ML20055D399
| ML20055D399 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 06/25/1990 |
| From: | Devincentis J YANKEE ATOMIC ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20055D400 | List: |
| References | |
| BYR-90-88, PC-235, NUDOCS 9007060267 | |
| Download: ML20055D399 (3) | |
Text
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YANKEEATOMIC ELECTRIC COMPANY
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580 Main Street, Bolton, Massachusetts 01740-1398 3v.
June 25, 1990 BYR 90-88 PC-235 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555
Reference:
(a)
License No. DPR-3 (Docket No. 50-29) 3 i
Subject:
Changes in Safety Injection Tank Minimum Water Inventory j
1
Dear Sir:
}
Pursuant to Section 50.90 of the Commission's Rules and Regulations, the j
Yankee Atomic Electric Company I.ereby requests authorization to make the j
following changes, i
Proposed Change Reference is made to the Technical Specifications of the Yankee Nuclear-Power Station's (YNPS's) Operating License No. DPR-3.
We hereby propose to simplify Technical Specifications by specifying only the_ tank level and-J deleting the redundant gallons values for the-Safety Injection Tank (SIT).
Also, the " Bases" for Section 3/4.5.4 will be revised to show that the SIT reserve is increased from 40,000 gallons to_52,000 gallons. This is based on i
the new and larger SIT.
It has.no impact on Yankee's accident analyses, and is only administrative in nature.
-Reason and Basis for Change The three limiting conditions for operation being revised provide both'a Lvolume of water and a tank level. These two parameters are redundant. All monitoring of the volume.of water in the tank is done b) tank level. The applicable action statements are entered based on the tank level, and not the number of gallons in the tank.
Since the gallon figure is redundant and is not directly monitored, it is being deleted. Fhintaining the tank at or above the specified level ensures the required gallons of water are available.
hf 9007060267 900625 O
f PDR ADOCK 05000029
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A Uqlted States Nuclear Regulatory Commission-June 25, 1990 Attention: Document Control Desk-Page 2 The YNPS is installing a new stainless steel safety injection water storage tank to replace the existing aluminum tank. The configuration of the two tanks are different. The existing tank holds 125,000 gallons of borated water in a 30' diameter cylinder with radiused heads and is mounted above grade by support legs. The new tank will store 159,000 gallons in a 30' l
diameter cylinder with a flat bottom built on grade.
To maintain the system Net Positive Suction Head (NPSH) equivalent or better with the new tank, the current working water elevations will be duplicated in the new tank. The minimum level in the new tank will remain at 25.5'.
The usable water volume of the new tank is increased because of the straight cylinder and flat-bottom construction being built on grade.
The l
existing tank has 117,000 usable gallons at 25.5', measured f rom the tottom of l
the tank, the new tank will contain 129,000 usable gallons at 25.5', measured from the top of the suction nozzle.
The Technical Specification " Bases" for Section 3/4.5.4 states that the injection of 77,000 gallons is sufficient to limit core temperatures and containment pressure for the full spectrum of pipe ruptures in the LOCA analysis. The existing tank then allows for up to 40,000 gallons in the SIT-as reserve. The new tank will provide 52,000 gallons as reserve. The word
" level" is being substituted for " volume" to show gallonage relationship.
Safety Considerations This change is requested in order to delete the redundant water volume requirements in Sections 3.1.2.10, 3.1.2.11, 3.5.4, and to increase the reserve water volume in " Bases" 3./4.5.4 of the YNPS Technical i
Specifications.
Both changes are administrative. As such, this proposed i
change would not:
1 1.
Involve a significant increase in the probability or consequences of an accident previously evaluated.
The replacement SIT will provide equivalent or better KPSH to the safety injection pumps for all operating i
conditions.
It will also provide an increased water inventory for accident mitigation. The replacement tank will have no affect on the probability or the consequences of any accident previously evaluated.
2.
' Create the possibility of a new or dif ferent kind of accident from any previously evaluated. This changt upgrades the minimum water volume of the safety injection water storage tank while maintaining the available NPSH to the pumps equal to or better than the existing tank. The new tank and founda: ion was load designed for the larger water inventory.
This replacement tank will therefore not create the possibility of a new or different kind of accident from any previously evaluated.
3.
Involve a significant reduction in a margin of safety.
The change in minimum water volume from 117,000 to 129.000 gallons increases the reserve volume after 77,000 gallons required by accident analyses have been injected. The current tank leaves 40,000 gallons, while the new tank will provide 52,000 gallons of reserve water.
This increased water volume increases the margin of safety provided by the tank.
United States Nuclear Regulatory Commission June 25, 1990 Attention:
Document Controi Desk Page 3 Based on the discussion above, it is concluded that there is reasonable assurance that operation of the Yankee plant, consistent with the proposed Technical Specifications, will not endanger the health and safety of the public. This proposed change has been reviewed by the Nuclear Safety Audit and Review Committee.
We trust that you will-find this submittal satisfactory; however, should you desire additional information, please contact us.
Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY J. DeVincentis Vice President
.JD/tlp/WPP79/37
-Attachment cc USNRC Region I USNRC Resident Inspector, YNPS C0ttl0NWEALTH OF MASSACliUSETTS)
)ss l
WORCESTER COUNTY'
)
i Then personally appeared before me, J. DeVincentis, who, being duly i
sworn, did state that he is Vice. President of Yankee Atomic Electric Company, that he is duly authorized to execute and file the foregoing document 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.
Webisv {$. AlammtareJ~
Helen D. Sammarco Notary Public My Commission Expires November 7, 1991
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