ML20125D571

Informs of Change 11 to License DPR-11,permitting Reactor Cooling Rates in Excess of 200 F/Hr During Initial Reactor Tests When Reactor Superheater Drained

ML20125D571
Person / Time
Site:	05000130
Issue date:	05/10/1966
From:	Doan R US ATOMIC ENERGY COMMISSION (AEC)
To:	Mcelroy D NORTHERN STATES POWER CO.
Shared Package
ML20125A538	List: ML20125D123 ML20125D151 ML20125D175 ML20125D208 ML20125D224 ML20125D241 ML20125D271 ML20125D310 ML20125D324 ML20125D333 ML20125D352 ML20125D364 ML20125D385 ML20125D404 ML20125D418 ML20125D526 ML20125D534 ML20125D541 ML20125D545 ML20125D551 ML20125D554 ML20125D559 ML20125D561 ML20125D563 ML20125D567 ML20125D571 ML20125D582 ML20125D587 ML20125D595 ML20125D618 ML20125D671 ML20125D691 ML20125D706 ML20125D718 ML20125D736 ML20125D760 ML20125D771 ML20125D787 ML20125D800
References
FOIA-85-54 NUDOCS 8506120407
Download: ML20125D571 (3)

Text

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$ rL , p,d EN,g 8,

UNITED STATES ATOMIC ENERGY COMMISSION g Ft.E C0FT

( WASHINGTON, D.C. 20545 p /f 1

Docket No. 50-130 -

l pk EAY101E l I Northern States Power Company ' '

414 Micollet Avenue  ; ',A Minneapolis, Minnesota 55401 Attention: Mr. David F. McElroy Change No. 11 Vice President, Engineering Gentlemen:

This refers to your request dated May 3,1966, for authorisation of a change in the Technical Specifications of Provisional Opera-ting License No. Upt-11 pursuant to tlee provisions of section 50.59 of the Coenission's regulations. The request would permit Pathfinder reactor cooling rates in excess of 200*F/hr during initial reactor tests when the reactor's superheater is drained.

/ This change has been requested because certain of the initial tests with the reactor will result in cooling rates in excess of the present limit.

We have concluded that Change No. 11, as set forth below, does not present significant hasards considerations not described or implicit *

. in the Final Nasards Summary Report, and' that there is reasonable I assurance that the health and safety of the public will not be I endangered. A copy of our related safety evaluation is enclosed.

In view of the foregoing, the Technical Specifications of License No. Dpt-11 (Appendix A) are hereby changed to add the following paragraph to Section 8.0.

"During testing of the emergency condenser and during l initial power escalation up to 40 percent power, and l_

with the superheater drained, the controlled cooling rate of the reactor may enceed 200'F/hr under either of the following conditions:

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Northern States Power Company -2* lpK 10 %$6 j (a) A temperature reduction not to exceed 50*F may ,

occur at higher rates during any half-hour period in which the overall temperature variation does not exceed 100*F, or (b) During performance testing of the emergency condenser, -

cooling at higher rates may occur during a single 20 minute period occurring within any given hour.

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The cooling shall not exceed 80'F during this 20 minute period, and the number of such tests to be performed under this temporary authorisation shall not exceed five."

Sincerely yours, .

OriginalSliMd BI R.LDean I

R. L. Doan, Director Division of Reactor Licensing ,

gnclosure:

ABC gefety Evaluation ,

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planned cooldown rates (and hence induced stresses) during testing to values less than those analysed and would be done with the superheater voided. We have r; viewed the applicants analyses and believe that the higher cooldown rates under .

the proposed change are acceptable. I la view of the foregoing, we believe that the Technical Specifications should be '

changed by adding the following paragraph to Section 8.0.

"During testing of the emergency condenser and during initial power 5 escalation up to 40 percent power, and with the superheater drained. [

the controlled cooling rate of the reactor may exceed 200'F/hr under  !

either of the following conditions: l (a) A temperature reduction not to exceed 50*F may occur at higher rates during any half-hour period in which the overall tempera-ture variation does not exceed 100'F, or  ;

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(b) During performance testing of the emergency condenser, cooling at higher rates may occur during a single 20 minute period occurring within any given hour. The cooling shall not exceed 80'F during this 20 minute period, and the number of such teses to be performed under this temporary authorisation shall not exceed five."

t Conclusion We have concluded that Change No.11 does not present significant hasards consider-ctions not described or implicit in the Final Hasards Suassary Report, and that there is reasonable assurance that the health and safety of the public will not be cadangered.

Odg,r.a! :ip* '

C:5:tS.C','

Roger S. Boyd, Chief Research & Power Reactor Safety Branch Division of Reactor Licensing Dates y;;( , ( ;pg

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