United States Nuclear Regulatory Commission - Protecting People and the Environment


ACCESSION #: 9704160113



                                                  United States

                                                  Enrichment Corporation



                                                  2 Democracy Center

USEC                                              6903 Rockledge Drive

                                                  Bethesda, MD 20817



United States                                     Tel: (301) 564-3200

Enrichment Corporation                            Fax: (301) 564-3201



George P. Rifakes                                 Dir: (301) 564-3301

Executive VICE PRESIDENT, Operations              Fax: (301) 571-8279



                             April 11, 1997



                                                      SERIAL: GDP 97-0063



U.S. Nuclear Regulatory Commission

Attention: Document Control Desk

Washington, D.C. 20555-0001



Paducah Gaseous Diffusion Plant (PGDP)

Docket No. 70-7001

Written Notification of 10 CFR 21 Report



     The purpose of this letter is to provide Written Notification to

satisfy the requirements of 10 CFR 21.21(d)(3)(ii) of a reportable defect

that was discovered at the Paducah Gaseous Diffusion Plant (PGDP).  This

Written Notification is a follow up to the Initial Notification sent to

the NRC by letter GDP 97-0036, dated March 14, 1997.



     The defect is associated with the packing nuts on 1 inch valves used

on UF sub 6 cylinders.  The firm supplying the items is Hunt Valve Co,

Inc., 1913 E. State Street, Salem, Ohio, 44460.  The defect was initially

discovered on January 19, 1997.



     The nature of the defect was cracking of the valve packing nut.

Metallurgical analysis of the cracked nuts has shown intergrannular

cracking to be the degradation mechanism.  Packing nuts with

intergrannular cracks were found in cylinder valves which had been used

in various stages of the enrichment process.  In addition, intergrannular

cracking was found in the packing nuts of cylinder valves removed from

new cylinders to allow internal inspection of the cylinders.  The removed

cylinder valves were in storage and had not been exposed to the plant

process chemicals or handling practices which affect the packing nut.

This indicates that the problem is probably a material or manufacturing

problem with the nuts.  Three valve packing nut materials are currently

used:  monel, ASTM B150 613 alloy, and CDA 636 alloy.  An inspection of

valves from other suppliers that are manufactured from all three

materials indicate that the cracking problem is observed only in the 636

alloy nuts on valves supplied by Hunt Valve Co., Inc.



U.S. Nuclear Regulatory Commission

Attn: Document Control Desk

March 11, 1997

GDP 97-0063 Page 2



     Failure of the stem packing nut during plant operations to fill or

empty a UF sub 6 cylinder could allow the stem packing rings to be

forcefully ejected from the valve, resulting in a UF sub 6 release, a

hazard to plant personnel, and a challenge to plant safety systems.

Failure of a cylinder valve packing nut and ejection of the valve packing

with an open valve on a full cylinder would constitute a failure of a UF

sub 6 confinement system, and, therefore, could create a substantial

safety hazard.  Cracking of the stem packing nut on closed cylinder

valves does not pose a hazard since the packing gland is isolated from

the UF sub 6 cylinder contents.



     The 1 inch cylinder valves are used in the 30B Portsmouth Gaseous

Diffusion Plant (PORTS) cylinders and the 48X 48Y, 48G, and 48H PGDP

cylinders.  The 1 inch cylinder valves are procured by PGDP for use on

all of the cylinders identified above at both PGDP and PORTS.  The valves

are provided by PGDP to the cylinder vendors for installation on new

cylinders supplied to PGDP and PORTS.  The 1 inch cylinder valves are

supplied by PGDP to PORTS for any replacements required on the 30B

cylinders.  The total number of applications is bounded by the number of

valves supplied with CDA 636 packing nuts by Hunt Valve Co.  The total

number of valves provided was 4500.  The number of valves with CDA 636

packing nuts currently in service is less than 4500 due to valves removed

for cylinder inspections, repairs, replacements, etc.  The exact number

in service is currently unknown.  The 1 inch cylinder valves are not used

on any of the other cylinder designs.



     The corrective action that has been taken at PGDP is to prohibit

feed and withdrawal operations for cylinders equipped with 1 inch Hunt

Valve Co. valves equipped with CDA 636 packing nuts. CDA 636 packing nuts

are replaced with monel or ASTM B150 613 packing nuts prior to use of a

valve in feed or withdrawal operations.  Long Term Orders have been

established in accordance with the governing procedure to ensure

compliance with the prohibition.  The Long Term Orders require checking

of the cylinder valve prior to use to identify any Hunt valves equipped

with CDA 636 packing nuts and prohibit their use.  The valve body is

clearly marked with the name of the manufacturer and the nut is marked

with the material designator.  Therefore, Hunt valves equipped with CDA

636 packing nuts can be readily identified and excluded from use.



     PORTS has been notified of the Hunt Valve Co packing nut defect.  A

PORTS Daily Operating Instruction was issued for the X-342, X-343, and X-

344 facilities to implement stop work notices which require inspection of

all cylinder valves prior to heating, filling, and transferring of

cylinders.  Any cylinder found to have a 1 inch Hunt cylinder valve with

a CDA 636 packing nut installed will not be heated, filled, or

transferred.  Caution tags are installed on all prohibited valves, and

operations may not continue until the valve packing nuts have been

replaced with approved replacements (i.e., non-CDA 636 material).  A

procedure containing guidelines for inspection and rejection of cylinders

was revised to include the requirement to immediately replace any packing

nuts on Hunt cylinder valves stamped with "636", or hang a caution tag on

the subject valve and reject the cylinder.  Hunt cylinder valves with the

CDA 636 packing nuts were removed from stock.  The valves will not be put

back into stock until the packing nuts are replaced with another

material.



U.S. Nuclear Regulatory Commission

Attn: Document Control Desk

March 11, 1997

GDP 97-0063 Page 3



     PGDP efforts to determine the root cause of the failure mechanism

are continuing.  These efforts are focused on the nut fabrication methods

and the raw material production.  The suspect population of 1 inch

cylinder valves may be narrowed to a subset of the current 4500 valves as

a result of the investigation.  In the event that some number of the 4500

valves can be excluded from the potentially defective population, the

corrective actions may be revised at that time to allow the use of Hunt

Valve Co. 1 inch cylinder valves with CDA 636 packing nuts from the

population excluded from being potentially defective.  The prohibition on

the use of valves with nuts from the suspect population for withdrawal or

feed will be maintained.  This corrective action is adequate to preclude

a UF sub 6 release due to the identified defect.



     The associated PGDP 10 CFR 21 evaluation checklist and a copy of

pertinent PGDP problem reports are enclosed.  New commitments made in

this letter are to continue the ongoing corrective actions described

above to prohibit the use of cylinders with 1 inch Hunt Valve Co. valves

with CDA 636 packing nuts at both PGDP and PORTS.  Any questions related

to this subject should be directed to Mark Lombard at (301) 564-3248.



                              Sincerely,



                              George P. Rifakes

                              Executive Vice President, Operations



Enclosures: as stated



cc:  NRC Region III Office

     NRC Resident Inspector - PGDP

     NRC Resident Inspector - PORTS

     Mr. Randall M. DeVault (DOE)



                               ENCLOSURES



           PGDP PART 21 CHECKLIST AND RELATED PROBLEM REPORTS



UE2-EG-GE1039, Rev. 1                                       Page 17 of 18



[illegible print]



                   10 CFR PART 21 EVALUATION CHECKLIST

                               Page 1 of 2



     Following questions provide the criteria for evaluation of 10 CFR

     Part 21 reportability:



A.1  No x Yes       Has the NRC already been informed of this condition

                    pursuant to 10 CFR 21 (for example, by a supplier)?



A.2  No   Yes       If yes, has USEC or LMUS been named as a recipient of

                    the defective item?



A.3  No x Yes       Has this condition already been reported to NRC in

                    accordance with procedure UE2-MC-RE1030?



If the answer to Questions A.1 and A.2 are "Yes", or the answer to

Question A.3 is "Yes", the condition need not be reported under 10 CFR

21.  Attach objective evidence of notification of the NRC and complete

Part #.



If the answers to Questions A.1, A.2, and A.3 are "No", continue with the

evaluation.



B.1  No   Yes x     Is the identified condition a deviation or failure to

                    comply associated with a basic component (including

                    design, analysis, inspection, testing, fabrication,

                    replacement parts, or consulting services)?



If the answer to Question B.1 is "No", the condition is not reportable

under 10 CFR 21; attach basis for conclusions and proceed to Section E.

If the answer to Question B.1 is "Yes", continue the evaluation.



     No   Yes x     If the answer to Question B.1 is "Yes", has the basic

                    component been delivered to USEC/LMUS and accepted

                    for use in the plant or an activity (includes USEC-

                    dedicated commercial grade items)?



If the answer to Question B.2 is "No", the condition is not reportable

under 10 CFR 21; attach basis for conclusions and proceed to Section E.

If the answer to Question B.2 is "Yes", condition is potentially

reportable.  Continue with the evaluation.



C.   Further, does the activity or basic component contain any of the

     following types of conditions?  (Deviation means a departure from

     the technical requirements included in a procurement document.)



     No   Yes x     1)   The installation, use, or operation of a basic

                         component containing a deviation?



     No x Yes       2)   A condition or circumstance involving a basic

                         component that could contribute to exceeding a

                         safety limit as defined in the GDPs Technical

                         Safety Requirements (TSRs)?



     No x Yes       3)   A failure to comply with any applicable

                         regulation, order, or certificate issued by the

                         NRC?



If all of the answers in this section are "No", the condition is not

reportable; attach basis for conclusion and proceed to Section E.  If any

answers are "Yes", continue with the evaluation.



[illegible print]



UE2-EG-GE1039, Rev. 1                                       Page 18 of 18



UE-141 (11-22-96)              Page 2 of 2



     Could the deviation or failure to comply create a substantial safety

     hazard resulting in any of the following (assume there is no

     redundant or back-up systems):



     No x Yes       1)   Exposure in excess of 10 CFR 20.1201 limits



     No x Yes       2)   Exposure of an individual in an unrestricted

                         area to more than 0.5 rem in one calendar year

                         (10 CFR 20.1301(c))



     No x Yes       3)   Release of radioactive material to an

                         unrestricted area in excess of the limits in 10

                         CFR 20, Appendix B, Table 2



     No   Yes x     4)   A deficiency which seriously compromised the

                         ability of a UF sub 6 confinement system to

                         perform its designated function



     No x Yes       5)   Other (explain)



If all answers in this section are "No", the condition is not reportable;

complete Part E.  If any answer is "Yes", condition is reportable.

Continue with evaluation.



E.   Evaluation results and recommendation.  Recommend condition be

     reported?



     No   Yes x     If answer is "Yes", sign this part and continue to

                    follow procedure, UE2-EG-GE1039.  Sign the evaluation

                    checklist and forward to the Manager, NRA.  If answer

                    is "No", evaluation is complete.  Sign the evaluation

                    checklist and forward to Commitment Management for

                    closure of Problem Report.



     Attach written summary of evaluation and basis for conclusions.



Investigator:

                         Name           Signature           Date



Independent Reviewer:

                         Name           Signature           Date



NRA:                     Name           Signature           Date



     (illegible print)



                   10CFR PART 21 EVALUATION CHECKLIST

                               Page 3 of 3



             SUMMARY OF EVALUATION AND BASIS FOR CONCLUSIONS



The 1 inch cylinder valve used on UF sub 6 cylinders is equipped with a

packing not which [illegible] the packing gland follower and packing

rings.  USEC-651, Rev 7, Uranium Hexafloride, A Manual of Good Handling

Practices, section 5.4.6, discusses past defects in 1 inch cylinder

valves and the potential adverse effects.  One past defect was packing

nuts which have split during service.  It is identified that this

condition could allow the stem packing rings to be forcefully ejected

from the valve, resulting in a UF sub 6 release.



Failure of a cylinder valve packing nut and ejection of the valve packing

with an open valve on a full cylinder, would constitute a failure of a UF

sub 6 confinement system.  Therefore, the cylinder valve packing nut is a

basic component for which failure could create a substantial safety

hazard.



The cylinder valves were procured by the Paducah Gaseous Diffusion Plant

as commercial grade items and were dedicated for use on the UF sub 6

cylinders.  The dedication process has been completed for any valves

installed on UF sub 6 cylinders thereby establishing the applicability of

10 CFR 21 to these components.



On 1/19/97, a UF sub 6 release was detected during pigtail purging

operations on a full cylinder.  The release was visible as a small wisp

of smoke after the pigtail was pressurized above atmospheric.  The

cylinder valve was closed and the release was terminated.  Inspection of

the valve revealed a visible crack in the valve packing nut.  An

investigation was initiated to determine the cause of the valve nut

failure.  A similar failure occurred on 2/7/97 and was included in the

investigation.



The 2 failed nuts were examined metallurgically and were found to exhibit

intergrannular cracking.  Both of these nuts are from Hunt valves and are

CDA 636 material.



Valve packing nut inspections were performed as part of the investigation

in order to determine the extent of the problem, Eddy current inspection

techniques were used in addition to visual inspections to help identify

potentially degraded valve packing nuts.  As a result of the inspections

additional cracked valve packing nuts were identified.  The following is

a summary of the additional nut inspection:

o    136 Hunt CDA 636 nuts from valves from Paducah Gaseous Diffusion

     Plant cylinders have been inspected by eddy current.  13 of these

     have exhibited cracks.  One of these was on a cylinder stored in the

     [illegible] yard and the cracks were detected visually.  Another,

     detected by eddy current, was on a "new" valve in storage following

     removal to allow inspection of a new UF sub 6 cylinder.

     Metallurgical analysis was performed on the "new" nut and confirmed

     the presence of intergrannular cracks.

o    25 Hunt B150 613 nuts were eddy current tested and no eddy current

     indications were detected.  One of these was subjected to

     metallurgical analysis and no cracking was detected.

o    28 Superior valve nuts of CDA 636 were eddy current tested and no

     indications were detected.

o    20 Hunt 636 nuts were examined from customer cylinders.  3 showed

     indications including 1 with a visible crack.  2 of these were

     metallurgically examined and the indications confirmed.  Three nuts

     that showed no indications were examined metallurgically and only

     one showed very slight indications that would not be picked up by

     eddy current.



Three valve packing nut materials are currently used; monel, ASTM B150

613 alloy, and CDA 636 alloy.  The cracking problem has been observed

only in the 636 alloy nuts on valves supplied by Hunt Valve Co., Inc.

The intergrannular cracking has been detected in Hunt CDA 636 cylinder

valve packing nuts which have been used in various stages of the

enrichment process and in the packing nuts of "new" cylinder valves

removed from new cylinders to allow receipt inspections.  The removed

valves were placed in storage and were not exposed to plant process

chemicals or handling practices affecting the packing nut.  This

indicates that the problem is a material or manufacturing problem with

the nuts.  No defects or failures have been identified in nuts of CDA 636

material on other vendors valves or in nuts of alternate materials on

Hunt valves.



A total of 4500 valves were supplied by Hunt Valve Co. with CDA 636

packing nuts.  Investigation and analysis is continuing to determine if

the entire population is susceptible to the intergranular cracking

problem or if the affected population is a subset of the 4500.  Until

further analysis determines otherwise, it will be assumed that the entire

4500 is affected.



[illegible]          Business Prioritization System                Page 1

                      Problem Report Response Sheet



ISSUE TITLE...:     SMOKE RELEASED FROM           Response Due: / /

                    CYLINDER VALVE ON PP-2569

ASSESSMENT....:     PROBLEM REPORTS JANUARY -

                    DECEMBER 1997 [UC97A00001]



ISSUE TO......:     UC9710318           MANAGER......: PENROD SR

FINDING NO....:     PR-CO-97-0289       FUNC. ORG....: 12' v

                                                       Operations

STATUS........:     CANC                GROUP........: __ - [Unassigned]

TYPE..........:     PR - Problem Report

SUB-TYPE......:     NO - Notification   ORIGINATING

                                        FUNC. ORG....: 12 - Operations

PRIORITY......:     0                   ORIGINATING

                                        GROUP........: 793 - UF6

                                                       Handling Shifts

LOCATION......:                         INITIATED BY.: 28539

BUILDING......:     C-310               DISCOVERY

                                        DATE.........: 01/19/1997 2200

MAIL STOP.....:     C-331

                                        PROCEDURE/

                                        SPEC/DRAW....:



ROOT CAUSE DETERMINATION



TapRoot Code(s):



FLAGS



DESCRIPTION



     UPGRADED TO EVENT REPORT PAD-ER-1997-001



     A small wisp of smoke was released from the cylinder valve on

     cylinder PP-2569.  PGLD YE-75 over the [illegible] withdrawal

     position pigtail was actuated.  The operations were in the process

     of evacuating/purging the pigtail on a full product cylinder.  The

     wisp was observed after the pigtail was pressured above atmosphere.

     A noticeable crack circumvents the packing nut.  The operators

     exited the area and donned additional PPE.  The pigtail was purged

     using subatmospheric doubling purges and the cylinder valve

     confirmed closed.  Cylinder was disconnected with no further

     incident and defective valve cap and caution tag was placed on the

     cylinder.  [Illegible] and uranium samples were pulled with negative

     results.  The ARP was followed and the PSS notified.



ACTIONS TAKEN



     NONE



RECOMMENDED ACTIONS



     Replace cylinder valve on pp-2549.  Analyze [illegible] of valve cap



PSS JUSTIFICATION/COMMENTS



     Urine samples were obtained.  UF6 detection safety system was

     actuated and operated as designed.  24 hour event report PAD-1997-

     002 issued.  Criteria met Appendix E 1 (a) Unusual and Appendix F, J

     (2) 24 hour.  Small wisp released from cracked packing nut when

     pigtail pressured up.  [Illegible] smears were negative.  This PR

     should be evaluated for 10CFR21 responsibility.



REMARKS



MANAGEMENT RESPONSE



Issue Revised 02/05/1997 at 13:12:29       Printed 02/19/1997 at 11:41:31



UC97I0699            Business Prioritization System                Page 2

                      Problem Report Response Sheet



ISSUE TITLE...:     C-310 RELEASE FROM            Response Due:

                    CYLINDER VALVE PR-591                   04/04/97

ASSESSMENT....:     PROBLEM REPORTS JANUARY -

                    DECEMBER 1997 [UC97A0001]



ISSUE TO......:     UC97I0699           MANAGER......: PENROD SR

FINDING NO....:     PR-CO-97-0640       FUNC. ORG....: 12 -

                                                       Operations

STATUS........:     PART                GROUP........: 070 - Operations

                                                       Management

TYPE..........:     PR - Problem Report

SUB-TYPE......:     __ - [Unassigned]   ORIGINATING

                                        FUNC. ORG....: 12 - Operations

PRIORITY......:     0                   ORIGINATING

                                        GROUP........: 793 - UF6

                                                       Handling Shifts

LOCATION......:                         INITIATED BY.: 28539

BUILDING......:     C-320               DISCOVERY

                                        DATE.........: 02/07/1997 0827

MAIL STOP.....:     C-331

                                        PROCEDURE/

                                        SPEC/DRAW....: CP4-CU-

                                                       CN2010 Rev. 0



ROOT CAUSE DETERMINATION



TapRoot Code(s):



FLAGS

                              CAQ



DESCRIPTION



     A small wisp of smoke was released from the cylinder valve on

     cylinder PK-S91 during purging operations.  This activated FOLD YE-

     73 in the #3 withdrawal position ventilation duct.  The wisp was

     observed after the pigtail was pressured above atmosphere.  A

     noticeable crack circumvents the packing nut.



ACTIONS TAKEN



     Operations immediately exited the area.  Alarm was responded to per

     procedure.  HF samples and wipes were negative.  The pigtail was

     purged using subatmospheric doubling purges.  Cylinder was

     disconnected with no further incident.



RECOMMENDED ACTIONS



     Replace cylinder valve packing nut on PK-591.  Investigate failure

     of packing nut.



PSS JUSTIFICATION/COMMENTS



     24 Hour Event Report per UE2-MC-RE1036, Appendix E criteria 2. 5.

     unusual (a), and Appendix F criteria J.2.  Appropriate response was

     made.  HF and HP surveys were negative.  Precautionary urine samples

     were obtained from the two workers who were present.



REMARKS



     03/06/97:  Per PRSC, assign to Operations for disposition.  This PR

     will be closed to PR-00-97-0648 which is a SCAQ.



     03/06/97:  DOE reportable events due to DOE on/after 03/03/97 (date

     NRC assumed regulatory oversight) have been downgraded to problem

     reports.  PR-CO-97-0440 has been placed back in PART status and will

     be taken back to the Screening Committee for SCAQ determination,

     action plan due date, etc.  Event Report FAD-ER-1997-094D

     (OC97I06100 has been cancelled.



MANAGEMENT RESPONSE



Issue Revised 03/06/1997 at 15:49:37       Printed 03/13/1997 at 10:44:09



UC97:1002            Business Prioritization System                Page 1

                      Problem Report Response Sheet

                          "31" PROBLEM REPORTS



ISSUE TITLE...:     PACKING NUT ON CYLINDER       Response Due:

                    PP-2520 ON 6 YARD CRACKED               03/20/1997



ASSESSMENT....:     PROBLEM REPORTS JANUARY -

                    DECEMBER 1997 [UC97A0001]



ISSUE TO......:     UC97I1002           MANAGER......: BROWN JR

FINDING NO....:     PR-SU-97-08588      FUNC. ORG....: 37 -

                                                       Engineering

STATUS........:     PART                GROUP........: 814 - Mechanical

                                                       & Process

TYPE..........:     PR - Problem Report

SUB-TYPE......:     __ - [Unassigned]   ORIGINATING

                                        FUNC. ORG....: 38 - Production

                                                       Support

PRIORITY......:     0                   ORIGINATING

                                        GROUP........: 340 - Process

                                                       Technical & NDA

LOCATION......:                         INITIATED BY.: 28539

BUILDING......:     C-743-E             DISCOVERY

                                        DATE.........: 02/18/1997 1445

MAIL STOP.....:     C-710

                                        PROCEDURE/

                                        SPEC/DRAW....:



ROOT CAUSE DETERMINATION



TapRoot Code(s):



FLAGS

                              CAO



DESCRIPTION



     The packing nut on cylinder PB-2520 in the E yard was found cracked

     around the circumference (at approximately the cap thread) through

     approximately 80% of the section.  This is a "Hunt" valve alley "6-

     36" nut.  (Lot #390795-8).  This packing nut failure was found while

     inspecting Paducah Plant cylinders with an eddy current probe for

     indications of cracked nuts, but was clearly visible with crack

     opening of approximately 1/8".  The cylinder appeared to be empty.



ACTIONS TAKEN



     NONE



RECOMMENDED ACTIONS



     NONE



PSS JUSTIFICATION/COMMENTS



     Found during a random sampling of Hunt valves with the "6-36"

     packing nut.  No sign of any leakage.  10 ton cylinder.  Per NMC&A

     records, is an empty cylinder with notation requiring a valve

     change.  This should be evaluated for 10 CFR 21 and 71.95

     applicability.



REMARKS



     02/20/97:  Part A is assigned to Operations and Management response

     provided at PRSC.  No further actio required.  Part 6 is assigned to

     Engineering to evaluate for 10 CFR applicability.



MANAGEMENT RESPONSE



     Name of person providing response:



Issue Revised 02/20/1997 at 09:59:34       Printed 02/20/1997 at 13:23:43



FUEL CYCLE FACILITY                          EVENT NUMBER:  31954



FACILITY: PADUCAH GASEOUS DIFFUSION PLANT    NOTIFICATION DATE: 03/14/97

  RXTYPE: URANIUM ENRICHMENT FACILITY        NOTIFICATION TIME: 13:30

                                                                 [ET]

COMMENTS: 2 DEMOCRACY CENTER                 EVENT DATE:        03/14/97

          6903 ROCKLEDGE DRIVE               EVENT TIME:        00:00

          BETHESDA, MD 20817 (301)564-3200                       [CST]

                                             LAST UPDATE DATE:  04/11/97

CITY:     PADUCAH             REGION: 3

COUNTY:   McCRACKEN           STATE: KY           NOTIFICATIONS

LICENSE#: GDP-1               AGREEMENT: Y

DOCKET:   0707001                            WAYNE KROPP         RDO

                                             JOSEPHINE PICCONE   EO

NRC NOTIFIED BY: MARK LOMBARD                KEVIN RAMSEY (FAX)  NMSS

HQ OPS OFFICER:  STEVE SANDIN



EMERGENCY CLASS: NOT APPLICABLE

10 CFR SECTION:

CDEG 21.21(c)(3)(i)      DEFECTS/NONCOMPLIANCE



                               EVENT TEXT



10 CFR PART 21 NOTIFICATION REGARDING STRESS CORROSION CRACKING OF

CYLINDER VALVE PACKING NUTS



IT HAS BEEN DETERMINED THAT STRESS CORROSION CRACKING OF THE 1-INCH

CYLINDER VALVE PACKING NUTS USED IN VARIOUS STAGES OF THE

ENRICHMENT

PROCESS HAS, IN ONE CASE, RESULTED IN A REPORTABLE RELEASE OF UF6. 

THIS

PROBLEM HAS ONLY BEEN OBSERVED IN THE 636-ALLOY NUTS ON VALVES

SUPPLIED

BY HUNT VALVE CO., INC.



*  *  *  UPDATE 1740EDT 4/11/97 FROM MARK LOMBARD To S. SANDIN *  *  *



THE LICENSEE SUBMITTED AN UPDATE VIA FAX.  NOTIFIED R3DO(MADERA) AND

FORWARDED TO NMSS(RAMSEY).



                  UNITED STATES ENRICHMENT CORPORATION



Two Democracy Center o 4th Floor o 6903 Rockledge Drive o Bethesda, MD

20817



                             Fax Memorandum



                                          DATE:   April 11, 1997

                                          TIME:   5:39 pm



TO:       NRC Operations Center           FAX:



                                          PHONE:



FROM:     Mark Lombard                    FAX:    301 564-3210

                                          PHONE:  301 564-3248



NUMBER OF PAGES (including cover sheet): 10



SUBJECT:  Part 21 written report attached, for concurrence.  Please call

me if you have any questions.  The hard copy will follow by mail.



*** END OF DOCUMENT ***

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