ML20034C474
| ML20034C474 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 04/27/1990 |
| From: | Chrzanowski R COMMONWEALTH EDISON CO. |
| To: | Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20034C475 | List: |
| References | |
| 0936T, 936T, NUDOCS 9005030368 | |
| Download: ML20034C474 (8) | |
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Comm:nwealth Edisin -
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( _- [1400 Opus Place Downers Grove, Illinois 60515
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April 27, 1990 Dr. Thomas E. Murley, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
.s Attu. Document Control Desk
Subject:
Zion Station Units 1 and 2 Application for Amendment to Facility Operating License DPR-39 and DPR-48 NBC_DackeLRon_10-12 Land 50-30A bear Dr. Murley:
Commonwealth Edison proposes to amend Appendit A, Technical Specifications for Facility-Operating Licenses DPR-39 and DPR-48 for the Zion Station, pursuant to 10 CFR 50.90.
This proposed Technical Specification
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change is based upon an evaluation that determined a specific Technical Specification should be written to address the containment spray recirculation phase function.
On May 31, 1989, an Enforcement Conference was~ held at the NRC Region III office regarding the inoperability.of one train of the Unit 1. Containment Spray System due to the inoperability of 1MOV-CS-0049.
The inoperability of this valve rendered one train of the Containment Spray System unable to
-function in the recirculation phase of operation.
The conclusion of the Enforcement Conference was that operation with an inoperable train of containment spray resulted in a Severity Level IV violation of the Zion Technical Specifications.
Zion Station has reviewed-the Byron /Braidwood and Westinghouse Owners Group Standardized Technical Specifications for similar application.- As a result, a new Limiting Condition for Operation (LCO) 3.6.2, titled
" Containment Spray Recirculation Phase Systems: will be added to the basis section of Specification 3.6, containment Spray.
In addition, a paragraph will be added to the basis section of Specification 3.8, Emergency Core Cooling System (ECCS) to address the functional requirements of the system during the recirculation phase of operation.
The new LCO addressing Containment Spray Recirculation System operation and the new paragraph describing the functional requirements of the ECCS system during the recirculation phase of operation, will improve the overall safety of the plant by providing better operability decision making.
process regarding containment spray.
Attachment A contains a description and justification of the proposed changes. Attachment B contains marked up Technical Specification pages and a copy of the retyped Technical Specification pages.
9005030368 900427
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The proposed changes have been reviewed and approved by both onsite and offsite review in accordance with 10 CFR 50.92 (c).
Commonwealth Edison has determined that no significant hazards consideration exists-and has performed an Environmental Assessment. -Documentation of these reviews is contained in Attachments C and D.
Commonwealth Edison is notifying the State of Illinois of this application for amendment by transmitting a copy of this. letter and its attachments to the designated state official.
Please direct any questions regarding this matter to this office.
Very truly yours, R. A. C rzanowski Nuclear Lie neing Administrator I
i Attachments:
- 1) Description and Justification i
of Changes i
B) Marked up Technical Specification Pages and Typed Technical Specification Pages C) Evaluation of Significant llazards Consideration-D) Environmental Assessment cc:
C. Patel - NRR Resident Inspector - Zion I
Region III Office l
Office of Nuclear Facility Safety - IDNS i
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ATTACHMENT A.
Description and Justification of Changes to TSC 90-01 The Containment Spray System is designed to furnish containment atmosphere
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cooling to limit post-accident pressure and temperature to less than design limits.
In addition the containment Spray System operates to inject sodium hydroxide solution into the' spray water.- The injection of-sodium hydroxide ensures that the pH of the solution injected and leter recirculated from the containment recirculation sump is alkaline. This will-aid in minimizing
. chloride and caustic stress corrosion and' enhance-the ability of the spray to scavenge iodine fission products from the containment atmosphere. The; Containment -Spray and Sodium Ilydroxide Addition systems are evaluated as separate systems because:of the differing functions they provide.
Zion Station Containment Spray System is unique when compared:to other-Containment Spray Systems.
The pressure reduction and-iodine removal functions of the system are fulfilled by 3 independent, 100% capacity trains (ref. Figure 1).
The recirculation phase function is fulfilled by 2.100%
capacity systems (ref. Figure 1 &'2)-
The Containment Spray Recirculation Phase System does not utilize the containment spray pumps.
In this phase of operation, the containment spray pumps will be shutdown and the Residual.llent Removal (RHR) pumps will supply water from the containment recirculation sump to the containment spray headers via the containment spray valves CS-0049 or CS-0050.
Operation of the Containment Spray System is divided into two distinct phases of operation, injection and recirculation. During the initial stages of an accident, containment spray water is supplied from the Refueling Water Stora6e Tank (RWST), this is considered to-be the injection phase for containment spray. The injection phase for containment spray will continue until the RWST is emptied. At this time, the Containment Spray Recirculation Phase System may be placed in operation to continue containment spray function.
The pressure reduction and iodine removal function of the Containment Spray System actuate simultaneously upon initiation.
The pressure reduction 3
function of the Containment Spray System is maintained in operation using all i
3 pressure reduction systems until containment pressure is reduced to less than 20 peig. When pressure is reduced to less than 20 psig, the operator is instructed by Emergency Operating Procedures to-secure all but 1 of the pressure reduction spray systems. Operation in this mode is continued until the RWST is emptied, at which time the Containment Spray Recirculation Phase System is placed into service. Operation of the sprayc will centinue until containment pressure is reduced to less than 4 psig.
If the event is u l
primary system LOCA, spray operation will continue.for a minimum of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to j
scavenge iodine fission products from the containment atmosphere.
At this time the sprays will be terminated.
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p The iodine removal function is actuated whenever the Containment Spray; System is started.
The sodium hydroxide solution is added to.the spray water from the Spray Additive Tank.
This addition will continue until the Spray Additive Tank is empty, at which time the Spray Additive Tank to eductor stop valves are closed.
Through full injection of the Spray Additive Tanks content, the containment recirculation sump will achieve an alkaline pH.
The current Limiting Condition For Operation (LCO) 3.6.1, Containment Spray System, identifies operability requirements for the Containment Spray System during the injection phase of-Containment Spray Actuation.
It. defines; i
the operability requirements of the Containment Spray System for providing-pressure reduction and iodine removal. However, LCO 3.6.1 does not clearly <
defina the requirements of providing containment spray during the recirculation phase of operation.
LCO 3.6.2 is being proposed requiring "Two Containment Spray Recirculation Phase Systems to be operable and capable of~providing containment spray with water supplied by independent Residual Heat Removal Pump Systems taking suction from the containment recirculation sump. This LCO will be applicable during Modes 1, 2, 3 and 7.
This is consistent with the current modes of-applicability for the Containment Spray and RHR Pump Systems. -Index page 11 7
has been revised to account for the addition of this new LCO.
l The action statement associated with the Containment Spray Recirculation Phase System will allow continued operation for a period of time not to. exceed 7 days as long as at least'3 Reactor Containment Fan Coolers (RCFCs) are operable. The 7 day period and shutdown time frames are' consistent with LCO 3.8.3, for the RHR Pump System.
In addition, the~7 day allowable outage time frame is considered to be a logical extension of the existing 7 day allowable ~
outage time for the RHR Pump System. This time frame is further_ justified by the relatively insignificant contribution that'the recirculation phase' system.
has on containment pressure response. The requirement'to assure at least 3
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RCFCs are operable, is based on an analysis performed showing containment pressure response. This is felt to be a conservative action because it -is l
linked only to the recirculation phase requirements which by this time containment pressure will have been significantly reduced.
For the injection j
phase pressure reduction and iodine removal functions, the' requirement.to have l
at least 4 RCFCs operable, if either' function is found to be inoperable, will i
remain the same. The results of the analysis conducted are as shown in l to this attachment. With regards to iodine removal, it has been shown that spray additive plays a relatively minor role in iodine removal.
Studies by Westinghouse (WCAP 11611) have shown that elementa1' iodine is j
removed from the atmosphere and deposited onto containment surfaces regardless I
of the spray pH.
The organic forms of iodine are not easily removed by.
sprays, and are assumed to be removed by decay only. Particulate iodine is removed by rprays and also through decay.
It sbould be noted that the FSAR does not take credit-for iodine removal in the recirculation phase of operation.
In addition, the Zion Station i
Probabilistic Safety Study does not take credit for recirculation phase operation at all. These allowable outage times will provide.for adequate time to effect repairs to inoperable components prior to requiring a unit i
shutdown.
In the event the system continues to be inoperable after 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> in Hot Shutdown, the unit shall be placed in Cold Shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
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A
-Surveillance requirements for Containment Spray Recirculation Phase System-components shall be in accordance with Zion Station Inservice Testing Program-for ASME Code Class 1, 2 and 3 pumps and components. The Containment Spray valves CS0049 and CS0050 are the only active components not currently tested by either the Containment Spray System or the RHR Pump System Technical Specification. As such, the IST program requirements are the only testing requirements found to be applicable.
Table 4.6-1, Containment Spray System Components has been revised to
-include RHR Train to 1A(2A) & IB(2B) Header Stop Valves (MOV-CS-0049 L-MOV-CS-0050). The component noun names in this table have also been revised to reflect new labeling as part of Zion. Station't' Detailed Control. Room Design Review Program.
The Basis for Section 3/4.6 Containment Spray has been revised to include the following; 1)
New paragraph describing operation of containment spray in the~
recirculation phase including reference to applicable FSAR section 6.4.2.
2)
New paragraph providing justification for a 7 day inoperable period for one Containment Spray Recirculation Phase System..
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3)
Revised paragraph in Basis 4.6 to include Containment Spray j
Recirculation Phase System components and reference to testing j
periodicity.. Changes to the testing frequency are required to
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address the differences between the current Technical Specification 1
testing frequency for the Containment Spray System and the j
Containment-Spray Recirculation Phase System.
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Other minor. changes have been made. These changes are aditorial in
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nature, made to improve readability of the basis. None of these-changes alter the intent of this section, j
The basis for Section 3/4.8 has been revised to include a paragraph
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describing the operation of the Emergency. Core Cooling System during the i
This para 6raph states the purpose of the RilR Pump System to provide
' f recirculation phase including reference to applicable FSAR section 6.2.2.1.3.
l recirculation water to the Containment Spray Recirculation Phase Systen.
l Other minor changes have been made which are editorial in nature and made to i
improve readability-of the basis. None of these changes alter the intent of this section.
a In conclusion, the new LCO addressing Containment Spray Recirculation
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System and the new paragraph describing the functional requirements of the ECCS system during the recirculation phase of operation, will improve the-overall safety of the plant by providing' better operability decision making process in regards to Containment Spray, i.
(Zion Station Containment Response i
with Loss of RHR Spray During LOCA y
RSA-Z-89-03, June 23, 1989) f 3
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