ML20039E412
| ML20039E412 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/02/1976 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML111090060 | List:
|
| References | |
| FOIA-80-515, FOIA-80-555 NUDOCS 8201070255 | |
| Download: ML20039E412 (10) | |
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NUCLEAR REGULATORY COMidlSSION T
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l-D. G. Eisenhut, Assistant Director for Operating Technology E 3. [
TECilNICAL ASSISTANCE REQUEST NO. ORB 4 - 43 Your assistance is requested in the following:
I PLANT NAME:
"Ihree Mile Island Unit 1 DOCKET NO.:
50-289 RESPONSIBLE FRANC!!:
Operating Reactors Branch #4 (ORB 4)
CONTACT:
D. N. Bridges.'
(x27435)
OPERATIGNAL TECilNOLOGY BRANCilES:
Plant Systems Branch Engineering Branch TARGET COMPLETION DATE:
October 1, 1976 f
DESCRIPTION OF REQUEST: 'Ihe Metropolitan Edison Company (Meted) has l
submitted an analysis (attached as an enclosure) dated February 14, 1976 for the Spent Fuci Cask l
Drop Accident for Three Mile Island Unit 1 (TM1-1).
Please review this submittal and provide us with your comments and input to the safety evaluation report.
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Robert W. Reid, Chief Operating Reactors Branch #4 Division of Operating-Reactors ccPCDNiiridges RIngram
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Engineering Branch 1
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REQUEST FOR ADDITIONAL INFORMATION 2i THREE MILE ISLAND UNIT 1 CASK DROP ANALYSIS DOCKET NO. 50-289 1.0 The Cask Drop Evaluation for Three Mile Island Unit 1 (TMI-1),
enclosed with your February 14, 1976 letter, states; (1)
"During transfer of the cask to and from the decontamination pit and raising and lowering of the cask within the pit, results s
of evaluations indicate that with the present system, cask drop accidents could possibly result in unacceptable damage to engin-cered safeguard circuits, spent fuel pool cooling pipes, and cooling water pipes to the spent fuel pool coolers. Met Ed is currently evaluating possible plant modifications and changes l
to operating procedures to correct this situation." and (2) "When the location for cask decontamination operations is selected, the specific plant modifications and changes to operating pro-cedures and technical specifications that are required will be described to NRC. Uniti such time, the present cask decontamination l ~
l pit will not be used."
Furhter, in the proposed changes to the Technical Specifications enclosed with your September 21, 1976 letter, it is proposed to relocate the cask l
l decontamination area in the shaded area shown in Figure 3.11-2.
(September 21, 1976 submittal).
Further, FSAR Figure 1-3 shows that Unit 1 new fuel storage area is located parallel to the transporter railroad tracks and apparently in the path of the spent fuel cask as it q
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' 'i travels to and from the Unit 1 decontamination area as well as the v/ock gj ~,
corresponding stations in Unit 2.
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~-S-S It is expected that an incoming empty shipping cask will be moved from
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L moved to loading pit. Conversely for the Unit 1 loaded cask, it is expected that it will be moved from the cask storage and loading pit l
co,a c.,+we c< erd + me ave, 46,c nea 4uet sa c.a 9m va at& 3 across the railroad tracks /to tee decontamination area for decontamina-
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tion before being loaded on the transporter.
I To enable us to complete our review and evaluation of the safety implications of the proposed changes, once the shipping cask and trans-porter has entered the Unit 1 building for the offsite shipment of fuel from either Unit 1 or Unit 2, we will require the following additional l
information.
1.1 Provide one drawing showing the relative location of the following areas of both Units 1 and 2; the new fuel storage areas, the spent fuel storage pools, the spent fuel cask storage and loading pits and, the specific location of the cask decontamination areas.
1.2 To adequately evaluate the potential for unsafe conditions occurring l.
in Units 1 & 2 following a cask drep accident at any point along l
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its revised path of travel between the transporter, the newly located decontamination area, and the spent fuel cask loading pits, superimpose the travel path of the shipping cask for Units 1 and 2 on the drawing requested above.
i 1.3 Verify that the path of travel of the spent fuel cask from the d
transporter to Unit 2 stations have not changey due to these
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proposed changes or describe, discuss and demonstrate that no safety related consequences could result from these changes.
1.4 Assuming the proposed changes, ic;entify all equipment which may become essential in attaining a safe reactor shutdown which is located below or adjacent to the cask handling travel path.
Where possible reference the appropriate Figures in the FSAR which show the location of the above essential equipment.
2.0 It is stated in your submittal that:
(1) the cask will be handled above and adjacent to engineered safeguard equipment (2) the floor slabs are not designed to withstand the impact of a dropped cask (without disclosing to the reviewer the critical input parameters such as cask weight, impact area, drop height, drop loca-tion, and the assumptions regarding credit taken in the analysis for the action of impact limiters).
(3)f cask sizes considered in the evaluation included small truck casks weighting approximately 25 tons up to the large rail casks weighting up to the rated capacity of the fuel handling crane of 110.
Assuming the proposed revised paths of travel of the spent fuel shipping cask, indicate the points along the travel path where cask drop accidents Yrc:cek were analyzed.
Describe the assumed critical analyses input parameters.
Discuss and demonstrate that under all creditable cask drop accidents' that unacceptable damage will not occur to any of the above identified essential equipment such as piping, pumps, electrical trays. Mr i
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,f, demonstrate that following a cask drop accident the cask will not tip, roll olr impact on Unitstored new fu -or caus the sp ng /
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between the/new fuel assemblie do be' ecreased such as to-1 d to a criticality
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In all cas[ provide the assumptions made in the analyses accident.
and the resulting safety margins which support your conclusions.
3.0 For each of the spent fuel shipping casks that will be handled, demon-strate that the crane hoist will not subject the various cask trunnions and handling yokes, considered in your evaluation to excessive decelera-tion loads under the following assumption:
(1) the cask is near its upper limit of travel (2) the cask is being lowered at its maximum speed as defined by the hoist controls, and (3) the crane experiences a loss ofpowerandtherebycu)singthehoistmechanicalloadbrakeandthe solenoid brake to automatically set.
Accordingly, in tabular form for each cask, provide the following information:
c (a) the statif factors of safety of the cask handling yoke, the cask trunnions and the weight of cask (b) the maximum lowering speed as defined by the hoist controls (c) the results of dynamic analyses which demonstrate that the cask trunnions and handling yoke have sufficient design margin to a
preclude their failure due to the decjeration loads created by the hoist brakes.
4.0 Your evaluation showed that during a cask transfer to and from the transporter, " cask drops" could possibly result ir unacceptable damage j
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~ ~ ~ ' ~ ~ will not tip, roll, or' impact'on Unit I stored new fuel in' a manner which
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In particular,- state a maximum
-~~-~' credible value for 'the multiplication factor (Keff) f 11 wing such a cask-4
- - - - drop accident considering the-effects-of any possible change-in fuel.
j spacing, fragmentation and compaction, and the introduction of. any t
possible moderating material (concrete, aqueous. foam, water fron u_ _ _..
ruptured. pipes or fire-fighting apparatus, etc.). _ This eximum credible
_.value should. include _ reflective _ effects _from s_tr.uctural conc _ rete and any other moderating materials near the fuel mass.
In all cases...
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-5 l1De j j to engineered safeguards circuits. To correct this you are evaluating plant modifications, such as relocating one of the engineered safeguards 4
0 circuit trays.
Assuming the engineered safeguard circuit trays have been relocated as (f c be e, s 14,imt. evk m.tta Qj proposed in Figures IV-3 and IV-4,aiid~a~caik~ drop accidi~nt occurs such
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l as to disable one of the two separated engineered safeguard trays when
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the reactor is at power.
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(a) Under this assi:mption, describe, discuss, and demonstrate that the single event (cask drcp) will not initiate another event that potentially could prevent a safe reactor shutdown or degrade the spent fuel pool cooling system.
If either of the above could occur your response should also assume that a single failure may also l
occur in the systems associated with the remaining intact engineered safeguards tray or other essential systems.
(b)
In reference to the criteria that will be followed in making the modifications, the following statement is made " Damage to[ulti- [.c.
colored circuits along with damage to circuits associated with one of those colors is acceptable since the multicolored circuits are protected interconnections b'etween two redundant channels."
Provide further clarification which demonstrates the protected interconnections between two redundant channels will provide adequate protection in the event of:
(a) any open circuit, (b) any short circuit and (c) any short circuit between any two conductors that could develop as a result of a cask drop accident,and thereby 1
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.1 provide assurance that no more'than one channel of redundant engineered safeguards system, or reactor protection system could
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be degraded or disabled.
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5.0 It has been noted that the bases provided in the September 21, 1976 submittal for Item 3.11.2 of the revised Technical Specifications has omitted reference to FSAR Figure 9-18A entitled Fuel Handling Building Crane Key Interlock System Limits'.' Provide a revised Figure 9-18A showing the new key interlocked limits of travel of the crane.
g uml]by Further, the present Technical Specification states that in the event of a l'arge load drop accident, there would be no possibility of this
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n resulting in any damage....
The proposed corresponding statement in the revised Technical Specification states there "would be p%hl, discuss and clarify the purpose of this Describe less possibility."
revision and the particular equipment and structures involved.
S 6.0 Since the keyed interlock limits of crane travel only applief when 15-the load being handled exceeds Q tons, provide the following informa-j tion regarding the system acceptability when there is no load on the J
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crane hook, and it is over the stored spent fuel when "two blocking" occurs (i.e., the upper limit switch fails and the lower hoist block contacts the lower load block).
Demonstrate that either (a) the
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resulting radiological release will remain within acceptable limits should the lower load block and hook drop and impact on the stored spent H
fuel; or (b) the lower load block and hook will not drop should two blocking" occur. l ~ .b ^ rJ
.e E] s -7 j (in the latter case the analysis should take into account the peak , W -3, stall torque of the hoist motor plus the kinetic energy of the hoist .M power train and motor when the hook is being raised at its maximum ] rated speed as allowed by the control system). NA > !r e,w a e c yj 0.: >.,.u,.y rh j.u u.< L e f.r-pn.{...r 6.0 pescribe and-discuss _the following with the aid of legible drawings: (a) locate and identify the engineered safeguards equipment and other equipment that may be required for hfe-operation-or]a cold shutdown of the reactor and whose operation may potentially be threatened by a cask drop at any point along its travel path as it moves between the following areas: (1) the transporter (2) the decontamination pit and (3) the spent fuel storage pool cask loading area. (b) assuming the most adverse combination of cask drop conditions, demonstrate by analysis that sufficient design margin exists to Oc enable the staff to conclude that, for specific shipping casks 3 considered in the analyses, the resulting damage will not endanger kafe-teactoroperation-and/on]the facility's ability to attain and maintain a controlled, cold, safe reactor shutdown following a cask drop event at any point edm7 d< b d1. 3 i (c) in regard to the shipping cask crane which is shared by Units 1 and 2 it has been noted that the staff's Safety Evaluation Report for Unit 2 contains the following statement "We find the fuel 70 handling system to be acceptable for a cask not exceeding )6 tons in weight, and will condition the operating license accordingly and unless the applicant justifies use of a larger cask." Section 3.11.4 ' - + ~ ~~mm-a P v g <g ry g g
y sto % $rau h j u 2L, na.eay.cf.A t wm ,. B{ _ g.. j of the Unit 1 Technical Specifications would permit the crane to x I handle loads up to 110 tons since it states " Loads in excess 'of ? hookcapacityshallnotbelifted,excketforloadtesting." J f Describe and discuss any differences which exist between Units.1 and 2-l S (-asitrelategtocaskdropaccidents. Further, the depth of detail' e-s y.t$, up a p,rovided should enable the reviewer to conclude tfist the crane rated 0 n.Z.n A l -tLeJ _A e;kt cvas load-kHO ton)-for/ Ilit 1 dracceptal e. to.bOj (Feb e,y i 4 t *,% l 7.0 Figure IV-3,Ishowing the modified cask transfer path and new location for engineered safeguards tray, indicates that the rail car is located ( partially outside the building during those times when the cask is being lifted from and lowered onto the rail car. Describe and discuss what. means will be provided to prevent the rail car position from being accidceA adversely altered during cask handling, such that it spans both the red and green cable trays, during a cask drop accident and thereby being in pw.6 ug we a position to dause damage to both redundant portions of engineered safeguards cable trays. l l-I 8.0 Describe, discuss and demonstrate that there are no significant adverse safe'ty consequences resulting from having the heavy rolling door, shown in FSAR Figure 1-8, Section E) - E, open during spent fuel cask handling j operations involving the offsite shipment of spent fuel from either Units -t 1 or 2 should a cask handling accident occur. Should the open doors result in a potential hazard to public health and safety, describe your proposed corrective measures. 1 e 4 L.
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- 9. 0 On Page III-l of your report, you state "The height of the cask lower surface is administrative 1y maintained at less than 1 foot above the top of the spent fuel pool walls (elevation 348' - 0").
On Page IV-4, you state " Administrative procedures will be used to j limit the height the cask lower surface is raised above the top of the "B" spent fuel pool to 6 inches maximum." Clarify what will be the carrying height of the cask bottom surface, with respect to fixed structures, at all points along the path of travel of the spent fuel shipping cask while it is within the building. What are the measures, other than administrative controls, which could be incorporated to preclude cask drop heights exceeding the aboveYvalues ". ('.l_. _ _. ~. " '. 10.0 The FSAR states "A Whiting automatic paddle-type limit switch is e e, installed for upper hoist limit to prevent two-blocking situations." Describe the design features or procedures that will be used to provide assurance that a single failure will not defeat this protec-n tion against two-blocking. .,.._.s. _.- _ ~ + - .-.g.-,~..,-- s.w. - -. ~, -.. - -., _ - _. ~... < - -. - - ~ - -.... - - - - - - - - - - - +. + -. -., - >. ~. - - -
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ip l k / March 24, 1976 p p. m Docket No. 50-289 I detropolitan Edison Company ATTN: Mr. R. C. Arnold Vice President - Generation P. O. Box 542 Reading, Pennsylvania 19603 i Gentlemen: RE: THREE MILE ISLAND Our letter, dated February 18, 1976, provided guidance with i respect to information that must be filed with the Ccamission l under the provisions of Section 7.B of Appendix I.to 10 CFR Part 50, l issued May 5, 1975 As discussed in a telephone conversation on March 23, 1976, the NRC staff will host a 1-day meeting at our Region I Cffice, 631 Park Avenue, King of Prussia, Pennsylvania, April 8,1976, beginning at 9:00 a.m., to provide additional guidance and to discuss the submittal of data and methods of evaluation. To assure that the discussions are productive, we are requesting that you send technical representatives to this neeting who will be directly involved in furnishing the required information and data, with respect to the radwaste treatment and effluent centrol syste=s, site =eteorology and hydrology and radiological dose assessment. The< enclosure was prepared by Region I to assist you in making travel arrangements for the meeting. Cur contact at Region I will be Peter Knapp. If we can assist you in making arrangements for your participation in this meeting or if you have problems or questions concerning your travel arrangements, please contact Peter Knapp at Area Code 215/337-1150 or FTS 488-1221. Sincerely, ! hb h-+u su Robert 'd. Reid, Chief Operating Reactors Branen #4 Division of Operating Reactors
Enclosure:
Travel Arrangements cc: See next page e _.l L .o_ ,1 Q &Ah .~
y., Metropolitan Edison Company cc :. w/o enclosure G. F. Trowbridge, Esquire Shaw, Pittman, Potts, Trowbridge 5 Madden Barr Building 910 17th Street, N. N. Washingtcn, D. C. 20006 l GPU Service Corporation l Richard W. Howard, Project Manager Thomas M. Cricains, Jr., Safety and Licensing Manager 260 Cherry Hill Road Parsippany, New Jersey 07054 Pennsylvania Electric Company Mr. R. Pl. Conrad Vice President, Concration 1001 Broad Street Johnstoten, Pennsylvania 1S907 Mr. Weldon 3. Archart, Chairman Bcard of Supervisors of Londonberry Tour. ship 2143 Fo.xiana Road Middletown, Pennsylvania 17057 Miss Mary V. Southard, Chairnan Cititens for a Safe Environment P. O. Box 405 HarrisburS, Pennsylvania 17108 Covernment Publications Section State Library of Pennsylvania Box 1601 (Education Building) Harrisburg, Pennsylvania 17126 i .}}