ML17309A292
| ML17309A292 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 10/08/1982 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17256A347 | List: |
| References | |
| NUDOCS 8210180158 | |
| Download: ML17309A292 (5) | |
Text
t UNITED STATES NUCLEAR REGULATORY COMMISS ION
'IVASKINGTON,D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AYiEHDHENT NO.
55 TO PROVISIONAL OPERATING LICENSE HO.
DPR-18 ROCHESTER GAS AND ELECTRIC CORPORATION R.
E.
GINNA NUCLEAR POllER PLANT DOCKET NO. 50-244
1.0 INTRODUCTION
Following the January 25, 1982 steam generator tube rupture event at the R ~
E, Ginna Nuclear Power Plant, Rochester Gas and Electric Corporation (RG&,E) and the NRC staff conducted extensive evaluations on the cause of the incident and on the corrective actions that were necessary prior to restart.
The NRC staff's evaluation is contained in NUREG-0916, SAFETY EVALUATION REPORT Related to the Restart of the R.
E. Ginna Nuclear Power Plant.
At that time, RGEE committed to perform an inspection of the steam generators after 120 days to assure that the corrective actions taken to preclude further peripheral tube 'degradation had been successful.
The steam generator inspections, which included eddy current, fiber
'optics, video and visual inspections, were performed during the present outage that began September 25, 1982.
During the inspection of the S-steam generator, a previously plugged tube (Row 39 Column 69) was found to have a fish-mouth rupture.
The opening faced outward towards the steam generator shell and is approximately 1.25 inches long, 3/8 inch at the widest opening and begins approximately 3.5 inches above the top of the tube sheet.
Representatives of RGEE and the NRC staff have had several discussions dealing with the cause of the burst and RGE E's proposed repair program.
By letter dated October.
6,
- 1982, RG&E submitted their analysis of the
~ cause of the tube failure and the details of their repair program.
In
~ the submittal RG&E committed to perform a steam generator inspection.'uring their next refueling outage, which is scheduled to begin in mid-flarch 1983.
In a telephone conversation on October 7,
- 1982, RGEE agreed to incorporate this commitment into its License Ho.
DPR-18, which authorizes operation of R.
E.
Gonna Nuclear Power Plant.
2.0 EVALUATION The burst tube (R39C69) is on the periphery of the hot leg side of the B-steam generator.
The burst occurred in a wear area which is approxi-mately 5 inches long and 3/8 inch wide on the tube that had previously y
P
2 been identified during the outage following the January 1982 steam rupture (see HUREG-0916).
RGEE has stated that the current video inspection of the burst tube indicates that the wear.pattern.has not changed since the last inspection.
The tube was originally plugged in January, 1976 for a defect measured as 565 through-wall by eddy current testing (ECT).
E RGEE has postulated that the most probable cause of the burst in R39C69 is a reduction in the tube wall due to wear, and subsequent pressurization from the primary side thro'ugh a leaking plug.
RGKE has reviewed the plant operations during the period from May 1982 to the shutdown in September 1982 and based on analyses and calculations has determined that the burst most probably occurred during the routine. hydrostatic test performed as part of the startup in May.
The differential pressure across the steam generator tubes during the test is approximately 2200 psi.
RGEE performed calculations based on the size of the wear area as seen by the video inspections and has concluded that the tube wall thickness could have been sufficiently reduced to result in a burst failure given the 2200 psi differential pressure.
.The wear area is postulated to have occurred as the result of the presence of the foreign objects that were removed during the outage following the January 25 tube rupture.
One foreign object, a 4 inch piece of weld rod, was found during the video inspections performed this outage.
The appearance of the weld rod indicates that it had been buried in the sludge pile and had been washed to the periphery during the water lancing performed at the beginning of the present outage.
The recent ECT and video in-spections indicate that no further degradation of the peripheral tubes has occurred.
IJestinghouse explosive plugs were used when this tube was plugged in January 1976.
RGE E has stated that the industry has experienced a
history of small leakage of these plugs over time as a result of stress corrosion cracking.
RGKE has reviewed the variations of secondary:
system activity at Ginna for the period of May to September 1982.
They
'eel the change in activity levels are consistent with industry experi-ence with leaking plugs of this type.
Ouring the period, Ginna had a
calculated primary-to-secondary leak rate of approximately 3cc per minute.
- RGBE is removing the portion of the burst tube between the tube sheet and 'the first support p'late in order to'verify the fai lure mechanism'f the tube.
The section of tube is being removed by drilling out the explosive plug, cutting the tub'e from the primary channel
- head,
-and removing th'e pieces through access ports on the secondary side.
The removed hot leg plug will be replaced with a seal welded plug.
The associated cold.leg plug and both the hot and cold leg plugs of the
'djacent two', plugged tubes (R39 C67 and R39 C70) will be repaired in a similar manner.
These t< o tubes have wear patterns that are similar to, but smaller than, that found.on the burst tub Although'o leakage
. in i.hese plu'gs is ev'ident, they will be preventatively repaired also.
RGEIE has stated that the secondary side video inspections have shown no other periphery tubes in either the A or B-steam generators with the type of wear that is believed'o have contributed'o the burst of tube R39 C69.
3.0 4.0 RGEE has corrImitted to perform a steam generator inspection during'he next refueling outage which is currently scheduled to begin in mid-Narch 1983.
RGLE has stated that the inspection program will be comparable to that conducted during the present outage and will in-clude complete ECT and visual inspections as well as water lancing.
SUIII<ARY The staff has reviewed the licensee's submittal and proposed course of action and have determined that RGEE's program of repair and their analysis of the problem are satisfactory.
Therefore, with the addition of this proposed License Condition, the staff has concluded that the operation of the Ginna Plant will not pose a
safety hazard.
ENVIRONl1ENTAL CONSIDERATION We have determined that the amendment does not author i ze a change in effluent types, increase in total amounts of effluents, or an increase
'in power level, and will not result in any significant environmental impact.
Having made this determination, we have concluded that the amendment involves an action which is insignificant from the standpoint of environmental
- impact, and pursuant to 10 CFR 51.5(d)(4), that an environmental impact statement or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of this amendment.
5.0 CONCLUSION
We also conclude, based on the considerations discussed above, that:
(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously considered, does not involve a significant decrease in a safety margin, and does not create ihe possibility of an accident of a type different from any evaluated previously, the amendment does not involve a significant hazards consideration; (2) there is reasonable assurance that the health and.safety of the public will not be endangered by the operation in the proposed manner; and (3) such activities will be conducted in com-pliance with the Commission's regulatioqs and the issuance of this
- amendment
~ii 11 not be inimical to the common defense and security or the health and safety of the public, 6.0 ACVNOWLEDGEhENTS This safety evaluation report was prepared by J.
Lyons.
c Ue 0~-: ber c,
>go2
~ g h,
r l
iioeo).S.
NUClEAR REGULATORYCOM ION REACTOR FACILITYFEE DETERMINATION
- 1. FEF. FORM TYPE(Check one)
PREUMINARY FINAL AMENDEO INSTRUCTIONS. Fill In Items 1 Ihrovph 14, as applicable, and send the odpinal copy Io Ihe Lienee Fee Manapement Branch.
- 2. DOCKET NUMBER(S)
Q ~
v~r'.
LICENSEE i'X
- 5. PLANTNAMEANDUNITts) !
- 3. *CCESSIOII NUMBER
- 6. DATEOF APPOCATION f.~ c.~.
i I('.
. 9, SUBJECT
- 7. FEE REMITTEO YES NO CLASS I CLASS a CLASS SI L LICENSEE FEE DETERMINATION CLASS IV CLASS V CLASS Vl EX EM((T
- 10. TAC NUMBERASSIGNED(llavellablei NONE I
e
- 12. NRC FEE DETERMINATION 11 APPROVAL LETTER OROER AMENDMENTNUMBER(S) s DATE OF ISSUANCE The above application has been reviewed In accordance with S ection 170 22 of Part 170 and is proparty categor)zed.
The above application has been reviewed In accordance with Section 170.22 of Part 170 and Is incorrectly classified.
Fee should be class(es):
JUSTIFICATION FOR CLASSIFICATIONOR RECLASSIFICATION:
(Or ThlsappllcatlonlsaCIass
~
~ r +
typeofactionandIsexemptffomfeesbecause itis: ~
Flied by a nonprofil educational institution.
Flied by a Government agency and Is not for 6 power reactor.
For a Class I ~ II, or III amendment which results from an NRC request dated for the application and the amendment Is to simplify or clarlf License or Technical Specifications; has only minor safety significance: and Is being issued for.the convenience of NRC (must meet sll of the crilerla]
orher(s(ere re(roe(here(or(~
L er r r
~
r;
. ~
r ~
. a'~
win.
/np~ir'r~ '/
(
r l L~)~
rirL I r(7.ri >-rr-C. 'P
.C4~r (2
H7
~
Pr~-r. ~e
~ rA'P~ r l7 rl
'rr'r c rhea !,r r ~ (((
t(r S
~y-+ 64~~7'-~ r~~'
r~
- 13. SIGNATURE(Branch C elf r '/~~~
(r~
Q ~+y~)~
/~~
DATE
~~~err,
(
7j ~
L Lf' Ta. FINAL SIGNA ICA ON: The preliminary fae deierminaiion has been res seas ed and ls hereby alfirmed.
E(Projecf Manaperor B~anch erl DATE FOR LICENSE FE ANAGEMENTBRANCH USE ONLY(Allolhers do no! write below this(fnef The above exemption request has been reviewed and ls hereby accepted as beinp exempt.
SIGNATURE(Chief. LFMBl
(
( t((perh, I I I (
(
DISTRIBUTIONBY LFMB Records Services Branch DLBranch Chief LFMBExemption Fife LFMBReactor File