IR 05000219/1988002
| ML20150B629 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 02/29/1988 |
| From: | Cowgill C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20150B612 | List: |
| References | |
| 50-219-88-02, 50-219-88-2, IEB-79-24, NUDOCS 8803170084 | |
| Download: ML20150B629 (11) | |
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U. S. REGULATORY COMMISSION
REGION I
Report No.
50-219/88-02 Docket No.
50-219 License No.
DPR-16 Priority'--
Category C Licensee:
GPU Nuclear Corporation 1 Upper Pond Road Parsippany, New Jersey 07054 Facility Name: Oyster Creek Nuclear Generating Station Inspection Conducted: January 25-29, 1988
Participating Inspectors:
A. Cerne, Senior Resident Inspector, Seabrook
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O. Johnson,. Resident Inspector, Three Mile Island 1
E. Collins, Resident Inspector, Oyster Creek i
W. Baunack, Project Engineer i
Approved By:
fit _
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[f C. Cowfill, ief Reactor Projects Section 1A ate j
Inspection Summary:
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Areas Inspected: A special inspection by four Region I inspectors (70 hours8.101852e-4 days <br />0.0194 hours <br />1.157407e-4 weeks <br />2.6635e-5 months <br />) was
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conducted to assess the safety implications of the. freezing conditions identified in the reactor building on January 6,1988 and to evaluate the effectiveness of the licensee corrective measures. The inspectors specifically reviewed the reactor building HVAC design, the adequacy of procedural controls, licensee compliance with FSAR and other commitments, the effectiveness of the implemented corrective actions, licensee reportability determinations, and the generic applicability of the subject event to other safety-related plant systems and components.
Results: Two violations were identified involving: (1) failure to perform a safety evaluation for a change to the plant configuration, and (2) failure to perform an adequate procedure review.
The subject event will be reported in accordance with 10 CFR 50.73.
Further licensee analysis of the safety and design basis implica-tions of the sJbject event continues.
The results of such analysis may require
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further action on the part of the licensee.
Interim corrective measures and com-pensatory action appear adequate to preclude adverse cold weather impact upon safety systems.
I 8803170004 800229 i
PDR ADOCK 05000219
G PDR
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DETAILS 1.
Persons Contacted GPUN Personnel R. Aitken, Job Supervisor
- J. Barton, Deputy Director, Oyster Creek R. Brown, Manager, Plant Operations
- G. Busch,. Licensing Engineer P. Cervenka, Plant Engineer
- P.
Fiedler, Director, Oyster Creek V. Foglia, Operational Manager, M/PM, and Surveillance Manager M. Jacobs, Nuclear Engineer, New Jersey State DEP D. Jones, Senior Engineer
- K. Mulligan, Operations Engineer 0. Perez, Plant Engineer
- M. Radvansky, Manager, Technical Functions, Oyster Creek
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- 0 Ranft, Manager, Maintenance Engineering
- A. Rone, Plant Engineering Director
- E. Scheyder, MC&F Director, Oyster Creek J. Solakiewicz, QA Engineer and Systems Manager W. Stewart, Safety Review Manager
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- J. Sullivan, Plant Operations Director
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- R. Weltman, Mechanical Material Manager (JRC Personnel
- W. Baunack, Project Engineer
- A. Cerne, Senior Resident Inspector, Seabrook
- E. Collins, Resident. Inspector, Oyster Creek
- C. Cowgill, Chief, Reactor Projects Section 1A
- D. Johnson, Resident Inspector, Three Mile Island 1
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- J. Wechselberger, Senior Resident Inspector, 0yster Creek l
- Denotes attendance at the exit meeting.
The inspector also contacted other licensee. personnel during the inspection.
2.
Background On January 6,1988 control room operators noted the "B" and "E" recirculation pump #2 seal pressure increased from approximately 520 psig (normal pressure
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indications) to about 800 psig. After suspecting a seal failure initially, the operators determined that reactor building temperatures were only 33 de-grees F on the 23' elevation and that potentially the instrument lines had frozen.
In addition, shutdown cooling pump discharge pressure showed indica-tions of freezing.
Operators secured normal reactor building ventilation and
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initiated the standby gas treatment system to reduce the amount of cold air
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flow to the reactor building.
This was effective as within approximately 30
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minutes the recirculation seal pressures had recovered.
In subsequent system walkdowns it was determined that the penetrations for~ seal pressures were directly exposed to ventilation air flow in the shutdown cooling room.
The NRC resident-inspectors continued to monitor _the events surrounding both the freezing weather conditions and the identified non-safety component fail-
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ures. NRC plant inspections of the reactor building confirmed the restoration of area temperatures to acceptable conditions. While immediate licensee actions were evaluated to have been adequate, the effectiveness of the licen-see's cold weather protection efforts and the safety implications of the sub-ject event required further review and analysis. An NRC Region I special inspection, as documented in this report, was planned and commenced January 25 to address these issues.
3.
Sequence of Events This sequence details the events on January 6, 1988 ' hen extremely cold weather resulted in actual freezing conditions.inside the Reactor Building (RB).
This information was obtained from personnel interviews and operator logs.
Time Activity 3:45 a.m.
Control Room operator noticed "E" Reactor recirculation pump
- 2 seal pressure increasing (520 to 800 psig).
4:00 a.m.
The Group Shift Supervisor (GSS) suspecting possible seal failure instructed hourly level readings to be taken on the drywell equipment (DW) drain tank and the DW floor drain sump in order to identify any leakage.
5:35 a.m.
"B". Reactor Recirculation pump #2 seal pressure observed to increased (520 to 800 psig), also, "B" and "C" shutdown cooling pump discharge pressures were observed to increase (pumps were not operating).
Suspecting freezing conditions, an operator was dispatched to the Reactor Building (RB) with a hand held digital thermometer.
The coldest region identified by the operator was the 23' ele-vation of the RB, near the drywell oxygen analyzer, at 33 de-grees F.
6:05 a.m.
Based on these indications, the GSS directed the normal venti-lation line up to be secured and the Standby Gas Treatment System (SBGTS) to be placed into service.
This operation would significantly reduce the amount of cold outside air drawn into the RB and would act to elevate R8 temperatures.
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u 6:20-a.m.
Reactor Recirculation seal _ pressures returned"to normal.
RB temperatures were_ observed to increase, i
8:30~a.m.
Detailed RB temperature profiles were obtained by Operations Department personnel.
10:30 a.m.
Event critique held by the licensee which included representa-tives from plant Engineering, Operations, and plant management.
1:00-3:00 p.m. Resident inspectors accompany licensee-personnel in a RB in-
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spection to identify the extent of freezing conditions and the systems that were possibly affected.
RB temperatures directed to be taken twice/ shift unless'the.
outside air temperature is less 'than 10 degrees, then tempera-
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tures are to be taken every 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.
3:00 p.m.
Heating steam to RB returned to service, normal ventilation line up restored.
During the RB inspection, the resident inspectors checked the extent of freezing conditions. Based upon these observations, it was concluded that no freezing conditions were experienced in s'afety systems required for opera-
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tion during this event.
4.
Scope of Inspections / Findings
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The inspectors met with licensee manag'ement, engineering, QA and licensing personnel to discuss their assessment of the subject cold weather occurrence on January 6, 1988.
The Oyster Creek updated FSAR, the Integrated Plant
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Safety Assessment (Systematic Evaluation Program, NUREG-0822), and selected plant drawings and procedures were reviwwed to determine the design bases and operational control criteria for the reactor building heating and venti-lating system. A plant inspection tour of various zones within the reactor
building was conducted and other areas of the plant were inspected, as neces-sary, to evaluate cold weather concerns and licensee corrective-measures.
The inspectors specifically examined procedural controls, system design, lic-ensee corrective actions, and their compliance with documented commitments.
The reportability under 10 CFR 50.73 of the subject occurrence and the generic applicability of cold weather concerns were also reviewed.
The specific in-
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spection details and findings are discussed below.
The inspectors noted that licen.ee engineering and QA documents do not establish the heating subsystem of the reactor building HVAC system as one that is "Important-to-Safety".
While this non-c.afety classification and-the technical basis upon which it is based were considered during this inspection, the full implication of the impact of such nonessential services, in this case HVAC, to the reliable operation of safety systems are yet to be determined.
The licensee appears.
to have initiated a substantial engineering effort to evaluate this particular
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safety systam/non-safety system interaction.
NRC follow-up of this ongoing evaluation process and its results will continue and is addressed further in the following paragraphs.
4.1 Design and Procedural Controls The updated Oyster Creek FSAR describes the reactor building heating and ventilation systems.
Since this inspection represents a followup to a freezing event which occurred in the reactor building, the primary in-spection effort was directed toward the reactor building heating nortion of the heating and ventilation system.
The FSAR states that heating and cooling units are installed within the ventilation system to maintain temperatures for personnel comfort-and-equipment protection.
Reactor building heating is provided by a single heating coil assembly which is provided steam from from the facility auxiliary boilers through an air operated automatic temperature control valve.
The FSAR states, the reactor building ventilation system is nor-mally operating and that any failure is easily detected.
Furthermore, the system flow diagram indicates the minimum winter temperature of the ventilation supply air to the reactor building is 50 degrees F.
The licensee's procedure which provides instructions for the operation of the system is Station Procedure No. 329, Reactor Building heating, Cooling and Ventilation System.
This procedure states the reactor build-ing heating, cooling and ventilation system should be operated to main-tain a minimum temperature of 50 degrees F in the reactor building.
The procedure describes the wintertime steam system alignment, and includes a caution that the reactor building-heating, cooling and ventilation system is normally never shut down unless the standby gas treatment system is placed in operation.
The following facts and findings associated with the operation of the reactor building heating, cooling and ventilation system were identified during this inspection:
For some extended period of time the condition of the entire system
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piping, dampers, ductwork, temperature control system, and heating coils were permitted to fall into a state of disrepair.
The exact state of disrepair could not be determined.
While a search of short forms (work requests) was attempted, such a lacge number had been written that a complete review was not possible. Since the point in time that a computerized tracking system was placed into service in mid 1986, 161 short forms were written for the reactor building ventilation system. Ninety-one of these have been closed. The number of short forms written prior to mid 1986 was not determined.
During the last several years considerable effort has been made to
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repair the system and restore it to its design configuration.
Duct-work, dampers, heating coils, and piping have been repaired. Also,
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instrumentation associated with the temperature control system was entirely replaced. -This work was somewhat hampered by' engineering and planning personnel changes during this period of time.
Operators have been concerned about the' need for proper operation
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of the reactor building HVAC system during periods of cold weather.
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The inspector reviewed memoranda indicating that shift personnel had alerted management of system deficiencies prior to the arrival of cold weather, during each of the last two years.
The cold temperature conditions present in the shutdown cooling-
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enclosure on January 6,1988 damaged the B and C shutdown cooiing
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pump discharge pressure transmitters which transmit the pump dis-charge pressure to.the control room.
These indicators have been properly tagged out in the control room.
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During the NRC inspection tour of the reactor building HVAC system,
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the inspector was informed by operations management and the GSS that the reactor building temperature control system was working in auto-matic.
Subsequent inspection of the system revealed, however, the automatic control valve was isolated and steam to the heating coils was being provided by the bypass. When the' automatic steam control valve was unisolated, a leak was identified.
The valve was again isolated and a short form prepared to repair the leak.
The auto-matic temperature control was known to have been working on January 6, 1988.
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procedure 329, Reactor Building heating Cooling and Ventilation System, which provides instructions for the operation of_the system was identified to contain certain errors.
For one, it describes a reactor building temperature indicator on panel 11R in the control room when in fact no such temperature indicator exists.
This indi-cation was apparently part of the original system description but was cancelled in 1968 and never installed.
Also, the procedure wintertime steam supply alignment isolates the pneumatic controi valve and provides steam only through the bypass. Operators believe this alignment was specified to compensate for equipment which in the past had not been functioning. Additionally, the procedure includes a valve check-off list for the HVAC system. However, the last time this check-off was performed was June 28, 1980. The last periodic review of this procedure was performed during October,1936.
Procedure revisions were made as late es December,1987.
As a result of NRC inspection and subsequent review of the above findings,
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two violations of regulatory requirements'were identified, as follows:
(1) The Code of Federal Regulations 10 CFR 50.59 permits licensees to l
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make changes in the facility as described in the safety analysis report provided a written safety evaluation is performed which pro-vides the bases for the determination that the change does not in-
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volve an unreviewed safety quest lon.
Station Procedure 125, Conduct of Plant Engineering, Section 6.8 requires written safety evalu-ations per 10 CFR 50.59 (a) for any change to the plant configura-tion whether or not the item is considered nuclear safety-related.
Contrary to these requirements no written safety evaluation was performed or other compensating operational or design measures im-piemented for the inoperative condition of the rcactor building heating system relative to its cesign basis documented in the up-dated FSAR.
Such a condition, outside of the design basis, was permitted to exist for approximately two years (50-219/88-02-01).
(2) Technical Specification 6.8.1, specifies that written procedures shall be maintained.
Station Procedure 107, procedure Control, Section 3.3.4 requires a periodic review of procedures be conducted once every two years.
This review is defined as a documented read-ing of the procedure to assure it continues to satisfy its objective in a manner consistent with plant requirements.
In addition, the reviewer should contact a "user" of the procedure (operator. tech-nician, etc.) for feedback on adequacy of the procedure.
In the case of Procedure 329, a current operational step describes a reac-tor building temperature indicator on panel 11R in the control room which apparently had never been installed. This procedural inade-quacy appears to have existed for approximately twenty years and through 13 revisions of the subject procedure, indicating an inade-quate procedural review process as prescribed by Procedure 102 (50-219/88-02-02).
4.2 Corrective Action and Compliance with Commitments The inspector reviewed the program established by the licensee to ensure that systems and components were protected against the effects of low temperatures.
Commitments in this area ralate to previous NRC guidance, specifically the response to IF " nletin 79-24. The licensee response to this bulletin is contained i., a letter dated October 31, 1979.
In this response only one previous problem with frozen lines was noted.
A program was being implemented at the time to accomplish functional checks on safety-related systems to ensure that heat tracing was operable prior to the onset of freezing conditions.
This was the only documented action taken at that time.
The most recent inspections of licensee freeze protection, NRC inspection reports 50-219/87-04 and 87-41 noted various problems with licensee action to ensure that low ambient temperatures did not affect safety-related systems. On January 26, 1987, a drain valve on the condensate storage tank (CST) froze and caused a leak in the tank.
This situation led to the declaration of an unusual event.
Inspection report 87-04 also described several deficient conditions related to freeze protection, one of which was persistent cold temperatures on the 23' elevation of the reactor building.
The licensee had been aware of this oroblem at least a year previous to the event of January,
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The licensee had been involved in the process of accomplishing repairs e
to the reactor building heating and ventilation system for the past several years but had not completed them in sufficient time to have the-heating portion of the system operable during the present cold weather
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conditions. -A discussion of the licensee attempts to repair the system e
and the problems encountered are described in Section 4.1 of this report.
Inspector reviews of the facts and evaluation of available.information revealed that licensee corrective action relating to freeze protection at Oyster Creek, while active, has been only partially adequate.
The present preventative, maintenance program which checks heat tracing on _
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all safety-related systems was inspected during November of 1987 and is
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documented in Inspection Report 50-219/87-41.
During this current in-spection the inspector examined the equipment operator (E0) check sheets that are utilized daily for temperature monitoring and appear to ade-quately note conditions in areas where. low temperatures can exist. While these checks appeared to be adequate, the licensee was not successful in repairing the reactor building heating system in oroer for it to function as needed. The cause of this problem is viewed as poor coordin-
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ation of the total overall effort to ensure proper measures are taken for freeze protection.
There is no one systematic procedure or surveil-lance program for cold weather which fixes responsibility for establish-ing an adequate freeze protection program.
Licensee operations personnel are preparing an evaluation of this event with proposed corrective action.
The results of this report will be.
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j reviewed by the inspectors during future inspections of this area.
An issue was raised by the inspectors concerning the ability of the
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emergency diesel generators fuel oil system and piping to withstand the effects of cold temperatures.
The diesel generators and main 15,000 l
gailon fuel oil tank are located in unheated buildings which can be ex-posed to potentially low temperatures that can cause the diesel fuel oil
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to gel.
This situation could prevent the main tank from being able to
fill the 1-2 hour supply day tanks which are located inside the heated diesel skids.
The licensee installed a portable heater inside the 15,000 gallon tank building in order to ensure that exposed pipirg in that area would not be exposed to conditions below the 5 degree F temperature which causes diesel fuel oil to begin to gel.
The inspector verified that the room was adequataly heated when outside temper-atures were approximately 10-15 degrees F.
It appeared that the licensee corrective action in this area was acceptable.
The inspector also noted some length of fuel oil supply piping in each diesel building that was exposed to a potentially cold environment.
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licensee has established a program whereby ambient temperatures in the
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diesel buildings are monitored whenever outside temperatures approach
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the point at which adverse cold weather conditions exist.
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Engineering personnel are also planning some modifications on a long term basis to install building heating and a fuel oil recirculation system to ensure that these exposed fuel oil. lines are not allowed to approach
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conditions near the point at which a gel might commence.
The short term corrective action to ensure diesel generator. operability appears adequate.
Long term corrective action by the licensee to evaluate possible modifi-cations will be reviewed by the NRC after completion of licensee engi-neering assessment of the consequences of the freezing problem.
The inspectors also noted that the FSAR section 3.8, Table 3.8-13 speci-fies a 55 degree F maximum temperature gradient across the drywell con-crete shield wall.
During the recent event it appeared that this limit may have been exceeded. The lowest temperatures noted in the' reactor building were in the 40 degree F range with one temperature _ recorded at 33 degrees F.
The temperatures in the drywell normally are at 135 de-grees F with an assumed temperature on the inside at the drywell shield wall at 115 degrees F.
This 20 degree F drop is due to the insulating effect of the FIREBAR-D material between the shield wall on the steel drywell pressure retaining liner.
These numbers result in potential
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delta T's across the drywell shield wall of as much as 75 degrees F.
The inspectors questioned the licensee about this apparent discrepancy.
Licensee engir.nering personnel stated that temperature gradients of this magnitude were not a safety concern.
The ability of the shield wall steel reinforcing material and the concrete to react to this temperature differential was not deemed to be a problem.
The inspectors noted, however,-that this design basis number in the FSAR was not accurate and apparently was not given any attention. Addition-ally, the ability of the reactor building heating system to maintain temperature was also questioned. A 10 degree F outside temperature is postulated as a low ambient temperature in the FSAR. The heating system is designed to raise this temperature 40 degrees F resulting in only 50 degrees F air being supplied to the building.
Thus, even operating at
design basis minimum temperatures results in a greater than 55 degree F temperature gradient across the shield wall.
This item should be part of the licensee engineering review of the ef-fects of cold temperatures in the reactor building and should be so documented with FSAR revisions, if required.
4.3 Reportability and Generic Applicability As of the start of this inspection on January 25, 1988, the licensee had not yet made a decision as to the reportability of the subject freezing occurrence on January 6.
The Deviation Report (DR No.88-037) Indicated that reportability in accordance with 10 CFR 50.73(a)(2)(11)(B) and (a)(2)(v) were being considered as a possible basis for the reporting
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i requirement. As of the inspection exit meeting on January 29, 1988, the licensee had not' yet determined how the subject event would be reported,.
but indicated that an LER would-be submitted in any case.
The inspector discussed with both licensing and management. personnel the basis for their technical judgment in not reporting this event in ac-cordance with 10 CFR 50.72, as well as their views on 10 CFR 50.73 ap-plicability.
It was noted the the Federal Register, dated August 29, 1983, which promulgated changes to 10 CFR 50.72 provided guidance on the
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interaction of non-safety systems-(eg: HVAC) with safety systems.
If safety functions cannot be assured because of the degradation of some interacting non-safety system, reportability is advised. The licensee indicated that they would consider such guidance in the evaluation of the subject event and for future' situations.
Additionally, the inspector discussed with engineering and management personnel their approach to cold weather problems from an analytical
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standpoint to ensure that components, systems and structures can ade-quately perform or support safet9 related functions.
The licensee's approach to the problem, which evidenced itself with freezing ~ tempera-tures in the reactor building on January 6, 1988, is still being de-veloped.
The inspector reviewed draft documents which appeared to in-
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dicate a well-directed effort which will involve engineering reviews of limiting component /systsm area temperatures, maintenance and monitoring of the areas of concern at certain predesignated low action limiting
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temperatures, and an overall proceduralized approach to the subject cold weather problems.
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Since this effort of scoping both engineering reviews and operational
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controls is ongoing and subject to licensee management review, specific NRC technical questions or unresolved items are not appropriate at this time but may be raised after review of the licensee's fully developed i
program.
NRC interest in this overall issue remains high and will be tracked not only with respect to the licensee reply to the identified i
violation, but also in regard to the discussion points which the licensee has been asked to respond to in Appendix B to the letter transmitting
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this inspection report.
Therefore, even though no new inspection item
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has been opened to track the noted licensee evaluation efforts, final resolution of this issue will involve further NRC review.
Initici evaluation of the licensee's preliminary plans appear to have adequately
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addressed the NRC concerns.
5.
Conclusions 5.1 The operators' reaction to the discovery of freezing problem of January i
6, 1988, appeared to be timely, methodical and comprehensive, given the
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options available to the operator to immediately remedy the problem.
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5.2 Two violations of regulatory requirements were identified. One involved the' existence of degraded conditions and a plant ccnfiguration within the reactor building heating system which exceeded the design bases' and which represented an unanalyzed safety question.
Contrary to federal
regulations and station procedures, no written safety evaluation had been
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performed.
The second violation represented identification of procedural inconsistencies with the as-built plant; specifically, missing tempera-
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ture indicators on the main control board.
This condition which ap-parently existed since the plant was first constructed raised questions as to the adequacy of the implementation of the station procedural review process.-
Further details on both violations are discussed in Section~4.1 of this inspection report.
5.3 The licensee has indicated that a-Licensee Event Report (LER) will be submitted to discuss the conditions surrounding-the cold weather event of January 6,1988.-
5.4 Licensee engineering and operational review efforts are in progress to scope and analyze the safety implications and impact of cold weather conditions on the plant.
Such ongoing evaluations will assess the need
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for additional short-term corrective action and any long-term design measures to ensure that safety-related components or systems are not adversely affected by cold weather conditions.
The results of such analyses, specifically as they affect individual components and/or FSAR
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design basis commitments, will be further reviewed by the NRC.
6.
Management Meeting The inspectors met with licensee representatives (denoted in Paragraph 1) at the conclusion of the inspection on January 29, 1988. The inspectors sum-marized the scope of the inspection and the inspection findings.
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