ML20080C820

Safety Evaluation Supporting Amends 158 & 162 to Licenses DPR-24 & DPR-27,respectively

ML20080C820
Person / Time
Site:	Point Beach
Issue date:	12/12/1994
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20080C818	List: ML20080C815 ML20080C820
References
NUDOCS 9412200206
Download: ML20080C820 (3)

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NUCLEAR REGULATORY COMMISSION -

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s SAFETY EVALUATION BY THE 0FFICE OF NUCLEAR REACTOR' REGULATION o

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ELATED TO AMENDMENT NOS.158 AND 162 TO-FACILITY OPERATING LICENSE NOS.'DPR-24 AND DPR-27 WISCONSIN ELECTRIC POWER COMPANY POINT BEACH NUCLEAR PLANT. UNIT NOS. 1 AND 2 DOCKET NOS. 50-266 AND 50-301-

1.0 INTRODUCTION

By letter dated March 29, 1994, Wisconsin Electric Power Company, the licensee for Point Beach Nuclear. Plant (PBNP), submitted a proposal to change.the Technical Specifications (TS). Specifically, the proposed changes modify

~ TS 15.3.2, " Chemical and Volume Control System," by decreasing the boric acid storage tank (BAST)-boric acid concentration, removing the boric acid system heat tracing and extending the allowed outage time for one of the two charging; pumps,.one of the two boron injection flow paths, or one of the two boric acid transfer pumps from 24 to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

Proposed changes to the associated basis for TS 15.3.2 and the applicable surveillances in Table 15.4.1-2 are also included in the submittal.

2.0 EVALUATION The PBNP concentrated boric acid system consists of three 5000 gallon BASTS and four boric acid transfer pumps (two per unit), along with the associated piping, valves, and heat tracing circuitry. One BAST is normally aligned to each unit and the third BAST can be used as a swing tank and aligned to either unit.

Boric acid, currently with a concentration between 11.5'and 12.5 weight ~

percent (wt%), can be injected into the reactor coolant system with the charging pumps through either the emergency, manual, or boric acid blender flow paths, or with the safety injection (SI) pumps. One 275,000 gallon refueling water storage tank (RWST) per unit is also available, as a source of 2000 ppm boric acid.

Upon an SI actuation, the engineered safety features (ESF) logic opens the valve between the BAST and the suction of the SI pumps, aligning the BAST as the initial suction source of the SI fluid. When the BAST low-low level' setpoint is reached, the suction line-up from the BAST to SI isolates and the suction valves between the RWST and the SI pumps open automatically.

The proposed system changes include lowering the boric acid concentration of the BAST from the current 11.5-12.5 wt% to the values delineated in the new t

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iTable 15.3.2-1,-removing the heat; tracing system, and eliminating the' logic'

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which automatically. opens the valves in the flow path from the BASTS to the.SI'

, pumps on. an. ESF signal..

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The: proposed TS 15.3.2.8.2 and C.2 ensure that two flow paths.and._ associated; Esources.of borated water are available to maintain long' term subcriticality.

If the BASTS are used as the source for,boration, C.ne'has to be sufficient

boron to meet.the range of concentrations'specified in Table 15.3.2-1.

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licensee-has determined, through the use'of the BORDER Boron Design U,

Requirements) methodology, that 300 pounds of stored bor(on<is'sufficientifor-PBNP's annual fuel cycle.

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' The minimum temperature requirement listed:in Table 15.3.2-1 provides:

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protection against boron precipitation. The temperatures specified in the..

1 proposed table represent the solubility temperature plus 5 *F (for boric acid concentrations less than'5 wt%), and.the solubility temperature plus.7.8.*F.

(for. boric acid concentrations greater than or equal to 5 wt%). The 7.8 *F margin corresponds to the present margin for 12.5 wtX boric acid solution.

.l The 5 *F solubility temperature margin was chosen by the licensee, because of I

operational flexibility and the solubility. temperature being nearly equal;to.

the ambient. temperature, i

t The licensee determined that these' changes could have an effect on the l

analysis of the loss of coolant accident (LOCA) and steamline break (SLB) eventsLin the Final Safety Analysis Report-(FSAR).. The licensee re-analyzed i

these two events, accounting for the proposed changes, and determined that the results remain within the acceptance criteria of the accident analyses.

The: licensee also completed an.in-house calculation to verify that, for a typical fuel cycle and assuming worse-case conditions, the reactor can he maintained hot subcritical following a reactor. trip. Specifically, the l

licensee determined that the amount of negative reactivity that can be

.i inserted by one chargin i

as its suction source, g pump, borating at a minimum speed and using the RWST-is greater than the positive reactivity added'from the decay of xenon in the longterm.

The applicable surveillances 4 Table 15.4.1-2 are proposed to be changed by removal of the boric acid heai, f racing operability requirements, and by

. addition of a surveillance to be done, after each boric acid concentration change, during the period that the BASTS are relied upon, as a. source of borated water.

i The licensee proposed an increase in the allowable outage time in TS 15.3.2.D1

for one.of-the two boration flow paths from 24 to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The licensee has, based this change on the design capability of-the boration system to provide sufficient volume through one flow path, meeting the required shutdown margin, xenon-free, from any operating condition. This change is consistent with NUREG-0452, Revision 4, " Standard Technical Specifications for Westinghouse Pressurized Water Reactors" (STS).

The licensee also proposed an increase in the TS 15.3.2.D hot shutdown requirement time from 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, an additional requirement for i

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' boration, as part of the hot shutdown requirement, an increase in the time to restore operability from 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> to.7. days,.and a decrease.in the cold ~-

shutdown requirement from 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> to 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.; These changes are consistent:

with the current staff positions for the proposed ~ system configurations,. and' o

L with the STS.

1 The licensee has, demonstrated that these changes do not adversely affect.the' h

FSAR. accident analyses and that, with the changes, the plant willLstill be L

.able.to mitigate the consequences of accidents and anticipated operational occurrences.

Based on this. demonstration by.the licensee, the' staff-finds

. these changes acceptable. -In addition, the staff-agrees with the licensee, that the proposed changes to the bases-are consistent with, and support the above' changes.

3.0 STATE CONSULTATION

In accordance with the Commission's re was notified of the proposed issuance' gulations, the Wisconsin State ' official of the amendment. The State official had no comments.

4.0 ENVIRONMENTAL CONSIDERATION

This amendment changes a requirement with respect to the installation or use' of a facility component located within the restricted area as defined in 10 CFR Part 20.and changes surveillance requirements. The staff has determined that the amendment involves no significant. increase in the amounts, and no significant change in the types, of any effluent that may be released offsite and that there is no significant increase in individual or cumulative y

occupational ~ radiation exposure. The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding (59 FR 37091). Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).

Pursuant to-10 CFR 51.22 need be prepa(b), no environmental impact statement or environmental assessment red in connection with the issuance of this amendment.

5.0 CONCLUSION

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The staff has concluded, based on the considerations discussed above,-that:

s (1) there is reasonable assurance that the health and safety of the public 1

will not be endangered by operation in the prososed 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:

S. Brewer Date: December 12, 1994 J