ML20207B893

Proposed Tech Specs,Changing Limiting Conditions for Operations Re Surveillance Requirements for Steam Generator Isolation Signal

ML20207B893
Person / Time
Site:	Fort Calhoun
Issue date:	07/17/1986
From:	OMAHA PUBLIC POWER DISTRICT
To:
Shared Package
ML20207B882	List: ML20207B877 ML20207B886 ML20207B893
References
TAC-61975, NUDOCS 8607180312
Download: ML20207B893 (10)

Text

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ATTACHMENT A PROPOSED WORDING I

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i 0607100312 PDR 060717ADOCK P Dit 0D000285 P

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2.0 LIMITING CONDITIONS FOR OPERATION 2.14 Engineered Safety Features System Initiation Instrumentation Settings Applicability Applies to the engineered safety features system initiation instrumentation settings.

Objective To provide for automatic initiation of the engineered safety features in the event that principal process variable limits are exceeded.

Specifications The engineered safety features system initiation instrumentation setting limits shall be as stated in Table 2-1.

Basis (1) High Containment Pressure The basis for the 5 psig set point for the high pressure signal is to establish a setting which would be exceeded quickly in the event of a DBA, cover a spectrum of break sizes, and yet be far enough above normal operation maximum internal pressure to prevent spurious initiation.

High containment pressure initiates the steam generator iso-lation signal which will close the main steam isolation and bypass valves and the main feedwater isolation and bypass valves.

(2) Pressurizer low Pressure The pressurizer low pressure safety injection signal is a diverse signal to the high containment pressure safety injection signal. The 1600 psia setting includes an uncertainty psia and is the setting used in the safety analysis.tl)of 122 (3) Containment High Radiation (Air Monitoring)

The containment air monitoring system comprises a moving paper filter particle monitor (channel RM-050) and a sample chamb gas monitor (channel RM-051) installed in a common housing.9r) 52 Optionally, the sampling point for channels RM-050 and RM-051 can be switched from the containment to the ventilation discharge duct.

2-61

' ' ' . 2'. 0" . LIMITING CONDITIONS FOR OPERATION Engineered Safety Features System Initiation Instrumentation 2.14 Settings (Continued)

(3) Containment High Radiation (Air Monitoring) (Continued)

The ventilation discharge monitoring system consists of a moving paper filter particle monitor (RM-061) and a sample chamber gas monitor (RM-062) installed in a common housing. An iodine monitor for I-131 (RM-060) also monitors these releases.

The setpoints for the isolation function will be calculated in accordance with the ODCM.

Each channel is supplied from a separate instrument A.C. bus and each auxiliary relay requires power to operate. On failure of a single A.C. supply, the A and B matrices will assume a one-out-of-two logic.

(4) Low Steam Generator Pressure A signal is provided upon sensing a low pressure in a steam generator to close the main steam isolation valves in order to minimize the temperature reduction in the reactor coolant system with resultant loss of water level and possible addition of reactivity. The setting of 500 psia includes a 122 psi uncertainty)and analysis.ld was the setting used in the safety Closure of the MSIV's (and the bypass valves, along with main feedwater isolation and bypass valves) is accomplished by the steam generator isolation signal which is a logical combination of low steam generator pressure or high containment pressure.

As part of the AFW actuation logic, a separate signal is -

provided to terminate flow to a steam generator upon sensing a low pressure in toat steam generator if the other steam generator pressure is greater than the pressure setting. This is done to minimize the temperature reduction in the reactor coolant system in the event of a main steamline break. The setting of 466.7 psia includes a +31.7 psi uncertainty; therefore, a setting of 435 psia was used in the safety analysis.

(5) SIRW Tank Low Level Level switches are provided on the SIRW tank to actuate the valves in the safety injection pump suction lines in such a manner so as to switch the water supply from the SIRW tank to '

the containment sump for a recirculation made of operation after a period of approximately 24 minutes following a safety injection signal. The switchover point of 16 inches above tank bottom is set to prevent the pumps from running dry during the 10 seconds required to stroke the valves and to hold in reserve approximately 28,000 gallons of at least 1700 ppm b9rated water. The FSAR loss of coolant accident analysis L4 )

assumed the recirculation started when the minimum usable volume of 283,000 gallons had been pumped from the tank.

2-62 Amendment No.J, JJ,

/J,JJ,86

2.0 LIMITING CONDITIONS FOR OPERATIONS

2. I'4 Engine: red Safety Fratures Syst o Initiation Instrumentation Settings (Continued)

(6) Low Steam Generator Water Level As part of the AFW actuation logic, a signal is provided to initiate AFW flow to one or two steam generators upon sensing a low water level in the steam generator (s) if the absolute steam generator pressure criteria or differential steam generator pressure criteria are satisfied. This function ensures adequate steam generator water level is maintained in the event of a failure to deliver main feedwater to either steam generator. The setting of 28.2% of wide range tap span includes a +13.2% uncertainty; therefore, a setting of 15% of wide range tap span was used in the safety analysis.

(7) High Steam Generator Delta Pressure As part of the AFW actuation logic, a high steam generator differential pressure signal is generated to provide AFW to the higher pressure steam generator with a concurrent low level signal if both steam generator pressures are less than 466.7 psia. If the differential pressure between steam generators is less than the setting, neither steam generator is supplied with AFW in the presence of a low level signal. The setting of 119.7 psid includes a -15.3 psi uncertainty; therefore, a setting of 135 psid was used in the AFW safety analysis.

References (1) USAR, Section 14.1.3 (2) USAR, Section 11.2.3.2 (3) USAR, Section 14.12 (4) USAR, Section 14.15 (5) USAR, Section 7.4.6 (6) USAR, Section 7.5.2.5 (7) USAR, Section 14.4.1 2-63 Amendment No. 65

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TABLE 2-1 -

Encineered Safety Features System Initiation Instrument Settina Limits Functional Unit Channel Settina Limit

1. High Containment a. Safety Injection 5 5 psig Pressure b. Containment Spray (3)

c. Containment Isolation

d. Containment Air Cooler DBA mode

e. Steam Generator Isolation

2. Pressurizer Low / Low a. Safety Injection 2 1600 psia (1)

Pressure b. Containment Spray (3) ,

c. Containment Isolation '

d. Containment Air Cooler DBA mode

3. Containment High Containment Ventilation Isolation In accordance with the Offsite Radiation Dose Calculational Manual

4. Low Steam Generator a. Steam Generator Isolation 2 500 psia (2)

Pressure b. Auxiliary Feedwater Actuation 2 466.7 psia l t

5. SIRW Low Level Recirculation Actuation 16 inches +0, -2 in. above Switches tank bottom l

6. 4.16 KV Emergency Bus a. Loss of Voltage (2995. "

j Low Voltage -<5.9j4)-ggj8 r Trip seconds _f j b. Degraded Voltage 1) Bus 1A3 Side 2 3825.52 volts )

(4.8 .5) seconds), Trib 2-64 Amendment No. /J, JJ, 86

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• 2.0 LIMITING CONDITIONS FOR OPERATION 2.15 Instrumentation and Control Systems Applicability Applies to plant instrumentation systems.

Objective To delineate the conditions of the plant instrumentation and control systems necessary to assure reactor safety.

Specifications The operability, permissible bypass, and Test Maintenance and Inoper-able bypass specifications i / the plant instrument and control systems shall be in accordance with Tables 2-2 through 2-5.

(1) In the event the number of channels of a particular system in service falls one below the total number of installed channels, the inoperable channel shall be placed in either the bypassed or tripped condition within one hour if the channel is equipped with a key operated bypass switch, and eight hours if jumpers or blocks must be installed in the control circuitry. The inoper-able channel may be bypassed for up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> from time of discovering loss of operability; however, if the inoperability is determined to be the result of malfunctioning RTDs or nuclear detectors supplying signals to the high power level, thermal margin / low )ressurizer pressure, and axial power distribution channels, these channels may be bypassed for up to 7 days from time of discovering loss of operability. If the inoperable channel is not restored to operable status after the allowabic time for bypass, it shall be placed in the tripped position or, in the case of malfunctioning RTDs or linear power nuclear de-tectors, the reactor shall be placed in hot shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. If active maintenance and/or surveillance testing is being performed to return a channel to active service or to establish operability, the channel may be bypassed during the period of active maintenance and/or surveillance testing. This nel when the plant is at or above 10specificationappliestothehighratJ.

7 power and is operating trip-w below 15Y. of rated power.

(2) In the event the number of channels of a particular system in I service falls to the limits given in the column entitled " Min-imum Operable Channels", one of the inoperable channels must be placed in the tripped position or low 1cvel actuation permissive position for the auxiliary feodwater system within one hour, if the channel is equipped with a bypass switch, and within eight hours if jumpers or blocks are required. If the channel has not been restored to operable status after 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> from time of dis-covering loss of operability, the reactor shall be placed in a hot shutdown condition within the following 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />; however, operation can continue without containment l

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• TABLE 2-4 4

JFSTRUMENT OPERATING CONDITIONS FOR ISOLATION FUNCTIONS

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Test Maintenance i Minimum Minimum Permissible and 4

Operable Degree of Bypass Inoperable NA Functional (Jpit Channels Redundancy Condition Bvoass

! I Containment Isolation h

A Manual 1 None None N/A

B Containment High i Pressure A 1 During Leak (f)

B 2((a)(e) 2 a)(e) 1 Test I Pressurizer Low / Low A 1 Reactor Coolant (f) i B 2fa)(e) 2 a)(e) 1 PressuregsThan I 1700 psia 2 Steam Generator Isolation l j A Manual 1 None None N/A

! B Steam Generator Isolation 1 None None N/A

) (i) Steam Generator ,

i Low Pressure A 2/St9ag 1/ Steam Steam Generator (f)

Gen gel Gen Lg Pressure (c,ss Than 550 psia j B 2/Stpa 1/ Steam ,

Gen \*g!

' Gen (ii) Containment High Pressure A 1 During Leak (f) i B 2((a)(e) 2 a)(e) 1 Test l 3 Ventilation Isolation A Manual 1 None None N/A i

B Containment High Radiation A 2((d)

None If Containment (f)

B 2 d) None Ventilation Isolation Valves Are closed I

a A and B circuits each have 4 channels.

b Auto removal of Lypass above 1700 psia.

c Auto removal of bypass above 550 psia, i 2-69 Amendment No. ES, 93 l

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(Continued) 1 l d A and B circuits are both actuated by any one of the five VIAS initicting l

channels; RM-050, RM-051, RM-060, RM-061, or RM-062; however, only RM-050 l

and RM-051 are required for containment ventilation isolation. ~

e If minimum operable channel conditions are reached, one inoperable channel must be placed in the tripped condition within eight hours fr6m the time of discovery of loss of operability. The remaining inoperable channel may be bypassed for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> from the time of discovery of loss.'.of operability and, if an inoperable channel is not returned to operable status within this time frame, a unit shutdown must be initiated [see Specification 2.15(2)].

! f If one channel becomes inoperable, that channel must be placed in the tripped or bypassed condition within eight hours from the time of discovery cf loss of operability. If bypassed and that channel is not returned to operable status within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> from the time of discovery of Joss of operability, that channel must be placed in the tripped condition within

the following eight hours. (See Specification 2.15(1) and exception l associated with maintenance.) I i .

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l 2-69a Amendment No. 83

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e ATTACHMENT B JUSTIFICATION

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Discussion, Justification and No Significant Hazard Consideration In response to IE Bulletin 80-04, OPPD changed the logic which provides Main Steam Isolation to avoid the overpressurization of containment in the event of a Main Steam Line Break with continued feedwater addition. The logic used to close the Main Steam Isolation Valves was duplicated for the Main feedwater isolation valves. The signal has also been subsequently renamed " Steam Generator Isolation Signal" in order to better state its function.

A Steam Generator Isolation Signal (SGIS) is composed of a logical combination of a Containment High Pressure Signal or a Steam Generator Pressure Low Signal. The proposed changes to the technical specifications will accomplish the folicwing:

1. Correct the wording of Specification 2.14. The specification currently states that the " setting limits and permissible bypasses shall be as stated in Table 2-1." Table 2-1 does not contain permissible bypasses, so this statement has been reworded.

2. A paragraph has been added to 2.14 Basis items (1) and (4) to discuss the steam generator isolation signal. Additionally, Section 2.14 References have been changed from FSAR to the current terminology, USAR.

3. Item e, Steam Generator Isolation, has been added as a channel of  ;

functional Unit 1, High Containment Pressure, of Table 2-1.

4. Table 2-1, Item 4a has been reworded to " Steam Generator Isolation" from

" Steam Line Isolation."

5. The wording of Specification 2.15 has been revised to more accurately reflect the contents of Tables 2-2 through 2-5.

6. Table 2-4 has been modified to correctly specify those signals which comprise a signal to isolate the steamline.

The addition of the signal, correctly defined, to the Technical Specifications will alleviate a portion of the confusion on this subject. It should also be noted that the mode of operation (or isolation) has not changed, it has only been clarified.

No Sianificant Hazards Considerations This change will not increase the probability of any accident previously analyzed. The changes serve to clarify the Technical Specifications concerning the Steam Generator Isolation Signal.

This change will not create the possibility of a new or different accident than previously analyzed. There has been no change in the method of operation, only clarification of existing modes of operation.

This change will not reduce the margin of safety as defined in the basis of any Technical Specification. Again, no new mode of operation is being employed; the changes simply serve to clarify existing practices.