ML19347C035
| ML19347C035 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 10/09/1980 |
| From: | Hovey G METROPOLITAN EDISON CO. |
| To: | Jay Collins Office of Nuclear Reactor Regulation |
| References | |
| TLL-395, NUDOCS 8010160488 | |
| Download: ML19347C035 (2) | |
Text
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Metropolitan Edison Company y
Post Office Box 480 gj
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Middletown, Pennsyhania 17057 Wnter's Direct Dial Nornoer October 09, 1980 TLL 395 TMI Program Office Attn:
Mr. John T. Collins, Depucy Director U. S Nuclear Regulatory Commission c/o Three Mile Island Nuclear Station Middletown, Pennsylvania 17057
Dear Sir:
Three Mile Island Nuclear Station, Unit 2 (TMI-2)
Cperating License No. DPR-73 Docket No. 50-320 Process Water Storage Tanks In reference to Met-Ed/GPU letter, TLL 029, dated Januarv 24, 1980, from R. F. Wilson to J. T. Collins, " Processed Water Storage inks", we submitted Met-Ed/GPU's basis for not requiring dikes as part of ths foundation design for the process water storage tanks.
These tanks will contain fluid of very low radionuclide concentrations; therefore, the tanks do not need extra-ordinary leakage control features, such as protective dikes.
The NRC, via NRC letter NRC/IMI-80-026, dated February 1, 1980, from J. T. Collins to R. C. Arnold, " Design Criteria for Processed Water Storage Tanks", concurred with this assessment: however, the NRC also suggested the following con-l straints:
l a)
Administrative controls must be established for concentrations l
of tritium and cesium and strontium isotopes that can be stored 4n the tanks.
1
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b)
Acceptable concentrations are:
Tritium luci/cc
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Cesium isotopes 1 X 10 " uCi/cc Strontium isotopes 1 X 10' uCi/cc i
l In the opinion of Met-Ed/GPU, the imposition of specific limits on the con-l l
centrations of a few isotopes is overly restrictive.
Therefore, we intend to load the tanks in accordance with 10 CFR 20 guidelines at the nearest potable water supply using the dilution factor, as discussed in our letter, TLL 029.
Additionally, the PWSTs will be restricted to a total curie content, excluding e(
tritium end noble gases.
As discussed below, positive control will be maintained on the radionuclides h7 0 in the PWSTs.
Using the release model of reference letter TLL 029, the t{
concentration of Cs-134 and Cs-137 in a full PWST needed to exceed 10 CFR 20, Appendix B, Table II, Column 2, requirements at the nearest potable water supply are 6.9 X 10-' uCi/cc and 1.53 X 10-2 uCi/cc, respectively; thus, the proposed limit for cesium in the PWST is less than 2 percent of the applicable 10 CFR 20 limit.
Similarly, the concentrations of Sr-89 and Sr-90 needed in a full PWST Metrocc.itan Ec;sen Camcany s a Ye-ter of tre Gemrat Putnc Uetes S< stem g010160 g
John T. Collins TLL 395 to exceed the 10 CFR 20, Appendix B, Table II, Column 2 limits at the nearest potable water supply are -pproximately 2.29 X 10-3 uCi/cc and 2.29 X 10 " uCi/ce, respectively; thus the proposed limits for strontium in the PWST are less than 5 percent and 45 percent of the 10 CFR 20 limit for Sr-89 and Sr-90, respectively.
We recognize, of course, that the 10 CFR 20 limits must be applied such that the summation of all radionuclide concentrations is within MFC limits, so that each individual radionuclide concentration limit is viewed with respect to the other radionuclides present.
In addition, the NRC suggested limits do not allow for the case when the PWST is only partially filled.
In this event, the concentrations in the PWST could be increased in accordance with this formula (500,000 gal./ actual tank volume)3/2 This formula is based on the weir formula discussed in reference letter, TLL 029.
In summary, it is our intention that during operation, the radionuclide concentrations in the PWST will satisfy all of the following criteria:
a)
Tritium concentration of luCi/cc.
b)
A maximum of 10 curies in the PWST for all radionuclides, excluding tritium and noble gases.
c) 10 CFR 20 limitations at the nearest potable water supply for the combined radionuclides present in the PWST as a function of actual tank volume.
In order to ens' ire that these limits will be observed, administrative centrols will be estab; 2d to control the contents of the PWSTs.
All water entering the PWSTs will oe processed by one of the TMI-2 contaminated water processing systems.
Each of these systems contain effluent monitor tanks.
These effluent monitor tanks permit thesamplingoftheprocessedwaterbeforedhnsferring the fluid from the respective system and results in batch additions of a known quantity and quality of water to the PWSTs. These samples will check the process water for radionuclide concentrations to determine whether the water should be reprocessed, or is suitable for transfer to the PWSTs. The determination of which of the above options to choose will be based on con-centration levels.
By this method, an inventory record will be maintained of the radionuclides entering the PWSTs.
Sincerely,
/
G. K. Hovey Vice-President and Director, TMI-2 GKH:JJB: dad cc:
Bernard J. Snyder