ML20154N257
| ML20154N257 | |
| Person / Time | |
|---|---|
| Issue date: | 10/15/1998 |
| From: | Essig T NRC (Affiliation Not Assigned) |
| To: | Sohinki S ENERGY, DEPT. OF |
| References | |
| PROJECT-697 TAC-MA0118, TAC-MA118, NUDOCS 9810210226 | |
| Download: ML20154N257 (9) | |
Text
- _
Octob::r 15,1998 Stephen M. Schinki, Director Office of Commercial Light Water Reactor Production Defense Programs DP-62 l
U.S. Department of Enerry Washington, DC 20585
SUBJECT:
SUPPLEMENTAL REQUESTS FOR ADDITIONAL INFORMATION REGARDING DOE TOPICAL REPORT ON TRITIUM PRODUCTION CORE (TAC NO. MA0118)
Dear Mr. Sohinki:
The NRC staff is reviewing your topical report entitled " Tritium Production Core (TPC) Topical Report" submitted by letter dated July 30,1998. By letter dated September 29,1998, the staff transmitted its initial request for additional information (RAl). The review by the Plant Systems Branch has identified a '. umber of other areas where additionalinformation is needed before the staff can complete its review.
You are requested to provide a response to the enclosed requests for additionalinformation (RAls) in the form of a letter or as revisions to your TPC topical report by December 15,1998.
If you have any questions regarding this request, or if you wish to schedule a meeting with the staff to discuss the RAls and your proposed response, please contact the project manager, J. H.
Wilson, at (301) 415-1108.
Sincerely, N
Thomas H. Essig, Acting Chief Generic Issues and Environmental Projects Branch Division of Reactor Program Management Office of Nuclear Reactor Regulation
Enclosure:
As stated Project No. 697 cc: See next page
)l Distribution:
Central Files PGEB R/F RArchitzel RJolly BSheron JRoe/DMatthews PUBLIC JHWilson TEssig STurk GTracy DOCUMENT NAME: g:\\ tritium \\tpctrrai.sup Office PGEB gs SC:PGEB (A)BC:PGliB,
f Name JHWilsonf RArchitzel[b7Essig '
9\\
Date 10//f/98 10//f/98 10/ lh98 OFFICIAL RECORD COPY 9810210226 981015
~
PDR ORG EUSDOE PDR Y p o r VY 7 a
9pDs V d'
hR090 p fFFIAQMQV g
C Cleoq O
1 UNITED STATES g
g NUCLEAR REGULATORY COMMISSION 2
WASHINGTON, D.c. 2066tMio01 o
o 4****Ag October 15,1998 Stephen M. Sohinki, Director Office of Commercial Light Water Reactor Production Defense Programs DP-62 U.S. Department of Energy Washington, DC 20585
SUBJECT:
SUPPLEMENTAL REQUESTS FOR ADDITIONAL INFORMATION REGARDING DOE TOPICAL REPORT ON TRITlUM PRODUCTION CORE (TAC NO. MA0118)
Dear Mr. Schinki-The NRC staff is reviewing your topical report entitled " Tritium Production Core (TPC) Topical i
Report" submitted by letter dated July 30,1998. By letter dated September 29,1998, the staff transmitted its initial request for additional information (RAl). The review by the Plant Systems Branch has identified a number of other areas where additionalinformation is needed before the staff can complete its review.
You are requested to provide a response to the enclosed requests for additionalinformation (RAls) in the form of a letter or as revisions to your TPC topical report by December 15,1998.
If you have any questions regarding this request, or if you wish to schedule a meeting with the staff to discuss the RAls and your proposed response, please contact the project manager, J. H.
Wilson, at (301) 415-1108.
Sincerely, Thomas H. Essig, Acti Chief Generic issues and Environmental Projects Branch Division of Reactor Program Management Office of Nuclear Reactor Regulation
Enclosure:
As stated i
Project No. 697 cc: See next page l
OFFICE OF NUCLEAR REACTOR REGULATION SUPPLEMENTAL REQUEST FOR ADDITIONAL INFORMATION REGARDING DOE'S TRITIUM PRODUCTION CORE (TPC) TOPICAL REPORT PROJECT NO. 691 A. Containment Systems and Severe Accid 6nt Branch The Containment Systems and Severe Accident Branch has no additional requests for additional information (RAls) at this time.
B. Emeraency Preparedness and Radiation Protection Branch The Emergency Preparedness and Radiation Protection Branch has no additional RAls at this time.
C. Electrical Enaineerina Branch The Electrical Engineering Branch has no additional RAls at this time.
D. Instrumentation and Controls Branch The Containment Systems and Severe Accident Branch has no additional requests for additional information (RAls) at this time.
E. Materials and Chemical Enaineerina Branch The Materials and Chemical Engineering Branch has no additional RAls at this time.
F. Mechanical Enaineerina Branch The Mechanical Engineering Branch has no additional RAls at this time.
G. Plant Systems Branch 2.6 Engineered Safety Features 1.
Section 2.6.1 of the topical report, SRP 6.4 " Control Room Habitability System," states that only the radiation hazard limit criteria is potentially impacted by the incorporation of TPBARs. Tritium radiation is considered insignificant in meeting the dose guidelines of SRP 6.4 for operating plants because of its very low site release and 10 CFR 20 does not provide guidance on site tritium release restriction. Explain what modification in analysis should be made for a plant with TP core to meet the radiation hazard criteria of SRP 6.4.
What is the potential impact of tritium concentration from plant release due to additional tritium from TPBARs on radioactive exposure to plant operators?
i
.. 7 2.9 Auxiliary Systems 2.
Section 2.9.1 of the topical report, SRP 9.2.1, " Station Service Water system," states that the physicallayout and operation of the Station Service Water System are not required to be modified. However, the system heat transfer and flow requirements may be impacted by the TPC due to the increase in the spent fuel pool heat load during cooldown operations and the subsequent impact on the Component Cooling Water System.
Provide an evaluation of the effects of the new heat loads introduced by the TPC on the station service water system for the reference plant.
3.
Section 2.9.1 of the topical report, SRP 9.3.4, " Chemical and Volume Control System (CVCS)," states that the physical design and operation of the CVCS are not being modified for the TPC, and the RCS parameters and the safety injection function of the I
CVCS are not affected by the TPC. Discuss the capability of the CVCS with respect to the change of boration requirements due to the TPC.
4.'
Se : tion 2.9.2.1.4 of the topical report states: it is expected that for most plants the weight of an assembly with TPBARs would not be significantly greater than that evaluated in the existing seismic analysis for the fuel storage racks. Discuss how the seismic analysis could be affected when the plant's spent fuel pool is designed with high-density storage racks. (to be referred to ECGB) 1 5.
Section 2.9.3.2 of the topical report states that Westinghouse provided the spent fuel pool j
cooling system design for the reference plant based on removal of 1/3 of a core and a 12-month fuel cycle. Section 2.9.3.1 of the topical report states that a significant portion of the TP core (approximately 75 percent) will be removed during a normal refueling.
This will increase the heat load in the spent fuel pool and cause an increase in the maximum pool temperature. For the reference plant, discuss how the forced cooling capability of the existing spent fuel pool cooling system will maintain the bulk average pool temperature under conditions of maximum heat generation.
6.
Westinghouse performed decay heat load analysis to examine two best-estimated cases; i.e., (1) actual number of assemblies removed from the core for an 18-month fuel cycle and (2) removal of the required assemblies during a TPC equilibrium cycle. Section 2.9.3.5 of the topical report provides the results of the analysis of the decay heat loads for a normal core and a TP equilibrium core. The analysis indicates that the maximum pool temperatures with a normal core at the end of Cycle 7 are calculated to be 138 F and i
with a TP core,147 "F, at the end of Cycle 11. SRP 9.1.3, " Spent Fuel Pool Cooling and j
Cleanup System," states that, for the maximum heat load with the normal cooling system i
in operation, the temperature of the pool should be kept at or below 140 F. If the normal cooling system is not capable of maintaining the pool temperature within the acceptable limit of the SRP for a TP equilibrium core, what is the remedy for resolving this problem?
7.
Based on its heat load analysis, Westinghouse concluded in Section 2.9.3.6 of the topical report that the increase in temperature is not trivial and there is a negative impact on j
system heat removal capability. However, in Section 2.9.3.2 of the topical report i
Westinghouse states that the heat load from each TPBAR itself is on the order of a few watts, even with as many as 3344 TPBARs in the core, and the total additional heat load is trivial.
. r The staff noted that the statements in these sections appear to be inconsistent with respect to the impact of the TP core. Clarify the rate change of heat load due to TPBARs contributing to the change of temperature in the spent fuel pool based on this analysis.
8.
Section 2.9.3.6 of the topical report states that the FSAR description of the spent fuel pool cooling system will be revised to reflect the new input and the resulting maximum pool temperatures. Table 2.9.3-1 of the topical report provides an assessment for the effects of the TPBARs on the spent fuel pool cooling system based on the reference plant's FSAR. The staff reviewed the FSAR and found that the data provided in Table 2.9.3-1 of the topical report that is attributed to the FSAR is not in the reference plant's FSAR. Provide the FSAR information related to the assessment of Table 2.9.3-1 and indicate the portions of the FSAR that need to be revised.
9.
When analyzing fuel handling accidents for a spent fuel pool, it is assumed that a spent fuel assembly is dropped in the pool during refueling operation and that all of the fuel rods in the dropped assembly are breached. Discuss whether a dropped assembly with TPBARs will be bounded by the current fuel handling accident analysis. In the reference plant, does the current water level of the pool above the top of the spent fuel assemblies provide the minimum required water shielding depth for the assemblies with TPBARs?
- 10. Section 2.9.4 of the topical report states that, for plant cooldown, there are two analysis of record. The second anafysis is referred to as single train cooldown from 350
- F to 200 F, in which only one RHR and one CCW heat exchanger are available and the cooldown time limit is 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. It further states that the CCWS of the reference plant is designed with a capacity to provide cooling water only to the heat exchangers and pump coolers of the RHR system, and the spent fuel pool heat exchangers.
The additional heat load generated by TPBARs from the spent fuel pool heat exchangers could increase the demand for CCW flow. Discuss whether the single CCW operating train has the capability to cooldown the plant to the cited temperature range within the time limit.
- 11. Section 2.9.4 of the topical report states that during plant refueling, more fuel assemblies are removed from the core when TPBARs are incorporated and that this would appear to increase the heat load on the component cooling water system (CCWS). It also states that there is no net effect on the CCWS during refueling because the increase in the her load is offset by a corresponding reduction in the heat load from the residual heat removal (RHR) system heat exchangers and that this is because less decay heat is coming from l
the RCS.
j l
Address how the CCW flow distribution to these system heat exchangers is balanced.
l Explain whether the CCW flow to the RHR heat exchangers and the spent fuel pool heat j
exchangers are from separate and independent trains. Discuss whether flow indication
]
in the CCWS is required to control CCW flow during refueling.
l l
i
4-
- 12. Section 2.9.5 of the topical report states that, due to the incorporation of TPBARs, the tritium levels in the reactor coolant system will increase and the makeup water requirements will also increase to maintain the tritium concentration within acceptable levels. It is expected that the demineralized water makeup system will operate more frequently.
Clarify whether the domineralized water storage tank of the reference plant has the capability to satisfy the higher demand on demineralized water supply.
2.11' Radioactive Waste Management
- 13. Section 2.11.2 of the topical report uses the term " Design Basis Sources". Define the
" design basis sources". Specify the design basis fuel defect level and parameters used in the calculation of design basis fission product activities.
- 14. Section 2.11.2.2 of the topical report concludes that the operation with a TPC is expected to have a negligible impact on the design basis sources by comparing noble gas and lodine isotope inventories. Furthermore, the report concludes that the small differences noted in the fission product activities associated with a TPC operation are not expected to affect the ability of the plant to meet the applicable regulatory requirements.
The staff finds that the comparison in the report includes only noble gas and iodine isotopes, but not the other fission product sources such as radioactive isotopes of Cs, Mn, Rb, Sr,...etc., that may also be presented in the design basis sources. The comparison can not support the point that there is a negligible impact with respect to the
- overall design basis sources. Consequently, the comparison is not sufficient to conclude that a TPC operation will not affect the ability to meet the applicable regulatory requirements. Provide additional data of a more complete spectrum of the fission products in the design basis source to show a comparison of the whole spectrum of the design basis sources.
- 15. In Section 2.11.2.1, a design goal of less than 1.0 curie per year per TPBAR release to the primary coolant was established. In Section 2.11.3.2, a maximum tritium concentration of 3.5 uCi/g in the RCS is recommended.
- a)
What are the bases for using these quantities as the design goal and recommended tritium concentration?
b)
Describe the tritium monitoring ano surveillance programs. What quantity and how willit be monitored? Willit be monitored continuously? How frequently willit be sampled and analyzed? Is it going to be under plant technical specifications control? What will the operator do if the monitored tritium activity / concentration is above the specified design goal or recommended concentration level?
- 16. Section 2.11.3.2 of the report uses the assumption of two failed TPBARs for the worst case impact analysis. It states that the failure of two TPBARs is based on a conservative projection of burnable absorber rod experience (operating plant with other types of bumable poison rods). Insufficient information was provided in the report to justify the above assumption. Provide the data base (number of rods, duration of operation, types L
f
. wa
- e.
4 -em e.
at
-'e+-
. of burnable absorber rods, types of rod failure mode, applicability of the data from the referenced rods to TPBAR) to justify the conservatism of this assumption.
- 17. In the Section 2.11.J.2 subsection on Liquid Release for Boron Control, it is stated that the dilution required over an equilibrium cycle for both the TPC and a typical conventional core is found to be approximately 5 RCS volumes over an 18-month fuel cycle. In the subsection on Tritium Control by Liquid Discharge, it is stated that the amount of RCS discharge must be increased to about 6 RCS volumes per year (i.e.,9 RCS volumes per 18 month cycle) in order to remain below the recommended maximum RCS tritium concentration of 3.5 uCi/g. In Section 2.11.5.2, it is stated that based on the design basis release from the TPBARs, on the order of 7% RCS volumes will be discharged in order to maintain the in-plant tritium concentrations to acceptable levels, a)
Clarify whether the discharge rate of 7 % RCS volumes is per year or per 18-month fuel cycle, b)
The three numbers: 5 RCS volumes over 18-month fuel cycle,6 RCS volumes per year, and 7 % RCS per et cetera, are not consistent. Explain the inconsistency.
For example, the required RCS discharge rate for RCS tritium controlis higher than the rate for the boron control. Explain how to control both the tritium concentration and boron concentration at the same time.
- 18. Section 2.11.5.3 states that the additional number of resin bed changes due to the use of TPBARs is approximately one per year, or about a 10% increase in the estimated annual volume of primary resins and a small percentage of the total annual radwaste generation.
How much is a "small percentage?"
j Furthermore, Section 2.11.5.3 states that the estimated solid waste activity increase is I
from 2000 Ci to 2600 Ci which constitute a 30% increase in the low level solid waste generation rate. Consideration of two failed TPBARs results in an increased number of resin bed changes from one to approximately four per year.
l In light of the above estimated increases in solid waste, how could the plant still comply with the regulations stated in Section 2.11.5.17 l
- 19. Section 2.11.6.2 states that the current process and effluent radiological monitonng instrumentation and sampling systems that are in place at the reference plant, as well as at other operating PWR plants, include the capability for monitoring the tritium levels i
within the plant and in plant effluent pathways.
Clarify the specifics (locations, types) and capability (range) of the current process, monitoring instrumentation, and sampling systems that are mentioned in the above I
statement for monitoring tritium.
H. Quality Assurance and Maintenance Branch The Quality Assurance and Maintenance Branch has no additional RAls at this time.
- l. Reactor Systems Branch l
The Reactor Systems Branch has no additional RAls at this time.
j
.l
?
J Project No. 697 -
Max Clausen Office of Commercial Light-Water Reactor Production DP-62 Tritium Project Office
. U.S. Department of Energy 1000 Independence Avenue, SW Washington, DC 20585 1
DP-60 Records Management Office of Commercial Light Water Reactor Production RM/SS (CLWR/05-01)
Tritium Project Office U.S. Department of Energy 1000 Independence Avenue, SW Washington, DC 20505 4
Walter W. Laity, Tritium Project Manager Environmental Technology Division Pacific Northwest National Laboratory.
Battelle Blvd. P.O. Box 999 Richland, WA 99352 Gerald Sorensen, Regulatory Task Manager Pacific Northwest National Laboratory P.0, Box 999 Richland, WA 99352 i
.' ohn E. Kelly J
Sandia National Laboratories 4
P.O. Box 5800, MS 0742 Albuquerque, NM 87185-0742
)
Michael Travis Westinghouse Electric Comapany P.O.. Box 355 -
Pittsburgh, PA 15230-0355 Steven Stack, Regulatory Task Manager Office of Commercial Light-Water Reactor Production DP-62 Tritium Project Office
' U.S. Department of Energy 1000 Independence Avenue, SW Washington,' DC 20585
y
- lf
.b-DISTRIBUTION: ' RAls Related to NRC Staff's Review of DOE's TPC Topical Report "Centralfile-PGEB r/f JRoe H
- DMatthews TEssig -
RArchitzel.
JHWilson
. RJolly CBerlinger (0-8-H7) '
EThrom (0 8-H7)L LMarsh (0-11-A1)
HWalker(0-11-A1)
- JGuo (0-11-A1)L
.' CLlang (011-A1)
TCollins (0-8-E23)
EWeiss (0-8-E23)
. LKopp (0-8-E23)
AAttard (0-8-E23)
-CLiang (O-8 E23)
ESullivan (0-7-D4)
JDavis (0-7-D4)
KParcewski (0-7-E23) -
< BElliot (0-7-E29)
RWessman (0-7-E23)
. KManoly (0-7-E23)
. JRajan (0-7-E23)
JCalvo (0-7-E1)
PShemanski(0-7 E1)
REmch (0-12-H2)
CWillis (0-12-H2)
SBlack (0-9-E7)
RGramm (0-9-E7)
=- GCwalina (0-9D4)
KHeck (0-7D24)
JWermiel (0-8-H1)
'JMauck (0-8-H1)
PLoeser (0-8H3)
STurk (0-15-B-18)
THiltz (0-16-E-15)
LPlisco (Rll)
)
,