ML13317A571

Draft Operating Instruction SO1-1.5-3,Rev 0, Technical Guideline for Response to High Containment Radiation Level

ML13317A571
Person / Time
Site:	San Onofre
Issue date:	04/08/1983
From:	Southern California Edison Co
To:
Shared Package
ML13317A570	List: ML13317A568 ML13317A571
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.B.2, TASK-TM SO1-1.5-3-DRFT, TAC-44128, NUDOCS 8304130121
Download: ML13317A571 (11)

Text

SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTPUCTION S01 -1

.-?

UNIT 1 EMERGENCY REVISION 0 PAGE 1 TECHNICAL GUIDELINE FOR RESPONSE TO HIGH CONTAINMFNT RADIATION LFVFL ei4130121 830408 PDR ADOCK 05000206 P

PDR

SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION 501-1.5-3 UNIT I EMERGENCY REVISION 0 PAGE 2 TECHNICAL GUIDELINE FOR RESPONSE TO HIGH CONTAINMENT RADIATION LEVEL PURPOSE The purpose of this guideline is to provide criteria for the operator to isolate containment ventilation and fluid systems. This will minimize radiological hazards outside of the containment that may result from a significant casuality.

SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTPUCTION S01-1.5-3 UNIT 1 EMERGENCY REVISION 0 PAGE 3 TECHNICAL GUIDELINE FOR RESPONSE TO HIGH CONTAINMENT RADIATION LEVFL STEP ACTION/EXPECTED RESPONSE PESPONSF NOT OBTAINED 1

VERIFY High Containment Radiation Level:

Verify containment IF neither containment radiation monitors:

radiation monitor is

HIGH, ORMS R 1212 -

GREATER THAN ALARM SET POINT, THEN co to procedure OR in effect.

ARMS R T32 -

GREATER THAN 600 MR/HR.

2 CHECK Containment Ventilation Penetrations:

Check containment IF any containment purge and exhaust valves purge and exhaust CLOSED.

valve is NOT CLPSFD, THEN manually close the valve.

3 CHECK For Fuel Failure Indi cation:

Check containment IF both containment high radiation on high range monitors are range monitors:

LESS THAN 10 P/HR, ARMS R 1255 - GREATER THEN go to procedure THAN 10 R/HR, in effect.

OR ARMS R 1257 -

GREATER THAN 10 R/HR.

SAN ONOFRE NUCLEAR-GENERATING STATION OPERATING INSTRUCTION S01-1.5-3 UNIT 1 EMERGENCY REVISION 0 PAGE 4 TECHNICAL GUIDELINE FOR RESPONSE TO HIGH CONTAINMENT RADIATION LEVEL STEP ACTION/EXPECTED RESPONSE RESPONSE NOT OBTAINED CAUTION During high containment radiation conditions all process lines penetrating containment shall be isolated. Letdown and radwaste systems will remain isolated to allow access to the west side of containment, to the alternate hot leg recirculation valve, and to the wide range gas monitor.

Letdown and radwaste systems will not be restored to service without the Emergency Coordinator's approval.

4 ISOLATE Containment Fluid Systems:

a. Check all automatic

a. IF all containment containment isolation valves are NOT valves -

CLOSED.

CLOSED, THEN evaluate need for associated systems to remain IN SERVICE.

b. Manually isolate systems penetrating containment that are not required.

5 SUBSEQUENT Action:

Go to procedure in effect.

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SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION So1-1.5-3 UNIT 1 EMERGENCY REVISION 0 PAGE 1 BACKGROUND DOCCUMENT FOR RESPONSE TO HIGH CONTAINMENT PADIATION.EVEL TABLE OF CONTENTS Section Page

1.0 INTRODUCTION

2 2.0 RECOVERY TECHNIQUE 2.1 Description 2

2.2 Flow Chart 3.0 BASIS FOR EOI STEPS 5

4.0 REFERENCES

7

SAN ONOFRE NUCLEAR GENERATING STATION OPERATING INSTPUCTION SOl-1.5-3 UNIT 1 EMERGENCY REVISION 0 PAGF 2 BACKGROUND DOCUMENT FOR RESPONSE TO HIGH CONTAINMENT RADIATION LEVEL

1.0 INTRODUCTION

The entrance into this instruction requires that containment radiation monitors indicate a high enough radiation level to require operator response to evaluate containment isolation status. The first level of response to high radiation relates to the normal set point for isolation of the containment ventilation system.

The second level of response relates, as a maximum, to a 1% fuel failure following a significant casuality in containment.

The containment is designed to accommodate radiation levels coincident with a core meltdown.

However, verification of proper containment isolation is required in order to minimize the potential for the release of radioactive material from the containment following an accident. Also, to minimize the possibility of a radiological release outside containment and excessive exposure to individuals working in the vicinity of process lines outside containment, isolation of fluid systems that are not necessary to recover from the accident should be performed.

Once required containment isolation is accomplished the operator is directed to go to the procedure in effect.

2.0 RECOVERY TECHNIQUE 2.1 Description High containment radiation is addressed at two levels. The first is a high radiation indication that would indicate the need to isolate or verify the isolation of containment ventilation systems.

The second high radiation level, which indicates clad and possible fuel failure, identifies the need to isolate fluid systems that penetrate containment to minimize potential radiation exposure to the outside environment. This is accomplished in the following seouence:

1. Entry conditions for containment high radiation are verified and containment ventilation penetrations are closed.

2. A check for fuel failure is made using containment high range monitor indication. If fuel failure is not evident the operator is directed to go to the procedure in effect.

3. If fuel failure is indicated all fluid lines penetrating containment are isolated that are not required for emergency response.

4.

The operator is directed to return to the procedure in effect.

SAN ON0FRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S01-1.5-3 UNIT 1 EMERGENCY REVISION 0 PAGE 3 BACKGROUND DOCUMENT FOR RESPONSE TO HIGH CONTAINMENT RADIATION LEVEL 2.1 Description (continued)

During subsequent monitoring of the CONTAINMENT Critical Safety Function Status Tree, high containment radiation level will be continuously addressed.

As this is a yellow path the operator will be directed to review this procedure for applicable actions when not involved in more significant operator actions.

SAN ONOFRE NUCLEA ENERATING STATION OPEPATN INS PJCTTIN S01-1.5-3 UNIT 1 EMERGENCY REVISION 0 PAGE 4 BACKGROUND DOCUMENT FOP RESPONSE TO PIGH CONTAIVMFNT PAPTATITOP LFVFL 2.2 Flow Chart IS R15 R 1257 ALARM is >

?

ARMS No ES P 1232 0T 600MR/HP PROCEDUPF IN EFFECT YES ARE PURGE AND N 0 EXHAUST VALVES CLOSED NY OPEN VALVE YES ARE ARMS NO G

R1255 OR R1257 GO TOUP

> 10R/HR A

PPCUP

?

IN EFFECT YES C

ARE ALL AUTO CONT.

NO EVALUATE NEED FOR ISOLALTION VALVES ASSOCIATED SYSTFM CLOSED TORM IN ISERVICE YES WMALLY ISOLATE SYSTEMS NOT REOUIPED llPPOCEDURE IN EFFECT--//

SAN ONOFRE NUCLEAR G ERATING STATION OPERATING INSTRUCTION S01-1.5-?

UNIT 1 EMFRGFNCY PEVISION V' PAMF F BACKGROUND DOCUMENT FOR RESPONSE TO HIGH CONTAINMENT RADIATION LEVEL 3.0 BASIS FOR EOI STEPS Step 1 This step is to verify the entry conditions on-hioh radiation level from the CONTAINMENT Critical Safety Function Status Tree which has a yellow terminus indicating an abnormal condition.

Two indications are used as an entry point to this instruction. The normal automatic setpoint for containment ventilation isolation originates from ORMS R 1212 which may be isolated..or out of service during the casuality that could address a high containment radiation condition.

Therefore, the second indication of ARMS 1232 is used to assure that containment ventilation is isolated on high radiation level.

The radiation levels selected are derived from the following:

1. ORMS Channel P 1212 at greater than 2 times background radiation level complies with the Technical Specification Table 3.5.5.2, "Containment Isolation Instrumentation Trip Set -Points", for Purge and Exhaust Isolation (Reference 3).

2.

ARMS Channel 1232 at areater than 600 mr/HP complies with a Pechtel Calculation ARA-NC-01.1, Rev. 1, "Containment Radiation Monitor Dose Rate", June 27, 1980 (Reference 2).

This calculation indicates that a total release of reactor coolant (at maximum allowable Tech. Spec.

activity) to containment would result in an initial radiation level in containment in excess of 6 R/HR.

This value has been reduced by a factor of 10 as an entry point to ensure containment ventilation system isolation.

.Step 2 This step ensures the containment ventilation system, normally isolated automatically from the ORMS Channel R 1212 set point, is indeed secured.

Step 3 If containment pressure is lower than the isolation set point of 1.A PSIC and SI is reset or CIS is overridden due to the need to place a system in service, the criteria in this step of 10 P/PR on high range radiation monitors is used to determine if the operator should return.fluid systems to service or perform additional isolation, i.e., letdown and PrP seal water return. This criteria is based on a Bechtel Calculation (Reference

2) which indicates for a 1% fission product release from fuel the radiation levels in containment would stablize at 5000 R/HR.

From the calculation indicating maximum activity level in containment following a loss of coolant with no fuel or clad damage addressed in the basis for step 1, the activity level in containment would not exceed 6.4 R/HR.

SAN CNOFRE NUCLEAR GENERATING STATION OPERATING INSTRUCTION S01-1.5-3 UNIT 1 EMERGENCY REVISION 0 PAGE 6 BACKG R2UND DOCUMENT FOR RSPONSE TO HIGH CONTAINMENT RADIATION LEVEL Step 3 (continued)

Therefore, a conservative set point of 10 R/HR on containment high rance monitors is used for the operator to access the need for returning containment fluid system to service or to go to the procedure in effect.

Caution Before Step 4 During a major casuality, fuel damage may be evident. Radiation levels in the containment and RCS activity could be higher than plant systems outside the containment (i.e., radwaste and shielding) are designed to accommodate (Reference 4 and 5).

Reinitiation of letdown and/or radwaste systems may prevent access to equipment, in the reactor auxiliary building area; such as, the alternate hot leg recirculation valve and the wide range gas monitor. Therefore the Emergency Coordinator will evaluate the need for future accessibility prior to any operator action to reinitiate letdown flow or to utilize the radwaste system.

Step 4 The criteria he will use for the degree of containment isolation, once the radiation level is verified, will depend on the casuality being addressed. For instance, if a major LOCA has occured there will be no option but to place the SI recirculation system in service after the RI4ST is depleted. However, letdown and RCP seal water return nay be isolated and containment sump pump discharge and gas vent process line from containment to radwaste coul.d be left isolated.

Step 5 After the operator has reviewed containment status following verification of fuel damage indication he is directed to return to the procedure in effect.

SAN 0 0FRE NUCLEAR GENERATING STATION OPERATING I NSTRUCTI ON 501-1.5-3 IEMERGENCY REVISION 0 PAGE BACKGROUND DOCUMENT FOR RESPONSE TO HIGH CONTAINMENT RADIATION LEVEL

4.0 REFERENCES

1. Westinghouse Owners Group Emergency Response Guideline FR-Z.3, Res onse to High Containment Radiation Level.

HP-Basic, September 1,

2. Bechtel Calculation ARA-NC-01.1, Revision 1, Containment Radiation Monitor Dose Rate, June 27, 1980.

3. Technical Specification Table 3.5.5.2, Containment Isolation Instrumentation Trip Set Point, Revised December 16, 1981.

4. SCE letter from R. W. Krieger to H. B. Ray dated December 20 1982 5Post-TUn Shielding.Design Review San Onofre Nuclear Generating Station Unit I".

5. SCE letter from K. P. Baskin (SCE) to D. G. Eisenhut (NRC) dated January 17, 1980, "Additional Information In Support of Responses to NRC TDI Requirements".

DR:%Js:0057A