ML19337A187
| ML19337A187 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 07/10/1980 |
| From: | Kemper J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML19337A186 | List: |
| References | |
| NUDOCS 8009090226 | |
| Download: ML19337A187 (4) | |
Text
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- PHILADELPHIA ELECTRIC COMPANY 2301 MARKET STREET P.Cl. BOX 8699 PHILADELPHIA. PA.19101 (215)841 45o2 JOHN S. KEMPER v ec E+R Es4 D E NT emessessasMG AseCD mESE AshCM JUL 10 E80 Mr. Boyce Grier, Director United States Nuclear Regulatory Commission Office of Inspection and Enforcement, Region I 631 Park avenue King of Prussia, PA 19406
SUBJECT:
USNRC IE Region I Letter dated June 10, 1980 RE:
Site Inspection of March 19-21 and April 2-4, 1980 Inspection Report No. 50-352/80-04 & 50-353/80-04 Limerick Generating Station - Units 1 and 2 i
File:
QUAL 1-2-2 (352/80-04 and 353/80-04)
Dear Mr. Grier:
In response to the subject letter regarding items identified during the subject inspection of construction activities authorized by NRC License Nos. CPPR-106 and -107, we transmit herewith the following:
Attachment I - Response to Deviation Should you have any questions concerning these items, we would be pleased to discuss them with you.
l Sincerely, Skf J.
- s. Kemper JMC:drd Attachment 8 009 0 9 02.2.(a
Attachment I Response to Compressive Strength of D-Mix Concrete in 28 days-A Deviation Deviation Compressive Strength of D-Mix Concrete in 28 Days During the review of NCR trends, the inspector noted a compilation of NCRs initiated for D-Mix concrete for failure to meet the specified strength criterion in 28 days. There were seventeen (17) NCRs initiated within a period of August h, 1978, to January 3, 1979 Following this trend the inspector initiated a review of records for D-Mix of concrete. The following records.were reviewed by the inspector:
1.
Philadelphia Electric Company letter to Mr. Edson G. Case, Acting Director, Office of Nuclear Reactor Regulation, dated April 19, 1977, with. attachment A.
2.
U.S. Nuclear Regulatory Commission letter to Philadelphia Electric Company to the attention of Mr. Edward G. Bauer, Jr.,
Vice President and General Counsel, dated August 5, 1977 3
Bechtel Power Corporation, Inter 0ffice Memorandum FME-29hi, dated July 25, 1978.
h.
3echtel Power Corporation memorandum EMF-3789, dated August 9, 1978.
5 SAR change notice, Bechtel Serial No. 5-86, dated February 16, 1979 6.
Bechtel Specification for Concrete, 8031-C-61, Furnishing and Delivery of On-Site Concrete.
7 Chronological Sequence of D-1 concrete mix design and related data covering a period of 3-h-7h to 6-h-76 (not dated).
The inspector's observations as a result of the above records review are as follows:
The licensee submitted to the NRC a proposed change in its SAR commitment as Amendment No. 22.
In the proposed amendment the licensee indicated that in the production of high strength concrete, the licensee had not always been able to attain the specified l
compressivestrengthintwentyeight(28) days. Therefore, it was proposed the criterion of acceptance for such concrete be changed to meet the specific strength in ninety days instead of the twenty eight -(28) days as required by ACI 318-71.
Attachment I 50-352/80-04 50-353/80-0h 1/3
The response from NRC dated August 5, 1977, to the licensee stated that the proposed change in acceptance criterion for concrete strength was not acceptable to NRC. It was NRC's position that the twenty eight day strength should be used because it is a conservative estimate of the ultimate concrete strength.
The licensee did not take any further action to obtain relief from the 28 day requirement.
In July,1978, Bechtel field engineering sent a memorandum (INE-2941) to project engineering expressing concern over the adequacy of concrete mix design N1H and N2G. The memo requested immediate action to alleviate this recurring problem.
In August,1978, the project engineering response (EMF-3789) to field engineering regarding the problem with NMixes acknowledged that tha problem of NMixes attnining required compressive strength in twenty eight days. The project engineering did not intend to initiate any corrective action but advised the field engineering to transmit NCRs to project engineering for resolution.
J l
The SAR change notice issued by Bechtel on February 16, 1979, and approved by PECO on March 8, 1979, stated that exceptions taken to ACI 318-71 (PSAR Amendment No. 22) were not approved by the NRC, therefore Section 5 2 5 2.1(b), items 6 and 7, on page 5 2-16 or PSAR required deletion. It also stated that it was not necessary to notify the NRC.
The applicable specification for concrete 8031-C-61 indicated that the acceptance criteria for concrete strength to be in accordance with ACI 214, and ACI 318 "1, and any deviation from these criteria to be reported on NCR.
It also required that two additional compressive strength test cylindars be made from N Mixes for testing at ninety days.
The inspector observed that seventeen NO3s had been initiated between August h, 1978, and January 3, 1979, and two NCRs were initiated in June,1979, for failure of NMix to attain the required strength. All of these 3CRs were resolved by the project engineering (October 10, 1978-August 2h, 1979) to accept "as-is" on the basis of fifty six and ninety day strength of the additional cylinders.
Based on the above observation the inspector concluded that the licensee is still committed to design NMixes of concrete to attain fivethousand(5000)psiintwentyeightdays. ee licensee, however, has not fulfilled his commitment described in Section 5 2.5.2.1(b) of the Prelim 4 = v Safety Analysis Report for Limerick l
Generatina Station by accepting NMix concrete on the basis of fifty sixandninetydaystrengths.(80-Oh-02).
This is a deviation.
Attachment I 50-352/80-04 50-353/80-Oh 2/3
c
'e.
Response
Our plan of resolution for this deviation is to file with the Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, an amendment to the Limerick PSAR which will modify Section 5.2.5.2.1 (b),
page 5.2'-15a as follows:
b.
ACI 318 Building Code Requirements for Reinforced Concrate is used except as noted below:
-(Sections referenced are in ACI 318-71.)
6.
The following requirements apply in lieu of the first sentence of Section 4.1.4 "F'c for 5000 psi design strength concrete shall be
'_ based on tests of 90 days.
F'c for all other concrete design strengths shall be based on 28 day tests".
- 7. -
The following requirements apply in lieu of the last sentence of Section h.3.1:
"Each strength test result shall be the average of two cylinders from the same sample tested at 28 days for concrete with a design strength of 4000 psi or less and at 90 days for concrete with a design strength of 5000 psi."
In the production of 5000 psi desisn strength concrete (SMix) the specified compressive strength at 28 days has not always been attainable despite our rigorous efforts to identify the specific cause and correct it.
All stone concrete, regardless of the design strength, uses the same materials. However, only the W Mix exhibits the slower strength gain characteristic.
Use of the 90 day compressive strength tests for the NMix is based on Section 4.1.4 of ACI-318-71 which permits the acceptance of concrete tested at ages other than 28 days.
Since full design loading will not be imposed on the structures until well beyond the 90 day period, the acceptance of concrete based on 90 day compressive strength tests is both justified and concesvative.
-A Memorandum from Philadelphia Electric Company Project Manager is being distributed to all disciplincs cautioning that adherence to PSAR commitmento must be followed unless a modification has been approved by the NRC.
The actionc ' described above will be taken within h5 days of the date of this letter.
Attachment I i
50-352/80-Oh 50-353/80-Oh 3/3l
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