U-602141, Responds to NRC Bulletin 93-002, Debris Plugging of ECC Suction Strainers. Only Fibrous Matls Used within Containment or Drywell,Not Located within Separate Room, Consists of Rigid Fiberglass Insulation Matl
| ML20045B232 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 06/09/1993 |
| From: | Jamila Perry ILLINOIS POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-93-002, IEB-93-2, U-602141, NUDOCS 9306170001 | |
| Download: ML20045B232 (2) | |
Text
a lihnos Power Company Chnton Power Stat on P o. Box 670 Chnton. IL 61727 Tel 217 935-8081 ILLIN 9IS POWER u-60214i L30-93(0604P SG.130 50-461 June 9, 1993 u.S. Nuclear Regulatory Commission Document Control Desk Washington D.C. 20555
Subject:
Illinois Power's Response to Bulletin 93-02, " Debris Plugging of Emergency Core Cooling Suction Strainers"
Dear Sir:
The Nuclear Regulatory Commission's (NRC)Bulletin 93-02 requested Illinois Power (IP) to identify fibrous air filters or other temporary sources of fibrous material not designed to
- withstand a Loss of Coolant Accident (LOCA) which are installed or stored in the primary containment at Clinton Power Station (CPS). The NRC requested that immediate compensatory measures be taken to assure the functional capability of the Emergency Core Cooling System (ECCS) due to the potential for plugging of the ECCS suction strainers from fibrous material.
At CPS, the only fibrous material used within the containment or the drywell, that is not located within a separate room, is a rigid (board form) fiberglass insulation material that is used in the containment and drywell coolers. The material is used to protect the coolers from sweating and is installed as a liner on the inside of the equipment enclosures. The coolers are LOCA-qualified devices and their construction is such that the rigid fiberglass material is enclosed and encapsulated within the coolers. This constructi.on assures that the material will remain in place and not be transported into the suppression pool during a LOCA.
Materials that are used or stored in the containment are controlled by CPS procedure 1019.04, " Control ofTransient Equipment and Foreign Material Exclusion Areas (FMEA)." The procedure provides for the logging, storage and securing of all materials that are used within the primary containment during operational modes 1,2, and 3, when reactor coolant is above 200 degrees. Whenever the control of materials program is suspended (e.g., during outages), a walkdown of containment and the drywell is required to ensure compliance with the procedure prior to reentering modes I,2, or 3.
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o The installation of temporary equipmerit is controlled by the temporary modification program. The program requires that any equipment modifications receive a design review prior to installation. This review ensures that any material is installed in a manner which protects against the possibility of the material being transported into the j
suppression pool.
i At CPS, a Suppression Pool Cleanup system provides continuous cleanup.of the suppression pool water. The system removes most suspended solids from the suppression pool water. The suppression pool water clarity is good, allowing personnel to perform a visual inspection of the pool, including the strainers. This enables personnel to identify any debris that could restrict the flow of water into the strainers. Supervisors / assistant t
supervisors are responsible for performing monthly tours of the plant, including l
containment. Material deficiencies are identified and corrected in accordance with the CPS maintenance program.
l In summary, fibrous filter material not designed to withstand a LOCA is not used in the containment at CPS. A walkdown of the primary containment and a review of all open temporary modifications indicates that procedure controls have been and remain effective.
No compensatory measures are required and, since no fibrous material not designed to withstand a LOCA is installed or stored in the containment, no schedule for removal of such material is required.
In response to the NRC's request for information relative to the cost of complying with this bulletin, CPS personnel have expended approximately 100 man-hours in reviewing procedures, performing walkdowns, and conducting interviews with personnel to ensure that the programs at CPS implement the actions requested in this bulletin.
I hereby affirm that the information provided in this letter is correct to the best of my knowledge.
l t
Y Sincerely yours, Q
i J. S. Perry Senior Vice President JSP/WTD/nis cc:
NRC Clinton Licensing Project Manager NRC Resident Office, V-690 Regional Administrator, Region 111, USNRC I!!inois Department of Nuclear Safety i
.