ML20212Q974
| ML20212Q974 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 04/17/1987 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML20212Q900 | List: |
| References | |
| NUDOCS 8704240178 | |
| Download: ML20212Q974 (2) | |
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UNITED STATES 8
~1 NUCLEAR REGULATORY COMMISSION WASHINGTON. D. C. 20555 April 17, 1987 ASSESSMENT OF THE EFFECT ON LICENSE DURATION ON MATTER'S DISCUSSED IN THE FINAL ENVIRONMENTAL STATEMENT FOR THE CLINTON POWER STATION UNIT NO. 1 (DATED JANUARY 1986)
INTRODUCTION The Final Environmental Statement (FES) for the operation of the Clinton Power Station, Unit No. I was published in May 1982.
It has been Past practice to issue operating licenses for a period of 40 years from the date of the construction permit.
For Clinton, the CP was issued in February 1976, thus, approximately 30 years of operating life would be available.
By letter dated September 18, 1985, Illinuis Power Company (IP) requested that the operating license for Clinton Power Station, Unit No. I have a duration of 40 years from the date of issuance.
DISCUSSION The NRC staff has reviewed the Clinton FES to determine which aspects considered in the FES are affected by the duration of the operating license.
In general, the FES assesses various impacts associated with operation of the facility in terms of annual energy production benefits. Thus, the overall assessment and conclusions would not be dependent on specific operating life. Tnere are, however, three ar3as in the FES for which a specific operating life was assumed:
1.
Radiological assessments are based on a 15-year plant midlife.
2.
Uranium fuel cycle impacts are based on one initial core load and 29 annual refuelings.
3.
Uranium availability is evaluated through 30 years of operation.
EVALUATION The NRC staff's appraisal of the significance of the use of 40 years of operation rather than 30 as it affects these three areas is presented in the following discussions:
Radiological Impact on Normal Operation - The NRC staff has calculated dose comitments to the human population residing around nuclear power reactors to assess the impact on people from radioactive material released from these reactors. The annual dose comitment is that dose that results from a one year intake of radioactive materials and would be received over a period of 50 years following intake. However, for the majority of radionuclides considered in this analysis, the total dose from a one year intake occurs during the year of intake.
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To perform the dose assessment the NRC staff assumes environmental conditions that would exist at the midpoint of plant life. This assumption accounts for the effect of the buildup of deposited radionuclides in the soil in succeeding years of operations.
For Clinton Power Station a 15 year period was chosen for radiological environmental assessment purposes as the midpoint of plant operation and was used for the calculations in the Clinton Unit 1 FES. For a 40 year license the 20 year period should be chosen for, the assessment.
The NRC staff has evaluated the IP request for a 40 year license and finds that increasing the buildup period from 15 to 20 years will increase the annual dose commitment by less than 10%. This increase is due primarily to ingestion of the longer-lived radionuclides deposited in the environment. Table C.4. of the FES indicates that the dose commitment to the thyroid, the most critical organ, via the ingestion pathway is about 4 mrem for each year of plant operation.
The 10 CFR Part 50, Appendix I design objective is 15 mrem maximum. Thus an increase of as much as 10% in the most critical pathway (to about 5 mrems) remains below the regulatory guidelines.
Uranium Fuel Cycle Impact - The impacts of the uranium fuel cycle were based on 30 years of operation of a model LWR. The fuel requirements for the model LWR were assumed to be one initial core load and 29 annual refuelings of approximately 1/3 core change for each refueling for an equivalent of 10.7 full core loads over 30 years (0.36 core per year average). The fuel require-ment of the model LWR over a 40 year operating life is 1 initial core load and 39 annual refuelings for an equivalent of 14 full loads over 40 years (0.35 core per year average). Thus the average annual fuel requirement for a 40 year license is slightly lower when compared to the annual fuel require-ment for a 30 year license. The new result would be a small reduction in the annual fuel requirement for the model LWR. This small reduction would not i
lead to changes in the impacts of the uranium fuel cycle.
Uranium Resources - A 33% increase in the Clinton Unit 1 operating life (to j
40 years) would still be within the projected uranium resources since the cancellation of many reactors will result in an off-setting reduction in demand. Furthermore, the increase in operating life assumption to 40 years will reduce the need for replacement generating capacity, including nuclear, l
at the end of the 30 years.
' CONCLUSION The NRC staff has evaluated the environmental impact of these areas which are dependent on a specific operating life for Clinton Power Station Unit I and j
concluded, based on the reasons discussed above, that the impacts associated j
i with a 40 year operating license duration are not significantly different from
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i those associated with a 30 year operating license duration and are not signifi-l cantly different from those assessed in the Clinton FES.
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