ML20197C769
| ML20197C769 | |
| Person / Time | |
|---|---|
| Site: | 05000054 |
| Issue date: | 07/28/1998 |
| From: | Merges P NEW YORK, STATE OF |
| To: | Mcgovern J CINTICHEM, INC. |
| References | |
| NUDOCS 9809140194 | |
| Download: ML20197C769 (13) | |
Text
D. Onjs h sb.5 y New York State Department of Environmental Conservation Division of Solid & Hazardous Materials Bureatt of Pesticides & Radiation 50 Wolf Road, Albany, New York 12233-7255 518-485-8981 FAX 518-485-8390 John P. Cahill Commissioner July 28,1998 Mr. J. J. McGovern Plant Manager / President Cintichem, Inc.
P.O. Box 816 Tuxedo, New York 10987
Dear Mr. McGovern:
Re: Order on Consent Case #D200059005 This responds to your June 9,1998 letter requesting an amendment to the above referenced Order on Consent.
The Order currently requires sampling for radioanalysis of discharges, ground water, surface water, and the Indian Kill Reservoir. You have requested that these monitoring requirements be ended. Enclosed is a review of the radiological monitoring data that has been collected under the Order. Based on that data, the Order on Consent is amended to delete certain requirements in paragraphs IV and V, and all of paragraph VI.
II Amendment No.10 of the Order is enclosed. This amendment requires that sampling of
>j the 00loutfall and the retention pond (S-12) continue. Those samples are to be analyzed for Sr-90. Until the NRC radioactive materials licenses are terminated, the residual radioactive M'h material on site is regulated material, and the discharge of that material is subject to 6 NYCRR Part 380 (copy enclosed). Sampling of the 001 outfall and S-12 is required to comply with I
Subpart 380-6 and section 380-9.1 of 6 NYCIUt Part 380.
The enclosed amendment requires Cintichem to continue sampling the 00loutfall and S-7 for pollutants other than radioactive materials; however, for S-7 samples, Cintichem is no longer required to analyze for arsenic, beryllium, cadmium, mercury, nickel, silver, or thallium.
After the NRC licenses have been terminated, and any continuing discharges to surface water are authorized under Article 17 of the Environmental Conservation Law (SPDES),
Cintichem may request termination of the remaining requirements in the Order. That request must be accompanied by all monitoring results required under the Order and not previously 9809140194 980728 PDR ADOCK 05000054 W
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Mr. McGovern Page 2 submitted to the Department. The data may be submitted in a database file. It must include all gamma spectroscopy results, as well as the Sr-90 monitoring results.
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Please note that after the Order is terminated, Cintichem will still be subject to sections 380-8.l(c) and 380-9.1. Under Section 380-8.l(c) Cintichem (or Hoffman LaRoche) must retain the records identified in Subpart 380-8 for three years after the record was made or until the license is terminated, whichever is longer. In your request for termination of the Order, include the location at which those records will be stored. Section 380-9.1 requires an annual
. report of discharges of radioactive material. Although that report will not be due until March 31, 1999, we strongly recommend that it be submitted as soon as possible following the termination
. of the NRC licenses.
If you have any questions, please call Barbara Youngberg of this Bureau at 518-457-2225.
Sincerely, Paul J. Merges, Ph.D.
Director, Bureau of Pesticides & Radiation Enclosures
- cc w/ encls:
R. Aldrich,NYSDOL i
T. Dragoun, NRC
' K. Magar, Town of Tuxedo T. Michaels, NRC D. Orlando, NRC 4
,m
STATE OF NEW YORK DEPARTMENT OF ENVIRONMENTAL CONSERVATION In the Matter of Violations of the Environmental Conservation Lau ("ECL"), Articles 3,17,19 and Parts 201,380,703,750-757 ORDER ON CONSENT of Title 6 of the Official Compilation of Codes Rules and Case #D200059005 Regulations of the State of New York ("6 NYCRR") by:
Amendment No.10 CINTICHEM, INC., and Hoffman-La Roche, Inc.,
Respondents.
In accordance with Paragraph XXVI of the January 1995 Order on Consent, Paragraph VI of the Order on Consent is deleted, and Paragraphs IV and V of the Order on Consent are amended to read, IV.
Discharges through SPDES Outfall 001 (A) All waste water containing radioactive material shall be discharged from the site through the 001 outfall in accordance with the following:
(1) The outfall shall be sampled biweekly by grab sample.
Samples shall be collected in the 001 outfall before the discharge enters the Indian Kili Stream. The samples shall be analyzed for strontium-90.
(2) The average concentration (averaged over any one calendar year) of radioactive material in the waste water discharged shall not exceed the effluent concentrations for releases to water in Section 380-11.7, Table II, Column 2 of 6 NYCRR Part 380. When more than one radionuclide is detected in the waste water, the sum of ratios rule (Section 380-11.7, Note 4) shall apply. The total activity released shall not exceed 10 millicuries in any one calendar year.
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(B) All wastewater discharged from the site through the 001 outfall shall comply with the requirements of this subparagraph.
(1) The following limitations and monitoring requirements apply to wastewater discharged through the 001 outfall:
Measurement Sample Parameter Daily Maximum MDill Frecuency Iy.pg Flow Manitor GPD Monthly Estimate pH (range) go.0-9.0)
SU Monthly Composite Copper, Total
.05 mg/l Monthly Composite Iron, Total 3.3 mg/l Monthly Composite Zinc, Total 0.15 mg/l Monthly Composite Lead, Total 0.025 mg/l Monthly Composite Solids, Total Susp.
35 mg/l Monthly Composite Oil & Grease 15 mg/l Monthly Composite (2) The monthly sampling event shall consist of a flow-weighted j
composite made up of release from boiler house operations and the retention pond (S-12) during a representative time period of approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
V. Release of Surface Runoff (A) Retention pond (1) Releases from the retention pond to the 001 outfall shall be on a batch-release basis. A water sample shall be collected prior to each batch release. The water may be released prior to sample analysis. If more than one sample is collected in one calendar day, the samples may be composited for analysis. The samples shall be analyzed for strontium-90 within 15 working days of the day the sample was collected.
(2) In the event of heavy rainfall or surface run-off entering the retention pond, water may be continuously pumped from the retention pond to the 001 outfall if this is necessary to preserve the integrity of the pond. In that case, the retention pond shall be sampled every four hours. If more than one sample is collected in one calendar day, the samples may be composited for analysis. The samples shall be analyzed for strontium-90 within 15 working days of the day the sample was collected.
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(3) Strontium-90 detected in releases from the retention pond shall be considered waste water subject to the limits set in Paragraph IV(C) of this Order.
(B) S-7 Runoff Cintichem may allow surface water runoff from S-7 to flow into the reservoir. Respondents shall collect a n:c::ily grab sample at S-7 and analyze those samples for the following metals: antimony, chromium, copper, lead, selenium, and zir.c).
YA-Paul J. M6fges, Ph.D.'
Director, Bureau of Pesticides & Radiation Division of Solid & Hazardous Materials Date:
7/' M ff Page 3 of 3
Order on Consent No. D200059005 Residual Strontium-90 on the Cintichem Site Monitoring Requirements in Amendment No. 9 & Changes to be Made in Amendment No.10 July 27,1998 Residual Strontium-90 on the Cintichem Site Strontium-90 (Sr-90) is the only radionuclide required to be monitored under the Consent Order that is still found in detectable concentrations in groundwater at the Cintichem site. Sr-90 is detected in several groundwater monitoring wells on site and in the S-4 monitoring point.
The S-4 sampling location was originally a small, subsurface catch basin with an access hole, in the parking lot on the south side of Building 3. A pipe apparently coming from the southwest comer of the building emptied into the catch basin. S-4 was one of the first locations where radionuclides were detected in 1989, when I-131 had been leaking from ventilation ducts under the hot cells. As a result, Cintichem began pumping the contaminated water to holding tanks and running the water through ion exchange columns before releasing it through the 001 outfall.
In June 1996, the Order on Consent was amended to allow ion exchange treatment to cease and the waste water to be held in the retention pond, because the waste water tanks were removed as part of the site decommissioning.
Construction drawings had indicated that the pipe entering the S-4 sump came from a footing drain running along the west wall of Building 3 (see, for example the July 3,1996 report on radioactivity in water due to residual radioactive in bedrock submitted to the NRC, by Jay Adler, Cintichem's manager of Health, Safety, and environmental affairs.) However, later in 1996, Cintichem excavated the pipe that entered the S-4 and found that the pipe was connected to two other pipes, which simply ended, under the floor of the carpenter shop, in the southwest comer of the building. The floor of the shop was removed, along with some contaminated soil and rock undemeath. The resulting excavation was thereafter referred to as the carpenter shop excavation.
None of the pipes had connected to a footing drain. The two pipes that ended under the carpenter shop apparently collected groundwater that seeped out through cracks in the rock.
After the S-4 catch basin and access hole were removed in 1997, the water that collected in the carpenter shop excavation was sampled and the results were reported as S-4 results. (The water that collected in the carpenter shop excavation was pumped to the retention pond and from there, discharged through the 001 outfall.)
Cintichem requested and received an amendment to the Consent Order in February 1998, which eliminated sampling at most monitoring wells. In the amendment, sampling was required Page 1 of 8
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to' continse at monitoring wells 1D,2S,2D,3S,4,5,6,7,10, and 15. Those wells were, for the most part, down gradient of the area of highest bedrock contamination, the northeast corner of Building 2 (the hot cell building).
The concentration of Sr-90 in all ten monitoring wells and S-4 has decreased since 1990.
In all but one (MW-7) the highest concentration of Sr-90 was measured prior to January 1,1995.
The concentration in MW-7 has been low; the maximum concentration was found twice:
4.4 +/- 0 49 pCi/l in, April 1993, and 4.4 +/- 0.8 pCi/1, in April 1997.
l The primary source of the Sr-90 was the bedrock and soil under the northeast corner of Building 2, which area was remediated during the decommissioning. Contaminated soil was removed, and the bedrock was cored to estimate the remaining inventory of Sr-90. That work was essentially complete by the end of 1996. (Cintichem reported in the Final Status Survey Report that the final status survey of the Hot Cell building was performed between April 1996 and April 1997.) Therefore, the groundwater monitoring results from the beginning of 1997 tmtil the present represent post-remediation conditions.
Since the beginning of 1997, the Sr-90 concentration in monitoring wells ID. 2D,3S,6, 7,10, and 15 has not exceeded 7 pCi/1. Of the other sampling points (MW-2S, MW-4, MW-5 and S-4), MW-2S and S-4 have always had the highest concentrations of Sr-90; therefore, the data from S-4 and MW-2s are the upper bound to Sr-90 concentrations measured in groundwater at the site.
For the time period between January 1997 and July 2,1998,'he average concentration of t
Sr-90 in S-4 and MW-2s is less than 42 pCi/1. The average concentration in MW-2s is 39 pCi/l and in S-4,33 pCi/1.
The running average for the past 12 months is also less than 42 pCi/l: in MW-2s, the 12-month running average is 36 pCi/l and in S-4, it is 32 pCi/1.
The annual average concentration of Sr-90 has decreased during the time following the completion of remediation. The average concentration of Sr-90 in MW-2s in 1997 was 50 pCi/1.
In 1998 (as of 7/2/98), the average concentration is 27 pCi/1. In S-4, the average concentratio 1 in 1997 was 40 pCi/1. In 1998 (as of 7/2/98), the average is 20 pCi/1.
DEC Water Quality Standards The Department of Environmental Conservation's water quality standard. (6 NYCRR Parts 700-705) do not include a water quality standard for Sr-90 in groundwater. In the absence of such a standard, the groundwater monitoring data can be compared to the Sr-90 standard for those classes of surface waters that are to be used as a source of drinking water. That standard is 8 pCi/1, or if two or more radionuclides are present, the sum of their doses shall not exceed an annual potential dose of 4 millirems per year (6 NYCRR 703.5). Thus, the goal of the water Page 2 of 8
quality st'andard is to limit the concentration of radionuclides so that a person using the water as the only source of drinking water would received a radiation dose from those radionuclides no greater than 4 millirems per year. The 8 pCi/l standard was derived from the 4 millirem per year (mrem /y) dose limit. When the 8 pCi/l standard was adopted, it was calculated to be the concentration of strontium 90 that would deliver a radiation dose of 4 millirems per year. The 8 pCi/l concentration was calculated using the then-current radiation dose calculation method.
That method has since been superseded in state and federal radiation protection regulations (10 CFR 61 and 6 NYCRR 380, respectively) Using the currently accepted methods for calculating radiation doses, a dose of 4 millirems per year would result from drinking water containing 42 pCi/l of Sr-90.
As described on page 2, the average concentration of Sr-90 at all groundwater monitoring locations on site for the period since January 1997 is less than 42 pCi/1. Therefore, groundwater on site meets the intent of the surface water standard (i.e., to limit the radiation dose to no more than 4 mrem /y).
The Cintichem site is on the shore of the Indian Kill Reservoir and some groundwater from the site enters the reservoir. The Order required the reservoir to be sampled weekly and analyzed for Sr-90. Since January 1997 (the post-remediation period, for this analysis), Sr-90 has not been detected in the reservoir'.
' More than 300 samples were collected from the Reservoir and analyzed for Sr-90 (sampling began in April 1992). The two samples with the highest results for Sr-90 were collected in November of 1992. They were 7.9 +/- 3.6 pCi/l on ' November 13 and 7.78 +/- 5.4 pCi/l on November 20. The large error of each result and the fact that no Sr-90 was detected in a second sample collected on November 13, nor in the next two weekly samples, cast doubt on the validity of these results.
With only two possible exceptions, all other results were either less than the detection limit or were reported as positives but had errors that equaled 25% or more of the reported value (e.g.,1.05 +/- 0.4 pCi/1) Those reported positives were in the range of a few tenths of a pCi/l to 1 pCi/1, i.e., they were at the limit of detection. It is doubtful that they were true positives. The two exceptions were slightly higher than the detection limit: 2.64 +/- 0.42 pCi/1, collected on August 27,1993, and 1.99 +/- 0.42 pCi/1, collected on September 16,1994. The lack of similar results in samples collected before and after these samples indicates either that these two results are suspect, or they represent transitory traces of Sr-90 in the reservoir water. Using the conservative assumption that the sample results represent the concentration of Sr-90 for one week, the radiation dose from drinking water containing 3 pCi/l of Sr-90 for one week is calculated to be 0.01 millirem, which is one quarter of one percent of the 4 millirem per year water quality standard. This is negligible.
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i The data support the conclusion that the residual Sr-90 in the bedrock and groundwater on the Cintichem site does not adversely affect the water quality of the Indian Kill Reservoir, nor i
impair its use as a source of drinking water, DSHM TAGM 4003 i
The Department's Cleanup Guidelinefor Soils Contaminated with Radioactive Materials, Division of Solid & Hazardous Materials Technical Administrative Guidance Memorandum 4003 ("TAGM 4003") states, The total effective dose equivalent to the maximally exposed individual of the general public, from radioactive material remaining at a site after cleanup, shall be as low as reasonably achievable and less than 10 mrem above that received from background levels of radiation in any one year, j
l The soil decontamination criteria for all radionuclides, including Sr-90. were selected to provide reasonable assurance that the residual radioactive material would not 'esult in a rad % tion dose greater than 10 mrem /y. The Department approved those alteria based on our review ano 1
our concurrence that, properly applied, the soil criteria would result in the site's meeting j
TAGM 4003. The NRC's contractor, Oak Ridge Institute fbr Science and Education (ORISE),
reviewed all the final status survey results and performed confirmatory surveys of all areas but the former landfill (DEC performed confirmatory surveying and sampling there; no residual Sr-90 was found.)
ORISE performed a RESRAD dose assessment for the resident farmer scenario [ June 1, 1998 letter to Tl omas Dragoun, NRC, from Wade C. Adams, Oak Ridge Institute for Science and Education]. This is the most conservative scenario, although it is not a plausible scenario for this particular site due to its topography and rocky nature. Plausible land uses are commercial, light industrial, residential, and recreational, all of which would result in lower doses than the resident farmer scenario. The industrial rock mining and crushing scenario was modeled by Cintichem. This is not a plausible land use for the time period during which the residual radionuclides will remain on site. In addition, Cintichem's dose projections were lower than the resident farmer scenario examined by ORISE.
ORISE predicted the dose from all residual radionuclides would be 1.98 mrem /y at time 0 (i.e., no allowance for decay since the final status survey samples were taken). The predicted dose declines with time. This is well below the 10 mrem /yr guideline in TAGM 4003.
The ORISE RESRAD model run used the average concentration of residual radionuclides in soil and bedrock to predict the dose from all pathways. The dose from Sr-90 was delivered through the water dependent pathways; the committed effective dose due to residual Sr-90 was prerlicted to be 0.55 mrem /yr. Based on this RESRAD modeling, the dose Page 4 of 8
dui: to residual radioactive material (including the Sr-90) in soil and bedrock would be less than 10 mrem /yr and therefore the residual Sr-90 meets the guidance in TAGM-4003.
CONCLUSION The monitoring data for S-4 and Monitoring wells 1D,2S,2D,3S,4,5,6,7,10, and 15 have demonstrated that the residual Sr-90 in the groundwater meets the intent of the Department's water quality standards and complies with the Department's guidelines for cleanup of soils contaminated with radioactive materials.
Monitoring Reauirements to be Deleted from the Order
- 1. Waste Water in Holding Tanks -- Waste water holding tanks, prior to batch release, are to be analyzed for gamma emitters and strontium-90 [ Paragraph VI(A)(1)].
There are no longer any waste water holding tanks in use on site.
- 2. S-7 Diversion -- Weekly grab samples of the water released from S-7 are to be analyzed for strontium-90 [ Paragraph V(B)(1)].
The S-7 water has been flowing into the reservoir since February 1995 (prior to that the diversion was only used when the inflow to the retention pond was too great to safely pump to the 001 outfall). Sr-90 concentrations have been at or below the detection limit set in the Consent Order (1.5 pCi/l) since S-7 sampling was begun in 1993. As was noted when the S-7 diversion was allowed to be used continuously (amendment no.4), there is no source of radioactive material in the portion of the site that drains to S-7. The sampling that has continued since the 1995 amendment has confinned that this water does not contain regulated radioactive material. There is no need to continue monitoring the S-7 diversion for radionuclides.
- 3. S-4 -- S-4 must be sampled and analyzed weekly [ Paragraph VI(A)(1)].
The monitoring data for S-4 have demonstrated that the residual Sr-90 in the groundwater meets the intent of the Department's water quality standards and complies with the Department's guidelines for cleanup of soils contaminated with radioactive materials. There is no need to continue monitoring at S-4.
- 4. Monitoring Wells --Monitoring wells 1D,2S,2D,3S,4,5,6,7,10, and 15 shall be sampled and the samples analyzed for strontium-90. The frequency of sampling and analysis ranged from daily to quarterly, based on the previous results. [ Paragraph VI (C)]
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t Th'e monitoring data from Monitoring wells ID,2S,2D,3S,4,5,6,7,10, and 15 have demonstrated that the residual Sr-90 in the groundwater meets the intent of the Department's water quality standards and complies with the Department's guidelines for cleanup of soils contaminated with radioactive materials. There is no need to continue sampling the groundwater on site.
- 5. The Indian Kill Reservoir -- The intake to the water treatment plant (S-13) shall be sampled and analyzed for gamma-emitters and strontium-90 on a weekly basis.
[ Paragraph VI(B)]
The results from monitoring the Indian Kill Reservoir are discussed above, under Residual Strontium-90 on Site. The data demonstrate that the Sr-90 in the bedrock and groundwater on the Cintichem site does not adversely affected the water quality of the Indian Kill Reservoir, nor impair its use as a source of drinking water. There is no need to continue to require Cintichem to sample and analyze the Indian Kill Reservoir for Sr-90.
Gamma emitters were detected in the reservoir only in 1990, when the State Department of Health (DOH) detected iodine-131. The DOH reported in its 1990 Annual Report of Environmental Radiation in New York State, The maximim I-131 level in treated water from the reservoir next to Cintichem was less than 5 pCi/1. Three other measurable samples were all lest than 1.2 pCi/1.
The USEPA Safe Drinking Water Standard of 4 mrem per year to any organ, implies ingestion of water with a concentraiton of 3 pCi/l ofI-131 continuously for one year. The I-131 was only present in the treated reservoir for a few weeks.
The actual thyroid dose for drinking that water is estimated to be much less than 1 mrem.
There is no need for Cintichem to continue montoring the reservoir water for gamma emitting radionuclides.
- 6. S-1, S-3, S-18-- Sampling locations S-1, S-3, S-18 are to be sampled and analyzed for struntium-90. The frequency of sampling and analysis ranged from daily to quarterly, based on the previous results. [ Paragraph VI (C)]
Surface sampling locations S-1, S-3, and S-18 were sampled quarterly from April 1992 through January 1996 and again in July 1998. S-1 and S-18 were downslope of the retention pond and S-3 was a storm drain from the area of the reactor building. There was only one sample with a positive result greater than 1 pCi/1. That was taken from S-3 in 1994; the result was 1.45 +/.36 pCi/1. All other results were either less than 1 pCi/l or less than the detection Page 6 of 8 l
4 liniit. These results are not indicative of contamination, and there is no need for further sampling.
Monitoring Reauirements to be Retained in the Order Until the NRC Licenses are Terminated
- 1. Outfall 001 -- The 001 Outfall (to the Indian Kill, downstream of the reservoir) is to be sampled biweekly and analyzed for gamma emitting radionuclides and strontium-90
[ Paragraph VI(A)(2)].
Monitoring at this location was required to demonstrate compliance with the limit on discharge of radioactive materials, which was set in paragraph IV(A)(3) of the Order, (3) The average concentration (averaged over any one calendar year) of radioactive material in the waste water discharged shall not exceed the effluent concentrations for releases to water in Section 380-11.7, Table II, Column 2 of 6 NYCRR Part 380. When more than one radionuclide is detected in the waste water, the sum of ratios rule (Section 380-11.7, Note 4) shall apply. The total activity released shall not exceed 10 millicuries in any one calendar year.
In accordance with the Order, Cintichem reported monthly the total activity and average concentration of radionuclides discharged through the 001 outfall. In 1997, the only radionuclide reported was strontium-90; the total activity reported discharged was 130 microcuries. The average concentration was 1.72 E-9 microcuries per milliliter ( Ci/ml)2. The ratio of the annual
- concentration to the applicable concentration in Table II, Column 2 of Part 380-9 (5 E-7 Ci/ml) is 0.003. To date in 1998, the total activity reported for the year is 33 Ci Sr-90, and the average concentration is 2.59 E-10 Ci/ml. These data indicate that the discharge has been far below the applicable limits set in paragraph IV(A)(3) of the Order.
The source of the Sr-90 in the discharge through 001 is the soil and bedrock under the northeast corner of Building 2. Groundwater from that area collects in the carpenter shop excavation (under Building 3, sampling point S-4). From there, it is pumped to the retention pond, and is then discharged through the 001 outfall. Since the beginning of 1997, the Sr-90 concentration in the water collecting in the carpenter shop excavation has averaged about 40 pCi/l or 4.0 E-8 Ci/ml. All other sources of radioactive material have been removed from the site. There is no reason to expect an increase in the concentration of radioactive material discharged through the 001 outfall.
2 Microcuries per milliliter are the units used in Part 380, instead of pCi/1. One pCi/l equals 1 E-9 Ci/ml.
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6 6 'NYCRR Part 380 requires parties that discharge radioactive material to the environment to perfbrm surveys necessary to determine the concentration of material discharged. Therefore, this monitoring should continue until the NRC licenses are terminated. Once the licenses are terminated, the residual radioactive material will no longer be licensed material and Part 380 will not apply. This monitoring requirement should expire when the NRC licenses are terminated.
- 2. Retention Pond - Releases from the retention pond to the 001 outfall are to be sampled prior to batch release to the 001 outfall or every four hours during continuous pumping. Samples are to be analyzed for Sr-90 [ Paragraph V(A)(1)].
The concentration of Sr-90 in the retention pond has ranged from a maximum of 59 +/- 4 pCi/1, in February 1993 to less than the required detection limit of 1.5 pCi/1. The Sr-90 concentration has not exceeded 8 pCi/l since February 1997. In 1997, the average concentration was 3.3 pCi/1. In 1998 (as of May 28,1998), most sample results have been less than a detection limit of 1 pCi/1. In the past year (June to May), the highest concentration detected was 3.3 +/-
1.1 pCi/1.
The data demonstrate that the Sr-90 in the retention pond water is now less than the Department's water quality standard for Sr-90 in surface water. However, because these monitoring results are used to assess the activity and concentration of radioactive material discharged to the 001 outfall, the sampling should continue until the NRC licenses are terminated. There is no need to require sampling of the retention pond for radionuclides after that. This monitoring requirement should expire when the NRC licenses are terminated.
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