ML20214G210
| ML20214G210 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 11/12/1986 |
| From: | Bernhard R, Jape F, Matt Thomas NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20214G203 | List: |
| References | |
| 50-416-86-36, NUDOCS 8611260016 | |
| Download: ML20214G210 (8) | |
See also: IR 05000416/1986036
Text
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UfAITED STATES
NUCLEAR REGULATORY COMMISSION
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101 MARIETT A STREET, N.W.
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' Report No.:
50-416/86-36
Licensee: Mississippi Power and Light Company
Jackson, MS 39205
Docket No.:
50-416
License No.: NPF-29
Facility Name: Grand Gulf
Inspection Conducted: October 14-17,~1986
Inspectors:
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M. ~homas 0
/Date/ Signed
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R. H. Be'rnhard
Date Signed
Approved by:
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F. Jape, Chief, Test Programs Settiod
Date Signed
Engineering Branch
Division of Reactor Safety
SULMARY
Scope:
This routine, unannounced inspection was conducted in the areas of
service water system problems, review of previous enforcement items and review of
previously identified inspector followup items (IFIs).
Results:
No violations or deviations were identified.
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8611260016 861113"
ADOCK 05000416
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REPORT DETAILS
1.
Persons Contacted
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Licensee Employees
- J.
E.-Cross, Site Director
- C. R. Hutchinson, General Manager, Grand Gulf Nuclear Station
- J. W. Yelverton, Operations Tec5nical Assistant
- R. V. Moomaw, Maintenance Manager
- L. F. Daughtery, Compliance Superintendent
- J. V. Parrish, Chemistry / Radiation Control Superintendent
- J. D. Bailey, Compliance Coordinator
J. Lasseter, Acting Plant Chemist
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Other licensee employees contacted included engineers, technicians,
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operators, mechanics, security office members, and office personnel.
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NRC Resident Inspectors
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- R. C. Butcher, Senior Resident Inspector
- W. F. Smith, Resident Inspector
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- Attended exit interview
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2.
Exit Interview
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The inspection scope and findings were summarized on October 17, 1986, with
those persons indicated in paragraph 1 above.
The inspector described' the
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areas inspected and discussed in detail the inspection findings.
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inspector informed the licensee that unresolved item 416/86-01-02, which was
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closed in NRC report 416/86-06, was incorrectly listed in that repor.t as
item 416/86-01-01.
Item 416/86-01-01 was a violation.
The violation is
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still open.
No dissenting comments were received from the licensee.
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following new items were identified during this inspection.
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IFI 416/86-36-01, Establish Criteria for Determining When to Clean ESF
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Electrical Switchgear Room Coolers Piping.- paragraph 5.b.(1)
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IFI 416/86-36-02, Adequacy of Plant Service Water Flow to Containment -
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Penetrations - paragraph 5.b.(1)
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3.
Licensee Action on Previous Enforcement Matters
This subject was not addressed in the inspection.
4.
Unresolved Items
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Unresolved items were.not identified during the inspection.
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Service Water System
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Inspection of the service water system involved reviews of systems design
requirements, service water system problems which have been identified by
the licensee, Technical Specification (TS) requirements, preventive
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maintenance program, and chemistry control.- The reviews in ea:h of these
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areas are discussed below along with determinations made by the inspectors.
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a.
Review of System Design
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The inspectors reviewed the service water system design for the standby
service water (SSW) and plant service water (PSW) systems. The systems
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are described in subsections 9.2.1 and 9.2.8 of the Grand Gulf Final
Safety Analysis Report (FSAR), Mississippi' Power and Light (MP&L)
system descriptions, and applicable drawings (M-1061A,1061B,1061C,
10610, 1072A, 1072B, 1072C, 1072D).
The intent was to identify the
safety-related components cooled by service water and subsequently
determ ne w eh ther MP&L's plans and procedures for detecting and
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controlling fouling addressed all of these components.
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The SSW system, containing the plant ultimate heat sink, is designed to
remove heat from plant auxiliaries that are required for a safe reactor
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shutdown following a design basis loss-of-coolant-accident (LOCA).
The PSW system has no safety design function. The PSW system provides
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makeup to the SSW system cooling tower basins, but this makeup
capability is not required to safely shut down the reactor following a
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LOCA.
The PSW system also provides cooling water to the control room
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air conditioning unit and the engineered safety features (ESF)
electrical switchgear room coolers (both of which have safety functions
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during a LOCA) during normal plant operations because the SSW system
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operates only during reactor shutdown, reactor isolation, and post
LOCA.
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b.
Service Water System Problems
The licensee has identified three problems associated with the SSW
system.
These problems are low flow to essential components couled by
SSW, piping corrosion, and seismic qualification of ESF electrical
switchgear room cooler nozzles.
Each of the problems are discussed
below.
(1)
Inadequate Flow to Essential Equipnent
The licensee has reported that during flow testing with the SSW
system aligned in the post LOCA configuration, they were unable to
obtain design-flows to loop A control room air conditioning unit,
ESF electrical switchgear room coolers, reactor core isolation
cooling (RCIC) room cooler, residual heat removal (RHR) pump seal
cooler A, and loop B ESF electrical switchgear room coolers. The
low flow problem is discussed'in licansee event report (LER)
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86-029-00 dated September 25, 1986, and licensee letters
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AECM-86/0283, 0309, and 0319, dated September 10, October 3, and
October 8,-1986, respectively.
This problem is also discussed in
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NRC. inspection reports 416/86-32 and 416/86-34.
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The licensee stated that the low flows were due in part to partial
blockage of the small diamete" piping supplying these components.
- The blockage was determined to be iron reducing bacteria and
chemical deposits from the PSW (which supplies the components
during normal operation) combined -with low flow through the
coolers.
In order to reduce future blockage, licensee plans
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include maximizing SSW flow through'the room coolers to obtain the
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highest velocities possible. . In addition, the small diameter
piping is being modified to allow periodic flushing and hydro-
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lazing.
Monthly flow measurements of the ESF electrical
switchgear room coolers will be performed to detect signs of flow
blockage.
Based on the results of the trended data, flushing or
hydrolazing will be performed to :naintain system design flow rate.
The licensee has issued procedures to perform the flow tests. The
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inspector reviewed procedure 04-1-03-T46-1, 'A" ESF Switchgear
Room Coolers Flow Test, Revision 0, ~ dated September 19, 1986.
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During review of the procedure and discussions with -cognizant
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licensee personnel, the inspector raised the question concerning
whether a flow criteria had been established.for personnel to use
in determining when the piping needed cleaning.
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personnel stated that no criteria had been developed yet. Nuclear
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Plant Engineering (NPE) will develop the criteria to be used based
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on data obtained during monitoring of flow to the ESF switchgear
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coolers during this outage.
The inspectors informed the licensee
that the question will be tracked as IFI 416/86-36-01, Establish
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Criteria for Determining when to Clean ESF Switchgear Room Coolers
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Piping.
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While reviewing PSW system drawings, the inspectors noted that
several containment penetration cooling water jackets receive PSW
which is supplied through small diameter piping. The penetrations
are high energy line penetrations.
Given the fouling problems
attributed to the PSW supplied portions of the SSW system with
small diameter piping, the inspectors raised the question
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concerning whether the PSW lines supplying the penetrations had
been inspected to determine if there was any blockage due to
fouling.
If the penetrations do not receive adequate cooling, the
concrete temperatures in the vicinity of the penetrations could
possibly exceed design values.
Licensee personnel stated that
most of the high energy line containment penetrations are not
cooled by PSW.
Applicable drawings will be reviewed to identify
the containment penetrations which are still supplied by PSW. The
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PSW piping will be inspected for fouling.
If fouling is found to
be - a problem, an evaluation will be performed to determine
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appropriate corrective actions.
The inspector informed the.
licensee.that this question will be tracked as IFI 416/86-32-02,
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Adequacy.of Plant Service Water Flow to Containment Penetrations.
(2) Stand ~by Service Water System Piping Corrosion
Report Number 50-416/06-34 discussed microbiological 1y induced
corrosion -(MIC) problems discovered in the "A" standby service
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water basin.
Inspection 86-36 coincided with the initial draining
of the "B" service water basin. The inspectors examined piping in
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the upper portions of the B standby service water basin. Evidence
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of MIC damage was present. The licensee was removing the external
tubercles by mechanical means - with sanders and chippers,
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inspecting the pipe to verify minimum wall thickness, applying a
weld overlay or replacing the sections.of pipe as required, and
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painting the pipe with a protective coating. The "A" loop service
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water basin had been returned to service prior to taking "B".out
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of service. A molybdate cerrosion inhibitor had been added to the
"A" loop standby service water basin as a preventative measure.
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Upcn completion of "B" basin cleaning and inspection, the same
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chemical treatment is planned.
The licensee anticipates the
molybdates will be distributed through the associated loops'
piping as the periodic equipment surveillances are performed. The
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chemical distributors furnishing the inhibitor have indicated to
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the licensee that molybdate in the system could also restrict
growth of the sulfur reducing bacteria responsible for.the MIC.
Inspections performed by the licensee on the loads served by the
"A" Standby service water loop showed evidence of MIC in the -
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Division 1 Diesel generator and RHR heat exchangers.
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Division 3 Emergency Diesel Generator, which is served by loop "C"
SSW also showed evidence of MIC. The inspectors examined pictures
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of the heat exchangers prior to and after cleaning. The corrosion
appeared to be superficial.
Tne licensee indicated the heat
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exchangers would be inspected in the future to monitor for
additional MIC.
The "B" loop load, will be inspected while loop
"B" is out of service.
Administrative Procedure 01-S-08-16, Revision
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" Chemical
Treatment Program", Chemistry Procedure 08-S-03-10, Revision 6,
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" Chemistry Sampling Program", and Chemistry Procedure 08-S-03-14
Revision
5, " Chemical additions to Plant Systems" were reviewed.
The molybdate additions are not specifically addressed in the
procedures reviewed. The licensee indicated the procedure will be
revised to incorporate the necessary changes to allow monitoring
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and addition of molybdate to maintain proper concentration.
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Current chemical additions were made per 08-S-03-14 which allows
the Plant Chemist to make additions not specifically addressed by
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the procedures.
Current sampling is performed under 08-S-03-10,
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which allows sampling not specifically addressed in the procedures
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to be performed if directed by the plant chemist.
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The licensee indicated moritoring of other closed loop systems
with conditions that might allow MIC would be performed as
conditions permit, possibly during planned outages. The licensee
indicated no specific program for chemical addition to the Fire
Protection System exists.
(3) Seismic Qualification of ESF Electrical Switchgear Room Cooler
Nozzles
Although not related to potential fouling problems within the SSW
system, the licensee nctified the NRC on October 17, 1986, that
the nozzle loads for several ESF electrical switchgear room
coolers appeared to be in excess of that specified by the vendor.
The licensee was still evaluating this problem at the conclusion
of this inspection.
It was stated that corrective actions will be
completed during the current refueling outage.
c.
Review of Technical Specification
The inspectors reviewed Grand Gulf Technical Specification (TS)
requirements to determine the extent to which related surveillance
testing was being used to detect system or component fouling.
Specifications 4.7.1.1.a and 4.7.1.2.a of TS require verification at
least once per 31 days, that each SSW system subsystem and high
pressure core spray (HPCS) service water system valve in the flow path
that is not locked, sealed, or otherwise secured in position, is in its
correct position.
Specifications 4.7.1.lb and 4.7.1.2b require
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verification, at least once per 18 months during shutdown that each
automatic val */e servicing safety-related equipment actuates to its
correct positicn on an actuation test signal. The inspectors reviewed
the following procedures that are to be used to satisfy these
surveillance recuirements:
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06-0P-1P41-M-0001, High Pressure Core Spray Service Water and Standby
Service Water Loops A and B Operability Check
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06-0P-1P41-Q-0004, Standby Service Water Loop A Vt.lve and Pump
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Operability Test
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06-OP-1P41-Q-0005, Standby Service Water Loop B Valve and Pump
Operability Test
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06-0P-1P41-Q-0006, High Pressure Core Spray Service Water System Valve
and Pump Operability Test
06-0P-1P75-R-0003, Standby Diesel Generator 11 (SDG) 18 Month
Functional Test
06-0P-1P75-R-0004, Standby Diesel Generator 12 (SDG) 18 Month
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Functional Test
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The inspectors concluded that of the surveillance requirements related
- to SSW operability, none are useful for detecting fouling in small
diameter. lines supplying the various coolers.
The surveillance
requirements related to the above TS can be satisfied.
d.
Review of Preventive Maintenance Program
' The inspectors reviewed MP&L's preventive maintenance program for the
SSW system to identify provisions for detecting and controlling
fouling.
This review revealed that, prior to the recent fouling
problems which resulted in lower than SSW system design flows to
various components, the control room air conditioning unit was the.only
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component supplied by SSW through small diameter piping which was
covered by the preventive maintenance program. The inspectors reviewed
related procedure 07-S-24-Z51-B002-1, Control P,oom Air Conditioning
Unit Inspection and Maintenance.
As a result of the ' fouling problems, the licensee is developing a
preventive maintenance program.
Portions of the plan were included in
the corrective actions discussed in the MP&L letters referenced above,
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Review of Chemistry Control Program
The inspectors reviewed MP&L's chemistry control program for the SSW
system.
A molybdate corrosion inhibitor was added to the "A" loop SSW
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basin and is 7.lso scheduled to be added to the "B" loop SSW basin. The
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effects of the molybdate on microorganisms in the SSW system are
discussed above.
Cognizant licensee personnel stated that the
chemistry procedures referenced above will be revised to include the
molybdate as one of the chemicals being added to the SSW basins. The
SSW system will be sampled on a regular basis to ensure that the
molybdate concentration is being maintained within specified limits.
Licensee -personnel also indicated that selected components will be
inspected during the next refueling outage to determine the effective-
ness of tha chemical treatment in reducing the corrosion rate.
f.
Conclusions of Service Water System Review
Based on the existing fouling problems, the inspectors concluded that
MP&L's plans and procedures for detecting and controlling SSW fouling
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appear to be adequate.
The most likely fouling agents are fron
reducing bacteria combined with chemical deposits from the PSW system
and MIC. The ongoing chemistry control program, the planned preventive
maintenance and flow monitoring programs, and the system modifications
to allow periodic flushing and hydrolazing, appear to be adequate for
detecting and controlling these agents.
No violations or deviations were identified.
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6.
Followup on Previously Identified Items (92701)
a.
(0 pen) IFI 416/85-29-02, concerning licensee commitment to include a
revised thermal power versus core flow curve (graphical partion of FSAR
Figure 14.2-4) in the Startup Report.
It was stated that MP&L and the
NSSS vendor (General Electric) are reviewing this item to assess
whether there is a need to revise the curve.
b.
(0 pen) IFI 416/85-29-03, which is related to the above it.em, concerns a
licensee commitment to submit the corresponding change to the FSAR and
Bases of the Technical Specification for NRC/NRR review concurrently
with the Startup Report.
This item is also being reviewed by MP&L and
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