ML052380128
| ML052380128 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 08/31/2005 |
| From: | Dave Solorio Plant Systems Branch |
| To: | Raghavan L NRC/NRR/DLPM/LPD3 |
| Whitney L, NRR/DSSA/SPLB, 415-3081 | |
| References | |
| BL-03-001 | |
| Download: ML052380128 (6) | |
Text
August 31, 2005 MEMORANDUM TO: L. Raghavean, Chief, Section 1 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation FROM: David L. Solorio, Chief /RA/
Balance of Plant Section Plant Systems Branch Division of Systems Safety and Analysis Office of Nuclear Reactor Regulation
SUBJECT:
CLOSEOUT LETTER FOR BULLETIN 2003-01, POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY SUMP RECIRCULATION AT PRESSURIZED-WATER REACTORS The Plant Systems Branch (SPLB) has reviewed and evaluated the information provided in responses to Bulletin 2003-01 by the licensee for Point Beach, Unit 1 and Unit 2. SPLB has determined that the licensees actions have been responsive to and meet the intent of Bulletin 2003-01. Attached to this letter is the proposed close-out letter for the above plants. If you have any questions, please contact Leon Whitney or Alan Wang. Please include Alan Wang and Leon Whitney on the distribution list.
Docket Nos: 50-266, 50-301
Attachment:
As stated CONTACTS: Leon Whitney, SPLB/DSSA 415-3081 Alan B. Wang, DLPM, PD IV 415-1445
August 31, 2005 MEMORANDUM TO: L. Raghavean, Chief, Section 1 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation FROM: David L. Solorio, Chief /RA/
Balance of Plant Section Plant Systems Branch Division of Systems Safety and Analysis Office of Nuclear Reactor Regulation
SUBJECT:
CLOSEOUT LETTER FOR BULLETIN 2003-01, POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY SUMP RECIRCULATION AT PRESSURIZED-WATER REACTORS The Plant Systems Branch (SPLB) has reviewed and evaluated the information provided in responses to Bulletin 2003-01 by the licensee for Point Beach, Unit 1 and Unit 2. SPLB has determined that the licensees actions have been responsive to and meet the intent of Bulletin 2003-01. Attached to this letter is the proposed close-out letter for the above plant. If you have any questions, please contact Leon Whitney or Alan Wang. Please include Alan Wang and Leon Whitney on the distribution list.
Docket Nos: 50-266, 50-301
Attachment:
As stated DISTRIBUTION:
LWhitney HChernoff Awang Accession No.: ML052380128 NRR-106 OFFICE DLPM/PDIV-2/PM DSSA/SPLB DSSA/SPLB NAME AWang LWhitney DSolorio DATE 08/ 30 /05 08/ 26 /05 08/ 31 /05 OFFICIAL RECORD COPY
Nuclear Management Company, LLC 6590 Nuclear Road Two Rivers, Wisconsin 54241
SUBJECT:
POINT BEACH UNITS 1 AND 2 - RESPONSE TO NRC BULLETIN 2003-01, POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY SUMP RECIRCULATION AT PRESSURIZED WATER REACTORS (TAC NOS. MB9599, MB9600)
Dear Mr. Middlesworth:
This letter acknowledges receipt of your response dated August 8, 2003, to Nuclear Regulatory Commission (NRC) Bulletin 2003-01, Potential Impact of Debris Blockage on Emergency Sump Recirculation at Pressurized Water Reactors, dated June 9, 2003. The NRC issued Bulletin 2003-01 to all pressurized-water reactor (PWR) licensees requesting that they provide a response, within 60 days of the date of Bulletin 2003-01, that contains either the information requested in following Option 1 or Option 2 stated in Bulletin 2003-01:
Option 1: State that the emergency core cooling system (ECCS) and containment spray system (CSS) recirculation functions have been analyzed with respect to the potentially adverse post-accident debris blockage effects identified in the Discussion section, and are in compliance with all existing applicable regulatory requirements.
Option 2: Describe any interim compensatory measures that have been implemented or that will be implemented to reduce the risk which may be associated with potentially degraded or nonconforming ECCS and CSS recirculation functions until an evaluation to determine compliance is complete. If any of the interim compensatory measures listed in the Discussion section will not be implemented, provide a justification. Additionally, for any planned interim measures that will not be in place prior to your response to this bulletin, submit an implementation schedule and provide the basis for concluding that their implementation is not practical until a later date.
You provided an Option 2 response.
Bulletin 2003-01 discussed six categories of interim compensatory measures (ICMs):
(1) operator training on indications of and responses to sump clogging; (2) procedural modifications if appropriate, that would delay the switchover to containment sump recirculation (e.g., shutting down redundant pumps that are not necessary to provide required flows to cool the containment and reactor core, and operating the CSS intermittently); (3) ensuring that ATTACHMENT
Mr. Middlesworth 2 alternative water sources are available to refill the RWST or to otherwise provide inventory to inject into the reactor core and spray into the containment atmosphere; (4) more aggressive containment cleaning and increased foreign material controls; (5) ensuring containment drainage paths are unblocked; and (6) ensuring sump screens are free of adverse gaps and breaches.
You stated in your bulletin response of August 8, 2003, that you had implemented the following ICMs (1) training on sump recirculation and loss of sump recirculation with annual reviews of associated shutdown emergency procedures - ICM category #1; (2) a revision to the Emergency Operating Procedures (EOPs) for indications and required actions for sump blockage, with associated training lesson plan - ICM category #1; (3) an OPS Notebook entry on Bulletin 2003-01 and sump blockage mitigation, with the information included in the Licensed Operator Requalification cycle - ICM category #1; (4) a lesson plan to address sump plugging - ICM category #1; (5) a pre-existing Simulator Guide on loss of containment recirculation - ICM category #1; (6) EOP network changes to prolong refueling water storage tank (RWST) inventory as well as reduce flow to the sump screens, and evaluate long term plant status following a large break LOCA (directing operators and Technical Support Center (TSC) staff to monitor containment sump level, RHR operation, SI pump operation, low head injection flow and high head injection flow, and to take appropriate actions if sump blockage is observed - ICM category #1 and ICM category #2; (7) procedures to makeup to the RWST from alternate sources as well as depressurize the RCS to minimize break flow (we note that you stated that RWST level is already required to be maintained at a minimum of 95% of Technical Specifications) - ICM category #3; (8) procedure requirements for containment closeout and foreign materials control for post-outage and quarterly on-line inspections (containment entries), the purpose of which is to ensure that no materials are left in containment and that equipment left in containment are adequately secured - ICM category #4; (9) installation of metallic insulation in place of calcium silicate blocks in the refueling cavity -
ICM category #4; (10) inherent design features which minimize potential for drainage path blockage to the sump -
ICM category #5; (11) sump screen inspections every refueling outage, including removal and inspection for structural integrity/distress, cracking, corrosion, etc., and sump screen inspection for adverse gaps and breaches - ICM category #6.
Mr. Middlesworth 3 You also stated in your response that you would be implementing the following ICMs: (1) the implementation of more aggressive containment foreign material control by January 14, 2004, -
ICM Category 4; and (2) an implementation schedule for revising plant EOPs, where appropriate, to stop or throttle redundant pumps that are not necessary to provide required flows to cool the containment and the reactor core within 30 days of the issuance of the generic guidance by Westinghouse Owners Group (then expected by March 31, 2004).
In a May 14, 2004, supplement to your August 8, 2003, Bulletin 2003-01 response you stated that the Westinghouse Owners Group (WOG) had formally transmitted WCAP-16204, Revision 1, Engineering Evaluation and Analysis Report, Evaluation of Potential ERG and EPG Changes to Address the NRC Bulletin 2003-01 Recommendations, and that the WOG had evaluated 11 Candidate Operator Actions (COAs). You further stated that:
(1) for COA #1, Secure One Containment Spray Pump Before Recirculation Alignment, Point Beach EOPs already secure one train of containment spray during the verification of automatic action steps in EOP-0, Reactor Trip or Safety Injection - ICM Category #2; (2) for COA #2, Manually Initiate One Train of Containment Sump Recirculation Earlier, that this action does not provide clear benefit because of other existing actions to prolong RWST inventory and would not be implemented at Point Beach; (3) for COA #3, Terminate One Train of HPSI/high-head injection after recirculation alignment, that Point beach currently implements this strategy - ICM Category #1; (4) for COA #4, Terminate LPSI/RHR Pump Prior to Recirculation Alignment (CE), that this COA was not applicable to Point Beachs Westinghouse design; (5) for COA #5, Refill Refueling Water Storage Tank (RWST), that NMC will implement this strategy at Point Beach by July 15, 2005, by providing instrucitons in the EOPs to refill the RWST from normal or alternate water sources - ICM Category #3; (6) for COA #6, Inject More Than One RWST Volume from Refilled/diluted RWST or By Bypassing RWST, that this is not risk beneficial due to concerns including dilution of Boron and maintaining pH, and the need for a special evaluation for any problems with thermally stressing the reactor vessel by direct immersion, and that this COA would not be implemented at Point Beach; (7) for COA #7, Provide a More Aggressive Cooldown and Depressurization Following a Small Break LOCA, that EOP 1.2 calls for cooldown at up to 100 degrees F per hour in such a situation (in an August 19, 2005, letter to the NRC you stated that the background document for Point Beach EOP-1.2, Small Break LOCA Cooldown and Depressurization, had been revised to state that the intent was to rapidly cool down the RCS at a rate as close to 100 degrees F/hour without exceeding that rate) - ICM Category #2; (8) for COA #8, Provide Guidance on Symptoms and Identification of Containment Sump Blockage, that this strategy would be implemented at Point Beach by July 15, 2005, by adding a continuous action step immediately after establishing sump recirculation, to check indications of sump blockage and transition to the new sump blockage procedure, ECA 1.3, if blockage is indicated - ICM Category #1;
Mr. Middlesworth 4 (9) for COA #9, Provide Contingency Actions in Response to Containment Sump Blockage, Loss of Suction, and Cavitation, that the new WOG SBCRG (Sump Blockage Control Room Guidance) generic guideline document (that seeks to prevent sump blockage or the maintenance of at least one train of ECCS in the presence of sump blockage indications) will be factored into the development of new procedure EOP 1.3 by July 15, 2005 - ICM Category #1; (10) for COA #10, Terminate HPSI/High-head Injection Prior to Recirculation Alignment, that this COA was deemed not risk beneficial due to the risk of core damage considering the potential for single failures; (11) for COA #11, Delay Containment Spray Actuation for Small Break LOCA in Ice Condenser Plants, that this COA is not applicable at Point Beach.
The NRC staff has considered your Option 2 response for compensatory measures that were or were to have been implemented to reduce the interim risk associated with potentially degraded or nonconforming ECCS and CSS recirculation functions. Based on your response, the NRC staff considers your actions to be responsive to and meet the intent of Bulletin 2003-01. Please retain any records of your actions in response to Bulletin 2003-01, as the NRC staff may conduct subsequent inspection activities regarding this issue.
Should you have any questions, please contact me at 301-415-[xxxx] or the lead PM for this issue, Alan Wang at 301-415-1445.
Sincerely,
[Name], Project Manager, Section [1 or 2]
Project Directorate [I, II, III, or IV]
Division of Licensing Project Management Office of Nuclear Reactor Regulation cc: See next page [Plant Mailing List]
ADD TO DISTRIBUTION: AWang, RArchitzel, DSolorio, MKowal, LWhitney, THafera