ML20198F885
| ML20198F885 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 12/22/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20198F881 | List: |
| References | |
| NUDOCS 9801120194 | |
| Download: ML20198F885 (4) | |
Text
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NUCLEAR REGULATORY COMMISSION f
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION CONCERNING TECHNICAL SPECIFICATION CHANGES REGARDING THE POST ACCIDENT MONITORING SYSTEM FLORIDA POWER CORPORAT1QN CRYSTAL RIVER UNIT 3 DOCKET NO. 50-302
1.0 INTRODUCTION
By letter dated July 29,1997, as supplemented by letter dated October 29,1997, the Florida Power Corporation (FPC) proposed a revision to Crystal P.iver 3 (CR 3) Technical Specifications (TS) to: (a) add subcooling margin monitors; (b) add decay heat removal (Iow pressure injection) flow to the post accident monitoring (r'AM) instrumentation; (c) add emergency diesel generator (EDG) kilowatt indication to the PAM instrumentation to support the CR 3 restart issue of emergency diesel generator load management; (d) revise the required thermccouple distribution in the assurance of availability of temperatures across the core; and (e) revise the description of containment pressure indication for post-accident monitoring. The clarifying information provided in the October 29,1997, letter did not affect the original no significant hazards determination, 2.0 EVALUATION The primary purpose of the PAM instrumentation is to display plant variables that provide information required by the control room operators during accident situations. This information provides the necessary support for the operator to take manual actions, for which no automatic controlis provided, that are regulied for safety systems to accomplish their sa'ety functions for Design Basis Events. The OPERABILITY of PAM instrumentation ensures that there is sufficient information available on selected plant parameters to monitor and assess plant status and behavior following an accident.
2.1 Subcoolina Marain Monitors FPC conducted a review of the plant Emergency Operating Procedures (EOPs) and determined that the ' degrees of subcooling" instrumentation in the EOPs monitors were a Type A variable. Regulatory Guide (RG) 1.97, " Instrumentation for Ught Water Cooled 9001100194 971222 PDR ADOCK 05000302 P
j 2-Nuclear Power Plants to Assess Plant and Environs Conditions During and Following an I
Accident," specifies that instrumentation that monitors Type A variables should be designed to Category 1 criteria. Type A variables are those that provide primary information needed to permit the control room personnel to take the specified mentally I
controlled actions for which no automatic control is provided and that are required for
- l safety systems to accomplish their safety functions for design basis events. This j
- Instrumentation is considered to be a Type A variable since degrees of subcooling are used as criteria for manualinitiation of high pressure injection, tripping of reactor coolant pumps and selection of the steam generator high level setpoint on the Emergency Feodwater initiation and Control System du.ing loss-of coolant accidents (LOCAs).
The subcooling margin monitoring instrumentation at CR 3 is comprised of two trains of instrumentation. Each train has the following inputs: two reactor coolant system (RCS) hot leg temperature signals; two RCS pressure wide range signals; two RCS pressure narrow range signals; and eight incore thermocouple signals.
Two of the hot leg temperature signals, one for each monitor, originate at RC-4A TE1 (Train A) and RC 48 TE4 (Train B) and go to separate remote shutdown auxiliary cabinets in the respective 4160 volt engineered safeguards switchgear room. From the switchgear room, this instrumentation goes into the non nuclear instrumentation (NNI) cabinets and to the Safety Parameter Display System (SPDS) In the main control room.
The other two hot leg temperature signals, one for each monitor, originate at RC 48 TE1 (Train A) and RC 4A TE4 (Train B) and go directly to separate NNI cabinets and from there to the SPDS in the main control room.
The two wide range RCS pressure signals that feed both trains of the subcooling margin monitor originate at RC 3A PT3 and RC 38 PT3 and go to separate engineered safeguards cabinets and the SPDS where they are u6ed in subcooling margin calculations when RCS pressure is greater than 600 psig.
The "A" side narrew range RCS pressure signal feeds both trains of the subcooling margin monitor. It originates at RC 147 PT and goes to the "A" remote shutdown auxiliary cabinet in the "A" 4160 volt engineered safeguards switchgear room. From the switchgear room, it goes to the SPDS where it is used in subcooling margin calculations when RCS pressure is below 600 pela.
' As part of the Inhancement to the subcooling margin instrumentation feeding the SPDS, l
the licensee intends to provide a redundant "B" side narrow range pressure signal to both
- trains of the subcooling margin monitor. This narrow range RCS pressure signal will
. originate at RC 148 PT, and go to the "B" remote shutdown auxiliary cabinet in the "B" 4160 volt engineered safeguards switchgear room., From the switchgear room, it will go to 1
the SPDS where it will be used in subcooling margin calculations when RCS pressure is below 600 psig, i
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3-The 16 incore thermocouple signals go into the Reactor Coolant Irwaw vu 4e,
System (RCITS) cabinet in the control complex, with 8 of the 16 ete ovaR W 29 subcooling margin monitor and the other 8 poing to the other moniten br.m s.e RCITh cabinets, the signals go to SPDS,8 to each train, where they are auct6oneered in the i
software so that the highest reading incore temperature is used in the subcooling margin calculation.
The staff agrees with the licensee's classification and considers that the subcooling margin monitors would provide adequate indications to the operators under post accident conditions. Therefore, the proposed T8 changes are acceptable, t
in addition, the staff notes that the licensee ~ intends to implement the following enhancements to the subcooling monitors: addition of a redundant '8' side narrow range RCS pressure signal; the enhancement to the 2eismic design of the existing SPDS system components; and the separation of trains and power from safety related invertors which are backed up by the station standby power sources (EDGs).
2.2 Low Prannure intaction Flow The licensee has classified low pressure injection flow as a Type A variable since low t
pressure injection flow must be manually throttled prior to switching from the borated water storage tank to the containment sump in order to prevent loss of not positive suction head. This instrumentation meets the RG 1.g7 Category 1 criteria of redundant divisions and each has a single qualified channel of flow instrumentation. Therefore, the licensee's low pressure injection system flow instrumentation, and the proposed TS for this instrumentation, is acceptable.
t 2 J EDG Kilowatt Indication The licensee proposed adding EDG kilowatt indication to the post accident. sampling system 6 ASS) LCOs since it had recently been reclassified as Type A per RG 1.g7. The indication L
I would enable the operator to monitor load and perform load management (detem)ine if
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additional loads could be added to the EDG under post accident conditions) on the EDGs i
during post LOCA conditions. The licensee indicated that instrumentation used for this
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function will meet the design criteria for RG 1.g7 Category 1 instruments prior to restart from the current outage. The staff agrees with the reclassification; therefore, the proposed TS change is acceptable. -
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j 2.4 Thermocounia Distribution The proposed change would require three instruments per core quadrant for the core exit I
. temperature function as opposed to two sets of five for the entire core presently required i
by the TS. This change assures that a more representative distribution of temperatures across the core will be available to the operator. The revision presents a more logical i
relationship to the installed configuration than the existing requirement. The staff considers this change acceptable since three instruments per quadrant would provide better j
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assurance that a rep'esentative distribution of temperatures across the core will be
- available to the operators under PAM conditions.
2.6 Containment Framayr, The licensee proposed to revise the description of the Containment Pressure i
instrumentation for PAM from
- Narrow Range" to " Expected Post Accident Range." The descriptor was proposed to eliminate confusion with the instruments used to monitor containment pressure during normal ooerotion which have a range narrower ( 5 to + 5 psig) than the instruments controlled by the PAM TS ( 10 to + 70). No plant changes are being -
made in association with this request since the only change is in the description of the instruments which are currently installed for PAM. The staff agrees with this editorial change and considers the change acceptable.
3.0 STATE CONSULTATION
Based upon written notice of the proposed amendment the Florida State offeial had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
S The amendment changes requirements with respect to installation or use of a facility component located within the restrided area as defined in 10 CFR Part 20,es.asa.
admmiskehm The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and thM there is no significant increase in individual or cumulative occupational radiation exposure. Th6 ?ommission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding (62 FR 4336g). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(g) emmet). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
Based on the discussion is section 2, the staff concludes that the proposed changes tc the PAM system such as the additions of subcooling margin monitors, decay host removal flow, emergency diesel generator kilowatt indication, and the assurance of better indication across the core to the operators are consistent with the recommendations of RG 1.g7, and-
- are, therefore, acceptable.. The revised description of the Containment Pressure instrumentation for PAM is considered an editorial change and is acceptable.
PrincipalContributor: F. Gee Date: Decamher 22, 1997
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