ML20198A848
| ML20198A848 | |
| Person / Time | |
|---|---|
| Site: | Portsmouth Gaseous Diffusion Plant |
| Issue date: | 12/30/1997 |
| From: | John Miller UNITED STATES ENRICHMENT CORP. (USEC) |
| To: | Paperiello C NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| GDP-97-0225, GDP-97-225, TAC-L32037, NUDOCS 9801060112 | |
| Download: ML20198A848 (16) | |
Text
,
WUSEC A Globel Energy Company JAMES H. Mil.t.ER Der (301)564 3309 Wct PRESIDENT, PRODUCTION Fax: (301) 671-8279 December 30,1997 Dr. Carl J. Paperiello SERIAL: GDP 97-0225 Director, Office of Nuclear Material Safety and Safeguards Attention: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555 0001 Portsmouth Gaseous Diffusion Plant (PORTS)
Docket No. 70-70n2 Transmittal of Safety Analysis Report Revision 16 and Compliance Plan Revision 5
Dear Dr. Paperiello:
In accordance with 10 CFR Part 76, the United States Enrichment Corporation (USEC) hereby submits twenty (20) copics of Safety Analysis Report (SAR) Revision 16 (January 4,1998) and Plan for Achieving Compliance at the Portsmouth Gaseous DilTusion Plant (Compliance Plan) Revision 5 (January 4,1998), lloth of these documents are part of USEC-02, Application for United States Nuclear Regulatory Commission Certification, Portsmouth Gaseous Diffusion Plant.
SAR Revision 16 and Compliance Plan Revision 5 incorporate changes that were previously submitted for Nuclear Regulatory Commission (NRC) review in accordance with 10 CFR 76.45, and were app.oved as Amendment 8 to the Certificate of Compliance GDP 2 in NRC letter dated December 29, 1997 (TAC No. L32037). Revision bars are provided in the right-hand margin to identify the changes. / J SAR Revision 16 and Compliance Plan Revision 5 will be implemented effective January 4,1998.
v/yy
- k 9901060112 971230 PDR ADOCK 07007002 5
C PDR 6903 Rockledge Drive. Bethesda MD 20817-18i8 Telephone 301464-3200 l'as 30! 564-3201 http://www.uscc.com Offices in 1.tvermore, CA Ibducah, KY Ibrtsmouth, OH Washington. DC
I Dr. Carl J. Paperiello December 30,1997 GDP 97 0225 Page 2 There are no new commitments made in this submittal. Should you have any questions or comments regarding these revisions, please call hiark Smith at (301) $64 3244.
Sincerely, P
ytts ames 11. Miller Vice President, Production linclosure:
USl!C-02, Application for United States Nuclear Regulatory Commission Certification, Portsmouth Gaseous DilTusion Plant, SAR Revision 16 and Compliance Plan Revision S Copy Numbers 1 through 20 ec: NRC Region 111 Omcc Copy Numbers 21,172 NRC Resident inspector PGDP Copy Number 22 Mr. Joe W. Parks (Doli)
Copy Numbers 24 through 28 NRC Resident inspector PORTS, w/o
OATil AND AFFIRhtATION 1 James 11. hiiller, swear and affirm that I am Vice President, Production, of the United States Enrichment Corporation (USEC), that I am authorized by USEC to sign and file with the Nuclear Regulatory Commission this SAR Revision 16 and Compliance Plan Revision 5, both part of the USEC Application for United States Nuclear Regulatory Commission Certification, Portsmouth Gaseous Diffusion Plant (USEC-02), that I am familiar with the contents,nereof, and that the statements made and matters set forth therein are true and correct to the best of my knowledge, information, and belief.
N ev J.a[ l1. hiiller On this 30th day of December,1997, the otricer signing above personally appeared before me, is known by me to be the person whose name is subscribed to within the instrument, and acknowledged that he executed the same for the purposes therein contained.
In witness hereofI hereunto set my hand and ofricial seal.
_ hU Al ll/m v Lauric hi. Knisley, Notary Public
(/
State of hiaryland, hiontgomery County hiy commission expires hiarch 17,1998
I APPI,1 CATION FOR UNITED STATES NUCLEAR REGULATORY COMMISSION CERTIFICATION PORTSMOUTil GASEOUS DIFFUSION PLANT REMOVE / INSERT INSTRUCTIONS SAR REVISION 16 COMPLIANCE PLAN REVISION 5
.IANUARY 4.1998 Remc ve Pages insert Pages Vol.UME1 List of Effective Pages 1,lst of Effective Pages 1/ii, ix/x i/ii.ix/x S AR 3.2 SAR 3.2 3.2 9 through 3.212 3,2 9 through 3.2.I2 PLAN FOR ACillEVING COMPLI ANCE WITil NRC REGULATIONS AT Tile i
PORTSMOUTil GASEOUS DIFFUSION PLANT issue 3 issue 3 Pages 1/2,3/4 Pages I/2,3/4 i
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K
SAR PORTS January 4,1998
. Rey,16 of 100 psig whereas, heavywall cylinders ate rated for 200 psig. Normal operation at 220"F to 230"F, however, produces UF. pressures in the range of 80 90 psia. Thus, it is practical and safe to keep the pressure switch set for the worst-case cylinders. UF, cylinders exhibiting an excessive cold pressure (greater than 10 psia) are cold burped to remove contaminant gases that can cause excessive pressure to result upon heating.
In order to ensure that the cylinder valve and pigtail are opened to the pressure monitoring circuit, a pressure switch and timer are employed. During initial heating of a UF, cylinder, if the pressure indi:ator indicates to the operator that cylinder pressure will be less than 20 psia within one hour, then the steam input ullt be checked. If steam now had already been established, then steam now will be shut off, the autoclave will be shut down and opened, and the cylinder safety valve and cylinder valve will be verified open. The autoclave is then reclosed and the heating cycle is reinitiated. A check of cylinder valve clarity is m;det if valve clarity cannot be established, then the cause is investigated and corrected before further heating of the cylinder. The cylinder low pressure cutoff system serves as a backup to the operator and has been designated a Limiting Condition for Operation (LCO).
At the conclusion of a heating cycle, steam is exhausted from the autoclave through the blowdown exhaust system. This system consists cf an air jet ejector (aspirator) connected to the blowdown piping and is capable of exhausting steam from any one or all of the autoclaves simultaneously. A check valve located in each autoclave blowdown line prevents steam exhausted from one autoclave from entering another autoclave. A vacuum breaker is employed to allow a sweep of air through the autoclavc. The Locking Ring interlock system consists of a high and low pressure switch interlocked with the hydraulic locking ring to prevent the autoclave from being opened unless the autoclave pressure is within i0.5 psig. This feature is intended to prevent the mechanical damage and hazard to employees that would be expected to occur 4
if the autoclave were unlocked while pressurized with steam or UF, release products.
U P.
release detection and contakunent shutdown are accomplished by the steam-sampling / conductivity-monitoring system, the high autoclave pressure steam shutdown and the extreme high autoclave pressure containment shutdown. Each autoclave employs two independent steam sampling systems which withdraw steam through two small diameter lines each leading to a water-cooled condenser and reservoir. A conductivity cell is located in each reservoir 10 measure the conductivity of the condensate as the condensate Dows through the reservoir, llF is formed by the reaction of UF. with water when released mside the autoclave. IlF in the condensate causes the conductivity to increase. This system is designed to detect UF. releases (as small as 2 lbs/ min) and cause the autoclave to automatically go into a containment-shutdown mode. This mode consists of appropriate alarms and closure of all the containment bk)ck valves. Additional features of the conductivity sampling system are a now switch and a sanitary water supply tap. The now switch will signal steam shutdown upon loss of cooling water now to either condenser. The sanitary water tap is used to test the conductivity cells each time the autoclave is used. Sanitary water has sufficient conductivity to simulate e sma!! UF. release. Although the steam condensate conductivity system can initiate autoclave shutdown it is not considered to be necessary for i
autoclave operation and is not a safety system.
l 3.2-9
SAR-PoltTS January 4,1998
, Rev.16 in the event of a large release of UF. inside an autoclave, a faster reacting system is evallable to effect a contaltunent shutdown mode. Tha' system is the Autoclave Shell liigh Pressure isolation system.
During a large release, a massive amount of IIF gas would be rapidly produced by the reaction of UP. with water. The llF gas will increase the pressure in the autoclave and upon the autoclave internal pressure reaching the autoclave shell high pressure containment shutdown setpoint, a redundant pressure sensor will trigger containment shutdown. The amount of IIF gas produced is directly proportional to the amount of water available to react with UF..
In erder to limit the amount of water inside the autoclave, two independent and redundant water level probes are installed in the condensate drain line directly beneath the autoclave. These probes will trigger steam shutdown if the water level in the condensate drain should rise because of blockage downstream. This liigh Condensate !xvel Cutoff system has been designated a safety 6ystem. An initial water inventory test is perfonned on each new autoclave to detertnine the arnount of water nonnally entrained w4hin an operating autoclave. Past experience indicates that seven foot feed and sampling and six foot lu3 autoclaves can have excess entrained water during normal operation.
Consequently, these six foot autoclaves are not full containment vessels in the event of a catastrophic cylinder rupture in a closed autoclave because the stated pressure vessel limits will be exceeded and the pressure relief system will vent excess material outside the X 343 Facility.
I!ach autoclave is equipped with an Autoclave Shell liigh Pressure Relief system to prevent the internal pressure from exceeding the maximum allowable working pressure (MAWP) as determined by Section Vill of the ASMll Pressure Vessel Code. 'inis system consists of a pressure relief valve and rupture disc, r ch rated at or below the M AWP. The rupture disc is necessary only to prevent constant expo ute of the pressure relief valve to steam during nonnal operation. Such constant exposure could cause undesirable corrosion and scaling of the valve. Pressure above the rating of the pressure relief valve would be vented. (in the X 342A and X 343 Iluildings, the safety relief valve exhaust is outside the building. Due to the configuration of the equipment in the X 344A fluilding, the PRV exhaust is inside the building.) The valve is expected to re4 eat at the M AWP to contain pressure (reaction products) up to that amount.
1he autoclaves are equipped with a pressure switch which is interlocked with the hydraulic system l
to prevent opening the autoclaves at greater than 0.5 psig. Only steam pressure would be present under nonnal conditions; however, opening the autoclave may cause enough thrust between the head and shell to pmpel the shell and cause equipment damage. The X 342 and X 343 autoclaves have been fitted with an emergency hydraulic override switch. Using this switch, the shell can be opened at any time, as long as the internal pressure is below 0.5 psig.
The autoclave shells are thennally insulated. Under the insulation and against the outer surface shell is tubing (tracing) through which steam or cold water can be passed lleating or cooling an autoclave may be necessaiy during clean-up operations following a release.
3.2-10
SAR PORTS January 4,1998
. Rev.16 In summary, the following autoclave-related devices are identified as active safety systems:
The liigh Corxlensate level Cutoff System activates to stop the input of steam and sound appropriate alarms if the condensate approaches an unsafe level in the condensate drain line.
ne UF Cylinder liigh Pressure Cutoff System activates to stop the input of steam to the autoclave ano to sound appropriate alarms if the cylinder pressure approaches an unsafe level.
The UF. liigh Temperature Cutoff System activates to stop the input of steam to the autoclave and sourxl appropriate alarms if the cylinder temperature approaches an unsafe level.
The Autoclave Shell liigh Steam Pressure Shutdown System activates to stop the input of
+
steam, close the containment valves, and sound appropriate alarms if a large release or other undesirable high pres.sure situation exists inside the autoclave.
Tbc Autoclave Shell liigh Pressure Relief System activates to prevent the internal autoclave pressure from exceeding the maximum allowable working pressure for the autoclave as determined by the ASME rating.
The Autoclave Shell liigh I ressure Containment Shutdown System activates to stop the input of steam, close the containment valves, and sound appropriatu alarms, if a large release or other undesirable high pressure situation exists inside the autouve.
Containment and pressure systems include the code rating on the autoclave vessel and all associated piping appendages up to the second containment block valve (if present).
In addition to the safety systems summarized above, the following systems and limits are present to enhance safety:
The 1.ocking Ring Interlock contains a pressure switch which interlocks with the hydraulic l
system to prevent opening the autoclave shell while under pressure (above 0.5 psig).
Although only steam may be present in the autoclave, opening while the autoclave is under pressure may cause a thrust between the shell and the head which could cause equipment damage or personnel injury.
The Conductivity Monitoring cells cause containment shutdown and appropriate alarms if a small UF release occurs inside of an autoclave.
3.2-11
SAR-PORTS September 15,1995
. Rev.1 A Cylinder Safety Valve is installed between the cylinder valve and pigtail connection prior to heating and serves as one of the redundant containment valves in the process piping.
Void Volume Requirements are established to prevent hydrauhe rupture of a cylinder at maximum allowable heating temperatures.
A UP laiw Cylinder Pressure Cutoff system activates to stop the input of steam to the autoclave and to sound appropriate alarms if a predetermined UF pressure is not achieved within a specified time after heating begins, Failure to achieve the specified pressure could indicate a plugged or closed cylinder valve. This system is not a Limiting Condition for Operation when dumping sample bombs directly to the cascade or when cold feeding.
A Cylinder Assa) Limitation of 5% is established for any cylinder to be heated in an autoclave.
The Steam Interlock System is designed to prevent admitting steam to an autoclave unless the locking ring is closed and locked. The position of the locking ring is monitored by limit switches. When these switches confirm locking ring closure, contacts in the elec'ric power supply to the solenoid valve are closed. This pennits opening the steam regulating valve.
The Roll / Tilt Interlock System prevents the use of the roll or tilt motors on 84 in, autoclaves (and 96 in, autoclaves in the X 344A Toll Enrichment Facility) unless the autoclave shell is more than 3 ft. open. The safety function of this system is to ensure the operator has a clear view of the pigtail during roll / tilt operations. The shell position is monitored by limit switches. If the shell is open more than 3 ft, the motors will operate.
General Surveillance Requirements are in place to specify safety system / components testing after maintenance or when autoclaves are taken out of service for an extended perkid of time. Also, surveillance requirements provide for testing the Roll / Tilt System and the Steam Interlock System.
3.2.1.1.2 Stalc The fill limits for all UF, cylinders are set at a value to allow the cylinders to be heated within the specified limits without causing hydraulic rupture of the cylinder. It is therefore necessary to have accurate weighing devices available to ensure that the cylinders are filled within acceptable limits before the processing begins, Production quality scales are used to check fill limits, and are calibrated annually to a tolerance of i10 pounds from 0-6,600 pounds and i20 pounds from 6,600 pounds upward.
3.2 12
l Issue 3. Page 1 Autoclave Upgrades REQUIREMENTS 10 CFR 76.35(a)(6) "The application for an initial certificate of compliance must include the information identified in this f.ection. (a) A safety analysis report which must include the following information:... (6) A description of equipment and facilities which will be used by the Corporation to protect health and minimize danger to life or property..."
10 CFR 76.85 "The Corporation shall perform an analysis of potential accidents and con.equences to establish the basis for limiting conditicas for operation of the plant with respect to the potential for releases of radioactive material. Special attention must be directed to assurance that plant operation will be conducted in a marmer to prevent or to mitigate the consequences from a reasonable spectrum of postulated accidents which include internal and external events and natural phenomena in order to ensure adequate protection of the public health and safety."
10 CFR 76.87(c)(5) "(c) Appropriate references to established procedures and/or equipment to address each of the following safety topics must be included in technical safety requirements:...
1 (5) Radiation protection."
COMMITMENTS Sourcet Safety Analysis Report
- 3. Facility and Process Description 3.2 UP. Feed, Withdrawal, Sampling.11andling, and Cylinder Storage Facilities and Systems 3.2.1 Cascade UF. Feed and Sampling Systems 3.2.1.1 X 343 Feed Vaporization and Sampling Facility 3.2.1.1.1 Autoclaves [Rev. 3, S/31/96]
l "A seal is maintained between the lautoclavel head and shell with a Viton rubber 0-ring located in a machined groove in the sealing face of the head....
In summary, the following autoclave-related devices are identified as active safety systems:
l 4
The liigh Condensate Level Cutoff System activates to stop the input of steain and sound appropriate alarms if the condensate approaches an unsafe level in the condensate drain line.
The UF Cylinder liigh pressure Cutoff System activates to stop the input of steam to the mitoclave and to sound appropriate alarms if the cylinder pressure approaches an unsafe level.
The UF. liigh Temperature Cutoff System activatee to stop the input of steam to t'n-autoclave and [to] sound appropriate alarms if the cylinder temperature approaches an unsafe level.
PORTS Rev. 3,7/17/96 i
4 l
Inoue 3. Page 2 Amoctn e tfppmics De Autoclave Shell liigh Steam Pressure Shutdown System activates to stop the input of stearn and [to] sound appropriete alarms if a large release or other undesirable high pressure situation exists inside the autoclave, i
The Autoclave Shell liigh Pressure Relief System activates to prevent the intemal autoclave pressure from exceeding the maximum allowable working pressure for du autoclave as determined by the ASMP rating.
The Autoclave Shellliigh Pressure Containment Shutdown System activates to stop the input of steam, close the containment valves, and sound appropriate alarms, if a large release or other undesirable high pressure situation exists inside the autoclave....
In addition to the safety systems summarized above, the following systems and limits are present to enhance safety:
l The locking Ring intedock.contains a pressure switch which interlocks with the hydraulic system to prevent opening the autoclave shell while under pressure (above 0.5 psig). Although only steam may be present in the autoclave, opening while the autoclave is under pressure may cause a thrust between the shell and the head with could cause equipment damage or personnel i:Vury."
3.2.1.2 X 342A Feed Vaporization Facility 3.2.1.2.1 Autoclaves lRev. 3,5/31/%)
2 "See 3.2.1.1.1. The operation and safety systems are identical to X-343 Feed and Sampling Autoclaves."
3.2.1.3 X 344A Toll Enrichment Services Facility 3.2.1.3.1 Autoclaves 3.2.1.3.1.2 X 344A Autoclave Safety Systems [Rev. 3, 5/31/96]
"The safety systems for autoclaves at X 344A are functionally the same as described for autoclaves m the X 343 Feed Vaporization Facility (see 3.2.1.1.1)."
DESCRIPTION OF NONCOMPLIANCE nis issue involves a total of thirteen autoclaves. There are two autoclaves in X-342A, seven autoclaves in X 343, and four autoclaves in X 344A.
1.
The capability to test the containment valves (i.e., inner and outer loop valves) separately for the autoclaves in X-342A, X 343, and X 344A is not provided.
2.
The UF feed isolation and flow control valves in X 342A and X 343 are not fail safe on loss-of air'or electric power. The containment valves on the liquid UF, drain line are not fall safe on loss of air or electric power on autoclaves 3 and 4 in X 344A. The daughter cylinder isolation valves on the autoclaves in X 344A do not fait closed on loss of air.
. POR!$ Ret 5.1/4% -
~
1 4
Autoclave Upgrades issue 3, Page 3 3.
Autoclave 2 in X-344A does not have a low air pressure switch to initiate containment upon loss of air.
4.
The fligh pressure Containment Shutdown System control logic for the autoclaves in X-342A, X 343, and X 344A does not k>ck out the hydraulics to prevent the autoclaves from being inadvertently opened when the pressure in the autoclave exceeds the setpoint.
5.
The internal autoclave and UF cylinder pressure transmitters have too large of a pressure range and insuf6cient temperature compensation to perform within the operational accuracy and calibration tolerances needed.
6.
There are no alarms to alert operators of possible upset conditions prior to the activation of l
the autoclave safety systems.
7.
The design and connguration of the autoclave steam supply and condensate iemoval systems i a X-342A, X 343, and X 344 A are not adequate to prevent excess condensate from collecting in the autoclave, activating the liigh Condensate Level Cutoff System.
8.
The head /shell sealing surfaces for the autoclaves in X 342, X-343, and X-344A are experiencing significant corrosion, which affects their t.bility to seal.
9.
The UF, cylinders are not provided with pressure relief protection.
l
- 10. Pressure decay testing procedures and autoclave modificatiors that ensure that backpressure does not mask leak rate determinations have not been implemented.
JUSTIFICATION FOR CONTINUED OPERATION 1,
in the event of a release of UF., the Smoke Detection System will actuate an alarm. In response to such an alarm, administrative controls require the operator to immediately investigate and take necessary action to mitigate the consequences of any UF, releases. This may include manual actuation of the autoclave containment valves to place the autoclaves into containment. In addition, the following surveillances will be performed: (1) quarterly system channel functional tests to verify the containment valve closure and (2) quarterly overall autoclave containment pressure decay or leak rate tests.
2.
Until fail safe containment valves can be added or replaced, the existing valves will either be cycled twice or verified operable prior to each cylinder heating cycle. In addition, the following surveillances will be performed: (1) quarterly system channel functional tests to verify the containment valve closure and (2) quarterly overall autoclave containment pressure decay or leak rate tests.
3.
For autoclave 2 in X-344 A, there is redundant instrumentation to initiate containment upon a high-pressure indication. One channel of this instrumentation is a pressure switch which is not dependent on instrument air to perform its containment initiation function. This is sufficient for safe operation until the low instrument air pressure switch is added.
PORTS Rev. 3. 7/17N6 t
J
o Issue 3, Page 4 Autxlase tygrado 4.
The alarm response procedure fer the autoclaves in X 342A, X 343, and X 344A only allow the operator to open the autoclaves after clearing the liigh Pressure Contairunent Shutdown System ;larm condition. Also, the autoclave locking ring interlock contains a pressure switch which locks out the hydraulics to prevent the utoclaves from being opened when the internal pressure is greater than 0.5 psig. The autoclave locking ring interlock is tested quarterly to verify its ability to perform this function.
5.
Until replaced, the present pressme transmitters that monitor internal autoclave and UF.
cylinder pressure will continue to provide marginally acceptable accuracy The high autoclave steam shutdown trip set point will be reduced to compensate for the known inaccuracies to prevent the autoclaves or the UF, cylinder from exceeding their allowable operating pressure as defined in the Technical Safety Requirements.
6.
The operational alarms will not activate the safety system. Their sole purpose is as an early warning to the operator that the system is going off normal. All unplanned activations of a safety system require autoclave shutdown and reporting.
7.
The liigh Condensate Level Cutoff System is designed to limit the amount of water that can be present in an autoclave to react with or moderate UF during a release. Until the steam supply and condensate removal systems are upgraded, a hose will be used during the first hour of heating to allow the condensate to drain to an open drain instead of a steam trap. This temporary modifkation has been shown to reduce the activation of the high condensate level alarms to almost zero. Those alarms that do occur will require autoclave shutdown and reporting.
8.
Until the autoclave head /shell sealing surfaces are restored, thin strips of Viton " shim" will be used, as necessary, behind the 0-ring gasket to compensate for irregularities in the sealing surfaces. In addition, the autoclaves will be pressure decay or leak rate tested quarterly and each time the 0-ring gasket is replaced.
9.
The design of the UF, cylinders was constrained by the need to protect against a catastrophic release of liquid UF. to the work or general environment. This constraint was addressed by providing administrative procedures, positive controls on the source of heat, and redundant steam cutoffs.
- 10. Until the autoclaves in X 342A, X-343, and X-344A are modified and testing procedures are revised to allow appropriate, separate leak testing of all inner and outer loop containment valves, an autoclave will be declared inoperable and taken out of service when any containment valve is determined to be inoperable.
The above discussion provides justification that the plant can continue to operate safely until the autoclave upgrades are installed as discussed in the Plan of Action and Schedule are completed.
PORTS Ret $, t/498