ML19256A132
| ML19256A132 | |
| Person / Time | |
|---|---|
| Site: | Waltz Mill |
| Issue date: | 10/31/1978 |
| From: | Dipiazza R WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| WRD-LS&S-582, NUDOCS 7811030146 | |
| Download: ML19256A132 (3) | |
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Westinghouse Water Reactor PWR Systems D: vision Electric Corporation Divisions m ass Pittstuq;h Pernsylvana15230 October 31, 1978 WRD-LS&S-582 U.
S.
Nuclear Regulatory Commission Office of Nuclear Regulation Division of Reactor Licensing Washington, D.C.
20555 Attention:
Mr. Robert W.
Reid, Chief Operating Reactors Branch #4 Gentlemen:
Subject:
Addendum to Annual Report - License No. TR-2, Docket 50-22 The Westinghouse Electric Corporation transmits herewith the attached
" Addendum to Annual Inspection Report for TR-2".
This addendum has been prepared to address questions forwarded from Mr. Peter Erickson of the NRC.
If you have any questions regarding this matter, please write me at the above address or telephone me on 412-373-4652.
Very truly yours, Mgk onald P. DiPiazza, Manager NES License Administration slw/ Attachment Copies Transmitted:
3 notarized & 10 conformed COMMONWEALTH OF PENNSYLVANIA) ss.
COUNTY OF ALLEGHENY,
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e Addendum Annual Inspection of Retired WTR per NRC License TR-2 This document is submitted in response to questions which have been asked or-ally by NRc,.ersonnel relative to radioactivity in the water of the WTR canal as reported in our Annual Inspection Report for 1978 which was transmitted on August 30, 1978.
(WRD-LS+S-532).
1.
What is the isotopic composition of the radioactivity in the canal?
The radioactivity of the canal water on August 7,1978 was 2.85 X 10-4pCi/ml.
The values reported in the Annual Reports for the years 1971 through 1977 av-eraged 3.25 X 10-4 r.i/ml, indicating essentially no change in the radioactiv-p ity over the last seven (7) years. We have 60,000 gallons of water in the WTR canal so we have a total of 66 millicuries of activity in the canal.
An iso-topic analysis of the 1978 sample showed that the radioactivity was 66% Cs-137, 265 Sr-90/Y-90, 7% Co-60 and 1% Cs-134.
2.
How do we know that the canal is not leaking?
There are several factors which give assurance that water is not leaking from the canal:
a.
To prevent ground water from seeping into the WTR structure at a level 16 feet below ground surface, which is the level of the canal water sur-face, it is necessary to operate several sump pumps located adjacent to the structure and with the intake for these pumps below the canal water surface.
Samples of water taken from the discharge of these pumps have shown normal background levels of radioactivity.
It is expected that any leakage from the canal would have found its way into these sumps during the time the pumps have been operating.
b.
Water samples were taken from several manholes and sumps which are in close proximity to tae retired WTR facilities'and below the water level of the canal.
The activity found in these samples was in the normal background range indicating that the source of water in these cavities was ground water rather than WlR canal water.
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c.
The radiological environment monitoring program, which has been in effect for many years, has produced no evidence of canal leakage.
This program includes the analysis of samples routinely taken from various streams and creeks that flow through the Waltz Mill Site.
During the period 1972 through June, 1978 the average concentration of gross beta-gamma activity found in these samples was in the normal background range.
d.
For the last several years we have manually measured the water level in the canal as a part of our annual survey and have found no significant change in the level.
However, to give more positive assurance that there is no canal water leakage, a water level indicator will be installed in the WTR canal.
The indicator will be set to alarm when the water level drops two (2) inches.
The alarm will be connect-ed to the Site Alarm System which is continuously monitored.
Activation of this alarm will result in an investigation to determine the reason for the alarm. A record of these investigations will be maintained.
In addition, water will be added to the canal manuaily '9d the volume added will be measured.
A record will be kept of the volume of water added to the canal to maintain normal water level.
The addition of a quantity greater than that needed to replace evaporation will al-so trigger an investigation.
3.
What is the source of the radiation level (7.6 mr/hr) that was reported in the Annual Report for the Canal water?
The radiation level reported is obtained by holding the radiation detector above the canal water at arms length from the canal parapet wall and at approximately the same height as the parapet vall.
Approximately 15 readings are taken at varioe5 locations and the average value is reported.
For the years 1971 through 1977, tie values reported varied from 25 mr/hr to 7.5 mr/hr.
A more precise radiation survey of the canal area has recently been made and indicates that the source of this general radiation field is the surface of the canal walls above the water level, rather than the canal water itself.
This was confirmed by immersing a sealed tube at variou locations in the canal water and slowly lowering a radiation detector into the tube.
When the detecta was below the water level, the radiation level was always less than 0.5 mr/hr and did not vary significantly to a depth of 36 inches.