ML19276H618
| ML19276H618 | |
| Person / Time | |
|---|---|
| Site: | 07000903 |
| Issue date: | 08/22/1974 |
| From: | Hamada G US ATOMIC ENERGY COMMISSION (AEC) |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML19276H604 | List: |
| References | |
| FOIA-79-370, FOIA-79-398, FOIA-79-423 NUDOCS 7912070376 | |
| Download: ML19276H618 (6) | |
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' Files In response to the meco dated July 17, 1974, from C. W. Kuhlm, to J. J. Davis, "Pu Concentrations in Soil," a meeting was held on July 29, 1974, to discuss this matter. Present for this teeting were C. Gacertsfelder (RS), R. Baker (RS), R. Alexander (RS), D. Sly (RS),
J. Henry (RS), W. Crow (L:FM), B. Weiss (RO) and G. Hamada (RS).
As a consequence of a deco:nissioning action, the memoranduo had requested guidance on recommended levels of Pu in soil for unrestricted areas. The staf f reco:= ended that the ALAP approach be used and each site be treated on a case-by-case basis at this time.
It was clear, however, that there was not enough data to make an evaluation one way or the other for the site in question.
It was therefore reco= ended that a site visit be made to talk to the principals and inspect the site -
is it level, clear, forested, etc.? - and to determine what kind and how nuch tore information would be needed.
Peter Knapp from Regica I:R0 and G. Hamada (RS) are scheduled to meet with the Gulf-United Suclear people at the site (Pawling,11. Y.) on 8/8/74.
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G. Hamada Site Standards Branch Directorate of Regulatory Standards n
7912070 3 76
Draft 8/23/74
SUBJECT:
Decommissioning of Pu Facility - Pawling, N.Y.
On August 8, 1974, Peter Knapp of Region 1 - R0 and G. Hamada (RS) met with representatives of Gulf, United Nuclear and ATCOR at Pawling, N.Y. to discuss matters related to the decommissioning of this facility and release of the site for unrestricted use.
As a consequence of incidents involving accidental releases of Pu to the environs immediately outside the "Pu building", two small areas of the ground next to the building were found to contain Pu in quantities significantly above levels expected from fallout for this area.
A sample of soil from the tuo areas measured 12 dpm Pu239 per go of coil and 5 dpa Pu239 per gm of soil respectively. Other soil samples taken at locations
,ithin 5 - 10 feet of these samples measured 1 - 2 orders oE magnitude louer - 0.1-0.5 dpa/ga. Visual inspection of the area which gave the h ghest soll reading indicated that stray pieces of glass not much bigger than grains of coarse beach sand were still present. The "high" soil reading could have occurred as a res..lt of a piece of glass being included in the soil sample taken for analysis. The glass came from a window located en the side of the "Pu building" which was blown out by a chemical explosion a n the building.
The explosion caused Pu contamination in several areas i
inside the'guilding. A small amount cf Pu also escaped from the building through the shattered vindow and possibly from other pathways.
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. ATCOR is the organization that was contracted by Culf-United Nuclear to decontaninate the facility and also to assess the extent of contanination of the environs, if any, that night have been caused by the incident.
ATCOR surveyed the environs by taking soil samples at selected locations and ha.k i 'E:3 these aralyzed for Pu by CEP, a subcontractor for ATCOR. The CEP results for these soils became suspect when unusually high Pu-238 to Pu-239, 240 ratios were reported for many of the samples. Region I - R0 subsequently resampled a few of these areas and had the soil samples analyzed at liSL-Idaho, an AEC laboratory. The two high results mentioned earlier were those froa two of the four soils analyzed by HSL-Idaho. The following are the co:parative results of the 4 soils:
DPM/GM DRY SOIL Sanple No.
Pu-238 (CEP)
Pu-239 (CEP) 1 0.76 1 0.02 0.07 + 0.05 12.2 1 0.03 1.01 1 0.07 2
0.028 1 0.004 3.40 1 0.14 0.30 1 0.01 1.35 1 0.09 3
0.001 1 0.003 2.29 1 0.11 0.11 1 0.01 0.56 1 0.06 4
0.34 1 0.02 4.05 1 0.15 5.3 1 0.1 0.49 1 0.04 The above data cic1 not represent a comparison between dup.licates.
The AEC analyses were perforned on soils collected in the vicinity of the samples taken by ATCOR, and therefore, it is possible that differences between tlese sanples are real. Also, while there oay be questions about CEP's Pu-238 values because of the high Pu-238 to Pu-239, 240 ratios, it does not neces-sarily follow that the Pu-239, 240 numbers are also bad.
In the analysis of 1522 127
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6 6 ju 6 soil for Pu, there are usually three other alpha emitters, At-241, U232 and Th-228, that can produce a positive bias in the Pu-238 value if they are not quantitatively separated from the Pu fraction. The Pu-239, 240 peak region, however, does not generally suffer from such interferences.
The following are New York State data for soil and seditent samples from the Pawling site.
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c Pu238 Pu239,2LO Sample Location dpm/gm dry dp'/cn drv Soil
~10 ft. from shattered 0.02 1 0.01_
0.64 i 0.09 window
,o s ?
- * " W.' c &
Soil Behind building, near 0.01 1 0.01 0.29 1 0.03 where the 5 dpm/gm 1
sample was taken we Soil A clearing in the woods 0.02 1 0.01 0.20 1 0.04 some distance from the Pu building Sediment
//c < < 0""
O.03 0.02 0.05 1 0.02 Sediment In lake near Pu building 0.01 1 0.006 0.04 i 0.01 Sediment In stream near entrance 0.01 1 0.004 0.03 i 0.006 to site Gulf United Nuclear is obviously anxious to settle this carter in a canner such as to preclude any future problems.
New York State's position on this (as expressed by Fred Strnisa, Ato._ic Energy Council, N.Y. State Dept. of Commerce) is that the Pu in soil criteria should not exceed those set by the State of Colorado for Colorado soils.
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. 2 These values are 2 dpm/gm of dry soil and 0.01 pC1/m. The two areas thatgIvesoilconcentrationvaluesgreaterthanthisthereforewould need to be decontaminated as far as the state is concerned.
The RS staff recommendation was to treat this question, i.e.,
the
. level of Pu in soil which would be acceptable for unrestricted use, on a case-by-case basis using the ALAP approach. One of the objectives of the field trip to the Pawling site was to obtain a feel for what would be or not be practicable.
Af ter some discussion on the accuracy and meaning of some of the soil data, it was informally agreed that the following actions would be taken. Gulf United Muclear would propose a course of action in which the two areas that yielded higher than normal Pu values would be decontaminated by scraping off a layer of the soil surface.
Subsequently, a confirmatory analysis would be conducted to check on the decontamination effort. The meeting ended without a clear understanding of exactly how this last phase was going to be worked out between Region I - RO and the Licensee. Presumably, the details will be decided on later.
It is anticipated that a final judgement will 'oe rendered on the basis of the results of the confirmatory check.
IG111e we don't disagree with the proposed actions, we would like to point out that there are some questions which if not answered satis-factorily, may create potential future problems. The most important of these concerns the validity of the soil analyses performed by CEP.
Although our earlier arguments tried to show that CEP's Pu239,240 numbers 1522 129
\\
d need not be incorrect, neither is there any positive indi-cation of the validity of these values.
On the contrary, there is evidence that CEP's Pu in soil data may be suspect.
It would be desirable, therefore, that at least some minimal effort be made to determine how good or how bad CEP's data are.
It is desirable also, to establish a Pu background number for the Pawling site.
While estimates of fallout concentration in soil can be extrapolated to this site from data generated at other locations, it is possible to have a relatively..ide range of fallout values from site to site.
Therefore, an actual measurement at the Pawling site would be desirable.
A carefully taken preoperational soil sample would be ideal for this purpose.
If such a sample is not available, a soil sample taken as close as possible to the facility but known to be free of any influence from potential plant releases should be adequate for establishing the control value.
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