ML20138C384
| ML20138C384 | |
| Person / Time | |
|---|---|
| Site: | 07007001 |
| Issue date: | 04/25/1997 |
| From: | NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | |
| Shared Package | |
| ML20138C373 | List: |
| References | |
| 70-7001-97-203, NUDOCS 9704300102 | |
| Download: ML20138C384 (13) | |
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.: , 7 U.S. NUCLEAR REGULATORY COMMISSION inspection Report No. 70 7001/97-203 Docket No. 70-7001
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Facility Operator:
United States Enrichment Corporation Facility Name: Paducah Gaseous Diffusion PI' ant.
Observations At: Paducah, KY Inspection Conducted: March 24-27,1997 ,
- Inspectors: Yen-Ju Chen, FCOB Rex Wescott, FSPB Courtney Blanchard, Rill Approved By: Philip Ting, Chief Operations Branch DivMien of Fuel Cycle Safety and Safeguards, NMSS ]
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1 Enclosure 1 1
9704300102 970425 .
EXECUTIVE
SUMMARY
PADUCAH GASEOUS DIFFUSION PLANT NRC INSPECTION REPORT 70-7001/97-203 Introduction NRC performed a routine, announced fire safety inspection of the U.S. Enrichment Corporation (USEC) Paducah Gaseous Diffusion Plant (PGDP) at Paducah, KY, on 3
March 24-27,1997. The inspection was performed by staff from NRC Headquarters and ,
Region Ill. The focus of this inspection was on the effectiveness .of the facility's fire safety l program and systems to provide adequate protection.
i Major fire safety performance elements reviewed at PGDP included: l i
e < Fire suppression systems
- Fire detection systems
- Internal tests and surveillance
- Building appraisal / reappraisal j
- Event report and investigation Sianificant Findinas and Conclusions 1
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- The design basis and the installation of the sprinkler systems appear to be adequate to I protect against the actual plant hazards observed during the process building walk throughs. However, the Pre Fire Plan did not adequately identify plant areas with specific criticality safety concerns that require special fire fighting considerations nor identify the type of suppression agents authorized for those areas (Detail 1.0).
- The fire alarm system was considered to be of adequate design (Detail 1.0).
- The material condition of fire protection related items was generally satisfactory.
However, one violation was identified regarding an inoperable section of sprinkler system piping. While this condition was initially observed on March 1,1997,
, adequate corrective action was not initiated until the NRC found it during a building walk through. This indicates a weakness with the identification and corrective action program for fire safety systems. (Detail 2.0).
- The inspectors noted that a lack of "as exists" drawings appears to have hindered plant personnel in the performance of system surveillance and inspection activities, and may have contributed to the violation. Other minor concerns were promptly addressed by Fire Services (FS) (Detail 2.0).
- The inspectors noted differences between the test frequencies specified in the National Fire Protection Association (NFPA) Code 25, the Safety Analysis Report (SAR), and/or the facility's current procedures. Further analysis is needed to determine whether these differences require a safety justification and the concern has 2
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been forwarded to the Special Projects Branch for evaluation. The inspectors also noted a performance weakness in the reporting and follow-up corrective action for out-of-spec surveillance data (Detail 3.0).
- A general weakness was noted in the building fire protection appraisal program. The current building reappraisals did not address all SAR building survey elements and did not provide adequate fire protection appraisals of major buildings. In addition, some building reappraisals have not been performed on an annual basis as specified in the SAR. However, Procedure CP4-SS-FS6106, Rev. O, appears to be acceptable for preparing building appraisals (Detail 4.0).
- The failure to properly evaluate and coordinate the cooling tower demolition project was a performance weakness (Detail 5.0).
DETAILS 1.0 Fire Protection Sy_ stem Desians
- a. Scoce The NRC inspection team conducted discussions with the fire protection engineering staff, reviewed the information contained in the SAR and sprinkler system drawings, and conducted a walk-through of portions of the process buildings to verify that the installed fire protection systems provided adequate protection against the existing fire hazards.
- b. Observations Fire Suporession System SAR Section 5.4.1.1 states that the process buildings are considered to meet the definition for Ordinary Hazard Occupancy (Group 2) as per NFPA 13, " Standard for the installation of Sprinkler Systems (1994)." Ordinary Hazard (Group 2) is defined in NFPA 13 as " occupancies or portions of other occupancies where quantity and combustibility of contents is moderate to high, stockpiles do not exceed 12 feet, and fires with moderate to high rates of heat release are expected." From a walk-through inspection of Process Buildings C-333, C-331 and C-310, the inspectors concluded that the amount and types of combustibles justified the SAR classification. Although the amount of lubricating oil in the building is substantial, the oil is pumped under relatively low pressure or supplied under gravity feed and stored in large closed steel tanks. The process buildings are of noncombustible unprotected steel frame construction; therefore, the operability of the fire suppression system is necessary to maintain structural integrity of the buildings during a fire.
The design of the sprinkler systems was also reviewed to determine if the sprinkler systems, as installed, would meet the performance requirements of Ordinary Hazard Occupancy (Group 2). The FS Manager stated that the process building sprinkler systems were designed to fight a fire resulting from a single large tube' oil spill. This 3
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which concluded that a lube oil spill followed by a fire would cause the worst case i accident. The likelihood of a lube oil fire has since been reduced by changing to a l synthe'ic t oil with a higher flash point according to the certificate holder. ;
1 Through a review of maintenance records, system drawings, dialogue with fire )
protection personnel, and a partial walk down of water sprinkler system 17 in j Building C 331, the inspectors noted that the f acility did not have an up-to-date 1 comprehensive and detailed description of the location of sprinklers. The most up-to-date drawings for the process building sprinkler systems were last revised in the -
1960s and have not been maintained to reflect subsequent system modifications. l Until approximately two years ago, the certificate holder did not require that modifications involving changes to or temporary disconnection of the fire water sprinkler systems to be reviewed by the fire services group. The inspectors noted that a lack of "as-exists" drawings appears to have hindered plant personnel in the performance of system surveillance and inspection activities, and may have contributed to the violation identified (Detail 2.0). l The sprinkler system design calculations could not be located at the beginning of the I inspection, so the inspectors evaluated selected parts of the system using the pipe schedule requirements in NFPA 13. Although the number of sprinklers fed from a given size pipe was found to be close to meeting the pipe schedule requirements, ,
small departures were found. Later, near the end of the inspection, hydraulic j calculations for the sprinkler systems were obtainod. These calculations indicated that the Paducah fire water system was hydraulically designed (or verified) to meet specifications that would satisfy the Ordinary Hazard Group 2 criteria in terms of area coverage per sprinkler head and gpm per square foot of covered area.
The FS initiated a sample walkdown of the sprinkler systems in the major process buildings in the summer of 1996. No significant concern / problem was raised as the result of the sample walkdown. However, a few problems in fire safety systems were identified after the sample walkdown, which prompted a "100- percent" walkdown of sprinkler systems in major process buildings to identify missing fire water pipes / sprinkler heads. For the "100-percent" walkdown, fire fighters walked down sprinkler systems one-by one and documented identified anomalies. The FS engineers then used fire fighters' notes to verify the findings and took appropriate actions.
Recent system walkdowns by plant personnel have discovered that numerous branch lines had not been connected. The facility has initiated several problem reports in this area and made the appropriate notifications. It was noted that the facility made a number of modifications to the fire sprinkler systems in 1976 to provide additional
, coverage of various building ventilation systems, and most of the disconnected pipes l were part of that modification. The plant is currently investigating this issue and i
. taking additional compensatory measures to ensure fire patrol coverage.
' The inspectors also raised a concern in using water as the suppression agent in process buildings, where large quantities of fissile materials exist. According to FS, the use of wet pipe sprinkler systems in criticality controlled areas has been analyzed 4
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- section in these Pre Fire Plans only stated that application of water using hose lines in
- the vicinity of fissile material can potentially cause an accidental criticality and requires fire fighters to get information from the SCADA system in the C-300 building. This i guidance is inadequate because it does not identify specific locations with criticality !
concerns and the type of fire suppression agent authorized for use in these areas by fire-fighting personnel responding to an emergency. For example, the inspector noted
, that the use of solid water streams in fire fighting may disturb. criticality control 1 i configurations and potentially cause an accidentai criticality ' A similar concern has i been raised by an NRC criticality inspection team earlier. This was brought to the FS l
- Manager's attention at the exit meeting, and the FS Manager stated that the Nuclear .!
' Criticality Safety (NCS) group would be contacted in order to evaluate the l interrelationship between fire fighting and criticality safety.
fire Detection and Alarm Systems in the process buildings, the fire alarm system is designed to provide indication in the main control room for the opening of sprinkler alarm valves, activation of manual pull switches, and the closing of electrically supervised valves in the high-pressure fire water system. There are no electronic smoke detectors or heat detectors for the l purpose of fire detection in the process buildings; the sprinkler system is both the fire detection and suppression system. The alarm system, as described by information supplied by FS personnel, uses class A, style 7 signaling line circuits to send either a l trouble signal or an alarm signal from one of the local data gathering panels (DGPs) to the main control room. The style and class indicate that the DGPs to main control room circuits can send an alarm signal in the event of relatively simple trouble condition such as a single open circuit, single ground, or a single wire-to-wire short.
More serious trouble conditions or combinations may result in a trouble signal only being sent, even during an alarm condition. For the initiating devices, the supervisory switch circuits are class B (will not alarm under a trouble condition) and the alarm cwitch circuits are class A (can send an alarm signal under certain trouble conditions).
The alarm system was considered to be of adequate design.
- c. Conclusions The inspectors concluded that the design and installation of the sprinkler systems appear to be adequate for the hazards protected against as determined from the process building walk throughs and the review of selected drawings. However, while on site, the inspectors did not have sufficient time to review the hydraulic design of the sprinkler systems to verify the calculation. Further evaluation of the hydraulic analysis will be tracked as inspector Follow-up Item (IFI) 97-203-01.
The alarm system also was considered to be of adequate design in regard to class and style of the signaling and initiating device circuits.
The inspectors noted that the criticality control information in the current Pre-Fire Plan 5
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is insufficient to serve the purpose of the Pre-Fire Plan. It does not specify the locations with criticality concerns, nor suggest the type fire suppression agent for j these areas. The FS Manager agreed to coordinate with NCS group in evaluating the I use of water as a fire suppression agent in the vicinity of fissile materials. Such j information should also be adequately addressed in the Pre-Fire Plan to assist fire- j fighting in an emergency. This will be tracked as IFl 97-203-02. '
l 2.0 Facility Walk-Throuah .
- a. Scope ,
in addition to the sprinkler systems, described in Section 1.0 above, the inspectors walked through selected buildings to determine the adequacy of other fire protection related items. Buildings inspected included C-631-1, C-631-3, C 333-A, C-333, C-331, C 310, and C-710. ,
- b. Observations Buildinas C-631-1 and C-631-3 the Pumo Houses The inspectors did not find any concerns while walking through Pump House C 631 1.
The two fire pumps were free of foreign material, no leaks were observed, and !
associated valves were labeled. General housekeeping and lighting for this pump i house was good. j The inspectors found a few minor concerns while inspecting pump house C-631-3.
These concerns are as follows: .
l e burnt out bank of lights and an exit sign, e leaking stem and missing handwheel on a Recirculating Cooling Water Pump 2-HOV-17 instrument valve, e and a missing set of emergency lights.
The FS Manager acknowledged all these concerns and had initiated actions to fix them. The work was completed by the end of inspection.
1 Buildino C 333-A. Feed Vaoorization Facility During the walk-through, it was noted that the operator's aid on the dry-pipe system riser was missing. This is a single sheet identifier of the system and provides the location of the inspector's test valve. This was replaced immediately. Also noted was a tap off the bottom of the dry-pipe system riser upstream of the dry pipe valve but downstream of the system control valve. This tap supplies water for the steam .
condensers associated with the thermochemical UF, detection device on the autoclaves. The purpose of the tap is to provide an additional source of condenser water to prevent damage to the condensers if the normal water source should be shut )
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off. Due to the small quantity and intermittent use of the water, the inspectors noted that the tap would not degrade the operability of the dry-pipe sprinkler system.
The inspector raised a concern about the access to a fire extinguisher from the autoclave platform. One visible fire extinguisher was located off of the platform in a maintenance area for which there was not adequate access from the west end of the autoclave platform. The FS Manager addressed this concern and a fire extinguisher was added to the west end of the autoclave platform.
Buildina C-331. Process Buildina Many sprinkler system deficiencies were found during the 100-percent process building walkdown. During the walk-through, NRC inspectors also identified some deficiencies in the sprinkler systems, such as obstructed sprinklers. Follow-up record review showed that these deficiencies had been identified during facility's system walkdown. These deficiencies have been evaluated, required compensatory measures were taken, and corrective acticns had been identified.
During discussions with FS engineers about the facility's walkdown, the inspectors learned that the walkdown was conducted without using any drawings. The inspectors were concerned that the walkdown may not be effective in that the ,
certificate holder's inspectors did not know the "as-exists" layout of the sprinkler i systems. )
I While tracing a section of water sprinkler system 17 pipe in Process Building C-331 on March 26,1997, the inspector and a FS engineer identified that a section of 18.5 feet of sprinkler pipe and two associated sprinkler heads were missing. The missing sprinkler heads and piping caused part of the water sprinkler system 17 of Building C-331 to be inoperable. Once this pipe was identified as missing, the FS engineer declared the system inoperable, and issued Problem Report PRSP-97-1629. Within l 30 minutes, the control room operator had established a fire watch.
The inspectors noted that the plant walkdown team identified this problem on March 1,1997, as a plugged " Tee"-fitting. The FS engineer did not investigate this finding until March 22,1997, to determine the appropriate corrective action.
Although the FS engineer filed problem reports for other deficiencies, this problem was overlooked and closed inadvertently. The inspectors noted that this missing pipe could have been identified by the fire fighters and corrective actions could have been taken immediately if drawings were used during the facility walkdown.
Technical Safety Requirement (TSR) 2.4.4.5, requires that the fire protection sprinkler system in process buildings C-331, C-333, C-335, and C-337 shall be operable. The missing water sprinkler system piping is Violation 97-203-03.
The inspectors also identified two safety concerns for the bridge between Process Buildings C-331 and C-333. The bridge runs about 300 feet between Buildings C-331 and C 333, and about 200 feet between Buildings C-335 and C-337. The certificate holder uses these bridges to transport production equipment and simplify employee 7
t transit between process buildings. NFPA 10 requires that the maximum travel distance shall not exceed 75 feet for access to a fire extinguisher. NFPA 72 requires that fire alarm boxes be distributed throughout the protected area and readHy accessible, and limits the travel distance to the nearest fire alarm box to 200 feet.
The inspectors did not find a fire extinguisher or an alarm pull box installed on these i bridges. The inspectors estimated that the closest fire pull box in Process Building l C-333 to the end of the bridge was approximately 60 feet. For someone at the middle I of the bridge, the distance to the nearest pull box may exceed the 200 feet limit. The !
inspector brought this concern to the FS Manager's attention, and a work request was issued to install two fire extinguishers and a fire pull box on each bridge. This will be tracked as IFl 97-203-04.
D_uildina C-710. Technical Services Buildina (Laboratory)
The inspectors toured the library, the vault, chemical storage area (cabinets), and three laboratories. Heat detectors were used in these areas, and sprinklers protection was provided. The library and the vault contain quantity combustibles, however, there does not appear to be any ignition source in the vicinity. The vault is protected by 4-hour fire rated door. The major fire hazards in the laboratories are combustible and flammable chemicals. The inspectors noted that there are two portable fire extinguishers in each laboratory inspected and along the hallway. The inspectors concluded that the fire protection measures appear to be appropriate for the type of fire hazards in the building.
- c. Conclusions The inspectors determined that the materian condition of fire protection related items was generally satisfactory. However, one violation was identified regarding an inoperable section of sprinkler system piping. Other minor concerns were promptly l addressed by the FS.
3.0 Internal Tests and Surveillance
- a. Scope The certificate holder's fire protection test and surveillance program was evaluated and compared with NFPA code to determine whether the test and surveillance program requirements are adequate to insure fire safety. Four surveillance and/or l tests were selected from a review of SAR Section 5.4.4, NFPA 25, " Standards for the inspection, Testing, and Maintenance of Water Based Fire Protection Systems" (1995), and Fire Safety Procedures CP4-SS-6111, Rev.1, "TSR Surveillance, inspection, and Testing of Wet Pipe Sprinkler Systems."
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- b. Observations The four surveillance / tests selected for comparison were:
e inspect the wet pipe sprinkler system risers.
e Test the sprinkler water flow alarm.
- Visually inspect the sprinkler heads, e Calibrate riser water pressure gauges.
According to the SAR, the inspection frequencies were developed by DOE-Oak Ridge and are, in some cases, an adjustment of NFPA frequencies to meet site-specific situations. The following table compares the frequency of the above four surveillance / tests as required by the SAR, recommendations from " Oak Ridge Operations - Fire Prevention and Protection Policies" (1989 edition), PGDP Fire Safety Procedures, and NFPA 25 (1995 edition). The inspectors noted that the facility is not committed to NFPA 25 inspection frequencies at the time of NRC inspection; however, NFPA 25 is used as the standard industry practice in this comparison.
i SAR Oak Ridge Paducah NFPA 25 Requirement Operation Procedure Policy Requirement inspect wet monthly monthly monthly monthly system risers Trip wet annually semi-annually semi annually quarterly system flow alarm lTV Visual not listed not listed monthly annually inspection of sprinklers Calibrate riser not listed not listed every 5 years every 5 years gauges With regard to the inspection frequencies in the procedure, the wet pipe system flow alarm trip test is conducted on a semi-annual basis, whereas the NFPA requirement is quarterly. The SAR requirement of an annual inspection frequency does not meet the requirements of either the Oak Ridge Operations policies or of the NFPA. Although the practiced frequency (procedure requirement) is semi-annual, the SAR commitment of
. an annual inspection does not appear to have a justified safety basis.
Also, the inspectors noted that the visualinspection of sprinklers, as required in the inspection procedure, does not appear to meet the intent of the annual inspection
-required by NFPA 25. NFPA 25 requires sprinklers to be inspected from the floor level 9
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annually (with the exception of sprinklers installed in concealed spaces or speces inaccessible for safety reasons). Because of the size and complexity of the sprinkler systems in the process buildings, the NRC inspectors noted that the present procedure may not assure an adequate 100-percent inspection. In addition, one cannot conduct the inspection effectively without up-to-date location drawings and/or checklists. The present procedure requires a visual check but does not require assurance that all accessible sprinklers have been looked at.
The inspectors also audited selected surveillance records for Buildings C-333-A, C-333, C-331, and C-310. The inspectors found that fire water sprinkler system 30 in Building C 3'e had a gauge that was reported as reading high on July 29,1996,and was again recorded as reading high on a surveillance dated January 9,1997. A note for corrective action was made on the July 1996 surveillance record but none was made on the January 1997 record. During the inspectors' walk-through of Building C-310 on March 26,1997, the gauge on system 3 was noted as reading .
high (about 146 psi). In the audit of surveillance, this gauge was recorded as reading 145 psi on February 16,1997, but no note for corrective action was made on the surveillance record even though the reading was 10 psi above the allowable range.
The inspectors reported these observations to FS, and problem reports were issued.
The safety significance of the out-of-spec gauges is relatively low in that system problems that may be indicated by the gauges can often be discovered through other inspection procedures (or gauges on adjacent risers). However, the reporting and follow-up corrective action for out-of-spec surveillance data appears to be a weakness.
The inspectors talked to several fire fighters / emergency medical technicians to determine their knowledge in conducting tests and surveillance. It appears that these fire fighters are familiar with the procedures and inspection frequency. When conducting surveillance in radiation controlled areas, these fire fighters will follow the appropriate procedures, i.e., contacting the Health Physicist and signing the Radiation Work Permit.
! c. Conclusions The fire protection test and surveillance program frequencies meet the SAR l commitments. However, these commitments are not consistent with the indus.try I
standards contained in NFPA 25. Determination of the potential safety significance of this discrepancy has been forwarded to the NRC Special Projects Branch for evaluation.
l The Fire Safety Procedure CP4-SS FS6111 does not provide positive assurance that all l unconcealed and accessible sprinklers are visually inspected in accordance with the I plant requirement.
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The reporting and follow-up corrective action for out-of-spec surveillance data appears to be a performance weakness. This will be tracked as IFl 97 203-05.
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4.0 Buildina Appraisal /ReaoJgaisal
- a. Scope The inspectors reviewed building appraisals / reappraisals and the procedure to determine whether the reports provide adequate evaluations of fire hazards for major :
buildings.
- b. Observations The inspectors reviewed the reappraisals for Buildings C-331 (dated November 8, 1995), C-333 (dated December 21,1994), C-337/337-A (dated November 17,1993),
and C-710 (dated December 6,1994), to assure that they addressed the building survey elements described in SAR 5.4.1.2. The inspectors noted that the format between the reappraisals was not consistent and the reports did not provide adequate fire protection appraisals for these buildings. The inspectors also noted that all the reviewed building reappraisals had not been completed within the frequency stated in the SAR. Specifically, a program had not been established to conduct fire protection appraisals of process buildings on an annual basis in 1996. Since this problem happened prior to March 3,1997, a violation will not be issued. However, this matter was brought to management's attention for corrective action and will be tracked as IFl 97-203-06.
The inspectors also reviewed Procedure CP4-SS 6106, Rev. O, " Fire Protection Building Appraisals," effective April 30,1996. This procedure describes the format, contents, and types of evaluation for building appraisals / reappraisals. This procedure appears to adequately address the SAR annual building survey requirement. The FS Manager indicated that future building appraisals / reappraisals will be prepared following this procedure.
- c. Conclusions The performance of past building reappraisals for major buildings appears weak in that the reports did not provide adequate fire protection appraisals and did not address all the building survey elements in SAR 5.4.1.2. In addition, the facility has not prepared building reappraisals on an annual basis as specified in the SAR. However, Procedure CP4-SS 6106, Rev. O, appears to be an adequate guideline for conducting building surveys.
5.0 Coolina Tower Event
- a. Scope The inspectors looked into the report and investigation of a fire event to ensure adequate event analysis and corrective actions were taken or planned.
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There was a fire on February 26,1997, during the demolition of a cooling tower. This l fire was caused by a short in an electrical extension cord igniting dry red wood it q was extinguished manually with a hose line because the cooling tower fire suppression )
system had been de-activated. Originally, de-activation of the cooling tower fire suppression system was a later step in the process in order to provide fire protectior.
during demolition. Scheduling delays, however, apparently affected the order of ]
i progression of the steps in the demolition process and no re-evaluation of the effects ;
on fire safety was performed. The inspectors reviewed the engineer's input to the ;
event report, but the final event investigation report has not been issued at the time of inspection. Since this event happened prior to March 3,1997, a violation will not be i issued. However, the failure to adequately coordinate and evaluate the project i appears to be a weakness. Inspector review of the event investigation and corrective t ' actions will be tracked as IFl 97-203-07. ,
- c. Conclusions )
. The failure to properly evaluate and coordinate the cooling tower demolition project is a weakness.
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MANAGEMENT MEETINGS Exit Meetino Summarv Inspectors met v ith PGDP management representatives throughout the inspection. The exit meetiry w: a held on March 27,1997. No classified or proprietary information was identified. ' c.t the exit meeting, PGDP acknowledged the potential violation and other deficie1cies, and agreed to take appropriate actions. The following is a list of exit meeting attendess:.
S. Polston, USEC/LMUS W. Sykes, USEC/LMUS D. Holt, USEC/ Contractor H. Pulley, USEC/LMUS H. Lang, Ill, USEC/LMUS S. Holshouser, USEC/LMUS S. Cowne, USEC/NRA M. Fletchur, USEC/LMUS R. Wimbrow, USEC/LMUS C. Hicks, USEC/LMUS V. Belt, USEC/LMUS G. Bazzell, DOE /SSR Y. Chen, NRC/NMSS R. Wescott, NRC/NMSS K. O'Brien, NRC/SRl/PGDP C. Blanchard, NRC/ Rill LIST OF ACRONYMS USED FS Fire Services SAR Safety Analysis Report NFPA National Fire Protection Association NCS Nuclear Criticality Safety
, DGPs Data (lathering Panels IFl Inspec. tor Follow-up Item
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