ML052990284
| ML052990284 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 10/18/2005 |
| From: | Koehl D Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| BL-03-001, NRC 2005-0134 | |
| Download: ML052990284 (5) | |
Text
Committed to Nuclear Excellene Point Beach Nuclear Plant Operated by Nuclear Management Company, LLC October 18, 2005 NRC 2005-0134 BL 2003-01 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington DC 20555 Point Beach Nuclear Plant, Units 1 and 2 Docket Nos. 50-266 and 50-301 License Nos. DPR-24 and DPR-27 Supplement 3 to 60-Day Response to Bulletin 2003-01, "Potential Impact of Debris Blockage on Emergency Sump Recirculation at Pressurized-Water Reactors"
References:
- 1) Letter from NMC to NRC dated August 8, 2003 (NRC 2003-0068)
- 2) Letter from NMC to NRC dated May 14, 2004 (NRC 2004-0050)
- 3) Letter from NMC to NRC dated August 19, 2005 (NRC 2005-0106)
In Reference 1, Nuclear Management Company, LLC (NMC), provided the 60-day response to Bulletin (BL) 2003-01, "Potential Impact of Debris Blockage on Emergency Sump Recirculation at Pressurized-Water Reactors", for the Point Beach Nuclear Plant (PBNP). References 2 and 3 supplemented the response. In those supplements, NMC stated that Candidate Operator Action (COA) #6, Inject more than one refueling water storage tank (RWST) volume from refilled/diluted RWST or by bypassing RWST, would not be implemented at Point Beach.
During a telephone conference between NMC personnel and Nuclear Regulatory Commission (NRC) staff on October 3, 2005, the staff questioned the basis for not implementing COA #6 at PBNP for beyond design basis conditions. NMC subsequently identified enhancements to both COA #5 and COA #6 that would allow implementation of COA #6 at PBNP. Revised commitments for COAs #5 and #6 are provided in.
This submittal contains two revised regulatory commitments as stated in Enclosure 1.
X o3 6590 Nuclear Road
- Two Rivers, Wisconsin 54241 Telephone: 920.755.2321
Document Control Desk Page 2 I declare under penalty of perjury that the foregoing is true and correct.
Executed on October 18, 2005 Dennis L. Koehl Site Vice-President, Point Beach Nuclear Plant Nuclear Management Company, LLC Enclosure cc:
Administrator, Region Ill, USNRC Project Manager, Point Beach Nuclear Plant, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC PSCW
ENCLOSURE I SUPPLEMENT 3 TO 60-DAY RESPONSE TO BULLETIN 2003-01, "POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY SUMP RECIRCULATION AT PRESSURIZED-WATER REACTORS" Introduction The following revised commitments for Candidate Operator Actions (COAs) #5 and #6 are hereby submitted in response to Bulletin (BL) 2003-01, "Potential Impact of Debris Blockage on Emergency Sump Recirculation at Pressurized-Water Reactors". These replace the original respective commitments for these COAs in their entirety.
Revised Candidate Operator Actions COA #5 Refill refueling water storage tank The intent of this COA is to provide inventory for re-establishing reactor coolant system (RCS) injection and containment spray (if necessary) in the event the containment sump source is not available.
The overall strategy is to refill the refueling water storage tank (RWST) following initiation of recirculation, or line up an alternate makeup source bypassing the RWST, in anticipation of possible sump blockage.
NMC implemented this strategy at Point Beach by providing instructions in the emergency operating procedures (EOPs) to refill the RWST from normal or alternate water sources. Specifically, Procedure ECA-1.3, Containment Sump Blockage, Attachment A, provides direction to refill the RWST from the following sources as available:
- Chemical and Volume Control System (CVCS) Blender
- Fuel Transfer Canal
- CVCS Waste Holdup Tanks
- Opposite Unit's RWST
- Boric Acid Storage Tanks In addition, direction will be included in Procedure EOP-1.3, Transfer to Containment Sump Recirculation - Low Head Injection, and Procedure EOP-1.4, Transfer to Containment Sump Recirculation - High Head Injection, to initiate refill of the RWST using the CVCS blender once the RWST has been depleted.
Implementation Date: December 15, 2005
COA #6 Inject more than one RWST volume from refilled/diluted RWST or by bypassing RWST The intent of this COA is to provide procedures for re-establishing injection to the RCS from either the refilled RWST or alternate makeup source.
The overall strategy is to secure recirculation and align equipment to re-establish injection from a refilled RWST or from an alternate source bypassing the RWST.
NMC has implemented this strategy by directions contained in Procedure ECA-1.3 that direct the establishment of safety injection (SI) (high head injection) by drawing from the RWST.
Other than the containment accident sump, Severe Accident Management Guideline (SAMG) SAG-3, Inject into the RCS, tabulates three potential Si pump suction sources and the necessary supporting equipment and conditions for each:
- Boric Acid Storage Tanks (BAST) A and C
- BAST B Additionally, SAMG SAG-3 tabulates six potential charging pump injection paths and the equipment necessary to support each:
- RWST.
- Volume Control Tank (VCT)
- BAST via the blender
- BAST via the boration flowpath
- Reactor Makeup Water Storage Tank (RMWST) via the blender
- RMWST via the alternate dilution path Although such actions would only be necessary for conditions beyond those contemplated in either the design or license basis of the facility, NMC will further enhance Procedure ECA-1.3 for re-establishing injection to the RCS utilizing the following potential alternate suction sources and/or injection paths:
- Charging pumps from the RWST
- Charging pumps from the VCT
- Si pumps from the BASTs Additionally, Attachment A of Procedure ECA-1.3 will be enhanced to include an option of making up to the RWST from the spent fuel pool.
NMC had considered using Si pumps from the opposite unit's RWST via the common BAST outlet header. However, there are no isolation valves in the necessary piping to prevent overflow of the B BAST. Such a condition would create the potential for flooding of the RHR pump compartments.
Injection of more than one RWST into the containment and/or the depletion of the opposite unit's RWST inventory are consistent with actions already directed by SAMG SAG4, Inject into the Containment, and would need to be weighed against any other available options at the time based on prevailing conditions.
Implementation Date: December 15, 2005