ML20091A571

Proposed TS 3.4.11 Re RCS - RCS Vents

ML20091A571
Person / Time
Site:	Davis Besse
Issue date:	03/20/1992
From:	CENTERIOR ENERGY
To:
Shared Package
ML20091A570	List: ML20091A564 ML20091A571
References
NUDOCS 9203300003
Download: ML20091A571 (7)

Text

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i Docket Number 50-346 License Number NPF-3 Serial Number 2032 Attachment 1 Page 6 REAC*0R 0 0LANT SYSTEM RIACT R C: LA.NT SYSTEM VENTS LIMI!!N ::NDITION FOR OPERATION 1

o 3.e.;; O.t f o' loving reactor coolant systes vent paths shd ' be operacles

a. Peactor Coolant Systen Loop 1 vith vent path through valves KC 4608A Ano RC 46088.

2. Reactor Ccolant Systen Loop 2 vith vent path through valves RC 4610A 4

ano RC 46108.

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c. Pressutizers with vent path through EITHER valves RC11 and RC *.A (PORV) l} OR valves RC 239A and RC 200. .

", APPLICABIL**Tt Modes 1, 2 and 3

]^ctio"'fw Mdi Ah a J j c h b r. NiThb M 0: r: vant yathlfr.noperante, restora the inoperable t vent pata to OPERAELI stsitus%in 30 days, or, be in BOT STANDIT

' \ vithin 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in 80T SRUTDOWN vithin the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

d h,j c. f. Vith two of the above vent paths inoperable, restore at least one of l

the inoperable vent paths to OPERA 81.E status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or ce in j(( HOT STANDBT within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Esyt SEUIDOWN vithin the follovter 30 q

hours.

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} } c) cr. g Vith three of the above vent paths inoperabls, restore at least tvo of '

./ tne inoperable vent paths to OPr1 Anti status within 72. hours or be is l

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HOT STANDSY vithin 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in 80T SHUTDOVN virhin the following 30 (

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( g/ The provisions of specification 3.0.4 are not applicable.

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SURVEILLANCE REQUIREMDrf5

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. Each reactor coolant systen vent path shall be demonstrated CPERAILE at

[least once per 18 months by:

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Verifying all manual isolation valves in each vent path are loctea in j tne open position, and i

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. Cycling each valve in the vent path througn at least one casolete cycle

f full travel from the control room during COLD SHUTDOVN or RETLT. LING.

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2. Verifying flov through the reactor coolant vent system vent ;atns

uring COLD SHITIDOVH or REFUELING.

CAVIS-3 ESSE. UNIT 1 3/4 4 32 Amencuent No. 33. H 9203300003 920320 PDR P ADOCK 05000346 ppg

. Docket Numbar 50-346 License Number NPF-3 Serial Number 2032 Attachment 1 Page 7 New 3.4.11 Action

a. Vith either vent path a or vent path-b inoperable (but not both),

restore the inoperable vont path to OPERABLE status within 30 days, or prepare and submit a Special Report to the NRC pursuant to Specification 6.9.2 vittia the naxt 30 days outlining ~the action taken, the cause of the inoperability, and the plans and schedule for restoring the vent path to OPERABLE status.

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Docket humber 50-346 License Number NPF-3 Serial Number 2032

?IA;T E ~20LANT STITIM -

Attachment 1 e -**U Page 8 q( y;ne e rg.:r-.,[:f 3,.,;

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,;, a IASES

- .:: STRUCT.RAL !NTEGR:T:'

The :nspection programs f or ASMI code Class 1, 2 and 2 components, except steam generator tubes, ensure that the structural integrity of itese

=ponents vill be maintainen at an acceptable level througnout the life

i tne plant. To the extent applicable, the inspection program for these

=ponents is in compliance with Section XI of the ASME Boiler and Pressure 7essel Code.

The internals vent valves are provided to relieve the pressure generated

,; ty steaming-in the core following a LOCA so that the core remains suffi-i-  ::ently covered. Inspection and manual actuation of the internals vent

.alves 1) ensure OPERABILITY, 2) ensure, that the valves are not stuck open

uring normal operation, and 3) dewoostrates that the valves are fully

.  : pen at the forces equivalent to the differential pressures assuLed in the safety analysis.

3.4.a.11 HIGH POINT VENTS i'

,, The Raaetor_ Coolant System high point vents are installed per NUREG-0737 i

tem II.B.1 requirements. The operability of the system ensures-capability ll of venting steam or noncondensable gas bubbles in' the reactor cooling

!l system to restore natural circulation following a small break loss of ti coolant acetdent.

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AVIS-SESSE. 'JNIT 1 s 1/; .. U Amenament Sc. 15

Docket Number 50-346 License Number NPF-3 Serial Number 2032 __

Attachment 1 ...,,- ce

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Page 9 . ,

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Serial No ,#9 '

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ADMINIS ?.AT!*.*I CONTROLS SPECIAL P.IPO?.TS 6.9.2 Special reports shall be submitted to the U.S. Nuclear Regulatory Com=tssion in accorcance with 10 CTR 50.4 vithin the time period specified for eacn report. These reports shall be submitte:d covering the activities identified below pursuant to the requirementn of the applicable reference spec'.fications

a. ECCS Actuation, Specifications 3.5.2 and 3.5.3.

b. Inoperable Seismic Monitoring Instrumentation, Specification 3.3.3.3.

c. :noceratls Meteorological Monitoring instrumentation, Specification 2.3.3.4.

d. Seismic event analysis. Specification 4.3.3.3.2.

e. Fire Detection Instrumantation, Specification 3.3.3.8.

f. Fire Suppression Systems. Specifications 3.7.9.1 and 3.7.9.2.

g. Dose 3r dose commitment exceedences to a MEMBER OT V1E PUBLIC from radioactive materials in liquid effluents released to UNRESTRICIED

AREAS (Specification 3.11.1.2).

h. The discharge of radioactive liquid vaste without treatment and in excess of the limits in Specification 3.11.1.3.

i. The calculated air dose frca radioactive gases exceeding the limits in Specification 3.11.2.2.

{ j. The calculated dose frcm the relekse of iodine-131, tritium, and radionuclides in particulate form vith half-lives greater thsn 8 days, in gaseous affluents exceeding the limits in Specification 3.11.2.3.

!! k. We discharge of radioactive gaseous vaste without treatment and in i

excess of the limits in Specification 3.11.2.4.

! 1. '"he calculated doses f:ca the release of radioactive materials in

-i liquid or gaseous effluents exceeding the limit.1 in Specifica:1on

,j 3.11.4.

.s I, z. The level of radioactivity as the result of plant ef fluents in an

l environmental sampling mecium exceeding tne reporting levels of Table

.; 3.12-2 (Specification 3.12.1).

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j DAVIS-BESSE. UNIT 1 6 18 Amendment No. 9, I2. fl. 26. ICf.'.33

Dock.et Number 50-346 License Number NPF-3 Scri'al Number 2032 Attachment 2 Page 1 ENVIRONMENTAL ASSESSMENT Identification of Proposed Action This proposed action involves the Davis-Besse Nuclear Fover Statior.

(DBNPS), Unit Number 1, Operating License Number NPF-3, Appendix A, Technical Specifications (TS). A license amendment is proposed to revise the Action statements for TS 3.4.11. Reactor Coolant System -

Reactor Coolant System Vents. Specifically, the proposed amendment vould allow continued plant operation without one of the Reactor Coolant System (RCS) hot leg loop vent paths (either through Loop 1 valves RC 4608A and RC 4608B, or through Loop 2 valves RC 4610A and RC 4610B) for more than 30 days. .The current Action statement requires that a vent path be restored to operable status within 30 days, or the plant placed in Hot Standby (Mode 3) within six hours and Hot Shutdown (Mode 4) within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

The propored amendment veeld add a new Action statement requirement that if an RCS loop vent path was not= restored within 30 days, a Special Repcrt vould be submitted tn the Nuclear Regulatory Commission (NRC) pursuant to TS 6.9.2 vithin the next 30 days describing the action taken, the cause of the inope; ability, and the plans and schedule for restoring the loop vent path. -Technical Specification 6.9.2 vould also be amended to add a requirement for submittal of this Special Report.

Need for the Proposed Action The changes proposed are needed to allow continued plant operation beyond 30 days and avoid an unwarranted plant shutdown due to the inoperability of one of the two RCS loop vent paths.

Environmental Impact of the Proposed Action.

During normal plant operation the two RCS loop vent paths are isolated by two solenoid-operated valves on-each of the_ vent paths._ These solenoid-operated valves can be remotely operated from the' control room to vent noncondensible gases from the RCS. The loop vent paths are routed to the containment atmosphere it. an unobstructed area. A manual valve in each path upstream of these solenoid-operated valves is locked open during Modes 1-through 3 plant operation.

In the event one RCS vent path.is inoperable, the present Technical Specifications vill only allow continued plant operation under these circumstances for 30 days. At that time the vent path must be restored or the plant shutdown. For example, should the manual valve in one of the RCS vent paths be closed to mitigate RCS leakage past the solenoid-operated valves to the containment atmosphere, the present TS vculd require either shutting down the plant or re-opening the manual valve within 30 days (ptovided the leakage requirements of Technical Specification 3/4.4.6.2, RCS - Operational Leakage were met).

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Docket Number 50-346 License Number NPF-3 Serial Number 2032 Attachment 2 Page 2 The proposed amendment to TS 3.4.11 vould remove the requirement of a ,

plant shutdown in the event that either the RCS Loop 1 or the RCS Loop 2 vent path (but not both) is inoperable for longer than 30 days. The RCS vent paths can be used to help restore natural circulation conditions folluving an event in which natural circulation was lost due to ncncondensible gas collection. As stated in the DBNPS Updated Safety Analysis Report (USAR) Section 5.5.10.2, redundancy of one RCS Loop vent path is provided by the other RCS Loop vent path. However, as described in USAR 6.3.3.1.*, design basis events do not generate sufficient noncondensible gases to block natural circulation. The RCS vent paths are, accordingly, not required by the USAR to function to ultigate a Design Basis Accident. Since the RCS Loop vent path's only safety function is to act as part of the RCS pressure boundary, the inability to open the valves or to vent the RCS via these flovpaths vill have no adverse effect on safety, therefore the present TS requirement to shutdovn the plant with only one of the two RCS Loop vent paths inoperable is overly conservative.

The Continuous Vent Line serves to transport steam and noncondensible gases from the reactor vessel upper head to the inlet plenum of Steam Generator (SG) 1-2 and to improve flov in the reactor vessel upper head region during natural circulation cooldovn. Relocation of steam and gases to the RCS loop could cause an interruption of natural circulation to RCS Loop 2 during a small break loss of coolant accident (LOCA). However, the DBNPS small break LOCA analyses have taken credit for reflux cooling (coupled heat transfer-from the RCS to the SG secondary side) to keep the reactor cooled. Toledo Edison has previously submitted information to the NRC (Serial No. 1543 dited August 23, 1988) regarding the effectiveness of reflux cooling.

Consequently, there is no specific need to be able to removt. the steam or noncondensible gases transported from the reactor vessel epper head to the RCS loop high point by the CVL. Therefore, removal of the requirement to shutdown the plant if a RCS Loop vent path becomes  ;

inoperable has no adverse effect on safety.

The proposed change vill reduce the potential for unduly requiring cooldown and heatup transitions of plant equipment, thus preserving the cycling margin between plant design and actual operating history. The proposed change vill also allow repairs to an inoperable RCS vent path to be deferred to a refueling outage when the radiation dose rate associated with the repair can be better planned and scheduled in order to minimize individual and occupational doses in accordance with the As Lov As Reasonably Achievable (ALARA) Program.

The proposed amendment involves a change to a requirement with respect to the use of a facility component located within the restricted area as defined in 10CFR Part:20. As discussed in the Significant Hazards Consideration, this proposed amendment does not involve a significant hazards consideration. The proposed change to allow continued plant operation with one RCS vent path inoperable does not alter source terms, containment isolation or allovable releases. Accordingly, changing the Action statement and reporting requirements does not

.. Docket Number 50-346 License Number NFF-3 Seilal Number 2032 Attachment 2 Page 3 involve an increase in the amounts, and no change in the types, of any radiological effluents that may be allowed to be released offsite.

Furthermore, there is no increase in the individual or cumulative  ;

occupational radiation exposure.

Vith regard to potential non-radiological impacts, the proposed amendment involves no increase in the amounts or change in types of any non-radiological effluente that may be released offsite, and has no other environmental impact.

Based on the above, Toledo Edison concludes that there are no significant radiological or non-radiological environmental impacts associated with the proposed amendment.

Alternatives to the Froposed Action Since Toledo Edison has concluded that the environmental effects of the proposed action are not significant, any alternatives vill have only similar or greater environmental impacts. The principal alternative vould be not to amend the TS. This vould not reduce the environmental impacts attributable to the facility. Furtheimore, it vould necessitate that either personnel enter containment with the reactor at power to restore a vent path or, if necesssry, force a shutdown of the facility in accordance with the present TS to effect repairs to restore a vent path. Under these circumstances, occupational exposures to plant personnel vould be incurred at a higher dose rate than if the reoairs were deferred to a refueling outage.

Alternative Use of Resources This action does not involve the use of resources not previously considered in the Final Environmental Statement Related to the Operation of the Davis-Besse Nuclear Power Station, Ur.it Numter 1 (NUREG 75/097).

Finding of No Significant Impact Toledo Edison has reviewed the proposed license amendment against the criteria of 10CFR51.30 for an environmental assessment. .As demonstrated above, the proposed amendment does not involve a significant hazards consideration, does not increase the-types or '

amounts'of effluents that may be released offsite, and does not increase individual or cumulative occupational radiation exposures.

Accordingly, Toledo Edison finds that the proposed license amendment, if approved by the Nuclear Regulatory Commission, vill have no significant impact on the environment and that no Environmental Impact Statement is required.

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