ML20062A241
| ML20062A241 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 10/12/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20062A237 | List: |
| References | |
| NUDOCS 9010190249 | |
| Download: ML20062A241 (3) | |
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' UNITED ST ATES
.8 NUCLEAR REGULATORY COMMISSION h
WASHINGTON, D. C. 20sss 1
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION
' RELATED TO AMENDMENT NO. 60 TO FACILITY OPERATING LICENSE NO. NPF-43 DETROIT EDISON COMPANY FERMI-2 DOCKET NO. 50-341 1.'O IMRODUCTION By letter dated February 1, 1989, The Detroit Edison Company (Deco or the licensee) requested amendment to the Technical Specifications (TS) appended to Facility Operating License No NPF-43 for Fermi-2.
The proposed amendment would revise the TS to ct.ange Trip Setpoints and Allowable Values for Isolation Actuation Instrumen'.ation which are listed in TS Table 3.3.2-2, Isolation Actuation Instrumentation Setpoints. The affected setpoints are currently indicated to be initial setpoints since the operational information necessary to finalize the setpoints came from the startup test program which was completed in November 1988.
The licensee proposes to finalize the setpoints which will reflect the startup test program information.
In order to enhance safe plant operation, some of the affected setpoints will be changed from their initial values.
The affected setpoints are for the following trip functions:
Primary Containment Isolation - Main Steam Tunnel Temperature - High Secondary Containment Isolation - Fuel Pool Ventilation Exhaust Radiation - High Reactor Water Cleanup System Isolation - Heat Exchanger / Pump /High Energy Piping Area Tet a rature - High Reactor Water Cleanup System Isolation - Heat Exchanger / Pump Area / Phase Separator Area Ventilation Delta Temperature - High Reactor Core Isolation Cooling (RCIC) System Isolation - RCIC Equipment Room Temperature - High High Pressure Coolant Injection (HPCI) System Isolation - HPCI Equipment Room Temperature - High 2.0 EVALUATION 1he proposed TS finalizes the setpoints for three trip functions with the same s,ttpoint as initially provided in the TS.
The trip functions in this category ate the Primary Containment Isolation on Main Steam Tunnel high temperature and the Reactor Water Cleanup System (RWCU) isolction on piping area high temperature and ventilation delta temperature.
9010190249 901012 PDR ADOCK 05000341 p
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J The Main Steam Line Tunnel Temperature - High Signal acts to initiate a primary Containment isolation of the Main Steam System in the event of a high energy piping rupture in the steam tunnel.
The automatic closure of these valves act both to prevent the excessive loss of reactor coolant and to prevent the release of a significant amount of radioactive material from the reactor coolant boundary.
The two RWCU system Temperature signals act to isolate the RWCU system from the nuclear process system upon indication of a pipe break in the areas monitored.
The signal closes the primary containment isolation valves to preclude the loss of water inventory in the reactor.
The licensee has validated the existing Trip Setpoints and Allowable Values for these three Trip Functions.
Startup testing information has confirmed that the existing setpoint values ensure that the trip functions occur prior to exceeding the values for the parameters used in any accident analysis and that an acceptable margin exist from nermally expected operating temperatures to avoid spurious isolation actuation.
Therefore the proposed TS deletes the ** footnote notation, which denotes that the setpoint is an initial value, from the Trip Setpoint and Allowable Value for these trip functions.
The staff finds the proposed changes acceptable.
The Secondary Containment Isolation setpoint for Fuel Pool exhaust radiation level is proposed to be lowered from its initial value.
The Fuel Pool Ventilation Exhaust Radiation - High signal acts to initiate a secondary containment isolation, start the Standby Gas Treatment System (SGTS) and shift the Control Room Emergency Filtration System (CCHVAC) to the recirculation mode.
The licensee has determined that the limiting consideration for the Trip Setpoint and Allowable Value for the Fuel Pool Ventilation Exhaust Radiation - High signal is that of ensuring that the signal terminates a radiation release at a point conservative with respect to the radiation limits in 10 CFR Part 20.
The revised Off site Dose Calculation Manual (ODCM) submitted to the staff on October 14, 1984 committed to adjusting this trip set point to levels conservative to 10 CFR Part 20.
In order to assure that 10 CFR Part 20 limits are not exceeded the trip setpoint and allowable value for this signal must be reduced from their initial values of < 10 millirem /hr and < 15 millirem /hr respectively.
The proposed final trip setpoint is s 5 mi1Iirem/hr with an allowable value of i 6 millirem /hr.
The proposed changes enhance safety by lowering the trip setpoint and allowable value causing the isolation of secondary containment and the starting of the SGTS and placing the CCHVAC in the recirculation mode at lower radiation levels.
These lower levels assure that the limits of 10 CFR Part 20 are not exceeded.
Therefore the staff finds the proposed changes to the TS acceptable.
The licensee has determined that the equipment room high temperature setpoints for the HPCI and RCIC systems should be increased to' avoid spurious isolation actuation during normal system operation.
The initial trip setpoints of 1 150*F are proposed to be finalized at 5 154*F.
The associated allowable values are proposed to be finalized at i 162*F.
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3 These sigt.els'act to isclate the respective systen, from the nuclear process syster upcn indicatior, of a break of the HFCI or RCIC systercs ir, the areas monitoied._ The signals close the appropriate system primary containment' isolatior, valves. 'In the event of a steam line break in tht affected room during systen, operation, the small s#tpoint increase could delay the isoletion actuatio Es11ghtly. However, any sus delay has been determined to have insignificant irnpact upon the isclation function. The rate of room ternperature increase during a steam lir.E break is extremely rapid. As a result, the tine required to reach the isolation setpoint is essentie11y unchanged by the small setpoint increase.
The proposed TS provide a safety imprevement by reducing the probability cf a spurious isolation actuation of the system during normal operation. The change eliminates unnece,sary challenges to the isolation valves and associated equipment._ In addition, the change increases the systems availability and a
reducts the protability that the system will fail to perforn wher, requir(c'.
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Therefore the staff finds the proposed chenge to be acceptable.
In its' application the licensee stated thet
- instrumentatior, used to detect tr.n.Hreture increase in the'RCIC and the PPC1 pump reores are riot taken credit i
fcr in ary accident anblysis. The staff strorgly disegrees with this position.
The staff does oct _heve a probleni with the proposed change to the TS for
'ircreasing the alarm set points of the instrun+r.tation es indicated above; 1
bcwever the staff will issue a series of questions (cocerning the Fermi-P staten.er.t on the use of the ten;perature strscrs in-the licensee's design basis eccident analysis.
l 3.0 ENVIRONMENTAL 00h510 ERA 110h P
This amendment invcives a charge in the installatien or use of a facility corrponent located within the restricted area as defir.ed in 10 CFR part 20 erd char.gts ir, surve111erce requirements.- Ve have determir4d that this entndnent involves no significant increase in-the amounts, and no significant cterge in the types, of any effluents which niay be released effsite, and that there is ne significant increase in individual or cbn.ulative occupational radiation u
- exposure. The Cenirission has previously issued a proposed findir.g that this enendment involves no'significant hazards consideration and there has beer ro public cou.ent on such finding. Accordingly, this an,endment raeets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
I Pursuant to 10 CFR 51.22(b), no environmental impct statener.t or enviror. mental
_ esses.sment need be prepared in connection with the issuarice of this amendment.
4.0 CONCLUSION
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La We have concluded, based on the considerations discussed above, that (1)
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' thes e is reasonable assuran e that the health and safety of the public will i
nct be endangered by operation it. the proposed manner, and (?) such activities i
will be cor. ducted in compliarce with the CorrJrission's regulations, and the l
issuance of this e.Teridnent will r.ct be inimical to the connon defense erd sr.curity or to the health ar.d safety of the public.
Principal _ Contributor: John Stang i
Date: October 12, 1990 l
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