ML20154D854
| ML20154D854 | |
| Person / Time | |
|---|---|
| Site: | Mcguire, Catawba, Harris, Farley, McGuire, 05000000 |
| Issue date: | 12/30/1987 |
| From: | Ernst M NRC |
| To: | Ross D NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| Shared Package | |
| ML20154D839 | List: |
| References | |
| IEB-85-001, IEB-85-1, NUDOCS 8809160154 | |
| Download: ML20154D854 (3) | |
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.w yf UNITED STATES g W r.
g NUCLEAR REGUi.ATORY COMMISSIC'N 7
l W ASM NG T O N, D. C. 20555 S
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Decerrber 30, 1987 VEMORANDdM FOR: Denwood F. Ross, Deputy Director for Research Office of Nuclear Regulatory Pesearch FROM:
Malcolm L. Ernst. Deputy Regional Administrator
SUBJECT:
CRGR MEETING ISSUE Enclosed, per your request of December 29, is inferration on AFW check valves for Farley, McGuire, i.nr.' Catawba. Also, information on Harris is provided. Please advise, if you need more.
w.
(Signed by M. L. Ernst)
Malcolm L. Ernst
Enclosure:
Info on AFW Check Valves for Farley, McGuire, Catawba and Harris 9}'809160154 900111 DR REVCP N#GCMGR MEETINQ127 PNV
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i EhCLOSUoE Ct'AWBA UNITS
!EB 85 Steam Binding of Auxilia., reedwater Pumps (Units 1 and 2) (92703)
The licensee responded to this bulletin by correspondero dated February 25, 1986.
Procedures were developed to monitor fluid conditions in the auxiliary feedwater piping once per day using a hand held pyrometer.
This procedure (OP/1(2)/A/6250/02) also included information to recognize steam binding and to I
restore the system to operable status.
Hardware modifications have been made j
to the suxiliary feedwater system to install therinocouples that provide tes-perature instrumentation with alarm capability to identify leakage past the check valves. The procedures are developed and approved in accordance with tha licensee's coarnitments and requirements.
Personnel have been trained in the use of these procedures and how steam binding is precluded.
6a:ed on this review, ti,is item is closed in Ranort 87-05, The discharge check valves on the steam turbine auxiliary feedwater (AFW) pumps i
have not experienced s1% ificant leakage.
The discharge check valves on the motor driven AFW pumps have experienced significant leakage M1ch was attri-buted to the disc being hinged from the bonnat and thus bei.1g a maintenance assembly problem.
These four valves per unit Fave beer; rr,placed with valves that have the disc internally hinged and no significant 1eakage has been noted.
The valves were char.ged on Unit 1 this last outage, he the piant is still in startup and has had only a short period of optratN1 to judg7 the fix. Unit 2 changed the valves during a mini-outage this fa1*, and the valves have operated el!.
i MCGUIRE 1 AND 2 i
The discharge check valvss cn the auxiliary feedwater (AFW) pumps at McGuire L
have experienced signifft. ant leakage (as rentioned fn IEB 85 D G, Fuch of the leakage c:.' be attributid to improper installation cf the diMarge check valves.
Joce of tne chtck valves were installed in herfrontal runs of pipe preventing proper clossre of the valves which were desyred to be aided by gravity in vertical pipe.
As an inti rim fix, th$ licemee installed resistance temperature detectors (RTO) in the discharr * *pt./, of each auxiliary feedwater pump.
The RTD trdication is a comput e-
- on the operator aids computer.
During refueling cutages 987, all the anack valves on the discharge side of r
the AfW pumps were replac (Walworth to Anchor / Darling).
Tne valves have operated well.
SHEAR 0h WARRIS l
in Jaruary 1987. Regicn !! inspectors reviewed the licenseeN Niponse osted April 29, 1986, to IE Bulletin 8bO2, Steam Binding of Auxiliar/ Feedwater
- Pumps, he ir.fpketors reviewed the following items discussed in the re tpense, r
a.wan s..
Mcnitoring of fluid cenditions w shin the auxiliary feedwat'r (AFW) system is performed through the use of s rap-on thermoccuples which are installed on the AFP system discharge lines to monitor system temperature.
Should tte AFW dischcrge line temperature exceed the established set point, the condition will be alarmed in the main control room.
Abnormal Operating Procedure (AOP) 010. Feedwater Malfunctions, which addresses symptoms of AFW system steam binding and corrective actions to restore the affected components to operational status.
A0P-010 has been approved for use by the licensee.
Training received by operations personnel on recognition and recovery actions for AFW system steam binding was also reviewed. These items were I
addressed in a lesson plan which covered AFW pump steam binding and A0P-010. The lesson plan was completd September 30, 1986.
Independent of the above effort, NRC personnel also inspected the AFW systein and performed a walk through of A0P-010 with licensee operations per:onnel.
Based on the above inspection efforts, the inspectors determined th.t the licensee's response of April 29, 1986, to IE Bulletin 85-01 adequately addressed the requirements of the bulletin.
Measures established to monitor AFF system temperatures, procedures which address recognizing and recoverirg from steam binding should it occur, and material provided for operator training i
dlI appear to be adequate.
I In early 1987, the plant began to experience back leakage through the AFW l
downstream check valves to the extent that an AFW pump was required to be ruit j
every eight hours to maintain temperature control.
In May and June 1987, a e
mcdification of the AFW piping was made to fix the problem.
The modification required that an additional heavier check valve be installed in each of the three AFW lines between the two mctor driven pumps and the original check i
valves and also in the one line from the steam driven pump. Back leakage has j
been since this mcdification and the back leakage redeced to the point where an
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AFK purp is operated every several weeks.
At present, the licensee plans no additieral AFL modifications with respect to this prcblem, t
a FARLEY i
- i IEB 85-01 was not addressed to Farley since th(y were part of event described.
Farley responded in a letter dated April 30, 1984, based en an AE00 report cf l
this subject.
Equipment changes included added counterweights and replacing hinge pins and bushings of AFW check valves.
Therwocouplet installed on AFW pipes are monitored and infrequent operation of AFW pumps is utilized te reintain AFV temperatures within administrative limits.
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