ML20094P176
| ML20094P176 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 08/10/1984 |
| From: | Kober R ROCHESTER GAS & ELECTRIC CORP. |
| To: | Paulson W Office of Nuclear Reactor Regulation |
| References | |
| IEIN-83-05, IEIN-83-5, NUDOCS 8408170047 | |
| Download: ML20094P176 (4) | |
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N"" l ROCHESTER GAS AND ELECTRIC CORPORATION e 89 EAST AVENUE, ROCHESTER, N.Y. 14649'-0001 % )
ROGER W. MOBER WE MESDDdT T EL f emON E ELECTRfC E STEAM PRODUCTION ang A Cone no 546.2700 August 10, 1984 Director of Nuclear Reactor Regulation Attention:
Mr. Walte'r A. ' Paulson, Acting Chief Operating Reactors Branch No. 5 U.S.
Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
Exemption per 10 CFR 20.302 R. E. Ginna Nuclear Power Plant Docket No. 50-244
Dear Mr. Paulson:
In accordance with IE Notice No. 83-05, Disposal of Very Low-request permission Level Radioactive Waste and 10 CFR 20.302, we to dispose of 70. tons of very low level radioactive waste in a municipal landfill.
The material is from the roofs of the auxiliary building and other plant buildings.
It consists o f ' g r a'v e l, tar and plywood pieces.
Several analyses of the material have seen perfoined and are included in Attachment 1 for your review.
ihe average con-centration is 14.4 picocuries per gram
,1 samplas takun from the auxiliary building roof (see Figure 1).
This roof has the highest concentrations.
The annual dose equivalent assuming continuous occupancy has been calculated to be approximately 1 mrem when this material is covered by two feet of certh in a landfill.
The radiological impact of this type of disposal la negligible.
The concentrations of radioactive isotopes present are exempt according to the New York State Industrial Code Rule 38, Ionizing i
Radiation Protection (12NYCRR38).
V r truly yours, Y.
M Ro er W.
Kober Attachments 8408170047 840R10
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In order. to determine the radioactivity levels in the material to be disposed, samples were taken f rom the auxiliary building and intermediate building roof s.
To determine the average value -f or the auxiliary building, samples were taken in eight dif f erent locations, as'shown in Figure 1.
The measured values, the average and the standard deviation f or the building roof are shown below.
Based on sampling, it was determined that the activity levels f or the intermediate building are bounded by those f or the auxiliary
. building.
Sample Area Sample Analysis (pCi/ gram)
6.0 2.9 11.5 2
1.9 1.8 7.4 3
2.1 2.0 8.4 4
1.5 1.2 5.0 5
3.3 3.8 15.7 6
4.7 3.0 12.3 7
3.2 2.2 9.4 8
1.3 1.0 3.9 Averages 3.0+1.66 2.24+1.0 9.2+3.4 pCi7' ram pCi/ gram pCi7 gram g
The dose rate at one meter above the ground was then calculated assuming a unif orm distribution at the average concentration of the auxiliary building roof, no shielding f rom covering soil, and using the dose conversion f actors in NCRP Report No. 50, Table 2-17.
The resulting dose rate and annual dose, assuming continuous occupancy are:
Co-60 8.64 uR/ hour Cs-134 2.51 uR/ hour Cs-137 6.67 uR/ hour Total 17.8 uR/ hour or 156 mR/ year For determining the shielding f actor f or two f eet of sogl cover in l
a landf ill, it was assumed the soil density was 1 gm/cm and the average energy was 1 Mev gamma / disintegration.
Using Taylor expansion f or an inf inite plane source, the shielding f actor was calculated to be 0.0085.
The calculation is described in Introduction to Nuclear Engineering, LaMarsh, J.R.,
page 431, i
Eddison-Wesley, 1975.
Similar shielding f actors are determined using Table 6.3 or Figure 6.10 in the Health Physics and Radiological Health Handbook, Nuclear Lectern Associates, 1984.
The shielded dose rate is then 156 mR/ year x 0.0085 = 1.3 mR/ year.
Conservatively assuming 1 mrem = 1 mR, the annual dose equivalent rate f or continuous occupancy is 1.3 mrem / year.
- According to Industrial Code Rule 38 of the State-of New York
. (12NYCRR38) entitled, " Ionizing Radiation Protection", th o --
concentrations-of the radioactive isotopes found on the~ roof are exempt.
The exempt concentrations listed in Table 2 ot Rule 38 are:
~4 Co-60 5 x 10 uCi/ gram 3
Cs-134 9 x 10,4 uCi/ gram
-Cs-137 2 x 10 uCi/ gram Also, the; sum of the quotients of concentrations-present to exempt concentrations shall not exceed 1.
In this case, the. individual concentrations satisfy the criteria and the sum of the quotient, which is 0.076, also satisfies the criteria.
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. Sampling Locations-N L-Sample
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