ML20195J004

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Summary of 981028 Meeting with Usec Re Portsmouth & Paducah Gaseous Diffusion Plant SAR Chapter 3 Update Project.Major Issues Discussed,Listed.With Attendance List,Agenda & Usec Handout
ML20195J004
Person / Time
Site: Portsmouth Gaseous Diffusion Plant, 07007001
Issue date: 11/18/1998
From: Yen-Ju Chen
NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
To: Pierson R
NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
References
NUDOCS 9811240174
Download: ML20195J004 (52)
v • d • e


Text

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UNITED STATES l . g j 4

NUCLEAR REGULATORY COMMISSION o WASHINGTON. D.C. 20555-4001 k * * * *

  • p November 18, 1998 MEMORANDUM TO: Robert C. Pierson, Chief Special Projects Branch Division of Fuel Cycle Safety and Safeguards j
FROM
Yen-Ju Chen p[

Enrichment Sect n Special Projects ranch Division of Fuel C cle Safety and Safeguards

SUBJECT:

MEETING

SUMMARY

- PORTSMOUTH AND PADUCAH GASEOUS DIFFUSION PLANT SAR CHAPTER 3 UPDATE PROJECT l

USEC is undertaking an SAR Chapter 3 Update Project to review, update, and confirm the information in Chapter 3. On October 28,1998, NRC staff met with staff from USEC to discuss l this Update Project. USEC staff presented the plan and process of the Update Project and the methods and criteria for handling issues identified from the project. At the conclusion of the meeting, USEC staff agreed to submit a letter describing the update process, criteria, and milestone schedule in a revised amendment request.

Major issues discussed during the meeting included:

1. USEC will perform verification and validation to confirm accuracy of information in SAR Chapter 3. USEC staff indicated that safety systems, such as O and AO systems, will be verified through physical field walkdown. However, the criteria of conducting the walkdown were not formally developed at this time. USEC staff agreed to formally develop the walkdown criteria.
2. USEC is taking a graded approach to categorize structures, systems, and components (SSCs)into four grades. All O and AQ systems will be Grades 1 or 2--SSCs credited in SARUP for prevention / mitigation of r%te or onsite consequences. l

< 3. The USEC preoosed Chnpier 3 update process to resolve as-found conditions includes I the following. ;ps: (a) Determine operability based on Generic Letter 91-18; and (b) l Determine safety significance of the as-found condition. If the condition is not safety significant, USEC will not revise Chapter 3. If the condition is safety significant, USEC '/

will use ine current process for updating the application to resolve as-found conditions.

4. USEC identified criteria for evaluating whether an as-found condition is safety .. ,.

significant. A condition will be considered safety significant if: (a) operability of O, AQ- / i NCS, or AO SSCs cannot be reasonably assured or (b) the condition adversely impacts the assumptions or conclusions of the accident analyses contained in the Application

! SAR Chapter 4.

9811240174 981118 PDR ADOCK 07007001 , -.m ka " ~ ~ ~ " }

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Mr. Robert C. Pierson 5.' . USEC cannot meet the milestone schedule stated in its submittal dated March 30,1998.

USEC will submit a new schedule in the revised amendment request indicated above.

However, the schedule for the final submittal for the Chapter 3 Update Project will remain October 31,1999.

Attachments: List of Attendees USEC Handout -

Dockets 70-7001 and 70-7002 DISTRIBUTION: .

Dockets 70-7001 and 70-7002 NRC File CentiP, "

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i MEETING OF U.S. NUCLEAR REGULATORY COMMISSION AND UNITED STATES ENRICHMENT CORPORATION October 28, 1998 TOPIC:

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NRC/USEC Meeting, Chapter 3 Update Project October 28,1998,10:00am NRC Headquarters, Bethesda, MD l

AGENDA l

I. Introduction I

A. Purpose of Meetmg '

B. Goals of Chapter 3 Update ,

1 II. Chapter 3 Update Project Plan A. Organization B. Chapter 3 Update Process III. Presentation of Sample Sections IV. Chapter 3 As-Found Process V. Miscellaneous Topics VI. Closing Remarks l

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10/28/98 1 F U.

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I Introduction ,

Purpose of Meeting

  • Present the Goals of the Chapter 3 Update Project ,
  • Describe the Chapter 3 Update Process

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  • Present Proposed Table of Contents and Sample Sections i
  • Discuss Chapter 3 As-Found Process
  • Present Miscellaneous Topics 1

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i Introduction Goals of Chapter 3 Update

  • Ensure the Updated Chapter 3 of the SAR Accurately Reflects the Plant Configuration through August 31,1999 1
  • Ensure the Updated Chapter 3 of the SAR Fully Supports the SARUP Accident' Analyses '
  • Ensure Consistency in the PGDP and PORTS Updated Chapter 3, Except Where Plant Differences Exist 10/28/98 3 (U..S.EC .-

1 Chapter 3 Update Project Plan Organization e Dedicated Chapter 3 Update Team

. USEC HQ Sponsor Project Manager /

Site Coordinators Writers e Team Responsibilities USEC HQ Sponsor - Provides USEC Direction and Senior Management Support to Project Manager Project Manager -

Responsible for Management of Project

- Site Coordinators -

Directs Activities of Writers at Applicable GDP.

- Writers -

Responsible for Preparation of Chapter 3 Sections e Plant Support

. Available to Chapter 3 Personnel to Support Chapter 3 Effort, such as Assisting Plant Walkdowns, Reviewing Sections and Providing Technical Input e -- Organization Chart Included in Enclosure 1 10/28/98 4 - U.~S,EC c,

.. . - . . - .. . . - ~ ._ . . . . _ _ - . . . . . . . . . .

Chapter 3 Update Project Plan i Chapter 3 Update Process e Assemble Baseline System and Facility Information e Prepare Draft Sections e Verification and Validation of Draft Sections e Review, Approve and Place Under Configuration Control 1 e NRC Submittal 10/28/98 .5 USEC A Genes SmerEr Campany

Chapter 3 Update Proiect Plan Chapter 3 Update Process e Assemble Baseline System and Facility Information Supporting Documentation Including Current Application SARs, Programs and Plans and TSRs SARUP and SARUP Amendments SARUP Supporting Documentation Design Analysis and Calculations (DACs)

Preliminary Hazard Screening (PHS)

Process Hazard Analyses (PrHAs)

Plant Safety Operational Analyses (PSOAS)

DOE SAR (POEF-LMES-89 and KY/EM-174)

Plant Procedures Operating Maintenance Alarm Response, etc System and Facility Drawings Facility Layout P& ids Logic, etc Boundary Definition Manuals Safety System Setpoint Analyses Plant Modification Packages ,

In-Process Requests for Application Changes l In-Process Problem Reports / Action Tracking and Assessment l Reports NCSA/NCSEs

- Field Walkdown of Accessible SSCs l l

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10/28/98 6 USEC A Gehad Emery Company

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Chapter 3 Update Proiect Plan Chapter 3 Update Process 1

  • Prepare Draft Section Focus on Consistency Between Plants, Except Where Plant Differences Exist Establish a Common Content, General Format and Style i

Common Methodology Established for Researching, Assembling and Archiving Facility and System Information Derived From Supporting Documents l

Single Writer Prepares Both PGDP and PORTS Sections Concurrently Proposed Chapter 3 Table of Contents Included in Enclosure 2 l

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e 10/28/98 7 (U.~SEC.-

Chapter 3 Update Project Plan Chapter 3 Update Process e Verification and Validation of Draft Sections Two Distinct Processes to Confirm Accuracy ofInformation Verification -

Process to Confirm Information Correctly Translated from Source Documentation Validation -

Process to Ensure Physical Plant and Chapter 3 Section are Consistent Methods for Validation Include, But are not Limited to:

Physical Field Walkdown Review of Controlled Plant Records Controlled Drawings Expert Review Confirmatory Calculations curynllance Test Results Operational Test Results Controlled Vendor Manuals Each Updated Chapter 3 Section Subject to Verification and Validation For Repetitive Systems, Updated Chapter 3 Section will be Validated Against a Sample of Components (i.e., Not 100 Percent Field Walkdown). For Example:

Cascade Components Plant Lube Oil System i

c 10/28/98 8 USEC

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Chapter 3 Update Proiect Plan Chapter 3 Update Process e Review, Approval and Distribution of Sections Multiple Drans Prepared and Reviewed by Plant Organizations and USEC HQ Each Section Presented to PGDP and PORTS PORC for Approval Following Approval, Sections Placed Under Configuration Control l

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Chapter 3 Undate Project Plan Chapter 3 Update Process

. e NRC Submittal Separate PGDP and PORTS Submittal Containing a Complete Update to Chapter 3 Submittal Date - Scheduled for October 31,1999 I

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Presentation of Sample Sections e Graded Approach to Categorization of Chapter 3 Structures, Systems and l

l Components L

l Grades Related to Accident Analysis Methodology Utilized for SARUP Grade 1 -

SSCs Credited in SARUP for Prevention / Mitigation of Offsite Consequences Grade 2 - SSCS Credited in SARUP for Prevention / Mitigation of i Onsite Consequences Grade 3 - SSCs Not Credited in SARUP for Prevention / Mitigation ofAccidents Grade 4 - Non-Safety Facility Descriptions Graded Approach Used to Determine the Content and Level of Detail for Updated Chapter 3 Sections

- Content of Updated Chapter 3 Section  !

TITLE Grade Grade Grade Grade 1 2 3 4 Introductory Description X X X X Safety Function X X Functional Requirement X X System Vescription X X

  • System Evaluation X X Support System X X
  • System Operation X X
  • I Maintenance and Testing X X  ;

X X * '

Administrative Controls

  • Indicates subsection Not Normally Needed. May Be Discussed in Certain Sections l-10/28/98 11 U h.SEC .-

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[ Presentation of Sample Sections Description of Section Contents Introductory Description - Provides General Information of the SSC to be Discussed Such as i

Location, Function, Safety Classification, etc.

Safety Function -

Safety Function Performed by the SSC Functional Requirements- Design Attributes of the SSC Which Ensure Accomplishment of the Safety Function System Description -

Equipment Description and Functions, Interaction / Interface with Other Systems, Materials of Construction (If Important to Accomplishment of Safety Function), and Unique Features or Arrangements of SSC.

System Evaluation -

Discussion of the Ability of the SSC to Accomplish the Safety Function Support System -

Discussion of Systems Required to Support SSC and How the Support Systems Assist in Accomplishing the SSC Safety Function. If System is Fail Safe, the Aspects Which Accomplish Fail Safe Operation Will Be Described.

System Operation -

Discussion of Operational Modes or Operating Configurations, Key Operational Instrumentation and Controls, Alarms and Location of Alarms, System Trips, Interlocks.  ;

Maintenance and Testing- Listing of Maintenance and Testing l Requirements Associated with SSC Not Described in Other Application Sections l

10/28/98 12 USEC A Gebel Emery Campeg l

Presentation of Sample Sections Administrative Controls - Listing of Administrative Controls Associated with SSC Not Described in Other Application Sections Safety Function, Functional Requirements, and System Evaluation Taken from SARUP Sections 3.8 and 3.15

. Level of Detail for Sections

- Commensurate with Safety Importance of SSC Grade 1 - SSC Description Very Detailed Grade 4 - Brief Description e Four Example Sections, Typical of Each Grade, are Included in Enclosure 3 Grade 1 Section - Withdrawal Station Isolation System Grade 2 Section - Fluorine Generation System Grade 3 Section - Autoclave Pressure Relief System Grade 4 Section - Administration Building e Request NRC Review of These Sample Sections to Determine if the Format, Content, and Level of Detail are Appropriate 4

10/28/98 13 USEC A N Emery Compery i

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Chapter 3 As-Found Process e Chapter 3 Update Process Will Identify Any Conditions Which Do Not Agree with the Current Application (i.e., As-Found Conditions) e Current GDP Process For Updating the Application to Resolve As-Found Conditions Requires:

Operability Determination Safety Significance Detennination Request for an Application Change (RAC)

Plant Change Review (PCR)

Safety Evaluation (USQD) e Proposed Chapter 3 Process to Resolve As-Found Conditions:

Identification of As-Found Condition Determine Safety Significance

-If Condition is Not Safety Significant No Revision to Current Chapter 3 If Condition is Safety Significant Process Request for an Application Change (RAC)

Prepare Plant Change Review (PCR)

Prepare Safety Evaluation Revise Current Chapter 3 e As-Found Condition Considered Safety Significant If:

Operability of Q, AQ-NCS or AQ SSCs Cannot be Reasonably Assured, Or, Adverse Impact on the Assumptions or Conclusions of the Accident Analyses Contained in the Application SAR, Chapter 4.

= 10/28/98 14 US_EC

Chapter'3 As-Found Process l

  • Highlights of Proposed Process l

l Utilizes Existing Processes for Resolution of As-F ound Conditions Continue to Update the Non-Chapter 3 Sections of Current Application Regardless of Safety Significance Determinations As Found Conditions Determined to be Not Safety Significant Incorporated Into Updated Chapter 3, as appropriate e USEC Proposes to Add a Condition to the Certificate of Compliance Addressing Resolution of As Found Conditions Associated with Chapter 3 Update Proposed Condition to the Certificate Provided in Enclosure 4 l

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Miscellaneous Topics e Upgrade Versus Rewrite Providing a Rewrite of Existing Chapter 3 to Support the SARUP Submittalincluding Chapter 4 Accident Analysis SSC Descriptions for Chapter 3 Update May Significantly Differ from Current Chapter 3 Descriptions e Chapter 3 Level of Detail Reducing Level of Detail for Some Sections  !

Descriptive or Detailed Design Information Not Required to  !

Understand System Configuration or Operation Fluorine Generation System Example of Reduction in Level of Detail Increasing Level of Detail for Some Sections Withdrawal Station Isolation System Example ofIncreased Level of Detail e Chapter 3 Figures l Used to Illustrate the Descriptive Material in Chapter 3 Update Basic Representation of Systems Only (Typical Figures Included in Sample Sections)

Limited Use of Controlled Plant Drawings (i.e., P& ids, Electrical Schematics, etc)

Used in Those Cases Where Safety Aspects of the System Dictates Additional Detail Beyond Basic System Representation i

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Miscillaneous Topics Schedule Updated Chapter 3 Submitted by October 31,1999.

. Necessary and Related SARUP Changes Submitted by October 31, 2000 Schedule Submitted in March 30,1998 USEC Letter (GDP 98-0062) 1

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' Closing e USEC is Committed to Provide an Updated Chapter 3 By October 31,1999

.o . Utilizing a Dedicated Project Team with USEC Management Oversight to Accomplish This Commitment e USEC Requests NRC Review of Sample Sections and Proposed Certificate Condition e USEC Intends to Continue Open Dialogue with NRC Related to Chapter 3 Update I

10/28/98 18 3 USEC

& Gabel beery Cangeer

Enclosure 1 Organization Chart (2 Pages) 10/28/98 i U.~S.EC l

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Chapter 3 Undate Project Plan Drganization l l

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I USEC HQ Sponsor PGDP PORTS Engineering --------------..------------ Engineering Manager Manager Project Manager l

l l PGDP Site PORTS Site Coordinator Coordinator

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Writers Plant Support Writers Plant Support l

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Enclosure 2 Proposed Table of Contents l

(3 Pages) l

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l l'- PROPOSED October 28,1998 {

CHAMER 3 TABLE OF CONTENTS '

3.0 FACILITY AND PROCESS DESCRIMION l

3.1 INTRODUCTION

3.2 ' FACILITY AND PROCESS DESCRIPTION i

t. 3.3 ENRICHMENT FACILITIES 3.3.1 Enrichment Cascade 3.3.2 Purge Cascade 3.3.3 Freezer / Sublimer 3.3.4 Cold Recovery 3.3.5 Wet Air / Seal Exhaust 3.3.6 Datum System 3.3.7 Freon Degrader 3.3.8 Cell Treatment 3.3.9 Building Structures and Confinement 3.4 UF, FEED, TRANSFER AND SAMPLING FACILITIES 3.4.1 Feed and Transfer Facility Systems 3.4.2 Autoclaves and Autoclave Systems 3.4.3. Sampling System -

3.5 UF, WITHDRAWAL FACILITIES 3.5.1 Withdrawal Systems 3.5.2 Product Withdrawal 3.5.3 Tails Withdrawal 3.6 UF, CYLINDERS, CYLINDER HANDLING AND STORAGE 3.6.1 _ UF, Cylinders 3.6.2 UF. Cylinder Handling and Weighing 3.6.3 UF. Cylinder Storage 3.6.4 UF, Pigtails l- 3.7 GENERAL FACILITY SAFETY SUPPORT SYSTEMS, UTILITY SYSTEMS

! AND COMMUNICATION SYSTEMS 3.7.1_ Criticality Accident Alarm System 3.7.2 Fire Protection Systems 3.7.3 'UF, Release Detection System ,

3.7.4 Communications Systems i 3.7.4.1 Normal Communication System 1 3.7.4.2 ' Plant /Public Warning System l 3.7.4.3 Emergency Lighting System I I . - - - \

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l PROPOSED October 28,1998 CIIAI"TER 3 TABLE OF CONTENTS 3.7.5 Non Radiological Chemical Systems 3.7.6 AC Electrical Systems l 3.7.7 DC Electrical Systems 3.7.8 Utility Systems l 3.7.8.1 Plant Water System l 3.7.8.2 Plant Nitrogen System 3.7.8.3 IIeating and Ventilation Systems 3.7.8.4 Plant Steam and Condensate Systems 3.7.8.5 Plant Air System 3.8 - DECONTAMINATION, WASTE STORAGE AND MISCELLANEOUS SUPPORT FACILITIES i

3.8.1 Decontamination Facility and Systems 3.8.2 Miscellaneous Waste Storage and IIandling Facilities 3.8.3 Miscellaneous Support Facilities 3.8.4 Radiation Calibration Facility 3.9 GENERAL SUPPORT FACILITIES AND SYSTEMS 3.10 SAFETY SYSTEM CLASSIFICATION i

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Enclosure 3 i Sample Sections l l

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i SAR-PGDP PROPOSED-GRADE 1 October 28,1998 RAC 98C-XXXX l

3.5 WITHDRAWAL FACILITIES 3.5.1 Withdrawal Systems TO BE PROVIDED MTER 3.5.1.1: UF6Withdrawal Primary System TO BE PROVIDED UTER 3.5.1.2 Process System Pressure and Temperature Monitoring TO BE PROVIDED UTER 3.5.1.3 Buffer System TO BE PROVIDED UTER 3.5.1.4 Seal Feed and Exhaust System TO BE PROVIDED MTER 3.5.1.5 Lube Oil System TO BE PROVIDED L-1TER 3.5.1.6 Lube Oil System Monitoring and Alarms TO BE PROVIDED UTER 3.5.1.7 Coolant System l TO BE PROVIDED MTER l

3.5.1.8 Coolant High Pressure Relief System TO BE PROVIDED MTER 4

3.5-1

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1 l SAR-PGDP - PROPOSED-GRADE 1 October 28,1998

( RAC 98C-XXXX 1

l l 3.5.1.9 Coolant System Monitoring Instrumentation J TO BE PROVIDED UTER l 3.5.1.10 Condenser Coolant Overpressure Relief  ;

TO BE PROVIDED UTER 3.5.1.11 Outleakage Detection TO BE PROVIDED UTER 3.5.1.12 UF6Release Detection System TO BE PROVIDED UTER 3.5.1.13 . Withdrawal Station isolation System

. The Product (C-310 Building) and Tails (C-315 Building) Withdrawal Facilities are equipped with a UF 6release detection and isolation system for the withdrawal positions. Consequences of a UF6

. release from a withdrawal facility pigtail failure are mitigated by the Withdrawal Station Isolation System as discussed in Sections 4.3.2.2.4 and 4.3.2.2.11. In the event of a pigtail failure, the system is utilized to isolate the withdrawal position to minimize the amount of UF6 released. This system is classified as important to safety as described in Section 3.10.

3.5.1.13.1 Safety Function I i

Radiological /Nonradiological. The Withdrawal Station Isolation System is capable ofisolating the withdrawal station to prevent. exceeding the radiological /nonradiological Evaluation Guidelines (EGs) for the Evaluation Basis Event (EBE) category.

Criticality. The Withdrawal Station Isolation System, in the Product Withdrawal Facility, isolates product cylinders to preclude further releases of fissile material. Released UF. reacts with moisture in the air to form UO 2F2, which further absorbs moisture from the air. UO2 F2 and water in nonfavorable geometry have the potential to achieve criticality. This active engineered feature does not

- include the manual isolation system.

3.5.1.13.2 Functional Requirements The Withdrawal Station isolation System includes: (1) automatic UF6 detection and isolation; and (2) manual isolation. The system is designed in accordance with the following functional requirements to ensure the capability to accomplish the required safety functions:

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e SAR-PGDP PROPOSED-GRADE 1 October 28,1998 RAC 98C-XXXX The system is capable of accomplishing the required safety function independent of the plant air supply, The system is capable of accomplishing the required safety function independent of the normal AC power supply to the facility.

The automatic detection and isolation portion of the system is capable of detecting UF6 outleakage and isolating the withdrawal position pigtail at both ends.

The automatic detection and isolation portion of the system closes the cylinder valve and isolates the withdrawal header for the station within 30 seconds after actuation of the ionization detectors.

The manual isolation portion of the system is capable of isolating the liquid source and is accessible outside the withdrawal room.

3.5.1.13.3 System Description The Withdrawal Station Isolation System, in the Product (C-310 Building) and Tails (C-315 Building) Withdrawal Facilities, consists of two low-voltage detectors. The low-voltage UF6 release detectors are located above each withdrawal position, one detector located at the ceiling and one detector located directly above each withdrawal drain position and are discussed in more detail in Section 3.7.3.3.

In addition, the system consists of UF6 line isolation valves (e.g. cylinder valve and liquid drain block valves), cylinder valve motor and closure assembly, air supply piping, associated circuitry (including alarms and indicator lights), manual isolation switches, system support power, a backup nitrogen supply, and solenoid valves necessary to operate the liquid drain block valves. The Withdrawal Station isolation System operates off the plant 120 VAC power system, which supplies 24-VDC to the detectors and initiates alarms. Figure 3.5.1.13-1 shows a typical Withdrawal Station Isolation System. A high-voltage UF6 release detection system, located adjacent to the low-voltage detectors, activates alarms and is discussed in more detail in Section 3.7.3.1.3.

Activation of a low-voltage detector above any drain position pigtail will initiate isolation of that withdrawal position causing the following actions to occur: (1) closes the two liquid drain block valves located between the accumulators and the withdrawal pigtail; (2) closes the withdrawal cylinder valve; and (3) initiates alarms in the withdrawal area and in the respective Area Control Rooms (ACRs).

Activation of any low-voltage detector at the withdrawal room ceiling will only close the liquid drain block valves for all withdrawal positions in the withdrawal room and initiate n Wm in the respective ACR.

f l The UF6line isolation valves associated with the Withdrawal Station Isolation System include f air-operated liquid drain block valves (spring actuated! fail closed), cylinder valve (with an air-operated / motor driven closure assembly), and miscellaneous valves associated with the building

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! SAR-PGDP PROPOSED-GRADE l October 28.1998 I

RAC 98C-XXXX air / nitrogen systems that support withdrawal isolation. The liquid drain block valves are I diaphragm-actuated valves that require air to open and springs to close and are fail-safe. The cylinder i valve is a manual valve that is equipped with an air-operated / motor-driven closure assembly. The air-  !

control solenoid for the cylinder valve closure assembly is deenergized during activation of the isolation j system. Air is then supplied to the cylinder valve closure motor, which closes the cylinder valve, l l isolating the UF6 cylinder from the withdrawal position. A backup nitrogen system, provided for the cylinder valve closure assembly, activates upon failure of the plant air system. The evacuation block

! valves are not part of the Withdrawal Station Isolation System safety system boundary but they provide  ;

defense in depth to minimize the consequences of a failure in the withdrawal pigtail. The air-operated )

l valves associated with the evacuation line open, allowing UF 6 to be evacuated from the pigtail to the evacuation header during automatic activation of the isolation system as described in Section 3.5.1.1.

If the automatic Withdrawal Station Isolation System fails to activate due to a failure in the system, liquid drain block valves can be closed with controls located outside the withdrawal room. in the ACR, or in the Central Control Facility (CCF). The pushbutton located immediately outside the withdrawal area closes the liquid drain block valves (those associated with the Withdrawal Station Isolation System) and the cylinder valve in all withdrawal positions within the building. The ACR and CCF have separate manual isolation pushbuttons or switches for each withdrawal position within the Product and Tails withdrawal area. These buttons also close the Withdrawal Station Isolation System liquid drain block valves and the cylinder valve.

3.5.1.13.4 System Evaluation The Withdrawal Station Isolation System was evaluated to assess its ability to accomplish its required safety function. In addition, a qualitative fault tree analysis was performed to determine the system's capability to accomplish its safety function. The results of these evaluations are provided in this section.

Safety function analysis. The safety function required of this section is to limit the release of UF6and its reaction products to less than the radiological /nonradiological EGs for an EBE. A review of

! the withdrawal facility operations determined that the bounding event for this system is pigtail failure at a withdrawal position, described in Section 4.3.2.2.11. In order for the Withdrawal Station Isolation System to accomplish its safety function, the system must detect a UF 6 release at the withdrawal position and close the UF6 line isolation valves before the release exceeds these guidelines. In addition, manual isolation must be capable of isolating the withdrawal station.

The hazard and accident analyses assumed that a significant UF6 release (see Section 4.3.2.2.11) at a withdrawal position would be detected by the withdrawal position detectors within 15 seconds and the liquid source is automatically isolated (i.e., the UF6 line isolation valves close, isolating the pigtail from the accumulator and the cylinder) within 30 seconds after initiation to close. This event was evaluated in Section 4.3.2.2.11 and the consequences were determined to be below the applicable EGs.

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SAR-PGDP PROPOSED-GRADE 1 October 28.1998 RAC 98C-XXXX The manual isolation capability provides operational flexibility for conditions where the l

automatic detection capability is out of service. In order to assure a timely initiation of the system, continual surveillance of the withdrawal room is provided for quick detection of any releases. The l environmental conditions associated with this circuitry are not significantly different, other than the

" smoke" generated from the reaction of UF6 and the moist air, from normal operation due to the short response time.

Based on this analysis, the (Vithdrawal Station Isolation System will prevent exceeding the radiological and nonradiological EGs for the most limiting UF6 Primary system integrity failure at a withdrawal position provided the system automatically closes the UF6 line isolation valves within 45 seconds after the release occurs. Events where the cylinder valve cannot be closed due to the event are addressed in Section 4.3.2.2.11.

Qualitative fault tree analysis. In addition to the safety function analysis, a qualitative fault l tree analysis of the Withdrawal Station Isolation Sys:em was performed in accordance with Section 4.3.1.1.3 to evaluate the capability of the system to accomplish its required safety function. The ability of the system to meet the functional requirements is described below.

As indicated in the functional requirements, the system is required to accomplish the required safety function independent of plant air and electrical supply. The system configuration can accomplish its required safety function independent of the plant air and electrical distribution system including the nitrogen bottle backup to the plant air system (valve closures). These nitrogen bottle backups are considered part of this system and are required to be tested periodically to verify their operability.

Therefore, the system can accomplish its required safety function independent of plant air.

The UF 6detectors are required for the automatic detection system. Should these detectors be determined as inoperable, a continuous smoke watch is instituted to allow for quick detection to initiate manual isolation.

In addition to the functional requirements associated with the loss of electric power and air, the I

automatic operation of the system is required to isolate equipment within 30 seconds after actuation of the UF 6detectors. The analysis assumes the detectors will actuate within 15 seconds after a significant release. Past operational history with the UF 6detectors has indicated a response time of less than 15 seconds for any significant release (see Section 4.3.2.2.11) as a result of the amount of " smoke" generated by the release. Valve closure time is verified periodically by surveillance tests to ensure the 30-second closure time is met. Therefore, the system can accomplish the required automatic detection and isolation.

The location of the manual isolation is outside the immediate area of the release with a closed door providing limited protection for the operating personnel. Therefore, the manual isolation functional requirement is also achieved by the system configuration.

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' S AR-PGDP. PROPOSED-GRADE 1 October 28,1998 RAC 98C-XXXX Based on the capability to detect and isolate a release and the various controls associated with the system, the Withdrawal Station Isolation System can meet its functional requirements.

3.5.1.14 HEPA Exhaust System TO BEPROVIDED LATER 3.5.1.15 Assay Monitoring System TO BE PROVIDED LATER 3.5.1.16 Auxiliary Backup Power System TO BE PROVIDED LATER 3.5.1.17 DC Power Distribution System TO BE PROVIDED LATER 3.5.1.18 Support Systems 3.5.1.18.1 Electrical System The 120-VAC power to operate the Withdrawal Station isolation System is supplied from 480-VAC power at the motor control center. Supplied 120-VAC power is then used to develop the 24-VDC power supply for the UF6 release detection circuit. A separate 120-VAC power circuit feeds the solenoid valves that actuate the liquid drain block valves, the cylinder valve closure assembly, and the evacuation block valves. The liquid drain block valves and the evacuation block valves are designed to close (i.e., fail-safe) upon loss of 120-VAC power. The cylinder valve is designed to close (by activation of the nitrogen backup system) upon loss of power. There are no backup power systems, since

'the liquid drain block valves (those associated with the Withdrawal Station Isolation System) and the cylinder valve fait closed on loss of power.

3.5.1.18.2 Plant Air System Nominal 85-psig air is supplied from the plant air system and provides the motive power for the cylinder valve closure assembly. The cylinder valve closure assembly is also provided with a nitrogen backup system. . On loss of plant air or low plant air pressure, a pressure switch on the air supply line actuates to open a solenoid valve making nitrogen available through the air supply line. The nitrogen is supplied from a portable tank in sufficient quantity and pressure to completely close the cylinder valve within 30 seconds. The nitrogen supply is isolated from the plant air system by a check valve that prevents loss of nitrogen pressure. The liquid drain block valves require air to open and are spring 3.5-6 l

l i .

SAR-PGDP PROPOSED-GRADE 1 October 28,1998 RAC 98C-XXXX closed. Therefore, on loss of plant air, the valves fail in the closed position, isolating the withdrawal l

' position from its liquid source.

3.5.1.19 System Operation 3.5.1.19.1 Operational Modes The Withdrawal Station isolation System is designed to be operable during the Withdrawal Mode as defined in the Technical Safety Requirements (TSR). Automatic operation of the system isolates equipment within 30 seconds after actuation of the UF6 detectors.  !

Detectors are required for the automatic actuation of the Withdrawal Station Isolation System. l in the event that the UF6 release detection portion of the system fails, a continuous smoke watch is ,

established in the affected area. If an operator detects (visually or through smell) a UF6release, he/she l can initiate isolation of the withdrawal positions by actuating the manual isolation pushbuttons/ switches.

In addition, operators in the CCF can initiate isolation of all withdrawal stations at each facility by actuating hand switches.

During off-normal operating conditions, loss of plant air or loss of AC power, the liquid drain block valves fail in the closed position. The cylinder valve fails closed with either the loss of plant air or l AC power. A backup nitrogen supply is provided in the event that the air supply fails.

3.5.1.19.2 Instrumentation, Controls,and Alarms Alarms indicating Withdrawal Station Isolation System activation include indicating lights and audible devices located as follows:

  • local panel or withdrawal area (C-310 and C-315 Buildings)- lights and horn
  • ACR (C-310, C-315, C-33 i Buildings) - lights and horn
  • CCF(C 300 Building) -

lights 3.5.1.20 Maintenance and Testing Requirements TO BE PROVIDED LATER 3.5.1.21 Administrative Controls in addition to the Administrative Controls in 4.3.2.2.4 and 4.3.2.2.11, and those controls covered by programs and plans, the following ensure safe operation of the Withdrawal Station Isolation System.

3.5-7 l

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SAR-PGDP ' PROPOSED-GRADE 1 October 28,1998 RAC 98C-XXXX e Inspecting cylinders prior to filling for physical defects.

. . Cylinder handling equipment is inspected daily (whw used) for obvious defects associated with the lifting system and potential fuel / hydraulic leaks.

  • No cylinder /similar weight load shall be moved over a cylinder containing liquid UF6 -
  • Only approved cylinder handling equipment will be used by qualified operators for maneuvering cylinders and other heavy loads.

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i SAR-PORTS PROPOSED-GRADE 2 October 28,1998 RAC 98X-XXXX 3.7.5 Non-Radiological Chemical Systems The non-radiological chemical systems produce, store, or distribute chemicals for use in the cascade process or support systems. The chemicals included in this group are Quorine (F2 ), chlorine (Cl 2), hydrogen Huoride (HF), and chlorine trinuoride (CIF 3 ) F 2, and/or a mixture of F2 and CIF 3, can be used in the cascade process for drying or unplugging treatments, HF is the feed material used to produce F2 , and Cl 2 si used in sanitary water treatment and sewage treatment for microbiological control. Process hazards analyses have been prepared to evaluate the risks associated with the operation of these systems and to determine the controls necessary for their safe operation. Controls established at PORTS for chemical safety are described in Section 5.6.

3.7.5.1 Fluorine Generation System Fluorine gas (F2), which is used for cascade equipment maintenance, is produced in the Fluorine Generation System using HF gas as the feed material. HF cylinders are delivered to the Plant by commercial motor freight. The HF cylinders are stored and the F2generating equipment is housed in the X-342A Feed Vaporizat;on and Fluorine Generation Building. Fluorine generated in the system is stored in tanks in the X 342B Fluorine Storage Building. From the storage tanks, the F2 is piped throughout the cascade and other support facilities. The Fluorine Generation System consists of HF cylinders, Duorine generators, Duorine storage tanks, associated piping and equipment, gas release detectors, and gas release detection alarm components. The Fluorine Generation System portion of the nonradiological chemical systems boundaries are defined in Table 3.10-2.

The X-342A Building, located in the north-certral part of the Plant, occupies the southeast portion of the X-344A/342A complex. X-342A is a single-story, slab-on-grade, steel frame building with transite board siding. In addition to the building ventilation system, a dedicated ventilation system is provided for the Fluorine Generation Room and the NaF Trap Room. HF detectors with automatic alarms, as well as manually-operated gas release alarms, are located in the F2 generation areas. The building is equipped with emergency showers and eye baths, Ore alarm boxes, and portable extinguishers. In addition to the F2 system, UF6cylinder sampling equipment is located in X-342A. A separate high-bay part of tiie building cutains two actoclaves with scales, cranes, and other associated UF6feed and sampling equipment. The F process 2 areas are separated from the UF6 areas by concrete block and transite walls. The two F 2headers from the storage tanks in X-342B are routed through the UF6high bay, and the HF cylinders are moved through the high bay area in route to the HF storage room. No other interactions occur between the two systems.

The X-342B Fluorine Storage Building is located just east of X-342A. It is a single story, slab-l on-grade, steel beam structure with concrete block and transite board siding. A manually actuated exhaust fan is used to increase the ventilation rate when maintenance is performed in the building. An evacuation air jet is available for use in emptying the storage system for maintenance. The building is 3.7-1

- . -. ~ ~ . - - - - . - . . . - - --

! n SAR PORTS PROPOSED-GRADE 2 October 28, !998 i RAC 98X-XXXX l

t equipped with HF vapor detectors and a fire alarm pull box. No processes, other than the F2 storage tanks and associated piping, are located in the building.

The HF cylinders are owned by PORTS and are filled off-site by commercial vendors. Cylinders comply with Department of Transportation specifications. The condition of the cylinders and cylinder l ' valtes are noted in the receipt inspection at X-746. Each cylinder has a capacity of 1,000 lb of HF; however, an 850-lb fill limit i emposed by PORTS to maintain a safety factor.

Plant systems that support the Fluorine Generation System are described in Sect. 3.7.5.4 3.7.5.1.1 Chemical Safety Function The non-radiciogical chemical systems described in this section are important to safety. They are required to perform the following chemical safety functions:

  • Maintain integrity to the process, which minimizes the potential for releasing toxic gas into the atmosphere.

Ensure that the fluorine primary system is relieved on high pressure to minirnize the L potential for a failure of the primary system integrity, e Detect releases fro'm the primary system and provide a local alarm indication of the relerse. .

3.7.5.1.2 Functional Requirements The ncn-radiological chemical systems shall be designed and maintained for the intended service. The fluorine system pressure relief system shall be available on storage tanks that contain

'luorine at pressures greater than atmospheric. The system shall actuate at or below the MAWP for the Juorine storage tank and discharge to an elevated stack. The toxic gas leakage detection system shall be designed to provide local alarm indications upon detection of releases from the piimary system.

' 3.7.5.1.3 System Description 3.7.5.1.3.1 Equipment Descriptions and Functions Fluorine is generated from anhydrous hydrogen fluoride. A typical HF delivery to PORTS l consists of up to four cylinders, each containing up to 850 lb of HF, delivered to the plant site via l commercial motor freight in protective shipping baskets. Cylinder valves are protected by steel valve l covers that are hinged to allow access to the valves. The cylinders are delivered to the X-746 Materials

, Receiving and Inspection Facility where they are unloaded from the delivery truck, visually inspected, and placed in an adjacent storage area. When needed, up to four cylinders are moved, in their shipping baskets, to the X-342A Feed Vaporization and Fluorine Generation Building. At X-342A, the cylinders 3.7-2 I

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SAR-PORTS PROPOSED-GRADE 2 October 28,1998 RAC 98X-XXXX are removed from the shipping baskets by an overhead crane and placed onto wheeled dollies. The cylinders are then inspected and moved to the HF Storage Room where they are secured in place with cl.ains. The X-342A HF Storage Room is equipped to store up to 12 full cylinders.

The primary components of the Fluorine Generation Syste n consist of a heated cabinet in the Vaporizer Room, F2 generators, a surge drum, sodium fluorie traps, sintered metal filters, F2 compressors, F2storage tanks, and associated control valves and piping. (Fig. 3.7-x)

The heated cabinet is equipped with an liF detector and an air exhaust line. The cabinet walls are insulated, and interior heat is supplied by electric heaters An airjet is provided to purge the cabinet prior to opening the access doors. Gas purged from the cabinet is exhausted outside the building through an elevated stack. The cabinet contains a mounting saddle that accommodates two HF cylinders. A slot in the HF cylinder skirt must be aligned with a peg on the mounting saddle. Otherwise, the system )

pigtail cannot physically be connected to the cylinder. De cylinders are secured to the saddles with chains.

Four fluorine generators, each capable of producing up to 5 lb of F2 Per hour, are located in the Generator Room. The primary components of the generators are the rectangular steel outer cell body, the electrolyte, the electrodes, the Monel inner vessel, the hyaogen collector, and the fluorine collector. The outer cell body serves as a water jacket that allows the electrolyte solution to be heated with steam or cooled with water. HF is fed from the feed ey rser at a rue sufficient to produce the desired F2 generation rate. A typical HF feed rate is about .M to aer hour. The generators produce 2F by applying a high amperage DC current through the electrolyte m the presence of the HF feed gas. The net result of the reaction is the decomposition of HF to produce F2 at the anode and H2 at the cathode. A gas separator skirt between the electrodes prevents mixing of the H 2 and F2 gases. )

Electrostatic precipitators are installed in the F2 outlet piping from each fluorine generator w  ;

collect any electrolyte mist or dust carryover before it can enter the system piping. An electrolf entrainment separator is installed in the H 2outlet piping for the same purpose. j From the generators, the F2 flows to a 110 ft3 surge drum in the Generator Room that helps to control the flow to the storage tanks.. The maximum operating pressure for the tank is 5 psig and the maximum operating temperature is 180 F. At 5 psig and 80 *F, the surge drum contains approximately 14 lb of F2-In the event that high pressure develops in the system, F2 can be manually vented to the atmosphere through an elevated stack. H2 gas, which is a byproduct of F2 generation, is normally routed through a flame arrestor and discharged to the atmosphere through an elevated stack.

From the surge drum, F2 flows through sodium fluoride (NaF) traps and sintered metal filters located in the Trap Room. The traps and the filters are provided to remove residual HF and particulate, respectively, from the product stream. The system contains four NaF traps, any two of which can be operated in parallel. The medium in the traps is hardened NaF pellets. The system has two sintered metal filters w;$ Monel filter elements---one normally on-line and one available as a backup.

3.7-3

l

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- j SAR-PORTS PROPOSED-GRADE 2 October 28.1998 RAC 98X-XXXX

' Multi-diaphragm compressors are used to pamp the2F to the sterage tanks in X-3428. These compressors provide multiple barriers between the F2 gas and the pump oil to prevent contamination of the F2. Leakage of F or 2 oil through any diaphragm is detected and annunciated by audible and visual alarms located in *he Control Room. Two compiessors are installed in parallel. They are normally operated one at a time.

The compressors pump F 2 nto i the three 1,000 f3 F2 storage tanks located in the X-3428  !

Fluorine Storage Building. At a maximum normal operating pressure of 45 psig, each tank contains about 430 lb of F2at 30 "F. The carbon steel tanks have a maximum .Mawable working pressure of 194 psig and a maximum operating temperature 250 'F. Each tank is equipp.<i with a relief device consistir,g j of a pair of rupture discs with a nitrogen buffer in the piping between the dires. The discs are designed to rupture at 85 psig. The buffered zone is instrumented to detect and annunciate pressure changes. In the )

event that both discs rupture, excess system pressure is vented outside the building through a 30-ft stack. l

- Valves in X-342B are equipped with handles on the ope rators so the valves can be operated from outside the building. Instrumentation for this portion of the system is also mounted on the outside wall of the building.

]

From the storage tanks, F2 Gows to buildings X-330 and X-333 through the black iren header or  !

the process gas (PG) return header. A metering station monitors the flow of F2 to the PG return header. j Double valves are used for equipment isolation to reduce the likelihood of leaks to the environment during maintenance (see Fig 3.7-x). The black iron header normally operates at a pressure of j approximately 5 psig, which is maintained by a control valve in X-3428.

Hydrogen fluoride leak detectors are located in the Building X-342A HF Storage Room; the Vaporizer Room above the vaporizer, and in the heated cabinet. HF detectors are also located above each of the fluorine storage tanks in the X 342B Building. The detectors are commercially available ionization-type smoke detectors. These detectors are suitable for F2 eaks l because the reaction of fluorine and moisture in the air rapidly produces HF, whose characteristic white smoke is readily detected by ionization detectors. Actuation of the detectors results in alarms locally and in the ACR.

Refer to Section 3.7.3.4 for a description of detector system components.

3.7.5.1.3.2 Materials of Construction Gaseous HF and F2 are not extremely corrosive to piping. Carbon steel, stainless steel, Monel or copper are suitable materials of construction for use when no moisture is present. System piping is schedule 80 carbon steel, tanks are heavy gauge carbon steel, pigtails are copper, and valves are Monel or stainless steel.

l 3.7.5.1.3.3 Chemistry Requirements

The following chemicals are used or produced in the F2Generation System
  • Potassium bifluoride-primary electrolyte used in the F 2generators.

3.7-4 I'

o SAR-PORTS PROPOSED-GRADE 2 October 28.1998 RAC 98X-XXXX e Lithium fluoride-electrolyte additive used in the F2generators.

  • Hydrogen fluoride - feed material used to produce F2 .
  • Fluorine -primary system product.

e Soda ash (Na2 CO3)- used to neutralize equipment contaminated by contact with F2 or HF.

  • Slaked lime (Ca(OH)2)- used to trap free fluorides present in the soda ash.
  • Hydrogen-a byproduct of F2generation.

The hazards associated with these chemicals are considered to be standard industrial hazards.

3.7.5.1.4 System Evaluation The non radiological chemical systems are requiced to prevent releases of toxic gas to the atmosphere during normal operations. This safety function is accomplished by retaining system integrity

during normal operations and upset events. The design requirements ensure that the primary systems can

! withstand the operating conditions assumed in the accident analysis and are appropriate for the chemical

. being used.'

Primary fluorine system integrity is protected by minimizing the potential for a release of .

fluorine' from a line at the storage tank at X-342B caused by overpressurization. A release of fluorine l from a ruptured primary system could result in an uncontrolled release at ground level. The system l accomplishes its safety function by relieving excessive pressure to the atmosphere through an elevated stack.

l Toxic gas detectors are located in areas where a significant release of toxic gas could occur. The L required safety action is to detect e. release and provide local indications of the release. The safety action

l. is accomplished by having detectors appropriate to the toxic gas present (chlorine, fluorine, etc.) and )

l providing both audible and visual alarm indications in X-342-A and X-342-B. The system providas on-site protection for personnel by detecting a release and alerting personnel to immediately evacuate the area.

_ 3.7.5.2 Chlorine Trifluoride later j 3.7.5.3 Chlorine System later 3.7-5  !

1 1

l SAR-PORTS PROPOSED-GRADE 2 October 28,1998 RAC 98X-XXXX i

i 3.7.3.4 Support Systems  !

?.7.5.4.1 DC Electrical System DC electrical power for the F 2generators comes from two selenium diode rectifiers, each rated at 6,000 amps at 60 V. The rectifiers are located in a room adjacent to the F2 generators.

3.7.5.4.2 AC Electrical System Electrical power from the plant 120 VAC system supplies the fluorine release detectors and alarms.

'3.7.5.4.3 Plant Air System Plant air is used to purge HF system pigtails, F2 tanks, and other equipment for maintenance.

Plant air also provides motive power for pneumatic valve actuators.

3.7.5.4.4 Plant Steam Syster.:

Plant steam is piped to the Fluorine Generator waterjackets to keep the electrolyte warm and prevent solidification during maintenance.

3.7.5.4.5 Fluorine Generator Cooling Water l Cooling Water is supplied to the F2 generator water jackets to cool the generator during operation. The cooling water is a closed loop, recirculating system with a collection drum and two recirculating pumps located in the F 2Generator Room. Plant sanitary water provides makeup as needed.

l- 3.7.5.4.6 Ventilation System Room exhaust ventilation in ti.c Generator Room and the Trap Room is provided by a dedicated system. The roof-mounted exhaust fan ( 3erates constantly when 2F generation is in progress . An alarm L actuates in the Control Room if the exh ist system stops. The Control Room is maintained at a positive

_ pressure relatiIr. to tb operating areas ta prevent any inleakage of2F . The X-342B Building is open to j ti ..iv,;onment. A minnally actuated ;xhaust fan in the building is used when maintenance is being o performed.

l, 3.7-6

1 i

SAR-PORTS PROPOSED-GR ADE 2 October 28,1998 RAC 98X-XXXX 3.7.5.5 System Operation 3.7.5.5.1 Operational Modes Operational modes for the toxic gas systems as defined in the Plant Operational Safety Analysis are:

e feed of DOT cylinders into process, e storage / distribution of toxic gas, and e out of operation.

The cylinder feed mode applies from the time the .:ylinder cap is removed to initiate the feed process until disconnection of the feed cylinder from the system is complete. The storage mode applies any time gas storage takes place, in tanks or cylinders. The system is "out of operation" when the valves connecting the system to any supply of toxic gas are closed, and the system is purged of the toxic gas such that the PrHA screening thresholds are not exceeded.

I 3.7.5.5.2 Instrumentation, Controls, and Alarms The primary safety concern for the Fluorine Generation System is personnel exposure to a large l leak of fluorine or HF gas. Consequently, operational instrumentation, controls, and alarms are designed l to protect the system's confinement integrity. l The Fluorine Generation System is equipped with the means for en rgency shutdown to protect the F2generating equipment and to isolate the piping and the storage tanks. The electrical circuit that i powers the shutdown system is activated by any of several alarms on the control panel in the X-342A Fluorine Control Room or by either of two manual switches (on the control panel and on the outside west wall of the fluorine generator room) as follows:

e high pressure in an 2H or F2 cell e rectifier cooling fan failure e high differential pressure in an H2 or F cell e rectifier high temperature header e hign differential pressure between F2 and H2

  • F2 compressor shutdown (high F2 discharge pressure) e rectifier power overload e manual switch in the Control Room o rectifier cooling water pump failure e manual switch outside of the west wall of the F2generator room.

! Other key operational instrumentation for the system includes a microprocessor-based controller that maintains an internal temperature of 180 F, or less, in the HF cylinder heated cabinet. The 3.7-7

SAR-PORTS PROPOSED-GRADE 2 October 28,1998 RAC 98X-XXXX  :

J controller actuates audible and visual alarms in the X-342A Fluorine Control Room and shuts off the

. heaters if the internal cabinet temperature exceeds the high temperature setpoint or if the pressure in the system exceeds the high pressure setpoint.

An indicating pressure transmitter is located on the main HF feed line. This instrument indicates pressure locally and also transmits a signal to a digital indicator and alarm module in the Generator Room. System pressure is monitored by pressure switches on the fluorine and hydrogen headers. The switches activate an audible alarm and a light in the X-342A Fluorine Control Room if pressure exceeds j the setpoint.

A control valve located upstream of the NaF traps protects the F2 generating equipment from I high systera pressure. In the event that pressure in the F2 distribution headers exceeds the setpoint, the i valve automatically closes. A second control valve located downstream of the F2compressors closes on compressor shutdown to prevent distribution system pressure from reaching the F2 generating equipment. ..

Each of the two cylinder pigtail connections has a pneumatic indicator located on the HF piping  ;

above the cabinet. A third pressure indicator is located in the main HF feed line. This indicator '

produces a digital pressure readout in the X-342A Fluorine Control Room and actuates an alarm'if the high or Jow pressure setpoints are exceeded.

The nitrogen buffer between the rupture disks on the F2storage tanks is monitored by a pressure indicator and a pressure blind switch that actuates an alarm on high or low pressure. High pressure would indicate leakage through the inboard rupture disk. Low pressure would indicate leakage of the nitrogen buffer or the outboard rupture disk. If the pressure exceeds the setpoint, an alarm is actuated in the X 342A Fluorine Control Room.

Pressure blind switches are also located on the F 2 and H2headers that activate visual and audible alarms in the X-342A Fluorine Control Room when fluorine or hydrogen header pressure exceeds the setpoint.

Leakage of F2or oil through any diaphragm of the F compressors 2 is detected and annunciated by audible and visual alarms in the X-342A Fluorine Control Room.

Actuation or failure of any of the fluorine leak detectors in X-342A will result in an alarm locally and in the X-342A Control Room. In addition, manual gas release alarms are located throughout the X-342 Building. Activation of these alarms will sound the building evacuation siren. Actuation of a detector in X-3428 results in audible alarms locally and in the fluorine system control room in X-342A.

I 3.7.5.6 Maintenance and Testing Requirements l The following maintenance and testing activities are conducted on the Fluorine Generation System due to the hazard present in the system:

i e system tanks and piping are visually inspected annually, 3.7-8 i

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SAR-PORTS PROPOSED-GRADE 2 October 28,1998 RAC 98X-XXXX e ultrasonic thickness tests are performed on the F2 storage tanks every three years, e an internal inspections of the walls and welds of the storage tanks and the surge tank are i conducted every 10 years, and j

. ultrasonic thickness tests are performed on the cooling / heating tubes in the fluorine generators when they are disassembled for maintenance.

3.7.5.7 Administrative Controls Administrative controls have been implemented to minimize the potential for a leak of HF or F2 from the Fluorine Generation System and to minimize the health effects to personnel in the event of such a leak, as discussed in the Plant Safety Operational Analysis.

  • DOT-approved valve covers are in place on the HF cylinders during storage and transport.

= Only cylinder pigtails that have been inspected, approved, and tagged by a qualified inspector shall be used.

  • Pigtails shall be leak tested when connected to cylinders and prior to use.

. Lines shall be purged and evacuated prior to opening the primary system.

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i SAR-PGDP PROPOSED-GRADE 3 October 28.1998 RAC 98C-XXXX l

3.4 UF. FEED, TRANSFER AND SAMPLING FACILITIES 3.4.2 Autoclaves and Autoclave Systems This section (to be provided later) contains brief descriptions of the C-333A, C-337A, and C360 autoclave facilities with references to sections 3.4.1, 3.4.3, and 3.4.4 that describe the overall l facilities, the sampling systems, and the building structures and confinement systems in detail.

3.4.2.1 Autoclave liigh Pressure Isolation System TO BE PROVIDED L4 TER 3.4.2.2 Autoclave Primary Containment System TO BE PROVIDED UTER 3.4.2.3 Autoclave Water Inventory Control System TO BE PROVIDED MTER 3.4.2.4 Autoclave Opening Prevention System TO BE PROVIDED UTER 3.4.2.5 Autoclave Steam Conductivity Isolation System TO BE PROVIDED UTER 3.4.2.6 High Cylinder Pressure System TO BE PROVIDED UTER 3.4.2.7 Low Cylinder Pressure System TO BE PROVIDED L4TER l 3.4.2.8 Autoclave Steam Pressure Control System l TO BE PROVIDED L4 TER l

3.4.2.9 Autoclave Pressure Relief System i

3.4-1 l

I

. h SAR-PGDP PROPOSED-GRADE 3 October 28,1998 RAC 98C-XXXX Each autoclave is equipped with an Autoclave Pressure Relief system to prevent the internal pressure from exceeding 110% of the maximum allowable working pressure (MAWP) as determined by Section VIII of the ASME Pressure Vessel Code. This system consists of a pressure relief valve and a rupture disc, each rated at the MAWP for the autoclave on which they are installed. The rupture disc prevents constant exposure of the pressure relief valve to steam that is present during normal operation.

Such constant exposure could cause undesirable corrosion and scaling of the valve, which, in turn, could cause the valve to weep or otherwise fail to perform its design function.

Pressure above the rating of the pressure relief valve would be vented to the atmosphere through a vent line above the roof. The relief valve closes when the autoclave pressure drops below the MAWP to limit the amount of any release. Reaction products would not be released through the pressure relief valve at pre::sures below the set point of the valve. This relief system could only be caused to function if there were an excessive amount of water (see Section 3.4.2.3) in the autoclave at the time of a UF6 release within the autoclave.

The pressure rupture disc performs a passive safety function as a component of the autoclave primary containment system (Section 3.4.2.2).

No support systems are required for this pressure relief system.

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3.4-2

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  • SAR-PGDP 1 PROPOSED-GRADE 4 October 28,1998

? - $ '-

- RAC 98C-XXXX. --

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=.1.9.1 C.100 Administration Building The C 100 administration building provides the offices for plant administration, support personnel. and the Nuclear Regulatory Commission. The building location is shown on Figure 2.1 4.

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I Enclosure 4 Proposed Addition to Certificate of Compliance (3 Pages)

V 10/28/98 i

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i October 28.1998 Proposed Treatment of As-Found Conditions That Are Identified During the Chapter 3 Rewrite Effort Revised Certificate Condition (PORTS. PGDP similar)

The United States Enrichment Corporation shall review, update, and confirm the information in Chapter 3," Facility and Process Description," of the Application Safety Analysis Report (S AR), as described in letter GDP 97-0148 dated August 18,1997, and shall submit changes to this chapter to the NRC by October 31,1999. By October 31,2000, USEC shall submit to the NRC necessary and related changes to the SA.R Update originally submitted by letter dated October 31,1997 (GDP 97-0189). In accordance with 10 CFR 76.68(b), USEC shall evaluate any as-found conditions identified l during this effort in accordance with the requirements of 10 CFR 76.68(a). For as-found conditions I that are not safety significant and whose resolution would necessitate a change to the wording of the i existing Application SAR Chapter 3, USEC is hereby gran.ed an exemption against the requirements l of 10 CFR 76.68(b) such that the appropriate changes to Application SAR Chapter 3 will be l provided as part of the October 31,1999 submittal and need not be prepared, approved, and l submitted prior to that date. l Justification The SAR Chapter 3 rewrite effort is expected to identify as-found conditions that do not agree with the submitted Application SARs. There are three potential scenarios to ultimately correct an as-found condition that does not agree with the Application SAR:

(1) The condition is accepted "as-is" resulting in the need to change the description in the Application SAR (2) The condition is modified to be consistent with the Application SAR description and no change to the SAR is needed (3) Some combination of(l) and (2)

For items (1) and (3) where resolution of the as-found condition involves changes to the S AR, USEC proposes that Requests for Application Changes (RACs) to change the wording of the current Application SAR Chapter 3 need not be prepared for those as-found conditions that are not safety significant. An as-found condition would be considered safety-significant if:

The operability of Q, AQ-NCS, or AQ structures, systems, or components cannot be reasonably assured l

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e i s October 28,1998 There is an adverse impact on the assumptions or conclusions of the accident analyses contained in Application SAR Chapter 4.

For those as-found conditions that are not safety significant, the appropriate changes S AR Chapter 3 would be included as part of the October 31,1999 submittal. If c to other sections of the SAR or other portions of the Application, a RAC would be pre accordance with current plant procedures.

Not processing changes to Application SAR Chapter 3 to resolve as-found cond safety significant is justified for the following reasons:

- Appropriate operability and safety significance determinations will be pe all as-found conditions identified during the Chapter 3 rewrite effort to ensure t safe operation of the facility is not compromised.

- No change to the process for handling as-found conditions that are safety s is proposed.

- No change to the process for handling as-found conditions that are identified from the Chapter 3 rewrite effort is proposed.

+ If plant changes or changes to other sections of the SAR or Applica to resolve an as-found condition that is not safety significant, these will b in accordance with current plant procedures.

USEC's commitment to review, update, and confirm the information in S AR 3 vias based, in part, upon a recognition that the current SAR Chapter discrepancies from as-found conditions in the plant. Recognizing that th SAR Chapter 3 will eventually be replaced by the October 31,1999 s will correct the above noted discrepancies, continuing to update the curr Chapter 3 for those as-found conditions that are not safety significa resources more appropriately utilized in conducting day-to-day plant as efforts associated with the Chapter 3 rewrite effort.

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