ML20062C349
| ML20062C349 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 10/22/1990 |
| From: | Beckman W CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9010310149 | |
| Download: ML20062C349 (3) | |
Text
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Consumers Power
= am ' 8 * **a 1%mt Manager POWERCNE MEN 66AN'E PROGRESS Big Rock Point Nuctoar Plant,10269 US 31 North, Charlevoix, MI 49720 October 22, 1990 i
t Nuclear Regulatory Commission t
Document Control Desk Washington, DC 20555 DOCKET $0-155 - LICENSE DPR BIC ROCK POINT PLANT -
RESPONSE TO INSPECTION REPORT 50-155/90013 (DPR)
Inspection Report No. 50-155/90013, received on September 24, 1990 expressed two concerns which deserve further explanation.
The first, described on Page 8 of the report, states that Big Rock Point was not performing scram time tests as suggested in a Ceneral Electric Operating Experience Report dated July 12, 1972.
Big Rock Point was informed of the concern raised at Nine Mile Point by the Resident Inspector. After promptly contacting General Electric to obtain the date of the report (attached), a review of plant actions in 1972 was conducted.
As can be seen, the report recommended that plants utilizing Creer accumulators verify the status of their bladders at the earliest opportunity by performing scram tests at zero pressure with the charging water valve closed.
Big Rock Point performed this requested test in November 1972 which was the l
first shutdown following receipt of the Operating Experience Report. Results l
of these tests showed that scram times with the charging water valved in and l
out, varied by a nuximum of.37 seconds and all times well within Technical I
Specification requirements.
The General Electric Operating Experience Report did not recommend that all
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testing be performed with the charging water isolated but only recommended a
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one-time test. The results at Big Rock also concluded that a revised test method was not necessary.
In follow-up discussions with General Electric personnel about Scram testing at Q {p Big Rock Point, they felt that although the Big Rock Point CRD's are different O
than the newer drives, testing with the charging water valved out was a prudent method.
g*C General Electric felt that this method would detect drive filter or l
ball check valve degradation. This discussion with General Electric led us to
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g the conclusion that a test method change was appropriate..
With regard to the delay in issuance of Amendment No. 102 to the Big. Rock Point-n Technical Specifications, it should be noted that the amendment contained See administrative and eeitorial changes exclusively. The majority of the changes t
OC1090-0001-BL01
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,Nucicar R:gulatory Commissicn Big Rock Point Plant 2
Response to Inspection Report 90013 October 22, 1990 contained in the amendment included corrections to typographical errors, i
capitalization of terms, and reformatting of text, in the words of Inspection Report 90-013, "these changes had no direct safety impact on plant operations."
Because it was administrative in nature, issuance of Amendment No.102 received a lower priority that would have an amendment of technical significance. The majority of the preparation time involved in issuance of the amendment involved verifying that the more than one hundred (100) separate technical specification
- hanges were correct and matched the changes requested.
It should be noted that within Amendment No. 102, the NRC incorporated six (6) separate Consumers Power Company Technical Specification Change Requests dating back as far as February 6, 1987.
Regarding the issuance of the correction to Amendment No. 102, Nuclear Licensing Department (NLD) procedures require that a Document Transmittal Sheet be attached to all new Technical Specification pages when distributed. The Document Transmittal Sheet contains a request for comments and acknowledgt.ent of receipt and is required to be returned to the NLD within 14 working days.
Once all comments are received and resolved, necessary corrections are made, and new pages are issued. The correction was issued on September 19, 1990.
As noted in the report, it is normally our practice to issue Amendments quickly to insure that Administrative and Working Level Procedures can be changed to reflect the Amendments. Ilowever, in this case, procedure changes were not necessary since the Amendment contained editorial changes exclusively and we felt it appropriate to assign issuance a lower priority.
WL-in(ckman
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7M w blantManager CC Administrator, Region III, NRC NRC Resident Inspector - Big Rock Point Attachment l
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OC1090-0001A-BL01
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p gexperience report Ref. No.1000 July 12,1975 CRO GREER Pl ADDER-TYPE ACCUMULATORS _
During recent control rod drive testing at an operating BWR plant with bladder-type accumulators, approximately 25 CRDs did not fully insert when being individually scrammed with the water charging valve closed.
Subsequent investigations revealed that the failure of the CRD to completely The insert was due to premature closure of the accumulator poppet valve.
In some premature closure was caused by stretching of the gas bladder.
cases the bladder had stretched between two to three inches past its original length.
CRD scram testing at " vessel head off conditions", with the we.ter charging valve closed, is performed to test the capability of the assoc;ated accumu.
lator without any assist from the CRD Hydraulle System Pr.mps..!n single scram testing with the water charging valve open, the pmnp acts as a back-up accumulator and can mask accumulator deficiencies such as pre-Individual scram testing at the above-mentioned mature poppet closure.
plant on the same CRDs with the charging valve open indicated normal CRD performance.
The test with the charging valve closed is not a hypothetical test. It simulates system scram performance when a scram occurs at low pressure, such as When this occurs, the pump does not have the l
a scram at initial criticality.
i capacity to simultaneously back up all the accumulators, and slow or partial Premature closure at insertions due to premature accumulator can occur.
normal reactor pressure most probably would not have been noted since
'4 most of the water required for scram under these conditions comes from the reactor rather than the accumulators.
Because of the experience we have gained, we are recommending that other plants utilising these Greer bladder-type accumulators verify the status of their bladders at the earliest opportunity. The t.est must be conducted at,
" sero vossa pressure", with the appropriate accumulator water charging 4 yalie' i:losed.
D. G. Bridenbaugh.
Manager - Product Service Nucicar Energy Marketing Department j
Mail Code 132 NUCLEAR ENERGY DIVISION
- PRODUCT SERVICE
- SAN JOSE, CAllFdRNIA GEN ER Al @ ELECTRIC) y