ML18052B475

Discusses Results of Evaluation & Survey of 871113 Flooding Incident at Plant,Per Util 871112 Request to Dispose of Soil Inplace,Per 10CFR20.302.Relocation of Activities to New Radwaste Facility Scheduled for Completion in 1988

ML18052B475
Person / Time
Site:	Palisades
Issue date:	01/25/1988
From:	BORDINE T C CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
NUDOCS 8802010155
Download: ML18052B475 (13)

Text

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consumers Power l'OWERIN&

lllllCHl&AN'S l'RO&RESS General Offices: 1945 West Parnell Road, Jackson, Ml 49201 * (517) 788-0550 January 25, 1988 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 -LICENSE DPR-20 -PALISADES PLANT -SUPPLEMENT

-REQUEST TO RETAIN SOIL IN ACCORDANCE WITH 10CFR20.302 Consumers Power Company letter dated November 12, 1987, requested zation to dispose of soil in place as specified by The letter included the results of a survey and evaluation performed in August, 1987. Following submittal of that letter, a cooling tower overflow on November 13, 1987 again flooded the South Radwaste Building.

The flooding caused additional activity that necessitated Consumers Power Company to request placing our November 12, 1987 request on hold until further evaluation and surveys could be completed.

This .letter includes the results of our evaluation and survey of the November 13, 1987 flooding incident and is intended to supplement our original November 12, 1987 request. Following the cooling tower overflow, a survey indicated additional activity had been released from the building.

The building was being maintained in a non-contaminated condition to prevent this type of occurrence; however, during this period a destructive testing program on waste packages was being ducted in a small area of the building.

The survey clearly showed the release of activity from the building adjoining the testing area. The top six inches of soil from the sectors adjoining the building were removed and packaged (588 cubic feet) to prevent additional dispersion of radioactivity.

The area was then completely resurveyed.

An evaluation of the August 1987 and November 1987 (post packaging) activities is attached.

The survey indicates a drop of 49% in activities between the August and November surveys. We propose the activities specified in the November 12, 1987 submittal be used as justification for the request because they are conservative.

In addition since the November 13, 1987 flooding and following the most recent survey the area was subject to heavy rains which could have diluted some activities to below minimum detectable activity (MDA is nominally lE-06

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r eeo201015s 2 5 5 .( \ . J -PDR "*LJ / *. -. ', -Ji (\ . . *--' L OC0188-0018-NL02 e Nuclear Regulatory Commission Palisades Nuclear Plant Retain Soil in Accord. with 10CFR20.302 January 25, 1988 2 The one non-conservative value from our August survey and evaluation is the maximum dose rate at 18 inches' above the surface. The November survey value from MICROSHIELD is 1.17 mR/hr as opposed to 1.02 mR/hr. This small increase only slightly changes the radiation workers' conservative dose estimate from 4.08 mR/year to 4.7 mR/year. Following approval of this application, it is proposed to account for the most conservative values of activity, which was stated in the November 12, 1987 submittal, as an abnormal release in the semi-annual report. In order to prevent recurrence of these releases to the environment, Consumers Power Company is also committing to transfer radwaste activities from this area, except for high level vault use which is not a potential flooding release problem. Relocation of these activities to a new radwaste facility is currently scheduled to be completed in 1988. A check in the amount of $150.00 was attached to our November 12, 1987 submittal pursuant to 10CFR170.12(c).

Thomas C Bordine Administrator, Nuclear Licensing CC Administrator, Region III, NRC NRC Resident Inspector

-Palisades Attachment OC0188-0018-NL02

• . Attachment A Consumers Power Company Palisades Nuclear Plant Docket 50-255 Evaluation and Survey Results Comparison Post November Flood and Packaging*Versus the November 12, 1987 Submittal MI0188-0001A-HP01

• . 'A' Cooling Tower -South Radwaste Flood In August of 1987, a resurvey was co.nducted of the soil at the South Radwaste Building and its adjacent areas. The resurvey was conducted to verify the of ground contamination and if any contamination migrated further into the ground since the 1986 survey. After submittal of the 198) soil results and request to retain, in accordance with 10CFR20.302, 'A' Cooling Tower Basin overflowed again flooding the South Radwaste Building and outlying areas. Immediately following the occurrence, one liter sample was taken with no activity detected on the Multi-Channel Analyzer (MCA). Then, another complete survey was conducted which included at least two surface samples and core samples in every sector (Figures 1 and 2). Surface sample results showed that activities have increased as well as new sectors contaminated.

The most heavily affected sectors were I-10, I-11, J-9-and K-9 (Figure lA).. To keep these areas from spreading, the t0-p 6" of each of these sectors was removed and placed in 6 LSA boxes (approx. 588 cu.ft) and stored for disposition at a later date. After removal of soil, the sectors were resurveyed (Figure lB) and core samples were taken in each sector in 6-inch increments.

Core samples were-taken as far down as in.the 1986 and August 1987 surveys, and in some instances even further in this survey. Results showed that no activity was detected below 6 inches as shown in Figure 2. Table 1 and Table 2 show comparisons between the August and November 1987 soil surveys. Table 1 compares the depths, the. activities, the total cu.ft. and total µCi per sector. After the removal of soil, the November 1987 soil survey results showed approximately a 49.3% drop in total contaminated soil (cu.ft.) and a 51.1% drop in total µCi in comparison to the August 1987 survey results. In Table 2 the comparison is between sectors affected in each survey and the depth at which each of these sectors were sampled. No activity was detected past 6 inches in the November 1987 soil survey, in comparison to that of 18 inches detected in August Direct dose to an individual working in the affected areas was calculated using the MICROSHIELD code. The activities from sectors H-9 and J-9 were used for a dose at 18" inches above the surface. The dose rates from H-9 and-J-9 are 9.97E-6 R/hr and 1.17E-5 R/hr, respectively.

Therefore, a SO-hour occupancy in one week could result in a maximum exposure of .59 millirem.

Normal -occupancy of *this area is on an "as needed basis" and averages less than 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />s/week per individual in contact with the contaminated soil. In reviewing the soil results between August and November 1987, the August 1987 soil survey remains more conservative based on the information shown on Tables 1 and 2. Therefore, the August 1987 soil survey still valid in support of our request to retain the soil in accordance with 10CFR20.302.

MI0188-0001A-HP01

• • *.Table 1 Comparison Table Between Total Cu. Ft. and Total µCi August 1987 .Sector ff Sg,.ft. x DeEth ft 3 x g/ft 3 x µCi/g, = Total µCi E-11 375 0.5 187.5 48144 2.07E-6 18.7 E-13 . 375 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.l H-11 625 2.0 1250* 48144 3.75E-5 2256.8 I-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 4325 4173 3071.9 *1250 .*2256.8 = 73.57. of total activity November 1987 *E-11 375 0.5 187.5 48144 l.80E-6 16.25 H-9 625 0.5 312.5 48144 . 4.35E-5 654.46 H-10 . 625 0.5 312.5 48144 3.20E-6 48.14 H-.11. 625. 0.5 . 312.5 48144 3.22E-5 . 484 .45. H-12 250 0.5 125 48144 2.20E-6 13.24 I-9 527 0.5 263.5 48144 6.79E-6 86.14 I-12 220. 0.5 110 48144 3.0E-6 15. 89 . J-9 450 0.5 225 48144 2.05E-5 222.06 J-12 200 0.5 100 48144 2.60E-6 12.52 K-9 216 0.5 108 48144 3 .39E-6 . 17.63 4113 . 2056.5 1570.78 = MI0188-0001A-HP01 Ta.ble 2 Survey Comparison Between August and. November 1987 Soil Surveys August 1987 November 1987 Sector Surface 6" 12" 18" 24" 30" 36 11 42 11 E-11 2.07E-6 <MDA <MDA

<MI>A e l *. 80E-6 <MDA <MDA

<MDA E-13 .4.39E-6 <MDA <MDA <MDA <MDA N/A <MDA <MDA H-9 4 .19E-6 . <MDA .4. 79E-6 <HDA <HDA <HDA 4.35E-5 <HDA <HDA <HDA <HDA

<HDA H-10 2.60E-6 <MDA <MDA 3.20E-6 <MDA <HDA H-11 3.75E-5 <HDA <HDA 8.45E-6 <HDA <HDA <HDA 3.22E-5 <HDA <HDA <HDA <HDA <MDA <HDA H-12 <HDA N/A 2.20E-6 N/A I-9 l.24E-5 <HDA <MDA 6.79E-6 <MDA <HDA I-10 <HDA <HDA 5.39E-6 <MDA <HDA <HDA <HDA <HDA <HDA <MDA <HDA <MDA <HDA <HDA

<HDA <HDA I-11 <MDA' N/A <HDA <HDA <HDA

<HDA I-12 <MDA N/A 3.00E-6 N/A J-9 5.39E-6 <HDA <HDA 2.0SE-5 <HDA <MDA J-12 6.39E-6 <HDA <HDA 2.60E-6 N/A <HDA K-9 <MDA N/A 3.39E-6 <HD.A <HDA <MDA <HDA <MDA <HDA L-9 <MDA 6.77E-6 .<HOA <HOA <HDA N/A <HDA <HDA MI0188-0001A-HP01 Microshield

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CConsuMer's Power CoMpany -#0371 Page I File SOIL1 .MSH Run date: January 18, 1988 Run tiMe:

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 6f second shield ......... .........

T2 60.960 762. 762. 15. 240 . 45. 720 *Source VoluMe: 8.84901e+6 cubic centiMeters MATERIAL DENSITIES Cg/cc): Material Air AluMinuM Source Shield 2 .001220 Carbon 1 .70 Concrete Hydrogen Iron Lead LithiUM Nickel Tin TitaniuM Tungsten*

Urania UraniuM Water I .0

• Zirconiul'i

' CM, r

• . . Page 2 e eiie: SOfLi .MSH CASE: CONTAMINATED SOIL @ H-9 LOCATION (6 INCHES DEEP> BUILDUP FACTOR: based TAYLOR Method.* Using the. characteristics of the Materials in shield 1

• INTEGRATION PARAMETERS:

NuMber of lateral angle segMents (Ntheta).;

.. . *5 NuMber of aziMuthal angle segMents CNpsi)...

.. 5 NuMber of radial segMents (Nradius)....

....... 5 SOURCE NUCL IDES: Ba-i37M: 3.8493e-04 curies RESULTS: Group # Energy CMeV) 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: 1 . 282e+07 4.808e+00 9.969e-03 1 . 282e+07

• 4*. 808e+00 9.969e-03

• ... *. Microshield 3.02 (ConsuMer's Power CoMpany Page File Run date: January 18, 1988 Run tiMe: 4:26 p.M. #037) CASE: CONTAMINATED J-9 LOCATION INCHES DEEP> GEOMETRY 1 I:

solid source slab shields Distanc.e to detector ......................... . x 60.960 Source width ............................. , ... : w 762. Source length .. , ..*..*.. , ............ , .. *,.; .. L 548.640 Rectangular solid, thickness toward dose pt .. Tl 15.240 Thickness of second shield .............. ... . T2 45. 720 Source VoluMe: 6.37129e+6 cubic centiMeters Mat er"! al Air AluMinuM MATERIAL DENSITIES

• source Shield 2 . .001220 .001220 Carbon l.70 Con-crete Hydrogen * *Iron Lead LithiuM Nickel Tin Titaniul'l .Tungsten Urania UraniuM Water I .0 ZirconiuM CM,

.. Page 2 Ai* i* "' * "'1* T; ., M. <; H .. _, * ...J..l-l-'-*

'-. *CASE: CONTAMINATED SOIL@ J-9 LOCATION (6 INCHES OEEPI BUILDUP FACTOR: based on TAYLOR Method.

the characteristics of the Materials in shield 1. INTEGRATION PARAMETERS:

NuMber of lateral angle segMents (Ntheta>.....

5 NuMber of aziMuthal angle .segMents (Npsi ).. . . . 5 NuMber of radial segMents (Nradius)

... ... , . 5 SOURCE NUCLIDES:

Co-S0: 8.9198e-05 curies RESULTS: .Group # Energy (MeV) Activity (photons/sec)

Dose point flux MeV/(sq cril)/sec Dose rate (Mr/hr) 1 2 3 4 5 s *7 8 9 10 11 .. 12 13 14 15 16 17 18 19 20 1 .336 1. 180 .695 TOTALS: 3.300e+06 3.300e+06 5.383e+02 6.601e+06 3A 11 e+00 2.958e+00 2.889e-04 6.370e+00

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6.155e-03 5.497e;_03 5.950e-07 1 .1S5e-02 FIGURE 1A SURFACE ..

FIGURE 18 I..., ' *"" I . SURFACE . . . . . ..... / ./** LEGEND .*. . . . . I q.l A . . ft.'

• .

fOl . 1U11MCe AllEA IHIER ASl'HAL T l . . . . L.Q_J CORE SAMPLE UNDER FOUNDATION_

• , ..... SURFACE ACTIVITY OF SECTOR ASPHALT AREAS* -EXAMPLE:

ONLY ..

... *