ML20002A469
| ML20002A469 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 09/14/1973 |
| From: | Johnson W YANKEE ATOMIC ELECTRIC CO. |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8011170291 | |
| Download: ML20002A469 (4) | |
Text
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Wr:pasasTcilmga Wo. 388 I- ? MIC' FL fM Tel:phona 617 366-90tt TwX 710 390-0739 YANKEE ATOMIC ELECTRIC COMPANY 20 Turnpske Road Westborough, Massachusetts 01581 Y
, ~AN KEE September 14, 1973 AM_..,
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i United States Atomic Energy Commission
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u Attention: Directorate of Licensing
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Reference:
License No. DPR-3 (Docket No. 50-29) s _i..W
Dear Sir:
Pursuant to Section 50-59 of the Commission's regulations, Yankee Atomic Electric Company hereby requests to make the following change:
PROPOSED CHANGE: Reference is made to the description of the Emergency Core Cooling System in Yankee Atomic Electric Company Change number 97 and in particular to the description of the initiating circuitry in Attachment B of Supplement #3, Change #97. We propose the following:
To provide vapor container overpressure signals to the WL relays in parallel with the existing main coolant pressure and pressurizer pressure signals in order to provide a diverse method of emergency core cooling system initiation.
REASON FOR CHANGE: This proposed change is the result of a study undertaken by Yankee Atomic Electric Company to determine an additional method of initiatir.g the emergency core cooling system. The study was proposed in our letter dated March 30, 1972 and confirned by your approval to Change #97, dated April 14, 1972.
DESCRIPTION OF CHANGE: Diverse initiation of the emergency core cooling system will be accomplished by providing vapor container over-pressure signals to the WL relays in parallel with the existing main coolant and pressurizer pressure signals. Two pressure switches will be mounted in the primary auxiliary building. One switch, designated PS-238, will sense the vapor container pressure via the open bulb system and be electrically connected to trip WL 1-1.
The other pressure switch, designated PS-239, will use the vapor container closed bulb system piping to sense vapor container over pressure and will be icctrically connected to trip WL-1.
The closed bulb system will be
,.t.. < vented to the vapor container pressure. Use of the closed bulb system
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United States Atomic Ensrgy Commission _
September 14, 1973 Attn: ' Directorate of Licensing Page Two (which is isolated from service at the present time) does not constitute a reduction in the containment leak rate monitoring capability, as the absolute method of containment leak rate monitoring is used.
SAFETY CONSIDERATIONS: Within the capability of the existing installation-this change will meet the requirement of the IEEE 279 criteria, in that (1) the switches are on separate taps and are physically separated, p
(2) they have been environmentally and seismically qualified, (3) the wiring is physically separated, and (4) the switches are connected to
-existing circuits that are on separate battery supplies as shown on the attached figures.
over0.14ft.gasbeenconductedwhichindicatesthatforeverybreak I
A study
, the new signal will provide a more rapid actuation 4
signal thereby providing protection which is equal to or better than thatprovidedinthepregentsignalinitiatingsystem. For break l
si:es less than 0.14 ft., the current low pressuri:er pressure signal i
is the first to be initiated. However, the analysis shows that this will not result in increased peak clad temperatures above those_ presented in Change 97.
The Nuclear Safety Audit and Review Committee.has concluded that there are no unreviewed safety considerations relative to this Proposed Change.
SCEEDULE OF CHANGE: This change will'be implemented during the next regularly scheduled refueling period.
We trust you will find the above information' satisfactory Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY
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/ u'n ityPdC7L-Wende o)n)on Assistant Vigg President EWJ/kg 3
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COUNTY OF WORCESTER
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Then personally appeared before me,-Wendell~P. Johnson, whe. being duly sworn did state that he is Assistant Vice President of-Yankee Atomic Electric Company,_that he is duly authori:cd to execute and file the foregoing request in the name and on the behalf of Yankee Atomic Electric Cog any, and that the statements therein are true to the best of his knowledge and belief.
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/Armand R. Soucy Notary Public My Commission Expires' September 9, 1977
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SAFETY INJECTION WL1 TRIP CIRCUIT FIGURE 3 i
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Westinghouse Style 293B255A20 125 V DC, Contact Ratings: Single 2.4A, 2 IN Series 20A.
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Barksdale Type B2T-M32SS Differential IS-34 PSI Range 0 to 3000 PSI
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' SAFETY INJECTION WL1-1 TRIP CIRCUIT FIGURE 4 I
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