ML20141G295
| ML20141G295 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 04/14/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20141G283 | List: |
| References | |
| NUDOCS 8604230349 | |
| Download: ML20141G295 (7) | |
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jo UNITED STATES g
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NUCLEAR REGULATORY COMMISSION n
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WASHINGTON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS.117AND og TO FACILITY OPERATING LICENSE NOS. DPR-53 AND DPR-69 s
BALTIMORE GAS AND ELECTRIC COMPANY CALVERT CLIFFS NUCLEAR POWER PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-317 AND 50-318 INTRODUCTION By applications for license amendments dated February 22, 1985 and October 25, 1985, Baltimore Gas and Electric Company (BG&E) requested changes to the Technical Specifications for Calvert Cliffs Units 1 and 2.
The proposed amendments would change the Unit 1 and Unit 2 TS to:
(1) revise the Basis for the Containment Isolation Signal (CIS)/ Safety Injection Actuation Signal (SIAS) setpoint for containment high pressure in TS Basis 2.2.1, " Reactor Trip l
Setpoints"; (2) change the allowable scheduling for moderator temperature coefficient (MTC) determination as required by TS 4.1.1.4.2c, " Moderator Temperature Coefficient"; (3) require that two charging pumps, required to be operable above 80% power, each be provided with an independent power supply per TS 3.1.2.4, " Charging Pumps - Operable" (Unit 1 only); (4) provide for additional channels associated with measurement of containment water level and change the statement regarding implementation of remedial actions in TS 3/4.3.3.6, " Post-Accident Instrumentation"; (5) correct a syntax error in TS 3.4.4, " Pressurizer" and a spelling error in TS 3/4.6.1.1., " Containment Integrity"; (6) update and clarify the reporting requirements of TS 6.9.2, "Special Reports"; (7) delete the Surveillance Requirements of TS 4.5.2g, "ECCS Subsystems T remainingSurveillEe[greaterthanorequalto]300F"-andredesignatethe Requirements; (8) delete the reference to the 1971 Edition of the ASME Boiler and Pressure Vessel Code in TS Basis 3/4.7.1.1,
" Safety Valves"; (9) delete a seismic sway arrester (snubber) from the operability and Surveillance Requirements of TS 3/4.7.8, " Snubbers" (Unit 1 only); (10) replace a reference in TS Basis 3/4.3.3.4, " Meteorological Instrumentation", with an alternate reference; (11) Allow the use of a containment atmosphere grab sampling capability as a backup to the hydrogen l
analyzers in TS 3.6.5.1, " Hydrogen Analyzers," and (12) incorporate additional l
reporting requirements in TS 6.9.2, "Special Reports."
This evaluation is partially responsive to the February 22, 1985 and October 25, 1985 applications.
The remaining issues will be addressed in j
i future correspondence.
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. DISCUSSION AND EVALUATION BG&E has requested a change to TS Basis 2.2.1, " Reactor Trip Setpoints", with regard to the setpoint for reactor trip on containment pressure.
The reactor protection system (RPS) for Calvert Cliffs Units 1 and 2 is an automatic safety system which trips the reactor when certain process variables exceed preset limits (setpoints).
These setpoints are established to ensure that the reactor core and reactor coolant system are prevented from exceeding their safety limits.
One such RPS setpoint would trip the reactor when containment pressure equals or exceeds 4 psig (per TS 2.2, " Limiting Safety System Settings",) and also initiate a containment isolation signal (CIS) to close key containment isolation valves.
A separate containment pressure sensing system associated with the safety injection actuation signal (SIAS) initiates backup systems, including emergency core cooling systems, when containment pressure equals or exceeds 4.75 ptig (per TS 3.3.2.1, " Engineered Safety Feature Actuation System Instrumentatic? ).
Following the accident at TMI-2 the NRC established TMI Action Item II.E.4.2,
" Containment Isolation Dependability", as set forth in NUREG-0737,
" Clarification of TMI Action Plan Requirements," November 1980.
Action Item II.E.4.2 requires, in part, that licensees study their containment pressure history and establish a CIS setpoint that is "... reduced to a minimum compatible with normal operating conditions." The Basis for the containment pressure setpoint in TS Basis 2.2.1 states:
"The Containment Pressure-High trip provides assurance that a reactor trip is initiated concurrently with a safety injection.
The setpoint for this is identical to the safety injection setpoint." A comparison of the RPS/CIS and SIAS setpoints in TS 2.2 and TS 3.3.2.1 indicates that there does not exist a requirement that these j
setpoints be " identical" or he initiated "concurrantly." Accordingly, BG&E j
has requested that TS Basis 2.2.1 be reworded as follows:
"The Containment Pressure-High trip provides assurance that a reactor trip is initiated prior i
i to, or at least concurrently with, a safety injection." This wording is consistent with TS 2.2 and 3.3.2.1, meets the NRC staff objectives of TMI Action Item II.E.4.2, and is therefore acceptable.
BG&E has requestr:d a change to TS 4.1.1.4.2c regarding the requirement to measure the end-of-cycle (E0C) moderator temperature coefficient (MTC).
At the p"esent time, the E0C MTC must be determined "...within 7 EFPD [ effective full poter days] after reaching a RATED THERMAL POWER equilibrium boron concentration of 300 ppm."
BG&E has requested that the word "after" be changed to "of" in the above requirement to also allcw measurement of the MTC up to 7 EFPD prior to reaching 300 ppm.
The Bases for TS 4.1.1.4.2 states the following, in part:
"The surveillance requirements for meast.rement of the MTC during each fuel cycle are adequate c
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to confirm the MTC value since this coefficient changes slowly due principally j
to the reduction in RCS boron concentration associated with fuel burnup.
The confirmation that the measured MTC value is within its limit provides assurances that the coefficient will be maintained within acceptable values throughout each fuel cycle." The need to measure the E0C MTC is associated
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with the need to confirm that this value will not be more negative than the I
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, mast adverse value assumed in the safety analysis. Since the MTC becomes more negative near E0C due to decreasing soluble boron concentration, early measurement of the MTC is beneficial in predicting, and subsequently correcting, adverse trends. Since early determination of the MTC decreases the probability of accidents occurring with an excessively negative MTC, the proposed change to TS 4.1.1.4.2 is conservative and acceptable.
BG&E has proposed a change to TS 3.1.2.4, " Charging Pumps-0peration" which would require that:
"Above 80% RATED THERMAL POWER the two OPERABLE charging pumps shall have independent power supplies." Recent loss-of-coolant accident (LOCA) analyses for Calvert Cliffs Units 1 and 2 have credited flow from the charging pumps in providing post-LOCA core cooling for LOCAs assumed to be initiated above 80% power.
During the most recent Unit 2 LOCA review, it was noted by the NRC that the Calvert Cliffs charging pumps had not been required, in the TS, to have independent power supplies, as is implicit in the TS requirements for emergency core cooling system pumps, when these pumps are required to be operable. The NRC subsequently requested that BG&E propose such a TS requirement concerning charging pumps which was subsequently incorporated in Amendment 90 to Facility Operating License DPR-69, issued on November 21, 1985. BG&E subsequently proposed the same TS requirement for the Calvert Cliffs Unit I charging pumps.
The proposed change to TS 3.1.2.4 is consistent with existing safety analyses, provides additional protection with regard to diversity of power supply to the charging pumps, and is acceptable.
BG&E has proposed a change to TS 3.3.3.6, " Post-Accident Instrumentation",
concerning the number of operable channels required for containment water i
level instrumentation. At the present time, TS 3.3.3.6 requires, in part, l
operability of a single channel of containment water level instrumentation.
BG&E has proposed that a second channel of containment water level instrumentation be required to be operable.
In addition, BG&E has proposed remedial action to be taken in the event that the additional channel of containment water level instrumentation becomes inoperable. While current remedial action requirements for a single inoperable containment water level monitor requires plant shutdown within 30 days should the instrumentation become inoperable, the remedial action requirement proposed for the additional containment water level instrumentation would only require its return to operation following an outage of sufficient duration to effect repairs. This proposed requirement notwithstanding, it is understood that other type: of potential instrument failures might not require a power decrease or shutdown to effect repairs. These types of failures would be promptly corrected by the licensee. The combined effect on the TS of the additional required containment water level instrumentation, together with the proposed remedial action, would be to provide for operability of two instrument channels under most expected conditions since these channels have proven to be reliable to date. Should one instrument channel become inoperable, the proposed TS would revert to the existing TS, should the second instrument channel become inoperable, which would require plant shut 6wn within 30 days if the instrumentation cannot be returned to operable
o status. The first inoperable instrumentation would have to be restored to operable condition at the earliest possible time. We conclude that the
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proposed change to TS 3.3.3.6 would improve the required availabt1ity of containment water level instrumentation and is acceptable.
BG&E has proposed the correction of one syntax and one spelling error in the TS.
The syntactic error appears in TS 3.4.4, " Pressurizer." The licensee has proposed deletion of the word " maximum" as it presently applies to both maximum and minimum values of allowable pressurizer level.
The second proposed change to the TS would correct the spelling of the word " Operation" as it appears in TS 3/4.6.1, " Primary Containment." Correction of spelling and similar errors in the TS is administrctive in nature and acceptable.
BG&E has requested a change to TS 6.9.2, "Special Reports" to add the following_ reporting requirements to this TS:
0.
Radiatioa Monitoring Instrumentation, Specification 3.3.3.1 (Table 3.3-6)
P.
Overpressure Protection Systems, Specification 3.4.9.3 While these reporting requirements are already incorporated in TS 3.3.3.1 and TS 3.4.9.3, they are proposed for incorporation in TS 6.9.2 to achieve consistency in the TS; therefore, the proposed change to TS 6.9.2 is acceptable.
BG&E has proposed deletion of TS 4.5.29, "ECCS Subsystem-T Thepurposeofthissurveillancereq69em[greaterthan or equal to] 300 F."
ent is to verify proper setting of the emergency core cooling system (ECCS) throttle valves.
The setting of the ECCS throttle valves had been a chronic problem at Calvert Cliffs.
Due to a previously restrictive value of high pressure safety injection (HPSI) flow of 170 1 5 gpm, the ECCS throttle valve settings had been required te be set at an intermediate opening position with a precision which exceeded the capability of the equipment.
This situation resulted in a lack of repeatability for the settings.
During the last reload for Calvert Cliffs Units 1 and 2, a combination of revised analysis and testing was presented in support of applications for license amendments which resulted in the elimination of the need for the restrictive HPSI flow requirement.
The resulting TS changes, issued with License Amendments 104 and 90 for Calvert Cliffs Units 1 and 2, eliminated the need for ECCS throttle valvc setting verification since these valves were now set to assume the full open position upon a safety injection actuation signal.
The licensee had not requested deletion of TS 4.5.2g as part of their applications supporting License Amendments 104 and 90 due to an oversight.
The deletion of TS 4.5.2g provides consistency with the existing TS with regard to the crediting of flow from the charging pumps in the approved ECCS analysis, as reflected in the TS and the more liberal limits on HPSI flow verification per TS 4.5.2h.
TheproposeddeletionofTS4.5.2gisthpafore acceptable.
e BG&E has proposed deletion of the reference to the 1971 Edition of the ASME Code,Section XI, in TS Basis 3/4.7.1.1, " Safety Valves".
This reference appears to be in error in that, by letter dated February 8,1982,-the NRC approved the use of.the 1974 Edition of the ASME Code,Section XI, for inservice testing of pumps and valves at Calvert Cliffs Units 1 and 2.
Moreover, TS 4.0.5 requires the licensee to use Section XI of the ASME Code for inservice inspection of pumps and valves in accordance with 10 CFR 50.55a(g) which specifies the correct edition of the code and addenda.
- Thus, deletion of the reference to the code edition provides consistency with existing TS 4.0.5 and is acceptable.
BG&E has proposed the deletion of a snubber from the operability and surveillance requirements of TS 3/4.7.8, " Snubbers." Table 3.7-4 of the TS contains a list of all snubbers which are the subject of operability and surveillance requirements.
In addition, TS Table 3.7-4 contains the following provision for.emoval of snubbers from TS requirements:
" Snubbers may be removed from safety related systems for the purpose of replacement by
- way struts in accordance with the NRC's Safety Evaluation dated April 19, 1984 provided that a revision to Table 3.7-4 is included with the next License Amendment request." The licensee's October 25, 1985 request for license amendment informed the NRC that a snubber had been removed from Calvert Cliffs Unit 1 and replaced with a rigid sway strut.
The deletion of the snubber from the TS is thus consistent with TS 3/4.7.8 and acceptable.
BG&E has proposed a change to TS Basis 3/4.3.3.4, " Meteorological Instrumentation." The proposed change would change the reference basis document as follows:
"Regelatory Guide 1.23, Rev. 1 (Proposed),
' Meteorological Programs in Support of Nuclear Power Plants,' September 1980,"
would be replaced by " Regulatory Guide 1.23, 'Onsite Meteorological Programs,' February 1972, as supplemented by Supplement 1 to NUREG-0737."
While existing and proposed references are equivalent, the latter consists of docunients that have been approved by the NRC in final form and thus are more appropriate for reference in a TS Basis.
Since both references are equivalent, the proposed change represents a. change in nomenclature and thus is acceptable.
BG&E has proposed a change to the Calvert Cliffs TS to allow the use of containment atmosphere grab sampling as a back-up means of measuring containment hydrogen concentration.
Current TS require plant shutdown within 30 days when one hydrogen analyzer becomes inoperable.
The proposed TS change would allow for continued plant operation provided a grab sampling capability is demonstrated.
The prime function of the hydrogen analyzers is to monitor the containmen*
atmosphere for hydrogen following a Loss-of-Coolant Accident (LOCA).
The hydrogen analyzing system is common to both units.
The system consists of two hydrogen analyzing subsystems, each consisting of a. hydrogen analyzer cabinet, sample select cabinet, hydrogen sequencer panel, and remote hydrogen recorder.
Each hydrogen analyzing subsystem can monitor the containment hydrogen concentration at six points, three in each containment structure.
These locations have been selected to providt representative samples of the containment atmosphere.
The sampling lines are run in groups of three through two separate containment penetrations.
9 During any period when one analyzer subsystem is out of service', the second subsystem is available to perform all necessary sampling evolutions.
In addition, the availability of the hydrogen " grab sampling" capability provides added redundancy.
A sample bomb equipped with a septum plug is located on the 45' level of the Auxiliary Building.
The Laboratory Analyst can use a syringe to withdraw and subsequently analyze a containment atmosphere sample with the analyzer pump operating and the sequencer lined-up to the appropriate 135' containment elevation sample point.
This capability has been demonstrated at Calvert Cliffs and represents a capability that provides a substantial backup for the installed analyzers.
The atmospheric grab sample capability incorporates design features, as enhanced by procedural controls, to prevent the uncontrolled release of containment atmosphere during sampling.
The sample line from each containment contains two key (capture) lack actuated valves to prevent inadvertent operation.
Down-stream of the key-lock valves and prior to the sample point, a manual isolation valve is provided which would allow the operator to quickly isolate the sample line in the event of anomalous conditions.
Finally, the samp;e point is provided with a double septum to minimize leakage.
The proposed change to TS 3.6.5.1 would, upon inoperability of one hydrogen analyzer, allow continued plant operation provided that the grab sampling capability is verified within 30 days or the plant must be shut down.
The licensee has also proposed that a special report be submitted within 30 days,
"... outlining the ACTION taken, the cause for the inoperability, and the plans and schedule for restoring the system to OPERABLE status." This reporting requirement would also be incorporated in TS 6.9.2, "Special Reports," for consistency.
The existing TS requirements specify that, in the event that one hydrogen analyzer becomes inoperable, the hydrogen analyzer must be made operable within 30 days or the plant must be shut down within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
Since the atmospheric grab sample represents a hydrogen monitoring capability that is equivalent to hn installed hydrogen analyzer, the operability of a single hyd* ogen analyzer with a grab sample backup capability would provide the same degree of redundancy as the operability of two hydrogen analyzers.
Thus, the proposed changes to TS 3.6.5.1 and TS 6.9.2 are acceptable.
ENVIRONMENTAL CONSIDERATION These amendments involve a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes in surveillance requirements.
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 involve no significant hazards consideration and there has been no public comment on such finding. Accordingly, these amendments meet the eligibility criteria for categorical exclusion set forth in
. t 10 CFR S51.22(c)(9).
These amendments also involve changes in recordkeeping, reporting or adminstrative procedures or requirements.
Accordingly, with respect to these items, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR S51.22(c)(10).
Pursuant to 10 CFR
$51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of these 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 4
endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations, 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.
Date:
April 14, 1986 Principal Contributors:
P. Shemanski E. Markee 1
R. Kendall D. Jaffe 4
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