ML19209C698
| ML19209C698 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/10/1970 |
| From: | Ross D US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Deyoung R US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 7910170866 | |
| Download: ML19209C698 (8) | |
Text
{{#Wiki_filter:L.- ',_ r -L March 10, 1970 R. C. DeYoung, Assistant Director, PWR Projects Division of Reactor Licensing TH.T : Charles G. Iong, Chief, PWR Project Branch 2 Division of Ecactor Licensing A RE'iIEW OF C01^tITMENTS BY MET-ED ON THEEE MILE ISLAND UNIT NO.1 (DOCKET 50-289) Now that the FSAE for Three Mile Island Unit No. I has been filed it may be useful to review commitments made at the CP and in the pos t-CP era. Most of these commitments are expressed in our letter to Met-Ed dated February 5,1969, a summary of which follows below. The items listed in this memo will be part of the POL review. We should take note of the fact that many post-CP coc:mitments were not fulfilled, as noted below. Perhaps a detailed review of the FSAR will divulge the information. he point is that letting items be deferred from CP resolution to a post-CP status did not seem to work in this We had many meetings, the record is replete with " nagging" case. letters on our part, and promises on Met-Ed's pat e. But in many ins tances the promised infornation simply was not sent in on a timely basis. 1. Airplane Hardening of Critical Structures (refer to C1 Safety Evaluation Ad tendum, p 5) We urged them, in our February 5,1969 letter, to make their preliminary designs available for review. Reir letter of May 9,1969 promised information by July 1969. In fact they supplied a topical report GAI-1716, filed on September 8,1969. We reviewed that document, met with them, and sent a letter dated November 13, 1969 requesting further information. On October 21, 1969 I sent a letter to files stating that Dr. A. Cluckmann of RT and Jim Proctor of NOL had no disagree =ent with the methods, but wanted sample calculations in the POL. The November 13 letter listed our interests in sa=ple calculations. Disposition: Our review in this area is still incomplete. 1476 107 OFFICE > ,[ l i l $URNAME> t _ l D ATE > ' Form AEC-H s ' Rn 4-53s AEC3t ch0 e s sovse..s e' ni=oe on,ca 'us o-au-en
R.'C. DeYoung 2 " arch 10, 1970 2. Eeactor ~4uildine Fan Cooley (refer to CP Safety Evaluatien. p 20) We stated in our February 5,1969 letter that Met-Ed should submit information en these coolers as soon as available. We understood April l')69 to be the availability date.. Met-Ed, in its May 9,1969 letter, gave a cocpletion schedule on tests, and a preliminary report on the coolers was enclosed. Three final reports were prcmised, the last due Janua: y 1970. Our review of the preliminary tcport divulged several deficiencies. (Refer to menos by D. Ross, dated June 4,1969 and August 22, 1969, and by R. Pollard dated Sugust 4,1969 on this subject.) We notified Met-Ed by letter of Octobc 5 J,1969, of these deficiencies. Met-Ed, in their letter of February 1J,1970, stated that tests have been completed and are being coepiled into a topical report. Tae es ti-mated filing date is in the third quarter of 1970. Disposition: Substantial schedule slippage by the applicant is indicated. 1 do not know when this item will be complete. 3. Seismic and IDCA loads (refer CP Safety Evaluation, pp 11, 35, and p 2 of ACRS letter) We stated in our CP safety evaluation that we would review these loading comblaations and deformation limits when available. B&W has submitted BAW-10008 to this end, and we are reviewing it currently. Disposition: Substantial schedule compliance was accomplAshed. 4. Dilution System Circuitrv (refer pp 21-23 CP Safety Evaluation) It was our understanding as noted in our February 5,1969 letter that preli=inary design of the dilutien system controls would be available in the second quarter of 1969. Met-Ed confirmed this in their May 9, 1969 letter. However it was never sent in. (Our letter did state that this information could be deferred to the FSAR stage.) Disposition: Review must be done from the FSAR. 5. Failed Fuel Element Detects (refer CP Safetv Evaluation p 43) We understood that Met-Ed would file information on this subject. Met-Ed said a study was in preparatien and implied that it would be forwarded to the AEC in mid-1969. It wasn' t. Disposition: We must accomplish review from the FSAR. 1476 108 i CFTlCE > ....)...... .I. I l l $URNWE > ..= = = = = = = =. =
ch 10, 1079 3 ?.. C. DeY o un a Pressure Vessel herral Shock (refer CP Safety Evaluation, p 24) 6. We understood that a topical report was to be prepared by BSU sub ject. Met-Ed confirmed E&W did file a topical, BAW-10018. a May 1969 submittal. No further ef fort is indicated. 01sposition: 7. n!g The seven R&D items, and the availability dates 5 e understood (Februa 1969 letter are: Early 1970 Xenon Oscillation. First Half 1969 a. b. Sodium Thiosulfate. Second Quarter 1069 Ther=al-Hydra '.'s Early 1969 c. d. Check Valve Vibration. Early 1970 Fuel P.od Failure. First Ealf 1969 c. f. In-Core Detectors............ Early 1970 Eigh Burnup Fuels. g. The Met-Ed letter of May 9,1969 essentially confirmed these dates, but I1 O f th-took exception to ites g, asserting it was not needed for TM remaining afx itecs, parts c. d, and f have topicals filed; irce b is partly satistied by BAW-10017 (nothing on removal ef ficiency); nothing is in yet for item e; some has been filed on "a" (BAW-10010). We must notify Met-Ed that the lack of these topicals vill Disposition: retard their review. letter are: Other co.:mit=ents, not expressed in our February 5,1960 S. Seoaration of Control and Safety (CP Safety Evaluation, p 16) a. We said that we would consider this item in our review o final design. Solitting Scram Bus _ (CP Safety Evaluation, p 20 and Hearing b. Transcript, pp 315-319) Met-Ed, the scram bus system be revised. The ACRS recommended that 2. we understand, did change to that described for Unit Diversified ECCS Signal (refer to C? Safety Evaluation, p 19) c. We said that we will require that the ECCS be actuated by a seccal method at the FOL. I I k omer > i t sua m e. ..}. kECM ono 5 .e. - .c s o n... o Form Af C h s = 1476 109 R
-n n W W 4 R. C. DeYoung '! arch 10, 1970 d. Pressure Vessel Inspection (refer to CP Safety Evsluation, p 24 and Transcript of liearing, pp 334-316) We said we would review the scope and f requency of the inspection program at the PCL. The capability for inspection is su=arized in the response to prehearing questions, and will be reviewed vith the FS AR material, Fire Protection System _s (refer CP Safety Evaluation Addendum, e. p 7) We said that we will require the applicant to take into considera-tien the following points in the desi;;n of the fire protection sys tem: (1) spray drop ~te size; (2) spray nozzle location; (3) combustible mixture detectors, and possible gas stratification; (4) exhaust hood designs ; (5) protective device actuation systems. f. General Design Criterion No. 11 (refer to CP Safety Evaluation, p 22, also applicant's su=ary p 17. and PSAR Volu=e 4, Q18.2) We should review the ability to provide a local station control for shutdown to the cold condition. F.et-Ed's design basis was (1) no second control room, (2) no damage to control roo=, (3) no specific time limit for cooldown, (4) offsite power available. g. Quality Assurance (refer to CP Safety Evaluation, p 29 and Transcript of IIearing, pp 342-347) We should review the extent to which Y.et-Ed fulfilled its com=itments as expressed in the hearing, as well as other OA =atters which arise. /$ Distribution: Denwood F. Ross De c ke t File PWR Project Branch 2 P JR-2 Re adi.g Division f Reactor Licensing D. F. Ecss (2) omer>!..pR-2/y1 fi-j / q R'. I .l, l Gj' sumwr > .kMS S. ;; t.. ..CiQ.m h our > ! 3./f / 70 '. 3 U ;. Up,,. _... , l,,,. },,d,7.. h., Form.uc-n s - nev 9-n ucx oz.a ...............m,c,
ENCLOSURE A ACRS CP-LET~ER ON THREE MILE ISLAND UNIT NO. 1 1. "Operatien of the ECCS is initiated automatically by redundant 1cw-pressure signals f rom transducers actuated by pressure in the two primary locer. The Committee recercends that in the interest of diversity another method, different in principal from the one proposed, should be added to initiate this function." Note: This has been done, re fer te FC.iR Volume 3, p 6-5, but does not accomplish a scram (.hich is needed to complete the ECCS function), 2. (In regard to splitting scram bus): "Failurc to interrupt either feeder, or any other event that presents de-energizing the single bus, will inhibit dropping all the rods. The Committee believes this syst2m can and should be revised to correct the deficiency. The revised design should be provided for review prior to installation cf the protection sys tem. " Note: This has not been reviewed yet. According to FSAR Volume 3, p 7-20 and Figures 7-1, 7-6, 7-7 a split bus has been incorporated. Whether the review can be accomplished prior to installation is vet to be seen. 3. "The applicant has proposed using certain signals from protection instruments for control purpcses. The Co.anittee believes that control and protection instrumentation should be separated to the fullest extent practi cable, and recommends that the applicant explore further the possibility of making safety instrumentation more nearly independent of control function." Note: I doub t that this commitment has been formally considered in the FSAR. We should ask Met-Ed to what extent this ACRS comment served to modify their design bases. 4. " Consideration should be given to the development and utilization of ins trumentation for promi t detection of gross failure of a fuel element." Note: A quick scan of the FSAR revealed no response to this comment. } k7 )
2 5. "The applicant is centinuing studies en the possible use of part-length rods for stabilizing potential xenon oscillations. Solid poison shims will be added to thu fuel eletents if necessary to make the moderator temperature coef ficient rore negative at the beginning of core life." Note: The n11-1 core has been modified to include burnable poison rods (as has Oconee Unit 2). Thus :'e t-Ed has been responsive to this corment. 6. "The regulatory staff should review the ef fects of blowdown forces on core internals and the developmert of appropriate load combina-tions and deformation limits. The regulatory staff should also review analyses of the possible ef fects upon pressure vessel integ-rity of theemal shock induced by ECCS operation." Note: Topicals BAN-lC008 and BAW-10018 have been submitted and ve are reviewing them. 7. "The, applicant described the research and development work planned r confirm the final design of the plant. The Committee centinues to emphasize the importance of work to assure that fuel-rod failures in loss-of-coolant accidents will not affect significantly the ao111ty of tne tLLb to prevent clad melting. Note: A *.opical on this subject is premised (p 1-47 of FSAR and in Met-{d letter of May 9, 1969). 8. "The applicant has proposed core barrel check valves between the hot leg and the cold leg to ensure proper operation of the ECCS under all circumstances. Analytical s tudies indicats that vibra-tions will not unscat these valves during normal cperation. This point should be verified experimentally." Note: B&W has filed topical 3AW-10005 to this end, and we are, reviewing it. 9 3 A76 II6
1 of 2 ENC 1.0SURE B SIGNIFICANT DESIGN CllANGES SINCE Tile PSAR Item Comment 1. !!od Drives Changed to Poller-Nut Oconee review should suffice (BAU-10307). Sys tem l 2. i +1 Assembly Changed to Open-Adequacy will be determined during Oconee review (HAN-10008, Part 2). l Lattice Type 1 3. Part-Length Rods Will be reviesed on Oconee. j ) 4. Burnable Poison Rods Oconee Unit 2 has; not yet reviewed in detail. Is- - 5. In-Core De t e c t o rs Now have auxiliary readout of 36 in-core de tectors ; this is in partial separation f rcm the computer if n cessary (detectors reviewed in 15 AU-10001). l 6. Trip Si;;nal The rate t rip v.eriod) has been & 'eted f rom the internediate channels. 7. ECCS Actuation RH pressure nrw actuates ECCS, in addition to low RC pressure. 8. Seismic Classes Some auxiliary building areas were uprated to Class I, and portions of the trakeup and purification were downgraded to II. 9. Tendon Ducts Ducts are now galvanized conduit (I don't believe they vere galvanized in PSAR). 10. Liner Exterior not to be painted; soap-bubble instead of sni f f leak-test; use N2 instead of air for leak munitoring of electric penetrat ion. ~4 11. Piping Some of B31.7 (February 1968) to be us --fabricatlon, test, inspection.) _ __J
2 of 2 Item Comment 12. NS Cooling Water Redundant lines changed to one line, in a protected tunnel. 13. Emergency Feedwater The two RB emergency cooling water pumps now provide water to the suction header of the emergency feedwater pumps (in addition to condensate tanks). 14. Emergency Feedwater Pump Cooling Pumps are now self-cooled. Ila te r 15. Various Changes Due to Airplane Many components of the steam and feeduater system were relocated. Ilardening 16. Condenser Of f-Gas Vent Condenser sir aff-gas vent relocated (monitor and alarm on high radiation). 17. Elect rical Diesel uprated (2850 to 3000 kw). 18. ESF Actuation ECCS nou starts on 1500 psig RC pressure (was 1800) and 4 psig RB pressure (al so 200 psig reactor pressure). Spray starts on 30 psig Rli pressure (was 10). Miscellaneous circuitry changes. O-l'). Liquid Raduaste Effluent 3 ate from cooling towers increased from 2000 to 5000 gpm. N 4 CV A N
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