ML19345A568
| ML19345A568 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 03/02/1977 |
| From: | Johnson W YANKEE ATOMIC ELECTRIC CO. |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19345A569 | List: |
| References | |
| WYR-77-24, NUDOCS 8011240208 | |
| Download: ML19345A568 (2) | |
Text
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b, opored Chang 2 No. 148 Tel phone 617 366-9011 TwX 750 390-0739 YANKEE ATOMIC ELECTRIC COMPANY "in -2<
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YANKEG 20 Turnpike Road West'.:arcugh, Massachusetts 015 Mn e
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4 Jegulatory 000ke{ g' March 2,1977 L
8 MAR 7 197/a D United States Nuclear Regulatory Cc= mission DM""84 S
Washington, D. C.
20555 amamen N
Attention: r.ffice of Nuclear Reactor Regulation
Subject:
Extension of YR Technical Specification Burnup Dependent Figures 3.2-1, 3, and 4 to 500 EFFD
'b pocum References (1) License No. DPR-3 (Docket No. 50-29)
/g unac (2) Letter, WYR 77-6, W. P. Johnson, YAEC, to A. Schwencer, USNRC, January 28, 1977.
7 1977> c (3) Proposed Change No. 125, Supplement No. 7, S-u.s moro muwon 5
February 19, 1976.
C "C (4)
Proposed Change No. 142, October 8, 1976.
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(5)
Letter, WYR 76-132, W. P. Johnson, YAEC, to USNRC, December 29, 1976.
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Dear Sir:
Pursuant to Section 50.59 of the Commission's Rules and Regulations, Yankee Atcmic Electric Company hereby proposes the following modifications to the Technical Specifications.
PROPOSED CHANGE:
It is proposed that the attached Figures 3.2-1, 3.2-3, i
and 3.2-4, replace the corresponding figures in the current Technical Specifications.
1 REASON FOR CHANGE: The above figures, na'nely the allowable peak rod linear heat generation rate, xenon multiplier and multiplier for reduced power curves, are all functions of Core XII fuel exposure. Currently, the existing figures are only drawn up to a Core XII fuel exposure of 389 EFPD.
In order to operate within Technical Specification limits beyond 389 EFPD during the power coastdown period, extension of these curves to a Core XII fuel exposure of 500 EFPD becomes necessary.
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SAFETY CONSIgERATIONS: Figure 3.2-1, Allowable Peak Rod Linear Heat Generation Rate versus Core XII Fuel Exposure was extended to 500 EFPD on the basis of the results of LOCA analyses performed for both Exxon and Gulf fuel types at their anticipated exposures at the end-of-core life for Core XII.
The results of these analyses are given in Attachments ?. and B (and also presented in Reference 2). The peak LHGR's were chosen for each fuel type such that maximum achievable power capability during power coast-down can be attained and, as such, the peak LEGR's at 500 EFFD were not y
optimized. Furthermore, the end-of-ccre life LOCA analysis was conducted so n no 2.0 5 P
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Unitcd Stat 0 Nuclecr'ROgulstory Commiscion Nirch 2, 1977 Attn Office of Nuclear Reactor Regulation Prga Two using the limiting break size and type (0.6 DECLG), identified in Reference (4), with YAEC's currently approved LOCA model. In addition, the corre-ponding heatup analyses are based on the results of the "r.6 DECIG blowdown calculation with the return-to-nucleate boiling lockout model reported in Reference (5).
The xenon multiplier and reduced power multiplier curves, (Figures 3.2-3 and 3.2-4) were linearly extrapolated to 500 EFPD.
The curves from 0 to 389 EFPD represent an t.pper envelope of the data (Reference 3) generated by calculating the xenon transient in the operating range of 75 to 90 inches assuming full power oper2 tion. During power coastdown, the neutron flux, power and xenon concentration are gradually being reduced so that rod motion between 75 and 90 inches would create smaller xenon transients. Therefore, under coastdown conditions, the xenon transient would not be as severe as under full power conditions. Based on this, the extension of full power curves to 500 EFPD is clearly conservative.
Based on the results of the Core XII End-of-Core-Life IDCA analysis given in Attachments A and B, and the above discussion it is concluded that Core XII operation with the revised Figures 3.2-1, 3 and 4 in effect will not endanger the health and safety of the public.
This proposed change has been reviewed by the Nuclear Safety Audit and Review Corr.ittee.
SCHEDULE OF CHANGE: Core XII fuel exposure is anticipated to reach 389 EFPD by March 15, 1977. We respectfully request review of this Proposed Change by the Commission as soon ar possible.
Any questions regarding this Proposed Change should be directed to.
Mr. W. J. Szymczak at our Engineering Office, 20 Turnpike Road, Westboro, Massachusetts, (617) 366-9011, Extension 2844.
Respectfully submitted, YANKEE A'IOMIC ELECTRIC COMPANY
/
W. P. Jo son Vice President COMMONWEALTH OF MASSACHUSETIS))ss.
COUNTY OF WORCESTER
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Then personally appeared before me, W. P. Johnson, who being duly sworn did state that he is Vice President of Yankee Atomic Electric Company, that he is duly authorized to execute and file the foregoing request in the name and on the behalf of Yankee Atomic Electric Company, 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 g
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