ML20082M399

Amends 101 & 100 to Licenses DPR-80 & DPR-82,respectively, Revising AOT of RWST for Adjustment of Boron Concentration from 1 to 8 H

ML20082M399
Person / Time
Site:	Diablo Canyon
Issue date:	04/14/1995
From:	Mark Miller NRC (Affiliation Not Assigned)
To:
Shared Package
ML20082M403	List: ML20082M399 ML20082M417 ML20082M437
References
NUDOCS 9504240210
Download: ML20082M399 (15)

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UNITED STATES p

NUCLEAR REGULATORY COMMISSION j

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WASHINGTON. D.C. SDess 0001 PACIFIC GAS AND ELECTRIC CONPANY l

i DOCKET NO. 50-275 DIABLO CANYON NUCLEAR POWER PLANT. UNIT NO. 1 AMENDMENT TO FACILITY OPERATING LICENSE P

Amendment No.101 License No. DPR-80 l

1.

The Nuclear Regulatory Comunission (the Commission) has found that:

A.

The application for amendment by Pacific Gas and Electric Company (the licensee) dated August 17, 1994, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's regulations set forth in 10 CFR Chapter I; i

P The facility will operate in conformity with the application, the i

provisions of the Act, and the rules and regulations of the Commission; C.

There is reasonable assurance (i) tLat the activities authorized by this amendment can be conducted without endangering the health i

and safety of the public, and (ii) that such activities will be i

conducted in compliance with the Commission's regulations; D.

The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public-and 1

E.

The issuance of this amendment is in accordance with 10 CFR i

Part 51 of the Commission's regulations and all applicable requirements have been satisfied, j

i 2.

Accordingly, the license is amended by changes to the Technical 1

Specifications as indicated in the attachment to this license amendment, i

and paragraph 2.C.(2) of Facility Operating License No. DPR-80 is hereby amended to read as follows:

j 9504240210 950414 PDR ADOCK 05000275 P

PDR

(2)

Technical Specifications The Technical Specifications contained in Appendix A and the Environmental Protection Plan contained in Appendix B, as revised through Amendment No.101, are hereby incorporated in the license.

Pacific Gas and Electric Company shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan, except where otherwise sti.+ed in specific license conditions.

3.

This license amendment is effective as of its date of issuance to be implemented within 30 days of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION Melanie A. Miller, Senior Project Manager Project Directorate IV-2 Division of Reactor Projects III/IV Office of Nuclear Reactor Regulation Attar' ment: Changes to the Technical Specifications Date of Issuance:

April 14, 1995 I

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' UNITED STATES -

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j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. sege64elH

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PACIFIC GAS AND ELECTRIC COMPANY DOCKET No. 50-323 Q1&BLO CANYON NUCLEAR POWER PLANT. UNIT NO. 2 AMENDMENT TO FACILITY OPERATING LICENSE I

Amendment No. 100 License No. DPR-82 l

1.

The Nuclear Regulatory Commission (the Commission) has found that:

l A.

The application for amendment by Pacific Gas and Electric Company (the licensee) dated August 17, 1994, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's regulations set forth in 10 CFR I

Chapter I; l

B.

The facility will operate in confonnity with the application, the provisions of the Act, and the rules and regulations of the Commission; l

C.

There is reasonable assurance (1) that the activities authorized i

by this amendment can be conducted without endangering the health I

and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations;

~

D.

The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and j

E.

The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

2.

Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, i

and paragraph 2.C.(2) of Facility Operating License No. DPR-82 is hereby i

amended to read as follows:

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(2)

Technical Snecifications The Technical Specifications contained in Appendix A and the Environmental Protection Plan contained in Appendix B, as revised through Amendment No.100, are hereby incorporated in the license.

Pacific Gas and Electric Company shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan, except where otherwise ' stated in specific license conditions.

3.

This license amendment is effective as of its date of issuance to be i

implemented within 30 days of issuance.

t FOR THE NUCLEAR REGULATORY C0pmISSION-l b

Melanie A. Miller, Senior Project Manager Project Directorate IV-2 Division of Reactor Projects III/IV Office of Nuclear Reactor Regulation l

Attachment:

Changes to the Technical Specifications

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Date of Issuance:

April 14, 1995 i

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1 ATTACHMENT TO LICENSE AMENDMENTS AMENDMENT NO.101 TO FACILITY OPERATING LICENSE NO. DPR-80 AND AMENDMENT NO. 100 TO FACILITY OPERATING LICENSE NO. DPR-82 DOCKET NOS. 50-275 AND 50-323 i

Revise Appendix A Technical Specifications by removing the pages identified below and inserting the enclosed pages. The revised pages are identified by Amendment number and contain marginal lines indicating the areas of change.

i Overleaf pages are also included to maintain document completeness REMOVE INSERT 3/4 1-13 3/4 1-13 3/4 1-14 3/4 1-14 3/4 5-11 3/4 5-11 B 3/4 5-3 B 3/4 5-3 B 3/4 5-4 B 3/4 5-5 B 3/4 5-6 l

B 3/4 5-7 B 3/4 5-8 j

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1 FEACTIVITY CONTROL SYSTEMS BORATED WATER SOURCES - OPERATING LIMITING CONDITION FOR OPERATION 3.1.2.6 The following borated water source shall be OPERABLE:

I a.

A Boric Acid Storage System with:

1)

A minimum contained borated water volume of 14,042 gallons, 2)

A boron concentration between 7,000 and 7,700 ppm, and 3)

A minimum solution temperature of 65'F.

I AEPLICABILITY: MODES 1, 2, 3 and 4.

ACTION:

L a.

With the Boric Acid Storage System inoperable, restore the system to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and borated to a SHUTDOWN MARGIN equivalent to at least 1% ok/k at 200*F; restore the Boric Acid Storage System to OPERABLE status within the next 7 days or be in COLD SHUTDOWN within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

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DIABLO CANYON - UNITS 1 & 2 3/4 1-13 Unit 1 - Amendment No. Ga 7B,101 r

Unit 2 - Amendment No. 6h-74,100

L REACTIVITY CONTROL SYSTEMS SURVEILLANCE RE0VIREMENTS 4.1.2.6 The borated water source shall be demonstrated OPERABLE:

l a.

At least once per 7 days by:

1)

Verifying the boron concentration in the water, 2)

Verifying the contained borated water volume of the water source, and 3)

Verifying the Boric Acid Storage System solution temperature.

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l DIABLO CANYON - UNITS 1 & 2 3/4 1-14 Unit 1 - Amendment No. 101 Unit 2 - Amendment No. 100

EMERGENCY CORE COOLING SYSTEM 1 3/4.5.5 REFUELING WATER STORAGE TANK-LIMITING CONDITION FOR OPERATION 3.5.5 The Refueling Water Storage Tank (RWST) shall be OPERABLE with:

a.

A minimum contained borated water volume of 400,000 gallons, b.

A boron concentration of between 2300 and 2500 ppm, and c.

A minimum solution temperature of 35*F.

APPLICABILITY: MODES 1, 2, 3 and 4.

ACTION:

a.

With the RWST inoperable due to boron concentration not within limits, restore the tank to OPERABLE status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

b.

With the RWST inoperable for reasons other than boron concentration not within limits, restore the tank to OPERABLE status within I hour i

or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

SURVEILLANCE REGUIREMENTS 4.5.5 The RWST shall be demonstrated OPERABLE:

a.

At least once per 7 days by:

1)

Verifying the contained borated water volume in the tank, and 2)

Verifying the boron concentration of the water.

b.

At least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by verifying the RWST temperature when the outside ambient air temperature is less than 35'F.

i DIABLO CANYON - UNITS 1 & 2 3/4 5-11 Unit 1 - Amendment No. GB,101 Unit 2 - Amendment No. 52,100

EMERGENCY CORE COOLING SYSTEMS BASES j

ECC5 SUBSYSTEMS (Continued)

The maximum flew Surveillance Requirement ensures that the minimus injection line resistance assumptions are met.

These assumptions are used to calculate maximum flows to the RCS for safety analyses which are limited by maximum ECCS flow to the RCS.

The Surveillance Requirement for the maximum difference between the minimum and maximum individual injection line flows ensures that the minimum individual injection line resistance assumed for the spilling line following a LOCA is met.

The maximum total pump flow Surveillance Requirements ensure the pump runout limits of 560 gpa for the centrifugal charging pumps and 675 gpm for the safety injection pumps are met.

The safety analyses are performed assuming the miniflow recirculation lines for the ECCS subsystems associated with the centrifugal charging and safety injection pumps are open. The flow balancing test is, therefore, performed with these miniflow recirculation lines open.

Some of the flow from the centrifugal charging pumps will go to the RCP seals during ECCS operation.

Therefore, the flow balance test is performed with a simulated flow from the centrifugal charging pumps to the RCP seals.

The simulated flow rate is consistent with the actual RCP seal resistance and the resistance of the RCP seals assumed in the calculation of ECCS flows for j

the safety analyses.

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DIABLO CANYON - UNITS 1 & 2 B 3/4 5-2a Amendment Nos.

55 & 54, 72 & 71 1

EMERGENCY CORE COOLING SYSTEMS BASES 3/4.5.5 REFUELING WATER STORAGE TANK BACKGROUND The Refueling Water Storage Tank (RWST) supplies borated water to the Chemical and Volume Control System (CVCS) during abnormal operating conditions, to the refueling cavity during refueling, and to the Emergency Core Cooling System (ECCS) and the Containment Spray (CS) System during accident conditions.

The RWST supplies both' trains of the ECCS through one header and both trains of the CS System through a separate supply header during the injection phase of a loss of coolant accident (LOCA) recovery. A motor-operated isolation valve is provided in each header to isolate the RWST from the ECCS and from the CS System once the RWST is no longer supplying flow to these systems. At that time, additional motor-operated isolation valves can isolate each ECCS and CS subsystem from the RWST flow header.

Use of a single RWST to supply both trains of the ECCS and CS System is acceptable since the RWST is a passive component, and a passive failure is not assumed to occur coincidentally with a Design Basis Accident (DBA).

During normal plant operation in MODES 1, 2, and 3, the Safety Injection (SI), CS, and Residual Heat Removal (RHR) pumps are aligned to take suction from the RWST. The Centrifugal Charging Pumps (CCPs) operate during normal plant operation with their suction aligned to the Volume Control Tank (VCT).

The switchover from normal operation to the injection phase of ECCS operation requires auto-transfer of the CCP suction from the CVCS VCT to the RWST.

When the suction for the RHR pumps is transferred to the containment sump, the RWST/RHR pump flow path must be isolated to prevent flow of containment sump water to the RWST, which could result in a release of contaminants to the atmosphere and the eventual loss of suction head for the RHR pumps due to loss of containment sump inventory.

j The reactivity control systems are available to the operators to ensure that negative reactivity is available during each mode of plant operation, j

This system is not an accident mitigation system, but is used under operator control if needed to increase the Reactor Coolant System (RCS) boration concentration.

The sources of borated water are the boric acid storage tanks in the CVS and the RWST. The RWST source of borated water is available as an alternate source to the boric acid storage traks. The RWST water can be used in the event of abnormal conditions, including fire and seismic events, that may impair the function of the boric acid storage tank source of borated water of the CVCS. The boration subsystem provides the means to meet one of the functional requirements of the CVCS, i.e., to control the neutron absorber (boron) concentration in the RCS and to help maintain the shutdown margin (SDM).

DIABLO CANYON - UNITS 1 & 2 B 3/4 5-3 Unit 1 - Amendment No. H,101 Unit 2 - Amendment No. H,100

EMERGENCY CORE COOLING SYSTEMS BASES 3/4,5.5 REFUELING WATER STORAGE TANK (Continued)

The Limiting Condition for Operation (LCO) ensures that:

The RWST contains a sufficient volume at an acceptable boron a.

concentration and temperature to support the ECCS and CS during the injection phase; b.

Sufficient water volume exists in the containment sump to support continued operation of the ECCS and CS System pumps at the time of transfer to the recirculation mode of cooling; c.

The reactor remains subcritical following a LOCA.

APPLICABLE SAFETY ANALYSES Any event that results in SI initiation, including inadvertent ECCS actuation, results in delivery of RWST water to the RCS. However, the events for which the RWST parameters provide mitigation or are limiting are large-break LOCA and steam line break. Feedwater line break and steam generator tube rupture (SGTR) also involve SI, but the RWST parameters are less significant to the analysis results. RWST boron concentration is an explicit assumption in the inadvertent ECCS actuation analysis, although it is typically a non-limiting event and the results are very insensitive to boron concentrations. The effect of these RWST parameters on large-break LOCA, main steam line break, feedwater line break and steam generator tube rupture are discussed below:

i LDLb Volume Insufficient water in the RWST could result in insufficient borated water inventory in the containment sump when the transfer to the recirculation phase Improper boron concentrations could result in a reduction of SDM or occurs.

excessive boric acid precipitation in the core following a LOCA, as well as excessive caustic stress corrosion of mechanical components and systems inside the containment. The deliverable volume limit is set by the LOCA and containment analyses.

For the RWST, the deliverable volume is different from the total volume contained since, due to the design of the tank, more water can be contained than can be delivered. The contained water volume limit includes an allowance for water not usable because of tank discharge location or other physical characteristics.

Boration During accident conditions, the RWST provides a source of borated water to the ECCS and CS System pumps. The minimum boron concentration limit ensures that the spray and the containment sump solutions, after mixing with DIABLO CANYON - UNITS 1 & 2 B 3/4 5-4 Unit 1 - Amendment No.101 Unit 2 - Amendment No.100

1 EMERGENCY CORE COOLING SYSTEMS BASES 3/4.5.5 REFUELING WATER STORAGE TANK (Continued) the sodium hydroxide of the spray additive tank, will not exceed the maximum pH values.

The maximum boron concentration limit ensures that the containment sump solution willnot be less than the minimum pH requirement.

The design basis transients and applicable safety analyses concerning each of these systems are discussed in the Diablo Canyon FSAR Update. These analyses are used to assess changes to the RWST in order to evaluate their effects in relation to the acceptance limits in the analyses.

For a large-break LOCA analysis, the RWST minimum contained water volume limit of 400,000 gallons and the lower boron concentration limit of 2300 ppm are used to compute the post-LOCA sump boron concentration necessary to assure subcriticality.

The large-break LOCA is the limiting case since the safety analysis assumes that all control rods are out of the core.

The upper limit on boron concentration of 2500 ppm is used to determine the maximum allowable time to initiate hot leg recirculation following a LOCA.

The purpose of initiating hot leg recirculation is to avoid boron precipitation in the core following the accident.

The use of minimum containment 64ckpressure in the LOCA analysis result in a conservative calculation of Peak Clad Temperature (PCT). The basis for this conclusion is the effect that the containment pressure has on the core reflood rate. A lower containment pressure has the effect of reducing the density of the steam exiting the break, which increases the differential pressure provided by the downcomer head (this phenomena is sometimes referred to as steam binding). Thus, a higher downcomer mixture level is required to maintain the same reflood rate as before. The additional time required to establish the downcomer head translates into a reduction in the reflood rate in the core. When the downcomer has completely filled, the equilibrium reflood rate for the low containment pressure case would be less than that calculated for a high containment pressure case. This reduction in reflood rate results in a reduction in heat transfer and ultimately an increase in the calculated PCT.

Thus, the regulations require that a low containment pressure be calculated in the large-break LOCA analysis.

Steam Line and Feedwater Line Breaks Volume Volume is not an explicit assumption in other than LOCA events since the required volume for those events is less than that required by LOCA.

Boration The minimum boron concentration is an explicit assumption in the main steam line break (MSLB) analysis to ensure the required shutdown capability.

Since Diablo Canyon no longer uses the boron injection tank, the minimum boron DIABLO CANYON - UNITS 1 & 2 B 3/4 5-5 Unit 1 - Amendment No.101 Unit 2 - Amendment No.100

EMERGENCY CORE COOLING SYSTEMS BASES 3/4.5.5 REFUELING WATER STORAGE TANK (Continued) concentration limit is an important assumption in ensuring the required shutdown capability.

For the containment response following an MSLB, the lower limit on boron concentration is used to maximum the total energy release to containment.

Feedwater line break results in high temperature /high pressure in the RCS. There is very little RWST water injection due to the high pressure.

Also, the analysis results are not affected by the negative reactivity provided by RWST water. Therefore, RWST boron concentration is not a consideration for the feedwater line break.

Steam Generator Tube Ruoture Volume The RWST volume needed in response to a SGTR is not an explicit assumption since the required volume is less than that required by a LOCA.

Boration The minimum boron concentration is an explicit assumption in the SGTR analysis to ensure the required shutdown capability.

Borated RWST water will be injected into the RCS for a SGTR event. The insertion of the control rods and the negative reactivity provided by the injected RWST solution provides sufficient SDM during the initial recovery operations. One of the initial operator recovery actions for this event is to equalize the RCS pressure and the faulted steam generator pressure to minimize or stop the primary-to-secondary tube rupture flow and terminate safety injection.

Further RCS boration will be initiated by the operator by manual makeup to the RCS.

LCD The RWST operability ensures that an adequate supply of borated water is available to cool and depressurize the containment in the event of a DBA, to cool and cover the core in the event of a LOCA, to maintain the reactor subcritical following a DBA, to ensure adequate level in the containment sump to support continued ECCS and CS function in the recirculation mode following a LOCA, and to provide an alternate borated water source for reactivity control.

To be considered OPERABLE, the RWST must meet the water volume and boron concentration established in the TS.

DIABLO CANYON - UNITS 1 & 2 B 3/4 5-6 Unit 1 - Amendment No.101 Unit 2 - Amendment No.100

EMERGENCY CORE COOLING SYSTEMS BASES 3/4.5.5 REFUELING WATER STORAGE TANK (Continued)

APPLICABILITY In MODES 1, 2, 3, and 4, RWST OPERABILITY requirements are dictated by ECCS and CS System OPERABILITY requirements. Since the ECCS and CS System must be OPERABLE in MODES 1, 2, 3, and 4, the RWST must also be OPERABLE to support their operation.

In MODES 5 and 6, RWST OPERABILITY requirements are dictated by reactivity control requirements in TS 3/4.1.2.5, " Borated Water Sources - Shutdown."

ACTIONS With RWST boron concentration not within limits, the boron concentration must be returned to within limits within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. Under these conditions, the ECCS and the CS System are not fully qualified to perform their design function. The 8-hour limit to restore boron concentration to within limits was developed considering the time required to change the boron concentration and the fact that the contents of the tank are still available for injection.

With the RWST inoperable for reasons other than boron concentration, it must be restored to OPERABLE status within I hour.

In this condition, sufficient water is not available in the RWST to assure core recovery and adequate sump volume for recirculation. Therefore, prompt action must be taken to restore the tank to OPERABLE status or to place the plant in a MODE in which the requirements for the RWST are less restrictive.

If the RWST cannot be returned to OPERABLE status within the associated Action Time, the plant must be brought to a MODE in which the LC0 for the RWST is less restrictive.

To achieve this status, the plant must be brought to at least Hot Standby (Mode 3) within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to Cold Shutdown (Mode 5) within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. Based on operating experience, the allowed Action Times are reasonable to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

EMRVEILLANCE RE0VIREMENTS Surveillance of the RWST ensures that an adequate supply of borated water is available to cool and depressurize the containment in the event of a DBA, to cool and cover the core in the event of a LOCA, to maintain the reactor subcritical following a DBA, to ensure adequate borated water level in the containment sump to support RHR pump operation in the recirculation mode, and to provide an alternate borated water source for reactivity control.

To be considered OPERABLE, the RWST must meet the water volume and boron cc, centration established in the surveillance requirements.

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DIABLO CANYON - UNITS 1 & 2 B 3/4 5-7 Unit 1 - Amendment No.101 Unit 2 - Amendment No.100

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EMERGENCY CORE COOLING SYSTEMS BASES 3/4.5.5 REFUELING WATER STORAGE TANK (Continued)

Surveillance Reauirement 4.5.5.a.1 The RWST water volume should be verified every 7 days to be above the required minimum level to ensure that a sufficient initial supply is available for injection and to provide a sufficient containment sump inventory to support continued RHR System pump operation on recirculation.

Since the RWST volume is normally stable and is protected by an alarm, a 7-day frequency is appropriate and has been shown to be acceptable through operating experience.

Surveillance Reauirement 4.5.5.a.2 The boron concentration of the RWST solution should be verified every 7 days to be within the required limits. Meeting this surveillance ensures that the reactor will remain subcritical following a LOCA.

Further, it assures that the resulting sump pH will be maintained within an acceptable range so that baron precipitation in the core will not occur and the effect of chloride and caustic stress corrosion on mechanical systems and components will be minimized.

Since the RWST volume is normally stable, a 7-day sampling frequency to verify boron concentration is appropriate and has been shown to be acceptable through operating experience.

DIABLO CANYON - UNITS 1 & 2 B 3/4 5-8 Unit 1 - Amendment No.101 Unit 2 - Amendment No.100