ML20126A305
| ML20126A305 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 12/08/1992 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20126A303 | List: |
| References | |
| NUDOCS 9212180139 | |
| Download: ML20126A305 (3) | |
Text
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UNITED STAT [s 8,
NUCLE AR REGULATORY COMMISSION r
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SAFETY EVALVATION BY THE OfflCE Of NVCLEAR REACTOR REGULATION ELATED TO AMENDMU{LI{p.176 10 FACILITY OPERATING LICENSE NO. NPF-3 TOLEDO EDE DN COMPANY CENTER 10R $1Ryl(LCOMPANY MD Tf]E CLEVEibND [lLCIMC_lLU)}DNATINGJ0MPANY DAVIS-BESSE NVCLEAB_E0EUL1TATION. UNIT NO.1 DQ[KET NO. 50-346 1.0,1NTRODUCT10N Bj letter dated May 1,1992, Toledo Edison Company (the licensee) propose.' an amendnient to the Technical Specifications for the Davis-Besse Nuclear Power Station, Unit 1 (DBNPS).
The proposed charge involves Technical S (TS) 3/4.1.1.2, " Reactivity Control Systems-Boron Dilution," and i.pecification ts Bases.
The change would allow the addition of water of lower boron concentration than the reactor coolant system (RCS) in Mode 6 (refueling) with the RCS flow rate less than 2800 gpm, provided that the boron concentratic., of the water to be added is greater than the boron concentration corresponding to the more re-strictive reactivity condition specified in TS 3.9.1, " Refueling Operations -
Boron Concentration."
2.0 [YALVATION Technical Specification 3.1.1.2 requires that the flow rate of reactor coolant through the RCS be greater than or equal to 2800 gpm whenever a reduction in RCS boron concentration is being made. This minimum flow rate provides adequate mixing, prevents stratification, and ensures that reactivity changes will be gradual in the RCS.
Maintenance activities during refueling may require that the RCS level be l
reduced.
When this occurs, procedural limits are placed on the maximum decay heat removal (DHR) flow rate to prevent vortexing and pump cavitation.
The proposed change to TS 3.1.1.2 would result in less burden to the o)erators and l
greater flexibility in the choice of water addition sources with tie DHR flow rate procedurally restricted to less than 2800 gpm. Without the proposed change, the boric acid addition tank is used to raise RCS level until it is high enough such that the DHR flow rate can be increased above 2800 gpm and then the desired water sources (e.g., borated water storage tank or a clean 9212100139 921200 PDR ADOCK 00000346 P.
waste receiver tank) can be used for any necessary water addition.
The proposed change eliminates the step of having to increase the RCS level using the boric acid addition tank.
Technical Specificat'on 3.9.1 requires a boron concentration such that the more restrictive of the following reactivity conditions is met:
- 1. Either a K-effective of 0.95 or less, which includes a 1% delta K/X conservative allowance for uncertainties, or
- 2. A boron concentration of greater than or equal to 1800 ppm, nich includes a 50 ppm :onservative allowance for uncertainties.
If the RCS meets these reactivity condition requirements, and water is added to the RCS that also meets these reactivity condition requirements, then the RCS is assured to remain in compliance with the reactivity condition requirements.
The possibility that the added water may be of lower boron i
concentration than the RCS is, therefore, of no adverse consequence to safety.
The NRC staff has reviewed the licensee's application and based on the above finds that the proposed change to the water addition boron concentration requirements is acceptable.
Therefore, the amendment is approved.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Ohio State official was notified of the proposed issuance of the amendment.
The State official had no i
comments.
4.0 ENVIRONMENTAL CONSIDERATIp))
This amendment changes a requirement with respect to installation or use of a facility com)onent located within the restricted area as defined in 10 CFR Part 20 or c;1anges a surveillance requirement. The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding.
(51 FR 40222). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental im)act statement or environmental assessment need be prepared in connection wit 1 the issuance of the amendment.
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5.0 (ONCLUSION The staff has concluded, based on the considerations discussed above, thatt (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the pro >osed manner, (2) such activities will be conducted in compliance wit 1 the Commission's regulations, and (3) the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
J. Hopkins Date: Decemler 8,1992 lf/
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