ML20236P146
| ML20236P146 | |
| Person / Time | |
|---|---|
| Site: | 07109271 |
| Issue date: | 07/09/1998 |
| From: | Shankman S NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Quennoz S PORTLAND GENERAL ELECTRIC CO. |
| References | |
| NUDOCS 9807160169 | |
| Download: ML20236P146 (11) | |
Text
r July 9, 1998
' Mr. St;v:n M. Qu;nnoz
- ' Trojan Sita Ex;cutiva Portland General Electric Company 71760 Columbia River Highway Ranier, OR 97048
Dear Mr. Quennoz:
I am responding to your application, dated March 31,1997, for approval of the one-time shipment of the Trojan Reactor Vessel Package (TRVP) to the US Ecology radioactive waste disposal facility on the Hanford Nuclear Reservation near Richland, Washington.
In connection with our review, we need the information identified in the enclosure to this letter.
Please provide this information within 30 days from the date of this letter. Additionalinformation related to the Safety Analysis Report or the Probabilistic Safety Study should be submitted in the fomi of revised pages.
Approval of the proposed action, i.e., the near-term shipment of the TRVP with intemals intact using operational controls under a 10 CFR 71.8 exemption, requires NRC to prepare an Environmental Assessment (EA)[10 CFR 51.30). The categorical exclusion from the need to prepare EAs that normally applies to package approvals does not apply when the approvalis issued under an exemption. We need certain environmental information in order to prepare the EA. Accordingly, provide an Environmental Report (ER) that addresses the topics identified in 10 CFR 51.30 with respect to the proposed action, also within 30 days of the date of this letter.
The enclosure contains more specific information requests regarding the ER. To the extent this information has been provided in documents already submitted to NRC, you may proside the appropriate references in the ER.
If you have any questions regarding this matter, we would be pleased to meet with you and your staff. John Cook is the Project Manager for our review of your application for transportation approval. Mr. Cook may contacted at (301) 415-8521.
Sincerely, original /s/ by CJH: for Susan F. Shankman, Deputy Director m m.N m t; o i :, n pc g,y Licensing and inspection Directorate b:rie E ELA. N d 9 Lt1 L d s Spent Fuel Project Office Office of Nuclear Material Safety and Safeguards Docket No. 71-9271 }^ D L _j
Enclosure:
As stated Distribution: NRC F/C Docket PUBLIC HLee EShum NJesen, OGC SFPO r/f NMSS r/f EZiegler NOsgood TJohnson, DWM
- See previous concurrence OFC SFPO* E SFPO* E SFPO* SFPp E NAME JCook:je EEaston WHodges SShrnE DATE 07/09/98 07/09/98 07/09/98 07/ /98 C = COVER E = COVER & Eh CLOSURE N = NO COPY OFFICIAL RECORD COPY Antrypttr.wpd
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l 9907160169 990709 l
. Mr. St;v;n M. Qu;nnoz -
' Troj:n Sita Ex cutiva '
Portland General Electric Company 71760 Columbia River Highway Ranier,,OR 97048
Dear Mr. Quennoz:
I am responding to your application, dated March 31,1997, for approval of the one-tim shipment of the Trojan Reactor Vessel Package (TRVP) to the US Ecology radioacti e waste disposal facility on the Hanford Nuclear Reservation near Richland, Washington.
In connection with our review, we need the information identified in the enclos e to this letter. I Please provide this information within 45 days from the date of this letter. A ditionalinformation f
related to the Safety Analysis Report or the Probabilistic Safety Study sh Id be submitted in the l form of revised pages.
Approval of the proposed action, i.e., the near-term shipment of the RVP with intemals intact {
using operational controls under a 10 CFR 71.8 exemption, requi s NRC to prepare an Environmental Assessment (EA)[10 CFR 51.30]. The categori I exclusion from the need to prepare EAs that normally applies to package approvals does ot apply when the approvalis i issued under an exemption. We need certain environment information in order to prepare the EA. Accordingly, provide an Environmental Report (ER) t at addresses the topics identified in 10 CFR 51.30 with respect to the proposed action, also ithin 45 days of the date of this letter. -
The enclosure contains more specific information req sts regarding the ER. To the extent this I information has been provided in documents alread submitted to NRC, you may provide the appropriate references in the ER. j if you have any questions regarding this matter we would be pleased to meet with you and your staff. John Cook is the Project Manager for r review of your application for transportation approval. Mr. Cook may contacted at (301 415-8521. I Sincerely, Susan F. Shankman, Deputy Director Licensing and Inspection Directorate Spent Fuel Project Office Office of Nuclear Material Safety and Safeguards Docket No. 71-9271
Enclosure:
As stat Distribution: N F/C Docket PUBLIC HLee EShum NJesen, OGC SFPO r/f SS r/f EZiegler NOsgood TJohnson, DWM OFC SkO p,4 , SFPO SFPO SFPO NAME 2 Cook h- EEaston N// WHodges SShankman DAT 07/ /98 07/ h/98 07/@ /98 07/ /98 C = COVER E = COVER & ENCLOSURE N = NO COPY OFFICIAL RECORD COPY Antrypttr.wpd 1
Trojan ReactorVessel Package l REQUEST FOR ADDITIONAL INFORMATION SAFETY ANALYSIS REPORT 1.0 GENERALINFORMATION 1
1-1. Verify that the listing of nuclides in Table 12 is complete, and that the activities and other data in the Table boand that of the TRVP at the time of shipment. Verify that the source terms used for the thermal, containment, and shielding analysis are consistent with the contents of this Table.
The presence of plutonium in the TRVP Indicates possible fuel failures, yet no uranium isotopes are listed. Isotopes listed in Table 3-1 differ from those listed in Table 1-2, and composition of the releasable source term was not specified (see 4-1).
1-2. Show how the release quantities, dose rates, etc., presented in Sec 1.1.1.4 were determined. What are the estimated doses to workers for recovery operations following TRVP breach overland or underwater?
A principal basis for TRVP approval under exernption is to demonstrate comparable safety under the proposed administrative and operational controls. The PGE assessment of accident consequences addressed doses to the general public, but detail on consequences of these accidents is minimal, and doses to response personnel were not considered. This information is needed to complete the assessment of possible shipment impacts. -
1-3. Provide a drawing that shows the to-be-shipped TRVP configuration, including bolt closure region, welded closures, welded shields, density of concrete, and impact limiter foam specification. Note that the shipped configuration must match this drawing.
This drawing is needed to establish final design control for the as-shipped configuration.
Deviations from this drawing will not be permitted without an amendment.
2.0 STRUCTURAL EVALUATION 2-1. Revise the SAR (page 1-11) to state:" Administrative controls will ensure that the RVP will be transported.9Dly if the forecasted daily low temperature is above 45F for the transportation route and the expected shipment duration.
ATI Consulting Engineering Documentation Package No. ATI 97-033-E001 requires that the daily low temperature be 45 F or higher in order to show an adequate safety margin against i brittle fracture under the postulated RVP drop and puncture loading condition.
2-2. Provide either a 'Soction' or a ' Detail' on Drawing No. M9259 showing how additional shield plates are attached at the locations of the longitudinal seam plates for the 2" or 5" shields.
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It appears that the longitudinal seam plates may interfers the placement of the additional shields (Figure 1-5, Drawing No. M-9259, Sht.1 & 2). .
2-3. Revise the circumferential seam weld between the 5" and 2" shields from the 3/4" fillet welds all around (Drawing No.M-9259, Sht.1) to 7/8" fillet welds all around.
The 2" upper shield and the 5" lower shield are connected by the circumferential seam weld.
Also, the impact limiters are attached to the shields. Thus, the shields and the impact limiters must stay on the RVP during the postulated drop loading condition. Appendix 2-10 provided the calculations for the sizing of the shield plate seam weld and it was shown that 7/8" fillet weld all around was required for the circumferential seem weld.
2-4. Show that the 11-11. drop height (page 1-9) during a postulated transportation accident is bounding. Provide calculation showing the total drop energy is based on the initial free drop height plus the drop distance associated with the crush of the impact limiters.
It appears that the 11-ft. drop height has been derived from the highest point of the crede when the package is mounted horizontally on the transporter minus the thickness of the impact limiter.
Since the impact limiter crush distance is approximately 24 inches to 40 inches (Appendix 7A),
the drop height for the package should be adjusted to account for the impact limiter crush distance.
2-5. Show the adjustments (e.g., design factors or other parameters) made for temperature, dynamic effects, and manufacturing variations of the nominal foam crush strength to derive the bounding crush strength curves shown in Figure 5.1 of Appendix 7A. How is tosting ofimpact limiter material accomplished? Provide additional detail on testing methods, and justify how the test results of samples correspond to performance under HAC (dynamic) conditions.
It is essential to know the adjustments made to the foam crush strength in order to conclude that the application has adequately considered the effects of temperature, dynamic loading, and manufacturing variations of the foam.
2-6. Provide detailed descriptions of how the Low Density Cellular Concrete (LDCC) will be poured into the RVP and cured (Section 2.1.1.2). The application should provide the procedures and testing requirements for the LDCC similar to those of impact limiter foam installation (Section 8.2.4).
The application relied on the LDCC to fix the contaminants in place, preventing movements of contaminants within the reactor vessel, and effectively preventing release of the contaminants to the environment. Thus, it is important to ensure the LDCC is property placed, cured, tested so that it will retain its design material properties.
2 7. Justify that the materials of construction for the steel components of the RVP are not I affected by operation and long term exposure to radiation. !
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The minimum mechanical properties for RVP materials are listed in Table 2-5 and Table 2-6. It appears that no adjustments are made for the allowable stresses and strains. The application should address potential material property degradation due to corrosion and irradiation effects.
2-8. Provide an explanation that the RVP outlet nozzle's max. local stress intensity induced by the 10g longitudinal tie-down force was calculated as 40.88 ksi but the plot of local stress intensities for the outlet nozzle showed much higher stress int 3nsities (Appendix 2-2).
During transport, the longitudinal restraint consists of a clamping assembly, that is built into the cradle support steel, to clamp two of the RVP outlet nozzles so that the package cannot move in the longitudinal direction. The plot oflocal stress intensities for the outlet nozzle showed stness intensities above material yield strength.10 CFR 71.45(b) requires that the stress in any material of the package below the material yield strength.
2-9. Pmvide a sketch or better descriptions how the tie-down forces are transferred from the RVP through straps to the cradle, to the transporter, and to the barge.
I The SAR should provide adequate description how the tie-down forces are transferred and resisted during normal transportation.
2-10. Pmvide a sketch showing how the impact limiter loads are applied to the reactor vessel to balance the inertia force during the free drop impact (22g HAC,9g NCT) conditions.
Show the distribution and the magnitude of the impact limiter reaction force.
The SAR did not provide adequate information regarding the analytical modelinertia loading and balancing by the impact limiter reaction force.
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3.0 THERMAL EVALUATION 3-1. Specify the vapor pressure that will result from the free moisture in the LDCC under both Normal Conditions of Transport and HAC, and the temperature on which this pressure based.
3-2. provide an analysis using the heat transferred by fire-induced convection.
l 4.0 CONTAINMENT 4-1. For the containment analysis in Reference 4 1, show how the source term isotopic and magnitude were calculated. Justify the assumptions that the isotopic distribution and the areal concentration of radioactivity present as surface contamination in the reactor vesselis the same as radioactivity in the steam generator tubes and a section of reactor coolant piping; include any physical data (e.g., analyses of samples taken from 3
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l components within the reactor vessel) that would support those assumptions.
4-2. Show the effect any scouring of surfaces from emplacement of LDCC will have on the releasable source term.
f 4-3. Show the effect any residual water will have on the releasable source term.
( 4-4. Provide an analysis of hydrogen produced by radiolysis. Show the distribution of any hydrogen produced, and compare it with limits for flammability and detonation.
5.0 SHIELDING EVALUATION 5-1. The following details should be included: (1) detailed derivation of the source term, including neutron flux and irradiation time of the intamal components, (2) how calculated dose rates were normalized to measured dose rates, (3) estimated errors associated with the source term calculations and normalization, (4) distribution of radioactivity in all activated components.
'5-3. Considering the uncertainties in the source term as well as possible hot spots, show that the addition of 0.5-in. steel plates are sufficient to ensure extemal radiation levels are within regulatory limits.
5-2. Why are the maximum dose rates summarized in Table 5-1 less than those in Table 5-77 4
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PROBABILISTic SAFETY STUDY
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TRANSPORT OF THE REACTOR VESSEL PACKAGE BY BARGE P-1. It is not clear what technique is being used to systematically assess the risk. From the text, it seems to be event tree methodology. However, no event trees have been
_ provided. Please specify the technique that was used to systematically assess the risk, provide the systematic methodology, and provide a graphical representation (e.g., event trees).
P-2. For barge and overtand trip segments, provide an assessment of the extemal event frequencies during this shipment, including earthquakes, volcanic activity, weather-related or pollution-related reduced visibility, tomadoes, extemal flooding, etc., and quantify the potential consequences (or lack thereof) if the initiating event is greater than 1E-7. Also, please justify any event frequencies that are less than 1E-7.
P-3. How has the scenario in which the barge breaks away from the tug been addressed in the analysis?
P-4. Is the accident rate data for years 1976 - 1980 sufficiently similar to the more recent accident rate data?
The PSS uses data foryears 1976 - 1980 from the U.S. Coast Guard Casualty database on accident rates and from the U.S. Army Corps of Engineer's Barge Traffic Volume database. To justify using these years for the traffic volume data, the PSS compares the barge traffic volume data from 1976 - 1980 with data from 1992 - 1995 and concluded that the traffic volume l remained relatively unchanged. However, no comparison was provided for the accident rate l data from 1976- 1980 to more recent accident data. Please provide a comparison of the accident rate data from 1976 - 1980 to more recent years such as 1992 thru 1996.
t-P-5. Specify the units of the U.S. Coast Guard Casualty database and show how the barge traffic volume data was used to construct a normalizing basis for placing accident rates on a per-mile basis [Page 2, paragraph 1) . Page 27 states that the majority of accidents occur on segments of rivers comprising only about 10% of the total navigable distance.-
What impact does this have on the accident rates for the Trojan region of travel?
P-6. Explain the adjustments made to the accident rates for collisions and ramming from the U.S. Coast Guard Casualty database to account for the multiple ways in which the berge carrying the RVP could become involved in an accident [Page 2). The adjustment increased the collision and ramming accident rates by a factor equal to one plus the probability that both the struck and striking vessels are freight barges. Provide Table 11.26 from Reference 1.
P-7. Explain the binning of the accident rates listed under ' Accident Types' [ Table 1 on Page 5]. Do these accident rates correspond to accident initiation events, accident progression events, or both?
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Accident initiators such as collision and ramming are grouped with accident progression events such as capsizing all under the heading of" Accident Types." Accident rates for all of these are then totaled. Capsizing is a possible consequence of some initiators such as collisions, ramming, foundering, severs weather, etc. Why are capsizing events summed with initiating events? Is the ' capsizing' heading in Table 1 referring to a separate initiating event accident rate that only relates to poor maintenance or low stability and severe weather? If not, it seems that .
there is implicit double counting in the Total, and therefore the Total would not have any meaning. What is meant by " Accident Type"? What does the TOTAL represent?
P-8. Table 1 shows the Accident Type ' Flooding / Swamping' has a relatively significant accident rate. Page 6 mentions that flooding or swamping as defined by the U.S. Coast Guard could not culminate in the Trojan barge sinking. Please explain why this is the case. What is this definition of flooding / swamping? Is this an initiating event? It is not discussed further in the PSS. Explain the reason why it is not considered to result in
! other possible accident progression events (e.g., capsize). .
P-g. Explain the 'All Other" Accident Type. In Table 1 on Page 5 under Accident Type there is an "All Other" category with an accident rate of 2.0E-7 per mile which equates to a discrete Trojan transit accident probability of 5.4E-5 (per 270.8 miles). This is not insignificant and yet it has obviously been dismissed because it is not discussed further.
Has it been assumed that the "All Other" accident type is so minor that no resultant consequences and therefore, risk is associated? If so, what is the basis for that assumption? If not, these accidents should be assessed and quantified.
P-10. What percentage of barges in the data from Table 3 are like the RVP barge and what percentage are ' typical' ? Does sinking probability data for the RVP type of barge exist which would support the PSS sinking analysis conclusion?
l The date in Table 3 is the probability of a " typical" inland barge sinking, given certain initiating events. The PSS states on page 7 that typicalinland barges have no LNitudinal subdivision l
and are transversely subdivided into six to eight watertight compartments. The barge carrying i the Trojan RVP will have two longitudinal watertight bulkheads resulting in 1g watertight compartments. The PSS presents a sinking analysis for the barge canying the RVP in order to justify lowering the Trojan barge's sinking probability below 1 E-6 for collision initiators.
P-11. The General Hydrostatics program described a stable situation that is not in immediately jeopardy of sinking or capsize in the event of extreme bottom raking [Page 12 paragraph 3]. What is the definition (in terms of time) of irnmediate jeopardy? What actions would be taken in this situation to mitigate the longer termjeopardy? Will these actions prevent t
the barge from eventually sinking or capsizing?
P-12. Provide a more detailed quantitative analysis for the TRVP barge foundering.
Page 12, last paragraph states that foundering is usually the result of either weather related I damage, and/or poor maintenance. What percentage of foundering events are the results of these causes? Are there any othercauses of foundering? Page 13, paragraph 1 states that 6
. 1 b::cause the Trojan barge will be classed, certificated, and inspected by marine surveyor to verify its " good" condition prior to use, poor maintenance may be dismissed as a probable cause of foundering. What about the tug boats' maintenance? The paragraph also states that heavy weather can be dismissed as a probable cause of foundering because the barge will not be subjected to severe wave conditions due to sailing instructions. The PSS asserts that these two assumptions change the probability of the accident sequence foundering-sinking from 2.1E-5 for the number of miles of Trojan barge travel (based on typicalinland barge data) to not credible (for the Trojan barge). These statements do not justify reducing the probability of this accident sequence to non-credible. For example, has the data on foundering been analyzed to show that i foundering occurs only on poorly maintained barges? Describe how inspection and certification of the barge by a marine surveyor rules out poor maintenance (include a description of what will be inspected). What are the maintenance practices of typical barges? The amount of time for the barge to travel up the Columbia River is approximately 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. How accurately can the weather be predicted for the full barge travel time (including local summer thunderstorms)?
Paragraph 1 on page 13 states that should wave heights on any of the Columbia River pools exceed 6.5 feet during the voyage, the barge will hold below the dam until the wind and wave conditions abate. Will the barge be docked or held by the tug? Are there docking locations along the entire route that are capable of holding the Trojan barge in the event of severe weather? Wha? protection is provided by holding the barge below the dam in these situations?
What is the definition of severe wave conditions? Can the barge handle the most severe waves recorded for this river?
P-13. Page 13 paragraph 3 states that the discrete probability of capsize for a typical barge of 8.1E-6 does not apply to the RVP barge because the conditions for capsize (poor maintenance and severe weather) do not apply. Questions from P-12 apply here as well.
P-14. Page 13 paragraph 3 states that if the barge is raked, it could capsize (reking can result from collision, ramming, or grounding). If the RVP remains attached to the barge, the deepest point of submergence for the RVP would be 42.7 feet. A PGE contractor has shown that the RVP retains its integrity when submerged to a depth of 50 feet in accordance with 10CFR71.73(c)(5). However, paragraph 3 states "The sea fastenings satisfy the ANSI N14.24 standard ..., so the RVP il jjigly to remain attached to the barge in the extremely unlikely event of a capsize." Please quantify "likely". This should be defined and shown quantitatively to be negligible before it can be dismissed. If it is not negligible, it should be included in the analysis.
P-15. Page 17 states "The cargo securing arrangement should be designed to maintain control of the RV Package under exposure to a peak transverse acceleration of 1.6g." "The probabilities of submergence due to causes other than acceleration induced failure of the I sea fastenings during a collision are effectively zero." What about acceleration induced l_ failure of the sea fastenings during a ramming? Was this dismissed due to the 10 knot l
limit? The PSS did not discuss the accident sequence Ramming - RVP overboard. The staff assumes the maximum acceleration for this sequence would not result in RVP overboard, but the analysis was not provided. Please provide your assessment of this sequence.
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- O TRANSPORT OF THE REACTOR VESSEL PACKAGE OVERLAND P-16. This study considers only that fraction of traffic accidents that occurin the 0 - 10 mph l range. (Page 4). The basis for this assumption is that the RVP transporter will be limited to 5 mph. However, other trafficis not limited to this speed. Therefore, what is the validity of this study's consideration of only the fraction of accidents that occurin the 0 -
10 mph range?
I ElWlRONMENTAL REPORT I
E-1. Provide an Environmental Report (ER) that addresses the topics identified in 10 CFR 51.30 with respect to the proposed action. Altematives to the proposed action should include (1) the removal, segmentation, and s'aparate shipment of the vessel, and vessel intemals, and (2) on-site vessel storage. Impacts should be addressed for routine and
! accident conditions in transport. These should include a detailed comparison of l occupational and public doses incurred by proposal action and attematives. To the l extent that some of this information is contained in documents already submitted to NRC,
!- provide the appropriate references.
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l Approval of the proposed action, i.e., the near-term shipment of the TRVP with intemals intact l using operational controls undera 10 CFR 71.8 exemption, requires NRC to prepare an Environmental Assessrrent (EA)[t0 CFR 51.30]. The categorical exclusion from the need to prepare EAs that normally applies to package approvals does not apply when the approvalis issued under an exemption. The information contained in an ER is needed by NRC to prepare the required EA.
E-2. Provios a summary of the regulatory provisions (s) for which exemption is required under t
10 CFR 71.8, and other requirements for which relief is required for the proposed action.
For each itern (e.g., normal condition tests, hypothetical accident initial test conditions and tests, brittle fracture analysis method, and in operability oflifting and tie-down
! devices). show how operational controls and/or other factors applicable to this shipment provide reasonable assurance of shipment safety. Describe any related exemptions being sought from DOT.
The scope of the exemption must be clear and complete so that the impacts of the proposed action may be properly addressed in the EA.
l E-3. Provide the rationale for not shipping the TRVP shipment in full compliance with the applicable NRC and DOT requkements,i.e., show why certification of the TRVP as a Type B package is impractical.
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Ex mptions cre considered cnly wh n NRC and DOT tra satisfad that compli nce with the regulations is impractical.
l l E-4. What is the recovery plan for the TRVP overboard scenario?
This is one of the most likely-to-be-asked questions regarding the shipment, and a response is needed to confirm that mitigation measures are in place, l
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