ML20134P323
| ML20134P323 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 08/26/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20134P312 | List: |
| References | |
| NUDOCS 8509060242 | |
| Download: ML20134P323 (3) | |
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UNITED STATES
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j WASHINGTON, D. C. 20555 k...o,/
i SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT N05.107 AND 88 TO FACILITY OPERATING LICENSE NOS. DPR-53 AND DPR-69 BALTIM0RE GAS AND ELECTRIC COMPANY CALVERT CLIFFS NUCLEAR POWER PLANT, UNIT N05. 1 AND 2
_ DOCKET NOS. 50-317 AND 50-318 Introduction By application for license amendment dated January 31, 1985, Baltimore Gas and Electric Company (BG&E) requested changes to the Technical Specifications (TS) for Calvert Cliffs Units 1 and 2 to reflect clarification and increased flexibility for detennination of reactor coolant system leakage as specified in TS 3/4.4.6.1, " Leakage Detection Systems" and TS 3/4.4.6.2, " Reactor Coolant System Leakage."
Discussior and Evaluation Technical Cpecification 3/4.4.6.1 provides operability and surveillance requirements for three instrumentation systems which will detect reactor coolant system D 'kage. Two of the instrumentation systems specified in 3.4.6.1, the containment particulate radioactivity monitoring (PRM) system and the containment atmospheric gaseous radioactivity monitoring (GRM) system, are not completely independent in that they both share the same sample pump.
The containment sump level alann system, the third leakage monitoring system addressed in TS 3/4.4.6.1, is independent of the PRM and GRM systems.
In the past, TS 3.4.6.1 has caused difficulty with regard to interpretation.
This difficulty is caused by the " action" statement which is applicable when one leak detection system is inoperable but which also requires remedial action to be taken when two systems (the GRM and/or the PRM) are inoperable.
The licensee has proposed a change to TS 3.4.6.1 to correct this ambiguity.
The proposed change would make the existing action statement the first of a two-part requirement. The first part would be applicable, unambiguously, when only one leakage detection system is inoperable by changing the phrase
...when the required gaseous and/or particulate radioactivity monitoring system is inoperable..." to "...when either the required gaseous or particulate radioactivity monitoring system is inoperchle...." The new second part of the action statement would be unambiguously applicable when two leakage detection systems are inoperable. This action statement requires that the existing remedial action be taken, obtaining and analyzing containment atmospheric grab samples at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and also that a reactor coolant system water inventory balance be undertaken every 24 0509060242 850026 P,DR ADOCK O 7
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1 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The reactor coolant system water inventory balance is an approved leak detection methodology that is currently required to be performed every 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> by TS 4.4.6.2c.
The operation of leak detection capabilities included in the proposed TS is as follows:
Sump level alarm system - Unit I has a 49 gallon sump while Unit 2 has a 44 gallon sump. When the sump is full, a control room alarm is sounded. The control room operator logs the time of the alarm and drains the sump. When the sump is empty, the alarm clears (and is reset). The time between sump level alarms would indicate the leak rate.
PRM and GRM - These radiation monitors provide indication of leakage but, due to the uncertainty associated with leak location and type and coolant activity, it is not practical to provide a correlation between containment radiation level and leakage rate. The PRM and GRM are provided with alann setpoints set at 1.5 multiplied by the background radiation level. Plant procedures require the control room operator to perform a reactor coolant system water inventory balance if a PRM or GRM alarm is sounded. The GRM and PRM share a common sample pump. Should this pump fail, an installed spare pump can be promptly made operable.
In the event that the installed spare pump is also inoperable, an on-site spare pump can be installed within 7 days.
Reactor coolant system water inventory balance - This method involves a calculation of reactor coolant system volume based upon the level in various tanks and other volumes. This method is accurate enough to detect a leak of 0.1 gpm, takes between 2 and 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to perform, and would provide adequate quantification of leakage detected by the GRM or PRM.
Grab sample - A sample of the containment atmosphere can be obtained.
This sample, analyzed by portable instruments, provides an indication of activity that is at least equivalent to the GRM or PRM.
Based upon our evaluation, we conclude that adequate means of reactor coolant system leak detection will be required to be operable as is presently the case in TS 3.4.6.1.
Moreover, numerous other systems and means for leak detection are described and discussed in Section 4.3 of the Updated FSAR and are used by reactor operators for leak detection purposes. They t
include: Containment Pressure and Temperature Indication, Pressurizer Pressure and Level Indication and Alarm, Containment Area Radiation Monitor Indication and Alann, Containment Humidity Indicators, Reactor Coolant Drain Tank Level Indication, and Reactor Coolant Make-up Water Flow Integrators.
The proposed TS does not increase the probability of accidents or reduce any safety margins since no changes in design or operating modes of the leak detection systems are involved. Consequently, the proposed changes to TS 3.4.6.1 are acceptable.
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Finally, the licensee has requested changes to TS 4.4.6.2 as follows:
Surveillance Requirement (SR) 4.4.6.2a which requires monitoring the containment atmosphere once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> with the PRM would be modified to also permit monitoring with the GRM or grab samples.
SR 4.4.6.2b which requires monitoring containment sump discharge every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> using the containment sump level alarm system would be modified j
to suspend this requirement when the containment sump level alann system is inoperable.
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SR 4.4.6.2c which requires a reactor coolant system water inventory balance at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> would be modified to require this l
balance every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> when used as an alternate leak detection method per TS 3.4.6.1.
l Ihe proposed changes to TS 4.4.6.2 are required to achieve consistency with existing and proposed requirements of TS 3.4.6.1 and are, therefore, acceptable.
Environmental Consideration These amendments involve a change in the installation or use and surveillance of a facility component located within the restricted area as defined in 10.CFR Part 20. The staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual'or cumulative occupational radiation exposure. The Commission has previously published a proposed finding that these amendments i
involve no significant hetards consideration and there has been no public coment on such finding. Accordingly, these amendments meet the eligibility J
criteria for categorical exclusion set forth in 10 CFR 651.22(c)(9). Pursuant' to 10 CFR 951.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of these amendments.
Conclusion r
We have con::luded, based on the considerations discussed above, that (1) there is re4sonable assurance that the health and safety of the public will not be l
endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Comission's regulations, and the issuance of the amendments will not be inimical to the common defense and security or to j
the health and safety of the public.
Date: August 26, 1985 Principal Contributor:
D. Jaffe
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