ML20207L034
| ML20207L034 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 01/08/1999 |
| From: | Margulies T AFFILIATION NOT ASSIGNED |
| To: | Vietticook A NRC OFFICE OF THE SECRETARY (SECY) |
| Shared Package | |
| ML20207L008 | List: |
| References | |
| NUDOCS 9903170339 | |
| Download: ML20207L034 (6) | |
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1213 River Bay Road Annapolis, Maryland 21401 January 8,1999
' Mrs. Annette Vietti-Cook United States Nuclear Regulatory Commission Washington, D.C. 20555-0001
Dear Annette:
The purpose of this letter concerns nuclear power plant risk, environmental protection, and probable Maryland jobs. An objective examination of severe accident information has been completed including a set of radiological risk and cost-benefit calculations for the Calvert Cliffs site. These are summarized in the enclosures.1 offer these to your staff to further support that safety improvements can be justified from engineering, perceptual, and cost-benefit viewpoints to help i
ensure public health and safety as the plants age. Thank you very much for your attention to this matter.
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Very trul yours,
[
,h Timothy Scott arg lies, Ph..
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Enclosure I: Severe Accident Resources for the Calvert Cliffs Nuclear Plants i
Enclosure ll: Nuclear Power Hazard and Cost-Benefit Risk Analyses O
t Severe Accident Resources For Calvert Cliffs Nuclear Plants T. Margulies Probabilistic risk calculations with cost estimates were made to evaluate potential cost-beneficialjustifications for safety improvements to engineering systems at the Calvert Cliffs site. The approach is consistent with an "as low as reasonably achievable" radiation protection policy endorsed by the International Commission on Radiological Protection '.
The two power generating units reside approximately 35 miles south of Annapolis,
, Maryland each supplying 845 mega-watts. Unit I began operating in 1975 and Unit li in 1977; hence, their licenses given by the U.S. Nuclear Regulatory Commission permitting them to operate expire in the years 2014 and 2016, respectively.
The dominant safety issues addressed concern severe accident scenarios such as a station black-out or containment bypass (Event V), each with approximately a one chance per one-hundred thousand likelihood of occurrence. Station black-out refers to the conditions that the alternating electrical supply onsite and offsite are unavailable for running cooling pumps and safety systems. Event V pertains to an " Achilles heel" of the containment where check valve failures would release coolant and radioactivity directly to the environment outside containment.
The transport calculations sample meteorological conditions, and include wind direction probabilities while simulating radiological exposures to over three million people within fifty miles of the plants and extending to people within 350 miles. Refer to the first bar chart showing the population distributed at various distances surrounding the site. An approach of the U.S. Nuclear Regulatory Commission to evaluate whether to augment existing designs for light water reactors to reduce population dose (Title 10, Code of Federal Regulations, Part 50: Appendix 1, FR Vol. 40, No. 87,19439, May 1975) is applied. The Nuclear Regulatory Commission's value for a cost-benefit analysis initially set radiation costs as $ 1000 per person-rem. Recent proposals have been made to increase this by a factor of two to five. The annual levelized cost results for various interest rates for the units are provided in the attached figures. These calculations corroborate previous analyses which neglect wind direction frequency, supported by the Chernobyl and Three Mile Island accidents during which the wind direction continually 2
shifted and did not generally persist uni-directionally,
The costs in the following figures represent potential expenditures to improve the safe operation over the remaining lives of the plants and to prevent the severe consequences from reactor accidents. Improvements such as instrumentation and monitoring to minimize a bypass scenario, and supplemental filtering and scrubbing to the present containments are cons:dered viable based on these analyses. Alternative allocations of resources to emergency preparedness measures such as stockpiling potassium iodide for thyroid protection would not have the additional protection benefits of reducing substantial non-inhalation pathway contributions of severe accident radioactivity releases to offsite whole body doses, as well as, protecting land from contamination.
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References:
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- 1. ICRP," Cost-Benefit Analysis in the Optimization of Radiation Protection," Annals of the ICRP. No. 37, Vol.10, No. 2/3,1983, Pergamon Press.
. 2. " Cost-Benefit Risk Analyses: Radioactive Waste Systems for Light Water Reactors,"
T. Margulies, U.S. Environmental Protection Agency, Manuscript,1998.
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Population Versus Distance Interval J
Calvert Cliffs, Maryland Site d
7
- 2. 10 7
1.5 10 7
- 1. 10 II 6
- 5. 10 1
2 3
4 5
6 7
8 9
10 11 4
t d
l 3
1 j
l'H " "LlO:: ME' '
J 02.0915 80 76.4558 66.7865 60 56.808 46.2168
. 53 5 20 8238 7375 7583 3737 3%
4%
54 6%
ip)<, rsi r dit 5 15 Years Remaining Plant Life 1
4
^
t d
Calvert Cliffs I Costs ( $ 1066 )
$ 5000 per person-rem averted 350 299.478 300 262.728
'238.582 250 232.628 207.241 200 181.81 160.98 150
. 56
.7269
.643
.841 50 2
g 3%
44 5%
6%
15 Years + 20 Years Plant Life Extension 3
a
..