ML20079D709
| ML20079D709 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 07/18/1991 |
| From: | Barkhurst R ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20079D710 | List: |
| References | |
| W3F1-91-0437, W3F1-91-437, NUDOCS 9107240232 | |
| Download: ML20079D709 (13) | |
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W3F1-01-0137 A1.05 QA July 18, 1991 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555
Subject:
Waterford 3 SES Docket No. 50-382 Licenao No. NPF-38 Technical Specification Change Itequest NPF-38-110 Gentlemen:
On August 9,1988, the NRC granted Waterford 3 a temporary change to Technical Speelfication (TS) Bases, B 3/1.7,0, " Control Itoom Air Conditioning System."
In the letter granting approval, the NRC recommended that conalderation be given to making a permanent revision to TS 3.7,0, " Control Room Air Conditioning System." On March 21, 1989, this request, identified ns NPF-38-95, was submitted. It proposed to subdivide TS 3.7.G into four TSs covering three separate functions: Control Room Emergency A!r Filtration System, Control lloom Air Temperature, and Control Room Isolation and Pressurization. The intent of this chango was to clearly relate the system design function to the surveillance program and TS limiting conditions for operation (LCOs). Changes to the bases were included to reflect these changes to the TS.
Since then, this submittal has undergone several changes as a result of discussions and correspondence following the original submittal. For convenience, the enclosed change request and safety analysis incorporates all of this information and is to replace the original request, NPF-38-95.
Because the design of the Waterford 3 Control Room Air Conditioning System is complex and therefore, difficult to describe, we would appreciate the opportunity to present this TS change request directly to the staff at your convenience.
Based on the positive impact of the March,1990, meeting on this subject, wo feel strongly that a direct presentation of this material will again eliminate confusion and streamlino the review process. Until such times the description of CRACS and accompanying drawings provided during the March,1990 presentation may assist the Staff in its initial review of this submittal.
9107240232 91071o
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1 W3F1-01-0137 Teclinical Specification Cliange Request NPF-38-11G Page 2 July 18, 1991
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k Please direct any questions or comments to Tim Gaudet on (501) 739-0600.
Very truly yours,
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I 'D/DA'Il ssf Attachments:
Affidavit NPF-38-116
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R.D. Martin, NitC Region IV D.L. Wigginton, NRC-NRR R.B. McGehee N.S. Reynolds NRC Resident inspectors Office Administrator Radiation Protection Division (State of Loulslana)
American Nuclear Insurers i
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7 UNITED STATES OF AMEltlCA NUCLEAlt itEGULAToltY COMMISSION in tlw raatter of
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Entergy Operations, hicorporated
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Docket No. 50-382 Waterford 3 Steam Electric Station
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AFFIDAVIT lt.P. Ilarkhurst, being duly sworn, hereby deposes and says that he is Vice President Operations - Waterford 3 of Entergy Operations, incorporatedt that he is duly authorized to sign azul file with the Nuclear llegulatory Comadssion the attached Technleal Specification Change lle<luest NPF-38-110; that he la familiar with the content thereof; and that the matters set forth therein are true and correct to the best of his knowledgo, infortantion and belief.
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it.P. liarkhurst Vice President Operations - Waterford 3 STATE OF LOUISl ANA
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) ss PAltlSil OF ST, CllAllLES
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Subscribed and sworn to before me, a Notacpfublic in and for the Parish and State above named this
/ F/4. day of Clgd
,1991.
O Qhhts L&>uv' Notary 'ublic g
My Commission expires /i [ ( h [ v
__m_____
1)l:ScitlPTION ANI) sal'l:TY ANAINSIS Ol' Pitol OSI:1) Cll ANGl: NPl%38-110 This justifies an amendment to the Waterford 3 Technleal Speelfications that subdivides TS 3/4.7,0, " Control lloom Air Conditioning System," into four separate TSs covering three functions: Control lloom 1:mergency Air l'ilt ration System, control room air temperature, and control room isolation and pressu rization.
Existing Speelfications See Attachment A proposed Speelfications See Attachment it 1)eneription This change subdivides Waterford 3 TS 3/4.7,0, " Control lloom Air Conditioning System" (CllACS) into four TSs covering three separate functions. New TSs 3/4.7. Gel and 3/4.7,0.2 will address requirements for operability of the Control Itoom 1:n ergoney Air I'lltration System during Modes 1 through 4, and Modes 5 and G, respectively. TS 3/4.7.6.3 is added to address requirementa for control room air temperature during all modes of operation, and 3/1.7.0.4 to address requirements for control room isolation and pressurization during all modes of operat ion,
liabitability systems are provided to assure that operators can remain in the control room and take effective acilons to operate the plant safelv uinier normal operation and maintain the plant in a safe condition following an itecident. The CitACS and the emergency filtration units are both designed and installed such that they can be operated together or separately as the situation dictates. The CitACS components ato designed to cool and heat the control room envelope while the emergency filtration units are designed to remove radioactivity from the control room envelope air. At Waterford 3, the CitACS and emergency fil' ration units are not functionally dependent upon each other. Ilowever, in its present form, TS 3.4.7.6 does not differentiate between these functions to determine operability. l'urthermore, four other inadequacies related to the funetton of control room isolation and pressurization exist in the present speelfication.
Theae involve the following:
1.
Maintenance: No provisions exist for the conduct of routino maintenance or the installation of necessary modifications to the plant if timt work involves a breach in the control room envelopo.
1
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2.
Allownblo our kno No provisions exist for un allowed outage timo Thili') tote 7eorrect unidentirlod bronches to the control room envelope. C t.
/, nny loan of envelopo integrity Imniedintely pinces the phat in n Teel Spoelflention 3.0.3 netton statement. This menns that within one hotn. ution shall be initinted to pineo the plant in a modo in whleh the speelflention does not apply by placing it, as applienble, in ut loust hot standby within the next a;x hours, at least hot uhutdown within the following six hours, and nt lenst cold shutdown within the subsequent twenty-four hours.
3.
Mnho-up ntr flow ren!rementas itecent opern:lonal exportence reflects the linportance to elently speelfyTJi control room envelopo operability requirements in the speelflention. Currently, a rostriction on differential pressuro exists for the control room envelope, onlyl thoro are no requirements on the allowablo make up air flow rato assoelnted with the difforontlal pressuro.
4.
Toxic chemient threat to operators: No provtalons exist in the present speciffention that recognfitho thrent to plant operations personnel from a toxic chemlen1 relenso concurrent with a hrench in the control room onvelope when the plant is in Modes 5 or 0. The possibility of n toxic gas event is unreinted to too operational modo.
The proposed change addresses all these concerns. It inemnses operational flexibility while still maintaining the requisite level of protection.
The Cit ACS consists of two full capnelty redundant air han:lling units ( All 12 (3A SA) und All 12 (311-Sil)), a computer rem supplementury air luuidling unit
( All-31 (3)), two toilet exhuust fans, each with one hundred percent enpacity (E-34 (3A SA) and E-34 (311 S11)), and a conference room and kitchen exhaust fan (E-42 (3)). The Chllled Water System supplies cooling water to the colls to the All-12 units. The All-31 (3) unit does not have a safety related function.
Soparately, two full onpacity, rodundant emergoney air filtration units (S-8 (3A-SA) and S-8 (311-S11)) assure radionuclide filtration following a design basis secident. No cooling coils are providad in the S-8 unitsi however, S-8 honting coils nro provided for proper charcoal filter operation, 3/4.7.0.1 and 3/4.7.G.2, Eraorgoney Air Filtration Tho. existing TS addresses all functional aspoets of the CitACS. This proposed change incorporntos action statements from the existing TS applienble to the Control Itoom Emergency Air Filtration System into two now TSs TS 3/4.7,0.1 applienble for Modus 1 through 4, and TS 3/4.7,0.2 for Modes 5 and G. All requirements in the proposed TSs are from the existing spoefflention with two exceptions.
1.
The existing TS has no netton statement addressing the inopornbility of both trains of emergency air filtration while in Operational Modes 1 through
- 4. As such, required netton would be in necordance with TS 3.0,3. As stated above, this monns that within one hour, action shall be initinted to place the plant in a modo in which the specification does not apply by placing it, as applienble, in at least hot standby within the next six hours, ut least hot shutdown within the following six hours, and at least cold shutdown within tho subsequent twenty-four hours.
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Tho now n}n cification additsses tho inoperability of both trains with the t
action statement, "With both control room emergency air filtration trains inoperable, restore one train to Ol'EllAllLE status or be lu at least ilOT STANDilY within the next G hours and in Col D SilVTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />."
'a.:Is is essentially the action required by TS 3.0.3 except TS 3.0.3 requires linillating action to ho taken in the first hour. llegardless, the real protection of the TS, the hot standby aiul cold shutdown conditions, are required to be reached by both speelfications within the next six aint the following thirty hours. This la similar to other action statements.
Despite the lark of the required initiating netloa within ono hour, the proposed action statement of fers protection equivalent to the existing action statement.
2.
The existing TS has netton statements addressing either one or both trains of emergency adr filtration inoperablo whilo lii Operational Modes 5 and G.
The requested TS, 3/4.7,0.2 only addresses the Inoperability of both t rains. As such, no netton is required in Modes 5 or G if one train is luoperablo.
During an emergency, both S-8 units are started to provide filtration and adsorption of outsido air atid control room envelopo recirculated air
( reference: FSAlt G.4.3.3). Dosages received in the control room af ter a full power design basis loss of coolant neeldent (LOCA) were calculated to bo orders of magnitudo higher than other accidents involving rmliation releases to the envhonment, llecause the consequences of a full power design basis LOCA are triore severo theini those ocetirrling dtirliig COLD SilUTDOWN aiul itEFUEhlNG, speelflention 3/4.7.G.2 requires only ono OPUllAllLE S-8 unit to guard against nechtents during Modes 5 and G.
This is typical for similar TSs during Modos 5 and G.
All other requirements for the emergency air filtration system in tho existing TS are speelfled in the ameinled TS. As such, the full protection of the original specification regarding emergency air filtration is retained in proposed TSs 3/4.7.G.1 and 3/4.7.G.2.
3/4.7,0.3, Control lloom Air Temperaturo Proposed TS 3/4.7 G.3 addret. sos requirements for control room air temperature, in the existing TS, the action statements require different operability levels based on the operational inodo. From the existing TS:
MODES 1 through 4:
"With ano control room air conditioning system inoperable, restore the inoperablo system to OpEllAllLE status with 7 days or be in at least ilOT STANDitY within the next G hours and 11: COLD SilVTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
3
. MODES 5 and 0:
n.
"With one control room air conditioning system inoperablo, restore the inoperable system to OPEllAlthE status within 7 days or Initiate and maintain operation of tho remaining OPEllAlthE control room air conditioning system in the recirculation modo, b.
"With both control room air conditioning systems inoperable, or l
with the OPEllAllLE control room air conditioning system, required to be in the recirculation modo by action a, not i
capable of being powered by an OPERAllLI: emergency power source, suspend all operations involving CORE ALTEllATIONS i
or positivo reactivity changes."
For Modes 1 through 4, operator actions are retained in proposed action statement "a".
For Modes 5 and G, existing Action Statement "a" (abovo) protects against toxic gas and radiologleal events, it is unrelated to the maintenance of control room temperature, and therefore is irrelovant to the subject function of TS 3/4.7,0.3. Ilowever, Action Statement "b" has direct relevance and thereforo, is retained in the amended TS as Action Statement "c" with a qualifier identifying the cause of the inoperability to be a loss of cooling capability.
l Proposed Action Statements "b" and "d" cover occurrences when both units are inoperablo due to a loss of cooling capability (Action "b") or a loss of air circulation capability ( Action "d"):-
b.
"With two control room air conditioning units inoperable due to t
a '.oss of cooling capability, roturn one unit to an OPEllADLE atatus within 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> or be in llOT STANDllY within the next 0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> and in COLD SilUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
d.
"With two control room air conditioning units inoperablo due to a loss of air circulation capability, take the appropriato-ACTION in Specification 3.7,0.1 or 3.7,0.2."
With both units inoperablo, the existing TS requires actions to be taken in accordance with TS 3.0.3 which allows one hour beforo initiating shutdown.
Action-Statement "b" from the proposal allows a throo hour AOT. A common cause for failure of one of those units is the loss of a chiller. Ily providing three hours beforo initiating shutdown, sufficient timo exists for the operators to identify the problem, transfer busses and align the standby chiller and return the unit to operable servico. This also assures the Waterford 3 remains below the maximum temperaturo limit allowed in the station blackout analynis. Although three hours are loss restrictive than TS 3.0.3, this change is supported by the Waterford 3 station blackout analysis.
Proposed Action Statement "d" addresses both units being out of servico due to a loss of air circulation copaniitty. Under these conditions, it defors to the appropriato action statements from the TS for emergoney air filtration. Although~
t.
It directs the operator to another speelfication, this statement is included here to acknowledge air circulation capability as a function of the control room air conditioning units, i
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.The proposed surveillanco requirement fccr TS 3/4.7,0.3 requires the averago air temperature to be verified to be less than 60 F at least onco overy twelvo hours.
Presently, the temperaturo is to ho veriflod every twelve hours as being less than 110 F. Since the proposed surveillance speelfles 60oF, it is more restrictivo than the existing.
80*F was chosen for several reasons. In the Waterford 3 Final Safety Aimlysis lleport, the control room design temperature is defined to ho 75 F.
Ily defining 80"F for the surveillance, some variance from the design temperature is allowed.
80*F is also consistent with the initial conditions for the current station blackout calculation. Furthermoro, the proposed surveillanco is more realistic for determination of operability of the air coolers sineo a unit will be inoperable long before temperatures reach 1101.
3/4.5 0.4, Control lh>om Isolation and Pressurization There are four perceived inadequacies related to the function of control room isolation and pressurization as it is presently described in the TSs. These are:
1.
The existing specification is silent with respect to the threat to plant operations personnel from a toxic chemleal release concurrent with a breach in the control room envelope.
2.
The existing specification does not include a limit on the allowablo make-up air flow rato associated with the pressurization surveillance.
3.
.in the existing TS, there is no true allowance made for the conduct of routino maintenance or the installation of necessary modifications to the plant if that work involves a breach in the control room envelope.
4.
_ The present specification is inflexible with respect to a loss of control room envelopo integrity while the plant is at power.
The proposed chango creates a specification that eetains requirements from tho original TS while addressing all of the abovo concerns.
The proposed change adds action statements, not in the present TS, specific to the function for control room isolation and pressurization, Actions "a" and "b" address operability of the cor.irol room isolation valvo normal outsido air flow path and the emergency filter outsido air intake valvo, if a control room envelope
-isolation valvo falls, Action "u" requires that valve to be restored to operable status within sovon days, or the affected flow path to be teolated within the following six hours._ Action "b" similarly requires the affected flow path to be isolated within six hours should an emergency outsido air lutako isolation valvo becomo inoperable and cannot be restored within seven days.
Action "c" covers all other falhires of the envelope. Under these conditions, ono action statement stipulatos that emergency breathing airbank pressuro will be L
verified and that immediato actions be taken to restoro the envelopo to operable status should a toxic gas event occur. The present specification only requires i
the suspenalon of activities involving coro alterations or positive reactivity changes when the ability to pressurize the envelop 9 is lost and the plant is in Mode 5 or G.
The proposed version merely recognizes tho threat of a toxic gas l
event and requires action to ensure that installed backup systems remain functional such that they are available should need arise, in Modes 1 through 4, the proposed version allows three days to identify the cause of a failure and i
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. initiate corrective action, if the cause is identified, seven days (minus the time it took to identify the cause) are allowed to correct the failure and restore the ability to pressurize the control room envelope. Otherwise, a plant shutdown is required, l'inally, all operations involving core alterations or positive reactivity changes are suspended for envelopo failures occurring during Modes 5 and G.
Surveillance requirements for control room isolation and pressurization are similar to the existing TS. The purpose of these is to verify the funettons of pressurization and isolation. Three surveillances are in the proposed version.
The first surveillance varies from the existing TS only in the addition of a new requirement. In the existing TS, pressurization of the control room is verified per 4.7.G e.3. :
"Each control room air conditioning system shall bo demonstrated OpEllABLE... at least once per 18 months by... verifying that the system maintains the control room at a positive pressure of greater than or equal to 1/8 luch water gauge relative to the outside atmosphere during system operation."
The proposed surveillance adds a specific make-up air flow rate for which the pressure differential is to be established. Tho proposed surveillance, 4.7.G.4 n.
is as follows:
"The control room envelope isolation and pressurization boundaries shall be demonstrated OpEllABhE at least once per 18 months by...
verifying that the control room envelope can be maintained at a positive pressure of greater than or equal to 1/8 inch water gauge relative to the outside atmosphere with a make-up air flowrato less than or equal to 200 efm during system operation."
An pointed out previously, the existing TS does not include a limit for make up air flow. Itecent operational experience (i.e., LElt 90-010-00 and Enforcement Action 91-06) has highlighted the fact that the system make-up air flow rate when in the high radiation mode of emergency operation has clear implications for system operability. As such, this limit is requested to be included in the TSs.
Another surveillance, taken verbatim from the existing specification, requires verification of isolation on receipt of a toxic gas signal (4.7.G.4 b). The protection offered by this surveillance remains unchanged. The final surveillance (4.7.G.4 c), requiring verification of normal outside air flow path isolation following a safety injection actuation test signal, is only changed to reflect verification of the function about which this TS is concerned (l.o.,
isolation). The existing surveillance requires verification that the system automatically switches into a recirculation mode of operation with flow thcough the llEpA filters and charcoal adsorber banks on the test signal. Since the existing requirement la retained, word for word, in proposed surveillance 4.7.G.1 d.2. '
address the filtration fu-tion of that speelfication), protection of the surynllianco is not comp.
21 sed.
The proposed change includes a means of performing routine maintenance on the envelope and provides an opportunity to perform modifications that necessarily involve breaches in the envelope. Continued, reliable, safe plant operation demands regular maintenance and installation of equipment upgrades. llowever, the control room envelope is, essentially, a single component that must remain operable in all modes. Under present TSs, most maintenance actions or modifications involving an envelope breach must be performed with the plant in an action statement. The proposed specification provides a seven day window for maintenaneo and modification in proposed Action 3.7.G.4 c.3. The intent of this G
. action statement is to recognizo distinct differences between two envelopo breaches that might otherwise appear identical, it serves to emphasizo the importance of identifying the exact cause of a failure whilo recognizing that when the cause of the failure is positively known, even simplo temporary actions, when combined with inherent design conservativisms, can effectively protect control room personnel. On the other hand, the continued existeneo of an onvelopo breach that is not identified can clearly result in unsatisfactory emorgency performanco. Thorofore, plant operation la not allowed to continue when reasonablo efforts have failed to identify the cause of the failuro.
-The request for a savon day maintenance window is based on an analysis of the maintenance tasks for those systems needed to maintain the envelopo at a positivo pressure. In brief, the analysis c >ncluded that to conduct non-emergoney system lovel maintenance would require four days. The remaining three days are included to allow for complientions and other unforseen events. This, however, j
does not Imply that safo plant operation could be subordinate to the desirability of a seven day maintenance opportunity. As such, Action 3.7.G.4 c.2. Is included to require that the operators immediately restore the integrity of the control room-envelope on the occurrence of a toxic gas event.
The proposed speelfication also provides a significant increase in operational flexibility, Under the present TS, any failure that results in the inability to pressurize the control room envelopo requires entry into TS 3.0.3 and the
-Initiation of unit shutdown. The proposed version allows plant personnel a total of seventy-two hours to identify the speelfic cause of the failuro and initiato correctivo action. To identify a reasonable perh>d for an allowable outage, po'ontial failures that affect the ability to pressurlzo the control room onvelope woco reviewed. If maintenance personnel work around the clock, analysla i
indicates that three days are required f or correction of the range of creditable failu res.
)
Some conservatisms exist that support this proposed change. The control room habitability analysos assumo the Waterford 3 control room envelope is surrounded by a cloud of toxic gas and that post-Isolation in-leaka.To would occur directly c
from that cloud. In fact, the control room onvelopo is surrounded on three sidos by the Ilonctor Auxillarlos Ilullding (ItAll) and on a fourth side the Turbino
-Ilullding. Only two sides, neither of which has doors or other penetrations, are exposed to the outsido atmosphere. Since the Turbino Building wall has only an air-lock door, the greatest porcentage of in-lonkage to the control room would be from the ItAB because of the penetrations. The analysis revoulod that toxic chemical concentrations in the control room are ulmost entirely from in-leakage af ter isolation. (This analysis had boon reviewed by the Commission.)
Furthermore, including the effect of the ItAll in the inmlytical model, a reduction by at least an order of magnitudo was realized in the chemical concentrations in
, the air leaking into the control room. in the final tumlysis, control room toxic chemical concentrations were found to build up at a rato slower than previously assumed,- This should, for any credible breach in the envelope, provide
' operators witti enough timo to don breathing apparatus before being exposed to clevated levels of toxic chtm! cal concentrations.
i Still further conservativisms exist, llegulatory Guido.l.78, " Assumptions for Evaluating the liabitability of a Nuclear power plant Control Itoom During a postulated llazardous Chemical Release," paragraph C.13 states, in part:
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"If consideration of the possible accident for any hazardous chemical Indicates that the applienble toxletty limits may be exceeded, self-contained breathing apparatus of at least one-half houe capacity or a tank sourco of air with manifold outlets... should bo provided for each operator in the control room. Additional air capacity with appropriato equipment should be provided if a chemleal hazard can persist longer than one-balf hour, l'or neeldents of longer duration, sufficient air for six hours (coupled with provisions for obtaining additional air within this period) is suffielent."
These requirements have already been implemented at Waterford 3. Additional protection is also offered. For instance, any rise in concentration of a chemical sampled by the installed gas detection systems can be monitored at the plant monitoring computer. Also, Waterford 3 is a participant in the St. Cl.arles Parish Emergency Preparedness / industrial llotline System and feuki bo informed of any the St. Charles Parish Emergency Operations local industrial emergency b3 Center. Taking into account the Waterford 3 control room design character!stics, the industrial hotline, and the installed emergency breathing equipment combined with the limited timo that the plant may continue to operate with an envelopo breach, a prudent level of protection is provhled for the plant operators to ensure the safe operation of Waterford 3.
Included in Attachment 11 is an amendment to the bases. This amendment reflocts the proposed changes made to TS 3/4.7.G.
_ Safety Analysis:
The proposed changes 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 the cperation of Waterford 3 in accordance with these proposed changes involve a significant lucrease in the probability or consequence of any accident previously evaluated?
ltesponse:
No The limiting accidents against which the Cit ACS protects are:
all Chapter 15 scenarios involving a release of radiation to the environment outside the cotitainment, toxic gas releases, and smoke resulting from control room eowlope fires.
Limiting accidents against whleh the emergency air filtration system protects are all Chapter 15 scenarios involving release of radiation to the environment outside the containment.
The probability and consequences of any of the limiting accidents listed above are unchanged by the specialization of the plant TSs. As pointed out in the description of the change, TSs 3/ l.7,0.1 and 3/4.7.6.2 have rotained all requirements from the existing TS with the addition of one 8
I.
action atutement based on the inoperability of both trains, and the oxeeption of ono action statement based on one inoperablo train in Modes 5 or G. This action statement is unnecessary sinco it is only appilcable in a modo unlikely to exportence the limiting design basis accidents against which this system protects. Therefore, the protoetion of tho original specification is uncompromised for the function of emergency air flitration.
Thoro are two differences between the existing TS and the pmposed TS 3/4.7.0.3 regarding control room air temperature. The first is the three hour outage allowed when both air conditioning units are luoperablo. This is two hours more than the existing TS allows (in accordaneo with TS 3.0.3). Ilowever, a three hours period provides operators with sufficient time to realign the standby chiller. This corrects most types of failures.
Although three hours are less restrictivo than TS 3.0.3, it le not significantly less and therefore, does not seriously reduce the protection of the original specification. The other chango la the reduction of tho surveillance temperature from 110 F to 80oF. This is more rostrictive than the existing version. All other requirements for air conditioning are retained in the pmposed TS.
Proposed TS 3/4.7,0.4, which concerns control room isolation and pressurization, allows more ihnited continued plant operation than the existing TS. When compared to existing actions required for continued operation with a known breach, the proposed speellication recognizes the potential consequences that could nrlso from operation with an unidentiflod breach in the envelope and imposes more restrictivo actions.
Engineering analysis also shows that, for most of the time, toxic chemient concentrat_lous in the control room envelope after a postulated release aro largely the result of in-leakage from the HAH after isolation. This has the effect of reducing the chemical concentration of gas leaking into the control room by at least an order of magnitudo and ultimately results in a control room chemical concentration buildup rato slower than previously assumed.
These charnetoristics make it likely that the operators would have sufficient timo to don the breathing apparatus installed in the control room, it is also noteworthy that this emergency breathing apparatus is considered by Hegulatory Guido 1.78 to provido sufficient operator protection for those cason whero chemical toxicity limits might bo exceeded.
The limited continued operation allowed by the pmpsed chango, the design characteristics of the control room, and the installed breathing -
l apparatus provhlos a reasonablo level of protection for plant personnel.
Somo now restrictions are identified for the control room isolation and pressurization. Theso were not previously identified and therefore offer enhanced protection to the TS. All existing requirements speelfic to the isolation and pressurization function are retained in the proposed version.
As such, the proposed specification offers more protection than the existing TS.
Based on the above, those revisions to the TS will not adversely affect tho l
reliability or performance of any installed equipment. Thero are no dosign changes associated with this proposed amendment. Consequently, all aspects of the safety analysis will remain unchanged and thoro will be no physic 4J change to the facility, and operation of Waterford 3 in accordaneo with those proposed changes will not involvo a significant increase in the probability or consequence of any accident previously evaluated.
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, 2.
Will the operation of Waterford 3 in accordance with those proposed changes create the possibility of a now or different kind of accident from any accident previously evaluated?
Response - No To create a now or different kind of accident, these changes must-introduce a new failuro path. In this regard, those revisions are benign since they do not alter the system or its operation. With a few exceptions, all existing TS restrictions have been retained. The exceptions have bee-shown to have Inc.ignificant impact. Furthormore, soveral additional i
restrictions, not in the existing specification, have been added.
Based on the above information, these changes do not introduce a now failure path and therefore, cannot creato n' now, unevaluated sequence of events. The current plant safety analyses are bounding and this revision will nor create the possibility of a now or different kind of accident from any accJdont previously evaluated.
3.
Will the operation of Waterford 3 in accordance with these proposed changes involvo a significant reduction in the margin of safety?
Responset No Safety margins related to the control room envelopo air systems are established for control room temperaturo and the habitability of the control room following all credible accidents. This chango does not modify the equipment installed in the plant or its operation. Therefore, existing margins of safety are retained, and the operation of Waterford 3 in accordance with this proposed change will not involve a significant reduction in a margin of safety.
Safety and Sir:nificant flazards Determination Based on the above Safety Analysis, it is concluded that: (1) the proposed chango does not constitute a significant hazards consideration as defined by 10 l
CFR 50.92; and (2) there is a reasonable assurance that the health and safety of the public will not be ondangered by the proposed change; and (3) this action will not result in a condition that significantly alters the impact of the station on the
-environment as described in the NRC Final Environmental Statement.
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