ML20148S060
| ML20148S060 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 04/11/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20148R802 | List: |
| References | |
| NUDOCS 8804150400 | |
| Download: ML20148S060 (2) | |
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SAFETY EVALUATION BY THF OFFICE OF NUCLEAR REACTOR REGULATTON DEL ATED TO AMENDMENT NO. 80 TO FACILITY OPERATING LICENSE NDF-9 AND AMENDMENT NO. 61. TO FACILITY OPERATING LICENSE NPF-17 DllKE POWER COMPANY COCKET NOS. 50-369 AND 50-370 McGillRE NUCLEAR STATION, UNITS 1 AND 2 INTRODUCTION By letter dated February 5, 1988, Duke Power Company (the licenseel proposed amendments to increase the minimum volume of borated water reouired by McGuire Technical Specifications ITS) 3.1.?.5 and 3.1.9.6 to be maintained in the Rnric Acid Storage System during Modes 5 and 6 and Modes 1, 2, 3 and A, respectively.
[. VALUATION The present PcGuire TS 3.1.0.6, "Reactivity Control Systems-Porated Water Source-Operating," which applies to Modes 1, 2, 3 and 4, specifies as part of its limiting conditions for operation that the Soric Acid Storage Svstem contain a minimum borated water volume of 19,500 gallons. Similarly TS 3.1.2.5 "Reactivitv Control Systems-Borated Vater Source-Shutdown," presently specifies for Modes 5 and 6 a minimum contained borated water volume in this System o' 5100 gallons. As noted in associated TS Bases 3/4.1.?, these values are based on boration capehility requirements to provide a shutdown margin from expected operatino conditions of 1.3% delta k/k after xenon decay and cooldown to ?00 decrees-F (16,3?1 gallers of 7000 ppm borated water), and a shutdown margin of 1% delta k/k afcer xenon decay and cooldown from ?00 degrees-F to la0 degrees-F (2000 callons of 7000 ppm borated water), to ensure that neoative reactivity control is available during each mode of facility operation.
These current technical specifications reflect a minimum usable level (i.e.,
zero percent level) in the Unit 1 and 9 Roric Acid Tanks corresponding to the outlet pipe centerline.
The outlet pipe is nominally 4 inches in diameter with a centerline locatrd 6 inches above the bottom of the tank.
Six inches of uru;able tank level corresponds to approximately 3100 callons of urusable volume.
Therefore, 3100 + ?000 = 5100 gallons and 3100 + 16,321 =
19,421 gallons. This is conservatively rounded up to 19,500 gallons.
The licensee has recentiv discovered that the hichest point for the piping associated with the Rotic Acid Tanks is higher than the piping tap on the tank. The minimum usable level for the Boric Acid Tanks should be at the top of the cutlet pipe, rather than the pine centerline. The new zero percent level of the tank occurs at 8 inches above the bottom of the tank (i.e., at the tcp of the outlet pipe), which corresponds to an unusable volume of about 4132 gallons.
This means that, in order to satisfy the existino 8804150400 000411 PDR ADOCK 05000369 P
p-boration capabilitv requirements, the present minimum values in TS 3.1.7.5 and 3.1.2.6 should be increased.
Specifically, T5 3.1.9.5 should require minimum tank levels of 4132 + ?000 = 6132 gallons, and TS 3.1.7.6 should require 413? + 16,321 = 20,453 gallons.
The NRC staff has reviewed the proposed changes and finds that they appropriately correct the present non-conservative values by substitutina 1
more restrictive (i.e., increased) barated water volumes.
The revised values restore the boration capability to that which will satisfy the originally intended shutdown margins.
Therefore, the sta#f concludes that the changes enhance safety and are acceptable.
ENVIRONMENTAL CONSIDERATION These amendments involve changes to the installation or use of facility com-ponents located within the restricted area as defined in 10 CFR Part 20.
i The staff has datermined that the amendments involve no sianificant increase in the amounts, and no significant change in the types, of any effluents that mov be released offsite ard that there is no significant increase in individual or cumulative occupational exposure.
The NRC staff has made a determination that the arendments involve no significant hazards consideration, and there has been no public comment on such finding. Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.??fc)(9).
i Pursuant to 10 CFR 51.??(b) no environmental impact statement or environmental i
I assessment need be prepared in connection with the issuance of these amendments.
l CONCLilSION The Commission made a proposed determination that the amendments involve no significant hazards consideration which was published in the Federal Register l
) on March 9, 19PA.
The Commission consulted with the state o#
l North Carolina. No public comments were received, and the state of North Carolina did not have anv comments.
l We have concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safetu of the public will not be endangered by operation in the proposed manrer, and (?) such activities will be conducted in compliance with the Commission's regulations, and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
l Principal Contributor:
- 0. Hood, P081'-3 Dated: April 11, 1988 l
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