ML20078G267
| ML20078G267 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 12/12/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20078G270 | List: |
| References | |
| NUDOCS 9502030048 | |
| Download: ML20078G267 (6) | |
Text
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i UNITED STATES E
NUCLEAR REGULATORY COMMISSION f
WASHINGTON. D.C. 2068H001
.....,o SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED 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 D0CKET 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 l
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 S! Oc4ua-t4en, the engineered safety feature: (ESF) logic cpen the vehe between the BAST cnd the suction of the SI pump:, aligning the SAST :
%e-4*R4el ;uction :curce of the SI fluid.
" hen the BAST lcw lcw level setpekt-1 recched, the cuct4en-44ne up frc= the St.ST te S! i:clate: nd the suet 4cn valve; between the INST and the S! pump Open cutomatically.
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 950203C:048 950203 PDR ADOCK 05000266 ENCLOSURE 1 p
I Table 15.3.2-1,%d removing the heat tracing system, and climinating the 4 4c which automat 4eally cpens t40 valvc in the f4ew path from the MST: to 9
The proposed TS 15.3.2.B.2 and C.2 ensure that two flow paths and associated sources of borated water are available to maintain long term subcriticality.
If the BASTS are used as the source for boration, there has to be sufficient boron to meet the range of concentrations specified in Table 15.3.2-1.
The licensee has determined, through the use of the BORDER (Boron Design Recuirements) methodology, that 300 pounds of stored boron is sufficient for PBNP's annual fuel cycle.
The minimum temperature requirement listed in Table 15.3.2-1 provides protection against boron precipitation. The temperatures specified in the 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 wt% boric acid solution.
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.
The licensee determined that these changes could have an effect on the analysis of the loss of coolant accident (LOCA) and steamline break (SLB) events in the Final Safety Analysis Report (FSAR).
The licensee re-analyzed 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 be maintained hot subcritical following a reactor trip.
Specifically, the licensee determined that the amount of negative reactivity that can be inserted by one charging pump, borating at a minimum speed and using the RUST as its suction source, is greater than the positive reactivity added from the decay of xenon in the longterm.
The applicable surveillances in Table 15.4.1-2 are proposed to be changed by removal of the boric acid heat tracing 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.
The licensee proposed an increase in the allowable outage time in TS 15.3.2.D 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
~
baration, 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 with the STS.
i The licensee has demonstrated that these changes do not adversely affect the FSAR accident analyses and that, with the changes, the plant will still be 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 adclition, the staff agrees with the licensee that the proposed changes to the bases are consistent with, and support the i
above changes.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Wisconsin State official was notified of the proposed issuance 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 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(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
5.0 CONCLUSION
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with 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: Deceuer 12, 1994
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1 UNITED STATES g
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NUCLEAR REGULATORY COMMISSION 2
WASHINGTON. D.C. 20566-0001 Y..../
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 158 ANC 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 l
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 tiine for one of the two charging pumps, one of the two boron injection flow paths, or one of the two boric acid trar.sfer 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 LVALVATION 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 reat. tor coolant system with the 1
charging pumps through either the emergency, manual, or boric acid blender flow paths, or with the safety injection (SI) pumps.
One 275,000 gallon j
refueling water storage tank (RWST) per unit is also available, as a source of 2000 ppm boric acid.
l I
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 Table 15.3.2-1, and removing the heat tracing system.
l The proposed TS 15.3.2.B.2 and C.2 ensure that two flow paths and associated sources of borated water are available to maintain long term subcriticality.
{
If the BASTS are used as the source for boration, there has to be sufficient 1
boron to meet the range of concentrations specified in Table 15.3.2-1.
The licensee has determined, through the use of the BORDER (Boron Design
}
ENCLOSURE 2 e
l Requirements) methodology, am 300 pounds of stored boron is sufficient for
. PBNP's annual fuel cycle.
The minimum temperature requirement listed in Table 15.3.2-1 provides protection against boron precipitation.
The temperatures specified in the 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 wt% boric acid solution.
The 5 *F solubility temperature margin was chosen by the licensee, because of o)erational flexibility and the solubility temperature being nearly equal to i
tie ambient temperature.
The licensee determined that these changes could have an effect on the analysis of the loss of coolant accident (LOCA) and steamline break (SLB) events in the Final Safety Analysis Report (FSAR).
The licensee re-analyzed 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. hat, for a typical fuel cycle and assuming worse-case conditions, the reactor can be maintained hot subcritical following a reactor. trip.
Specifically, the licensee determined that the amount of negative reactivity that can be inserted by one charging pump, borating at a minimum speed and using the RWST as its suction source, is greater than the positive reactivity added from the decay of xenon in the longterm.
The applicable surveillances in Table 15.4.1-2 are proposed to be changed by removal of the boric acid heat tracing 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.
The licensee proposed an increase in the allowable outage time in TS 15.3.2.0 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 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 with the STS.
The licer.see has demonstrated that these changes do not adversely affect the FSAR accident analyses and that, with the changes, the plant will still be 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 regulations, the Wisconsin State official was notified of the proposed issuance of the amendment.
The State official had no comments.
t 4.0 [NVIRONMENTAL 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 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(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
5.0 CONCLUSION
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with 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 i
I
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