ML20205Q825

Forwards Documentation on Licensee 980928 Proposed Changes to TS on Control Room & Fuel Handling Bldg Ventilation Sys, Per 990304 Discussion with Util

ML20205Q825
Person / Time
Site:	South Texas
Issue date:	04/15/1999
From:	Alexion T NRC (Affiliation Not Assigned)
To:	NRC (Affiliation Not Assigned)
References
NUDOCS 9904220085
Download: ML20205Q825 (4)

Text

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MEMORANDUM TO: File April 15,1999  ;

FROM: Thomas W. Alexion, Project Manager, Section 1 ORIG SIGNED BY:

Project Directorate IV & Decommissioning Division of Licensing Project Management

SUBJECT:

DISCUSSIONS WITH LICENSEE ON ITS SEPTEMBER 28,1998, i

PROPOSED CHANGES TO TECHNICAL SPECIFICATIONS ON THE CONTROL ROOM AND FUEL HANDLING BUILDING VENTILATION SYSTEMS, SOUTH TEXAS PROJECT, UNITS 1 AND 2 During a March 4,1999, phone call between the NRC staff and the licensee (STP l Nuclear Operating Company), the licensee's September 28,1998 (ACN 9810020302),

proposed technical specification change was discussed. In order to facilitate the discussion, the licensee provided the information in the attachment. The purpose of this memorandum is to place the attachment in the Public Document Room.

Docket Nos. 50-498 and 50-499 l

Attachment:

As stated DISTRIBUTION:

Docket Files (50-498 and 50-499)

PUBLIC DOCUMENT NAME: 1:\STPFINAL\MEMA3849.WPD  !

To receive a copy of the document, indicate in the bor C= Copy w/o attachment / enclosure E Copy with attachment / enclosure N = No copy OFFICE PM/PDIV-1_ .E LA/PDIV-1 E SC/PDIV-1 6 NAME TAlexh CJamerson h RGramm b DATE / ~/99 k/ b /99 (/g{ /99 ,

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April 15,1999 MEMORANDUM TO: File FROM: Thomas W. Alexion, Project Manager, Section 1 Project Directorate IV & Decommissioning Division of Licensing Project Management

SUBJECT:

DISCUSSIONS WITH LICENSEE ON ITS SEPTEMBER 28,1998, PROPOSED CHANGES TO TECHNICAL SPECIFICATIONS ON THE CONTROL ROOM AND FUEL HANDLING BUILDING VENTILATION SYSTEMS, SOUTH TEXAS PROJECT, UNITS 1 AND 2 During a March 4,1999, phone call between the NRC staff and the licensee (STP Nuclear Operating Company), the licensee's September 28,1998 (ACN 9810020302),

proposed technical specification change was discussed. In order to facilitate the discussion, the licensee provided the information in the attachment. The purpose of this memorandum is to place the attachment in the Public Document Room.

Docket Nos. 50-498 and 50-499

Attachment:

As stated

f1AR-04-1999 08:19 MJCLEAR LICENSING 512 972 8298 P.02/03 4

3/4/1999 l South Texas Project Nuclear Operating Company l Fuel Handling Building (FHB) and Control Rooin (CR) Ventilation Systems Tech Spec Change Discussion Points for Deterministic Basis of Proposed Change FHB HVAC Applicable Design Basis Accident (DBA) l Fuel Handling Loss of Coolant Accident (LOCA)

Accident in the Fuel  ;

Handling Building (FHB) 4 Discussion DBA Concems Concerits due to ESF system leakage in FHB Points Avoided by Prohibiting following swap-over to ECCS sumps.

Fuel Movement in FHB l ECCS sump swap over occurs approx.10 to 20 i minutes after LOCA.

• Can recover by closing plenum / restoring integrity

• Conservative lodine release value assumed

• Lack of air flow results in extended period of i time before airbome contaminants reach upper levels of FHB e LOCA unlikely

. LOCA not credible / Leak before break

• Source term timing / amount not credible (if iodine elemental, flashing would result in plate-out in lower FHB elevations)

• ESF leakage lower than assumed 1

• X/O estimates overly conservative CR HVAC Applicable Design Basis Accident (DBA)

Fuel Handling LOCA ,

Accident in the FHB /

RCB Discussion DBA Concerns Concems due to containment feakage resulting in Points Avoided by Prohibiting CRHVAC system uptake containment leakage is Fuel Movsment in assumed to be approx. 90% of dose.

FHB/RCB e Can recover by closing plenum / restoring integrity

• SystemINOP nointake

• LOCA unlikely LOCA not credible / Leak before break

• Source term timing / amount not credible

• Con'.ainment leakage rates not credibts

• Containmentleak tight a X/Q estimates overty conservative

• Control Room occupancy rates conservativety hiah ATTACl&!FET

[ f1AR-04-1999 08:19 NUCLEAR LICENSING 512 972 8298 P.03/03 6

3/4/1999 South Texas Project Nuclear Operating Company Fuel Handling Building (FHB) and Control Room (CR) Ventilation Systems Tech Spec Change Discussion Points for Deterministic Basis of Proposed Change i

CR HVAC (cont'd)

Main Steam Line Steam Generator Tube Rupture (SGTR)

Break (MSLB)

Discussion

• Can recover by

• Can recover by closing plenum / restoring Points closing plenum / integrity restoring = SystemINOP nointake integrity . X/Q estimates overty conservative l = System INOP -

• Control Room occupancy rates conservatively l no intake high l

= X/Q estimates overty

. conservative a Control Room occupancy rates '

conservatively high I

l TOTAL P.03

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