Text

Annual Operating Rept for 1980
	ML17193B225
Person / Time
Site:	Dresden
Issue date:	03/11/1981
From:	; COMMONWEALTH EDISON CO.
To:	;
Shared Package
ML17193B224	List: ML17193B223; ML17193B225;
References
	NUDOCS 8103240353
	Download: ML17193B225 (23)
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'.Jl ANNUAL OPERATING REPORT OF DRESDEN NUCLEAR POWER STATION, COMMONWEALTH EDISON COMPANY FOR 1980 UNIT NO.

DOCKET NO.

LICENSE NO.

1 050-010 DPR-2 2.

050-237 DPR-19 3

050-249 DPR-25 8103240353

TABLE OF CONTENTS Section 1:

Dresden Unit 1

~-

- PLANT OR PROCEDURE. CHANGES, TESTS, EXPERIMENTS AND

.1 SAFETY-RELATED MAINTENANCE

- Amendments to Facility License or Technical.

Specifications

- Other Changes, Tests and Experiments

section 2:

Dresden Unit 2

- PLANT OR PROCEDURE CHANGES, TESTS, EXPERIMENTS AND SAFETY-RELATED MAINTENANCE

- Amendments to.Facility License or Technical Specifications

- Other Changes, Tests and Experiments

Section 3:

Dresden Unit 3.

... ~ PLANT OR PROCEDURE. CHANGES, TESTS, EXPERIMENTS AND SAFETY-RELATED MAINTENANCE

- Amendments to Facility License or Technical Specifications

- Other Changes, Tests and Experiments

- DRESDEN 2 AND 3 SAFETY/RELIEF VALVE STATEMENT

- GLOSSARY 1

2 4

7 10 14 19 20

AMENDMENTS TO FACILITY LICENSE DPR~2 (UNIT 1) OR ASSOCIATED TECHNICAL SPECIFICATIONS AMENDMENT 1!32

On November 17, 1980, the Nuclear Regulatory Commission issued Amendment #32 to the Dresden Facility License No. DPR-2.

The fol-lowing is a*list of the changes in the license for the incorpora-tion of the Amendment:

The Amendment states that the licensee shall fully implement and maintain in effect all provisions of the Commission-

. approved.Safeguards Contingency Plan, including amendments and changes made pursuant to the authority of 10 CFR 50.54(p).

UNIT l OTHER CHANGES, TESTS AND EXPERIMENTS MODIFICATION Ml2-l-75-36 High Energy Line Brea~ Study of the Feedwater Heater Valve Gallery The change involved installing a submarine door-in the west*

end.of the valve gallery, installing a* vent opening to the turbine floor in the ceiling of the valve gallery to avoid over-pressurization, and installing energy absorbing. snubbers in the valve gallery to prevent un-restricted pipe impurgement on the wall of the cableway between the sphere and Main Control Room.

The intent of this modification is to further assure that all safety equipment will be available for shutdown of the reactor in the unlikely event of a high energy pipe rupture out-side containment.

The safety evaluation concluded that the proposed change did.

not constitute an unreviewed safety question because the modification *

actually increases the margin of safety by providing additional protec-tion and support in the unlikely event of a pipe rupture *.

MODIFICATION Ml2-l-75-37 High Energy Line Break Study of the Feedwater Heater Valve Gallery The change involved replacing the existing condensate. pump room door with a door which can*withstand the pressure created by a postulated pipe failure.

The intent of this modification is to further assure that all safety equipment will' be available for shutdown of the reactor in the unlikely event of a high energy pipe rupture outside containment.

The safety evaluation concluded that the proposed change did not constitute an unreviewed safety question because the modification actually increases the margin of safety by providing additional protec-tion and support in the unlikely event of a pipe rupture.

MODIFICATION Ml2-l-77-43 Installation of Additional*Restraints to the Battery Support Rack.and Power Centers 5 and 6 The change involved. installing steel side and end. rails to the battery racks and installing steel channels to the power center, connect-ing them to the structural steel of the intake building.

The intent of this modification is to provide additional assurance of this equipment's capability to perform its safety function during and after a seismic event.

The safety evaluation concluded that the proposed change did not constitute an unreviewed safety question because the modification actually increases the margin of safety.

The batteries and power centers will be able to withstand physical shocks with the addition of protective equipment.

MODIFICATION Ml2-l-80-17

.~

Addition of Flow Holes to Instrument Tubes of Exxon Fuel Bundles The change involved drilling four (4) flow holes in the instru-ment tube contained within each of the twelve (12) fuel bundles stored in the Dresden l fuel pool.

The intent of this modification is that the bundles are required to meet all applicable Technical Specification cri-teria prior to refueling.

The* safety*. evaluation concluded that the proposed change did no't constitute an unreviewed safety question.

The modification returns the instrument tubes to their previous design and will insure that they function as intended when incorporated in the initial core assemblies at Dresden 1.

Hence, all relevant bundle and cycle reload analyses remain applicable as stated in Technical Specification criteria for reloading fuel.

AMENDMENTS TO FACILITY LICENSE DPR-19 (UNIT 2) OR ASSOCIATED TECHNICAL SPECIFICATIONS AMENDMENT 1!44 On February 28; 1980,. the Nuclear Regulatory Commission issued Amendment 1F44 to the Dresden Facility License No. DPR-19.

The fol-lowing is a list of the changes in the license for the incorpora-tion of the Amendment.

Paragraph 4.6.B.3 The Amendment allows removal and testing of neutron flux moni~

tors and samples that are in the reactor as outlined in Table 4.6.2.

Paragraph Bases B The Amendment introduced new Table 4.6.2 which defines testing requirements of Section 11.C.3.a of 10 CFR 50, Appendix H, and ASTI1 El35-77, and also defines exceptions.

Paragraph Bases C The Amendment placed Bases C on new page 93A.

Paragraph Table 4.6.2

.The Amendment establishes Table 4.6.2, showing a schedule of neutron flux and samples withdrawal* for Dr.esden 2 t~rough the year 2000.

. AMENDMENT 1!45 On January 2, 1980, the Nuclear Regulatory Commission issued Amendment #45 to the Dresden Facility License No. DPR-19.

The fol-lowing is a list of the changes in the license for the incorpora-tion of the Amendment.

The Amendment has been previously implemented and documented.

(The Amendment requirements were to change the appropriate process computer arrays and surveillances of the MAPLHGR limits to make them automatic.)

Thus, no new.action is required.

AMENDMENT 1!46 On February i, 1980, the Nuclear Regulatory Commission issued Amendment #46 to the Dresden Facility License No. DPR-19.

The fol-lowing is a list of the changes in the license for the incorpora-tion of the Amendment.

AMENDMENT #46 (Continued)

Paragraph 3.5.D.3.a The Amendment authorizes continued plant operation per 3.5.D.2 and 3.5.D.3 except for the current operating cycle 7; four of the five relief valves of ADS shall be operable.

Paragraph 4.5.D.l.b The Amendment specifies that during each operating cycle and with the reactor at pressure, each relief valve shall be manually opened.and verified.

AMENDMENT 4!4 7

On February 1, 1980, the Nuclear Regulatory Commission issued

, Amendment #47 to the Dresden Facility License No. DPR-19.

The fol-lowing is a list of the changes in the license for the incorpora-tion of the Amendment.

Paragraph 3.6.I.2 The Amendment authorizes continued reactor operation only during the succeeding 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months if a snubber is determined to be inoperable unless repaired or*replaced.

Torus ring header snubbers may be inoper~ble in groups of up to three (J) pairs.

until September 1, 1980 to facilitate the Mark I.Torus Support.

Paragraph 3.6.I.4 The Amendment states that if a snubber is determined to be

inoperable while the reactor is.iri cold shutdown-or refuel mode, the snubber shall.be made operable or replaced prior to reactor startup.

This Amendment does not apply to torus ring header snubbers identified in Paragraph 3.6.I.2 2 above.

Paragraph Bases I The Amendment states that during normal operation plus QBE, neither the header nor the torus penetrations are over-stressed with all snubbers inoperable and reiterates snubbers identified in Paragraph 3.6.I.2 above.

AMENDMENT

~F48 On April 17, 1980, the Nuclear Regulatory Commission issued Amendment iF48 to the Dresden Facility License No. DPR-19.

The fol-lowing 'is a list of the changes in the license for the incorpora-tion of the Amendment.

Table 3.7.l The Amendment specifies the addition of the torus to condenser drain valv.e to the Primary Isolation Group II valves.

-s-

AMENDMENT 4fo49 On September 8, 1980, the Nuclear Regulatory Commission issued Amendment #49 to the Dresden Facility License No. DPR-19.

The fol-lowing is a list of the changes in the license for the incorpora-tion of the Amendment.

Paragraph 4.10.B The Amendment allows exceptions to the requirement of daily testing surveillances of the SRM's.

AMENDMENT :ffo50 On November 12, 1980, the Nuclear Regulatory Commission issued Amendment #50 to the Dresden Facility License No. DPR-19.

The fol-lowing is a list of the changes in the license for the incorpora-tion of the Amendment.

Paragraph 3.5.I The Amendment establishes the maximum values of the LHGR and<

updates the graphs depicting the maximum values to accommo-date the values.

AMENDMENT 4fo5 l On November 17, 1980, the Nuclear Regulatory Commission issued Amendment #51 to the Dresden Facility License No. DPR-19.

The fol-.

lowing is a list of the changes in the license for the incorpora-tion o-f tJ1e Amendment.

The Ame.ndment states that the licensee shall fully. implement and maintain.in effect all provisions of the Commission-approved Safeguards Contingency Plan, including amendments*

and changes made pursuant to the authority of 10 CFR 50.54(p).

.. I UNIT 2 OTHER CHANGES, TESTS AND EXPERIMENTS MODIFICATION Ml2-2-76-60 Resupport the Main Steam Line Instrument Racks to Eliminate Vibration Problems

. The change involved isolating the MSL high flow. switch instru-ment racks 2202-lOB and 2202-lOC from the floor grat"ing material arid stiffening the structure of the instrument racks themselves.

The intent of this modification is to provide overall reliability of the MSL in-struments by being less ~usceptible to external influences.

The safety evaluation concluded that the possibility of spurious reactor scrams resulting from rack vibr.ation is reduced with the installation of this modification.

MODIFICATION Ml2-2-77-34 Replace Unit 2 Reactor Furnace Sensitized Safe-Ends with New Stainless Steel Safe-Ends The change involved replacing the existing Control Rod Drive safe-end with a safe end that is not furnace-sensitized and has a carbon content that makes it less susceptible to intergranular stress corrosion cracking than the original.

The intent of this modification is part of a prevent"ive maintenance program. to replace furnace-sensitized safe-ends on the reactor vessel to preclude loss of. plant *availability due to potential safe-end failure.

The safety evaluation concluded that since the new safe-end meets the original design bases, the margin of safety is not reduced.

MODIFICATION Ml2-2-79-29 Install a 2" Pipe Through the Lower Corner of the East Torus*

Submarine.Door

.The change involved installing a 2" pipe through the lower corner of the east submarine door to the torus to facilitate draining the torus without opening the door (the west door was c0mpleted previ-ously by Ml2-2-78-2).

The safety evaluation concluded that since the new pipe meets or exceeds design *requirements, all existing Technical Specification re-quirements pertaining to thi~ system will remain unchanged.

MODIFICATION Ml2-2-79-40 Modify the Control Switches and Appropriate Circuitry for All Group II Primary Containment Isolation Valves (NRC COIIDDitment)

The change involved modifying existing logic of the control switches and appropriate circuitry such that the Group II primary con-tainment isolation val.ves are prevented from automatically opening when the isolation sigx_ia~ is reset.

The automati7 opening of the. valves upon

'reset has been eliminated, and they now require manual opening by an

- ' operator, thus avoiding accidental automatic opening.

The safety evaluation concluded that the margin of safety actually increases by eliminating the automatic reopening and requiring manual opening of the valves by an operator.

MODIFICATION Ml2-2-79-53 Limit the Maximum Opening Angle of the Containment Vent and Purge Valves (NRC Commitment)

The change involved the installation of a passive mechanical blocking modification to limit valve travel in the open direction for the following valves:

2-1601-21,.-22, -23, -24, -56, -60 and -63.

The safety evaluation concluded that. the margin of safety has been increased by the modifications to thevalves because their per-formance of the isolation function has increased.

MODIFICATION Ml2-2-80-5.

Add Special Components to the HPCI D.C. Automatic Throwover

Circuit

The change involved adding HPCI motor gear unit, motor speed

changer, turbine stop valve reset, overspeed test solenoid, and valves AO 2301-31 and SOV 2301-32 control circuits to the HPCI D.C. automatic throwover circuit.

The addition of these components and functions to the D.C. throwover scheme will provide for the more efficient operation o'f the HPCI system.

- The safety evaluation concluded that this modification will increase the margin of safety by increasing the reliability of tµe HPCI.

system and insure that it will ope~ate as-postulated in the F~S.A.R. bi providing backup power for essential HPCI equipment.

MODIFICATION Ml2-2-80-25 Modify the Reactor Water Cleanup Isolation Valve 2-1201-1 to Allow for Throttling of the Valve The change involved modifying the R.W.C.U. isolation valve 2-1201-1 circuitry such that the valve can be throttled open to slowly fill the system when it is being started up.

The safety evaluation concluded that the margin of safety has not been reduced because its primary containment isolation function has not been changed and that its surveillance requirement as defined in the Technical Specifications is still the same.

-9~

AMENDMENTS TO FACILITY LICENSE DPR-25 (UNIT 3) OR ASSOCIATED TECHNICAL SPECIFICATIONS AMENDMENT /fa39

,~*

On February 28, 1980, the Nuclear Regulatory Commission issued Amendment #39 to the Dresden Facility License No. DPR-25.

The fol-lowing is a list of the changes in the license for the incorpora-*

tion of the Amendment.

Paragraph 4.6.B.3 The Amendment allows removal and testing of neutron flux moni-tors and samples that are in the reactor as outlined in Table 4.6.2.

Paragraph Bases B The Amendment introduced new Table 4.6.2 which defines testing requirements of Section 11.C.3.a of 10 CFR 50, Appendix H, and ASTM El35-77, and also defines exceptions.*

Paragraph Bases C The Amendment placed Bases C on new page 93A.

Paragraph Table 4~6.2 The Amendment establishes Table 4.6.2, showing a schedule of neutron flux and samt>les withdrawal for Dresden 3 through the year 2000.

AMENDMENT #40 On February l, 1980, the Nuclear Regulatory Commission issued Amendment /fa40 to the Dresden Faeility License No.. DPR-25.

The fol-lowing is a list of the changes in the license for the incorpora-tion of.the Amendment.

Parag~aph 3.5.D.3.a The Amendment authorizes continued plant operation per 3.5.D.2 and 3.5.D.3 except for the current operating cycle 6; four.of the five relief valves of ADS shall be operable.

Paragraph 4.5.D.l.b The Amendment specifies that during each operating cycle and with the.reactor at pressure, each relief valve shall be manually opened and verified.

AMENDMENT fF41 On February 1, 1980, the Nuclear Regulatory Commission.issued Amendment #41 to the Dresden Facility License No. DPR-25.

The fol-lowing is a list of the changes in the license for the incorpora-tion of the Amendment.

Paragraph 3.6.I.2 The Amendment authorizes continued reactor operation only during the succeeding 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months if a snubber is determined to be inoperable unless repaired or replaced, Torus ring header snubbers may be inoperable in groups of up to three (3) pairs until September 1, 1980 to facilitate the Mark I Torus Support.

Paragraph 3.6.I.4 The Amendment states that if a.snubber is determined to be inoperable while the reactor is in cold shutdown or refuel mode, the snubber shall be made operable or replaced prior to reactor startup.

This Amendment does not apply to torus ring header snubbers identified in Paragraph 3.6.I.2 above.

Paragraph Bases I The Amendment states that during normal operation.plus OBE, neither the header nor the torus penetrations are over-stressed with. all snubbers inoperable and reiterates snubbers identified in Paragraph 3. 6. I.2 above.

AMENDMENT #42.

On April 16, 1980, the *Nuclear*Regulatory Commission issued Amendment #42 to the Dresden Facility License No. DPR-25.

The fol-

_lowing is a list of the changes in the license. for the incorpora-tion of the Amendment:

The Amendment allows the cycle 7 reload of fuel into the Unit 3 reactor per 10 CFR 50.59.

Significant changes are listed below.

1)

A generalization of the MCPR Safety Limit to include core configurations with retrofit 8x8 fuel (8x8R).

2)

The Rod Drop Accident figure of merit has been changed fr0m 1.3%

K to 280 cal/gm.

3)

New MAPLHGR curves which reflect the improved flooding characteristics of the 8x8R fuel design during a postu-lated LOCA.

4)

The LHGR spiking penalty for postulated fuel densification for 8x8 fuel types (standard and retrofit) has been in-

. eluded in t~e transient analysis.

5)

Reference to the LTPF has been eliminated and replaced with reference to the. MPLPD for adjustment of the APRM fiux scram and rod block settings.

I e AMENDMENT #42 (Continued)

. 6)

The Target-Rock safety/relief valve setpoint has been changed to 1115 psig for both functions of the valve.

7)

The reactor low water level scram setpoint and the ECCS initiation setpoint have been set at 144" and 84", re-spectively, to accommodate the 8x8R active fuel length which is 1.24" longer than previously utilized fuel bundle designs.

8)

A 25 psi margin is maintained between the calculated peak steam line* pressure of.the most limiting abnormal opera-*

tional transient and the lowest spring safety valve limit.

9)

The "Generic Reload Fuel *Application," NEDE-24011-P-A, has been referenced wherever applicable.

10)

The limiting safety system bases for the APRM rod block trip. setting has been clarified to indicate the setting provides protection against grossly exceeding the MCPR Fuel Cladding Integrity Safety Limit.

AMENDMENT* {fo43 on* April 17, 1980, the Nuclear Regulatory Commission issued Amendment {fo43 to the Dresden Facility License No. DPR-25.

The fol:-

lowing is a list of the changes in the license for the incorpora-tion of the Amendment.

Tab.le 3. 7. l The Amendment specifies the add'ition 'of the torus to.cot:idenser drain valve to the Primary Isolation Group II valves.

AMENDMENT {fo44 On September 18, 1980, the Nuclear Regulatory Commission issued.

Amendment #44 to the Dresden Facility License No. DPR-25.

The fol-lowing is a list of the changes in the license for* the it~.corpora:

tion of the Amendment.

Paragraph 4.10.B The Amendment allows exceptions to the requirement of daily testing.surveillances of the SRM' s.

AMENDMENT #45 On November 17, 1980,. the NuClear Regulatory Commission issued Amendment #45 to the Dresden Facility License No~ DPR-25.

The fol-lowing is a*list of the changes in the license for the incorpora-tion of the Amendment.

-H-

AMENDMENT #45 (Continued)

The Amendment states that the licensee shall fully implement and maintain in effect all provisions of the Connnission-approved Safeguards Contingency Plan, including amendments and changes made pursuant to the authority of 10 CFR 50.54(p).

-13~

UNIT 3 OTHER.CHANGES, TESTS AND EXPERIMENTS MODIFICATION Ml2-3-76-60 Resupport the Main Steam Line Instrument Racks to Eliminate Vibration Problems The change involved isolating the MSL high flow switch instru-ment racks 2203-9B and 2203-lOB from the floor grating material and stiffening the.structure of the instrument racks themselves.

The intent of this modification is to provide overall reliability of the MSL in-struments by being less susceptible to external influences.

The safety evaluation concluded that the possibility of spurious reactor scrams resulting from rack vibration is reduced with the installation of this modification.

. MODIFICATION Ml2-3-77-2 Replace All Drywell Hydraulic Snubbers with Mechanical Snubbers Over the Next Three Refueling Outages The change involved replacing all the hydraulic snubbers in the Unit 3 drywell with mechanical. snubbers over a time period of three (3) refueling outages.. This was accomplished in the stated. time period so that the radiation dose incurred by station personnel would be kept to a minimum.

The safety evaluation concluded that the hydraulic snubbers are being replaced with mechanical snubbers of equal ratings and the min-*

imum performance requirements as specified by ASME Section III, Sub-section NF, are not being modified.

MODiFICATION Ml2-3-78-18 Modify LPCI Loop Selection Logic.Closure of the Recirculation Suction System Valve The change involved modifying the LPCI loop selection circuitry to disable closure of the recirculation pump selection valve so that when completed, there would be two (2) open contacts in. the closing cir-cuit which would reduce the likelihood of a short causing spurious oper-ation.

The safety evaluation concluded that the margin of safety is unaffected because maintaining both recirculating suction valves in open position decreases chance£? of vessel pressure buildup in the unlikely event of a water.line break and also the surveillance requirements remain as.before; thus, no new accident or malfunction is created; and the system remains unchanged as previously evaluated.

MODIFICATION Ml2-3-78~33 Provide Local Control Capability for Unit 3 Control Rod Drive Pumps The change involved modifications of the locai controls to the main feed circuit breakers that are necessary for energizing the buses which feed the CRD pumps.

The following 4160 volt circuit breakers are provided with local control:

3310, 3306, 3323, 3333, 3403, 3406, 3432, 3427, and 3421.

f' The safety evaluation concluded that in the unlikely event of a fire in the Control Room or Auxiliary Electric Room, local control of these breakers will insure that a high pressure system (CRD) will be available to provide reactor make-up water and that the buses that feed the CRD pumps can be energized.

Local control of the breakers will not impair the capability of the CRD's because their automatic tripping and closing logic has not been altered; also, manual initiation from the Con-trol* Room has not been hinde.red *

. MODIFICATION Ml2-3-78-34 Install a Local Control Indication System for the Isolation Condenser Shell Water The change involved the addition of a local level indicator on the Isolation *condenser to allow local reading of the shell water level in the unlikely event of Control Room inoperability because of a loss of*

power.

The safety evaluation concluded that the margin of safety is increased by allowing for local checks in addition to remote. indicators presently in the Control Room.

MODIFICATION Ml2-3-79-05 Modify the HPCI Control C_ircuit to Bypass the Pump Low Suction Pressure Trip During Automatic Start The change involved a few wiring changes.in the Auxiliary Electric Room panel 903-39, and the electrical drawings were revised to show this modification.*

The safety evaluation concluded that eliminating this trip of the HPCI pump because of a low booster pump suction pressure will* no.t impede its ability to perform its intended function.

MODIFICATION Ml2-3-79-25.

Affect Permanent Repairs of the West Reactor Building Blow-Out Panel Temporarily Repaired by Modification Ml2-3-79-10 The change involved replacing the temporary panels installed when the panel was blown off on February 2,* 1979, with like-for-like material as the original panels.

Also, some modifications were done to the instrumentation controls by the addition of differential pressure transmitters within the reactor building and on the four outside walls to sense the~P of the reactor building.

The safety evaluation concluded that reactor building integrity is maintained during normal operation, while providing pressure relief

in the event of a tornado. *Materials and components used for the perma-nent repair will increase reliability and maintain design performance.

,'~.

'MODIFICATION Ml2-3-79-40 Modify the Control Switches and Appropr.iate Circuitry for All Group II Primary Con.tainment Isolatian Valves (NRC Commitment)

The change involved modifying existing logic of the control switches and appropriate circuitry such that the Group II primary con-tainment isolation valves are prevented from automatically opening when the isolation signal is reset.

The automatic opening of the valves upon reset has been eliminated, and they now require manual opening by an operator, thus avoiding accidental automatic opening.

The safety evaluation concluded that the margin of safety actually inc'reases by eliminating the automatic reopening and requiring manual opening* of the valves by an operator.

MODIFICATION Ml2-3-79-53 Limit the Maximum Opening Angle of the Containment Vent and Purge Valves (NRC Commitment)

The change. involved the installation of a passive mechanical blocking modification to limit valve travel in the open direction for the following valves:

3-1601-21, -22, -23, -24, -56, -60, and -63.

The safety evaluation concluded that the margin of. safety has been increased by the modifications to the valves because their performance of the' isolation function has *increased..

MODIFICATION Ml2-3-79-54 Replace Five (5) NA-100 LPRMStrings with Five (5) Reuter-Stokes LPRM Strings The change involved replacing the existing five (5) NA-100 Local Power Range Monitors (LPRM) with five (5) Reuter-Stokes Model 212 LPRM strings because of improved design and manufacturing features.

The safety evaluation concluded that the basic.LPRM is un-changed and that its functioning and mode of operation is also unchanged.

Therefore, the margin of safety as defined in the Technical Specifica-tions is not reduced.

MODIFICATION Ml2-3-80-l Provide Additional Pipe*, Supports for Seismic Qualification of the Target Rock Safety Relief Valve Pneumatic Supply Line (NRC C0tmnitment)

The change involved adding pipe supports and brackets to the Target Rock Safety Relief Valve pneumatic supply line so that the line is ensured to have seismic capability and also enhance the overall re-

'~iability of the pneumatic supply system.

The safety evaluation concluded that this modification upgrades the capability of existing equipment to withstand design basis events and enhance. its operability, thus increasing its margin of safety arid that its intended function will not be changed.

MODIFICATION Ml2-3-80-5 Add Special Components to the HPCI D.C. Automatic Throwover Circuit The change involved adding HPCI motor gear unit, motor speed changer, turbine stop valve reset, overspeed test.solenoid, and valves.

AO 2301-31 and SOV 2301-32 control circuits to the HPCI D.C. automatic*

.throwover circuit.

The addition of these components and functions to the D.C. throwover scheme will provide for the more efficient operation of the HPCI system.

The safety evaluation concluded that this modification will.

increase the margin of safety by increasing the reliability of the HPCI system arid insure that it will operate as postulated in the F.S.A.R.

by providing backup power for essential HPCI equipment.

MODIFICATION Ml2-3-80-6 Replace the Shaft Bushings on All.Twelve (12) Vacuum Breakers*

With Phosphor-Bronze Bushings

.The change involved replacing the teflon torus to drywell vacuum breaker. valve bushings with phosphor-bronze bushings on all.twelve (12) of the valves.

The safety evaluation concluded that the new bushings are softer and make a better seal; and as the new bushings have greater re-liability, the function of the valves remains unchanged; thereby, the potential for creation of a new accident remains unchanged.

MODIFICATION Ml2-3-80-7 Provide Disc Replacement for the Twelve (12) Torus-Drywell Vacuum Breakers with Stronger. and Dimensionally Same Discs

The change involved replacing the 18-inch torus-drywell vacuum breaker valve discs of~sand cast aluminum with wrought aluminum alloy discs for all twelve (12) of the valves.

The safety evaluation concluded that the new discs are stronger and have increased reliability; and as the function of the valves remains unchanged, the potential for creation of a new accident remains unchanged.

~.

MODIFICATION Ml2~3-80-25 Modify the Reactor Water Cleanup Isolation Valve 3-1201-1 to Allow for Throttling of the Valve The change involved modifying the R.W.C.U. isolation valve*

3-1201-1 circuitry such that the valve can be throttled open to slowly fill the system when it is being started up.

The safety 1evaluation concluded that the margin of safety has not been reduced because its primary containment isolation.function has not been changed and that its surveillance requirement as.defined in the Technical Specifications is still the same.

~ r DRESDEN 2 AND 3 SAFETY/RELIEF VALVE STATEMENT During the year 1980, the pressure setpoint of the safety valves and relief valves on Units 2 and 3 were not challenged, and the safety and relief valves ~

~

actuate automatically.

Four (4) of the eight (8) safety valves are replaced and tested at the end of each. operating cycle (the remaining four (4) are tested after the next operating cycle), and no failures have been noted,to date.

GLOSSARY The following is a list of abbreviations which may appear in this report *.

- Pneumatic OperatedValve AP LR GR

- Average Planar Linear Heat Generation Rate APRM

- Average Power Range Monitor ARMS

- Area Radiation Monitoring System BKR

- Motor Control Center or Bus Breaker ccsw

- Containment Cooling Service Water Pump CRD

- Control Rod Drive DPIS

- Differerttial Pressure Indicating Switch ECCS

- Emergency Core Cooling System EGC

- Economic Generation Control EHC

- Electro-Hydraulic Control ESS