ML20215N181
| ML20215N181 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 10/24/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20215N177 | List: |
| References | |
| NUDOCS 8611040410 | |
| Download: ML20215N181 (4) | |
Text
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SAFETY EVALUATION BY_THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO Af4ENDMENT N0. 17 TO FACILITY OPERATING LICENSE NPF-35 AND AMENDMENT N0. 7 TO FACILITY OPERATING LICENSE NPF-52 CATAWBA NUCLEAR STATION, UNITS 1 AND 2 DUKE POWER COMPANY, ET AL.
I.
INTRODUCTION By letter dated June 6,1986, Duke Power Company, et al., (the licensee) pro-posed changes to the Technical Specifications (TS) for Catawba Nuclear Station, Units 1 and 2.
One of the proposed changes for Unit I would permit installation of a Boron Dilution Mitigation System (BDMS) in Unit 1.
By letter dated September 9,1986, the licer see provided clarification to the June 6,1986, sub-mittal in that proposed surveillance requirements 4.3.3.12.1 and 4.9.2.1.1 were
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augmented for Unit I to ensure that all actuated components are tested at least once per 18 months to verify their operability.
II.
EVALUATION 1.
Description The BDMS consists of circuitry which detects an increase in response of the source range detectors and acts to isolate potential sources of dilution water from the core. The system also aligns the suction of the charging pumps to the Refueling Water Storage Tank, thus allowing the operator to initiate reboration imediately.
Two seismically qualified source range detectors are to be added in spare wells in the prima'ry shield wall.
Signals from each detector are carried in a cable to its amplifier located outside containment. The output ~of each amplifier then goes to a corresponding signal processor which provides inputs to a system trouble alann with indicators in the control room and on the remote shutdown panels.
In addition, the signal processors provide input to their corresponding Shutdown Margin Monitors (SMM) which are located in the control room.
Each SMM determines whether the Unit is proceeding toward an unexpected criticality and provides a contact closure signal for control of valves and pumps when a high neutron count rate setpoint is exceeded. Annunciation is also provided.
The i
staff has reviewed the valves and puaps which are controlled and concludes that the stopping of the reactor makeup water pumps would terminate the dilution event. The operator is then able to reborate 'at leisure to assure.that proper concentration water is being supplied.
The installed system has two trains which meet the criteria for separation, re-dundancy,' safety grade power supplies, and environmental qt.alification.
Each SEM is capable of stopping each reactor makeup water puno and each SMM can operate 8611040410 861024 PDR ADOCK 05000413 p
.. g the valve in its corresponding train. The licensee has confirmed that actuation of the BDMS does not disable any equipment which would be needed to mitigate the consequences of any. accident identified in the accident analyses of the Final Safety Analysis Report.
Based on the above discussion, the staff concludes that the BDMS is acceptable for use in mitigation of the consequences of the baron dilution event.
2.
TS Changes Several TS changes were proposed to support the installation of the BDMS in Unit 1.
The staff reviewed each ch6nge as discussed below.
(a) TS 4.1.1.1.3, 4.1.,1.,1,.4, and 4.1.1.2.2 These TS regarding the surveillance on the Reactor Water Makeup pumps are re-lated to the rate of dilution and the time for operator action. Since operator action is no longer required to halt the dilution event, this surveillance is not required.
Therefore, limiting the surveillance to Unit 2 is acceptable.
(b) Table 3.3-1 This proposed change in the operability requirements for the Source Range lieutron Flux of Unit 1 in Modes 3, 4, and 5 to require it to be operable only if the capability to withdraw control rods is present is acceptable. Separate source range neutron detectors are used in the BDMS. Their operability is addressed in TS 3/4.3.3.12.
(c) Table 4.3.1, Note (9)
This note requires surveillance of the Boron Dilution Alann setpoint.
Since this is not required for Unit 1, restriction of its applicability to Unit 2 is acceptable. Surveillance of the BDMS is addressed in TS 3/4.3.3.12.
(d) TS 3/4.3.3.12 This TS requires both trains of the BDMS to be-operable in Modes 3, 4, and 5 and specifies actions to be taken if one is (or both are) inoperable. These actions require that the valve which provides potential sources of low boron content water be closed and operations involving reactivity additions be sus-pended and that the Unit revert to the prior method of mitigating the baron dilution event.
In the latter case the maximum allowed ficw rates from makeup pumps are reduced to allow adequate time for operator action. The times per-mitted for restoring the BDitS to operability are 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> and 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> for I and 2 inoperable trains, respectively.
This TS also includes surveillance re-quirements (channel check, analog channel and system operational tests) for the system and surveillance requirements for the dilution alarm, if used.
The system operational tests which were implied in the June 6,1986, submittal were clarified in the Septen,ber 9,1986, submittal. These times and surveillarces are reasonable and, therefore, the staff finds that the proposed TS change is acceptable.
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, (e) TS 4.9.1.3 This TS would be changed for both Units I and 2.
The change would substitute the requirement that Valve NV-230 be verified to be closed and secured in position for the previous requirement that valves NV-231, 237, 240, 241, and 244 be closed and secured.
Since closing NV-230 accomplishes the same purpose as closing the other five valves, the staff finds this to be acceptable.
(f) _TS 3/4.9.2.1 This TS requires that both trains of the BDMS be operable in Mode 6 and specifies actions to be taken with one or both trains not operable.
These actions require that core alterations or positive reactivity changes cease or that the Source Range Neutron Flux Monitors be operable with the alarm setpoint less than or equal to one-half decade above the steady state count rate. These actions' re-quiren'ents are the same as those currently in effect and are acceptable. This TS also includes surveillance requirements (channel check, analog check and system operational tests) for the BDMS and the Source Range Neutron Monitor, if used. The system operational tests which were implied in the June 6,1986, sub-mittal were clarified in the September 9,1986, submittal. These requirements are reasonable and thus the staff finds them acceptable.
(g) TS 3/4.9.2.2 This TS is the sante as that currently in effect but its applicability has been limited to Unit 2.
Since Unit I requirements are addressed in TS 3/4.9.2.1, this is acceptable.
(h) Bases 3/4.3.3.12 These bases have been added to describe the function of the BDMS and are acceptable.
(i) Bases 3/4.9.2 The BDMS has been added to these bases and is acceptable.
III.
EN,VIRONMENTAL CONSIDERATION The an.endments involve a change in use of facility components located within the restricted area as definea in 10 CFR Part 20 and changes in surveillance requiren.ents.
The staff has determined that the amendments involve no signif-icant 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 in-crease in individual or cumulative occupational exposure. The C6ncission has previously issued a proposed finding that the amendnents involve no significant hazards consideration, and there have been no public comments on such finding.
4 Accordingly, the amendments meet the eligibility criteria for categorical ex-clusion set forth in 10 CFR Section 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact staten>ent or environmental assessnent need be prepared in connection with the issuance of the amendments.
. -5 a IV. CONCLUSION The Commission nade a proposed determination that the amendments involve no significant hazards consideration which was published in the Federal Register (51 FR 28997) on August 13, 1986, and consulted with the state of South Carolina.
No public comments were received, and the state of South Carolina did not have any corxients.
We have concluded, based on the consideraticns 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, and (2) such activities will be conducted in compliance with the Commission's regulations, i
and the issuance of the amendments will not be inimical to the connon defense and security or to the health and safety of the public.
Principal Contributors:
Kahtan Jabbour, PWR#4/DPWR-A Walter Brooks, RSB/PWR-A Fred Burrows, EICSB/PWR-A Dated: October 24, 1986 h
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