ML19329E444
| ML19329E444 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 11/04/1977 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Howell S CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| NUDOCS 8006160249 | |
| Download: ML19329E444 (1) | |
Text
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US NOV 041977 Docket 0-3 Docket No.
330 Consumers Power Cotipany ATTN Mr. Staphen H. Howell I
Vies President 1945 Weet Parnall Road Jackson, MI 49201 Centlemen:
Enclosed is IE Ballatin No. 77-04 which requires action by you with regard to your power reactor facilities with an operating license or a construction permit.
Should you have questions regarding this Bulletin or the actions required of you, please contact this office.
Sincerely, James G. Keppler Director i
Enclosures:
i 1.
2.
List of IE Bulletins Issued in 1977 THIS DOCUMENT CONTAINS
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November 4, 1977 IE Bu11etin No. 77-04 CALCULATIONAL ERROR AFFECTING THE DESIGN PERJORMANCE OF A SYSTEM FOR CONTROLLING pH OF CONTAINMENT SUMP WATER FOLLOWING A LOCA Description of Circumstances:
On September 29, 1977, the Baltimore Gas and Electric Company reported that for Calvert Cliffs Unit I and Unit 2, the amount of trisodiu=
phosphate dodecahydrate (TSP) speeffied in the techrical specifications may not be sufficient under all operating conditions to perform its intended design function.
The TSP is used to centrol the pH of the contrineent su=p water following a LOCA in order to reduce the probability of chloride stress corrosion cracking leading to equipment failure or loss of containment integrity and to ensure lov volatility of dissolved radioiodices. At Calvert Cliffs, the TSP is stored in three dissolving baskets located on the lowest level of the containment. Original design specifications (FSAR) required a sufficient quantity of TSP to raise the pH of the sump water to approximately 7.0.
The more recent guidance provided by the Standard Review Plan (SRP) states that, for Post Accident Chemistry, the optimu=
PH control consists of stabilizing pH between 7 and 8 within four hours.
For the Calvert Cliffs facilities, the quantity of TSP required to meet the PSAR design specifications was initially calculated to be 75 cubic feet. E vever, these calculations were not based on maximum boron concen-trations and water volumes permitted by the technical specifications for the contain=ent sump water sources, e.g., Refueling L'ater Tank (R'n'T),
Safety Injection Tanks (SIT), Boric Acid Tanks (BAT) and the Reactor Coolant System (RCS). Revised calculations indicated that the quantity of TSP required to meet design specifications under worst case conditions was approximately 82 cubic feet.
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II Bu11etin No. 77-04 November 4, 1977 As a result, administrative controls have been implemented at the Calvert Cliffs facilities to limit the maximum boron concentration in the RWT and SITS to 2200 ppm. The minimum boron concentration specified in the tach-nical specifications vill still apply. Although the problem described above occurred at a facility utilizing TSP for pH control of containment sump water, this problem may be applicable to facilities utilizing dif-ferent methods of pH control of containmant sump water e.g., sodiu=
hydroxide (NaOH). This would be the case if themical requirements for pH control were based on values less than the maximum values for boron concentrations and water volume permitted by the technical specifications for the containment sump water sources.
Action to be Taken by Licensees and Permit Holders:
For all PWR Power Reactor Tacilities with an operating license or a construction permit:
1.
If your facility utilizes or plans to utilize a system for pH control of containment sump post LOCA solution, describe what action you have taken or plan to take to assure that the system design specifications vill be met for all operating conditions Permitted by the technical specifications, as applicable to the contain=ent sump water sources.
2.
Report in writing within 45 days for facilities with an operating Ideense and within 60 days for facilities with a construction permit, your plan of action and schedule with regard to Item 1.
Reports should be submitted to the Director of the appropriate NRC Regional Office and a copy should be forwarded to the NRC Office of Inspection and Enforcement, Division of Reactor Operations Inspection, Washington, D.C.
20555.
Approved by GAO, B-180225 (R0072); clearance expires 7-31-80. Approval was given under a blanket clearance specifically for identified generic problems.
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II Bulletin No. 77-04 November 4, 1977 LISTING OF IE BULLETINS ISSUED IN 1977 Bulletin Subject Date Issued Issued To No.
77-03 on-Line Testing of 9/12/77 All W Power Reactor the W Solid State Facilities with an Protection System Operating License or Construction Permit 77-02 Potential Tailure 9/12/77 All Holders of Mechanism in Certain Operating Licenses W AR Relays with (OL) or Construc-Relays with Latch tion Permits (CP)
Attachments 77-01 Pneumatic Time 4/29/77 All Holders of Delay Set Point Operating Licenses Drift (OL) or Construc-tion Pemits (CP)
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