ML20213G763
| ML20213G763 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 11/11/1986 |
| From: | MISSISSIPPI POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20213G756 | List: |
| References | |
| TAC-61607, TAC-63558, TAC-64095, NUDOCS 8611180317 | |
| Download: ML20213G763 (10) | |
Text
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J A -INITIAL SYSTEM HYDROTEST IMIT ttom Head Pe tration -
m, 8 - NITIAL NON+luCLEAR G LIMIT C -lNITIAL NUCLEAR (COR CRITICAL) 1200 LIMIT BASED ON G.E BWR LICENSING TOPICAL REPORT DO-21778-A Core Belt offer A', B', C' - A, B, C Ll TS AFTER AN ASSUMED 26 CORE BELTLINE TEMP.
SHIFT FRO AN INITIAL SHELL PLATE 1000 "
RT OF T. A* IS NOT SMWN NOT (TOT Ll IT!NG) l B' an.
C' are coincident wit 8 and C, respectively.
u 800 a
rves A, B and C are predicted to E
b plicable for service periods up t 32 EFPY.
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-Feedwater a
Nozzle Limits h
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Acceptablereghnofoper-400 Boltup Limit ation is to the ight of 70*F m 312 ps.ig q
the applicable c e.
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/O 100 200 300 400 500 RPV Metal Temperature ( F)
MINIMUM REACTOR PRESSURE VESSEL METAL TEMPERATURE VS. REACTOR VESSEL PRESSURE
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8611180317 861111 Figure 3.4.6.1-1 PDR ADOCK 05000416 p
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MINIMUM REACTOR PRESSURE VESSEL METAL TEMPERATURE VS. REACTOR VESSEL PRESSURE Figure 3.4.6.1-1 GRAND GULF-UNIT 1 3/4 4-21 Amendment No.
REACTOR COOLANT SYSTEM BASES 3/4.4.5 SPECIFIC ACTIVITY (Continued)
The surveillance requirements provide adequate assurance that excessive specific activity levels in the reactor coolant will be detected in sufficient time to take corrective action.
3/4.4.6 PRESSURE /TEMPERATbRE LIMITS All components in the reactor coolant system are designed to withstand the effects of cyclic loads due to system temperature and pressure changes.
These cyclic loads are introduced by normal load transients, reactor trips, and startup and shutdown operations.
The various categories of load cycles used for design purposes are provided in Section 3.9 of the FSAR.
During startup and shutdown, the rates of temperature and pressure changes are limited so that the maximum specified heatup and cooldown rates are consistent with the design assumptions and satisfy the stress limits for cyclic operation.
During heatup, the thermal gradients in the reactor vessel wall produce thermal stresses which vary from compressive at the inner wall to tensile at the outer wall.
These thermal induced compressive stresses tend to alleviate the tensile stresses induced by the internal pressure.
Therefore, a pressure-temperature curve based on steady state conditions, i.e., no thermal stresses, represents a lower bound of all similar curves for finite heatup rates when the inner wall of the vessel is treated as the governing location.
The heatup analysis also covers the determination of pressure-temperature limitations for the case in which the outer wall of the vessel becomes the con-trolling location.
The thermal gradients established during heatup produce tensile stresses which are already present.
The thermal induced stresses at i
the outer wall of the vessel are tensile and are dependent on both the rate of heatup and the time along the heatup ramp; therefore, a lower bound curve similar to that described for the heatup of the inner wall cannot be defined.
Subse-quently, for the cases in which the outer wall of the vessel becomes the stress controlling location, each heatup rate of interest must be analyzed on an individual basis.
The reactor vessel materials have been tested to determine their initial RT The RT f r welds and base material in the closure flange region is NDT.
< 10 F.
The initial hydrostatic test pressure was 1563 psig.
The results of these tests are shown in Table B 3/4.4.6-1.
Reactor operation and resultant fast neutron, E greater than 1 Mev, irradiation will cause an increase in the RT Therefore, an adjusted reference temperature, based upon the fluence, NDT.
phosphorus content and copper content of the material in question, can be predicted using Bases Figure B 3/4.4.6-1 and the recommendations of Regulatory Guide 1.99, Revision 1, " Effects of Residual Elements on Predicted Radiation Damage to Reactor Vessel Materials." The pressure / temperature limit curve, Figure 3.4.6.1-1, curves A', B' and C', includes predicted adjustments for this shift in RT f r the end of life fluence.2: tecl' :: adjustment for p0:0ible NDT errer: " the prectur and temperature censing instruments.
Curves B' and C' are coincident with curves B and C, respectively.
GRAND GULF-UNIT 1 B 3/4 4-4 Amend.menh O -
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Item 2 PS-85/09 Drywell air lock leak testing requirements
SUBJECT:
Technical Specifications 4.6.2.1.b, 3.6.2.3, 4.6.2.3 and 3/4.6.2.3; pages 3/4 6-13, 15 and 16, and B 3/4 6-3.
DISCUSSION:
The proposed changes to the Technical Specifications are as follows:
1.
Clarify the wording in the LCO, Surveillances and Bases to indicate only one Drywell air lock instead of "each".
2.
Reorganize Technical Specification 3.6.2.3 Action a to clarify the intent of the action statement.
3.
Change the overall air lock leak test frequency in Surveillance Requirement 4.6.2.3.b.1 from the present interval of at least once per 6 months to each cold shutdown if not performed within the previous 6 months.
4.
Change Surveillance Requirement 4.6.2.3.c regarding the verification that only one door in the air lock can be opened at a time from once per 6 months to once per 18 months.
5.
Delete the drywell airlock inflatable seal pressure instrumentation channel calibration test in Surveillanct Requirement 4.6.1.2.d.1 JUSTIFICATION: Mississippi Power & Light (MP&L) proposed deletion of the drywell air lock seal pressure instrumentation 31 day channel functional test from surveillance requirement 4.6.2.3.d.1 in a l
letter submitted May 28, 1986. MP&L indicated in the May 28, 1986 submittal that further review of Technical Specification t
3/4.6.2.3 may result in additional changes. This submittal I
documents the additional changes that have been identified and l
provides justification in the same numerical order as presented l
in the discussion section above for the changes as follows:
1.
The proposed change is to clarify the wording in the LC0 and Surveillance to indicate only one Drywell air lock instead of "each".
Since the Drywell contains only one personnel air lock the present technical specification wording does not accurately describe the single drywell air lock.
l 2.
Technical Specification 3.6.2.3 Action a is proposed to be reorganized to eliminate confusion and potential inter-pretation problems. As presently written, parts 1, 2 and 3 i
l of Action a could be interpreted as being separate action j
statements while the intent is to be three parts of the same action statement. The actual wording of these actions requirements has not been modified by this proposed change.
This proposed change for Grand Gulf Unit I has already been put into effect for another operating BWR-6 plant.
J16ATTC86102701 - 1
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3.
Surveillance Requirement 4.6.2.3.b.1 is proposed to be changea to allow the overall air lock leak test to be performed each cold shutdown if not performed within the previous six months. As presently written this surveillance may come due when the plant is at power.
In order to perform the test the air lock must be entered and the work performed in a high radiation area (approximately 225 mrem /hr neutron, 400 mrem /hr gamma at 67% power).
Since the air lock is not used for drywell entry at greater than 5% power, the proposal to perform this testing each cold shutdown if not performed within the previous six months provides adequate assurance of air lock integrity. This proposed change has been implemented at other BWR-6 plants with a similar air lock arrangement.
4.
Verification that only one door in the air lock can be opened at a time is proposed to be changed to at least once per 18 months. This change will allow testing during refueling outages when the plant is shutdown. During plant operation above 5% power drywell entry is not allowed, thus the verification that only one door can be opened at a time is not needed. Technical Specification Surveillance 4.6.2.3.d.2 requires verification of seal air flask pressure thus ensuring seal integrity. This proposed change has also been implemented at other BWR-6 plants.
5.
Another part of the proposed changes to the Grand Gulf Technical Specifications is the deletion of the drywell air lock inflatable seal pressure instrumentation channel calibration test contained in surveillance requirement 4.6.2.3.d.1.
This proposed change in conjunction with the proposal in the May 28, 1986 submittal, deletes from the Technical Specification testing of the drywell air lock door inflatable seal system instrumentation channels. The purpose of the inflatable seal pressure instrumentation is to provide a signal to local indicating lights and also provide a pennissive for the hydraulic door operating system. These lights provide personnel entering one door of the air lock with an indication that the other door is properly sealed. A mechanical interlock exists which prevents the opening of both doors simultaneously. The drywell air lock inflatable seal pressure instrumentation activates no control room status lights or alarms, and thus, serves no function in warning of drywell integrity violation. The remaining Technical Specification Surveillance Requirements in 4.6.2.3.d verify seal air flask pressure once per 7 days and provides for a seal leak test once per 18 months thus ensuring seal integrity. During plant operation above 5% power, drywell entry is not allowed thus the inflatable seal pressure instrumentation is not needed for personnel entry.
This proposed change has also been implemented at other operating BWR-6's with similar instrumentation arrangements.
J16ATTC86102701 - 2
SIGNIFICANT HAZARDS CONSIDERATION:
The proposed technical specification change would reorganize Technical Specification 3.6.2.3 Action a to clarify the intent of the action, delete the required drywell inflatable seal pressure instrumentation channel calibration test and change the overall air lock leak test to be performed during COLD SHUTDOWN.
The change would also allow verification that only one door in the air lock can be opened at a time to be once per 18 months and clarify the LC0 and Surveillances wording to indicate only one Drywell air lock instead of "each".
The proposed change does not involve a significant hazards consideration because operation of Grand Gulf Unit 1 in accordance with this change would not:
(1) involve a significant increase in the probability or consequences of an accident previously evaluated. The reorganization of Technical Specification 3.6.2.3 Action a clarifies the intent of the action statement without changing any of the requirements. Therefore, technical specification testing requirements for this instrumentation is not required. Performance of the overall air lock leak test during COLD SHUTDOWN provides adequate assurance of air lock integrity.
The drywell seal pressure instrumentation supplies indication to personnel entering the air lock that the other door is sealed. This instrumentation actuates no control room status lights or alarms, and thus, serve no function in warning of drywell integrity violation.
(2) create the possibility of a new or different kind of accident from any previously analyzed. The actual wording of action a in Technical Specification 3.6.2.3 has not been modified by this proposed change. The reduction in testing the seal pressure instrumentation does not create the possibility of a new or different kind of accident since this instrumentation serves no function in the warning or maintaining of drywell integrity.
(3) involve a significant reduction in the margin of safety.
By allowing the overall leakage testing during COLD SHUTDOWN, personnel performing the test will not be exposed to a high radiation area. The seal pressure instrumentation serve no safety related function, nor does it actuate any control room status lights or alarms.
Its only purpose is to provide personnel with an indication of drywell air lock status. Verification once per 18 months that only one door in the air lock can be opened at a time does not reduce the margin of safety, however since personnel do not have to enter a high radiation area as often to perform the test ALARA considerations are improved.
J16ATTC86102701 - 3
r CONTAINMENT SYSTEMS 3/4.6.2 DRYWELL DRYWELL INTEGRITY LIMITING CONDITION FOR OPERATION 3.6.2.1 DRYWELL INTEGRITY shall be maintained.
APPLICABILITY:
OPERATIONAL CONDITIONS 1, 2* and 3.
ACTION:
Without DRYWELL INTEGRITY, restore DRYWELL INTEGRITY within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
SURVEILLANCE REQUIREMENTS 4.6.2.1 DRYWELL INTEGRITY shall be demonstrated:
At least once per 31 days by verifying that all drywell penetrations **
a.
h not capable of being closed by OPERABLE drywell automatic isolation valves and required to be closed during accident conditions are closed by valves, blind flanges, or deactivated automatic valves secured in position, except as provided in Table 3.6.4-1 of Specification 3.6.4.
-G e b.
By verifying 6 drywell air lock is in compliance with the l
requirements of Specification 3.6.2.3.
c.
By verifying the suppression pool is in compliance with the requirements of Specification 3.6.3.1.
See Special Test Exception 3.10.1.
AA Except valves, blind flanges, and deactivated automatic valves which are located inside the drywell or containment and are locked, sealed or otherwise secured in the closed position.
These penetrations shall be verified closed during each COLD SHUTDOWN except such verification need not be performed more often than once per 92 days.
4*8dd*8"t Nb" ~ l GRAND GULF-UNIT 1 3/4 6-13
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CONTAINMENT SYSTEMS
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DRYWELL AIR LOCKG l
LIMITING CONDITION FOR OPERATION The 3.6.2.3 fee # drywell air lock shall be OPERABLE with:
l a.
Both doors closed except when the air lock is being used for normal transit entry and exit through the drywell, then at least one air lock door shall be closed, and b.
An overall air lock leakage rate of less than or equal to 2 scf per hour at P, 11.5 psig.
a APPLICABILITY: OPERATIONAL CONDITIONS 1, 2* and 3.
ACTION:
a.
With one drywell air lock door inoperable:
1.
Maintain at least the OPERABLE air lock door closed and either restore the inoperable air lock door to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or locktheOPERABLEairlockdoorclosed.9
-2, L0peration may then continue provided that the OPERABLE air lock door is verified to be locked closed at least once per 31 days.
-3 L0therwise, be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
2-4, The provisions of Specification 3.0.4 are not, applicable.
b.
With the drywell air lock inoperable, except as a result of an inoperable air lock door, maintain at least one air lock door closed; restore the inoperable air lock to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
i With one drywell air lock door inflatable seal system seal pressure c.
instrumentation channel inoperable, restore the inoperable channel to OPERABLE status within 7 days or verify the associated inflatable seal pressure to be > 60 psig at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
i "See Special Test Exception 3.10.1.
k GRAND GULF-UNIT 1 3/4 6-15 Amendmend MO.
CONTAINMENT SYSTEMS SURVEILLANCE REQUIREMENTS The.
4.6.2.3 Eeek drywell air lock shall be demonstrated OPERABLE:
I Within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> # after each closing, except when the air lock is being a.
used for multiple entries, then at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> #, by verifying seal leakage rate less than or equal to 2 scf per hour when the gap between the door seals is pressurized to P, 11.5 psig.
a b.
By conducting an overall air lock leakage test at P, 11.5 psig a
and verifying that the overall air lock leakage rate is within its limit:
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2.
Prior to establishing DRYWELL INTEGRITY when maintenance has 4
been performed on the air lock that could affect the air lock P
sealing capability.
E IS At least once per fr months by verifying that only one door in e&e 7l ac-4
-t c.
air lock can be opened at a time.
j J
d.
By verifying each airlock dv,r inflatable seal system OPERABLE by:
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instrum ion channels per airlock door OPERABLE by mance f
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_ cnce per 31 deys, md,0ELETED l
3)
CHANNEL C ON at least once per 1
' s, a low nrossure setonint of > 60 nsio.
2.
At least once per 7 days verifying seal air flask pressure to be greater than or equal to 90 psig.
3.
At least once per 18 months, conducting a seal pneumatic system leak test and verifying that system pressure does not decay more than 2 psig from 90 psig within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.
- The provisions of Specification 4.0.2 are not applicable.
GRAND GULF-UNIT 1 3/4 6-16 Anvendmenb Mo. -
i CONTAINMENT SYSTEMS BASES CONTAINMENT PURGE SYSTEM (Continued)
Leakage integrity tests with a maximum allowable leakage rate for purge supply and exhaust isolation valves will provide early indication of resilient material seal degradation and will allow the opportunity for repair before gross leakage failures develop.
The 0.60 L leaking limit shall not be a
exceeded when the leakage rates determined by the leakage integrity tests of these valves are added to the previously determined total for all valves and penetrations subject to Type B and C tests.
3/4.6.2 DRYWELL 3/4.6.2.1 DRYWELL INTEGRITY Drywell integrity ensures that the steam released for the full spectrum of drywell pipe breaks is condensed inside the primary containment either by the suppression pool or by containment spray.
By utilizing the suppression pool as a heat sink, energy released to the containment is minimized and the severity of the transient is reduced.
3/4.6.2.2 DRYWELL BYPASS LEAKAGE The limitation on drywell bypass leakage rate ensures that the maximum leakage which could bypass the suppression pool during an accident would not result in the containment exceeding its design pressure of 15.0 psig.
The design drywell leakage rate is expressed a A/ 8 and has a value of 0.90 ft. A/8 is dependent 2
only on the geometry of drywell leakage paths where A = flow area of leakage paths in ft and 8 is a lumped constant which considers geometric and friction 2
loss coefficients such as discontinuities and Reynolds number.
At a 3 psid 2 has an dif ferential pressure from drywell to containment an A/8 of 0.90 ft equivalent mass flow of 35,000 scfm.
The integrated drywelI leakage value is limited to 10% of the allowable drywell leakage capability, which is equivalent to 3500 scfm at 3 psid drywell to containment.
2 is derived from the analysis of " bypass The A/8 value of 0.90 ft capability with containment spray and heat sinks" (FSAR 6.2.1.1.5.5).
The limiting case accident is a very small reactor coolant system break which will not automatically result in a reactor depressurization.
The long term differen-tial pressure created between the drywell and containment will result in a signi-ficant pressure buildup in the containment due to this bypass leakage.
3/4.6.2.3 DRYWELLAIRLOCK/
The limitations on closure for the drywell air lock / are required to meet the restrictions on DRYWELL INTEGRITY and the drywell leakage rate given in Specifications 3.6.2.1 and 3.6.2.2.
The specification makes allowances for the fact that there may be long periods of time when the air lock / will be in l
a closed and secured position during reactor operation.
Only one closed door in g air lock is required to maintain the integrity of the drywell.
)
Verification that each air lock door inflatable seal system is OPERABLE by the performance of a local leak-detection test for a period of less than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> is permissible if it can be demonstrated that the leakage rate can be accurately determined for this shorter period.
This is in accordance with Sections 6.4 and 7.6 of ANSI N45.4-1972.
b*8ddM8d A/#'
l GRAND GULF-UNIT 1 B 3/4 6-3
.