L-96-107, Forwards Response to NRC Bulletin 96-001, Control Rod Insertion Problems
| ML17353A669 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 05/01/1996 |
| From: | Hovey R FLORIDA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-96-001, IEB-96-1, L-96-107, NUDOCS 9605070247 | |
| Download: ML17353A669 (16) | |
Text
CATEGORY 1 4
REGULA Y 'INFORMATION DISTRIBUTIO
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ACCESSION NBR:9605070247 DOC.DATE: 96/05/01 NOTARIZED: YES DOCKET FACIL:.50'-251 Turkey Point Plant, Unit 4, Florida Power and Light C 05000251 AUTH.NAHg..
AUTHOR AFFILIATION HOVEY,R.J.
Flori'da Power
& Light Co.
RECIP.NAME RECIPIENT AFFILIATION
.Document Control Branch (Document Control Desk)
SUBJECT:
Forwards response to NRC Bulletin 96-001, "Control Rod Insertion Problems. "
DISTRIBUTION CODE:
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TITLE: NRC Bulletin 96-01 Control Rod Insertion Problems NOTES:
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- PK?L MAYO1 tggg L-96-107 10 CFR 550.54(f)
U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C.
20555 Gentlemen:
Re:
Turkey Point Unit 4 Docket No. 50-251 NRC Bulletin 96-01 NRC Bulletin 96-01, "CONTROL ROD INSERTION PROBLEMS", issued March 8,
- 1996, requested licensees take specific actions and provide information to the NRC.
In accordance with the bulletin, Florida Power and Light Company provides the attached response relative to the Turkey Point Plant Unit 4 Cycle 16 Refueling Outage.
Should there be any questions, please contact us.
Very truly yours, R. J.
Hovey Vice President Turkey Point Plant Attachment cc:
S.
D. Ebneter, Regional Administrator, Region II, USNRC T..
P. Johnson, Senior Resident Inspector,
- USNRC, Turkey Point Plant OOOO".~
9605070247 960501 PDR ADQCK 05000251 8
PDR an FPL Group company 5n-ga t
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STATE OF FLORIDA COUNTY OF DADE
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being first duly sworn, deposes and says:
That he is
- Company, the Licensee herein; of Florida Power and Light That he has executed the foregoing document; that the statements made in this document are true and correct to the best of his knowledge, information and belief, and that he is authorized to execute the document on behalf of said Licensee.
R. J..Hove Subscribed and sworn to before me this S~
day of 1996.
Cr~YP arne of Notary Public (Type or Print)
NOTARY PUBLIC, in and for the County of
- Dade, State of Florida My Commission expires Commission No.
9+o
""""rp'".
~AMES E KNORR vj.:<j EXPIRES: JSNcfjl 22> ~~
.;:" aeeaaruuoeuy Pic ~
R. J.
Hovey is personally known to me.
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Attachment Page'1of5" L-96-107 On March 8, 1996, the NRC issued Bulletin 96-01, CONTROL ROD INSERTION PROBLEMS. This bulletin was intended to alert licensees to problems encountered at South Texas and WolfCrcck during winch control rods failed to completely insert upon a scram signal. In addition, thc bulletin requires licensees to assess the operability ofcontxol rods, particularly in high burnup assemblies.
The bulletin requested licensees to perform four actions to ensure that the rcquircd shutdown margin is maintained during a reactor trip. Action (3) ofBulletin 96-01 requested licensees to measure and cvaluatc at each outage ofsufficient duration during calendar year 1996 (end ofcycle, maintenance, etc.), the control rod drop times and rod recoil data for all control rods. Ifappropriate plant conditions exist where the vessel head is removed, measure and evaluate drag forces for all rodded fuel assemblies.
The bulletin also states that:
Rods failing to meet the rod drop time in Technical Specifications shall bc deemed inoperable.
Rods failing to bottom or exhibiting high drag forces shall require prompt corrective action in accordance withAppendix B to Part 50 ofTitle 10 ofthe Ce~lz Q
)
The bulletin requires that within30 days after completing Requcstcd Action (3) foreach outage, a report that summarizes the data and that documents the results obtained be submitted to.the NRC. In response to this commitment, the enclosed information is provided.
This report w'illhighlight the followingevolutions:
Unit4 End-of-Cycle (EOC) -15 Manual Reactor Trip, Unit4 EOC-15 Rod Control Cluster Assembly (RCCA) Drag Test, and Unit4 Beginning-of-Cycle (BOC) -16 Hot Rod Drop Tests.
Each evolution willbe discussed in a separate section.
On March 4, 1996, Turkey Point Unit4 commenced a refueling outage. Prior to thc issuance ofNRC Bulletin 96-01, an EOC-15 manual reactor trip was performed in accordance withWestinghouse Owners Group recommendations to assist in the root cause investigation. This.trip was performed during the unit down-power prior to entering the Cycle 16 refueling outage. Atthe time the control rods were manually tripped, reactor power was at approximately 2%, control bank D rods were at 74 steps and control bank C rods were at 202 steps withdrawn. AllRod Bottom Lights energized, confirming that all RCCAs had reached the 20 step withdrawn position. AllRPI's indicated 0 steps.
Table 1 summarizes the core configuration and burnup history for the EOC-15 Manual Reactor Trip Test.
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Attachment Page2bf5 L-96-107 During the Unit4 Cycle 15 refueling outage, FPL performed an RCCA Drag Test using the Control Rod Drive Mechanism (CRDM) latch and unlatch tool inside containment.
Operating procedure OP-16900.1, Uncoupling Full Length Control Rods, was revised to include procedural steps to raise the combined weight (RCCA, drive shaft and latching tool) approximately 10 feet and monitor the load indicator to confirm there were no abrupt changes in the indicated weight. FPL drag tested all 45 RCCAs in Turkey. Point Unit4.
Table 1 of.this attachment provides the EOC burnups which range Rom 26,000 - 50,800 MWD/MTU. FPL Letter L-96-082, the initialresponse to NRCB 96-01, also transmitted the End-of-Cycle burnups for the 45 fuel assemblies tested during the RCCA Drag Test.
The methods ofthe test were independently verified by Westinghouse (nuclear fuel supplier) and vcrificd to be consistent with similar methods used to collect data at WolfCreek.
Asummary ofthe testing results are as follows:
The data showed that all fuel assemblies met the dashpot criteria as specified in Westinghouse's Inspection Specification.
There were a total ofnine fuel assemblies that did not meet the criteria specified in Westinghouse's Inspection Specification for the upper guide thimbles.
Ofthese nine assemblies, only five fuel assemblies clearly exceeded the 40 pound guideline, while the remaining four assemblies were classified as "marginal",. Both FPL'nd Westinghouse confirmed the fact that in the "marginal" range, itis difficultto classify fuel assemblics in this range ofdrag because ofthe accuracy ofthe traces and measurement technique.
Westinghouse indicated that 15x15 fuel assemblies normally indicate a higher drag than 17x17, fuel assemblies.
The type of"marginal" drag load measured has been experienced at other 15x15 plants withno insertion anomalies observed.
The five fuel assemblies that exceeded the upper guide thimble inspection criteria werc discharged at the End-of-Cycle 15. Allofthe RCCAs in these fuel assemblies fullyinserted followingthe EOC-15 manual reactor trip. Based upon Westinghouse's review ofthe RCCA Drag Test data, Westinghouse concluded that the behavior ofthe assemblies at Turkey Point is not similar to that ofthe anomalous assemblies at WolfCreek. Therefore, all the RCCAs continue to be operable and no corrective action is required.
The test data does not clearly indicate an increase'in'drag force with burnup.
Based on the test results, both Westinghouse and FPL concluded that there is no concern for RCCA insertion anomalies at Turkey Point.
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Attachment Page 3 @f5 '.
L-96-107 The bulletin requests that licensees measure and evaluate the control rod drop times and recoil data for all control rods, at each outage ofsufficient duration during calendar year 1996. For Turkey Point, the Unit4 Cycle 16 refueling outage represents the only scheduled refueling outage for 1996. On April4 and 5, 1996, FPL performed Hot Rod Drop Tests. The results ofthe Rod Drop Tests are provided in the attached Figure 1 forTurkey Point Unit4 Cycle 16. Turkey Point Units 3 and 4 Technical Specification 3.1.3.4 requires that the individual full-length (shutdown and control) rod drop time from the fullywithdrawn position shall be less than or equal to 2.4 seconds from beginning ofdecay ofstationary gripper coil voltage to dashpot entry.
AllRCCAs met the Technical Specification requirements.
In addition to the rod drop times, FPL reviewed the rod recoil data for all control rods. Ofthe 45 RCCAs tested, 43 RCCAs indicated some rod recoil. RCCA R59 located in core location'M-6 and RCCA R77 located in core location N-9 did not indicate rod recoil, however these RCCA's did'insert within the Tcchnical Specification rod drop time limit.
FPL also reviewed the rod recoil data from the Unit4 BOC-15 Hot Rod Drop Test and confirmed that all but one RCCA indicated rod recoil. RCCA R77 located in core location M-6 did not indicate rod recoil, however this RCCA did not experience any problems during the operating cycles or during either the Cycle 15 or Cycle 16 Hot Rod Drop Tests.
Based on the above information, Turkey Point has not observed any indication of a control rod insertion problem related to the anomalies observed at either WolfCreek or South Texas.
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Attachment Page4of5
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Turkey Point Unit 4 Cycle 15 Core Location Rod Boner Current Burnup Approximate EOC Typo of (ae af 3/10/96)
Burnup Fuel MWD MWD Bumup at Trlp Teat (3/4/96)
MWD
&)5 L45 L-11 E-11 F48 H4B K48 H-10 C47 G43 AQ M<7 M%9 J-13 G-13 C49 E47 GA5 J%5 L47 L49 J-11 G-11 E49 B46 F42 K42 P46 P-10 K-14 F-14 8-10 D~
F44 K44 M46 M-10 K-12 F-12 D-IO 048 H44 M48 H-12 H4B SBB SBB SBB SBB SBB SBB SBB SBB SBA SBA SBA SBA SBA SBA SBA SBA CBA CBA CBA
- CBA, CBA CBA CBA CBA CBB CBB CBB CBB CBB CBB CBB-CBB CBG CBC CBC CBG
.CBC CBG CBG
'CBG CBO CBO CBO CBO CBO QFA/DRFA QFA/DRFA QFA/DRFA OFA/DRFA OFA/DRFA QFA/DRFA OFA/DRFA OFA/DRFA OFA/DRFA OFA/DRFA QFA/DRFA QFA/DRFA OFA/DRFA OFA/DRFA OFA/DRFA OFA/DRFA OFA/DRFA OFA/DRFA OFA/DRFA OFA/DRFA OFA/0RFA OFA/DRFA OFNDRFA OFA/DRFA OFA/DRFA OFA/DRFA
,OFA/DRFA OFA/DRFA OFA/DRFA OFA/DRFA OFA/DRFA OFNDRFA OFA/DRFA OFA/DRFA OFA/DRFA OFA/DRFA QFA/DRFA OFA/DRFA OFA/DRFA OFA/DRFA QFA/DRFA QFA/DRFA OFNDRFA OFNDRFA OFA In Retuoling ln Retueling In Reheling In Refueling In Reheling In Roheling In RofueNng In RohoNng In ReheHng In Retueling In Retueling ln Retueling In Retueling In Reheling In Refueling In Retueling ln RetuoHng In RetuoHng In Retueling In Refueling In RotuoHng In Retuobng In RotuoNng In Retueling In RehoHng ln ReheHng ln RotueHng In Retuoling In ReheHng In Refueling In Reholing In Refueling ln ReheHng ln RetueHng ln Refueling In Retuoling In ReheHng In Retuoling In Refueling In RehoHng In Rotuoling In Rotuoling In RetueNng In ReheNng In ReheHng 43.800 43,800 43,800 43.800 34,300 34,300 34,300 34~
31,600 31,600 31,600 31,600 31,600 31,600 31.600 31,600 42.000 42.000 42,000 42,000 42,000 42,000 42,000 42,000 26.000 26,000
'26,000 26,000 26.000 26,000 26,000 26,000 47,900 47,900 47,900 47.900 47,900 47.900 47.900 47,900 34,000 34,000 34,000 34,000 50,800 43.800 43,800 43,800 43,800 34,300 34,300 34,300 34,300 31,600 31,600, 31,600 31.600'1,600'1.600 31,600 31,600 42,000 42,000 42,000 42,000 42,000 42,000 42,000 42,000 26,000 26,000 26,000 26,000 26,000 26.000 26,000 26,000 47,900 47,900 47,900 47,900 47,900 47,900 47,900 47,900 34,000 34,000 34,000 34,000 50,800 FWI Insenhn Full Insonhn Full Insonhn FuN Insorthn FuN Insorthn Full Insonhn FuN Insorthn FuN InsorNon FuN InsorNon
'FuN Inserthn Full Insonhn Full Insenhn Full Insorlhn FuH Insonhn Full Insonhn FuN Insorthn Full Insonhn Full Inserthn FuN Insorlhn FuN inserthn FuN Insonhn FuN Insorthn Full Insorthn FuN InsorNon FuN Insorthn FuN Insonhn FuH Insonhn FuN Insorlhn FuN Inserlhn Full Insonhn Full Insorlhn Full Insenhn Full Insorlhn Full Insorthn Full InserNon Full Inserthn Full InserNon Full Insorthn Full InserNon FuNlnsenhn Full Insorthn Full Insorthn FuN Insoltkn FuN Insonhn FuN Inserthn
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Attachment Page5of5 F~IURK1 FLORIDAPOWER ANDLIGHTCOMPANY TURKEYPOINT NUCLEAR UNIT4, CYCLE 16 L-96-107 CONTROL ROD BANKLOCATIONSANDROD DROP TIMES
- 150, 14 13 12 11 10 9
8 6
5 4
3 2
1 B
1.39 2.13 B
1.34 1.88 SA 1.34 1.95 SA 1.34 1.92 C
1.33 2.00 D
1.32 1.90 C
1.34 1.91 SB 1.34 1.93 A
1.34 1.92 A
1.34 1.87 SB 1.35 1.88 B
1.35 1.98 C
1.33 1.96 SB 1.35 C
1.34 2.05 B
1.34 1.93 SA 1.34 1.82 A
1.34 2.01 A
1.35 1.92 SA 1.33 1.96 D
1.34 1.96 SB 1.35 1.91
,D 1.39 1.97 SB 1.35 1.97 D
1.34 1.94 SA 1.34 1.90 1.32 1.90 A
1.32 1.96 SA 1.34 1.91 B
1.34 1.90 C
1.33 2.20 SB 1.35 1.93 C
1.35 1.94 B
1.40 2.00 SB
,1.34 1.89 A
1.32 2.01 A
1.36 1.97 SB 1.33 1.98 C
1.35 2.05 D
1.33 1.91 C
1.34 2.05 SA 1.32 1.88 iSA 1.35 1.92 B
1.34 1.96 B
1.34 1.98 N
H E
D A
BANK ID NUMBEROP LOCATIONS A
. CONTROL BANK TIMETO DASHPOT (scc)
TIMETO BOTTOM (scc)
41 li
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