ML18139A460
| ML18139A460 | |
| Person / Time | |
|---|---|
| Site: | Surry, North Anna  |
| Issue date: | 05/28/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Ferguson J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| NUDOCS 8007210477 | |
| Download: ML18139A460 (8) | |
Text
..
J 1-,
~t>" REO<,, _
~c, e
e UNITED STATES
(~~"'
NUCLEAR REGULATORY COMMISSION REGION II 0
~
~
~...
0~
~
~
........ ~
In Reply Refer To:
>.filil§~HLl 9:3ao o-2a1 101 MARIETTA ST., N.W., SUITE 3100 ATLANTA, GEORGIA 30303 MAY 28 1980 Virginia Electric and Power Company Attn:
J. H. Ferguson Executive Vice President~Power P.O. Box 26666 Richmond, Virginia Gentlemen:
23261 The enclosed Circular No. 80-13, is forwarded to you for information.
If there are any questions related to your understanding of the suggested actions,_please contact this office.
Enclosures:
- 1.
IE Circular No. 80-13
- 2.
List of Recently Issued IE Circulars Sincerely,
~s~---
James P. O'Reilly Director
.-~-
Virginia Electric and Power Company cc w/encl:
e W.R. Cartwright, Station Manager Post Office Box 402 HU,.eral, Virginia 23117 t'
P. *G. Perry Senior Resident Engineer Post Office Box 38 Mineral, Virginia 23117 J. L. Wilson, Manager Post Office Box 315 Surry, Virginia 23883
- -j!"
e MAV 28 1980 '.
\\/
e UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 May 28, 1980 GRID STRAP DAMAGE IN WESTINGHOUSE FUEL ASSEMBLIES Description of Circumstances:
C-;
SSINS No. : 6830 Accessions No.:
7910250495 IE Circular No. 80-13 During the refueling operation at Salem Unit 1, it was noted by the licensee that some of the assemblies that were removed had suffered 'grid strap mechanical damage.
This was reported to the NRC in LER 79-44.
Subsequent to this discovery all fuel assemblies were removed from the core for examination.
The degree of the damage to.the grid straps was classified in three cate-gories: small pieces missing (15 assemblies), grid material ripped and laid over (5 assemblies), larger sections missing and fuel pins exposed (11 assemb-lies).
No damage to the fuel pins was observed.
A total of 31 assemblies suffered some grid damage.
The damage appeared to be the result of corner to corner interaction of the grid straps of diagonally adjacent fuel assemblies during the vertical loading and unloading movements.
No correlation of the damage to core location, grid strap elevation, or manufacturing and shipping batches has been identified.
The* licensee and the fuel manufacturer established the following guidelines for reloading damaged assemblies: (1) those assemblies with full width pieces missing will not be reloaded for cycle 2, (2) those assemblies with deformed edges and those with small pieces missing will be reloaded with special pro-cedures to prevent further damage.
Salem Unit 1 is fueled with 17X17 Westinghouse assemblies.
Similar grid problems have occurred at other facilities fueled w:ith 14X14 and 15X15 Westinghouse assemblies; however, fewer assemblies were damaged in those instances.
Reconnnended Actions:
All licensees using 14X14, 15X15, or 17X17 Westinghouse assemblies are advised to:
(1) Visually inspect grid straps of those fuel assemblies which are
- discharged from the core as well as those assemblies which are moved to the spent fuel pool for control rod replacement and are subsequently returned to the core.
e IE Circular No. 80-13 May 28, 1980 Page 2 of 2 (2) 1 t Review the fuel handling precautions recommended by Westinghouse at a meeting on May 25, 1979, with NRC and the licensee for Sal.em (Attachment 1).
Adopt those recommendations which are pert~~ent.
\\;:
No written response to this information regarding these NRC Regional Office.
Attachment:
Summary of Meeting Notice dated 5/30/79 Circular is required.
If you require additional matters, contact the Director of the appropriate Y
~
. I I t t
- f. I LICENSEE:
FACILITY:
SUBJECT:
f, On ~.ay 25. 1979, we met with representatives of Public Service Electric a Gas COmpany (PSE&G) and w,st1nghouse to discuss the caus,e and extent of damage observed to the Salem Unit No. 1 fuel grid ass8:11b)1es during t.,he current refueling outage for cycle 2.
A 11st of attende*es fs enclosed.
.. *~,
->~<~~.r;~ ~
. ;:*~.. ~;:- ~.:
... -:;~r~:.~*~:;:;~J~,:Jiii;Jif ~tt: *. ~:;i;~l1+
Stgn1f1cant discussions are sunmar1zed belOM. ! :
The licensee and Westinghouse pr0:v1ded a detailed d1scuss1on*0,f the*
'..,:<"-'*"~-'"~_.,,
_i./_'k_;.:... *,:_t;_.::*,:i dar..age observed to the Salem fuel grid assemblies during the cycle z*,.s,;:f".l':if':1~~i{..
refueling outage which comnenced in April 1979.
Due to the 1nd1cat1ons
. observed during the initial stages of the outage. the decision was ll'lllde to unload all fuel assemb1ies from the core.
Of the fuel assemblies (193) inspected, 28 assemblies were determined to have varying degrees j,.,:
of ear.age to on! or more of the eight grid -essembl ies per fuel assembly.~
The grid asse.":blfes provide lateral support to the fuel rods.
In no case was daaage observed to the fue1 rods themselves. The grid i$Sembly dar:~ge observed, which was generally 1ocat~d at the corners of the grid**
asse.-nblies, ~s cetegori2ed as follows:
. c,,~egorx.
1 2
3 Type of.Darr.age small pieces m1ss1ng grid ~teria1 ripped end la.id over 1erger sections missing and fuel p1ns exposed
?
No. of Grid Assemblies 15 4
{.,*
- -. -~~;
1fI.{1J:-1;,
-'~:.:\\.
, '~~:.:-i;~~}:i'tfi??i~~tft~/t.,{J;JL::~;s,::
J- ~--*
I I
~.
-w* f*' ~~f;!~(-~~~~f,t"r"'*~*~Jt~:c:;:1c~*;;;, '.'.,.,,;~r~,~~~;;;i~:~*:<:: -~ *11\\~;'.'};c'r.-)<0~1, ~~~ ~~~~~~~~~:s- 'y,:.,.. ;
!. i ~ *~~ the~ a~"W!~¥v.rassemb11es w1t11**:-'c'ii'tegories
- 1f';ancf t damage -~'tl',*~~'4:~f/r t
- l,; ;d.termined by tha licensee to be a_c_eeptable*f~ JlSe ~
will *~ reJ~ded...:,i~;r,,
'\\*
- for cycle 2; as n precautionary measure assemblies with category 3 damage
. f
- will not be relo1ded. The basts for this determination was that assemblies -
with category 1 and 2 damage can ~ used w1tho'ut any loss of function of
- ha ~~9.4I 9r~de.
~...,
~CCOfflk1fae W4~h C~~aoer~, dam*o*. howaVGP, ftO
- longer fully restrain al 1 fuel rods in the manner provided for in the design. Tha1r reuse should be based on further analysfs.
Of the data co11ected and the reload -films reviewed, no pattern ha!. been established for the observed dainag~ *. Also, it ha.s not been determined i
- whether the dulage occurred during fuel insertion for cycle 1, or during r~val or rud.justments for cycle 2. or both. It is believed that corner-to-c:oMU!r interaction may have occurred between grid assemblies of adjacent fuel as.sellbl ies especially when diagona1 fuel assemblies have '
been removed and SGIIIII! degree of lateral movement is possible. Under these conditions the grid assemblies ma.y have been aligned $UC:h that the corners interacted during vertical movement.
Of the pieces m1ssfng (about 61), 1 total area of about 25in2 ts involved.
These pieces range fran about.3in2 up to about 5.SinZ. Approximately
. 12in2 of aterfal has been recovered from-the core or the fuel assembl 1es during the unloading of the core.
In addition. the core was inspected wfth a TY camera. With regard to the potential for flow blockage from the 11fssing materi11, Westinghouse indicated that 1f a11 the peices originally missing were to be located such as to partially block the inlet nozzle area of the cne fuel assernbl. ana1yses s1m11ar to that described 1n Section 3.4 of the Salem FSAR ;ndicate that no problem would exfst. The snraller pieces still missing are expected to easily pass up through the fuel assemblies during operation and not present any problems to the control rod drive mechanisms.
The largest that any of the missing pieces could be* based on the base areas on grid assemblies, is slightly greater than 2inZ.
~est1nghouse has recor.:nende~ additicnal fuel assembly handling precautions to minimize the potential for corner-to-corner interaction between grid assemblies. Included among these recomnendations ar~, 1) a revised loading sequence wh1eh would load fue1 assemb11es "from the sides of the corp toward the center, 2) a slight offset in position as corner fuel assemblies are lowered into the core until they are about 10" above the base plata and then making a lateral adjustment into final position, 3} the conditionally accepted asse!!l~lies in categories 1 and 2 would be loaded in a special sequence to m1n1m1.ze relative motion with adjacent assemblies.. 4) those assembli~s in category 2 would be loaded against the core baffle. ~her~ possible and 5) revised load ce11 limits 0t1 the mani-pulator crane in an attempt ::o more easil,Y. detect increased loads during fuel handling.
~
,,1 --'J...
- '**-:')
- ~ -..,. '-* ~~*
~,,,,... *
- d::,::.'~e;:.~::Jtr~:;~; :::~:~::1~::~::~;:~;'.::;~~~.::"",
... -,~~.:
,_:;~~-~1[.;~.:~ t~ have ~r-,J *~ ~~er facilities. AJlthough these other -Q_Ceu_rr.ences..,**/-., _,.,:_,
- "<f'.!'.:-=,,*:* d1cf not involve as many fuel assemblies as in this Salem sftuat1on,
.. similar damage has been observed to 14x14, 15.xlS and 17x17 fuel assemblies.*
In some instances the fuel was removed. and in others. the fuel was re-
,,. *~-loaded with no known adverse effects.
Wfth regard to the Sal* Unit 1 refueling analysis. the licensee indicated**
pre11minar11y, that the core parameters are expected to be essentially
. unchanged due to the revised core loading that will result.
'.\\>-"i;.*:; J;
~ -*.
~. -
'*;*-*=
,l
,-: The licensee agrreed to address the potential effects that the unaccounted
. for pieces of grtd *terial might have on the core thenna.1 hydraulic analysis and on control rod operation. This infcnnation will be included prior to restart of Salea l in a supplement to the licensee*s reload application for cycle 2.
Enclosure:
- -.:* ' *tii_::\\(/; *** '..-* *_:
List of Attendees cc: w/enclosure See next page j:'
-~f#!/9&--
Gary G. Zech, Project Manager Operat 1 ng Reactors Branch #1 Division of Operating Reactors
... ' *:-'.;<;fa-"~.
.*.-:-f****.**
IE Circular No. 80-13 May 28, 1980 e
RECENTLY ISSUED IE CIRCULARS Circular Ne*
80-13 80-12 80-11 80-10 80-09 80-08 80-07 80-06 80-05 80-04 80-03 80-02
~
Subject Grid Strap Damage in Westinghouse Fuel Assemblies Valve-Shaft-To-Actuator Key May Fall Out of Place When Mounted Below Horizontal Axis Emergency Diesel Generator Lube Oil Cooler Failures Failure to Maintain Environmental Qualification of Equipment Problems With Plant Internal Communications Systems BWR Technical Specification Inconsistency - RPS Response Time Problems with HPCI Turbine Oil System Control and Accountability Systems for Implant Therapy Sources Emergency Diesel-Generator Lubricating Oil Addition and Onsite Supply Securing of Threaded Locking Devices on Safety-Related Equipment Protection from Toxic Gas Hazards Nucl*ear Power Plant Staff Work Hours Date of Issue 5/28/80 5/14/80 5/13/80 4/29/80 4/28/80 4/18/80 4/3/80 4/14/80 4/1/80 3/14/80 3/6/80 2/1/80 e*
Enclosure Issued 1to t",j
~~:.
All holders of Reactor OL and Construction Permits for PWRs All holders of Re.actor OLs and CPs All holders of a power reactor OL or CP All holders of Reactor OLs and CPs All holders of a power reactor OL or CP All General Electric BWR's holding a power reactor OL All holders of a power reactor OL or CP Medical licensees in Categories G and Gl All holders of a power reactor OL or CP All holders of a power reactor OL or CP All holders of a power reactor OL All holders of Reactor OLs, including research and test reactors, and CPs