ML20207D996

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Forwards Info Requested Re Hydrogen Storage at Facility
ML20207D996
Person / Time
Site: South Texas  STP Nuclear Operating Company icon.png
Issue date: 05/26/1999
From: Morris J
HOUSTON LIGHTING & POWER CO.
To: Alexion T
NRC (Affiliation Not Assigned)
Shared Package
ML20207D994 List:
References
NUDOCS 9906040137
Download: ML20207D996 (3)
v • d • e


Text

7,.

6'MAY-26-1999 09:43 NUCLEAR LICENSING 512 972 9298 P.02/04 May 28,1999 To:

Tom Alexion Nuclear Regulatory Commission, NRR Project Manager, South Texas Project

' From: Jim Morris STPNOC, Licensing Re:

Licensee Survey - Hydrogen Storage Facilities

Tom, Attached is the information requested regarding hydrogen storage at the South Texas Project. If there are any questions concoming this information, please give me a call at 512 972-8852.
Regards, Jim Morris l

9906040137 990528 PDR ADOCK 05000498 P

PDR 1

I ATI ENT

7 i_ MAY-26-1999 09843 NUCLEAR LICENSING 512 972 8298 P.03/04 Ssuth Tsxas Project Licensee Survey - Hydrogen Storage Facilities (1) The hydrogen storage sources (excluding portable bottles) and associated volumes.

The Bulk Gas Storage Facility (BGSF) contains bulk quantKes of hydrogen and nitrogen (both liquefied and low-pressure). The storage facilities for these gases are sized to accommodate the maximum expected usage for initial filling of user systems and for two weeks of operational use. The applicable guidance of Electric Power Research Institute (EPRI) Special Report NP 5283-SR A has been incorporated into the design of the BGSF.

The BGSF on site will store up to 200,400 standard cubic feet (scf) of hydrogen in twenty-four pressurized tubes.

(Ref: STP UFSAR Sect. 2.2.1 and 2.2.2)

(2) The distance from the hydrogen storage sources to the closest safety-related or risk-significant (per maintenance rule guidance) structures, systems or components (SSCs).

The Bulk Gas Storage Facility is located approximately 275 feet north of the Unit 2 Instrument Air Compressors (located in the Unit 2 Turbine Generator Building),350 feet

' north of the Technical Support Center Diesel Generator, and approximately 525 feet north of the Unit 2 Diesel Generator Building (DGB) and ESF Transformers.

(Ref: STP UFSAR Sections 2.2.2 and 9.5.8; General Arrangement Drawings)

(3) The distance from the hydrogen storage sources to the closest ventilation system Intake.

The Bulk Gas Storage Facility is located approximately 250 feet north-northeast of the Unit 2 Turbine Generator Building and approximately 500 feet northwest of the Unit 1 Turbine j

Generator Building. Each Unit's Turbine Generator Building Heating Ventilation and Cooling (HVAC) System provides ventilation to its respective Turbine Generator Building, as 1

well as specific areas / envelopes within the Turbine Generator Building, which are: the Cold Chemistry Lab HVAC subsystem, the Battery Room and Battery Charging Room HVAC subsystem, the Emergency non-Class 1E Diesel Generator Room HVAC subsystem, the 13.8 kV Switchgear Room and Cable Vault Ventilation subsystem, the 4.16 kV Switchgear Room Ventilation subsystem, the Elevator Machine Room Ventilation subsystem, the j

Excitation Room HVAC subsystem, the Operator's Station Room HVAC Subsystem, and the Electro-Hydraulic Cabinet Enclosure HVAC subsystem.

The Bulk Gas Storage Facility is located approximately 525 feet North of the Unit 2 Diesel Generator Building (DGB). The Combustion Air intake for each D'esel Generator is located on the north side of the DGB at approximately 65* olevation and is completely independent of the intake of the other two Emergency Diesel Generators (EDGs). The Diesel Generator Building Ventilation intake is located on the south side of the DGB (approximately 605 feet south of the Bulk Gas Storage Facility) at approximately 93* elevation.

An analysis has been performed which shows that in the unlikely event of an instantaneous rupture of any of these bulk gas storage tanks, the resulting gas concentrat'ons at the EDG air intake would not adversely affect EDG operation, and the diesel is still capable of carrying its rated load.

(Ref: STP UFSAR Sections 2.2.2. g.4.4, and 9.5.8; General Arrangement Drawings)

Page 1 of 2

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V.WQ3 South Tcxas Project Licensee Survey-Hydrogen Storage Facilities 1

(4)- BrWf description of actions taken (if any)in response to GL 93 06. If a risk analysis pertaining to this issue is described in a document submitted to the NRC (e.g., IPEEE,

' license amendment submittel), please refer us to those submittals.

In response to Generic Letter 93-06, the Risk and Reliability Analysis department rev'ewed the STP Probabilistic Safety Assessment (PSA) and Individual Plant Examination (lPE) to determine if the potential core damaga threat due to highly combustible gases in vital areas had been adequately considered. This review, completed March 29,1994, identified the following areas that will require further analysis in the spatial interactions update to the STP PSA:

J

  • The Volume Control Tank (VCT) will be further evaluated as a source of hydrogen that could cause a fire / explosion.
  • Hydrogen supply lines such as Line HY1001WN7, which supplies the VCT, will be further evaluated. This evaluation will include both supply and waste gas lines that could affect equipment important to core damage frequency.

Batteries have already been adequately considered in the spatial interactions analysis.

In the spatial interactions update, only the locations of the batteries will be verified.

  • The STP iPE concluded that large fires in the Turbine Generator Building are insignificant to core damage frequency compared to other initiating events that have i

similar consequences, therefore the impact of a generator hydrogen fire / explosion was i

not considered a credible core damaging event. In the spatialinteractions update, equipment locations will be verified to ensure that no physical changes to the plant have occurred that would affect the results of the analysis.

l

= The hazard considered for pressurized canisters in the spatial interaction analysis is that of a potential missile, in the spatial interactions update, a further evaluation of pressurized canisters as a potential source for a hydrogen explosion will be performed.

l Page 2 of 2 TOTAL P.04

l May' 28,1999 MEMORANDUM TO: Rio FROM:

Thomas W. Alexion, Project Manager, Section 1 ORIG. SIGNED BY Project Directorate IV & Decommissioning DMalon of Licensing Project Management

SUBJECT:

LICENSEE SURVEY ON HYDROGEN STORAGE FACILITIES, SOUTH TEXAS PROJECT, UNITS 1 AND 2 (TAC NO. M95689)

The NRC staff has requested that licensees respond to a survey on their hydrogen storage facilities. The staff plans to collect the information from the survey to support a preliminary evaluation to determine if additional study is warranted.

The response from the South Texas Project licensee is attached. 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 DISTAIBUTION:

Docket File (50 498 ar(50 499)

PUBLIC PDIV-1 Reading DOCUMEN._,T NAME:. G:\\PDIV_1\\SouthTexas\\MEM95689.WPD OFFICE PDIV-1/PM

-~li PDIV-D/LA E

NAME TAlexion:dt

'I CJamerson h oats fP r /07 /99 9

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/99 OFFICIAL RECORD COPY a IfAd M r// I W

>RCEEu UNITED STATES g

j NUCLEAR REGULATORY COMMISSION o

WASHINGTON. D.C. 30886-0001 May 28, 1999 MEMORANDUM TO: File FROM:

Thomas W. Alexion, Project Manager, Section 1 Project Directorate IV & Decommissioning D. Vision of Licensing Project Management j

SUBJECT:

LICENSEE SURVEY ON HYDROGEN STORAGE FACILITIES, SOUTH TEXAS PROJECT, UNITS 1 AND 2 (TAC NO. M95689)

The NRC staff has requested that licensees respond to a survey on their hydrogen storage facilities. The staff plans to collect the information from the survey to support a preliminary evaluation to determine if additional study is warranted.

l The response from the South Texas Project licensee is attached. The purpose of this memorandum is to place the attachment in the Public Document Room.

4 Docket Nos. 50-498 and 50-499

Attachment:

As stated j

i

)

I j

MAY-26-1999 09fi3 NUCLEAR LICENSING 512 972 8299 P.02/04 May 26,1999 To:

Tom Alexion Nuclear Regulatory Commission, NRR Project Manager, South Texas Project From: Jim Morris STPNOC, Licensing Re:

Licensee Survey - Hydrogen Storage Facilities

Tom, Attached is the information requested regarding hydrogen storage at the South Texas Project. If there are any questions conceming this information, please give me a call at 512-972-8652.
Regards, Jim Morris ATTACHMENT

MRY-26-1999 09i43 NUCLEAR LICENSING 512 972 8298 P.03/04 South Texas Project Licensee Survey - Hydrogen Storage Facilities (1) The hydrogen storage sources (excluding portable bottles) and associated volume.s.

The Bulk Gas Storage Facility (BGSF) contains bulk quantities of hydrogen and nitrogen (both liquefied and low pressure). The storage facilities for these gases are sized to accommodate the maximum expected usage for initial filling of user systems and for two weeks of operational use. The applicable guidance of Electric Power Research Institute (EPRI) Special Repon NP 5283-SR A has been incorporated into the design of the BGSF.

The BGSF on-site will store up to 200,400 standard cubic feet (sof) of hydrogen in twenty-four pressurized tubes.

(Ref: STP UFSAR Sect.2.2.1 and 2.2.2)

(2) The distance from the hydrogen storage sources to the closest safety-related or risk-significant (per maintenance rule guidance) structures, systems or components (SSCs).

The Bulk Gas Storage Facility is located approximately 275 feet north of the Unit 2 Instrument Air Compressors (located in the Unit 2 Turbine Generator Building),350 feet north of the Technical Support Center Diesel Generator, and approximately 525 feet north of the Unit 2 Diesel Generator Building (DGB) and ESF Transformers.

(Ref: STP UFSAR Sections 2.2.2 and 9.5.8; General Arrangement Drawings)

(3) The distance from the hydrogen storage sources to the closest ventilation system Intake.

The Bulk Gas Storage Facility is located approximately 250 feet nonh-northeast of the Unit 2 Turbine Generator Building and approximately 500 feet northwest of the Unit 1 Turbine Generator Building. Each Unit's Turbine Generator Building Heating Ventilation and Cooling (HVAC) System provides ventilation to its respective Turbine Generator Building, as well as specific areas / envelopes within the Turbine Generator Building, which are: the Cold Chemistry 1.ab HVAC subsystem, the Battery Room and Battery Charging Room HVAC subsystem, the Emergency non-Class 1 E Diesel Generator Room HVAC subsystem, the 13.8 kV Switchgear Room and Cable Vault Ventilation subsystem, the 4.16 kV Switchgear Room Ventilation subsystem, the Elevator Machine Room Ventilation subsystem, the Excitation Room HVAC subsystem, the Operator's Station Room HVAC Subsystem, and the Electro Hydraulic Cabinet Enclosure HVAC subsystem.

The Bulk Gas Storage Facility is located approximately 525 feet North of the Unit 2 Diesel Generator Building (DGB). The Combustion Air intake for each Diesel Generator is located on the north side of the DGB at approximately 65* elevation and is completely independent of the intake of the other two Emergency Diesel Generators (EDGs). The Diesel Generator Building Ventilation intake is located on the scuth side of the DGB (approximately 605 feet south of the Bulk Gas Storage Facility) at approximatehy 93' elevation.

An analysis has been performed which shows that in the unlikely event of an instantaneous rupture of any of these bulk gas storage tanks, the resulting gas concentrations at the EDG air intake would not adversely affect EDG operation, and the dieselis still capable of carrying its ratedload.

(Ref: STP UFSAR Sections 2.2.2. 9.4.4, and 9.5.8; General Arrangement Drawings)

Page 1 of 2 m..

MAY-26-1999 09:43 NUCLEAR LICENSING 512 972 8298 P.04/04 South Tcxas ProJ:ct Licensee Survey-Hydrogen Storagefacilities (4) Brief description of actions taken (if any)in response to GL 93 06. If a risk analysis pertaining to this issue is described in a document submitted to the NRC (e.g., IPEEE, license amendment submittel), please refer us to those submittels.

In response to Generic Letter 93-06, the Risk and Reliability Analysis department reviewed the STP Probabilistb Safety Assessment (PSA) and individual Plant Examination (IPE) to determine if the potential core damage threat due to highly combustible gases in vital areas had been adequately considered. This review, completed March 29,1994, identified the following areas that will require further analysis in the spatial interactions update to the STP PSA:

  • The Volume Control Tank (VCT) will be further evaluated as a source of hydrogen that could cause a fire / explosion.
  • Hydrogen supply lines such as Line HY1001WN7, which supplies the VCT, will be further evaluated. This evaluation willinclude both supply and waste gas lines that could affect equipment important to core damage frequency.
  • Batteries have already been adequately considered in the spatial interactions analysis, in the spatial interactions update, only the locations of the batteries will be verified.
  • The STP IPE concluded that large fires in the Turbine Generator Building are insignificant to core damsge frequency compared to other initiating events that have similar consequences, therefore the impact of a generator hydrogen fire / explosion was not considered a credible core-damaging event. In the spatialinteractions update, equipment locations will be verified to ensure that no physical changes to the plant have occurred that would affect the results of the analysis,
  • The hazard considered for pressurized canisters in the spatial interaction analysis is that of a potential missile. In the spatialinteractions update, a further evaluation of pressurized canisters as a potential source for a hydrogen explosion will be performed.

)

l l

l Page 2 of 2 TOTAL P.04

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