ML20149H330
| ML20149H330 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 07/21/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20149H329 | List: |
| References | |
| NUDOCS 9707240338 | |
| Download: ML20149H330 (3) | |
Text
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UNITED STATES g
j NUCLEAR REGULATORY. COMMISSION 2
WASHINGTON, D.C. 20666-0001 ha * * * *
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO APiENDHENT NO.16.0 TO FACILITY OPERATING LICENSE NPF-35 AND AMENDMENT N0' 152 TO FACILITY OPERATING LICENSE NPF-52 DUKE POWER COMPANY. ET ALu i
CATAWBA NUCLEAR STATION. UNITS 1 AND 2 DOCKET NOS. 50-413 AND 50-414
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1.0,' INTRODUCTION l
By letter dated May 27, 1997, Duke Power Company, et al. iDPC, the licensee),
l submitted a request for changes to the Catawba Nuclear Station, Units 1 and 2.,
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Technical Specificacions (TS).
The proposed changes would delete l
Section 4.7.13.3.a.2 regarding minimum borated water volume and boron concentration for the standby makeup pump (SMP) of the standby shutdown system (SSS),
i 2.0 RLS MSSION AND EVALUAT @
J The Catawba SSS is a non-safety-related system that is shared between Units I and 2.
Details of the staff's review of the SSS functions and design L
objectives are delineated in Section 9.5.1.5, Supplement 4 of the Safety-Evaluation Report (SSER 4) for Catawba., NUREG-0954,idated December 1984.
SSER 4 provides the following description of the SSS:
The standby shutdown system (SSS) is designed to mitigate the consequences of a postulated fire incident to either Catawba Unit 1 or Unit 2 and consists of normal plant safety-related equipment (i.e.,
each unit's turbine-driven auxiliary feedwater pump) and dedicated equipment (i.e., the standby diesel generator and each unit's standby makeup pump). The SSS is designed to remove decay heat through the steam generator and provide normal reactor coolant system makeup to maintain hot standby. The SSS supplements the current shutdown capability described in Section 7.4 of the Final Safety Analysis Report (FSAR).
It would be operated only in the event that installed normal and emergency systems were inoperable. Manual operator action is required to actuate the system. There is one SSS for both units of the station, but each unit has separate SSS centrols.
SSER 4 describes the.SMP as follows:
The standby makeup pump, which supplies reactor coolant makeup during SSS operation, is located in the containment annulus of each unit.
The pump provides makeup for normal reactor coolant system leakage and reactor coolant pump seal leakage. The pump draws water from the spent fuel pool transfer canal through a pipe connected to the fuel 9707240338 970721 PDR ADOCK Of.;OOO413 P
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, L transfer. tub'e in the annulus...[and) will provide at least 26 gallons s
per minutes (gpm) of borated ~ water to the reactor _ coolant system.
s Approximately 14 gpm will. be available for seal leakage, and the (c
remaining 12 gpm is for reactor coolant system makeup and boration.
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.The SMP flow rate of 26 gpm. is specified by TS Section 4.7.13.3 b, which is not a~ subject of the current amendment request.
The licensee's data obtained:
from.in-plant testing has shown that the actual flow rate of the SMP is in the.
' range cf 264-;32 gpm. ' For the low end. (as specified by the TS) of the flow-rate, theLtotal volume of borated water needed would be 112,320 gallons, as currently specified by TS Section 4.7.13.3.a.2; for the high end, the total
. volume would be 138,240 gallons.
.5Section~E4.1 of'NRC. Inspection Report 50-413,414/96-13 raised' questions
~concerning such apparent nonconservative design assumptions. As a result, r
during' additional review of this issue, the licensee determined that the.
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? source of borated water, the spent fuel pool, has much more water available to p
the SMP (415,000 gallons) than would be required by thelSHP for a 3-day operation at maximum flow rate. While SMP suction from the spent fuel pol o
i would. deprive it of some: inventory, borated makeup water can be supplied from.
the refueling water storage tank,_ demineralized water can be supplied by the~
reactor makeup water pumps, and emergency makeup water can be supplied from the nuclear service water system (see Section 9.1.3.1.4 of the Update _ Final
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. Safety Analysis Report, and Section.9.1.3 of the_ Catawba Safety Evaluation Report,NUREG-0954). Thus, there is no shortage of water fo i
Tpent. fuel pool for the required 3-day operation capability.r the SMP from the i
H The minimum
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volume requirement. of TS Section 4.7.13.3.a.2 can.be deleted with no impact on 1
SMP performance.
The spent fuel pool water is required to be borated to "within the limit
- specified in the core operating limits report"'(Section 3.9.12 of the TS).
'This requirement is identical-to that currently specified for the SMP boratod water. source in TS Section 4.7.13.3.a.1.
The minimum boration requirement of TS Section 4.7.13.3.a.2 can thus be deleted with no impact on SMP performance._
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Other than the proposed deletion of TS Section 4.7.13.3.a.2, which has been shown.above as redundant and unnecessary, the licensee proposed nn change to.
- SMP design or operation. There is no relaxation of any limiting conditions
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for. operation, and no decrease _in surveillance requirements. The staff, IThe volume of water available in the spent fuel pool to the SMP is
'415,000 gallons..The minimum depth of. water in the pool is at_least 37.6 feet, corres'ponding to 23 feet over the top of irradiated fuel assemblies
'specified by Section 3.9.10lof the TS. 'In practice, the licensee keeps the water above.the alarm level of 39 feet, nominally at.39.9 feet. Since 1 foot l._
-corresponds to about 17,000 gallons, the SMP could take suction from the spent 4
U ifuel pool for about 8.8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />s-before the alarm limit is reached, and about 20 b
hours before the TS limit is reached. There is thus ample time to activate f
any of the several-makeup sources to prevent reaching the alarm or TS minimum level.
f lE l
r i therefore, finds the licensee's proposed deletion of TS Section 4.7.13.3.a.2 accept able.
3.0 STATE CONSULTATION
. In accordance with the Commission's regulations, the South Carolina State official was notified of the proposed issuance of the amendments. The State official had no comments.
4.0 EHyIRONMENTAL CONSIDERATION
.The amendments change surveillance requirements. The NRC sicff has determined that the amendments involve no significant increase in the amounts, and no i.
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 i
proposed finding that the amendments involve no significant hazards
.J consideration, and there has been no public comment on such finding (62 FR-33121 dated June 18,.1997). Accordingly, the amendments meet the i
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 the amendments.
4 5.0 CONCLUSIQN i
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, i
- and-(3).the, issuance of the amendments will not be inimical to the common
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defense and security or to the health and safety of the public.
Principal Contributor:
Peter S. Tam-1 i
Date:
-July 21, 1997 v
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