ML20235K469
| ML20235K469 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 09/25/1987 |
| From: | Zimmerman S CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML20235K472 | List: |
| References | |
| 87TSB07, 87TSB7, NLS-87-214, NUDOCS 8710050104 | |
| Download: ML20235K469 (5) | |
Text
_ _ - - _ _ _
1 CD&L L
Carolina Power & Light Company SERIAL:' NLS-87-214 10CFR50.90 SEP 2 5 337 87TSB07 United States Nuclear Regulatory Commission-ATTENTION: Document Control Desk Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50-325 & 50-324/ LICENSE NOS. DPR-71 & DPR-62
. SUPPLEMENT TO REQUEST FOR LICENSE AMENDMENT FUEL ASSEMBLY / FUEL STORAGE TECHNICAL SPECIFICATIONS Gentlemen:
On June 12,1987, Carolina Power & Light Company (CP&L) submitted a proposed Technical Specification change request for the Brunswick Steam Electric Plant (BSEP)
. Unit Nos. I and.2 relating to the fuel assembly descriptions and storage. Based on recent discussions with members of your staff, the Company has been informed that information may be needed by the Staff for evaluating the environmental consequences of the proposed Technical Specification change..
1
. Enclosed is a copy of _CP&L's evaluation of the environmental impact of extending the j
fuel burnup for BSEP. This evaluation supports our conclusion that there is no significant environmental impact associated with the increased fuel burnup.
The current generic bases for assessing the environmental impacts of the fuel cycle are provided in Tables S-3 and S-4 of 10CFR$1. Both of the BSEP units were licensed prior to the dates established in 10CFR51 for using Tables S-3 and S-4 as the basis for evaluating fuel cycle environmentalimpacts. However, the results of evaluation for a reference 1000 MWe light water reactor (which bounds BSEP) have been expressed in terms of extended values of Tables S-3 and S-4 to provide a basis of comparison for the Staff.
If you have any questions concerning this submittal, please contact Mr. S. D. Floyd at (919) 836-6901.
Yours very truly,
[
PDR 87100 0 324 PDR S. R. Zimmerman P
Manager Nuclear Licensing Section WRM/lah (5300 BAT)
UY Enclosure Dr. J. Nelson Grace 80! M.' MM cc:
Mr. Dayne H. Brown Mr. W. H. Ruland Mr. E. D. Sylvester I
411 revetteme si eet. P. o Box isst. Raleign. N C 27602 rewawmauxmummamamma
l l
l FINAL ENVIRONMENTAL EVALUATION OF EXTENDED FUEL BURNUP FOR THE BRUNSWICK PLANT TRANSITION TO GENERAL ELECTRIC GE8x8EB FUEL (53000AT/l ah )
l
6 FINAL ENVIRONMENTAL EVALUATIO.N EXTENDED FUEL BURNUP INTRODUCTION This Final Environmental Evaluation applies to the Carolina Power & Light Company proposal to extend the fuel burnup at the Brunswick Plant up to 60,000 megawatt days per metric ton of fuel (MWD /MT). As shown by the following evaluation, there is no significant environmental impact associated with the increased burnup.
EVALUATION The current generic assessment of the environmental impact of the nuclear fuel cycle contained in the Code of Federal Regulations and other NRC reports is not app'ticable to discharge fuel burnups beyond 33,000 MWD /MT.
The current generic assessments of the environmental impacts of the fuel cycle are contained in Tables S-3 and S-4 of 10CFR51. Table S-3 presents the environmental impact of the fuel cycle in terms of natural resource use and chemical and radiological effluents. Table S-4 presents the environmental impacts of the transportation of fresh fuel to, and spent fuel and solid waste from, a reference reactor. These analyses are supplemented by a generic analysis prepared by the NRC staff on the release of radon-222 (Rn-222) and technetium-99 (Tc-99) and the environmental dose commitments associated with radionuclides releases from fuel cycle facilities.
1 A study, AIF/NESP-032 dated June 1985 entitled "The Environmental Consequences of L
Higher Fuel Burnup," was conducted by the Atomic Industrial Forum National l
Environmental Studies Project. The results of this report are expressed in terms of extended values of Tables S-3 and S-4, extended burnup source terms for Rn-222 and Tc-99, and environmental dose commitment. The study concluded that extending fuel burnup to 60,000 MWD /MT results in environmental consequences which are either less l
than or virtually the same as those assumed in the current regulations. Accordingly, extended burnup does not result in any significantly increased environmental impact.
Data extracted from AIF/NESP-032 are reproduced in Table 1. The environmental impacts were prorated by the projected fuel cycle requirements at higher burnups.
AIF/NESP-032 used the following reference conditions for the development of the front-end requirements: a) 80 percent capacity factor; b) 1000 MWe reference reactor; c) 0.25 w/o tails; d) uranium recycle; e) 18-month refueling cycle; f) U-236 neutron effect; g) 0.1 percent ore grade; and h) 90 percent milling efficiency. These reference conditions are the same as those used by the NRC in Table S-3 except for the last four items which were updated to reflect current conditions or knowledge more accurately.
The 18-month cycle is considered more typical than the 12-month cycle previously used.
The neutron poison effect of U-236 was included to maintain the conservative nature of the requirements. The ore grade and milling ef ficiency were reduced from previous l
values of 0.2 percent and 100 percent, respectively, to reflect expected average conditions over the next twenty years. AIF/NESP-032 also utilized the updated ORIGEN 2 code to determine the isotopics of the back-end of the fuel cycle.
L The principal reason for the difference in the Table S-3,33,000 MWD /MT values and the NESP,33,000 MWD /MT column in Table 1, is not due to extended burnup but due to the reduction in ore grade (from 0.2 percent to 0.1 percent) assumed in AIF/NESP-032.
(5300 BAT /lah)
A review of each category of effluents in Table 1 is briefly discussed in the following paragraphs.
The effects of extended burnup on the environmental impact of land use, as shown in Table 1, are that the impacts decrease with increasing burnup. This is to be expected since the land use attributed to the nuclear fuel cycle is predominantly due to the mining of ore, and since ore requirements decrease with increasing burnup, the land impacts decrease with increasing burnup.
1 The use of water and fossil fuel decreases with increasing burnup to 50,000 4WD/MT and then increases with additional increases in burnup. At 60,000 MWD /MT, the fossil fuel use is similar to that at 33,000 MWD /MT. As burnup increases, the enrichment requirements increase. But because the separative work requirements increase logarithmically with enrichment level, the benefits of increased fuel utilization above 33,000 MWD /MT begin to be offset at burnups which exceed 50,000 MWD /MT. Chemical effluents behave in a manner similar to that for fossil fuel use because most of the chemical effluents are due to the combustion of fossil fuels.
Radiological effluents for natural radionuclides releases associated with the front end of the fuel cycle decrease with increasing burnup. This is primarily due to a reduction in ore and yellowcake requirements as burnup increases.
The release of relatively short-lived fission products from the back end of the fuel cycle decreases with increasing burnup. This occurs because the inventory of these radionuclides per metric ton of spent fuel is at equilibrium and does not increase with increasing burnup, while the number of metric tons of fuel discharged per referenced reactor year decreases in direct proportion to increases in fuel burnup.
The release of relatively long-lived radionuclides is essentially independent of burnup.
This occurs because at higher burnup the increase in radionuclides inventory per metric ton of spent fuelis offset by the reduction in the number of metric tons of discharge fuel per reference reactor year.
1 The radiation exposure models conservatively assume the radiation field is already at the i
regulatory limit for most instances. Extended burnup would not change the regulatory limits but would affect the exposure time. To a first order approximation, the exposure time would be proportional to shipment miles. Hence, the extended burnup radiation dose to workers and the general public would decrease slightly with increased burnup.
Likewise, extended burnup decreases the fuel throughput per reactor year at the reprocessing plant and proportionally occupational worker exposure time per reactor year.
A comparison of transportation impacts currently provided in Table S-4 of 10CFR51 with those for extended burnup shown in Table 2 reveals that the impacts either remain the same or decrease slightly. The controlling factor for this pattern is the reduced number of shipments required in support of extended burnup.
Table 3 presents the 100-year environmental dose commitment for radionuclides releases from the fuel cycle. The results from AIF/NESP-032 reveal that the environmental dose commitment (EDC) decreases with increasing burnup. The table shows that the EDC calculated by NESP is approximately 20% greater than that calculated by NRC for l
33,000 MWD /MT. The main dif ferences are due to increases in the EDC per curie released for the liquid release of radium-226 (Ra-226) and for the gaseous release of tritium (H-3). These increases are the result of improvements which have been made to (5300 BAT /lah) l l
3
the RABGAD (NUREG-0002) and LADTAP (NUREG/CR-1276) codes since the original NRC analyses were made. Increases in Rn-222 were due to differences in assumptions used by NESP as previously discussed.
It is concluded that when these differences in assumptions are taken into account, along with the numerous conservatism inherent in the analyses, the current NRC Staff assessment of the EDCs is considered applicable to the nuclear fuel cycle required to support higher burnup. These EDCs are vanishingly small compared to exposures due to natural background radiation.
CONCLUSION When dif ferences in assumptions are taken into account, extending fuel burnup results in environmental consequences which are either less than or virtually the same as those evaluated in 10CFR51 by the NRC. The NRC evaluation is, therefore, considered applicable to the nuclear fuel cycle required to support Carolina Power & Light's proposal to extend fuel burnup up to 60,000 MWD /MTU. Based on this evaluation, it is concluded that no unreviewed environmental question exists.
l l
I (53OOBAT/leh) j
(