ML083380590
| ML083380590 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 12/03/2008 |
| From: | Richard Ennis Plant Licensing Branch 1 |
| To: | Chernoff H Plant Licensing Branch 1 |
| Ennis R, NRR/DORL, 415-1420 | |
| References | |
| TAC MD8576 | |
| Download: ML083380590 (4) | |
Text
December 3, 2008 MEMORANDUM TO:
Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM:
Richard B. Ennis, Senior Project Manager /ra/
Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
HOPE CREEK GENERATING STATION, DRAFT REQUEST FOR ADDITIONAL INFORMATION (TAC NO. MD8576)
The attached draft request for information (RAI) was transmitted on December 3, 2008, to Mr. Lee Marabella of PSEG Nuclear LLC (the licensee). This information was transmitted to facilitate an upcoming conference call in order to clarify the licensee=s amendment request for Hope Creek Generating Station dated April 25, 2008. The proposed amendment would revise the Technical Specifications to remove the restriction on operation of the hydrogen water chemistry system at low power levels.
This memorandum and the attachment do not convey or represent an NRC staff position regarding the licensee's request.
Docket No. 50-354
Attachment:
Draft RAI
December 3, 2008 MEMORANDUM TO:
Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM:
Richard B. Ennis, Senior Project Manager /ra/
Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
HOPE CREEK GENERATING STATION, DRAFT REQUEST FOR ADDITIONAL INFORMATION (TAC NO. MD8576)
The attached draft request for information (RAI) was transmitted on December 3, 2008, to Mr. Lee Marabella of PSEG Nuclear LLC (the licensee). This information was transmitted to facilitate an upcoming conference call in order to clarify the licensee=s amendment request for Hope Creek Generating Station dated April 25, 2008. The proposed amendment would revise the Technical Specifications to remove the restriction on operation of the hydrogen water chemistry system at low power levels.
This memorandum and the attachment do not convey or represent an NRC staff position regarding the licensee's request.
Docket No. 50-354
Attachment:
Draft RAI DISTRIBUTION PUBLIC LPL1-2 R/F RidsNrrDorlLpl1-2 Resource RidsNrrDorlDpr Resource RidsNrrPMREnnis Resource ACCESSION NO.: ML083380590 OFFICE LPLI-2/PM NAME REnnis DATE 12/3/08 OFFICIAL RECORD COPY
DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED LICENSE AMENDMENT HYDROGEN WATER CHEMISTRY LOW POWER RESTRICTION HOPE CREEK GENERATING STATION DOCKET NO. 50-354 By application dated April 25, 2008 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML081430002), PSEG Nuclear LLC (PSEG or the licensee) submitted a license amendment request for the Hope Creek Generating Station (HCGS). The proposed amendment would revise the Technical Specifications (TSs) to remove the current restriction on operation of the hydrogen water chemistry (HWC) system at low power levels.
The Nuclear Regulatory Commission (NRC) staff has reviewed the information the licensee provided that supports the proposed amendment and would like to discuss the following issues to clarify the submittal.
- 1)
Sections 3.0 and 5.1 of Attachment 1 of PSEG's application dated April 25, 2008, indicate that the consequences of a postulated control rod drop accident (CRDA) are only of concern, with respect to potential fuel failure, below 10% of rated thermal power (RTP). Based on review of Section 3.1 of General Electric (GE) Report NEDO-10567, "Rod Drop Accident Analysis for Large Boiling Water Reactors," dated March 1972 (ADAMS Accession No. ML010870249); HCGS Updated Final Safety Analysis Report (UFSAR) Sections 7.7.1.1.5 and 15.4.9; and TS 3/4.1.4, "Control Rod Program Controls,"
and its Bases, it appears that the 10% of RTP value correlates to the low power setpoint (LPSP) associated with the rod worth minimizer. Specifically, as discussed in Bases for TS 3/4.1.4, when thermal power is greater than the LPSP, there is no possible rod worth which, if dropped at the design rate of the velocity limiter, could result in a peak enthalpy greater than 280 calories/gram (which is the fuel design limit as discussed in NEDO-10567 and UFSAR Section 15.4.9).
The HCGS extended power uprate amendment (Amendment No. 174 dated May 14, 2008 (ADAMS Accession No. ML081230540)) changed the LPSP from 10% of RTP to 8.6% of RTP. As such, please confirm that, for HCGS, a postulated design basis CRDA is only of concern below 8.6% of RTP (i.e., instead of the 10% value cited in the application).
- 2)
The tripping of the mechanical vacuum pumps (MVPs) on a main steam line radiation monitor (MSLRM) high-high signal is credited to mitigate the radiological consequences of a CRDA as described in UFSAR Section 15.4.9. As shown in TS Table 3.3.2-2, the MSLRM high-high setpoint is required to be set at 3 times the full power background radiation levels. In accordance with footnote ### in this table, below 20% of RTP, the setpoint is based on normal full power operation without the HWC system in operation.
Please provide the following information related to the CRDA mitigation function provided by the MSLRMs:
a)
What are the expected dose rates near the MSLRMs for a postulated CRDA?
Attachment b)
What are the typical normal full power background radiation levels (without the HWC system in operation) in the vicinity of each of the MSLRMs?
- 3)
The original HWC system hydrogen injection rates caused significant increases in the main steam line (MSL) background radiation levels. As discussed in the licensee's application dated September 28, 1988, associated with HCGS Amendment No. 23, the normal full power background radiation levels at that time ranged from 33 to 45 millirem/hour (mR/hr) for the four MSLs. During a hydrogen injection test, with an injection rate of 18 to 20 standard cubic feet per minute, the full power MSL background radiation levels increased to approximately 75 to 80 mR/hr. Since the MSLRMs setpoints were established at 3 times normal full power background (i.e., 99 to 135 mR/hr),
sufficient margin was not afforded for any occasional radiation spiking or inherent instrument inaccuracies or drift to justify HWC operation at power levels where a CRDA may be of consequence. As such, as part of HCGS Amendment No. 23, HWC system operation was prohibited below 20% of rated thermal power. Provide the following information regarding the potential impact of the proposed use of the HWC system operation at low power levels:
a)
What are the expected background radiation levels with the HWC system in operation for 0 to 20% of rated thermal power in the vicinity of each of the MSLRMs?
b)
For 0 to 20% of rated thermal power, quantify the margin to inadvertent MSLRM alarms, tripping of the MVPs, and reactor water sample valve closure taking into consideration: (1) increased background radiation levels due to HWC system operation; (2) instrument uncertainties (e.g., accuracy, drift, etc.); and (3) any other uncertainties (e.g., radiation spiking).
- 4)
Please provide a response to address the following comment on the proposed amendment from the State of New Jersey, Department of Environmental Protection, Bureau of Nuclear Engineering (letter to NRC from Mr. Patrick Mulligan dated December 3, 2008):
Hope Creek should provide verification that the implementation of the power uprate in 2008 did not result in a significant increase in Main Steam Line background radiation at full power with HWC in service and that the power uprate did not have any adverse impact on the operation of the HWC system at low power.