ML20054E637
| ML20054E637 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 06/09/1982 |
| From: | Vincent R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| TASK-06-01, TASK-6-1, TASK-RR NUDOCS 8206140015 | |
| Download: ML20054E637 (4) | |
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Consunsers POVver Con 1pany General Offices: 212 West Michigan Avenue, Jackson. MI 49201 e (617) 788-0660 June 9, 1982 Dennis M Crutchfield, Chief Operating Reactors Branch No 5 Nuclear Reactor Regulation US Nuclear Regulatory Com.ission Washington, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POIh"r PLANT - SEP 'IOPIC VI-1, Organic Materials and Post Accident Chemistry By letter dated March 16, 1982, Consumers Power Company submitted an evaluation of SEP Topic VI-1 for the Big Rock Point Plant. Su'osequent to that submittal, several additional questions were raised by the staff on this topic.
This letter responds to those additional questions.
Question 1.
Describe how the chemistry of water (other than recirculation water) which is to be used for emergency core cooling and containment spray, such as the water from the plant fire protection system, suppression pool, and condensate storage tank, is controlled under normal plant operations in accordance with acceptance criterion II.B.lb in Standard Review Plan Section 6.1.1:
U Conductivity = 3 to 10 pmhos/en at 25 C
(
Chloride concentration.CO.50 pim pH = 5 3 to 8.6 at 25 C Response :
If ECCS water were ever required, it woull come directly from l
Lake Michigan through the fire protection system. The chemistry of this water is not controlled as suggested in SRP 6.1.1.
Lake Michigan water would meet the pH guideline specified in the ERP but would exceed the stated values for conductivity and chloride. Lake Michigan chloride concentration is approximately 10 ppm. As discussed below, however, CPCo has concluded that the use of Lake Michigan water is acceptable for ECCS purposes.
OD Water from the condensate storage tank would not be used for ECCS in the context of this question. This tank is, however, sampled weekly for conductivity and pH.
Overall chemistry control 13 monitored through the daily reactor coolant samples. Chloride concentration in the reactor coolant is typically about 20 ppb.
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r DMCrutchfield, Chief 2
Big Rock Point Plant SEP Topic VI-l June 9, 1982
Response
(continued)
Big Rock Point has a dry containment with no suppression pool or drywell. The containment sphere is most comparable to a PWR containment.
Question 2.
Verify that the chloride concentration in the sodium pentaborate solution of the Standby Liquid Control Tank is maintained at less than 0.5 ppm under normal plant conditions.
Response: The sodium pentaborate is not routinely sampled for chlcride concentration. In view of the fact that Lake Michigan water is used for ECCS, and that the sodium pentaborate volume is.
quite small, the chloride concentration in this tank is not considered significant.
He should be noted that sampling of the sodium pentaborate tank may not be performed during power operation.
Question 3 a) Provide information that demonstrates that the levels of leachable chlorides or fluorides in non-metallic thermal insulation meets the guidance of Regulatory Guide 1 36; or b) Provide the following information:
Identify the type and amount of materials inside containment that contain leachable enloride. Include specifically the amount of non-metallic thermal insulation exceeding the guidelines of Regulatory Guide 136 which is wrapped on stainless steel piping vs carbon steel piping. Provide an analysis of chloride leaching from these materials following an accident which may wet the materials as a result of containment spray or pipe leaks. Evaluate the chloride concentration and conductivity of the water in the water in the reactor vessel, containment and core spray, and pressure suppression pool up to 30 days following an accident which requires containment spray. Provide a basis for concluding that chloride stress corrosion cracking of austenitic stainless steel material is un-likely under the design basis accident conditions.
Response: Branch Technical Position MTEB 6-1 pH for Emergency Coolant Water for PWR's references a Wectinghouse report (ref.1) that concludes that if the ECCS solutions have a pH of 7.0 or greater, no cracking should be observed at chloride concentrations up to 1000 ppm during the time of interest. For solutions of 7.0 pH having 100 ppm chloride time to initiation of cracking of type 304 austenitic stainless steel was seven and one-half and ten months for sensitized and nonsensitized specimens, respectively.
PH of post-LOCA solutions at Big Rock Point is expected to be approximately 8.0 due to the use of Lake Michigan water with or L
DMCrutchfield, Chief 3
Big Rock Point Plant SEP Tbpic VI-l June 9, 1982
Response
(continued) without the poison tank injection. The Branch Technical position states that the higher the pH (in the 7.0 to 9 5 range), the greater the assurance that no stress corrosion cracking will occur. The pH and relatively low chloride concentration of the post-LOCA environment indicates that initiation of stress corrosion cracking at Big Rock Point is not expected.
Our submittal of March 16, 1982, on SEP topic VI-l referenced the above Branch position on page 2.
References 1.
Dr. D. Whyte and L. F. Ficone, " Behavior of Austenetic Stainless Steel in Post Hypothetical Loss of Coolant Environment," WCAP "/798-L Westinghouse Nuclear Energy Systems, Nove;ber 1971'(NES Proprietary Class 2).
i 44Y Y-( O b Robert A Vincent Stnff Licensing Engineer CC Director, Region III, USNRC NRC Resident Inspector-P!g Rock Point
LICENSING CORRESPONDENCE - RECORD
SUMMARY
DATE:
June 9, 1982 DOCKET 50-155 LICENSE DPR-6 BIG ROCK POINT PLANT SEP TOPIC VI-1, Organic Materials and Post Accident Chemisty
SUMMARY
COMMITMENTS MADE: None Previous NRC/CP Co Correspondence:
Special Distribution:
CP Ltr 3/16/82 DDBowman NRC Memo Benaroya to Russell of4/22/82 AIR No UFI No A-NL-82-69 740 - 99*12 Individuals Providing Information:
Individuals Assigned Responsibility DD Bowman for Implementing Commitments:
G Fox NA Concurrences:
Cost / Budget Impact:
Actual / Potential Year (s)
Haterials/ Parts Labor Capital Contractors Originator:
RA Vincent ic0981-0016a142 L