ML20084N511
| ML20084N511 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 04/19/1984 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20084N504 | List: |
| References | |
| NUDOCS 8405170051 | |
| Download: ML20084N511 (7) | |
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UNITED STATES 8'
N NUCLEAR REGULATORY COMMISSION 5
- p WASHINGTON, D. C. 20SS5
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NOS. 92 ANO 73 TO FACILITY OPERATING LICENSE NOS. DPR-53 AND DPR-69 BALTIMORE GAS AND ELECTRIC COMPANY CALVERT CLIFFS NUCLEAR POWER PLANT UNIT NOS. 1 AND 2 DOCKET NOS. 50-317 AND 50-318 Introduction By application for 1.icense amendment dated December 22, 1983, Baltimore Gas and Electric Company (BGAE) requested changes to the Technical Specifications (TSI for Calvert Cliffs Units 1 and 2.
The application was supplemented by two letters dated January 27, 1984 The proposed amendments would change the TS to reflect:
(1) changes to surveillance requirements for safety related hydraulic sway arrestors (snubbers), (2) a change to the Limiting Conditions for Operation (LCO) for the emergency fuel oil storage system to allow removal of the storage tanks from service for inspection, (3) clari-fication of the surveillance requirements for the 125V DC batteries and chargers, (4) clarification of'the LC0 and surveillance requirements for the off-site electrical power sources, g5) a change to the list of containment isolation valves to allow intermittent opening of certain valves, under administrative control during reactor operation, to allow testing of the containment hydrogen sampling capability and, (6) deletion of an outdated LC0 associated with the control room emergency ventilation system (Unit 1 only).
Discussion and Evaluation The first TS change topic relates to the safety related hydraulic sway arrestors (snubbers) addressed in TS 3/4.7.8.1, " Snubbers". Two types of channes are proposed.to this TS.
First, a number of snubbers addressed in 3/4.7.8.1 have been proposed for removal. These snubbers have been re-evaluated by the licensee and have been found to be suitable for replacement by rigid sway struts due to the low thermal expansion attributable to the supported equipment. Since sway struts, unlike snubbers, are completely passive (they have no moving parts), they need not be addressed by TS surveillance. Moreover, since these sway struts are similar in desian to those already in safety-related service at Calvert Cliffs and since nn changes will be made in mounting configuration, no decrease in the seismic resistance of the associated systems will occur.
The second change associated with Unit 2 TS 3/4.7.8.1 involves the deletion of comon-reservoirs notations from those designated snubbers in Unit 2 TS Table 3.7-4.
These sixteen snubbers, associated with the Steam Generators, 840S170051 840419 PDR ADOCK 05000317 P
PDR.._.
. will be modified such that each snubber will have its own reservoir.
The reservoirs, together with all associated fittings, will be designed, manu-factured, mounted and maintained to the same seismic standards as the snubbers which they serve. Removal of these common reservoirs and replacement with individual units improves the seismic design in that it eliminates the possi-bility that a single reservoir failure would result in efoht snubbers being inoperable.
Since these sixteen snubbers are the only snubbers served by common reservoirs, the surveillance requirements for these common reservoirs specified in TS 4.7.8.lf have been proposed for deletion. Although the actual modifications will not be undertaken until the April 1984 Unit 2 outage, the licensee has committed to undertake this surveillance every 31 days 25% until such time as the modifications are undertaken. The proposed changes in the snubbers addressed above and their associated TS assure an equivalent degree of seismic resistance. For this reason we find the proposed changes to TS 3/4.7.8.1 to be acceptable.
The second topic addressed herein involves the fuel oil storage system for the on-site emergency AC power diesel generators.
Indication of leaks in fuel oil tank bottons at other non-BG&E fossil faci-lities has pointed out the necessity of periodic inspection of fuel oil storage tanks. A plan to inspect these tanks by visual inspection and statis-tical metallurgical sample of the tank bottons using ultrasonic depth meters has been developed. This program cannot be undertaken at present due to the
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requirements of TS 3.8.1.1b, "A.C. Sources".
In this TS, the operability of each diesel generator in Modes 1, 2, 3, or 4 requires, "A common fuel storage system consisting of two independent storage tanks each containing a minimum volume of 18,250 gallons of fuel..."
Therefore, if only one fuel oil storage tank is available, it renders all of the diesels inoperable.
TS 3.8.1.1.b requires either returnino the diesels to operable status within two hours or being in hot standby within the next six hours.
This clearly makes any inspection of a fuel oil storage tank which reouires that the tank be drained impossible without first shutting down both units. Moreover, it is unlikely that simultaneous unit outage of greater than ten days will be scheduled for Calvert Cliffs.
In order to permit the desired tank inspections, the licensee has proposed a change to TS 3.8.1.lb.
The proposed change requires that two redundant sources of diesel fuel oil be maintained even with one of the two fuel oil storage tanks out of service for inspection. This will be accomplished by use-of an 8,000 gallon alternate fuel source, enough to run two diesels for 21.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> at full load. The required minimum fuel oil volume in the remaining (operable) safety-grade fuel oil storage tank would be 36,500 gallons.
Furthermore, it limits the period of time these inspections can be performed to the April 1984 Unit 2 refueling outage when the Unit 2 reactor is in Mode 5 or 6, a period expected to last approximately two
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. months. The proposed change also requires the alternate fuel source to be connected to the existing safety-related fuel oil source so as not to degrade the systen integrity in the event of a rupture of the alternate fuel oil source or its connecting piping.
In addition, since only one fuel oil tank is protected from tornado missiles, this tank is required to be maintained operable until May 15, 1984. This requirement is necessary since the tornado probability is comparatively high during the month of April and is judged to be appropriately low by May 15.
Although redundancy with regard to the safety grade fuel oil supply would be decreased in that, during the inspection, only a single safety grade fuel oil source would be operable (the 8,000 gallon source would be non-safety grade), this situation is compensated for by the following factors:
(1) the 36,500 gallon fuel oil supply now required to be maintained in two safety grade tanks would represent the minimum capacity for the remaining operable safety grade fuel oil tank, (P.).an additional 8,000 gallon non-safety grade fuel oil source would be available, and (3) during the two months during which the tank inspections would be undertaken, Unit 2 would be in a refueling outage, such that the potential need for emergency AC power would be reduced together with a c~ responding reduction in the need for fuel oil. Thus, overall, there is no significant reduction in the availability of fuel oil for emergency AC power diesel generators.
Since an equivalent, reliable, source of fuel oil would be maintained, the proposed changes to TS 3.8.1.1h are acceptable.
The third topic addressed herein involves proposed changes to TS 3/4.8.2.3, "D.C. Distribution - Operating." The first such change, TS 3.8.2.3, Action c, involves the remedial action to be taken in the event that both battery chargers on a 120V DC bus become inoperable. This remedial action requires the reactor to be shut down if a battery charger cannot be restored to operable status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. This requirement directly conflicts with TS 4.8.2.3.Pd which allows the 18 month battery capacity test to be per-formed by actually powering the emergency loads associated with a 125V DC bus. Performing the capacity test in this manner requires that both battery chargers associated with the 125V DC battery to be tested be rendered in-operable.
The licensee has requested a change to Action "c" to allow both battery chargers on a 125V DC bus to be inoperable for the purpose of per-forming a " live load" battery capacity test (TS 4.6.2.3.2.d.1).
This proposed change represents an insignificant decrease in reliability with. regard to supplying emergency loads on the 125V DC buses in that the duration of the subject test is expected to last approximately 4-hours and would be conducted at approximately 18 month intervals.
The second proposed change relates to-TS 3.8.2.3, Action d which reouires
- a 1?5V DC bus whose battery has been made inoperable for the purpose of testing (TS 4.8.2.3.2.c.2 and 4.8.2.3.2.d.2) to be powered by an operable battery charger. The licensee has indicated that, when the 125V DC batteries are removed from service for testing, the associated bus is powered by.the
. reserve battery and an operable charger. The licensee has therefore requested that Action d be modified to require an operable charger and the reserve battery to power a bus whose battery has been removed from service for sur-veillance.
In this regard, since the reserve battery would power a bus whose battery has been removed from service to perform an 18-month capacity test using a " dummy load" (TS 4.8.2.3.2.d.2), the need to recharge the tested battery in less than or equal to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> becomes less significant since the bus would be powered by a fully qualified, reserve battery. The licensee has proposed to exclude a stabilization period of approximately 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> from the recharging 'nterval. While the battery would still be demonstrated to be capable of being recharged in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, an additional stabilization time would be implemented, prior to returing the battery to service, to allow the battery parameters to return to normal. This period would serve to extend the life of the battery. While the battery capacity test is performed on the dumy load, and during subsequent re-charging, the reserve battery can still serve as the power supply to the bus.
Using this configuration will allow the discharged battery to be charged in a normal manner, using the reserve battery charger versus using the DC bus battery chargers for the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period specified in the TS. This will prolong the life of the station batteries and improve overall battery system reliabil ity. Additionally, if the reserve battery remains on the bus during the recharging period, safety will be improved by ensuring an essentially fully charged battery is on the DC bus at all times. The requirements of TS 4.8.2.3.2.d and 4.8.2.3.2.e have been renumbered to accommodate these changes together with the references to these sections elsewhere in TS 3/4.8.2.3.
Finally, the licensee has proposed that the 18-month battery charger test described in TS 4.8.2.3.2.e be changed to allow the option for use of dumy loads that are equal to or greater than that reouired to recharge a battery at a rate of less than or equal to 400 amperes while supplying normal DC loads. At the present time, the battery charger test is to be performed by demonstrating the capability of recharging the battery at a rate of less than or equal to 400 amperes while supplying normal DC loads.
The use of dummy loads for 125V DC battery tests is presently permitted under TS 4.8.2.3.2.d.
Moreover, the proposed change to the TS would allow the battery chargers to be tested "off-line" while the DC bus in question is being powered by 5 fully charged reserve battery. Under the existing requirements, the charger would be tested on the DC bus with a discharged battery, thus degrading the capacity of that bus until the battery is fully _
recharged.
For this reason, the proposed change to TS 4.8.2.3.2.e would improve the availability of DC power during the performance of the battery charger test.
As indicated above, the proposed changes to TS 3/4.8.2.3 maintain or improve the reliability of the DC power supply. The proposed changes to TS 3/4.8.2.3 are therefore acceptable.
. The fourth topic addressed herein relates to proposed changes to TS 3/4.8.1.
"A.C. Sources - Operating." The first proposed change is intended to provide a clarification to the LC0. At the present time, TS 3.8.1.1 allows use of a 69kV offsite power source (supplies by SMECO) to substitute for a 500kV offsite power circuit. This " credit" is presently implemented by references within action statements a, b, and c.
The licensee has proposed that the references in the action statements be removed and the ability to use the SMEC0 line be incorporated directly in the LCO.
In the Conunission's November 2,1981 Safety Evaluation (SE) issued in support of License Amendments 58 and 40 for Units 1 and 2, the Commission concluded that the SMEC0 line met all requirements for use as
"...an independent, preferred source of offsite electrical power as stated in General Design Criterion 17, Appendix A to 10 CFR Part 50."
The present referencing of the SMECO line in the Action Statements of TS 3.8.1.1 implies operation in a degraded mode. This is inconsistent with the Consnission's November 2,1981 SE which concluded that the SMEC0 line was fully acceptable. The November 2, 1981 SE concluded that no significant hazards considerations were associated with use of the SMEC0 line,.however as indicated in the LCO, the 500kV circuit represents the perferred power source.
Finally, the licensee has proposed changes to TS 4.8.1.1.1.
One such change provides a new surveillance require-ment in the TS for the SMECO line. This surveillance requires that the SMECO offsite power source be demonstrated operable as follows:
For the 69kV SMECO offsite power circuit, within one hour of substitution for a 500kV offsite power circuit, and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereaf ter during use by verifying correct breaker alignments and indicated power availability.
While this requirement would be new to the TS, it represents an existing commitment by the licensee as documented in the NRC's SE dated November 2, 1981. The proposed change to TS 4.8.1.1.1 also deletes mention of a test to assure operability of the automatic shift from the normal to alternate circuit.
This test is already performed under TS 4.8.1.1.2.c.3 ard thus its deletion does not affect plant safety.
As indicated above, the propose [1 changes to TS 3/4.8.1 do not reduce the reliability of off-site power. For the reasons stated above, the proposed changes to TS 3/4.8.1.1 are acceptable.
The fifth topic addressed herein involves a proposed change to TS 3/4.6.4.1,
" Containment Isolation Valves." This proposed change would allow operation of the Hydrogen Sample and Hydrogen Sample Return containment isolation valves for brief periods under administrative control. These valves are currently required to be closed during reactor startup and operation.
These penetrations are described in Section 5.2.2 and Table 5-3 of the Updated Final Safety Analysis Report as a Type II isolation valve configuration which satisfies. the criteria of General Design Criterion 56 of 10 CFR 50.
. Each penetration line is i inch in diameter, as described in Table 5-3 of the Updated FSAR. These valves must be operated to obtain or return a gaseous sample for the Post Accident Sampling System (PASS) or the contain-ment hydrogen analyzers.
The proposed change only involves the use of certain containment isolation valves and does not involve a change in design or equipment or in procedures.
This is because the valves are normally closed during reactor operation.
A key must be inserted to physically open each valve under administrative control. Also, both containment isolation valves must be opened for each penetration to expose the containment atmosphere to either the PASS or the Hydrogen Analyzers. This provides a dual protection for ensuring containment integrity is maintained.
Based on the above considerations, the proposed changes to 3/4.6.4.1 are acceptable.
The final topic addressed herein applies to Unit 1 TS 3/4.7.6, " Control Room Emergency Ventilation System." The proposed change would delete the following interim LC0 which expired with startup of Unit 2 following the October 1982 refueling outage:
For the duration of the October 1982 Unit 2 refueling outage with Unit 2 in MODES 5 or 6 and one air conditioning unit inoperable, restore the inoperable unit to operable status within 21 days or 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 />.
Since this TS is no longer applicable to Unit 1, its deletion from the Unit 1 TS has no effect on plant safety. Deletion of this TS is a purely admini-strative action and is acceptable.
Environmental Consideration We have determined that the amendments do not authori7e a change in effluent types or total amounts nor an increase in power level and will not result in any sinnificant environmental impact. Having made this determination, we have further concluded that the amendments involve an action which is in-i significant from the standpoint of environmental impact and, pursuant to 10 CFP, %51.5(d)(4), that an environmental impact statement or negative i
declaration and environmental inpact appraisal need not be prepared in connection with the issuance of the amendments.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) there is~ reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such
7-4 h Commission's regulations
~ activities will be conducted in compliance with t e and the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
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j Date: April 19, 1984 Principal Contributor:
D. Jaffe l
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