ML20249C786
| ML20249C786 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 06/29/1998 |
| From: | Dugger C ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20249C787 | List: |
| References | |
| W3F1-98-0045, W3F1-98-45, NUDOCS 9807010197 | |
| Download: ML20249C786 (14) | |
Text
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y Entergy Oporations, Inc.
Kdiona, LA 70066-0751 Tel 504 739 6660 ce Presad n O e a uns Waterford 3 l
A4.05 PR June 29,1998 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555
Subject:
Waterford 3 SES Docket No. 50-382 License No. NPF-38 Technical Specification Change Request NPF-38-205 Gentlemen:
The attached Description and No Significant Hazards Evaluation support changes to the Waterford 3 Technical Specifications (TS). The proposed changes modify TS 3.3.3.7.1 (Chlorine Detection System), TS 3.3.3.7.3 (Broad Range Gas Detection),
and the associated Bases. The TS will be modified by adding a footnote to the Action statements to allow the control room ventilation system to be unisolated periodically under administrative controls.
Waterford 3 current TS Actions require the control room ventilation system to be placed in the isolate mode of operation indefinitely if the Broad Range Gas Detection System or the Chlorine Detection System is inoperable. When the control room ventilation system is placed in the isolate mode of operation, no outside air is brought into the control room envelope, so carbon dioxide levels in the control room envelope increase. Periodic control room envelope purging is necessary to reduce the carbon dioxide levels; however, no provisions exist in the current Waterford 3 TS to allow the control room ventilation system to be unisolated for purging.
Waterford 3 recently identified this issue while reviewing the basis for the administrative control which limits the control room envelope to sixteen people when isolated. The broad range gas and chlorine detection TS were revised in TS Change Y
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9807010197 900629 PDR ADOCK 05000382 P
Technical Specification Change Request NPF-38-205 W3F1-98-0045 Page 2 June 29,1998 Request (TSCR) NPF-38-94 (approved as Amendment 53 by the NRC on March 23, 1989). This Amendment changed the requirement for the control room ventilation to be placed in the isolate mode of operation instead of the recirculate mode of operation when the chlorine detection system or broad range gas detection system is inoperable. Both of these systems automatically place the control room ventilation system in the isolate mode, instead of the recirculation mode, upon detection of a toxic chemical. The isolate mode of operation isolates the control room envelope from outside air. The recirculate mode of operation (with the emergency outside air intakes open) continuously allows approximately 200 cfm of outside air into the control room envelope for pressurization. Although Amendment 53 required the control room ventilation system to be placed in the isolate mode of operation when the chlorine or broad range gas detection system is inoperable, it did not allow the control room envelope to be unisolated to purge carbon dioxide. Also, since the TS Applicability is "All MODES," the only time the cc. trol room envelope can currently be unisolated, while in the TS Actions, is when the reactor is defueled or if TS 3.0.5 is entered to perform control room ventilation Surveillance Requirements.
Waterford 3 recognizes the primary goal is to restore the inoperable equipment to service; however, if the equipment cannot be restored, the proposed change will allow Waterford 3 to unisolate the control room envelope to purge. The footnote will restrict the time the control room envelope can be unisolated by limiting the time to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period. This will allow time for at least one exchange of the air in the control room envelope. The proposed Bases were revised to discuss the administrative controls that will be in place while the control room envelope is unisolated.
This proposed change has been evaluated in accordance with 10CFR50.91(a)(1),
using the criteria in 10CFR50.92(c), and it has been determined this request involves no significant hazards consideration.
The circumstances surrounding this change do not meet the NRC's criteria for exigent or emergency review. However, because the Actions of TS 3.3.3.7.1 and TS 3.3.3.7.3 do not allow the control room envelope to be unisolated, and a potential hazard to the control room staff exists when the control room envelope is isolated due to the build up of carbon dioxide, an expedited review is requested. We request
- the effective date of this TSCR be within 60 days of approval.
I Technical Specifications Change Request NPF-38-205 W3F1-98-0045 Page 3 l
June 29,1998 Should you have any questions or comments concerning this request, please contact Early Ewing at (504) 739-6242.
Very truly yours, C.M. Dugger Vice President, Operations Waterford 3 CMD/CED/rtk
Attachment:
Affidavit NPF-38-205 cc:
E.W. Merschoff, NRC Region IV C.P. Patel, NRC-NRR J. Smith N.S. Reynolds NRC Resident Inspectors Office Administrator Radiation Protection Division (State of Louisiana)
American Nuclear Insurers
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____________________0
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION in the matter of
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Entergy Operations, incorporated
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Docket No. 50-382 Waterford 3 Steam Electric Station
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AFFIDAVIT Charles Marshall Dugger, being duly sworn, hereby deposes and says that he is Vice President Operations - Waterford 3 of Entergy Operations, Incorporated; that he is duly authorized to sign and file with the Nuclear Regulatory Commission the attached Technical Specification Change Request NPF-38-205; that he is familiar with the content thereof; and that the matters set forth therein are true and correct to the best of his knowledge, information and belief.
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Charles Marshall Dugger 6N Vice President Operations - Waterford 3 STATE OF LOUIS!ANA
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) ss PARISH OF ST. CHARLES
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Subscribed and sworn to before me, a Notgry Public in and for the Parish and State above named this > y e day of ihA
,1998.
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Notary Public
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My Commission expires dMd4
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DESCRIPTION AND NO SIGNIFICANT HAZARDS EVALUATION OF PROPOSED CHANGE NPF-38-205 l
l The proposed change revises Technical Specifications (TS) 3.3.3.7.1 (Chlorine Detectinn System) and 3.3.3.7.3 (Broad Range Gas Detection) by adding a footnote s
allowing the control room ventilation system to be unisolated under administrative controls while in the TS Action to place the control room ventilation system in the isolate mode of operation. The associated Bases are also being changed.
Existina Specification See Attachment A Proposed Specification See Attachment B References See Attachment C Backaround Waterford 3 submitted TS change request (TSCR) NPF-38-94 to the NRC on December 23,1988 (Reference 1). The TSCR chan0ed the Actions in TS 3.3.3.7.1 and 3.3.3.7.3 from maintaining the control room ventilation system in the recirculate mode of operation to maintaining the control room ventilation system in the isolate mode of operation. During toxic chemical events, no outside air should enter the control room envelope. Both the recirculate and isolate mode of operation recirculates the bulk of control room envelope air. However, the recirculate mode of operation pressurizes the control room (with 200 cfm of outside air via the control room emergency outside air intakes) while the isolate mode of operation does not. The TSCR was approved on March 23,1989 as Amendment 53 to the Waterford 3 Operating License (Reference 2).
Therefore, Waterford 3 contains TS Actions to place the control room ventilation system in the isolate mode of operation when one chlorine detection or broad range gas detection system is inoperable for greater than seven days or when both trains of either detection system are inoperable. The Actions allow Waterford 3 to operate indefinitely with the control room ventilation system in the isolate mode of operation. The isolate 1
mode ensures the control room envelope is in its safety position in case of a toxic chemical event. However, no provisions exist in the Waterford 3 TS to allow for unisolating the control room envelope to purge carbon dioxide which builds-up when the contro! room envelope is isolated. ' Carbon dioxide should be periodically purged, because it can begin to affect operator performance at small concentrations. Also, because the Chlorine Detection System and Broad Range Gas Detection TS are applicable in all Modes, the only time the control room envelope can be unisolated, while in the TS Actions, is when the reactor is defueled or when TS 3.0.5 is entered to perform Surveillance Requirements (SRs). Note that SRs are performed every 14 days on the control room ventilation system, but calculations show the control room may need to be purged more often.
The ASHRAE Handbook, Environmental Control For Survival (Reference 3), states that carbon dioxide concentration should not exceed 3% by volume and preferably should be maintained below 0.5%. At concentrations of 3% and above, performance deteriorates and basic physiological functions are affected. At 1.5%, basic performance and physiological functions are not affected, but slow adaptive processes have been l
observed that might induce pathophysiological states on long exposure. At 0.5 to 0.8%,
no significant physiological or adaptive changes occur. Regulatory Guide 1.78 I
(Reference 4) lists the toxicity limit of carbon dioxide as 1% when evaluating control room habitability.
Waterford 3 performed a calculation (Reference 5) that shows 16 peopl'e can be in the control room envelope (when control room ventilation is in the isolate mode of operation) for approximately 6 days before the carbon dioxide levels approach 1%. In add 8cn, the calculation shows the maximum number of people that can be in the control room envelope for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> before the 1% carbon dioxide limit is reached versus an initial percent carbon dioxide limit. With an initial limit of 0.10% carbon dioxide,44 people can be in the control room envelope for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to the concentration reaching 1%. With an initial limit of 0.80% carbon dioxide,9 people can be in the control room envelope for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> prior to the limit being reached. The l
48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> is based on encompassing the maximum duration (25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br />) that a toxic gas cloud can be blown directly towards Waterford 3.
Since 1994, Waterford 3 has experienced eight events which have caused entry into the Toxic Chemical Contingency Procedures. Our analysis indicates that in none of
. these cases did the toxic chemical release pose an actual threat to Waterford 3.
L St. Charles Parish maintains an industrial hotline which links major industries with the St. Charles Parish Emergency Operations Center (EOC). It is tested by Waterford 3 1
once 'per month and by the St. Charles Parish EOC once per week. On several occasions, Waterford 3 personnel have identified a chemical release prior to receiving a call from the St. Charles Parish EOC. It should be noted the St. Charles Parish EOC notification priorities are directed at industries and population groups in direct line of the release. in addition to the industrial hotline, Waterford 3 is linked to the control rooms of surrounding chemical facilities and the railroad by the Taft Industrial Communications Complex (TICC) radio for immediate notification of a chemical event posing a direct L
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l threat to site personnel. This radio system is checked with all participants weekly, and a drill on the system is held monthly.
Description and Safety Considerations I
Technical Specifications 3.3.3.7.1 and 3.3.3.7.3 contain Actions that require the control room ventilation system to be maintained in the isolate mode of operation when one (greater than 7 days) or both trains, of the broad range gas detoction system or the l
chlorine detection system are inoperable. The proposed TSCR adds the following footnote to these Actions:
The control room ventilation system may be unisolated under administrative contmls for S2 hours per24 hourpedad. Other TS ACTIONS that require the controlroom ventilation system to be placed in the isolate orrecirculate mode l
of operation do not apply while operating in accordance with this footnote.
Bases Section 3/4.3.3.7 will be modified by adding the following discussion of the administrative controls, i
When the controlroom ventilation system is placed in the isolate mode of operation for a prolonged pedod of time, carbon dioxide levels in the control room envelope increase, as describedin calculation EC-M96-002. Carbon dioxide can affect operatorperformance as describedin The ASHRAE Handbook, Environmental Control For Survival. Therefore, the control room ventilation system may be unisolated under administrative controls for s2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 24 hourperiod to purge the controlroom envelope. The administrative controls shall consist of requirements to:
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1) prohibit unisolating the control room envelope if a toxic chemical release is in pmgress and is a direct threat to Waterford 3, 2) isolate the control room envelope if Waterford 3 is aleded to a toxic chemical release that is a direct threat to Waterford 3, 3) contact the St. Charles Parish Emergency Operations Center within 1 hourprior to unisolating the controlroom envelope to ensure there is no toxic chemical release in progress that is a direct threat to Waterford 3, and 4) verify the St. Charles Parish Industdal Hotline is operational within nourprior to unisolating the control room envelope.
s The administrative controls provide reasonable assurance that while the I
control room envelope is unisolated, when both trains of the broad range gas or the chlonne monitors are out of service, Waterford 3 will be aleded of a l
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i toxic chemical event and take action to limit the exposure to the controlroom staff. Contacting the St. Chades Pansh Emergency Operations Centerprior to unisclating the control room envelope provides assurance that a toxic chemicalrelease mat is a direct threat to Waterford 3 is not taking place prior to unisolating the control room envelope. Vedfying the St. Chades Pansh Industdal Hotline is operationalprovides a means of rapid notification in the event of a toxic chemical event in the vicinity of Waterford 3. The administrative controls will also preclude unisolating the control room envelope if a toxic chemical release is a direct threat to Waterford 3.
The basis for allowing the control room to be unisolated for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 24 hourpedod is that it allows for at least one exchange of airin the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> l
. period the control room envelope can be unisolated. This is a result of an air exchange rate of 0.6 exchanges perhour using the normal control room outside airintake. When the controlroom envelope is in recirculation (using the emergency outside airintakes), it takes approximately 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br /> for one complete air exchange (at an air exchange rate of 0.06 exchanges per hour).
j Therefore, the control room normal outside airintake is the preferred method of purging the control room while it is unisolated.
The footnote also allows the controlroom envelope to be unisolated for purging while not being required to comply with other TS ACTIONS that require the control room ventilation system to be placed in the isolate or recirculate mode of operation (i.e., TS 3.3.3.1,' Table 3.3-6 ACTION 26
[ Control Room Intake Radiation Monitor] u id TS 3.7.6.2 ACTION a [ Control f
Room Emergency Air Filtration System] to place the control room ventilation system in the recirculate mode of operation, and the requirement of TS 3.7.6.5 ACTION a [ Control Room Isolation and Pressudzation] to place the control room ventilation system in the isolate mode of operation). Therefore, the controlroom ventilation system can be unisolated without having to immediately be placed in the isolate or recirculate mode of operation to comply with other TS ACTIONS. However, upon indication of any event that.
would require the control room ventilation system to be in the isolate or recirculate mode, the control room ventilation system will be placed in the isolate mode of operation.
The proposed change to the TS and Bases allow the control room envelope to be unisolated to purge a toxic gas (carbon dioxide) produced from within the control room envelope while ensuring proper precautions are taken for a potential toxic chemical event from outside the control room envelope.
The proposed change is acceptable because there will be administrative controls in place to prevent unisolating or to immediately isolate the control room envelope during l
a toxic chemical release that is a direct threat to Waterford 3. The administrative l
controls will provide assurance that, prior to unisolating the control room envelope, a toxic chemical event is not taking place. The administrative controls will also ensure the 4
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St. Charles Parish Industrial Hotline is operational to provide a rapid means of notification in the event of a toxic chemical release in the vicinity of Waterford 3. The St. Charles Parish EOC will be contacted to ensure a toxic chemical release is not taking place and to ensure the EOC is notified of Waterford 3's potential vulnerability to a toxic chemical release.
Along with the administrative controls, Waterford 3 has other means available to alert the control room and to ensure appropriate actions are taken if a toxic chemical event were to occur. Waterford 3 participates in the TICC radio system. As stated previously, the TICC is a direct communication system (via radio) between the industries surrounding Waterford 3 and Waterford 3 to communicate any impending threats to the health and safety of the general public and personnel present at each site. Waterford 3 has toxic chemical event response procedures which ensure proper steps are taken in response to a toxic chemical event. Every four years, Waterford 3 is required by TS (6.9.1.9) to perform a survey of the toxic chemicals in the vicinity of Waterford 3, to determine the impact on safety, and to submit the survey and analysis to the Nuclear Regulatory Commission (NRC). This allows Waterford 3 personnel to be aware of the toxic chemical being released and its potential hazards. Waterford 3 also has an emergency breathing air system which is sized to accommodate 17 people for 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
1 Although this system will not provide protection against skin irritants and may not provide enough air for the duration of the worst case toxic chemical event, it does provide a measure of protection that is available to the control room.
1 An additional safety measure, if the control room envelope is isolated as a result of one train of either the broad range gas detection system or chlorine detection system being inoperable, is the ability of the operable train to detect a toxic gas and isolate the control room envelope while it is unisolated and purging is in progress. Finally, the following events would have to occur simultaneously in order for Watudord 3 to be unprotected against a toxic chemical event: 1) both trains of either the broad range gas detection system or chlorine detection system inoperable; 2), a toxic chemical event occurring; 3) Waterford 3 being downwind of the toxic chemical release; 4) Wate,rford 3 not being notified and remaining unaware of the toxic chemical event; and E) the e/ent
- occurring at the exact time the Waterford 3 control room envelope is unisola'ed. The probability of all the above occurring simultaneously is low, such that, the scenario is non-risk significant.
As discussed earlier, Waterford 3 performed analysis of chemical releases at the
- industries surrounding Waterford 3 since 1994. In more than one occasion Waterford 3 personnel have identified the event prior to receiving a call from the St. Charles Parish EOC. This has caused some concern within the NRC. However, none of the events were an actual threat to Waterford 3. The St. Charles Parish EOC notification priority is to first notify the industries and population groups in direct line of the chemical release.
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- The Waterford 3 staff conducts annual Emergency Plan training for representatives of major industries in St. Charles Parish and the St. Charles Parish EOC. Included in this training is Waterford 3's Toxic Chemical Contingency Procedure. Also, Operations 5
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personnel from participating industries meet periodically to discuss communications issues and priorities.
l Waterford 3 was allowed by the NRC to operate during the first cycle without a broad range gas detection system. This configuration was approved by the NRC as outlined in an NRC Safety Evaluation Report (SER) dated July 21,1987 (Reference 6). The SER stated, "Waterford 3 was allowed to operate during the first cycle without a broad range gas detector due to the near-term compensatory measures i.e., periodic surveys of toxic gas inventories, a hotline communication with the St. Charles Parish '
Emergency Operations Center, a control room operator and plant personnel training program, and procedures with respect to response to toxic gases." The compensatory i
measures taken by Waterford 3 in order to operate for one complete cycle without the broad range gas detection system are similar to the administrative controls and other measures, as described above, that will be utilized by Waterford 3 in order to operate l
with limited toxic gas protection for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period. Also, in most cases, both trains of either the broad range gas or chlorine detection systems will not be out of I
service at the same time; therefore, the operable train is available to isolate the control j
room envelope if a toxic chemical event were to occur.
Final Safety Analysis Report (FSAR) change (LDCR # 98-0054, Reference 7) to Section 6.4.4.2.e states that due to wind speed, dispersion, etc.,
Sulations show that j
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the duration the control room would have to remain isolated for a toxic chemical event is no greater than 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. This is less than the time required to reach unacceptable levels of carbon dioxide because the control room staff limits for a toxic chemical event
- are based on a 30 hour3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> duration. Specifically, FSAR Section 2.2A.1 (Reference 8) analyzes the Livingston derailment postulated to occur at Waterford 3. This analysis l
shows that the persistence occurrence for this postulated event (duration the wind blows the toxic gas cloud directly towards Waterford 3) is 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />. The maximum persistence occurrence from any direction is 25 hours2.893519e-4 days <br />0.00694 hours <br />4.133598e-5 weeks <br />9.5125e-6 months <br />. Since it is unknown when an event may occur, a footnote is being proposed to allow the control room to be unisolated for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period. This allowance will provide assurance that the effect of carbon dioxide on control room personnel will be minimized.
The proposed footnote also contains provisions to allow the control rocm to be unisolated for purging while not being required to comply with the requirements of TS
. 3.3.3.1, Table 3.3-6 Action 26 (Control Room Intake Radiation Monitor) and TS 3.7.6.2 Action a (Control Room Emergency Air Filtration System) to place the control room ventilation system in the recirculate mode of operation, and the requirement of TS 3.7.6.5 Action a (Control Room isolation and Pressurization) to place the control room ventilation system in the isolate mode of operation. This provision will allow the control room ventilation system to be unisolated without having to immediately be placed in the isolate or recirculate mode of operation to comply with other TS Actions. However, upon indication of any event that would require the control room ventilation system to be in the isolate or recirculate mode, the control room ventilation system will be placed in the isolate mode of operation.
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This proposed change will allow Waterford 3 to unisolate the control room envelope for l
' 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period when one (for more than 7 days) or both trains of the chlorine detection system or the broad range gas detection system are inoperable. This will allow Waterford 3 to purge the control room envelope of carbon dioxide (which can impair operator performance at low concentrations) while taking adequate precautions i
against a toxic chemical event. Purging ensures that carbon dioxide does not have time to build up to toxic levels in the control room envelope during the duration of a toxic chemical event.
No Significant Hazards Evaluation i
The proposed change described above shall be deemed to involve a significant hazards consideration if there is a positive finding in any of the following areas:
1.
Will operation of the facility in accordance with this proposed change l
involve a significant increase in the probability or consequences of an accident previously evaluated?
Response
No i
This proposed change adds a footnote to allow the control room envelope to be unisolated under administrative controls for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period when one (for more than 7 days) or both trains of the chlorine detection system or the broad range gas detection system are inoperable. This change allows a toxic gas (carbon dioxide) to be purged from the control room. The associated Technical Specifications (TS) Bases are also being changed to discuss the administrative controls. This change will not significantly increase the probability of an accident. Neither the chlorine detection system nor the broad range gas detection system are initiators of any analyzed event. There are no accidents analyzed in the Final Safety Analysis Report (FSAR) that are initiated by the toxic gas detection systems.
This cWice will not significantly increase the consequences of an accident.
Although, the control room envelope will be open to the outside atmosphere when one or both trains of the chlorine detection system or the broad range gas l
detection system are inoperable, administrative controls will be in place to alert l
the control room of a toxic chemical event. When one train is inoperable, the other train is available to detect the toxic gas and isolate the control room
- envelope. Also, the time the control room envelope is allowed to be unisolated is limited to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period. The administrative controls will ensure one hour prior to unisolating the control room envelope, no toxic chemical release is in progress that is a direct threat to Waterford 3, and the St. Charles Parish Industrial Hotline is operational to provide a rapid means of notification in the event of a toxic chemical release in the vicinity of Waterford 3. The administrative controls will also ensure the control room envelope will be isolated 7
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I upon indication of any event that would require the control room ventilation I
system to be in the isolate or recirculate mode of operation.
l Therefore, the proposed change will not involve a significant increase in the probability or consequences of any accident previously evaluated.
2.
Will operation of the facility in accordance with this proposed change l
create the possibility of a new or different type of accident from any accident l
previously evaluated?
Response
No.
This proposed change wds a footnote to allow the control room envelope to be unisolated under administrative controls for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period when one j
'(for more than 7 days) or both trains of the chlorine detection system or the broad range gas detection system are inoperable. The associated TS Bases are also being changed to discuss the administrative controls. These changes do l
not alter the design or configuration of the plant. There has been no physical change to plant systems, structures, or components. This change will allow a toxic gas (carbon dioxide) to be purged from the control room. Therefore, the l
proposed changes will not create the possibility of a new or different kind of i
accident from any accident previously evaluated.
t 3.
Will operation of the facility in accordance with this proposed change involve a significant reduction in a margin of safety?
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Response
No l
p This proposed change adds a footnote to allow the control room envelope to be unisolated under administrative controls for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period when one (for more than 7 days) or both trains of the chlorine detection system or the l
broad range gas detection system are inoperable. The associated TS Bases are l
also being changed to discuss the administrative controls. The control room will be open to the outside atmosphere when one or both trains of the chlorine detection system or the broad range gas detection system are inoperable and the control room is unisolated. However, administrative controls are in place to I
alert the control room of a toxic chemical event. Also, when one train is inoperable, the operable train is capable of detecting a toxic gas event and isolating the control room. The time the control room envelope is allowed to be L
unisolated is limited to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> per 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period. During this time, the carbon L
dioxide will be purged from the control room envelope.' Small concentrations I
(approximately.1.5% by volume) of carbon dioxide are capable of impairing operator performance. _ Thus, allowing the control room envelope to be unisolated to purge a toxic gas is acceptable based on the administrative
. controls in place to alert the control room, and the low probability of a toxic chemical event, that is a direct threat to Waterford 3, occurring when the control 8
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room envelope is unisolated. Therefore, the proposed change will not involve a significant reduction in a margin of safety.
Safety and Significant Hazards Determination l
Based on the above No Significant Hazards Evaluation, it is concluded that: (1) the proposed change does not constitute a significant hazards consideration as defined by 10CFR50.92; and (2) there is a rea'ionable assurance that the health and safety of the public will not be endangered by th proposed change; and (3) this action will not result in a condition which significantly sers the impact of the station on the environment as described in the NRC final envirt/.: mental statement.
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