ML20237C593
| ML20237C593 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 12/11/1987 |
| From: | Wigginton D Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20237C595 | List: |
| References | |
| NUDOCS 8712220015 | |
| Download: ML20237C593 (3) | |
Text
a N
\\
(
.i 7590-01 UNITED STATES NUCLEAR REGULATORY COMMISSION NORTHERNSTATES_POWERCOMPANh' DOCKET N0.,50-263 ENVIRONMENTAL ~ ASSESSMENT AND FINDING 0F
,N0 SIGNIFICANT IMPACT The U. S. Nucleer T<egulatory Commission (the Conrnission) is issuing an exemption from'the requirements of 10 CFR 50.62(c)(4), to Northern States Power Company (the licensee), for the Monticello Nuclear Generating Plant, located l'n Wright County, Minnesota.
ENVIRONMENTAL ASS _ESSMENT Identification of Proposed Action: The exemption allows the use of a minimum flow rate of 26 GPM and the available sodium pentaborate concen-tration ranging from 13 weight percent (w/o) to 18 w/o. depending on the volume of solution existing in the standby liquid control system (SLCS) storage tank. The flow rate and concentration of sodium pentaborate are different from existing requirements of 10 CFR 50.62(c)(4) consisting of a flow rate of 86 GPM and a concentration of 13.0 w/o of sodium pentaborate.
The exemption responds to the licensee's application for exemption i
dated August 18, 1987.
l The heed for,the Proposed Action:
The exemption ir needed because the licensee proposes to depart from 10 CFR 50.62(c)(4) requirements in view of the Monticello Nuclear Generating Plant having a reactor vessel diameter which is smaller than that used to establish the minimum flow and boron content requirements set forth in the regulation.
For the Monticello reactor size, a lesser flow rate and different ranges in the concentration of 8712220015 871211
$DR ADOCK 050gg3
2 sodium pentaborate solution will provide a negative reactivity injection in an anticipated transient without scram (ATWS) event equivalent to that called for_by the regulation.
Environmental Impacts of the Proposed Action: The exemption provides a degree of protection for the Monticello reactor equivalent to that requircd by *.e regulation for reactors with larger reactor vessels for prompt injection of negative reactivity into e boiling water reactor pressure vessel in the event of an ATWS.
Consequently, the probability of accidents has not been increased by the exemption and the post-accident radiological q
releases would not be greater than previously determined.
The exemption does not otherwise affect radiological plant effluents. Therefore, the Comission concludes that there are no significant radiological environmental impacts associated with this exemption.
The exemption does not affect nonradiological plant effluents and has no other environmental impact. Therefore, the Comission concludes that there are no significant nonradiological environmental impacts associated with the exemption.
Alternatives to the Proposed Action: Since the Comission has concluded that there are no significant environmental effects that would result f rom the action, any alternatives with equal or greater environmental impacts need not be evaluated.
The principal alternative would be to deny the reouested exemption.
This would not reduce the environmental impacts attributable to this I
facility and would result in a larger expenditure of licensee resources to comply with the Commission's regulations.
l r
, Alternative Use of Resources: This action involves no use of resources not previously considered in the Final Environmental Statement related to operation of the Monticello Plant, dated November 1972.
Agencies and Persons Consulted: The Commission's staff reviewed the licensee's request and did not consult other agencies or persons.
FINDING OF NO SIGNIFICANT IMPACT Based upon the foregoing environmental assessment, we co.1clude that I
the action will not have a significant effect on the quality of the human environment. The Commission has, therefore, determined not to prepare an environmental impact statement for the exemption.
For further details with respect to this action, see the application for the exemption dated August 18, 1987 which is available for public inspection at the Commission's Public Document Room, 1717 H Street, N.V.,
Washington, D.C., and at the Environmental Conservation Library, Minneapolis Public Library, 300 Nicollet Mall, Minneapolis, Minnesota.
Dated at Bethesda, Maryland this lith day of December 1987.
FOR THE NUCLEAR REGULATORY COMMISSION David L. Wigginton, Acting Director Project Directorate III-3 Division of Reactor Projects Office cf Nuclear Reector Regulation
-