ML20127L550

Notice of Granting Exemption from Requirements of General Design Criterion 50, Containment Design Basis, of App a to 10CFR50

ML20127L550
Person / Time
Site:	Monticello
Issue date:	03/22/1978
From:	Lear G Office of Nuclear Reactor Regulation
To:
Shared Package
ML20127J760	List: ML20127J757 ML20127L550
References
NUDOCS 9211240375
Download: ML20127L550 (3)

Text

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. . . . (1 J UNITED STATES NUCLEAR REGULATORY COMMISSION DOCKET NO. 50-263 NORTHERN STATES POWER COMPANY NOTICE OF GRANTING AN EXEMPTION FROM THE REQUIREMENTS OF GENERAL DESIGN CRITERION 50,

" CONTAINMENT DESIGN BASIS", OF APPENDIX A TO 10 CFR PART 50 The U.S. Nuclear Regulatory Commission (The Commission) has granted an exemption from the requirements of General Design Criterion 50, "Contain-ment Design Basis", of Appendix A to 10 CFR Part 50 to Northern States Power Company (the Licensee). This exenption relates to the demon-strated safety margin of the Mark I containment system for Monticello Nuclear Generating Plant for recently identified hydrodynamic supopression pool loads associated with a postulated design basis loss of coolant accident and provides for operation under the conditions specified in the NRC staff's " Mark 1 Containment Short Term Program Safety Evaluation Report" and under any resulting Technical Spec-ification requirenents. To this extent, this exemption encompasses any related requirements of 10 CFR Part 50, Section 50.55(a), and General Design Criterion 1. This exemption is effective as of the date of its issuance.

The Commission has evaluated the demonstrated safety margin of the con-tainment system for the Monticello Nuclear Generating Plant under present i

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conditions and has concluded that sufficient margin exists to preclude:

4 undue risk to the health and safety of the public. This evaluation _

! is documented in the staff's " Mark I Containment Short Term Program i

j Safety Evaluation Report," NUREG-0408, December 1977.

l This exemption is granted for an interim period of approximately two years i

i while a more detailed review is conducted. At the conclusion of this re-view, the design safety nargin of the containment system for the Monticello Nuclear Generating Plant will be restored to that which was originally intended

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at the time Monticello Nuclear Generating Plant was licensed for operation. .

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The-basis for this exemption is set forth in the letter to the licensee granting i

! the exemption, dated February 28, 1978.

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! The Commission has detemined that the granting of this exemption will not i

i result in any significant environmental impact and that pursuant to 10 CFR g Section 51.5(d)(4) an environnental impact statement or negative declara-tion and environmental impact appraisal need not be prepared in connection l .

l-with this action.

! For'further details with respect to- this action, see (l) the Commission's i .

l -letter to the licensee dated February 28, 1978, and (2) the Commission's:

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"tiark I Containment Short Term Progran Safety Evaluation Report," NUREG-0408, December 1977.

These items are available for public inspection at the Commission's Public Document Room,1717 H Street, N.W. , Washington, D. C. and at the Environmental Conservation Library, Minneapolis Public Library, 300 Nicollet Mall, Minneapolis, Minnesota 55401. A copy of item (1) may be obtained upon request addressed to the U. S. Nuclear Regulatory Commission, Washington, D.C. 20555, Attention: Director, Division of Operating Reactors. A copy of item (2) may be obtained upon request addressed to the National Technical Information Service, Springfield, Virginia 22161.

Dated at Bethesda, Marylano tSis 22nd day of March 1978.

~0R THE NUCLEAR REGULATORY COMMISSION A,

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George Lear, Chief Operating Reactors Branch #3 Division of Operating Reactors