ML19339A397
| ML19339A397 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 05/12/1972 |
| From: | Skovholt D US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Vandenburgh D YANKEE ATOMIC ELECTRIC CO. |
| References | |
| NUDOCS 8011030758 | |
| Download: ML19339A397 (2) | |
Text
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. Distribution WDooly, DR Compliance (3) fdAY 121972 HShapar, OGC L
NDube, DL (5) 1 JRBuchanan, ORNL
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Docket No. 50-29 TWLaughlin, DTIE u
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DL Reading
.1 Branch Reading Yankee Atomic Electric Company ACRS (16)
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ATTN:
Mr. Donald E. Vandenburgh DJSkovholt, DL 4
Vice President TJCarter, DL
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20 Turnpike Road RJSchemel, DL A
Westboro, Massachusetts 01581 ABurger, DL (cont, p 2) y Change No. 99 6
Gentlemen:
License No. DPR-3 T4 This refers to your Proposed Change No. 99 dated May 9, 1972, and supple-4' mental information contained in two teletypes dated May 10 and 11, 1972,
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respectively, requesting authorization of a change in the Technical Specifications appended to License No. DPR-3 for the Yankee reactor.
$i The proposed change would modify the specification relating te, the j,
boron concentration in the reactor coolant.
y The information you have submitted indicates that the presently specified 3
main coolant system boron concentration imposes operational restrictions g
that prevent operating the plant above 15 m'e.
This is the result of
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4 the previously revised limits on control rod withdrawal which are necessary to meet the increased shutdown margin specified in Change g
._s No. 97.
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You have determined that a reactor coalant boron concentration above the presently specified value of 1700 ppm is necessary to compensate for the effect of the additional control rod withdrawal.
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You propose irplicit limits on the boron concentration in terms of specified values 1
4, of the moderator temperature coefficient.
During Core X physics testing, f-you will determine the boron concentration in terms of values in ppm corresponding to measured values of the moderator temperature coefficient.
4 You will use this information for controlling operational changes in the boron concentration within the specified values of the moderator y
['4 temperature coefficient.
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Ue have reviewed the information you have submitted on your evaluation of the safety considerations associated with the change in the reactor k
ti coolant boron concentration, including the effects on accidentsanalyzed X
previously.
Increase of boron in the reactor ecolant would affect the 4
consequences of only the boron dilution accident assumed to occur when
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the reactor is at full power. Your reanalysis of this accident in
@r support of Proposed Change No. 99 shows that the added boron causes
!R a snall increase in the rate of reactivity addition.during the accident Q
@h that results in an increase of the DNB ratio for operation with 4 loops and a decrease of the DNB ratio from 1.94 to 1.92 for operation with 3 loops. We conclude that thia decrease is not significant compared 4
with the required minimum DNB ratio of 1.3.
We have also concluded Q
that the boron concentration can be controlled within the proposed q'M values of the rc,derator tenperature coefficient, and that these r
values are acceptable.
Consequently, we have concluded that the a
proposed enange does not present significant hazards considerations not described or implicit in the Final Safety Analysis Report, and d
that the health and safety of the public will not be endangered by operation of the Yankee reactor in the nanner proposed.
g Accordingly, pursuant to Section 50.59 of 10 CUR Part 50, subparagraph ipM t f.
(6) of Section D.2.d of the Technical Specifications of Facility Licunse Uo. DPR-3 is hereby changed in its entirety to read:
M "D. 2. d (6) At zero power, except during physics testing, the T?
moderator temperature coefficient shall not be 3
positive. At rated steady state power, the
- h. A moderator temperature' coefficient shall be core negative than -0.5 x 10-4 A k/k per *F."
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>4 Sincerely, h
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Donald J. Skovholt Assistant Director for Operating Reactors Directorate of Licensing 4Q cc.
C. Duane Blinn, Esquire Day, Berry 611oward Dis tribution (cont.)
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Counselors at Law RBoyd, DL 3
1 Constitution Plaza RDeYoun,g, DL 2
Ilartferd, Connecticut 06103
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