ML19296D241
| ML19296D241 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 02/13/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19296D239 | List: |
| References | |
| NUDOCS 8003030063 | |
| Download: ML19296D241 (2) | |
Text
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NUCLEAR REGULATORY COMMISSION
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,o ENVIRONMENTAL IMPACT APPRAISAL BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT N0.
TO PROVISIONAL OPERATING LICENSE NO. DPR-22 MONTICELLO NUCLEAR GENERATING PLANT NORTHERN STATES POWER COMPANY DOCKET NO. 50-263 Description of Prooosed Action By letter dated September 17, 1979, Northern States Power Company proposed an amendment to the Technical Specifications for the Monticello Nuclear Generating Plant revising the MCPR and MAPLHGR limits to permit extended operation of eight fuel assemblies from 40,000 to 50,000 MWD /T, The licensee stated that the fuel assemblies to be operationally ef tended were first inserted in the Monticello plant at the beginning of the third cycle in 1974.
These assemblies include, the three highest 8 x 8 fuel assemblies and five lower exposure assemblies from the same reload batch.
These eight bundles will be operated throughout cycle 8 in symmetrically loaded locations.
Fol-lewing cycle 8, the integrity of the extended exposure fuel bundles will be again ascertained and two of the highest exposure bundles and two of the lower exposure bundles reinserted for cycle 9 All four bundles will exceed 40,000 MWD /T peak pellet exposure during cyc.e 9 with the highest exposure bundles approaching 50,000 MWD /T.
The licensee stated that adequate assurances exist to ensure that no significant hazard will be presented to the public health and safety in the performance of extended burnup program.
Mechanical failure of fuel rcds in the core, if any, will be detected by reactor offgas readings prior to the extended turnup pro-gram outage.
If there is evidence of failed duel rods in the core, the extended burnup bundles will be sipped for' fission product release as part of the total sipping program.
There snall be no fuel bundle abnce alities which could reasonably be expectec to cause mechanical failure durin; the subsequent cycle of operation.
Fuel bundle dimensional changes, due all or in part to irradiation growth, should r.ct exceed soecified limits which are compatible with initial bundle design criteria.
Environmental Imoacts of Prcoosed Action The NRC has evaluated the pctential environmantal impact associated with operation of the Monticello plant in the exteaded burnup program as required by NEPA and paragraph 51.7 of 10 CFR Part 51.
This evaluation is concerned with the irradiation of eight fuel assemblies in the eighth cycle and four fuel assemblies in the nintn cycle to extended burnuos up to about 50,000 MWD /,T.
8003030Q Q
' We have reviewed the Final Environmental Statement (FES) dated November 1972, related to the operation of the Monticello nuclear generating plant.
Irradi-ating spent Monticello fuel to extended burnups during cycle 8 and 9 will increase the amount of long-lived fission products in the core.
The only significant long-lived radionuclide with respect to potential consequences of the postulated design basis accidents is the noble gas Krypton 85.
Extending burnups of the core up to about 44,000 MWD /T will not increase the amount of Kr-85 which was assumed in the fuel at Monticello for the postulated design basis accident.
The increase in the amount of Kr-85 in the eight fuel assemblies from 44,000 MWD /T up to 50,000 MWD /T is not significant compared to the total amount of fission product noble gases in the fuel.
Therefore, the environmental impacts of the postulated accidents given in Chapter VI of the FES will not significantly change because eight fuel assemblies in the core are irradiated to burnups up to 50,000 MWD /T.
Operating Monticello with eight extended burnup fuel assemblies may increase the concentration of activity in the primary coolant and the amount'of activity released from the plant as compared to operating the plant during previous cyclu due to potentially more fuel cladding failures.
We would not expect this increase to be significant because (1) only eight fuel assemblies in the core (1.65%) will be irradiated to the extended burnups; (2) the licensee has stated that the eight fuel assemblies will be examined prior to their insertion in the core for cycle 8 and will irradiate them after these assemblies have demonstrated satisfactory fuel performance in the previous cycle, (3) the Technical Specifications impose reactor coolant and steam air ejector radio-activity limits in the event of fuel failures to limit fission product release, and (4) the augmented offgas system operates with about a 500 hour0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> holdup time to provide adequate noble gas decay time so that the release rate of these gases will be within the permissible stack release rate.
Conclusion and Basis for Necative Declaration On the basis of the NRC evaluation' and information supplied by the licensee, it is concluded that there will be no environmental impact attributable to the proposed action other than has already been predicted and described in the Commission's FES for Monticello.
Having Reached these conclusions, the Coninission has determined that an environmental impact statement need not be prepared for the proposed license amendment and that a Negative Declaration to that effect should be issued.
Dated:
February 12, 1980