ML17332A397
| ML17332A397 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 11/10/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17332A398 | List: |
| References | |
| NUDOCS 9411180059 | |
| Download: ML17332A397 (5) | |
Text
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UNITED STATES N
LEAR REGULATORY COMMISS N
WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR EACTOR REGULAT ON RELATED TO DISPOSAL OF SLIGHTLY CONTAMINATED SLUDGE INDIANA HICHIGAN POWER COMPANY DONALD C.
COOK NUCLEAR PLANT UNIT OS.
1 AND 2 DOCKET NOS.
50-315 AND 50-316
- 1. 0 INTRODUCTION By letters dated October 9, 1991, October 23,
- 1991, September 3,
- 1993, and September 29,
- 1993, Indiana Michigan Power Company (I&N) requested approval pursuant to 10 CFR 20.2002 for the onsite disposal of licensed material not previously considered in the D. C.
Cook Final Environmental Statement dated August 1973.
Specifically, this request addresses actions taken in 1982 in which approximately 942 cubic meters of slightly contaminated sludge were removed from the turbine room sump absorption pond and pumped to the upper parking lot located within the exclusion area of the D.
C.
Cook Plant.
The contaminated sludge was spread over an area of approximately 4.7 acres.
The sludge contained a total radionuclide inventory of 8.89 millicuries (mCi) of Cesium-137, Cesium-136, Cesium-134, Cobalt-60 and Iodine-131.
In its submittal, the licensee addressed specific information requested in accordance with 10 CFR 20.2002(a),
provided a detailed description of the licensed material, thoroughly analyzed and evaluated information pertinent to the impacts on the environment of the proposed disposal of licensed material, and committed to follow specific procedures to minimize the risk of unexpected exposures.
2.0 DESCRIPTH)N OF WASTE The turbine room sump absorption pond is a collection place for water released from the plant's turbine room sump.
The contamination was caused by a primary-to-secondary steam generator leak that entered the pond from the turbine building sump, a recognized release pathway.
- Sludge, consisting mainly of leaves and roots mixed with sand, built up in the pond.
As a result, the licensee dredged the pond in 1982.
The radioactive sludge removed by the dredging activities was pumped to a containment area located within the exclusion area.
The total volume of 942 cubic meters of the radioactive sludge that was dredged from the bottom of the turbine room absorption pond was subsequently spread and made into a graveled road over the upper parking lot area of approximately 4.7 acres.
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The principal radionuclides identified in the dredged material are listed below.
TABLE 1
NUCLIDE (hal f-life)
Cs (13. 2 d)
"4Cs 2.1 y Cs (30.2 y)
Activity (mCi)
'1982 0.03 2.34 5.59 Activity '(mCi)
. '1991 NA*
0.18 4.57 Co (5.6 y) 8.04 d
TOTAL:
0.90 0.03 8.89 0.27 NA*
5:02
- NA:
not applicable due to decay 3.0 RADIOLOGICAL IMPACTS The licensee in 1982 evaluated the following potential exposure pathways to members of the general public from the radionuclides in the sludge:
(1) external exposure caused by groundshine from the disposal site; (2) internal exposure caused by inhalation of resuspended radionuclide; and (3) internal exposure from ingesting ground water.
The staff has reviewed the licensee's calculational methods and assumptions and finds that they are consistent with NUREG-1101, "Onsite Disposal of Radioactive Waste,"
Volumes 1
and 2, November 1986 and February
- 1987, respectively.
The staff finds the assessment methodology acceptable.
Table 2
lists the doses calculated by the licensee for the maximally exposed member of the public based on a total activity of 8.89 mCi disposed in that year.
TABLE 2
~Pathwa Groundshine Inhalation Groundwater Ingestion Total Whole Bod Dose Received b
Haximall Ex osed Individual mrem ear 0.94 0.94 0.73 2.61 On July 5, 1991, the licensee re-sam'pled the onsite disposal area to assure that no significant impacts and adverse effects had occurred.
A counting procedure based on the appropriate environmental low-level doses was used by the licensee;
- however, no activity was detected during the re-sampling'.
This is consistent with the original activity of the material and the decay time.
The 1991 re-sampling process used by the licensee confirms that the environmental impact of the 1982 disposal was very small.
The staff finds the licensee's methodology acceptable.
4.0 ENVIRONMENTAL FINDING AND CONCLUSION The staff has evaluated the environmental impact of the proposal to leave in place approximately 942 cubic meters of slightly contaminated sludge underneath the upper parking lot on the D.
C.
Cook site.
In 1982, the licensee evaluated the potential exposure to members of the general public from the radionuclides in the sludge and calculated the potential dose to the maximally exposed member of the public, based on a total activity of 8.89 mCi disposed in that year, to be 2.61 mrem/yr.
The staff has reviewed the licensee's calculational methods and assumptions and found that they are consistent with NUREG-1101, "Onsite Disposal of Radioactive Waste,"
Volumes 1 and 2, November 1986 and February 1987, respectively.
The staff finds the assessment methodology acceptable.
For comparison, the radiation from the naturally occurring radionuclides in soils and rocks plus cosmic radiation gives a person in Michigan a whole-body dose rate of about 89 mrem per year outdoorsy Subsequent licensee sampling in 1991 identified no detectable activity.
The staff evaluated the licensee's sampling and analysis methodology and finds it acceptable.
The results of the 1991 re-sampling by the licensee confirms that the environmental impact of the 1982 disposal was very small.
Based on the above the staff finds that the potential environmental impacts of leaving the contaminated sludge in place are insignificant.
With regard to the nonradiological
- impacts, the staff has determined that leaving the soil in place represents the least impact to the environment.
5.0 CONCLUSION
Based on the staff's review of the licensee's discussion, the staff finds the licensee's proposal to retain the material in its present location as documented in this Safety Evaluation acceptable.
Also, this Safety Evaluation shall be permanently incorporated as an appendix to the licensee's Offsite Dose Calculation Manual (ODCH),
and any future modifications shall be reported to NRC in accordance with the applicable ODCH change protocol.
Therefore, the licensee's proposal to consider the slightly contaminated sludge disposed by retention in place in the manner described in the D. C.
'SN letter from E.E. Fitzpatrick to the NRC Document Control
- Desk, September 29, 1993
4 Cook submittals dated October 9,
- 1991, October 23,
- 1991, September 3,
- 1993, and September 29, 1993, is acceptable.
The guidelines used by the NRC staff for onsite disposal of licensed material and the staff's evaluation of how each guideline has been satisfied are given in Table 3.
Pursuant to 10 CFR 51.32, the Commission has determined that granting of this approval will have no significant impact on the environment (October 31,
- 1994, 59 FR 54477).
Principal Contributor:
J.
Minns Date:
November 10, 1994
TABLE 3 20,2002 GUIDELINE [OR ONSITE DISPOSAL 1.
The radi oacti ve materi al should be disposed of in such a manner that it is unlikely that the material would be recycled.
'STAFF'S EVALUATION Due to the nature of the disposed material, recycling to the general public is not considered likely.
2.
Doses to the total body and any body organ of a maximally exposed individuals (a member of the general public or a
non-occupationally exposed worker) from the probable pathways of exposure to the disposed material should be less than 1 mrem/year.
2.
This guideline was addressed in Table 2.
Although the 2.61 mrem/yr is greater than staff's guidelines, the staff finds it acceptable due to 9 yrs decay following analysis and the expected lack of activity detected in the 1991 survey.
3.
Doses to the total body and any body organ of an inadvertent intruder from the probable pathways of exposure should be less than 5
mrem/year.
Doses to the total body and any body organ of an individual from assumed recycling of the disposed material at the time the disposal site is released from regulatory control from all likely pathways of exposure should be less than 1 mrem.
3.
4.
Because the material will be land-spread, the staff considers the maximally exposed individual scenario to also address the intruder scenario.
Even if recycling were to occur after release from regulatory control, the dose to a maximally exposed member of the public is not expected to exceed 1 mrem/year, based on exposure scenarios considered in this analysis.
E.F.
- Branagan, Jr, and F.J.
- Congel, "Disposal of Contaminated Radioactive Wastes from Nuclear Power Plants,"
presented at the Health Physics Society's Hid-Year Symposium on Health Physics Consideration in Decontamination/Decommissioning, Knoxville, Tennessee, February
- 1986, (CONF-860203).