ML20054E761

Discusses ACRS Interim Rept Re CP Application.Addl QA Info Requested.Recommendation Re full-power Operation Deferred Pending Review of Audit Plan

ML20054E761
Person / Time
Site:	Midland
Issue date:	06/08/1982
From:	Shewmon P Advisory Committee on Reactor Safeguards
To:	Palladino N NRC COMMISSION (OCM)
References
ACRS-R-0979, ACRS-R-979, NUDOCS 8206140166
Download: ML20054E761 (6)

Text

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UNITED STATES d8' NUCLEAR REGULATORY COMMISSION

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,E ADVISORY COMMITTEE ON REACTOR SAFEGUARDS W ASHINGT ON, D. C. 20555 f

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1. p June 8, 1982 Honorable Nunzio J. Palladino Chai rman U. S. Nuclear Regulatory Commission Washington, D.C. 20555

SUBJECT:

ACRS INTERIM REPORT ON MIDLAND PLANT, UNITS 1 AND 2 During its 266th meeting, June 3-5, 1982, the Advisory Committee on Reactor Safeguards reviewed the application of Consumers Power Company for a li-cense to operate the Midland Plant, Units 1 and 2.

This coplication was also considered at Subcommittee meetings held on April 29, 1982 in Washing-ton, D. C.,

on May 20-21,1982 in Midland, Michigan and on June 2,1982 in Washington, D. C.

On May 20,1982 members of the Subcommittee toured the plant.

In the course of these meetings the Committee had the benefit of discussions with representatives anr consultants of Consumers Power Company, Babcock and Wilcox Company, Bechb i Corporation, the Nuclear Regulatory Commission Staff, and members of the public.

The Committee also had the benefit of the documents listed below.

The ACRS reported on June 18, 1970 regarding the construction permit ap-plication for the Midland Plant; on September 23, 1970 regarding several arnendments to the application; and on November 18, 1976 regarding applica-ble generic matters.

The Midland Plant site is located on the south bank of the Tittabawassee River adjacent to the southern city limits of Midland.

The main industrial complex of the Dow Chemical Company lies within the city limits directly across the river from the site.

There are about 2000 industrial workers within one mile of the site, and the estimated 1980 population was about 51,400 residents within five miles of the site.

This makes the Midland site one of the more densely populated sites at distances close to the Plant.

Each of the two Midland units employs a Babcock and Wilcox designed nuclear steam supply system rated at 2468 MWt with a stretch porer rating of 2552 MWt.

The Midland Plant is unique in that the heat generated will be used not only to produce electricity but also to produce process steam for the Dow Chemical Company plant via a tertiary system.

The Midland Plant has been the subject of several major problems related to quality assurance during plant construction.

One of these problems relates to the soil fill under several safety-related structures.

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Honorable Nunzio J. Palladino June 8,1982 deficiencies relhting to soil fill have led to excessive settleri.ent and some cracking of these structures, and have also introduced questions concerning the adequacy of protection against liquefaction of the granular portions of the fill in the event of strong vibratory motion accompanying an earthquake.

The Applicant has proposed and is implementing, under close surveillance by the NRC Staff, remedial measures with regard to the foundation deficiencies.

We are generally satisfied with the approach being taken, subject to confir-mation of the overall quality assurance program and the seismic design basis.

Both of these items are discussed below.

With regard to quality control of design and construction, the report of the NRC Staff's Systematic Assessment of Licensee Performance (SALP) review for the period July 1,1980 to June 30, 1981 revealed deficiencies in the instal-lation of piping and piping suspension systems, in the pulling of electrical cables, and in the handling of problems relating to soils and foundation.

Deficiencies by the Applicant in the handling of soils-related matcers have continued to occur, subsequent to issuance of the SALP report.

We believe that the NRC Staff is handling the corrective actions for specifically identified quality assurance deficiencies in an appropriate manner.

In view of the overall concern about Midland quality assurance the NRC should arrange for a broader assessment of Midland's design adequacy and construction quality with emphasis on installed electrical, control, and mechanical equipment as well as piping and foundations.

We wish to receive a report which discusses design and construction problems, their disposi-tion, and the overall effectiveness of the effort to assure appropriate quality.

Our reservation concerning seismic design relates to the lack of adequate assurance that the Midland Plant will be capable of accomplishing shutdown I

heat removal for low probability earthquakes more severe than the safe l

shutdown earthqueke (SSE).

The Midland seismic design basis at the con-l struction permit stage corresponded to a MMI VI, peak ground acceleration of 0.12g, employing a modified Housner spectrum.

For the operating license review, the NRC Staff has reevaluated the original seismic design basis and l

the Applicant and the NRC Staff have agreed on the use of site-specific analyses which have led to increases in the design response spectra for frequencies above about 2 cycles /sec.

Historically, no earthquakes stronger than the newly proposed SSE have occurred within 200 miles of the Plant.

However, expert opinion differs widely on the exceedance frequency of the proposed SSE and on the severity 4

at the site of earthquakes whose likelihood is less than 1 in 10 or 1 in 5

10 per year.

5 Honorable Nunzio J. Palladino June 8, 1982 The Applicant is currently 'eevaluating by selective audit the seismic capability of the plant, as originally designed, to withstand the revised SSE.

Measures taken to assure safe shutdown in the event of an earthquake include the use of dewatering to reduce the potential for soil liquefaction.

We recommend that all systems and components important to decay heat removal be carefully evaluated for their ability to accomplish necessary functions in the unlikely event of lower-probability, more severe earthquakes in order to provide the necessary degree of assurance.

This matter should be re-solved in a manner satisfactory to the NRC Staff.

We wish to be kept informed about the resolution of this matter.

We believe that any recom-mendations for changes in the plant resulting from this evaluation should be implemented by the end of the second refueling outage.

The Applicant has agreed to provide core exit thermocouples, a hot-leg-le.el measurement system, and subcooled margin monitors as instrumentation to detect inadequate core cooling.

Consumers Power Company also plans to include a remotely operable vent on top of both inlet loops to the steam generators; however, Consumers has not committed to supply a high point vent on the reactor vessel head.

This matter should be resolved in a manner satisfactory to the NRC Staff.

The ACRS recommends that the Applicant review further the potential for providing indications of water content or level within the reactor vessel.

The staff of the Applicant includes many personnel who have had nuclear power plant experience.

However, operating experience with this B&W type power reactor is limited, and the NRC Staff is requiring that at least one person having experience on a large commercial PWR be included on each shift for one year. We support the NRC Staff position.

The Applicant's experience with the operation of nuclear power plants should, in principle, place Consumers in a favorable position to provide l

continuing, careful oversight of the operations at the Midland Plant.

In view of some prior adverse operating experience at the Palisades Plant however, we recommend that the NRC Staff institute an augmented audit of operations at Midland, at least during the early years of operation at power.

We have reviewed the evaluation made of the tertiary process steam system for use by Dow Chemical Company.

This system appears not to impose any unacceptable impacts either on the safe operation of the Midland Plant or on the people working 'at the Dow Chemical Company.

The Applicant has undertaken an effort to have a probabilistic risk assess-ment (PRA) performed for the Midland Plant and stated that the results will be available in the fall of 1982.

We believe it desirable to have plant-specific PRAs performed for each commercial nuclear power plant and that

Honorable Nunzio J. Palladino June 8,1982 it is particularly appropriate for the Midland Plant because of its rela-tively high, close-in population density. We wish to have the opportunity to review the Midland PRA with assistance from the NRC Staff, and to offer comments or recommendations as appropriate.

We do not believe that this review need delay licensing of the Midland Plant for operation.

Recently, questions have come to light in connection with B&W plants con-cerning the availability of natural circulation in the presence of an interrupted or continuing small break loss-of-coolant accident.

We wish to see a proposed NRC Staff resolution of this issue.

1 The Applicant described an extensive systems interactions study being undertaken for the Midland Plant.

We wish to be informed of the results of I

this study.

We believe that, in view of the population density near this plant, addi-tional prudence is appropriate for the Midland Plant in the resolution of the ATWS issue and other Unresolved Safety Issues.

We endorse the participation of Dow Chemical Company plant personnel in emergency procedures developed on the basis of an assumed failure at the Midland Plant.

Similarly, there should be active participation by Midland Plant personnel in emergency procedures developed on the basis of an assumed failure at the Dow Chemical plant. The Applicant and the NRC Staff should promote continued coordination of these types of relationships, as well as those involving appropriate state and local groups to assure that I

the capability for an effective emergency response is developed and main-tained.

With regard to the eleven items identified in the ACRS Supplemental Report on Midland Plant, Units 1 and 2 dated November 18, 1976, we have the follow-ing comments.

The issues related to vibration and loose-parts monitoring, potential for axial xenon oscillations, behavior of core-barrel check valves during normal operation, fuel handling accidents, effects of blowdown forces on core internals, LOCA-related fuel rod failures, and improved quality assurance and in-service inspection for the primary system have all been resolved or are in a confirmatory stage of being resolved. Separation of protection and control equipment has been accomplished in an appropriate manner; however, the safety implications of control systems remains an Unresolved Safety Issue directly applicable to Midland.

Resolution awaits completion of the NRC Staff Task Action Plan A-47.

The effect of ECCS induced thermal shock on pressure vessel integrity has been resolved in part; however, the Unresolved Safety Issue on pressurized thermal shock will apply.

Environmental qualification of equipment remains a generic

Honorable Nunzio J. Palladino June 8, 1982 issue which is under review by the NRC Staff and whose resolution will apply to the Midland Plant.

Instrumentation to follow the course of an accident has been resolved in part by the development of revised Regulatory Guide 1.97.

We do not believe that licensing of the Midland Plant for operation need await further resolution of ar.y of the eleven issues dis-cussed above.

The various other matters identified by the NRC Staff as open or confirma-tory in the Safety Evaluation Report should be resolved in a manner satis-factory to the NRC Staff.

We wish to be kept advised concerning resolution of the turbine missile issue.

The ACRS believes that, subject to satisfactory completion of construction and staffing and if due regard is given to the comments above, the Midland Plant, Units 1 and 2 can be operated at power levels up to 5 percent of full power with reasonable assurance that there is no undue risk to the health and safety of the public.

We defer our recommendation regarding operation at full power until we have had the opportunity to review the plan for an audit of plant quality and the proposed resolution of the question regarding natural circulation in the presence of a small break LOCA.

Dr. Kerr did not participate in the Committee's review of this matter.

Sincerely,

k.

P. Shemnon Chai rman

References:

1.

Consumers Power Company, " Midland Plant Units 1 and 2 - Final Safety Analysis Report" including Amendments 1-43 2.

U.S. Nuclear Regulatory Connission, " Safety Evaluation Report Related to the Operation of Midland Plant, Units 1 and 2," NUREG-0793, dated Pby 1982 3.

U.S. Nuclear Regulatory Connission, "NRC Licensee Assessments,"

NUREG-0834, dated August 1981 4.

Letter from J. Cook, Consumers Power Company, to J. Keppler, NRC,

Subject:

Midland Project Response to Draft SALP Report, dated May 17,1982 5.

Letter from J. Cook, Consumers Power Company, to J. Keppler, NRC,

Subject:

Midland Project Quality Assurance Program Update, dated April 30,1981

Honorable Nunzio J. Palladino ~

June 8, 1982 6.

Letter from J. Hind, NRC, to J. Cook, Consumers Power Company, Subject :

Systematic Assessment of Licensee Performance (SALP),

dated April 20, 1982 7.

Letter from J. Cook, Consumers Power Company, to H. Denton, NRC,

Subject:

Summary of Soils-Related Issues at the Midland Nuclear Plant, dated April 19, 1982 8.

Letter from K. Drehobl, Consumers Power Company, to D. Fischer, ACRS, Subject : Midland Project Soils Information, dated April 12, 1982 9.

Statement of Ms. M. Sinclair to ACRS, dated June 4,1982 10.

Letter from B. Stamiris to Dr. D. Okrent and ACRS Members,

Subject:

Midland OL Review, dated May 29, 1982 11.

Letter from M. Sinclair to Dr. P. Shewmon, ACRS,

Subject:

Midland OL Review, dated May 28, 1982

12. Statement by Dr. C. Anderson to ACRS Midland Plant Subcommittee dated May 20-21, 1982 13.

Statement by Ms. M. Sinclair to ACRS Midland Plant Subcommittee dated May 20-21, 1982 14.

Letter from B. Stamiris to D. Fischer and ACRS Mambers,

Subject:

Soil Settlement and QA Issues, dated May 20, 1982 15.

Letter from M. Sinclair to Dr. C. Siess, ACRS,

Subject:

Midland Soil Settlement, dated April 26, 1982 M

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