ML20196L148

Forwards Info Provided by Licensee to Facilitate Conference Calls Re Licensee Desire to Propose Emergency Technical Specification Changes on Fuel Handling Building Exhaust Air Sys

ML20196L148
Person / Time
Site:	South Texas
Issue date:	07/07/1999
From:	Alexion T NRC (Affiliation Not Assigned)
To:	NRC (Affiliation Not Assigned)
References
NUDOCS 9907120331
Download: ML20196L148 (2)

Text

I '.D _ 9 o_

l July 7 1999 0

MEMORANDUM TO: File FROM:

Thomas W. Alexion, Project Manager, Section 1 ORIG. SIGNED BY Project Directorate IV & Decommissi:>ning Division of Licensing Project Management l

Office of Nuclear Reactor Regulation l

SUBJECT:

PRELIMINARY DISCUSSIONS WITH LICENSEE ON PROPOSED EMERGENCY TECHNICAL SPECIFICATION CHANGE ON THE FUEL HANDLING BUILDING EXHAUST AIR SYSTEM l

On July 1,1999, the NRC staff had several conference calls with the licensee (STP Nuclear Operating Company) to discuss the licensee's desire to propose emergency technical specification changes on the fuel handling building exhaust air system. The licensee provided the information in the attachment to facilitate the conference calls. The purpose of this memorandum is to place the attachment in the Public Document Room.

l The licensee subsequently made a formal application to the NRC later the same day.

I l

Docket Nos. 50-498

)

I and 50-499 l

l

Attachment:

As stated i

DISTRIBUTION:

Docket Files (50-498 and 50-499)

PUBLIC

/

Io receive a copy of Inis document, indicate "C" in the box OFFICE PDIV-yg C PDIV-D/LA C /

o[

1 TAleAhif CJamersonh t

NAME DATE

) /7 /9[

7 / 7 /99 DOCUMENT NAy: G:\\PDIV-1 \\SouthTexas\\M EMA5974.wpd OFFICIAL RECORD COPY 9907120331 990707 P

PDR ADOCK 05000498 P

PM t

antag1;te n s w sauunawmas vmpaa SOUTH TEXAS PROJECT NUCLEAR OPERATING

~

COMPANY m/gik,

-.m NUCLEAR LICNNSING

[_

[I f h[d

"7 l

~

l P. O.hx 289

, g; j [t Wadmorth,Texu 77485 l:

y F-t r'

n s

m i

t t

a 1

To:

@ ' /[./g w z i

Fax #:

Fmm:

TETRPHONE #/EXTN. -

Date:

i l

Re:

1. Pages

?6

. including this cover sheet h oT~ SI6HLT-NOTES:

/

1 IM f2-L co'1cb C-D r tooo c_ O r

.Nsto s Imc0

ausgesag, s %,57-ra j

VERMCATION #

l "Y

NTACHMENT l

j

e-m m

v%e:pm o

i I

Nuclear Opensting company 5W 3

- n n ao a, - ar l

July i,39W NOC-AE-000578 File No.: G21.02.01 10CFR50.90 STI: 30907801 U. S.NuclearRegulatory Commission Attention: Document Control Desk Washington,DC 20555 South Texas Project Unit 2 Docket No. STN 50-499 Proposed Emergency Amendment to South Texas Project Technical Specifications to Modify Requirements Associated with the Fuel Handline Building Exhaust Air System STP Nuclear Operating Company (STPNOC) proposes a one-time change to Technical Specifications 3.3.2 and 3.7.8 for Unit 2 only to allow all Fuel Handling Building (FHB) Exhaust Air System components to be inoperable for a period not to exceed 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to facilitate repair of the Train B exhaust booster fan. This one time change may be used twice and will only be effective from the date of amendment issuance through July 14,1999.

Technical Specification 3.7.8 Limiting Condition for Operation action for the FHB Exhaust Air System was entered at 0300 on June 29,1999 to perform scheduled maintenance.

On June 30,1999, a ground was discovered in FHB exhaust booster fan 21B during a surveillance following system maintenance. The fan was declared inoperable and the ACTION statement of Technical Specification 3.7.8 remained in effect, with 7 days to restore the fan or be in at least hot standby in the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and cold shutdown in the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. The 7 day allowed outage time expires at 0300, July 6,1999.

Prompt action is requested to approve this emergency technical specification amendment to allow replacement work to proceed on the failed fan. Restoring FHB Exhaust Booster Fan 21B to an operable status will require removal and replacement of the motor. The replacement requires the installation and subsequent removal of a temporary modification to isolate the duct to the failed fan from the common supply and exhaust plenums. STPNOC estimates installation of the temporary modification will take no longer than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, and removal of the temporary modification will take no longer than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. Work to install the temporary modification cannot begin until the request for this emergency technical specification amendment is approved because during the installation and subsequent removalit is necessary, for personnel safety, to disable the remaining exhaust booster fans and the FHB main exhaust fans. Without this amendment a unit

'lAh ccg pgp

a s

k shutdown will be required. STPNOC plans to replace the fan within the current 7-day allowed outage time depend mt upon approval of the requested amendment. The effective period being requested addresses the case should it become necessary to request extension of the 7-day allowed outage time through a separate licensing action.

1 Unit 1 FHB exhaust booster fan 11B failed in April 1998 and Unit 1 FHB exhaust booster fan 11 A failed in October 1998. In both occurrences, STPNOC received enforcement discretion for Technical Specification 3.0.3 from the NRC to support the use of the temporary modification to effect repairs. This emergency technical specification proposal is essentially the same as those previous requests for discretionary enforcement. As a result of these occurrences, STPNOC took action to alleviate a need for further licensing actions in the event of an exhaust boostw fan failure. A Technical Specification amendment request was developed and submitted to the NRC in September 1998. A plant modification was developed and implemented during the Spring 1999 Unit I refueling outage to allow replacement of PHB exhaust booster fan motors without a need to secure the remaining two FHB exhaust ventilation trains. This same modification is planned for implementation during the Fall 1999 Unit 2 refueling outage.

The root cause for fan failure has been determined and indicates failure was due to inadequate insulation design and manufacturing quality. A plan of action to address the FHB exhaust booster fan motors issues is in place. This plan includes,in addition to the actions described above:

i Establishment of a repair contract with a qualified vendor to rewind the fan motors utilizing STPNOC specifications.

Systematically replacement of fan motors with upgraded spares while rewinding and restocking the warehouse spares.

Enhancement of the preventive / predictive maintenance programs to closely monitor e

the performance of the FHB exhaust booster fan motors.

STPNOC has made reasonable efforts to put in place corrective actions to address this issue. However, a reasonable period of time was required to implement the necessary co actions.

South Texas Project has reviewed the proposed amendment pursuant to 10CFR50.92 and determined that it does not involve a significant hazards consideration In addition, South T Project has determined that the proposed amendment satisfies the criteria of 10C for categorical exclusion from the requirement for an environmental assessment. The Sout Texas Project Plant Operations Review Committee and the Nuclear Safety Review Board hav reviewed and approved the proposed amendment.

The required affidavit, a Safety Evaluation and Determination of No Significant Hazards Consideration, an Envitunmental Assessment, and the marked-up affected pages of the Te Specifications are included as attachments to this letter. In addition, a Probabilistic Saf Analysis 1mpact and Risk-Informed Decision Making Analysis is attached. In accordance with

\\

10CFR50.91(b), South Texas Project is notifying the State of Texas of this request for license amendment by providing a copy of this letter and its attachments.

i STPNOC requests approval of this proposed amendment in a timely manner to support this emergency situation. Failure to act in a timely way will result in shutdown of Unit 2. This l

emergency situation could not have been avoided for the reasons stated above. STPNOC has made reasonable efforts to put in place corrective actions to address this issue.

If there are any questions regarding the proposed amendment, please contact Mr. S. M.

l Head at (512) 972-7136 or myself at (512) 972-8757.

I J. J. Sheppard Vice President, Engineering andTechnical Services Attachments:

l. Affidavit

2. Description of Change and Safety Evaluation

3. Determination of No Significant Hazards

4. Description of Probabilistic Safety Analysis Impact and Risk Informed Decision Making Analysis

5. Environmental Assessment

6. Annotated Technical Specifications and Bases Pages 1

.=sv

rq# tis 8

a NOC-AE-000578 Page 1 of 2 1

i 1

i ATTACHMENT 1 l

l AFFIDAVIT l

r 1

e

exe u sswc m p uu m-NOC-AE-000578 Page 2 of 2 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter

)

)

South Texas Project, et al.,

)

Docket Nos. STN S4499

)

South Texas Project Unit 2

)

AFFIDAVIT I, J. J. Sheppard, being duly sworn, hereby depose and say that I am Vice President.

Engineering and Technical Services of STP Nuclear Operating Company; that I am duly authorized to sign and file with the Nuclear Regulatory Commission the attached proposed emergency Technical Specification changes to modify requirements associated wm. the Unit 2 fuel handling building ventilation system; that I am familiar with the content thereof: and that the matters set forth therein are true and correct to the best of my knowledge and belief.

J. J. Shep Vice President, Engineering and Techmc ervices STATE OFTEXAS

)

)

COUNTY OF

)

Subscribed and swom to befo e, a Notary Public in and for the State of Texas, this day of _

,1 Motary Publicin and the State of Texas V

NOC-AE-000578 Page 1 of 5 ATTACHMENT 2 DESCRIPTION OF CHANGE AND SAFETY EVALUATION

es,_&ueur uvu e en m mtwsssr jp.g:ggs S

1 NOC-AE-000578 Page 2 of 5 Description of Change and Safety Evaluation Descri tM of Change:

f This change proposes a one-time change to Technical Specifications 3.3.2 and 3.7.8 for U only to allow all Puel Handling Building (FHB) Exhaust Air System components to be inoperable for a period not to exceed 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to facilitate repair of the Train B exhaust bo fan. This one time change may be used twice and will only be effective from the date of amendment issuance through July 14,1999.

Technical Specifications 3.7.8 and 3.3.2 (Table 3.3 3, Functional Unit 11) require three independent Fuel Handling Building (FHB) Exhaust Booster Fans and three indepen Main Exhaust Fans and actuation instrumentation to be operable. In addition, Technical Specification 3.9.12 establishes requirements for FHB HVAC during movement of fuel. No change to Specification 3.9.12 is necessary because STPNOC will comply with the action of this specification not to move fuel or operate the crane over the spent fuel po Operability of the FHB Exhaust Air System ensures that radioactive material leaking Emergency Core Cooling (ECC) equipment within the FHB following a Loss of Coolant Accident (LOCA) and radioactive material release from an accident involving an irradiat assembly in the FHB are filtered prior to reaching the environment.

This occurrence is the first required replacement of exhaust booster fan 21B. Replace i

failed exhaust booster fan 21B will require a temporary modification to isolate the duc{

l the fan from the rest of the system. The process ofinstalling and subsequently remo temporary modification will require breaching the common exhaust and supply plen the three exhaust booster fans. During the time the plenums are breached, the requ Specification 3.7.8 for the FHE FNAC system are not met. In addition, while the modification is being installed and removed, the other exhaust booster fans and the ma fans will be put in pull-to-lock for personnel safety. In this condition, the system cannot automatically actuate and the requirements of Specification 3.3.2, Table 3.3-3, Functiona 11 are not met for all trains. Both of these conditions would require that Technica 3.0.3 be entered, and shutdown of Unit 2 would be required.

The proposed change will allow all FHB Exhaust Air System components in Unit 2 to be inoperable for a period not to exceed 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> for installation and not to exceed 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> removal of the temporary modification to allow repair of the exhaust booster fan. Installatio and removal of this temporary modification will only be allowed once by this change and limited to a dermed time period. The proposed change is required to address the Sou Project plant design, which incorporates unique, three-train design features. The i

of ventilation in the Fuel Handling Building HVAC typically use common plenums or d that must be opened to permit maintenance and required testing. The proposed c actions for the Specifications will permit this maintenance to be conducted w:thou 1

-4

L ME-Wi-iGTU6LE cutR4CFDMFARs W.t@ta NOC-AE-000578 Page 3 of 5 Technical Specification 3.0.3 requiring a shutdown of the unit. A permanent modification has been installed in Unit I to allow exhaust booster fan repairs without a need to secure the remaining two FHB exhaust ventilation trains. This same permanent modification is scheduled for installation in Unit 2 during the Fall 1999 refueling outage.

The following comp =wy action will be taken:

1. Administrative controls will ensure that, in the unlikely event that emergency operation is required, operators have adequate time to ensure that FHB Main and Exhaust Fan motors are manually started or placed in automatic as required. The following defines the conditions where the Fuel Handling Building Exhaust Air System can be maintained available while the Fans are in the " Pull-to-I.ock" position:

a) Prior to opening the FHB Exhaust Booster Fan common plenum access panels, Maintenance personnel will inform the Control Room of their intentions. This information will be noted in the Control Room bg.

b) Following the openin of the plenum access panels, Maintenance personnel will maintain a watchstander at each opening who is in continuous communication with the Control Room.

c) If at any time during this process, the Maintenance personnel are made aware, either i

via lo*pa=6 or radio, that a reactor trip has occurred, then the work will be secured, loose material removed, personnel will exit the plenums, and the access panels reinstalled as expeditiously as possible. The Control Room will confirm via continuous communication that the access panels have been reinstalled.

d) Once confirmed that plenum integrity is restored, the Operator will manually start the required FHB Main and Exhaust Booster Fans, or place them in automatic, as required.

e) If at any time during this process the Control Room notices an increase in Reactor Containment Building radioactivity that would be an indication of a Reactor Coolant System leak, Maintenance personnel will be informed to secure the work, exit the plenums, and install the access panels as expeditiously as possible. Once confirmed that plenum integrity is restored, the Operator will manually start the required FHB Main and Exhaust Booster Fans or place them in automatic as required.

2. During the repair of the FHB Exhaust Booster Fan, no irradiated fuel movement will occur and no loads will be moved over the Spent Fuel Pool.

3. During the repair of the FHB Exhaust Booster Fan, no activities will be conducted that could affect the level of the Spent Fuel Pool.

l

esaunsm*m agme i

NOC-AE-000578 Page 4 of 5 The above methodology is deemed acceptable because in A aes I through 4 the purpose of Fuel Handling Building Exhauct Air System is to filter ECCS radioactive leakage that occurs during the recirculation phase. Recirculation phase will not occur prior to 16 minutes after an accident. Following an accident, the reactor will be automatically tripped. The plant announcement of this fact or radio communications will provide sufficient noti 6 cation to inform the personnel to restore the plenum integrity. The 16 minutes prior to radioactive ECCS occurring is adequate time to secure work, ensure that the plenum integrity is restored and the FHB Main and Exhaust Booster Fans started, or placed in automatic, as required, and for the workers to exit theFHB.

In the request for enforcement discretion submitted to the NRC on October 22,1998, STPNOC estimated that ti.e installation of the temporary modification will take no longer than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, a removal of the temporary modification will take no longer than 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. This proposed emergency technical specification amendment allows 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> for both the installation and removal of the temporary modification. The additional 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> proposed fcr removal is insignificant from a risk standpoint and allows for consistency and clarity in application of th proposed exception.

Safety Evaluation:

The purpose of the Fuel Handling Building (FHB) HVAC System is to mitigate the co of a fuel handling accident as well as a Lossof Coolant Accident (LOCA) by limiting pla boundary dose to within the guidelines of10CFR100. This is accomplished by routing e from the spent fuel pool and the remainder of the FHB through ESF filter units contain filters and iodine removal carbon filters if high levels of airbome radioactivity are detected in exhaust air or automatically opon an SI signal.

The major components of the exhaust air ubsystem are:

• Three main exhaust fans

• Three booster fans

• Two carbon filters The three 50-percent-capacity exhaust booster fans are of the vaneaxial type. The fans a direct-drive type with single-speed motors. Fan motors are totally enclosed, air-cooled, an statically and dynamically balanced. Normally, exhaust air bypasses the filter units and is exhausted directly to the plant main vent stack. Upon detection of high radiation or SI s exhaust air is routed through the filter units, the exhaust booster fans, and main exha and is then delivered to the plant main vent stack.

n me,e-wecms<un masmsmuswa vinreis NOC-AE-000578 Page 5 of 5 As noted above, only two accident scenarios are relevant with regard to the FHB HVAC system.

The Puel Handling Accident will be precluded from occurring by ensuring that no loads will be l

l carried over the Spent Puel Pool and no movement of hradiated fuel will take place during the time that the repair activities are occurring. The Large Break LOCA (LBLOCA), although clearly within the design basis of the plant,is a highly unlikely occurrence. In the event that a LBLOCA were to occur, it would take a minimum of 16 minutes for the Refueling Water Storage Tank to empty and for the Emergency Core Cooling system (ECCS) to go into the recirculation mode by taking suction from the containment sump. At that point in time, it would be assumed that radiation leakage from the ECCS would occur that would require the FHB HVAC system to be functional. In the event that maintenance is in progress,16 minutes is considered ample time to secure the work, restore the plepum and take the fans out of pull-to-lock and for the workers to exit the FHB. Actual experience with previous replacements provides a high level of confidence that these actions can be effectively implemented.

In addition to the above,it should be noted that the Licensing Basis for the South Texas Project includes the Leak-Before-Break concept. This methodology has demonstrated that the deterministic LBLOCA is not a credible' event and that in fact any large pipe rupture of the Reactor Coolant System would be preceded by leakage that is detectable by Control Room personnel using instrumcmation installed in the containment. The time between initiation of the leakage and the actual break would allow for additional time, i.e., greater than 16 minutes, to restore the plenum and place the booster fans in the standby condition.

A goalitative risk assessment based on the proposed action has becn performed. The LBJ OCA is an unlikely event which contributes very little to Core Damage Frequency. The probability that a LBLOCA would occur during the 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> requested is less than 0.2% of the annual probability of the LBLOCA. The probability that the compensatory actions would subsequently fail is also considered to be small, making the likelihood of any adverse consequences essentially not c edible. Additional discussion of the risk assessment performed is contained in Attachment 4.

Based on the above, STPNOC believes that safety significance and potential consequences of t proposed plan of action are extremely small.

4 I

a nn.m _ n w

rs-

~' ' -

m m

m

(.

NOC-AE-000578 Page 1 of 3

(

/

l ATTACHMENT 3 DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION i

j l

NOC-AE-000578 Page 2 of 3 l

No Significant Hazards Determination In accordance with the criteria set forth in 10CFR50.92, the South Texas Project has evaluated these proposed Technical Specification changes and determined they do not represent a

. significant hazards consideration. The following is provided in suppon of this conclusion.

1.

Does the change lavolve a significant increase in the probability or consequences of an accident previously evaluated?

The proposed change is to allow all FHB Exhaust Air System components and actuation channels to be inoperable twice for a limited period of time before a plant shutdown is required. The proposed allowed outage times do not represent a significant change to the probability of an accident because the inoperability of the FHB Exhaust Air System is not identified as a precursor to a design basis event. The low likelihood of a design basis accident during the limited period of allowed inoperability of this system coupled with compensatory actions that will be simple, straightforward, and well briefed prior to starting this evolution do not represent a significant increase in the consequences of an accident.

In Modes 1 through 4 the purpose of the Puel Handling Building Exhaust Air System is to filter ECCS radioactive leakage that occurs during the recirculation phase. Recirculation phase will not occur prior to 16 minutes after an accident. Following an accident, the reactor will be automatically tripped. The plant announcement of this fact will provide sufficient notification to inform the personnel to restore the plenum integrity. The 16 minutes prior to radioactive ECCS leakage occurring is adequate time to secure the work, ensur: that the plenum integrity is restored and the FHB Main and Exhaust Booster Fans staned or placed in automatic, as required, and for the workers to exit the FHB.

Therefore, the propsed changes do not represent an increase in the probability or consequences of any accident previously evaluated.

2.

Does the change create the possibility of a new or different kind of accident from any accident previously evaluated?

Allowing'all FHB Exhaust Air System components and actuation channels to be inoperable for a limited period of time before a plant shutdown is required does not have the potential to create a new or different kind of accident from any previously evaluated.

The proposed changes do not introduce any new equipment into the plant or significantly alter the manner in which existing equipment will be operated. The system affected by the proposed changes is not identified as a contributing causal factor in design basis

,w u

ogo-

.wp-

N 9JP99&ILQAa3L@MS P.14/26 j

NOC-AE-000578 Page 3 of 3 accidents. The system will continue to respond as required by the design with the compensatory measures established to restore plenum integrity. Since the proposed changes do not allow activities that are significantly different from those present allowed, no possibility exists for a new or diffemnt kind of accident from those previously evaluated.

3.

Does this change involve a significant reduction in a margin of safety?

The proposed changes do not involve a significant reduction in a margin of safety the ability of the Fuel Handling Building HVAC will be maintained. The margin of safety is defined by the ability of the systems to limit the release of radioactive mater and limit exposures to operators respectively following a postulated design basis acci 1

The only aspect of the proposed change that can be postulated to have any effect o margin of safety is the proposed allowance for all trains of Fuel Handling Building HVAC to be inoperable for a limited period. The low probability of a design basis that would require the system to perfonn its safety function during the limited pe allowed by the proposed action assures that the change does not involve a signific change in a margin of safety. In addition, the compensatory measures will restom th Fuel Handling Building Exhaust Air System prior to the time it is required to remove contaminants in the accident condition. Therefore, the proposed changes do not significantly affect them operating restrictions and the margin of safety which ability to make and maintain the reactorin a safe shutdown and limit the release of

{

radioactive material is not affected.

Based on the above, the South Texas Project has evaluated the proposed Technical Specification change and determined it does not represent a significant hazards consideration.

1 i

l i

l 1

m.m m

m

~'

NOC-AE-000578 Page 1 of 3 ATTACHMENT 4 DESCRIPTION OF l

PROBABILISTIC SAFETY ANALYSIS IMPACT AND RISK-INFORMED DECISION MAKING ANALYSIS l

i

de5RAFhT brets mLwmmgaAswa p g_ygg e

NOC-AE-000578 J

Page 2 of 3 Description of Probabilistic Safety Analysis Irnpact and Risk-Informed Decision Making Analysis The PRA does not credit the Fuel Handling Building Ventilation System formitigating c damage accidents.

The design basis accidents that the FHB HVAC is designed to mitigate are:

Fuel Handling Accident in the Fuel Handling Building Loss of Coolant Accident The effects of a Fuel Handling Accident are precluded by suspending all operation movement of fuel within the spent fuel pool or crane operations with loads over the spen pool with no FHB air filter trains OPERABLE as required by Specification 3/4.9.12.

During the Loss of Coolant Accident, the concem in the FHB is the leakage of Reactor Containment Building emergency sump water from the Emergency Core Cooling Sy lowerregions of the building. Should the FHB HVAC common plenum be breached for maintenance, the leak-Before-Break concept discussed previously provides adequate restore the ventilation plenum and FHB HVAC operability. The modification previously described has been installed in Unit I and is scheduled for installation current plant conditions, prior to commencing maintenance activities, and an evaluation of the need for compensatory measures or action plans, are part of the normal work contro the station.

In addition, it would take a minimum of 16 minutes for the Refueling Water Storage T empty and the Emergency Core Cooling System to go into the recirculation mode b suction from the containment emergency sump. This also provides additional time to r ventilation plenum and PHB HVAC operability. Total Emergency Core Coolin is monitored periodically. Three redundant Emergency Core Cooling Systems are ava during recirculation.

Another factor minimizing dose to the outside environment and providing time to resto HVAC operability is that the lack of airflow with no ventilation would result in an exten period of time before airborne contaminants reached the upper levels of the Fue Building. The safety analysis assumes that 95.5% of the iodine released to the Building is in the elemental form. A large portion of this would plate out in the lower lev the Puel Handling Building during leakage from the Emergency Core Cooling Syste A Fuel Handling Accident is prevented during maintenance to restore a FHB HVAC fan OPERABLE status by South Texas Project's Technical Specifications, which will not a Q

_ _ _ ~

N Rapaggighte:%JD P.17/26 Attachm:nt 4 1

NOC-AE-000578 Page 3 of 3 operations leading to a potential Puel Handling Accident during this maintenance condition. The probability that a LBLOCA would occur during the 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> requested is less than 0.2% of the annual pretability of the LBLOCA. Event precursors would allow time to restore system operability.

l l

~

c e

l NOC-AE-000578 Page 1 of 2 l

f i

l ATTACHMENT 5 4

ENVIRONMENTAL ASSSESSMENT L

NOC-AE-000578 Page 2 of 2 ENVIRONMENTAL ASSESSMENT This proposed Technical Specification Change has been evaluated against the criteria for and identification of licensing and regulatory actions requiring environmental assessment in accordance with 10CFR51.21. It has been detennined that the proposed changes meet the criteria for categorical exclusion as provided for under 10CFR51.22 (c) (9). The following is a discussion of how the proposed Technical Specification Change meets the criteria for categorical exclusion.

10CPR51.22 (c)(9): Although the proposed change involves changes to requirem nts with respect to system operability requirements; (i) the proposed change involves no Significant Hazards Consideration (refer to the No Significant Hazards Consideration section of this Technical Specification Change Request),

(ii) there is no significant change in the types or significant increase in the amounts of any effluents that may be released offsite since the proposed changes do not affect the generation of any radioactive effluents nor do they affect any of the permitted release paths, and (iii) there is no significant increase in individual or cumulative occupational radation exposure.

Accordingly, the proposed change meets the eligibility criteria for categorical exclusion set forth in 10CFR51.22 (c)(9). Based on the aforementioned and pursuant to 10CFR51.22 (b), no environmental assessment or environmental impact statement need be prepared in connection with issuance of an amendment to the Technical Specifications incorporating the proposed changes of this request.

1 L _

AGE;t#-lM6T 1#!b3 KuML%1 LK44GB!NG P.20/26

e.,,,

NOC-AE-000578 Page 1 of 7 ATTACHMENT 6 Annotated Technical Specification and Bases Pages i

i M

NOC-AE-000578 Page 2 of 7 Annotated Technical Specification and Bases Pages The following Technical Specification and Bases pages are annotated with changes designated by change bars in the right har.d column.

Page 3/4 3/28 Page 3/4 7-19 Page B 3/4 7-4 withInsert g

s

v. w e*;

l NOC-AE-000578 Page 3 of 7 TABLE 33-3 (Continued)

ACTION STATEMENTS (Continuad)

ACTION 26-With the number of OPERABLE channels one less than the Minimum Chan OPERABLE requirement, declare the affected Auxiliary Feedwater Pump inoperab take ACTION tequired by Specification 3.7.1.2.

ACTION 27-MODES 1,2,3,4: With the number of OPERABLE channels one less than the Minimum Channels OPERABLE requirement, restore the inoperable channel to OPERABLE status within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or be in at least HOT STANDBY w hours and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

MODES 5 and 6: With the number of OPERABLE channels less than th Minimum Channels OPERABLE requirement, restore the inoperable Channel to OPERABLE status within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or initiate and maintain operation of the Control Room Makeup and Cleanup Filtration System (at 100% capacity) in the recirculation makeup filtration mode.

ACTION 28-MODES 1,2,3,4: With the number of OPERABLE channels less than the M Channels OPERABLE requirement, within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> isolate the Control Room En and maintain operation of the ventilation system in the filtered recirculation mode.

MODES 5 and 6: With the number of OPERABLE channels less th Channels OPERABLE requirement, within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> initiate and maintain operation o Control Room Makeup and Cleanup Filtration System (at 100% capacity) in the recirculation and makeup filtration mode.

ACTION 29'- MODES 1,2,3,4: With the number of OPERABLE channels one less than the Minimum Channels OPERABLE requirement, restore the inoperable channel to l

OPERABLE status within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or either initiate and maintain operation of the PH exhaust air filtration system (at 100% capacity) or be in at least HOT STANDBY with the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> ACTION 30-With irradiated fuel in the spent fuel pool: With the number of OPERABLE channe less than the Minimum thr.nels OPERABLE requirement, fuel movernent within t spent fuel pool or crane operation with loads over the spent fuel pool may proce provided the FHB exhaust air filtration system is in operation and dischargin least one train of HEPA filters and charcoal adsorbers.

l

• With 2 or more PHB Exhaust Air actuation channels inoperable, restore the PH actuation channels to a condition that satisfies the ACTION statemen in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOW 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. This exception is effective until July 14,1999 for Unit 2 only. The ex used twice during this time period.

1

_]

M R E; E T Ldibrd GUL49K1 LMKd8Kd P.23/26

• 'e C

• NOC-AE-000578 Page 4 of 7 PLANT SYSTEMS 1Ud 71 MIM MANDI TNG BTm MTNG (FHR) FYMAf fRT AtR MYb r.nd LIMrrING CONDITION FOR OPERATION 3.7.8 The FHB Exhaust Air System comprised of the following components shall be OPERABI.E.

Two independent exhaust air filter trains, a.

b.

Three independent exhaust booster fans, c.

Three i=d =adat main exhaust fans, and d.

Associated darpers.

APPLICABILrrY: MODES 1,2,3, and 4.

ACTION:

• With less than the above FHB Exhaust Air System components OPERABLE but with at least one FHB exhaust air filter train, two FHB exhaust booster fans, two FHB main exhaust fans and associated dampers OPERABLE, restore the inoperable system to OPERABLE status within 7 days or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUIDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> SURVEILLANCE REQUIREMENTS 4.7.8 The Fuel Handling Building Exhaust Air System shall be demonstrated OPERABLE:

At least once per 31 days on a STAGGERED TEST BASIS by initiating, from the control a.

room, flow through the HEPA filters and charcoal adsorbers and verifying that the system operates for at least 10 continuous hours with the heaters operating with two of the three exhaust booster fans and two of the three main exhaust fans operating to maintain adequate a flowrate; b.

At least once per 18 months and (1) after any structural maintenance onf the HEPA filter or charcoal adsorber housings, or (2) following painting, fire, or chemical release in ventilation zone communicating with the system by:

1) Verifying that the cleanup system satisfies the in-place penetration and bypass leakage testing acceptance criteria ofless than 0.05% for HEPA filter banks and 0.10% for charcoal adsorber banks and uses the test procedure guidance in Regulatory Positions C.S.a. C.S.c, and C.5.d of Regulatory Guide 1.52, Revision 2, March 1978, and the system flow rate is 29,000 cfm 10%;

2) Verifying, within 31 days after removal, that a laboratory analysis of a representative carbon sample obtained in accordance with Regulatory Position C.6.b of Regulatory Guide 1.52,

e m

=.* e NOC-AE-000578 Page 5 of 7

• With ALL PHB Exhaust Air System components inoperable, restore the FHB Exhaust Air System to a condition that satisfies the ACTION statement above within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least HOT STAN within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN in the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. This exception is effective until July 14,1999 for Unit 2 only. The exception may be used twice during this time period.

SOUTH TEXAS -UNITS 1 & 2 3/4 7-19

=.4.

NOC-AE-000578 1

Page 6 of 7 PLANT SYSTEMS BASES The limitations on minimum water level and maximum temperature are based on providing a 30-day cooling water supply to safety-related equipment without exceeding its

. design basis temperature and is consistent with the recommendations of Regulatory Guide 1.27, " Ultimate Heat Sink for Nuclear Plants,' March 1974 T4.7.6 (Not used) 3/4.7.7 CONTROL ROOM MAKEUP AND CLEANUP FILTRATION SYSTEM i

The OPERABILtTY of the Control Room Makeup and Cleanup Filtration System ensures

{

that: (1) the ambient air temperature does not exceed the allowable temperature for continuous-duty rating for the equipment and instrumentation cooled by this system, and (2) the control room will remain habitable for operations personnel during and following all credible accident conditions. Operation of the system with the heaters operating for at least 10 continuous bours in a 92-day period is sufficient to reduce the buildup of moisture on the adsorbers and HEPA filters. The OPERABILITY of this system in conjunction with control room j

design provisions is based on limiting the radiation exposure to personnel occupying the control room to 5 rems or less whole body, or its equivalent. This limitation is consistent with the requirements of General Design Criterion 19 or Appendix A,10 CFR Part 50. ANSI N510-1980 will be used as a procedural guide for surveillance testing.

3/4.7.8 FUEL HANDLING BUILDING EXHAUST AIR SYSTEM The OPERABILITY of the Fuel Handling Building Exhaust Air System ensures that radioactive materials leaking from the ECCS equipment within the FHB following a LOCA are filtered prior to reaching the environment. Operation of the system with the heaters operating for the least 10 continuous hours in a 31-day period is sufficient to reduce the buildup of moisture on the adsorbers and HEPA f:!ters. The operation of this system and the resultant effect on offsite dosage calculations was assumed in the safety analyses. ANSI N510-1980 will be used as a procedural guide for surveillance testing.

Q NSERT )

3/4.7.9 (Not Used)

SOUTH TEXAS - UNITS 1 & 2 B 3/4 7-4 Unit 1 - Amendment No. 49,109 Unit 2 - Amendment No. 9 96

., ~ _

.+,,,...,...m-.

m,~ amer -w v~~~,

r y-Anachment 6 NOC-AE-000578 Page 7 of 7 Insert to page B3/4 7-4 Insert For Unit 2 only, from the date of amendraent issuance through July 14,1999, the limited allowed outage time is allowed for all of components of the Fuel Handling Building Exhaust Air System to be out of service in recognition of the fact that there are common plenums and the repair to the exhaust booster fan requires opening or entry into these plenums, This is acceptable based on the low probability of a design basis event in the brief allowed outage time and because administrative controls are imposed on the activities that provide for compensatory action to restore integrity of the system.

TOTAL P.26

-.