ML20031F195
| ML20031F195 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Indian Point  |
| Issue date: | 04/21/1978 |
| From: | Diianni D Office of Nuclear Reactor Regulation |
| To: | Shao L Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML13319A640 | List:
|
| References | |
| FOIA-81-313 NUDOCS 8110190334 | |
| Download: ML20031F195 (10) | |
Text
{{#Wiki_filter:.-c L ~ - ~ d-b, &c., n.bdw j UNITED STATES 3-NUCLEAR REGULATORY COMMISMON h, WASHINGTON,0. C 20555 .- g
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'i I +., v, APR 211978 MEMORANDUM FOR: L. C. Shao, Chief. Engineering Branch, D0R FROM:
- 0. C. Dilanni, Engineering Sranch, 00R THRU:
V. S. Noonan, Section Leader Engineering Branch, 00R
SUBJECT:
TRIP REPORT CONSOLIDATED EDISON INDIAN POINT 1 & 2 (IP-1 & IP-2) CHEMICAL CLEANING 50-010, 50-247 On March 22, 1978, the NRC Engineering staff attended a meeting at Consolidated Edison's Van Nest shops in New York, N.Y. The purpose of this meeting was for Con Edison and its contractors to informally brief the staff on the status of the Chemical Cleaning project. A list of j attendecs is attached. The meeting covered the inspection results of IP-2 steam generators 23 and 24, pilot tests results in IP-1, proposed plans for cleaning IP-2, vibration model testing, radiation and waste consideration and the overall schedule. The pertinent observations on these topics are as follows: I. Inspection Results of IP-2 Steam Generators Steam generators 23 and 24 were inspected in accordance with Reg. Guide 1.83 and the procedures used for steam generators ~21 and 22 in April 1977. The dant size in this inspection was found not to be substantially different from the previous inspection period in November 1976. A summary of the results of this inspection is as follows: Steam Generator No, 23 ,24 Yotal tube population inspected 463(14%) 473(15%) Average dent size (mils) 2.5 2.0 Max. Dent size measured (based on standard 700 mil probe) 9.0 9.0 Total number of tubes restricted by 675 Mil probe 29 44 Total number of tubes restricted by 640 Mil probe 15 17 Total number of tubes plugged (610 Mil probe restricted) 2 6 v) 3 PDR
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- t. C. Shao..
Support plate hourglassing in steam generators 23 and 24 is similar to that existing in steam generators 21 and 22. The hourglassing in steam generators 21 and 22 has increased 60 mils average from April 1977 to March 1978. Similar past measurements are not available for steam generators 23 and 24. Photographs did show two cracks in the 3rd flow slot in the second support plate in steam generator No. 24. It is not known when these cracks developed because this is the first examination in this area since the steam generators were fabricated. Y The primary system is currently filled for refueling and IP-2 is scheduled to startup during the weak of May 23, 1978. Based on the results of this inspection, con Edison is accelerating the chemical cleaning project. If unexpected problems do not arise IP-2 could be shutdown as early as Mid August 1978 and the demonstration cleaning would commence approximately 30 days later. II. Pilot Test Results in IP-1 Phase 1 of the chemical cleaning project has been completed by United Nuclear Industries UNI and Halliburton Services. Using IP-1, both contractors developed a chemical process that removed i.., sludge (consisting of Fe & Cu) from the steam generators and removed magnitite from the reverse dent samples furnished by 'destinghouse Corp. The contractors further demonstrated that low corrosion rates can be achieved during the cleaning processes. A summary of the cleaning processes developed by each contractor is tabulated below: A. UNI Using Steam Generator No.12 at IP-1 Application Temp. Chemical Cleaning Step Time (hours)_ 'F Composittoas 1. Sludge Removal * (a) Iron Oxide Phase 13 185 10% Citric Acid 1% HEEDTA 3.5 NH40!! Ph 3.5 )
( ..a -,~ 3 , 'N APR 211978 L. C. Shao... ~ Application Temp. Chemical Cleaning Step Time (hours) 'F Comoc-itions (b) Copper Oxide Removal 12 140 25% NH 0H 4 1% nan 09 air sparge PH 9.5 2. Rinses 5 ambient Demineralized water 3. Crevice cleaning
- 102 180 3% citric acid 3% ascorbic acid 1.2% NH 0H 4
PH-3.5 4. First Rinse (a) Copper phase 3.5 ambient 1* NH40H air sparga Ph-10 ~ (b) Passivation 5 ambient 0.1% N H22 5. Final Rinse 2 ambient Demineralized water Note:
- Sludge and crevice ' leaning solvents are N2 sparged and contain a c
0.3% diethyl-thicurea as a corrosion inhibitor. l l B. Halliburton Using Steam Generator No.11 at IP-1 I Cleaning Step Application Temp. Chemical Time (hours)
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'Comoositions 1. Sludge Removal (a) Iron Oxide 16 200 4% EDTA Phase .1% OSI-1 (b) Copper Oxide 9 150 nan 02 l Phase NH 0H 4 Ph 9.5 U =-
m 2:.. + L _ ex ~.~ .1 1 1' -i 3 } L. C. Shao APR 211978 { l 1 2 Application Temp. Chemical Cleaning Steo Time (hours) 'F Composi+.fons j 2. Crevice Cleaning 144 200 8% EDYA i 4% C1:~ic .67. USI-l NH40'i for i Ph ' control ; Ph 4.0-4.5 -{' During the Halliburton sludge removal and crevice cleaning the chemical solvent circulated at 150GPM and the average velocities past dented samples and corrosion specimens were approximately l* ~ 2/3 ft/sec. While the U;iI employed sample exposure velocities ranging from.044 to.584 tt/sec. In the Halliburton process corrosion of less 2.5 mils were observed for carbon steels while less.05 mils were observed for the high nickel alloys. UNI's process showed the corrosion of 9.32 mils MAX for stressed carbon steel alloy and.014 mil MAX the high nickel alloys. The high corrosion results for carbon steel was due to mistakenly in-troducing air sparging during sludge removal while the solution Ph was 4.5. This low Ph solution exposed to air created a highly corrosive condition for carbon steel hiloys. III. Prooosed Plans for Cleaning IP-2 (Phase 2) A steel beaker assembly is being designed to resemble the IP-2 i steam generator in minature and will be connected to the IP-1 System. In phase 2 the steel beaker will be used to study various solvent velocities that can be achieved in IP-2 including the effects of these i velocities on corrosion rates and crevice cleaning. A section i of the suppo'rt plate containing tubes from rows 1 & 2 will be removed from IP-2 steam generator No. 23 and placed in the steel beaker-to demonstrate the effectiveness of magnitite removal. Con Edison has mocked up the section of the steam generator and the surrounding area to test the feasibility of the support plate removal before the operation is performed on the actual steam generator No. 23. This also serves ~to train the Nuclear Utility Services (NUS) ~~ j technician performing the work. 'The NRC staff toured the steam generator neck up area at Van Nest shops. l ~IV. Vibration Model Testing Vibratory Model Testing will determine potential effects of tube vibration that may occur after chemical cleaning. Such concerns exist because the removal of corrosion products can result in the d
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+ I g i APR21B@ f t,_,, L. C. Shao,. I enlargement of the tube crevice at the support plate. Normally th'ere is a radial design clearance of.014 inches in a new steam generator. Up to.025 inch increase in clearance is being studied which is greater than the worse case condition observed at other plants. The studies will detennine if increased flow-induced vibration of the ttbes would cause high tube alternating stresses and possible tube impact or fretting. Such abnormal conditions could lead to accelerated tube fatigue as well as local wear at the fretting location that e could eventually lead to postulated tube and/or support plate failures. These studies which have been contracted to Wyle Laboratories are to be completed within six to seven months. Wyle's proposed tube vibration program involve: 1. Dynamic Response tests consisting of mechanical vibration of I straight and U-bend tube bundles. 2. Vibratiori flow tests consisting of flow-induced vibration of the tube bundles (in 1 above) in water and two phase flow. 3. Analytical evaluation of test results to assess the likelihood of failure for the expected life of the. steam generator. ~ These studies will include as built and post cleaning tolerances for crevice conditions. V. Radiation and Waste Consideration As part of the chemical cleanir.g program Con Edison is monitoring personnel radiation exposures for the UNI and Halliburton processes and consideration is given to minimize the total vol,umes of spent solvents and rinse solutions. It is recognized that if these processes are to be applied nation-wide, the need to dispose o.f waste as radioactive solutions must be addressed because some steam generators have operated with primary to secondary leaks. Con Edison stated that the corporate policy is to establish administrative controls, l, design practices, operational procedures, maintainence practices and organizational responsibilities to fulfill its responsibilities in maintaining occupational exposure as low as reasonably achievable J (ALARA).: As evidenced in the fulfillment of this policy, the following has been reported to the NRC staff. [ A. Radiation exposures collected during the first phase of the chemical cleaning using IP-1 steam generators 11 and 12 are sunnarized as follows: sh .)
._A 3 l t.. C. Shao. Q-APR 211978 i s Radiation Exposure Halliburton (S.G.11) (in man rem) ) UNI (S.G. 12 Construction 12.8 21.5 Cleaning Operation 3.2 10.0 Total 16.0 31.5 B. Spent solvents contained radioactivity levels ranging from o0,0-3 to 3 x 10-2 uCi/ml. Chemical analyse's of the waste 3 1 The majorlonc lived isotopes were 5 Cel34,13/ and Mn54 Co containing spent solvent showed dissolved and suspended Fe, Cu and Ni. C. Because of the radiacactive level, all waste was processed through l the waste evaporator of IP-1. Distillate which was discharged to the nonnal rad-waste system of IP-1 contained radioactivity levels of 2 x 10-4 uCi/ml. Evaporator bottoms showed radioactivity levels of 2.9 y Cf/ml and w:s stored in drum after solidification. The total volume of liquid waste before processing for this phase of chemical cleaning at IP-1 was - 44,000 Gals. D. During the second phase of this program sludge samples taken from IP-2 will be tested in IP-1. The radiation field of this sludge is 15CMR/hr (few inch away) and a factor of 100 increase could be expected if there had been communication between primary and secondary side. Approximately 500 lbs of sludge has been collected from each of the IP-2 steam generators. Handling the waste during the second phase of this program will be the same as described above. During this phase, laboratory tests will address three techniques consisting of the following: 1. Removal of radioactive ions from the rinse solutions using ion-exchange resins. 2. Concentration of solvent prinr to solidification. 3. Solidification of solvent or evaporator concentrate. Cepending on the test results any combination of these three technioues could be acolied to IP-2 steam oenerators cleanino. E. Following laboratory testing further testing using IP-2 drains co develop specific operating procedures equipment design and modification will begin. Based on the results from phase one of this program it is expected that the cleaalng process will involve four fills for each steam generator. ~ 'J . -. ~ i
J* ~- i y i I 3 L. C. Shao Apg 211973 ) g3 i s_/ 1. Sludge removal 2. Rinse 3. Crevice cleaning and Passivation 4. Final Rinse Waste volume for cleaning all four steam oeneratars in IP-2. is expected to approach 350,000 gallons. Present thinking is that this ~ volume can be transferred via the S.G. blowdown system to holdup tanks in IP-1 containment building. These tanks will be purchased specifically for this project and the piping wi'.1 permit solution segregation according to radioactivity level. i VI. Overall Planned Schedule The following schedule was presented at the meeting. l 1. Steam Generator Inspection Program and results submittal to NRC March 24,1978 2. NRC's completion of the Review of Item 1 April 10,1978 3. IP-2 startup May 23,1978 4. Con Edison docketing the chemical cleaning of IP-2 April 14,1978 5. Con Edison's submittal of the Safety Analysis Report on Cheuical Cleaning IP-2 June 30,1978 6. Shutdown of IP-2 to prepare the plant for.hemical cleaning Aug.15,1978
- 7.
Earliest possible start IP-2 chemical cleaning Sept. 15, 1978*
- These are the earliest possible dates provided that unforeseen problem's do not arise.
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D. C. Dilanni Engineering Branch j Division of Operating Reactors a cc: See pag. 2 9 3 s) \\ = _..
- =. 1 1' ,T L. C. Shao 1 , APA 21 B73 4 cc: V. Stello
- 8. Grimes W. Butler B. D. Liaw A. Schwencer i
^ R. Ried D. Eisenhut J,. C. Guibert B. Buckley P. O'Connor W. Hazelton T. Wambach L. Barrett J. Strosnider G. Cwalina i J. Colliot P. Knapp, Region I Attendees i t 6 4 e f 1 s <j-a i
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l I i i; N LIST OF ATTENDEES f
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USDOE/ CON EDISON S.G. CHEM. CLEANING PROJECT l VAN NEST SHOP - MARCH 22, 1978 Name Organization Function Relative to Project Frank Almeter NRC Engrg. Staff Review ~ Harry Bahrenburg Con Edison Sr. Field Engr. (Shops) William Cahill con Edison Vice President-OA&R and R&D William Caldwell, Jr. Con Edison Sr. Vice President John Callahan Con Edison Contract / Subcontract Adminitrator Paul Cohen Independent Consultant to Project Steve Collard Con Edison Chem. Laboratory Supervisor Dominic Dilanni NRC Engrg. Otaff Review John Dusch Con Edison Froject Engineer Jack Frost Halliburton Lead Scientist John Gatewood Halliburton Project Manager Robert Gordon con Edison Reliability Review Bill Greenway NUS Consulting Service on Solvents Johnathan Huza Con Edison Sr. Technician Sherman Ip Con Edison Vibration & Press. Vessel Analyses Klaus Kappel Wyle Chief Engr.-Vibration Al Larrick UNI Project Manager George Leven UNI Waste Management i Irving Lewinski Independent Consultant to Brookhaven Labs. Jimy Mark Con Edison Metallurgy & Inspection Paul F. McTigue con Edison Project Manager Eric alsen Cs Edison Nuclear Licensing ,j John O'Toole con Edison Asst. Vice Pres. Engrg. Paul Pettit USD0E Program Manager a cliff Poor UNI Project Control Coordinator Jack Robertson 'Wyl e Vibration Study Manager Samuel Rothstein Con Edison Engineering Leader i - - - - = f, = _....
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- ' 3 Name Organization Function Relative to ProJA-t NRC Engineering Review Lar:y Shao Paul Silliman Con Edison Solvent Development Peteris Skulte con Edison Metallurgy & Inspection Frank Smith Con Edison Shop Manager Walter Stein on Edison Waste Processing -.
Jchn Van Royan Brookhaven Technical Review for NRC John Weeks Brookhaven Technical Review for NRC l 1 i b i. 1 ,6 ~ . m. ~ U 1 i = I -. _ _}}