ML19337A357

Forwards Plan for Investigation of Interaction Between Electromagnetic Pulse & Commercial Nuclear Plant Sys

ML19337A357
Person / Time
Issue date:	08/05/1980
From:	Harold Denton Office of Nuclear Reactor Regulation
To:	Ahearne J NRC COMMISSION (OCM)
References
NUDOCS 8009090599
Download: ML19337A357 (10)

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UN11 ED STATES

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. NUCLEAR REGULATORY COMMISSION

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..p AUG 5 1980 MEMORANDUM FOR: Chairman Ahearne Willi am J.. Dircks,.

Executive Director for Ope (siEU@YTE".mJ.DiW TilRU:

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liarold R. Denton, Director Office of Nuclear Reactor Regulation

SUBJECT:

PLAN.FOR INVESTIGATION OF T}iE -INTERACTION BETWEEN ELECTRQ4AGNETIC PULSE AND COMMERCIAL NUCLEAR PLANT SYSTEMS The enclosed. plan is-currently being implemented.

Arrangements for funding an NRC contractor and for transfer of funds to the Defense Nuclear Agency, are being made with the inmediate objective of holding the initial plant visit by October 1,1980.

Negotiations are also underway to establish a Review Panel.

TVA has.been very receptive to the plan and has agreed to cooperate.

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liarold R. Denton, Director Office of Nuclear Reactor Regulation

Enclosure:

Study Plan cc:

' Commissioner llendrie Commissioner Gilinsky Commissioner Bradford-SECY i

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.8000090 N -

o U. S. NUCLEAR REGULATORY COMMISSION PLAN FOR INVESTIGATION OF THE INTERACTION BETWEEN ELECTROMAGNETIC PULSE AND COMMERCIAL NUCLEAR PLANT SYSTEMS I

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I. - J3:KGROUNDL Electromagnetic _ Pulse (EMP) is the term used to describe the intense electromagnetic. field generated by a high altitude nuclear weapon

-_ expl osion.

The EMP from a single explosion at sufficient altitude could generate large currents and voltag'es in' electrical equipment over the continental United States.

U. S. Defense Department strategists have be'en concerned that EMP could be used to temporarily immobilize our land based retaliatory missiles, allowing these missles to be destroyed, while on the ground, by highly

. localized nuclear strikes.

Vital communications networks could also be disabled-by EMP as a precursor to an attack. _ As a result,

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weapons systems and defense-communications systems have been " hardened" against EMP by shielding or by installation of protective devices.

The possibility of nuclear; attack'against missile sites, preceded by EMP but not including directed attacks on population centers, leads to the concern

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that commercial: nuclear plants may be adversely affected by EMP causing significant health effects, even when compared with those of the nuclear attack.

In addition to FMP generated as a part of a general nuclear attack by a major power thece are the possibilities of terrorist explosions of nuclear devices and generation of EMP-like signals using land based generators.

Commercial nuclear plants have not been hardened against EMP.

The effects of. EMP on a' nuclear. plant (Sequoyah) have been studied by Oak Ridge National Laboratory, but too many issues were left unresolved by that study to conclusively show that nuclear. plants can be safely shut down subsequent.

to an EMP.

Some of the newer operating plants and plaats still under construction use electrical equipment such as transistors, integrated circuits and other semi-conductors considered to be particu'orly vulnerable to high currents and voltages expected to be generated c, EMP.

Because of the uncertainty about the effects of EMP on commercial nuclear plant shutdown capability, the NRC will conduct a study of these effects and how they can be avoided or mitigated.

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m fl1 GENERAL' DESCRIPTION 0F NRC STUDY PLAN

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Objective The study.will have.the following objectives:' (1)_to determine the vulnerabilitf of selected safe shutdown systems of a specific nuclear plant to jD4P effects due to nuclear weapons and non-nuclear generators, (2) to determine how those safe shutdown systems vulnerable to EMP may L best be hardened against _ EMP, L(3) to characterize-to the extent possible the _ effects of. EMP on nuclear plants in general based on the study of

' specific. systems of. the - subject plant.

Organizational Responsibilities The overall effort will be under direction of the Division of Systems Inte g ration of the Office of Nuclear Reactor Regulation. NRC will be aided in directing the ~ study by the Defense Nuclear Agency (DNA).

The NRC will employ a contractor to undertake those aspects of the study requiring knowledge of the design, construction, and operation of-nuclear plants. The DNA will employ contractors to undertake those aspects of the study requiring knowledge of the effects of EMP and the methods of hardening against EMP.. The specific tasks assigned to these contractors are described in Section III.

Review Panel

- A panel of experts, each of whom is familiar with EMP or nuclear plants, will regularly review the progress of. the study. The review panel will provide independent judgment of the validity of the conclusions of the-study and can recomcend additional tasks or studies to be pursued by the contractors at the discretion of the NRC.

Meetings will be held at approximately two month intervals.

Plant Chosen for Study TVA has agreed to assist in the study and will choose a TVA PWR as the-subject plant.

The plant systems to be evaluated are discussed in Section IV.

Duration of Study and Schedule The overall goal is to complete all program objectives by May 1,1982.

In addition,.the NRC and DNA contractors will be requested to detennine the vulnerabilityLof the systems necessary for decay heat removal to hot

-shutdown and to develop necessary hardening recommendations for these systems by October 1,1981.

An outline of the currently projected _ schedule is given in Table 2.

A more detailed s'chedule will be prepared by the contractorc.

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- Additional' Studies If;.'after the~ initial study is complete, the infonnation available is

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insufficient to-arrive at conclusive judgments regarding the general vulner-

' ability of. nuclear plants to EMP A plan for further studies will be developed.

- The studies may involve evaluati,on,of BWR, _ human factors in responding to an EMP induced event,;. additional systems for a PWR, and computer protection

systems.:

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p III. NECESSARY-TASKS AND RESPONSIBILITIES IN THE STUDY OF THE INTERACTION OF EMP WITH.

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F NUCLEAR. POWER. PLANT SYSTEMS 1.

Ide'ntify the 'resctor plant'sys'tems or functions for which EMP vulnerability is to be adcressed; indicate the priority or sequence in which these systems are to be. investigated.

(NRC. Staf f)

2.

Identify the electrical components.needed to operate those systems or to perfom those functions specified in Step 1.

(NRCContractor)*

3.

Determine the physical configurations of the structure housing the subject system, the arrangement of power cables and conductors entering these structures or connected to the system, or any other characteristic by which EMP can be coupled'to the electrical components identified in Step 2.

(NRC Contractors working with DNA Contractors)*

4.

Based on just.ifiable assumptions regarding EMP sources and the infomation from Step 3, detemine the EMP indeced currents and voltages to which the electrical components of Step 2 will be subjected.

(DNA Contractor) 5.

Investigate and make a judgment of the validity of detemining bounding values of currents and voltages for evaluating vulnerability of cmponents during the remainder of the study.

(DNA Contractor) 6..

Based on the infomation from Step 4, detemine whether the electrical components of the subject system will malfunction and/or be pennanently damaged due. to EMP.

(NRC Contractor) 7.

For each system with malfunctioning or iailed components, detemine whether the component malfunctions or failures will prohibit the system from ful-filling,its intended functions.- (NRC Contractor) 8.

For those systems which will fail to function due to an EMP identify hardening alternatives and determine a recommended choice taking into account effectiveness and cost.

(DNA Contractor) 9.

Determine the impact of recommended hardening against EMF on the system performance and reliability in the absence of EMP.

(NRC Contractor) 10.

Based on the analysis of the effects of EMP on a specific set of plant systems and functie. _ as outlined above,.and on the similarities and differences between those systems. and comparable systems at other plants, characterize the effects of EMP on nuclear plants in general including a judgment as to whether nuclear plants ~will retain safe shutdown capability subsequent to an EMP.

(NRC Contractor 'and NRC Staff)

• TVAls. contribution is essential to the successful completion of this task.

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' 11.. Upon request of the NRC, perfona additional studies based-on (a)11nfonnation generated during the' investigation (b) recomaendations~ of the.

' Review Panel. - (NRC Contractors and DNA Contractors)

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Prepare ~ a report ~ summarizing the above studies, including-findings and

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recommendations. '(NRC. Staff and NRC Contractors) 3 h

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. IV.

PLANT _ SYSTEMS TO BE EVALUATFD'

The plant systems to be evaluated will be chosen from those systems which must

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function properly to bring the' pl'anf to a stable condition such as hot shutdown or cold _ shutdown.

A representative sample of plant. electrical.. equipment 'should be included but the number of systems evaluated and the depth of the evaluation-

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of-some systems will be~ limited, if necessa'y, to meet the overall program r

schedul e. -

A preliminary selection of systems or functions to be evaluated is given in-Table 1.

The Priority. I~ systems are primarily associated with achieving decay heat removal to hot _ shutdown; the Priority II systems are associated with achieving: cold shutdown, reactivity control, and preventic, or control of loss of coolant.. Table 1 is subject' to changes based on selection of a specific pi t.nt.

The success of the-program is not predicateri on the evaluation of al_1 the systems listed in. Table 1.

Modifications to the extent and sequence of systems to be evaluated may become desirable during the study as a better understanding of the nature and difficulty of the problem is gained.

Such modifications will be consistent with the objectives and schedule of the program.

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TNBLErl PWR SYSTEMS'AND FUNCTIONS TO BE CONSIDERED IN EMP STUDY _

- Priorityil L(1) - AC 'and'DC Eme.rgency Power

.(2)' Auxiliary Feedwater System

-(3) Atmospheric' St'eam Relief Valves (4)' Monitoring Systems -(steam generator level ~ and pressure, pressurizer level and pressure)-

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-(5)._' Steam Generator -Isolation-(6)' Boration System

-(7) Service and Cooling Water System (8)

Instrument Air (9)' Ventilation Systems for the' Above Priority II (1) ' Power Opet ated Relief Valves (2). Residual Heat Rhmoval System (3) Pressurizer Heaters and Sprays (4). Charging and Letdown Systems

'(5).. Reactor. Protection System -

'(6) Cor.imunications tietwork For Coordinating Shutdown by Operators

. (7) Offsite Power'

'(8) High Pressure Injection System

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.(9) ~ Engineered Safeguards Actuation System.

l(10) Post Accident Monitoring Instrunents

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tj JTABLEi2 SCHEDULE FOR' INVESTIGATION'0F INTERACTION BETWEEN EMP AND NUCLEAR PLANT SYSTEMS-F L

Completion -

f Milestone Date

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. Select Plantoand Indentify Systems -

-1 Sept 1980~

L for. Study Initial. Plant Visit 1 Oct. 1980 Characterization of Coupling 1 Jan.1981

-Modes for Prio:ity 'I' Systems Evaluation of EMP Induced Currents' 1 April 1981 and Voltages for Priority _I Systems Determination of Failure Potential' 1 July '1981

-For Priority I Systems-l' Hardening Recanmendations -for 1 Oct.1981

. Vulnerable Priority I Systems

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Determine Impact of Hardening 1 Dec.1981 on Priority I. System Reliability Completion of Study Through Task 9 1 Feb. 1982 for Priority' 11 Systems (As Allowed' l

By Time 1and Resourc'es)l Report on Potential Impact of EMP on 1 March 1982

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Nuclear Plants in General Final. Report Including Recomaendations.

1 May 1982 t

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