ML20140D648
| ML20140D648 | |
| Person / Time | |
|---|---|
| Site: | 07000036 |
| Issue date: | 05/30/1997 |
| From: | Sharkey R ABB COMBUSTION ENGINEERING NUCLEAR FUEL (FORMERLY |
| To: | Weber M NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| NUDOCS 9706110021 | |
| Download: ML20140D648 (14) | |
Text
f(t9-ADD M
2% B F pp.e
- May 30,1997 gl l.
Docket No. 70-36 License No. SNM-33 Mr. Michael Weber, Chief Licensing Branch Division of Fuel Cycle Safety and Safeguards, NMSS Office of Nuclear Materials Safety and Safeguards U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Subject:
Decommissioning of Former Evaporation Ponds
References:
(A) CE (R. Sharkey) letter to NRC (R. Pierson), dated October 26,1994 (B) CE (M. Michelsen) letter to NRC (R. Pierson), dated March 10,1995 (C) NRC (R. Pierson) License SNM-33 Amendment 4 to CE (R. Sharkey), dated May 4,1995
Dear Mr. Weber:
Enclosure I provides for your approval an updated Decommissioning Plan for the two former Evaporation Ponds.
In accordance with the Decommissioning Plan by submitted by Combustion Engineering (CE)
[Ref. A as amended Ref. (B)] and approved by the NRC [Ref. (C)], CE has completed preremediation characterization and has updated the decommissioning plan. The characterization indicated that remediation beyond that limited to hot spots is required. Therefore, the solubility study was postponed because the removal of a significant portion of surface material will impact the results of a solubility stydy in a non-conservative manner.
As part of the update a new schedule has been proposed. The schedule originally proposed was developed under the assumption that little remediation would be necessary. With the additional emediation, work was delayed while staff efforts focused on Safety Condition S-2, beta activity in burial well #4, and investigation into former 20.304 burial pits.
If there are questions regarding this matter, please feel free to contact Dr. Earl Saito of my staff at (314) 937-4691 Ext. 461 or myself at (314)937-4691 Ext. 399.
/( / f CY Cordially, j
COMBUSTION FNGINEERING INC.
W Robert W. Sharkey Director, Regulatory Affairs MIEINIlEMI.ER.
cc: Tim Ridinger Region 111
- ==o
[
j RA97/583 l
Enclosures:
As stated 000?
ABB CENO Fuel Operations Combunon Engineenng. Inc.
3300 State Road P Telephone (314) 93 /4691 Post Oft'ce Bon 107 St Louis (314) 296 5640 9706110021 970530 Hema'ife. M: noun 63047 Fax (314) 937-7955 PDR ADOCK 07000036-C PDR J
Enclosure I to RA97/583 Evaporation Ponds Decommissioning Plan Update p
l This document provides supplementalinformation to the " Hematite Evaporation Ponds Decommissioning Plan" submitted to the NRC on October 26,1994. In 3
particular, this document supersedes Section 2.1 and Chapter 4 of the original submittal. In addition, Chapter 7 provides characterization details of the retention ponds, and Chapter 8 provides details of decommissioning activities.
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'2.1 Decommissioning Objectives, Activities, Tasks and Schedules j:
2.1.1 - Objective i
The purpose of the decommissioning effort for the former evaporation j
ponds is to characterize residual uranium from previous decontamination effods, remediate by removing the contamination to an acceptable level, and then demonstrate through the final status survey that the radiological i
conditions of the ponds satisfy NRC approved guidelines. The acceptable level will be based on the solubility of the residual uranium. Near surface i
material that will be removed as part of this effort is most likely insoluble l
uranium while material at depth is most likely soluble. Therefore, solubility j
measurements will not be made until remediation is performed to i
determine the actual condition of the soil that will be left. Analysis indicate i
that Resource Conservation and Recovery Act (RCRA) contaminants are not above regulatory limits. The specific objectives of the final status
~
survey are to show that:
i i
1)
Average radionuclide concentrations are within the authorized j
values, i.e.,250 pCi/g for insoluble uranium and 100 pCi/g for i
soluble uranium using sum of the fractions when both soluble and l
insoluble uranium are present.
2)
Reasonable efforts have been made to identify and remove hotspots that may exceed the average guideline by greater than a factor of(100/A) 2, where A is the area of the hot spot.
3)
Exposure rates do not exceed 5 R/h above background at 1 m 2
above the surface. Exposure rates may be averaged over 100 m grid areas. Maximum exposure rates over any discrete area of 2
<100 m may not exceed 10 R/h above background.
2.1.2 Decommissioning Activities and Schedules
)
Table 2.1 provides an overview of the major activities and tasks associated with this decommissioning project. Table 2.2 provides the proposed schedule for the project, including major milestones.
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Enclosure I ta RA97/583 Evaporation Ponds Decommissioning Plan Update Depending on uranium concentration, water pumped from the pond will be discharged to the site creek, evaporated, or used for dust suppression in the controlled area of the plant. The limit on the concentration of uranium discharged will be 3 x 10 pCi/mi as measured at the confluence of the site creek and Joachim Creek (site boundary) or upon application when used for dust suppression.
i Measurements taken at closer locations may also be used to demonstrate compliance with this limit when discharging to the site creek.
I 2.1.3 Safety Evaluation The activities and tasks of this limited scope decommissioning project of the former evaporation ponds are simple and not hazardous to the workers, environment or public. There have been i
no operational occurrences that could adversely affect i
j decommissioning safety. The current assessmeret of residual l
radioactive contamination of the ponds is such the workers will not l
be exposed to significant radioactivity or radiation from the project.
)
Other than common industrial safety concerns, there is no foreseen potential for accidents that could have a significant impact on decommissioning safety. The decommissioning project can therefore be conducted in a safe manner.
f 2.1.4 Procedures
[
As stated in Section 3.,3, decommissioning activities and tasks will be performed in accordance with approved written procedures. The j
j control system concerning procedures is described in Section 2.6 of i
I; I
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_. - _ _ _. _ _. _. ~. _.. _ _. _. _ _ _ _ _ _ _ _. _ _ _ _.... _ _.
A Enclosure I to RA97/583
}
Evaporation Ponds Decommissioning Plan Update j
3 Table 2.1 t
i t
Overview of Maior Activities and Tasks Activities Tasks Evaluate Contamination Potential 1.
Review history -done j
- 2. Prepare decommission work plan-done l
- 3. Collect random soil and water sample for RCRA analysis -done i
l 4.
Radiological Characterize -done i
Characterize Background Levels
- 1. Measure outdoor background exposure rates
- 2. Collect background soil sample -done Perform Remediation 1.
Secondary Pond i
- a. Drain pond
- b. Remove berm
)
- c. Scan and remediate hot spots
- d. Establish solubility and perform l
additional remediation if necessary i
2.
Primary Pond
- a. Drain pond i
- b. Remove berm l
- c. Scan and remediate hot spots i
- d. Establish solubility and perform additional remediation if necessary i
Establish Grid Reference System 1.
Install grids i
2.
Prepara survey maps Collect Samples 1.
Collect samples i
Analyze Samples 1.
Analyze samples l
Interpret Data 1.
Convert data to standard units 2.
Calculate average levels 3.
Compare data with criteria 4.
Compute total residual activity inventory l
Prepare Final Status Survey Report 1.
Construct data tables
- i..
2.
Develop graphics 3.
Prepare text i
4.
Submit report to NRC I-
'l 1
I 3L
... - -.-. = -
.2 Decommissioning Schedule 1997 1998 1999 ID Task Name MaylJunl Jul lAuglSeplOct lNovlDec Jan lFebl Mar l Apr lMaylJun l Jul l Aug lSepl Od lNovlDec Jan lFebjMarl AprlMaylJunl Jul 1
Update Decommissioning Plan i
gl 2
Submit Updated Decommissioning Plan to NRC 3
NRC Revew Updated Plan 4
NRC Concur with Updated Plan 5
Remediate Secondary Pond 6
Final Status Sunrey Secondary Pond I
{.
7 Bacx fm Secondary Pond El o
8 Compiete Secondary Pond Remediation 5m
- b/3 o o t
a n 9
Remediate Pnmary Pond 10 Final Status Survey Primary Pond 11 Back fill Pnrnary Pond E$
12 Complete Pnmary Pond Remediatiof.
k 11/13 g3
- 2. G; E'
Ea 0 13 Final Status Survey of Area With in Pond Fence 1
14 Appy Cover Matenal g
5 K
IT 2
15 Prepare Final Status Survey Report 7
C l
J E
16 Submet Finai Status Survey Report to NRC
& 61 m
a s
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Task Summary Rolled Up Progress Progress
- Rolled Up fask D
N M'97 Milestone Rotted Up Milestone Q
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_ ~. -... _ -. _
____.-_.m
_, ____... _......_._ ~
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Encl:sure I to RA97/583 l-Evaporation Ponds Decommissioning Plan Update r
4.0 Planned Final Radiation Survey Upon completion of the decontamination activities described in this plan, l
areas within the scope of the project will be surveyed to determine if they meet the objectives as specified in Section 2.1.1.
4.1 Final Status Survey Instrumentation l
Due to the short range of alpha and beta particles, which comprise l
the majority of radiation emitted by low enriched uranium, scanning for uranium contamination has limited value. However, the area will be scanned using Geiger-Muelier, Scintillation and/or gas proportional detectors. instructions regarding instrument selection, calibration, use, and control will be included in final status survey procedures.
4.2 Methodology for Ensuring Adequate Survey Coverage The Final Status Survey will be designed to ensure that data generated are statistically meaningful. The methodology will follow the guidelines set out in NUREG/CR-5849. In particular, surface samples, first six inches, will be collected within the pond areas following the triangular sampling pattern specified in Figure 4-5 of NUREG/CR-5849. Surface samples will be collected following the
" standard sample pattern" specified in Figure 4-4 of NUREG/CR-5849 for areas outside the ponds but inside the pond fence.
Preliminary characterization indicated increased activity at shallow depths. Therefore, within the pond atea samples will be collected at depths of 6-12" and 12-18" following the " standard sampling pattern" i
specified in Figure 4-4 of NUREG/CR-5849.
4.3 Analysis of Soil Samples Soil samples will be analyzed for uranium by any (or combination) of the following methodologies.
4.3.1 Kinetic Phosphorescence Analysis 4.3.2 Gross Alpha Analysis 4.3.3 Gamma Spectroscopy 4.3.4 Alpha Spectroscopy 5
1 Enclosure I to RA97/583 Evaporation Ponds Decommissioning Plan Update s
4.3.5 Direct soil counting by using a gas flow proportional counter or an alpha scintillator coupled to a photomultiplier.
4.3.6 In-situ gamma spectroscopy 4.4 Background Radiation and Radioactivity l
Previous analyses have shown soil in the general vicinity of the Hematite plant to have approximately 2-3 pCi/g total uranium background activity. The background exposure rate is approximately 5 pR/h. Background will be checked at a neutral site prior to and after direct dose measurements.
7.0 Site Characterization The ponds have been characterized using a combination of historical data, current sampling and knowledge of historic utilization. Previous efforts to decontaminate the ponds removed uranium from the pond but left the berms in place. As a consequence of these actions, rain events would wash contamination from the berms back into the ponds. The ponds berms were made of contaminated scrubber rock from the UFe conversion process. Therefore, areas above the remediation goal exist at the bottom of the primary pond, the west side of the secondary pond and along the berms. Contamination also exists at depth along the pipe line from the plant to the ponds. This contamination at depth is most likely to be a soluble form of uranium.
7.1 Primary Pond The primary pond is roughly elliptical in shape with a major axis of 50 feet and a minor axis of approximately 30 feet. The sides slopes smoothly to a depth of approximately 10 feet at the center.
Historic data indicate that contamination washed to the bottom of the pond with contamination levels of approximately 1,000 pCilg, Figure 7-1. Recent characterization also indicates that the berm surrounding the pond is contaminated in excess of the remediation goals. In addition, contamination has been found at depth in the area where the pipe from the plant entered the pond, Figure 7-2.
7.2 Secondary Pond 1
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Enclosure I to RA97/583 Evaporation Ponds Decommissioning Plan Update L
The secondary pond is roughly rectangular with a length of approximately 100 feet and a width of approximately 30 feet. The majority of the pond is less than 200 pCi/g with the exception of the west side of the pond, Figure 7-3. As with the primary pond, the berms are also contaminated above the remediation goals, Figure 7-4.
7.3 Areas Outside the ponds and inside the pond fence Only low levels of contamination were found in the area outside of the pond and inside the pond fence.
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FIGURE 7-1 1
PRIMARY POND SURFACE URANIUM IN pCi/g s
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1 E:cic:ure I to RA97/583 l
Evaporation Ponds Decommissioning Plan Update 8.0 Remediation Plan The secondary pond will be the first to be remediated and surveyed.
After the secondary pond is completed, the primary pond will be remediated and surveyed.
8.1 Secondary Pond To dry the secondary pond, water from the secondary pond will be i
pumped to the site creek, the primary pond, evaporated, or a hold tank to be used for dust suppression. The berm will be removed, and to the extent practicable the scrubber rock will be separated.
j The scrubber rock will be disposed as low level waste and the soil j
will be sampled. If the soil is above 200 pCi/g it will be disposed of as low level radioactive waste. Soil under 200 pCilg will be returned to the berm area. A " walk over" survey will be performed to identify 1
areas of increased beta / gamma activity. These areas will be evaluated to determine if remediation is needed. Areas found to have contamination above 250 pCl/g will be remediated.
j Once all remediation activities are complete, a triangular grid as specified in Section 4.3 will be set up and samples collected. The results will be compared to the remediation levels specified in Section 2.1. If additional remediation is necessary it will be performed. When the remediation levels have been achieved, the pond will be back filled.
8.2 Primary Pond To dry the primary pond, water from the primary pond will be pumped to the site creek, evaporated, or a hold tank to be used for dust suppression. The berm will be removed and to the extent practicable the scrubber rock will be separated. The scrubber rock will be disposed of as low level waste and the soil will be sampled.
If the soil is above 200 pCi/g it will be disposed of as low level radioactive waste. Soit under 200 pCi/g will be returned to the berm area. The pipe which fed the pond will be removed back to the pond fence and capped. Soilin the near vicinity of the pipe will be remediated to a level of 100 pCi/g. A " walk over" survey will be performed to identify areas of increased beta / gamma activity.
These areas will be evaluated to determine if remediation is needed. Areas found to have contamination above the 250 pCi/g t
I will be remediated.
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Enclosure I to RA97/583 Evaporation Ponds Decommissioning Plan Update 4
e Once all remediation activities are complete, a triangular grid as specified in Section 4.3 will be set up and samples collected. The results will be compared to the remediation levels specified in Section 2.1. If additional remediation is necessary it will be performed. When the remediation levels have been achieved, the pond will be back filled.
8.3 Areas Outside of the pond and inside the pond fence A " walk over" survey will be performed to identify areas of increased beta / gamma activity. These areas will be evaluated to determine if remediation is needed. A grid as specified in section 4.3 will be set up and samples collected. The results will be compared to the remediation levels specified in Section 2.1. If additional remediation is necessary it will be performed. When the remediation levels have been achieved, the area will be covered such that any area with average uranium levels above 30 pCi/g is covered by at least 4 feet of fill.
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