ML20151H756

Proposed Tech Specs Re RCS Leakage Detection Sys

ML20151H756
Person / Time
Site:	North Anna
Issue date:	07/20/1988
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML20151H750	List: ML20151H748 ML20151H756
References
NUDOCS 8808020040
Download: ML20151H756 (10)

Text

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ATTACliNENT 1 PROPOSED TECllNICAL SPECIFICATIONS CllANGE

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1 8 sos 020040 880720 ADOCK 05000338 PDR FDC p

4 RE' ACTOR COOLANT SYSTEM 3/4.4.6 REACTOR COOLANT SYSTEM LEAKAGE LEAKAGE DETECTION SYSTEMS LIMITING CONDITION FOR OPERATION 3.4.6.1 The following Reactor Coolant System leakage detection systems shall be OPERABLE:

a.

The containment atmosphere particulate and gaseous radioactivity monitoring system, and b.

The containment sump level and discharge flow measurement system.

6PPLICABILIII: MODES 1, 2, 3 and 4.

ACTICN:

With one of the above required leakage detacitan systems inoperable, operation may continue for up to 30 days provideo a RCS leakrate calculation (Specification 4.4.6.2.1.d) is performed at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Otherwise, 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 />.

SVRVEILLANCE RE0VIREMENTS 4.4.6.1 The leakage detection systems shall be demonstrated OPERABLE by:

a.

Containment atmosphere particulate and gaseous radioactivity l

monitoring system performance of CHANNEL

CHECK, CHANNEL CALIBRATION and CHANNEL FUNCTIONAL TEST at the frequencies specified in Table 4.3 3, b.

Containment sump level and discharge flow measurement system l

performance of CHANNEL CAllBRATION at least once per IB months, t

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o R ACTOR COOLANT SYSTEM l

3/4.4.6 REACTOR COOLANT SYSTEM LEAKAGE a

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LEAKAGE DETECTION SYSTElil 2

LIMITING CONDITION FOR OPERATION I

i 3.4.6.1 The following Reactor Coolant System leakage detection systems shall j

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a.

The containment atmosphere particulate and gaseous radioactivity i

j monitoring system, and t

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b.

The containment sump level and discharge flow measurement system.

i efPLICABILITY: MODES 1, 2, 3 and 4.

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ACTION:

I With one of the above re:;uired leakage detection systems inoptrable, operation j

may continue for up to 30 days provided a RCS leakrate calculation l

(Specification 4.4.6.2.1.d) is performed at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

I Otherwise, 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 t

j SHUTOOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

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i SURVEILLANCE RE0VIREMENTS f

i 4.4.6.1 The leakage detection systems shall be demonstrated OPERABLE by:

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j a.

Containment atmosphere particulate and gaseous radioactivity l) t monitoring system performance of CHANNEL

CHECK, CHANNEL i

CAllBRATION and CHANNEL FUNCTIONAL TEST at the frequencies specified l

i in Table 4.3-3, f

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Containment sump level and discharge flow measurement system

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performance of CHANNEL CALIBRATION at least once per 18 months.

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2 ATTACHMENT 2 e

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DISCUSSION OF PROPOSED TECHNICAL i

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SPECIFICATION CHANGE AND BASIS i

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DISCUSSJDj The purpose of this change is to clarify the Technical Specification 3.4.6.1 regarding reactor coolant system leakage detection systems and to bring the Technical Specification into closer agreement with Regulatory Guide 1.45 and revision 4 of the Standard Technical Specifications.

The specific changes are described below.

The LIMITING CONDITION FOR OPERATION (LCO) is revised to require that both the containment atmosphere particulate and gaseous radioactivity monitoring system and the containment sump level and discharge flow measurement system shall be operable.

The current LC0 is difficult to understand because it appears to require only two of +hre. identified leakage detection methods (particulate radiation monitor snd gaseous radiation monitor at sump discharge flow measurement) to be operable, whereas the associated ACTION can be interpreted to require three separate and independent methods to be operable.

Further, due to the design considerations, the two radiation monitors cannot be considered as two irdependent systems.

Specifically, the two radiation monitors share a common piping system, power supply and pumping arrangement, and therefore are not truely independent.

The sump level monitor has been added 7.s a required element of the leakage detection systems in accordance with Regulatory Guide 1.45 and the related Technical Specification 3/4.4.6.2 regarding reactor coolant system leakage limits.

Therefore, the proposed Technical Specification LC0 continues to require two separate and independent leakage detection systems.

The ACTION is modified to achieve consistency with the LC0.

If either of the two required leakage monitoring systems is inoperable, a compensatory leakage

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measurement using the reactor coolant system water inventory balance method is F

specified.

The compensatory leakage measurement using the inventory balance 1

method replaces the current grab sample method which is employed if one of the j

radioactivity monitors is inoperable.

This new method is considered to be l

equivalent in terms of sensitivity to the grab samplo method and the I

capability currently exists to perform an on line calculation of leak rate i

via this method using the plant process computer.

In addition, it should be j

noted that the current specification does not require a compensatory leakage i

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measurement if the containment sump discharge flow measurement system is inoperable whereas the new specification will require a compensatory leakage l

measurement using the mass balance method in this case as well.

The actions to be taken if one of the two required leakage detection systems is inoperable for more than 30 days, or if both of the required systems are inoperable, are unchanged.

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l The SURVEILLANCE REQUIREMENTS have been rewritten to require a periodic l

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calibration of the containment sump level monitor.

j The proposed Technical Specifications for leakage detection systems are

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consistent with the recommendations of Regulatory Guide 1.45 and the Technical i

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Specifications Bases.

The Technical Specifications require two diverse and j

redundant means of continuously u nitoring

leakage, and provides for

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j alternative means of performing a compensatory leakage measurement if one of i

the two required monitors is inoperable.

Thus Regulatory Guide 1.45, and specifically regulatory position 9 which requires "the availability of various j

types of instruments to assure adequate coverage at all times," is satisfied.

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f BASIS FOR NO SIGNIFICANT HAZARDS DETERMINATION l

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We have reviewed the proposed changes and determined that the changes will I

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(a) result in a significant increase in the probability or consequence of an accident previously evaluated, i.e.,

a loss of coolant i

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accident, because the specification continues to require two j

redundant and diverse means of continuously monitoring for reactor I

coolant system leakage.

In addition, an operability requirement for l

the containment sump level monitor has been added to the LCO, and a 1

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requirement to implement a compensatory leak &ge measurement (i.e.

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j inventory mass balance) if either or both of the sump leakage

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monitors are inoperable has been added to the ACTION Statement.

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Finally, the requirement to obtain and analyze appropriate j

containment grab samples if one of the radioactivity monitors is inoperable has been replaced with a requirement to perform a compensatory leakage measurement using the mass balance method.

l This method is considered equivalent to the grab sample method in j

terms of leakage detection sensitivity and therefore will provide l

j the same level of protection as previously provided.

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i (b) create the possibility of a new or different Lind of sccident. The j

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additional required reactor coolant system leakage monitor (i.e.

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sump level) is already required by the related Technical Specification 3/4.4.6.2 regarding reactor coolant system leakage limits (see Specification 4.4.6.2.lb) and therefore does not introduce any new or unique accident precursors.

Similarly, the i

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additional required compensatory leakage measurement (i.e. inventory mass balance) is a test that is routinely performed in accordance with Specification 4.4.6.2.ld and existing Station periodic test procedures, and therefore does not create any new or unique accident

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precursors.

(c) result in a significant reduction in the margins of safety as defined in the bases for any technical specification because the 3

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proposed Technical Specifications continue to require two redundant i

i and diverse means of leakage monitoring as well as a compensatory 1

leakage measurement each 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> if either of the two required l

l leakage monitoring systems is inoperable, and therefore the

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Technical Specifications Bases and the recommendations of Regulatory i

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Guide 1.45 (regulatory position 9

regarding Technical 1

J Specifications) continue to be satisfied.

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19 CFR 50.59 SAFETY EVALVATION The proposed change to the Technical Specifications for reactor coolant system detection systems has been determined not to pose an unreviewed safety question as defined in 10 CFR 50.59.

The basis for this determination is as follows:

(a)

The probability of an accident (i.e., loss of coolant accident) or malfunction of equipment important to safety previously evaluated in the safety analysis report is not increased.

The specification continues to require two redundant and diverse means of continuously monitoring for reactor coolant system leakage.

In addition, an operability requirement for the containment sump level monitor has been added to the LCO, and a requirement to implement a compensatory leakage measurement (i.e. inventory mass balance) if either or both of the sump leakage monitors are inoperable has been added to the l

ACTION Statement.

Finally, the requirement to obtain and analyze 1

appropriate containment grab samples if one of tha radioactivity monitors is inoperable has been replaced with a requirement to l

perform a compensatory leakage measurement using the mass balance i

method.

This method is considered equivalent to the grab sample method in terms of leakage detection sensitivity and therefore will provide the same level of protection as previously provided.

I (b)

The possibility for an accident or malfunction of a different type than any evaluated previously in the safety analysis report is not I

created.

The additional required reactor ccolant system leakage 1

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monitor (i.e.

sump level) is already required by the related Technical Specification 3/4.4.6.2 regarding reactor coolant system leakage limits (see Specification 4.4.6.2.lb) and therefore does not introduce any new or unique a:cident precursors.

Similarly, the additional required compensatory leakage measurement (i.e. inventory mass balance) is a test that is routinely performed in accordance with Specification 4.4.6.2.ld and existing Station periodic test procedures, and therefore does not create any new or unique accident precursors.

(c) The margins of safety as defined in the basis for any technical specification is not reduced by the proposed change.

The proposed Technical Specifications continue to require two redundant and I

diverse means of leakage monitoring as well as a compensatory leakage measurement each 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> if either of the two required leakage monitoring systems is inoperable, and therefore the Technical Specifications Bases and the recotaendations of Regulatory Guide 1.45 (regulatory positinn 9

regarding Technical Specifications) continue to be satisfied.

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