ML17262A045
ML17262A045 | |
Person / Time | |
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Site: | 07109309 |
Issue date: | 09/18/2017 |
From: | Tae Ahn Renewals and Materials Branch |
To: | Harrison J Global Nuclear Fuel |
Garcia-Santos N | |
Shared Package | |
ML17262A085 | List: |
References | |
Download: ML17262A045 (3) | |
Text
NRC FORM 699 **.,,.. ...~.,. U.S. NUCLEAR REGULATORY COMMISSION DATE OF SIGNATURE (03-2013) f ~d ,**s
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...... .J." CONVERSATION RECORD 1/f1(UJJIJ NAME OF PERSON(S) CONTACTED OR IN CO NTACT WITH YOU DATE OF CONTACT TYPE OF CONVERSATION D E-MAIL James Harri son. et al. 08/ 16/20 17 E-MAIL ADDRESS TELEPHONE NUMBER 0 TELEPHONE D INCOMING james. harrison@ge.com (9 10) 620-18 26 0 OUTGOING ORGANIZATION DOCKET NU MBER(S)
Globa l Nuclear Fuel - Ameri cas (GNF-A) 07 109309 LICENSE NU MBER(S) CONTROL NUMBER(S)
NA NA SUBJECT NON-P ROPRI ETA RY INFORMATIO ---8/ 16/2017, 10:00 AM CO FERENCE CA LL TO DISCUSS THE STATUS OF THE REV IEW OF THE LETTE R AUTHORIZATIO REQUEST FOR THE MODEL UM BER RAJ-II (CAC 0. L25239)
SUMMARY
Attendees:
NRC GNF-A John Mc Ki rgan James Harri son Travi s Tate Ju stin Lamy Norma Garcia Santos Christopher Kmi ec Tae Ahn James Fawcett Andrew Barto Robert Rand Kim Yong Mine Yi lmaz Joseph Borowsky Brian Eber Cay lee Kenny Russ Fawcett Daniel Forsyth Continue on Page 2 ACTION REQUIRED (IF ANY)
See umm ary.
Continue on Page 3 NAME OF PERSON DOCUMENTING CONVERSATION Norma Garcia Santos, et al.
SIGNATURE NRC FORM 699 (03-2013) Page 1 of 3
NRC FO RM 699 U.S. NUCLEAR REGULATORY COMMISSION (03-2013)
CONVERSATION RECORD (continued )
SUMMARY
- (Continued from page 1) I On August 16, 2017, NRC and G F-A participated on a phone call to discuss status of the rev iew of the letter authorization for the Model o. RAJ- II for transporting accident tolerant fuel (ATF) lead test assemb lies (LT As), ga in a co mm on understanding about the licensing action requested , co mmunicate chall enges associated with the revieJ, and di scuss a possible path fo rward to continue the review of the app li cation . The fo ll owing items summ arize the di scuss ion during the August 16 telephone ca ll.
The staff started the meeting by go ing over the main as pects of the cover letter1submitted with the app li cation to ensu re th at the staff and the applican t had a comm on understanding of the li censi ng actions being requested. The pa11icipants agreed on the fol low ing:
I. The li censing action request consisted of up to 16 ATF lead test rods in side of two G F2 fuel assembli es (a maximum of 8 ATF lead test rods per assembly) per package with a maximum of two packages per shipm ent.
- 2. The ATF rods may conta in Type A fissile fuel and th e G F2 fu el will contai n previously approved Type B quantity fuel.
- 3. The ATF will be transported in a Type B shipm ent.
- 4. The app li cant is requestin g one shipm ent per year from 2017 to 2019.
In terms of the number of ATF assembli es to be shipped per year, on th e top of page 2 of the cover letter, the app li cant menti oned that there wo uld be max imum of 4 ATF lead tests assemblies per shipm ent. The statement on th e top of page 2 of the cover letter seemed to be in agreement with page 3 of the cover letter in which the applicant stated (in proposed condition 4) that "There sha ll be a maxi mum of two RAJ-II packages on single truck, each containing a maximum of two LT As." On th e propo ed condi ti on 5, th e app li cant mentioned that "RAJ- II packages with G F ATF LT As shall commingle with other RAJ- II packages ... " Therefore, it was not clear fo r the staff th e maximum number of ATF FeCrA I rods per package and the number of packages that will be shipped at any given time on a truck, including GNF ATF LTAs. The ap plicant indicated th at the fo llow ing:
I. The maximum number of ATF rods in a package will be 16.
- 2. The maximum number of packages per truck (including the packages containing ATF LTAs) will be 13- 14 packages.
- 3. The near term plan is to ship two RAJ-II packages containing ATF LTAs commingling with other packages co ntaining GNF fuel.
- 4. The applicant requested the fl ex ibili ty to ship GNF fuel with GNF fuel containing ATF FeCrAI rods .
The wording of the proposed Condition 4 was clea r th at a maximum of two packages could be loaded per truck. When one member of the applicant ' s organi zation mentioned that the condition did not prec lude addi tional packages on a truck . anoth er G F-A member ri ghtly stated that the word ing could be improved to ex press the app lication's clea r intenti on.
Based on the eva luation section of the cover letter, the staff asked ifthe appli cant was relying on the claddin g as th e containment boundary or not, since the evalu ation section mentions that the structural and thermal eva luations demonstrated that the G F FeCrA I fuel rods would not rupture. The applicant clarified that since th e app lication Ii i1i ts FeCrA I fue l rods to Type A fissile con tent, the app li cant is not relying on the cladding as the containment boundary , but as a barrier to maintai n the pellets in a safe geometry (i .e ..
for criticality safety purposes). The applicant also indi cated that it analyzed water entering into the pe ll et-c ladd ing gap. The staff mentioned that a concern was fa ilure of the cladding resu lting in pell ets getting out of the cladding and radioactive material reconfi gurati on. The applicant menti oned that ifthe cladding burst, the app licant does not have physica l data to indi cate that pell et migration outside of the rod is possible. The app li cant pointed out th at UREG/CR-1 I 458 and NU REG/CR-5892 document a transportation acc ident in vo lving a shipment ofG F fuel assembli es (in cluding a beyond design basis tire), whi ch caused a breach of the cladding. These NU REGs concluded that there was no fuel or pe ll et mi grat i n outsid e of the fuel rod and that a criti ca lity accident was not possible during the acc ident or after th e tire. The appli cant pointed out thi s was in cluded in Section 6.6.2.2 of th e Letter Authorizat ion Req uest. The appli cant pointed out that, currently, th e structural and thermal analyses do not support mi gration of pellets outs ide of the cladding under hypothetical acc ident conditions. Howeve r, staff had co mm ents/qu esti ons with th e structural and therm al analyses provided. The discussion below includes the staff s initial comm ents and questions related to th e appli cation.
Materials Eva luation The staff pointed out that the FeCrAI material is a ferritic stee l. Therefore, the ta ff indi cated that the appli cant shou ld use Regu latory Guide 7. I I as mentioned in the pre-appli cation meeting. The sta ff asked if the ssessment of the cladd ing integrity was based on th e 9 meter drop test ass uming zirconium materi al. The appli cant respond ed that was correct. The staff also mentioned th at Figure 2-1 of Attachm ent 3 of the appl icati on includes a strain curve at -20 F. The appli cant tated th at test in g of th e FeCrAI materi al was performed at a strain rate of[withh eld per 10 CF R 2,390 (app licati on)], to which the staff comm ented th at it wa hi gh in compari son of a conventional stra in rate . The appli cant indi cated that the stra in rate was based on the fo llow ing:
NRC FORM 699 (03-2013) Page 2 of 3
NRC FORM 699 U.S. NUCLEAR REGULA TORY COMMISSION (03-2013)
CONVERSATION RECORD (continued)
ACTION REQU IRE D (Continued from page 1)
I. the duration of the impact of the RAJ-II package in prev ious drop tests of zirconium all oy;
- 2. the strain rate of th e claddi ng is "contro ll ed" by the package des ign (since th e package des ign did not change, th e appli ca nt ass um ed that th e strain rate did not change); and
- 3. the ass umpti on that th e des ign of the zirconium alloy and ATF LT A fu el bundl e designs are simil ar fo r th e limited number of FeC rAI rods in an ATF LTA.
The appli cant did not perfo rm phys ical dro p tests with FeCrAI rods and ass um ed th ese were bounded by (or equi va lent to) th e testing perfo rm ed wi th zirconium all oy rods. Therefore, the applicant's approach is to use th e testing to certi fy th e RAJ-II package fo r th e ATF appli cati on.
The staff indi cated that th e strain rate may be acceptable, but the staff still needs in fo rm ation to determine whether th ere may be a loca li zed effect related to the FeCrAI materi al. The appli cant noted th at the FeC rAI survi ved from a high stra in ra te tensil e test without a fracture. Th e staff pointed out that the cladding of the ATF FeCrAI rod is very thin and the staff wo uld need the fo llow in g:
I. confirm (fro m related literature data or testing) that th e slope of stress-stra in curve is hi gher fo r FeCrAI compared to that fo r zirca loy. (Oth erwise, FeC rAI rod s among zirconiu m alloy rods may be bul ged out or broken during dro p. Prov ide the stress-stra in curves fo r FeCrAI and zircal oy claddings so th at a compari son can be made.)
- 3. strai n curve at low temperature (to veri fy whether the strain rate is appropri ate fo r FeCrAI); and
- 4. a temperature range to maintain th e integrity of the claddi ng.
The appli cati on contain s a requirement fo r the Young's Modulu s in Attachment 2 Table 2-5 (a lso repeated in A tt ac hm e nt ~ Tabl e 1-2) whi ch requires a minim um Modu lus of Elasti city for the G F FeCrAI materi al to be used. Th e app licant stated that th e lower temperature of the HA C is -40°C so that was the temperature th at th e test was perfo rm ed to bound th e necessary temperature range of operation. A Stress-Strain curve fo r th e GNF FeCrAI materi al at -40°C is provid e in Attachm ent 3 Figure 2-1 .
The Regul atory Guide 7. 11 requi rements are based off materia l that is 0.025 inch es and thi cker depend ing on th e catego ry class ifi cation. The fu el cladding wall thickness is below 0.025 inches fo r thi s a pl icati on. The appli cant stated th at the thin claddi ng wall provides an additional margin against brittl e fracture in the materi al relati e to the Regulatory Guide 7. 11 req uirements because th e stress states wo uld be geometri ca lly forced to be in pl ane stress loading which has a higher fracture toughness than the pl ane-stra in loading.
Creep Model Eva luation The staff noted th at it may have questions related to the fo ll ow ing topi cs:
I. bases for the allowable hoop stress of 65.2 mega pascals (MPa);
- 2. reference and j ustifi cation of the generalized creep equati on;
- 3. so me in consistencies with units (e.g., kil o Jo ul e per mol (kJ/mol) versus kil o Joul e per Kelvin mol (kJ /K*km ol)] needs to be rev ised;
- 4. demonstrate that the I0% creep stra in li mit is conservative and prov ide th e PeC rA I stress-strain curve at th e hi gh temperatures; and
- 5. discuss ion about how the hypotheti ca l acc ident condition therm al tests and analys is co nsider th e damage fro m other hypoth etica l acc ident condition tests (e.g., drop, impact). The staff asked simil ar questi ons in the recent rev ision to the Mode l No. RAJ-II (Ce11ificate of Comp liance, Rev ision 1 1) .
At the end of the meeting th e appli cant expressed interests on having additional phone ca ll s to di sc uss the staffs questi ons and a face-to-face meeting. Division of Spent Fuel Management staff and management noted that the app licant can also request a pu bli c 1
meeting to have a detailed discuss ion of the staffs questions. The app licant al o requested that if a meeting were to be schedul ed, hav ing RC questions at least a week in advance would enhance the va lue of th e meeting.
NRC FOR M 699 (03-2013) Page 3 of 3