ML18143A455
| ML18143A455 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 08/22/1978 |
| From: | White L Rochester Gas & Electric Corp |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| Download: ML18143A455 (5) | |
Text
REGULATORY INFORMATION DISTRIBUTION SYSTEM <RIDS)
DISTRlBUTION FOR INCOMING MATERIAL 50-244 REC:
ZIEMANN D L ORG:
NITRITE L D DOCDATE: 08/22/78 NRC ROCHESTER GAS 5 ELEC DATE RCVD: 08/28/78 h
DOCTYPE:
LETTER NOTARIZED:
NO COPIES RECEIVED
SUBJECT:
LTR 1
ENCL 0 FURNISHING REQUEST PUFF UANT TO APPENDIX 8 OF APPLICANT" QUALITY ASSURANCE MANUAL TG PERFORM A LIQUID PENETRANT EXAMINATION OF THE REACTOR COOLANT PUMP CASING WELDS BA ED ON DISCUSSION AS LISTED.
PLANT NAME: RE GINNA UNIT 1
h REVIEWER INITIAL:
XJM DISTRIBUTOR INITIAL:QPJ DISTRIBUTION OF Tl-IIS MATERIAL IS AS FOLLOWS FRACTURE TOUGHNESS 8c POTENTIAL FOR LAMELLAR TEARING.
(DISTRIBUTION CODE A018>
FOR ACTION:
INTERNAL:
EXTERNAL:
BR Cl-IIEF ORB3>2 BC4~~LTR ONLY(5)
+4LTR ONLY(i>
I h E~~LTR ONLY(2)
HANAUER~~~LTR ONLY(1 ENGINEERING BR44~LTR ONLY< 1)
PLANT SYSTEMS BR++LTR ONLY(1>
EFFLUENT TREAT SYS44LTR ONLY(i)
If.
LEVIN+~LTR ONLY(2>
LPDR S ROCIIESTERi NY4+LTR ONLY(1)
TERA+>LTR ONLY(i>
NSIC4~4LTR ONLY< 1)
ACRS CAT B++LTR ONLY(16)
NRC PDR4+LTR ONLY(i>
OELD~%LTR ONLY(i)
AD FOR SYS 5 PROJ+~LTR
'ONLY(i>
REACTOR SAFETY BR++LTR ONLY(i)
EEB>+LTR ONLY(i)
R SNAIDER+4~LTR ONLY< 1)
S.
PAWLICKI++LTR ONLY(1>
DISTRIBUTION:
LTR 40 FNCL 0 SIZE:
2P
%4%%4 4 4%4 4%4 HHf%%%4 4 4%%48%4%4%%8Fdf 4%%%
CONTROL NBR:
782350299 TIVE END
~ ~~~~~~~ ~~ ~~~~+~~~ ~~~+~~'~~may+~~~~
QqP
II N
I' h
t t
II
,(
p t
(r PINE (lllggE Ca
~ OalawO)
'ski!! ! i zszimrt ROCHESTER GAS AND ELECTRIC CORPORATION o
89 EAST AVENUE, ROCHESTER, N.Y. l4649 LEON D. WHITE, JR.
VICK PRKSIDKNT August 22, 1978 Director of Nuclear Reactor Regulation Attentiong Mr. Dennis L. Ziemann, Chief Operating Reactors Branch k2 U.S. Nuclear Regulatory Commission Washington, DC 20555 C'~>I
~CD riL>
O7 Cr>
r>
TKi. KP H0 N K ARCOCK 7IK RQ$6.2700 CO Qli G>
g ~C i 'iJ Oa:~n 0
CA
Subject:
Inservice Inspection of Reactor Coolant Pump R.
E. Ginna Nuclear Power Plant Unit No.
1 Docket No. 50-244
Dear Mr. Ziemann:
On March 1, 1976, we submitted our "Ginna Station Inservice Inspection Program For the 1977-1979 Period," Appendix B to the guality Assurance Manual.
After several revisions to this document to incorporate your staff's
- comments, we received your letter of approval dated May 17, 1977.
During your staff's review, the examination method for Reactor Coolant Pump Casing Welds was changed from visual during system hydrostatic pressure test to the liquid penetrant examination method.
Since that time we have reviewed the impact of that change and have reached the conclusion that a
liquid penetrant examination of these welds is technically not required nor justified when put in perspective to the radiation exposure incurred to perform such an examination.
The reactor coolant pump casing consists of four type 316 stainless steel cast rings with minimum thickness of 7.5 inches, nominally 8 inches.
The austenitic stainless weldment has very good crack sensitivity charac-teristics and the water chemistry of the primary system would not lead to any stress corrosion problems.
Service induced flaws would have to be caused by a cyclical mechanism (fatigue) which has an extremely low proba-bility due. to the. geometry of the pump bowl and fracture toughness of the austenitic stainless steel.
A liquid penetrant examination would only show indications which develop on the outside of the pump bowl or through-wall cracks.
Postulating a flaw developing on the outside of the pump bowl is extremely difficult because of design and operation considerations, as previously discussed.
Also, if a crack was to develop and grow to the extent of becoming through wall, it would be detected by the leakage from the bowl.
Therefore, the visual examination during system pressure test is the most valid (non-volumetric) inspection method for our reactor coolant pumps.
)0 (g
]/y
j 1
,/
...ROCHESTER GAS AND EL IC CORP.
DATE 'ugust 22, 19 8 To Mr. Dennis L. Ziemann SHEET NO.
2, Our review of the impact of this inspection was based upon radiation data collected during our 1976 and 1978 outages.
The average dose rate at the work level is 250 to 300 mr/hr.
The radiation level on contact at the bowl surface is over 400 mr/hr.
The following is a labor and exposure estimate for a one-pump inspection.
Job Man Hours Exposure Man-Rem l.
Install Scaffolding 2.
Remove 8 Dispose of Insulation 3.
Preparation and Inspection 60 100 22 12.4
- 13. 5 6.6 4.
Install New Insulation (Custom Fit) 1000 300.0 5.
Remove Scaffolding and Clean Area 24 7.2 TOTALS 1206 Hrs.
339. 7 Using the 2,000 mr plant administrative limit for each individual's exposure per quarter, this job will require a total manpower complement of 170 with total exposure at 339.7 Man Rem.
The total cost for this job is estimated well over 100,000 dollars.
One problem which has not been resolved is that in the Rochester area the Insulator Union has only 90 members who work for many different companies.
Our initial estimate for insulators is approaching 150, which is 60 more than the Local can supply.
With the 90 members of the Local working for several different companies, it is virtually impossible to get even a
majority of the members because of the exposure involved in this job and other normal commitments of their companies.
This letter is requesting relief from. this requirement to perform a
liquid penetrant examination of our Reactor Coolant Pump Casing Welds based on the above discussion.
In lieu of the surface examination, a visual examination for leakage during system pressure tests is proposed.
This examination will provide as much assurance of the continued safe operation of these pumps without the large radiation exposure required to perform surface examinations.
8ecause of the impact of this job, we would request your prompt atten-tion and response to our request.
If you have any further questions, please contact us.
Sincerely, LDW:bh