ML19345C059
| ML19345C059 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 11/19/1980 |
| From: | Eisenhut D Office of Nuclear Reactor Regulation |
| To: | Drey L AFFILIATION NOT ASSIGNED |
| Shared Package | |
| ML19345C060 | List: |
| References | |
| LSO5-80-11-025, LSO5-80-11-25, NUDOCS 8012030819 | |
| Download: ML19345C059 (3) | |
Text
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November 19, 1980 S
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Docket No. 50-10 S
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&J Mrs. Leo A. Drey a
Eis 515 West Point Avenue E
"5 University City, Missouri 63130 0
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Dear Mrs. Drey:
This is in response to those portions of your October 6,1980 letter to Mr. Robert Browning, Deputy Director of Waste Management, that have been referred.to the Division of Licensing. The remainder of your questions were addressed in Mr. Browning's October 24, 1980 letter to you.
Q A.l.
If you have any docunent describing the Dresden test loop experiment that you could send me, I would greatly appreciate it.
The enclosed report, " Radiation Level Assessment of the Dresden 1 Decontamination Pilot Loop-Final Report" (NEDC-12620-1) is provided for your information.
Q B.l.
If a one-fourth curie Peach Bottom drum registered 800 mr/hr, is it not correct that a 21/2 curie Dresden drum could register 8,000 mR/hr or 8 rem /hr? Some of the one-fourth curie Peach Bottom drums apparently regiec ed 1200 mR/hr. Extrapolating from that to the Dresden drums, und that not mean that some of the Dresden barrels could measure 12 rem per hour on contact?
Yes, it is possible that some barrels could read a little over 10 R/hr.
The radiation dose rate adjacent to a gansna emitting source of radiation is a conplex function which requires knowledge of the specific amounts and nature of the isotopes present, the self-absorption quality of the media in which the isotope is dispersed, and the spatial distribution of the source; therefore, it is not possible to predict in advance the precise radiation exposure rate that will exist at the surface of the waste drums.
You should keep in mind that these barrels will be handled remotely behind shielded walls and will be shipped to the burial site in shielded containers that reduce the external dose rate to levels that are acceptable under NRC and DOT regulations.
B012030
Mrs. Leo A. Drey November 19, 1980 Q B.2.
"What are the current radiation levels at a few of the hottest spots at Dresden One according to the Blue Diamond survey of the primary system piping and equipment? According to the Electric Power Research Institute Report, " Primary System Shutdown Radiation Levels at Nuclear Power Generating Stations", December 1975, the survey had just recently been installed.
I would be very interested in the results. The EPRI report is the only document I have that mentions specific radiation fields at Dresden One.
The hottest locations listed were the bottom drains and primary side vents of the secondary steam generators (1500 to 3900 millirem per hour at 2", as per page 18.5).
If crud was able to build up as dramatically as it did in the Peach Bottom heat exchangers fn less than three years, do you not expect the radiation levels near Dresden One's 19-year-old primary cooling system parts and piping to be far, far hotter?"
The " Blue Diamond Survey" was carried out by the participating ' utilities as a voluntary effort to better understand the causes and magnitude of primary cooling system shutdown radiation levels. The survey was not conducted in response to regulatory requests and has not been submitted to NRC. However, we have determined that in January 1980 a radiation level of 2 R/hr was measured at the bottom drain of steam generator A.
This reading taken 14 months after the shutdown is conparable with the 1.5 R/hr reading recorded in the 1975 Blue Diamond Survey. You may wish to request the survey results from EPRI or from Coninonwealth Edison.
With regard to your comments relating to your expectations of the radiation levels at Peach Bottom versus Dresden 1, you should note that EPRI 404-2, which you have referenced, states that "Results obtained at four of the surveyed plants are not felt to be representative of trends to be expected in current generation plants." because of difference in alloy conposition, water quality considerations and operatior.al techniques. Therefore, we are unable to make generalized projections and conparisons between Peach Bottom dose rates and Dresden dose rates.
Q C. "I was told all the waste: had been solidified and shipped for burial.
However, on Page 84 of Power, an article I received relatively recently, it is reported that "the last (step of. the experiment) was solidification of (only those) wastes that could not be handled by the plant's existing radwaste system."
(parenthetical words inserted).
Is it possiDie, then, that some of the Dow NS-1 may indeed have ended up in the Susquehanna?"
o Mrs. Leo A. Drey November 19, 1980 Concentrated NS-1 degrades the ion exchange capacity of the resins in the plant cleanup system. Therefore, the concentrated NS-1 waste from the decontamination and the first flushings were solidified by the Dow vinyl ester resin solidification method for disposal.
Subsequent rinses were tested for NS-1 content, pH, conductivity, radioactivity and iron content.
Depending on the results of these tests the rinse was either solidified or cleaned up by the ion exchange. No NS-1 was damped into tht: Susquehanna River.
I hope this letter has been responsive to your questions.
- ncerely,
([
Ei ector Division Licensing cc: Mr. R. Browning 1
,