ML18057A438

Forwards Info Re Contamination of South Radwaste Area,Per 10CFR20.302,in Response to NRC 900112 Request.Approval Requested to Dispose of Low Level Radwaste in Place

ML18057A438
Person / Time
Site:	Palisades
Issue date:	08/31/1990
From:	Slade G CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9009060175
Download: ML18057A438 (11)

Text

consumers Power POW ERIN& MICHl&AN'S PRD&RESS Palisades Nuclear Plant: 27780 Blue Star Memorial Highway, Covert, Ml 49043 August 31, 1990 Nuclear Regulatory Commission Document Control Desk D C 20555 DOCKET 50-255 -LICENSE DPR-20 -PALISADES PLANT GB Slade General Manager SUPPLEMENT

-REQUEST TO RETAIN SOIL IN ACCORDANCE WITH lOCFR 20.302 Consumers Power Company correspondence dated November 12, 1987 and January 25, 1988 requested authorization to dispose of contaminated soil in place as specified by lOCFR 20.302. The area known as the South Radwaste Area has been contaminated by numerous cooling tower overflows and contamination was redistributed by heavy rain showers. Although the majority of the radioactive material has been packed for waste shipment, a large volume of very low activity radioactive material remains. This volume of material would be very expensive to ship as waste. The NRC, by letter of March 15, 1988 to Consumers Power Company, requested additional inhalation dose information and clarification of the contaminated area. After discussions with the NRC reviewer, a supplement was submitted on June 27, 1988 which was based on generic approval.

It proposed that further submittals would not be required if flooding moved activity from an identified to an unidentified sector. Subsequently, on January 12, 1990, the NRC Staff requested additional information.

The information request required the licensee to submit a revised proposal incorporating the dose evaluation information of the measured contamination considered in the November 12, 1987 and January 25, 1988 submittals and updated, if appropriate, with dose evaluations of the inhalation pathway based on the same measured contamination.

As part of the proposal, the licensee was asked to record exactly what areas of measured contamination are covered by the request for which disposal under lOCFR 20.302 is proposed.

The attached material supplies the requested information.

The specific area contaminated is noted as Area B on the attached survey grid map. The entire area is fenced and is about 12,000 sq ft of soil exposed with the remainder buildings and asphalt. The inhalation pathway is for breathing suspended soil from this area. Table 2 addresses a radworker in Area B, and Table 3 addresses an infant on the site boundary.

The radworker could receive 8.03E-04 mRem/50-year maximum organ (liver) dose and the infant could receive 3.16E-05 mRem/50-year maximum organ (liver) dose, both of which are icant. °?(H)":.'J()6C>-l -----P.C1R Al--. --*-**-*

• 05000255 PDC OC0890-0074A-NL03 A CMS' ENER<SY COMPANY (}OOI If/

2 When the flooding problem was discovered and planning for a formal survey was done, the environmental sediment LLD was not considered, as this was a nuclear plant site. We attempted to get the best LLD we could using our equipment and the number of samples we were going to have to run. With the hundreds of samples run, we felt IE-06 uCi/gm was adequate.

To be conservative, we expanded the August and November I987 surveys to use I.OE-06 uci/gm Cs-I37 in any sector which showed LLD. This will increase the radioactivity to 5,006 uCi from 4,643 uCi, an increase of 8%. The activities are on Table I and IA. If this submittal is approved, we will add the released activity to the Liquid Semi-annual Effluent Report as an abnormal release, and the approval to retain the soil in place will be documented in the FSAR. In summation, Consumers Power Company requests approval to dispose of in place the low-level radioactive materials which are contaminated soil contained in the fenced area described as South Radwaste Area (Area B). Direct dose to a radiation worker would not exceed I.7E-02 mRem/hour from this contaminated soil. Inhalation doses to a radiation worker or at the site boundary would not exceed 8.03E-04 mRem/50-year.

Tables I and IA radioactive material release shall be identified in liquid Semi-annual Effluent Reports as an 'abnormal release'.

The disposal in place would be documented in the FSAR. The radwaste activities which caused the contamination of the soil have been completely relocated to a new east radwaste area. The South Building has been deconned and is being used for non-radwaste activities.

Some fixed contamination is present in floor cracks and vaults. This has been documented for plant decommissioning.

No further contamination will be added to the south area from the South Radwaste Building.

Gerald B Slade General Manager pc: Administrator, Region III, USNRC NRC Resident Inspector, Palisades OC0890-0074A-NL03 MI0890-0074A-HP01 Attachment A Consumers Power Company Palisades Nuclear Plant Docket 50-255 Tables 1 and lA, Survey Results Microshield Direct Dose Calculation Table 2 -Radworker Inhalation Dose Table 3 -Site Boundary Inhalation Dose Figure 1 -Survey Grid Figure 2 -Survey Results e e Table 1 August 1987 Survey Sector if Sg.ft. x De[!th = ft J x g/ft 3 x [:!Ci/ g = Total [:!Ci E-11 375 0.5 187.5 48144 2.07E-6 18.7 E-13 37 5 0.5 187.5 48144 4.39E-6 39.6 H-9 625 1.5 937.5 48144 4.79E-6 216.2 H-10 625 0.5 312.5 48144 2.60E-6 39.1 H-11 625 2.0 1250* 48144 3.75E-5 2256.8 1-9 527 0.5 263.5 48144 l.24E-5 157.3 I-10 275 1.5 412 .5 48144 5.39E-6 107. 0 J-9 450 0.5 225 48144 5.39E-6 58.4 J-12 200 0.5 100 48144 6.39E-6 30.8 L-9 150 1.0 150 48144 6. 77E-6 48.9 I-9 East 98 1.5 147 48144 l.40E-5 99.1 Subtotals 4325 4173 3071. 9 Remainder 7613 0.5 3807 48144 1.0E-06 183 of Section B TOTAL 11'938 3,255. MI0890-0074A-HP01 e e Table lA November 1987 Survey Sec tor lfo Sg.ft. x De Eth = ft 3 x g/ft 3 x [:!Ci/g = Total [:!Ci B-9 125 0.5 62.5 48144 lE-06 3 C-9 625 0.5 312.5 48144 lE-06 15 C-10 500 0.5 250 48144 lE-06 12 D-9 500 0.5 250 48144 lE-06 12 D-10 625 0.5 312.5 48144 lE-06 15 D-11 550 0.5 275 48144 lE-06 13 D-12 75 0.5 37.5 48144 lE-06 2 E-10 125 0.5 62.5 48144 lE-06 3 E-11 375 0.5 187.5 48144 l.8E-06 16 E-12 625 0.5 312.5 48144 1. E-06 15 E-13 550 0.5 275 48144 lE-06 13 F-12 300 0.5 150 48144 lE-06 7 F-13 625 0.5 312.5 48144 lE-06 15 G-12 750 0.5 125 48144 lE-06 6 G-13 625 0.5 312.5 48144 lE-06 15 H-9 625 0.5 312.5 48144 4.4E-05 662 H-10 625 0.5 312.5 48144 3.2E-06 48 H-11 600 0.5 300 48144 3.2E-05 462 H-12 250 0.5 125 48144 2.2E-06 13 H-13 625 0.5 312.5 48144 1. OE-06 15 I-9 527 0.5 263.5 48144 6.8E-06 86 I-10 275 0.5 137. 5 48144 1. OE-06 7 I-11 250 0.5 125 48144 l.OE-06 6 I-12 220 0.5 110 48144 3.0E-06 16 J-9 450 0.5 225 48144 2.lE-05* 227 J-12 200 0.5 100 48144 2.6E-06 13 K-9 216 0.5 108 48144 3.4E-06 18 L-9 150 0.5 75 48144 l.OE-06 4 L-10 150 0.5 75 48144 l.OE-06 4 L-11 150 0.5 75 48144 1. OE-06 4 L-12 150 0.5 75 48144 l.OE-06 4 Subtotals 11,938 ft 2 5,969 ft 3 Maximum 4.4E-05 1751 Average 6.lE-06 MI0890-0074A-HP01 Microshield 3.02 ================= (ConsuMer's Power CoMpany -#0371 Page 1 File SOILl .MSH Run date: January 18, 1988 Run tiMe: 4:17 p.M. CASE: CONTAMINATED SOIL@ H-9 LOCATION <6 INCHES DEEP) GEOMETRY 11: Rectangular solid source -slab shields Distance to detector *.**...*..**.............

X Source width .............. , ......... , ........ W Source length ..*...**.......... , .............

L Rectangular solid, thickness toward dose pt .. Tl Thickness of second shield *...............*..

T2 60.960 762. 762. 15.240 45. 720 Source VoluMe: 8.84901e+6 cubic centiMeters Material Air Alu111inul"1 MATERIAL DENSITIES Cg/cc): Source Shield 2 .001220 .001220 Carbon 1 .70 Concrete Hydrogen Iron Lead Lithiul"I Nickel Tin TitaniuM Tungsten Urania Uraniul"I Water i.0 Zirconiul"I CM,

--*-*

_._ .:: . I*

.-.=.=.:., . -. "'*'. -----' .... -BUILDUP FACfOR: based on TAYLOR method. Using the characteristics of the materials in shield 1

• INTEGRATION PARAMETERS:

NuMber of lateral angle segl"lents

<Nthetal..

.. . 5 Number of az1l"luthal angle segl"lenh

<Nps1 ). . . . . 5 Nurriber or radial segl"lents (Nradius)...........

5 SOURCE NUCLIOES:

Ba-1371"1:

• 3.8493e-04 curies Actual . 6.SlE-04 Ci (4.4E-05 uCi/gm) RESULTS: Group # Energy (MeVJ Activity (photons/sec)

Dose point flux MeV/(sq cM)/sec Dose rate <Mr/hr) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 .664 TOTALS: 6.51 Ci 1

• 282e+07 4.808e+00 1 .282e+07 4.808e+00 Ratio of 3.85 Ci= 1.69 x 9.969E-03

= l.7E-02 mR/hr 9.969e-03 9.969e-03 Dw = cs Table 2 Inhalation Dose From Contaminated Soil -Adult Radiation Worker Where: Cs concentration of waste -4.4E04 pCi/Kg Cs-137 (actual max concentration)

Ef occupancy factor -2080 worker hours 8760 hrs/yr = 0.237 f13 = a real/mass available for resuspension (top 1 cm of soil) -16 Kg/m 2 f14 resuspension factor -8.5E-9/m f15 adult annual inhalation rate -7300 m 3 (RC 1.109) DCFi = 7.76E-05 mRem/50 yr

• pCi -Cs-137 adult liver (RC 1.109) Substituting:

Dw = 8.03E-04 mRem/50 yr -maximum organ dose

Reference:

AIF/NESP-035 Evaluation of the Potential for De-regulated Disposal of Very Low Level Wastes From Nuclear Power Plants MI0890-0074A-HP01 Dss Cs Table 3 Inhalation Dose At Site Boundary -Infant Most Limiting X/Q µ A Where: Terms are identified in Table 1 and F16 2045 m 3 -infant annual breathing rate (RG 1.109) X/Q 1.4 E-6 sec/m 3 -actual 5 year site average µ = 3.8 m/sec average wind speed -actual 1986 A -1110 m 2 -contaminated area DCFj -4.37E-04 mR/50 yr

• pCi -Cs-137 infant liver (RG 1.109) Substituting:

Dss = 3.16E-05 mRem/50 yr -maximum organ dose MI0890-0074A-HP01 1 .FIGURE 1B SURFACE L L. ..

FIGURE I

• SURVEY GRID LEGEND ASPHALT AREAS D . 21* x 25. SECTORS -----rJ Contaminated IL_j A8EA *9* El

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