any radiological problems due solely to natural terrestrial radioactivity will not be ignored; but yet, any Edgemont homeowner who has such a problem will not be penalized by withholding HUD financing.
So that we may begin our work on schedule, we would appreciate your concurrence in the enclosed Edgemont Cleanup Action Program by September 22, 1980.
If you have any questions on this matter, please contact Ross A. Scarano or Gregory Eadie of my staff. They may be re.iched at 301-427-4103.
Si
- rely, kYi hIl d
/ ohn B. Martin, Director Division of Waste Management Office of Nuclear Material Safety and Safeguards
Enclosure:
Edgemont Cleanup Action Program cc:
John Giedt, US EPA, Denver J. R. Richardson, South Dakota R. Perkins, BPNL Mayor Zeimet, Edgemont, SD
EiiCLOSURE United States Nuclear Regulatory Comission and The State of South Dakota Edgemont Cleanup Action Program l
, Criteria #1 Any weighted indoor Working Levela (WWL) determined to be above 0.02WWL (including background) in existing residences shall be classified as l
exceeding that level determined te he acceptable by the Department of Housing and Urban Development (HUD).
Criteria #2 l
l If a weighted indoor working level measurement exceeds 0.02WWL, but is less than 0.05WWL, a confirmatory grab-WL sample or other specia'l procedure such as a gama radiation survey or soil sample analysis shall i
l be made to verify the anomaly.
Criteria #3 l
Average size individual residential lots for which construction of residential dwellings has ngt yet begun may be screened by performing a i
l gama radiation grid survey or soil sample analysis. Any gamma radiation l _
grid survey's arithmetic average determined to be greater than 14.5 vR/hr shall be considered unacceptable by HUD.
l Criteria #4 Large size individual residential lots or multiple lot development areas where construction of residential dwellings has not get begun may be i
screened by performing a gama radiation grid survey or soil sample l
analysis. Any gama grid survey's arithmetic average determined to be l
greater than 14.5 pR/hr shall be considered unacceptable by HUD.
Criteria #5 Unique circumstances not identified in the above Criteria shall be handled on a case-by-case basis with consultation of HUD/8 and EPA /8.
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^ Grab-Working Level samples shall be performed using the procedure outlined in Procedure I -- Grab-WL Sampling.
bThe gamma radiation grid surveys shall be perfon ed using the procedure outlined in Procedure II -- Gamma Radiation Survey-Small Lots.
I cThe gamma radiation grid survey shall be performed using the procedure outlined in Procedure III -- Gamma Radiation Survey-Large Lots.
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Procedure I -- Grab WL Sampling In detemining acceptability of a residence for federally-supported financing in Edgemont, South Dakota, the South Dakota State Health Department (SDHD) will assure that indoor radon daughter measurements are made in the following manner:
1.
For each measurement, an. air sample having a minimum volume of 20 liters will be drawn through a Millipore Type AA filter having a pore size of 0.80 microns.
Either the modified Kusnetz or Tsivoglou (Thomas) methods may be used for counting alpha activity with a scintillation counter.
The radon decay product concentration in working levels (WL) will be calculated and recorded.
2.
A house closed reading (HCR) shall be made on the ground floor 4
after the residence has been sealed for an optimum period of eight hours, but a minimum period of three hours.
Sealed means that all windows, doors and outside vents are closed.
Wintertime conditions 4
between November 15 and April 1 will be consi.dered a substitute for the house. sealed requirement.
3.
If the house has a finished and routinely used basement sleeping quarter, an additional HCR shall be made in the basement. The two calculated HCR's will then be averaged and recorded.
4.
The weighted working level (WWL) shall be used to approximate the annual concentration.
In the Edgemont area, approximately seven months (60% of the year) are chosen as precluding the use of outside ventilation due to inclement weather.
Accordingly, the WWL is derived as follows: WL (0.6) = WWL.
i 5.
Special circumstances, such as air conditioning, hot water heating, space heating, wood burning stoves or life style, may be documented but will not be evaluated.
6.
An alternate method of determining acceptability of a residence is the use of data acquired by measurement of an integrated indoor radon decay product sample.
Individual 6 ta will be derived from a minimum sampling time of 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> sii ce sht -ter integrating time periods are frequently the result of plugged filt ars for which the airflow is not readily determinable.
The average o/ the data acquired in the period between November 15 and April 1 may be substituted for HCR.
The arithmetic average of measurements taken at interals over the entire year will be considered as equivalent to the weighted working level (WWL).
7.
Confirmation of the grab sample measurements determined to be between 0.02WWL and 0.05WWL shall be performed to prevent unwarranted penalization of dwellings affected.
This-is necessary because of increased easurement uncertainty with the grab sampling technique in this range.
The measurement uncertainty in this range is due, in part, to variables which may cause unrepresentative radon / radon decay product disequilibrium.
In lieu of repeated grab-Working Level measurements, a combination of inSor and outdoor gama radiation surveys, soil sample analysis for ra:ium-226 content, and bore hole logging techniques may be utilized to identify all radiation anomalies, i
Procedure II -- Gamma Radiation Survey-Small Lots Individual residential lots not exceeding 75' x 125' for which construction
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of a residential dwelling has not yet begun will be screened in the j
following manner:
1.
The narrower side of the lot will be divided into four equal lengths and the wider side of the lot divided into five equal lengths, forming a total of twenty measurement areas; 2.
The center of each measurement area will be measured for gamma i
radiation with a pressurized ion chamber rate meter (PIC) or portable radiation detector which is cross-calibrated with the PIC using the gamma ray energies of interest; 3.
The center of the detector will be three feet from the ground.
If a PIC is used, the digital rate meter and power supply will be i
separated from the ion chamber by the full cable distance during each measurement.
At each measurement location, af ter the rate meter stabilizes, ten measurements will be taken at one second. intervals and the average recorded; 4.
After all measurements have oesn taken, the arithmetic average shall be determined; 5.
If it can be shown that removal of surface radioactivity by 4
scraping, leveling or other lot preparat, ion will reduce an unacceptable gamma radiation level to an acceptable level, the lot.will be reconsidered on a case-by-case basis.
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Procedure III -' Gamma Radiation Survey-Larae Lots Large size individual lots or multiple lot development areas for which construction of residential dwellings has not yet begun will be screened in the following manner:
1.
A 200' grid measurement pattern will be developed utilizing a chain or a tape to determine measurement intervals.
However, the entire lot will be screened by a walk--through gamma radiation survey to determine the pr9sence of any area having greater than background radiation levels.
2.
Measurements will be taken in the sr.me manner as described for small lots.
3.
After all measurements have been taken, the arithmetic average will be determined.
4.
If it can be shown that removal of surface radioactivity can be removdd in the same manner as described for small lots, larger lots will be reconsidered on a case-by-case basis.
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Procedure IV -- Indoor Gamma Radiation Survey A portable gamma survey meter (e.g., micro R meter) shall be used to complete the gamma radiation measurements both inside and outside of the structure. This survey meter shall be cross-calibrated with a Pressurized Ionization Chamber (PIC) in order to provide realistic exposure measurements.
This survey shall be designed to detect the presence of any possible residual radioactivity under, witSin or around the structure. A map shall be provided indicating all locations having above background radiation levels.
This survey need only be performed once for each qualifying structure.
Measurements shall be made at the three foot height level.
Measurements shall be made on all floors and the basement at 25 square foot intervals, and averaged separately per floor.
The outside gamma radiation measurements ~
shall be made on a 50 square foot interval.
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Procedure V -- Soil Sampling or Bore Hole Logging and Analysis Appropriate soil samples shall be obtained and analyzed for the radium-
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226 concentration, and all areas having greater than 5 pCi/gm of radium-226 shall be indicated on a suitable site map.
l Bore hole loggirg may also be substituted for actual soil sampling and analysis but the bore hole log shall indicate the radium-226 soil concentration.
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