ML20027B997
| ML20027B997 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs, Sequoyah  |
| Issue date: | 09/27/1982 |
| From: | Fioravante M, Harrison G, Jaffe D Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20027B995 | List: |
| References | |
| NUDOCS 8210120139 | |
| Download: ML20027B997 (9) | |
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UNITED STATES I,o NUCLEAR REGULATORY COMMISSION l
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a,i W ASHINGTON, D. C. 20555 f
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BALTIMORE GAS AND ELECTRIC COMPANY f
CALVERT CLIFFS UNITS 1 AND 2 f
DOCKET NOS.30-317 AND 50-318 ITEM 3.2.10F THE FIRE PROTECTION SAFETY EVALUATION REPORT APPENDIX R TO 10 CFR PART 50, ITEMS III.G.3 AND III.L
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INTRODucTf0M I
On February 17, 1981, the fire protection rule for nuclear power l
t plants, 10 CFR 50 and Appendix R to 10 CFR Part 50, became effec-
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tive.
This rule required a LL Licensees of plant's Licensed prior I
to January 1, 1979, to submit by March 19, 1981:
(1) plans and l
f schedules for meeting the applicable requirements of Appendix R, j
t (2) a design description of any modifications proposed to provide j
alternative safe shutdown capability pursuant to Paragraph III.G.3
.of Appendix R, and (3) exemption requ". cs for which the tolling provision of Section 50.48(c)(6) was to be invoked.
Sections III.G and III.L of Ap'pendix R are retrofit items to all pre-1979 plants regardless of previous SER positions and resolutions.
I Previously the staff's fire protection Safety Evaluation Report j
i (SER) dated September 14, 1979, noted that the Licensee's entire j
fire hazard analysis (3.2.1) was unsatisfactory and, therefor ~e, j
was an open item.
The NRC requested a revised fire hazard analysis, _
i which included a requirement for an alternative safe shutdown system capability.
A Letter dated May 19, 1980 from the NRC staff to the Licensee requested that nine specific plant areas 1
ne covered by an alternative safe shutdown system.
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PDR ADOCK 05000317 F_
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. By submittats dated March 19,1981, May 18,1981rSeptember 30,1981, January 29 1982, May 24,1982, and setpember 7, 1982, the Licensee described proposed modifications to the Calvert Clif fs plant, Units 1 and 2, to meet the require-1 ments of Appendix R to 10 CFR Part 50, Items III.G.3 and III.L.
The Licensee i
also responded to staff reouests for additional information transmitted to the, Licensee by letters dated February 20, 1981, and August 6,1982. Additional information and clarification was obtained through telephone conferences of j
December 14, 1981 and December 24,1981, and through a meeting held on June 18, 1982.
r The Licensee has provided a safe shutdown analysis for a fire i
event, and has demonstrated that adequate redundancy and/or I
an alternative safe shutdown system exist for those systems l
t required to assure safe shutdown.
Our evaluation of this fotLovs.
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I SYSTEMS USED FOR POST-FIRE SAFE SHUTBOWN A.
svatems Reaui red for Safe Shutdown Safe shutdown of the reactor is initially performed by rod insertion from the control room; it can also be accomplished by removing the 240 volt A.C.
supply at th'e panels in the cable spreading room and by removing the 480 volt A.C.
supply
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to the motor generator sets in the switchgear room.
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. Reactor coolant inventory and the reactor shutdown are main-l tained by one of three charging pumps-taking suction from the l
concentrated boric acid tanks or the refueling water storage i
tank (RWST).
i Decay heat removat is accomplished by the auxiliary feedwater (AFW) pumps supplying water to the steam generators from 1
the condensate storage water tank #12.
The atmospheric dump l
l system (ADS) or the steam generator safety valves wiLL be used to remove heat from the steam generators.
Primary system pressure is maintained by the pressurizer heaters and spray or the charging pumpsitaking suction from the boric acid tanks combined with Letdown.
For cold shutdown, shutdown is maintained by increasing pri-i mary coolant boration using one of three charging pumps taking j
q suction from the boric acid tanks or the RWST.
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Primary system water cooling is done by the use of a LPSI f
pump to ' circulate this water through the shutdown cooling
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heat exchanger where component cooling water is used as the l
heat sink.
The component cooling water in turn is cooled by t
t salt water in the component cooling water heat exchanger.
There t
- is an existing cross tie between units f ano 2 for component l
cooling water systems.
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4 B.
Areas Whers_ Alternate Safe Shutdown in Reauired The NRC Staf f, in its fire protection SER, requested that the Licensee install alternative shutdown capability independent of the cabling and equipment in the control room, 2 cable l
spreading rooms (wi th their adjoining cable chases), 6 cable chases and other plant areas where " redundant cabling / equip-ment required for safe shutdown cannot be separated by fi re barriers of appropriate r a t i n g.s. "
The Licensee wiLL provide the required alternative safe shutdown system.
This commit-ment is documented in the Licensee's Letter dated May 14, 1982.
The Licensee's alternate sate shutdown system com-pliance is discussed Later on in this SER.
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C.
Section III.G.2 of Anmend4v R
The Licensee also stated in the May 14, 1982 Letter that atL other areas of the plant not required to have an alternate safe shutdown system witL comply with the requirements of Section III.G.2 of Appendix R..unless an exemption req >est l
has been approved by the staff.
D.
M1ernate Safe Shutdown System In the September 30, 1981 submittal, the licensee stated tthat a room by room study of the post-fire safe shutdown
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capability has been made and concluded that the changes proposed for the post-fire requiIements should be combined with the post-TMI requirements because equipment such as
.new electric AFW pumps wi LL be used to meet RHR requirements and post fire shutdown capability requirements.
This entails the removal of the existing auxiliary shutdown panel CASP) from room 603 and the installation of a new ASP in room 430.
The Licensee stated that controls, instrumentation, and con-o trol power wilL be installed in this new ASP.
The new ASP, coupled with manual operation of existing equipment, provides an alternative post-fire shutdown capability.
Electrical isolation devices are installed such that a fire at the new ASP wilL not prevent shutdown of the plant from the control room and vice versa.
A fire in a component cooling room of one unit could disable atL of the component cooling pumps in that room.
If this happened, component cooling water from the unaffected unit could be supplied by manually operating valves in an existing cross-connection between the two units.
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- EVALUATION A.
Performance Goals 1
i The performance. goals for post fire safe shutdown wiLL be l
met using the existing mechanical systems and equipment Listed in Section A above.
The control of these functions witL be accomplished using the new alternate shutdown panel or the i
control room depending on the fi re location.
- Controls, instrumentation, and cont roL power will be installed in the new alternate shutdown panet CASP).
For cold shutdown, in addition to the systems Listed in Section A of this report, reactivity shutdown margin can be provided by boric acid f rom the concentrated boric acid tanks by one of ' he two bori c acid pumps through a charging Line isolation valve or safety injection header valve.
Yhese valves can be manually operated.
The process monitoring instruments to be used for a post fire shutdown includes _ reactor hot and cold leg temperatures, pressurizer pressure and Level, steam generator pressure and Level, and auxilia ry feedwater pump discharge pressure and condensate boric acid, and refueling water storage tank levels.
However, an additional, electrically independent source range flux monitoring instrumentation needs to be made available.
By letter dated August 6,1982, we provided our position to BG8E regarding the need for installation of additional, electrically independent, source range flux monitoring instrumentation. At that time, we indicated that this instrumentation does not.have to be " safety grade," but should only meet the requirements of Section III.L.6 of Appendix R.
BG&E responded by letter dated September 7,1982 and provided a commitment to install
. I one channel of source range flux monitoring instrumentation, per reactor, to be located on the Alternate Shutdown Panel. We find this commitment acceptable.
.The support systems for the post-fire safe shutdown are redun-dant trains of 4KV unit buses, 480 volt unit buses, 480 volt j
motor control centers, 120 volt A.C.
instrument buses, 120 volt A.C. inverter buses and 125' volt D.C.
battery buses.
Other support systems that have been satisfactorily addressed a re switchgear air conditienings plant communicationsi and the onsite emergency diesel.cenerators.
l B.
72 Hour Requi rement.
The Licensee has committed by Letter dated May 14, 1982, to provide capability to achieve cold shutdown within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after a fire event.
C.
Repairs No repairs are planned by the Licensee to comply with Appendix R post-fire shutdown requirements.
D.
Associated Circuits and Isolation _
The Licensee stated that safe shutdown associated circuits are now part of the operating device circuits for separation purposes.
They are treated as safe shutdown circuits and are separated from redundant trains as such.
They further stated in their telephone conference call that non-safety related
. circuits never run from one train to another and so could not propagate a fire between redundant circuits.
The Licensee-has addressed a LL three. type's of associated circuits as discussed below:
1.
Power Source case - AlL of the power and control circuit breakers and fuses are coordinated and are part of an ongoing coordination program.
This includes control power for instrumentation Loops.
2.
Sourious Sienal case.- The devices whose inadvertent operation by spurious signals could affect safe shutdown have been identified as shutdown circuits and are included in the separation analysis.
The Licensee has provided us assurance that shorts to ground, open ci rc ui t s and hot shorts were considered in the analysis.
The Licensee has stated that their annunciator cables have dry contacts and as such are isolated.
A spurious signal could not put control power on another circuit and so saf e shutdown would not t he reby be endangere'd.
False readings due to a fire could be tracked down by the control room operators.
We find the analysis and the isolation devices proposed satisfactory.
3.
Common Enclosure case - The common enclosure problem has been satisfactoril'y resolved.
The Licensee stated at the i
meeting June 18., 1'982, that.there are no non-safety i
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9-i related circuits that run from one redundant train to another.
They further stated that alL cables of concern I
were protected by, circuit breakers or fuses.
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E.
Safe Shutdown Procedures and ManDoWer, The -licensee wit L develop and implement detailed written procedures for ohtaining e safe shutdown condition given a l
fire event.
These procedures wiLL be approved and made opera-tional by the Licensee prior to the implementation date for the alternate safe shutdown system.
This commitment i s docu-mented in their Letter dated May 14, 1982.
The manposer necessary for accomplishing manual operations required for the alternate shutdown is available at the plant in suf ficient number on aLL three shifts.
No fire brigade menibers wi L L be included in the shutdown manpower requirements.
t CONCLUSION i
The goals of reactivity controle inventory control, decay heat removati and I
pressure control are met. The goal of process monitoring is met with the September 7, 1982 commitment by BG&E to instatt source range monitoring in accoruance with the August 6, 1982 NRC position. The goal of adequate support systems has been met. Based on our review we conclude that the proposed Calvert Cliffs Units 1 and 2 design meets th e requirements of ' Appendix R to 10 CFR Part 50 Items III.G.3 and III.L with respect to safe shutdown in the event of a~ fire.
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!'rincipal Contributors:
N. Fioravante G. Harrison D. Jaffe t
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