ML20113H943

Proposed TS Table 3.3-10 Re Accident Monitoring Instrumentation

ML20113H943
Person / Time
Site:	Catawba
Issue date:	07/27/1992
From:	DUKE POWER CO.
To:
Shared Package
ML20113H939	List: ML20113H937 ML20113H943
References
NUDOCS 9208060176
Download: ML20113H943 (7)

Text

_ _ _ _ _ _ _ _ _ _ _ . . _ . _ _ _ . _ _ . _ _ _ _ . _ _ _ _ _ . _ _ _ . _ _ _ _

's i i .-

I

_ 1 INSTRLSEWATWI I i '

ACCIDE S fW ITORING INSTRUE NTATION

, LIMITING C04 ! TION FOR OPERATION i i

1

! 3.3.3.6 The accident monitoring instrumentation channels shown in Table 3.3-10 l shall be OPERABLE.

l APPt!CA81LITY: M00E5 1, 2, and 3.

ACTION:

l a. With the numb:r of OPERABLE accident monitoring instrumentation i

shannels less than the Total Number of Channels shown in l Table 3.3-10, restore the inoperable channel (s) to OPERABLE l- status within 7 days .or be in at least HOT STA28Y within the next l.

6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. , ,

a l b. With the numer of OPERA 8LE accident monitoring instrumentation 1 channels except the unit vent-high-high range area monitor, the .

steam relief valve exhaust radiation monitor, the containment atmosphere-high range radiation monitor, and the mactor coolant L radiation level less than the Minimum Channels OPERABLE-requirements i of Table 3.3-10, restore-the inoperable channel (s) to OPERA 8LE status I

within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or be in at least HOT STA 2 8Y 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 H0T SHUTDOWN within>the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

i c. With the numeer of 0PERA8LE Channels for the unit vent-high-high l range area monitur, or the steam relief valve exhaust radiation

!. mon' tor, or the containment atmosphere-high range radiation monitor, l or the reactor coolant radiation level less than required by the Minimum Channels OPERABLE requirements, initiate an alternate method of monitoring the appropriate parameter (s)'within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />,.and either restore the inoperable channel (s) to OPERABLE status within 7 days or prepare and sutmit' a- Special: Report to-the Commission pursuant to Specification'6.9.2 within 14 days'that provides actions l- taken, cause of the inoperability, and the plans and schedule for-restoring the channels to OPER/BLE-status.-

d. The provisions of Specification 3.0.4 are not applicable. -

l- ,

I l })RVEILLANCEREQUIREMENTS l

l-l 4.3.3.6- -Esch accident monitoring instrumentatie channel- shall be dem6..tstrated.

l OPERABLE by performance of the CHANNEL CHECA and CHANNEL CALIBRATION operations at the frequencies shown in Table 4.3-7.

-l 9208060176 920727- -

• PDR -ADOCK 05000413 I p PDR i l

CATAWBA - UNITS 1 & 2 _3/4 3-65

[v- . _i .

e___ _ _ _ . _ . _ _ .-... _ _ _ _. _ _ .m _

TABLE 3.3-10 (Continuedl ACCIDENT MONITO?. LNG INSIRUMENTATION

• MINIMUM TOTAL CHANNELS NO. OF OPERABLE CHANNELS E' INSTRUMENT 4/ core quadrant 2/ core apsedrant Q

15. In Core Thermocouples L ,_W

] N.A. r -

e* 16.

Unit Vent - High-High Range Area Monitor (EMF-54) ancl ) 5 T E nrr) Litt/E N.A.

' - 17.

Steam Relief Valve Exhaust Radiation Monitor (IEMF-26, 27, 28 p'29

' and 2 EMF-10, 11, 12 p l3) I a rY.i N.A.

18.

Containment Area - High Range Radiation Monitor (EMF-53 A or 8) 1 2

19. Reactor Vess'el Water Level N.A. 1 o

$ 20. Reactor Coolant Radiation Level (EMF-48)

Y Q

TABLE N3 TAT 10NS

• Not applicable if the associated block valve is in the closed position. d

• • Not applicable if the associated block valve is in the closed position and power is remove I

- - - - - _ _ _ _ - o

.. - . . .... . . . . . . - - . . . _ - .~ ..... .._.. . .. .-.... . .... . - -. -. .- . .. - - -.

l 8

l e i

a e

i s

i i

i.

i t

4 j

i i

4 4

l . .

l ATTACIIMENT II e

t

~

I i

l l

i 8

9 i

)

i i.

i I

e t

O

'O w

4 v ----*- gr-yy- -1y 7 g- +-y e--*.

PROPOSED REVISION TO TECHNICAL SPECIFICATION This proposed Technical Specification (TS) revision changes Table 3,3-10, Accident Monitoring Instmmentation, Item 17, Steam Relief Valve Exhaust Radiation Monitor, Minimum Channels Operable from "1" to "l/ Steam Line".

DISCUSSION AND TECHNICAL JUSTIFICATION An area radiation monitor is located adjacent to each Main Steam Line, upstream of tne Main Steam isolation valves, to detect secondary system radiation releases. Steam teleases are calculated on the plant computer, and the information is printed out on the alann typer.

The current Catawba Nuclear Station TS indicate that only one steam line monitor must be operable. Therefore, it is possible to have three Main Steam Lines with ir. operable radiation monitors wit'nout entering into the TS ACTION statement. Since there is only one radiation monitor per steam line, entry into the ACTION statement, which requires that alternate monitoring be provided within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, should be made when a Main Steam Line Monitor is inoperable.

During the original licensing process for Catawba, credit was taken for EMF-34 (Steam Generator Water Sample Monitor) as a back-up for the Main Steam Line Monitors. The original design of EMF-34 allowed it to be aligned to the affected Steam Generator to identify any leakage and to provide backup for the Main Steam Line Monitors. There have been continuous operability problems with EMF-34. Since Catawba has not been able to maintain the operability of EMF-34, a modification is scheduled that will change the design basis of the equipment. _In doing so, the "back-up" function that EMF-34 served for the Main Steam Line Monitors will be removed.

Catawba's msponse to Regulatory Guide 1.97 indicated that monitoring for all four steam lines would be available. The TS requirement to have only one of the Main Steam Line Monitors operable is not consistent with Catawba's response to Regulatory Guide 1.9_7.

In light of the fact that- Catawba's response to Regulatory Guide 1.97 indicates that-monitoring will be available for_all four Main Steam Lines, and that the Main Steam Line Monitors are the best method to assess releases through the Main Steam code safeties and the PORVs, Catawba requests to change the TS to require each steam line to have an ,

operable radiation monitor ("l/ Steam Line").

With the TS table revised at requested, TS 3.3.3.6 ACTION c would apply if one of Steam Relief Valve Exhaust Radiation Monitors is inoperable. This ACTION requires that, with

-l of 4

l l

less than the Minimum Channels OPERABLE Catawba must " initiate an ahernate method of monitoring the appropriate parameter (s) within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, and either restore the

inoperable channel (s) to OPERABLE status within 7 days or prepare and submit a Special Report to the Commission pursuant to Specification 6.9.2...'. This proposed revision to the TS has already been implemented administratively by a TS Interpretation. In order to be able to apply this ACTION, Catawba must have an alternative method for monitoring.

Two alternate methods have been developed and implemented through procedures. The two cases are 1) Steam Generator Tube Rupture (SGTR) with offsite power, and 2) SGTR with loss of offsite power.

In the event that a SGTR' occurs while the Main Steam Line Monitor for that Steam i Generator (SG) is inoperable, if offsite power is available, the Unit Vent can be used for offsite dose estimation. Steam would be routed to the condenser, and the condenser air i ejector would inute the activity to the Unit Vent. In this case the amount of activity released woulJ be assessed using the Unit Vent Monitor (EMF-36). It should be noted, that under normal circumstances it is preferable to cooldown in this manner, using the i condenser rather than dumping steam directly to the atmosphere through the Power i Operated Relief Valves or the Main Steam Code Safeties, i

In the unlikely event (9E-6/Yr.) of a SGTR concurrent with a loss of offsite power, ancther attemative for dose assessment is provided.

i This calculation provides correlation factors (in terms of uCi/cc/R/Hr of Xenon 133 equivalent) to ascertain the source term present in the Reactor Coolant System (RCS) based on-EMF-53 (High Radiation Inside Containment) indication. Source term release is calculated from the source tenn present in the RCS, primary to-secondary-leakrate, and i mass of steam released from the PORVs or code safeties. Iodine ratios are also provided i

along with the correlation factors to ascertain the iodine source term present, and these

iodine ratios are based on theoretically and empirically derived gap release fractions of noble gases versus iodines, along with partitioning in the Steam Generator.

. Since EMF-53 is a high range radiation monitor, a low-end cutoff value of 5 R/Ur is used as a multiplier for the correlation factors. This will create a significant degree of 4 conservatism in the estimation of offsite dose for the design basis case SGTR. A SGTR is not pirdicted to yield any fuel failure, and the only release would involve the previously_

existing breached fuel pins. Nor.aally, Catawba operates with no'more than 1 or 2-

breached fuel pins in the core. At 264 pins per assembly and 193 assemblies, this is a fuel fraction of only 4E-5. An EMF-53 indication of 5 R/Hr correlates to approximately I% .

i failed fuel.

In addition to conservatively over-estimating offsite dose for the design basis case SGTR, this methodology is capable of predicting offsite dose for fuel damage well above the design .

L basis case, and thus meets the intent of the Main Steam Line radiation monitor. Regulatory 2 of 4

Guide 1.97 requires a range for the Main Steam Line radiation monitor of 1E-1 to 1E3 uCi of XE-133 equivalent. The intent of Regulatory Guide 1.97 is to trea: the Main Steam Line radiation monitor as an effluent release point, which involves concentrations well above the amount that would be prescat in a design basis SGTR. Since the correlation data is insensitive to the absolute dose rate value, offsite dose can be estimated for any degree of core damage.

This methodology will conservatively predict offsite dose, and therefore may be used as an alternative to EMF-34 as a backup to the Main Steam Line radiation monitor.

This proposed change to the Technical Specifications will make the requirement in the TS ,

consistent with Catawba's Regulatory Guide 1.97 commitment. The intent of the change is to have the Main Steam Line Monitors operable at all times, or to comply with the action statement. The current TS only requires entry into the ACTION statement if all four Main Steam Line Monitors are inoperable. The proposed TS is more conservative because entry into the ACTION statement is made with one monitor inoperable, ensuring entry into the TS ACTION statement which provides alternative monitoring within-72 hours. The-alternative methods which Catawba plans to implement in the event that a monitor is inoperable are described above. This TS change will ensure that an adequate means of estimating offsite dose is available in the event of a SGTR.

NO SIGNIFICANT IIAZARDS ANALYSIS and ENVIRONhlENTAL IhlPACT STATEhlENT 10 CFR 50.92 states that a proposed amendment involves no significant hazards consideration if operation in accordance with the amendment would not:

1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or

2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or

3) ' Involve a significant reduction in a margin of safety.

This proposed change does not increase the probability or consequences of an accident previously evaluated. The Main Steam Line Monitors do not play a role in the initiation . l of an accident. The purpose of these monitors is to provide offsite dose assessment in the  !

event of a SGTR. This proposed TS amendment will more conservatively ensure that the Main Steam Line Monitors are operable than the current TSs. Procedures have also been developed and implemented to ensure that in the event that a monitor is inoperable, a backup method for dose assessment is available.

3 of 4 ,

1

4

-As stated above, the Main Steam Line Monitors do not play a role in accident initiation, therefore, this proposed TS amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated. This proposed amendment will ,

more conservatively ensure that the monitors will be available _to perform their intended function of dose assessment.

This proposed amendment does not involve any reduction in the margin of safety. These monitors do not play any role in accident initiation, they provide dose assessment. This proposed amendment will more conservatively ensure that a monitor is operable on each Main Steam line than the current TS which only requires one monitor to be operable.

Currently all four Main Steam Line monitors would have to be inoperable to enter the action statement. The proposed TS will require entry into the ACTION statement with one monitor inopemble, therefore ensuring that alternate monitoring is provided within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

The proposed Technical Specification change has been reviewed against the criteria of 10 CFR 51.22 for environmental considemtions. - As shown above, the proposed change does ,

not involve any significant hazards consideration, nor increase the types and amounts of effluents that may be released offsite, nor increase the individual or cumulative occupational radiation exposures. Based on this, the proposed Technical Specification change meets the criteria given in 10 CFR 51.22(c)(9) for categorical exclusion from the requirement for an EnvimnmentalImpact Statement.

~

l 4 of 4 i

. _ . -- . . - ._ ,.- . . - - . - . . , , - - . , - . , . ;.. , . , - , . , .